JPH06344665A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a thermal recording material excellent in water resistance, oil resistance, sticking resistance and surface gloss by successively laminating a thermal color forming layer and a protective layer composed of a mixture of a specific silane compd. and a water dispersible polymer on a support. CONSTITUTION:A coating soln. prepared by dispersing a known leuco dye, a known coupler, other various necessary additives and auxiliary agents in a proper binder is applied to a support such as paper or a plastic film and the formed coating layer is dried to form a thermal color forming layer. Separately, a silane compd. A represented by formula (wherein R<1> is H, a lower alkyl group or an aryl group, R<2> is H or an acyl group, m is 0 or 1, n is 3 or 4 and m+n is 4) mixed with a water-soluble polymer B obtained by hydrolysis and condensation in an aq. solvent to prepare a coating compsn. which is, in turn, applied to the thermal color forming layer to laminate a protective layer. The wt. ratio A/B of the components A, B in the coating compsn. is 10-0.1 (the component A is converted to R<1>mSiO4-m/2 and the component B is converted to a solid).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermal recording material,
In particular, the present invention relates to a heat-sensitive material having excellent water resistance, oil resistance, etc., stick resistance, surface gloss, and print density.

[0002]

2. Description of the Related Art In recent years, a thermosensitive recording material having a dye-based thermosensitive coloring layer formed by combining a leuco dye and a phenolic acidic substance has been widely applied in the fields of thermal printers, facsimiles, measuring instruments, etc. , The whiteness of the paper, the adaptability to various recording equipment, the economy, etc. have been evaluated, and new applications are being developed. As the applications expand, the demands for improving the quality of thermal recording materials will also diversify.
And it is becoming more sophisticated.

[0003]

In the conventional heat-sensitive recording material in which only the heat-sensitive material is coated on the support, the printing of the image area may be erased when exposed to solvent, water, light, plasticizer, etc. It has a drawback that the non-image area is colored. Further, the same tendency is observed even when the heat-sensitive recording material is stored for a long period of time, and it is desired to improve the storage stability of the heat-sensitive recording material.

As a method for improving these drawbacks, it has been proposed to provide a protective layer on the heat-sensitive layer. As a binder for forming these protective layers, conventional polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, starches,
Casein, polyacrylamide polymer, styrene-
Water-soluble polymer substances such as maleic anhydride copolymers and polyacrylic acid esters, and aqueous emulsions such as SBS latex are known, but their water resistance and oil resistance are not sufficient, and they also have stick resistance. There was a problem that noise was induced at the time of image formation due to a defect, and in some cases, the coating film adhered to the thermal head and a normal image could not be obtained.

[0005]

Means and Actions for Solving the Problems The present inventors have
In a thermosensitive recording material having a thermosensitive coloring layer on a support,
Component A on the surface of the thermosensitive coloring layer; the following general formula (I)

[0006]

[Chemical 1]

A water-soluble polymer obtained by hydrolyzing and condensing a silane compound A represented by: in a water solvent and a component B; an emulsion polymerization of a polymerizable monomer in water. And the weight ratio of the A component and the B component (A /
B) is 10 to 0.1 (however, A component is R ¹ _m SiO 2
A heat-sensitive recording material characterized in that a coating composition characterized in that the component B is converted to a solid content at _{4-m / 2} ) is provided as a protective layer to solve the above problems. Heading, arrived at the present invention.

As the support in the present invention, paper, plastic film, synthetic paper or the like can be used.

The heat-sensitive color forming layer formed on the support is coated with a coating solution in which a known leuco dye, a color developer, and other various additives and auxiliary agents described below, if necessary, are dispersed in a suitable binder and dried. Is obtained.

