JPH04303677A - Thermal recording body - Google Patents

Abstract

PURPOSE:To improve a safety to human bodies and for environmental protection at the time of production by a method wherein an emulsion made of a UV-or EB-curing resin is applied as a cured film. CONSTITUTION:A heat-sensitive layer containing a color former and a color developer is provided on a substrate. An overcoat layer is further formed thereon, and a thermal recording body is obtained. At this time, as the overcoat layer, a cured film is formed in such a manner that a UV-or EB-curing resin is dispersed in water and emulsified to form an emulsion, the emulsion is applied, and the water content is evaporated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording medium. More specifically, in forming a heat-sensitive recording material that has excellent recording running properties and storage stability before and after coloring, and has a glossy and luxurious feel, U is excellent in workability and environmental safety.
This invention relates to a heat-sensitive recording material in which a cured film is formed by coating an emulsion in which a V or EB curable resin is dispersed and emulsified in water.

0002

[Prior Art] Conventionally, heat-sensitive recording media that produce recorded images by causing a color former and a color developer to react with heat have been widely used in facsimiles, word processors, etc. because they are relatively inexpensive, the device is compact, and maintenance-free. has been done. Recently, it has also been used for printing on various labels such as POS labels and cards, and has a wide range of applications.

However, these heat-sensitive recording materials have problems in storage stability (especially fading of colored images due to plasticizers, oil, and water) and also have drawbacks such as background fog. As a method to solve this problem, there is a method of providing a UV or EB curable resin on the heat sensitive layer (Japanese Patent Publication No. 58-35478), or a method of providing a UV or EB curable resin layer on the heat sensitive layer via an intermediate layer. Accordingly, methods have been proposed for obtaining heat-sensitive recording materials with excellent storage stability and recording characteristics without fogging. (Unexamined Japanese Patent Publication No. 59-26291)

0004

[Problem to be solved by the invention] Recently, issues such as safety and health, environment, and pollution have been attracting attention, and conventional overcoat liquids using organic solvents will be increasingly used in the future from the viewpoint of the Fire Service Act and Industrial Safety and Health Act. It is becoming difficult to do so. On the other hand, UV or EB curable resins have the advantage of being able to be used without solvents, but without solvents, the coating methods are limited and organic solvents are currently used as diluents.

[0005] In addition, in recent years, with the diversification and higher performance of thermal recording methods, advances in printers and facsimile machines have been remarkable. For example, when recording with a video printer that prints at high speed, UV or EB Even with overcoating with a curable resin, a good recorded image has not been obtained. Also, UV or EB curing resin has a Tg point of 200℃.
A method using the above (Japanese Patent Application Laid-Open No. 1-125277) and a method of adding a pigment of 15 microns or less into the resin (Japanese Patent Application Laid-Open No. 1-210381) have been proposed, but in either case, the particles on the thermal head are There are problems such as adhesion and the generation of sound during printing (sticking sound), so we developed a thermal recording material that has excellent storage stability of thermal recording materials and colored images, high-speed recording characteristics, and has a glossy feel that gives a luxurious feel. The purpose of obtaining it has not yet been achieved.

[0006]

[Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive research to solve the above-mentioned problems. That is, the present invention provides (1) a heat-sensitive recording material in which a heat-sensitive layer containing a color former and a color developer is provided on a support, and an overcoat layer is further formed, in which a UV or EB curable resin is soaked in water as the overcoat layer; A heat-sensitive recording material characterized by coating a dispersed and emulsified emulsion and forming a cured film after evaporating water. (2) The heat-sensitive recording material according to item 1, wherein the overcoat layer contains fine pigment powder. (3) The heat-sensitive recording material according to item 1, wherein the overcoat layer contains a lubricant. (4) The heat-sensitive recording material as described in item 1 above, wherein the overcoat layer contains a reactive silicone compound. It provides:

The heat-sensitive recording material of the present invention has high gloss and excellent high-speed recording properties, and has excellent storage stability of the heat-sensitive recording material and its colored image.
By using a curable resin emulsion, there is no need to use organic solvents that can have a negative impact on the human body and the environment. In the present invention, the color forming agent and color developer contained in the heat-sensitive layer are not particularly limited, and any known ones can be used, and the color forming agent and color developer contained in the heat-sensitive layer are coated onto the support using a common binder. Further, fillers, sensitizers, and other additives can be mixed as necessary.

