JPH11105432A - Photosensitive thermal recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive thermal recording material which is almost free from the coloring of a texture part after the fixing of an image and shows the adequately high density of developed color of a developed color image and a remarkable shelf stability in a raw material state. SOLUTION: In the photosensitive thermal recording material with a photosensitive thermal recording layer containing a diazonium salt and a coupling component, formed on a support, the diazonium salt is a chemical compound represented by formula (wherein, Ar is an aryl group; R<1> is an alkyl group; y is an alkyl group with a branch at an α position; and X is an anion).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light- and heat-sensitive recording material using a diazonium salt and a coupling component as color-forming components, and more particularly to a light- and heat-sensitive recording material having improved background coloring after image fixing. The present invention also relates to a light- and heat-sensitive recording material having a high raw storage property and a high color density during thermal recording.

[0002]

2. Description of the Related Art A diazonium salt is a compound having a very high chemical activity. It reacts with a phenol derivative or a compound having an active methylene group, a so-called coupling component, to easily form an azo dye, It decomposes by light irradiation and loses its activity. Therefore,
A diazonium salt has been used for a long time as an optical recording material represented by diazo copy ("Photographic Engineering Fundamentals-Non-Silver Salt Photography-" edited by The Photographic Society of Japan, Corona Co., Ltd. (1982)).
P89 to P117, P182 to P201).

Further, utilizing the property of decomposing by light and losing activity, it has recently been applied to a recording material which requires fixing of an image. As a typical example, a recording layer containing a diazonium salt and a coupling component is used. A so-called light-fixing type heat-sensitive recording material has been proposed in which a recording material provided with is heated according to an image signal to cause a reaction to form an image and then irradiate light to fix the image (Koji Sato et al. Magazine No. 11
Vol. 4 (1982) P290-296).

However, in these recording materials using a diazonium salt as a coloring element, the chemical activity of the diazonium salt is extremely high, and even in a dark place, the diazonium salt gradually decomposes and loses its reactivity. Therefore, there was a disadvantage that the shelf life as a recording material was short.

Various methods have been proposed as means for improving the instability of such a diazonium salt. One of the most effective means is a method of encapsulating a diazonium salt in a microcapsule. . By microencapsulating the diazonium salt in this way,
Since the diazonium salt is isolated from water and bases that promote decomposition, such decomposition is significantly suppressed, and the shelf life of the recording material using the salt is dramatically improved. Vol. 2 (1987) P115-125).

A general method for encapsulating a diazonium salt in microcapsules is to dissolve the diazonium salt in a hydrophobic solvent (oil phase) and add it to an aqueous solution (water phase) in which a water-soluble polymer is dissolved. By emulsifying and dispersing with a homogenizer or the like, and by adding a monomer or prepolymer to be the wall material of the microcapsule to either or both of the oil phase and the aqueous phase, a polymerization reaction occurs at the interface between the oil phase and the aqueous phase. Or forming a wall of a polymer compound by precipitating a polymer to form microcapsules.

These methods are described, for example, by Asashi Kondo, "Microcapsule", Nikkan Kogyo Shimbun (published in 1970),
Tamotsu Kondo et al., "Microcapsule" Sankyo Publishing (197
7 years). As the microcapsule wall to be formed, various materials such as crosslinked gelatin, alginate, celluloses, urea resin, urethane resin, melamine resin and nylon resin can be used.

In the case of a microcapsule having a glass transition temperature such as a urea resin or a urethane resin and having a glass transition temperature slightly higher than room temperature, the capsule wall at room temperature shows material impermeability, Since it shows a substance permeability above the glass transition temperature, it is called a thermo-responsive microcapsule and is useful for a light- and heat-sensitive recording material.

That is, by preparing a recording material having a thermoresponsive microcapsule containing a diazonium salt and a photosensitive and heat-sensitive recording layer containing a coupling component and a base on a support, the diazonium salt can be stabilized for a long time. And a colored image can be easily formed by heating, and the image can be fixed by light irradiation. As described above, the microencapsulation of the diazonium salt can dramatically improve the stability as a light and heat sensitive recording material.

However, even if the diazonium salt is microencapsulated in this way, there are various problems as a light and heat sensitive recording material. One of them is coloring after fixing the diazonium salt. That is, the photosensitive and heat-sensitive recording material using the conventional diazonium salt, after thermal printing, photodecomposes unnecessary diazonium salt and loses the reactivity with the coupling component, but when this photodecomposition proceeds,
There is a problem that undesired coloring occurs.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light- and heat-sensitive recording material which has little coloration of a background portion after fixing an image, has a sufficiently high color density of a color-formed image, and has good raw storability. It is in.

[0012]

Means for Solving the Problems The present inventors have made intensive studies focusing on the photolysis of this diazonium salt and found that the diazonium salt represented by the following general formula (1) causes coloring after photolysis. The inventor has found that this is not the case, and has completed the present invention. That is, the light and heat sensitive recording material of the present invention is a light and heat sensitive recording material in which a light and heat sensitive recording layer containing a diazonium salt and a coupling component is provided on a support, wherein the diazonium salt is represented by the following general formula (1). Characterized in that the compound is

General formula (1)

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[0014] (In the formula, Ar represents an aryl group, R ¹
Represents an alkyl group, Y represents an alkyl group having a branch at the α-position, and X ⁻ represents an anion. The diazonium salt is more preferably a compound represented by the general formula (2).

General formula (2)

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(In the formula, R ² represents an unsubstituted alkyl group, and R ³ represents an alkyl group which may have a substituent.)

In the present invention, the coupling component is preferably a compound represented by the following general formula (3).

General formula (3)

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(In the formula, E ¹ and E ² each independently represent an electron-withdrawing group. E ¹ and E ² may combine to form a ring.)

Further, these diazonium salts are preferably contained in microcapsules, and the capsule walls of the microcapsules are more preferably capsule walls containing polyurethane and / or polyurea as a constituent.

According to the present invention, there is provided a light- and heat-sensitive recording material having less coloring of a background portion after fixing an image, a sufficiently high coloring density of a color-developed image, and excellent raw storability.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The diazonium salt of the present invention is represented by the general formula (1).

In the formula, Ar represents an aryl group, and has 6 to 30 carbon atoms in view of the solubility of the diazonium salt in a solvent.
Are preferred.

The aryl group may be unsubstituted or have a substituent. Examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, and an acyloxy group. Group, acylamino group, carbamoyl group, cyano group, alkylsulfenyl group, arylsulfenyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfonamide group, sulfamoyl group, carboxy group, sulfonic acid group ,
Acyl groups and heterocyclic groups are preferred.