As the leuco dye, known leuco compounds such as triphenylmethane dyes, fluoran dyes, phenothiazine dyes, auramine dyes, subilopyran dyes and indolinophtalide dyes can be used. Specific examples of such leuco dyes include 3,3-bis (p-dimethylaminophenyl) phthalide and 3,3-bis (p-
Dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-
Bis (p-dimethylaminophenyl) -5-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino -6-Chlorfluorane, 3-dimethylamino-
5,7-Dimethylfluorane, 3-diethylamino-7
-Chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3- (Np-tolyl-) N-ethylamino) -6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2-
(N- (3'-trifluoromethylphenyl) amino)
-6-diethylaminofluorane, 2- (3,6-bis (diethylamino) -9 (o-chloroanilino) xanthyl benzoate lactam), 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane , 3-dimethylamino-7- (o-chloroanilino)
Fluoran, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-N-methyl-N-amylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N-cyclohexamino-6. -Methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7
-Anilinofluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino)
Fluoran, benzoyl leuco methylene blue, 6'-
Chloro-4'-methoxy-benzoindolino-pyrrilospirane, 3'-bromo-3'-methoxy-benzoindolino-pyrrillospirane, 3- (2'-hydroxy-4 '
-Dimethylaminophenyl) -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- (2'-methoki-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5 '
-Methylphenyl) phthalide, 3-morpholino-7-
(N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-
(N-benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluorane, 3-diethylamino-5
-Chloro-7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (α-methoxycarbophenylamino) fluorane, 3- (N-ethyl-p-toluidino) -7- (α-phenylethylamino) ) Fluorane, 3-diethylamino-5-methyl-7- (α-phenylethylamino) fluorane, 3-diethylamino-7-piperidinofluorane, 2-chloro-3- (N-
Methyltoluidino) -7- (pn-butylanilino)
Fluoran, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo-7-α-naphthylamino-
4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino-4 ', 5'-benzofluorane and the like can be mentioned.

The color developer compounded in the coating solution is a compound that reacts with the leuco dye when heated to develop a color, and uses a phenolic substance, an organic or inorganic acidic substance, or an ester or salt thereof. Can be, for example,
Gallic acid, salicylic acid, 3-isopropylsalicylic acid,
3-cyclohexyl salicylic acid, 3,5-di-tert
-Butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 4,4'-isopropylidene diphenol, 4,4'-isopropylidenebis (2-chlorophenol), 4,4'-isopropylidenebis ( 2,6-
Dibromophenol), 4,4'-isopropylidene bis (2,6-dichlorophenol), 4,4'-isopropylidene bis (2-methylphenol), 4,4'-
Isopropylidene bis (2,8-dimethylphenol), 4,4'-iropropylidene bis (2-tert
-Butylphenol), 4,4'-sec-butylidene diphenol, 4,4'-cyclohexylidenebisphenol, 4,4'-cyclohexylidenebis (2-methylphenol), 4-tert-butylphenol, 4
-Phenylphenol, 4-hydroxydiphenoxide, α-naphthol, β-naphthol, 3,5-xylenol, thymol, methyl-4-hydroxybenzoate, 4-hydroxyacetophenone, novolac type phenol resin, 2,2'-thiobis ( 4,6-dichlorophenol), catechol, resorcin, hydroquinone,
Pyrogallol, phloroglysin, phloroglysin carboxylic acid.

4-tert-octylcatechol, 2,
2'-methylenebis (4-chlorophenol), 2,
2'-methylenebis (4-methyl-6-tert-butylphenol).

2,2'-dihydroxyphenyl, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-hydroxybenzyl p-hydroxybenzoate, p-hydroxybenzoate-o-chlorobenzyl, p-hydroxybenzoate-p-methylbenzyl,
p-Hydroxybenzoic acid-n-octyl, benzoic acid, zinc salicylate, 1-hydroxy-2-naphthoic acid, 2-
Hydroxy-5-naphthoic acid, zinc 2-hydroxy-6-naphthoate, 4-hydroxydiphenyl sulfone, 4
-Hydroxy-4'-chlorodiphenyl sulfone, bis (4-hydroxyphenyl) sulfide, 2-hydroxy-p-toluic acid, zinc 3,5-di-tert-butylsalicylate, tin 3,5-tert-butylsalicylate, Tartaric acid, oxalic acid, maleic acid, citric acid, succinic acid, stearic acid, 4-hydroxyphthalic acid, boric acid,
A thiourea derivative etc. can be mentioned.

Examples of the binder include polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic acid amide / acrylic acid. Ester copolymer, acrylic acid amide / acrylic acid ester /
Methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein and the like can be used.

In addition, the above-mentioned coating liquid, together with the above-mentioned leuco dye, developer and binder, may optionally contain additives such as sensitizers, fillers, surfactants and heat-fusible substances. Etc. may be used together. In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide,
Inorganic fine powder of aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium, silica, etc., as well as organic type of urea formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, etc. Examples of the heat-fusible substance include, for example, higher fatty acids or esters thereof, amides or metal salts, various waxes, mixtures of aromatic carboxylic acids and amines, phenyl benzoate esters, and the like. 5 such as higher linear glycol, 3,4-epoxy-dialkyl hexahydrophthalate, higher ketone, and other heat-fusible organic compounds
One having a melting point of about 0 to 200 ° C. can be mentioned.

