JPH0448120B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention is used in combination with a thermal transfer sheet to eliminate density unevenness and transfer omissions in images formed by transfer using a thermal head or the like.
It relates to an improved thermal transfer sheet,
It is particularly suitable for obtaining hard copies based on image signals, such as images on a CRT screen. Conventional technology A thermal transfer sheet has a thermal transfer layer containing a sublimable dye formed on a support, and a thermal transfer sheet has a dye-dyeable resin layer such as polyester resin formed on a base material such as paper. Attempts have been made to obtain hard copies or print characters and symbols by using a combination of printing means such as a thermal head controlled by electrical signals corresponding to image information. As for the thermal transfer sheet, although there are some items that require improvement, the conventional thermal transfer sheet technology used for sublimation transfer to acrylic fiber woven fabric etc. can be applied, but as the thermal transfer sheet, conventional acrylic New problems arise due to the change in woven fiber fabric to one that uses paper or plastic film as the base material and a dye-dyeable resin layer formed thereon, and the heating means and heating conditions to differ. is occurring. For example, the receiving layer, which is a resin layer capable of dyeing on a thermal transfer sheet, is required to have the following properties: (a) Short-time printing such as printing using a thermal head (b) Do not block when rolled or stacked sheets before use; (c) After use (after recording) (d) Even if the dye is overlapped with film or paper, the dye that has been received will not sublimate again. Concentration must be obtained. Of the requirements (a) to (d) above, problems (a) to (c) should be solved by the resin constituting the receptor layer, the additives included in the receptor layer, or the surface treatment of the receptor layer. However, regarding point (d), there remains a problem that cannot be solved only by improving the receptor layer. This is because in order to ensure shape reproducibility and density reproducibility during printing, the receiving layer should be made of a flexible resin, and the thermal transfer layer of the thermal transfer sheet and the thermal transfer sheet should be separated during printing. It is best to ensure complete adhesion with the receptor layer to prevent air gaps from occurring, but such resins have a low softening point and are prone to blocking, and dyes once received may re-sublime or bleed. do. Alternatively, if the surface smoothness of the receptor layer is improved so that the surface roughness is 2 to 3 μm or less, the adhesion with the thermal transfer sheet can be improved, but a receptor layer with such smoothness is not a simple coating. It is difficult to obtain it by itself, but if you were to make it, you would either (a) form a film using an extrusion method and paste it with paper, etc., or (b) apply paint, let it dry, and then smooth it using a calendar roll. With method (a), the production speed is slow and the resulting thermal transfer sheet becomes expensive, and with method (b), it is difficult to obtain a sheet of consistent quality and the production speed is slow. It has the disadvantage of adding a slow process. Problems to be Solved by the Invention Therefore, in the present invention, the above-mentioned problems of the thermal transfer sheet used in combination with the thermal transfer sheet are solved.
