(19)
(11)EP 3 169 833 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
14.08.2019 Bulletin 2019/33

(21)Application number: 14897773.9

(22)Date of filing:  23.12.2014
(51)Int. Cl.: 
C03C 13/00  (2006.01)
D01F 9/08  (2006.01)
C04B 35/622  (2006.01)
F16L 59/02  (2006.01)
D01F 1/10  (2006.01)
C03C 3/078  (2006.01)
C03C 3/087  (2006.01)
C04B 35/626  (2006.01)
(86)International application number:
PCT/US2014/072027
(87)International publication number:
WO 2016/010580 (21.01.2016 Gazette  2016/03)

(54)

INORGANIC FIBER WITH IMPROVED SHRINKAGE AND STRENGTH

ANORGANISCHE FASER MIT VERBESSERTEM SCHRUMPF UND FESTIGKEIT

FIBRE INORGANIQUE À RÉTRÉCISSEMENT ET RÉSISTANCE AMÉLIORÉS


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 16.07.2014 US 201462025142 P

(43)Date of publication of application:
24.05.2017 Bulletin 2017/21

(73)Proprietor: Unifrax I LLC
Tonawanda, NY 14150 (US)

(72)Inventors:
  • ZHAO, Donghui
    Amherst, New York 14221 (US)
  • ZOITOS, Bruce K.
    Williamsville, New York 14221 (US)
  • ANDREJCAK, Michael J.
    Tonawanda, New York 14150 (US)
  • HAMILTON, Jason M.
    Lancaster, New York 14086 (US)

(74)Representative: Keller, Günter et al
Lederer & Keller Patentanwälte Partnerschaft mbB Unsöldstrasse 2
80538 München
80538 München (DE)


(56)References cited: : 
WO-A1-95/32926
WO-A1-2006/048610
US-A- 4 604 097
US-A- 5 401 693
US-A1- 2005 032 620
WO-A1-97/16386
WO-A1-2015/100320
US-A- 4 830 989
US-A1- 2005 032 620
US-A1- 2013 225 025
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] A high temperature resistant inorganic fiber that is useful as a thermal, electrical, or acoustical insulating material, and which has a use temperature of 1260°C and greater is provided. The high temperature resistant inorganic fiber is easily manufacturable, exhibits low shrinkage after exposure to the use temperature, retains good mechanical strength after continued exposure to the use temperature, and exhibits low biopersistence in physiological fluids.

    BACKGROUND



    [0002] The insulation material industry has determined that it is desirable to utilize fibers in thermal, electrical and acoustical insulating applications, which are not durable in physiological fluids, that is, fiber compositions which exhibit a low biopersistence in physiological fluids.

    [0003] WO 2006/048610 A1 discloses a method of making refractory alkaline earth silicate fibers from a melt.

    [0004] WO 97/16386 A1 discloses a refractory glass fiber having a use temperature of greater than 1000°C up to at least 1260°C, having an after service mechanical integrity comparable to conventional refractory ceramic fiber and which is non-durable in physiological fluids, consisting essentially of the product of silica and magnesia.

    [0005] US 2005/032620 A1 discloses a temperature resistant vitreous fiber having a use temperature of greater than 1000°C up to at least 1260°C, having an after service mechanical integrity comparable to conventional refractory ceramic fiber and which is non-durable in physiological fluids, and is produced from a melt containing silica, magnesia and a lanthanide series element-containing compound

    [0006] WO 2015/100320 A1 discloses an inorganic fiber containing silica and magnesia as the major fiber components which further includes lithium oxide and strontium oxide.

    [0007] US 2013/0225025 A1 discloses a glass composition comprising about 70.6 to about 79.6% by weight silica, about 10 to 19% by weight alumina, about 10 to 18.5% magnesia and about 0.1 to 5% by weight calcia.

    [0008] While candidate materials have been proposed, the use temperature limit of these materials have not been high enough to accommodate many of the applications to which high temperature resistant fibers are applied. For example, such low biopersistence fibers exhibit high shrinkage at use temperatures and/or reduced mechanical strength when exposed to use temperatures ranging from 1000°C to 1400°C as compared to the performance of refractory ceramic fibers.

    [0009] The high temperature resistant, low biopersistence fibers should exhibit minimal shrinkage at expected exposure temperatures, and after prolonged or continuous exposure to the expected use temperatures, in order to provide effective thermal protection to the article being insulated.

    [0010] In addition to temperature resistance as expressed by shrinkage characteristics that are important in fibers that are used in insulation, it is also required that the low biopersistence fibers have mechanical strength characteristics during and following exposure to the expected use or service temperature, that will permit the fiber to maintain its structural integrity and insulating characteristics in use.

    [0011] One characteristic of the mechanical integrity of a fiber is its after service friability. The more friable a fiber, that is, the more easily it is crushed or crumbled to a powder, the less mechanical integrity it possesses. In general, inorganic fibers that exhibit both high temperature resistance and low biopersistence in physiological fluids also exhibit a high degree of after service friability. This results in a brittle fiber lacking the strength or mechanical integrity after exposure to the service temperature to be able to provide the necessary structure to accomplish its insulating purpose. Other measures of mechanical integrity of fibers include compressive strength and compression recovery.

    [0012] It is desirable to produce an improved inorganic fiber composition that is readily manufacturable from a fiberizable melt of desired ingredients, which exhibits low biopersistence in physiological fluids, low shrinkage during and after exposure to use temperatures of 1260°C and greater, such as 1400°C and greater, and, which exhibits low brittleness after exposure to the expected use temperatures, and which maintains mechanical integrity after exposure to use temperatures of 1260°C and greater, such as 1400°C and greater.

    [0013] Provided is a high temperature resistant alkaline-earth silicate fiber exhibiting improved thermal stability when the inorganic fiber is exposed to elevated temperatures of 1000°C to 1500°C. It has been found that the inclusion of suitable amount of lithium oxide to an alkaline-earth silicate inorganic fiber reduces fiber shrinkage and enhances mechanical strength beyond that of alkaline earth silicate fibers without the presence of the lithium oxide addition. The fiber exhibits low biopersistence in physiological solutions, reduced linear shrinkage, and improved mechanical strength after exposure to expected use temperatures.