[0008] Examples of color formers include fluoran compounds, triarylmethane compounds, spiropyran compounds, diphenylmethane compounds, thiazine compounds, lactam compounds, and fluorene compounds. Examples include the following compounds.

Fluoran compound: 2-anilino-3-
Methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-(N-methyl-N-cyclohexylamino)-fluorane, 2-anilino-3-methyl-6
-(N-ethyl-N-isopentylamino)fluoran, 2-anilino-3-methyl-6-dibutylaminofluoran, 2-(p-chloroanilino)-3-methyl-6
-diethylalaminofluorane, 2-(p-fluoroanilino)-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-(p-toluidinoethylamino)fluoran, 2- (p-toluidino)-
3-Methyl-6-diethylaminofluorane, 2-(o
-chloroanilino)-6-dibutylaminofluorane,
2-(o-fluoroanilino-6-diethylaminofluorane, 2-(o-fluoroanilino)-6-dibutylaminofluorane, 2-anilino-3-methyl-6
-biperidinofluorane, 2-anilino-3-methyl-
6-pyrrolidinofluorane, 2-ethoxyethylamino-3-chloro-6-diethylaminofluorane, 2-
Anilino-3-chloro-6-diethylfluorane, 2-
Chloro-6-diethylaminofluorane, 2-methyl-
Triarylmethane compounds such as 6-diethylaminofluorane: 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis(p-dimethylamino phenyl) phthalide, 3-(p-dimethylaminophenyl)-3-(1,2-dimethylaminoindol-3-ylphthalide, etc.

Spiropyran compound: 3-methyl-3-
Spiro-dinaphthopyran, 1,3,3-trimethyl-6
-nitro-8'-methoxyspiro(indoline-2,2
’-Benzopyran), diphenylmeth compounds:
N-halophenyl-leucoolamine, etc., thiazine compounds: benzoylleucomethylene blue, etc., lactam compounds: rhodamine-B-anilinolactam, etc.
Fluorene compound: 3,6-bis(dimethylamino)
Fluorenespiro(9,3')-6'-dimethylaminophthalide, [3,6-bis(dimethylamino)fluorenespiro(9,3')-6'-pyrrolidinophthalide],
Examples include [3-dimethylamino-6-diethylaminofluorenespiro(9,3')-6'-pyrrolidinophthalide]. These color formers may be used alone or in combination.

Further, as a color developer, p-octylphenol, p-tert-butylphenol, 1,1-bis(p-hydroxyphenyl)propane, 2,2-bis-
(p-hydroxyphenyl)cyclohexane, 4,4'
-Thiobisphenol, 4,4'-sulfonyldiphenol, bis-(3-allyl-4-hydroxyphenyl)
Sulfone, novolac type phenolic resin, benzyl p-hydroxybenzoate, ethyl p-hydroxybenzoate,
Dimethyl 4-hydroxyphthalate, ethyl 5-hydroxyisophthalate, 3,5-di-tert-butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, etc., and in aromatic carboxylic acids, their polyvalent metals Salt is an example.

[0012] Binding agents as components constituting the heat-sensitive layer include methylcellulose, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, silica-modified polyvinyl alcohol, and styrene acrylate. Alkaline salts of copolymers, polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, starch and its derivatives, casein, gelatin, alkaline salts of styrene-maleic anhydride copolymers, iso(or diiso)butylene-maleic anhydride copolymers Water-soluble emulsions such as polyvinyl acetate, vinyl chloride/vinyl acetate copolymers, polystyrene, styrene/butadiene/acrylic acid copolymers, etc. are used.

