JPS6140190A - Thermal recording material - Google Patents

Abstract

PURPOSE:To provide a thermal recording material having high preservability in raw state and high thermal color forming property, by microencapsulating a diazo compound while using a compound for lowering the glass transition point of a wall material for the microcapsules. CONSTITUTION:A diazo compound is microencapsulated and a compound for lowering the glass transition point of a wall material for the microcapsules (transition point controlling agent) is incorporated, in a thermal recording material in which a recording layer comprising a diazo compound, a coupling component and a basic substance or a substance becoming basic when being heated is provided on a base. The transition point controlling agent preferably lowers the glass transition point of the wall material to 80-150 deg.C. The agent may be a hydroxy compound, a carbamic acid ester compound, an aromatic methoxy compound or the like. Further, when a compound capable of lowering not only the glass transition point of the wall material but also the melting point of the coupling component or the basic compound is used as the agent, the color forming temperature is further lowered effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a heat-sensitive recording material, and particularly to a fixable diazo-based heat-sensitive recording material. More specifically, it has excellent storage stability before thermal recording.

Moreover, the present invention relates to a heat-sensitive recording material that has a high color density during thermal recording and can be optically fixed after thermal recording.

(Technical Background of the Invention) The heat-sensitive recording method has the following advantages: (1) Development is not required, (21) When the support is paper, the paper quality is similar to ordinary paper, (3) It is easy to handle, and (4) Color is developed. It has rapidly become popular in the field of facsimiles and printers in recent years due to its advantages such as high density, (5) simple and inexpensive recording device, and (6) no noise during recording. As a heat-sensitive recording material,
Leuco color-forming heat-sensitive recording materials are mainly used, which have excellent color development density and color development speed.

However, leuco color-forming heat-sensitive recording materials have the disadvantage that they develop color when handled, heated, or attached to solvents after recording, staining the recorded image, and the color is erased by the plasticizer in the cellophane tape. I also have In order to prevent color development due to careless handling, granular wax is added (Tokuko Sho IO-/11
13/) and providing a laminated layer to prevent the penetration of plasticizer (Utility Model Publication No. 13/2131μ). However, it is still not fully satisfactory and is not used particularly for the purpose of preventing falsification after recording.
Improvement was strongly desired. As a method to stop color development in unnecessary areas after thermal recording.

JP-A No. 17-123014, JP-A-Sho! 7-lko502
After thermal recording using a heat-sensitive recording material consisting of a diazo compound, a coupling component, and an alkali generator or coloring aid as disclosed in No. 2, etc., light irradiation is performed to decompose the unreacted diazo compound and develop color. There are known ways to stop it. However, in this recording material, the precoupling gradually deteriorates during storage, and undesirable discoloration (fogging) may occur. For this purpose, it is recommended to have one of the color-forming components present in the form of discontinuous particles (solid dispersion), which prevents contact between the components and prevents pre-coupling. There are disadvantages in that the storage stability (hereinafter referred to as raw storage stability) of the recording material is not yet sufficient and the thermal color development is reduced. As another measure, it is known to separate the diazo compound and the coupler component in separate layers to minimize contact between the components. 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 thermochromic properties, either the coupling component or the basic substance may be replaced with a non-polar waxy substance (JP-A No. 7-Reference No. 11Q, JP-A No. 17-17-263).
It is known that K may be isolated from other components by encapsulating it with a hydrophobic polymer substance (Japanese Patent Application Laid-Open No. 7-1 Takota Hiromu). However, these encapsulation methods involve dissolving wax or polymeric substances in their solvents, and dissolving or dispersing color-forming components in these solutions to form capsules. 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 which the wax or the solvent used to dissolve the polymeric substance must be removed after the capsules are formed, which is not completely satisfactory.

Therefore, in order to solve these problems, Tokugansho! As described in t-buj04AJK, excellent heat sensitivity can be achieved by a method in which a core material contains at least 4 species of components involved in a color reaction, and a wall is formed around this core material by polymerization to form a microcapsule. I found the recording material.

