JPH01130976A - Sheet to be thermally transferred - Google Patents

Abstract

PURPOSE:To improve the dyeing property of dye and the light-fastness and weather-proofness of an image by adding an altered polyester-polystyrene copolymer resin synthesized by radical polymerization to an accepting layer. CONSTITUTION:A sheet to be thermally transferred 1 consists of an accepting layer 3 on a sheet-like substrate 2, and the accepting layer 3 has an ester bond and a methylene group to a main chain synthesized by radical polymerization and also contains a modified polyester-polystyrene copolymer resin with a phenyl group as a side chain, In this way, the non-crystalline state of a polymer containing a phenyl group and an ester group can easily be formed, and consequently the dispersion of dye tends to occur more easily. Thus the dyeing property of dye improves. In addition, when a long-chain methylene group is contained, the number of ester bonds in a copolymer relatively decreases. Therefore, the probability, that the active oxygen generates in an area where the ester bond occurs by optical excitation reduces. This results in less chances of occurrence of optical decomposition in the presence of oxygen or moisture which causes a degradation of dye, and subsequently the weather-proofness of dye is improved.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is used in combination with a thermal transfer sheet, and the formed image has excellent light resistance and weather resistance, as well as a coating that has particularly excellent dye stainability. Regarding thermal transfer sheets 1-.

[Problems to be solved by conventional technology and invention]

Attempts have been made to heat a thermal transfer sheet with a dye layer containing a sublimable disperse dye in spots using a Saalmahesod or the like in response to an image signal, thereby forming an image made of the dye transferred to the surface of resin-coated paper. It is being said.

However, with conventional thermal transfer sheets, the dye adhesion is not sufficient, and in order to obtain high-density images, an excessive amount of heat is required during printing, which increases the burden on the thermal head and reduces the thermal head drive voltage. There was a downside to getting bigger.

Furthermore, with conventional thermal transfer sheets, the images formed thereon do not have sufficient light resistance and weather resistance, and the sharpness of the images once formed may decrease or discolor. This is thought to be because the dye transferred by a thermal head or the like exists near the surface of the receptor layer and is therefore easily affected by light and temperature.

Therefore, the present invention aims to eliminate the drawbacks of the above-mentioned conventional techniques, improve the dyeability of dyes, and improve the light fastness and weather resistance of images formed by dye migration.

[Means for solving problems]

Through research conducted by the present inventors, it has been found that by constructing the receptor layer using a modified polyester-polystyrene copolymer resin having an ester bond and a methylene group in the main chain and a phenyl group in the side chain, dye stainability, It was discovered that the light resistance and weather resistance were significantly improved, which led to the completion of the present invention.

In the present invention, a thermal transfer sheet is used in combination with a thermal transfer sheet having a dye layer containing a dye that is transferred by melting or sublimation by heat, and the dye that transfers from the thermal transfer sheet is transferred to the surface of a sheet-like base material. By having a configuration characterized in that the receiving layer includes a modified polyester-polystyrene copolymer resin synthesized by radical polymerization, the above-described conventional This technology was able to overcome the shortcomings in the technology.

The thermal transfer sheet 1 of the present invention includes, for example, a sheet-like base material 2
It has a structure having a receptive layer 3 thereon, and an intermediate layer 4 is provided between the sheet-like base material 2 and the receptive layer 3 if necessary. The receiving layer 3 may be provided on one side of the sheet-like base material 2.

