JPH08290662A - Thermal recording material - Google Patents

Abstract

PURPOSE: To provide a thermal recording material in which a component in a coat layer does not adhere to a heat head by melting at the time of heat coloring, adhering of residue is only a little, and density of coloring images is high (image density is not lowered by the protective layer). CONSTITUTION: In a thermal recording material, a thermal coloring layer having, as main components, a leuco dye, a developer for developing the color of the leuco dye with heat, and a binder resin as a binding agent is provided on a support body, and a protective layer is provided thereon. The protective layer contains a resin wherein silicone segments are bonded in a block shape or a graft shape.

Description

Detailed Description of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording medium utilizing a color-developing reaction between an electron-donating color-forming compound and an electron-accepting compound, which is a heat-sensitive recording material having high density and excellent head matching property. It is about.

[0003]

2. Description of the Related Art Various recording materials have been proposed which utilize a color-forming reaction between a colorless or light-colored leuco dye and a color-developing agent which develops color upon contact by heat or pressure. One of the heat-sensitive recording materials is that they do not require complicated processing such as development and fixing, can be recorded in a short time with a relatively simple device, generate little noise, and have low cost. It is useful as various recording materials for electronic calculators, facsimiles, ticket vending machines, label printers, recorders and the like. As the color-forming dye used in the heat-sensitive recording material, for example, a colorless or light-colored leuco dye having a lactone, a lactam or a spiropyran ring, and as a developer, an organic acid, a phenolic substance, or the like has been conventionally used. The heat-sensitive recording material using the leuco dye and the color developer is widely used because of its high image density and high whiteness of the background. Such a heat-sensitive recording material, when the heat-sensitive color development, the components in the coating layer are melted and stick to the thermal head or cause dust adhesion, resulting in a decrease in the density and sharpness of the color image.
There is a defect that the color image is easily distorted, and paper feeding problems are likely to occur. As a method of improving such a defect, a filler containing a large amount of oil is contained in the protective layer (JP-A-58-58).
No. 208091, JP-A-58-051189, etc.) have been proposed, but these proposed techniques have a drawback that although the adhesion of dust is improved, the transparency of the protective layer is lowered and the image density is lowered. In addition, a method of adding zinc stearate, aluminum stearate, and wax has been proposed, but these have the drawback of promoting sticking of debris, although sticking is improved because they melt and exhibit lubricity. Further, based on the total amount of all the monomer units, it has 30% by weight or more of styrene monomer units and has a glass transition point of 70.
Radical containing 1 to 20% by weight of a vinyl monomer which is a graft polymer having a branching component having a methyl methacrylate monomer unit as a main constituent and which is formed by a macromonomer and has a trunk component having a hydroxyl group, Method for forming a protective layer made of a graft polymer formed of a polymerizable monomer mixture (JP-A-2-151479)
Gazette) or polyvinyl alcohol or a completely saponified product thereof, modified polyvinyl alcohol such as silicon modified, carboxyl modified or acetoacetyl modified with (meth) acrylamide, (meth) acrylic acid ester and / or (meth) acrylic acid. A method of using a polymerized overcoating agent (Japanese Patent Laid-Open No. 1-230681) is also known, but these methods also have problems in coating property and thermosensitive color development, and in image contrast. There are drawbacks such as not being able to avoid dust residue. Further, a method of adding a silicon resin (Japanese Patent Laid-Open No. 57-105392,
JP-A-59-091090, JP-A-62-15699
0, JP-A-62-196624, JP-A-1-198838.
6, JP-A-3-057693, etc.) have been proposed, but since these resins have a weak binding force and a weak binding force with the lower layer, they are liable to be scraped and should not be mixed with other resins for use. There is no choice but to obtain a sufficient effect.
Furthermore, a method of adding silicone oil (JP-A-3-57)
No. 693) has been proposed, but it is not sufficient because it is liable to adhere to dust. JP-A-2-178084 discloses an aqueous silicone oil having a reactive substituent such as an amino group, an epoxy group, a carboxyl group, and an alkoxyl group on the heat-sensitive recording layer, specifically, Toray Silicone ( Epoxy polyether modified silicone oil (SF-8421), alcohol modified silicone oil (SF-8427) and silicone oil emulsion, for example, amino-modified silicone emulsion (SM- manufactured by Toray Silicone Co., Ltd.). 8702, SM-
8709, BY-22-812, BY22-816, B
Y22-819, BY22-823) or a carboxy-modified silicone emulsion (BY-22-820) or the like, but it is described that an overcoat layer containing a silicone oil and a water-soluble resin or a water-dispersible resin is provided. The water-soluble resin in this technique is polyvinyl alcohol or modified polyvinyl alcohol, for example, fully saponified or partially saponified polyvinyl alcohol, acetoacetylated polyvinyl alcohol having an acetoacetyl group introduced by reacting polyvinyl alcohol with diketene,
Reaction products of polyvinyl alcohol with polyvalent carboxylic acids such as fumaric acid, phthalic anhydride, trimellitic anhydride, and itaconic anhydride, or esterification products of these reactions, vinyl acetate and maleic acid, fumaric acid, itaconic acid, croton Acid, acrylic acid, carboxy-modified polyvinyl alcohol obtained as a saponification product of copolymerization with ethylenically unsaturated carboxylic acid such as methacrylic acid, vinyl acetate and ethylene sulfonic acid, and olefin sulfonic acid such as allyl sulfonic acid or a salt thereof. Sulfonic acid-modified polyvinyl alcohol obtained as a saponified product of the copolymer of olefin, modified olefin obtained by saponifying a copolymer of vinyl acetate with olefins such as ethylene, propylene, isobutylene, α-octene, α-dotecene, α-octadodecene Polyvinyl alcohol Nitrile-modified polyvinyl alcohol, which is obtained as a saponification product of a copolymer of vinyl acetate and acrylonitrile, methacrylonitrile, etc., obtained by saponifying a copolymer of vinyl acetate and amides, such as acrylamide and methacrylamide. An amide-modified polyvinyl alcohol, an epoxy-modified polyvinyl alcohol having an epoxy group as a substituent, a pyrrolidone-modified polyvinyl alcohol obtained by saponifying a copolymer of vinyl acetate and N-vinylpyrrolidone, and
The water-soluble or water-dispersible silicone and the water-soluble or water-dispersible polyvinyl alcohol or modified polyvinyl alcohol are simply mixed and not blocked or grafted with each other. Has not solved.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned drawbacks and to prevent the components in the coating layer from being melted and not sticking to the thermal head at the time of color development by heating, resulting in less dust adhesion and color development. Another object of the present invention is to provide a heat-sensitive recording material having a high image density (no reduction in image density due to the protective layer).