However, even in this method, a heat-sensitive recording material with even higher thermochromic properties has been 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 and high thermochromic properties.

The second purpose of the present invention is to photodecompose the diazo compound irradiated with light after thermal recording to stop color development in unnecessary areas (hereinafter referred to as
The object of the present invention is to provide a heat-sensitive recording material that can be fixed (referred to as "fixing").

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

(Structure of the Invention) As a result of intensive research, the present inventors have discovered that a heat-sensitive recording layer containing a diazo compound, a coupling component, and a basic substance (including substances that become basic by heat) is provided on a support. This was achieved by a heat-sensitive recording material that contains the diazo compound in microcapsules and has a compound that lowers the glass transition point of the wall material of the microcapsules.

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. It does not cause a reaction, but rather permeates through the microcapsule wall and causes a reaction by heating the reactive substance present in the core and outside of the microcapsule.

When used in combination with the microcapsules used in the present invention, the compound that lowers the glass transition point of the wall material of the microcapsules used in the present invention (hereinafter referred to as a transition point adjusting agent) is a commonly used thermoplastic material. Thermal coloring properties can be significantly improved compared to the above.

The glass transition point of the present invention was defined as the peak temperature of tan δ obtained from the following formula.

The transition point adjusting agent of the present invention is preferably one that lowers the glass transition point of the wall material of the microcapsule to t-10,/30°C, h0, and more preferably lowers it to ioo to lJO0C.

Specific examples of the transition point regulator of the present invention include the following.

That is, transition point adjusting agents include hydroxy compounds, carbamate ester compounds, aromatic methoxy compounds, etc. Specific examples of hydroxy compounds include pt-butylphenol, pt-octylphenol, p-α-cumyl Phenol, p-1-inchylphenol, m-xylenol, λ.

z-dime+ruphenol, 2. a, z-) IJ methylphenol, J-methyl-l-inopropylphenol,
p-benzylphenol% 0-cyclohexylphenol% p (diphenylmethyl)phenol% p (
α,α-diphenylethyl)phenol, 0-phenylphenol, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-methoxyphenol sp'toxy Phenol, p-hebutyloxyphenol, p-benzyloxyphenol, 3-
Dimethyl hydroxyphthalate, vanillin, /, /-bis(hydroxyphenyl)dodecane, 1. /-bis(
≠-hydroxyphenyl)-λ-ethylhexane, /
, l-bis(t-hydroxyphenyl)-2-methyl-
is methane, co.

Corbis (Hiro-hydroxyphenyl)-hebutane, λ-
Phenolic compounds such as t-i Chiru-Hiro-methoxyphenol-dimethoxyphenol, J,j'-dihydroxy-≠-methoxybenzophenone, co,j-dimethyl-2,! -hexanediol, resorcinol di(cohydroquiquethyl) ether, resorcinol mono(2-hydroxyethyl) ether, salicyl alcohol, 1,≠-di(hydroxyethoxy)benzene, p
-xylylene diol, l-phenyl-/,! -ethanediol, diphenylmethanol, /, /-diphenylethanol, 2-methyl-cophenylated 7.3-
Propanediol, 2. t-dihydroxymethyl-p-
Examples include alcohol compounds such as cresol benzyl ether, 2,6-dihydroxymethyl-p-cresol indyl ether, J-(o-methoxyphenoxy)-/, 2-pro/(andiol), etc.Specific examples of carbamate ester compounds Examples include N-phenylcarbamate ethyl ester, N-phenylcarbamate benzyl ester, N-phenylcarbamate phenethyl ester, carbamate hensyl ester, carbamate butyl ester, carbamate isopropyl ester, etc.Aromatic Specific examples of methoxy compounds include comethoxybenzoic acid, 3.j-dimethoxyphenylacetic acid, comethoxynaphthalene, /,J,!-)dimethoxybenzene, p-dimethoxybenzene, p-inzyloxymethoxybenzene, etc. .

These compounds are transported by the microcapsule wall material.
m or two or more types can be selected and used.

