JPH07276808A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a thermal recording material having light fastness, especially, both of light fastness and fixing properties by successively laminating a thermal recording layer containing a specific compd. represented by the specific chemical formulae and a protective layer on a support. CONSTITUTION:A thermal recording layer containing a compd. represented by either one of the formulae I, II, III, IV (wherein m is 1 or 2, A is -SO3 or the like, X is a hydrogen atom, an alkyl group, an alkylene group or the like, Z is a hydrogen atom, a halogen atom or the like, W is a hydrogen atom, an alkyl group or the like and Y is an alkyl group, an alkoxy group or the like) is provided on a support and a protective layer is laminated on the thermal recording layer to obtain a thermal recording material reconciled in light fastness and fixing properties. As the color forming component used in the thermal recording layer, a reaction product of a diazonium salt compd. and a coupler or an electron donating leuco dye and an electron acceptive compd. can be pref. used.

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 excellent light resistance and having both light resistance and fixing property.

[0002]

2. Description of the Related Art Thermal recording has recently been developed due to its simple recording device, high reliability and maintenance-free. As the heat-sensitive recording material, those utilizing the reaction between an electron-donating colorless dye and an electron-accepting compound and those utilizing the reaction between a diazonium salt compound and a coupler have been widely known. As a heat-sensitive recording material, research has recently been earnestly conducted to improve properties such as (1) color density and color sensitivity (2) fastness of a color body. However, heat-sensitive recording materials have the drawbacks that when exposed to sunlight for a long time or when they are posted in the office for a long time, the background part is colored by the light or the image part is discolored or faded. Was there. Various methods have been proposed in order to improve the coloring of the background portion and the discoloration or fading of the image portion, but sufficient effects have not always been obtained.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording material which has both light resistance, particularly light resistance and fixability.

[0004]

An object of the present invention is to provide a heat-sensitive recording material in which a heat-sensitive recording layer and a protective layer are sequentially provided on a support, containing a compound represented by the following general formula 1. Achieved with a thermal recording material.

[0005]

[Chemical 2]

In the above general formula, m represents 1 or 2. A is —SO ₂ —R, —CO—R, when m = 1 in general formula (1) and in general formulas (2) to (4).
_{-CO 2 -R, -CONH-R,} -POR 1 R 2, -C
Represents H ₂ R ₃ or -SiR ₄ R ₅ R _6, R in this
Is an alkyl group or an aryl group, R ₁ and R ₂ are an alkoxy group, an aryloxy group, an alkyl group or an aryl group, R ₃ is a phenyl group substituted with at least one of a nitro group or a methoxy group, and R ₄ , R ₅ and R ₆ are an alkyl group or an aryl group, and m = 2 in the general formula (1).
Then A is —SO ₂ R ₇ SO ₂ —, —CO—, —CO
_{CO -, - COR 7 CO -} , - SO 2 - or -SO-
And R ₇ represents an alkylene group or an arylene group.

X is represented by the general formulas (1), (3) and (4).
A hydrogen atom, an alkyl group, an alkoxy group, an aryl
In the general formula (2),
Alkylene group, -OR₇O- or -OCOR₇CO₂
Represents-. W is in the general formula (1), (2), (4)
Are hydrogen atom, alkyl group, alkoxy group, aryl
In the general formula (3), a group or a halogen atom is
OR ₇O- or -OCOR₇CO₂Represents-. Y is one
In the general formulas (1), (2), and (3), hydrogen atom,
Alkyl group, alkoxy group, aryl group or halogen atom
In the general formula (4), the child is -OR₇O-, -OC
OR₇CO₂-, -CH₂CH₂CO₂R₇OCOCH
₂CH₂-, -CH₂CH₂OCOR₇CO₂CH₂C
H₂-Or-CH₂CH₂CON (R₈) R₇N (R
₈) COCH₂CH₂-Is R₈Is a hydrogen atom or
Represents a kill group. Z is hydrogen atom, halogen atom, alkyl
Represents a group or an alkoxy group.

Of the above-mentioned substituents, the alkyl group may be linear or branched and may have an unsaturated bond.
Further, these alkyl groups may be substituted with an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an aryl group, a hydroxy group or the like. The aryl group may be further substituted with an alkyl group, an alkoxy group or a halogen atom.

Among the above-mentioned substituents, the alkylene group may be linear or branched and may contain an unsaturated bond, an oxygen atom, a sulfur atom or a nitrogen atom. The alkylene group may be further substituted with an alkoxy group, a hydroxy group, an aryloxy group or an aryl group.

Of the above substituents, the arylene group may be further substituted with an alkyl group, an alkoxy group, a halogen atom or the like.

Among the substituents represented by X, Y and W, hydrogen atom, an alkyl group having 1 to 18 carbon atoms, and 1 carbon atom
To 18 alkoxy groups, aryl groups having 6 to 18 carbon atoms, fluorine atoms, chlorine atoms, and bromine atoms are preferred, and among these, hydrogen atoms, alkyl groups having 1 to 12 carbon atoms, and 1 to carbon atoms are particularly preferred. 12 alkoxy groups, phenyl groups or chlorine atoms are preferred.

Of the substituents represented by Z, a hydrogen atom, a chlorine atom, a fluorine atom, an alkyl group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms are preferable, and among these, a hydrogen atom is particularly preferable. , Chlorine atom, carbon atom number 1-6
The alkyl group and the alkoxy group having 1 to 6 carbon atoms are preferable.

Of the substituents represented by R, the number of carbon atoms is 1
The alkyl group having 18 to 18 carbon atoms and the aryl group having 6 to 18 carbon atoms are preferable, and among these, the alkyl group having 1 to 12 carbon atoms and the aryl group having 6 to 12 carbon atoms are particularly preferable.

Of the substituents represented by R ₁ and R ₂ ,
Alkoxy group having 1 to 12 carbon atoms, 6 to 1 carbon atoms
An aryloxy group having 2 carbon atoms, an alkyl group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms are preferable.

Among the substituents represented by R ₃ , 2-nitrophenyl group, 3,5-dimethoxyphenyl group, 3,4
A 5-trimethoxyphenyl group is preferred.

Of the substituents represented by R ₄ , R ₅ and R ₆ , an alkyl group having 1 to 12 carbon atoms and a carbon atom having 6 carbon atoms
The aryl group of -12 is preferable. Of these, an alkyl group having 1 to 8 carbon atoms and a phenyl group are particularly preferable.

In the so-called bis form having two benzotriazole rings in one molecule, the substituent represented by R ₇ is an alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 12 carbon atoms. Preferably, the substituent represented by R ₈ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Among the substituents represented by A, --SO ₂ R
Is preferred.

Specific examples of the above substituents will be given below.
The present invention is not limited to this. Among the substituents represented by X, Y and W, a monovalent one is a hydrogen atom,
Methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group,
t-butyl group, pentyl group, hexyl group, octyl group,
Decyl group, dodecyl group, allyl group, 2-butenyl group, benzyl group, α-dimethylbenzyl group, methoxy group, ethoxy group, propyloxy group, butyloxy group, octyloxy group, dodecyloxy group, methoxyethoxy group, phenoxyethoxy group. Group, methoxycarbonylethyl group, ethoxycarbonylethyl group, propyloxycarbonylethyl group, butyloxycarbonylethyl group, octyloxycarbonylethyl group, phenoxycarbonylethyl group, phenyl group, tolyl group, chlorine atom, fluorine atom,
Examples thereof include a bromine atom, and examples of the divalent group include the following.

[0020]

[Chemical 3]

Specific examples of the substituent represented by Z include hydrogen atom, chlorine atom, methyl group, ethyl group, propyl group,
Hexyl group, methoxy group, ethoxy group, propyloxy group, octyloxy group and the like can be mentioned.