Specific examples of the aryl group include a phenyl group, a 4-methoxyphenyl group, a 4-chlorophenyl group, a 4-methylphenyl group, a 4-ethylphenyl group,
-Methoxyphenyl group, 2-chlorophenyl group, 2-methoxycarbonylphenyl group, 3-chlorophenyl group and the like.

In the formula, R ¹ represents an alkyl group and has 1 to 30 carbon atoms in view of the solubility of the diazonium salt in a solvent.
Are preferred.

The alkyl group may be unsubstituted or may have a substituent. Examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, Acylamino group, carbamoyl group, cyano group, alkylsulfenyl group, arylsulfenyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfonamide group, sulfamoyl group, carboxy group, sulfonic acid group, acyl Group,
And a heterocyclic group.

Examples of the alkyl group include methyl, ethyl, butyl, octyl, 2-ethylhexyl, decyl, dodecyl, octadecyl, 2-hydroxyethyl, 2-benzoyloxyethyl, 2- ( 4-
Butoxyphenoxy) ethyl, benzyl and 4-methoxybenzyl are preferred.

In the formula, Y represents an alkyl group having a branch at the α-position, and is not particularly limited as long as it has a branch at the α-position.
It includes a substituted or unsubstituted alkyl group. However, from the viewpoint of the solubility of the diazonium salt in the solvent, an alkyl group having 3 to 30 carbon atoms is preferable.

[0029] X ^- represents an anion. X ^- an anion represented by the examples of the inorganic anion, hexafluorophosphate ion, fluoroboric acid ion, chloride ion,
Sulfate ions are preferred, hexafluorophosphate ions,
Borofluoride ions are particularly preferred. As the organic anion, a polyfluoroalkyl carboxylate ion, a polyfluoroalkyl sulfonate ion, a tetraphenylborate ion, an aromatic carboxylate ion, and an aromatic sulfonate ion are preferable.

Among the diazonium salts represented by the above general formula (1), the diazonium salts represented by the above general formula (2) are more preferable from the viewpoint of improving coloring after fixing an image.
In the formula, Ar and R ¹ are the same as in the general formula (1).

In the formula, R ² represents an unsubstituted alkyl group, and is preferably an alkyl group having 1 to 20 carbon atoms in view of the solubility of the diazonium salt in a solvent.

The unsubstituted alkyl group is preferably an alkyl group having 1 to 12 carbon atoms, for example, a methyl group,
Ethyl, propyl, isopropyl, butyl, amyl, hexyl, heptyl, octyl, decyl and dodecyl groups are preferred.

In the formula, R ³ represents an alkyl group which may have a substituent, and examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, and an acyloxy group. Group, acylamino group, carbamoyl group, cyano group, alkylsulfenyl group, arylsulfenyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfonamide group, sulfamoyl group, carboxy group, sulfonic acid group , Acyl group,
Heterocyclic groups are preferred.

The alkyl group which may have a substituent is preferably an alkyl group having 1 to 20 carbon atoms in view of the solubility of the diazonium salt in a solvent. Examples thereof include a methyl group, an ethyl group and a propyl group. Group, isopropyl group, butyl group, amyl group, hexyl group, heptyl group, octyl group,
Benzyl group, α-methylbenzyl group, chloroethyl group,
Trichloromethyl and trifluoromethyl are preferred.

Hereinafter, specific examples of the diazonium salt represented by the general formula (1) or (2) of the present invention are shown, but the present invention is not limited thereto.

[0036]

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[0037]

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[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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[0044]

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In the present invention, the diazonium salt represented by the general formula (1) or (2) may be used alone or in combination of two or more. Further, the diazonium salt represented by the general formula (1) or (2) may be used in combination with an existing diazonium salt according to various purposes such as hue adjustment. For existing diazonium salts,
No. 33676, Japanese Patent Application No. 8-224252, Japanese Unexamined Patent Application Publication No.
59287, JP-A-8-156417, and Tokuhei 5-
No. 33676, JP-A-1-80588, JP-A-4-5
No. 9288, JP-A-6-328853, Japanese Patent Application No. 7-1.
No. 21208 and the like.

The diazonium salt represented by the general formula (1) or (2) can be produced by a known method.
That is, it is obtained by diazotizing the corresponding aniline using sodium nitrite, nitrosylsulfuric acid, isoamyl nitrite or the like in an acidic solvent. In order to stabilize the diazonium salt, a complex compound may be formed using zinc chloride, cadmium chloride, tin chloride or the like to stabilize the diazonium salt.

As the coupling component usable in the present invention, any compound can be used as long as it can form a dye by coupling with a diazonium salt in a basic atmosphere and / or a neutral atmosphere. All so-called 4-equivalent couplers for silver halide photographic materials can be used as coupling components. These can be selected according to the desired hue.

For example, there are a so-called active methylene compound having a methylene group next to a carbonyl group, a phenol derivative, a naphthol derivative and the like. Specific examples include the following, which are used in a range that meets the object of the present invention.

The coupling component which can be used in the present invention is particularly preferably a compound represented by the general formula (3). Next, the coupling component represented by the general formula (3) will be described in detail. The electron-withdrawing groups represented by E ¹ and E ² in the formula are substituents having a positive Hammett σ _P value, which may be the same or different, and include an acyl group and an alkoxycarbonyl group. Group, carbamoyl group, cyano group, nitro group, alkylsulfonyl group, arylsulfonyl group, heterocyclic group, phosphono group and the like are preferable. Acetyl, propionyl, pivaloyl, chloroacetyl, trichloroacetyl, trifluoroacetyl, 1-methylcyclopropylcarbonyl, 1
Acyl groups such as -ethylcyclopropylcarbonyl group, 1-benzylcyclopropylcarbonyl group, benzoyl group, 4-methoxybenzoyl group, and thenoyl group, methoxycarbonyl group, ethoxycarbonyl group, 2-methoxyethoxycarbonyl group, and 4-methoxyphenoxy An oxycarbonyl group such as a carbonyl group, a carbamoyl group, N, N-
Dimethylcarbamoyl group, N, N-diethylcarbamoyl group, N-phenylcarbamoyl group, N- [2,4-bis (pentyloxy) phenyl] carbamoyl group, N-
[2,4-bis (octyloxy) phenyl] carbamoyl group, carbamoyl group such as morpholinocarbonyl group,
Alkylsulfonyl or arylsulfonyl such as methanesulfonyl, benzenesulfonyl, and toluenesulfonyl; phosphono such as diethylphosphono; benzoxazol-2-yl; benzothiazole-2
-Yl group, 3,4-dihydroquinazolin-4-one-2
A heterocyclic group such as -yl group, 3,4-dihydroquinazoline-4-sulfon-2-yl group, a nitro group, an imino group and a cyano group are preferred.

