JPS6273991A - Photosensitive thermal recording material - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a background during storage, by obtaining a fixable thermal recording material wherein one of a diazo sulfonate compound and a coupling component is included in a capsule. CONSTITUTION:Diazo sulfonate or a coupling component is dissolved or dispersed in an org. solvent insoluble in water to be emulsified with said solvent. A microcapsule is formed by a method wherein a core substance containing diazo sulfonate or the coupling component is emulsified to form oil droplets and a wall comprising a high-molecular substance is formed at the periphery of each oil droplet. The reactant forming the high-molecular substance is added to the interior or exterior of the oil droplet. The thermal recording material obtained by adopting this method can be widely used, for example, as the printing paper of a facsimile or an electronic computer requiring high speed recording. By decomposing unreacted diazo solfonate by exposure fter thermal printing, a formed image can be fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to improved thermal recording paper. The thermal recording paper of the present invention does not cause so-called background fog in unprinted areas even when raw samples are stored for a long period of time, and provides stable images with beautiful backgrounds. Therefore, it is suitable for use in various recording devices.

"Technical Background of the Invention and Prior Art" In recent years, non-incident recording means have been put into practical use.
In particular, the thermal printing recording method can be said to be virtually maintenance-free, is noiseless, odorless, consumes little energy, and has a simple recording device, so its demand for use as computer output printers and data communication terminals is increasing. . Depending on the application, a recording method that allows image fixation after thermal recording is preferred, and development is progressing.

The reaction of diazosulfonate to heat and light has been studied for a long time, and its photobehavior can be explained as follows.

Azo dye Ar-8O3Na+N2 A copying method utilizing this property is described in U.S. Patent No. 2.
2/7779 is (1) → (2) by pattern exposure.
→ Perform the reaction (4) to decompose the diazosulfonate in the exposed area, and then heat the unexposed area to develop color (
A technique for obtaining an image by performing the reactions 1)→(2)→(3) is disclosed. Also, Tokukai Akira! /-'139.2
The method described in No. 2 advances the reaction of ke)→(2)→(3) by applying light and heat at the same time.

As described above, the so-called thermal development diazo recording technology using diazosulfonate is known, and its use as recording paper for thermal printers has also been attempted.

However, in the conventional method, a mixture of diazosulfonate and a coupling agent is applied, which may be activated by a small amount of light during storage, causing so-called pre-coupling, which worsens the scalp texture. There was a problem and a solution was desired.

"Summary of the Invention" As a result of research aimed at providing a heat-sensitive recording paper that solves this problem, the present inventor has found that in a light- and heat-sensitive recording material having a diazosulfonate compound, a coupling component, and a color development accelerator on a support, The above object was achieved by encapsulating at least one component of the compound in a capsule.

That is, one object of the present invention is to provide a heat-sensitive recording material that can be fixed, and a further object is to provide a heat-sensitive recording material whose texture does not deteriorate during storage.

"Detailed Description of the Invention" The diazosulfonate that can be used in this recording paper is a compound represented by the general formula. In the formula, R1 is an alkali metal,
R2, R3, R5 and R6 are hydrogen, halogen, alkyl group or alkoxy group, and R4 is hydrogen, halogen, alkyl group, amine group, benzoylamino group, morpholino group, tolylmercapto group, alkoxy group, aryloxy group , or a pyrrolidino group.

A large number of such diazosulfonates are already known and can be obtained by treating each diazonium salt with a metal sulfite salt. Particularly suitable is R4
is an amine group, benzoylamino group, morpholino group, trimercapto group or pyrrolidino group, and R2 and R
5 is hydrogen, and R3 and R6 are methoxy, ethoxy, or butoxy groups. This is a diazosulfonate obtained from a diazonium salt that has been conventionally used in wet diazocopy.

A specific list of these compounds is as follows.

Nimethoxy, 2-phenoxy, Ω-methoxy-g-phenoxy'/, '2, Q-ditomexy, coatathyl-gumethoxy 1.2+ goudimethyl, 2. Guotsu - [・
To rimethino J, g, +-trimethoxy, recognized.

