JPH1016404A - Heat-sensitive recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the coloring properties, shelf stability and stability of a colored image by using a compound represented by a specified formula as one kind of an electron receptive compound in a heat recording material with a heat recording layer containing an electron receptive colorless dye and an electron receptive compound and formed on a substrate. SOLUTION: In a heat-sensitive recording material used as a pressure-sensitive paper or the like and having a heat-sensitive recording layer containing an electron receptive colorless dye and an electron receptive compound, a compound represented by a formula I is used as the electron receptive compound. In the formula I, R<1> represents hydrogen atom, alkyl or the like, R<2> represents hydrogen atom, alkyl of total 4-30C or the like, R<3> represents hydrogen atom, alkyl, nitro or the like. Out of the compounds represented by the formula I, compounds represented by the formula II are preferred. In the formula II, R<1> represents hydrogen atom, alkyl or aryl, R<2> represents alkyl or total 4-20C, aryl of total 6-20C, cyano, amino, acyl amino of total 2-20C, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material having improved color developability, raw storage stability, and stability of a color image.

[0002]

2. Description of the Related Art Recording materials using an electron-donating colorless dye and an electron-accepting compound include pressure-sensitive paper, heat-sensitive paper, photosensitive pressure-sensitive paper,
It is already well known as a heat-sensitive recording paper and a thermal transfer paper. For example, British Patent No. 2,140,449, US Patent Nos. 4,480,052 and 4,436,92
No. 0, JP-B-60-23992, JP-A-57-179
No. 836, No. 60-123556, No. 60-1235
No.57 and more. In particular, heat-sensitive recording materials are available in
No.-4160 and Japanese Patent Publication No. 45-14039. A heat-sensitive recording material using a specific pyrazolone compound as an electron-accepting compound is known from JP-A-53-79551. These thermal recording systems are applied to various fields such as facsimile, printer, label, etc.
Needs are expanding. However, the heat-sensitive recording material has a drawback that fogging is caused by a solvent and the like, and a color-forming body is discolored due to fats and oils, chemicals, etc., so that labels, slips, word processing paper, plotters, and the like are used. In the field of paper and the like, the commercial value has been significantly impaired. The present inventors have studied each of an electron-donating colorless dye and an electron-accepting compound, and have pursued the development of good recording material materials and recording materials.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording material which is excellent in color developability, raw storage stability and stability of a color former image.

[0004]

An object of the present invention is to provide a thermosensitive recording material comprising a support and a thermosensitive recording layer containing a colorless electron-donating dye and an electron-accepting compound. This was achieved by a heat-sensitive recording material using a compound represented by the following general formula I as a receptive compound.

[0005]

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In the formula, R ¹ represents a hydrogen atom, an alkyl group, an aryl group, an alkoxycarbonyl group, or a carbamoyl group, and R ² represents a hydrogen atom, an alkyl group having 4 to 30 carbon atoms, and a C 6 to 30 carbon atom. Aryl group, cyano group, amino group, acylamino group having 2 to 30 total carbon atoms, alkoxycarbonylamino group having 2 to 30 total carbon atoms, carbamoyloxy group having 1 to 30 total carbon atoms, 1 to 3 total carbon atoms
0 ureido group, alkoxycarbonyl group having 6 to 30 total carbon atoms, carboxy group, acyl group having 2 to 30 total carbon atoms, alkylsulfonyl group having 1 to 30 total carbon atoms, arylsulfonyl group having 6 to 30 total carbon atoms A sulfonamide group having a total number of carbon atoms of 1 to 30, an alkylthio group having a total number of carbon atoms of 1 to 30, an arylthio group having a total number of carbon atoms of 6 to 30, an alkoxy group having a total number of carbon atoms of 1 to 30, a total number of 1 to 30
And R ³ represents a hydrogen atom, an alkyl group, a nitro group, a halogen atom, an aryloxy group, an arylthio group, or a heterocyclic group.

[0007] Among the compounds represented by the above general formula I, compounds represented by the following general formula II are particularly preferred.

[0008]

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In the formula, R ¹ represents a hydrogen atom, an alkyl group or an aryl group, and R ² represents an alkyl group having a total of 4 to 20 carbon atoms, an aryl group having a total of 6 to 20 carbon atoms, a cyano group, an amino group, An acylamino group having 2 to 20 carbon atoms, an alkoxycarbonyl group having 6 to 20 carbon atoms in total, a carboxy group,
Alkoxy group having 1 to 20 total carbon atoms, 1 to 2 total carbon atoms
Represents a carbamoyl group of 0.

