JPS6246689A - Coating composition for producing recording material for sublimation-type thermal transfer recording system - Google Patents

Abstract

PURPOSE:To provide a coating composition for producing a recording material for use in a sublimation-type thermal transfer recording system, by combining 100pts.wt. of a mixture of 10-70pts.wt. of a radiation-curable cross-linking agent and 30-90pts.wt. of an alkyl (meth) acrylate polymer with 0.01-10pts.wt. of a silicone or fluoro surfactant. CONSTITUTION:A coating composition comprising a specified alkyl (meth)acrylate polymer, a cross-clinking agent and a silicone or fluoro surfactant as main constituents is applied to the surface of a base (for example, in a thickness of 0.5-100mum), and is cured by irradiating with active radiations, whereby the recording material is obtained which is easily dyed, has favorable color forming properties and clearness and is improved in the property of blocking with a transfer sheet coated with a disperse dye. A solution of 1 part of Kayaset Blue 136 (a disperse dye produced by Nippon Kayaku K.K.) and 1 part of ethylcellulose in 100 parts of trichloroethylene is applied uniformly to a condenser paper (10m thick) so that the film thickness after drying is several micrometers, thereby preparing a transfer sheet. The transfer sheet is laid on the dry-type transfer recording material, with the dye- coated side of the former in contact with the dyeable layer side of the latter, and thermal transfer recording is conducted, whereby a dry-type transfer color forming material useful for color copying electrophotography or information recording is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating composition for a technical recording medium in a sublimation type thermal transfer recording system.

[Conventional technology]

With the recent rapid spread of office automation, the core of /! Color display gray is rapidly increasing in personal computers, word processors, office computers, etc., and the demand for practical use of recording methods based on color signals is rapidly increasing, and the demand for colorization is still strong even in the field of dry copying machines. There is.

Conventional color recording methods include the light pen method, wire dot method, and inkjet method, but each has its own shortcomings, such as slow recording speed, bird noises, and clogging of the tiny nozzles that emit ink. On the other hand, the dye-sublimation heat-sensitive transfer recording method does not generate any sound and is easy to operate, maintain, and operate the copying machine.
It has characteristics such as easy management. In addition, in this method, a transfer sheet coated with a sublimable dye is heated with a heat-sensitive recording head to sublimate and transfer the dye to the recording medium to obtain color recording, so the energy applied to the heat-sensitive head must be adjusted. Since it is possible to control the amount of sublimation of the dye, it is easy to express gradation, and compared to other recording methods, it is particularly advantageous for obtaining full-color hard copies. However, even though the recording principles and characteristics of this method have been announced as above,
The current situation is that a recording medium with excellent color development and color clarity using sublimable disperse dyes has not yet been developed, and there has been no example of a recording medium being coated on a cloth, so its development has been strongly desired.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a coating composition for obtaining a dry transfer recording material which can be easily dyed with a sublimable disperse dye in a sublimation type heat-sensitive transfer recording system and has excellent color development and clarity. It is in.

[Means for solving the problems] Crosslinking agent 1 curable with active energy rays according to the present invention
100 parts by weight of a mixture consisting of 0 to 70 parts by weight and 30 to 90 parts by weight of at least one (meth)acrylic acid alkyl ester polymer, and at least one of a silicone surfactant and/or a fluorine surfactant. Seed 0.0
Provided is a coating composition for a recording medium for sublimation type heat-sensitive transfer recording, which comprises 1 to 10 parts by weight.

According to the present invention, a coating containing the above-mentioned specific (meth)acrylic acid alkyl ester polymer, a crosslinking agent, and a silicone-based or/and fluorosurfactant as main components is provided on the surface of a substrate (for example, film-like or paper-like). The recording material obtained by coating the composition and curing it with active energy rays (for example, to a thickness of 0.5 to 100 μm) is more easily dyed with sublimable disperse dyes and has excellent color development and brightness. It has been found that the transfer sheet has good properties and that blocking properties with a transfer sheet coated with a disperse dye are improved.

The (meth)acrylic acid alkyl ester polymer used in the present invention is a (meth)acrylic acid alkyl ester polymer having a substituted or unsubstituted alkyl group or a copolymer thereof. Examples of copolymerizable monomers include styrene, (meth)acrylic acid, and the like. Examples of substituents for the alkyl group include a hydroxyl group, an amino group, and a carboxyl group.