Goojimethoxy-j-chloro, comethoxy! --Toro, cometkin! -acetamide, comethoxo s-N, N-diethylsulfonamine, 2-methquine-
Sodium benzenediazosulfonate with substituents such as 5-N-phenylcarbamyl, 3-methyl, goumethyl, goumethoxy, gouethoxy, gouphenyl, gouphenoxy, gouacetamide, or alternatively, e-
(N-ethyl, N-benzylamino), Gu (N, N-
diethylamino), a-(N,N-dimethylamino),
Gu(N,N-dimethylamino)-3-chloro,”(N
-ethylamino)-3-methyl, y-(N,N-diethylamino)-2-methyl, <t-(N-ethyl, N-β
-Hydroxyethylamino), goupyrosinol 3-chlor, na-pyrosinol 3-1! -dichlor, goomorpholino, termonopholino-3-chlor, y-morpholino-niemethoxy, goomorpholinoco,! -Jetoxy, termorpholyl/'-2. j-dibutoxy, <t-(<t'
-tolylmercapto)-X,Z-dimethoxy,q(4t
/b rylmercabut)-r,r-jethoxy,a
-(g'-methoxybenzoylamino)-2,! -Sodium benzenediazosulfonate having a substituent such as dibutoxy or goudiphenylamino.

The coupling component used in the present invention is one that forms a dye by coupling with diazosulfonate, and specific examples include resorcin, phloroglucin,
3-Dihydroxynaphthalene Sodium 2-sulfonate, /-Hydroxy-1-naphthoic acid morpholinopropylamide, O-dihydroxynaphthalene, Co,3-dihydroxynaphthalene, 2.3-Dihydroxy-O-sulfanylnaphthalene, Co-hydroxy-3- Naphthoic acid morpholinopropylamide, euhydroxy-3-naphthoic acid anilide, no-hydroxy-3-naphthoic acid ~co'-methylanilide, 2-hydroxy-3-naphthoic acid ethanolamide, -monohydroxy-3-naphthoic acid octylamide, 2-Hydroxy-3-naphthoic acid-N-
dodecyl-oxy-propylamide, cohydroxy-3-naphthoic acid tetradecylamide, acetanilide,
Acetoacetanilide, benzoylacetanilide, /
-phenyl-3-methyl-y-pyrazolone,' (2
′+Z′, 6Z )lichlorophenyl)-3-benzamide-! -pyrazolone, /-(,2/,g/,1
/)lichlorophenyl)-3-ani+)yr-
Pyrazolone, /-phenyl-3-phenylacetamide-! - Examples include pyrazolone. Furthermore, by using two or more of these coupling components in combination, an image of any color tone can be obtained.

It is preferable to add a basic substance to the heat-sensitive recording material of the present invention in order to promote color development. Examples of the basic substance include basic substances that are poorly water-soluble or water-insoluble, and substances that generate alkali when heated. used.

Basic substances include inorganic and organic ammonium salts, organic amines, amides, urea and thiourea and their derivatives, thiazoles, viroles, pyrimidines, radines, guanidines, indoles, imidazoles, and imidacillins. , triazoles, morpholines, biridines, amidines, formazines, pyridines, and other nitrogen-containing compounds. Specific examples of these include ammonium acetate, tricyclohexylamine, trihensylamine, octadecylbenzylamine, stearylamine, allyl urea, thiourea, methylthiourea, allylthiourea, ethylenethiourea, 2-benzylimidazole, gouphenylimida Sole, 2-phenylnib-methylimidazole, Coundecyl imidazoline, Co, Ri,! - triflyru 2-imidacillin, /
, cordiphenyl=9, coudimethyl-2-imidacillin, -1 phenyl-coimidazoline, /, co, 3-triphenylguanidine, /, couditolylguanidine,
/, kodicyclohexylguanidine 1 /, co, 3-
Tricyclohexylguanidine, guanidine trichloroacetate, N,N'-dibenzylpiperazine, '4,<j
'-dithiomorpholine, morpholinium trichloroacetate, co-aminobenzothiazole, copenzoylhydrazinopenzothiazole. Two or more of these basic substances can be used in combination.