Furthermore, some of these compounds not only lower the glass transition point of the microcapsule wall material, but also lower the melting point of coupling components and basic substances. This is effective because the temperature is further reduced.

Generally, preferred transition point modifiers are hydroxy compounds, more specifically p-benzyloxyphenol% p-t-butylphenol, p-xylylene diol, and 2.6-inchylphenol.

The transition point regulator of the present invention is used in an amount of o, i to 10 parts by weight per 1 part by weight of the basic substance.

More preferably, it is in the range of 0.1 to 3 parts by weight.

Further, the transition point adjusting agent is not particularly limited in the production of the heat-sensitive recording material, but it is preferable to use it in the same manner as the basic substance.

The diazo compound used in the present invention has the general formula ArNz+
It is a diazonium salt represented by X-, which can develop a color by causing a coupling reaction with a coupling component, and can be decomposed by light.

(In the formula, Ar represents an aromatic moiety, N represents a % diazonium group, and X- represents an acid anion.) The aromatic moiety is represented by the following general formula.

In the formula, Y represents a substituted amino group, an alkoxy group, an arylthio group, an alkylthio group, or an acylamino group, and R represents an alkyl group, an alkoxy group, an arylamino group, or a halogen (I%Br%ct, F).

The substituted amino group for Y is preferably a monoalkylamino group, dialkylamino group, arylamino group, morpholino group, pyrrolidino group, pyrrolidino group, or the like.

Specific examples of diazonium compounds that form salts include l
-Diazo-7-dimethylaminobenzene, l-diazo-
7-diethylaminobenzene, l-diazo-1-dipropylaminobenzene, di-diazo-l-methylbenzylaminobenzene, terdiazo-l-dibenzylaminobenzene, ≠-diazo l-ethylhydroxyethylaminobenzene, Hiro-diazo -l-diethylamine-3-methoxybenzene, ≠-diazo 1-dimethylamine-2
-Methylbenzene, diazo-7-penzoylamino-λ, j-jethoxybenzene, Hiro-diazo-l-morpholinobenzene, μm diazo-7-morpholino-2,5
-jethoxybenzene, ≠-diazo7-morpholinoco,! -Jethoxybenzene, μm siazo/-anilinobenzene, ≠-diazo/-tolylmercapto-λ
, j-jethoxybenzene, goodiazo-/, ≠-methoxybenzoylamino-λ, j-jethoxybenzene,
Gudiazo-1-pyrrolidino-costilbenzene 8 and the like can be mentioned.

Specific examples of acid anions include CnFzn+□Cω-
(n is an integer from 3 to 2), CmFl! rrrl-180
3 (m is an integer from 2 to t), (αFzl-4-tsOg)
Examples thereof include zcH (l is an integer of / to it), 0H (n is an integer of 3 to 2), BF4, PF, -, and the like.

In particular, among the acid anions, those containing a chili-fluoroalkyl group or perfluoroalkenyl group, or PF6-, are preferred because they cause less increase in fog during raw storage.

Specific examples of the diazo compound (diazonium salt) include the following examples.

CsH5 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 resorcinol, phloroglucin%-13-dihydroxy nanotare. Sodium t-sulfonate, /-hydroxy-λ-
Naphthoic acid morpholinopropylamide, l! -dihydroxynaphthalene, co,3-dihydroxynaphthalene,
λ.

3-dihydroxy-t-sulfanylnaphthalene, co-hydroxy-3-naphthoic acid morpholinopropylamide, co-hydroxy-3-naphthoic acid anilide, co-hydroxy-3-naphthoic acid--2'-methylanilide, co-hydroxy-3-naphthoic acid anilide Acid ethanolamide, λ-
Hydroxy-3-naphthoic acid octylamide, co-hydroxy-3-naphthoic acid-N-dodecyl-oxy-propylamide, co-hydroxy-3-naphthoic acid tetradecylamide, acetanilide, acetoacetanilide,
Benzoylacetanilide, l-phenyl-3-methyl-y-pyrazolone, /-(λ', reference'.

