JPS6299189A - Thermal recording material - Google Patents

Abstract

PURPOSE:To enhance preservability before a thermal recording and developed color density upon the thermal recording and secure photo-fixation after the thermal recording, by incorporating a specified sulfonamide compound in a recording layer, in a thermal recording material provided with the recording layer, which comprises a diazo compound and a coupling component, on a base by coating. CONSTITUTION:At least one arylsulfonamide compound in which the aryl is subst. by an alkyl, alkoxyl, aryloxyl or halogen is incorporated in a recording layer. A preferably compound of the arylsulfonamide compound is a compound of the general formula, wherein each of R1 and R2 is an alkyl, alkoxyl, aryloxyl or halogen, R1 being preferably a 2-12C alkyl, a 1-12C alkoxyl, a 6-9C aryloxyl, chlorine or fluorine, and R2 being preferably a 1-12C alkyl, a 1-12C alkoxyl, a 6-9C aryloxyl or hydrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a heat-sensitive recording material, and particularly to a fixable diazo heat-sensitive recording material. More specifically, the present invention relates to a heat-sensitive recording material that has excellent storage stability before thermal recording, high color density during thermal recording, and is capable of light fixing after thermal recording.

"Prior Art" A leuco coloring type heat-sensitive recording material is usually used as a recording material used in a heat-sensitive recording method. However, this heat-sensitive recording material has the disadvantage that color develops in unexpected places due to harsh handling, heating, or adhesion of solvents after recording, which stains the recorded image. In recent years, research has been actively conducted on diazo color-forming heat-sensitive recording materials as heat-sensitive recording materials that do not have these drawbacks. For example, JP-A-Shoji7-/
2301rt issue, Journal of the Institute of Image Electronics Engineers, //, 290 (/9
12), etc., thermal recording is performed on a recording material using a diazo compound, a coupling component, and a basic component (including substances that become basic when heated), and then light irradiation is performed to detect unreacted components. It decomposes the diazo compound and stops color development.

Indeed, according to this method, it is possible to stop color development (hereinafter referred to as fixing) in areas that do not require recording.

However, this recording material also undergoes gradual pre-coupling during storage, and undesirable coloring (fogging) may occur. To this end, it has been attempted to prevent contact between the components and prevent pre-coupling by making any seven of the color-forming components exist in the form of discontinuous particles (solid dispersion). Preservability of recording materials (hereinafter referred to as preservability)
However, it still has the drawback of not being sufficient, and that the thermal coloring property is reduced. As another measure, it is known to separate the diazo compound and the coupling component as separate layers in order to minimize contact between the components (for example, the above-mentioned Japanese Patent Application Laid-Open No. 67-1989-1).
123014). Although this method improves raw storage stability, the thermal coloring properties are greatly reduced, and it cannot respond to high-speed recording with short pulse widths, making it impractical. Furthermore, as a method to satisfy both raw storage stability and thermal color development, either the coupling component or the basic substance is replaced with a non-polar waxy substance (JP-A No. 7-≠≠/≠-1, JP-A No. 7-7- /≠2
tJt) and hydrophobic polymer substances (JP-A-Sho!7-/?2
? It is known that it can be isolated from other ingredients by encapsulating it with ≠Hiroshi.

However, these encapsulation methods involve dissolving wax or polymeric substances in their solvents, and dissolving or dispersing the color-forming components in the heart abdomen to form capsules, with a shell surrounding the core substance. This is different from the concept of a normal capsule covered with water.

For this purpose, when the coloring component is dissolved and formed, the coloring component does not become the core material of the capsule, but mixes uniformly with the encapsulating material, and pre-coupling gradually progresses during storage at the wall interface of the capsule. Raw storage stability is not fully satisfied. In addition, when a color-forming component is dispersed and formed, the color-forming reaction does not occur unless the capsule wall is thermally melted, resulting in a decrease in thermal color-forming properties. Furthermore, there is a manufacturing problem in that the solvent used to dissolve the wax or polymer substance must be removed after the capsules are formed, and this method is not completely satisfactory.

Therefore, in order to solve these problems, there is a method in which at least seven of the components involved in the color reaction are contained in a core material, and a wall is formed around this core material by polymerization to form a microcapsule. 5r-tro≠3 specifications), an excellent heat-sensitive recording material was discovered.

``Problems to be Solved by the Invention'' However, even with heat-sensitive recording materials made using this microencapsulation method, the optical density of the image-recording area may apparently decrease due to long-term storage after heat recording, and further improvement is required. was desired.

``Object of the Invention'' Therefore, the first object of the present invention is to provide a heat-sensitive recording material that has excellent raw storage stability, high thermochromic property, and less decrease in recorded image density during long-term storage after thermal recording. There is a particular thing.

A second object of the present invention is to provide a heat-sensitive recording material that can be fixed by photodecomposing unreacted diazo compounds after heat recording.

