JPS6367189A - Recording material in sublimation thermal transfer recording system - Google Patents

Abstract

PURPOSE:To enable easy dyeing with dispersed sublimation dye with high density, by applying a composition where a specific surfactant is mixed by specific quantity into polyester resin and a bridging agent mixed in a specific ratio, then hardening through active energy beam thus providing a recording material. CONSTITUTION:Preferably, polyester resin being applied onto the surface of basic material is linear thermoplastic polyester resin produced from dicarboxylic acid and diol and/or an unsaturable polyester resin produced from an unsaturable poly basic acid having double bond and polyhydric alcohol. More preferably, a linear thermoplastic polyester resin produced from two kinds or more of dicarboxylic acid and two kinds or more of diols having the crystallization less than 1% is employed. Preferably, bridging agent and polyester resin are mixed in the range of 40-95wt%. A composition applied with the bridging agent is hardened by active energy beam. Total mixing quantity with polyester resin 5-60wt%. Preferably, the polymerizing group of the bridging agent is a monomer having (metha)cryloyl oxy group. At least one of silicon surfactant or fluoro surfactant is mixed in 0.01-10wt%. Preferably, the ratio between CH3-(SiO)1/2- group and -OR- group (R: alkylane residual group) in the surfactant is in the range of 1/10-1/0.1.

Description

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

[Conventional technology] Recent rapid progress in office automation! Along with this, color displays are rapidly increasing in the core of PCs, word processors, office computers, etc., and the demand for practical use of recording methods from color signals is rapidly increasing. There is a strong demand for colorization.

Conventional color recording methods include a light pen method, a wire dot method, and an inkjet method, but each method has drawbacks such as slow recording speed, noise, and clogging of the tiny nozzles that eject 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, the final method is a method in which a transfer sheet coated with a sublimable dye is heated with a thermal recording head to sublimate and transfer the dye to the recording medium to obtain color recording, so by adjusting the energy applied to the thermal head. Since the amount of sublimation of the dye can be controlled, it is easy to express gradation, and compared to other recording methods, it is especially advantageous for obtaining full-color hard copies.

For this reason, JP-A-60-81359, JP-A-60-1/
No. 2493 and the like propose recording materials that can be used in the Y-shaped thermal transfer recording method, but these are articles that can be dyed with sublimable cationic dyes and lack stability against light. For this reason, there has been a demand for the development of a recording medium that can be dyed with sublimable disperse dyes that have good light resistance.

[Problems to be Solved by the Invention] The object of the present invention is to provide a disperse dye dry transfer method that can be easily dyed with a disperse dye under low energy conditions in a sublimation type thermal transfer recording system and has excellent color development and clarity. The objective is to provide a recording medium.

As a result of extensive studies, the present inventors have found that a recording medium obtained by coating a composition comprising a specific ratio of polyester resin, a crosslinking agent, and a specific amount of a specific surfactant and curing it with active energy rays. The present invention was completed by discovering that A-type disperse dyes can be easily dyed under low energy conditions and dyed at high concentrations.

[Means for Solving the Problems] That is, the present invention provides polyester resin 40 on the surface of the substrate.
0.01 to 10 parts by weight of at least one selected from silicone surfactants and fluorine surfactants per 100 parts by weight of a mixture consisting of ~95% by weight and 60 to 5% by weight of a crosslinking agent that can be cured by active energy rays. This is a recording material for sublimation type heat-sensitive transfer recording method obtained by coating a composition consisting of parts by weight and curing with active energy rays.

The present invention will be explained in detail below.

According to the present invention, the polyester resin constituting the composition applied to the surface of the substrate is well stained by sublimable disperse dyes and functions as a binder for the composition, and is one of the essential components of the present invention. It is one.

The polyester resin used in the present invention is a linear thermoplastic polyester resin obtained by condensation polymerization of a dicarboxylic acid and a diol, and/or an unsaturated polybasic acid having a reactive double bond and a polyhydric alcohol. Unsaturated polyester resins obtained by polycondensation are preferred. Among them, a linear thermoplastic polyester resin with a molecular weight of 2,000 to 40,000 obtained by polycondensation of two or more dicarboxylic acids and two or more diols, and with a crystallinity of 1%.
The following polyester resins are more preferable in terms of solubility in organic solvents, ease of dyeing, and good light resistance.