(Sheet-like base material) As the sheet-like base material 2, ■synthetic paper (polyolefin type, polystyrene type, etc.), ■high-quality paper, art paper, coated paper, cast coated paper, wallpaper-backed paper, synthetic resin or emulsion-impregnated paper. , synthetic rubber latex-impregnated paper 1, synthetic resin-loaded paper, paperboard or natural fiber paper such as cellulose fiber paper, ■Various plastic films or sheets such as polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, methacrylate, polycarbonate, etc. Can be used. Among these, the synthetic paper (2) is preferable because it has a microbuoid layer on its surface with low thermal conductivity (in other words, with high thermal insulation properties). Also, the above ■
A laminate made of any combination of ~■ can also be used. Examples of typical laminates include cellulose fiber paper and synthetic paper.
Alternatively, a laminate of cellulose fiber paper and a plastic film or sheet may be used. Among these, a laminate of cellulosic fiber paper and synthetic paper exhibits high printing thermal sensitivity due to the low thermal conductivity of synthetic paper, with the cellulose fiber paper compensating for the thermal instability (expansion and contraction, etc.) of synthetic paper. It's good to be able to do it. In addition, in order to balance the front and back sides of the laminate in this combination, it is preferable to use a three-layer laminate of synthetic paper, cellulose fiber paper, and synthetic paper, which can reduce curling caused by printing.

As the synthetic paper used for the above-mentioned laminate, generally any material can be used as long as it can be used as a base material for a thermal transfer sheet, but in particular synthetic paper with a paper-like layer having micropores is used. (For example, commercially available synthetic paper: Yubo: manufactured by Oji Yuka Synthetic Paper) is desirable. The fine pores in the above-mentioned paper-like layer can be formed, for example, by stretching a synthetic resin containing a fine filler. A thermal transfer sheet made of synthetic paper provided with a paper-like layer containing micropores has the effect that when an image is formed by thermal transfer, the image density is high and there is no variation in the image. This is thought to be because the fine pores have a heat insulating effect and the thermal energy efficiency is good, and the fine pores have good cushioning properties, which contribute to the receiving layer provided on the synthetic paper and on which images are formed. It will be done. Moreover, it is also possible to provide the paper-like layer containing the above-mentioned micropores directly on the surface of a core material such as cellulose fiber paper.

A plastic film can be used in addition to the cellulose fiber paper in the laminate, and a laminate of the cellulose fiber paper and a plastic film can also be used.

Examples of methods for bonding synthetic paper and cellulose fiber paper include bonding using a conventionally known adhesive, bonding using an extrusion lamination method, and bonding by thermal adhesive. The method for attaching the plastic film is the lamination method, which also serves as the formation of the plastic film at the same time.
Examples include pasting by a calendar method or the like. The above-mentioned pasting means is appropriately selected depending on the material of the synthetic paper and the material to be pasted.

Specific examples of the above adhesives include emulsion adhesives such as ethylene-vinyl acetate copolymer and polyvinyl acetate, and water-soluble adhesives such as polyester containing carboxyl groups. Examples include organic solvent solution type adhesives such as polyurethane adhesives, acrylic adhesives, and the like.

(Receiving Layer) The material constituting the receiving layer 3 is a layer for receiving (image receiving) an image of a dye transferred from a thermal transfer sheet, such as a sublimable disperse dye, and for maintaining the image formed by reception.

In the present invention, the receptor layer 3 is composed of a modified polyester-polystyrene copolymer resin synthesized by radical polymerization and having an ester bond and a methylene group in the main chain and a phenyl group in the side chain.

The molecular weight of the modified polyester-polystyrene copolymer is 5
Any molecular weight that has a film-forming ability of 0.000 to 100.00 may be used, and any copolymerization ratio of polystyrene to polyester within the range of 5:1 to 1:5 may be used.

The modified polyester-polystyrene copolymer is produced by dissolving monomers such as cyclic ketene acetal neck or unsaturated spiro-orthoesters and styrene monomer in bulk or in a solvent such as Hensen and placing it in a pressure-resistant tube in a Di-t-butylper.
1 using oxide (hereinafter referred to as DTBP) as an initiator.
It is obtained by radical polymerization at 00°C or higher.

For example, (1) Copolymer of cyclic ketene acetal monomer and styrene monomer The double bond of cyclic ketene acetal is surrounded by two oxygen atoms, so it has a large electron density and reacts well with electrophilic reagents. . Examples of cyclic ketene acetal monomers include the following monomer (A) synthesized from diethylacecool of bromoacetaldehyde.