A third object of the present invention is to provide a heat-sensitive recording material with excellent manufacturing suitability.

"Means for Solving the Problems" As a result of intensive research, the present inventors have found that in a heat-sensitive recording material in which a recording layer containing a diazo compound and a coupling component is coated on a support, the aryl group is an alkyl group, The problem was solved by a heat-sensitive recording material characterized in that the recording layer contains at least one type of arylsulfonamide compound substituted with an alkoxy group, an aryloxy group, or a halogen atom. Incidentally, it is preferable that either the diazo compound or the coupling component is contained in the microcapsule.

The microcapsules of the present invention are destroyed by heat or pressure, as used in conventional recording materials, and color is developed by bringing the reactive substance contained in the core of the microcapsule into contact with the reactive substance outside the microcapsule. Rather than causing a reaction, the reaction is caused mainly by permeating through the microcapsule wall by heating the reactive substance present in the core and outside of the microcapsule.

As a result of intensive research into heat-sensitive recording materials using such microcapsules, the present inventors have found that they have excellent raw storage stability, good thermochromic properties, and improve the optical density of recorded images during long-term storage after heat recording. In order to eliminate the drop, it has been found that it is extremely effective to include a sulfonamide compound in the layer in addition to the diazo component and the coupling component.

Preferred examples of the arylsulfonamide compound in the present invention include compounds represented by the following general formula (I).

That is, in the above formula, R1 and R2 are an alkyl group, an alkoxy group, an aryloxy group, or a halogen atom, and in particular, R1 has a carbon number of λ to
Alkyl group with lλ, alkoxy group with carbon number /~/2, aryloxy group with one carbon number, chlorine atom, fluorine atom,
R2 is preferably an alkyl group having 7 to 2 carbon atoms, an alkoxy group having 1 to 2 carbon atoms, an aryloxy group having 6 to 2 carbon atoms, or a hydrogen atom. More preferably, R in formula (I)
1 is an alkyl group having 2 to 2 carbon atoms or a carbon atom number/~
j is an alkoxy group. These alkyl groups may have a linear, branched, or cyclic structure, and may further have a substituent. Examples of these substituents include aryl, norogen, cyano, hydroxy, acyloxy, aryloxy, and acyl groups. Specific examples of R1 and R2 are given below.

Hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, allyl group, dimethylbutyl group, t-amyl group,
Hexyl group, isoamyl group, cyclohexyl group, cyclohexylmethyl group, riO/l/atom, methylcyclohexyl group, chloroethyl group, β-acetoxyethyl group, 3
- Ketobutyl group, benzyl group, α and β-7enethyl group, vinyl group, methoxy group, thiomethoxy group, ethoxy group, propoxy group, butoxy group, hydroxy group, diethylamino group, butylamino group, butoxycarbonyl group, ethylhexyl Oxycarbonyl group, N-hexylcarbamoyl group, β-acetoxyethoxy group, hydroxyethoxy group, phenoxyethyl group, λ-chlorophenoxycomethylethoxy group, dichlorophenoxy group, dichlorophenyl group, trimethylphenyl group, amine group, nitro Examples include bases.

Further specific examples include ethylbenzenesulfonamide, ethyltoluenesulfonamide, chloroethoxybenzenesulfonamide, (iso)propylbenzenesulfonamide, ethoxytoluenesulfonamide, t-amylbenzenesulfonamide, diethylbenzenesulfonamide, allylbenzenesulfonamide, Examples include ethoxybenzenesulfonamide and cyclohexylbenzenesulfonamide.

More preferably p-ethylbenzenesulfonamide,
Examples include p-methoxybenzenesulfonamide, p-ethoxybenzenesulfonamide, p-isopropylbenzenesulfonamide, and m-ethylbenzenesulfonamide.

The diazo compound used in the present invention has the general formula A r N
2 +X (wherein, Ar represents an aromatic moiety, and N
2+ represents a diazonium group, and X- represents an acid anion. ) It is a compound that can develop a color by causing a coupling reaction with a coupling component, and can be decomposed by light.

Specifically, as the aromatic moiety, those having the following general formula are preferable.

In the formula, Y represents a hydrogen atom, a substituted amine group, an alkoxy group, an aryloxy group, an alkylthio group, an alkylthio group, or an acylamino group, and R represents a hydrogen atom, an alkyl group,
an alkoxy group, an aryloxy group, an arylamino group, or a norogen (1, Br.

α, F).

The substituted amine group of Y includes a monoalkylamino group, a dialkylamino group, an arylamino group, a morpholino group,
A piperidino group, a pyrrolidino group, etc. are preferred.

