JP2641197B2 - Sublimation type thermal transfer recording system - Google Patents

Description

The present invention relates to a recording medium in a sublimation type thermal transfer recording system.

[Prior art] With the rapid spread of office automation in recent years, the color display of personal computers, word processors, office computers, etc., which are at the core, has increased rapidly, and the demand for practical use of a recording method from color signals has been rapidly increasing. There is also a strong demand for colorization in the field of dry copying machines.

Conventional color recording methods include a light pen method, a wire dot method, an ink jet method, and the like. However, these methods have disadvantages such as low recording speed, noise, and clogging of small nozzles from which ink is ejected. On the other hand, the sublimation type thermal transfer recording method is characterized in that no sound is generated, and the handling, maintenance and management of the copying machine are easy. In addition, since this method is a method in which a transfer sheet coated with a sublimable dye is heated by a thermal recording head to sublimate and transfer the dye to a recording medium to obtain color recording, the energy applied to the thermal head must be adjusted. This makes it possible to control the amount of dye sublimation, thereby facilitating gradation expression, and is particularly advantageous in obtaining a full-color hard copy as compared with other recording methods.

For this reason, JP-A-60-81359, JP-A-60-112493 and the like have proposed recording media that can be used in a sublimation-type thermal transfer recording method, but these are articles that can be dyed with a sublimable cationic dye. Yes, lacks stability to light. For this reason, there has been a demand for the development of a recording medium that can be dyed with a sublimable disperse dye having good light resistance.

[Problems to be Solved by the Invention] An object of the present invention is to provide a dye sublimation type thermal transfer recording system which is easily dyed with a disperse dye under low energy conditions, and has excellent color developability and sharpness. It is to provide a recording medium.

As a result of intensive studies, the present inventors have applied a composition obtained by blending a specific ratio of a polyester resin and a crosslinking agent with a specific surfactant and a polyester compound of an aromatic polycarboxylic acid in a specific amount. It has been found that a recording medium obtained by curing with the above method is easily dyed with a sublimable disperse dye under a low energy condition and is dyed at a high density, thereby completing the present invention.

[Means for Solving the Problems] That is, the present invention relates to a method in which a polyester resin 40
~ 95% by weight and a crosslinking agent 60 curable by active energy rays
100 parts by weight of a mixture composed of a polyoxyalkylene derivative of polydimethylsiloxane, 0.01 to 10 parts by weight of a silicone surfactant having a polymerization degree of 5 to 5% by weight.
Sublimation type thermal transfer recording system obtained by applying a composition comprising 0.1 to 30 parts by weight of a solid aromatic polycarboxylic acid polyester compound plasticizer at room temperature, and curing with an active energy ray Recording object. It is.

 Hereinafter, the present invention will be described in detail.

According to the present invention, the polyester resin used in the composition applied to the substrate surface is dyed by a sublimable disperse dye and has a function as a binder of the composition, and is indispensable to the present invention. belongs to.

As the polyester resin, a linear thermoplastic polyester resin obtained by polycondensation of a dicarboxylic acid and a diol or / and a polycondensation of an unsaturated polybasic acid having a reactive double bond with a polyhydric alcohol can be used. Unsaturated polyester resins are preferred. Above all, a linear thermoplastic polyester resin having a molecular weight of 2,000 to 40,000 obtained by condensation polymerization of two or more dicarboxylic acids and two or more diols and having a crystallinity of 1% or less is an organic solvent. It is more preferable from the viewpoints of solubility in water, ease of dyeing, and good light fastness.

The amount of the polyester resin in the mixture with the crosslinking agent is 40
~ 95% by weight is preferred. When the amount is less than 40% by weight, the dyeing concentration of the sublimable disperse dye does not become high under low energy conditions. Conversely, when the amount of the polyester resin exceeds 95% by weight, the amount of the crosslinking agent decreases, and the sublimable disperse dye is applied. As the non-blocking property with the color sheet (transfer paper) becomes poor, the article and the color sheet coated with the sublimable disperse dye easily dyeable composition and cured with active energy rays cause blocking (sticking) during thermal transfer. Become.
More preferably, it is in the range of 55% by weight to 93% by weight.