Specific examples of the monovalent substituent represented by A include methanesulfonyl group, ethanesulfonyl group, butanesulfonyl group, benzenesulfonyl group and 4-
Methylbenzenesulfonyl group, 2-mesitylenesulfonyl group, 4-methoxybenzenesulfonyl group, 4-octyloxybenzenesulfonyl group, 2,4,6-triisopropylbenzenesulfonyl group, β-styrenesulfonyl group, vinylbenzenesulfonyl group, 4 -Chlorobenzenesulfonyl group, 2,5-dichlorobenzenesulfonyl group, 2,4,5-trichlorobenzenesulfonyl group, 1
-Naphthalenesulfonyl group, 2-naphthalenesulfonyl group, quinolinesulfonyl group, thiophenesulfonyl group,

Acetyl group, propionyl group, butyryl group, pivaloyl group, lauroyl group, stearoyl group, benzoyl group, cinnamoyl group, furoyl group, nicotinoyl group, methoxycarbonyl group, ethoxycarbonyl group,
Phenoxycarbonyl group, hexylaminocarbonyl group, phenylaminocarbonyl group, diphenylphosphoryl group, diethylphosphoryl group, 2-nitrobenzyl group,
3,5-dimethoxybenzyl group, 3,4,5-trimethoxybenzyl group, trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group, diethylisopropylsilyl group, dimethylphenylsilyl group, diphenylmethylsilyl group, triphenyl Examples thereof include a silyl group, and examples of the divalent group include the following.

[0024]

[Chemical 4]

When A is —SiR ₄ R ₅ R _6, a photoacid generator such as an ammonium salt, a diazonium salt, an iodonium salt, a sulfonium salt, a phosphonium salt or an onium salt is used in combination for improving photoreactivity. Good. Specific examples of these photoacid generators are described in detail in "Organic materials for imaging" (edited by Organic Electronics Material Research Group, 1993).

Specific examples of the compound represented by the general formula 1 of the present invention are shown below, but the present invention is not limited thereto.
Further, these compounds may be used either individually or as a mixture of two or more kinds.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

[Chemical 5]

The compound represented by the general formula 1 of the present invention does not absorb the fixing light when fixing the heat-sensitive recording material, but further absorbs long-wave ultraviolet rays by being irradiated with light after the image is formed, thereby forming an image. The light stability can be improved.

In the heat-sensitive recording material containing the compound represented by the general formula 1 of the present invention, (1) a method of using it as a solid dispersion, (2) a method of using it as an emulsion dispersion, and (3) a polymer dispersion And (4) latex-dispersed method, (5) microencapsulated method, and the like. Among them, microcapsulated method is particularly preferable.

The compound represented by the general formula 1 of the present invention can be contained in any of the undercoat layer, the heat-sensitive recording layer, the intermediate layer and the protective layer, but it is particularly preferably contained in the protective layer. The content of the compound of formula 1 is 0.05 to 3.0.
It is preferably g / m ² , and more preferably 0.
1 to 2.0 g / m ²

As a method of emulsifying and dispersing, the compound represented by the general formula 1 is first dissolved in oil. This oil may be solid or liquid at room temperature, or may be a polymer. Low boiling auxiliary solvent such as acetic acid ester, methylene chloride, cyclohexanone and / or phosphoric acid ester, phthalic acid ester, acrylic acid ester, methacrylic acid ester, other carboxylic acid ester, fatty acid amide, alkylated biphenyl, alkylated terphenyl , Alkylated naphthalene, diarylethane, chlorinated paraffin,
Examples thereof include alcohol-based, phenol-based, ether-based, mono-olefin-based, epoxy-based and the like. Specific examples include tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, tricyclohexyl phosphate, dibutyl phthalate, dioctyl phthalate, dilaurate phthalate, dicyclohexyl phthalate, butyl oleate,
Diethylene glycol benzoate, dioctyl sebacate, dibutyl sebacate, dioctyl adipate, trioctyl trimetate, acetyltriethyl citrate, octyl maleate, dibutyl maleate, isoamylbiphenyl, chlorinated paraffin, diisopropylnaphthalene, 1,1′-ditolylethane, 2 , 4-ditertiary amylphenol, N, N-dibutyl-2-butoxy-5-tert-aryoctylaniline, hydroxybenzoic acid 2-ethylhexyl ester, polyethylene glycol, and other high-boiling oils are mentioned. , Phosphoric acid ester type, carboxylic acid ester type, alkylated biphenyl, alkylated terphenyl, alkylated naphthalene, and diarylethane are preferable. Further, an antioxidant such as hindered phenol or hindered amine may be added to the high boiling point oil.

The oil solution containing the compound of the above general formula 1 is added to an aqueous solution of a water-soluble polymer and emulsified and dispersed by a colloid mill, a homogenizer or ultrasonic waves. As the water-soluble polymer used at that time, a water-soluble polymer such as polyvinyl alcohol is used, but an emulsion or latex of a hydrophobic polymer can also be used together. As the water-soluble polymer, polyvinyl alcohol,
Silanol modified polyvinyl alcohol, carboxy modified polyvinyl alcohol, styrene-maleic anhydride copolymer, butadiene maleic anhydride copolymer, ethylene maleic anhydride copolymer, isobutylene maleic anhydride copolymer, polyacrylamide, polystyrene sulfonic acid, polyvinyl Examples thereof include pyrrolidone, ethylene-acrylic acid copolymer, gelatin and the like. Among these, polyvinyl alcohol and gelatin are particularly preferable. Examples of the emulsion or latex of the hydrophobic polymer include styrene-butadiene copolymer, carboxy-modified styrene-butadiene copolymer, acrylonitrile-butadiene copolymer and the like. At this time, a conventionally known surfactant or the like may be added if necessary.

As a method of microencapsulation, a conventionally known method of microcapsule can be used.
That is, the compound of the general formula 1 and the microcapsule wall precursor are dissolved in a water-insoluble or insoluble organic solvent, added to an aqueous solution of a water-soluble polymer, emulsified and dispersed using a homogenizer, and the temperature is raised. Thus, a polymer substance that becomes a microcapsule wall can be prepared by forming a wall film at the oil / water interface. Specific examples of the polymeric substance that becomes the wall film of the microcapsule include, for example, polyurethane resin, polyurea resin, polyamide resin, polyester resin, polycarbonate resin, aminoaldehyde resin, melamine resin, polystyrene resin, styrene-acrylate copolymer resin, Examples thereof include styrene-methacrylate copolymer resin, gelatin, polyvinyl alcohol and the like. Among these, a particularly preferable wall agent is a microcapsule having a wall film made of polyurethane / polyurea resin.

A microcapsule having a wall film made of a polyurethane / polyurea resin is prepared by mixing a microcapsule wall precursor such as polyisocyanate with a core substance to be encapsulated and emulsifying it in an aqueous solution of a water-soluble polymer such as polyvinyl alcohol. It is manufactured by dispersing and raising the liquid temperature to cause a polymer formation reaction at the oil drop interface.

Here, some of the specific examples of the polyvalent isocyanate compound are shown below. For example, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-
Tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,
3'-diphenylmethane-4,4'-diisocyanate, xylene-1,4-diisocyanate, 4,4'-
Diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,
Diisocyanates such as 2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, 4,4 ′, 4 ″ -triphenylmethane triisocyanate, toluene-2,
Triisocyanates such as 4,6-triisocyanate, 4,4′-dimethyldiphenylmethane-2,2 ′,
Tetraisocyanates such as 5,5′-tetraisocyanate, adducts of hexamethylene diisocyanate and trimethylolpropane, adducts of 2,4-tolylene diisocyanate and trimethylolpropane, xylylene diisocyanate and trimethylolpropane Examples thereof include adducts, isocyanate prepolymers such as adducts of tolylene diisocyanate and hexanetriol, and the like. If necessary, two or more types can be used in combination. Of these, particularly preferred are those having three or more isocyanate groups in the molecule.

In the method of microencapsulation, the oil shown in the emulsified dispersion can be used as the organic solvent in which the compound represented by the general formula 1 is dissolved. The same applies to water-soluble polymers.

The particle size of the microcapsules is 0.1 to 1.0.
μm is preferable, and more preferably 0.2 to 0.7 μm.