4'-)dicyclophenyl)-3-benzamide-! −
Pyrazolone, /-(2',≠I,41)dicyclophenyl)-3-anilino-yo-pyrazolone, l-7
enyl-3-phenylacetamido-j-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.

As the basic substance of the present invention, a poorly water-soluble or water-insoluble basic substance or a substance that generates an alkali upon heating is used.

Basic substances include inorganic and organic ammonium salts, organic amines, amides, urea and thiourea and their derivatives, thiazoles, virols, pyrimidines, piperazines, guanidines, indoles, imidazoles, imidacillins, and triazoles. Examples include nitrogen-containing compounds such as morpholines, piperidines, aquidines, formazines, and pyridines. Specific examples of these are:
For example, ammonium acetate, tricyclohexylamine,
Tribenzylamine, octadecylamide, stearylamine, allyl urea, thiourea, methylthiourea, allylthiourea, ethylenethiourea, copendylimidazole, ≠-phenylimitasol, 2-phenyl-44-7f-ruimidazole, coun Decyl imidazoline.

Ko, ≠,! - triflyleucoimidazoline, l.

J-diphenyl-≠, 3-dimemethy-imidazoline, -1-phenyleucoimidazoline sl.

λ, 3-triphenylguanidine, /, 2-ditolylguanidine% / 9.2-dicyclohexylguanidine, /
, 2.3-) dicyclohexylguanidine, guanidine trichloroacetate, N,N'-dibenzylpiperazine,
Examples include p,p'-dithiomorpholine, morpholinium trichloroacetate, co-aminobenzothiazole, and λ-penzoylhydrazinopenzothiazole. These basic substances can also be used in combination.

The present invention improves shelf life and speeds up color development by dissolving the diazo compound contained in the core material of microcapsules in a water-insoluble organic solvent, emulsifying it, and then forming microcapsule walls through polymerization. It is also effective for increasing color density. /106 as an organic solvent
Those with a boiling point of 6 or higher are preferred, such as phosphoric acid esters, phthalic acid esters, other carboxylic acid esters, fatty acid amides, alkylated biphenyls, alkylated terphenyls,
Chlorinated paraffins, alkylated 7-talenes, diarylethanes, etc. are used. Specific examples include tricresyl phosphate, trioctyl phosphate, octyldiphenyl phosphate, tricyclohexyl phosphate, didutyl phthalate, dioctyl phthalate, dilauryl phthalate, dicyclohexyl phthalate, phthyl oleate, diethylene glycol dibenzoate, dioctyl sepacate, Dibutyl sepacate, dioctyl adipate, trioctyl trimellitate, acetyltriethyl citrate, octyl maleate, didutyl maleate, isopropylbiphenyl,
Isoamyl biphenyl, chlorinated paraffin, diisopropylnaphthalene%/11'-ditolylethane, J,
4t-Ditertiary aminophenol, N,N-dibutyl-cobutoxy! -Tertiary octylaniline and the like.

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

The microcapsules of the present invention are produced by emulsifying a core material containing a diazo compound, 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, and 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, more preferably polyurethane and polyurea.

Among the diazo compound, coupling component, and basic substance that are the main components used in the present invention, as the core material of the microcapsule, in addition to the diazo compound, a diazo compound and a coupling component, a diazo compound and a basic substance, or A diazo compound, a coupling component, and a basic substance can be used. When two types are used as core materials, they can be contained in the same microcapsule or in separate microcapsules. When using 3s as a core material, the three types cannot be contained in the same microcapsule, but there are various combinations. Other ingredients not used as the core material of the microcapsules are used in the heat-sensitive layer outside the microcapsules.

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 having a uniform particle size within a short period of time and which are suitable as recording materials with excellent shelf life.

This method and specific examples of compounds are described in U.S. Patent J.
, 7, 24, IO+ issue, same! , 7ft ,
It is described in the specification of No. tgt.