R ¹ and R in the above-mentioned general formula I or II
^The substituent represented by ² or R ³ may further have a substituent. The substituents represented by R ¹ , R ² , and R ³ may have a pyrazolone nucleus as a substituent, and may form a bis-form, a tris-form, or a multimer thereof.

In the above general formula I or II, the alkyl group represented by R ¹ is preferably an alkyl group having 1 to 30 carbon atoms, for example, methyl, ethyl, propyl, octyl, decyl, methoxyethyl, ethoxyethyl. , Methoxycarbonylmethyl, ethoxycarbonylethyl, 2-chloroethyl, carboxymethyl, carboxyethyl, methylcyclohexyl, cyclohexyl, benzyl, chlorobenzyl, and phenethyl are preferred.

In the above general formula I or II, the aryl group represented by R ¹ is preferably an aryl group having 6 to 30 carbon atoms in total, such as phenyl, 4-tolyl,
-Chlorophenyl, 2,4-dichlorophenyl, 2,
4,6-trichlorophenyl, 4-carboxyphenyl, 4-nitrophenyl, 4-acetamidophenyl,
4-hydroxyphenyl, 4-methoxyphenyl, 4-
Ethoxyphenyl, 4-ethoxycarbonylphenyl,
1-naphthyl, 2-naphthyl, 4- (5- [4- (3-
Phenyl-5-hydroxypyrazol-1-yl) phenylaminocarbonyl] pentanoylamino) phenyl is preferred.

In formula (I), the alkoxycarbonyl group represented by R ¹ is preferably an alkoxycarbonyl group having a total of 2 to 30 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl,
Octyloxycarbonyl is preferred.

In the general formula I, the carbamoyl group represented by R ¹ is preferably a carbamoyl group having a total of 2 to 30 carbon atoms, for example, an unsubstituted carbamoyl group, a dimethylaminocarbonyl group, and a diethylaminocarbonyl group.

In the above formula I or II, the alkyl group represented by R ² is preferably an alkyl group having a total of 4 to 30 carbon atoms, for example, normal butyl, t-butyl, 1-methylcyclopropyl, 1-methylcyclopropyl, Ethylcyclopropyl, 1-benzylcyclopropyl, 4- (1-phenyl-5-hydroxypyrazol-3-yl) butyl are preferred.

In the above formula I or II, the aryl group represented by R ² is preferably an aryl group having 6 to 30 carbon atoms, for example, phenyl, 4-methoxyphenyl, 4-hydroxyphenyl, 4-nitro Phenyl, 4-nitro-3-methoxyphenyl, 4-methanesulfonamidophenyl, 4-butanesulfonamidophenyl, and acetamidophenyl are preferred.

In formula (I) or (II), the amino group represented by R ² is preferably an unsubstituted or substituted amino group, and an alkylamino group (eg, methylamino, dimethylamino, diethylamino, morpholino, piperidino, pyrrolidino) ), Anilino groups (eg, anilino, 2-chloroanilino, 2-chloro-5-ethoxyanilino, 2-methoxy-5-benzenesulfonamidoanilino, 4-dodecylsulfonyl-2-chloroanilino).

In the above general formula I or II, the acylamino group represented by R ² has a total carbon number of 2 to 30.
Are preferred, for example, acetamido, propionylamino, butanoylamino, benzoylamino, 4-methoxybenzoylamino, cinnamoylamino, palmitoylamino, lauroylamino, and pyridinecarbonylamino.

In the above formula I, the alkoxycarbonylamino group represented by R ² is preferably an alkoxycarbonylamino group having a total of 2 to 30 carbon atoms, such as methoxycarbonylamino, ethoxycarbonylamino, butoxycarbonylamino, t -Butoxycarbonylamino, hexyloxycarbonylamino, octyloxycarbonylamino, 2-ethylhexyloxycarbonylamino, and benzyloxycarbonylamino are preferred.

In the general formula I, the carbamoyloxy group represented by R ² is preferably a carbamoyloxy group having 1 to 30 carbon atoms, such as unsubstituted carbamoyloxy, N-methylcarbamoyloxy, N-ethyl. Carbamoyloxy, N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy, piperidinocarbonyloxy, and pyrrolidinocarbonyloxy are preferred.