The amount of polyester resin in the mixture with the crosslinking agent is 40
~95% by weight is preferred. If it is less than 40% by weight, the dyeing density with the sublimable disperse dye will not become deep under low energy conditions, and conversely, if the amount of polyester resin blended exceeds 95% by weight, the amount of crosslinking agent will decrease and the sublimable disperse dye will not be applied. The non-blocking property with the colored color sheet (transfer paper) was poor, and the color sheet and the article coated with the R-color disperse dye dyeable composition and cured with active energy rays caused blocking (sticking) during thermal transfer. It becomes like this. More preferably, it is in the range of 55% to 93% by weight.

Specific examples of linear thermoplastic polyester resins obtained by condensation polymerization of two or more dicarboxylic acids and two or more diols include polyester resins obtained from terephthalic acid/isophthalic acid/ethylene glycol/neopentyl glycol. , other terephthalic acid/isophthalic acid/ethylene glycol/ethylene oxyto adduct to bisphenol, terephthalic acid/inphthalic acid/ethylene glycol/1,8-hexanediol, terephthalic acid/isophthalic acid/sebacic acid/ethylene glycol/neopentyl Examples include polyester resins obtained from glycol, terephthalic acid/sebacic acid/ethylene glycol/neopentyl glycol, terephthalic acid/isophthalic acid/adipic acid/ethylene glycol/neopentyl glycol, and two or more types are used in combination. You can also do that. Note that it is of course possible to use esterified dimethyl terephthalate, dimethyl isophthalate, etc. as a raw material for condensation polymerization instead of terephthalic acid, isophthalic acid, etc.

Examples of unsaturated polyester resins obtained by condensation polymerization of unsaturated polybasic acids with reactive double bonds and polyhydric alcohols include maleic anhydride/phthalic anhydride/propylene glycol, maleic anhydride/inphthalic anhydride/ Examples include resins obtained from propylene glycol, maleic acid/fumaric acid/isophthalic acid/1,3-butanediol, maleic acid/inphthalic acid/neopentyl glycol, maleic anhydride/tetrahydrophthalic anhydride/dipropylene glycol, etc. I can do it.

The crosslinking agent is necessary to cure the composition to be coated with active energy rays and to obtain anti-blocking properties of the composition, and the preferred amount is 5% of the total amount with the polyester resin.
-60% by weight, more preferably 7-45% by weight. If the amount of crosslinking agent is less than 5% by weight, blocking tends to occur, whereas if it exceeds 60% by weight, blocking resistance will be good, but the proportion of polyester resin will decrease and sufficient dyeing density will not be obtained. It becomes difficult.

Considering the curing of the composition by the crosslinking agent and the blocking resistance of the composition, it is preferable that the crosslinking agent has at least one type of polyfunctional monomer, and when using ultraviolet rays that are easy to handle as active energy rays. The polymerizable group of these crosslinking agents is preferably a monomer having an acryloyloxy group or a methacryloyloxy group.

Examples of monomers having a (meth)acryloyloxy group include polyether acrylate or polyether methacrylate (hereinafter, "acrylate or methacrylate" is simply abbreviated as "(meth)acrylate"), polyester (meth)acrylate, Polyol (meth)acrylate type, epoxy (meth)acrylate type, amide urethane (meth)acrylate type,
Urethane (meth)acrylate type, spiroacetal (
Examples include oligomers such as meth)acrylate and polybutadiene (meth)acrylate.