Regarding point (d), the purpose is to solve the problem that could not be solved in the past, and it is possible to secure sufficient adhesion with the thermal transfer sheet without adversely affecting various points required for the receptor layer. The present invention provides a thermal transfer sheet. Means for Solving the Problems In the present invention, the above-mentioned problems are solved by laminating the heat transfer sheet with a cushion layer interposed between the base material and the receiving layer. That is, the thermal transfer sheet of the present invention is a thermal transfer sheet consisting of a base material and a receiving layer formed on the base material and receiving the dye that migrates from the thermal transfer sheet when heated. , an intermediate layer mainly made of a resin having a 100% modulus of 100 Kg/cm ² or less as defined in JIS-K-6301 is interposed between the base material and the receptor layer. ``something to do.'' (Thermal transfer sheet) Hereinafter, the present invention will be explained using drawings. FIGS. 1 to 3 are schematic cross-sectional views of the thermal transfer sheet of the present invention, and FIGS. 4 and 5 are schematic cross-sectional views of the thermal transfer sheet of the present invention. FIG. 6 is a schematic cross-sectional view of a thermal transfer sheet used in combination with the thermal transfer sheet of FIG. FIG. 1 shows an embodiment of the thermal transfer sheet of the present invention, in which the thermal transfer sheet A has a receiving layer 3 laminated on a base material 1 with an intermediate layer 2 interposed therebetween. or,
In FIG. 2, in addition to the structure shown in FIG. 1, a mold release agent layer 4 is provided on the outermost layer, or as in FIG. 3, a mold release agent layer 4 is provided on a part of the receptor layer 3. Alternatively, a release agent may be contained inside the receiving layer 3. (Base material) The base material 1 has the role of holding the intermediate layer 2 and the receptor layer 3, and since heat is applied during thermal transfer, it has a mechanical strength that does not cause any trouble in handling even in a heated state. This is desirable. Specific examples of such a substrate 1 include condenser paper, glassine paper, parchment paper, highly sized paper, and flexible thin-layer sheets such as plastic films. Among these, capacitor paper and polyethylene terephthalate film are often used. When heat resistance is important, capacitor paper is mainly used, and when handling with mechanical devices is important, polyethylene terephthalate film is used. Mainly used. The thickness of this base material 1 is usually about 3 to 50 μm, preferably about 5 to 15 μm. (Intermediate layer) The intermediate layer 2, which is a characteristic part of the present invention, is a JIS-
100% modulus specified in K-6301 is 100Kg/
^cm2 or less, and if the 100% modulus exceeds 100Kg/ ^cm2 , the rigidity will be too high, so even if such a resin is used to form the intermediate layer, thermal transfer will not be possible. Sufficient adhesion between the sheet and the thermal transfer layer during printing cannot be maintained. Also, the above 100
The lower limit of %modulus is actually about 0.5Kg/cm ² . Examples of resins that meet the above conditions include the following. Polyurethane resin Polybutadiene resin Polyacrylate ester resin Epoxy resin Polyamide resin Rosin-modified phenol resin Terpene phenol resin Ethylene/vinyl acetate copolymer resin The above resins can be used singly or in a mixture of two or more. The resin of
Since it is sticky, if there is a problem during processing, inorganic additives such as silica, alumina, clay, calcium carbonate, etc., or amide-based substances such as stearic acid amide may be added. . The intermediate layer 2 can be formed by kneading the resin as 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 about 0.5 to 10 μm, more preferably about 2 to 20 μm. If the thickness is less than 0.05 μm, it will not be able to absorb the roughness of the surface of the base material provided, and therefore it will not be effective.On the other hand, if it exceeds 100 μm, not only will there be no improvement in the effect, but the thermal transfer sheet will become too thick. If it is rolled up or piled up, it becomes bulky and is not economical. In the present invention, the reason why the adhesion between the thermal transfer sheet and the thermal transfer sheet is improved when such an intermediate layer 2 is formed is thought to be because the intermediate layer 2 itself has low rigidity and is deformed by pressure during printing. However, the above-mentioned resins usually have low glass transition points and softness points, and the thermal energy applied during printing causes their rigidity to decrease even more than at room temperature, making them easier to deform. It is assumed that the (Receptive layer) As mentioned above, the receptor layer 3 of the thermal transfer sheet A functions to receive the dye that migrates from the thermal transfer sheet when heated, and specifically, the following dyes are used. used. (a) Products with ester bonds: polyester resins, polyacrylic ester resins, polycarbonate resins, polyvinyl acetate resins, styrene acrylate resins, vinyl toluene acrylate resins, etc. (b) Materials with urethane bonds such as polyurethane resins (c) Materials with amide bonds such as polyamide resins. (d) Materials with urea bonds Urea resins, etc. (e) Others having highly polar bonds, such as polycaprolactone resin, styrene-maleic anhydride resin, polyvinyl chloride resin, polyacrylonitrile resin, etc. In addition to the synthetic resins mentioned above, mixtures or copolymers thereof may also be used. Further, the receiving layer 3 can also be formed from two types of resins having different properties. For example, −100 to 20