0C211S 0-CH
2(A) When the above monomer (A) and the following styrene monomer (a) are polymerized using DTBP as an initiator, a modified product having an ester bond and a methylene group in the main chain and a phenyl group in the side chain as shown below is obtained. Polyester-polystyrene copolymer (i
) is obtained. (See the following formula) Q-CI (20φ → +CH2COCl1zCH-)-.

0 φ C) I 2 = C) l-→[R-CHz-CH3→
(C)12-CB')φφ
φ(a) (A) + (a) →(Cl2-CH+T+CH
zCOCHgC[).

Examples of cyclic ketene acetal monomers similar to those in (A) above include those shown in (8) to (G) below.

＼　1 0-CH OC1+2 CH.

-CH CH3 1-CH2 These polymers and styrene monomer (a) can be polymerized in the same manner to obtain modified polyester-polystyrene polymers (ii) to (vii) used in the present invention shown below. .

(B) + (a) → +CHz-CI+-T-+CI(z-C-0-CHz-
C) 12+v(C) +(a)→ +CHz -CH-)-T+CHz -C-0-CHz
-CH2-CH2-C112+ vl
II (D) + (a) → + CH2-CHmo "→CH2-C-0-CH2-CH
2-CH2-CHz -CH2÷71]I (E) 10(a)→ φ □ + CHx -CH+-r-+CH2-C-0-CHz
-CH2-CH÷11]1 (F) + (a) → +CH2-CH+-R-+C1h-C-0-CH-CH
2-CH2-CH) + vl]
](G) + (a) →
0]1 Examples of monomers of unsaturated spiro-orthoesters include the following monomers (H) to (J) synthesized from lactones of epichlorohydrin.

○ C1(2-OCI+2 (J): n=5 The above monomers (H) to (J) and styrene monomer (a)
When radical ring-opening polymerization is performed at 180'C using DTBP as an initiator, a modified polystyrene-polyester copolymer (vi) having ester bonds and ketone groups as shown below is obtained.
i) to (x) are obtained.

CH2-○ CHz CI2 0 CH2 0CH2 R-CHz-C-CH20C(Ctl□)fiR-+C
H2-C-CH2-O-C-(CH2) 11+7)I
I] ()l) ~ (J) + (a) R → R-(-CH2-CH+T+CH2CCH20C-
(-CI(2÷lower-masu.

(x): n=5 The thermal transfer sheet made using the above-mentioned modified polyester-polystyrene copolymer has excellent dyeability, but this is because the polymer contains phenyl groups and ester groups. This is thought to be due to the fact that the dye becomes more diffusible as a crystalline state is more likely to be formed. It is also believed that the inclusion of a phenyl group increases the solubility or affinity of dyes, particularly anthraquinone dyes, in polymers, which also contributes to dye dyeability.

When the modified polyester-polystyrene copolymer has a long chain methylene group, the weather resistance of the dyed dye is improved. The reason for this is that the number of ester bonds in the copolymer is relatively reduced, which reduces the probability that active oxygen will be generated at the ester bond sites due to photoexcitation, which reduces the possibility of generation of active oxygen in the presence of oxygen and moisture that cause dye deterioration. This is thought to be because photodecomposition is difficult to occur. In this sense, it is desirable that the monomer composition ratio of polystyrene to polyester is in the range of 5:1 to 1:5.

Sublimable anthraquinone dyes include Solvent Blue 63, Solvent Blue 59, Solvent 36, Solvent 14, Solvent 74, Solvent Violet 14, Solvent 11, and Disperse Red 60.
, Disperse Violet 26, Disperse Blue 26, Disperse Blue 26, Disperse Blue 40, etc. When these dyes are used in combination with a modified polyester-polystyrene copolymer, the light resistance is good and there is almost no coloration under tertiary irradiation.