In the present invention, a compound known as a reducing agent can be used together with the compound of the general formula 1 in order to further reduce the coloration during photobleaching. This reducing agent may be inside or outside the microcapsules when the microcapsules are used. When the reducing agent is outside the microcapsules, the reducing agent enters into the microcapsules when printed by heating. As these additives, hydroquinone compounds, hydrazide compounds, hydroxy compounds, phenidone compounds, catechol compounds, resorcinol compounds, hydroxyhydroquinone compounds, pyrologricinol compounds,
Phenolic compounds, phenylhydrazide compounds, gallic acid compounds, ascorbic acid compounds, ethylene glycol compounds and the like can be mentioned. Regarding these, JP-A-3-191341 and JP-A-3-25434.
Japanese Patent Laid-Open No. 1-252953, Japanese Patent Laid-Open No. 2-35
No. 02753, Japanese Patent Application Laid-Open No. 1-129247, Japanese Patent Application Laid-Open No. 1-2227145, Japanese Patent Application Laid-Open No. 1-243048.
Japanese Patent Laid-Open No. 2-262649 and the like. Specifically, N-phenylacetohydrazide,
In addition to N-phenylbutyryl hydrazide, p-t-butylphenol, 2-azidobenzoxazole, the following compounds may be mentioned.

[0042]

[Chemical 6]

In the present invention, as the color-forming component used in the heat-sensitive recording layer, conventionally known ones can be used, but those utilizing the reaction of a diazonium salt compound and a coupler, or an electron-donating colorless dye and an electron-accepting property. Those utilizing the reaction with the compound are preferable, and those utilizing the reaction between the diazonium salt compound and the coupler are particularly preferable.

The compound used in the heat-sensitive recording layer containing the diazonium salt compound used in the present invention and the coupler that reacts with the diazonium salt compound to produce a color when reacted with the diazonium salt compound or the diazonium salt compound. Examples thereof include couplers capable of forming dyes and basic substances that accelerate the reaction between the diazonium salt compound and the coupler. The diazonium salt compound is a compound represented below, and these can control the maximum absorption wavelength depending on the position and type of the substituent of the Ar moiety.

[0045]

[Chemical 7]

Ar represents an aryl group and X ⁻ represents an acid anion.

Specific examples of the diazonium salt compound in the present invention include 4- (N- (2- (2,4-di-
tert-amylphenoxy) butyryl) piperazino)
Benzenediazonium, 4-dioctylaminobenzenediazonium, 4- (N- (2-ethylhexanoyl))
Piperazino) benzenediazonium, 4-dihexylamino-2-hexyloxybenzenediazonium, 4-
N-ethyl-N-hexadecylamino-2-ethoxybenzodiazonium, 3-chloro-4-dioctylamino-2-octyloxyobenzenediazonium, 2,5
-Dibutoxy-4-morpholinobenzenediazonium,
2,5-octoxy-4-morpholinobenzenediazonium, 2,5-dibutoxy-4- (N- (2-ethylhexanoyl) piperazino) benzenediazonium, 2,
5-diethoxy-4- (N- (2- (2,4-di-te
rt-amylphenoxy) butyryl) piperazino) benzenediazonium, 2,5-dibutoxy-4-tolylthiobenzenediazonium, 3- (2-octyloxyethoxy) -4-morpholinobenzenediazonium and other acid anion salts and Diazonium salt compound D-1
~ 5. Particularly, hexafluorophosphate salt, tetrafluoroborate salt and 1,5-naphthalene sulfonate salt are preferable.

[0048]

[Chemical 8]

Of these diazonium salt compounds, compounds particularly preferable in the present invention are 300 to 400.
4- (N- (2-
(2,4-di-tert-amylphenoxy) butyryl) piperazino) benzenediazonium, 4-dioctylaminobenzenediazonium, 4- (N- (2-ethylhexanoyl) piperazino) benzenediazonium,
4-dihexylamino-2-hexyloxybenzenediazonium, 4-N-ethyl-N-hexadecylamino-2-ethoxybenzodiazonium, 2,5-dibutoxy-4- (N- (2-ethylhexanoyl) piperazino) Benzenediazonium, 2,5-diethoxy-4-
(N- (2- (2,4-di-tert-amylphenoxy) butyryl) piperazino) benzenediazonium and the compounds shown in the above specific examples D-3 to 5 can be mentioned. The maximum absorption wavelength of the diazonium salt compound referred to herein is a spectrophotometer (Shimazu MPS-200) obtained by coating each compound with a coating film of 0.1 g / m ² to 1.0 g / m ^2.
0).

The couplers used in the present invention which react with the above-mentioned diazonium salt under heat to give a color are resorcin, flurglucin, and 2,3-dihydroxynaphthalene-6-.
Sodium sulfonate, 1-hydroxy-2-naphthoic acid morpholinopropylamide, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-
Dihydroxy-6-sulfanylnaphthalene, 2-hydroxy-3-naphthoic acid anilide, 2-hydroxy-3
-Naphthoic acid ethanolamide, 2-hydroxy-3-
Naphthoic acid octylamide, 2-hydroxy-3-naphthoic acid-N-dodecyloxypurupyramide, 2-hydroxy-3-naphthoic acid tetradecylamide, acetanilide, acetoacetanilide, benzoylacetanilide, 2-chloro-5-octylacetate Acetanilide, 1-phenyl-3-methyl-5-pyrazolone, 1-
(2'-octylphenyl) -3-methyl-5-pyrazolone, 1- (2 ', 4', 6'-trichlorophenyl)
-3-benzamido-5-pyrazolone, 1- (2 ',
4 ', 6'-trichlorophenyl) -3-anilino-5
-Pyralone, 1-phenyl-3-phenylacetamido-5-pyrazolone, and the compounds of C-1 to 6 shown below. Two or more of these couplers may be used in combination to obtain a desired color hue.

[0051]

[Chemical 9]

The basic substance includes not only inorganic or organic basic compounds but also compounds capable of decomposing upon heating and releasing an alkaline substance. Representative examples include organic ammonium salts, organic amines, amides, urea and thiourea and their derivatives, thiazoles, pyrroles, pyrimidines, piperazines, guanidines, indoles, imidazoles, imidazolines,
Examples thereof include nitrogen-containing compounds such as triazoles, morpholines, piperidines, amidines, formazines and pyridines. Specific examples of these include tricyclohexylamine, tribenzylamine, octadecylbenzylamine, stearylamine, allylurea, thiourea,
Methylthiourea, allylthiourea, ethylenethiourea,
2-benzylimidazole, 4-phenylimidazole, 2-phenyl-4-methylimidazole, 2-undecylimidazoline, 2,4,5-trifuryl-2-imidazoline, 1,2-diphenyl-4,4-dimethyl-
2-imidazoline, 2-phenyl-2-imidazoline,
1,2,3-triphenylguanidine, 1,2-dicyclohexylguanidine, 1,2,3-tricyclohexylguanidine, guanidine trichloroacetate, N, N '
-Dibenzylpiperazine, 4,4'-dithiomorpholine, morpholinium trichloroacetate, 2-aminobenzothiazole, 2-benzoylhydrazinobenzothiazole and the like. These can be used in combination of two or more.

Examples of the electron-donating dye precursor used in the present invention include triarylmethane compounds, diphenylmethane compounds, thiazine compounds, xanthene compounds,
Examples thereof include spiropyran compounds, and particularly triarylmethane compounds and xanthene compounds are useful because of their high color density. Some examples of these are 3,3
-Bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (that is, crystal violet lactone), 3,3-bis (p-dimethylamino) phthalide,
3- (p-dimethylaminophenyl) -3- (1,3-
Dimethylindol-3-yl) phthalide, 3- (p-
Dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (o-methyl-p-diethylaminophenyl) -3- (2-methylindole-
3-yl) phthalide, 4,4′-bis (dimethylamino) benzhydrin benzyl ether, N-halophenyl leuco auramine, N-2,4,5-trichlorophenyl leuco auramine, rhodamine-B-anilino Lactam, Rhodamine (p-nitroanilino) lactam, Rhodamine-B- (p-chloroanilino) lactam, 2-
Benzylamino-6-diethylaminofluorane, 2-
Anilino-6-diethylaminofluorane, 2-anilino-3-methyl-6-diethylaminofluorane, 2-
Anilino-3-methyl-6-cyclohexylmethylaminofluorane, 2-anilino-3-methyl-6-isoamylethylaminofluorane, 2- (o-chloroanilino) -6-diethylaminofluorane, 2-octylamino-6 -Diethylaminofluorane, 2-ethoxyethylamino-3-chloro-2-diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, benzoyl leuco methylene blue, p-nitrobenzyl leuco methylene blue, 3-methyl- Spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3'-dichloro-spiro-dinaphthopyran, 3
-Benzylspirodinaphthopyran, 3-propyl-spiro-dibenzopyran and the like can be mentioned.