For example, when polyurethane is used as a capsule wall material, polyvalent incyanate and a second substance that reacts with it to form the capsule wall (for example, P IJol) are mixed into the oily liquid to be encapsulated and emulsified and dispersed in water. Then, by 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 polyinsyanate to be used and the polyol and polyamine to be reacted with it, -c refers to U.S. Patent J/Jj7/, U.S. Patent No. 1ariJIJ, U.S. Patent No. 3≠≦
tri JJ number, 37734Yj number, 37?3.2jf
No., Special Public Show 1it-1103≠7, Same Kota-≠7!
No. 2, Tokukai Showa 4A! -za0/9/issue, same 4Lt-rao
tt No. IICR shows that you can also use them.

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

Furthermore, by combining polyvalent isocyanate, which is a wall film-forming substance, and polyol, which is a second wall film-forming substance, the thermal permeability of the reactive substance can be changed arbitrarily.

Examples of the polyvalent isocyanate which is the seventh wall film-forming substance in the present invention include m-phenylene diisocyanate, S roof 1 di-diisocyanate, co-tolylene diisocyanate, 2゜4'-) IJ diisocyanate, etc. , naphthalene-l.

Daytime - diisocyanate, diphenylmethane -≠.

≠'-diisocyanate, J, J'-dimethoxy-1,
3'-biphenyl diisocyanate, 3゜3'-dimethyldiphenyl methanada, 3'-diisocyanate,
xylylene-/, Kujiinshi7ne-), 4', μ'-
Diphenylpronone diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate,
Propylene-7゜-1 diisocyanate, butylene-/
, J-diincyanate, cyclohexylene-7,λ-
diisocyanate, cyclohexylene-/, l-diisocyanate, etc.)% ” + ” t
≠“-triisocyanates such as triphenylmethane triisocyanate, toluene-J, 4<, 4-) diisocyanate, +, p'-dimethyldiphenylmethane-
2,2',j,! - tetraincyanates such as tetraisocyanate, adducts of hexamethylene diisocyanate and trimethylolpropane; There are incyanate prepolymers such as adducts of diisocyanate and hexanetriol.

Examples of the polyol that is the first wall-forming substance in the present invention include aliphatic and aromatic polyhydric alcohols, hydroxy polyesters, and hydroxyl alkylene ethers. Preferred polyols include the following CI)% (IT), (m) or (I) between two hydroxyl groups.
Examples include polyhydroxy compounds having the group V) in their molecular structure and having a molecular weight of j000 or less.

(I) an aliphatic hydrocarbon group having a carbon number of -1 (IV)
-〇-Ar-C-Ar-0-■ Here, Ar in (n), (II[), (■) represents a substituted or unsubstituted aromatic moiety, and the aliphatic hydrocarbon in (I) The group has a b -CnH2n 't'' basic skeleton, and the hydrogen group may be substituted with another element.

To give specific examples, examples of (I) include ethylene glycol, /, 3-propanediol, /, ≠-butanediol, l,! -bentanediol, /, 7-hexanediol, /, 7-hebutansinol, /, I-octanediol, propylene glycol, co, 3-dihydroxybutane, /, 2-dihydroxybutane, /, 3
-dihydroxybutane, λ, 2-dimethymethi, J--
10 pandiol, λ, 44-w<ntandiol, λ
, j-hexanediol, 3-methyl-/ , 2--
<Methanediol, /, 4! -Cyclohexane dimetatool, dihydroxycyclohexane, diethylene glycol, /, 2. Examples include t-trihydroxyhexane, phenylethylene glycol, /, /, /-trimethylolpronone, hexanetriol, pentaerythritol, and glycerin.

Examples of (I[) include %/l≠-di(cohydroxyethoxy)benzene, condensation products of aromatic polyhydric alcohols such as resorcinol dihydroxyethyl ether, and alkylene oxides.

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

Examples of (IV) include 4/-'-dihydroxydiphenylmethane, λ-(1)+p'-dihydroxydiphenylmethyl)indyl alcohol, and an adduct of ethylene oxide to bisphenol.