In formula (I), the ureido group represented by R ² is preferably a ureido group having 1 to 30 carbon atoms in total, such as unsubstituted ureido, N, N-dimethylcarbonylamino, N, N- Diethylcarbonylamino, morpholinocarbonylamino, piperidinocarbonylamino, and pyrrolidinocarbonylamino are preferred.

In the above formula I or II, the alkoxycarbonyl group represented by R ² has a total carbon number of 6
To 30 alkoxycarbonyl groups, for example, hexyloxycarbonyl, methoxybutoxycarbonyl, ethoxybutoxycarbonyl, and 2- [2- (1-phenyl-5-hydroxypyrazol-3-ylcarbonyloxy) ethoxy] ethoxycarbonyl.

In formula (I), the acyl group represented by R ² is preferably an acyl group having a total of 2 to 30 carbon atoms, for example, acetyl, propionyl, butanoyl, isobutanoyl, pivaloyl, benzoyl and 4-methoxybenzoyl. preferable.

In the general formula I, the alkylsulfonyl group represented by R ² is preferably an alkylsulfonyl group having a total of 1 to 30 carbon atoms, for example, methanesulfonyl, ethanesulfonyl, propanesulfonyl, butanesulfonyl, pentanesulfonyl, Hexanesulfonyl,
Octanesulfonyl and ethoxycarbonylmethanesulfonyl are preferred.

In the above formula I, the arylsulfonyl group represented by R ² is preferably an arylsulfonyl group having a total of 6 to 30 carbon atoms, such as benzenesulfonyl, toluenesulfonyl, 4-methoxybenzenesulfonyl, and 4-chlorobenzene. Sulfonyl and ethoxybenzenesulfonyl are preferred.

In formula (I), the sulfonamide group represented by R ² is preferably a sulfonamide group having a total of 1 to 30 carbon atoms, such as methanesulfonylamino, ethanesulfonylamino, propanesulfonylamino, butanesulfonyl. Amino, pentanesulfonylamino, hexanesulfonylamino, octanesulfonylamino, ethoxycarbonylpropanesulfonylamino, benzenesulfonylamino, toluenesulfonylamino, 4-methoxybenzenesulfonylamino, 4-chlorobenzenesulfonylamino, and ethoxybenzenesulfonylamino are preferred.

In formula (I), the alkylthio group represented by R ² is preferably an alkylthio group having 1 to 30 carbon atoms in total, such as methylthio, ethylthio, propylthio, butylthio and hexylthio.

In the above general formula I, the arylthio group represented by R ² is preferably an arylthio group having a total carbon number of 6 to 30, for example, phenylthio, tolylthio,
4-chlorophenylthio, 4-methoxyphenylthio,
4-ethoxyphenylthio is preferred.

In formula (I) or (II), the alkoxy group represented by R ² is preferably an alkoxy group having 1 to 30 carbon atoms, such as methoxy, ethoxy,
Butoxy, methoxyethoxy, methoxybutoxy, ethoxybutoxy are preferred.

In the above general formula I or II, the carbamoyl group represented by R ² includes a total of 1 to 30 carbon atoms.
Are preferred, for example, unsubstituted carbamoyl, N, N-dimethylcarbamoyl, N, N-diethylcarbamoyl, morpholinocarbonyl, piperidinocarbonyl, and pyrrolidinocarbonyl.

In the general formula I, the alkyl group represented by R ³ is preferably an alkyl group having a total of 1 to 30 carbon atoms, such as methyl, ethyl, butyl, 2-methoxyethyl, 2-ethoxyethyl, -(1,3-diphenyl-5-hydroxypyrazol-4-ylbutyl, 4
-(1,3-diphenyl-5-hydroxypyrazole-
4-ylhexyl is preferred.

In the above general formula I, the halogen atom represented by R ³ is preferably fluorine, chlorine or bromine.
Chlorine is particularly preferred.

In the above general formula I, the aryloxy group represented by R ³ is preferably an aryloxy group having a total of 6 to 30 carbon atoms, for example, phenoxy, 4-methoxyphenoxy, 4-ethoxyphenoxy, 4-methoxy Preference is given to carbonylphenoxy, 4-decanoylaminophenoxy, naphthyloxy.

In formula (I), the arylthio group represented by R ³ is preferably an arylthio group having 6 to 30 carbon atoms, for example, phenylthio, 4-methoxyphenylthio, 4-ethoxyphenylthio, 4-hexyl Oxyphenylthio and 4-decanoylaminophenylthio are preferred.