forming a first region of the receptor layer from a synthetic resin having a glass transition temperature of ℃ and having a polar group;
Further, the second region of the receptor layer can be formed of a synthetic resin having a glass transition temperature of 40° C. or higher. Both the first region and the second region are exposed on the surface of the receptive layer, the first region occupies 15% or more of the surface, and the first region exists independently from each other in the form of an island. It is preferable that the length of each of the shaped portions in the longitudinal direction is 0.5 to 200 μm. In the thermal transfer sheet 1 of the first aspect of the present invention, a dye-permeable release agent is contained in the receiving layer 3 made of the resin as described above. Such mold release agents include solid waxes,
Fluorine-based or phosphate-based surfactants, silicone oils, etc. are used. These compounds are added in advance to the resin forming the receptor layer, and the resulting resin mixture solution is applied onto a base material and dried to obtain the receptor layer.Each release agent will be specifically explained below. The solid wax is preferably dispersed as fine particles in the resin forming the receptor layer 3. Therefore, the solid wax is preferably processed using a ball mill, a sand mill, etc. before being added to the resin. As the solid wax, polyethylene wax, amide wax, Teflon powder, etc. are used. This solid wax is
It is added to the resin in an amount of 5 to 50% by weight, preferably 10 to 20% by weight of the resin weight. If the amount added is less than 5% by weight, a sufficient mold release effect cannot be obtained,
The thermal transfer layer may thermally adhere to the receiving layer. If the amount added exceeds 50% by weight, the dye that migrates from the thermal transfer layer during heating cannot be sufficiently received, and the resulting image may not have sufficient resolution. A fluorine-based or phosphate-based surfactant is also added as a mold release agent to the resin forming the receiving layer. It is thought that a part of the surfactant added to the resin appears on the surface of the receptor layer, and therefore a mold release effect is obtained. Examples of such surfactants include phosphoric acid ester compounds such as Plysurf A208S, Plysurf A210G, Plysurf DB-01 (Daiichi Kogyo Seiyaku Co., Ltd.), Gafac RS-410, Gafac RA-
600, Gafatsuku RE610 (Toho Chemical Industries), and as a fluorine-based surfactant, Unidyne
DS501, Unidyne DS502 (Daikin Industries),
Examples include FC430 and FC431 (Sumitomo 3M). This surfactant is added to the resin by 0.5 of the weight of the resin.
Added in an amount of ~10% by weight. If the amount added is less than 0.5% by weight, a sufficient mold release effect cannot be obtained.
If the amount added exceeds 10% by weight, the surface of the receptor layer becomes sticky, dirt tends to adhere to the surface, and when the transfer layer and receptor layer come into contact with each other,
Even without heating, the dye in the transfer layer transfers to the receiving layer, causing background smearing. Furthermore, silicone oils are also added as a mold release agent to the resin forming the receiving layer. Although oily silicone oils can be used, hardened silicone oils are preferred. Examples of the curable silicone oil include reaction curable, photocurable, and catalytic curable silicone oils. Among these, reaction-curing silicone oils are particularly preferred. When using such curable silicone oils as a mold release agent, the surface of the receiving layer may become sticky or have dust attached, compared to the case of the surfactant-based mold release agents mentioned above. Therefore, it can be used in large amounts. The curable silicone oil is added to the resin in an amount of 0.5 to 30% of the resin weight.
It can be added in an amount of % by weight. If the amount added is less than 0.5% by weight, a sufficient mold release effect may not be obtained, and the thermal transfer layer may thermally adhere to the receptor layer. If the amount added exceeds 30% by weight, the dye that migrates from the thermal transfer layer during heating cannot be sufficiently received, and the resulting image may not have sufficient recording density. The reaction-curing silicone oil is preferably one obtained by reaction-curing an amino-modified silicone oil and an epoxy-modified silicone oil. Specifically, amino-modified silicone oils include KF-393, KF-857, and KF- manufactured by Shin-Etsu Chemical Co., Ltd.