Examples include adducts of propylene oxide and bisphenol A. It is preferable to use the polyol in a ratio of 0.02 to 2 moles of hydroxyl groups to 7 moles of incyanate groups.When making microcapsules, water-soluble polymers can be used, but water-soluble polymers and includes water-soluble anionic polymers, nonionic polymers, and amphoteric polymers. The anionic polymers can be either natural or synthetic, such as -coo, -8Oa groups, etc. Examples include those having the following. 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-based (including hydrolyzed) copolymers, acrylic acid-based (including methacrylic acid-based) polymers and copolymers, and vinylinzenesulfonic acid-based polymers and copolymers. , carboxy-modified polyvinyl alcohol, etc.

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 0.0/-10 wt% aqueous solution. The particle size of the microcapsules is adjusted to 20μ or less. Generally, if the particle size exceeds 0μ, the print quality tends to deteriorate.

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

When making microcapsules, the diazo compound to be microencapsulated is 0. -2 wt'lr or more and can be made from a secondary emulsion.

The coupling component and basic substance used in the present invention are:
Whether it is contained inside the microcapsules or in the photosensitive layer outside the microcapsules, the amount of the coupling component is 0.0% per 1 part by weight of the diazo compound. /-10
It is preferable to use the coloring aid in an amount of O1/20 parts by weight. Further, it is preferable to apply the diazo compound by o, or-co, or 017m''.

When the coupling component, basic substance, and transition point regulator used in the present invention are not microencapsulated, they are preferably used after being dispersed in solid form using a sand mill or the like. Preferred water-soluble polymers include water-soluble polymers used when making microcapsules. At this time, the concentration of the water-soluble polymer is ~JOwt%, and the coupling component, basic substance, and transition point regulator are each added to n!% of the water-soluble polymer solution. It is added so that it becomes ~4'Owt%.

The dispersed particle size is preferably less than ioμ.

The heat-sensitive recording material of the present invention contains silica, barium sulfate, titanium oxide, aluminum hydroxide, zinc oxide,
Pigments such as calcium carbonate.

Fine powders such as styrene beads, urea-melamine resin, etc. can be used.

Similarly, metal soaps can also be used to prevent sticking. The amount of these used is 0.
2-7 fl/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.

Examples of heat-melting substances include substances that are solid at room temperature and have a melting point of 10 to 10°C and melt when heated by a thermal head, such as diazo compounds, coupling components, or basic substances. The thermofusible substance is 0. /, 10μ
Dispersed in the form of particles, solid content O1λ~7i/WL
Examples of thermofusible substances include:
Examples include fatty acid 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.

Binders include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, stardexypropylcellulose, gum arabic, gelatin, polyvinylvinyl, rubirolidone, casein, styrene-butadiene latex, acrylonitrile-butadiene latex, polyvinyl acetate, polyacrylic acid ester, ethylene-acetic acid. Various emulsions of vinyl copolymers can be used. The amount used is 0 solids, j,! fg/TrL2.

In the present invention, in addition to the above-mentioned materials, enoic acid,
Tartaric acid, oxalic acid, boric acid, phosphoric acid, picric acid can be added.

The heat-sensitive recording material of the present invention includes a coupling component, a basic substance, a main component of a transition point adjusting agent, and other additives as a core material of microcapsules, or as a solid dispersion, or as an aqueous solution. After dissolving and mixing, a coating solution is prepared and applied onto a support such as paper or synthetic resin film using coating methods such as par coating, blade coating, air knife coating, gravure coating, roll coating, spray coating, and dip coating. After coating and drying, the solid content is λ8! ~J
j Providing a heat-sensitive layer of 97 m 26 Another method is to add the coupling component, basic substance, main component of the transition point regulator, and other additives as the core material of the microcapsules, or to solidly disperse them. Alternatively, a coating solution is prepared by dissolving it as an aqueous solution and then mixing it, coating it on a support and drying it to form a precoat layer with a solid content of λ ~ 10g/WL2. The additive is added as the core material of the microcapsule, or is dispersed as a solid, or dissolved as an aqueous solution and then mixed to form a coating solution, which is then dried to form a coating layer with a solid content of /-/jfi/1rL2. It is also possible to use a laminated type.

