(19)
(11)EP 2 484 534 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
16.01.2019 Bulletin 2019/03

(21)Application number: 10820109.6

(22)Date of filing:  27.09.2010
(51)Int. Cl.: 
B41M 5/333  (2006.01)
B41M 5/323  (2006.01)
(86)International application number:
PCT/JP2010/005788
(87)International publication number:
WO 2011/039987 (07.04.2011 Gazette  2011/14)

(54)

RECORDING MATERIAL USING PHENOLIC COMPOUND

AUFZEICHNUNGSMATERIAL MIT EINER PHENOLVERBINDUNG

MATÉRIAU D'ENREGISTREMENT UTILISANT UN COMPOSÉ PHÉNOLIQUE


(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 SE SI SK SM TR

(30)Priority: 29.09.2009 JP 2009224317
29.09.2009 JP 2009224094
16.10.2009 JP 2009239571

(43)Date of publication of application:
08.08.2012 Bulletin 2012/32

(73)Proprietor: Nippon Soda Co., Ltd.
Tokyo 100-8165 (JP)

(72)Inventors:
  • SAKAI, Hiroshi
    Ichihara-shi Chiba 290-0045 (JP)
  • AIHARA, Toshio
    Odawara-shi Kanagawa 250-0280 (JP)
  • KODAMA, Satoshi
    Ichihara-shi Chiba 290-0045 (JP)
  • KINOSHITA, Shuntaro
    Ichihara-shi Chiba 290-0045 (JP)
  • JYUJYO, Kazumi
    Ichihara-shi Chiba 290-0045 (JP)
  • KONDO, Tadahiro
    Ichihara-shi Chiba 290-0045 (JP)

(74)Representative: Wibbelmann, Jobst 
Wuesthoff & Wuesthoff Patentanwälte PartG mbB Schweigerstrasse 2
81541 München
81541 München (DE)


(56)References cited: : 
EP-A1- 0 574 879
EP-A1- 2 394 985
GB-A- 2 396 704
JP-A- 2003 305 959
JP-A- 2009 137 220
EP-A1- 2 394 820
EP-A1- 2 612 847
JP-A- 2003 305 959
JP-A- 2009 137 220
  
     
    Remarks:
    The file contains technical information submitted after the application was filed and not included in this specification
     
    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] The present invention relates to a recording material containing a color-forming compound and a color-developing agent and particularly relates to a recording material containing a phenolic compound as a color-developing agent.

    Background Art



    [0002] Recording materials that employ color development through the reaction between a color-forming compound and a color-developing agent allow recording in a short time using a relatively simple apparatus without performing complicated treatments such as development and fixation and are thus widely used in thermal recording paper for output recording in facsimiles, printers, etc., or pressure-sensitive copying paper or the like for forms for simultaneous multiple copying. These recording materials are required to immediately develop colors, maintain the whiteness of an uncolored part (hereinafter, referred to as a "background"), and offer the high colorfastness of colored images. Particularly, recording materials excellent in the light resistance of the background are desired in terms of long-term storage stability. For this purpose, attempts have been made to develop color-forming compounds, color-developing agents, storage stabilizers, etc. Nevertheless, recording materials that have well-balanced, sufficiently satisfactory color-developing sensitivity, background and image stabilities, etc., have not been found yet.

    [0003] Also, 2,4'-dihydroxydiphenylsulfone and 4-hydroxy-4'-isopropoxydiphenylsulfone have heretofore been known as recording materials excellent in background stability and are, however, still unsatisfactory in terms of, for example, the light resistance of the background.

    [0004] The present inventors have already proposed a recording material excellent in the light resistance of the background using a cinnamamide compound as a color-developing agent (see patent document 1). However, this recording material is still not sufficiently satisfactory in terms of, for example, the heat resistance of images, and practical recording materials remain to be obtained.

    Prior Art Document


    Patent Document



    [0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-305959

    Summary of the Invention


    Object to be Solved by the Invention



    [0006]  An object of the present invention is to improve the disadvantages of conventional recording materials as described above and to provide a recording material or a recording sheet that is excellent in background and image stabilities, particularly, the light resistance of the background, further excellent in color-developing sensitivity and exceedingly excellent in the heat resistance, plasticizer resistance, and oil resistance of images.

    Means to Solve the Object



    [0007] The present inventors have conducted diligent studies on various color-developing agents used in recording materials and consequently completed the present invention by finding that a recording material that is excellent in color-developing sensitivity and the light resistance of the background, excellent in background and image stabilities, and further excellent in image stability is obtained by using a cinnamamide compound and an additive in combination.

    [0008] The recording material and recording sheet according to the present invention are defined in claims 1 to 4. Disclosed are the following examples which would facilitate the understanding of the invention, in which
    1. (1) a recording material that contains a fluoran color-forming compound, the recording material containing at least one compound represented by formula (I) and an additive:

      [wherein R1 and R4 each independently represent a hydroxy group, a halogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group; p represents 0 or any integer of 1 to 4; q represents 0 or any integer of 1 to 5; when p and q represent 2 or more, each of R1 and each of R4 are the same or different; R2 and R3 each independently represent a hydrogen atom or a C1-C6 alkyl group; R5 represents a hydrogen atom, a C1-C6 alkyl group, a phenyl group, or a benzyl group; and the bond represented by the wavy line represents E, Z, or a mixture thereof],
    2. (2) the recording material according to (1), wherein the compound represented by formula (I) is represented by formula (II):

      [wherein R2 to R5 are the same as R2 to R5 in formula (I); R7 represents a C1-C4 alkyl group or a C1-C4 alkoxy group; and R6 represents a hydrogen atom when R7 represents a C1-C4 alkyl group, and represents a C1-C4 alkoxy group when R7 represents a C1-C4 alkoxy group],
    3. (3) the recording material according to (1), wherein the compound represented by formula (I) is represented by formula (III):

      [wherein R2 to R5 and q are the same as R2 to R5 and q in formula (I)],
    4. (4) the recording material according to any one of (1) to (3), wherein the additive is at least one compound represented by formula (IV):

      [wherein R81 and R82 each independently represent a halogen atom, a C1-C6 alkyl group, or a C2-C6 alkenyl group; n1 and n2 each independently represent 0 or any integer of 1 to 4; m represents 0 or any integer of 1 to 2; and R9 represents a C1-C6 alkyl group]
      or at least one compound represented by formula (V):

      [wherein R101 to R106 each independently represent a halogen atom, a C1-C6 alkyl group, or a C2-C6 alkenyl group; Y represents a linear or branched, saturated or unsaturated C1-C12 hydrocarbon group optionally having an ether bond or the following formula:

      (wherein R11 represents a methylene group or an ethylene group, and T represents a hydrogen atom or a C1-C4 alkyl group); b, c, d, e, f, and g each independently represent 0 or any integer of 1 to 4; m represents 0 or any integer of 1 to 2; and a represents 0 or any integer of 1 to 10],
    5. (5) the recording material according to (4), wherein the compound represented by formula (IV) is represented by formula (VI):

      [wherein R12 represents a hydrogen atom, a C1-C6 alkyl group, or a C2-C6 alkenyl group],
    6. (6) the recording material according to (4), wherein the compound represented by formula (V) is represented by formula (VII):

      [wherein Y represents a linear or branched, saturated or unsaturated C1-C12 hydrocarbon group optionally having an ether bond or the following formula:

      (wherein R11 represents a methylene group or an ethylene group, and T represents a hydrogen atom or a C1-C4 alkyl group); and a represents 0 or any integer of 1 to 10],
    7. (7) the recording material according to any one of (1) to (3) wherein the additive is an image stabilizer,
    8. (8) the recording material according to (7), wherein the image stabilizer is a hindered phenol compound,
    9. (9) the recording material according to (8), wherein the image stabilizer is a hindered phenol compound represented by formula (VIII):

      [wherein R13 and R14 each independently represent a C1-C6 alkyl group; p' and q' each independently represent any integer of 1 to 4; when p' and q' represent 2 or more, each of R13 and each of R14 are the same or different, provided that at least one of R13 and R14 represents a C1-C6 alkyl group bonded via secondary or tertiary carbon to the ortho position of the hydroxy group; and R15 is represented by formula (IX):

      [wherein R16 represents a C1-C6 alkyl group; r represents 0 or any integer of 1 to 4; and * represents a binding position],
      provided that the contents of the compound represented by formula (I) and compound represented by formula (VIII) are both 0.5 to 10 parts by mass with respect to 1 part by mass of the color-forming compound.
    10. (10) the recording material according to any one of (1) to (3), wherein the additive is a sensitizer,
    11. (11) the recording material according to any one of (1) to (11), wherein the color-forming compound is a fluoran dye, and
    12. (12) a recording sheet having a recording material layer formed from a recording material according to (9) on a support.

    Effect of the Invention



    [0009] According to the present invention, a recording material that is excellent in color-developing sensitivity and more excellent in background and image stabilities than ever before can be obtained by combining a particular cinnamamide compound with an additive in a recording material containing a color-forming compound. Particularly, a recording material or a recording sheet that is excellent in the light resistance and moist heat resistance of the background and exceedingly excellent in the heat resistance of images can be obtained.

    Brief Description of Drawings



    [0010] 

    Figure 1 is a diagram showing results of a dynamic color-developing sensitivity test using each recording paper prepared in Examples 11 to 15 and Comparative Example 7.

    Figure 2 is a diagram showing results of a dynamic color-developing sensitivity test using each recording paper prepared in Examples 16 to 20 and Comparative Example 8.

    Figure 3 is a diagram showing results of a dynamic color-developing sensitivity test using each recording paper prepared in Examples 21 and 22 and Comparative Example 9.

    Figure 4 is a diagram showing results of a dynamic color-developing sensitivity test using each recording paper prepared in Examples 25 to 27 and Comparative Example 12.

    Figure 5 is a diagram showing results of a dynamic color-developing sensitivity test using each recording paper prepared in Examples 28 to 30 and Comparative Example 13.


    Mode of Carrying Out the Invention


    (Recording material)



    [0011] A recording material of the present invention is a recording material containing a color-forming compound, the recording material containing at least one compound represented by formula (I) and an additive.

    (Compound represented by formula (I))



    [0012] In the formula of the compound represented by formula (I), R1 and R4 each independently represent a hydroxy group, a halogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group. Specifically, examples of the halogen atom can include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the C1-C6 alkyl group can include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a sec-butyl group, a t-butyl group, an isobutyl group, a n-pentyl group, an isopentyl group, a neopentyl group, a t-pentyl group, a n-hexyl group, an isohexyl group, a 1-methylpentyl group, and a 2-methylpentyl. Examples of the C1-C6 alkoxy group can include a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, a sec-butoxy group, a t-butoxy group, an isobutoxy group, a n-pentoxy group, an isopentoxy group, a neopentoxy group, a t-pentoxy group, a n-hexoxy group, an isohexoxy group, a 1-methylpentoxy group, and a 2-methylpentoxy group.

    [0013] R2 and R3 each independently represent a hydrogen atom or a C1-C6 alkyl group. Examples of the C1-C6 alkyl group can specifically include the same as the specific examples of R1.

    [0014] R5 represents a hydrogen atom, a C1-C6 alkyl group, a phenyl group, or a benzyl group. Examples of the C1-C6 alkyl group can specifically include the same as the specific examples of R1.

