JP7043760B2 - Manufacturing method of thermal transfer image receiving sheet - Google Patents

Description

The present invention relates to a thermal transfer image receiving sheet. The thermal transfer image receiving sheet of the present invention can form a transfer image by transferring the dye of the thermal transfer sheet by superimposing the sublimation type thermal transfer sheet on the heat transfer image receiving sheet and heating the sheet.

Conventionally, a sublimation type thermal transfer method, a melt type thermal transfer method, or the like has been adopted as a printing method for forming characters, images, or the like on a transfer target. In the sublimation type thermal transfer method, the colored ink layer in the sublimation type thermal transfer sheet and the image receiving layer in the thermal transfer image receiving sheet are superposed on each other, and then heated by a thermal head whose heat generation is controlled by an electric signal in the colored ink layer. The dye is sublimated and transferred to the image receiving layer to form desired characters, images, etc. on the image receiving layer. Since the sublimation type thermal transfer method can freely adjust the density gradation by using the sublimation type dye, it is possible to reproduce a natural image relatively faithfully, but further improvement in performance is required.

For example, as a heat transfer image receiving sheet for improving the color density of the shadow portion of the transferred image, Patent Documents 1 and 2 describe a heat transfer image receiving sheet in which an acrylic resin, a hydrophilic binder and a wax additive are used for the image receiving layer. A thermal transfer image receiving sheet using a binder resin, a specific wax additive, and a silicone mold release agent is disclosed.

Japanese Unexamined Patent Publication No. 2011-073340 Japanese Unexamined Patent Publication No. 2013-208856

However, although it is possible to improve the color development density of the shadow portion of the printed image to some extent by dealing only with the thermal transfer image receiving sheet as described in Patent Documents 1 and 2, the color development density of the highlight portion of the transferred image is possible. Is also increasing, and it is not always sufficient in terms of faithfully reproducing natural images.

The present invention has been made in view of such circumstances, and provides a thermal transfer image receiving sheet capable of improving the color development density of a shadow portion of a transferred image and reducing the color development density of a highlight portion, and a method for manufacturing the same. The purpose is to do.

That is, the invention according to claim 1 is a method for manufacturing a thermal transfer image receiving sheet in which an image receiving layer is laminated on an image receiving sheet base material via a heat insulating layer, and a sublimation type thermal transfer sheet is laminated on the image receiving layer. In the method for manufacturing a thermal transfer image receiving sheet that forms a transferred image,
The thermal conductivity of the heat insulating layer is 0.050 to 0.060 W / m · k.
When the image receiving layer is obtained by applying a coating liquid containing the following emulsion A and emulsion B and cross-linking the coating film, and the coating liquid has a solid content of emulsion A of 1 part by mass. , A method for producing a heat transfer image receiving sheet, which comprises the solid content of emulsion B in a proportion of 1 to 5 parts by mass.
Emulsion A: A vinyl chloride emulsion having a crosslinkable functional group and a crosslinkable agent and using an emulsifier.
Emulsion B: A vinyl chloride emulsion having a crosslinkable functional group with a crosslinking agent and polymerized using an acrylic resin as a protective colloid without using an emulsifier.

Next, the invention according to claim 2 is the method for manufacturing a thermal transfer image receiving sheet according to claim 1, wherein the image receiving layer is crosslinked with a crosslinking agent.

Next, the invention according to claim 3 is the method for producing a thermal transfer image receiving sheet according to claim 1 or 2, wherein the functional group of emulsion A is composed of a carboxyl group.

Next, the invention according to claim 4 is the method for producing a thermal transfer image receiving sheet according to any one of claims 1 to 3, wherein the functional group of emulsion B is composed of a carboxyl group.

As can be seen from the examples described later, according to the present invention, when a transfer image is formed on the image receiving layer by stacking sublimation type thermal transfer sheets, the shadow portion of the image has a high color development density and the highlight portion has a color development. It is possible to faithfully reproduce natural images by keeping the density low.

On the other hand, as can be seen from Comparative Examples 1 to 4, when the thermal conductivity of the heat insulating layer exceeds 0.060 W / m · k, the color density of the shadow portion becomes low, while the thermal conductivity is 0. If it is less than .050, the color density of the highlight portion becomes high, and in any case, it becomes difficult to faithfully reproduce the natural image.

Further, when the solid content of emulsion A is 1 part by mass and the proportion of solid content of emulsion B is more than 5 parts by mass, the color development concentration of the shadow portion becomes low (Comparative Example 5), and the proportion of solid content of emulsion B. When is less than 1 part by mass, the color density of the highlight part becomes high (Comparative Example 6). In either case, it is difficult to faithfully reproduce the natural image.