The electron-withdrawing groups represented by E ¹ and E ² may be combined with each other to form a ring. The ring formed by E ¹ and E ² is preferably a 5- or 6-membered carbon ring or heterocyclic ring.

Specific examples include resorcin, phloroglucin, 2,3-dihydroxynaphthalene, sodium 2,3-dihydroxynaphthalene-6-sulfonate,
-Hydroxy-2-naphthoic acid morpholinopropylamide, 2-hydroxy-3-naphthalenesulfonic acid sodium salt, 2-hydroxy-3-naphthalenesulfonic acid anilide, 2-hydroxy-3-naphthalenesulfonic acid morpholinopropylamide, 2-hydroxy- 3-naphthalenesulfonic acid-2-ethylhexyloxydipropylamide, 2-hydroxy-3-naphthalenesulfonic acid-2-
Ethylhexyl amide, 5-acetamido-1-naphthol, 1-hydroxy-8-acetamidonaphthalene-
Sodium 3,6-disulfonate, 1-hydroxy-8
-Acetamidonaphthalene-3,6-disulfonic acid dianilide, 1,5-dihydroxynaphthalene, 2-hydroxy-3-naphthoic acid morpholinopropylamide, 2-
Hydroxy-3-naphthoic acid octylamide, 2-hydroxy-3-naphthoic acid anilide, 5,5-dimethyl-
1,3-cyclohexanedione, 1,3-cyclopentanedione, 5- (2-n-tetradecyloxyphenyl) -1,3-cyclohexanedione, 5-phenyl-
4-methoxycarbonyl-1,3-cyclohexanedione, 5- (2,5-di-n-octyloxyphenyl)
-1,3-cyclohexanedione, N, N'-dicyclohexylbarbituric acid, N, N'-di-n-dodecylbarbituric acid, Nn-octyl-N'-n-octadecyl barbituric acid, N- Phenyl-N '-(2,5
-Di-n-octyloxyphenyl) barbituric acid,
N, N'-bis (octadecyloxycarbonylmethyl) barbituric acid, 1-phenyl-3-methyl-5-
Pyrazolone, 1- (2,4,6-trichlorophenyl)
-3-anilino-5-pyrazolone, 1- (2,4,6-
Trichlorophenyl) -3-benzamido-5-pyrazolone, 6-hydroxy-4-methyl-3-cyano-1-
(2-ethylhexyl) -2-pyridone, 2,4-bis- (benzoylacetamido) toluene, 1,3-bis- (pivaloylacetoamidomethyl) benzene, benzoylacetonitrile, thenoylacetonitrile, acetoacetanilide, benzoylacetanilide, Pivaloylacetanilide, 2-chloro-5- (Nn-butylsulfamoyl) -1-bivaloylacetamide benzene, 1- (2-ethylhexyloxypropyl) -3-
Cyano-4-methyl-6-hydroxy-1,2-dihydropyridin-2-one, 1- (dodecyloxypropyl) -3-acetyl-4-methyl-6-hydroxy-
1,2-dihydropyridin-2-one, 1- (4-n-
Octyloxyphenyl) -3-tert-butyl-5
-Aminopyrazole and the like. For details of the coupling component, see JP-A-4-201483 and JP-A-7-2.
No. 23367, JP-A-7-223368, JP-A-7-223
No. 323660, Japanese Patent Application No. 5-278608, Japanese Patent Application No. 5
-297024, Japanese Patent Application No. 6-18669, Japanese Patent Application No. 6
-18670, Japanese Patent Application No. 7-316280, Japanese Patent Application No. 8
No. 027095, Japanese Patent Application No. 8-027096, Japanese Patent Application No. 8-030799, Japanese Patent Application No. 8-12610, Japanese Patent Application No. 8-132394, Japanese Patent Application No. 8-358755, Japanese Patent Application No. 8-358756. And Japanese Patent Application No. 9-069990.

Hereinafter, specific examples of the coupling component represented by the general formula (3) of the present invention will be shown, but the present invention is not limited thereto.

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[0056]

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[0057]

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In the light and heat sensitive recording material of the present invention, a diazonium salt is preferably encapsulated in microcapsules in order to improve the raw preservability before use. As a forming method thereof, a known method can be used. The polymer substance forming the capsule wall is impermeable at room temperature and needs to be permeable at the time of heating, and particularly preferably has a lath transition temperature of 60 to 200 ° C. Examples of these include polyurethane, polyurea, polyamide, polyester, urea / formaldehyde resin, melamine resin, polystyrene, styrene / methacrylate copolymer, styrene / acrylate copolymer, and a mixture thereof.

As a method for forming microcapsules, an interfacial polymerization method and an internal polymerization method are suitable. The details of the capsule forming method and specific examples of the reactants are described in U.S. Pat. Nos. 3,726,804 and 3,796,669. For example, when polyurea or polyurethane is used as a capsule wall material, a polyisocyanate and a second substance (for example, polyol or polyamine) which reacts with the polyisocyanate to form a capsule wall are mixed in an aqueous medium or an oil medium to be encapsulated, and then mixed with water. These are emulsified and dispersed, and then heated to cause a polymer formation reaction at the oil droplet interface to form microcapsule walls. Note that polyurea is also generated when the addition of the second substance is omitted. In the present invention, the polymer substance forming the microcapsule wall is preferably at least one selected from polyurethane and polyurea. Hereinafter, a method for producing a diazonium salt-containing microcapsule (polyurea / polyurethane wall) in the present invention will be described.

First, the diazonium salt is dissolved or dispersed in a hydrophobic organic solvent serving as a core of the capsule. As the organic solvent in this case, an organic solvent having a boiling point of 100 to 300 ° C is preferable. In the core solvent, polyvalent isocyanate is further added as a wall material (oil phase).

On the other hand, as the aqueous phase, an aqueous solution in which a water-soluble polymer such as polyvinyl alcohol or gelatin is dissolved is prepared, and then the oil phase is charged, and emulsified and dispersed by means such as a homogenizer. At this time, the water-soluble polymer acts as a stabilizer for emulsification and dispersion. A surfactant may be added to at least one of the oil phase and the aqueous phase in order to perform the emulsification and dispersion more stably.

The amount of the polyvalent isocyanate used is determined so that the microcapsules have an average particle size of 0.3 to 12 μm and a wall thickness of 0.01 to 0.3 μm. The dispersed particle diameter is generally about 0.2 to 10 μm. In the emulsified dispersion, a polymerization reaction of the polyvalent isocyanate occurs at the interface between the oil phase and the aqueous phase to form a polyurea wall.