    [0015] The compound represented by the general formula (I) used in the present invention can be obtained by reacting a compound represented by formula (X) with a compound represented by formula (XI) in the presence of a base such as pyridine in an organic solvent such as acetonitrile:

    [wherein R1 represents a hydroxy group, a halogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group; p represents 0 or any integer of 1 to 4; when p represents 2 or more, each of R1 is the same or different; and R5 represents a hydrogen atom, a C1-C6 alkyl group, an optionally substituted phenyl group, or an optionally substituted benzyl group], and

    [wherein R4 represents a hydroxy group, a halogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group; q represents 0 or any integer of 1 to 5; when q is 2 or more, each of R4 is the same or different; R2 and R3 each independently represent a hydrogen atom or a C1-C6 alkyl group; Z represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom; and the bond represented by the wavy line represents an E form, a Z form, or a mixture thereof].

    [0016] The compound represented by formula (I) has geometric isomers as shown below. Depending on reaction conditions and a purification method, only any one of the isomers may be obtained, or an isomeric mixture may be obtained. These isomers are all included in the scope of the present invention.



    [0017] Examples of the compound represented by formula (I) can specifically include compounds described in Table 1.









    [0018] The compound represented by formula (I) is particularly preferably a compound represented by formula (II) :

    [wherein R2 to R5 are the same as R2 to R5 in formula (I); R7 represents a C1-C4 alkyl group or a C1-C4 alkoxy group; and R6 represents a hydrogen atom when R7 represents a C1-C4 alkyl group, and represents a C1-C4 alkoxy group when R7 represents a C1-C4 alkoxy group].

    [0019] In formula (II), examples of the C1-C4 alkyl group or the C1-C4 alkoxy group represented by R7 can specifically include, of those exemplified as the specific examples of R1, groups satisfying the condition of C1-C4.

    [0020] R6 represents a hydrogen atom when R7 represents a C1-C4 alkyl group, and represents a C1-C4 alkoxy group when R7 represents a C1-C4 alkoxy group. Examples of the C1-C4 alkoxy group represented by R6 can specifically include, of those exemplified as the specific examples of R1, groups satisfying the condition of C1-C4.

    [0021] Examples of the compound represented by formula (II) can more specifically include N-(4-hydroxyphenyl)-3-methylcinnamoylamide, N-(3-hydroxyphenyl)-3-methylcinnamoylamide, and N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide.

    [0022]  Moreover, the compound represented by formula (I) is also particularly preferably a compound represented by formula (III):

    [wherein R2 to R5 are the same as R2 to R5 in formula (I)].

    [0023] Examples of the compound represented by formula (III) can more specifically include N-(2-hydroxyphenyl)-cinnamoylamide.

    [0024] These compounds represented by formula (I) can be used alone or in combination of two or more thereof, as needed, as a color-developing agent. The two or more compounds represented by formula (I) can be combined at any ratio.

    (Additive)



    [0025] In the present invention, the additive is a compound that is added to the recording material containing a color-forming compound combined with the particular cinnamamide compound, for the purpose of improving performance, for example, improving color-developing performance or improving image-stabilizing performance. One or two or more additives can be contained therein, as needed. The amount of the additive used is 0.5 to 10 parts by mass, with respect to 1 part by mass of the color-forming compound.

    [0026] Hereinafter, the additive of the present invention will be exemplified, but is not limited to these compounds.

    (Color-developing agent other than compound represented by formula (I))



    [0027] In the present invention, when at least one compound represented by formula (I) is used in combination with a color-developing agent other than the compound of formula (I), the combination is preferably with a compound represented by formula (IV) and/or a compound represented by formula (V).

    (Compound represented by formula (IV))



    [0028] In formula (IV), R81 and R82 each independently represent a hydroxy group, a halogen atom, a C1-C6 alkyl group, or a C2-C6 alkenyl group. Specifically, examples of the halogen atom and the C1-C6 alkyl group can include the same as the specific examples of R1. Examples of the C2-C6 alkenyl group can include a vinyl group, an allyl group, an isopropenyl group, a 1-propenyl group, a 2-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1,3-butanedienyl group, and a 2-methyl-2-propenyl group.

    [0029] R9 represents a hydrogen atom, a C1-C6 alkyl group, or a C2-C6 alkenyl group. Examples of the C1-C6 alkyl group can include the same as the specific examples of R1. Examples of the C2-C6 alkenyl group can include the same as the specific examples of R81.

    [0030] The compound represented by formula (IV) is preferably a diphenylsulfone compound represented by formula (VI).

    [0031] Examples of the compound represented by formula (IV) can specifically include 4,4'-dihydroxydiphenylsulfone, 2,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxy-3,3'-diallyldiphenylsulfone, 4-hydroxy-4'-methoxydiphenylsulfone, 4-hydroxy-4'-ethoxydiphenylsulfone, 4-hydroxy-4'-n-propoxydiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-n-butoxydiphenylsulfone, 4-hydroxy-4'-sec-butoxydiphenylsulfone, 4-hydroxy-4'-t-butoxydiphenylsulfone, and 4-hydroxy-4'-allyloxydiphenylsulfone.

    [0032] These compounds of formula (IV) can be used alone or in combination of two or more thereof, as needed, as a color-developing agent. The two or more compounds represented by formula (IV) can be combined at any ratio.

    (Compound represented by formula (V))



    [0033] In formula (V), R101 to R106 each independently represent a halogen atom, a C1-C6 alkyl group, or a C2-C6 alkenyl group; and Y represents a linear or branched, saturated or unsaturated C1-C12 hydrocarbon group optionally having an ether bond or the following formula:

    (wherein R11 represents a methylene group or an ethylene group, and T represents a hydrogen atom or a C1-C4 alkyl group). Specifically, examples of the halogen atom and the C1-C6 alkyl group can include the same as the specific examples of R1. Examples of the C2-C6 alkenyl group can include the same as the specific examples of R81.

    [0034] Examples of the C1-C4 alkyl group represented by T can include, of those exemplified as the specific examples of R1, groups satisfying the condition of C1-C4.

    [0035] Examples of Y can include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a methylmethylene group, a dimethylmethylene group, a methylethylene group, a methyleneethylene group, an ethylethylene group, a 1,2-dimethylethylene group, a 1-methyltrimethylene group, a 1-methyltetramethylene group, a 1,3-dimethyltrimethylene group, a 1-ethyl-4-methyltetramethylene group, a vinylene group, a propenylene group, a 2-butenylene group, an ethynylene group, a 2-butynylene group, a 1-vinylethylene group, an ethyleneoxyethylene group, a tetramethyleneoxytetramethylene group, an ethyleneoxyethyleneoxyethylene group, an ethyleneoxymethyleneoxyethylene group, a 1,3-dioxane-5,5-bismethylene group, a 1,2-xylyl group, a 1,3-xylyl group, a 1,4-xylyl group, a 2-hydroxytrimethylene group, a 2-hydroxy-2-methyltrimethylene group, a 2-hydroxy-2-ethyltrimethylene group, a 2-hydroxy-2-propyltrimethylene group, a 2-hydroxy-2-isopropyltrimethylene group, and a 2-hydroxy-2-butyltrimethylene group.

    [0036] The compound represented by formula (V) is preferably a cross-linked diphenylsulfone compound represented by formula (VII).

    [0037] Examples of the compound represented by formula (V) can specifically include 4,4'-bis[4-[4-(4-hydroxyphenylsulfonyl)phenoxy]-2-trans-butenyloxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy-4-butyloxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy-3-propyloxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy-2-ethyloxy]diphenylsulfone, 4-[4-(4-hydroxyphenylsulfonyl)phenoxy-4-butyloxy]-4'-[4-(4-hydroxyphenylsulfonyl)phenoxy-3-propyloxy]diphenylsulfone, 4-[4-(4-hydroxyphenylsulfonyl)phenoxy-4-butyloxy]-4'-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-ethyloxy]diphenylsulfone, 4-[4-(4-hydroxyphenylsulfonyl)phenoxy-3-propyloxy]-4'-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-ethyloxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy-5-pentyloxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy-6-hexyloxy]diphenylsulfone, 4-[4-[4-(4-hydroxyphenylsulfonyl)phenoxy]-2-trans-butenyloxy]-4'-[4-(4-hydroxyphenylsulfonyl)phenoxy-4-butyloxy]diphenylsulfone, 4-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-trans-butenyloxy]-4'-[4-(4-hydroxyphenylsulfonyl)phenoxy-3-propyloxy]diphenylsulfone, 4-[4-[4-(4-hydroxyphenylsulfonyl)phenoxy]-2-trans-butenyloxy]-4'-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-ethyloxy]diphenylsulfone, 1,4-bis[4-[4-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-trans-butenyloxy]phenylsulfonyl]phenoxy]-cis-2-butene, 1,4-bis[4-[4-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-trans-butenyloxy]phenylsulfonyl]phenoxy]-trans-2-butene, 4,4'-bis[4-[4-(2-hydroxyphenylsulfonyl)phenoxy]butyloxy]diphenylsulfone, 4,4'-bis[4-[2-(4-hydroxyphenylsulfonyl)phenoxy]butyloxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy-2-ethyleneoxyethoxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenyl-1,4-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenyl-1,3-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenyl-1,2-phenylenebismethyleneoxy]diphenylsulfone, 2,2'-bis[4-[4-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-ethyleneoxyethoxy]phenylsulfonyl]phenoxy]diethyl ether, α,α'-bis[4-[4-[4-(4-hydroxyphenylsulfonyl)phenyl-1,4-phenylenebismethyleneoxy]phenylsulfonyl]phenoxy]-p-xylene, α,α'-bis[4-[4-[4-(4-hydroxyphenylsulfonyl)phenyl-1,3-phenylenebismethyleneoxy]phenylsulfonyl]phenoxy]-m-xylene, α,α'-bis[4-[4-[4-(4-hydroxyphenylsulfonyl)phenyl-1,2-phenylenebismethyleneoxy]phenylsulfonyl]phenoxy]-o-xylene, 2,4'-bis[2-(4-hydroxyphenylsulfonyl)phenoxy-2-ethyleneoxyethoxy]diphenylsulfone, 2,4'-bis[4-(2-hydroxyphenylsulfonyl)phenoxy-2-ethyleneoxyethoxy]diphenylsulfone, 4,4'-bis[3,5-dimethyl-4-(3,5-dimethyl-4-hydroxyphenylsulfonyl)phenoxy-2-ethyleneoxyethoxy]diphenylsulfone, 4,4'-bis[3-allyl-4-(3-allyl-4-hydroxyphenylsulfonyl)phenoxy-2-ethyleneoxyethoxy]diphenylsulfone, 4,4'-bis[3,5-dimethyl-4-(3,5-dimethyl-4-hydroxyphenylsulfonyl)phenyl-1,4-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[3,5-dimethyl-4-(3,5-dimethyl-4-hydroxyphenylsulfonyl)phenyl-1,3-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[3,5-dimethyl-4-(3,5-dimethyl-4-hydroxyphenylsulfonyl)phenyl-1,2-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[3-allyl-4-(3-allyl-4-hydroxyphenylsulfonyl)1,4-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[3-allyl-4-(3-allyl-4-hydroxyphenylsulfonyl)1,3-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[3-allyl-4-(3-allyl-4-hydroxyphenylsulfonyl)1,2-phenylenebismethyleneoxy]diphenylsulfone, 4,4'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy-2-hydroxypropyloxy]diphenylsulfone, and 1,3-bis[4-[4-[4-(4-hydroxyphenylsulfonyl)phenoxy-2-hydroxypropyloxy]phenylsulfonyl]phenoxy]-2-hydroxypropane.