The (meth)acrylic acid alkyl ester polymer has a (meth)acrylic acid alkyl ester component of 50% by weight.
It is a polymer containing the above-mentioned amount and has a Tg of 40°C or more.

If the Tg of the polymer is less than 40° C., the transfer sheet coated with the sublimable disperse dye and the recording medium will stick together when heated with a thermal recording head. In other words, a phenomenon called blocking becomes more likely to occur. On the other hand, if the amount of (meth)acrylate in the polymer is less than 50% by weight, the color development by the sublimable disperse dye will be reduced.

The blending amount of the (meth)acrylic acid alkyl ester polymer is from 30 to 100 parts by weight of the mixture of crosslinking agent and polymer.
It is 90 parts by weight, preferably 40 to 85 parts by weight. If the amount of the (meth)acrylic acid alkyl ester polymer is less than 30 parts by weight, the color development by the sublimable disperse dye will decrease, and if it exceeds 90 parts by weight, it will block when heated by a thermal recording head. It becomes easier to appear,
The curing properties due to active energy rays may be poor, and the adhesion to the substrate may be reduced.

Specific examples of (meth)acrylic acid alkyl ester polymers include homopolymers such as methyl methacrylate, sec-butyl methacrylate, cyclohexyl methacrylate, inbutyl methacrylate, benzyl methacrylate, phenyl methacrylate, and ethyl methacrylate; methyl methacrylate/styrene = 80/ 20
Part by weight, methyl methacrylate/ethyl acrylate =
9515, methyl methacrylate/methyl acrylate = 90/10, methyl methacrylate/n-butyl methacrylate = 40/60, methyl methacrylate/ethyl methacrylate = 30/70, methyl methacrylate/ethyl acrylate = 70/30, methyl methacrylate/ Methyl acrylate/methacrylic acid = 60/3
515, methyl methacrylate/lauryl methacrylate = 90/10, methyl methacrylate/methyl acrylate/2-hydroxyethyl methacrylate = 80
/1515, methyl methacrylate/l5o-butyl methacrylate/dimethylaminoethyl methacrylate=
Mention may be made of copolymers such as 80/1515,
These polymers may be used alone or in combination of two or more.

Any crosslinking agent can be used as long as it can be cured by active energy rays and has good compatibility with the (meth)acrylic acid alkyl ester polymer, but if the radiation source is ultraviolet rays, Preferably, the polymerizable group is at least one polyfunctional monomer and/or at least one monofunctional monomer having a methacryloyloxy group or an acryloyloxy group. It should be noted that although the polyfunctional monomer is essential for heating the coating composition with active energy rays, the monofunctional monomer is not essential.

However, when applying the coating composition without using a solvent, it is better to use a monofunctional monomer to reduce the viscosity of the coating composition.

Examples of monomers having a (meth)acryloyloxy group include #i polyether acrylate or polyether methacrylate (hereinafter, "acrylate or methacrylate" is simply abbreviated as "(meth)acrylate"), polyester (meth) Monomers such as acrylates, polyol (meth)acrylates, epoxy (meth)acrylates, amide urethane (meth)acrylates, urethane (meth)acrylates, subiroacetal (meth)acrylates, and polybutadiene (meth)acrylates. , oligomers.