Examples of the electron accepting compound include phenol derivatives, salicylic acid derivatives, hydroxybenzoic acid esters and the like. Particularly, bisphenols and hydroxybenzoic acid esters are preferable. Examples of some of these include 2,2-bis (p-hydroxyphenyl) propane (ie, bisphenol A), 4,4 ′-(p-phenylenediisopropylidene) diphenol (ie, bisphenol P), 2,2-bis (p-hydroxyphenyl) pentane, 2,2-bis (p-hydroxyphenyl) ethane, 2,2-bis (p-hydroxyphenyl)
Butane, 2,2-bis (4'-hydroxy-3 ', 5'
-Dichlorophenyl) propane, 1,1- (p-hydroxyphenyl) cyclohexane, 1,1- (p-hydroxyphenyl) propane, 1,1- (p-hydroxyphenyl) pentane, 1,1- (p-hydroxyphenyl) ) -2-Ethylhexane, 3,5-di (α-methylbenzyl) salicylic acid and its polyvalent metal salt, 3,5-di (tert-butyl) salicylic acid and its polyvalent metal salt, 3-α, α- Dimethylbenzyl salicylic acid and its polyvalent metal salts, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-hydroxybenzoic acid-
2-ethylhexyl, p-phenylphenol, p-cumylphenol and the like can be mentioned.

As the sensitizer, a low melting point organic compound having an aromatic group and a polar group in the molecule is preferable,
Benzyl p-benzyloxybenzoate, α-naphthylbenzyl ether, β-naphthylbenzyl ether, β-
Naphthoic acid phenyl ester, α-hydroxy-β-naphthoic acid phenyl ester, β-naphthol- (p-chlorobenzyl) ether, 1,4-butanediol phenyl ether, 1,4-butanediol-p-methylphenyl ether, 1,4-butanediol-p-ethylphenyl ether, 1,4-butanediol-m-methylphenyl ether, 1-phenoxy-2- (p-tolyloxy) ethane, 1-phenoxy-2- (p-ethylphenoxy ) Ethane, 1-phenoxy-2- (p-chlorophenoxy) ethane, p-benzylbiphenyl and the like.

In the present invention, the above-mentioned diazonium salt compound, a coupler which reacts with the diazonium salt compound under heat to develop a color, a basic substance, and an electron-donating colorless dye, an electron-accepting compound, and a sensitizer are used. Is not particularly limited. That is, as in the case of the compound of general formula 1,
(1) a method of dispersing and using a solid, (2) a method of dispersing and using an emulsion, (3) a method of dispersing and using a polymer,
(4) A method in which latex is dispersed and used, (5) Method in which microcapsule is used, and the like. Among them, a method in which microcapsule is used is preferable from the viewpoint of preservability, and a diazonium salt compound is particularly preferable. In the color development system that utilizes the reaction between a dye and a coupler, the diazonium salt compound is microencapsulated.In the color development system that utilizes the reaction between an electron-donating colorless dye and an electron-accepting compound, the electron-donating colorless dye is microencapsulated. Is preferred.

In the present invention, the thermosensitive recording layers described above may be laminated, and a multicolor thermosensitive recording material can be obtained by changing the hue of each thermosensitive recording layer. Although the layer structure is not particularly limited, it is particularly preferable that the layer having a different photosensitive wavelength is used.
Two thermosensitive recording layers in which a diazonium salt compound of each species and a coupler that reacts with each diazonium salt compound to develop a different hue when heated are combined, and a thermosensitive recording in which an electron-donating colorless dye and an electron-accepting compound are combined. A multicolor thermosensitive recording material in which layers are laminated is preferred. That is, the first containing the electron-donating colorless dye and the electron-accepting compound on the support
A heat-sensitive recording layer, a second heat-sensitive recording layer containing a diazonium salt compound having a maximum absorption wavelength of 360 ± 20 nm and a coupler that reacts with the diazonium salt compound to produce a color, and a maximum absorption wavelength of 400 ± 20 nm The third heat-sensitive recording layer contains a diazonium salt compound and a coupler that reacts with the diazonium salt compound to produce a color when heated. In this example, full-color image recording is possible by selecting the hues of the heat-sensitive recording layers to be the three primary colors in subtractive color mixing, yellow, magenta, and cyan.

In the recording method of this multicolor heat-sensitive recording material, first, the third heat-sensitive recording layer is heated to cause the diazonium salt compound and the coupler contained in the layer to develop color. Next 400 ± 20
nm light to decompose the unreacted diazonium salt compound contained in the third thermosensitive recording layer, and then the second
Sufficient heat is applied to the thermosensitive recording layer to develop a color, whereby the diazonium salt compound and the coupler contained in the layer are developed. At this time, the third thermosensitive recording layer is also strongly heated at the same time, but the diazonium salt compound has already been decomposed and the coloring ability is lost, so that no color is produced. Further 360 ± 20
nm light is irradiated to decompose the diazonium salt compound contained in the second thermosensitive recording layer, and finally, sufficient heat for coloring the first thermosensitive recording layer is applied to develop the color. At this time, the third and second thermosensitive recording layers are also strongly heated at the same time, but the diazonium salt compound has already decomposed and the coloring ability has been lost, so that no coloring occurs.

In the present invention, in order to further improve the light resistance, the following known antioxidants can be used. For example, European Patent Publication No. 310551,
German Published Patent No. 3435443, European Published Patent No. 310552, JP-A-3-121449.
Japanese Patent Publication, European Patent Publication No. 459416, Japanese Patent Laid-Open No. 2-262654, Japanese Patent Laid-Open No. 2-71262, Japanese Patent Laid-Open No. 63-163351, US Pat. No. 4,814,262, Japanese Patent Laid-Open No. 54-48535. ,
JP-A-5-61166, JP-A-5-119449
U.S. Pat. No. 4,980,275, JP-A-63
-113536, Japanese Patent Laid-Open No. 62-262047, European Patent No. 223739, European Patent No. 309402, European Patent No. 309401, and the like.
Specific examples include the following.

[0060]

[Chemical 10]

[0061]

[Chemical 11]

[0062]

[Chemical 12]

It is also effective to use various additives already known as heat-sensitive recording materials and pressure-sensitive recording materials. If some of these antioxidants are shown, they are disclosed in JP-A-60-12.
5470, JP-A-60-125471, JP-A-60-125472, and JP-A-60-2874.
85, JP-A-60-287486, JP-A-60-287487, and JP-A-62-146680.
JP, JP-A-60-287488, JP-A-62.
-282885, JP-A-63-89877, JP-A-63-88380, and JP-A-63-08
8381, Japanese Patent Application Laid-Open No. 01-239282, Japanese Patent Application Laid-Open No. 04-291685, Japanese Patent Application Laid-Open No. 04-2916
84, JP 05-1888687, JP 05-188686, and JP 05-110490.
Japanese Patent Laid-Open No. 05-1108437 and Japanese Patent Laid-Open No.
5-170361, JP-A-63-203372, JP-A-63-224989, JP-A-63-267594, JP-A-63-182484, JP-A-60-107384. , JP-A-60-1
No. 07383, JP-A-61-160287,
JP-A-61-184583, JP-A-61-211
079, JP-A-63-251482, JP-A-63-051174, JP-B-48-04329.
Examples thereof include compounds described in JP-A No. 4 and JP-B-48-033212.

Specific examples include 6-ethoxy-1-phenyl-
2,2,4-trimethyl-1,2-dihydroquinoline,
6-ethoxy-1-octyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, 6-ethoxy-1-octyl-2,
2,4-trimethyl-1,2,3,4-tetrahydroquinoline, nickel cyclohexanoate, 2,2-bis-4
-Hydroxyphenylpropane, 1,1-bis-4-hydroxyphenyl-2-ethylhexane, 2-methyl-
4-methoxy-diphenylamine, 1-methyl-2-phenylindole, and the compounds shown below can be given.

[0065]

[Chemical 13]

[0066]

[Chemical 14]

[0067]

[Chemical 15]

[0068]

[Chemical 16]

These antioxidants can be added to the heat-sensitive recording layer, the intermediate layer or the protective layer. When these antioxidants are used in combination, for example, specific examples (Q
-7), (Q-45), (Q-46) or the compound (Q
-10) and the compound (Q-13) in combination.