    [0038] These compounds represented by formula (V) can be used alone or in combination of two or more thereof, as needed, as a color-developing agent. The two or more compounds represented by formula (V) can be combined at any ratio. When the two or more compounds represented by formula (V) are combined, the combination of compounds differing in the degree of polymerization (differing in a), which are obtained from the same starting materials, is preferable. In this case, these compounds may be mixed for use, or a mixture comprising some compounds differing in the degree of polymerization can be formed by reaction and used directly as a color-developing agent. Preferable examples thereof can include a product mixture obtained by the reaction between 4,4'-dihydroxydiphenylsulfone and bis(2-chloroethyl) ether. This mixture does not have to contain all compounds wherein a = 0 to 10 and may contain products differing in production ratio depending on reaction conditions, etc. Particularly preferably, the mixture is composed mainly of 2,2'-bis[4-(4-hydroxyphenylsulfonyl)phenoxy]diethyl ether, which is a compound wherein a = 0, wherein the compound wherein a = 0 occupies 5 to 80% by mass, preferably 10 to 60% by mass, particularly preferably 20 to 50% by mass, in the solid content of the mixture.

    (Image stabilizer)



    [0039] Examples of the image stabilizer used in the present invention can specifically include the followings:
    epoxy group-containing diphenylsulfones such as 4-benzyloxy-4'-(2-methylglycidyloxy)-diphenylsulfone and 4,4'-diglycidyloxydiphenylsulfone; and 1,4-diglycidyloxybenzene, 4-[α-(hydroxymethyl)benzyloxy]-4'-hydroxydiphenylsulfone, 2-propanol derivatives, salicylic acid derivatives, metal salts (particularly, zinc salts) of oxynaphthoic acid derivatives, metal salts of 2,2-methylenebis(4,6-t-butylphenyl)phosphate, and other water-insoluble zinc compounds, hindered phenol compounds such as 2,2-bis(4'-hydroxy-3',5'-dibromophenyl)propane, 4,4'-sulfonylbis(2,6-dibromophenol), 4,4'-butylidene(6-t-butyl-3-methylphenol), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), 2,2'-methylene-bis(4-ethyl-6-t-butylphenol), 2,2'-di-t-butyl-5,5'-dimethyl-4,4'-sulfonyldiphenol, 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, and 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, phenol novolac compounds, and epoxy resins.

    [0040] The image stabilizer is preferably a compound that is solid at room temperature, particularly preferably has a melting point of 60°C or higher, and is poorly soluble in water.

    [0041] Moreover, the image stabilizer is preferably a hindered phenol compound. The hindered phenol compound is not only a compound having a phenol structure having bulky substituents such as t-butyl groups at both ortho positions of the hydroxy group but also may be substituted by at least one C1-C6 alkyl group bonded via secondary or tertiary carbon to the ortho position of the hydroxy group. The alkyl group may be cyclized, as in a cyclohexyl group. Any number of sites having the hindered phenol structure may be present in one molecule.

    [0042] The hindered phenol compound according to the invention is a compound represented by formula (VIII). In formula (VIII), R13 and R14 each independently represent a C1-C6 alkyl group. p' and q' each independently represent any integer of 1 to 4, and when p' and q' represents 2 or more, each of R13 and R14 are the same or different, provided that at least one of R13 and R14 represents a C1-C6 alkyl group bonded via secondary or tertiary carbon to the ortho position of the hydroxy group. Specifically, examples thereof can include the same as the specific examples of R1. R15 is represented by formula (IX):

    [wherein each R16 independently represents a C1-C6 alkyl group; r represents 0 or any integer of 1 to 4; and * represents a binding position]. Examples of the C1-C6 alkyl group represented by R16 in formula (IX) can specifically include the same as the specific examples of R1.

    [0043] Examples of the compound typified by formula (VIII) can specifically include 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 4,4'-butylidene-bis(6-t-butyl-m-cresol), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), and 2,2'-methylene-bis(4-ethyl-6-t-butylphenol).

    [0044] These image stabilizers can be used alone or in combination of two or more thereof, as needed. The two or more image stabilizers can be combined at any ratio.

    (Sensitizer)



    [0045] Examples of the sensitizer can specifically include the followings:

    higher fatty acid amides such as stearic acid amide, stearic acid anilide, and palmitic acid amide;

    amides such as benzamide, acetoacetic acid anilide, thioacetanilide acrylic acid amide, ethylenebisamide, ortho-toluenesulfonamide, and para-toluenesulfonamide;

    phthalic acid diesters such as dimethyl phthalate, dibenzyl isophthalate, dimethyl isophthalate, dimethyl terephthalate, diethyl isophthalate, diphenyl isophthalate, and dibenzyl terephthalate;

    oxalic acid diesters such as dibenzyl oxalate, di(4-methylbenzyl) oxalate, di(4-chlorobenzyl) oxalate, a mixture of benzyl oxalate and di(4-chlorobenzyl) oxalate in equal amounts, and a mixture of di(4-chlorobenzyl) oxalate and di(4-methylbenzyl) oxalate in equal amounts;

    bis(t-butylphenols) such as 2,2'-methylenebis(4-methyl-6-t-butylphenol) and 4,4'-methylene-bis-2,6-di-t-butylphenol;

    4,4'-dihydroxydiphenylsulfone diethers such as 4,4'-dimethoxydiphenylsulfone, 4,4'-diethoxydiphenylsulfone, 4,4'-dipropoxydiphenylsulfone, 4,4'-diisopropoxydiphenylsulfone, 4,4'-dibutoxydiphenylsulfone, 4,4'-diisobutoxydiphenylsulfone, 4,4'-dipentyloxydiphenylsulfone, 4,4'-dihexyloxydiphenylsulfone, and 4,4'-diallyloxydiphenylsulfone;

    2,4'-dihydroxydiphenylsulfone diethers such as 2,4'-dimethoxydiphenylsulfone, 2,4'-diethoxydiphenylsulfone, 2,4'-dipropoxydiphenylsulfone, 2,4'-diisopropoxydiphenylsulfone, 2,4'-dibutoxydiphenylsulfone, 2,4'-diisobutoxydiphenylsulfone, 2,4'-dipentyloxydiphenylsulfone, 2,4'-dihexyloxydiphenylsulfone, and 2,4'-diallyloxydiphenylsulfone;

    terphenyls such as m-terphenyl and p-terphenyl;

    carbonic acid derivatives such as diphenyl carbonate, guaiacol carbonate, di-p-tolyl carbonate, and phenyl-α-naphthyl carbonate;

    1,2-bis(phenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(phenoxymethyl)benzene, 1,2-bis(4-methoxyphenylthio)ethane, 1,2-bis(4-methoxyphenoxy)propane, 1,3-phenoxy-2-propanol, 1,4-diphenylthio-2-butene, 1,4-diphenylthiobutane, 1,4-diphenoxy-2-butene, 1,5-bis(4-methoxyphenoxy)-3-oxapentane, 1,3-dibenzoyloxypropane, dibenzoyloxymethane, 4,4'-ethylenedioxy-bis-benzoic acid dibenzyl ester, bis[2-(4-methoxy-phenoxy)ethyl] ether, 2-naphthylbenzyl ether, 1,3-bis(2-vinyloxyethoxy)benzene, 1,4-diethoxynaphthalene, 1,4-dibenzyloxynaphthalene, 1,4-dimethoxynaphthalene, 1,4-bis(2-vinyloxyethoxy)benzene, p-(2-vinyloxyethoxy)biphenyl, p-aryloxybiphenyl, p-propargyloxybiphenyl, p-benzyloxybenzyl alcohol, 4-(m-methylphenoxymethyl)biphenyl, 4-methylphenyl-biphenyl ether, di-β-naphthylphenylenediamine, diphenylamine, carbazole, 2,3-di-m-tolylbutane, 4-benzylbiphenyl, 4,4'-dimethylbiphenyl, 1,2-bis(3,4-dimethylphenyl)ethane, 2,3,5,6-tetramethyl-4'-methyldiphenylmethane, 4-acetylbiphenyl, dibenzoylmethane, triphenylmethane, phenyl 1-hydroxy-naphthoate, methyl 1-hydroxy-2-naphthoate, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, benzyl p-benzyloxybenzoate, phenyl β-naphthoate, methyl p-nitrobenzoate, diphenylsulfone, 1,1-diphenylpropanol, 1,1-diphenylethanol, N-octadecylcarbamoylbenzene, dibenzyl disulfide, stearic acid, Amide AP-1(7:3 mixture of stearic acid amide and palmitic acid amide), and stearates such as aluminum stearate, calcium stearate, and zinc stearate; and zinc palmitate, behenic acid, zinc behenate, montanic acid wax, and polyethylene wax.



    [0046] Preferable examples thereof can include 2-naphthylbenzyl ether, m-terphenyl, 4-benzylbiphenyl, benzyl oxalate, di(4-chlorobenzyl) oxalate, a mixture of benzyl oxalate and di(4-chlorobenzyl) oxalate in equal amounts, di(4-methylbenzyl) oxalate, a mixture of di(4-chlorobenzyl) oxalate and di(4-methylbenzyl) oxalate in equal amounts, phenyl 1-hydroxy-2-naphthoate, 1,2-bis(phenoxy)ethane, 1,2-bis-(3-methylphenoxy)ethane, 1,2-bis(phenoxymethyl)benzene, dimethyl terephthalate, stearic acid amide, Amide AP-1(7:3 mixture of stearic acid amide and palmitic acid amide), diphenylsulfone, and 4-acetylbiphenyl.

    [0047] More preferable examples thereof can include di(4-methylbenzyl) oxalate, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(phenoxymethyl)benzene, diphenylsulfone, and 2-naphthylbenzyl ether.

    [0048] These sensitizers can be used alone or in combination of two or more thereof, as needed. The two or more stabilizers can be combined at any ratio.

    (Other components in recording material)



    [0049] The recording material of the present invention can contain, in addition to the color-forming compound and the compounds represented by formulas (I), and (VIII), one or two or more color-developing agents, sensitizers, image stabilizers, fillers, dispersants, antioxidants, desensitizers, anti-tack agents, antifoaming agents, light stabilizers, fluorescent brightening agents, etc., known in the art, as needed. The amount of each component used is in the range of usually 0.1 to 15 parts by mass, preferably 0.5 to 10 parts by mass, with respect to 1 part by mass of the color-forming compound.

    [0050] These agents may be contained in a color-developing layer or may be contained in any layer, for example, a protective layer, when they consist of a multilayer structure. Particularly, when an overcoat layer or an undercoat layer is provided in the upper and/or lower parts of the color-developing layer, these layers can contain antioxidants, light stabilizers, etc. Furthermore, these antioxidants or light stabilizers can be contained in a form encapsulated in microcapsules, as needed, in these layers.