Specific examples of such monomers or oligomers include 1.2.6-hexandriol/glopyrene oxide/acrylic acid, trimethylol-! / ethylene oxide / methacrylic acid, trimethylol gulon /
f Polyether (meth)acrylate synthesized from robylene oxide/acrylic acid, pentaerythritol/ethylene oxide/acrylic acid; adipic acid/1.6
-Hexanephor/acrylic acid, succinic acid/1,4-
Polyester (meth)acrylate synthesized from butanol/acrylic acid, succinic acid/trimethylolethane/acrylic acid, cepachi/acid/1 type 6-hexaneol/methacrylic acid; ethylene glyfur noacrylate, triethylene glycol Diacrylate, ethylene glycol dimethacrylate, hexapropylene glycol noacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1.6-hexanediol diacrylate, 1.4-
Butanediol dimethacrylate, butyl acrylate, 2-ethylhexyl acrylate, lauvyl methacrylate, cyclohexyl acrylate, te]-rahydrofurfuryl acrylate, 2-hydroxyethyl methacrylate, 1,4-butanediol monoacrylate, benzyl methacrylate , ethyl carpitol acrylate, trimethylol nolopane triacrylate, trimethylolethane trimethacrylate, pentaerythritol pentaacrylate, pentaerythritol trimethacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexamethacrylate), 2 ．．
2-bis(4-acryloxyethoxyphenyl)gulonone, 2,2-bis(4-acryloxyjethoxyphenyl)propane, 212-bis(4-methacryloxyjethoxyphenyl)propane, 2,2-bis (meth)acrylate or polyol (meth)acrylate such as (4-acryloxyethoxyphenyl)propane; diglycidyl etherified bisphenol A/acrylic acid, diglycidyl etherified polybisphenol A/acrylic acid, triglycidyl etherified glycerin/acrylic acid,
Epoxy (meth)acrylates such as triglycidyl etherified trimethylolethane/methacrylic acid, diglycidyl etherified aniline/acrylic acid; γ-butyrolactone/N-methylethanolamine/bis(4-isocyanatocyclohexyl)methane/2-vitro Amide urethane (meth)acrylates such as xyethyl acrylate, γ-butyrolactone/N-methylethanolamine/2,6-tolylene diisocyanate)/tetraethylene glycol/2-hydroxyethyl acrylate; 2.
6- Urethane acrylates such as tolylene diisocyanate diacrylate, inphorone diisocyanate cyacrylate, inphorone diisocyanate cyacrylate, urethane acrylate synthesized from hexanediol/isophorone diisocyanate/2-hydroxyethyl acrylate, hexamethylene diisocyanate diacrylate; Redenbentaerythrinoth/2-
Examples include spiroacetal arylate synthesized from hydroxyethyl acrylate; acrylated iributadiene synthesized from oxidized butadiene/2-hydroxyethyl acrylate; these monomers and oligomers may be used alone or in combination of two or more. Used in mixed systems.

Among the above monomers and oligomers, the following general 9 [in the formula,
n is an integer from Fii to 4, and at least 3 or more of ~8
represents an alkylene group or a polyoxyalkylene group having an alkylene group having 1 to 8 carbon atoms. ), with the remainder having 1 to 8 carbon atoms (D 7 k-I
F group, hydroxyl group, amine group, formula: +oa, +H (wherein R2 represents an alkylene group having 1 to 8 carbon atoms,
m is a positive integer. ) Group or formula represented by: (-O
Represents a group represented by R,-)-OH (in the formula, R2 and m have the same meanings as above). It is preferable to use the compound represented by the following in an amount of 30 parts or more among monomers and oligomers. Oligomers represented by these general formulas have excellent curing properties when exposed to ultraviolet rays in the air, so they can improve key arinder properties when using ultraviolet rays, and improve stickiness and blocking properties on the coating film surface. However, if monomers or oligomers that have poor curing properties when exposed to ultraviolet rays in air are used, the surface of the coating film becomes sticky or blocking occurs. Specific examples of the compounds represented by the above general formula include dipentaerythritol tetraacrylate, sopentaerythritol bentaacrylate, dipentaerythritol hexaacrylate, triintererythritol pentaacrylate, tripentaerythritol hexaacrylate, and tripentaerythritol hexaacrylate! Examples include cyacrylate.

The amount of the crosslinking agent exemplified above is 10 to 70 parts by weight, preferably 15 to 60 parts by weight, based on 100 parts by weight of the total fi of the crosslinking agent and the alkyl (meth)acrylate polymer. When the amount of crosslinking agent exceeds 70 parts by weight of gold, the blocking resistance becomes good, but the dyeability decreases;
If it becomes less than 01HN%, blocking will occur.

Such blocking becomes more noticeable as the amount of energy AI applied to the thermal head (thermal recording head) increases and the temperature of the thermal head increases, but silicone surfactants and/or fluorine surfactants If the agent is blended in the range of 0.01 to 10 parts by weight to 10,021 parts of the mixture of the crosslinking agent and the alkyl (meth)acrylate polymer, the blocking property will be significantly improved, and the dyeing density and the smoothness of the coating will be improved. It was also found that sex was improved. The preferred blending amount of the silicone surfactant and/or fluorine surfactant is 1d, which is in the range of 0.05 to 5 parts by weight. If it is less than 0.01 part by weight, the effect of improving the blocking property is small, and if it exceeds 10 parts by weight, blocking may occur more easily, and the film may have a rough or milky appearance.