    [0014] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, and up to about 0.05 weight percent lithium oxide.

    [0015] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, calcia, and up to about 0.05 weight percent lithium oxide.

    [0016] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, calcia, and up to about 0.05 weight percent lithium oxide.

    [0017] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, lithium oxide and a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0018] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, calcia, lithium oxide, and a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0019] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, calcia, lithium oxide, and a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0020] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, lithium oxide, and alumina as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0021] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, calcia, lithium oxide, and alumina as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0022] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, calcia, lithium oxide, and alumina as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0023] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, lithium oxide, and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0024] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, calcia, lithium oxide, and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0025] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, calcia, lithium oxide, and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0026] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, lithium oxide, and a mixture of alumina and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0027] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, calcia, lithium oxide, and a mixture of alumina and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0028] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, calcia, lithium oxide, and mixture of alumina and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0029] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, zirconia, lithium oxide, and a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0030] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, zirconia, lithium oxide, and alumina as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0031] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, zirconia, lithium oxide, and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0032] According to certain embodiments, the inorganic fiber comprises the fiberization product of silica, magnesia, zirconia, lithium oxide, and a mixture of alumina and boria as a viscosity modifier. Lithium oxide may be included in an amount up to about 0.05 weight percent.

    [0033] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, and up to about 0.05 weight percent lithium oxide.

    [0034] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide.

    [0035] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, and greater than 0 to about 0.01 weight percent lithium oxide.

    [0036] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, and greater than 0 to about 0.005 weight percent lithium oxide.

    [0037] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0038] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0039] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0040] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide and from 0 to about 11 weight percent zirconia.

    [0041] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and from 0 to about 11 weight percent zirconia.

    [0042] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and from 0 to about 11 weight percent zirconia.

    [0043] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide, from 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0044] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, from 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0045] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 65 to about 86 weight percent silica, about 14 to about 35 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, from 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0046] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide.

    [0047] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, and greater than 0 to about 0.01 weight percent lithium oxide.

    [0048] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, and greater than 0 to about 0.005 weight percent lithium oxide.

    [0049] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0050] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0051] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0052] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0053] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0054] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 70 to about 80 weight percent silica, about 20 to about 30 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0055] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide.

    [0056] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, and greater than 0 to about 0.01 weight percent lithium oxide.

    [0057] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, and greater than 0 to about 0.005 weight percent lithium oxide.

    [0058] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0059] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0060] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0061] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0062] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0063] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 75 to about 80 weight percent silica, about 20 to about 25 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0064] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide.

    [0065] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, and greater than 0 to about 0.01 weight percent lithium oxide.

    [0066] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, and greater than 0 to about 0.005 weight percent lithium oxide.

    [0067] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0068] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0069] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0070] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0071] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0072] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 76 to about 80 weight percent silica, about 20 to about 24 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0073] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide.

    [0074] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, and greater than 0 to about 0.01 weight percent lithium oxide.

    [0075] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, and greater than 0 to about 0.005 weight percent lithium oxide.

    [0076] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0077] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0078] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0079] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0080] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0081] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 77 to about 80 weight percent silica, about 20 to about 23 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0082] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide.

    [0083] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide.

    [0084] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide.

    [0085] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present is may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0086] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0087] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0088] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia, and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.05 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia, and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0089] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia, and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia, and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, greater than 0 to about 0.01 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0090] According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 81 weight percent silica, about 19 to about 22 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia, and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 79 to about 81 weight percent silica, about 19 to about 21 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia, and a viscosity modifier. According to certain illustrative embodiments, the inorganic fiber comprises the fiberization product of about 78 to about 80 weight percent silica, about 20 to about 22 weight percent magnesia, greater than 0 to about 0.005 weight percent lithium oxide, greater than 0 to about 11 weight percent zirconia and a viscosity modifier. The viscosity modifier can be selected from alumina, boria, and mixtures of alumina and boria. When a viscosity modifier is present it may include greater than 0 to about 2 weight percent alumina, or greater than 0 to about 1 weight percent boria, or a mixture of greater than 0 to about 2 weight percent alumina and greater than 0 to about 1 weight percent boria.

    [0091] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product of silica in any of the range disclosed herein, magnesia in any of the ranges disclosed herein, optionally calcia in any of the ranges disclosed herein, optionally zirconia in any of the range disclosed herein, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0092] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 65 to about 86 weight percent silica, from about 14 to about 35 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0093] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 70 to about 80 weight percent silica, from about 20 to about 30 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0094] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 75 to about 80 weight percent silica, from about 20 to about 25 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0095] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 76 to about 80 weight percent silica, from about 20 to about 24 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0096] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 77 to about 80 weight percent silica, from about 20 to about 23 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0097] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 78 to about 80 weight percent silica, from about 20 to about 22 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0098] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 78 to about 81 weight percent silica, from about 19 to about 22 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0099] According to further illustrative embodiments, the inorganic fiber may comprise the fiberization product from about 79 to about 81 weight percent silica, from about 19 to about 21 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0100] According to any of the above illustrative embodiments, the inorganic fiber contains 1 weight percent or less calcia. According to any of the above illustrative embodiments, the inorganic fiber contains 0.5 weight percent or less calcia. According to any of the above illustrative embodiments, the inorganic fiber contains 0.3 weight percent or less calcia.

    [0101] According to any of the above embodiments, provided is a high temperature resistant inorganic fiber which exhibits a linear shrinkage of 5% or less when exposed a use temperature of 1260°C and greater for 24 hours, and which maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids.

    [0102] According to any of the above embodiments, provided is a high temperature resistant inorganic fiber which exhibits a linear shrinkage of 5% or less when exposed a use temperature of 1260°C and greater for 168 hours, and which maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids.

    [0103] According to any of the above embodiments, the high temperature resistant inorganic fiber exhibits a linear shrinkage of 4% or less when exposed a use temperature of 1260°C and greater for 24 hours, maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids.

    [0104] According to any of the above embodiments, the high temperature resistant inorganic fiber exhibits a linear shrinkage of 4% or less when exposed a use temperature of 1260°C and greater for 168 hours, maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids.