In the above general formula I, the heterocyclic group represented by R ³ is preferably a nitrogen-containing aromatic heterocyclic ring, particularly preferably triazole, benzotriazole and pyrazole.

The electron-accepting compound represented by formula I or II of the present invention can be easily synthesized by a conventional synthesis method, that is, a synthesis method of a magenta coupler for a silver halide photographic light-sensitive material. For example, it is described in detail in U.S. Pat. No. 5,418,841, JP-A-1-145657, and the like.

Specific examples of the compound represented by formula (I) or (II) of the present invention are shown below, but the present invention is not limited thereto.

[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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The compounds of the present invention represented by formula I or II may be used alone or in combination of two or more. A compound of the general formula I or II according to the invention,
Using well-known electron-accepting compounds such as phenol derivatives, phenolic resins, novolak resins, metal-treated novolak resins, metal complexes, salicylic acid derivatives, metal salts of aromatic carboxylic acids, acidic clay, and bentonite Is also good. Examples of these are disclosed in Japanese Patent Publication Nos. 40-9309, 45-14039 and 52-1
40483, JP-A-48-51510, JP-A-57-210886, and JP-A-58-8708.
No. 9, JP-A-59-11286, JP-A-60-11
JP-A-177675, JP-A-61-95988, JP-A-63-65797, and JP-A-6-729.
No. 84, JP-A-7-278098 and the like.

Examples of some of these are 4-tert-butylphenol, 4-phenylphenol, 2,2′-dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 2-bis- (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (3-phenyl-4-hydroxyphenyl) sulfone, 4-hydroxyphenyl-3 ′, 4 '-Dimethylphenylsulfone, 4- (4-
Isopropoxyphenylsulfonyl) phenol, 4,
4'-dihydroxydiphenyl sulfide, 1,4-bis [2- (4-hydroxyphenyl) propan-2-yl] benzene, 1,3-bis [2- (4-hydroxyphenyl) propan-2-yl] Benzene, 4,4′-thiobis (2-t-butyl-5-methylphenol),
1,1,3-tris (2-methyl-4-hydroxy-5
-T-butylphenyl) butane, 1,1-bis- (4-hydroxy-3-methyl-6-t-butylphenyl) butane, 4,4'-dihydroxydiphenylsulfone,
-Benzylhydroxybenzoate, 3-phenyl-5-
(Α, α-dimethylbenzyl) salicylic acid, 3-cumyl-5-t-octylsalicylic acid, 3,5-di-t-butylsalicylic acid, 3-phenyl-5-t-octylsalicylic acid, 3-methyl-5-α -Methylbenzylsalicylic acid, 3-methyl-5-cumylsalicylic acid, 3,5-bis (α-methylbenzyl) salicylic acid, 3-cumyl-5-
Phenylsalicylic acid, 5-n-octadecylsalicylic acid, 4-pentadecylsalicylic acid, 3,5-bis (α,
α-dimethylbenzyl) salicylic acid, 3,5-bis-t
-Octylsalicylic acid, 4-β-dodecyloxyethoxysalicylic acid, 4-methoxy-6-dodecyloxysalicylic acid, 4-β-phenoxyethoxysalicylic acid, 4-
β-p-ethylphenoxyethoxysalicylic acid, 4-β
-P-methoxyphenoxyethoxysalicylic acid, 4-octyloxycarbonylaminosalicylic acid, 2-phenoxymethylcarbonylaminobenzoic acid, 4,4'-bis (p-toluenesulfonylureido) diphenylmethane and the like, and metal salts thereof. is there.

The electron-accepting compound used in the heat-sensitive recording material of the present invention is an electron-donating colorless dye of 50 to 800.
% By weight, more preferably 10% by weight.
0 to 500% by weight. When two or more electron-accepting compounds are used in combination, it is preferable that the compound represented by the general formula I or II according to the present invention is contained in an amount of 30% or more, particularly 50% or more.