As silicone surfactants, compounds represented by the following general formula (1) or (II) are particularly suitable for preventing blocking,
It is effective in improving dye density and film smoothness.

CH5 and n1ii12131... are positive integers, and X and y are 0.1, 2, 3... ..., and takes a value that satisfies the formula % O1≦□≦10. itl represents m-H, an alkyl group, an acyl group or an aryl group.

) H3, and m and n are 1, 2.3. A positive integer of...
Also, X and y are 0, 1.2, 3. The number of ..., 2 is 0
or a positive integer from 1 to 5, and -H represents an alkyl group, an acyl group, or an aryl group, and R3 represents -H, an alkyl group, an acyl group, or an aryl group. ) The silicone surfactants of the above formulas (1) and (If) do not exist alone, but are known as a mixture of compounds with different m and n.

The fluorine-based surfactant may be nonionic, cationic, anionic, or amphoteric as long as it is compatible with the mixture of the crosslinking agent and the alkyl (meth)acrylate polymer and exhibits surface activity. Fluorine surfactants can also be used. For example, anionic surfactants such as fluoroalkoxypolyfluoroalkyl sulfates, fluorocarbon sulfonates, and fluorocarbon carboxylates; for example, N-fluoroalkylsulfonamide alkylamine salts, N-fluoroalkylamidoalkylamine quaternary ammonium salts; Cationic surfactants such as N-fluoroalkylamidoalkylamine salts, N-fluoroalkylsulfonamide alkyl halomethyl ether quaternary ammonium salts, fluorocarbon sulfonamide, fluorocarbine aminosulfo/amide, fluorocarbon carboxysulfonamide, fluorocarbon Carphone hydroxysulfonamide, fluorocarbon sulfonamide ethylene oxide adduct,
Fluorocarbon hydroxysulfonamide sulfate esters, fluorocarbon amino acid amides, fluorocarbon acid amides, fluorocarbon hydroxyamides, ethylene oxide adducts of fluorocargenic acid amide, fluorocarme hydroxy acid amide sulfate esters, fluorocarme hydroxy acid amide sulfate Nonionic surfactants such as esters, fluorocarbon sulfonic acids, fluorohydrocarmen carboxylic acids, fluorohydrocarbon alcohol esters, fluorocarbon hydroxyamides, fluorohydrocarbon alkyl sulfates, fluoroalkyl diamines, Examples include amphoteric surfactants such as alkylamines having a betaine type fluorocarbon sulfonamide bond and alkylamines having a betaine type fluorocarbon acid amide bond. In consideration of coating workability, blocking resistance of the resulting film, improvement of dye density, and surface properties, it is particularly desirable to use a nonionic surfactant. These silicone surfactants and/or fluorine surfactants may be used alone or in combination.

When an electron beam is used as an active energy beam when curing a coating composition composed of the above crosslinking agent, (meth)acrylic acid alkyl ester polymer, silicone surfactant or/and fluorine surfactant does not need to contain a photopolymerization initiator, but at wavelength 1
When using ultraviolet rays of 00 to 800 nm, the amount of photopolymerization initiator or photosensitizer is 0.1 to 0.1 to 100 parts by weight of the crosslinking agent and (meth)acrylic acid alkyl ester polymer mixture.
It is preferable to add 10.0 parts by weight. Specific examples of photopolymerization initiators include benzoin, benzoin isobutyl ether, and pennoldimethyl ketal.

Ethylphenylglyoxalate, noetogythiacetophenone, 1,1-dichloroacetophenone, 4'-inzolobyl-2-hydroxy-2-methylglobiophenone, 1-hydroxycyclohexylphenylketone, benzophenone, benzophenone/jetanol amine,
4. Carbonyl compounds such as 4'-bisdimethylaminobenzophenone, 2-methylthioxanthone, tert-butylanthraquinone, and benzyl; Sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; azobisisobutyronitrile, Azo compounds such as azobis-2,4-dimethylvaleronitrile;
Examples include i4-oxide compounds such as benzoyl peroxide and di-tert-butyl sulfur oxide, and these compounds may be used alone or in a mixture of two or more.