Specific examples of diazonium that forms salts include dahdiazo/-dimethylaminebenzene, Hiro-diazo-/-diethylaminobenzene, ≠-diazo/-dipropylaminobenzene, Hiro-diazo-/-methylbenzylaminobenzene, and Hiro-diazo-/-diethylaminobenzene. Cyazo-7-divandylaminebenzene, ≠-thiaso/-ethylhydroxyethylaminobenzene, μm diazo-/-diethylamino-3-methoxy(benzene, Hiro-diazo-/-dimethylamine-2-methylbenzene, Hiro- dia/-/-hensyylamino-2,
! -diethoxybenzene, μm sheaso/-morpholinobenzene, ≠-thiasaw/-morpholino λ,! -jethoxybenzene, Hiro-diazo-/-morpholino-λ, j
-dibutoxybenzene, ≠-diazo/-anilinobenzene, μ-diazo/-tolylmercapto-2,! −
Examples include jetoxybenzene, Hiro-diazo-7,≠-methoxy7penzoylamino-λ, j-jethoxybenzene, ≠-diazo/-pyrrolidino-λ-etherbenzene, and the like.

Specific examples of acid anions include CnF2n+ICO〇-
(n is an integer from 3 to 3), CmF2m+lSO3- (m is an integer from 2 to t), "1Fzl+18Oz) 2CH(
(1 is an integer of / to /I), (n is an integer of 3 to 2), BF4 +PF6-, and the like.

In particular, as the acid anion, one containing a perfluoroalkyl group or a perfluoroalkenyl group, or PF6- is preferable because it causes less increase in fog during raw storage.

Specific examples of diazo compounds (diazonium salts) include the following examples.

The coupling component used in the present invention is one that forms a dye by coupling with a diazo compound (diazonium salt) in a basic atmosphere, and specific examples include resorcin, 70loglucin, and λ.

Sodium 3-dihydroxynaphthalene-6-sulfonate, l-hydroxy-λ-sulfonate morpholinopropylamide, /,! -dihydroxynaphthalene, 2.3-
Dihydroxynaphthalene, λ.

3-dihydroxy-6-sulfanylnaphthalene, λ-
Hydroxy-3-naphthoic acid morpholinopropylamide, λ-hydroxy-3-naphthoic acid anilide, 2-hydroxy-3-naphthoic acid-λ'-methylanilide, non-hydroxy-3-naphthoic acid ethanolamide, -monohydroxy-3-naphthoic acid Octylamide, λ-hydroxy-3-naphthoic acid It-N-dodecyl-oxy-propylamide, λ-hydroxy-3-7toic acid tetradecylamide, acetanilide, acetoacetanilide,
Benzoylacetanilide, l-7enyl-3-methyl-y-virazolone, /-(,2', Hiro'.

z'-trichlorophenyl)-3-benzamide-yo-
Pyrazolone, / -(2',l,4'-trichlorophenyl)-3-anilino-yo-pyrazolone, l-
Phenyl-3-phenylacetamide! -Pyrazolone and the like. 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 sparingly water-soluble or water-impossible, and those that generate alkali upon heating. Substances are used.

Basic substances include inorganic and organic ammonium salts, organic amines, amides, urea and thiourea and their derivatives, thiazoles, virols, BiIJ midines, radines, guanidines, indoles, imidazole molecules,
Examples include nitrogen-containing compounds such as imidacillins, triazoles, morpholines, lysines, amidines, formazines, and pyridines. Specific examples of these include ammonium acetate, tricyclohexylamine, tribenzylamine, octadecylbenzylamine, stearylamine, allylurea, thiourea, methylthiourea, allylthiourea, ethylenethiourea, λ-benzylimidazole, 4(-phenyl imidasol, 2-
Phenyl-p-methyl-imidazole, undecyl-imidazoline, λ, ≠, j-trifuryl-1-imidacillin, /.

λ-diphenyl-Hiro, ≠-dimethyl-coimidasoline, λ-phenyl-2-imidacilline, /.

λ, 3-triphenylguanidine, /, cordytolylguanidine, /, λ-dicyclohexylguanidine, /,
2.3-Tricyclohexylguanidine, guanidine trichloroacetate, N,N'-dibenzylpi is radin, ≠
, ≠′-dithiomorpholine, morpholinium trichloroacetate, λ-aminobenzothiazole, λ-penzoylhydrazinopenzotheazole. Two or more of these basic substances can also be used in combination.

In the present invention, a reactive substance 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 by polymerization. Those having a boiling point of ♂o Oc or higher are preferable.

Specifically, phosphoric acid esters, phthalic acid esters, other carboxylic acid esters, fatty acid amides, alkylated hyphenyls, alkylated terphenyls, chlorinated nonraphine, alkylated heptalenes, diarylethanes, and the like are used. Specific examples include tricresyl phosphate, trioctyl phosphate, octyldiphenyl phosphate, tricyclohexyl phosphate, dibutyl phthalate, dioctyl heptathalate, diuryl phthalate, dicyclohexyl phthalate, phthyl oleate, diethylene glycol dibenzoate, and cepacin. Dioctyl acid, dibutyl sepacate, dioctyl adipate, trioctyl trimellitate, acetyltriethyl citrate, octyl maleate, dibutyl maleate, inopropylbiphenyl, inamyl biphenyl, chlorinated notraffin, diisopropylnaphthalene, l, l' Examples thereof include -cyto+j-ethane, λ,≠-ditertiary aminophenol, N,N-diphthyl-cobutoxyj-ter-7yaliocteraniline, and the like.