858, X-22-3680, X-22-3801C, etc., while KF-100T, KF-101,
103 etc. are used. Catalysts or photocurable silicone oils include KS705F-PS (catalyst), KS705F-PS-1 (catalyst), KS720, KS770-PL-3 (catalyst), KS774-
Examples include PL-3. As described above, the thermal transfer sheet 1 according to the second aspect of the present invention includes the receptor layer 3 made of the resin on the base material 2, and further includes a release agent on at least a part of the receptor layer 3. The mold release agent layer 4 is formed by dissolving or dispersing the above-mentioned mold release agent in a suitable solvent and applying the resulting solution or dispersion onto the receptor layer 3. , and then drying. The film thickness of this mold release agent layer is preferably 0.01 to 5 μm.
The thickness is preferably 0.05 to 2 μm. If the thickness of the release agent layer is less than 0.01 μm, sufficient mold release effect cannot be obtained, while if it exceeds 5 μm, dye permeability will be hindered, which is not preferred. As described above, the release agent layer 4 may be provided on the entire surface of the receptor layer 3, or may be provided only on a portion of the receptor layer 3. Generally, it is difficult to print explanatory text on the mold release agent layer, but
It is possible to print onto the receiving layer. Therefore, when it is necessary to print on a thermal transfer sheet, it is preferable to provide a release agent layer only on a portion of the receptor layer. The third aspect of the thermal transfer sheet according to the present invention is characterized in that the above-described receptor layer contains fine silica powder. In the present invention, silica refers to silicon dioxide or a substance containing silicon dioxide as a main component. The fine powder silica to be contained in the receptor layer has an average particle size of 10
~100mμ, specific surface area less than ^250m2 /g, more preferably average particle size 10~50mμ, specific surface area 20~
200m ² /g is used. If the average particle size of the fine powder silica is larger than this range, the dispersion stability of the fine powder silica in the coating composition for the thermal transfer layer used for forming the receptor layer will decrease,
In addition, the smoothness of the surface of the receptor layer of the thermal transfer sheet is significantly impaired, and the image obtained by thermal transfer becomes unclear. Furthermore, if the average particle size of the fine powder silica is smaller than this range, the fluidity of the coating composition for the thermal transfer layer used to form the receptor layer will decrease, and the effect of adding the fine powder silica to the thermal transfer sheet will not be sufficiently exhibited. Not done. Specific examples of fine powder silica that satisfy these conditions include AEROSIL R972, AEROSIL 130,
AEROSIL 200, AEROSIL OX50, AEROSIL
TT600, AEROSIL MOX80, AEROSIL
Examples include MOX170 (silica powder manufactured by Aerosil Co., Ltd.). Further, the content of fine powder silica is 5 to 20% by weight, more preferably 5 to 20% by weight, based on the weight of the receiving layer.
It is in the range of 10% by weight. These finely powdered silicas are added in advance to the resin forming the receptor layer, and the resulting resin mixture solution is applied onto a substrate and dried to form the receptor layer. When forming the receptor layer, various additives can be added in addition to the above-mentioned finely powdered silica, but these ingredients are selected from those that do not interfere with the fixation of the dye that migrates from the thermal transfer sheet during heating. It should be. Examples of such additives include cured products of silicone compounds, such as cured products of epoxy-modified silicone oil and amino-modified silicone oil, which improve the releasability from the thermal transfer sheet. Details of each of these modified silicone oils are as described above. Alternatively, the receiving layer may be formed by providing a dispersion coating film of at least one resin and water on a substrate and then drying it. The resins used as dispersoids constituting the dispersion with water include (a) resins having a single type of dyeing ability;
A mixture of resins of the same type with high and low dyeability; (c) a mixture of one or more resins, at least one of which has dyeability and which are mutually incompatible; etc. can be used. The size of the dyeability of the resin depends on the physical properties of the resin,