FIG. 1 is a cross-sectional view of a specific example of the thermal transfer image receiving sheet of the present invention. FIG. 2 is a cross-sectional view of a specific example of the sublimation type thermal transfer sheet.

Hereinafter, the present invention will be described with reference to the drawings. As described above, the thermal transfer image receiving sheet of the present invention forms a transferred image by superimposing a sublimation type thermal transfer sheet on the thermal transfer image receiving sheet. FIG. 1 shows a specific example of this thermal transfer image receiving sheet, and FIG. 2 shows a specific example of a sublimation type thermal transfer sheet that transfers a transferred image on the thermal transfer image receiving sheet.

As shown in FIG. 1, the thermal transfer image receiving sheet is formed by laminating an image receiving layer on a substrate of an image receiving sheet via a heat insulating layer. In addition, other layers may be provided between each layer or on the back surface of the image receiving sheet base material. For example, an adhesive or an adhesive resin for adhering each layer, a plastic film, or the like. In this example, the back surface resin layer is provided on the back surface of the image receiving sheet base material.

The base material of the image receiving sheet is not particularly limited as long as it can be used as a support for the thermal transfer image receiving sheet, but it is preferable that the substrate has mechanical strength to the extent that it does not hinder handling even in a heated state in thermal transfer.

As the base material of the image receiving sheet, condenser paper, glassin paper, sulfate paper, synthetic paper (polyolefin type, polystyrene type), high quality paper, art paper, coated paper, resin coated paper, cast coated paper, wallpaper, backing paper, synthetic resin Alternatively, emulsion-impregnated paper, synthetic rubber latex-impregnated paper, synthetic resin inner paper, paperboard, cellulose fiber paper and other paper, polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, polyethylene, ethylene-vinyl acetate. Copolymers, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyether sulfone, tetrafluoroethylene, perfluoroalkyl vinyl ether, polyvinyl fluoride , Tetrafluoroethylene / ethylene, tetrafluoroethylene / hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride and the like. The thickness thereof is not particularly limited, and is, for example, 90 to 120 μm.

The heat insulating layer has a role of making the printing pressure uniform and preventing printing leakage and density unevenness during thermal transfer. In the present invention, in addition to this, it has a role of contributing to increasing the color density of the shadow portion of the image and suppressing the color density of the highlight portion to be low. For this purpose, the thermal conductivity of the heat insulating layer measured by ISO / FDI22007-3 needs to be 0.050 to 0.060 W / m · k. When the thermal conductivity of the heat insulating layer exceeds 0.060 W / m · k, the color density of the shadow portion becomes low, and it becomes difficult to form a high-density transfer image. On the other hand, when the thermal conductivity is less than 0.050, the color development density of the highlight portion becomes high, and it becomes difficult to form a low-density transfer image. In either case, it becomes difficult to faithfully reproduce a natural image in which a high-density shadow portion and a low-density highlight portion are mixed.

As the heat insulating layer, for example, a plastic sheet formed by foaming to form microvoids can be used. It is also possible to use a sheet in which a thermoplastic resin containing an inorganic powder is melt-extruded into a sheet and then stretched to form a microvoid around the inorganic powder as a core. Further, it is also possible to use a sheet in which microvoids are formed by melt-extruding a thermoplastic resin containing a water-soluble inorganic powder and then dissolving and removing the water-soluble inorganic powder.

As such a heat insulating layer, a heat insulating sheet commercially available from Yupo Corporation under the trade name of "Yupo" can be used. Since YUPO has heat insulating sheets with various thermal conductivitys depending on the grade, it is sufficient to select and use a heat insulating sheet having an appropriate thermal conductivity from these various grades.

Next, the image receiving layer is a layer for forming a transfer image by dyeing a sublimation dye contained in the colored ink layer of the sublimation type thermal transfer sheet. At the time of this thermal transfer, in order to increase the color development density of the shadow portion of the transferred image and suppress the color development density of the highlight portion to be low, the image receiving layer needs to be formed by cross-linking a coating film containing the following emulsion A and emulsion B. be.
Emulsion A: A vinyl chloride emulsion having a crosslinkable functional group and a crosslinkable agent and using an emulsifier.
Emulsion B: A vinyl chloride emulsion having a crosslinkable functional group with a crosslinking agent and polymerized using an acrylic resin as a protective colloid without using an emulsifier.