Specific examples of the linear thermoplastic polyester resin 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 / bisphenol A-ethylene oxide adduct, terephthalic acid / isophthalic acid / ethylene glycol / 1,6-hexanediol, terephthalic acid / isophthalic acid / sebacic acid / ethylene glycol / neopentyl glycol, terephthalic acid / sebacic acid / ethylene glycol / Neopentyl glycol, terephthalic acid /
Examples include polyester resins obtained from isophthalic acid / adipic acid / ethylene glycol / neopentyl glycol. Two or more polyester resins can be used in combination. It is also possible to use esterified dimethyl terephthalate, dityl isophthalate or the like as a raw material for the condensation polymerization instead of terephthalic acid or isophthalic acid.

Unsaturated polyester resins obtained by polycondensation of an unsaturated polybasic acid having a reactive double bond with a polyhydric alcohol include maleic anhydride / phthalic anhydride / propylene glycol, maleic anhydride / isophthalic acid / Propylene glycol, maleic acid / fumaric acid / isophthalic acid / 1,3-butanediol, maleic acid / isophthalic acid /
Examples include resins obtained from neopentyl glycol, maleic anhydride / tetrahydrophthalic anhydride / dipropylene glycol, and the like.

The crosslinking agent is necessary for curing the composition to be coated with active energy rays and obtaining the blocking resistance of the composition, and is preferably used in an amount of 5 to 60% by weight of the total amount with the polyester resin. And more preferably 7 to 45% by weight. If the amount of the cross-linking agent is less than 5% by weight, blocking tends to occur. Conversely, if the amount exceeds 60% by weight, the blocking resistance becomes poor, but the ratio of the polyester resin decreases, and a sufficient dyeing concentration is obtained. It becomes difficult.

Considering the curing of the composition by the cross-linking agent and the blocking resistance of the composition, the cross-linking agent preferably has at least one kind of polyfunctional monomer, and when ultraviolet rays which are easy to handle are used as active energy rays. Preferably, the polymerizable group of these crosslinking agents is a monomer having an acryloyloxy group or a methacryloyloxy group.

Examples of the monomer having a (meth) acryloyloxy group include polyether acrylate or polyether methacrylate (hereinafter, “acrylate or methacrylate” is simply abbreviated to “(meth) acrylate”). Polyester (meth) acrylate, polyol Monomers and oligomers such as (meth) acrylate type, epoxy (meth) acrylate type, amide urethane (meth) acrylate type, urethane (meth) acrylate type, spiroacetal (meth) acrylate type and polybutadiene (meth) acrylate type Can be.

Specific examples of such a monomer or oligomer include 1,2,6-hexanetriol / propylene oxide / acrylic acid, and polyol (meth) synthesized from trimethylolpropane / propylene oxide / acrylic acid.
Acrylate; polyester (meth) acrylate synthesized from adipic acid / 1,6-hexanediol / acrylic acid, succinic acid / trimethylolethane / acrylic acid; triethylene glycol diacrylate, hexapropylene glycol diacrylate, neopentyl glycol Diacrylate, 1,4-butanediol dimethacrylate, 2-ethylhexyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl methacrylate, ethyl carbitol acrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, Dipentaerythritol pentaacrylate, 2,2-bis (4-acryloyloxydiethoxyphenyl) propane (Meta) such as 2,2-bis (4-acryloyloxypropoxyphenyl) propane
Acrylate or polyol (meth) acrylate; epoxy (meth) acrylate such as diglycidyl etherified bisphenol A / acrylic acid, diglycidyl etherified polybisphenol A / acrylic acid, triglycidyl etherified glycerin / acrylic acid; γ-butyrolactone
/ N-methylethanolamine / bis (4-isocyanatocyclohexyl) methane / 2-hydroxyethyl acrylate, γ-butyrolactone / N-methylethanolamine
Amidourethane (meth) acrylates such as / 2,6-tolylene diisocyanate / tetraethylene glycol / 2-hydroxyethyl acrylate; urethanes such as 2,6-tolylene diisocyanate diacrylate, isophorone diisocyanate diacrylate, hexamethylene diisocyanate diacrylate Acrylates; spiroacetal acrylates synthesized from diarylidenepentaerythritol / 2-hydroxyethyl acrylate; acrylated polybutadienes synthesized from epoxidized butadiene / 2-hydroxyethyl acrylate, and the like. These monomers and oligomers may be used alone or Used in a mixture of two or more.