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

The microcapsules of the present invention are made by emulsifying a core material containing a reactive substance 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,
Examples include styrene methacrylate copolymer, styrene-acrylate copolymer, gelatin, polyvinylpyrrolidone, polyvinyl alcohol, and the like.

Two or more types of polymeric substances can also be used in combination.

Preferred polymeric materials are polyurethane, polyurea, polyamide, polyester, polycarbonate, and more preferred are 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, it is possible to obtain capsules, which are desirable as a recording material and have a uniform particle size and excellent storage stability, within a short period of time.

This method and specific examples of compounds are described in U.S. Pat.
, No. 726.10≠, No. 3.7FA, No. 669.

For example, when polyurethane is used as a capsule wall material, polyvalent incyanate and a second substance (for example, polyol) that reacts with it to form the capsule wall are mixed into an oily liquid to be encapsulated, emulsified and dispersed in water, and then heated to As the oil rises, 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, US Pat. Evening issue, 3793
No. 261, Tokuko Sho≠♂−≠03≠7, same≠? -2 Hiroshi/
! ri issue, JP-A Show μg-roiyi issue, same 4t, r-ra
ort, and they can also be used.

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

In particular, it is preferable to use a polyvalent isocyanate as the first wall-forming substance and a polyol as the second wall-forming substance because of their good shelf life. Furthermore, by combining the two, it is also possible to arbitrarily change the thermal permeability of the reactive substance.

Examples of the polyvalent incyanate which is the first wall film-forming substance include m-phenylene diisocyanate, p-phenylene diisocyanate), j,A-tolylene diisocyanate, 2. ≠-tolylene diinocyanate, naphthalene-7, ≠-diisocyanate, diphenylmethane-Hiroshi, ri'-diisocyanate, 3,3'-dimethoxy-Hiro pl-biphenyl-diisocyanate, 3,3'-dimethyldiphenylmethane-μ, 4! '-Diisocyanate, xylylene-/, l/--diisocyanate, Hiroshi,
≠'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-7, λ-diisocy'71-), butylene-/, 2-diisocyanate, cyclohexylene-/
, 2-diisocyanate, cyclohexylene-7,p-
Diisocyanate such as diisocyanate, μ, Hiro′, ≠
〃-triphenylmethane triisocyanate, toluene-λ, ≠, A-) triinocyanate such as diisocyanate, ≠, μ′-dimethyldiphenylmethane-λ,
2',r,! Tetraisocyanates such as '-tetraisocyanate, adducts of hexamethylene diisocyanate and trimethylolpronone,2. ≠-There are isocyanate prepolymers such as an adduct of tolylene diisocyanate and trimethylolpronone, an adduct of xylylene diisocyanate and trimethylolpropane, and an adduct of tolylene diisocyanate and hexanetriol.

The polyol, which is the second wall-forming substance, includes aliphatic and aromatic polyhydric alcohols, hydroxy polyesters,
There are things like hydroxy polyalkylene ether. Preferred polyols include polyhydroxy compounds having the following groups (I), (II), (III), or (IV) in the molecular structure between two hydroxyl groups and having a molecular weight of too much or less.

(1) Aliphatic hydrocarbon group having carbon number λ to t, where (
Ar in If), (III), and (IV) is substituted or
It represents an unsubstituted aromatic moiety, and the aliphatic hydrocarbon group (■) has Cn H2n- as its basic skeleton, and the hydrogen group may be substituted with another element.

To give specific examples, examples of (I) include ethylene glycol, /, J-furopanediol, t, 4cm-
ftanediol, l, tertanediol, /, t-
Hexanediol, l,7-hexanediol, /,?
-Octanediol, propylene glycol, co, 3-
dihydroxybutane, /, 2-dihydroxybutane, /
, 3-dihydroxybutane, co, 2-dimethyl-/, 3
-Propanediol, Ko, Hiro-Intanediol, 2.
yo-hexanediol, 3-methyl-1,1--:ntandiol, /, tercyclohexane dimetatool, dihydroxycyclohexane, diethylene glycol, /
, λ, monotrihydroxyhexane, phenylethylene glycol, /, /, /-trimethylolzolo·ξ,
Examples include hexanetriol, hantaerythritol, and glycerin.

Examples of (II) include condensation products of aromatic polyhydric alcohols and alkylene oxides such as l,≠-di(2-hydroxyethoxy)yne, resorcinol dihydroxyethyl ether, and the like.