As the binder in the present invention, conventionally known binders can be used, and examples thereof include water-soluble polymers such as polyvinyl alcohol and gelatin, and polymer latex. As the support in the present invention, plastic film, paper, plastic resin laminated paper, synthetic paper, or the like can be used.

In the present invention, when heat-sensitive color-developing layers having different hues are laminated, an intermediate layer can be provided to prevent color mixing. A water-soluble polymer compound is used for the intermediate layer. Examples thereof include polyvinyl alcohol, modified polyvinyl alcohol, methyl cellulose, sodium polystyrene sulfonate, styrene-maleic acid copolymer, gelatin and the like.

In the protective layer in the present invention, various pigments, releasing agents and the like can be added in addition to the same water-soluble polymer compound as in the intermediate layer.

[0073]

EXAMPLES All "parts" in the examples represent parts by weight. The reflection density was measured using a reflection density meter RD918 manufactured by Macbeth. The photo-fixing property of the diazo heat-sensitive recording layer was evaluated by confirming that after the fixing operation by irradiation of light for a predetermined time, heat of 86 mJ / mm ² was applied again to the non-printed part and no color was developed (that is, it was fixed). Was done. Light resistance is evaluated by WEATHER OMETER CI 65 (ATLAS ELECTRIC DEVICES
(Manufactured by CO 2) was irradiated with 0.9 W / m ² for 48 hours. The evaluation was performed by the reflection density (yellow component) in the non-printed area. In the image section,
Remaining rate of image area (%) = [(reflection density after fluorescent lamp irradiation)
/ (Reflection density before fluorescent lamp irradiation)] × 100, the residual rate of the dye in the image area was obtained and evaluated.

[Example-1] [Preparation of coating liquid for protective layer containing compound of general formula 1] 5.3 parts of the compound shown in the specific example (3) is shown in 6.6 parts of ethyl acetate and A-1. It was mixed with 2.9 parts of a phthalate ester solvent. Xylylene diisocyanate / trimethylolpropane adduct (75% ethyl acetate solution Takenate D110N: trade name of Takeda Pharmaceutical Co., Ltd.) as a capsule wall material 2.0
Parts were further added to this solution and stirred so as to be uniform. Separately, 60 parts of a 10% by weight aqueous solution of polyvinyl alcohol (PVA217E: trade name of Kuraray Co., Ltd.) to which 3.2 parts of a 10% by weight sodium dodecylsulfonate aqueous solution was added was prepared, and the above solution was added and emulsified and dispersed by a homogenizer. The obtained emulsion was heated to 50 ° C. with stirring and the encapsulation reaction was carried out for 3 hours to obtain a target capsule liquid. The average particle size of the capsule was 0.2 μm. To 13 parts of this capsule solution, 50 parts of ion-exchanged water was added and uniformly stirred to prepare a target coating solution.

[0075]

[Chemical 17]

[Preparation of Thermosensitive Recording Layer Liquid] (Preparation of Diazonium Salt Compound Capsule Liquid) 2.8 parts of a compound represented by a-1 having a maximum absorption wavelength of decomposition at 365 nm as a diazonium salt compound, dibutyl sulfate 2.8.
Part, 2,2-dimethoxy-1,2-diphenylethane-
0.56 parts of 1-one (Irgacure 651: trade name of Ciba Geigy) was dissolved in 19.0 parts of ethyl acetate. Furthermore, 5.9 parts of isopropyl biphenyl, which is a high-boiling point solvent, and 2.5 parts of tricresyl phosphate were added to the above liquid, and heated to uniformly mix. As a capsule wall agent, xylylene diisocyanate / trimethylolpropane adduct (75% ethyl acetate solution Takenate D11)
7.6 parts (0N: trade name of Takeda Pharmaceutical Co., Ltd.) was further added to this solution and stirred uniformly. Separately, 64 parts of a 6% by weight gelatin (MGP-9066: trade name of Nippi Gelatin Co., Ltd.) aqueous solution containing 2.0 parts of 10% by weight sodium dodecylsulfonate aqueous solution was prepared, and the above diazonium salt compound solution was added. , Which was emulsified and dispersed by a homogenizer. After 20 parts of water was added to the obtained emulsion to homogenize it, the temperature was raised to 40 ° C. with stirring and the encapsulation reaction was carried out for 3 hours. After that, the liquid temperature is lowered to 35 ° C., 6.5 parts of an ion exchange resin Amberlite IRA68 (manufactured by Organo) and 13 parts of Amberlite IRC50 (manufactured by Organo) are added, and the mixture is further stirred for 1 hour. Then, the ion exchange resin was filtered to obtain the target capsule liquid. The average particle size of the capsule is 0.64
was μm.

[0077]

[Chemical 18]

(Preparation of Coupler Emulsion Dispersion) As a coupler, 3.0 parts of compound b-1 shown below, 4.0 parts of triphenylguanidine and 1,1- (p-hydroxyphenyl) -2-ethylhexane were used. 4.0 parts, 4,4 '-(p
-Phenylene diisopropylidene) diphenol
0 part, 2-ethylhexyl-4-hydroxybenzoate 8.0 parts, b-2 as an antioxidant 2.0 parts,
1,1,3-tris (2-methyl-4-hydroxy-5)
2.0 parts of -t-butylphenyl) butane was dissolved in 10.5 parts of ethyl acetate, and 0.48 parts of tricresyl phosphate as a high boiling point solvent, 0.24 parts of diethyl maleate,
1.27 parts of Pionein A41C (manufactured by Takemoto Yushi Co., Ltd.) was added and then heated and mixed uniformly. Separately, it was added to 93 parts of an aqueous solution of 8% by weight gelatin (# 750 gelatin: trade name of Nitta Gelatin Co., Ltd.) and emulsified and dispersed by a homogenizer. The remaining ethyl acetate was evaporated from this emulsion to obtain the target emulsion dispersion. (Preparation of coating liquid) The above-mentioned diazonium salt compound capsule liquid, coupler emulsion dispersion, and styrene-butadiene rubber (trade name SBR: SN307 manufactured by Sumitomo Nogatak Co., Ltd.)
Were mixed so that the ratio of the diazonium salt compound / coupler would be 1/2 and the ratio of the diazonium salt compound / styrene-butadiene rubber would be 1 / 6.4 to prepare the desired coating liquid. .

[0079]

[Chemical 19]

[Preparation of Protective Layer] 20.5% by weight zinc stearate dispersion liquid (Hydrin F115: in a 5.0 parts by weight itaconic acid-modified polyvinyl alcohol (KL-318: Kuraray Co., Ltd. trade name) aqueous solution). 2.0 parts by weight of Chukyo Yushi Co., Ltd.) was added, 8.4 parts of a 2% by weight aqueous solution of the compound represented by c-1, and a fluorine-based release agent ME
313 (manufactured by Daikin) and 8.0 parts of wheat starch KF-4 (manufactured by Kagoshima Starch) were added and stirred uniformly. This is called mother liquor. Separately, ion-exchanged 20% by weight aqueous solution of chaogros (Shiraishi Industry Co., Ltd.) 1
2.5 parts, Poise 532A (manufactured by Kao) 0.06 parts, Hydrin Z-7 (manufactured by Chukyo Yushi Co., Ltd.) 1.87 parts, 10% by weight polyvinyl alcohol (PVA105: trade name of Kuraray Co., Ltd.) 1.25 parts 0.39 parts of a 2% by weight sodium dodecyl sulfonate aqueous solution were mixed and finely dispersed with Dynomill. This liquid is called a pigment liquid. To 80 parts of the above mother liquor, 4.4 parts of the pigment liquid is added and stirred for 30 minutes or more. After that, Wetmaster 500 (manufactured by Toho Chemical Co., Ltd.) 2.
8 parts was added and further stirred for 30 minutes or more to obtain the desired coating liquid.