Examples of the electron-donating colorless dye used in the present invention include triphenylmethanephthalide compounds, fluoran compounds, phenothiazine compounds, indolylphthalide compounds, leuco-auramine compounds, rhodamine lactam compounds. Various compounds such as compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, fluorene compounds, pyridine compounds and pyrazine compounds can be mentioned. Specific examples of phthalides are described in U.S. Reissue Patent No. 23,024, U.S. Pat.
Nos. 491,111, 3,491,112, 3,491,116 and 3,
509, 174, specific examples of fluorans are described in U.S. Pat. Nos. 3,624,107, 3,627,
No. 787, No. 3, 641, 011, No. 3, 462, 828, No. 3, 681, 39
No. 0, 3,920, 510, 3,959,571, and specific examples of spiropyrans are described in US Pat. No. 3,971,808, pyridine-based and pyrazine-based compounds. The compounds are disclosed in U.S. Pat.
No. 24, 3, 853, 869, 4, 246, 318 and specific examples of fluorene compounds are described in detail in JP-A-63-94878. . Of these, an electron-donating colorless dye represented by the general formula III is particularly preferred.

[0048]

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[0049] In the ^{formula, R 4, R 5, R} 6, R 7 each independently represent a hydrogen atom, an alkyl group, an aryl group, R ⁸
Represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom. R ⁴ and R ⁵ , or R ⁶ and R ⁷ may combine with each other to form a ring.

In the general formula III, R ⁴ , R ⁵ ,
The substituents of R ⁶ , R ⁷ and R ⁸ may further have a substituent.

In the general formula III, R ⁴ , R ⁵ ,
As the alkyl group represented by R ⁶ , R ⁷ , and R ⁸ , an alkyl group having 1 to 10 carbon atoms is preferable.
Ethyl, propyl, isopropyl, normal butyl, isobutyl, s-butyl, octyl, decyl, methoxyethyl, ethoxyethyl, methoxyethoxyethyl, ethoxycarbonylmethyl, 2-chloroethyl, cyclopentyl, cyclohexyl, methylcyclohexyl and benzyl are preferred. As the ring structure formed by R ⁴ , R ⁵ , R ⁶ and R ⁷ , a 5- to 6-membered nitrogen-containing saturated heterocycle is preferable, and for example, piperidine, pyrrolidine, morpholine, piperazine, and substituted piperazine are preferable.

In the general formula III, R ⁴ , R ⁵ ,
The aryl group represented by R ⁶ and R ⁷ has a total carbon number of 6
To 20 aryl groups are preferred, for example, phenyl, tolyl, chlorophenyl, 1-naphthyl and 2-naphthyl are preferred.

In the above general formula III, the halogen atom represented by R ⁸ is preferably a fluorine atom, a chlorine atom or a bromine atom.

In the above general formula III, the alkoxy group represented by R ⁸ is preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy, ethoxy, propyloxy, methoxyethoxy, dodecyloxy, benzyloxy, -Methoxybenzyloxy is preferred.

Among the electron-donating colorless dyes represented by the general formula III, 2-arylamino-3- (H, halogen, alkyl or alkoxy) -6-substituted aminofluorans are preferred. Specific examples of the electron-donating colorless dye represented by Formula III are described below, but the present invention is not limited thereto.

[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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A known sensitizer can be used in the heat-sensitive recording material of the present invention. Examples of sensitizers are disclosed in
Compounds disclosed in JP-A-8-57989, JP-A-58-87094, JP-A-63-39375 and the like can be mentioned. Specifically, aromatic ethers (particularly, benzyl ethers, di (substituted phenoxy) alkanes), aromatic esters, oxalic esters, aliphatic amides, aliphatic ureas, aromatic amides, aromatic ureas, etc. Representative.

The binder used in the heat-sensitive recording material of the present invention is preferably a compound which dissolves in water at 25 ° C. in an amount of 5% by weight or more. Specifically, polyvinyl alcohol (carboxy-modified, itaconic-modified, maleic acid-modified) Modified, silica-modified and other modified polyvinyl alcohols), methylcellulose, carboxymethylcellulose, starches (including modified starch), gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, polyacrylamide, acetic acid Saponified vinyl-polyacrylic acid copolymers and the like can be mentioned. These binders are used not only at the time of dispersion but also for the purpose of improving the strength of the coating film. For this purpose, styrene-butadiene copolymer, vinyl acetate copolymer, acrylonitrile-butadiene copolymer, acrylic Latex binders of synthetic polymers such as methyl acid-butadiene copolymer and polyvinylidene chloride can also be used in combination. If necessary, a crosslinking agent for an appropriate binder may be added according to the type of the binder.

Examples of the pigment used in the heat-sensitive recording material of the present invention include calcium carbonate, barium sulfate, lithopone, wax, kaolin, silica and amorphous silica.