This image receiving layer can be formed by applying a coating liquid containing emulsion A and emulsion B and cross-linking both emulsion A and emulsion B. For the cross-linking, a cross-linking agent is applied to the coating liquid. It is desirable to mix. Further, in order to crosslink with this cross-linking agent, it is desirable that the functional group consists of a carboxyl group in both emulsion A and emulsion B.

In addition, other components can be added to this coating liquid. For example, a urethane association agent or a mold release agent.

As the vinyl chloride-based emulsion (emulsion A) having a cross-linking agent and a cross-linkable carboxyl group and using an emulsifier, an emulsion commercially available from Nissin Chemical Co., Ltd. can be used. For example, Viniblanc 690, Viniblanc 985 and the like.

A vinyl chloride emulsion (emulsion B), which has a crosslinkable carboxyl group with a crosslinking agent and is polymerized using an acrylic resin as a protective colloid without using an emulsifier, is also an emulsion commercially available from Nissin Chemical Co., Ltd. Can be used. For example, Viniblanc 700, Viniblanc 701 and the like.

When the solid content of the emulsion A is 1 part by mass, the emulsion A and the emulsion B need to be blended in a ratio of 1 to 5 parts by mass of the solid content of the emulsion B. As can be seen from Examples and Comparative Examples described later, when the solid content of Emulsion A is 1 part by mass and the ratio of the solid content of Emulsion B is more than 5 parts by mass, the color density of the shadow portion becomes low (Comparative Example). 5) When the proportion of the solid content of the emulsion B is less than 1 part by mass, the color density of the highlight part becomes high (Comparative Example 6). On the other hand, when the ratio of the solid content of the emulsion B is 1 to 5 parts by mass, the shadow part of the image has a high color density, and the highlight part has a low color density to faithfully reproduce the natural image. It can be reproduced (Examples 1 to 4).

Next, as the cross-linking agent, aziridine, carbodiimide, oxazoline and the like can be used. Aziridine is commercially available from Nippon Shokubai Co., Ltd. under the name of "Chemitite PZ-33". In addition, carbodiimide is commercially available from Nisshinbo Chemical Co., Ltd. under the names of "carbodilite E-05" and "carbodilite V-02". Further, as the oxazoline, "Epocross WS" of Nippon Shokubai Co., Ltd. can be exemplified.

As the urethane association agent, commercially available products may be used, for example, UH450VF, UH526, UH530, UH540, UH472, UH420, UH752, UH756VF (all manufactured by ADEKA Corporation), Rheovis PU1191, Rheovis PU1291 and Rheov. Examples thereof include Rheovis HS1212 (all manufactured by BASF Corporation).

Moreover, as a mold release agent, for example, a silicone mold release agent, a fluorine-based mold release agent and the like can be mentioned. Above all, a silicone release agent can be preferably used. For example, KF351A, KF352A, KF353, KF354L, KF355A, KF615A, KF945 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

The image receiving layer can be formed by blending each component in a solvent to prepare a coating liquid, applying the coating liquid by a gravure coating method or the like, and then drying to crosslink the emulsion A and the emulsion B. It is possible. Prior to the coating formation of the image receiving layer, a base layer for improving the adhesiveness with the heat insulating layer may be applied.

Next, the back surface resin layer is provided for the purpose of imparting performance related to the back surface, for example, writing performance, gluing performance, handling performance, head cleaning performance, and the like, if necessary. The back resin layer may be made of, for example, a binder resin. Examples of the binder resin include styrene / acrylic resin, polyester resin, polyurethane resin, acrylic resin and the like. Further, as the back resin layer, a plastic film such as a polyethylene film, a polypropylene film, or a polyester film may be used. The thickness of the back resin layer is not particularly limited and may be, for example, 1 to 5 μm.

Next, the sublimation type thermal transfer sheet used for thermal transfer will be described. The sublimation type thermal transfer sheet is formed by printing a colored ink containing a sublimation dye on a thermal transfer sheet base material. By superimposing this sublimation type heat transfer sheet on the heat transfer image receiving sheet and heating it from the back surface of the sublimation type heat transfer sheet with a thermal head, the dye in the ink is sublimated and dyed on the image receiving layer. By controlling the heat generation energy of the thermal head, it is possible to control the amount of dye that sublimates from the ink, and it is possible to form a transfer image with shades according to the amount of this dye.