In the present invention, a diazosulfonate or a coupling component contained in the core material of a microcapsule is dissolved or dispersed in a water-insoluble organic solvent, and after emulsification, a microcapsule wall is formed around it by polymerization. The organic solvent preferably has a boiling point of 00C or higher. Specifically, phosphoric acid esters, phthalic acid esters, other carboxylic acid esters, fatty acid amides, alkylated biphenyls, alkylated terphenyls, chlorinated halaffins, alkylated naphthalenes, diarylethanes, etc. are used. Specific examples include trioctyl phosphate, octyldiphenyl phosphate, tricyclohexyl phosphate, dibutyl phthalate, dioctinope heptathalate, dilauryl phthalate, dicyclohexyl phthalate, butyl oleate,
Diethylene glycol dipenzoate, dioctyl sebacate, diptyl sebacate, dioctyl adipate,
trioctyl trimellitate, acetyltriethyl citrate, octyl maleate, dibutyl maleate, isopropylbiphenyl, inamyl biphenyl, chlorinated halafine, diisopropylnaphthalene, /,7'-ditolylethane,',''-ditertiary-aminophenol, N, Examples include N'-dibutyl-cobutoxyj-tertiary octylaniline.

Among these, ester solvents such as dibutyl phthalate, tricresyl phosphate, diethyl phthalate, and dibibutyl maleate are preferred.

The microcapsules of the present invention are produced by emulsifying a core material containing diazosulfonate or a coupling component, and then forming a wall of a polymeric material around the oil droplets. The actant forming the polymeric material is added to the interior of the oil droplet and/or to the exterior of the oil droplet. Specific examples of polymeric substances include polyurethane, polyurea, polyamide, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene methacrylate copolymer, styrene-acrylate copolymer, gelatin, polyvinylpyrrolidone, polyvinyl alcohol, etc. can be mentioned.

More than one type of polymeric substance can also be used in combination.

Preferred polymeric materials are polyurethane, polyurea, polyamide, polyester, polycarbonate, more preferably polyurethane and polyurea.

The microcapsule wall of the present invention is particularly effective when using a microencapsulation method by polymerizing a glue actant from inside an oil droplet. That is, capsules, which are suitable as a recording material having a uniform particle size and excellent storage stability, can be prepared within a short time.

This method and specific examples of compounds are covered by a US patent! ,
721. ．． ．． ! "0da No. 3, 79. <, l, stated in the specification of Otsu No. 9.

For example, when polyurethane is used as a capsule wall material, polyvalent incyanate and a second substance (e.g. polyol) that reacts with it to form the capsule wall are mixed into an oily liquid to be encapsulated, and then emulsified and dispersed in water. By subsequently increasing the temperature, a polymer formation reaction occurs at the oil droplet interface, forming a microcapsule wall. At this time, a co-solvent with a low boiling point and strong dissolving power can be used in the oily liquid.

In this case, regarding the polyisocyanate to be used and the polyol and polyamine to be reacted with it, see U.S. Pat.
No. 3.79j, 2g? No., Special Public Shogu and Ichigu 03
Gua issue, Datakoku LRQ issue, Tokukai 41e! ? -,
! '0/9/ issue, same! −? It is disclosed in the Japanese version No. 0r, and you can also use them.

Furthermore, a tin salt can also be used in combination to promote the urethanization reaction.

When making microcapsules, water-soluble polymers can be used, and the water-soluble polymers may be any of water-soluble anionic polymers, nonionic polymers, and amphoteric polymers.

Both natural and synthetic anionic polymers can be used, such as -coo, -80,3
- groups, etc. can be mentioned. Specific anionic natural polymers include gum arabic and alginic acid, while semi-synthetic products include carboxymethyl cellulose, phthalated gelatin, sulfated starch, sulfated cellulose, and lignin sulfonic acid.

Synthetic products include maleic anhydride (including hydrolyzed) copolymers, acrylic (including methacrylic) polymers and copolymers, and carboxy-modified polyvinyl alcohol. Examples of nonionic polymers include polyvinyl alcohol, hydroxyethyl cellulose, and methyl cellulose.