The metal soap used in the heat-sensitive recording material of the present invention includes zinc stearate, calcium stearate, aluminum stearate and the like.

The heat-sensitive recording material of the present invention may optionally contain
A wax, a surfactant, an antistatic agent, an ultraviolet absorber, an antifoaming agent, a conductive agent, a fluorescent dye, a coloring dye and a pigment may be added.

Examples of the support used in the heat-sensitive recording material of the present invention include papers such as acidic paper and neutral paper, coated paper coated with pigments and the like, plastic film laminated paper obtained by laminating a plastic film such as polyethylene, Examples include synthetic paper made from polypropylene or polyester resin, and plastic films such as polyethylene terephthalate and polyethylene naphthalate.

In the method for producing a thermosensitive recording material of the present invention, an electron-donating colorless dye, an electron-accepting compound, a sensitizer and the like are first mixed with a water-soluble polymer aqueous solution such as polyvinyl alcohol using a ball mill, sand mill or the like for several microns. Disperse to: The sensitizer is added to one or both of the electron-donating colorless dye and the electron-accepting compound, and is dispersed at the same time, or in some cases, a eutectic is prepared in advance with the electron-donating colorless dye or the electron-accepting compound. And may be dispersed. Next, these dispersions are mixed, and if necessary, a pigment, a surfactant, a binder, a metal soap, a wax, an antioxidant, an ultraviolet absorber and the like are added to obtain a coating solution for a heat-sensitive recording layer. The obtained heat-sensitive recording layer coating solution is coated on a support,
dry. The coating amount of the coating solution for the heat-sensitive recording layer is preferably from 1 to 15 g / m ² in a state where the coating solution layer is dried, and from ² to 10 g.
/ M ² is particularly preferred. Then, if necessary, smoothness is imparted by a calendering process to obtain a thermosensitive recording material.

The heat-sensitive recording material of the present invention includes a protective layer on the heat-sensitive recording layer, an undercoat layer between the support and the heat-sensitive recording layer, and a backcoat on the surface of the support opposite to the heat-sensitive recording layer. Layers can be provided. All of these layers can be provided using a known method.

Hereinafter, the present invention will be described in detail with reference to Examples of the present invention, but the present invention is not limited to only these.

[0070]

【Example】

Example 1 Compound B- as an electron-donating colorless dye
13. Exemplified compound A-1 as an electron accepting compound, di (p-methylbenzyl) oxalate as a sensitizer,
20 g of each was dispersed with a 100% 5% aqueous solution of polyvinyl alcohol (Kuraray PVA-105) in a ball mill for 24 hours to make the average particle size 1.5 μm or less to obtain each dispersion. In addition, 80 g of calcium carbonate was dispersed with a homogenizer together with 160 g of a 0.5% sodium hexametaphosphate solution to obtain a calcium carbonate dispersion. Each dispersion prepared as described above was used as an electron-donating colorless dye dispersion 5 g,
10 g of an electron accepting compound dispersion, 10 g of a di (p-methylbenzyl) oxalate dispersion, and 5 g of a calcium carbonate dispersion are mixed at a ratio of 5 g, and 3 g of a 21% zinc stearate emulsion is further added thereto to form a thermosensitive recording layer. A coating solution was obtained. This solution was applied on a high-quality paper having a basis weight of 50 g / m ² using a wire bar so that the dry weight of the coating layer was 5 g / m ² , and dried at 50 ° C. for 1 minute to obtain a heat-sensitive recording material.

Example 2 Exemplified Compound A-1 of Example 1
Was used in the same manner except that Exemplified Compound A-3 was used to prepare a coating solution for a heat-sensitive recording layer, to thereby obtain a heat-sensitive recording material.

Example 3 Exemplified Compound A-1 of Example 1
Was used in the same manner, except that Exemplified Compound A-9 was used to prepare a coating solution for a thermosensitive recording layer, to thereby obtain a thermosensitive recording material.

Example 4 Exemplified Compound A-1 of Example 1
Was used in the same manner except that Exemplified Compound A-12 was used to prepare a coating solution for a heat-sensitive recording layer, to thereby obtain a heat-sensitive recording material.

Example 5 Exemplified Compound A-1 of Example 1
Was used in the same manner, except that Exemplified Compound A-13 was used to prepare a coating solution for a heat-sensitive recording layer, to thereby obtain a heat-sensitive recording material.