As described above, the sublimation type thermal transfer sheet may be simply formed by printing a colored ink layer on the thermal transfer sheet substrate, but is used for forming a multicolored natural image or is formed and transferred. It is also possible to print a plurality of colored ink layers in a surface-sequential manner, or to use a sublimation type thermal transfer sheet in which a protective layer is arranged.

The sublimation-type thermal transfer sheet shown in FIG. 2 is an example of a sublimation-type thermal transfer sheet in which a three-color colored ink layer and a protective layer are arranged in a surface-sequential manner, and the three-color colored ink layer is a yellow ink layer and a magenta ink layer. , Consists of a cyan ink layer. Further, a heat-resistant slipping layer is laminated on the back surface of the thermal transfer sheet base material.

As the heat transfer sheet base material, a plastic film such as a polyester film, a polyethylene naphthalate film, a polystyrene film, a polysulfon film, a polyimide film, a polycarbonate film, or a polypropylene film can be used.

The coloring ink can be formed by blending a sublimation coloring dye in a binder. The binder may be any resin, but for example, a binder obtained by cross-linking a polyol and isocyanate can be used. Further, as the yellow dye, C.I. I. Solvent Yellow 14, 16, 29, 30, 33, 56, 93, etc., C.I. I. Disperse yellow 7, 33, 60, 141, 201, 231 and the like can be mentioned, and examples of the magenta dye include C.I. I. Solvent Red 18, 19, 27, 143, 182, etc., C.I. I. Dispersed threads 60, 73, 135, 167, etc., C.I. I. Disperse violet 13, 26, 31, 56 and the like can be mentioned, and examples of the cyan dye include C.I. I. Solvent Blue 11, 36, 63, 105, etc., C.I. I. Disperse blue 24, 72, 154, 354 and the like can be mentioned.

The protective layer is composed of a peeling layer that can be peeled off from the thermal transfer sheet substrate during thermal transfer, and an adhesive layer that is superposed on the peeling layer. As the release layer, waxes such as paraffin wax, carnauba wax, montan wax, higher fatty acid, higher alcohol, higher fatty acid ester, and higher fatty acid amide can be used. Further, as the adhesive layer, a polyester resin, a polyvinyl chloride resin, an acrylic resin or the like can be used.

The heat-resistant slipping layer is provided to prevent heat adhesion between the thermal head and the sublimation type thermal transfer sheet, and is, for example, a composition containing a binder resin, a functional additive, a filler, a curing agent, or the like. Can be configured with. Examples of the binder resin include polyvinyl butyral resin, polyvinyl acetal acetal resin, polyester resin, polyether resin, polybutadiene resin and the like. Examples of the functional additive include waxes and surfactants. Examples of the filler include talc, silica, polyethylene resin particles, polypropylene resin particles, polystyrene resin particles, polymethylmethacrylate resin particles and the like. Examples of the curing agent include various isocyanates.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. Both the thermal transfer image receiving sheets of the following examples and comparative examples have the layer structure shown in FIG. Further, the sublimation type thermal transfer sheet used in the transfer test has the layer structure shown in FIG.

(Example 1)
Paper (NATURAL manufactured by Nippon Paper Industries, Ltd.) was used as the base material of the image receiving sheet, and a biaxially stretched polypropylene film was laminated on the back surface thereof to form a back surface resin layer. The paper (image receiving sheet base material) and the biaxially stretched polypropylene film were laminated by melt-extruding low-density polyethylene between them and using their adhesive force.

Next, as the heat insulating layer, a foamed commercially available stretched polypropylene sheet was used. Its thermal conductivity is 0.055 W / m · k. In the laminating of paper (image receiving sheet base material) and effervescent stretched polypropylene sheet (heat insulating layer), low-density polyethylene was melt-extruded between them and laminated by the adhesive force.

Next, a coating liquid for forming the image receiving layer was prepared. This coating liquid was prepared by blending emulsion A, emulsion B, a cross-linking agent, a mold release agent, and a urethane association agent. Each component is as follows.
Emulsion A: Viniblanc 690 (solid content 54% by mass) manufactured by Nissin Chemical Co., Ltd.
Emulsion B: Viniblanc 700 (solid content 30% by mass) manufactured by Nissin Chemical Co., Ltd.
Crosslinking agent: Carbodilite E-05 manufactured by Nisshinbo Chemical Co., Ltd.
Release agent: KF352A manufactured by Shin-Etsu Chemical Co., Ltd.
Urethane association agent: ADEKA NOL UH530 manufactured by ADEKA CORPORATION.