Examples of fillers include calcium carbonate, magnesium carbonate, magnesium oxide, silica, white carbon, talc, clay, alumina, magnesium hydroxide, aluminum oxide, barium sulfate, polystyrene resin, urea-formalin resin, etc. . Furthermore, examples of sensitizers include waxes such as animal and vegetable waxes, polyethylene waxes, and synthetic waxes, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, acetyl compounds of aromatic amines, aromatic ether compounds, biphenyl derivatives, etc. , those that are solid at room temperature and have a melting point of 80° C. or higher. Other additives include lubricants such as zinc stearate, calcium stearate, and aluminum stearate, and various other surfactants, antifoaming agents, and the like may also be added as necessary.

[0014] As a method for forming a heat-sensitive layer using the above-mentioned materials, first, a color former and a color developer are separately mixed with a binder, water or other additives as necessary, a protective colloid substance such as polyvinyl alcohol, etc. After pulverizing and dispersing with a dispersing machine such as a ball mill, attritor, or sand mill together with a surfactant, etc. (usually the color former or color developer accounts for 5 to 70% of the system subjected to dispersion, and the binder accounts for 5 to 50%).
Grinding and dispersion are carried out with a water content of 30 to 90%. ), prepare a heat-sensitive layer coating solution by mixing each (the ratio of color former and color developer is usually 1:1 to 1:10 by dry weight), and prepare a coating solution for the heat-sensitive layer, such as paper, plastic sheet, synthetic paper, etc. A heat-sensitive layer can be obtained by coating the film onto a support using a bar coater or the like at a density of 5 to 40 g/m2 and drying it.

In the present invention, an intermediate layer may be provided between the heat-sensitive layer and the overcoat layer, and when the intermediate layer is provided, a hydrophilic or water-based material such as polyvinyl alcohol, starch, styrene/butadiene latex, acrylic resin emulsion, etc. The main ingredients are dispersible resins, polyester resins, and solvent-soluble resins such as copolymers of acrylic resins and vinyl acetate resins, and as necessary, calcium carbonate, zinc oxide, talc, kaolin, clay, colloidal silica, etc. It can be provided by applying a coating liquid to which auxiliary agents such as fillers and various surfactants are added by a conventional method.

When forming an intermediate layer using these materials, for example, the hydrophilic resin, water-dispersible resin, or solvent-soluble resin is mixed with water or other fillers and surfactants as necessary by ball milling, After dispersion using a dispersing machine such as an attritor or a sand mill (usually the resin component is dispersed in a proportion of 5 to 80% of the system to be dispersed), the heat-sensitive layer obtained as described above is An intermediate layer is provided by applying the coating solution to a coating amount of 2 to 40 g/m2 using a bar coater or the like and drying it. By coating an emulsified and dispersed UV or EB curable resin directly on the intermediate layer thus formed and on the heat-sensitive layer to form an overcoat layer,
A thermosensitive recording medium of the present invention is obtained.

[0017] As the UV or EB curable resin used for this overcoat layer, the following prepolymers and monomers may be mentioned. Prepolymers include epoxy (meth)acrylate, urethane (meth)acrylate, saturated polyester/styrene, and polyethylene (meth)acrylate.
Acrylate, polyether (meth)acrylate, silicone (meth)acrylate, polybutadiene (meth)
Examples include acrylate, polyene/thiol, polystyrylethyl (meth)acrylate, and polyamide (meth)acrylate. As monomers, styrene,
Vinyl monomers such as vinyl acetate and N-vinylpyrrolidone, monomers such as butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate isobornyl acrylate, dicyclopentenyloxyethyl acrylate, and phenoxyethyl acrylate. Functional monomer, 1
, 4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate,
Polyethylene glycol 400 diacrylate, tripropylene glycol diacrylate, bisphenol A
Examples include polyfunctional monomers such as diethoxy diacrylate, tetraethylene glycol diacrylate, neopentyl hydroxypivalate glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. .

Furthermore, examples of photoinitiators that are usually required when using UV-curable resins include acetophenone, benzophenone, benzoin ether, chloroacetophenone, diethoxyacetophenone, hydroxyacetophenone, α-aminoacetophenone, benzyl methyl ketal, Thioxanthone, α-acyl oxime ester, acylphosphine oxide, glyoxy ester, 3-ketocoumarin, 2-ethyl anthraquinone,
Examples include camphorquinone, benzyl, Michler's ketone, etc., and these photoinitiators can also be used in the present invention.