Example 6 Exemplified Compound A-1 of Example 1
Instead of using Exemplified Compound A-3 and Exemplified Compound A
A heat-sensitive recording material was obtained in the same manner except that a coating solution for a heat-sensitive recording layer was prepared using an equal weight mixture of -13.

Comparative Example 1 Exemplified Compound A-1 of Example 1
Was used in the same manner as above, except that 2,2-bis (4-hydroxyphenyl) propane was used to prepare a coating solution for a heat-sensitive recording layer.

Comparative Example 2 Exemplified Compound A-1 of Example 1
Was used in the same manner as above, except that 1-phenyl-3-ethoxycarbonyl-5-hydroxypyral was used to prepare a coating solution for a heat-sensitive recording layer.

The heat-sensitive recording material obtained as described above is subjected to a surface treatment with a calender, and has a Beck smoothness of 300.
It was adjusted to be ± 50 seconds to obtain a heat-sensitive recording material. In the color development test of the heat-sensitive recording material, printing was performed at a printing energy of 30 mJ / mm ² using a printing tester manufactured by Kyocera, and color evaluation was performed. The plasticizer resistance test was carried out by superimposing a commercially available polyvinyl chloride sheet on the portion of the thermosensitive recording material which had been printed with a Kyocera printing tester at a printing energy of 30 mJ / mm ² , and the discoloration of the colored portion after 48 hours. Was visually evaluated.

[0079]

[Table 1]

[0080]

As is evident from the results shown in Table 1, the heat-sensitive recording material of the present invention has excellent properties of color development and fogging due to a plasticizer or discoloration of a colored portion.

Claims (3)

[Claims] 1. A thermosensitive recording material having a thermosensitive recording layer containing an electron-donating colorless dye and an electron-accepting compound provided on a support, wherein at least one of the electron-accepting compounds is represented by the following general formula I: A heat-sensitive recording material, which is a compound. Embedded image In the formula, R ¹ represents a hydrogen atom, an alkyl group, an aryl group, an alkoxycarbonyl group, or a carbamoyl group; R ² represents a hydrogen atom, an alkyl group having 4 to 30 carbon atoms, and a total carbon number of 6;
To 30 aryl groups, cyano groups, amino groups, acylamino groups having 2 to 30 total carbon atoms, alkoxycarbonylamino groups having 2 to 30 total carbon atoms, carbamoyloxy groups having 1 to 30 total carbon atoms, and 1 to 30 total carbon atoms 30 ureido groups, alkoxycarbonyl groups having 6 to 30 total carbon atoms, carboxy groups, acyl groups having 2 to 30 total carbon atoms, alkylsulfonyl groups having 1 to 30 total carbon atoms, 6 to 3 total carbon atoms
0 arylsulfonyl group, 1 to 30 carbon atoms sulfonamide group, 1 to 30 carbon atoms alkylthio group,
Represents an arylthio group having a total of 6 to 30 carbon atoms, an alkoxy group having a total of 1 to 30 carbon atoms, a carbamoyl group having a total of 1 to 30 carbon atoms, and R ³ represents a hydrogen atom, an alkyl group, a nitro group,
Represents a halogen atom, an aryloxy group, an arylthio group, or a heterocyclic group. 2. The heat-sensitive recording material according to claim 1, wherein the electron-accepting compound is a compound represented by the following general formula II. Embedded image In the formula, R ¹ represents a hydrogen atom, an alkyl group, or an aryl group, and R ² represents an alkyl group having a total of 4 to 30 carbon atoms, an aryl group having a total of 6 to 30 carbon atoms, a cyano group, an amino group, and a total number of 2 carbon atoms. To 30 acylamino groups, alkoxycarbonyl groups having 6 to 30 total carbon atoms, carboxy groups, alkoxy groups having 1 to 30 total carbon atoms, and carbamoyl groups having 1 to 30 total carbon atoms. 3. An electron-donating colorless dye represented by the following general formula III:
The heat-sensitive recording material according to claim 1, wherein the heat-sensitive recording material is a compound represented by the following formula: Embedded image In the formula, R ⁴ , R ⁵ , R ⁶ , and R ⁷ each independently represent a hydrogen atom, an alkyl group, or an aryl group; R ⁸ represents a hydrogen atom;
Represents an alkyl group, an alkoxy group, or a halogen atom. R ⁴
And R ⁵ , and R ⁶ and R ⁷ may combine with each other to form a ring.