    [0105] According to any of the above embodiments, provided is a high temperature resistant inorganic fiber which exhibits a linear shrinkage of 5% or less when exposed a use temperature of 1400°C or greater for 24 hours, and which maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids.

    [0106] According to any of the above embodiments, provided is a high temperature resistant inorganic fiber which exhibits a linear shrinkage of 5% or less when exposed a use temperature of 1400°C or greater for 168, and which maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids.

    [0107] According to any of the above embodiments, the high temperature resistant inorganic fiber exhibits a linear shrinkage of 4% or less when exposed a use temperature of 1400°C or greater for 24 hours, and which maintains mechanical integrity after exposure to the use temperature, and exhibit low biopersistence in physiological fluids.

    [0108] According to any of the above embodiments, the high temperature resistant inorganic fiber exhibits a linear shrinkage of 4% or less when exposed a use temperature of 1400°C or greater for 168 hours, and which maintains mechanical integrity after exposure to the use temperature, and exhibit low biopersistence in physiological fluids.

    [0109] Also described, but not claimed, is a method for preparing a high temperature resistant inorganic fiber having a use temperature of 1260°C or greater, which maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids. More generally the methods described hereafter are not part of the invention.

    [0110] According to any of the above embodiments, provided is a method for preparing a high temperature resistant inorganic fiber having a use temperature of 1400°C or greater, which maintains mechanical integrity after exposure to the use temperature, and which exhibits low biopersistence in physiological fluids.

    [0111] The method for preparing the fiber comprises forming a melt with ingredients comprising either (i) silica and magnesia, or (ii) silica and calcia, or (iii) silica, magnesia and calcia, lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0112] The method for preparing the fiber comprises forming a melt with ingredients comprising either (i) silica and magnesia, or (ii) silica and calcia, or (iii) silica, magnesia and calcia, and up to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt. The method for preparing the fiber comprises forming a melt with ingredients comprising either (i) silica and magnesia, or (ii) silica and calcia, or (iii) silica, magnesia and calcia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0113] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 65 to about 86 weight percent silica, from about 14 to about 35 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0114] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 70 to about 80 weight percent silica, from about 20 to about 30 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0115] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 75 to about 80 weight percent silica, from about 20 to about 25 weight percent magnesia, and up to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt. According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 75 to about 80 weight percent silica, from about 20 to about 25 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0116] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 76 to about 80 weight percent silica, from about 20 to about 24 weight percent magnesia, and up to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt. According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 76 to about 80 weight percent silica, from about 20 to about 24 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0117] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 77 to about 80 weight percent silica, from about 20 to about 23 weight percent magnesia, and up to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt. According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 77 to about 80 weight percent silica, from about 20 to about 23 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0118] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 78 to about 80 weight percent silica, from about 20 to about 22 weight percent magnesia, and up to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt. According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 78 to about 80 weight percent silica, from about 20 to about 22 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0119] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising silica in any of the range disclosed herein, magnesia in any of the ranges disclosed herein, optionally calcia in any of the ranges disclosed herein, optionally zirconia in any of the range disclosed herein, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0120] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 65 to about 86 weight percent silica, from about 14 to about 35 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0121] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 70 to about 80 weight percent silica, from about 20 to about 30 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0122] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 75 to about 80 weight percent silica, from about 20 to about 25 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0123] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 76 to about 80 weight percent silica, from about 20 to about 24 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0124] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 77 to about 80 weight percent silica, from about 20 to about 23 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0125] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 78 to about 80 weight percent silica, from about 20 to about 22 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0126] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 78 to about 81 weight percent silica, from about 19 to about 22 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0127] According to certain illustrative embodiments, the method for preparing the fiber comprises forming a melt with ingredients comprising from about 79 to about 81 weight percent silica, from about 19 to about 21 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0128] Without limitation, the viscosity modifier that is added to the melt of ingredients to prepare the inorganic fiber may be selected from alumina, boria, and mixtures of alumina and boria. The viscosity modifier is included in the melt of ingredients in an amount effective render the melt fiberizable.

    [0129] Also described, but not claimed, is a method of thermally insulating an article with fibrous insulation prepared from a plurality of the presently disclosed high temperature resistant low biopersistent inorganic fibers of any of the above disclosed illustrative embodiments. The method includes disposing on, in, near or around the article to be thermally insulated, a thermal insulation material comprising a plurality of the inorganic fibers comprising the fiberization product of either (i) silica and magnesia, or (ii) silica and calcia, or (iii) silica, magnesia and calcium, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier, wherein the fiberization product comprises any one of the above-disclosed fiberization products.

    [0130] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 65 to about 86 weight percent silica, from about 14 to about 36 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0131] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 70 to about 80 weight percent silica, from about 20 to about 30 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0132] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 75 to about 80 weight percent silica, from about 20 to about 25 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0133] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 76 to about 80 weight percent silica, from about 20 to about 24 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0134] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 77 to about 80 weight percent silica, from about 20 to about 23 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0135] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 78 to about 80 weight percent silica, from about 20 to about 22 weight percent magnesia, and greater than 0 to about 0.05 weight percent lithium oxide, optionally greater than 0 to 11 weight percent zirconia, and optionally a viscosity modifier; and producing fibers from the melt.

    [0136] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of silica in any of the range disclosed herein, magnesia in any of the ranges disclosed herein, optionally calcia in any of the ranges disclosed herein, optionally zirconia in any of the range disclosed herein, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0137] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 65 to about 86 weight percent silica, from about 14 to about 35 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0138] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 70 to about 80 weight percent silica, from about 20 to about 30 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0139] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 75 to about 80 weight percent silica, from about 20 to about 25 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0140] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 76 to about 80 weight percent silica, from about 20 to about 24 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0141] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 77 to about 80 weight percent silica, from about 20 to about 23 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0142] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 78 to about 80 weight percent silica, from about 20 to about 22 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0143] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 78 to about 81 weight percent silica, from about 19 to about 22 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0144] According to certain illustrative embodiments, the method of thermally insulating an article with fibrous insulation comprising a plurality fibers comprising the fiberization product of from about 79 to about 81 weight percent silica, from about 19 to about 21 weight percent magnesia, optionally calcia in any of the ranges disclosed herein, optionally from greater than 0 to about 11 weight percent zirconia, optionally a viscosity modifier in any of the ranges disclosed herein, and lithium oxide in any one of the following ranges: (i) greater than 0 to about 0.05 weight percent, (ii) greater than 0 to about 0.045 weight percent, (iii) about 0.002 to about 0.04 weight percent, (iv) from about 0.005 to about 0.04 weight percent, (v) from about 0.01 to about 0.04 weight percent, (vi) from about 0.02 to about 0.04 weight percent, (vii) from about 0.03 to about 0.04 weight percent, or (viii) from about 0.035 to about 0.04 weight percent.