Examples of (II[) include p-xylylene glycol,
m-xylylene glycol, α, α′-dihydroxy-
Examples include p-diisopropylbenzene.

Examples of (IV) include ≠ p/-dihydroxy-diphenylmethane, "(+)+p'" hydroxydiphenylmethyl)benzyl alcohol, adduct of ethylene oxide to bisphenol A, bisphenol A
Examples include adducts of zolopyrene oxide. The polyol is preferably used in a proportion of hydroxyl groups of 0.02 to λ mol per 7 mol of incyanate groups.

When making microcapsules, water-soluble polymers can be used, and the water-bathable 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,
Examples include those having a group or the like. Specific anionic natural polymers include gum arabic and alginic acid, while semi-synthetic products include carboxymethyl cellulose, phthalated gelatin, sulfated starch, sulfated cellulose,
These include lignin sulfonic acid.

Synthetic products include maleic anhydride-based (including hydrolyzed) copolymers, acrylic acid-based (including methacrylic acid-based) polymers and copolymers, vinylininsulfonic acid-based polymers and copolymers, Examples include 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 an aqueous solution of 0.0/~/θwt%. The particle size of the microcapsules is adjusted to 20μ or less. Generally, if the particle size exceeds 0μ, the print quality tends to be poor.

In particular, when heating with a thermal head is performed from the coated layer side, it is preferable that the thickness be less than rμ in order to avoid pressure capri.

Regarding the diazo compound, which is the main component used in the present invention, the coupling component, and the basic substance used if necessary, any seven of them may be used as the core material of the microcapsule, or two or three of them may be used. Seeds 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. Further, when three types are contained in the core material of a microcapsule, it is not possible to simultaneously contain the three types in the same microcapsule, but there are various combinations. Other ingredients not contained in the core material of the microcapsules are used in the heat-sensitive layer outside the microcapsules.

The arylsulfonamide compound of the present invention may be present in the core of the microcapsule or outside.

When making microcapsules, they can be made from an emulsion containing 0.2 wt% or more of the component to be microencapsulated.

Diazo compound used in the present invention, coupling component,
And whether the basic substance used as necessary is contained inside the microcapsule or in the heat-sensitive layer outside the microcapsule, the coupling component is 0.1 to 10 parts by weight of the diazo compound. The basic substance is preferably used in an amount of 0.1 to 20 parts by weight. Also, diazo compounds are o, o-ol! , Oy/rrL
It is preferable to apply 2 coats.

When the diazo compound, coupling component, and basic substance used in the present invention are not microencapsulated, they are preferably used as a solid fraction together with the water-bathable polymer using a sand mill or the like. Preferred water bathing polymers include water-soluble polymers used for making microcapsules.

At this time, the m degree of the water bathable polymer is 2 to 30 Ht%,
The diazo compound, coupling component, and basic substance are added to this water-soluble polymer solution in an amount of 5 to ≠OWt, respectively.

The dispersed particle size is preferably 10 microns or less.

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

Specific examples of hydroxy compounds include p-t-butylphenol, p-1-octylphenol, p-α-cumylphenol, p-t-pentylphenol, m-xylenol, 2. j-dimethylphenol, ' + 4t
I')'Dimethylphenol, J-Meluhiro-
Isoprobylphenol, I)-benzylphenol,
0-Cyclo-hexylphenol, p-(diphenylmethyl)phenol, p-(α,α-diphenylethyl)
Phenol, 0-phenylphenol, ethyl p-hydroxybenzoate, chlorovir p-hydroxybenzoate,
Butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-methoxyphenol, p-methoxyphenol, p-hebutyloxyphenol, p-benzyloxyphenol, dimethylvanillin 3-hydroxyphthalate, /, /-bis (4t-hydroxyphenyl)
Dodecane, l, /-bis(Hiro-hydroxyphenyl)-
2-Ether-hexane, l,/-bis(<2-hydroxyphenyl)-λ-methyl-intane, x,z-bis(
Hiroshi-hydroxyphenyl)-hebutane vanillin, x-t
-Butyl-Hiro-methoxyphenol, 2゜6-simethoxyphenol 2,2/-dihydroxy-≠-methoxybenzophenone, etc., phenolic compounds, co-, j-
Dimethyl-2. ! -Hexanediol, resorcinol di(2-hydroxyethyl) ether, resorcinol mono(2-hydroxyethyl) ether, salicyl alcohol, /, Hiro-di(hydroxyethoxy)benzene
+)-xyIJ L/diol, /-F22/l/-
7,2-ethanediol, diphenylmethanol, l,
/-diphenylethanol, λ-methyl-2-722l, 3-propanediol, λ, t-dihydroxymethyl-p-cresol benzyl ether, 6-dihydroxymethyl-p-cresol benzyl ether, 3
Examples include alcohol compounds such as -(o-methoxyphenoxy)-/, 2--) lonoξandiol, and the like. Specific examples of carbamic acid ester compounds include N-phenylcarbamic acid ethyl ester, N-phenylcarbamic acid benzyl ester, N-phenylcarbamic acid 7
Examples include enethyl ester, benzyl carbamate, phthyl carbamate, isopropyl carbamate, and the like. Specific examples of aromatic methoxy compounds include 1-methoxybenzoic acid, 3. ! -dimethoxyphenylacetic acid, -monomethoxynaphthalene, /,! ,
j-) dimethoxybenzene, p-dimethoxybenzene,
Examples include p-benzyloxymethoxybenzene.