    [0051] Examples of the color-forming compound used in the recording material of the present invention can include, but not limited to, fluoran, phthalide, lactam, triphenylmethane, phenothiazine, and spiropyran leuco dyes. Any color-forming compound that forms a color by contact with the color-developing agent, which is an acidic substance, can be used. Moreover, these color-forming compounds can be used alone to produce a recording material with the color to be formed, as a matter of course. Alternatively, two or more thereof can be mixed for use. For example, three primary color (red, blue, and green)-forming compounds or black color-forming compounds can be mixed and used to produce a recording material that develops a true black color.

    [0052] Examples of black color-forming compounds include 3-diethylamino-6-methyl-7-anilinofluoran, 3-di(n-butyl)amino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluoran, 3-(N-methyl-N-propylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran, 3-diethylamino-7-(m-trifluoromethylanilino)fluoran, 3-di(n-pentyl)amino-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-ethoxypropylamino)-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-n-octylaminofluoran, 3-diethylamino-6-methyl-7-(m-methylanilino)fluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-diethylamino-7-(o-chloroanilino)fluoran, 3-dibutylamino-7-(o-chloroanilino)fluoran, 3-(N-ethyl-N-tetrahydrofurfurylamino)-6-methyl-7-anilinofluoran, and 3-dibutylamino-7-(o-fluoroanilino)fluoran.

    [0053] Examples of blue color-forming compounds include 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methyl-3-indolyl)-4-azaphthalide, and 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-octyl-2-methyl-3-indolyl)-4-azaphthalide.

    [0054] Examples of green color-forming compounds include 3-diethylamino-7-dibenzylaminofluoran, 3-(N-ethyl-N-p-tolyl)amino-7-N-methylanilinofluoran, 3,3-bis(4-diethylamino-2-ethoxyphenyl)-4-azaphthalide, and 3,6,6'-tris(dimethylamino)spiro[fluorene-9,3'-phthalide].

    [0055] Examples of red/orange/yellow color-forming compounds include 3-diethylamino-7-chlorofluoran, 3-diethylamino-benzo[a]fluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-cyclohexylamino-6-chlorofluoran, 3-diethylamino-6,8-dimethylfluoran, and 4,4'-isopropylidenedi(4-phenoxy)bis[4-(quinazolin-2-yl)-N,N-diethylaniline].

    [0056]  Moreover, examples of near infrared absorbing dyes include 2-chloro-3-methyl-6-p-(p-phenylaminophenyl)aminoanilinofluoran, 3,3-bis[1-(4-methoxyphenyl)-1-(4-dimethylaminophenyl)ethylen-2-yl]-4,5,6,7-tetrachlorophthalide, and 3,6,6'-tris(dimethylamino)spiro[fluorene-9,3'-phthalide].

    [0057] Examples of the color-developing agent can include the followings:
    BPA color-developing agents, for example, 4,4'-isopropylidenediphenol, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 4,4'-isopropylidenebis-o-cresol, 4,4'-(1-phenylethylidene)bisphenol, 4,4'-cyclohexylidenebisphenol, 2,2-bis(4-hydroxy-3-phenyl-phenyl)propane, 4,4'-(1,3-phenylenediisopropylidene)bisphenol, 4,4'-(1,4-phenylenediisopropylidene)bisphenol, and butyl bis(p-hydroxyphenyl)acetate.

    [0058] Examples of phenolic color-developing agents other than those described above include N-(2-hydroxyphenyl)-2-[(4-hydroxyphenyl)thio]acetamide, N-(4-hydroxyphenyl)-2-[(4-hydroxyphenyl)thio]acetamide, a mixture of N-(2-hydroxyphenyl)-2-[(4-hydroxyphenyl)thio]acetamide and N-(4-hydroxyphenyl)-2-[(4-hydroxyphenyl)thio]acetamide in equal amounts, benzyl p-hydroxybenzoate, di(4-hydroxy-3-methylphenyl)sulfide, 4-hydroxybenzenesulfonanilide, 1,5-di(4-hydroxyphenylthio)-3-oxapentane, bis(4-hydroxyphenylthioethoxy)methane, a condensed mixture composed mainly of a binuclear condensate of 2,2'-methylenebis(4-t-butylphenol) described in Japanese unexamined Patent Application Publication No. 2003-154760, and hydroquinone-monobenzyl ether.

    [0059] Examples of non-phenolic sulfonyl urea color-developing agents include 4,4'-bis(N-p-tolylsulfonylaminocarbonylamino)diphenylmethane and N-p-tolylsulfonyl-N'-3-(p-tolylsulfonyloxy)phenylurea.

    [0060] Examples of non-phenolic color-developing agents other than those described above include 4,4'-bis[(4-methyl-3-phenoxycarbonylaminophenylureido)], diphenylsulfone, 3-(3-phenylureido)benzenesulfonamide, zinc bis[4-(n-octyloxycarbonylamino)salicylate] dihydrate, zinc 4-[2-(4-methoxyphenoxy)ethoxy]salicylate, and zinc 3,5-bis(α-methylbenzyl)salicylate.

    [0061] Examples of the filler can include silica, clay, kaolin, fired kaolin, talc, satin white, aluminum hydroxide, calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, barium sulfate, magnesium silicate, aluminum silicate, plastic pigments, diatomaceous earth, talc, and aluminum hydroxide. Among them, preferable examples thereof can include alkaline earth metal salts, particularly, carbonates such as calcium carbonate and magnesium carbonate. The proportion of the filler used is 0.1 to 15 parts by mass, preferably 1 to 10 parts by mass, with respect to 1 part by mass of the color-forming compound. Moreover, these fillers may be mixed for use.

    [0062]  Examples of the dispersant can include: polyvinyl alcohols having various degrees of saponification and polymerization, such as polyvinyl alcohol, acetoacetylated polyvinyl alcohol, carboxy-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, and butyral-modified vinyl alcohol; cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, ethylcellulose, acetylcellulose, and hydroxymethylcellulose; and sodium polyacrylate, polyacrylic acid ester, polyacrylamide, starch, sulfosuccinic acid esters such as dioctyl sodium sulfosuccinate, sodium dodecylbenzenesulfonate, a sodium salt of lauryl alcohol sulfonic acid ester, fatty acid salt, styrene-maleic anhydride copolymers, styrenebutadiene copolymers, polyvinyl chloride, polyvinyl acetate, polyacrylic acid ester, polyvinylbutyral, polyurethane, polystyrene and copolymers thereof, polyamide resins, silicone resins, petroleum resins, terpene resins, ketone resins, and coumarone resins.

    [0063] The dispersant is used after being dissolved in a solvent such as water, alcohol, ketone, ester, or hydrocarbon. Alternatively, the dispersant may be used in a state emulsified in water or other solvents or in the form of paste dispersed therein.

    [0064] Examples of the antioxidant can include 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-propylmethylenebis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 4,4'-thiobis(2-t-butyl-5-methylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α,α-dimethylbenzyl}phenol, 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 1,3,5-tris[{4-(1,1-dimethylethyl)-3-hydroxy-2,6-dimethylphenyl}methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1,3,5-tris[{3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl}methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

    [0065] Examples of the desensitizer can include aliphatic higher alcohols, polyethylene glycol, and guanidine derivatives.

    [0066] Examples of the anti-tack agent can include stearic acid, zinc stearate, calcium stearate, carnauba wax, paraffin wax, and ester wax.

    [0067] Examples of the antifoaming agent can include higher alcohol, fatty acid ester, oil, silicone, polyether, modified hydrocarbon, and paraffin antifoaming agents.

    [0068] Examples of the light stabilizer can include: salicylic acid UV absorbers such as phenyl salicylate, p-t-butylphenyl salicylate, and p-octylphenyl salicylate; benzophenone UV absorbers such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, and bis(2-methoxy-4-hydroxy-5-benzoylphenyl)methane; benzotriazole UV absorbers such as 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-5'-(1",1",3",3"-tetramethylbutyl)phenyl)benzotriazole, 2-[2'-hydroxy-3'-(3",4",5",6"-tetrahydrophthalimidomethyl)-5'-methylphenyl]benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-[2'-hydroxy-3',5'-bis(,-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2'-hydroxy-3'-dodecyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-undecyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tridecyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tetradecyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-pentadecyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-hexadecyl-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-4'-(2"-ethylhexyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(2"-ethylheptyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(2"-ethyloctyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(2"-propyloctyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(2"-propylheptyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(2"-propylhexyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(1"-ethylhexyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(1"-ethylheptyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(1'-ethyloctyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(1"-propyloctyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(1"-propylheptyl)oxyphenyl]benzotriazole, 2-[2'-hydroxy-4'-(1"-propylhexyl)oxyphenyl]benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)]phenol, and a condensate of polyethylene glycol and methyl-3-[3-t-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate; cyanoacrylate UV absorbers such as 2'-ethylhexyl-2-cyano-3,3-diphenylacrylate and ethyl-2-cyano-3,3-diphenylacrylate; hindered amine UV absorbers such as bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, succinic acid-bis(2,2,6,6-tetramethyl-4-piperidyl) ester, and 2-(3,5-di-t-butyl)malonic acid-bis(1,2,2,6,6-pentamethyl-4-piperidyl) ester; and 1,8-dihydroxy-2-acetyl-3-methyl-6-methoxynaphthalene.

    [0069] Examples of the fluorescent brightening agent can include 4,4'-bis[2-anilino-4-(2-hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid disodium salt, 4,4'-bis[2-anilino-4-bis(hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid disodium salt, 4,4'-bis[2-anilino-4-bis(hydroxypropyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid disodium salt, 4,4'-bis[2-methoxy-4-(2-hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid disodium salt, 4,4'-bis[2-methoxy-4-(2-hydroxypropyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid disodium salt, 4,4'-bis[2-m-sulfoanilino-4-bis(hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid disodium salt, 4-[2-p-sulfoanilino-4-bis(hydroxyethyl)amino-1,3,5-triazinyl-6-amino]-4'-[2-m-sulfoanilino-4-bis(hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid tetrasodium salt, 4,4'-bis[2-p-sulfoanilino-4-bis(hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid tetrasodium salt, 4,4'-bis[2-(2,5-disulfoanilino)-4-phenoxyamino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid hexasodium salt, 4,4'-bis[2-(2,5-disulfoanilino)-4-(p-methoxycarbonylphenoxy)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid hexasodium salt, 4,4'-bis[2-(p-sulfophenoxy)-4-bis(hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid hexasodium salt, 4,4'-bis[2-(2,5-disulfoanilino)-4-formalinylamino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid hexasodium salt, and 4,4'-bis[2-(2,5-disulfoanilino)-4-bis(hydroxyethyl)amino-1,3,5-triazinyl-6-amino]stilbene-2,2'-disulfonic acid hexasodium salt.

    (Method for producing recording material)



    [0070] When the recording material of the present invention is used in thermal recording paper, it may be used in the same way as a known use method. For example, the thermal recording paper can be produced by separately dispersing fine particles of the compound of the present invention and fine particles of a color-forming compound in aqueous solutions of water-soluble binders such as polyvinyl alcohol or cellulose, mixing these suspension solutions, applying the mixture to a support such as paper, and drying it.

    [0071] The proportion of the compound represented by formula (I) to the color-forming compound used is 0.5 to 10 parts by mass, more preferably 1.0 to 5 parts by mass, with respect to 1 part by mass of the color-forming compound.

    [0072] The proportion of the color-developing agent other than the compound represented by formula (I) to the color-forming compound used is 0.5 to 10 parts by mass, more preferably 1.0 to 5 parts by mass, with respect to 1 part by mass of the color-forming compound.