If a polyol is added to the aqueous phase, the polyvalent isocyanate can react with the polyol to form a polyurethane wall. It is preferable to keep the reaction temperature high or to add an appropriate polymerization catalyst in order to increase the reaction rate. Details of polyvalent isocyanates, polyols, reaction catalysts, and polyamines for forming a part of the wall material are described in detail in the textbook (Polyurethane Handbook, edited by Keiji Iwaki, Nikkan Kogyo Shimbun (1987)).

As the polyvalent isocyanate compound used as a raw material for the microcapsule wall, a compound having three or more functional isocyanate groups is preferable, but a bifunctional isocyanate compound may be used in combination. Specifically, diisocyanates such as xylene diisocyanate and its hydrogenated product, hexamethylene diisocyanate, tolylene diisocyanate and its hydrogenated product, and isophorone diisocyanate are used as main raw materials, and dimers or trimers thereof (buret or isocyanurate) are used. ) In addition, adducts of polyols such as trimethylolpropane and bifunctional isocyanates such as xylylene diisocyanate, which are polyfunctional, and adducts of polyols such as trimethylolpropane and bifunctional isocyanates such as xylylene diisocyanate Examples include compounds into which a high molecular weight compound such as polyether having active hydrogen such as polyethylene oxide is introduced, and a formalin condensate of benzene isocyanate. JP-A-62-212190
JP, JP-A-4-26189, JP-A-5-31
Compounds described in JP-A-7694 / 1994 and Japanese Patent Application No. 8-268721 are preferred.

Further, a polyol or a polyamine may be added to a hydrophobic solvent serving as a core or a water-soluble polymer solution serving as a dispersion medium, and used as one of the raw materials for the microcapsule wall. Specific examples of these polyols or polyamines include propylene glycol, glycerin, trimethylolpropane, triethanolamine, sorbitol, and hexamethylenediamine. When the polyol is added, a polyurethane wall is formed.

As the hydrophobic organic solvent for dissolving the diazonium salt and forming the core of the microcapsule, an organic solvent having a boiling point of 100 to 300 ° C. is preferable. Specifically, alkylnaphthalene, alkyldiphenylethane, Alkyldiphenylmethane, alkylbiphenyl,
Alkyl terphenyls, chlorinated paraffins, phosphates, maleates, adipic esters, phthalates, benzoates, carbonates, ethers, sulfates, sulfonates, etc. No. These may be used as a mixture of two or more.

When the solubility of the diazonium salt to be encapsulated in these solvents is poor, a low-boiling solvent having high solubility in the diazonium salt to be used can be used in combination. Specifically, ethyl acetate,
Propyl acetate, isopropyl acetate, butyl acetate, methylene chloride, tetrahydrofuran, acetonitrile,
Acetone and the like can be mentioned. For this reason, the diazonium salt preferably has an appropriate solubility in these high-boiling hydrophobic organic solvents and low-boiling auxiliary solvents, and more specifically, has a solubility of 5% or more in the solvent. preferable. The solubility in water is preferably 1% or less.

The water-soluble polymer used in the water-soluble polymer aqueous solution in which the oil phase of the capsule thus prepared is dispersed is preferably a water-soluble polymer having a solubility in water of 5% or more at the temperature at which emulsification is to be performed. Specific examples thereof include polyvinyl alcohol and modified products thereof, polyacrylamide and derivatives thereof, ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer, isobutylene- Maleic anhydride copolymer, polyvinylpyrrolidone, ethylene-acrylic acid copolymer, vinyl acetate-acrylic acid copolymer,
Examples include carboxymethylcellulose, methylcellulose, casein, gelatin, starch derivatives, acacia, sodium alginate and the like.

These water-soluble polymers have no reactivity with isocyanate compounds, but preferably have low reactivity. For example, those having a reactive amino group in the molecular chain such as gelatin may be modified beforehand. It is preferable to eliminate the reactivity. When a surfactant is added, the amount of the surfactant added is 0.1 to the weight of the oil phase.
% To 5%, particularly preferably 0.5% and 2%.

The emulsification is performed by using a homogenizer, a Menton-Gawley, an ultrasonic disperser, a dissolver, a Keddy mill, or the like.
A known emulsifying apparatus can be used. After the emulsification, the emulsified product is 30 to 70 to promote the capsule wall forming reaction.
Warming to ° C is performed. During the reaction, in order to prevent the capsules from agglomerating, it is necessary to reduce the collision probability between the capsules by adding water or to perform sufficient stirring.

During the reaction, a dispersion for preventing aggregation may be added again. Generation of carbon dioxide gas is observed with the progress of the polymerization reaction, and the end thereof can be regarded as an approximate end point of the capsule wall forming reaction. Usually, by reacting for several hours, a desired diazonium salt-encapsulated microcapsule can be obtained.

The coupling component used in the present invention comprises:
A basic substance, together with other color-forming aids, etc., can also be used as a solid dispersion with a water-soluble polymer by a sand mill or the like, but after dissolving in a water-insoluble or insoluble organic solvent, the surfactant and It may be mixed with an aqueous phase having a water-soluble polymer as a protective colloid and used as an emulsified dispersion. From the viewpoint of facilitating emulsification, it is preferable to use a surfactant.

The organic solvent used in this case can be appropriately selected from, for example, high boiling oils described in JP-A-2-141279. Of these, the use of esters is preferred from the viewpoint of the emulsion stability of the emulsified dispersion, and tricresyl phosphate is particularly preferred. The above oils can be used together or with other oils.

An auxiliary solvent can be further added to the above-mentioned organic solvent as a low boiling point dissolution aid. As such co-solvents, for example, ethyl acetate, isopropyl acetate, butyl acetate, methylene chloride and the like can be mentioned as particularly preferable ones. In some cases, only a low-boiling auxiliary solvent without a high-boiling oil can be used.

The water-soluble polymer to be contained as a protective colloid in the aqueous phase mixed with the oil phase containing these components is as follows:
It can be appropriately selected from known anionic polymers, nonionic polymers, and amphoteric polymers. Preferred water-soluble polymers include, for example, polyvinyl alcohol, gelatin, cellulose derivatives and the like.

As the surfactant to be contained in the aqueous phase, an anionic or nonionic surfactant which does not cause precipitation or aggregation by acting on the above protective colloid is appropriately selected and used. Can be. Preferred surfactants include sodium alkylbenzenesulfonate, sodium alkylsulfate, dioctyl sodium sulfosuccinate, polyalkylene glycol (eg, polyoxyethylene nonyl phenyl ether), and the like.