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 existing outside the microcapsules. is preferred. In either case, the amount used is o, oi-io parts by weight, preferably O0/-1 parts by weight, per 1 part by weight of the coupling component, but it may be selected as appropriate to adjust the color density to the desired level. good.

A free radical generator (a compound that generates free radicals when irradiated with light) used in photopolymerizable compositions is added to the heat-sensitive recording material of the present invention for the purpose of reducing yellowing of the background after photofixing. be able to. Free radical generators include aromatic ketones (e.g. benzophenone, ≠, ≠'-bis(dimethylamino)benzophenone, ≠, ≠'-bis(diethylamino)benzophenone, ≠-methoxy≠'(dimethylamino)benzophenone, ≠ , Hiro'-dimethoxybenzophenone, ≠-dimethylaminobenzophenone, Hiro-
Methoxy, 3,3'-dimethylbenzophenone, /-hydroxycyclohexylphenylketone, Hiro-dimethylaminoacetophenone,! -Methyl-/-[≠-(methylthio)phenyl]-λ-morpholino-propanone-7
-acetophninone, benzyl), cyclic aromatic ketones (
For example, fluorenone, anthrone, xanthone, thioxanthone, 2-chlorothioxanthone, co, μ-dimethylthioxanthone, 2. Hiro-diethylthioxanthone, acridone, N-ethyl acridone, benzanthrone), quinones (e.g., benzoquinone, 2,3.j-
Trimethyl-6-bromobenzoquinone, 2. z-z-n
-decylbenzoquinone, /, Hiro-naphthoquinone, λ-impropoxy/, Hiro-naphthoquinone, /, λ-naphthoquinone, anthraquinone, 2-chloro-anthraquinone, λ-methylanthraquinone, λ-tert-butylanthraquinone, phenanthra quinone), benzoin, benzoin ethers (e.g., tt-j-<nzoin methyl ether, benzoin ethyl ether, 2゜2-dimethoxy-2-phenylacetophenone, α-methylolbenzoin methyl ether), aromatic polycyclic carbonization Hydrogens (e.g. naphthalene, anthracene, phenanthrene, pyrene), azo compounds (e.g. azobisisobutyronitrile, α-azo-/-cyclohexanecarbonitrile, azobisvaleronitrile), organic disulfides (e.g. , thiuram disulfide), and acyloxime esters (eg, benzyl-(0-ethoxycarbonyl)-α-monoxime).

The amount to be added is based on the ixt part of the diazonium compound.
It is preferable to use 0.0/-5 parts by weight of the free radical generator. More preferably 0. /~/Range of heavy site 'T: Yes.

By including the free radical generator together with the diazonium salt as a core material of the microcafucell, the yellow coloration of the skin after the above-mentioned light exposure can be eliminated.

In the heat-sensitive recording material of the present invention, a superpositionable 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 a compound having at least 7 ethylenically unsaturated bonds (vinyl group, vinylidene group, etc.) in its chemical structure, and the monomer,
Prepolymers, ie, those having chemical forms such as -mers, 3Wk-mers, and other oligomers, mixtures thereof, and copolymers thereof. Examples thereof include unsaturated carboxylic acids and their salts, 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 0.9% per part by weight of diazo.
Used at a rate of 2 to 20 times. Preferably 7-70
It is a proportion of parts by weight.

The vinyl monomer is used by being contained in the core material of the microcapsule together with the diazo compound, but at this time, the solvent for the core material (
Although up to 7 parts of the organic solvent used as a dispersion medium can be replaced with vinyl monomer, it is not necessary to add enough to harden the core material.

When the heat-sensitive recording material of the present invention contains a diazo compound as a core material, by incorporating a coupling reaction deactivator outside the microcapsules, the diazo compound present in the aqueous phase and the diazo compound in the incomplete capsules can be removed. (i.e., diazotized appendages that are not completely blocked by the capsule wall) and the coupling reaction quencher react, causing the diazo compound/substance to lose its coupling reaction (coloring reaction) ability and preventing fogging. can do.

The coupling reaction deactivator may be any substance that reduces the coloring of a solution containing a diazo compound. Other compounds can be selected by observing the color change of the diazo compound in addition to gold.

Specific examples include hydroquino/, sodium bisulfite, potassium nitrite, hypophosphorous acid, stannous chloride, and formalin. In addition to this, H.