The mixing ratio of emulsion A and emulsion B was 25 parts by mass for emulsion A and 45 parts by mass for emulsion B. This blending ratio is a ratio in which the solid content of emulsion A and the solid content of emulsion B are equal in quantity.

In addition, 14 parts by mass of the cross-linking agent was blended. This blending amount is an amount such that the molar equivalents of the carboxyl group (-COOH) contained in both emulsion A and emulsion B and carbodylite (-NCN-) are 1: 1.

The amount of the release agent was 3 parts by mass, the amount of the urethane association agent was 2 parts by mass, the amount of water was 11 parts by mass, and the total amount was 100 parts by mass.

Then, after applying the base layer to the surface of the foamed stretched polypropylene sheet (heat insulating layer), the coating liquid is applied by the reverse gravure coating method to form an image receiving layer, whereby the thermal transfer image receiving sheet of Example 1 is manufactured. did. The coating amount of the image receiving layer is 3.0 g / mm ² (dry).

(Example 2)
The thermal transfer image receiving sheet of Example 2 was produced in the same manner as in Example 1 except that a commercially available stretched polypropylene sheet having a thermal conductivity of 0.050 W / m · k was used as the heat insulating layer.

(Example 3)
A thermal transfer image receiving sheet of Example 3 was produced in the same manner as in Example 1 except that a commercially available stretched polypropylene sheet having a thermal conductivity of 0.060 W / m · k was used as the heat insulating layer.

(Example 4)
Except for the fact that a coating liquid containing 8.3 parts by mass of emulsion A (solid content 54% by mass) and 75 parts by mass of emulsion B (solid content 30% by mass) was used as the coating liquid for forming the image receiving layer. , The thermal transfer image receiving sheet of Example 4 was manufactured in the same manner as in Example 1. The blending ratio is a ratio in which the solid content of emulsion B is 5 parts by mass when the solid content of emulsion A is 1 part by mass.

(Comparative Example 1)
A thermal transfer image receiving sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that a stretched polypropylene sheet having a thermal conductivity of 0.140 W / m · k was used as the heat insulating layer.

(Comparative Example 2)
A stretched polypropylene sheet having a thermal conductivity of 0.140 W / m · k is used as the heat insulating layer, and 8.3 parts by mass of emulsion A (solid content 54% by mass) is used as a coating liquid for forming the image receiving layer. , A thermal transfer image receiving sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that a coating liquid containing 75 parts by mass of Emulsion B (solid content 30% by mass) was used. This compounding ratio is the same as the compounding ratio of Example 4, and is a ratio in which the solid content of emulsion B is 5 parts by mass when the solid content of emulsion A is 1 part by mass.

(Comparative Example 3)
A thermal transfer image receiving sheet of Comparative Example 3 was produced in the same manner as in Example 1 except that a commercially available stretched polypropylene sheet having a thermal conductivity of 0.045 W / m · k was used as the heat insulating layer.

(Comparative Example 4)
A commercially available stretched polypropylene sheet having a thermal conductivity of 0.045 W / m · k is used as the heat insulating layer, and emulsion A (solid content 54% by mass) is added as a coating liquid for forming the image receiving layer. The thermal transfer image receiving sheet of Comparative Example 4 was produced in the same manner as in Example 1 except that a coating liquid containing 3 parts by mass and 75 parts by mass of emulsion B (solid content 30% by mass) was used. This compounding ratio is the same as the compounding ratio of Example 4, and is a ratio in which the solid content of emulsion B is 5 parts by mass when the solid content of emulsion A is 1 part by mass.

(Comparative Example 5)
As a coating liquid for forming the image receiving layer, a coating liquid containing 8.3 parts by mass of emulsion A (solid content 54% by mass) and 76.5 parts by mass of emulsion B (solid content 30% by mass) was used. The thermal transfer image receiving sheet of Comparative Example 5 was produced in the same manner as in Example 1. In addition, this compounding ratio is a ratio that the solid content of emulsion B is 5.1 parts by mass when the solid content of emulsion A is 1 part by mass.

(Comparative Example 6)
As a coating liquid for forming the image receiving layer, a coating liquid containing 23.6 parts by mass of emulsion A (solid content 54% by mass) and 47.3 parts by mass of emulsion B (solid content 30% by mass) was used. The thermal transfer image receiving sheet of Comparative Example 5 was produced in the same manner as in Example 1. In addition, this compounding ratio is a ratio that the solid content of emulsion B is 0.9 part by mass when the solid content of emulsion A is 1 part by mass.

(Transfer test)
The sublimation type thermal transfer sheet used in the transfer test was manufactured as follows (see FIG. 2).