Examples of amphoteric compounds include gelatin.

These water-soluble polymers are used as a 0.07 to 70 wt% aqueous solution. The particle size of the microcapsules is adjusted to less than θμ. Generally, if the particle size exceeds 2θμ, the print quality tends to be poor.

In particular, when heating with a thermal head is performed from the coated layer side, the thickness is preferably jμ or less in order to avoid pressure fog.

Diazosulfonate, which is the main component used in the present invention,
As for the coupling components, any seven of them can be used as the core material of the microcapsules, or two of them can be used. When two types are contained in the core material of microcapsules, they may be in the same microcapsule or in separate microcapsules. Other ingredients not contained in the core material of the microcapsules can be used in the heat-sensitive layer outside the microcapsules.

The color development accelerator of the present invention may be present in the core of the microcapsule or outside.

Among these combinations, the most preferred method is to contain the diazosulfonate in the microcapsules and use the other components in the heat-sensitive layer outside the microcapsules.

Toki to make microcapsules, the ingredients to be microencapsulated are 0. It can be made from an emulsion containing Jwt% or more.

The diazosulfonate used in the present invention, the coupling component, and the basic substance used as necessary may be contained inside the microcapsule or in the heat-sensitive layer outside the microcapsule. /Coupling component is 0.1 to 7 parts by weight
It is preferable to use the basic substance in an amount of 0.67 to 20 parts by weight. Further, it is preferable to apply diazosulfonate at 0° θ, +-J-, θg/m2.

When the diazosulfonate, coupling component and basic substance used in the present invention are not microencapsulated,
It is preferable to use a solid dispersion together with a water-soluble polymer using a sand mill or the like. Preferred water-soluble polymers include water-soluble polymers used when making microcapsules. At this time, the concentration 1 of the water-soluble polymer is 2 to 3θv
t %, and the diazosulfonate, coupling component, and basic substance are added to this water-soluble polymer solution in an amount of t −gθwt %, respectively.

The dispersed particle size is preferably /Qμ or less.

A hydroxy compound, a carbamate ester compound, an aromatic methoxy compound, or an organic sulfonamide compound is added to the heat-sensitive recording material of the present invention for the purpose of improving thermal color development. It is thought that these compounds lower the melting point of the coupling component or basic substance or improve the heat permeability of the microcapsule wall, resulting in a higher color density.

Specific examples of hydroxy compounds include p-t-butylphenol, p-t-octyphenol, p-α-sulfurphenol, p-t-inchylphenol, m-xylenol, 2. ! -dimethylphenol, 2+ ” +
' ) ') Methylphenol, 3-methyl-guisopropylphenol, p-benzylpheno-/L/,
O-cyclohexylphenol, p-(diphenyl)methylphenol, p-(α,α-diphenylethyl)phenol, 〇-phenylphenol, p-human mixybenzoic acid'f-f, p-hydroxybenzoic acid chloropyr, p- Butyl hydroxybenzoate, benzyl p-hydroxybenzoate, methoxyphenol, p-butoxyphenol, p-hebutyloxyphenol, p-benzyloxyphenol, dimethylvanillin 3-hydroxyphthalate, /, /-bis(couhydroxyphenyl) )
dodecane, /, /-bis(9-hydroxyphenyl)-
Coethylhexane, /,/-bis(4-hydroxyphenyl)-comethylbentane, 2. ．． 2-bis (4
t-hydroxyphenyl)-hebutane vanillin, 2-t
-butyl-gumethoxyphenol, 2. Otsu-dimethoxyphenol, 2,2'-dihydroxydermethoxybenzphenone, and other fer compounds, 2,! -dimethyl-2. ! -Hexanediol, resorcinol di(
+2-hydroxyethyl) ether, resorcinol mono(cohydroxyethyl)ether, salicyl alcohol, /, cedar (hydrokine ethoxy)benzene,
p-xylylene diol, /-phenyl-/, 2-ethanediol, diphenylmethanol, /l/-diphenylethanol, cornyl-2-phenyl-/, 3-prono-ξandiol 1.2.1-dihydroxymethyl-p
Examples include alcohol compounds such as -cresol benzyl ether, 3-(0-methoxyphenoquine)-/, 2-pronoξandiol, and the like.