[0005]

The object of the present invention is to provide "a heat-sensitive material containing, as a main component, a leuco dye on a support, a color developer that heat-colors the leuco dye and a binder resin as a binder. A heat-sensitive recording material comprising a color-forming layer and a protective layer formed on the color-forming layer, wherein the protective layer contains a resin having a silicone segment bonded in a block or graft form. , "A thermosensitive coloring layer containing a leuco dye on a support, a color developer that heat-colors the leuco dye and a binder resin as a binder, as a main component, and a protective layer on the thermosensitive coloring layer. A thermosensitive recording material characterized in that the protective layer contains a (meth) acrylic acid ester resin in which a silicone segment is bonded in a block or graft form. A leuco dye on a carrier, a thermosensitive coloring layer mainly composed of a binder resin as a binder and a developer that heat-colors the leuco dye, and a thermosensitive recording material having a protective layer formed thereon, In the protective layer, a thermosensitive recording material characterized by containing a polyvinyl butyral resin in which a silicone segment is bonded in a block or graft form "," leuco dye on a support,
In a thermosensitive recording material comprising a thermosensitive coloring layer containing a binder resin as a developing agent and a binder for heating the leuco dye under heating, and a protective layer thereon, a silicone segment is contained in the protective layer. A heat-sensitive recording material containing a polyvinyl acetoacetal resin bound in a block or graft form "," a leuco dye on a support, a developer and a binder that cause the leuco dye to develop color by heating. In a thermosensitive recording material comprising a thermosensitive coloring layer containing a binder resin as a main component as a main component, and a protective layer formed on the thermosensitive coloring layer, cellulose acetate having a silicone segment bonded in a block or graft form in the protective layer. Thermal recording material characterized by containing propionate resin "," Leuco dye on support, color development by heating leuco dye In a thermosensitive recording material comprising a thermosensitive color-developing layer containing a binder resin as a developer and a binder as a main component, and further a protective layer provided thereon, a silicone segment is in a block or graft form in the protective layer. A heat-sensitive recording material containing ethyl cellulose bound to ",""a leuco dye on a support, a developer which heat-colors the leuco dye, and a binder resin as a binder as a main component. A heat-sensitive color forming layer, and a heat-sensitive recording material having a protective layer formed thereon, wherein the protective layer contains a polyurethane resin having a silicone segment bonded in a block or graft form. "A thermosensitive recording material" and "a leuco dye on a support, a color developer that heat-colors the leuco dye and a binder resin as a binder. The heat-sensitive coloring layer,
Further, in the heat-sensitive recording material having a protective layer formed thereon, the protective layer contains a resin in which silicone segments are bonded in a block or graft form, and the developer is represented by the following general formula (1). It is achieved by a thermosensitive recording material characterized by using a resin having a hydroxyl group in the molecule as a binder resin.

[0006]