In addition, each component at the time of synthesis|combination does not have to be single, and may combine two or more as appropriate.

The modified polyester-polystyrene copolymer resin can also be used in combination with other resins to form the receptor layer.

For example, the following synthetic resins from fat to tel can be used alone or in combination of two or more.

(Having an al ester bond.

Polyester resin (other than phenyl modified).

Polyacrylic ester resin, polycarbonate resin,
Polyvinyl acetate resin, styrene acrylate resin, vinyltoluene acrylate resin.

(Those with bl urethane bonds.

Polyurethane resin, etc.

[01 Those having an amide bond.

Polyamide resin (nylon).

Those with fdl urea bonds.

Urea resin etc.

tel and other substances with highly polar bonds.

Polycaprolactone resin, polystyrene resin, polyvinyl chloride resin, polyacrylonitrile resin, etc.

For example, the receptor layer 3 is composed of a mixed resin of a modified polyester-polystyrene copolymer resin and a normal polyester resin (not phenyl-modified). Examples of saturated polyester include Byron 200, Byron 290,
Byron 600 etc. (manufactured by Toyobo), KA-1038
C (additional type), TP220, TP235 (manufactured by Nippon Gosei), etc. are used.

Alternatively, the receiving layer is composed of a modified polyester-polystyrene copolymer resin and a vinyl chloride resin/vinyl acetate copolymer resin. The vinyl chloride/vinyl acetate copolymer resin has a vinyl chloride component content of 85 to 97% by weight and a polymerization degree of 2.
A value of about 00 to 800 is preferable. Vinyl chloride/vinyl acetate copolymer resin is not necessarily a copolymer of only vinyl chloride components and vinyl acetate copolymer components.
It may also contain a vinyl alcohol component, a maleic acid component, etc.

The receptor layer 3 may also be composed of a mixed resin of a modified polyester-polystyrene copolymer resin and a polystyrene resin, for example, a styrene monomer such as styrene, α-methylstyrene, or vinyltoluene alone. Or polystyrene resin made of copolymer,
Alternatively, a styrenic copolymer resin which is a copolymer of the styrene monomer and another monomer, for example, an acrylic or methacrylic monomer such as acrylic ester, methacrylic ester, acrylonitrile, methacrylonitrile, or maleic anhydride. can be mentioned.

When the modified polyester-polystyrene copolymer resin and other resin are used together, the amount of the other resin is 0 to 100 parts by weight per 100 parts by weight of the resin, although it depends on the modified polyester-polystyrene copolymer resin. It is better. In other words, when used in combination as described above, the modified polyester-polystyrene copolymer resin may account for 50 to 100 g in 100 g of the total resin weight.

In any of the above embodiments, the purpose is to improve the whiteness of the receptor layer 3 to further enhance the clarity of the transferred image, to impart writability to the surface of the thermal transfer sheet, and to prevent the transferred image from being retransferred. A white pigment can be added to the receiving layer 3. As the white pigment, titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, finely powdered silica, etc. are used, and as described above, two or more of these can be used in combination. Furthermore, in order to further improve the light resistance of the transferred image, one or more additives such as ultraviolet absorbers, light stabilizers, or antioxidants may be added to the receiving layer as necessary. The amounts of these ultraviolet absorbers and light stabilizers added are 0.05 to 10 parts by weight, respectively, per 100 parts by weight of the resin constituting the receptor layer 3.
0.5 to 3 parts by weight is preferred.

The thermal transfer sheet of the present invention may contain a release agent in the receptor layer in order to improve the releasability from the thermal transfer sheet. Examples of the mold release agent include solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants; and silicone oil, with silicone oil being preferred.

Although an oily silicone oil can be used as the silicone oil, a hardened type is preferable.