    [0145] Also described, but not claimed, is an inorganic fiber containing article comprising at least one of bulk fiber, blankets, blocks, boards, caulking compositions, cement compositions, coatings, felts, mats, moldable compositions, modules, papers, pumpable compositions, putty compositions, sheets, tamping mixtures, vacuum cast shapes, vacuum cast forms, or woven textiles (for example, braids, cloths, fabrics, ropes, tapes, sleeving, wicking).

    [0146] In order for a glass composition to be a viable candidate for producing a satisfactory high temperature resistant fiber product, the fiber to be produced must be manufacturable, sufficiently soluble (ie, having low biopersistence) in physiological fluids, and capable of surviving high temperatures with minimal shrinkage and minimal loss of mechanical integrity during exposure to the high service temperatures.

    [0147] The present inorganic fiber exhibits low biopersistence in physiological fluids. By "low biopersistence" in physiological fluids, it is meant that the inorganic fiber at least partially dissolves in such fluids, such as simulated lung fluid, during in vitro tests.

    [0148] Biopersistence may be tested by measuring the rate at which mass is lost from the fiber (ng/cm2-hr) under conditions which simulate the temperature and chemical conditions found in the human lung. This test consists of exposing approximately 0.1g of de-shotted fiber to 50 ml of simulated lung fluid (SLF) for 6 hours. The entire test system is maintained at 37°C, to simulate the temperature of the human body.

    [0149] After the SLF has been exposed to the fiber, it is collected and analyzed for glass constituents using Inductively Coupled Plasma Spectroscopy. A "blank" SLF sample is also measured and used to correct for elements present in the SLF. Once this data has been obtained, it is possible to calculate the rate at which the fiber has lost mass over the time interval of the study. The fibers are significantly less biopersistent than normal refractory ceramic fiber in simulated lung fluid.

    [0150] "Viscosity" refers to the ability of a glass melt to resist flow or shear stress. The viscosity-temperature relationship is critical in determining whether it is possible to fiberize a given glass composition. An optimum viscosity curve would have a low viscosity (5-50 poise) at the fiberization temperature and would gradually increase as the temperature decreased. If the melt is not sufficiently viscous (i.e. too thin) at the fiberization temperature, the result is a short, thin fiber, with a high proportion of unfiberized material (shot). If the melt is too viscous at the fiberization temperature, the resulting fiber will be extremely coarse (high diameter) and short.

    [0151] Viscosity is dependent upon melt chemistry, which is also affected by elements or compounds that act as viscosity modifiers. Viscosity modifiers permit fibers to be blown or spun from the fiber melt. It is desirable, however, that such viscosity modifiers, either by type or amount, do not adversely impact the solubility, shrink resistance, or mechanical strength of the blown or spun fiber.

    [0152] One approach to testing whether a fiber of a defined composition can be readily manufactured at an acceptable quality level is to determine whether the viscosity curve of the experimental chemistry matches that of a known product which can be easily fiberized. Viscosity-temperature profiles may be measured on a viscometer, capable of operating at elevated temperatures. In addition, an adequate viscosity profile may be inferred by routine experimentation, examining the quality of fiber (index, diameter, length) produced. The shape of the viscosity vs. temperature curve for a glass composition is representative of the ease with which a melt will fiberize and thus, of the quality of the resulting fiber (affecting, for example, the fiber's shot content, fiber diameter, and fiber length). Glasses generally have low viscosity at high temperatures. As temperature decreases, the viscosity increases. The value of the viscosity at a given temperature will vary as a function of the composition, as will the overall steepness of the viscosity vs. temperature curve. The present fiber melt composition possesses a viscosity profile of a readily manufacturable fiber.

    [0153] Linear shrinkage of an inorganic fiber is a good measure of a fiber's dimensional stability at high temperatures or of its performance at a particular continuous service or use temperature. Fibers are tested for shrinkage by forming them into a mat and needle punching the mat together into a blanket of approximately 4-10 pounds per cubic foot density and a thickness of about 1 inch. Such pads are cut into 3 inch x 5 inch pieces and platinum pins are inserted into the face of the material. The separation distance of these pins is then carefully measured and recorded. The pad is then placed into a furnace, ramped to temperature and held at the temperature for a fixed period of time. After heating, the pin separation is again measured to determine the linear shrinkage that pad has experienced.

    [0154] In one such test, the length and width of the fiber pieces were carefully measured, and the pad was placed in a furnace and brought to a temperature of 1260 or 1400°C for 24 or 168 hours. After cooling, the lateral dimensions were measured and the linear shrinkage was determined by comparing "before" and "after" measurements. If the fiber is available in blanket form, measurements may be made directly on the blanket without the need to form a pad.

    [0155] Mechanical integrity is also an important property since the fiber must support its own weight in any application and must also be able to resist abrasion due to moving air or gas. Indications of fiber integrity and mechanical strength are provided by visual and tactile observations, as well as mechanical measurement of these properties of after-service temperature exposed fibers. The ability of the fiber to maintain its integrity after exposure to the use temperature may also be measured mechanically by testing for compression strength and compression recovery. These tests measure, respectively, how easily the pad may be deformed and the amount of resiliency (or compression recovery) the pad exhibits after a compression of 50%. Visual and tactile observations indicate that the present inorganic fiber remains intact and maintains its form after exposure to a use temperature of at least 1260 or 1400°C.