[General formula 1] (R ₁ represents a straight-chain alkyl group having 12 to 28 carbon atoms) That is, according to the present invention, generally, a leuco dye, a developer and a binder for coloring the leuco dye by heating are formed on a support. A thermosensitive coloring layer containing a binder resin as a main component, and a thermosensitive recording material provided with a protective layer thereon,
There is provided a heat-sensitive recording material comprising a resin in which silicone segments are bonded in a block or graft form in the protective layer. The heat-sensitive recording material of the present invention uses a resin in which a silicone segment is bonded in a block form or a graft form in the protective layer, so that the components in the coating layer do not melt and stick to the thermal head during color development by heating. In addition, it is excellent in so-called head matching properties with less dust adhesion, and the protective layer is transparent, and the image density is excellent. Details of the thermosensitive recording medium of the present invention will be described. The support used in the present invention is not particularly limited, a polyester film such as polyethylene terephthalate and polybutylene terephthalate, a cellulose derivative film such as cellulose triacetate, a polypropylene film such as polypropylene and polyethylene, a polystyrene film or a transparent film obtained by laminating these. A film, general paper, synthetic paper or the like can be used. The color former used in the present invention is a compound exhibiting an electron-donating property, and is applied alone or as a mixture of two or more kinds, but it is a colorless or light-colored dye precursor per se, and is not particularly limited and is a conventionally known one. , For example,
Triphenylmethanephthalide type, triallylmethane type,
Fluoran-based, phenothidian-based, thioferolane-based, xanthene-based, indophthalyl-based, spiropyran-based, azaphthalide-based, chromenopyrazole-based, methine-based, rhodamine-anilinolactam-based, rhodamine-lactam-based, quinazoline-based, diazaxanthene-based, bis-lactone A leuco compound such as a system is preferably used. Examples of such compounds include those shown below. 2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-
(Di-n-butylamino) fluorane, 2-anilino-
3-Methyl-6- (Nn-propyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N
-Isopropyl-N-methylamino) fluorane, 2-
Anilino-3-methyl-6- (N-isobutyl-N-methylamino) fluorane, 2-anilino-3-methyl-
6- (Nn-amyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-sec-butyl-N-ethylamino) fluorane, 2-anilino-
3-Methyl-6- (Nn-amyl-N-ethylamino) fluorane, 2-anilino-3-methyl-6- (N
-Isoamyl-N-ethylamino) fluorane, 2-anilino-3-methyl-6- (Nn-propyl-N-isopropylamino) fluorane, 2-anilino-3-methyl-6- (N-cyclohexyl-N -Methylamino)
Fluoran, 2-anilino-3-methyl-6- (N-ethyl-p-toluidino) fluoran, 2-anilino-3
-Methyl-6- (N-methyl-ptoluidino) fluorane, 2- (m-trichloromethylanilino) -3-methyl-6-diethylaminofluorane, 2- (m-trifluoromethylanilino) -3- Methyl-6-diethylaminofluorane, 2- (m-trifluoromethylanilino) -3-methyl-6- (N-cyclohexyl-N-methylamino) fluorane, 2- (2,4-dimethylanilino)- 3-methyl-6-diethylaminofluorane,
2- (N-ethyl-ptoluidino) -3-methyl-6
-(N-ethylanilino) fluorane, 2- (N-methyl-p-toluidino) -3-methyl-6- (N-propyl-p-toluidino) fluoran, 2-anilino-6-
(Nn-hexyl-N-ethylamino) fluorane,
2- (o-chloranilino) -6-diethylaminofluorane, 2- (o-bromoanilino) -6-diethylaminofluorane, 2- (o-chloranilino) -6-dibutylaminofluorane, 2- (o-fluoroanilino)
-6-Dibutylaminofluorane, 2- (m-trifluoromethylanilino) -6-diethylaminofluorane, 2- (p-acetylanilino) -6- (Nn-amyl-Nn-butyl) Amino) fluorane, 2-benzylamino-6- (N-ethyl-ptoluidino) fluorane, 2-benzylamino-6- (N-methyl-2,4
-Dimethylanilino) fluorane, 2-benzylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-dibenzylamino-6- (N-methyl-p
Toluidino) fluoran, 2-dibenzylamino-6
-(N-ethyl-ptoluidino) fluorane, 2-
(Di-p-methylbenzylamino) -6- (N-ethyl-ptoluidino) fluorane, 2- (α-phenylethylamino) -6- (N-ethyl-ptoluidino) fluorane, 2-methylamino-6 -(N-methylanilino) fluorane, 2-methylamino-6- (N-ethylanilino) fluorane, 2-methylamino-6- (N-
Propylanilino) fluorane, 2-ethylamino-6
-(N-methyl-p-toluidino) fluorane, 2-methylamino-6- (N-methyl-2,4-dimethylanilino) fluorane, 2-ethylamino-6- (N-methyl-2,4-dimethyl) Anilino) fluorane, 2-dimethylamino-6- (N-methylanilino) fluorane,
2-Dimethylamino-6- (N-ethylanilino) fluorane, 2-diethylamino-6- (N-methyl-ptoluidino) fluorane, 2-diethylamino-6-
(N-ethyl-p-toluidino) fluorane, 2-dipropylamino-6- (N-methylanilino) fluorane, 2-dipropylamino-6- (N-ethylanilino) fluorane, 2-amino-6- (N-methylanilino) ) Fluoran, 2-amino-6- (N-ethylanilino) fluorane, 2-amino-6- (N-propylanilino) fluorane, 2-amino-6- (N-methyl-p)
Toluidino) fluorane, 2-amino-6- (N-ethyl-ptoluidino) fluorane, 2-amino-6-
(N-propyl-p-toluidino) fluorane, 2-amino-6- (N-methyl-p-ethylanilino) fluorane, 2-amino-6- (N-ethyl-p-ethylanilino) fluorane, 2-amino-6- (N -Propyl-
p-ethylanilino) fluorane, 2-amino-6-
(N-methyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-propyl-2,4) -Dimethylanilino) fluorane, 2-amino-6- (N-methyl-p-chloroanilino) fluorane, 2-amino-6- (N-ethyl-p-chloroanilino) fluorane, 2-amino-6- (N-propyl-) p
-Chloranilino) fluorane, 2,3-dimethyl-6
-Dimethylaminofluorane 3-methyl-6- (N-ethyl-ptoluidino) fluorane, 2-chloro-6-
Diethylaminofluorane, 2-bromo-6-diethylaminofluorane, 2-chloro-6-dipropylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 3-bromo-6-cyclohexylaminofluorane, 2- Chlor-6- (N-ethyl-N-isoamylamino) fluorane, 2-chloro-3-methyl-6-
Diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, 2- (o-chloroanilino) -3-chloro-6-cyclohexylaminofluorane, 2- (m-trifluoromethylanilino) -3-
Chlor-6-diethylaminofluorane, 2- (2,3
-Dichloroanilino) -3-chloro-6-diethylaminofluorane, 1,2-benzo-6-diethylaminofluorane, 1,2-benzo-6- (N-ethyl-N-isoamylamino) fluorane, 1,2- Benzo-6-dibutylaminofluorane, 1,2-benzo-6- (N-
Ethyl-N-cyclohexylamino) fluorane, 1,
2-benzo-6- (N-ethyl-toluidino) fluorane, etc. Specific examples of other color formers preferably used in the present invention are as follows. 2-anilino-3-methyl-6- (N-2-ethoxypropyl-N-
Ethylamino) fluorane, 2- (p-chloroanilino) -6- (Nn-octylamino) fluorane, 2
-(P-Chloranilino) -6- (N-n-partimylamino) fluorane, 2- (p-chloranilino) -6
-(Di-n-octylamino) fluorane, 2-benzoylamino-6- (N-ethyl-ptoluidino) fluorane, 2- (o-methoxybenzoylamino) -6-
(N-ethyl-p-toluidino) fluorane, 2-dibenzylamino-4-methyl-6-diethylaminofluorane, 2-dibenzylamino-4-methoxy-6- (N
-Methyl-p-toluidino) fluorane, 2-dibenzylamino-4-methyl-6- (N-ethyl-p-toluidino) fluorane, 2- (α-phenylethylamino)
-4-Methyl-6-diethylaminofluorane, 2-
(P-toluidino) -3- (t-butyl) -6- (N-
Methyl-p-toluidino) fluorane, 2- (o-methoxycarbonylanilino) -6-diethylaminofluorane, 2-acetylamino-6- (N-methyl-p-toluidino) fluorane, 3-diethylamino-6- (m
-Trifluoromethylanilino) fluorane, 4-methoxy-6- (N-ethyl-p-toluidino) fluorane, 2-ethoxyethylamino-3-chloro-6-dibutylaminofluorane, 2-dibenzylamino-4- Chlor-6- (N-ethyl-p-toluidino) fluorane, 2- (α-phenylethylamino) -4-chloro-
6-diethylaminofluorane, 2- (N-benzyl-
p-trifluoromethylanilino) -4-chloro-6-diethylaminofluorane, 2-anilino-3-methyl-
6-pyrrolidinofluorane, 2-anilino-3-chloro-6-pyrrolidinofluorane, 2-anilino-3-methyl-6- (N-ethyl-N-tetrahydrofurfurylamino) fluorane, 2-mesitidino- 4 ', 5'-benzo-6-diethylaminofluorane, 2- (m-trifluoromethylanilino) -3-methyl-6-pyrrolidinofluorane, 2- (α-naphthylamino) -3,4-benzo- 4'-Bromo-6- (N-benzyl-N-cyclohexylamino) fluorane, 2-piperidino-6-diethylaminofluorane, 2- (N-n-propyl-p-trifluoromethylanilino) -6-morpho Rinofluorane, 2- (di-N-p-chlorophenyl-methylamino) -6-pyrrolidinofluorane, 2- (N-n-propyl-m-trifluoro) Chiruanirino) -6-morpholinophenyl fluoran, 1,2-benzo-6- (N-ethyl -
Nn-octylamino) fluorane, 1,2-benzo-6-diallylaminofluorane, 1,2-benzo-6
-(N-ethoxyethyl-N-ethylamino) fluorane, benzoleucomethylene blue 2- {3,6-bis (diethylamino)}-6- (o-chloroanilino) xanthyl lactam benzoate, 2-
{3,6-bis (diethylamino)}-9- (o-chloroanilino) xanthyl lactam benzoate, 3,3-bis (p-dimethylaminophenyl) phthalide, 3,3-
Bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis (p-dimethylaminophenyl)-
6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-
Bis (p-dibutylaminophenyl) phthalide, 3-
(2-Methoxy-4-dimethylaminophenyl) -3-
(2-hydroxy-4,5-dichlorophenyl) phthalide, 3- (2-hydroxy-4-dimethylaminophenyl) -3- (2-methoxy-5-chlorophenyl) phthalide, 3- (2-hydroxy-) 4-dimethoxyaminophenyl) -3- (2-methoxy-5-chlorophenyl)
Phthalide, 3- (2-hydroxy-4-dimethylaminophenyl) -3- (2-methoxy-5-nitrophenyl) phthalide, 3- (2-hydroxy-4-diethylaminophenyl) -3- (2-methoxy- 5-methylphenyl) phthalide, 3,6-bis (dimethylamino) fluorene spiro (9,3 ′)-6′-dimethylaminophthalide, 6′-chloro-8′-methoxy-benzoindolino-spiropyran, 6 '-Bromo-2'-methoxy-benzoindolino-spiropyran and the like. Next, the color developer used in the present invention is an electron-accepting compound, and various conventionally known electron-accepting color developers can be used. It is an electron-accepting developer containing a long-chain alkyl group in the molecule, as disclosed in Japanese Patent No. 124360. For example, an organic phosphoric acid compound, an aliphatic carboxylic acid compound or a phenol compound having an aliphatic group having 12 or more carbon atoms, or a metal salt of mercaptoacetic acid having an aliphatic group having 10 to 18 carbon atoms, or 5 to 8 carbon atoms. Alkyl ester of caffeic acid with 1 alkyl group and 1 carbon
Examples thereof include acidic phosphoric acid esters having 6 or more aliphatic groups.
The aliphatic group includes a linear or branched alkyl group and alkenyl group, and may have a substituent such as a halogen, an alkoxy group and an ester. Specific examples of the developer will be illustrated below. (A) Organic Phosphoric Acid Compound In the present invention, an organic phosphoric acid compound represented by the following general formula (1) is preferably used.