Specific examples of such monomers or oligomers include 1,2,6-hexanetriol/propylene oxide/acrylic acid, polyether (meth)acrylate synthesized from trimethylolpropane/propylene oxide/acrylic acid: adipic acid/1 , 8-hexanediol/acrylic acid, succinic acid/trimethylolethane/
Polyester (meth)acrylate synthesized from acrylic acid, etc.; triethylene glycol diacrylate, hexabrobylene glycol diacrylate, neopentyl glycol diacrylate, 1,4-butanediol dimethacrylate, 2-ethylhexyl acrylate,
Tetrahydrofurfuryl acrylate, 2-hydroxyethyl methacrylate, ethyl carpitol acrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, 2,2-bis(4-acryloyl ethoxy) (meth)acrylate or polyol (meth)acrylate such as phenyl)propane, 2,2-bis(4-acryloylolopoxyphenyl)propane; diglycidyl etherified bisphenol A/acrylic acid, diglycidyl etherified polybisphenol A/acrylic Epoxy (meth)acrylates such as acid, triglycidyl etherified glycerin/acrylic acid; γ-butyrolactone/N-methylethanolamine/bis(4-incyanatocyclohexyl)methane/2-hydroxyethyl acrylate, γ-butyrolactone/N- Methylethanolamine/2,6-tolylene diisocyanate/tetraethylene glycol/amide urethane (meth)acrylate such as 2-hydroxyethyl acrylate: 2,6-
Urethane acrylates such as dolylene diisocyanate diacrylate, inphorone diisocyanate diacrylate-1, and hexamethylene diisocyanate diacrylate; spiroacetal acrylate synthesized from diarylidene pentaerythritol/2-hydroxyethyl acrylate; epoxidized butadiene/2 Examples include acrylated polybutadiene synthesized from -hydroxyethyl acrylate, and these monomers and oligomers are used singly or in a mixed system of two or more types.

Among the monomers and oligomers, the following general formula % formula % [wherein n is an integer of 1 to 4, and at least 3 Xs are represented by the general formula: CIh=CH-CD0-Rs- (wherein
8 represents a single bond, an alkylene group having 1 to 8 carbon atoms, or a polyoxyalkylene group having an alkylene group having 1 to 8 carbon atoms. ), the remainder is an alkyl group having 1 to 8 carbon atoms, a hydroxyl group, an amino group, or a group of the formula (Oh)*-H (wherein R9 represents an alkylene group having 1 to 8 carbon atoms; , m is a positive integer) or a group represented by the formula (OR9) II -OH (wherein R9 and m have the same meanings as above). ]
Compounds represented by, for example, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,
Tripentaerythritol pentaacrylate, tripentaerythritol hexaacrylate, tripentaerythritol hexaacrylate, etc., or the following general formula (■
) ゛... (II) (wherein, n is a positive integer of 1 to 10, and X is optionally -DH or -COCH=CI42.) A polyacrylate of polybisphenol A type, for example, Diacrylate of diglycidyl etherified bisphenol A, diacrylate of Epicote #1001 (n-3, manufactured by Shell), etc., or the following general formula (m) CH3 recognition... (■) (wherein, X, , X, , , ..., Xn are the same or different alkylene groups having 6 or less carbon atoms, or have a structure in which one hydrogen atom of the alkylene group is replaced with a hydroxyl group, and n
is an integer from 0 to 5), such as 2,2-bis(4-acryloyloxyjetoxyphenyl)propane, 2゜2-bis(4-acryloyloxytriethoxyphenyl)propane, 2,2 -Bis(4-acryloyloxydipropoxyphenyl)propane and the like have very good quick drying properties in air when ultraviolet rays are used as active energy rays, and are particularly preferred crosslinking agents.

The silicone surfactant and/or the fluorine surfactant are essential components in order to prevent blocking with the color sheet (transfer paper) during low energy thermal transfer. In other words, it has been found that in order to obtain a high concentration of color development by sublimable disperse dyes at low energy, it is sufficient to reduce the amount of the crosslinking agent of the present invention, but at the same time, blocking appears significantly. . However, it has been found that by adding a small amount of at least one selected from a specific silicone surfactant and a fluorine surfactant to this, blocking can be significantly eliminated even if the amount of crosslinking agent is small.

Among silicone surfactants, compounds containing blocks of polydimethylsiloxane and polyoxyalkylene (which may be slightly modified with other functional groups) are effective, and in particular CH3-( Sin)
The ratio of +/2- group and one OR- group (R: alkylene residue) is CH3-(SiO)+72-/-OR-=1
/10 to 110.1 has improved blocking properties,
When the composition is used as a coating agent, it is preferable because it has excellent ability to improve leveling, but surprisingly, these silicone surfactants are also effective in improving dye density and transparency of the cured composition. I discovered that. If a silicone surfactant is not added, the dyeing density may be poor or the cured composition may become white and cloudy. The preferred range of these is 115 to 110
．． The range is 2.