    [0156] According to certain embodiments, the low shrinkage, high temperature resistant inorganic fiber comprises the fiberization product of a melt containing magnesia and silica as the primary constituents. The low biopersistent inorganic fibers are made by standard glass and ceramic fiber manufacturing methods. Raw materials, such as silica, any suitable source of magnesia such as enstatite, forsterite, magnesia, magnesite, calcined magnesite, magnesium zirconate, periclase, steatite, or talc. Lithium may be included in the fiber melt as LiCO3. If zirconia is included in the fiber melt, any suitable source of zirconia such as baddeleyite, magnesium zirconate, zircon or zirconia, are introduced into a suitable furnace where they are melted and blown using a fiberization nozzle, or spun, either in a batch or a continuous mode.

    [0157] An inorganic fiber comprising the fiberization product of magnesia and silica is referred to as a "magnesium-silicate" fiber. An inorganic fiber comprising the fiberization product of calcia, magnesia and silica is referred to as a "calcia-magnesium-silicate" fiber. An inorganic fiber comprising the fiberization product of calcia and silica is referred to as a "calcium-silicate" fiber. The low shrinkage, high temperature resistant inorganic fiber also comprises and a lithium oxide-bearing raw material component as part of the fiber melt chemistry.

    [0158] According to certain embodiments, the present inorganic fiber has an average diameter of greater than 2 microns. According to certain embodiments, the present inorganic fiber has an average diameter of greater than 2 microns to about 7.5 microns. According to certain embodiments, the present inorganic fiber has an average diameter of about 3.5 to about 7 microns.

    [0159] According to any one of the illustrative fiberization products disclosed above, the inorganic fiber exhibits low shrinkage and good mechanical strength at temperatures from about 1100°C to about 1500°C and low biopersistence.

    [0160] According to any one of the illustrative fiberization products disclosed above, the inorganic fiber present exhibits low shrinkage and good mechanical strength at temperatures from about 1260°C to about 1500°C and low biopersistence.

    [0161] According to any one of the illustrative fiberization products disclosed above, the inorganic fiber exhibits low shrinkage and good mechanical strength at temperatures from about 1260°C to about 1400°C and low biopersistence.

    [0162] According to any one of the illustrative fiberization products disclosed above, the inorganic fiber exhibits low shrinkage and good mechanical strength at temperatures from about 1400°C to about 1500°C and low biopersistence.

    [0163] The magnesium-silicate fibers containing intended additions of lithium oxide exhibit a linear shrinkage after exposure to a service temperature of 1400°C for 24 hours of 10 percent or less. In other embodiments, the magnesium-silicate fibers containing intended additions of lithium oxide exhibit a linear shrinkage after exposure to a service temperature of 1400°C for 24 hours of 5 percent or less. In other embodiments, the magnesium-silicate fibers containing intended additions of lithium oxide a linear shrinkage after exposure to a service temperature of 1400°C for 24 hours of 4 percent or less.

    [0164] The inorganic fibers containing intended additions of lithium oxide are useful for thermal insulating applications at continuous service or operating temperatures of at least 1260°C and greater. According to certain embodiments, the fibers containing lithium oxide are useful for thermal insulating applications at continuous service or operating temperatures of at least 1400°C and it has been found that the magnesium-silicate fibers containing the lithium oxide additions do not melt until they are exposed to a temperature of 1500°C or greater.

    [0165] The inorganic fibers may be prepared by fiber blowing or fiber spinning techniques. A suitable fiber blowing technique includes the steps of mixing the starting raw materials containing magnesia, silica, lithium oxide, viscosity modifier, and optional zirconia together to form a material mixture of ingredients, introducing the material mixture of ingredients into a suitable vessel or container, melting the material mixture of ingredients for discharge through a suitable nozzle, and blowing a high pressure gas onto the discharged flow of molten material mixture of ingredients to form the fibers.

    [0166] A suitable fiber spinning technique includes the steps of mixing the starting raw materials together to form a material mixture of ingredients, introducing the material mixture of ingredients into a suitable vessel or container, melting the material mixture of ingredients for discharge through a suitable nozzle onto spinning wheels. The molten stream then cascades over the wheels, coating the wheels and being thrown off through centripetal forces, thereby forming fibers.

    [0167] In some embodiments, the fiber is produced from a melt of raw materials by subjecting the molten stream to a jet of high pressure/high velocity air or by pouring the melt onto rapidly spinning wheels and spinning fiber centrifugally. The lithium oxide is provided as an additive to the melt, and a suitable source of the lithium oxide raw material is simply added at the proper amount to the raw materials being melted.

    [0168] The addition of lithium oxide as a component of the raw materials which are fiberized results in a decrease of linear shrinkage of the resulting fiber after exposure to the use temperature. The lithium oxide may also be provided as either a continuous or discontinuous coating on the outer surfaces of the inorganic fibers.

    [0169] In addition to the lithium oxide-bearing compounds, the viscosity of the material melt of ingredients may optionally be controlled by the presence of viscosity modifiers, in an amount sufficient to provide the fiberization required for the desired applications. The viscosity modifiers may be present in the raw materials which supply the main components of the melt, or may, at least in part, be separately added. Desired particle size of the raw materials is determined by furnacing conditions, including furnace size (SEF), pour rate, melt temperature, residence time, and the like.

    [0170] The fiber may be manufactured with existing fiberization technology and formed into multiple thermal insulation product forms, including but not limited to bulk fibers, fiber-containing blankets, boards, papers, felts, mats, blocks, modules, coatings, cements, moldable compositions, pumpable compositions, putties, ropes, braids, wicking, textiles (such as cloths, tapes, sleeving, string, yarns, etc...), vacuum cast shapes and composites. The fiber may be used in combination with conventional materials utilized in the production of fiber-containing blankets, vacuum cast shapes and composites, as a substitute for conventional refractory ceramic fibers. The fiber may be used alone or in combination with other materials, such as binders and the like, in the production of fiber-containing paper and felt.

    [0171] The fiber may be easily melted by standard glass furnacing methods, fiberized by standard RCF fiberization equipment, and is soluble in simulated body fluids.

    [0172] A method of insulating an article using a thermal insulation containing the disclosed inorganic fibers is also provided. The method of insulating an article includes disposing on, in, near, or around the article to be insulated, a thermal insulation material that contains the inorganic fibers containing an intended lithium oxide addition.

