(19)
(11) EP 0 354 863 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
13.04.1994 Bulletin 1994/15

(21) Application number: 89480106.7

(22) Date of filing: 29.06.1989
(51) International Patent Classification (IPC)5B41J 31/02, B41M 5/34

(54)

Multicolored fabric printing ribbon

Mehrfarbengewebeschreibband

Ruban d'impression multicolore en tissu


(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 08.08.1988 US 229194

(43) Date of publication of application:
14.02.1990 Bulletin 1990/07

(73) Proprietor: LEXMARK INTERNATIONAL, INC.
Greenwich, Connecticut 06830 (US)

(72) Inventors:
  • Findlay, Hugh Thomas
    Lexington Kentucky 40505 (US)
  • Froman,, Kenneth Howard
    Versailles Kentucky, KY 40383 (US)
  • Martone, James Francis
    Lexington Kentucky (US)

(74) Representative: Skailes, Humphrey John et al
Frank B. Dehn & Co., European Patent Attorneys, 179 Queen Victoria Street
London EC4V 4EL
London EC4V 4EL (GB)


(56) References cited: : 
FR-A- 2 078 991
GB-A- 2 098 252
US-A- 4 543 380
GB-A- 885 813
US-A- 4 309 320
   
  • PATENT ABSTRACTS OF JAPAN vol. 11, no. 94 (M-574)(2541) 25 March 1987; JP-A-61 246083
   
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] This invention relates to fabric ribbons which are impacted by a print element to print more than one color. The print elements typically are fully formed character images on a daisy wheel or one or more columns of individual wires. Transferable colors are held in the fabric and expressed on to paper or other print-receiving medium by the pressure of printing. The colors are commonly located on the ribbon in strips which extend along the length of the ribbon or in blocks of one color alternating with blocks of another color along the length of the ribbon. Such ribbons become virtually useless if the colors blend together during storage or use.

Background Art



[0002] Prior to this invention, multicolored fabric ribbons were typically made using standard pigments as the coloring matter or dyes as part of the coloring matter with the different colors separated by some physical barrier or gap. The average particle size of standard pigments is nominally 4 to 5 microns, while dyes are molecular in size.

[0003] Inks with only standard pigments do not blend together in ordinary storage and use. This can be attributed to the fact that the pigment particles are relatively large in comparison with dye molecules, and ambient energy (which includes thermal, osmotic, capillary, Brownian, and other forces) is insufficient to move such pigment particles significantly. Different colored liquid inks with standard pigments only have been applied side-by-side on fabric ribbons without blending, but such ribbons do not replenish used areas well.

[0004] In contrast, dye molecules dissolved in a typical ink vehicle are so small as to be carried by the ink vehicle and to move when the ink vehicle is moved under the stresses of normal ambient heat, as well as other ambient forces. To control this movement, the ribbon has been designed in a way to block color movement. Commonly, the weave or continuity of the ribbon is physically interrupted at the boundary between colors, such as by adding an adhesive which is hardened or by crushing or melting the ribbon.

[0005] This invention completely avoids any change of the weave of the ribbon. In accordance with the instant invention, a particular coloring matter, specifically flushed pigments, are used (average nominally 1/2 to 1 micron, agglomerations up to 2 microns). These are pigments of very small particle size, but do not tend to mix even though the woven fabric of the ribbon is continuous at the boundary between inks of different colors. The very small particle size has been found to provide good ribbon life, the particles exhibiting sufficient limited mobility that colors reconstitute themselves sufficiently near locations from which impact printing has occurred.

[0006] U.S. Patent No. 385,391 to Underwood et al has an embodiment shown in its Fig. 2 in which no difference in the ribbon at the boundary between colors is specified. The other embodiments of this patent show embodiments in which barriers to mixing of colors are created by the manner the ribbon is woven or formed. Since the nature of the coloring matter in the Fig. 2 embodiment is only generally described, the use of flushed pigments is not suggested. U.S. Patent No. 2,590,200 to Neidich teaches a ribbon in which the the fiber of the ribbon is predominantly in the direction of the boundaries of the different colors to prevent mixing across the colors.

[0007] Although flushed pigments are not widely used, flushed pigments are known and generally available, and flushed pigments have been used in woven ribbons. No use of flushed pigments in multicolored ribbons is known. U.S. Patent No. 4,574,623 to Neumann is cited merely as illustrative that flushed pigments are known.