In the present invention, an organic base may be added for the purpose of promoting the coupling reaction between the diazonium salt and the coupling component. These organic bases can be used alone or in combination of two or more. Examples of the basic substance include nitrogen-containing compounds such as tertiary amines, piperidines, piperazines, amidines, formamidines, pyridines, guanidines, and morpholines. JP-B-52-46806, JP-A-62-46806
-70082, JP-A-57-169745, JP-A-60-94381, and JP-A-57-12.
No. 3086, JP-A-58-1347901,
JP-A-60-49991, JP-B-2-24916
Gazette, Japanese Patent Publication No. 2-28479, JP-A-60-1
65288 and JP-A-57-185430 can be used.

Among these, N, N'-bis (3-phenoxy-2-hydroxypropyl) piperazine and N, N'-bis [3- (p-methylphenoxy)-
2-hydroxypropyl] piperazine, N, N′-bis [3- (p-methoxyphenoxy) -2-hydroxypropyl] piperazine, N, N′-bis (3-phenylthio-2-hydroxypropyl) piperazine, N, N N'-
Bis [3- (β-naphthoxy) -2-hydroxypropyl] piperazine, N-3- (β-naphthoxy) -2-hydroxypropyl-N′-methylpiperazine, 1,4-
Piperazines such as bis {[3- (N-methylpiperazino) -2-hydroxy] propyloxy) benzene;
-[3- (β-naphthoxy) -2-hydroxy] propylmorpholine, 1,4-bis (3-morpholino-2-hydroxy-propyloxy) benzene, 1,8-bis (3-morpholino-2-hydroxy- Proviroxy)
Morpholines such as benzene, N- (3-phenoxy-
Preferred are piperidines such as (2-hydroxypropyl) piperidine and N-dodecylpiperidine, and guanidines such as triphenylguanidine, tricyclohexylguanidine and dicyclohexylphenylguanidine.

In the present invention, the amounts of the coupling component and the basic substance are preferably 0.1 to 30 parts by weight based on 1 part by weight of the diazonium salt.

In the present invention, in addition to the above-mentioned organic bases, a coloring aid may be added for the purpose of accelerating the coloring reaction. Color development aids include substances that increase the color density during heating recording or control the color development temperature, such as lowering the melting point of coupling components, basic substances, or diazonium salts, or softening the capsule wall. This is to create a situation in which the diazonium salt, the basic substance, the coupling component, and the like are apt to react by the action of lowering the concentration.

Examples of the color-forming auxiliary used in the present invention include a phenol derivative, a naphthol derivative, and a phenol derivative in a color-forming layer so that thermal printing can be performed quickly and completely with low energy.
Alkoxy-substituted benzenes, alkoxy-substituted naphthalenes, aromatic ethers, thioethers, esters, amides, ureides, urethanes, sulfonamide compounds, hydroxy compounds, and the like can be added.

In the light- and heat-sensitive recording material of the present invention, for the purpose of improving the fastness of the thermochromic surface image to light and ripening, or reducing the yellowing of unprinted portions due to light after fixing, It is preferable to use a known antioxidant or the like. Regarding the above-mentioned antioxidants, for example, EP-A-223439, EP-A-309401, JP-A-309402, JP-A-310551, JP-A-310552, JP-A-59-41616, and German published patent No. 3,435,443, JP-A-5
JP-A-4-48535, JP-A-62-262047,
JP-A-63-113536, JP-A-63-163351, JP-A-2-262654, JP-A-2-71
262, JP-A-3-121449, JP-A-5-61166, JP-A-5-119449, U.S. Pat. No. 4,814,262, U.S. Pat. No. 4,980,275, and the like.

Further, in the present invention, it is also effective to use various known additives already used in heat-sensitive recording materials and pressure-sensitive recording materials. Specific examples of these various additives include JP-A-60-107384 and JP-A-60-107384.
Nos. 0-107383, 60-125470, 60-125471, and 60-12547.
No. 2, No. 60-287485, No. 60-28
7486, 60-287487, 60
-287488, 61-160287,
Nos. 61-185483, 61-211079, 62-146678, 62-1466
Nos. 80, 62-146679 and 62-2
Nos. 82885, 63-051174 and 6
JP-A-3-89877, JP-A-63-88380, JP-A-63-088381, JP-A-63-203372, JP-A-63-224989, and JP-A-63-25128
No. 2, JP-A-63-267594, JP-A-63-18
2484, JP-A-1-239282, and 4
JP-291658, JP-A-4-291684, JP-A-5-188687, JP-A-5-188686,
JP-A-5-110490, JP-A-5-1108437, JP-A-5-170361, JP-B-48-0432.
No. 94, No. 48-033212 and the like.

Specifically, 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-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2- Ethyl hexane, 2
-Methyl-4-methoxy-diphenylamine, 1-methyl-2-phenylindole and the like.

The addition amount of these antioxidants and various additives is 0.05 to 1 with respect to 1 part by weight of the diazonium salt.
00 parts by weight, preferably 0.2 to
Preferably it is 30 parts by weight. Such known antioxidants and various additives may be used in a microcapsule together with a diazonium salt, or may be used as a solid dispersion together with a coupling component, a basic substance, and other color-forming aids, or It can be used as an emulsified product together with a suitable emulsifying aid, or both. It goes without saying that antioxidants and various additives can be used alone or in combination. Further, it can be added to or present in the protective layer.

These antioxidants and various additives need not be added to the same layer. Furthermore, when a plurality of these antioxidants and various additives are used in combination, structurally classifying them into groups such as anilines, alkoxybenzenes, binderd phenols, hindered amines, hydroquinone derivatives, phosphorus compounds, and sulfur compounds. Alternatively, different structures may be combined, or a plurality of same structures may be combined.

The light- and heat-sensitive recording material of the present invention contains a free radical generator (a compound which generates free radicals upon irradiation with light) used in a photopolymerizable composition or the like for the purpose of reducing yellowing of the background after recording. Can be added. Examples of the free radical generator include aromatic ketones, quinones, benzoin, benzoin ethers, azo compounds, organic disulfides, acyl oxime esters, and the like. The amount to be added is preferably 0.01 to 5 parts by weight of a free radical generator per 1 part by weight of a diazonium salt.

Similarly, for the purpose of reducing yellow coloring, a polymerizable compound having an ethylenically unsaturated bond (hereinafter, referred to as a vinyl monomer) can be used. A vinyl monomer is a compound having at least one ethylenically unsaturated bond (vinyl group, vinylidene group, etc.) in its chemical structure, and has a chemical form of a monomer or prepolymer. Examples thereof include unsaturated carboxylic acids and salts thereof, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohols, and amides of unsaturated carboxylic acids and aliphatic polyamine compounds. The vinyl monomer is used in an amount of 0.2 to 20 parts by weight based on 1 part by weight of the diazonium salt. The free radical generator and the vinyl monomer can be used in a microcapsule together with a diazonium salt.