    [0173] The high temperature resistant inorganic fibers are readily manufacturable from a melt having a viscosity suitable for blowing or spinning fiber, are non-durable in physiological fluids, exhibit good mechanical strength up to the service temperature, exhibit excellent linear shrinkage up to 1400°C and above and improved viscosity for fiberization.

    EXAMPLES



    [0174] The following examples are set forth to describe illustrative embodiments of the inorganic fibers containing lithium oxide addition in further detail and to illustrate the methods of preparing the inorganic fibers, preparing thermal insulating articles containing the fibers and using the fibers as thermal insulation. However, the examples should not be construed as limiting the fiber, the fiber containing articles, or the processes of making or using the fibers as thermal insulation in any manner.

    Linear Shrinkage



    [0175] A shrinkage pad was prepared by needling a fiber mat using a bank of felting needles. A 3 inch x 5 inch test piece was cut from the pad and was used in the shrinkage testing. The length and width of the test pad was carefully measured. The test pad was then placed into a furnace and brought to a temperature of 1400°C for 24 hours. After heating for 24 hours, the test pad was removed from the test furnace and cooled. After cooling, the length and width of the test pad were measured again. The linear shrinkage of the test pad was determined by comparing the "before" and "after" dimensional measurements.

    [0176] A second shrinkage pad was prepared in a manner similar to that disclosed for the first shrinkage pad. However, the second shrinkage pad was placed in a furnace and brought to a temperature of 1260°C for 24 hours. After heating for 24 hours, the test pad was removed from the test furnace and cooled. After cooling, the length and width of the test pad were measured again. The linear shrinkage of the test pad was determined by comparing the "before" and "after" dimensional measurements.

    Compression Recovery



    [0177] The ability of the inorganic fibers to retain mechanical strength after exposure to a use temperature was evaluated by a compression recovery test. Compression recovery is a measure of the mechanical performance of an inorganic fiber in response to the exposure of the fiber to a desired use temperature for a given period of time. Compression recovery is measured by firing test pads manufactured from the inorganic fiber material to the test temperature for the selected period of time. The fired test pads are thereafter compressed to half of their original thickness and allowed to rebound. The amount of rebound is measured as percent recovery of the compressed thickness of the pad. Compression recovery was measured after exposure to use temperatures of 1260°C for 24 hours and 168 hours, and 1400°C for 24 hours and 168 hours. According to certain illustrative embodiments, the test pads manufactured from the inorganic fibers exhibit a compression recovery of at least 10 percent.

    Fiber Dissolution



    [0178] The inorganic fiber is non-durable or non-biopersistent in physiological fluids. By "non-durable" or "non-biopersistent" in physiological fluids it is meant that the inorganic fiber at least partially dissolves or decomposes in such fluids, such as simulated lung fluid, during in vitro tests described herein.

    [0179] The biopersistence test measures the rate at which mass is lost from the fiber (ng/cm2-hr) under conditions which simulate the temperature and chemical conditions found in the human lung. In particular, the fibers exhibit low biopersistence in Simulated Lung Fluid at a pH of 7.4.

    [0180] To measure the dissolution rate of fibers in simulated lung fluid, approximately 0.1g of fiber is placed into a 50 ml centrifuge tube containing simulated lung fluid which has been warmed to 37°C. This is then placed into a shaking incubator for 6 hours and agitated at 100 cycles per minute. At the conclusion of the test, the tube is centrifuged and the solution is poured into a 60 ml syringe. The solution is then forced through a 0.45 µm filter to remove any particulate and tested for glass constituents using Inductively Coupled Plasma Spectroscopy analysis. This test may be conducted using either a near-neutral pH solution or an acidic solution. Although no specific dissolution rate standards exist, fibers with dissolution values in excess of 100 ng/cm2 hr are considered indicative of a non-biopersistent fiber.

    [0181] Table I shows fiber melt chemistries for various comparative and inventive fiber samples.
    TABLE I
    ExampleSiO2MgOAl2O3CaOFe2O3Li2O
     wt%wt%wt%wt%wt%wt%
    C1 80.05 18.60 1.13 0.15 0.07 0
    2 80.19 18.45 1.13 0.15 0.07 0.004
    3 80.07 18.54 1.16 0.15 0.08 0.013
    4 79.9 18.79 1.14 0.15 0.07 0.022
    5 79.73 18.93 1.12 0.15 0.07 0.03
    6 79.42 19.28 1.08 0.15 0.08 0.033
    7 79.33 19.35 1.1 0.15 0.08 0.035
    8 79.25 19.42 1.1 0.14 0.09 0.041
    C9 80.1 18.4 1.3 0.15 0.11 0
    10 79.4 18.7 1.4 0.31 0.24 0.037


    [0182] Table II shows the green thickness (inches) blankets prepared from the fibers of Table I:
    TABLE II
    Example24 hours/1260°C168 hours/1260°C24 hours/1400°C
     ThicknessThicknessThickness
     InchesInchesInches
    C1 1.2   1.2
    2 1.2   1.2
    3 1.2   1.2
    4 1.2   1.1
    5 1.3   1.2
    6 1.2   1.2
    7 1.2   1.2
    8 1.1   1.0
    10   1.14  


    [0183] Table IIIa-1 and IIIa-2 show the green and fired densities (pcf) of blankets prepared from fibers of Table I. Table IIIb shows the diameters, fiber index, green density, green thickness and initial tensile strength of fibers of Table I.
    Table IIIa-1
    Example24 hours/1260°C24 hours/1400°C24 hours/1260°C24 hours/1400°C
     GreenGreenFiredFired
     DensityDensityDensityDensity
    C1 5.6 6.7 9.4 13.3
    2 6.9 7.3 9.8 13.0
    3 6.7 6.7 9.6 11.1
    4 6.7 6.5 8.8 9.4
    5 6.9 7.2 9.0 9.9
    6 6.6 6.3 8.6 8.9
    7 5.9 6.3 7.7 9.1
    8 6.8 5.7 8.7 7.8
    Table IIIa-2
    Example168 hours/1260°C24 hours/1260°C
     GreenFired
     DensityDensity
    10 7.2 11.2
    TABLE IIIb
    SampleDiameter (micron)Fiber Index%Green Density (pcf)Green Thickness (inches)Tensile Strength (psi)
    C9 6.65 45 6.8 1.1 6.3
    10 5.22 41.2 7.7 1.2 8.2