Examples of emulsifying and dispersing agents that can be used in the present invention include polyoxyethylene alkyl ether, polyoxyethylene alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene derivatives, and oxyethylene derivatives. Oxypropylene block copolymer. Nonionic surfactants such as polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, fatty acid salts, alkyl sulfate ester salts, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfosuccinates, alkyldiphenyl ethers Anionic compounds such as terdisulfonate, alkyl phosphate, polyoxyethylene alkyl sulfate, naphthalene sulfonic acid formalin condensate, special polycarboxylic acid type polymer surfactant, polyoxyethylene alkyl phosphate, etc. There are various commonly commercialized emulsifying and dispersing agents such as surfactants, but U that emulsifies and disperses
Depending on the type of B or EB curing resin, one type or several types can be selected, and if necessary, it can be used in combination with emulsifying/dispersing agents other than those mentioned above.

The amount of the emulsifying/dispersing agent used is generally 0.5 to 30% by weight, more preferably 1 to 20% by weight, based on the total solid content of the overcoat liquid. If less than 0.5% by weight is used, a stable emulsion cannot be obtained, whereas if it exceeds 30% by weight, problems such as adhesion of residue to the head and storage stability will occur.

[0021] UV or EB with excellent heat resistance as described above
When an emulsion of a curable resin is applied via an intermediate layer or directly onto a heat-sensitive layer and cured by UV or EB, a heat-sensitive recording material with high gloss can be obtained without coloring the heat-sensitive layer. However, in order to further enhance the effect of preventing scum from adhering to the head and sticking, especially during high-speed printing, calcium carbonate, magnesium carbonate, and oxidized Inorganic pigments such as magnesium, aluminum oxide, silicon dioxide, talc, clay, kaolin, colloidal silica, pigments surface-treated with organic acids, organic pigments such as styrene microballs, polyethylene powder, zinc stearate, stearin Acid amide, aspartic acid ester derivative, alkyl phosphate ester compound, lubricant such as polyethylene wax, and reactive silicone compound such as radically reactive silicone macromer, polyester-modified siloxane with terminal hydroxyl group are added, and dispersion is performed using a ball mill, roll mill, sand mill, etc. An overcoat liquid can also be obtained by dispersing it in a machine and then emulsifying and dispersing it.

[0022] The overcoat liquid contains the above-mentioned UV or EB curing resin, emulsifier/dispersant, pigment,
In addition to lubricants and silicone compounds with polymerizable unsaturated groups, additives such as polymers, leveling agents, antifoaming agents, ultraviolet absorbers, fluorescent dyes, fluorescent pigments, colored dyes, and colored pigments may be added as necessary. can do. Generally known methods are used to emulsify and disperse the components forming the overcoat layer in water. For example, after dissolving or dispersing an emulsifier/dispersant in water, UV or
B While stirring the phase containing the curable resin at low speed, gradually add the aqueous phase in which the emulsifier/dispersant has been dissolved or dispersed in advance.
Emulsification and dispersion using a high-speed stirrer such as a homomixer, sand mill, or microfluidizer (UV or EB curable resin composition accounts for 20 to 90% of the system subjected to dispersion, and the above-mentioned Pluronic type emulsifier/dispersant accounts for 0.00% of the system to be dispersed. Emulsification and dispersion are carried out by containing 5 to 10% of the pigment, 0.5 to 10% of the pigment, 0.5 to 5% of the lubricant, and 0.5 to 10% of the silicone compound having a polymerizable unsaturated group.) There are methods such as doing this, but the method is not limited to this.

The milky-white uniform emulsion of UV or EB curable resin thus obtained is stable over time, and the emulsion diluted with water as necessary during coating is also stable. It is. To form the overcoat layer, the obtained emulsion is applied onto the heat-sensitive layer or intermediate layer by a method known per se using a gravure coater, screen printer, flexographic printer, or the like. The coating amount is not particularly limited, but if the dry weight is less than 0.2 g/m2, the object of the present invention cannot be achieved, and if the dry weight is more than 20 g/m2, the recording sensitivity of the heat-sensitive layer will decrease. Therefore, the dry weight is usually 0.2 to 20 g/m2, more preferably 0.2 to 20 g/m2.
It is preferable to apply the coating at a rate of 5 to 10 g/m2.