    [0073] When the recording material of the present invention is used in pressure-sensitive copying paper, it can be produced in the same way as in use of a known color-developing agent or sensitizer. For example, a color-forming compound microencapsulated by a method known in the art is dispersed in an appropriate dispersant and applied to paper to prepare a sheet of the color-forming compound. Moreover, a dispersion solution of a color-developing agent is applied to paper to prepare a sheet of the color-developing agent. Both the sheets thus prepared are combined to prepare pressure-sensitive copying paper. The pressure-sensitive copying paper may be a unit consisting of: upper paper carrying a microcapsule containing a solution of a color-forming compound in an organic solvent, wherein the microcapsule is applied on the underside of the upper paper; and lower paper carrying a color-developing agent (acidic substance) applied on the top surface of the lower paper. Alternatively, the pressure-sensitive copying paper may be so-called self-contained paper comprising the microcapsule and the color-developing agent applied on the same paper surface.

    [0074] Those conventionally known are used as the color-developing agent used in the production or the color-developing agent mixed therewith for use. Examples thereof can include: inorganic acidic substances such as Japanese acid clay, activated clay, attapulgite, bentonite, colloidal silica, aluminum silicate, magnesium silicate, zinc silicate, tin silicate, fired kaolin, and talc; aliphatic carboxylic acids such as oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, and stearic acid; aromatic carboxylic acids such as benzoic acid, p-t-butylbenzoic acid, phthalic acid, gallic acid, salicylic acid, 3-isopropylsalicylic acid, 3-phenylsalicylic acid, 3-cyclohexylsalicylic acid, 3,5-dit-butylsalicylic acid, 3-methyl-5-benzylsalicylic acid, 3-phenyl-5-(2,2-dimethylbenzyl)salicylic acid, 3,5-di-(2-methylbenzyl)salicylic acid, and 2-hydroxy-1-benzyl-3-naphthoic acid, and metal (e.g., zinc, magnesium, aluminum, and titanium) salts of these aromatic carboxylic acids; phenol resin color-developing agents such as p-phenylphenol-formalin resins and p-butylphenol-acetylene resins, and mixtures of these phenol resin color-developing agents and the metal salts of the aromatic carboxylic acids.

    [0075] Paper, synthetic paper, a film, a plastic film, a foamed plastic film, nonwoven cloth, recycled paper (e.g., recycled paper pulps), or the like, conventionally known can be used as the support used in the present invention. Moreover, the combination thereof can also be used as the support.

    [0076] Examples of methods for forming a recording material layer on the support include a method comprising applying a dispersion solution containing a dispersion solution of a color-forming compound, a dispersion solution of a color-developing agent, and a dispersion solution of a filler to a support, followed by drying, a method comprising spraying such a dispersion solution onto a support with a spray or the like, followed by drying, and a method comprising dipping a support in such a dispersion solution for a given time, followed by drying. Moreover, examples of the application method include hand coating, a size press coater method, a roll coater method, an air knife coater method, a blend coater method, a flow coater method, a curtain coater method, a comma direct method, a gravure direct method, a gravure reverse method, and a reverse roll coater method.

    Examples



    [0077]  Hereinafter, a recording material of the present invention will be described in detail with reference to Examples. However, the present invention is not necessarily limited to them. Examples in which a compound of formula (I) is not contained in combination with a compound of formula (VIII) are comparative examples.

    (Preparation of thermal recording paper)


    [Example 1]



    [0078] 
    (parts: parts by mass)
    Dispersion solution of color-forming compound (solution A)  
     3-di-n-butylamino-6-methyl-7-anilinofluoran 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent (solution B)  
     N-(4-hydroxyphenyl)-3-methylcinnamoylamide 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent 2 (solution C)  
     4-hydroxy-4'-isopropoxydiphenylsulfone 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of filler (solution D)  
     Calcium carbonate 27.8 parts
     10% aqueous solution of polyvinyl alcohol 26.2 parts
     Water 71 parts


    [0079] First, each mixture having the composition of the solution A, B, C, or D was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A to D. 1 part by mass of the solution A, 0.5 part by mass of the solution B, 1.5 parts by mass of the solution C, and 4 parts by mass of the solution D were mixed to prepare a coating solution. This coating solution was applied to white paper using a wire rod (manufactured by Webster, Wire Bar No. 12), and the paper was dried. Then, calendering treatment was performed to prepare thermal recording paper (coating solution: approximately 5.5 g/m2 in terms of dry mass).

    [Examples 2 to 20]



    [0080] Thermal recording paper was prepared by the method described in Example 1 except that: N-(4-hydroxyphenyl)-3-methylcinnamoylamide described in Example 1 was changed to color-developing agents described in Table A; 4-hydroxy-4'-isopropoxydiphenylsulfone described in Example 1 was changed to additives described in Table A; and the composition of each dispersion solution of Example 1 was changed to part by mass described in Table A.

    (Comparative Examples 1 to 8)



    [0081] Thermal recording paper was prepared by the method described in Example 1 except that: N-(4-hydroxyphenyl)-3-methylcinnamoylamide described in Example 1 was changed to color-developing agents described in Table A; 4-hydroxy-4'-isopropoxydiphenylsulfone described in Example 1 was changed to additives described in Table A; and the composition of each dispersion solution of Example 1 was changed to part by mass described in Table A.
    Table A
     A SolutionB SolutionC SolutionD SolutionColor-developing agentEffect brought about by additionAdditive
    Part by mass
    Example 1 1 0.5 1.5 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent 4-hydroxy-4'-isopropoxydiphenylsulfone
    Example 2 1 1.0 1.0 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent 4-hydroxy-4'-isopropoxydiphenylsulfone
    Example 3 1 1.5 0.5 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent 4-hydroxy-4'-isopropoxydiphenylsulfone
    Example 4 1 0.5 1.5 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent D-90(Color-developing agent for thermal recording paper manufactured by Nippon Soda Co., Ltd.)
    Example 5 1 1.0 1.0 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent D-90(Color-developing agent for thermal recording paper manufactured by Nippon Soda Co., Ltd.)
    Example 6 1 1.5 0.5 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent D-90(Color-developing agent for thermal recording paper manufactured by Nippon Soda Co., Ltd.)
    Comparative Example 1 1 2.0 - 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide   Absent
    Comparative Example 2 1 - 2.0 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent 4-hydroxy-4'-isopropoxydiphenylsulfone
    Comparative Example 3 1 - 2.0 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Color-developing agent D-90(Color-developing agent for thermal recording paper manufactured by Nippon Soda Co., Ltd.)
    Example 7 1 2 1 4 N-(3-hydroxyphenyl)-3-methylcinnamoylamide Image stabilizer 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl) butane
    Example 8 1 2 1 4 N-(3-hydroxyphenyl)-3-methylcinnamoylamide Image stabilizer 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane
    Example 9 1 2 1 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Image stabilizer 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane
    Example 10 1 2 1 4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide Image stabilizer 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane
    Comparative Example 4 1 2 - 4 N-(3-hydroxyphenyl)-3-methylcinnamoylamide   Absent
    Comparative Example 5 1 2 - 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide   Absent
    Comparative Example 6 1 2 - 4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide   Absent
    Example 11 1 2 1 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Sensitizer Di(4-methylbenzyl) oxalate
    Example 12 1 2 1 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Sensitizer 1,2-bis(3-methylphenoxy)ethane
    Example 13 1 2 1 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Sensitizer 1,2-bis(phenoxymethyl)benzene
    Example 14 1 2 1 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Sensitizer Diphenylsulfone
    Example 15 1 2 1 4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide Sensitizer 2-naphthylbenzyl ether
    Example 16 1 2 1 4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide Sensitizer Di(4-methylbenzyl) oxalate
    Example 17 1 2 1 4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide Sensitizer 1,2-bis(3-methylphenoxy)ethane
    Example 18 1 2 1 4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide Sensitizer 1,2-bis(phenoxymethyl)benzene
    Example 19 1 2 1 4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide Sensitizer Diphenylsulfone
    Example 20 1 2 1 4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide Sensitizer 2-naphthylbenzyl ether
    Comparative Example 7 1 2   4 N-(4-hydroxyphenyl)-3-methylcinnamoylamide   Absent
    Comparative Example 8 1 2   4 N-(4-hydroxyphenyl)-2,3-dimethoxycinnamoylamide   Absent

    [Test Example 1] (Evaluation on moist heat resistance of background)



    [0082] Each test paper of Examples 1 to 6 and Comparative Examples 1 to 3 was subjected to a stability test under conditions shown below. Evaluation determined based on the results is summarized in Table 2.

    Before test



    [0083] A portion of each thermal recording paper prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was cut off, and the optical concentration of the background was measured using a Macbeth reflection densitometer (filter used: #106).

    Moist heat resistance test



    [0084] A portion of each thermal recording paper prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was cut off and kept in a low-temperature thermohygrostat (trade name: THN050FA, manufactured by ADVANTEC Toyo Kaisha, Ltd.) under conditions involving 50°C and 80% humidity for 24 hours. The optical concentration of the background after being kept was measured using a Macbeth reflection densitometer (filter used: #106).

    [Test Example 2] (Evaluation on light resistance of background)



    [0085] Each test paper of Examples 1 to 6 and Comparative Examples 1 to 3 was subjected to a stability test under conditions shown below. Evaluation determined based on the results is summarized in Table 2.

    Before test



    [0086] A portion of each thermal recording paper prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was cut off, and the optical concentration of the background was measured using a Macbeth reflection densitometer (filter used: #106).

    Light resistance test of background



    [0087] A portion of each thermal recording paper prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was cut off and subjected to a light resistance test using a light resistance tester (trade name: UV Long-Life Fade Meter model U48, manufactured by Suga Test Instruments Co., Ltd.). After 8 hours, the optical concentration of the background was measured using a Macbeth reflection densitometer (filter used: #47).

    [Test Example 3] (Heat resistance of image)



    [0088] Each test paper of Examples 1 to 6 and Comparative Examples 1 to 3 was subjected to a stability test under conditions shown below. Evaluation determined based on the results is summarized in Table 2.

    Before test



    [0089] A portion of each thermal recording paper prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was cut off and colored under conditions involving a printing voltage of 17 V and a pulse width of 1.8 ms using a thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.). The concentration of the colored image was measured using a Macbeth reflection densitometer (filter used: #106).

    Test on heat resistance of image



    [0090] The colored image was subjected to a heat resistance test in a thermostat (trade name: DK-400, manufactured by Yamato Scientific Co., Ltd) at a temperature of 100°C. After 24 hours, the concentration of the colored image was measured using a Macbeth reflection densitometer (filter used: #106).
    Table 2
     Evaluation test
    Moist heat resistance of backgroundLight resistance of backgroundHeat resistance of image
    Example 1
    Example 2
    Example 3
    Example 4
    Example 5
    Example 6
    Comparative Example 1 Δ
    Comparative Example 2 Δ
    Comparative Example 3 Δ
    ⊙: Practically no problem
    ○: Slightly poor, but practically no problem
    Δ: Practically impossible to use


    [0091] As is evident from the results of Table 2, the recording material of the present invention was hardly adversely affected by the combined use of color-developing agents and was excellent in the light resistance and moist heat resistance of the background and the heat resistance of colored images.