    [0184] Table IV shows the results for shrinkage for the fibers after exposure to 1260°C and 1400°C for 24 and 168 hours.
    TABLE IV
    ExampleThickness ShrinkageLinear ShrinkageThickness ShrinkageLinear ShrinkageThickness ShrinkageLinear Shrinkage
     1260°C 24 hours1260°C 24 hours1400°C 24 hours1400°C 24 hours1260°C 168 hours1260°C 168 hours
      % % % %    
    C1 30.9 6.9 35.8 11.4    
    2 21.8 5.2 31.3 9.4    
    3 22.9 5.4 29.7 7.4    
    4 18.8 3.7 23.6 4.9    
    5 18.0 3.3 21.0 4.1    
    6 18.5 2.9 22.5 4.5    
    7 18.1 3.4 23.6 4.4    
                 
    ExampleThickness ShrinkageLinear ShrinkageThickness ShrinkageLinear ShrinkageThickness ShrinkageLinear Shrinkage
     1260°C 24 hours1260°C 24 hours1400°C 24 hours1400°C 24 hours1260°C 168 hours1260°C 168 hours
    8 16.5 3.3 20.3 4.2    
    C9   5.6   11.5    
    10   4.9   6.2 28.5 5.3


    [0185] Table IV shows that a magnesium-silicate inorganic fiber composition including a synergistic combination of lithium oxide as a component of the fiberization product results in lower linear shrinkage at both 1260°C and 1400°C as compared to magnesium-silicate inorganic fiber without the intended and lithium oxide addition.

    [0186] Table V shows the results compression recovery after exposure to 1260°C and 1400°C for 24 and 168 hours, and solubility for the fibers of Table I:
    TABLE V
    ExampleComp RecComp RecComp RecSolubility (k)
     1260°C 24 hours1400°C 24 hours1260°C 168 hoursng/cm2 hr
     %%% 
    C1 53.2 26.2   587
    2 53.7 27.5   814
    3 53.2 27.6   757
    4 53.6 31.5   613
    5 55.1 30.8   616
    6 56.4 30.1   1053
    7 56.9 29.3   559
    8 54.9 25.4   723
    C9 42 17   783


    [0187] Table V shows that a magnesium-silicate inorganic fiber composition including an intended addition of lithium oxide as a component of the fiberization product results in an improvement in compression recovery at both 1260°C and 1400°C as compared to magnesium-silicate inorganic fiber without the intended and lithium oxide addition. The magnesium-silicate inorganic fiber composition including lithium oxide as a component of the fiberization product exhibits a compression recovery after exposure to 1260°C for 24 hours of greater than about 50%. The magnesium-silicate inorganic fiber composition including lithium oxide as a component of the fiberization product exhibits a compression recovery after exposure to 1400°C for 168 hours of greater than about 15%. The magnesium-silicate inorganic fiber composition including lithium oxide as a component of the fiberization product exhibits a compression recovery after exposure to 1400°C for 24 hours of greater than about 25%.

    [0188] Table VI shows the results compressive strength after exposure to 1260°C and 1400°C for 24 and 168 hours for the fibers of Table I:
    TABLE VI
    ExampleComp StrengthComp StrengthComp Strength
     1260°C 24 hours1400°C 24 hours1260°C 168 hours
     psipsipsi
    C1 9.9 14.1  
    2 12.7 13.4  
    3 12.8 7.8  
    4 10.4 6.2  
    5 10.9 7.1  
    6 10.2 5.9  
    7 7.1 5.4  
    8 7.4 3.2  
    C9 8 7.3  
    10 13 6.2 9



    Claims

    1. An inorganic fiber comprising the fiberization product of 65 to 86 weight percent silica, 14 to 35 weight percent magnesia, and lithium oxide in any one of the following ranges: (i) greater than 0 to 0.05 weight percent, (ii) greater than 0 to 0.045 weight percent, (iii) from 0.002 to 0.04 weight percent, (iv) from 0.005 to 0.04 weight percent, (v) from 0.01 to 0.04 weight percent, (vi) from 0.02 to 0.04 weight percent, (vii) from 0.03 to 0.04 weight percent, or (viii) from 0.035 to 0.04 weight percent, and which does not contain strontium oxide.
     
    2. The inorganic fiber of claim 1, comprising the fiberization product of 70 to 80 weight percent silica, 20 to 30 weight percent magnesia, and lithium oxide in any one of the ranges (i) through (viii) disclosed in claim 1.
     
    3. The inorganic fiber of claim 1, comprising the fiberization product of 77 to 80 weight percent silica, 20 to 23 weight percent magnesia, and lithium oxide in any one of the ranges (i) through (viii) disclosed in claim 1.
     
    4. The inorganic fiber of claim 1, comprising the fiberization product of any one of the following:

    (a) 78 to 80 weight percent silica, 20 to 22 weight percent magnesia, greater than 0 to 0.05 weight percent lithium oxide;

    (b) 78 to 80 weight percent silica, 20 to 22 weight percent magnesia, greater than 0 to 0.01 weight percent lithium oxide; or

    (c) 78 to 80 weight percent silica, 20 to 22 weight percent magnesia, greater than 0 to 0.005 weight percent lithium oxide.


     
    5. The inorganic fiber of any one of claims 1 to 4, further characterized by at least one of the following:

    (i) the fiberization product comprises greater than 0 to 11 weight percent zirconia;

    (ii) the fiberization product contains 1 weight percent or less iron oxide, measured as Fe2O3;

    (iii) the fiberization product contains 1 weight percent or less calcia; and/or

    (iv) the fiber has an average diameter of greater than 3.5 to 7.5 microns.


     
    6. The inorganic fiber of any one of claims 1 to 5, wherein said fiber exhibits a shrinkage of 5% or less at 1260°C for 24 hours.
     
    7. The inorganic fiber of any one of claims 1 to 5, wherein said fiber exhibits a shrinkage of 5% or less at 1400°C for 24 hours.
     