[0024] When the overcoat layer coated as described above is cured with an electron beam, the coating temperature is 100 to 500e.
An electron beam accelerator having an energy of V is preferred. On the other hand, when curing with ultraviolet rays, an ultraviolet irradiation device with a xenon lamp, high-pressure mercury lamp, or metal halide lamp is used as a light source, and the amount of light and the arrangement of the light source are determined as necessary.
It is preferable to cure by irradiating 1 to 4 times with a lamp having a light intensity of 120 W/cm at a transport speed of 20 to 60 m/min.

[0025]

EXAMPLES The present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. still,
In the examples, parts mean parts by weight.

Example 1 ■ Formation of thermosensitive coloring layer [A] Solution: 20 parts of 2-(o-fluoroanilino-6-diethylaminofluor)
Oran 25% PVA aqueous solution

8. Water

72 [B] Solution: 10 parts of bis(3-allyl-4-hydroxyphenyl)sulfone
p-benzyldiphenyl
8
〃 25% PVA aqueous solution

10〃
water

72 [C] Liquid: Calcium carbonate

40 copies
25% PVA aqueous solution
8〃
water

52. Grind each of the above compositions separately using a sand grinder until the average particle size is 1.
It was pulverized and dispersed to a size of ~3 μm.

Next, 10 parts of liquid [A], 55 parts of liquid [B],
A heat-sensitive layer coating solution was prepared by mixing 30 parts of liquid [C] and 5 parts of hydrous carboxylated SB latex copolymer (solid content = 50%), and the dry solid content was 9 g/m2 on high-quality paper.
It was coated and dried to obtain a heat-sensitive sheet. ■ Formation of middle layer PVA
25 parts water
74〃Colloidal Silicate 1〃Mix the above composition to prepare an intermediate layer coating solution, and apply it on the polyester sheet with the heat-sensitive layer obtained in ① so that the dry solid content is 2 g/m2. A thermal paper having an intermediate layer was obtained by coating and drying.

■ Formation of overcoat layer On top of the thermal paper having the obtained intermediate layer, an overcoat layer coating solution having the following composition was applied at a density of 2 g/m2 and 80 W/c.
Ultraviolet irradiation equipment (GS AS) equipped with a high-pressure mercury lamp of
E-20 (manufactured by Nippon Battery Co., Ltd.) at a conveyance speed of 40 m/mi
The resin component was cured by irradiating it with ultraviolet rays twice at 300 nm to form an overcoat layer, thereby obtaining the heat-sensitive recording material of the present invention. dipentaerythritol hexaacrylate
25 copies
(Product name: Kayarad DPHA,
Nippon Kayaku Co., Ltd.) Trimethylolpropane triacrylate
7〃 (Product name; Ka
yarad TMPTA, manufactured by Nippon Kayaku Co., Ltd.)
Tripropylene glycol diacrylate
8〃
(Product name: Kayarad TPGDA, manufactured by Nippon Kayaku Co., Ltd.) Photoinitiator (Irgacure 1
84 Nippon Ciba Geigy Co., Ltd.) 5
〃 Pluronic F-68 (oxyethylene/oxypropylene block
Polymer manufactured by Asahi Denka Co., Ltd.) 5 Water


50〃

Example 2 The thermosensitive recording material of the present invention was prepared in the same manner as in Example 1 except that 5 parts of calcium carbonate having an average particle size of 0.2 μm was further used as a component to form an overcoat. I got a body.

Example 3 The same procedure as in Example 1 was carried out, except that 2 parts of magnesia (high-purity ultrafine powder magnesia 500A, manufactured by Ube Industries, Ltd.) was used as a component to form the overcoat. A thermosensitive recording material of the present invention was obtained.

Example 4 Example 1 was repeated except that 5 parts of zinc stearate was used in combination as a component to form the overcoat.
A thermosensitive recording material of the present invention was obtained in the same manner as in the above.