In the present invention, in addition to the above-mentioned materials, citric acid, tartaric acid, oxalic acid, boric acid, phosphoric acid, pyrophosphoric acid and the like can be added as an acid stabilizer.

The light and heat sensitive recording material of the present invention comprises a microcapsule containing a diazonium salt, a coupling component,
And a coating solution containing an organic base and other additives is prepared and coated with a bar on a support such as paper or a synthetic resin film,
1. Coating and drying by a coating method such as blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, curtain coating, etc.
It is preferable to provide a thermosensitive layer of 5 to 30 g / m ² . In the light- and heat-sensitive recording material of the present invention, microcapsules, coupling components, bases and the like may be contained in the same layer, but may have a laminated structure in which they are contained in different layers. Also, on the support, Japanese Patent Application No. 59-177
After the provision of an intermediate layer as described in the specification of US Pat. No. 669 or the like, a heat-sensitive layer can be applied.

As the binder used in the light and heat sensitive recording material of the present invention, known water-soluble polymer compounds and latexes can be used. Water-soluble polymer compounds include methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, starch derivatives, casein, gum arabic, gelatin, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, polyvinyl alcohol , Silanol-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, epichlorohydrin-modified polyamide, isobutylene-maleic salicylic anhydride copolymer, polyacrylic acid, polyacrylamide, and the like, and modified products thereof. Butadiene rubber latex, methyl acrylate-butadiene rubber latex, vinyl acetate emulsion and the like. Preferably, hydroxyethyl cellulose, starch derivatives, gelatin, polyvinyl alcohol derivatives, polyacrylamide derivatives and the like are mentioned.

As the pigment which can be used in the light and heat sensitive recording material of the present invention, any known organic or inorganic pigment can be used. Specifically, kaolin, calcined kaolin,
Talc, fluorite, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, lithopone, amorphous silica, colloidal silica, calcined stone, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, sulfuric acid Barium, mica, micro balloon,
Examples include urea-formalin fillers, polyester particles, and cellulose fillers.

In the light and heat sensitive recording material of the present invention, if necessary, known waxes, antistatic agents, defoamers,
Various additives such as a conductive agent, a fluorescent dye, a surfactant, an ultraviolet absorber and a precursor thereof can be used.

The light- and heat-sensitive recording material of the present invention may be provided with a protective layer on the surface of the recording layer, if necessary. Two or more protective layers may be laminated as necessary. Materials used for the protective layer include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, vinyl acetate-acrylamide copolymer, silicon-modified polyvinyl alcohol, starch, modified starch,
Methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, gelatins, gum arabic,
Casein, styrene-maleic acid copolymer hydrolyzate,
Styrene-maleic acid copolymer half ester hydrolyzate, isobutylene-maleic anhydride copolymer hydrolysate, polyacrylamide derivative, polyvinylpyrrolidone, polystyrene sodium sulfonate, water-soluble polymer compounds such as sodium alginate, and styrene- Latexes such as butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion are used.The water-soluble polymer compound of the protective layer is crosslinked to further improve the storage stability. Any known crosslinking agent can be used as the crosslinking agent. Specifically, N-methylol urea, N-methylol melamine, a water-soluble initial condensate such as urea-formalin, glyoxal,
Dialdehyde compounds such as glutaraldehyde, boric acid,
Examples include inorganic crosslinking agents such as borax, polyamide epichlorohydrin, and the like. For the protective layer, well-known pigments, metal soaps, waxes, surfactants and the like can also be used. The coating amount of the protective layer is preferably 0.2-5 g / m ^2, more preferably 0.5 to 2 g / m ^2. Further, the film thickness is preferably 0.2 to 5 μm, particularly 0.5 to 2 μm
Is preferred.

When a protective layer is used in the light and heat sensitive recording material of the present invention, the protective layer may contain a known ultraviolet absorber or a precursor thereof.

As the support of the present invention, any paper support used for ordinary pressure-sensitive paper, thermal paper, dry or wet diazo copy paper, and the like, as well as acid paper, neutral paper, Coated paper, plastic film laminated paper,
Synthetic paper, plastic film and the like can be used. To correct the curl balance of the support, or
For the purpose of improving the chemical resistance of the back surface, a back coat layer may be provided, or a label may be formed by combining release paper with an adhesive layer on the back surface. This back coat layer can be provided in the same manner as the above protective layer.

When the recording surface of the light and heat sensitive recording material of the present invention is heated with a thermal head or the like, the capsule wall of polyurea and / or polyurethane is softened, and the coupling component and the basic compound outside the capsule enter the capsule. Color develops. After color development, irradiation with light having an absorption wavelength of the diazonium salt causes decomposition of the diazonium salt and loss of reactivity with the coupling component, thereby fixing the image.

As a fixing light source, various fluorescent lamps, xenon lamps, mercury lamps, and the like are used. It can be efficiently fixed that the emission spectrum substantially matches the absorption spectrum of the diazonium salt used in the light and heat sensitive recording material. preferable. In the present invention, the emission center wavelength is 360 to 44
A fixing light source of 0 nm is particularly preferred.

In the present invention, a multicolor recording material can be obtained by using a photodecomposable diazonium salt having a different photodecomposition wavelength in another layer. Japanese Patent Application Laid-Open Nos. Hei 3-288688 and Hei 4-135787 disclose multicolor light- and heat-sensitive recording materials.
JP-A-5-194842, JP-A-5-34860
No. etc.

When the light- and heat-sensitive recording material of the present invention is a multilayer multi-color light- and heat-sensitive recording material, an intermediate layer may be provided to prevent color mixing between the light- and heat-sensitive recording layers. This intermediate layer is made of a water-soluble polymer compound such as gelatin, phthalated gelatin, polyvinyl alcohol, and polyvinylpyrrolidone, and may appropriately contain various additives.