The protective layer formed on the thermosensitive coloring layer is the component A; the following general formula (I)

[0017]

[Chemical 1]

A water-soluble polymer obtained by hydrolyzing and condensing the silane compound A represented by the formula (1) and a component B; an emulsion polymerization of a polymerizable monomer in water. And the weight ratio of the A component and the B component (A /
B) is 10 to 0.1 (however, A component is R ¹ _m SiO 2
It is obtained by applying a coating composition characterized in that the component B is converted to a solid content of _{4-m / 2} ). The coating composition will be described below.

The silane compound (A) used in the present invention is not particularly limited as long as it satisfies the general formula (I), and one or more thereof can be used. Specific examples of the silane compound (A) include tetramethoxysilane,
Tetraethoxysilane, tetrapropoxysilane, tetraptoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyl Trimethoxysilane, i-propyltriethoxysilane,
γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ- (meta ) Acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4- Epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltriethoxysilane, dimethyldimethoxysilane,
Examples include dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, and the like.
One or more of these can be used,
From the viewpoint of versatility, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane and methyltriethoxysilane are preferable.

In the present invention, it is desirable that the silane compound is hydrolyzed and condensed in the presence of an emulsifier in an aqueous solvent solution before mixing with the emulsion polymer. As the emulsifier used here, a known emulsifier can be used, but from the viewpoint of the stability of the siloxane component, an anionic emulsifier is desirable,
In particular, dodecylbenzene sulfonate is more preferable. The amount of the emulsifier used in this case is 100 silane compound.
0.001 to 10 parts by weight is preferable with respect to parts by weight,
More preferably, 0.01 to 5 parts by weight is desirable. 0.0
If it is less than 1 part by weight, the storage stability may be poor, and if it is more than 5 parts by weight, the water resistance of the polymer formed may be poor. In addition, in the case of carrying out hydrolysis condensation after mixing with the emulsion polymer which is the component A, there is a case where it is not particularly necessary to add since the emulsion polymer contains an emulsifier. The emulsifier in these cases has an effect of suppressing a rapid reaction of the silane compound and preventing gelation.

The hydrolysis-condensation reaction of the silane compound is 0 to
It is carried out under a temperature condition of 200 ° C. This hydrolysis-condensation reaction is represented by the following formula when, for example, tetraethoxysilane is used as the silane compound.

[0022]

[Chemical 2]

In the present invention, it is carried out in a water solvent.
Examples of the component B polymerizable monomer used in the present invention include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and 4-t-butylcyclohexyl (meth). ) Acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth)
Acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
(Meth) acrylic acid esters such as triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, (meth) acrylic acid, styrene,
Examples thereof include aromatic vinyl compounds such as α-methylstyrene, divinylbenzene and their substituted derivatives, but are not limited thereto.

As the emulsion polymerization method, any conventionally known emulsion polymerization can be applied. For example, a conventionally known polymerization catalyst, water, a conventionally known emulsifier, a method in which a polymerizable monomer is mixed and polymerized at once, or a so-called monomer dropping method, a pre-emulsion method, a seed polymerization method, a multi-step polymerization method, etc. can do.

Examples of conventionally known polymerization catalysts used in emulsion polymerization include persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate; 2,2'-azobis (2-amidinopropane) dihydrochloride, 4 , 4'-
Water-soluble azo compounds such as azobis (4-cyanopentanoic acid); hydrogen peroxide and the like can be mentioned.

Conventionally known emulsifiers used in emulsion polymerization include anionic emulsifiers such as sodium dodecylbenzene sulfonate and sodium dodecyl sulfate; nonionic emulsifiers such as polyethylene oxide having a nonylphenyl group and block polymers of polypropylene glycol and polyethylene oxide. Emulsifiers: mention may be made of cationic emulsifiers such as trimethylstearyl ammonium chloride.

The polymerization temperature is 0 to 100 ° C., preferably 50 to 80 ° C., and the polymerization time is 1 to 10 hours.