[0007]

[General formula 1] (R ₁ represents a linear alkyl group having 12 to 28 carbon atoms) Specific examples of the organic phosphoric acid compound represented by the general formula (1) include the following. Dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, docosylphosphonic acid, tetracosylphosphonic acid, hexacosylphosphonic acid, octacosylphosphonic acid and the like. As the organic phosphoric acid compound, α-hydroxyalkylphosphonic acid represented by the following general formula (2) is also preferably used.

[0008]

[General formula 2] (However, R ₂ is an aliphatic group having 11 to 29 carbon atoms.) Specific examples of the α-hydroxyalkylphosphonic acid represented by the general formula (2) include α-hydroxydodecylphosphonic acid and α-hydroxytetracarboxylic acid. Examples thereof include decylphosphonic acid, α-hydroxyhexadecylphosphonic acid, α-hydroxyoctadecylphosphonic acid, α-hydroxyeicosylphosphonic acid, α-hydroxydocosylphosphonic acid, and α-hydroxytetracosylphosphonic acid. Also,
As the organic phosphoric acid compound, an acidic organic phosphoric acid ester represented by the following general formula (3) is also preferably used.

[0009]

[General formula 3] (In the formula, R ₃ represents an aliphatic group having 16 or more carbon atoms, and R ₄ represents a hydrogen atom or an aliphatic group having 1 or more carbon atoms.) An acidic organic phosphate ester represented by the general formula (3) Specifically, dihexadecyl phosphate, dioctadecyl phosphate, dieicosyl phosphate, didocosyl phosphate, monohexadecyl phosphate,
Examples include monooctadecyl phosphate, monoeicosyl phosphate, monodocosyl phosphate, methyl hexadecyl phosphate, methyl octadecyl phosphate, methyl eicosyl phosphate, methyl docosyl phosphate, amyl hexadecyl phosphate, octyl hexadecyl phosphate, and lauryl hexadecyl phosphate. To be

(B) Aliphatic carboxylic acid compound In the present invention, as the aliphatic carboxylic acid compound, α-hydroxy fatty acids represented by the following general formula (4) are preferably used.