[0008] U.K. Patent No. 885,813, Titled "Improvements in or relating to Ink Ribbons," published Dec. 26, 1961, teaches a multicolored ribbon in which the weave of the ribbon is not modified to prevent mixing. Instead, the liquid vehicles of the inks are selected to be immiscible. In accordance with the instant invention the vehicles are not essential to preventing mixing and the vehicles for each color may be identical.

Disclosure of Invention



[0009] This instant invention is a fabric ribbon having multicolored regions of coloring matter in a liquid vehicle. The coloring matter of the regions is essentially only flushed pigments, which are pigments of particle size generally less than 2 microns and of average particle size of nominally 1/2 to 1 micron. (By contrast, standard pigments are nominally 4 to 5 microns in particle size.) Flushed pigments do not migrate between colored regions under normal conditions, and therefore mixing of the colors is avoided without alteration of the fabric or use of a fabric with special characteristics or regions.

[0010] The vehicles of the different colored regions are not significant in preventing migration, as the flushed pigments do not migrate with the vehicles. Nevertheless, the flushed pigments have sufficient mobility in regions from which ink has been depleted by printing to refill used areas of the ribbon with pigment, thus providing a ribbon of long useful life.

[0011] Colored strips having essentially only standard pigments do not tend to mix, but the ribbon life from ribbons having only such standard pigments is unsatisfactory because they do not replenish used areas well. Flushed pigments, being of very small particle size, do provide satisfactory life. Yet, no barrier is needed to prevent mixing between color regions. This invention also has the potential of preventing face-to-face mixing of the ribbon colors when the ribbon is in a stuffed chamber, which is a common cartridge design.

Best Mode for Carrying Out the Invention



[0012] Three subtractive colors of the preferred embodiment of this invention are as follows:

Subtractive Yellow



[0013] 
Component Percent by Weight
Flushed SICO Yellow MO 12 MO-1434 (Trademarked product of BASF Corporation) 49.7%
Butoxy ethyl oleate (vehicle) 44.7%
Castor oil (vehicle, increases viscosity) 5.6%


[0014] The 12-MO-1434 is described by its supplier as 25% flushed yellow pigment and treated mineral oil as a vehicle. The approximate proportion of pigment to vehicle in the yellow ink therefore is 12.5% by weight pigment to 87.5% by weight vehicle.

Subtractive Red



[0015] 
Component Percent by Weight
Flushed LITHOL Rubine 45-MO-1998 (Trademarked product of BASF Corporation) 53.7%
Butoxy ethyl oleate (vehicle) 40.3%
Castor oil (vehicle, increases viscosity) 6.0%


[0016] The 45-MO-1998 is described by its supplier as 35% flushed red pigment and treated mineral oil as a vehicle. The approximate proportion of pigment to vehicle in the red ink is therefore 19% by weight pigment to 81% by weight vehicle.

Subtractive Blue



[0017] 
Component Percent by Weight
Flushed HELIOGEN Blue, MO 70-MO-2324 (Trademarked product of BASF Corporation) 37%
Butoxy ethyl oleate (vehicle) 56%
Castor oil (vehicle, increases viscosity) 7%


[0018] The 70-MO-2324 is described by its supplier as 37% flushed blue pigment, 58% vehicle solids, and treated mineral oil vehicle. The approximate proportion of pigment to vehicle in the blue ink is therefore 14% by weight pigment to 86% by weight vehicle and vehicle solids.

[0019] Each of the formulas is homogenized in a high speed mixer. The formulas are applied in any conventional manner, such as by a reverse roll coater, to adjoining regions of fabric. The fabric may be a conventional nylon woven fabric commonly used for impact printer ribbons. More specifically, in this preferred embodiment the fabric is highest quality filament nylon type 6,6; pH of 4.5 - 7, 4.0 mil (approximately 0.01016 cm) diameter; weight of 1.6 ounce per square yard (approximately 54.3 grams per square meter); warp (long direction) 174.0 threads per inch (approximately 68.5 threads per cm) and fill (cross direction) 114 threads per inch (approximately 45.7 threads per cm).

[0020] The details of the fabric are not considered limiting, and fabrics of other materials, such as cotton and other man-made polymers, are considered alternatives for use with this invention. The threads of the fabric may be woven, felted, or otherwise intermixed. However, if the interstices are exceptionally large, which would result from a very loose felting, for example, the boundaries between the colors would be uneven.