Among the above monomers and oligomers, the following general formula (II) [In the formula, n is an integer of 1 to 4, and X is at least three general formulas: CH ₂ CHCH—COO—R ₈ — (wherein, R ₈ is a single bond, having 1 to 8 carbon atoms. Alkylene group or 1-8 carbon atoms
Represents a polyoxyalkylene group having an alkylene group. ), The remainder being 1 to 8 carbon atoms
An alkyl group, a hydroxyl group, an amino group of the formula: — (OR ₉ ) _m −
A group represented by H (wherein R ₉ represents an alkylene group having 1 to 8 carbon atoms and m is a positive integer) or a formula represented by the formula:
(OR ₉ ) _m —OH (wherein R ₉ and m are as defined above). A compound represented by the following general formula (for example, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol pentaacrylate, tripentaerythritol hexaacrylate, tripentaerythritol heptaacrylate, etc.) III) (Wherein, n is a positive integer of 1 to 10, X is arbitrarily -OH or -OC
It is a OCH = CH _2. ) A polyacrylate of the polybisphenol A type, for example, diglycidyl etherified bisphenol A
Or a diacrylate of Epicoat # 1001 (n = 3, manufactured by Shell) or the following general formula (IV) (Wherein, X ₁ , X ₂ ,..., X _n are the same or different alkylene groups having 6 or less carbon atoms or a structure in which one hydrogen atom is substituted with a hydroxyl group, and n is an integer of 0 to 5) For example, 2,2-bis (4-acryloyloxydiethoxyphenyl) propane, 2,2-bis (4-acryloyloxytriethoxyphenyl) propane, 2,2-bis (4-acryloyl) Oxydipropoxyphenyl) propane is a particularly preferred crosslinking agent because it has a very good quick drying property in air when ultraviolet rays are used as active energy rays.

A silicone-based surfactant and / or a fluorine-based surfactant are essential components for preventing blocking with a color sheet (transfer paper) when performing thermal transfer with low energy. That is, the result that the amount of the cross-linking agent of the present invention may be reduced in order to obtain the coloring by the sublimable disperse dye at a high concentration at a low energy has been obtained, but the blocking has come to appear remarkably. . However, it has been found that by adding a small amount of at least one selected from a specific silicone-based surfactant and a fluorine-based surfactant to this, blocking is remarkably eliminated even if the amount of the crosslinking agent is small.

Among the silicone-based surfactants, compounds in which polydimethylsiloxane and polyoxyalkylene are blocked (may be slightly modified with other functional groups) are effective. In particular, CH ₃ − in the silicone-based surfactant is effective. (SiO)
The proportion of _{1 / 2} -group and -OR- group (R: alkylene residue) is CH ₃
-(SiO) _1/2 -/-OR- = 1/10 to 1 / 0.1 is preferable because it is excellent in blocking improving property and leveling improving property when the composition is used as a coating agent. In particular, it has been found that these silicone surfactants are also effective in improving the dyeing concentration and the transparency of the cured composition. When no silicone surfactant is added, the dyeing density is poor or the cured composition becomes cloudy white. Their preferred range is from 1/5 to 1 / 0.2.

Specific examples of the silicone-based surfactant include those represented by formulas (V) and (VI). (Where P is And m and n are positive integers of 1,2,3, ..., and x and y are
Represents the number 0,1,2,3,… Take a value that satisfies R ₁ represents —H, an alkyl group, an acyl group or an aryl group, an acetoxy group or the like. ) (Where Q is Where m and n are positive integers of 1, 2, 3, ..., x and y are numbers of 0.1, 2, 3, ..., z is 0 or an integer of 1 to 5, and To be satisfied.

R ₂ -H, represents an alkyl group, an acyl group or an aryl group,
R ₃ represents —H, an alkyl group, an acyl group or an aryl group, an acetoxy group, or the like. ), And these can be used in combination of two or more.