The Aromatic D by Sawn ders
iaz.

-Compounds and Their T
electricalApplicationsJM,c,
, M.A.

(Cant ab,) B, Sc, (London) /
'? You can also choose from those listed on pages 103 to 304, published in 1986.

The coupling reaction quenching agent is preferably one that has little coloring itself and has few side effects. More preferably, it is a water-soluble substance.

The coupling reaction deactivator is used to the extent that it does not inhibit the thermal coloring reaction of the diazo compound.
It is used in a range of 2 o, oi moles to 2 moles of the deactivator per mole. More preferably, it is used in a range of 0.02 mol to 1 mol.

The coupling reaction quencher of the present invention comprises a liquid in which microcapsules containing a Kugo diazo compound dissolved in a solvent are dispersed;
Alternatively, a coupling agent or basic substance can be dispersed.
It can be used by adding it to a liquid or a mixture of these. Preferably, the quencher is used in the form of an aqueous solution.

The heat-sensitive recording material of the present invention contains silica, barium sulfate, titanium oxide, aluminum hydroxide, zinc oxide,
Pigments such as calcium carbonate, styrene beads, imitation powders such as urea-melamine resin, etc. can be used.

Similarly, metal soaps can also be used to prevent sticking. The usage amount of these is O1
λ~79/m2.

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

The thermofusible substance is a substance that is solid at room temperature and has a melting point of jθ~/ro0c that melts when heated by a thermal head, and is a substance that dissolves a diazo compound, a coupling component, or a basic substance. The thermofusible substance is 0. /~10μ
It is used by dispersing it in the form of particles with a solid content of 0.2 to 7 y/m2. Specific examples of heat-melting substances include fatty acid amides, N-substituted fatty acid amides, ketone compounds, urea compounds, esters, and the like.

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

Binders include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, gum arabic, gelatin, polyvinylpyrrolidone, casein, styrene-butadiene latex, acrylonitrile-butadiene latex, polyvinyl acetate, polyacrylic acid ester, ethylene-vinyl acetate, etc. Various types of emulsions of polymers can be made. The amount used is solid content o, r~jf/m2.

In addition to the above-mentioned materials, Mikage also uses citric acid as an acid stabilizer.
Tartaric acid, oxalic acid, boric acid, phosphoric acid, birophosphoric acid can be added.

The heat-sensitive recording material of the present invention is prepared by preparing a coating solution containing all the main components of a diazo compound, a coupling component, a basic substance, and their additives, and coating it on a support such as paper or a dispersed 1σ/1 fat film. Par coating, blade coating, air knife coating,
Apply and dry using coating methods such as gravure coating, roll coating, spray coating, and dip coating to reduce the solid content!
,! ~Koyo? /m2 heat sensitive layer? establish. Another method is to add the main component of the coupling component, the SA-based substance, and other additives as the core material of the microcapsule, or to disperse them as a solid, or to dissolve them as an aqueous solution and then mix and apply. Prepare a liquid, apply it on the support, dry it, and precoat with solid content λ ~ 101/rrL2/1l.
A coating method is prepared by adding the main component, diangohi metals, and other additives as the core material of the microcapsules, or dispersing them as a solid, or dissolving them as an aqueous solution, and then mixing them. , is applied and dried to solid content /~/! It is also possible to use a laminated type with a coating J- of 1/m2. In the stack-up type heat-sensitive recording material, the order of stacking the layers 1i may be reversed, and the coating method may be sequential coating or simultaneous coating of the stacked layers.

This laminated heat-sensitive recording material exhibits particularly excellent performance in long-term storage.

Also, on the support is a Japanese patent application Shojter/7761. Rigomei+1
It is also possible to apply a heat-sensitive counterfeit layer after providing the intermediate layer described in a4F and the like.

The paper used for the support is thermally extracted pHj sized with a neutral sizing agent such as an alkyl ketene dimer.
- Neutral paper (described in JP-A-11-1999/Ko 2r1)
'Jjr: Use is advantageous in terms of storage stability over time.

In addition, in order to prevent the coating liquid from penetrating into the paper and to improve the contact between the recording heat head and the heat-sensitive recording layer, Japanese Patent Laid-Open No. 77-//A
The paper described in No. t♂7 which has a (meter tsubo t)2 and a Bekk smoothness of 0 seconds or more is advantageous.

The optical surface roughness described in Mayu JP-A-5R-I3TARI No. 2! Paper of μ or less and thickness of 4Lo to 7A, density 0°2 as described in Japanese Patent Application Laid-Open No. 2003-2010 JLR-B20-7? /cm3 or less and the optical contact ratio is l! Paper that is better than Chi, Tokukai Sho! Canadian standard P water level (JIS Pr
/s/) Paper made from sudden pulp that has been beaten to more than ctaooCc and prevents coating liquid from seeping in, JP-A-Sho! I-
tJ-69! JP-A-Shojter 3!, which improves color density and resolution by using the glossy side of base paper made by a Yankee machine as the coating surface, as described in No. '? The paper described in No. Ij, in which the base paper is subjected to a corona discharge treatment to improve its coating suitability, can also be used in the present invention and gives good results.