[0011]

[General formula 4] (However, R ₅ represents an aliphatic group having 12 or more carbon atoms.) Examples of the α-hydroxy aliphatic carboxylic acid compound represented by the general formula (4) include the following.
α-hydroxydecanoic acid, α-hydroxytetradecanoic acid, α-hydroxyhexadecanoic acid, α-hydroxyoctadecanoic acid, α-hydroxypentadecanoic acid, α-hydroxyeicosanoic acid, α-hydroxydocosanoic acid, α
-Hydroxytetracosanoic acid, α-hydroxyhexacosanoic acid, α-hydroxyoctacosanoic acid, etc. As the aliphatic carboxylic acid compound, an aliphatic carboxylic acid compound having an aliphatic group having 12 or more carbon atoms which is substituted with a halogen element and having a halogen element at at least the α-position or β-position carbon is also preferable. Used. Specific examples of such a compound include the followings. 2-bromohexadecanoic acid, 2-bromoheptadecanoic acid, 2-bromooctadecanoic acid, 2-bromoeicosanoic acid, 2-bromodocosanoic acid, 2-bromotetracosanoic acid, 3-bromooctadecanoic acid, 3-bromoeicosanoic acid 2,3-dibromooctadecanoic acid, 2-fluorododecanoic acid, 2-fluorotetradecanoic acid, 2-fluorohexadecanoic acid, 2-fluorooctadecanoic acid, 2
-Fluoroeicosanoic acid, 2-fluorodocosanoic acid, 2
-Iodohexadecanoic acid, 2-iodooctadecanoic acid,
3-iodohexadecanoic acid, 3-iodooctadecanoic acid, perfluorooctadecanoic acid and the like. Further, the aliphatic carboxylic acid is an aliphatic carboxylic acid compound having an aliphatic group having 12 or more carbon atoms and having an oxo group in carbon, and at least the carbon at the α-position, β-position or γ-position becomes an oxo group. Those that are used are also preferably used. Specific examples of such a compound include the followings. 2-oxododecanoic acid, 2-oxotetradecanoic acid, 2-oxohexadecanoic acid, 2-oxooctadecanoic acid, 2-oxoeicosanoic acid, 2-oxotetracosanoic acid, 3-oxododecanoic acid, 3-oxotetradecanoic acid, 3-oxohexadecanoic acid, 3-oxooctadecanoic acid, 3-oxoeicosanoic acid, 3-oxotetracosanoic acid, 4-oxohexadecanoic acid, 4-oxooctadecanoic acid, 4-oxodocosanoic acid and the like. Further, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (5) is also preferably used.

[0012]

[General formula 5] (However, R ₆ represents an aliphatic group having 12 or more carbon atoms,
X represents an oxygen atom or a sulfur atom, and n represents 1 or 2. Specific examples of the dibasic acid represented by the general formula (5) include:
For example: Dodecylmalic acid, tetradecylmalic acid, hexadecylmalic acid, octadecylmalic acid, eicosylmalic acid, docosylmalic acid, tetracosylmalic acid, dodecylthiomalic acid, tetradecylthiomalic acid, hexadecylthiomalic acid,
Octadecyl thiomalic acid, eicosyl thiomalic acid,
Docosylthiomalic acid, tetracosylthiomalic acid, dodecyldithiomalic acid, tetradecyldithiomalic acid,
Eicosyl dithiomalic acid, docosyl dithiomalic acid,
Tetracosyldithiomalic acid, etc. Furthermore, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (6) is also preferably used.

[0013]

[General formula 6] (However, R ₇ , R ₈ , and R ₉ represent hydrogen or an aliphatic group, at least one of which is an aliphatic group having 12 or more carbon atoms.) Specific examples of the dibasic acid represented by the general formula (6) For example,
For example: Dodecyl butanedioic acid,
Tridecyl butanedioic acid, tetradecyl butanedioic acid, pentadecyl butanedioic acid, octadecyl butanedioic acid, eicosyl butanedioic acid, docosyl butanedioic acid, 2,3-dihexadecyl butanedioic acid, 2,3-dioctadecyl Butanedioic acid, 2-methyl-3-dodecylbutanedioic acid, 2-methyl-3-tetradecylbutanedioic acid, 2-methyl-3-hexadecylbutanedioic acid, 2-ethyl-3-dodecylbutanedioic acid, 2-propyl-3-dodecylbutanedioic acid, 2-octyl-3-hexadecylbutanedioic acid, 2-tetradecyl-3-octadecylbutanedioic acid and the like. Furthermore, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (7) is also preferably used.

[0014]

[General formula 7] (However, R ₁₀ and R ₁₁ represent hydrogen or an aliphatic group, at least one of which is an aliphatic group having 12 or more carbon atoms.) Specific examples of the dibasic acid represented by the general formula (7) ,
For example, the following may be mentioned. Dodecylmalonic acid, tetradecylmalonic acid, hexadecylmalonic acid, octadecylmalonic acid, eicosylmalonic acid, docosylmalonic acid, tetracosylmalonic acid, didotecilmalonic acid,
Ditetradecylmalonic acid, dihexadecylmalonic acid, dioctadecylmalonic acid, dieicosylmalonic acid, didocosylmalonic acid, methyloctadecylmalonic acid, methyldocosylmalonic acid, methyltetracosylmalonic acid, ethyloctadecylmalonic acid, ethyl Eicosyl malonic acid, ethyl docosyl malonic acid, ethyl tetracosyl malonic acid, etc. Furthermore, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (8) is also preferably used.

[0015]

[General formula 8] (However, R ₁₂ represents hydrogen or an aliphatic group, n represents 0 or 1, m represents 1, 2 or 3, and when n is 0, m is 2 or 3 and n is 1 If m is 1 or 2
As a specific example of the dibasic acid represented by the general formula (8),
For example, the following may be mentioned. 2-dodecyl-
Pentanedioic acid, 2-hexadecyl-pentanedioic acid, 2-
Octadecyl pentanedioic acid, 2-eicosyl-pentanedioic acid, 2-docosyl-pentanedioic acid, 2-dodecyl-hexanedioic acid, 2-pentadecyl-hexanedioic acid, 2-octadecyl-hexanedioic acid, 2-eicosyl-hexane. Diacid, 2-docosyl-hexanedioic acid and the like. Furthermore, as the aliphatic carboxylic acid compound, a tribasic acid such as citric acid acylated with a long chain fatty acid is also preferably used. Specific examples thereof include the following.

[0016]

[A] O-palmityl citric acid

[B] O-stearyl citric acid

[C] O-eicosyl enoic acid (C) Phenol compound In the present invention, a compound represented by the following general formula (9) is preferably used as the phenol compound.