By coating the composition described above on the basic surface and curing, it is possible to easily dye with a sublimable disperse dye, but in order to dye at a higher concentration, It has been found that 0.1 to 30 parts by weight of the polyoxyalkylene derivative (based on the total 100 parts by weight of the polyester resin and the crosslinking agent) may be added.

Polyesters of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid,
There are polyesters such as pyromellitic acid and naphthalic acid, for example, dimethyl phthalate, diethyl phthalate, dimethyl terephthalate, diethyl terephthalate, dibutyl isophthalate, trioctyl trimellitate, triethyl trimellitate, tetramethyl pyromellitate, etc. From the viewpoint of improving the dyeing concentration and preventing bleed-out of additives, the polyester compound of an aromatic polycarboxylic acid is a diester of phthalic acid, isophthalic acid or terephthalic acid, and is a solid at room temperature. Compounds such as dimethyl terephthalate, diethyl terephthalate, bis-hydroxyethoxyethyl terephthalate and the like are preferred.

The general formula (I) (Where n is a positive integer from 1 to 5, the bond is at the ortho position,
This indicates that the position is an arbitrary position of the meta position or the para position, and can be arbitrarily changed according to n. R ₁ , R ₂ ,..., R _{n + 1} are the same or different alkylene groups. The polyester compound of an aromatic polycarboxylic acid which is a solid at room temperature has a further effect of improving dyeing density and an effect of preventing bleeding. More preferable examples are bis-hydroxyethyl terephthalate and bis-hydroxypropyl. Phthalate, And the like.

A suitable compounding ratio of these compounds is 0.
The range is 1 to 30 parts by weight, preferably 0.2 to 20 parts by weight. If the amount of the compounding agent is less than 0.1 part by weight, the effect of improving the dyeing concentration is small, and if it exceeds 30 parts by weight, these compounds may bleed on the surface or conversely lower the dyeing concentration.

When the composition of the present invention composed of the above components is used as a component of the cross-linking agent, such as tetrahydrofurfuryl acrylate, which has a high polymer solubility and a low viscosity, it can be used as a coating such as a roll coat, a bar coat, and a blade coat. Although it is possible, in order to improve the coating workability, these compositions in the solvent, for example, ethyl alcohol, methyl ethyl ketone, toluene, ethyl acetate,
It is better to mix dimethylformamide or the like and adjust the coating viscosity to an appropriate value. Thereby, curtain coating, flow coating, dip coating, and the like can be easily performed.

Further, depending on the purpose of using the above composition, fine inorganic fine particles of several μm or less, for example, silica, alumina, talc, titanium oxide and the like may be further blended.

The composition of the present invention is carried by an active energy ray such as an electron beam or an ultraviolet ray, but it is preferable to use an ultraviolet ray in consideration of the management of the radiation source. When ultraviolet rays are used as the active energy rays, the photopolymerization initiator is used in an amount of 0.1 to 100 parts by weight of the polyester resin and the crosslinking agent in the composition of the present invention in total.
It is preferable to add 10.0 parts by weight. Specific examples of the photopolymerization initiator include benzoin, benzoin isobutyl ether, benzyldimethyl ketal, ethylphenylglyoxylate, diethoxyacetophenone, 1,1-dichloroacetophenone, and 4'-isopropyl-2-hydroxy-2-methylpropio. Phenone, 1-hydroxycyclohexylphenyl ketone, benzophenone, benzophenone / diethanolamine, 4,4'-bisdimethylaminobenzophenone, 2-methylthioxanthone, te
carbonyl compounds such as rt-butylanthraquinone and benzyl; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile; benzoyl peroxide And peroxide compounds such as di-tert-butyl peroxide. These compounds are used alone or in a mixture of two or more.

As a substrate for applying the above composition and irradiating an active energy ray to obtain a recording medium, a substrate in the form of a film or paper is suitable, and a polyester film, a polypropylene film, a nylon film, and a vinyl chloride film are suitable. Plastic film such as; coated paper, baryta paper, art paper mainly composed of wood fiber; paper-like paper such as acrylic paper, PP paper, polyester paper mainly composed of plastic fiber, and transparent Polyester film is suitable for its properties, and PP paper is suitable for its image quality.

These papers or films may be used as they are, and if necessary, may be used those subjected to pretreatment such as washing, etching, corona discharge, irradiation of active energy rays, dyeing and printing. Good.