    Ansprüche

    1. Anorganische Faser, die das Defibrierungsprodukt von 65 bis 86 Gewichtsprozent Siliciumdioxid, 14 bis 35 Gewichtsprozent Magnesiumoxid und Lithiumoxid in einem der folgenden Bereiche: (i) mehr als 0 bis 0,05 Gewichtsprozent, (ii) mehr als 0 bis 0,045 Gewichtsprozent, (iii) 0,002 bis 0,04 Gewichtsprozent, (iv) 0,005 bis 0,04 Gewichtsprozent, (v) 0,01 bis 0,04 Gewichtsprozent, (vi) 0,02 bis 0,04 Gewichtsprozent, (vii) 0,03 bis 0,04 Gewichtsprozent oder (viii) 0,035 bis 0,04 Gewichtsprozent umfasst und die kein Strontiumoxid enthält.
     
    2. Anorganische Faser nach Anspruch 1, umfassend das Defibrierungsprodukt von 70 bis 80 Gewichtsprozent Siliciumdioxid, 20 bis 30 Gewichtsprozent Magnesiumoxid und Lithiumoxid in einem der in Anspruch 1 offenbarten Bereiche (i) bis (viii).
     
    3. Anorganische Faser nach Anspruch 1, umfassend das Defibrierungsprodukt von 77 bis 80 Gewichtsprozent Siliciumdioxid, 20 bis 23 Gewichtsprozent Magnesiumoxid und Lithiumoxid in einem der in Anspruch 1 offenbarten Bereiche (i) bis (viii).
     
    4. Anorganische Faser nach Anspruch 1, umfassend das Defibrierungsprodukt von einem der folgenden:

    (a) 78 bis 80 Gewichtsprozent Siliciumdioxid, 20 bis 22 Gewichtsprozent Magnesiumoxid, mehr als 0 bis 0,05 Gewichtsprozent Lithiumoxid;

    (b) 78 bis 80 Gewichtsprozent Siliciumdioxid, 20 bis 22 Gewichtsprozent Magnesiumoxid, mehr als 0 bis 0,01 Gewichtsprozent Lithiumoxid; oder

    (c) 78 bis 80 Gewichtsprozent Siliciumdioxid, 20 bis 22 Gewichtsprozent Magnesiumoxid, mehr als 0 bis 0,005 Gewichtsprozent Lithiumoxid.


     
    5. Anorganische Faser nach einem der Ansprüche 1 bis 4, ferner gekennzeichnet durch mindestens eines von Folgendem:

    (i) das Defibrierungsprodukt umfasst mehr als 0 bis 11 Gewichtsprozent Zirconiumdioxid;

    (ii) das Defibrierungsprodukt enthält 1 Gewichtsprozent oder weniger Eisenoxid, gemessen als Fe2O3;

    (iii) das Defibrierungsprodukt enthält 1 Gewichtsprozent oder weniger Calciumoxid; und/oder

    (iv) die Faser hat einen mittleren Durchmesser von mehr als 3,5 bis 7,5 Mikrometer.


     
    6. Anorganische Faser nach einem der Ansprüche 1 bis 5, wobei die Faser bei 1.260 °C für 24 Stunden eine Schrumpfung von 5 % oder weniger zeigt.
     
    7. Anorganische Faser nach einem der Ansprüche 1 bis 5, wobei die Faser bei 1.400 °C für 24 Stunden eine Schrumpfung von 5 % oder weniger zeigt.
     


    Revendications

    1. Fibre inorganique comprenant le produit de fibrage de 65 à 86 % en poids de silice, 14 à 35 % en poids de magnésie et d'oxyde de lithium dans l'une quelconque des plages suivantes : (i) plus de 0 à 0,05 % en poids, (ii) plus de 0 à 0,045 % en poids, (iii) de 0,002 à 0,04 % en poids, (iv) de 0,005 à 0,04 % en poids, (v) de 0,01 à 0,04 % en poids, (vi) de 0,02 à 0,04 % en poids, (vii) de 0,03 à 0,04 % en poids ou (viii) de 0,035 à 0,04 % en poids et qui ne contient pas d'oxyde de strontium.
     
    2. Fibre inorganique selon la revendication 1, comprenant le produit de fibrage de 70 à 80 % en poids de silice, de 20 à 30 % en poids de magnésie et d'oxyde de lithium dans l'une quelconque des plages (i) à (viii) indiquées dans la revendication 1.
     
    3. Fibre inorganique selon la revendication 1, comprenant le produit de fibrage de 77 à 80 % en poids de silice, 20 à 23 % en poids de magnésie et d'oxyde de lithium dans l'une quelconque des plages (i) à (viii) indiquées dans la revendication 1.
     
    4. Fibre inorganique selon la revendication 1, comprenant le produit de fibrage selon l'un quelconque des éléments suivants :

    (a) 78 à 80 % en poids de silice, 20 à 22 % en poids de magnésie, plus de 0 à 0,05 % en poids d'oxyde de lithium ;

    (b) 78 à 80 % en poids de silice, 20 à 22 % en poids de magnésie, plus de 0 à 0,01 % en poids d'oxyde de lithium ; ou

    (c) 78 à 80 % en poids de silice, 20 à 22 % en poids de magnésie, plus de 0 à 0,005 % en poids d'oxyde de lithium.


     
    5. Fibre inorganique selon l'une quelconque des revendications 1 à 4, caractérisée en outre par au moins un des éléments suivants :

    (i) le produit de fibrage comprend plus de 0 à 11 % en poids de zircone ;

    (ii) le produit de fibrage contient 1 % en poids ou moins d'oxyde de fer, mesuré en Fe203 ;

    (iii) le produit de fibrage contient 1 % en poids ou moins de calcia ; et/ou

    (iv) la fibre a un diamètre moyen supérieur à 3,5 à 7,5 microns.


     
    6. Fibre inorganique selon l'une quelconque des revendications 1 à 5, dans laquelle ladite fibre présente un rétrécissement de 5% ou moins à 1260 °C pendant 24 heures.
     
    7. Fibre inorganique selon l'une quelconque des revendications 1 à 5, dans laquelle ladite fibre présente un rétrécissement de 5% ou moins à 1400 °C pendant 24 heures.
     




    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description