In the coating composition obtained in the present invention, the ratio (A / B) of the component A and the component B is 10 by weight.
0.1 to 0.1 (provided that the component A is converted to R ¹ _m SiO _{4-m / 2} and the component B is converted to solid content), preferably 3 to 0.3. If A / B is larger than 3, flexibility such as flexibility may be poor, and if A / B is smaller than 0.3, chemical resistance and water resistance may be poor.

In the present invention, it is possible to add an organic solvent in order to improve the film forming property and the wettability. Examples of the organic solvent used here include alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol, diethylene glycol, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, and ketones such as acetone and methyl ethyl ketone. , Methyl acetate, tetrahydrofuran and the like, and it is possible to use them in combination. Of these, alcohols are preferably used. The amount of these organic solvents used is 20% of all the solvents.
It is less than 10 parts by weight, preferably less than 10 parts by weight, more preferably less than 5 parts by weight.

In the present invention, various inorganic and organic additives such as a curing agent, a wettability improver, a plasticizer, an antifoaming agent, a thickener, etc. are added, if necessary, within a range that does not impair the effects of the present invention. be able to.

The heat-sensitive recording material of the present invention may be prepared by coating a heat-sensitive color-forming layer on the support such as paper, plastics film and synthetic paper by a known method, and further coating the above-mentioned coating agent thereon and drying it. If present, it can be obtained by forming a protective layer by calendering. The thickness of the protective layer is not particularly limited, but in consideration of the effect and economy of the present invention, it is preferably in the range of 1 to 10 μm, more preferably 2 μm.
It is preferable that the thickness is in the range of 5 μm.

[0032]

EXAMPLES Examples of the present invention will be shown below, but these are given for the purpose of illustration and do not limit the scope of the present invention. In the following, parts and% are parts by weight,
Represents% by weight.

Reference Example 1 400 parts of ion-exchanged water and anionic emulsifier Hitenol N08 were placed in a flask equipped with a dropping funnel, stirrer, nitrogen introducing tube, thermometer and condenser.
1.4 parts of 15% aqueous solution (made by Dai-ichi Kogyo Seiyaku) was charged,
The mixture was heated to 80 ° C. while slowly flowing nitrogen gas, 4 g of a 10% aqueous solution of ammonium persulfate was added thereto, and then, using a dropping funnel, 158.6 parts of butyl acrylate and 218.
5 parts, 20.0 parts of divinylbenzene to Hitenol N0
8% 15% aqueous solution 24.4 parts, ion-exchanged water 100.0
The pre-emulsified polymerizable monomer pre-emulsion was added dropwise over 3 hours. After the completion of dropping, the mixture was stirred at 80 ° C. for 1 hour and then cooled to complete the polymerization.
(Component B) was obtained.

Reference Example 2 Except that the composition of the polymerizable monomer in Reference Example 1 was changed to butyl acrylate 158.6 parts, methyl methacrylate 235.5 parts, and methacrylic acid 3.0 parts.
The same operation as in Reference Example 1 was performed to obtain an emulsion polymer 2.

Reference Example 3 A flask equipped with a dropping funnel, a stirrer, a thermometer and a condenser was charged with 200.
0 parts, 30.0 parts of a 15% aqueous solution of Hithenol N08 were charged and heated to 50 ° C., and 72.0 parts of tetraethoxysilane and 84.5 parts of methyltrimethoxysilane were added thereto with a dropping funnel over 1 hour. After dropwise addition, stirring was continued at 50 ° C. for 1 hour after completion of the dropwise addition, and the mixture was cooled to obtain an aqueous polysiloxane solution 3 (component A).

Reference Example 4 The same operation as in Reference Example 3 was carried out except that the composition of the alkoxysilane was changed to 156.5 parts of methyltrimethoxysilane in Reference Example 3 to obtain an aqueous polysiloxane solution 4. Reference Example 5 Reference Example 1 or 2 and Reference Example 3 or 4
The compositions obtained in 1 above were mixed according to the formulation shown in Table 1 to obtain coating agents I to IV.