In particular, it is considered to be approximately proportional to the glass transition temperature. Generally, the glass transition temperature is -100℃~20℃
It can be said that resins generally have a low ability to be dyed, and resins with a glass transition temperature of 40°C or higher generally have a high ability to be dyed. In the present invention, the term "dispersion" includes both a liquid-liquid dispersion system (emulsion) and a liquid-solid dispersion system (suspension). Preferred specific examples of the above-mentioned resin-water dispersion include the following. (a) Natural rubber latex (natural rubber sap concentrate) (b) Synthetic rubber latex (synthetic rubber aqueous dispersion obtained by emulsion polymerization) SBR (styrene/butadiene copolymer) latex, polychloroprene latex, polybutadiene latex, Butyl rubber (polybutene) latex, etc. (c) Synthetic resin emulsion (synthetic resin aqueous dispersion obtained by emulsion polymerization) Polyacrylic ester emulsion, polyvinyl acetate emulsion, ethylene/vinyl acetate copolymer emulsion, polystyrene emulsion, polyvinyl chloride emulsion, etc. . (d) Synthetic resin aqueous dispersion (synthetic resin aqueous dispersion obtained by dispersing a synthetic resin solution or synthetic resin melt in water) polyester aqueous dispersion, polyurethane aqueous dispersion, polyethylene aqueous dispersion, etc. Further, the above-mentioned aqueous resin dispersion may contain a dispersant in order to stabilize dispersion. Preferred specific examples of the dispersant to be added include the following. () Emulsifiers Anionic surfactants such as carboxylates, sulfonates, sulfuric acid ester salts, phosphoric acid ester salts, and phosphonates; cationic surfactants such as amine salts, quaternary ammonium salts, phosphonium salts, and sulfonium salts. , amphoteric surfactants such as betaine and sulfobetaine, and nonionic surfactants such as fatty acid monoglycerin esters and fatty acid polyglycol esters. () Protective colloids Polyvinyl alcohol, ethylene/vinyl alcohol copolymer, polyacrylic acid, polymethacrylic acid, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, etc. () Self-emulsifying resin Dispersing resin itself has polarity, such as polyurethane containing polar groups, which is localized on the particle surface and provides dispersion stability. The composition of the above-mentioned aqueous resin dispersion is, in terms of weight ratio, resin component 20 to 70%, more preferably 30 to 60%, water content.
It ranges from 30 to 80%, more preferably from 40 to 70%. In addition, the dispersant is used in weight ratio to the resin component.
It is added in an amount of 0.1 to 10%, preferably 1 to 5%. Various additives may be added to the resin aqueous dispersion, but these components should be selected from those that do not interfere with the fixing of the dye that migrates from the thermal transfer sheet during heating. Examples of such additives include cured products of silicone compounds, such as cured products of epoxy-modified silicone oil and amino-modified silicone oil, which improve the releasability from the thermal transfer sheet. To form a receptor layer using a resin aqueous dispersion having the above composition, first, a resin aqueous dispersion coating film is provided on a substrate by an appropriate printing method or coating method, such as wire bar coating, and then this is dried. It is done by doing. The thickness of the receptor layer can be appropriately selected depending on the type of substrate, etc., but it is usually desirable that the thickness after drying be in the range of 1 to 20 μm, preferably 2 to 10 μm. Furthermore, if necessary, a release layer may be formed on the surface of the receptor layer in order to improve the releasability from the thermal transfer sheet. As a composition that provides such mold release properties, cured products of silicone compounds, such as cured products of epoxy-modified silicone oil and amino-modified silicone oil, are preferably used. Details of each of these modified silicone oils are as described above. (Thermal Transfer Sheet) The thermal transfer sheet 1 as described above is used in combination with a thermal transfer sheet. A typical thermal transfer sheet B has a support 6 as shown in FIG.