As a specific example of a silicone surfactant, general formula (IV
), (V) CH3 CH3(-5i-0)D-(P)y-R1...(I
V) CH3 (In the formula, P is +OH? CH20-)i-+ CH2CH
O)7-, CH3 m and n are 1,2,3. ..., and X and y are 0, 1, 2, 3, . ...represents the number of 10
Takes the value nx+ny. R1 represents -H, an alkyl group, an acyl group, an aryl group, an acetoxy group, or the like. )CH3CH3 l CH3(-3i-0)-r+5i-0)-rr-R2-
(V)CH3Q (in the formula, Q is (-CH2)z-0-(GH2CIhO)x
(-GH2CHO)v-hCH3, where m and n are 1, 2, 3. A positive integer of...
Also, X and y are 0. L, 2, 3. The number of ..., 2 is O
or represents an integer from 1 to 5, and the formula R2 is -3i-CH:
+, -H, an alkyl group, an acyl group, or a CH3 aryl group, and R3 represents -H, an alkyl group, an acyl group, an aryl group, an acetoxy group, or the like. ) There are compounds shown by the following, and these can also be used in combination with 2 inserts 1-.

The composition of the present invention consisting of the following two components can be directly coated by roll coating, barcode coating, or blade coating when using tetrahydrofurfuryl acrylate, which has strong polymer solubility and low viscosity, as a crosslinking agent. However, in order to improve coating workability, a solvent such as ethyl alcohol, methyl ethyl ketone, toluene, ethyl acetate, dimethyl formamide, etc. is blended with these compositions to form a suitable coating. It is better to adjust it to a technical viscosity. This makes it possible to easily perform curtain coating, flow coating, dip coating, etc.

Furthermore, depending on the purpose for which the above-mentioned composition is used, fine inorganic particles of several JLm or less, such as silica, alumina, talc, titanium oxide, etc., may be added.

The composition of the present invention is cured by active energy rays such as electron beams and ultraviolet rays, but in consideration of radiation source control, it is better to use ultraviolet rays. When ultraviolet rays are used as active energy rays, it is preferable to add 0.1 to 10.0 parts by weight of a photopolymerization initiator to 100 parts by weight of the total of the polyester resin and crosslinking agent of the present composition. Specific examples of photopolymerization initiators include benzoin, benzoin isobutyl ether, benzyl dimethyl ketal, ethylphenyl glyoxylate, jetoxyacetophenone,
1,1-dichloroacetophenone, 4'-isopropyl-2-hydroxy-2-methylpropiophenone, 1-
Hydroxycyclohexyl phenyl ketone, benzophenone, benzophenone/jetanolamine, 4,4'
-carbonyl compounds such as bisdimethylaminobenzophenone, 2-methylthioxanthone, tert-butylanthraquinone, and benzyl; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; azobisisobutyronidonyl, azobis-2,
Examples include azo compounds such as 4-dimethylvaleronitrile; peroxide compounds such as benzoyl peroxide and di-tart-butyl peroxide; these compounds are used singly or in a mixed system of two weighing amounts.

A film or paper-shaped substrate is suitable as a substrate for coating the following composition and irradiating active energy rays to obtain a recording medium, and polyester film, polypropylene film, nylon film, chloride Plastic film-like materials such as vinyl film: coated paper, baryta paper, and art paper that are mainly made of wood fibers; paper-like materials that are mainly made of plastic fibers such as acrylic paper, PP paper, and polyester paper. Polyester film is suitable in terms of transparency, and PP paper is suitable in terms of image quality.

These papers or films can be used as they are, or if necessary, they can be pretreated by washing, etching, corona discharge, active energy ray irradiation, dyeing, printing, etc. good.

By applying the sublimable disperse dye dyeable composition to these substrates by the above-described coating method, the film thickness after curing is 0.5 to 10.
Apply uniformly to 0 gm, preferably 1 to 50 gm.

When the film thickness becomes thinner than 0.5 gm, the diffusion of the dye reaches saturation midway through, making it impossible to dye the film in a deep color.

On the other hand, if the film thickness exceeds 1100 JL, blocking tends to occur during heating.