The above crosslinking agents, (meth)acrylic acid alkyl ester polymers, sidicone surfactants, and more! A coating composition consisting of /i/, a fluorine-based surfactant, and, if necessary, a photopolymerization initiator, can be applied to a film-like or paper-like base material by a roll coating method, a barcode method, a spray coating method, or a clavia method. Coating can be performed using a coating method, curtain coating method, pea coating method, 70-coating method, dirag coating method, etc., but in order to improve workability, these compositions may be coated with a solvent (for example, ethyl alcohol, Inglovir alcohol, acetone, methyl ethyl ketone,
methyl acetate, ethyl acetate, dimethylformamide, etc.)
It is better to adjust the coating viscosity to an appropriate level by blending.

The film thickness of the composition formed on the substrate is 0.5 to 100μ, preferably 1 to 50μ. When the film thickness becomes thinner than 0.5 μm, the diffusion of the dye reaches saturation halfway, making it impossible to dye the film in a deep color. On the other hand, if the film thickness exceeds 100 μm, blocking tends to occur during heating.

When stacking dyed films or papers, in order to prevent the transfer of disperse dyes, it is better to apply the composition that forms a dyed layer on only one side of the substrate, but actively prevent the transfer of this dye. In order to prevent dyeing, it is more preferable to provide a non-migration layer on the opposite side to the dyed layer.

The composition for forming the non-migration layer includes 100 parts by weight of a monomer/oligomer mixture consisting of the polyfunctional monomer and/or monofunctional monomer described above, and, if necessary, 0.1 to 10 parts by weight of the photopolymerization initiator described above. A coating agent consisting of 0 parts by weight can be used, but in order to sufficiently prevent dye migration due to disperse dyes, the monomer/oligomer mixture must have an average of 1.5 or more polymerizable groups per molecule. is necessary. These coating agents can also be adjusted in viscosity with a solvent, applied, and cured in the same manner as the coating composition for forming a dyed layer.

The film-like or paper-like base material used for the recording medium for thermal transfer may be any material that is normally used as a base material for dry transfer. film,
Specific examples of paper include polyester film, polypropylene film, nylon film, film-like materials such as vinyl film; paper such as art paper made mainly of wood fibers, acrylic paper made mainly of acrylic fibers, and polyester paper. In particular, polyester film, acrylic paper, or art paper is preferable in consideration of heat resistance, and polyester film is most preferable in consideration of transparency of the article.

These papers or films may be used as they are, or if necessary, they may be pretreated by washing, etching, corona discharge, active energy ray irradiation, dyeing, printing, etc. It's okay.

To prepare a recording medium for thermal transfer, the coating composition of the present invention is usually mixed uniformly in advance and applied to the surface of paper or film.

Next, the coating film on the paper or film is cured by active energy rays.

Active energy rays include ultraviolet rays emitted from sources such as xenon lamps, low-pressure mercury lamps, high-pressure mercury lamps, or ultra-high-pressure mercury lamps, electron beams usually extracted from 20-2000 kV electron beam accelerators, α rays, β rays, γ rays, etc. radiation, etc. Considering ease of handling and workability,
Ultraviolet light having a wavelength in the range of 100 to 800 nm is preferred.

〔Effect of the invention〕

The recording material for thermal transfer prepared using the coating composition of the present invention can be easily dyed with a sublimable disperse dye, and has significantly superior color development and clarity compared to conventional ones. The coating composition of the present invention has excellent blocking resistance and high heat resistance, and can perform dry transfer of disperse dyes at low temperatures and in a short time. It is extremely useful as a material for dry transfer color development, and its industrial value is great.

[Embodiments of the invention]

EXAMPLES Below, examples of the present invention will be given and explained in more detail. In addition, in Examples and Comparative Examples, all "parts" represent parts by weight.

Reference example 1. Preparation of transfer sheet: Spread a dye solution consisting of 1 part of Kayaset Blue 136 (Nippon Kayaku disperse dye), 1 part of ethyl cellulose, and 100 parts of trichlene onto a 10μ capacitor so that the film thickness after drying is several micrometers. to create a transfer sheet.

Reference example 2. Transfer recording method: The dye-coated surface of the transfer sheet was placed on the dye layer surface of the dry transfer recording medium, and thermal transfer recording was performed using an NTT mini-fax machine. At this time, a voltage of 20V was applied to the thermal head for 6 milliseconds, and the temperature of the head increased to 200°C or higher.

Reference example 3. Evaluation of blocking resistance: When the transfer recording material and transfer sheet were peeled off after the experiment in Reference Example 2, those that could be easily peeled off were evaluated as having "good" blocking resistance; Items that required some effort were labeled as ``defective.''