[0081]

[Chemical 20]

[Preparation of Thermosensitive Recording Material] A thermal recording layer, a protective layer containing the compound of the general formula 1 and a protective layer were sequentially coated and dried with a Meyer bar on a photographic paper support obtained by laminating polyethylene on high-quality paper. The desired thermosensitive recording material was obtained. The coating amount as solid content is 8.3 each per 1 m ^2.
It was 3 g, 2.50 g, and 1.23 g. (Thermal recording) Using Kyocera thermal head KST type,
(1) Recording energy per unit area is 62 mJ / m
The power applied to the thermal head and the pulse width were determined so as to be m ^2, and when the thermosensitive recording material was printed, it developed a magenta color. Then, this heat-sensitive recording material was exposed and fixed under an ultraviolet lamp having an emission center wavelength of 365 nm and an output of 40 W for 15 seconds.

Example-2 Similar to Example 1 except that the compound of Example (23) was used in place of Example (3) and tricresyl phosphate was used in place of A-1. A thermosensitive recording material was prepared and evaluated.

Example 3 General formula 1 in Example 1
A thermal recording material was prepared and evaluated in the same manner as in Example 1 except that the compound-containing protective layer of 2 was replaced with the following.

(Preparation of Emulsion Dispersion for Protective Layer Containing Compound of General Formula 1) 5.3 parts of the compound shown in the specific example (21) were combined with 6.6 parts of ethyl acetate and 2.9 parts of the compound shown in A-1. Mixed. Separately, prepare 83 parts of a 12% by weight gelatin (# 750 gelatin: trade name of Nitta Gelatin Co., Ltd.) aqueous solution to which 8.4 parts of 10% sodium dodecylsulfonate aqueous solution has been added, and add the solution of the previous specific example (21). It was emulsified and dispersed with a homogenizer. This prepared emulsion dispersion 3
7.5 parts of 2.5% by weight gelatin (# 750) to which 4.2 parts of 10% sodium dodecyl sulfonate aqueous solution was added.
Gelatin: trade name of Nitta Gelatin Co., Ltd.) was added to 133 parts of an aqueous solution and uniformly stirred to obtain a desired coating solution.

Example 4 In Example 2, except that 5.3 parts of the specific example (7) was used in place of the specific example (23) and 1.3 parts of the compound (R-6) was used as a reducing agent. In the same manner as in Example 2, a thermal recording material was prepared and evaluated.

[Example-5] In Example 1, between the support and the diazo heat-sensitive recording layer (hereinafter referred to as heat-sensitive recording layer A), the following leuco-type heat-sensitive recording layer B and these two heat-sensitive recording layers were formed. Example 1 except that the intermediate layer 1 was provided therebetween and the compound of the specific example (40) was used in place of the compound of the specific example (3).
Thermal recording materials were prepared and evaluated in the same manner as in.

[Preparation of Liquid B for Thermal Recording Layer] (Preparation of Capsule Liquid for Electron-Donating Dye Precursor) 3- (o-methyl-p-diethylaminophenyl) -3- (1- 0.39 parts of ethyl-2-methylindol-3-yl) -4-azaphthalide, 2-
Hydroxy-4-methoxybenzophenone 0.19 parts,
2,5-tert-octylhydroquinone 0.29
Parts, 0.27 parts of the compound of b-2 were dissolved in 0.93 parts of ethyl acetate, 0.54 parts of phenethylcumene as a high boiling point solvent was further added, and the mixture was heated and uniformly mixed. As a capsule wall agent, 1.0 part of a xylylene diisocyanate / trimethylolpropane adduct (75 wt% ethyl acetate solution: Takenate D110N: trade name of Takeda Pharmaceutical Co., Ltd.) was further added to this solution and stirred uniformly.

Separately, 6% by weight of gelatin (MG was added with 0.07 part of 10% sodium dodecylsulfonate aqueous solution).
P-9066: 36.4 parts of an aqueous solution (trade name of Nippi Gelatin Industry Co., Ltd.) was prepared, the above electron-donating dye precursor solution was added, and the mixture was emulsified and dispersed by a homogenizer. The emulsion dispersion thus obtained will be referred to as a primary emulsion dispersion. Separately 3- (o-methyl-p-diethylaminophenyl) -3- (1-ethyl-2-methylindole-3
-Yl) -4-azaphthalide (6.0 parts), 2-hydroxy-4-methoxybenzophenone (3.0 parts), 2,5-t
In a solution obtained by dissolving 4.4 parts of ert-octylhydroquinone in 14.4 parts of ethyl acetate and further adding 8.4 parts of phenethylcumene which is a high boiling point solvent and stirring the mixture uniformly, the Takenate D110N used above was added. 8 parts and 5.9 parts of methylene diisocyanate (Millionate MR200: trade name of Nippon Polyurethane Company) were added and uniformly stirred.
The solution thus obtained and 1.2 parts of a 10% sodium dodecyl sulfonate aqueous solution were added to the above-described primary emulsified dispersion, and the mixture was emulsified and dispersed by a homogenizer. The liquid thus obtained will be referred to as a secondary emulsion dispersion. 60.0 parts of water and 0.4 parts of diethylenetriamine were added to this secondary emulsified dispersion liquid to homogenize the mixture, and then the mixture was stirred while stirring.
The temperature was raised to 5 ° C. and the encapsulation reaction was carried out for 3.5 hours to obtain the target capsule liquid. The average particle size of the capsules is 1.9μ
It was m.

(Preparation of Electron-Accepting Compound Dispersion) 30 parts of bisphenol P as an electron-accepting compound was gelatin (MGP-9066: trade name of Nippi Gelatin Industry Co., Ltd.).
2 wt% 2 added to 82.5 parts of 2.0 wt% aqueous solution
-Sodium ethylhexyl sulfosuccinate aqueous solution 7.
5 parts was added and dispersed by a ball mill for 24 hours to prepare a dispersion liquid. 15% by weight gelatin (# 75
0 Gelatin: trade name of Nitta Gelatin Co., Ltd.) Aqueous solution 36.0
Parts were added and stirred uniformly to obtain the desired dispersion. The average particle size of the electron-accepting compound in the dispersion was 0.5 μm. (Preparation of coating liquid) Next, the above-mentioned electron-donor dye precursor capsule liquid, electron-accepting compound dispersion liquid, 15 wt% gelatin (# 750 gelatin: trade name of Nitta Gelatin Co., Ltd.) aqueous solution, stilbene-based fluorescent whitening Each of the agents (Whitex-BB: trade name of Sumitomo Chemical Co., Ltd.) has an electron donating dye precursor / electron accepting compound ratio of 1/14, electron donating dye precursor / # 750 gelatin = 1.1 / 1. , And electron-donating dye precursor / fluorescent brightening agent = 5.3 / 1 were mixed to prepare a target coating solution. [Preparation of 1-liquid of intermediate layer] 8.2 parts of 4% by weight boric acid aqueous solution in 14% by weight gelatin (# 750 gelatin: trade name of Nitta Gelatin Co., Ltd.) aqueous solution, (4-nonylphenoxytrioxyethylene) butylsulfonic acid 1.2 parts of a 2% by weight aqueous solution of sodium and 7.5 parts of a 2% by weight aqueous solution of the compound shown in d-1 were added and uniformly stirred to prepare a target coating solution.

[0091]

[Chemical 21]

[Coating] On a photographic paper support obtained by laminating polyethylene on high-quality paper, the above-mentioned heat-sensitive recording layer B, intermediate layer 1, heat-sensitive recording layer A, a compound-containing protective layer of the general formula 1, and a protective layer were applied using a Meyer bar. The desired heat-sensitive recording material was obtained by sequentially applying and drying. The coating amount as solid content is 7.12 g, 3.28 g, 8.33 g, and 2.5 per 1 m ^2, respectively.
It was 0 g and 1.23 g. [Thermal recording] Kyocera thermal head KST type is used.
(1) Recording energy per unit area is 62 mJ / m
The electric power applied to the thermal head and the pulse width were determined so as to be m ^2, and the thermal recording material was printed. The recording material was exposed to an ultraviolet lamp with an emission center wavelength of 365 nm and an output of 40 W for 15 seconds, and (2) again, the applied power to the thermal head and the pulse width were determined so that the recording energy per unit area was 86 mJ / mm ² . The thermal recording material was printed. In the obtained recorded image, an image was obtained in which the portion where only (1) was recorded was colored magenta and the portion where only (2) was recorded was blue. Further, the portions where the recordings of (1) and (2) were duplicated were purple, and the unrecorded portions were gray-white.