Specific examples of carbamate ester compounds and L7 are N-
Phenylcarbamic acid ethyl ester, N-phenylcarbamic acid benzyl ester, N-phenylcarbamic acid phenethyl ester, carbamic acid benzyl ester,
Examples include butyl carbamate, isopropyl carbamate, and the like. Specific examples of aromatic methoxy compounds include comethoxybenzoic acid, 3. ! -dimethoxyphenyl acetic acid e,'-methoxynaphthalene, /.

3,! -trimethoxybenzene, p-dimethoxybenzene, p-benzyloxymethoxybenzene and the like.

Specific examples of organic sulfonamides include p-toluenesulfonamide, 0-toluenesulfonamide, benzenesulfonamide, p-toluenesulfonanilide, N-
(p-methoxyphenyl)-p-toluenesulfonamide, N-(o-))xyphenyl)-p-toluenesulfonamide, N-(p-10lofenyl)-p-)toluenesulfonamide, N-(0- chlorophenyl)-p-
Toluenesulfonamide, N-(p-tolyl)-p-toluenesulfonamide, N-(o-to!J#)-p
-) luenesulfonamide, N-(0-hydroxyphenyl)-p-) luenesulfonamide, N-benzyl-
p-1 luenesulfonamide, N-(2-phenethyl)
-p-toluenesulfonamide, N-(,2-hydroxyethyl)-p-1-toluenesulfonamide, N-(3
-methoxypropyl)-p-) luenesulfonamide,
Methanesulfonanilide, N-(p-tolyl)sulfonamide, N-(0-tolyl)sulfonamide, N-(p-tolyl)sulfonamide, N-(p-tolyl)sulfonamide,
-methoxyphenyl)sulfonamide, N-(.

-methoxyphenyl) sulfonamide, N-(p-chlorophenyl) sulfonamide, N-(O-chlorophenyl) sulfonamide, N-(,2, guxylyl) sulfonamide, N-(p-ethoxyphenyl) sulfonamide, N -benzylmethanesulfonamide, N-(,z
-phenoxyethyl)methanesulfonamide, 7.3-
Examples include, but are not limited to, bis(methanesulfonylamino)benzene, 3-bis(p-1 luenesulfonylamino)pronoξ, and the like.

These compounds can be used by making microcapsules together with the core material of the microcapsules, or by being added to the coating solution of the heat-sensitive recording material and being present outside the microcapsules. It is preferable to use this method.

In either case, the amount used is θ, (17/, ?/θ parts by weight, preferably 0.5 parts by weight, based on 7 parts of the coupling component).
Although the amount is 736 parts by weight, it may be selected as appropriate to adjust the color density to the desired level.

A free radical generator (a compound that generates free radicals when irradiated with light) used in photopolymerizable compositions may be added to the heat-sensitive recording material of the present invention for the purpose of reducing yellowing of the background after photofixing. I can do it. Examples of free radical generators include aromatic ketones (e.g. benzophenone) and cyclic aromatic ketones (e.g. benzophenone).
For example, fluorenone, anthrone, xanthone, thioxanone), quinones (e.g. benzoquinone, /.

goonaphthoquinone, 2-naphthoquinone, anthraquinone), benzoin, benzoin ethers (e.g. benzoin methyl ether, 2,2-dimethoxycophenylacetophenone), aromatic polycyclic hydrocarbons (e.g. naphthalene, anthracene) , azo compounds (eg, azobisbutyronitrile), organic disulfides (eg, thiuram disulfide), and acyloxime esters.

In the heat-sensitive recording material of the present invention, a polymerizable compound having an ethylenically unsaturated bond (hereinafter referred to as a vinyl monomer) can be used for the purpose of reducing yellowing of the background after photofixing.