[0021] The fabric is entirely continuous and no change is made at the boundaries between the ink regions. The ink regions may be along the length of the ribbon, resulting in yellow, red, and blue strips side by side, each extending along the full length of a ribbon which typically is stuffed in the chamber of a ribbon cartridge or wound in a spool.

[0022] Mixing or blending of the ribbon colors is not experienced in normal use. The flushed pigments perform like dyes with respect to ribbon life, providing a ribbon which may be reused extensively, a characteristic of ribbons having dyes as the coloring matter. Yet, the ribbon colors do not bleed together, a characteristic of pigments.

[0023] Flushed pigments are understood to be made in a manner in which the pigments are never a dry solid. The resulting pigments are of much smaller particle size as compared to standard pigments.

[0024] Agglomerations in flushed pigments may be as large as 2 microns, while the average particle size is nominally 1/2 to 1 micron. By comparison, the average particle size of standard pigments is nominally 4 to 5 microns.


Claims

1. A fabric ribbon comprising adjoining areas having flowable ink of different colors in said areas characterized by said fabric being continous between said areas and the coloring matter of said flowable ink consisting essentially of flushed pigments.
 
2. The ribbon as in claim 1 in which said fabric is woven and said weave is continuous between said adjoining areas.
 
3. The ribbon as in claim 2 in which said ink of each of said different colors has coloring matter consisting of flushed pigment and also comprises a liquid vehicle.
 
4. The ribbon as in claim 1 in which said ink of each of said different colors has coloring matter consisting of flushed pigment and also comprises a liquid vehicle.
 
5. A fabric ribbon as in any one of claims 1 to 4, in which said flowable ink consists essentially of pigments having average particle size in the order of magnitude of 0.5 to 1.5 microns and substantially no particle size greater than 4 microns.
 


Ansprüche

1. Stoffband, umfassend nebeneinanderliegende Bereiche mit fließbarer Tinte mit verschiedenen Farben in den genannten Bereichen, dadurch gekennzeichent, daß der genannte Stoff zwischen den genannten Bereichen kontinuierlich vorhanden ist und der Farbstoff der genannten fließbaren Tinte im wesentlichen aus geflushten Pigmenten besteht.
 
2. Band nach Anspruch 1, in dem der genannte Stoff gewebt und die genannte Webung kontinuierlich zwischen den genannten nebeneinanderliegenden Bereichen vorhanden ist.
 
3. Band nach Anspruch 2, bei dem die genannte Tinte jeder der genannten verschiedenen Farben einen aus einem geflushten Pigment bestehenden Farbstoff aufweist und auch einen flüssigen Trägerstoff enthält.
 
4. Band nach Anspruch 1, bei dem die genannte Tinte jeder der genannten verschiedenen Farben einen aus einem geflushten Pigment bestehenden Farbstoff aufweist und auch einen flüssigen Trägerstoff enthält.
 
5. Stoffband nach einem der Ansprüche 1 bis 4, bei dem die genannte fließbare Tinte im wesentlichen aus Pigmenten besteht, die eine durchschnittliche Teilchengröße in der Größenordnung von 0,5 bis 1,5 µm und im wesentlichen keine Teilchengröße über 4 µm aufweisen.
 


Revendications

1. Ruban en étoffe comprenant des zones adjacentes contenant une encre fluide et ayant des couleurs différentes dans lesdites zones, caractérisé en ce que ladite étoffe s'étend continûment entre lesdites zones et que la substance colorante de ladite encre fluide est constituée essentiellement de pigments denses.
 
2. Ruban selon la revendication 1, dans lequel ladite étoffe est tissée et ladite armure s'étend continûment entre lesdites zones adjacentes.
 
3. Ruban selon la revendication 2, dans lequel ladite encre possédant chacune desdites couleurs différentes contient une substance colorante constituée par un pigment dense et comprend également un support liquide.
 
4. Ruban selon la revendication 1, dans lequel ladite encre possédant chacune desdites couleurs différentes contient une substance colorante constituée par un pigment dense et comprend également un support liquide.
 
5. Ruban formé d'une étoffe selon l'une quelconque des revendications 1 à 4, dans lequel ladite encre fluide est constituée essentiellement par des pigments ayant des particules possédant une taille moyenne de l'ordre de grandeur de 0,5 à 1,5 micron et ne comporte sensiblement aucune particule ayant une taille supérieure à 4 microns.