Example 5 Example 1 was repeated except that 3 parts of a phosphate ester surfactant (trade name: Perex RP, manufactured by Kao Corporation) was used as a component to form the overcoat. A thermosensitive recording material of the present invention was obtained in the same manner as in Example 1.

Example 6 In Example 1, radically reactive silicone macromer (trade name:
A thermosensitive recording material of the present invention was obtained in the same manner as in Example 1, except that 5 parts of -24-8200 (manufactured by Shin-Etsu Chemical Co., Ltd.) were used in combination.

Example 7 In Example 1, phenoxyhexaethylene glycol acrylate (trade name: NK Ester AMP-60) was used instead of tripropylene glycol diacrylate.
G: A thermosensitive recording material of the present invention was obtained in the same manner as in Example 1, except that G: manufactured by Shin Nakamura Chemical Industry Co., Ltd.) was used.

Example 8 In Example 1, caprolactone-modified hydroxypivalic acid ester neopentyl glycol diacrylate (
A thermosensitive recording material of the present invention was obtained in the same manner as in Example 1, except that the product name: KAYARAD HX-620 (Nippon Kayaku Co., Ltd.) was used.

Example 9 In Example 1, Pluronic F10 was used instead of Pluronic F68 among the components to form the overcoat.
A heat-sensitive recording material of the present invention was obtained in the same manner as in Example 2 except that Sample No. 8 was used.

Example 10 Example 1 is the same as Example 1 except that the intermediate layer is not provided.
A thermosensitive recording material of the present invention was obtained in the same manner as in the above.

Comparative Example 1 A comparative heat-sensitive recording material was obtained in the same manner as in Example 1 except that the intermediate layer and overcoat layer were not provided.

Using each of the heat-sensitive recording materials obtained in this way, characters were printed on a dot line type thermal printer with a resistance value of 239 ohms to evaluate the runnability and storage stability, and the results are shown in Table 1. It was shown to. In addition, the following evaluation criteria were adopted.

[0040]

(1) Sticking evaluation criteria ◎: During high-speed printing, there was no sound at all and recording was possible smoothly. ○: During high-speed printing, there was almost no sound and recording was possible smoothly. Δ: Very slight recording failure occurred during high-speed printing. ×: The heat-sensitive recording material did not run smoothly, resulting in poor recording. (2) Head scum adhesion evaluation criteria ◎: There was no head stain at all during high-speed printing. ○: There was almost no dirt on the head during high-speed printing. Δ: The head was slightly dirty after high-speed printing. ×: The head was dirty after high-speed printing.

(3) Water resistance test ◯: Even when the heat-sensitive recording material colored as described above was submerged in water at 20° C. for 24 hours, there was almost no fading of the colored area. ×: When the heat-sensitive recording material colored in the above manner was submerged in water at 20° C. for 24 hours, the coloring area faded. (4) Plasticizer resistance test ○: A plasticizer (D
Even when OP) was dropped, almost no discoloration was observed. ×: A plasticizer (D
When OP) was added dropwise, discoloration was observed.

(5) Stability test ○: Even when the obtained emulsion was left to stand, there was no layer separation at all. Δ: Even when the obtained emulsion was left to stand, there was only slight layer separation. ×: When the obtained emulsion was left to stand, the layers separated.

[0044]

[Effect of the invention] By coating an emulsion using UV or EB curable resin to form a cured film, safety for human health and the environment during manufacturing is improved, and recording running performance is improved even during high-speed printing. A high-gloss heat-sensitive recording material with excellent storage properties and colored images was obtained.

Claims (4)

[Claims] [Claim 1] A heat-sensitive recording material in which a heat-sensitive layer containing a color forming agent and a color developer is provided on a support, and an overcoat layer is further formed, in which a UV or EB curable resin is dispersed in water as the overcoat layer. Apply the emulsion,
A heat-sensitive recording material characterized by forming a cured film after evaporating water. 2. The heat-sensitive recording material according to claim 1, wherein the overcoat layer contains fine pigment powder. 3. The heat-sensitive recording material according to claim 1, wherein the overcoat layer contains a lubricant. 4. The heat-sensitive recording material according to claim 1, wherein the overcoat layer contains a reactive silicone compound.