[0017]

[General formula 9] (However, Y is -S-, -O-, -CONH-, or -C.
OO-, R ₁₃ represents an aliphatic group having 12 or more carbon atoms, and n is an integer of 1, 2 or 3) Specific examples of the phenol compound represented by the general formula (9) are shown below. Something like this. p- (dodecylthio) phenol, p- (tetradecylthio) phenol, p- (hexadecylthio) phenol, p- (octadecylthio) phenol, p- (eicosylthio) phenol, p- (docosylthio) phenol, p- (tetracosyl) Ruthio) phenol, p- (dodecyloxy) phenol, p- (tetradecyloxy) phenol, p- (hexadecyloxy) phenol, p- (octadecyloxy) phenol, p- (eicosyloxy) phenol, p- ( Docosyloxy)
Phenol, p- (tetracosyloxy) phenol,
p-dodecylcarbamoylphenol, p-tetradecylcarbamoylphenol, p-hexadecylcarbamoylphenol, p-octadecylcarbamoylphenol, p-eicosylcarbamoylphenol, p-docosylcarbamoylphenol, p-tetracosylcarbamoylphenol, hexa gallic acid Decyl ester,
Gallic acid octadecyl ester, gallic acid eicosyl ester, gallic acid docosyl ester, gallic acid tetracosyl ester, etc. As the phenol compound, a caffeic acid alkyl ester represented by the following general formula (10) can also be used.

[0018]

[General formula 10] (However, R ₁₄ is an alkyl group having 5 to 8 carbon atoms.) Specific examples of the caffeic acid alkyl ester represented by the general formula (10) include caffeic acid-n-ventil, caffeic acid-n-hexyl, and caffer. Acid-n-octyl etc. are mentioned. (D) Metal salt of mercaptoacetic acid In the present invention, a metal salt of an alkyl or alkenyl mercaptoacetic acid represented by the general formula (11) can be preferably used as the metal salt of mercaptoacetic acid.

[0019]

[General formula 11] (However, R ₁₅ represents an aliphatic group having 10 to 18 carbon atoms, and M represents tin, magnesium, zinc, or copper.) Specific examples of the mercaptoacetic acid metal salt represented by the general formula (11) include the following. Something like.
Decylmercaptoacetic acid tin salt, dodecylmarcaptoacetic acid tin salt, tetradecylmercaptoacetic acid tin salt, hexadecylmercaptoacetic acid tin salt, octadecylmercaptoacetic acid tin salt, decylmercaptoacetic acid megnesium salt, dodecylmercaptoacetic acid magnesium salt, tetradecylmercaptoacetic acid magnesium salt Salt, hexadecylmercaptoacetic acid magnesium salt, octadecylmercaptoacetic acid magnesium salt, decylmercaptoacetic acid zinc salt, dodecylmercaptoacetic acid zinc salt, tetradecylmercaptoacetic acid zinc salt, hexadecylmercaptoacetic acid zinc salt, octadecylmercaptoacetic acid zinc salt, decylmercaptoacetic acid Copper salt, dodecyl mercapto acetic acid copper salt, tetradecyl mercapto acetic acid copper salt, hexadecyl mercapto acetic acid copper salt, octadecyl mercapto acetic acid copper salt Etc..

Further, in the present invention, the color developer is not limited to the above-mentioned compounds, and various other compounds having electron accepting properties can be used. In the heat-sensitive recording medium of the present invention, the developer is used in an amount of 1 to 20 parts, preferably 2 to 10 parts, per 1 part of the color former. The color developer can be applied alone or in combination of two or more kinds, and also in the case of the color developer, it can be applied alone or in combination of two or more kinds.