[0037]

[Table 1]

(Example 1) [Solution A] 30 parts of 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane 10% aqueous solution of polyvinyl alcohol 30 parts Water 40 parts [Solution B] ] Bisphenol A 30 parts 10% polyvinyl alcohol aqueous solution 25 parts water 45 parts [C liquid] stearic acid amide 25 parts calcium carbonate A 30 parts 10% polyvinyl alcohol aqueous solution 20 parts water 25 parts Particles of each of the above compositions using a sand mill Diameter is 1
Dispersion was carried out until the particle size became μm, and A liquid, B liquid and C liquid were obtained.
Next, 20 parts of solution A, 70 parts of solution B, and 10 parts of solution C are mixed to prepare a coating solution for the thermosensitive color developing layer, which is weighed to 50 g / m ² on one side of a high-quality paper to give a coating amount after drying. Apply so that it is 5 g / m ^2.
It dried and formed the thermosensitive coloring layer.

Next, coating agents I to IV obtained in Reference Example 5
Was adjusted to a solid content of 10% by adding water, and coated on the thermosensitive coloring layer so as to have a dry weight of 3 g / m ² and dried to form a protective layer.

Then, using a super calender, the surface was treated so that its smoothness was 3000 sec or more,
Thermal recording materials 1 to 4 were obtained.

The water resistance, chemical resistance, stick resistance, and blackness of the black solid printed surface of the obtained thermal recording materials 1 to 4 were measured, and the results are shown in Table 2.

[0042]

[Table 2]

(Comparative Examples 1 to 4) The emulsion polymers 1 and 2 and the polysiloxane aqueous solutions 3 and 4 obtained in Reference Examples 1 to 4 were dried on the thermosensitive coloring layer so that the weight after drying was 3 g / m ^2. A protective layer was formed by coating and drying. Then, using a super calender, the smoothness of the surface was processed to 3000 sec or more, and comparative thermal recording materials 1 to 4 were obtained.

Physical properties of the obtained comparative thermal recording material were measured in the same manner as in Example 1, and the results are shown in Table 3.

[0045]

[Table 3]

Sticking resistance and blackness: Printing was carried out using a thermal head printing tester (Matsushita Electronics Co., Ltd.). The test conditions were an applied voltage of -20 V and a printing speed of -2 mm / sec. At this time, the presence or absence of the stick phenomenon was observed, and then the blackness was measured. The stick resistance was determined according to the following criteria.

5: No stick sound 4: Low stick sound 3: Medium stick sound 2: Large stick sound Partial print skipping is observed 1: Sticky sound print skipping is observed on the entire surface Blackness is Macbeth density RO914 (Kollmorgen C
o.). Water resistance; Thermal recording materials 1 to 4 and Comparative thermal recording materials 1 to 4
4 was immersed in ion-exchanged water for 24 hours, and those having no change in color were evaluated as ◯, and those having a change such as blackening were evaluated as x. Chemical resistance; thermal recording materials 1 to 4 and comparative thermal recording material 1
Samples Nos. 4 to 4 were immersed in an aqueous 50% ethanol solution for 5 minutes, and those having no change in color were evaluated as ◯, and those having changes such as blackening were evaluated as x.

[0048]

The present invention provides a high-performance heat-sensitive recording material which is excellent in water resistance, chemical resistance, etc., stick resistance, and printing density.

[0049]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadahiro Yoneda 5-8 Nishimitabicho, Suita City, Osaka Pref.

Claims (2)

[Claims] 1. A thermosensitive recording material comprising a support and a thermosensitive coloring layer provided thereon, wherein the surface of the thermosensitive coloring layer is a component A; the following general formula (I): A water-soluble polymer obtained by hydrolyzing and condensing the silane compound A represented by the formula (1) with a component B; an aqueous dispersion polymer obtained by emulsion-polymerizing a polymerizable monomer in water are mixed. And the weight ratio (A / B) of the A component and the B component is 10 to
0.1 (provided that the component A is converted to R ¹ _m SiO _{4-m / 2} and the component B is converted to solid content), the coating composition is provided as a protective layer. Thermosensitive recording material. 2. A thermosensitive recording material having a thermosensitive coloring layer provided on a support, wherein the surface of the thermosensitive coloring layer is component A; the following general formula (I): And a water-soluble polymer obtained by hydrolyzing and condensing the silane compound A represented by the formula (1) in a water solvent in the presence of a surfactant, and component B; water obtained by emulsion-polymerizing a polymerizable monomer in water. It is obtained by mixing the dispersion polymer, and the weight ratio (A / B) of the A component and the B component is 10 to 0.1 (provided that the A component is R ¹ _m Si
A heat-sensitive recording material comprising a coating composition, which is characterized in that the component B is converted to solid content in O _{4-m / 2} ) as a protective layer.