A thermal transfer layer 7 is provided on one side of the thermal transfer layer 7, and when the thermal transfer layer 7 is heated, the coloring material contained therein is transferred onto the thermal transfer sheet. Such coloring materials include disperse dyes, oil dyes, certain basic dyes, and intermediates that can be converted into these dyes, which have a relatively small molecular weight of about 150 to 400. From among them, thermal transfer temperature, thermal transfer efficiency, hue, color rendering,
They are selected and used in consideration of weather resistance, etc. The above coloring material is dispersed in a suitable synthetic resin binder forming a thermal transfer layer and provided on the support 6. As such a synthetic resin binder, it is usually preferable to select one that has high heat resistance and does not hinder the migration of the coloring material that occurs when heated; for example, the following are used. () Cellulose resins ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, hydroxypropylcellulose, methylcellulose, cellulose acetate, cellulose acetate butyrate, etc. () Vinyl resins polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinylpyrrolidone, polyester, polyacrylamide, etc. Among the above synthetic resin binders, polyvinyl butyral resin or cellulose resin is preferred from the viewpoint of heat resistance. To provide the thermal transfer layer 7 on the support 6, a coloring material and a synthetic resin binder are kneaded with a solvent or a diluent to form a coating composition for the thermal transfer layer, and this is applied onto the support 6 by an appropriate printing or coating method. It is sufficient to set it in Note that optional additives in the coating composition for a thermal transfer layer may be added as necessary. The basic structure of the thermal transfer sheet is as described above, but when the surface of the support is directly heated by a contact heating means such as a thermal head, the support 6 is heated as shown in FIG. By providing a slippery layer 8 containing a lubricant such as wax or a release agent on the side where the thermal transfer layer is not provided,
It is possible to prevent the heating means such as a thermal head from being fused to the support and to improve the sliding properties. The thermal transfer sheet and the thermal transfer sheet prepared as described above are stacked facing each other so that the thermal transfer layer of the thermal transfer sheet and the receiving layer of the thermal transfer sheet are in contact with each other, as shown in FIG. By applying thermal energy according to the image information to the interface, the coloring material in the thermal transfer layer can be transferred to the receiving layer according to the thermal energy. Functions and Effects According to the present invention, an intermediate layer functioning as a cushion layer is laminated between the base material of the thermal transfer sheet and the receiving layer, and the pressure during printing causes the thermal transfer sheet and the thermal transfer sheet to bond. The images, characters, symbols, etc. can be transferred clearly and without any defects because the images, characters, symbols, etc. are sufficiently adhered to each other, and there is no transfer omission or density unevenness under the same printing conditions. Example 1 (Creation of thermal transfer sheet) An ink composition for forming a thermal transfer layer having the following composition was prepared and applied to a 9 μm thick PET whose back surface was heat-resistant treated.
It was coated so that the dry coating amount was 1.0 g/cm ² and dried to obtain a thermal transfer sheet. Disperse dye: KST-B-136...0.4 parts by weight (Nippon Kayaku) Ethyl hydroxyethyl cellulose N14
...0.6 parts by weight (Harkyureth) Methyl ethyl ketone/toluene ...9.0 parts by weight (weight ratio 1:1) (Preparation of thermal transfer sheet) Synthetic paper as base material (manufactured by Oji Yuka Co., Ltd., Yupo FPG)
#150), the following intermediate layer forming ink compositions (A) to (I) were applied separately and dried, and then
The ink composition for forming a receptor layer having the following composition was applied in layers and dried at 100°C for 10 minutes, resulting in a coating weight of 4.5 when dried.
A receiving layer of g/m ² was formed to prepare a thermal transfer sheet. Ink composition for forming receptor layer Polyester resin: Vylon103...0.8 parts by weight (Toyobo Tg=47℃) EVA polymer plasticizer: Elvaloy 741P
...0.2 parts by weight (Mitsui Polychemical Tg = -37℃) Amino-modified silicone: KF857 ...0.04 parts by weight (Shin-Etsu Chemical) Epoxy-modified silicone: KF103 ...0.04 parts by weight (Shin-Etsu Chemical) Methyl ethyl ketone/toluene/ ... 9.0 parts by weight cyclohexanone (weight ratio 4:4:2)

【table】

[Table] The thermal transfer sheet and thermal transfer sheet obtained above are combined and output using a thermal head.