The laminated type heat-sensitive recording material may have a reverse order of lamination, and the coating method may be sequential coating or simultaneous coating of the laminated layers. This laminated heat-sensitive recording material exhibits particularly excellent performance in long-term storage.

As the paper used for the support, alkyl ketene die 1-
Thermal extraction pHt sized with neutral sizing agents such as
It is advantageous in terms of storage stability over time to use neutral paper (described in Japanese Patent Application Laid-Open No. 2001-211021).

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, JP-A-77-//4
The paper described in No. 417 (meter basis weight) 2 and Bekk smoothness of 20 seconds or more is advantageous.

Further, paper having an optical surface roughness of lμ or less and a thickness of 30 to 30 m is described in Japanese Patent Application No. 17-200117.

JP-A-1F-4909/ Paper with a density of 01g to 3 or less and an optical contact ratio of 1ze4 or more, JP-A-1F-4909/
Canadian standard ν water level (JIS Pr
Paper made from Norzo that has been beaten to a temperature of 00σ or higher using JP-A-1T-47, which prevents coating liquid from penetrating
j5'j, which improves the color density and resolution by using the glossy side of a base paper made by a Yankee machine as the coating surface, and the method described in Japanese Patent Application Shoyo 7-/≠1172, which applies a corona discharge treatment to the base paper. , paper with improved coatability, etc. can also be used in the present invention with 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 exposing it to light to decompose unreacted diazo compounds after heating printing. I can do it. In addition, it can also be used as a heat-developable copying paper.

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

Example 1 The following diazo compound λ' portion and xylylene diinocyanate and trimethylol pronogun C3:/) adduct/I@
f It was added to a mixed solvent of 21 parts of dibutyl phthalate and 3 parts of ethyl acetate and dissolved. A solution of this diazo compound is mixed with polyvinyl alcohol 3. ! Part, gelatin/, 7 parts, water! was mixed with an aqueous solution in which 1 part was dissolved, and emulsified and dispersed at 0°C to obtain an emulsion with an average particle size of Jtt. 100 parts of water was added to the resulting emulsion, and the mixture was mixed with stirring. 'cK warm,
After 2 hours, a capsule liquid containing a diazo compound in the core substance was obtained.

(Diazo compound) Next, add λ hydroxy-3-naphthoic acid anilide λO part,
! Tipolyvinyl alcohol aqueous solution lo.

part and dispersed in a sand mill for about λ≠ hours to obtain an average particle size of 3
A dispersion of μ coupling components was obtained.

Next K) In addition to 100 parts of IJ phenylguanidine 20WHtj% polyvinyl alcohol aqueous solution, about 2
Dispersion was carried out for 4 hours to obtain a triphenylguanidine dispersion having an average particle size of Jμ.

Furthermore, in addition to 20 parts of pt-butylphenol and 100 parts of a fit% polyhinyl alcohol aqueous solution, approximately
The mixture was dispersed for 24 hours for one hour to obtain a dispersion of p-1-butylphenol with an average particle size of 3 μm.

Capsule liquid of diazo compound obtained as above 6
75 parts of a coupling component dispersion, 75 parts of a triphenylguanidine dispersion, and 30 parts of a p-1-butylphenol dispersion were added to 0 parts to prepare a coating liquid. This coating solution was bar coated onto smooth high-quality paper (jO1/m2) using coach-in-blonde so that the dry weight was 20 g/1rL2, and ≠! A heat-sensitive recording material was obtained by drying at 0C for 30 minutes.

The image density and color development start temperature of the obtained heat-sensitive recording material were measured by the following test methods. The results are shown in Table 1.