Reference Example 4 Part Dyeing Density Measuring Method: The dyeing density was determined by measuring the light transmittance T using a color analyzer (manufactured by Hitachi, model 3o7) and obtaining it as -LogT.

Example 1. Comparative Examples 1 to 4 After mixing and preparing the coating compositions shown in Table 1, they were uniformly applied onto a 100 μm thick polyester film by a dipping method. This was irradiated with ultraviolet rays in air to obtain a recording medium for dry transfer having a dyed layer with a thickness of 5 μm.

Evaluation tests were conducted on these recording materials according to Reference Examples 1 to 4, and the results shown in Table 2 were obtained.

Examples 2-3. Comparative Examples 5 to 10 The coating composition shown in Table 1 was uniformly coated on a 100 μm polyester film treated with corona discharge (by dipping method). When these are irradiated with ultraviolet rays in the air, the film thickness is 4μ.
A recording medium for dry transfer having a dyed layer of 100% was obtained.

Evaluation tests were conducted on these recording media according to Reference Examples 1 to 4, and the results are shown in Table (2). In actual facsimiles, severe blocking appears, and in Comparative Example 5.6, which does not contain a silicone surfactant, blocking is significant. On the other hand, when comparing Comparative Example 5゜6 and Examples 2 and 3,
No blocking was observed in the examples containing silicone surfactants.

■Acrylic polymer B: methyl methacrylate/ethyl acrylate) = 70/30, Tg 50°C acrylic polymer 〇 dimethyl methacrylate/ethyl acrylate = 9515, Tg 100°C Acrylic I remer D: methyl methacrylate/lauryl methacrylate =
65/35, Tg 30°C Acrylic Polymer E: Methyl methacrylate/styrene = 30/70. TglO
0°C Silicone surfactant B: Example 4゜dipentaerythritol hexaacrylate io part 1
．． ,,>Intererythritol pentaacrylate 20
parts, dipentaerythritol tetraacrylate 10 parts, tetrahydrofur7lyl acrylate 1'-40 parts, 2-
A composition consisting of 6 parts of hydroxy-2-methylpropiophenone was coated on one side of a 100 .mu.m polyester film using a nyroll coater, and then irradiated with ultraviolet rays in the air to form a non-migration layer with a thickness of 7 .mu.m.

On the opposite side of the non-migration layer of this film, 5 parts of dipentaerythritol hexaacrylate, 5 parts of dipentaerythritol pentaacrylate, 5 parts of dipentaerythritol tetraacrylate, and a compound synthesized from succinic acid/trimethylolethane/acrylic acid were applied. 25 parts of oligomer, 60 parts of acrylic polymer A (butyl methacrylate/methyl methacrylate) = 60/40. Tg 50°C), 150 parts of methyl ethyl ketone, 50 parts of DMF, 6 parts of benzyl dimethyl ketal, and 1.2 parts of polyoxyethylene fluorocarbon amide as a fluorosurfactant were coated with a roll coater, and then coated in air. A dyed layer with a thickness of 4 μm was provided by irradiation with ultraviolet rays.

Evaluation tests were conducted on the dyed layer of the obtained recording medium according to Reference Examples 1 to 4, and the dyeing density was -1 og.
T = 0.67 was shown, and blocking resistance was also good.

Furthermore, even when 10 sheets of this dyed recording medium were stacked, a 2-Yu weight was placed on them, and they were left for 3 months, almost no dye migration to the non-migration layer was observed.

Claims (4)

[Claims] (1) Crosslinking agent 10 to 70 that can be cured by active energy rays
Mixture 10 consisting of parts by weight and 30 to 90 parts by weight of at least one (meth)acrylic acid alkyl ester polymer
0 parts by weight and at least one of silicone surfactants and/or fluorine surfactants 0.01 to 10 parts by weight
A coating composition for a recording medium of a sublimation type heat-sensitive transfer recording system, which comprises parts by weight. (2) The composition according to claim 1, wherein the crosslinking agent is at least one UV-curable polyfunctional monomer. (3) The composition according to claim 2, wherein the polyfunctional monomer has a polymerizable (meth)acryloyloxy group. (4) The above (meth)acrylic acid alkyl ester polymer is a polymer containing 50% by weight or more of a (meth)acrylic acid alkyl ester component having an unsubstituted or substituted alkyl group, and its Tg is 40°C or more. The composition according to claim 1, which is