Example-6 The following diazo color-forming heat-sensitive recording layer C was used, together with the diazo-type heat-sensitive recording layer A of Example 5 and the general formula 1.
Between the compound-containing protective layers, and the above-mentioned thermal recording layer C
A thermosensitive recording material was prepared and evaluated in the same manner as in Example 5 except that the intermediate layer 2 was provided between the thermosensitive recording layer A and the diazo thermosensitive layer A. [Preparation of Thermosensitive Recording Layer C] (Preparation of Diazonium Salt Compound Capsule Liquid) 3.5 parts of compound e-1 and 0.9 part of compound e-2 having a maximum absorption wavelength of decomposition at 420 nm as a diazonium salt compound. Was dissolved in 16.4 parts of ethyl acetate, 9.8 parts of isopropyl biphenyl as a high boiling point solvent was added, and the mixture was heated and uniformly mixed. As a capsule wall agent, xylylene diisocyanate / trimethylolpropane adduct (75
Wt% ethyl acetate solution: Takenate D110N: trade name of Takeda Pharmaceutical Co., Ltd.) 4.5 parts, and 4.2 parts of a 30 wt% ethyl acetate solution of xylylene diisocyanate / bisphenol A adduct were further added to this solution to homogenize. It was stirred.
Separately, Scrapph AG-8 (trade name of Nippon Seika Co., Ltd.)
77 parts of a 6% by weight aqueous gelatin solution containing 0.36 parts was prepared, the above diazonium salt compound solution was added, and the mixture was emulsified and dispersed by a homogenizer. 20 water is added to the obtained emulsion.
After adding parts and homogenizing, the encapsulation reaction was carried out for 3 hours while stirring at 40 ° C. After that, the liquid temperature is lowered to 35 ° C., 6.5 parts of an ion exchange resin Amberlite IRA68 (manufactured by Organo) and 13 parts of Amberlite IRC50 (manufactured by Organo) are added, and the mixture is further stirred for 1 hour. After that, the ion exchange resin is filtered, and 0.4 parts of a 1 wt% aqueous solution of hydroquinone is added to another part of the capsule solution, and the mixture is stirred. In this way, the target capsule liquid was obtained.
The average particle size of the capsule was 0.91 μm.

(Preparation of Coupler Dispersion) As a coupler, 2.4 parts of compound f-1 shown below and 2.5 parts of triphenylguanidine, 1,1- (p-hydroxyphenyl) were used.
2.5 parts of 2-ethylhexane and 3.6 parts of 4,4 '-(p-phenylenediisopropylidene) diphenol.
Parts, 3.2 parts of 2-ethylhexyl-4-hydroxybenzoate, 0.8 parts of f-2 were dissolved in 8.0 parts of ethyl acetate, and 1.0 part of pionein A41C (manufactured by Takemoto Yushi Co., Ltd.) was added. After heating, they were mixed uniformly. Separate gelatin (#
750 gelatin: manufactured by Nitta Gelatin Co., Ltd.) 10 weight aqueous solution 7
In addition to 5.0 parts, it was emulsified and dispersed by a homogenizer.
The remaining ethyl acetate was evaporated from this emulsion to obtain the target emulsion dispersion.

[0095]

[Chemical formula 22]

(Preparation of coating liquid) The above-mentioned diazonium salt compound capsule liquid, coupler emulsion dispersion, styrene-butadiene rubber (trade name SBR: SN307 Sumitomo Nogatac Co., Ltd. trade name) was used as the diazonium salt compound and the coupler ratio was 1. /3.2, and the weight of the styrene-butadiene rubber was mixed so as to be equal to the weight of gelatin of the coating liquid to prepare the target coating liquid.

[Preparation of Coating Solution for Intermediate Layer 2] 57 parts of a 13% aqueous gelatin solution was added to 0.4 parts of a 2% by weight aqueous solution of sodium (4-nonylphenoxytrioxyethylene) butyl sulfonate, and 2 parts of the compound shown in g-1. Wt% aqueous solution 8.3
Department, PVP-k15 (trade name of GAF Gokyo Sangyo Co., Ltd.) 2.
4 parts was added, and the mixture was uniformly stirred to prepare a desired coating liquid.

[0098]

[Chemical formula 23]

[Coating] Heat-sensitive recording layer B, intermediate layer 1, heat-sensitive recording layer A, intermediate layer 2, heat-sensitive recording layer C, general formula 1 on a photographic paper support obtained by laminating polyethylene on high-quality paper with a Meyer bar. The compound-containing protective layer and the protective layer were sequentially coated and dried to obtain the intended multicolor thermosensitive recording material. The coating amount as solid content is 7.12 g / m ² and 3.2, respectively.
8g, 8.33g, 3.13g, 8.06g, 2.50
g and 1.23 g. [Thermal recording] Kyocera thermal head KST type is used.
(1) Recording energy per unit area is 35 mJ / m
The electric power applied to the thermal head and the pulse width were determined so as to be m ² , the thermosensitive recording material was printed, and a yellow image was recorded. (2) Use the recording material with an emission center wavelength of 4
Irradiate for 10 seconds under a UV lamp of 20 nm and an output of 40 W, and (3) the recording energy per unit area is 66 again.
The applied power to the thermal head and the pulse width were determined so as to be mJ / mm ² , printing was performed, and a magenta image was recorded. Furthermore, (4) emission center wavelength 365 nm, output 4
Irradiation under a 0 W ultraviolet lamp for 15 seconds, (5) The applied power and pulse width to the thermal head were determined again so that the recording energy per unit area was 90 mJ / mm ^2, and printing was performed to record a cyan image. . As a result, in addition to the yellow, magenta, and cyan color-developed images, the recording area where the yellow and magenta recording overlap is red, the area where the magenta and cyan overlap is blue, and the area where the yellow and cyan overlap is green. And the image portion where the recordings of yellow, magenta, and cyan were overlapped developed black. The unrecorded area was gray white.

Example-7 The compound of the specific example (23) was replaced by the compound of A-1 in place of the specific example (40) in Example 6.
Example 6 except that tricresyl phosphate was used in place of
A thermal recording material was prepared and evaluated in the same manner as in.

Example-8 Example 6 was repeated except that the example (4) was used in place of the example (40) in the example 6 and 1.3 parts of the compound (R-12) was used as a reducing agent.
A thermal recording material was prepared and evaluated in the same manner as in.

Example-9 In Example 8, 3.3 parts of the compound of the specific example (25) and 2 parts of the compound of the specific example (26) were used in place of the specific example (4), and the compound of the reducing agent (R −
A thermal recording material was prepared and evaluated in the same manner as in Example 8 except that the compound (R-14) was used instead of 6).

Example-10 In Example 8, instead of the specific example (4), 0.75 parts of the specific example (1), 1.5 parts of the compound of the specific example (2), and the specific example (3). A heat-sensitive recording material was prepared and evaluated in the same manner as in Example 8 except that 3.0 parts of the compound of 1. was used.

Example-11 In Example 8, instead of the compound of Specific Example (4), the compound of Specific Example (3) 4.
A thermosensitive recording material was prepared and evaluated in the same manner as in Example 8 except that 0 part of the compound of Specific Example (22) was used in 2.3 parts.

Example-12 A thermosensitive recording material was prepared in the same manner as in Example 6 except that instead of using the intermediate layers 1 and 2 in Example 6, the following intermediate layer 3 was used. Created and evaluated. [Preparation of Liquid 3 of Intermediate Layer] Compound 1.1 shown in Specific Example (3)
The mixture was uniformly stirred with 0.7 part of ethyl acetate and 0.59 part of the phthalate ester solvent shown in A-1. To this solution, xylylene diisocyanate / trimethylol propane adduct (75 wt% ethyl acetate solution: Takenate D110)
N: 0.5 part of Takeda Pharmaceutical Co., Ltd.) is added, and the mixture is further stirred uniformly. Separately, 6% by weight of gelatin (MGP was added with 1.8 parts of 10% sodium dodecylsulfonate aqueous solution).
-9066: trade name of Nippi Gelatin Co., Ltd.) aqueous solution 36.
4 parts were prepared, the above-mentioned electron-donating dye precursor solution was added, and the mixture was emulsified and dispersed by a homogenizer. While stirring this emulsion dispersion at 40 ° C., the encapsulation reaction was carried out for 3 hours to obtain a target coating liquid. [Coating] Heat-sensitive recording layer B, intermediate layer 3, heat-sensitive recording layer A, intermediate layer 3, heat-sensitive recording layer C, general formula 1 on a photographic paper support obtained by laminating polyethylene on high-quality paper.
The compound-containing protective layer and the protective layer were sequentially coated and dried to obtain the intended multicolor thermosensitive recording material. The coating amount as solid content is 7.12 g, 4.58 g, and 8.3 per 1 m ^2, respectively.
It was 3 g, 4.57 g, 8.06 g, 1.23 g.