When stacking dyed films or papers, it is better to apply the composition to only one side of the substrate in order to prevent the disperse dye from transferring, but in order to actively prevent the dye from transferring, It is more preferable to provide a non-migration layer on the side opposite to the coated side of the sublimable disperse dye dyeable composition.

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 100 parts by weight of the photopolymerization initiator described above. However, in order to prevent dye migration due to disperse dyes within 1 minute, the monomer/oligomer mixture must have an average of 1.5 or more polymerizable groups per molecule. It is necessary. Similar to sublimable disperse dye dyeable compositions, these coating agents can also be used to adjust the viscosity with a solvent,
Coating and curing can be performed on a substrate.

[Example] Below, Examples of the present invention will be listed and explained in more detail. In addition, in Examples and Comparative Examples, all "parts" represent parts by weight.

Reference example 1. Making a transfer sheet: Use Kayaset Blue 136 on a commercially available transfer paper with a thickness of 60gm.
A transfer sheet was prepared by uniformly applying a 5% trichlorethylene solution (manufactured by Nikki Kayaku).

Reference example 2. Dry heat transfer method: Lay paper on an ironing board, place the recording material on the ironing board, and overlay the transfer sheet prepared in Reference Example 1. Furthermore, this I-
After layering commercially available paper with a thickness of 85 μm on
Heat on a hot plate at 145° C. for 10 seconds under pressure 2.

Reference example 3. Evaluation of Blocking Resistance After the dry heat transfer in Reference Example 2, when the dyed article and the transfer sheet were peeled off, the blocking resistance was expressed as "good" if the dyed article could be easily peeled off, and the dyed article was tacky. Items that required some force were designated as "r defective."

Reference example 4. Staining density measurement method Use a color analyzer (Hitachi Model 307) to measure the dye density, and in the case of a transparent recording medium, measure the light transmittance T and calculate it as -1ogT, and in the case of an opaque recording medium, calculate the reflectance. R was measured and calculated as -1ogR.

Example 1.・2: Comparative Examples 1 to 7 After mixing and adjusting the compositions shown in Table 1, 100 gm of these were mixed.
It was coated uniformly on one side of FX's transparent polyester film (Toshiba Lumirror product number 100, type 510) using the 20-coat method, and then irradiated with ultraviolet rays using a 2kW high-pressure mercury lamp in the air to achieve a film thickness of 4 mm. A recording material dyeable with a sublimable disperse dye was obtained. Regarding these articles, Reference Example 1
Table 1 shows the results of the evaluation according to 4. Further, when the adhesiveness of the cured composition to the polyester film was tested by peeling with cellophane tape, the article of the present invention was found to be good and did not peel off.

2P6A Nidipentaerythritol hexaacrylate 2P5A Nidipentaerythritol pentaacrylate 2P4A Nidipentaerythritol tetraacrylate A-DEP: 2,2-bis(4-acryloyloxyjetoxyphenyl)propane polyester Super fat A: Terephthalic acid/Isophthalic acid/Ethylene Resin made of glycol/neopentyl glycol (molecular weight: 15000-20000.Tg 65°C) Acrylic resin A Resin made of nibutyl methacrylate/methyl methacrylate (Tg Ei 5°C) Silicone surfactant A: CH30H3 CH3nSiOJr [5i04-y- HCH30--(
CTo CH20)y4cH2CHO)-v-CH3□ CH3 2m+n+1/nx+ny = 2.5 Example 3゜75 parts of polyester resin B, 10 parts of acrylic acid diacrylate of diglycidyl etherified bisphenol A, 5 parts of 2P6A, 5 parts of 2P5A 2P4A 5
part, silicone surfactant B5 parts, photopolymerization initiator 2-
A composition consisting of 6 parts of hydroxy-2-methylpropiophenone, 300 parts of toluene, and 100 parts of methyl ethyl was uniformly flow-coated on one side of PP paper, and then irradiated with ultraviolet light using a 2kW high-pressure mercury lamp in air to determine the film thickness. A recording medium having 5 layers of the composition of the present invention was obtained. When an experiment was conducted on this according to Reference Examples 1 to 4, it was well stained without blocking, and the reflected optical density = logR = 0-68.
showed that.