Examples of the curable silicone oil include reaction curable, photocurable, and catalytic curable silicone oils, with reaction curable silicone oils being particularly preferred. The reaction-curing silicone oil is preferably one obtained by reaction-curing an amino-modified silicone oil and an epoxy-modified silicone oil, and examples of the amino-modified silicone oil include KF-39.
3, KF-857, K1-858, X-21-3680
, X-22-380IC (manufactured by Shin-Etsu Chemical aI)
Epoxy modified silicone oils include KF-100T, KF-101, KF-60-164.
, KF-103 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. Catalyst-curing or photo-curing silicone oils include KS-705F, Ni-770 (catalyst-curing silicone oil: manufactured by Shin-Etsu Chemical Co., Ltd.), KS-7
20, KS-7'74 (photocurable silicone oil; manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. The amount of these curable silicone oils added is 0% of the resin constituting the receptor layer.
．． 5 to 30% by weight is preferred. Alternatively, a release agent layer can be provided by dissolving or dispersing the above-mentioned release agent in a suitable solvent and applying the solution to a part of the surface of the receiving layer 3, followed by drying. As the mold release agent constituting the mold release agent layer, a reaction cured product of the above-mentioned amine-modified silicone oil and epoxy-modified silicone oil is particularly preferred. The thickness of the release agent layer is preferably 0.01 to 5 μm, particularly preferably 0.05 to 2 μm.

Note that the release agent layer can also be formed by adding silicone oil when forming the receptor layer, allowing the silicone oil to bleed onto the surface after application, and then curing.

The above-mentioned white pigment, ultraviolet absorber, light stabilizer, antioxidant, and mold release agent can be applied so as to be included in the receiving layer on one side or both sides, if necessary.

The receptive layer N3 can be formed by a known coating or printing method using a receptive layer forming composition obtained by dissolving or dispersing the material for forming the receptive layer on the sheet-like base material 2. It may also be carried out by a method in which the image is once formed on a temporary carrier different from the base material 2 and then transferred onto the sheet-like base material 2 again.

- As a temporary carrier, a sheet with a releasable surface is used. For example, ■Cellulose fiber paper or synthetic paper with an undercoat layer and then a release silicone layer; ■Cellulose fiber paper with an extrusion coating of polyolefin resin or polyester resin. or (2) a release silicone layer applied to the surface of a plastic film such as a polyester film.

On the temporary carrier, a receptive layer is formed in the same manner as on the sheet-like substrate 2, and then, if necessary, an adhesive layer is formed. This adhesive layer is for ensuring adhesive force between the sheet-like base material 2 and the receptive layer 3 when the receptive layer is transferred onto the sheet-like base material 2. In this method, another layer, such as an intermediate layer imparting cushioning properties, is formed on the temporary carrier, and the sheet-like base material 2 is
The intermediate layer and the receiving layer may be transferred thereon at the same time. When the intermediate layer also serves as an adhesive, the adhesive layer need not be formed on the temporary carrier.

In any case, since the adhesive layer only needs to be interposed between the sheet-like base material and the uppermost layer on the temporary carrier, the adhesive layer is formed on the sheet-like base material 2. Then, only a receiving layer or a receiving layer and an intermediate layer may be sequentially formed on a temporary carrier and then transferred.

When a method is adopted in which the receptive layer 3 is formed on the sheet-like base material 2 by a transfer method in which the receptive layer 3 is once formed on the temporary carrier, the surface of the receptive layer formed on the sheet-like base material 2 is - Because the surface condition is transferred, it has very good smoothness, and the receiving layer formed directly on the sheet-like base material 2 has inferior smoothness and is clearer than that formed by the transfer method. If you want to obtain precise images, it is best to use the transfer method.

The adhesive may be any adhesive that can bond the receptor layer and the base material, such as polyester, polyacrylic ester,
Organic solvent solutions or emulsions of polyurethane, polyvinyl chloride, polyolefin, ethylene-vinyl acetate copolymers, synthetic rubber, etc. can be used. The adhesive may be a thermal adhesive type or a room temperature adhesive type. In the case of a thermal bonding type, thermal bonding using a true melt type adhesive such as wax, ethylene/vinyl acetate copolymer resin, polyolefin, or petroleum resin, or sandwich lamination using an extrusion film such as a polyolefin film may be used.