    [Test Example 4] (Evaluation on moist heat resistance/heat resistance of background)



    [0092] Each test paper of Examples 7 to 10 and Comparative Examples 4 to 6 was subjected to a stability test under conditions shown below. The results are summarized in Table 3.

    Before test



    [0093] A portion of each thermal recording paper prepared in Examples 7 to 10 and Comparative Examples 4 to 6 was cut off, and the optical concentration of the background was measured using a Macbeth reflection densitometer (filter used: #106).

    Moist heat resistance test



    [0094] A portion of each thermal recording paper prepared in Examples 7 to 10 and Comparative Examples 4 to 6 was cut off and kept in a low-temperature thermohygrostat (trade name: THN050FA, manufactured by ADVANTEC Toyo Kaisha, Ltd.) under conditions involving 50°C and 80% humidity for 24 hours. The optical concentration of the background after being kept was measured using a Macbeth reflection densitometer (filter used: #106).

    Heat resistance test



    [0095] A portion of each thermal recording paper prepared in Examples 7 to 10 and Comparative Examples 4 to 6 was cut off and kept in a thermostat (trade name: DK-400, manufactured by Yamato Scientific Co., Ltd) at respective temperatures of 100°C and 110°C for 24 hours. The optical concentration of the background after being kept was measured using a Macbeth reflection densitometer (filter used: #106).
    Table 3 Evaluation results of moist heat resistance/heat resistance of background
     Before testMoist heat resistance testHeat resistance test
      24 hours100°C110°C
    Example 7 0.05 0.05 0.06 0.08
    Example 8 0.06 0.06 0.06 0.07
    Example 9 0.07 0.08 0.06 0.09
    Example 10 0.08 0.08 0.05 0.07
    Comparative Example 4 0.04 0.04 0.05 0.05
    Comparative Example 5 0.07 0.06 0.08 0.10
    Comparative Example 6 0.07 0.07 0.10 0.11


    [0096] As is evident from the results of Table 3, the comparisons between Examples 7 to 8 and Comparative Example 4, between Example 9 and Comparative Example 3, and between Example 10 and Comparative Example 6 showed that the recording material of the present invention had exceedingly good moist heat resistance and heat resistance of the background and was hardly altered even by the addition of the image stabilizer, compared with the image stabilizer-free samples. Thus, the recording material was almost free from usually expected adverse effect caused by the addition and particularly produced exceedingly favorable results even in the heat resistance test conducted at 110°C.

    [Test Example 5] (Light resistance of background)



    [0097] Each test paper of Examples 7 to 10 and Comparative Examples 4 to 6 was subjected to a stability test under conditions shown below. The results are summarized in Table 4.

    Before test



    [0098] A portion of each thermal recording paper prepared in Examples 7 to 10 and Comparative Examples 4 to 6 was cut off, and the optical concentration of the background was measured using a Macbeth reflection densitometer (filter used: #106).

    Light resistance of background



    [0099] A portion of each thermal recording paper prepared in Examples 7 to 10 and Comparative Examples 4 to 6 was cut off and subjected to a light resistance test using a light resistance tester (trade name: UV Long-Life Fade Meter model U48, manufactured by Suga Test Instruments Co., Ltd.). After 12 hours and 24 hours, the concentration of the background was measured using a Macbeth reflection densitometer (filter used: #47).
    Table 4 Evaluation results of light resistance of background
     Before testTest on light resistance of background
      12 hours24 hours
    Example 7 0.06 0.19 0.25
    Example 8 0.07 0.19 0.24
    Example 9 0.13 0.17 0.24
    Example 10 0.15 0.19 0.23
    Comparative Example 4 0.06 0.17 0.21
    Comparative Example 5 0.12 0.17 0.22
    Comparative Example 6 0.14 0.17 0.22


    [0100] As is evident from the results of Table 4, the comparisons between Examples 7 to 8 and Comparative Example 4, between Example 9 and Comparative Example 5, and between Example 10 and Comparative Example 6 showed that the recording material of the present invention had exceedingly good light resistance of the background and was hardly altered even by the addition of the image stabilizer, compared with the image stabilizer-free samples. Thus, the recording material was almost free from usually expected adverse effect caused by the addition.

    [Test Example 6] (Heat resistance of image)



    [0101] Each test paper of Examples 7 to 10 and Comparative Examples 4 to 6 was subjected to a stability test under conditions shown below. The results are summarized in Table 5.

    [0102] A portion of each thermal recording paper prepared in Examples 7 to 10 and Comparative Examples 4 to 6 was cut off and colored under conditions involving a printing voltage of 17 V and a pulse width of 1.8 ms using a thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.). The concentration of the colored image was measured using a Macbeth reflection densitometer (filter used: #106). The colored image was subjected to a heat resistance test in a thermostat (trade name: DK-400, manufactured by Yamato Scientific Co., Ltd) at a temperature of 100°C. After 24 hours, the concentration of the colored image was measured using a Macbeth reflection densitometer (filter used: #106).

    [0103] As is evident from the results of Table 5, the comparisons between Examples 7 to 8 and Comparative Example 4, between Example 9 and Comparative Example 5, and between Example 10 and Comparative Example 6 showed that the heat resistance of the image was significantly improved in Examples 7 to 10.
    Table 5 Heat resistance of image
     Before testImage stabilizer
    AddedNot addedAddedNot added
    Example 7 1.16 1.10 (Comparative Example 4) 1.07 0.15 (Comparative Example 4)
    Example 8 1.22 1.09
    Example 9 1.27 1.25 (Comparative Example 5) 1.17 0.34 (Comparative Example 5)
    Example 10 1.25 1.23 (Comparative Example 6) 1.19 0.30 (Comparative Example 6)

    [Test Example 7]


    (Dynamic color-developing sensitivity)



    [0104] A portion of each recording paper prepared in Examples 11 to 20 and Comparative Examples 7 to 8 was cut off and subjected to a dynamic color-developing sensitivity test using a thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.). The portion was colored under conditions involving a printing voltage of 17 V and respective pulse widths of 0.2, 0.35, 0.5, 0.65, 0.8, 0.95, 1.1, 1.25, 1.4, 1.6, and 1.8 ms. Then, the concentration of the print was measured using a Macbeth reflection densitometer (filter used: #106).

    [0105] The results are summarized in Figures 1 to 2. Moreover, the values of the samples colored under the conditions of 1.1 and 1.25 ms are described as typical values in Tables 6 and 7.
    Table 6 Dynamic color-developing sensitivity
     Pulse width
     1.1 ms1.25 ms 
    Example 11 0.61 0.85  
    Example 12 0.61 0.88  
    Example 13 0.59 0.81  
    Example 14 0.68 0.88  
    Example 15 0.66 0.92  
    Comparative Example 7 0.41 0.61  
    Table 7 Dynamic color-developing sensitivity
     Pulse width
     1.1 ms1.25 ms
    Example 16 0.60 0.79
    Example 17 0.55 0.80
    Example 18 0.55 0.79
    Example 19 0.71 0.91
    Example 20 0.71 0.98
    Comparative Example 8 0.46 0.62


    [0106] As is evident from the results of Figures 1 to 2 and Tables 6 to 7, the comparisons between Examples 11 to 15 and Comparative Example 7 and between Examples 16 to 20 and Comparative Example 8 showed that the dynamic color-developing sensitivity was improved in Examples 11 to 20.

    [Test Example 8]


    (Evaluation on moist heat resistance/heat resistance of background)



    [0107] Each test paper of Examples 11 to 20 and Comparative Examples 7 to 8 was subjected to a stability test under conditions shown below. The results are summarized in Tables 8 and 9.

    Before test



    [0108] A portion of each thermal recording paper prepared in Examples 11 to 20 and Comparative Examples 7 to 8 was cut off, and the optical concentration of the background was measured using a Macbeth reflection densitometer (filter used: #106).

    Moist heat resistance test



    [0109] A portion of each thermal recording paper prepared in Examples 11 to 20 and Comparative Examples 7 to 8 was cut off and kept in a low-temperature thermohygrostat (trade name: THN050FA, manufactured by ADVANTEC Toyo Kaisha, Ltd.) under conditions involving 50°C and 80% humidity for 24 hours. The optical concentration of the background after being kept was measured using a Macbeth reflection densitometer (filter used: #106).

    Heat resistance test



    [0110] A portion of each thermal recording paper prepared in Examples 11 to 20 and Comparative Examples 7 to 8 was cut off and kept in a thermostat (trade name: DK-400, manufactured by Yamato Scientific Co., Ltd) at respective temperatures of 100°C and 120°C for 24 hours. The optical concentration of the background after being kept was measured using a Macbeth reflection densitometer (filter used: #106).
    Table 8 Evaluation results of heat resistance of background
     Before testMoist heat resistanceHeat resistance
      24 hours100°C120°C
    Example 11 0.07 0.06 0.08 0.13
    Example 12 0.07 0.07 0.07 0.11
    Example 13 0.07 0.06 0.08 0.12
    Example 14 0.06 0.06 0.07 0.13
    Example 15 0.05 0.07 0.08 0.11
    Comparative Example 7 0.07 0.07 0.05 0.08
    Table 9 Evaluation results of heat resistance of background
     Before testMoist heat resistanceHeat resistance
      24 hours100°C120°C
    Example 16 0.07 0.06 0.07 0.11
    Example 17 0.06 0.07 0.06 0.09
    Example 18 0.07 0.06 0.07 0.11
    Example 19 0.06 0.06 0.07 0.12
    Example 20 0.06 0.06 0.08 0.12
    Comparative Example 8 0.07 0.07 0.06 0.08


    [0111] As is evident from the results of Tables 8 and 9, the comparisons between Examples 11 to 15 and Comparative Example 7 and between Examples 16 to 20 and Comparative Example 8 showed that the recording material of the present invention had exceedingly good moist heat resistance and heat resistance of the background and was hardly altered even by the addition of the sensitizer, compared with the sensitizer-free samples. Thus, the recording material was almost free from usually expected adverse effect caused by the addition and particularly produced exceedingly favorable results even in the heat resistance test conducted at 120°C.

    [Test Example 9]


    (Light resistance of background)



    [0112] Each test paper of Examples 11 to 20 and Comparative Examples 7 to 8 was subjected to a stability test under conditions shown below. The results are summarized in Tables 10 and 11.

    Before test



    [0113] A portion of each thermal recording paper prepared in Examples 11 to 20 and Comparative Examples 7 to 8 was cut off, and the optical concentration of the background was measured using a Macbeth reflection densitometer (filter used: #106).