A vinyl monomer is defined as having at least 7
A compound having ethylenically unsaturated bonds (vinyl group, vinylidene group, etc.), including monomers, prepolymers,
That is, it has chemical forms such as dimers, trimers, other oligomers, mixtures thereof, and copolymers thereof. Examples thereof include unsaturated carboxylic acids and salts thereof, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds, amides of unsaturated carboxylic acids and aliphatic polyhydric amine compounds, and the like.

The vinyl monomer is used in a ratio of 01.2 to 20 parts by weight per part of diazosulfonate.

Preferably, the ratio is 7 to /θ parts by weight.

The vinyl monomer is used by being contained in the core material of the microcapsule together with the diazosulfonate, but at this time, 7 parts or all of the solvent in the core material can be replaced with the vinyl monomer. However, it is not necessary to add enough to harden the core material.

The heat-sensitive recording material of the present invention contains silica, Riyusan barium, titanium oxide, aluminum hydroxide, zinc oxide,
Pigments such as calcium carbonate, fine powders such as styrene beads, urea-melamine resin, etc. can be used. The amounts used are: o, 2 to 7 g, 7 mm2.

Furthermore, a heat-melting substance can be used in the heat-sensitive recording material of the present invention in order to increase the heat-recording density.

A thermofusible substance is a solid at room temperature, but has a melting point that melts when heated by a thermal head! It is a substance with θ0C~/, to0c, and is a substance that dissolves diazosulfonate, a coupling component, or a basic substance.

The thermofusible substance is dispersed in the form of particles of 0,/~70μ and used in an amount of solid content 0.2 to 7 g/m2.One specific example of the thermofusible substance is: Examples include aliphatic amides, N-substituted fatty acid amides, ketone compounds, urea compounds, and esters.

The heat-sensitive recording material of the present invention can be coated with a suitable binder.

As a binder, polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, gum arabic, gelatin, polyvinylpyrrolidone, casein, styrene-butadiene latex, acrylonitrile-butadiene latex, polyvinyl acetate, polyacrylic acid ester, ethylene- Various emulsions of vinyl acetate copolymers can be used. The amount used is 0.5~ solid content! g/m2.

In the present invention, in addition to the above materials, citric acid, tartaric acid, oxalic acid, boric acid, phosphoric acid, and pyrophosphoric acid can be added as acid stabilizers.

The heat-sensitive recording material of the present invention is prepared by preparing a coating liquid containing diazosulfonate, a coupling component, a main component of a color development accelerator, a basic substance, and other additives, and coating it on a support such as paper or a synthetic resin film. Top coating, blade coating, air knife coating, gravure coating, roll coating coating,
After coating and drying by coating methods such as spray coating, dip coating, and extrusion coating, the solid content is 5 to 26 g.
/'m, 2 heat-sensitive layer gold film is removed.

It is also possible to provide an intermediate layer on the support as described in Japanese Patent Application No. Sho J'9-/77g≦9.

Furthermore, a protective layer for the purpose of imparting scratch resistance, solvent resistance, etc. can also be provided on the heat-sensitive layer.

Furthermore, for applications such as magnetic cards, a magnetic layer can be provided on the back.

The heat-sensitive recording material of the present invention can be used in a wide range of applications, including printer paper for facsimiles and electronic computers that require high-speed recording, paper for various types of copiers, card materials for tickets, commuter passes, etc. Fixation can be achieved by decomposing unreacted diazosulfonate.

In addition, heat-developable copy paper and 1-7 can also be used.

"Example" Examples are shown below, but the present invention is not limited thereto. Note that "parts" indicating the amount added refer to "parts by weight."

Mix capsule liquid A, polyvinyl alcohol aqueous solution (♂ heavy ik% liquid) O 3 parts distilled water
Add to 100 parts,
Emulsification and dispersion was carried out at 0C to obtain an emulsion having an average particle size/μ. The resulting emulsion was kept stirring at 0°C for 3 hours.

This liquid was cooled to 20°C and filtered through a 100-mesh nylon mesh, and 100 cc each of Amberlite R-/CO0B and Amberlite IRA-900 (manufactured by Rohm and Haas) were added for 7 hours. The mixture was stirred and then filtered to obtain capsule liquid A.