In addition to these, any support commonly used in the field of heat-sensitive recording paper can be used as the support of the present invention.

The heat-sensitive recording material of the present invention can be used as printer paper for facsimiles and electronic computers that require high-speed recording, and can be fixed by being exposed to light after printing by heating to decompose unreacted diazo compounds. can.

In addition, it can also be used as a heat-developable copying paper.

"Example" Examples are shown below, but the present invention is not limited thereto. Is "parts" shown in addition t'"parts by weight"? represent.

"Embodiments of the Invention" Examples/The following diazotized compounds 3. μ! 1 part and 1 part of a (3:/) adduct of gysilylene diisocyanate and trimesterolpronoline were added to a mixed solvent of tricresyl phosphate and 5 parts of ethyl acetate and dissolved therein.

The solution of this diazo compound is mixed with polyvinyl alcohol.
Part 2 is water! Mix with the aqueous solution dissolved in part r 1.2
Emulsification and dispersion was carried out at 00C to obtain an emulsion with average particle diameters λ and jμ. 700 parts of water was added to the obtained emulsion and heated to 0°C while stirring, and after one hour, a capsule liquid containing a diazo compound in the core substance was obtained.

(Diazo compound) Next, 10 parts of λ-hydroxy-3-naphthoic acid anilide, 10 parts of triphenylguanidine, and 100 parts of a 1t% polyvinyl alcohol aqueous solution were dispersed in a sand mill for about λμ time to form a coupling component with an average particle size of 3μ. Consider a dispersion of triphenylguanidine.

Furthermore, 20 parts of p-ethylbenzenesulfonamide 1r, μ
Add filoo part of polyvinyl alcohol aqueous solution and ioo part of water to the rice cake, and use a paint shaker to disperse the average particle size over λ time.
? A dispersion of p-ethylbenzenesulfonamide of μm was obtained.

Diazo compound capsule Q1 obtained as above
A coating liquid was prepared by adding the coupling component, 2 μ parts of a triphenylguanidine dispersion, and 22 parts of a p-ethylbenzenesulfonamide dispersion to 0 parts. This coating liquid was applied to smooth high-quality paper (3097 m2) using a coating bar to give a dry type f109/rn2.2j 0C3
Dry for 0 minutes and remove the heat-sensitive material.

Example λ Example m A heat-sensitive recording material '#+ was obtained in the same manner as in Example 1, except that p-methoxybenzenesulfonamide was used instead of p-ethylbenzenesulfonamide in Example 1.

Example 3 A heat-sensitive recording material was prepared in the same manner as in Example 3 except for the following using p-(-2-chloroethoxy)benzenesulfonamide instead of p-ethylbenzenesulfonamide (7).

For example, p-octylbenzenesulfonamide was used for the p-ethylbenzenesulfone atomization in Example/.
A thermosensitive recording material was obtained in the same manner as in Example 1.

Comparative Example/A thermosensitive recording material was prepared in the same manner as in Example 1 except that p-)luenesulfonamide was used instead of p-ethylbenzenesulfonamide in Example/. Obtained.

(Test method) The obtained thermal recording material was thermally recorded using a Gl mode thermal printer (Hifax 700; manufactured by Hitachi, Ltd.), and then the entire surface was exposed using Ricoh Super Dry 1OO (Ricoh ■). It took root. The degree of blue m of the obtained recorded image was measured using a Macbeth reflection densitometer. In addition, the yellow density of the background area was also measured. The results are shown in Table 1. On the other hand, heat recording again on the fixing part? When I checked, it was confirmed that no image was recorded and the image was fixed.

Next, in order to examine the raw storage stability, we checked the background density (fog) of the heat-sensitive recording material, and also stored the heat-sensitive recording material in a dark place for 2 hours under the conditions of ≠000, relative humidity and 0% RH, and forced deterioration. After completing all the tests, the fog was measured using a Macbeth reflection densitometer to see changes in fog.

Next, in order to investigate the decrease in optical density of the colored part due to long-term storage after thermal recording, a forced deterioration test was performed by storing the recording 1ItIi image of the thermal recording material in a dark place at 0C for 76 hours. The degree of decrease in density of the recorded image afterward was completely evaluated.

The results are shown in Table 1.

Claims (1)

[Claims] In a heat-sensitive recording material in which a recording layer containing a diazo compound and a coupling component is coated on a support, at least an arylsulfonamide compound in which the aryl group is substituted with an alkyl group, an alkoxy group, an aryloxy group, or a halogen atom is used. A heat-sensitive recording material comprising one or more types of heat-sensitive recording material in the recording layer.