    Light resistance of background



    [0114] A portion of each thermal recording paper prepared in Examples 11 to 20 and Comparative Examples 7 to 8 was cut off and subjected to a light resistance test using a light resistance tester (trade name: UV Long-Life Fade Meter model U48, manufactured by Suga Test Instruments Co., Ltd.). After 12 hours and 24 hours, the concentration of the background was measured using a Macbeth reflection densitometer (filter used: #106 and #47).
    Table 10 Evaluation results of light resistance of background
     Before testLight resistance of background
      12 hours (B)24 hours (B)12 hours (Y)24 hours (Y)
    Example 11 0.07 0.07 0.10 0.16 0.23
    Example 12 0.07 0.07 0.10 0.15 0.23
    Example 13 0.07 0.07 0.10 0.16 0.22
    Example 14 0.06 0.08 0.10 0.17 0.20
    Example 15 0.05 0.08 0.10 0.16 0.21
    Comparative Example 7 0.07 0.08 0.11 0.17 0.22
    (In the table, B represents Macbeth filter Wratten No. 106 and Y represents Macbeth filter Wratten No. 47.)
    Table 11 Evaluation results of light resistance of background
     Before testLight resistance of background
      12 hours (B)24 hours (B)12 hours (Y)24 hours (Y)
    Example 16 0.07 0.08 0.10 0.17 0.22
    Example 17 0.06 0.07 0.09 0.17 0.21
    Example 18 0.07 0.07 0.10 0.18 0.22
    Example 19 0.06 0.08 0.10 0.17 0.20
    Example 20 0.06 0.08 0.10 0.16 0.21
    Comparative Example 8 0.07 0.08 0.11 0.17 0.22
    (In the table, B represents Macbeth filter Wratten No. 106 and Y represents Macbeth filter Wratten No. 47.)


    [0115] As is evident from the results of Tables 10 and 11, the comparisons between Examples 11 to 15 and Comparative Example 7 and between Examples 16 to 20 and Comparative Example 8 showed that the recording material of the present invention had exceedingly good light resistance of the background and was hardly altered even by the addition of the sensitizer, compared with the sensitizer-free samples. Thus, the recording material was almost free from usually expected adverse effect caused by the addition.

    [Example 21]


    (Sensitizer formulation: preparation of thermal recording paper)



    [0116] 
    Dispersion solution of color-forming compound (solution A)  
     3-di-n-butylamino-6-methyl-7-anilinofluoran 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent (solution B)  
     N-(2-hydroxyphenyl)-cinnamoylamide 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of filler (solution C)  
     Calcium carbonate 27.8 parts
     10% aqueous solution of polyvinyl alcohol 26.2 parts
     Water 71 parts
    Dispersion solution of sensitizer (solution D)  
     Di(4-methylbenzyl) oxalate 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts


    [0117] First, each mixture having the composition of the solution A, B, C, or D was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A to D. 1 part by mass of the solution A, 2 parts by mass of the solution B, 4 parts by mass of the solution C, and 1 part by mass of the solution D were mixed to prepare a coating solution. This coating solution was applied to white paper using a wire rod (manufactured by Webster, Wire Bar No. 12), and the paper was dried. Then, calendering treatment was performed to prepare thermal recording paper (coating solution: approximately 5.5 g/m2 in terms of dry mass).

    [Example 22]



    [0118] Thermal recording paper was prepared by the method described in Example 21 except that 1,2-bis(3-methylphenoxy)ethane was used instead of di(4-methylbenzyl) oxalate in the dispersion solution of the sensitizer (solution D) of Example 21.

    [Comparative Example 9]



    [0119] Thermal recording paper was prepared by the method described in Example 21 except that of the dispersion solutions prepared in Example 21, 1 part by mass of the solution A, 2 parts by mass of the solution B, and 4 parts by mass of the solution C were mixed to prepare a coating solution.

    [Test Example 10]


    (Dynamic color-developing sensitivity)



    [0120] 
    Table 12
     Pulse width
     1.1 ms1.25 ms
    Example 21 1.11 1.24
    Example 22 1.16 1.27
    Comparative Example 9 0.91 1.11
    Thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.)
    Printing voltage: 17 V, Pulse width: 0.2, 0.35, 0.5, 0.65, 0.8, 0.95, 1.1, 1.25, 1.4, 1.6, 1.8 ms

    [0121] As is evident from Table 12 and Figure 3, the comparison between Examples 21 to 22 and Comparative Example 9 showed that the dynamic color-developing sensitivity was improved in Examples 21 to 22.

    [Test Example 11]


    (Light resistance of background)



    [0122] 
    Table 13
     Before testLight resistance of background
      6 hours (B)12 hours (B)6 hours (Y)12 hours (Y)
    Example 21 0.07 0.10 0.12 0.17 0.24
    Example 22 0.07 0.09 0.13 0.16 0.25
    Comparative Example 9 0.07 0.08 0.13 0.15 0.26
    Light resistance tester (trade name: UV Long-Life Fade Meter model U48, manufactured by Suga Test Instruments Co., Ltd.)

    [0123]  As is evident from the results of Table 13, the comparison between Examples 21 to 22 and Comparative Example 9 showed that the recording material of the present invention had exceedingly good light resistance of the background and was hardly altered even by the addition of the sensitizer, compared with the sensitizer-free samples. Thus, the recording material was almost free from usually expected adverse effect caused by the addition.

    [Example 23]


    (Image stabilizer formulation; preparation of thermal recording paper)



    [0124] 
    Dispersion solution of color-forming compound (solution A)  
     3-di-n-butylamino-6-methyl-7-anilinofluoran 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent (solution B)  
     N-(2-hydroxyphenyl)-cinnamoylamide 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of filler (solution C)  
     Calcium carbonate 27.8 parts
     10% aqueous solution of polyvinyl alcohol 26.2 parts
     Water 71 parts
    Dispersion solution of image stabilizer (solution D)  
     1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl) butane 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts


    [0125] First, each mixture having the composition of the solution A, B, C, or D was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A to D. 1 part by mass of the solution A, 2 parts by mass of the solution B, 4 parts by mass of the solution C, and 1 part by mass of the solution D were mixed to prepare a coating solution. This coating solution was applied to white paper using a wire rod (manufactured by Webster, Wire Bar No. 12), and the paper was dried. Then, calendering treatment was performed to prepare thermal recording paper (coating solution: approximately 5.5 g/m2 in terms of dry mass).

    [Example 24]



    [0126] Thermal recording paper was prepared by the method described in Example 23 except that 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane was used instead of 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane in the dispersion solution of the sensitizer (solution D) of Example 23.

    [Comparative Example 10]



    [0127] Thermal recording paper was prepared by the method described in Example 23 except that of the dispersion solutions prepared in Example 23, 1 part by mass of the solution A, 2 parts by mass of the solution B, and 4 parts by mass of the solution C were mixed to prepare a coating solution.

    [Test Example 12]


    (Light resistance of background)



    [0128] 
    Table 14
     Before testLight resistance of background
     6 hours (B)12 hours (B)6 hours (Y)12 hours (Y)
    Example 23 0.09 0.10 0.13 0.19 0.26
    Example 24 0.09 0.11 0.13 0.18 0.25
    Comparative Example 10 0.06 0.08 0.13 0.15 0.26
    Light resistance tester (trade name: UV Long-Life Fade Meter model U48, manufactured by Suga Test Instruments Co., Ltd.)

    [0129] As is evident from the results of Table 14, the comparison between Examples 23 to 24 and Comparative Example 10 showed that the recording material of the present invention had exceedingly good light resistance of the background and was hardly altered even by the addition of the image stabilizer, compared with the image stabilizer-free samples. Thus, the recording material was almost free from usually expected adverse effect caused by the addition.

    [Test Example 13]


    (Heat resistance of image)



    [0130] 
    Table 15
     Before testImage stabilizer
    AddedNot addedAddedNot added
    Example 23 1.33 1.28 (Comparative Example 10) 1.10 0.51 (Comparative Example 10)
    Example 24 1.30 1.06
    Thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.)
    Color development conditions (printing voltage: 17 V, Pulse width: 1.8 ms)
    Thermostat (trade name: DK-400, manufactured by Yamato Scientific Co., Ltd)
    Test conditions (100°C, 24 hours)

    [0131] As is evident from the results of Table 15, the comparison between Examples 23 to 24 and Comparative Example 10 showed that the heat resistance of the image was significantly improved in Examples 23 to 24.

    [Example 25]


    (Color-developing agent formulation; preparation of thermal recording paper)



    [0132] 
    Dispersion solution of color-forming compound (solution A)  
     3-di-n-butylamino-6-methyl-7-anilinofluoran 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent 1 (solution B)  
     N-(2-hydroxyphenyl)-cinnamoylamide 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent 2 (solution C)  
     4-hydroxy-4'-isopropoxydiphenylsulfone 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of filler (solution D)  
    Calcium carbonate 27.8 parts
     10% aqueous solution of polyvinyl alcohol 26.2 parts
     Water 71 parts


    [0133] First, each mixture having the composition of the solution A, B, C, or D was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A to D. 1 part by mass of the solution A, 0.5 part by mass of the solution B, 1.5 parts by mass of the solution C, and 4 parts by mass of the solution D were mixed to prepare a coating solution. This coating solution was applied to white paper using a wire rod (manufactured by Webster, Wire Bar No. 12), and the paper was dried. Then, calendering treatment was performed to prepare thermal recording paper (coating solution: approximately 5.5 g/m2 in terms of dry mass).

    [Example 26]



    [0134] Thermal recording paper was prepared by the method described in Example 25 except that the composition of each dispersion solution of Example 25 was changed to 1 part by mass of the solution A, 1.0 part by mass of the solution B, 1.0 part by mass of the solution C, and 4 parts by mass of the solution D.

    [Example 27]



    [0135] Thermal recording paper was prepared by the method described in Example 25 except that the composition of each dispersion solution of Example 25 was changed to 1 part by mass of the solution A, 0.5 part by mass of the solution B, 1.5 parts by mass of the solution C, and 4 parts by mass of the solution D.

    [Example 28]


    (Preparation of thermal recording paper)



    [0136] 
    Dispersion solution of color-forming compound (solution A)  
     3-di-n-butylamino-6-methyl-7-anilinofluoran 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent 1 (solution B)  
     N-(2-hydroxyphenyl)-cinnamoylamide 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of color-developing agent 3 (solution E)  
     D-90 (color-developing agent for thermal recording paper manufactured by Nippon Soda Co., Ltd.) 16 parts
     10% aqueous solution of polyvinyl alcohol 84 parts
    Dispersion solution of filler (solution D)  
     Calcium carbonate 27.8 parts
     10% aqueous solution of polyvinyl alcohol 26.2 parts
    Water 71 parts


    [0137] First, each mixture having the composition of the solution A, B, D, or E was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A, B, D, and E. 1 part by mass of the solution A, 0.5 part by mass of the solution B, 1.5 parts by mass of the solution E, and 4 parts by mass of the solution D were mixed to prepare a coating solution. This coating solution was applied to white paper using a wire rod (manufactured by Webster, Wire Bar No. 12), and the paper was dried. Then, calendering treatment was performed to prepare thermal recording paper (coating solution: approximately 5.5 g/m2 in terms of dry mass).

    [Example 29]



    [0138] Thermal recording paper was prepared by the method described in Example 28 except that the composition of each dispersion solution of Example 28 was changed to 1 part by mass of the solution A, 1.0 part by mass of the solution B, 1.0 part by mass of the solution E, and 4 parts by mass of the solution D.

    [Example 30]



    [0139] Thermal recording paper was prepared by the method described in Example 28 except that the composition of each dispersion solution of Example 28 was changed to 1 part by mass of the solution A, 0.5 part by mass of the solution B, 1.5 parts by mass of the solution E, and 4 parts by mass of the solution D.

    [Comparative Example 11]



    [0140] Thermal recording paper was prepared by the method described in Example 28 except that the composition of each dispersion solution of Example 28 was changed to 1 part by mass of the solution A, 1.0 part by mass of the solution B, and 4 parts by mass of the solution D.