By the above-described coating method of the sublimable disperse dye dyeable composition on these substrates, the film thickness after curing is 0.5 to 100 μm.
m, preferably 1 to 50 μm.

If the film thickness is less than 0.5 μm, the diffusion of the dye reaches saturation on the way and it cannot be dyed dark. On the other hand,
If it exceeds 100 μm, blocking tends to occur during heating.

In addition, when stacking a dyed film or paper, it is better to apply the composition to only one side of the base material in order to prevent migration of the disperse dye, but to positively prevent migration of this dye It is more preferable to provide a non-migrating layer on the surface opposite to the coated surface of the dyeable dye sublimable dye composition.

As the composition for forming the non-migration layer, the above-mentioned polyfunctional monomer or / and a monomer comprising a monofunctional monomer, 100 parts by weight of an oligomer mixture and, if necessary, 0.1 to 100 parts by weight of the above-mentioned photopolymerization initiator. However, in order to sufficiently prevent transfer by a disperse dye, it is necessary that the polymerizable group of the monomer / oligomer mixture has an average of 1.5 or more polymerizable groups per molecule. These coating agents can also adjust the viscosity with a solvent, apply to a substrate, and cure as in the case of the dyeable sublimable disperse dye composition.

[Example] Hereinafter, an example of the present invention will be described in more detail. In the examples and comparative examples, all “parts” represent parts by weight.

Reference Example 1. Preparation of transfer sheet Kayaset Blue 136 on commercially available transfer paper with a thickness of 60 μm
A transfer sheet was prepared by uniformly applying a 5% trichloroethylene solution (manufactured by Nippon Kayaku).

REFERENCE EXAMPLE 2 Dry heat transferability Paper is spread on an ironing board, a recording medium is placed on the paper, and the transfer sheet created in Reference example 1 is overlaid. Further, a commercially available paper having a thickness of 85 μm is placed thereon, and then heated at 145 ° C. × 10 seconds on a hot plate under a pressure of 1 kg / cm ² .

Reference Example 3. Evaluation of blocking resistance After the dry heat transfer of Reference Example 2, when the dyed article and the transfer sheet were peeled off, those that could be easily peeled off were expressed with a blocking resistance of "good", Those which were tacky and required some effort were designated as "poor".

Reference Example 4. Staining concentration measurement method A color analyzer (Hitachi 307
), The light transmittance T was measured for a transparent recording medium and calculated as -logT, and the reflectance R was measured for an opaque recording medium and calculated as -logR.

Examples 1 and 2; Comparative Examples 1 to 7 After mixing and adjusting the compositions shown in Table 1,
Pressure-sensitive polyester film (Lumirror, product number 100, type S10, manufactured by Toray Co., Ltd.) is uniformly applied to one side by the flow coating method, and is further irradiated with ultraviolet light from a 2 kW high-pressure mercury lamp in the air to have a sublimation having a film pressure of 4μ. The recording material to be dyed with a dispersible dye was obtained. Table I shows the results of evaluation of these articles according to Reference Examples 1 to 4. The adhesiveness of the cured composition to the polyester film was subjected to a peel test with a cellophane tape. As a result, the article of the present invention was good and did not peel.

BHET: bis-hydroxyethyl terephthalate 2P6A: dipentaerythritol hexaacrylate 2P5A: dipentaerythritol pentaacrylate 2P4A: dipentaerythritol tetraacrylate A-DEP: 2,2-bis (4-acryloyloxydiethoxyphenyl) propane polyester resin A : Resin consisting of terephthalic acid / isophthalic acid / ethylene glycol / neopentyl glycol (molecular weight: 15,000 to 20,000, Tg65 ° C) Silicone surfactant A: Example 3. 75 parts of polyester resin B, acrylic acid-added diacrylate of diglycidyl etherified bisphenol A 10
Parts, 2P6A 5 parts, 2P5A 5 parts, 2P4A 5 parts, BHET 4
Composition, 5 parts of silicone surfactant B, 6 parts of photopolymerization initiator 2-hydroxy-2-methylpropiophenone, 300 parts of toluene, and 100 parts of methyl ethyl ketone are uniformly flow-coated on one side of PP paper. After application, 2k in air
Irradiation with UV light from a high-pressure mercury lamp of W was performed to obtain a recording medium having a composition layer of the present invention having a thickness of 5 μm. When this was tested according to Reference Examples 1 to 4, staining was good without blocking, and a reflection optical density-logR = 0.95 was shown.