In the light- and heat-sensitive recording material of the present invention, a multi-color heat-sensitive recording material can be obtained by further laminating heat-sensitive recording layers having different coloring hues. Further, examples of the heat-sensitive recording layer to be laminated include a heat-sensitive recording layer containing a photo-decomposable diazonium salt. This multicolor heat-sensitive recording material (photosensitive heat-sensitive recording material) is described in JP-A-4-135.
No. 787, No. 4-144784, No. 4-14
No. 4785, No. 4-194842, No. 4-2
Nos. 47447 and 4-247448, 4-
JP-A-340540, JP-A-4-340541, and JP-A-5-340541
-34860 and Japanese Patent Application No. 7-316280. For example, the layer structure of the full-color heat-sensitive recording material is not particularly limited. In particular, a coupler that reacts with two diazonium salts having different photosensitive wavelengths with respective diazonium salts at the time of heating to generate different hues is used. Combined two thermosensitive recording layers (B layer, C layer)
Layer) and a heat-sensitive recording material (A layer) in which an electron-donating colorless dye and an electron-accepting compound are combined, or two heat-sensitive recording layers (layers B and C)
A full-color heat-sensitive recording material, in which a heat-sensitive recording layer (layer A) in which a diazonium salt having a different photosensitive wavelength and a coupler which reacts with the diazonium salt to give a color when heated is combined. That is, from the support side, a first colorant containing an electron-donating colorless dye and an electron-accepting compound, or a coupler containing a diazonium salt having a maximum absorption wavelength shorter than 350 nm and a colorant which reacts with the diazonium salt when heated.
Thermosensitive recording layer (layer A), maximum absorption wavelength 360 nm ± 20
The second thermosensitive recording layer (B layer) containing a diazonium salt having a wavelength of 400 nm and a coupler which reacts with the diazonium salt when heated to form a color, and a diazonium salt having a maximum absorption wavelength of 400 ± 20 nm and the diazonium salt when heated This is a third heat-sensitive recording layer (C layer) containing a coupler which reacts and develops a color. In this example, if the color hues of the respective heat-sensitive recording layers are selected so as to be three primary colors in the subtractive color mixing, yellow, magenta, and cyan, a full-color image can be recorded.

In the case of a full-color recording material, the color layers of yellow, magenta and cyan may be laminated in any manner. However, from the viewpoint of color reproducibility, yellow, cyan, magenta or It is preferable to stack yellow, magenta, and cyan in this order.

In the recording method of the multicolor heat-sensitive recording material, first, the third heat-sensitive recording layer (C layer) is heated to develop a color of the diazonium salt and the coupler contained in the layer. Then 400 ±
After irradiating light of 20 nm to decompose the unreacted diazonium salt contained in the C layer, sufficient heat is applied to the second thermosensitive recording layer (B layer) to develop color, and the layer is contained in the C layer. The diazonium salt and the coupler are colored. At this time, the C layer is also strongly heated, but the diazonium salt has already been decomposed and the color forming ability has been lost, so that no color is formed. Further, by irradiating light of 360 ± 20 nm, the diazonium salt contained in the B layer is decomposed, and finally, the first heat-sensitive recording layer (A layer) is given sufficient heat to develop a color to develop a color. At this time, the heat-sensitive recording layers C and B are also heated strongly, but the diazonium salt has already been decomposed and the color-forming ability has been lost, so that no color is formed. The heat-sensitive recording material of the present invention is preferably a multicolor heat-sensitive recording material as described above. In this case, the coloring mechanism of the heat-sensitive recording layer (layer A) directly laminated on the support surface is determined by a combination of an electron-donating colorless dye and an electron-accepting compound, or a reaction between a diazonium salt and the diazonium salt when heated. Not limited to a combination with a coupler that produces a color, any of a base coloring system that forms a color in contact with a basic compound, a chelate coloring system, and a coloring system that develops a color by reacting with a nucleophile to cause an elimination reaction may be used. By providing a heat-sensitive recording layer containing a diazonium salt and a coupler that reacts with the diazonium salt to form a color on the heat-sensitive recording layer, a multicolor heat-sensitive recording material can be formed.

In the case of a multicolor heat-sensitive recording material, an intermediate layer may be provided to prevent color mixing between the heat-sensitive recording layers.
This intermediate layer is made of a water-soluble polymer compound such as gelatin, phthalated gelatin, polyvinyl alcohol, and polyvinylpyrrolidone, and may appropriately contain various additives.

In the case of a multicolor heat-sensitive recording material having a light fixing type heat-sensitive recording layer on a support, if necessary, a light transmittance adjusting layer or a protective layer, or a light transmittance adjusting layer and a protective layer may be further provided thereon. Is desirable. Regarding the light transmittance adjusting layer, see JP-A-9-39395 and JP-A-9-3939.
No. 9396, Japanese Patent Application No. 7-208386, and the like.

The light transmittance adjusting layer contains a component functioning as a precursor of an ultraviolet absorber, and does not function as an ultraviolet absorber before irradiation with light having a wavelength in a region necessary for fixing. High, when fixing the light fixing type thermosensitive recording layer, sufficiently transmit the wavelength of the region required for fixing,
The transmittance of visible light is high, and there is no problem in fixing the heat-sensitive recording layer.

The precursor of the ultraviolet absorbent is converted into an ultraviolet absorbent by reacting with light or heat after the light irradiation of the wavelength necessary for fixing the light fixing type thermosensitive recording layer by light irradiation is completed. As a result, most of the light in the ultraviolet region is absorbed by the ultraviolet absorber,
Although the transmittance is reduced and the light resistance of the heat-sensitive recording material is improved, the visible light transmittance is not substantially changed since there is no visible light absorbing effect.

At least one light transmittance adjusting layer can be provided in the light-fixing type heat-sensitive recording material, and is most preferably formed between the light-fixing type heat-sensitive recording layer and the protective layer. The rate adjusting layer may be used also as the protective layer.

[0109]

[Example 1]