    [Comparative Example 12]



    [0141] Thermal recording paper was prepared by the method described in Example 28 except that the composition of each dispersion solution of Example 28 was changed to 1 part by mass of the solution A, 1.0 part by mass of the solution C, and 4 parts by mass of the solution D.

    [Comparative Example 13]



    [0142] Thermal recording paper was prepared by the method described in Example 28 except that the composition of each dispersion solution of Example 28 was changed to 1 part by mass of the solution A, 1.5 parts by mass of the solution E, and 4 parts by mass of the solution D.

    [Test Example 14]


    (Dynamic color-developing sensitivity)



    [0143] 
    Table 16
     Pulse width
    1.1 ms1.25 ms
    Example 25 0.96 1.13
    Example 26 0.94 1.17
    Example 27 0.96 1.12
    Comparative Example 12 0.96 1.18
    Thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.)
    Printing voltage: 17 V, Pulse width: 0.2, 0.35, 0.5, 0.65, 0.8, 0.95, 1.1, 1.25, 1.4, 1.6, 1.8 ms

    [0144] As is evident from Table 16 and Figure 4, the comparison between Examples 25 to 27 and Comparative Example 12 showed that little adverse effect was caused even by the addition of the compound of the present invention to the color-developing agent 2, and favorable results were obtained even in the dynamic sensitivity test.
    Table 17
     Pulse width
    1.1 ms1.25 ms
    Example 28 0.61 0.80
    Example 29 0.73 0.92
    Example 30 0.83 1.04
    Comparative Example 13 0.46 0.60
    Thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.)
    Printing voltage: 17 V, Pulse width: 0.2, 0.35, 0.5, 0.65, 0.8, 0.95, 1.1, 1.25, 1.4, 1.6, 1.8 ms

    [0145] As is evident from Table 17 and Figure 5, the comparison between Examples 28 to 30 and Comparative Example 13 showed that the sensitivity was only slightly reduced even by the addition of the color-developing agent 3 to the compound of the present invention, and favorable results were obtained even in the dynamic sensitivity test.

    [Test Example 15]


    (Heat resistance of image)



    [0146] 
    Table 18
     Before testAfter test
    Example 25 1.34 1.23
    Example 26 1.33 1.34
    Example 27 1.34 1.42
    Example 28 1.30 0.99
    Example 29 1.28 1.13
    Example 30 1.21 1.28
    Comparative Example 11 1.28 0.51
    Thermal printing tester (trade name: model TH-PMH, manufactured by Ohkura Electric Co., Ltd.)
    Color development conditions (printing voltage: 17 V, Pulse width: 1.8 ms)
    Thermostat (trade name: DK-400, manufactured by Yamato Scientific Co., Ltd)
    Test conditions (100°C, 24 hours)

    [0147] As is evident from the results of Table 18, the comparison between Examples 25 to 30 and Comparative Example 11 showed that the heat resistance of the image was significantly improved in Examples 25 to 30.


    Claims

    1. A recording material containing a fluoran color-forming compound, wherein the recording material contains at least one compound represented by formula (I):

    wherein R1 and R4 each independently represent a hydroxy group, a halogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group; p represents 0 or any integer of 1 to 4; q represents 0 or any integer of 1 to 5; when p and q represent 2 or more, each of R1 and each of R4 are the same or different; R2 and R3 each independently represent a hydrogen atom or a C1-C6 alkyl group; R5 represents a hydrogen atom, a C1-C6 alkyl group, a phenyl group, or a benzyl group; and a bond represented by a wavy line represents E, Z, or a mixture thereof,
    and, as an additive, a hindered phenol compound represented by formula (VIII):

    wherein R13 and R14 each independently represent a C1-C6 alkyl group; p' and q' each independently represent any integer of 1 to 4; when p' and q' represent 2 or more, each of R13 and each of R14 are the same or different, provided that at least one of R13 and R14 represents a C1-C6 alkyl group bonded via secondary or tertiary carbon to the ortho position of the hydroxy group; and R15 is represented by formula (IX):

    wherein R16 represents a C1-C6 alkyl group; r represents 0 or any integer of 1 to 4; and * represents a binding position,
    provided that the contents of the compound represented by formula (I) and the compound represented by formula (VIII) are both 0.5 to 10 parts by mass with respect to 1 part by mass of the color-forming compound.
     
    2. The recording material according to claim 1, wherein the compound represented by formula (I) is represented by formula (II):

    wherein R2 to R5 are the same as R2 to R5 in formula (I); R7 represents a C1-C4 alkyl group or a C1-C4 alkoxy group; and R6 represents a hydrogen atom when R7 represents a C1-C4 alkyl group, and represents a C1-C4 alkoxy group when R7 represents a C1-C4 alkoxy group.
     
    3. The recording material according to claim 1, wherein the compound represented by formula (I) is represented by formula (III):

    wherein R2 to R5 and q are the same as R2 to R5 and q in formula (I).
     
    4. A recording sheet having a recording material layer formed from a recording material according to any one of claims 1 to 3 on a support.
     


    Ansprüche

    1. Aufzeichnungsmaterial, enthaltend eine Fluoran-farbbildende Verbindung, worin das Aufzeichnungsmaterial mindestens eine Verbindung enthält, wiedergegeben durch Formel (I):

    worin R1 und R4 jeweils unabhängig voneinander für eine Hydroxygruppe, ein Halogenatom, eine C1-C6-Alkylgruppe oder eine C1-C6-Alkoxygruppe stehen; p steht für 0 oder eine beliebige Ganzzahl von 1 bis 4; q steht für 0 oder eine beliebige Ganzzahl von 1 bis 5; wenn p und q für 2 oder darüber stehen, sind jeweils R1 und jeweils R4 gleich oder verschieden; R2 und R3 stehen jeweils unabhängig voneinander für ein Wasserstoffatom oder eine C1-C6-Alkylgruppe; R5 steht für ein Wasserstoffatom, eine C1-C6-Alkylgruppe, eine Phenylgruppe oder eine Benzylgruppe; und eine Bindung, wiedergegeben durch eine Wellenlinie, steht für E, Z oder eine Mischung davon;
    und, als ein Additiv, eine gehinderte Phenolverbindung, wiedergegeben durch die Formel (VIII):

    worin R13 und R14 jeweils unabhängig voneinander für eine C1-C6-Alkylgruppe stehen; p' und q' stehen jeweils unabhängig voneinander für eine beliebige Ganzzahl von 1 bis 4; wenn p' und q' für 2 oder darüber stehen, sind jeweils R13 und R14 gleich oder verschieden, vorausgesetzt, dass mindestens eines von R13 und R14 für eine C1-C6-Alkylgruppe steht, verbunden über ein sekundäres oder tertiäres Kohlenstoff an die Ortho-Position der Hydroxygruppe; und R15 ist wiedergegeben durch die Formel (IX):

    worin R16 für eine C1-C6-Alkylgruppe steht; r steht für 0 oder eine beliebige Ganzzahl von 1 bis 4; und * steht für eine Bindungsposition,
    vorausgesetzt, dass die Gehalte der Verbindung, wiedergegeben durch die Formel (I) und die Verbindung, wiedergegeben durch die Formel (VIII), jeweils 0,5 bis 10 Gew.-Teile, bezogen auf 1 Gew.-Teil der farbbildenden Verbindung, sind.
     
    2. Aufzeichnungsmaterial nach Anspruch 1, worin die Verbindung, wiedergegeben durch die Formel (I), wiedergegeben wird durch die Formel (II):

    worin R2 bis R5 gleich sind wie R2 bis R5 in Formel (I); R7 steht für eine C1-C4-Alkylgruppe oder eine C1-C4-Alkoxygruppe; und R6 steht für ein Wasserstoffatom, wenn R7 für eine C1-C4-Alkylgruppe steht, und steht für eine C1-C4-Alkoxygruppe, wenn R7 für eine C1-C4-Alkoxygruppe steht.
     
    3. Aufzeichnungsmaterial nach Anspruch 1, worin die Verbindung, wiedergegeben durch die Formel (I), wiedergegeben wird durch Formel (III):

    worin R2 bis R5 und q gleich sind wie R2 bis R5 und q in Formel (I).
     
    4. Aufzeichnungsblatt mit einer Aufzeichnungsmaterialschicht, gebildet aus einem Aufzeichnungsmaterial nach irgendeinem der Ansprüche 1 bis 3 auf einem Träger.
     


    Revendications

    1. Matériau d'enregistrement contenant un composé chromogène fluorane, dans lequel le matériau d'enregistrement contient au moins un composé représenté par la formule (I) :

    dans laquelle R1 et R4 représentent chacun indépendamment un groupe hydroxy, un atome d'halogène, un groupe alkyle en C1-C6 ou un groupe alcoxy en C1-C6 ; p représente 0 ou un nombre entier quelconque de 1 à 4 ; q représente 0 ou un nombre entier quelconque de 1 à 5 ; lorsque p et q représentent 2 ou plus, chacun des R1 et chacun des R4 sont identiques ou différents ; R2 et R3 représentent chacun indépendamment un atome d'hydrogène ou un groupe alkyle en C1-C6 ; R5 représente un atome d'hydrogène, un groupe alkyle en C1-C6, un groupe phényle ou un groupe benzyle ; et une liaison représentée par une ligne ondulée représente E, Z ou un mélange de ceux-ci,
    et, en tant qu'additif, un composé phénol encombré représenté par la formule (VIII) :

    dans laquelle R13 et R14 représentent chacun indépendamment un groupe alkyle en C1-C6 ; p' et q' représentent chacun indépendamment un nombre entier quelconque de 1 à 4 ; lorsque p' et q' représentent 2 ou plus, chacun des R13 et chacun des R14 sont identiques ou différents, à condition qu'au moins l'un des R13 et R14 représente un groupe alkyle en C1-C6 lié par un carbone secondaire ou tertiaire à la position ortho du groupe hydroxy ; et R15 est représenté par la formule (IX) :

    dans laquelle R16 représente un groupe alkyle en C1-C6 ; r représente 0 ou un nombre entier quelconque de 1 à 4 ; et * représente une position de liaison,
    à condition que les teneurs du composé représenté par la formule (I) et du composé représenté par la formule (VIII) représentent toutes deux 0,5 à 10 parties en masse par rapport à 1 partie en masse du composé chromogène.
     
    2. Matériau d'enregistrement selon la revendication 1, dans lequel le composé représenté par la formule (I) est représenté par la formule (II) :

    dans laquelle R2 à R5 sont identiques à R2 à R5 dans la formule (I) ; R7 représente un groupe alkyle en C1-C4 ou un groupe alcoxy en C1-C4 ; et R6 représente un atome d'hydrogène lorsque R7 représente un groupe alkyle en C1-C4, et représente un groupe alcoxy en C1-C4 lorsque R7 représente un groupe alcoxy en C1-C4.
     
    3. Matériau d'enregistrement selon la revendication 1, dans lequel le composé représenté par la formule (I) est représenté par la formule (III) :

    dans laquelle R2 à R5 et q sont identiques à R2 à R5 et q dans la formule (I).
     
    4. Feuille d'enregistrement ayant une couche de matériau d'enregistrement formée, à partir d'un matériau d'enregistrement selon l'une quelconque des revendications 1 à 3, sur un support.
     




    Drawing












    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