(Note) Polyester resin B: Resin consisting of terephthalic acid / sebacic acid / ethylene glycol / neopentyl glycol (molecular weight: 20,000-25,000, Tg10 ° C) Silicone surfactant B: Example 4. Coated paper on one side of polyester resin C60, 2P6A5
Part, 2P5A 5 parts, 2P4A 5 parts, 2,2-bis (4-acryloxydipropoxyphenyl) -propane 25 parts, diethyl terephthalate 5 parts, silicone-based surfactant C4 parts,
A composition comprising 5 parts of 2-hydroxy-2-methylpropiophenone, 250 parts of ethyl acetate, 250 parts of methyl ethyl ketone, and 50 parts of silica (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.) is coated to a thickness of 10 μm by blade coating. , And cured by irradiating with ultraviolet rays in the air. When this was subjected to dry heat transfer according to Reference Examples 1 to 4, it was well dyed without blocking and showed a reflection optical density-logR = 0.74.

(Note) Polyester resin C: resin consisting of terephthalic acid / isophthalic acid / sebacic acid / ethylene glycol / neopentyl glycol (molecular weight: 20,000 to 25,000, Tg 10 ° C) Silicone surfactant C: [Effect of the Invention] The recording medium for disperse dye dry transfer color formation of the present invention is easily dyed at a high concentration with a sublimable disperse dye, and has much better color developability and sharpness than conventional ones. In addition, it has excellent blocking resistance and high heat resistance, and can carry out dry transfer of a disperse dye under low energy of low temperature and short time. Therefore, the recording medium of the present invention
For example, for color copying, electrophotographic or information recording is very useful as a material for dry transfer color development, particularly the recording medium of the present invention using a transparent substrate is excellent in transparency and for OHP, the The industrial value is great.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-244696 (JP, A) JP-A-61-244589 (JP, A) JP-A-61-199997 (JP, A) JP-A-62-244 33684 (JP, A)

Claims (9)

(57) [Claims] 1. 100 parts by weight of a mixture comprising 40 to 95% by weight of a polyester resin and 60 to 5% by weight of a crosslinking agent curable by an active energy ray, and polyoxyalkylene-modified polydimethylsiloxane as a main component. A composition comprising 0.01 to 10 parts by weight of a silicone surfactant as a product and 0.1 to 30 parts by weight of a polyester compound plasticizer of an aromatic polycarboxylic acid fixed at room temperature having a degree of polymerization of 5 or less. And
A sublimation type thermal transfer recording type recording medium obtained by 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 a dicarboxylic acid and a diol. 3. The recording medium according to claim 1, wherein the polyester resin is an unsaturated polyester resin obtained by polycondensation of an unsaturated polybasic acid having a reactive double bond with a polyhydric alcohol. body. 4. A patent wherein 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 according to claim 2. 5. The recording medium according to claim 1, wherein the crosslinking agent has at least one polyfunctional monomer. 6. The recording medium according to claim 1, wherein the polymerizable group of the crosslinking agent is a (meth) acryloyloxy group. The main component of 7. A silicone surfactant is a polyoxyalkylene-modified product of _{polydimethylsiloxane, CH 3 - (SiO) 1/2} - the ratio of the -OR- is CH ₃ - (SiO) _{1 / 2}
2. The recording medium according to claim 1, wherein-/-OR- = 1/10 to 1 / 0.1. 8. The recording medium according to claim 1, wherein the polyester compound of the aromatic polycarboxylic acid is a diester of phthalic acid, isophthalic acid or terephthalic acid. 9. The recording medium according to claim 1, wherein the polyester compound of the aromatic polycarboxylic acid has the following general formula (I). (Where n is a positive integer from 1 to 5, / indicates that the bond is at any position in the ortho, meta or para position;
It can be arbitrarily changed according to n. R ₁ , R ₂ ,..., R _{n + 1} are the same or different alkylene groups. )