Capsule liquid B As diazosulfonate, goomorpholinoco,! −
Prepared in the same manner as capsule liquid A except that sodium dibutoxybenzenediazosulfonate was used Coupling component dispersion euhydroxy-3-naphthoic acid
732 parts of IJ vinyl alcohol aqueous solution (4 by weight) were mixed and dispersed in a Dynomill to obtain a coupling component dispersion having an average particle size of 3 μm.

Pigment Dispersion A Pigment Dispersion A was obtained by dispersing Univar 70 (manufactured by Shiraishi Kogyo ■) in a Dyno Mill to a 410% by weight solution.

Pigment Dispersion B Hydrin Z-7 (30% by weight, manufactured by Chukyo Yushi ■) was used as Pigment Dispersion B.

Pigment dispersion C Cellosol D-/3θ (22 weight liquid: manufactured by Naka Yushi ■)
This was designated as Pigment Dispersion C.

Basic substance dispersion Triphenylguanidine chloride 92 parts Polyvinyl alcohol aqueous solution (6.7% by weight) 7.2+ parts were mixed and Dynomil (WILLY A.

(manufactured by BACHOFEN AG) to obtain a basic substance dispersion having an average particle size of 3 μm.

Color development accelerator dispersion A 2 parts of Nomira hydroxybenzyl ether and 729 parts of a polyvinyl alcohol aqueous solution (7% by weight liquid) were mixed and dispersed in a Dynomill to obtain a color development accelerator dispersion A with an average particle size of 3 μm. Ta.

Color development accelerator dispersion B Mix part B of Nomiladruenesulfonamide 4tx parts polyvinyl alcohol aqueous solution (6.7% by weight liquid) and disperse with a Dynomill to obtain color development accelerator dispersion B with an average particle size of 3μ. Obtained.

The above solution was prepared, and then a coating solution having the composition shown in Table 1 was prepared.

+-! It was coated on a paper support using a 0-tofrod and air-dried to obtain a recording material.

<Comparative Example/> a) As the diazosulfonate, sodium g(y/)ruylmercapto)-jethoxybenzenediazosulfonate 3-part methyl cellosolve b) As the coupling agent, methyl cellosolve as the coupling agent and droxy-3-naphthoic acid part /? Part C) As a thermoplastic binder, polymethyl methacrylate (Sumibox B-MHO, glass transition point //j'c) 9 parts Methyl ethyl ketone 63 parts d) As a lubricant, polyethylene wax AF / part Toluene (
dispersion medium) 3 parts e) Teflon powder as a thermal mold release agent 0. / Department CAB
O, 3 parts toluene (dispersion medium)
θ. Text: Adjust each of the above A-E separately, mix them just before use, and apply jθg/m2 (diazosulfonate content: 7g/m2) onto coated paper using the roll coating method.
7 m2) was applied. Drying was performed at ≦0°C for 20 seconds.

Test Method> The recording paper thus prepared was subjected to an after-effect experiment immediately after its preparation and 30 days after its preparation.

After activating the recording paper by irradiating the entire surface with xenon flash (Litho-Xenofac, X, FX-/jOB) jJ/cm2, thermal printing was performed using a thermal printer. The thermal head used was a dot line type, and the applied energy was about 0.7 W/dot.

Next, the entire surface is irradiated again with a xenon flash (/lJ/
cm2) (photofixing was performed.

Thereafter, the density of the printed area and the density of the unprinted area (background fog) were measured using a Macbeth reflection densitometer.

The results are shown in Table 2.

As can be seen from Table 2, Comparative Example 2 in which diazosulfonate was not encapsulated had high fog, while Comparative Example 2 without a color accelerator, even though diazosulfonate was encapsulated in capsules, had high fog. Example 2 of the present invention with low color development degree
．． 3 had satisfactory values for both background fog and color density.

Patent applicant Fuji Photo Film Co., Ltd. Showa / Year K
month end date

Claims (1)

[Claims] A light and heat sensitive recording material having a diazosulfonate compound, a coupling component and a color development accelerator on a support, characterized in that at least one component of the compound is encapsulated in a capsule.