Separately, 20 parts of xylylene diisocyanate totrimethylolpropane (j:/) adduct was dissolved in 30 parts of ethyl acetate, coated on a polyethylene sheet with a bar, and submerged in water≠
After reacting and peeling at θ~to 0c, JIl, 'C%t
A film with a thickness of 10.20μ was obtained by air-drying at 1% RH"'CI. After immersing this film ep- in a methanol solution of 10% of 10% methylphenol for 30 hours, 2≠00% 4$ %
R) I was air-dried for one day to obtain a sample for measuring the glass transition point of the capsule wall material.

The glass transition point of the obtained sample film was measured by the following test method. The results are shown in Table 1.

On the other hand, the melting point of a /2/ mixture of triphenylguanidine and pt-butylphenol was investigated and the results are shown in Table 7.

(Test Method) (1) Measurement of Image Density and Color Development Start Temperature A heat-sensitive recording material was thermally recorded using GIII mode (Hifax 700> (manufactured by Hitachi, Ltd.). The image was fixed by exposing the entire surface to light using a commercially available commercially available product.

The image density, which is the blue density, of the obtained recorded image was measured using a laser reflection densitometer.

In addition, the heat-sensitive recording material is heated to J in the temperature range of tO,/100c.
OOg/cm'' using a heat stamp, and the temperature at which color development started was examined.

(2) Measurement of glass transition point Pybron DDV-II type (manufactured by Toyo Baldwin ■)
The dynamic storage modulus (E') and dynamic loss modulus (E") of the sample membrane were measured using .

Further, the heating rate at this time is λ'C/min.

(3) Measurement of melting point The mixture was heated using a scanning differential calorimeter DSC-IIC (manufactured by Perkin Elmer) at a heating rate of io 0c7min.
Measured by. The results are shown in Table 7.

Examples 2 to 6 Instead of p-t-butylphenol in Example 1, p-oxyindylphenol, p-xylylene diol, p-
A heat-sensitive recording material was obtained in the same manner as in Example 1, except that benzyl -oxybenzoate, j, J-dimethylphenol, or l, goudimethoxybenzyl was used. The color development start temperature and image density of the three types of heat-sensitive recording materials obtained were measured in the same manner as in Example 1.

Next, a sample for measuring the glass transition point of the capsule wall material was prepared in the same manner as in Example 1 using the above-mentioned transition point adjusting agent instead of pt-butylphenol. The points were measured.

Furthermore, the melting point of a 1:/ mixture of triphenylguanidine and the above transition point regulator was measured in the same manner as in Example 1.

The above results are shown in Table 1.

Comparative Example Samples for measuring the glass transition point of heat-sensitive recording materials and capsule wall materials were prepared in the same manner as in Example 1, except that pt-butylphenol in Example 1 was removed. Tested. On the other hand, the melting point was determined by measuring the melting point of pt-butylphenol alone. The results obtained are shown in Table 1.

Comparative example 2 In place of pt-butylphenol in Example 1.

λ, l-G-t-butyl! - Samples for measuring the glass transition points of heat-sensitive recording materials and capsule wall materials were prepared in the same manner as in Example 1, except that methylphenol was used, and tested in the same manner as in Example 1.

Also, triphenylguanidine and 2,4L-di-t-butyl-! - The melting point was determined for the mixture of l:/ with methylphenol. The results obtained are shown in Table 1.

As can be seen from Table 1, Examples 1, 2, 3, 4. In the case of li and 6, are there comparative examples in which these compounds are not added, or compounds that do not have the effect of lowering the glass transition point of the capsule wall material (although they do have the effect of lowering the melting point of triphenylguanidine)? Compared to Comparative Example 2, in which the material was added, the chromogenicity was lower and the image density was equally high, making it an excellent sympathothermal recording material.

Patent applicant: Fuji Photo Film Co., Ltd. Tesan Amendment J month 1985/7%

Claims (1)

[Claims] In a heat-sensitive recording material in which a recording layer containing a diazo compound, a coupling component, and a basic substance or a substance that becomes basic by heat is provided on a support, the diazo compound is contained in microcapsules, and the diazo compound is contained in microcapsules. A heat-sensitive recording material characterized by containing a compound that lowers the glass transition point of a wall material.