Next, various known resins can be used as the binder resin in the thermosensitive coloring layer used in the present invention.
For example, polyacrylamide, maleic acid copolymer, polyacrylic acid ester, polymethacrylic acid ester,
Vinyl chloride / vinyl acetate copolymer, styrene copolymer,
Polyester, polyurethane, polyvinyl butyral,
Ethyl cellulose, polyvinyl acetal, polyvinyl acetoacetal, polycarbonate, epoxy resin,
Polyamide etc. can be mentioned. As described above, the main component in the thermosensitive coloring layer of the thermosensitive recording material of the present invention, a leuco dye,
Specific examples of the color developing agent and the binder resin are given, but these are merely examples and the present invention is not limited to these.
In the present invention, if necessary, known fillers, pigments,
Surfactants and heat-fusible substances can be added. The silicone-modified resin used in the protective layer of the present invention is an organic solvent (toluene, methyl ethyl ketone, alcohols, etc.)
Since it is often used after being dissolved in, the leuco dye and the color developer are dissolved and brought into contact with each other, so that the color is developed immediately after the application. In order to prevent this color development, a leuco dye and / or a developer that are insoluble or slightly soluble in the solvent used are selected and used. The leuco dye and / or the developer are coated with microcapsules to obtain a dye and a developer. It is desirable to adopt a method of making it hard to contact with each other, providing a resin layer on the thermosensitive color developing layer to make it difficult for the dye and the developer to come into contact with each other, and the like. Among these, it is preferable to use the organic phosphoric acid compound represented by the general formula (1) as a developer in terms of fog due to a solvent, color sensitivity, color density and head matching. The heat-sensitive recording layer of the present invention is prepared by uniformly dispersing or dissolving a color former and a developer together with a binder resin in water or an organic solvent, coating this on a support, and drying it. Not limited. When the coating liquid for the recording layer is a dispersion liquid in which a color developer is dispersed, the particle size of the color developer is greatly influenced by the surface roughness of the protective layer, and in fact, the dot reproducibility during printing. It is preferably 5 μm or less. The thickness of the recording layer depends on the composition of the recording layer and the use of the thermal recording medium, but it is about 1 to 50 μm.
It is preferably about 3 to 20 μm. Further, if necessary, various additives commonly used in heat-sensitive recording paper may be added to the recording layer coating liquid for the purpose of improving coatability or recording characteristics. In the present invention, a layer containing a pigment, a binder, a heat-fusible substance or the like can be provided as an intermediate layer between the support and the thermosensitive color-developing layer as required for improving smoothness. . In the present invention, as described above, the protective layer is provided in order to improve chemical resistance, water resistance, abrasion resistance, light resistance, and head matching with a thermal head. For this protective layer, a resin in which silicone segments are bonded in a block or graft form is used. The block-like or graft-like bond makes the sliding with the thermal head good, and since the resin is silicone-copolymerized, it is difficult for the residue to adhere. The silicone segment to be copolymerized with the resin has a siloxane bond and an alkyl group such as a methyl group bonded to a silicon atom, and has a hydroxyl group, a carboxyl group, an epoxy group, an amino group, a mercapto group, etc. at the molecular end or in the molecule. Organopolysiloxane having a reactive functional group can be used. These silicone segments are bonded to each other in a block or graft form, and as the resin serving as a trunk, poly (meth) acrylic acid ester resin, polyvinyl butyral resin, polyvinyl acetoacetal resin, ethyl cellulose, methyl cellulose, cellulose acetate, hydroxy Ethyl cellulose, cellulose acetate propionate, polyurethane resin, polyester resin, polyvinyl acetate resin, styrene acrylate resin, polyolefin resin, polystyrene resin, polyvinyl chloride resin, polyether resin, polyamide resin, A thermoplastic resin such as a polycarbonate resin, a polyethylene resin, a polypropylene resin, or a polyacrylamide resin is used. Among these, heat resistance,
Particularly preferred resins in terms of solvent solubility are poly (meth) acrylic acid ester resins, polyvinyl butyral resins, polyvinyl acetoacetal resins, cellulose acetate propionate, ethyl cellulose, and polyurethane resins. The amount of the silicone segment in the resin modified with these silicones is preferably 1 to 30% by weight. If the content of the silicone segment is too low, the slipperiness is low and sticking is likely to occur, and if it is too high, the resin bondability and the adhesiveness to the lower layer are low, and the scum adhesion is likely to occur. Also, these silicone-modified resins are
Since it is used by dissolving it in a solvent instead of using it as an emulsion or dispersion as conventionally proposed, it has a high binding force and can be used alone or as a main component as a protective layer. If necessary, conventionally known inorganic and organic fillers, lubricants, and resins can be added. As these inorganic and / or organic pigments, one or more of the pigments commonly used in this type of heat-sensitive recording material can be selected. Specific examples thereof include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, inorganic pigments such as surface-treated calcium and silica, and urea-formalin resin. , Organic pigments such as styrene / methacrylic acid copolymers and polystyrene resins. The coating method of the protective layer is not particularly limited as long as it is within the above-mentioned condition that the surface smoothness is obtained, and the coating method can be a conventionally known method. The preferred protective layer thickness is 0.1 to 20.
μm, more preferably 0.5 to 10 μm. If the thickness of the protective layer is too thin, the function of the recording medium as a protective layer such as storability and head matching will be insufficient, and if it is too thick, the thermal sensitivity of the recording medium will decrease, which is disadvantageous in terms of cost. When the heat-sensitive recording material is obtained by the present invention,
Along with the leuco dye and the developer, if necessary, additional components commonly used in this type of heat-sensitive recording material, such as a filling amount, a surfactant,
A lubricant, a pressure color-developing inhibitor, etc. can be used in combination. In this case, as a filling amount, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide,
In addition to barium sulfate, clay, kaolin, talc, inorganic fine powder such as surface-treated calcium and silica, urea-
Organic fine powders such as formalin resin, styrene / methacrylic acid copolymer, polystyrene resin and vinylidene chloride resin can be mentioned. As the lubricant, higher fatty acid and its metal salt, higher fatty acid amide, higher fatty acid ester, Various waxes of animal, vegetable, mineral or petroleum type may be mentioned. The recording method of the heat-sensitive recording medium of the present invention is not particularly limited in its use mode to a hot pen, a thermal head, laser heating and the like. The heat-sensitive recording material of the present invention is also useful as a pass-through heat-sensitive recording material because the protective layer has excellent transparency.

[0022]

EXAMPLES The present invention will be described below with reference to examples. In the following, all parts and% are based on weight.

Example 1 The following composition was pulverized and dispersed by a ball mill to a particle size of 0.3 μm to prepare a recording layer coating solution. (Liquid A) 3-diethylamino-6-methyl-7-anilinofluorane 4 parts Octadecylphosphonic acid 12 parts Polyvinyl butyral 6 parts (Denka Butyral # 3000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) Toluene 57 parts Methyl ethyl ketone 57 parts or more The coating liquid prepared as described above was applied to a 75 μm thick polyester film (Liquid A) and then dried to form a 10 μm thick thermosensitive recording layer. Next, (B liquid) was applied onto this recording layer and dried to form a protective layer having a thickness of 3 μm, to prepare a heat-sensitive recording medium. (Liquid B) Silicon modified acrylic resin 35 parts (Toagosei, US-350, solid content, 30%) Methyl ethyl ketone 115 parts

Example 2 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. Further, apply (C liquid) on this recording layer.
A thermosensitive recording medium was prepared by drying to form a protective layer having a thickness of 3 μm. (C liquid) Silicon modified polyvinyl butyral resin 84 parts (Dainichi Seika Co., SP-712, solid content, 12.5%) Methyl ethyl ketone 66 parts

Example 3 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. Further, apply (D liquid) on this recording layer.
A thermosensitive recording medium was prepared by drying to form a protective layer having a thickness of 3 μm. (Solution D) Silicon modified polyvinyl acetoacetal resin 39 parts (silicon segment content 20 wt%, solid content, 27%) Methyl ethyl ketone 111 parts

Example 4 A thermosensitive recording layer was formed on a polyester film in the same manner as in Example 1. Further, apply (E liquid) on this recording layer.
A thermosensitive recording medium was prepared by drying to form a protective layer having a thickness of 3 μm. (Solution E) Silicon modified cellulose acetate propionate 35 parts (silicon segment content 20 wt%, solid content, 30%) Methyl ethyl ketone 115 parts

Example 5 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. Further, apply (F liquid) on this recording layer.
A thermosensitive recording medium was prepared by drying to form a protective layer having a thickness of 3 μm. (F liquid) Silicon modified ethyl cellulose 33 parts (silicon segment content 20 wt%, solid content, 32%) Methyl ethyl ketone 117 parts