[Comparative Example-1] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 1 except that the compound of B-1 was used in place of the compound of Example (3).

Comparative Example-2 General formula 1 in Example 1
A thermal recording material was prepared and evaluated in the same manner as in Example 1 except that the compound-containing protective layer of 2 was not provided. The results are shown in Table 1 below.
Name it.

[Comparative Example-3] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 2 except that the compound of B-1 was used instead of the compound of Example (23).

[Comparative Example-4] The general formula 1 in Example 2 was used.
A thermal recording material was prepared and evaluated in the same manner as in Example 2 except that the compound-containing protective layer of 2 was not provided.

Comparative Example-5 A thermosensitive recording material was prepared and evaluated in the same manner as in Example 3 except that the compound of B-1 was used in place of the compound of Example (21) in Example 3.

[Comparative Example-6] The general formula 1 in Example 3 was used.
A thermosensitive recording material was prepared and evaluated in the same manner as in Example 3 except that the compound-containing protective layer of 2 was not provided.

Comparative Example-7 A thermosensitive recording material was prepared and evaluated in the same manner as in Example 4 except that the compound of B-1 was used in place of the compound of Example (7) in Example 4.

Comparative Example-8 General formula 1 in Example 4
A thermal recording material was prepared and evaluated in the same manner as in Example 4 except that the compound-containing protective layer of 2 was not provided.

[Comparative Example-9] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 5 except that the compound of Example 1 (40) was replaced with the compound of B-1.

[Comparative Example 10] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 5 except that the protective layer containing the compound of the general formula 1 was not provided.

[Comparative Example-11] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 6 except that the compound of B-1 was used in place of the compound of Example (40) in Example 6.

Comparative Example-12 A thermal recording material was prepared and evaluated in the same manner as in Example 6 except that the protective layer containing the compound of the general formula 1 was not provided.

[Comparative Example-13] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 7 except that the compound of B-1 was used instead of the compound of Example (23) in Example 7.

[Comparative Example-14] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 7 except that the protective layer containing the compound of the general formula 1 was not provided.

Comparative Example-15 A thermosensitive recording material was prepared and evaluated in the same manner as in Example 8 except that the compound of B-1 was used in place of the compound of Example (4).

Comparative Example-16 A thermal recording material was prepared and evaluated in the same manner as in Example 8 except that the protective layer containing the compound of the general formula 1 was not provided.

[Comparative Example-17] A thermosensitive recording material was prepared in the same manner as in Example 9 except that the compound of B-2 was used in place of the compounds of specific examples (25) and (26) in Example 9.
evaluated.

Comparative Example-18 A thermosensitive recording material was prepared and evaluated in the same manner as in Example 9 except that the protective layer containing the compound of the general formula 1 was not provided.

[Comparative Example 19] A thermosensitive recording material was prepared in the same manner as in Example 10 except that the compound of B-1 was used in place of the compounds of Examples (1), (2) and (3) in Example 10. Was created and evaluated.

[Comparative Example-20] Example 1 except that the protective layer containing the compound of the general formula 1 was not provided in Example 10.
A thermal recording material was prepared and evaluated in the same manner as in No. 0.

[Comparative Example-21] A thermosensitive recording material was prepared in the same manner as in Example 11 except that the compound of B-1 was used in place of the compounds of Examples (3) and (22) in Example 11. evaluated.

[Comparative Example-22] Example 1 except that the protective layer containing the compound of General Formula 1 was not provided in Example 11.
A thermal recording material was prepared and evaluated in the same manner as in 1.

[Comparative Example-23] A thermosensitive recording material was prepared and evaluated in the same manner as in Example 12 except that the compound of B-1 was used instead of the compound of Example (40).

[Comparative Example-24] Example 1 except that the compound-containing protective layer of the general formula 1 was not provided in Example 12.
A thermal recording material was prepared and evaluated in the same manner as in 2.

[0130]

[Chemical formula 24]

[0131]

[Table 4]

The compound represented by the general formula 1 is 340 to 40
It is a compound having substantially no ability to absorb ultraviolet rays in the wavelength region of 0 nm. Only after being irradiated with intense short-wave light for a long time, it becomes possible to absorb light in this wavelength region.

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Claims (6)

[Claims] 1. A thermosensitive recording layer and a protective layer are sequentially formed on a support.
The thermal recording material provided is represented by the following general formula 1.
A thermosensitive recording material comprising a compound. [Chemical 1]In the above general formula, m represents 1 or 2. A is one
When m = 1 in general formula (1) and general formulas (2) to (4)
At -SO₂-R, -CO-R, -CO₂-R,
-CONH-R, -POR₁R₂, -CH₂R₃Or
-SiR_FourR_FiveR₆In which R is an alkyl group
Or aryl group, R₁And R₂Is an alkoxy group,
A reeloxy group, an alkyl group or an aryl group,₃
Is at least one substituted with a nitro group or a methoxy group
Phenyl group, R_Four, R_FiveAnd R₆Is an alkyl group
Represents an aryl group, and when m = 2 in the general formula (1), A
Is -SO₂R₇SO₂-, -CO-, -COCO-,-
COR₇CO-, -SO₂Represents --or --SO--, and R
₇Represents an alkylene group or an arylene group. X is one
In the general formulas (1), (3) and (4), hydrogen atom,
Alkyl group, alkoxy group, aryl group or halogen atom
In the general formula (2), the child is an alkylene group, -OR
₇O- or -OCOR₇CO₂Represents-. W is general
In formulas (1), (2) and (4), a hydrogen atom,
Kill group, alkoxy group, aryl group or halogen atom
In the general formula (3), ₇O- or -O
COR₇CO₂Represents-. Y is the general formula (1), (2),
In (3), hydrogen atom, alkyl group, alkoxy
A group, an aryl group or a halogen atom in the general formula (4)
In addition, -OR₇O-, -OCOR₇CO₂-, -C
H₂CH₂CO₂R₇OCOCH₂CH₂-, -CH₂
CH₂OCOR₇CO₂CH₂CH₂-Or-CH₂
CH₂CON (R₈) R₇N (R₈) COCH₂CH₂
Represents-, R₈Represents a hydrogen atom or an alkyl group. Z
Is a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.
Represents a group. 2. The heat-sensitive recording material according to claim 1, wherein the compound represented by the general formula 1 is encapsulated in microcapsules. 3. The heat-sensitive recording material according to claim 1, wherein the compound represented by the general formula 1 is contained in the protective layer. 4. The heat-sensitive recording material according to claim 1, wherein the heat-sensitive recording layer contains a diazonium salt compound and a coupler which reacts with the diazonium salt compound to develop a color. 5. A heat-sensitive recording layer A containing a electron-donating dye and an electron-accepting compound as a heat-sensitive recording layer, and a heat-sensitive recording layer B containing a diazonium salt compound and a coupler that reacts with the diazonium salt compound to develop a color. The heat-sensitive recording material according to claim 1, wherein the heat-sensitive recording material is laminated. 6. A heat-sensitive recording layer A comprising a heat-sensitive recording layer containing an electron-donating dye and an electron-accepting compound, and a maximum absorption wavelength of 3
A thermosensitive recording layer B containing a diazonium salt compound having a wavelength of 60 ± 20 nm and a coupler which reacts with the diazonium salt compound to develop a color, and a diazonium salt compound having a maximum absorption wavelength of 400 ± 20 nm and a dye which reacts with the diazonium salt compound. The heat-sensitive recording material according to any one of claims 1 to 3, wherein the heat-sensitive recording layers C containing color couplers are sequentially laminated.