Double-sided tape may be used as the adhesive that also serves as the intermediate layer. Double-sided tape is made by impregnating rayon paper with an acrylic adhesive and drying it, and after drying, the double-sided tape has micropores that seem to play the equivalent role of a foam layer.

(Intermediate Layer) The intermediate layer 4 is either a cushioning layer or a porous layer depending on the material it is made of, or may also serve as an adhesive in some cases.

The cushioning layer is 1 defined in JIS-6301.
00% modulus is 100 kg/cffl or less, and if the 100% modulus exceeds 100 kg/cfl, the rigidity is too high, so such a resin is used to form the intermediate layer. However, sufficient adhesion between the thermal transfer sheet and the layer to be thermally transferred during printing cannot be maintained. Also, the lower limit of the 100% modulus is actually 0.5
It is about kg/cJ.

Examples of resins that meet the above conditions include the following.

Polyurethane resin Polyester resin Polybutadiene resin Polyacrylic acid ester resin Epoxy resin Polyamide resin Rosin modified phenol resin Terpene phenol resin Ethylene/vinyl acetate copolymer resin The above resins can be used alone or in a mixture of two or more. The above resins are relatively sticky, so if there is a problem during processing, add inorganic additives such as silica, alumina, clay, calcium carbonate, or amide substances such as stearamide. You may.

The cushioning layer can be formed by kneading the resin described above with a solvent, diluent, etc. along with other additives as necessary to form a paint or ink, and drying it as a coating film using a known coating method or printing method. , its thickness is 0
．． It is about 5 to 50 μm, more preferably about 2 to 20 μm. If the thickness is 0.5 μm, it will not be able to absorb the roughness of the surface of the sheet-like base material provided, so it will not be effective;
If it exceeds this value, not only will there be no improvement in the effect, but the receiving layer will become too thick and protrude, which will be a hindrance when winding or stacking, and it will also be uneconomical.

Formation of such an intermediate layer improves the adhesion between the thermal transfer sheet and the sheet to be thermally transferred, probably because the intermediate layer itself has low rigidity and is deformed by pressure during printing. It is presumed that this type of resin usually has a low glass transition point or softening point, and the thermal energy applied during printing causes the rigidity to decrease even more than at room temperature, making it easier to deform. .

The porous layer 3 is made of ■synthetic resin emulsion such as polyurethane,
A layer in which a liquid made by mechanically stirring a synthetic rubber latex such as methyl methacrylate-I/-butadiene is applied onto the base material 2 and dried; Transfer the mixed liquid to base material 2.
A layer formed by applying a liquid mixture of synthetic resin such as PVC plastisol, polyurethane, or synthetic rubber foaming agent such as styrene-butadiene foaming agent onto the base material 2 and heating it to foam the layer. , ■ A solution in which a thermoplastic resin or synthetic rubber is dissolved in an organic solvent, and a solution that is less likely to be dissolved than the organic solvent and is compatible with the organic solvent and has no solubility in the thermoplastic resin or synthetic rubber. A microporous layer or the like is used, in which a mixed liquid with a non-solvent (including one containing water as a seed component) is applied onto the substrate 2 and dried to form a microscopically aggregated film. Above ■〜■
Since the size of bubbles in the layer is large, when a solution for forming the customer receiving layer 3 is applied on the layer and dried, there is a possibility that unevenness may occur on the surface of the drying and formed receiving layer 3. Therefore, in order to obtain a surface of the receptor layer 3 with small irregularities and on which a highly uniform image can be transferred, it is preferable to provide the microporous layer (2) above as the porous layer.