Example 6 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. Furthermore, apply (G liquid) on this recording layer.
A thermosensitive recording medium was prepared by drying to form a protective layer having a thickness of 3 μm. (G liquid) Silicon modified polyurethane resin 48 parts (Silicon segment content 8 wt%, solid content, 22%) Methyl ethyl ketone 102 parts

Example 7 (H solution) and (I solution) having the following compositions were separately pulverized and dispersed by a ball mill to a particle size of 1.0 μm, and (H solution):
(Liquid I) was mixed in a weight ratio of 1: 3 to prepare a recording layer coating liquid of Example 6. (Liquid H) 3-dibutylamino-6-methyl-7-anilinofluorane 6 parts 5% hydroxyethyl cellulose aqueous solution 6 parts water 18 parts (Liquid I) Bisphenol A 6 parts 5% hydroxyethyl cellulose aqueous solution 6 parts water 18 parts or more The coating solution prepared as described above was coated on a polyester film having a thickness of 75 μm and then dried to form a heat-sensitive recording layer having a thickness of 8 μm. Next, a 5% polyvinyl alcohol aqueous solution is applied and dried on this recording layer to form a layer having a thickness of 3 μm, and (C liquid) is further applied and dried on this recording layer to give a thickness of 3 μm.
A protective layer of m was provided to prepare a thermal recording medium.

Comparative Example 1 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. Furthermore, (J liquid) is stirred on this recording layer,
After dissolution, coating and drying were performed to provide a protective layer having a thickness of 3 μm, and a thermosensitive recording medium was produced. (Liquid J) Polyvinyl acetoacetal resin powder 3.5 parts (Sekisui Chemical Co., Ltd., S-REC KS) Toray Silicone SR-2411 3.5 parts (Toray Silicone) Methyl ethyl ketone 93 parts

Comparative Example 2 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. Particle size of the following composition in a ball mill 1.0
It was pulverized and dispersed up to μm. (K liquid) [K liquid]:
[Liquid J] is mixed in a weight ratio of 1: 3, coated on the previously obtained thermosensitive recording layer and dried to provide a protective layer having a thickness of 3 μm.
A thermal recording medium was prepared. (K liquid) Silica powder 10 parts (Mizukasil P-527 manufactured by Mizusawa Chemical Co., Ltd.) Methyl ethyl ketone 90 parts Further, (J liquid) is stirred and dissolved on this recording layer, and then applied and dried to form a protective layer having a thickness of 3 μm. To prepare a heat-sensitive recording medium.

Comparative Example 3 A thermosensitive recording layer was formed on a polyester film in the same manner as in Example 1. Further, apply (J liquid) on this recording layer.
A thermosensitive recording medium was prepared by drying to form a protective layer having a thickness of 3 μm. (Liquid L) 10% aqueous polyvinyl alcohol solution 10 parts Silicone emulsion 10 parts (manufactured by Toray Silicone) water 80 parts The thermal recording medium prepared as described above was evaluated as follows. Image density A solid black print was printed under the following printing conditions using a thermal printing simulator manufactured by Okura Electric. (Printing conditions) Thermal head dot density: 8 dot / mm Applied power: 0.68 W / dot Pulse width: 0.50 msec Line period: 10 msec / line Print length: 20 cm The transmission density of the printed image is 310TR manufactured by X-Rite. It was measured. Printing was performed under the same conditions as the sticking image density evaluation, and the sticking sound between the thermal recording medium and the thermal head at that time was evaluated according to the following criteria. (Reference) ○ ・ ・ ・ Almost no sticking sound △ ・ ・ ・ Slight sticking sound × ・ ・ ・ Sticking sound ・ Adhesion of dust Clean the heating resistor part of the thermal head with alcohol etc. in advance, and image The same printing as for density evaluation is performed, and the heating resistor after printing is printed with an optical microscope (magnification 50x).
The presence or absence of residue was confirmed by observing. The evaluation results are as follows.

[0033]

[Table 1]

[0034]

As is clear from the above detailed and specific description, the heat-sensitive recording material of the present invention can be improved by using a resin in which a silicone segment is bonded in a block or graft form in the protective layer. Those having excellent head matching properties in terms of concentration, that is, the components in the coating layer are less likely to melt and stick to the thermal head during color development by heating, and the protective layer has chemical resistance, water resistance, and abrasion resistance. It has excellent light resistance, excellent transparency, and excellent sliding with the thermal head.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiro Sawamura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (8)

[Claims] 1. A heat-sensitive color-developing layer containing a leuco dye, a developer that heat-colors the leuco dye and a binder resin as a binder as main components on a support, and a heat-sensitive coloring layer further provided thereon. In the recording material, a thermosensitive recording material characterized in that the protective layer contains a resin in which a silicone segment is bonded in a block form or a graft form. 2. The heat-sensitive recording material according to claim 1, wherein the resin in which the silicone segment is bonded in a block or graft form in the protective layer is a (meth) acrylic acid ester resin. 3. The heat-sensitive recording material according to claim 1, wherein the resin in which the silicone segments are bonded in a block or graft form in the protective layer is a polyvinyl butyral resin. 4. The heat-sensitive recording material according to claim 1, wherein the resin in which the silicone segments are bonded in a block or graft form in the protective layer is a polyvinyl acetoacetal resin. 5. The heat-sensitive recording material according to claim 1, wherein the resin in which the silicone segment is bonded in the form of block or graft in the protective layer is cellulose acetate propionate. 6. The heat-sensitive recording material according to claim 1, wherein the resin in which the silicone segment is bonded in the form of block or graft in the protective layer is ethyl cellulose. 7. The heat-sensitive recording material according to claim 1, wherein the resin in which the silicone segments are bonded in a block or graft form in the protective layer is a polyurethane resin. 8. The developer is an organic phosphoric acid compound represented by the following general formula (1), and a resin having a hydroxyl group in the molecule is used as a binder resin.
The heat-sensitive recording material described. [Formula 1] (R ₁ represents a linear alkyl group having 12 to 28 carbon atoms)