First, a polyester film having a thickness of 4.5 μm was used as the heat transfer sheet base material, and a heat-resistant slipping layer was formed on the back surface of the heat transfer sheet base material. Next, an ink containing a sublimation dye of each color was printed to form a yellow ink layer, a magenta ink layer, and a cyan ink layer in a surface-sequential manner. Next, the release layer and the adhesive layer were printed side by side on each of the colored ink layers to form a protective layer, thereby producing a sublimation type thermal transfer sheet. The peeling layer was printed on a portion where each colored ink layer was not present and the thermal transfer sheet substrate was exposed, and the protective layer was aligned with the peeling layer and printed on top of the peeling layer.

Then, the sublimation type thermal transfer sheet is superposed on each of the thermal transfer image receiving sheets of Examples 1 to 4 and Comparative Examples 1 to 6, and a V-step image is produced using a commercially available thermal transfer type sublimation printer (Mitsubishi digital color printer, CP-D70D). I made a print.

With respect to the transferred image thus formed, the optical density of the highlight portion and the optical density of the shadow portion were measured using a spectrocolorimeter (IliO2, manufactured by Xrite).

As for the highlight part, when the optical density is 0.62 or less, the reproducibility of the natural image and the color of human skin can be ensured, and the dye density of the highlight part is sufficiently lowered, which is good. ○ ”was judged. On the other hand, when the optical density does not satisfy the above numerical range, it is determined that the dye density in the highlight portion is not sufficiently lowered and the result is "x".

Further, regarding the shadow portion, when the optical density was 2.00 or more, the dye concentration in the shadow portion was sufficiently improved, and it was judged to be good “◯”. On the other hand, when the optical density does not satisfy the above numerical range, the dye density in the shadow portion is not sufficiently improved, and it is judged to be defective "x".

The results are shown in Table 1.

(Discussion)
From this result, the following can be understood.

That is, when the thermal conductivity of the heat insulating layer is 0.050 to 0.060 W / m · k and the solid content of the image receiving layer is 1 part by mass, the solid content of the emulsion B is 1 to 1. When it is contained in a proportion of 5 parts by mass (Examples 1 to 4), the shadow part of the image has a high color development density, and the highlight part has a low color development density to faithfully reproduce the natural image. Is possible.

On the other hand, when the thermal conductivity of the heat insulating layer exceeds 0.060 W / m · k (Comparative Examples 1 and 2), the color density of the shadow portion becomes low, while the thermal conductivity is 0.050. If it is less than (Comparative Examples 3 and 4), the color density of the highlight portion becomes high, and in any case, it becomes difficult to faithfully reproduce the natural image.

Further, when the solid content of emulsion A is 1 part by mass and the proportion of solid content of emulsion B is more than 5 parts by mass, the color development concentration of the shadow portion becomes low (Comparative Example 5), and the proportion of solid content of emulsion B. When is less than 1 part by mass, the color density of the highlight part becomes high (Comparative Example 6). In either case, it is difficult to faithfully reproduce the natural image.

Claims (4)

A method for manufacturing a thermal transfer image-receiving sheet in which an image-receiving layer is laminated on a substrate of an image-receiving sheet via a heat insulating layer, and a method for manufacturing a thermal transfer image-receiving sheet in which a sublimation-type thermal transfer sheet is laminated to form a transfer image on the image-receiving layer. In
The thermal conductivity of the heat insulating layer is 0.050 to 0.060 W / m · k.
When the image receiving layer is obtained by applying a coating liquid containing the following emulsion A and emulsion B and cross-linking the coating film, and the coating liquid has a solid content of emulsion A of 1 part by mass. , A method for producing a heat transfer image receiving sheet, which comprises the solid content of emulsion B in a proportion of 1 to 5 parts by mass.
Emulsion A: A vinyl chloride emulsion having a crosslinkable functional group and a crosslinkable agent and using an emulsifier.
Emulsion B: A vinyl chloride emulsion having a crosslinkable functional group with a crosslinking agent and polymerized using an acrylic resin as a protective colloid without using an emulsifier. The method for producing a thermal transfer image receiving sheet according to claim 1, wherein the image receiving layer is crosslinked with a crosslinking agent. The method for producing a thermal transfer image receiving sheet according to claim 1 or 2, wherein the functional group of the emulsion A is composed of a carboxyl group. The method for producing a thermal transfer image receiving sheet according to any one of claims 1 to 3, wherein the functional group of the emulsion B is composed of a carboxyl group.

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