The thermoplastic resin used for forming the above microporous layer includes saturated polyester, polyurethane,
Vinyl chloride/vinyl acetate copolymer 1, cellulose acetate propionate, etc. may be mentioned, and the synthetic rubbers that can be used similarly include styrene-butadiene, isoprene, urethane, and the like. Various organic solvents and nonsolvents can be used to form the microporous layer, but hydrophilic solvents such as methyl ethyl ketone and alcohol are usually used as the organic solvent, and water is used as the nonsolvent. It will be done.

The thickness of the porous layer in the present invention is preferably 3 μm or more, particularly preferably 5 to 20 μm. If the thickness of the porous layer is less than 3 μm, cushioning and heat insulation effects cannot be exhibited.

Although the explanation has been complicated, as mentioned in the explanation of the method for forming the receptor layer, the intermediate layer may also serve as an adhesive in some cases.

The above-mentioned intermediate layer may be provided on both sides of the thermal transfer sheet when the receiving layer is provided on both sides, or may be provided on only one side.

In order to suppress the generation of static electricity during the processing of the thermal transfer sheet or when it runs in a printer, an antistatic agent may be contained in the receptor layer on at least one side or on the surface of the receptor layer. Antistatic agents include surfactants such as cationic surfactants (e.g., quaternary ammonium salts, polyamine derivatives, etc.), anionic surfactants (e.g., alkyl phosphates, etc.), amphoteric ionic surfactants, or nonionic surfactants. type surfactants and the like.

The antistatic agent may be applied to the surface of the receptor layer by gravure coating, bar coating, etc., or may be kneaded into the resin of the receptor layer and transferred to the surface of the receptor layer during coating and drying of the receptor layer. A cationic acrylic polymer can also be used as an antistatic agent to be mixed with the receptor layer resin.

Since the thermal transfer sheet of the present invention has its receptor layer made of a modified polyester-polystyrene copolymer resin, the image formed by printing with a thermal head etc. in combination with a thermal transfer sheet is due to the polyol component. Because of its high concentration and dicarboxylic acid component, the color does not smear or become blurred and the clarity does not deteriorate even after long-term storage, and there is no problem such as discoloration.

〔Example〕

The present invention will be explained in more detail below by giving Examples and Comparative Examples.

In the following Examples and Comparative Examples, the production of a thermal transfer sheet and a thermal transfer sheet, printing using both sheets, and testing of a thermal transfer sheet were conducted as follows.

Thermal transfer sheet 6 μm thick polyethylene terephthalate film (manufactured by Toyobo: 5-PET) with corona discharge treatment on one side
Using this as a base material, a thermal transfer layer forming composition having the following composition is coated on the corona discharge treated surface of the base material by wire bar coating so that the dry thickness is 1 μm to form a thermal transfer layer. and silicone oil (X-4) on the back side.
1-4003A: Shin-Etsu Silicone) with a dropper
After drying, it was spread over the entire surface to form a slippery layer to obtain a thermal transfer sheet.

Composition for forming thermal transfer layer Disperse dye: 4 parts by weight (Nippon Kayaku: Kayasenoto Blue-714) Ethyl hydroxycellulose: 5 parts by weight (manufactured by Vercules) Toluene: ......4 oi parts Methyl ethyl ketone...40 parts by weight Dioxane...
...10 parts by weight Thermal transfer sheet Synthetic paper with a thickness of 150 μm (manufactured by Oji Yuka: Yupo FP (, -
150) was used as a base material, and on the surface thereof, a composition for forming a receptor layer having the following composition was coated to a dry thickness of 4 μm by wire bar coating, and after temporary drying with a dryer, it was placed in an oven at 100 °C. This was dried for 30 minutes to form a receptor layer, which was then used as a thermal transfer sheet.