(Preparation of diazonium salt-containing microcapsule liquid A) A diazonium salt (exemplified compound A-1) was added to 19 parts of ethyl acetate.
2.8 parts and tricresyl phosphate 10 parts were added and mixed uniformly. Next, 7.6 parts of Takenate D110N (manufactured by Takeda Pharmaceutical Co., Ltd.) was added to this mixed solution as a wall material, and mixed to obtain Liquid I. Next, the above-mentioned solution I was added to a mixture of 46 parts of an 8% aqueous solution of phthalated gelatin, 17.5 parts of water, and 2 parts of a 10% aqueous solution of sodium dodecylbenzenesulfonate.
For 10 minutes. After adding 20 parts of water to the obtained emulsion and homogenizing, a microencapsulation reaction was performed at 40 ° C. for 3 hours with stirring to obtain a diazonium salt-containing microcapsule liquid A. The average particle size of the microcapsules was 0.7-0.8 μm. (Preparation of Coupling Component Emulsion B) Ethyl acetate
5 parts of a coupling component (exemplified compound B-13) 3 parts,
Dissolve 3 parts of triphenylguanidine, 0.5 parts of tricresyl phosphate and 0.24 parts of diethyl maleate
Solution I was obtained. Next, a 15% aqueous solution of lime-processed gelatin 49
Parts, 9.5 parts of a 10% aqueous solution of sodium dodecylbenzenesulfonate and 35 parts of water were uniformly mixed at 40 ° C.
Add the solution and use a homogenizer at 40 ° C, 1000
The mixture was emulsified and dispersed at 0 rpm for 10 minutes. The obtained emulsion is
After stirring at 0 ° C. for 2 hours to remove ethyl acetate, water was added to obtain a coupling component emulsion B. (Preparation of Coating Solution C for Photosensitive Heat-Sensitive Recording Layer) 3.6 parts of diazonium salt-containing microcapsule solution A, 3.3 parts of water, and 9.5 parts of coupling component emulsified solution B were mixed to obtain a coating solution C for photosensitive-thermosensitive recording layer. Was. (Preparation of protective layer coating solution D) Itaconic acid-modified polyvinyl alcohol (KL-318; trade name, manufactured by Kuraray Co., Ltd.)
100 parts of 6% aqueous solution and epoxy-modified polyamide (FL-
71; trade name, manufactured by Toho Chemical Co., Ltd.) 30% dispersion 1
0 part and a dispersion of 40% zinc stearate (Hydrin Z; trade name, manufactured by Chukyo Yushi Co., Ltd.) 15
Were uniformly mixed to obtain a protective layer coating solution D. (Coating) Coating solution C for the light and heat sensitive recording layer on a photographic paper support obtained by laminating polyethylene on high quality paper using a wire bar.
After coating the protective layer coating solution D in this order, drying was performed at 50 ° C. to obtain a desired light and heat sensitive recording material. The coating amounts of the photosensitive and heat-sensitive recording layer and the protective layer as solids were 8.0 respectively.
g / m ² and 1.2 g / m ² .

(Coloring test) Using a thermal head (KST type) manufactured by Kyocera Corporation, the power and pulse width applied to the thermal head were determined so that the recording energy per unit area was 50 mJ / mm ^2, and the photosensitive and heat-sensitive recording material was determined. After thermal printing on an image, an emission center wavelength of 365 n
m, using a 40 W output ultraviolet lamp,
The whole surface was irradiated for seconds. The color density and the background density at this time were measured. The usable range of the density of the coloring portion is 1.2 or more, and the usable range of the density of the background portion is 0.15 or less. (Light fastness test) Thermal head (KS
(T-type), the colored portion was irradiated with a fluorescent lamp tester at 30,000 lux for 24 hours, and then the density of the colored portion was measured. The smaller the decrease in the density of the colored portion after the irradiation with the fluorescent lamp and the smaller the increase in the density of the background portion, the better the light resistance. (Raw storage test) The heat-sensitive recording material before recording was heated at 40 ° C and 90 ° C.
It was forcibly stored for 24 hours under the condition of% RH. After the forced storage, the above-described color development test was performed to measure the density of the color-developed portion and the background portion. The higher the density of the color-developed portion and the lower the density of the background portion after the forced preservation, the better the raw preservability. (Density measurement) The density of the coloring portion and the background portion was measured using a Macbeth densitometer “Macbeth RD918” (manufactured by Macbeth), and the density of the coloring portion was measured at the M position.
The density at the background portion was measured at the Y position.

Example 2 A light and heat sensitive recording material was prepared and evaluated in the same manner as in Example 1 except that Exemplified Compound A-2 was used as the diazonium salt.

Example 3 A light and heat sensitive recording material was prepared and evaluated in the same manner as in Example 1, except that Exemplified Compound A-3 was used as the diazonium salt.

Example 4 A light and heat sensitive recording material was prepared and evaluated in the same manner as in Example 1 except that Exemplified Compound A-13 was used as the diazonium salt.

Example 5 A light and heat sensitive recording material was prepared and evaluated in the same manner as in Example 1, except that Exemplified Compound B-25 was used as a coupling component.

Comparative Example 1 A photosensitive and heat-sensitive recording material was prepared and evaluated in the same manner as in Example 1 except that the following diazonium salt C-1 was used.

Comparative Example 2 A light and heat sensitive recording material was prepared and evaluated in the same manner as in Example 1 except that the following diazonium salt C-2 was used.

[0117]

Embedded image

The results are shown below.

[0119]

[Table 1]

From the results of the above Examples and Comparative Examples, it can be seen that the density of the background portion of the light- and heat-sensitive recording material of the present invention is kept low even when a fluorescent lamp is irradiated for a long time after image fixing. In addition, it can be seen that, even after thermal printing after the forced storage test, the color density is high and the density of the background portion is kept low. On the other hand, a diazonium salt in which the alkyl portion of the 2-position alkoxy group is a linear alkyl (Comparative Example 1), and a diazonium salt in which the alkyl portion of the 2-position alkoxy group is an alkyl having a branch at the β-position (Comparative Example) In the case of 2), when the fluorescent lamp is irradiated for a long time after the image is fixed, the discoloration in the colored portion is remarkable, and the density in the background portion is increased.
In addition, it can be seen that when the thermal printing is performed after the forced storage test, the density of the background portion increases.

The light- and heat-sensitive recording material of the present invention is excellent in the coloring of the background after fixing the diazonium salt, the light resistance of the image, and the color density during thermal recording.

Claims (5)

[Claims] 1. A light and heat sensitive recording material comprising a support and a light and heat sensitive recording layer containing a diazonium salt and a coupling component, wherein the diazonium salt is represented by the following general formula (1):
A light- and heat-sensitive recording material, which is a compound represented by the formula: General formula (1) (In the formula, Ar represents an aryl group, R ¹ represents an alkyl group, Y represents an alkyl group having a branch at the α-position, and X ⁻ represents an anion.) 2. The diazonium salt represented by the following general formula (2)
The light and heat sensitive recording material according to claim 1, which is a compound represented by the formula: General formula (2) (Wherein, R ² represents an unsubstituted alkyl group, and R ³ represents
Represents an alkyl group which may have a substituent. ) 3. The light and heat sensitive recording material according to claim 1, wherein the coupling component is a compound represented by the following general formula (3). General formula (3) (In the formula, E ¹ and E ² each independently represent an electron-withdrawing group. E ¹ and E ² may combine to form a ring.) 4. The light and heat sensitive recording material according to claim 1, wherein the diazonium salt is contained in a microcapsule. 5. The capsule wall of the microcapsule,
5. The light and heat sensitive recording material according to claim 4, wherein the material is a capsule wall containing polyurethane and / or polyurea as a constituent.