(Note) Polyester resin B: Resin consisting of terephthalic acid/sepacic acid/ethylene glycol/neopentyl glycol (molecular weight: 20,000-25,000.T g10℃
) Silicone surfactant B: CH30H3 CH3-[Si01m-[SiO]-n-H
l CH30- (fll: H2CHO crazy cH2CH20)
y-HCH3 2m+n+1/nx+ny = 0.35 Example 4゜060 parts of polyester resin on one side of coated paper, 2P6A
5 parts, 2P5A 5 parts, 2P4A 5 parts, 2.
2-bis(4-acrylonyloxydipropoxyphenyl)-propane 25 parts, silicone surfactant 04 parts, 2-hydroxy-2-methylpropiophenone 5 parts,
A composition consisting of 250 parts of ethyl acetate, 250 parts of methyl ethyl ketone, and 50 parts of silica (Aerosil R-972, [manufactured by Ichiki Aerosil Co., Ltd.]) was coated with a film thickness of 10% by blade coating.
It was applied uniformly to a pLm and cured by irradiating it with ultraviolet rays in the air. When this was subjected to dry heat transfer according to Reference Examples 1 to 4, it was dyed well without causing any blocking, and exhibited a reflection optical density of -1 part gR = 0°45.

(Note) Polyester resin C: Resin consisting of terephthalic acid/isophthalic acid/sebacic acid/ethylene glycol/neopentyl glycol (molecular weight: 20,000 to 25,000.T
g 10°C) Silicone surfactant C: CH3CH3 CH3-E-3i O-]r-(S i 03y-H+
+ CI(30-(CH2CH20y-CCOCH3)z
2m++n+1/nx= 1.3 [Effects of the Invention] The disperse dye dry transfer coloring recording material of the present invention is easily dyed with a sublimable disperse dye, and has significantly improved color development and clarity compared to conventional ones. It has excellent bronking resistance and high heat resistance, and can perform dry transfer of disperse dyes at low temperatures and in a short time with low energy. Therefore, the recording medium of the present invention is extremely useful as, for example, a dry transfer coloring material for color copying, electrophotography, or information recording. In particular, the recording medium of the present invention using a transparent substrate is transparent. It has excellent properties and has great industrial value for use in overhead projectors.

Claims (1)

[Claims] 1. On the surface of the substrate, 40 to 95% by weight of polyester resin and 60 to 5% by weight of a crosslinking agent that can be cured by active energy rays.
100 parts by weight of a mixture consisting of 0 and at least one selected from silicone surfactants and fluorine surfactants.
．． A recording medium for sublimation type heat-sensitive transfer recording method obtained by coating a composition comprising 01 to 10 parts by weight and curing with active energy rays. 2. The recording medium according to claim 1, wherein the polyester resin is a linear thermoplastic polyester resin obtained by polycondensation of dicarboxylic acid and diol. 3. The recording medium according to claim 1, wherein the polyester resin is an unsaturated polyester resin obtained by condensation polymerization of an unsaturated polybasic acid having a reactive double bond and a polyhydric alcohol. 4. Claims characterized in that the linear thermoplastic polyester resin is a resin obtained by polycondensation of two or more dicarboxylic acids and two or more diols, and has a crystallinity of 1% or less The recording medium described in item 2. 5. The recording medium according to claim 1, wherein the crosslinking agent contains at least one type of polyfunctional monomer. 6. The recording medium according to claim 1 or 5, wherein the polymerizable group of the crosslinking agent is a (meth)acryloyloxy group. 7. The main component of the silicone surfactant is a polyoxyalkylene modified product of polydimethylsiloxane, and CH_3
-(SiO)_1_/_2- and -OR- ratio is CH_3
-(SiO)_1_/_2-/-OR-=1/10~1
/0.1. 8. The recording medium according to claim 1, wherein the active energy rays are ultraviolet rays. 9. Mixture 100 consisting of polyester resin and crosslinking agent
9. The recording medium according to claim 1 or 8, wherein 0.01 to 10 parts by weight of a photopolymerization initiator is blended with respect to parts by weight. 10. The recording medium according to claim 1, wherein the substrate is a plastic film. 11. The recording medium according to claim 1, wherein the substrate is plastic paper. 12. The recording medium according to claim 1, wherein the base material is paper mainly composed of wood fibers.