Receptive layer forming composition resin (*1) 14 parts by weight Amino-modified silicone oil 1 part by weight (manufactured by Shin-Etsu Chemical Co., Ltd.:
KF-396) Epoxy modified silicone oil...1 part by weight (manufactured by Shin-Etsu Chemical: X-22-343>Toluene...
...42-fold HalE methyl ethyl ketone...
42 parts by weight *1 As the resin in the receptor layer forming composition, the modified polyester-polystyrene copolymer (i) described on page 10 of the specification was used for Example 1, and the modified polyester-polystyrene copolymer (i) described on page 10 of the specification was used for Example 2. The modified polyester-polystyrene copolymer (II) described on page 11 of the specification was used for Example 3, and the modified polyester-polystyrene copolymer (iii) described on page 12 of the specification was used for Example 3. For Example 4, the modified polyester-polystyrene copolymer (iv) described on page 12 of the specification was used, and for Example 5, the modified polyester-polystyrene copolymer (iv) described on page 1 of the specification was used.
Modified polyester-polystyrene copolymer described on page 2 (
For Example 6, the modified polyester-polystyrene copolymer (Vl) described on page 12 of the specification was used, and for Example 7, the modified polyester-polystyrene copolymer (Vl) described on page 13 of the specification was used. For Example 8, the modified polyester-polystyrene copolymer (Nuru) described on page 15 of the specification was used, and for Example 9, the modified polyester-polystyrene copolymer (1) described on page 15 of the specification was used. For Example IO, the modified polyester-polystyrene copolymer (X) described on page 15 of the specification was used, and for Example 11, the modified polystyrene copolymer (X) described on page 15 of the specification was used. - polyester copolymer) and vinyl chloride/vinyl acetate copolymer resin (manufactured by Union Carbide:
Vinylite VYHH) was used in a weight ratio of 1:1, and for Example 12, the modified polyester-polystyrene copolymer resin (viii) and a saturated polyester resin (Vylon 200 manufactured by Toyobo) were used. A mixture of 1:1 by weight was used.

Regarding Comparative Example 1, saturated polyester resins Vylon 200 and 290 (both manufactured by Toyobo) were mixed in a weight ratio of 1.
A 1:1 mixture was used. Furthermore, the monomer composition ratio of each of the modified polyester-polystyrene copolymer resins of Examples 1 to 10 was polyester monomer/polystyrene monomer-50150 mo1%.

The thermal transfer sheet and the sheet to be thermally transferred are stacked so that the thermal transfer layer and the receptor layer are in contact with each other, and the output IW of the thermal head is transferred from the base material side of the thermal transfer sheet using a thermal head.
/dot, pulse width 0.3~0, 45 m/sec
When the cyan disperse dye in the thermal transfer layer of the thermal transfer sheet was transferred to the receiving layer of the thermal transfer sheet by heating at a dot density of 3 dots/mm, a clear cyan image was formed in each of Examples 1 to 12. It was done. Moreover, Examples 1 to 12
Compared to the one in Comparative Example 1,
It was found that the optical reflection density was improved by 0.2 to 0.5.

〔Effect of the invention〕

As explained above, since the thermal transfer sheet of the present invention contains a modified polyester-polystyrene copolymer resin synthesized by radical polymerization as the resin constituting the receptor layer, it has extremely excellent dye adhesion to the receptor layer. The image formed by dye migration has excellent light fastness and weather resistance.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the thermal transfer sheet of the present invention, and FIG. 2 is a longitudinal cross-sectional view showing another embodiment. 1... Heat transfer sheet 2... Sheet-like base material 3... Receptive layer 4... Intermediate layer

Claims (2)

[Claims] (1) Used in combination with a thermal transfer sheet that has a dye layer containing a dye that transfers by melting or sublimating with heat, and has a receiving layer on the surface of the sheet-like base material that receives the dye that transfers from the thermal transfer sheet. 1. A thermal transfer sheet characterized in that the receptor layer contains a modified polyester-polystyrene copolymer resin synthesized by radical polymerization. (2) The thermal transfer sheet according to claim 1, wherein the receiving layer is made of a blend resin of a modified polyester-polystyrene copolymer resin synthesized by radical polymerization and another resin.