The results of printing under the conditions of 1 W/dot, pulse width 0.3 to 4.5 msec, and dot density 3 dots/mm are shown in Table 1 below, along with the 100% modulus of the intermediate layer resin and the coating amount of the intermediate layer.

[Table] Example 2 The same procedure as in Example 1 was carried out except that an ink composition for forming a receptor layer having the following composition was used for the receptor layer of the thermal transfer sheet, and the same results as L were obtained. Ink composition for forming receptor layer Vylon 290 (polyester resin manufactured by Toyobo Co., Ltd.)
8 parts by weight Aerosil 130 (Nippon Aerosil fine powder silica:
Specific surface area 1300m ² /g, average particle size 16mμ)
0.4 parts by weight KF-393 0.2 parts by weight (Amino-modified silicone oil manufactured by Shin-Etsu Silicon) X-22-393 0.2 parts by weight (Epoxy-modified silicone oil manufactured by Shin-Etsu Silicon) Toluene 35 parts by weight Methyl ethyl ketone 35 parts by weight Cyclohexanone 30 parts by weight Example 3 Example 1 was carried out in the same manner as in Example 1, except that an ink composition for forming a receptor layer having the following composition was used for the receptor layer of the thermal transfer sheet, and the same results were obtained. Ink composition for forming receptor layer Binalol MD-1930 67 parts by weight (polyester resin aqueous dispersion manufactured by Toyobo Co., Ltd.)
(In terms of solid content) Acnarol YJ-1100D 33 parts by weight (Acrylic emulsion manufactured by Yuka Verdice) (In terms of solid content) In Example 1, the one in which (F) was used as the ink composition for forming the intermediate layer, FIG. 7 shows the results of examining the gradation reproducibility using a reflection densitometer (RD-918, manufactured by Macbeth) for the case where only a receiving layer was provided without providing an intermediate layer. As is clear from Figure 7, when the intermediate layer is provided, the density increases by 0.1 to 0.25 compared to when no intermediate layer is provided, noise due to white spots etc. is reduced, and dot reproducibility is improved. It is clear that there are.

[Brief explanation of the drawing]

Figures 1 to 3 are cross-sectional views of the thermal transfer sheet of the present invention, Figures 4 and 5 are cross-sectional views of the thermal transfer sheet, and Figure 6 is a cross-sectional view of the thermal transfer sheet of the present invention, and Figure 6 shows the thermal transfer sheet and the thermal transfer sheet overlapped during transfer. A cross-sectional view showing the state, and FIG. 7 is a graph. A...Thermal transfer sheet, 1...Base material, 2...Intermediate layer,
3... Receptive layer, 4... Release agent layer, B... Thermal transfer sheet,
6...Support, 7...Thermal transfer layer, 8...Slip layer.

Claims (1)

[Scope of Claims] 1. A thermal transfer sheet comprising a base material and a receiving layer formed on the base material and receiving dye transferred from the thermal transfer sheet when heated, the sheet comprising: a base material; and the receptor layer, an intermediate layer mainly made of a resin having a 100% modulus of 100 Kg/cm ² or less as defined in JIS-K-6301 is interposed. 2 The resin that mainly constitutes the intermediate layer is one or two selected from the group consisting of polyurethane, polybutadiene, polyacrylic ester, epoxy, polyamide, rosin-modified phenol, terpene phenol, and ethylene/vinyl acetate copolymer. The thermal transfer sheet according to claim 1, which is made of the above resin. 3. The thermal transfer sheet according to claim 1 or 2, wherein the intermediate layer has a thickness of 0.5 to 100 μm. 4. The thermal transfer sheet according to any one of claims 1 to 3, wherein a dye-permeable release agent is contained on or inside the receiving layer. 5. The thermal transfer subject according to any one of claims 1 to 3, wherein the receiving layer contains silica powder with an average particle size of 10 to 100 mμ and a comparative surface area of less than 250 g/m ² sheet. 6. The receiving layer according to any one of claims 1 to 3, wherein the receiving layer is formed by applying a dispersion of at least one type of resin and water and drying the dispersion. Heat transfer sheet.