WO2016152832A1 - Method for producing thermal-transfer-image-receiving sheet support, and method for producing thermal-transfer-image-receiving sheet - Google Patents

Abstract

Provided is a method for producing a thermal-transfer-image-receiving sheet support with which it is possible to obtain a thermal-transfer-image-receiving sheet that has high uniformity of properties and is easily handled, air bubble formation in an adhesive layer of the thermal-transfer-image-receiving sheet being prevented, while maintaining glossiness. A resin 15 is supplied to one surface of a base material 1 and passed between a cooling roller A(12) and a rubber roller A(13); and a porous film 4 is superimposed on the other surface of the base material 1 with a resin 15 interposed therebetween, the porous film 4 being passed between a cooling roller B(22) and a rubber roller B(23). The ten-point average roughness (Rz) of the surface of the cooling roller A(12) is 5-30 μm, the ten-point average roughness (Rz) of the surface of the cooling roller B(22) is 0-20 μm, the rubber hardness (durometer (type A)) of the rubber roller A(13) is 60-95, and the rubber hardness of the rubber roller B(23) is 50-80.

Description

Method for producing support for thermal transfer image-receiving sheet and method for producing thermal transfer image-receiving sheet

The present invention relates to a method for producing a support for a thermal transfer image receiving sheet, and more specifically, for a thermal transfer image receiving sheet by laminating a base material and a porous film with a melt-extruded resin while passing between a pair of rollers. The present invention relates to a method for manufacturing a support. The present invention also relates to a method for producing a thermal transfer image receiving sheet in which a colorant receiving layer is laminated on the porous film layer of the support for the thermal transfer image receiving sheet.

A support for a recording material produced by melt extrusion coating a thermoplastic resin on at least one surface of a support such as a base paper is used with a photographic emulsion or a heat sensitive material applied thereto. In order to obtain a high-quality image, the recording material support is important for the smoothness of the support surface before coating with an emulsion or the like. As a method for producing a recording material support, a thermoplastic resin melted at a high temperature by an extrusion coating method is cast on the surface of a traveling base paper, and a press roller coated with an elastic resin is applied to a cooling roller via the base paper. A nip coating method is common.

As a method for improving the smoothness of the surface of a support produced by melt coating a thermoplastic resin, a method for defining the nip pressure, a method for thickening a thermoplastic resin layer, and a nip pressure at the time of coating a thermoplastic resin are increased. Methods, calendar processing for improving the smoothness of the base paper, and the like are known. However, the method of niping the support and the resin is affected by the surface shape of the support, the method of increasing the thickness of the resin is disadvantageous in terms of cost, and the calendering is disadvantageous in terms of cost due to an increase in equipment and steps. In addition, none of the conventional methods provides satisfactory satisfactory smoothness.

In order to solve such problems, in a method for manufacturing a recording material support in which at least one surface of the support is coated with a thermoplastic resin by a melt extrusion coating method, the support is coated between a cooling roller and a press roller. It has been proposed to pass a support coated with a thermoplastic resin through a gap set to a distance that is equal to or greater than the thickness of the support and less than the thickness of the support after coating (see Patent Document 1).

In Patent Document 2, a support sheet formed by bonding a back layer made of PET (polyethylene terephthalate), polyethylene, polypropylene, or the like to the back surface of paper, and a heat insulating layer bonded to the paper surface of the support sheet, There is described a thermal transfer image-receiving sheet comprising an intermediate layer and an image-receiving layer that are sequentially joined to the outside of the heat-insulating layer. For example, the back layer is bonded to paper by an extrusion laminating method (paragraphs 0020 to 0021).

Japanese Patent Laid-Open No. 9-177000 JP 2006-192684 A

The support for a thermal transfer image-receiving sheet produced by a conventional method is sufficient in terms of spreading properties, prevention of air stains in the adhesive layer, and glossiness and uniformity of properties of the resulting thermal transfer image-receiving sheet. It was not satisfactory.

The present invention has been made in view of the background art described above, and an object of the present invention is to obtain a thermal transfer image-receiving sheet that is excellent in curling properties, prevents air stains in the adhesive layer, and has high uniformity of properties. An object of the present invention is to provide a method for producing a support for a thermal transfer image receiving sheet. Another object of the present invention is to provide a method for producing a thermal transfer image receiving sheet using the thermal transfer image receiving sheet support.

As a result of intensive studies, the present inventors formed a first resin layer on one surface of the base material through the base material and the melt-extruded first resin between the cooling roller A and the rubber roller A. And passing the base material having the first resin layer between the cooling roller B and the rubber roller B together with the porous film and the melt-extruded second resin on the other surface of the base material. And forming a porous film layer through the second resin layer, the surface roughness of each cooling roller and the rubber hardness of each rubber roller within a specific range. In addition, it has been found that the above object can be achieved by corona treatment of the substrate surface when the substrate and the resin layer are preferably bonded together.

The present invention is based on such knowledge.

In the method for producing a support for a thermal transfer image-receiving sheet of the present invention, a first resin layer is provided on one surface of a substrate, and a porous film layer is provided on the other surface via a second resin layer. A method for manufacturing a thermal transfer image-receiving sheet support, wherein the first resin is supplied to one surface side of the base material, and is passed between a cooling roller A and a rubber roller A so as to pass through the first resin layer. A first step of forming a film, and a porous film is superimposed on the other surface of the base material on which the first resin layer is formed via a second resin, and passes between the cooling roller B and the rubber roller B. And a method for producing a thermal transfer image-receiving sheet support having a second step of forming the second resin layer and the porous film layer, or porous on the one surface side of the substrate via a second resin. Overlay the quality film and pass between the cooling roller B and the rubber roller B The first step of forming the second resin layer and the porous film layer and the first resin is supplied to the other surface side of the substrate on which the second resin layer and the porous film layer are formed, and then cooled. And a second step of forming the first resin layer by passing between the roller A and the rubber roller A, and a method for manufacturing a support for a thermal transfer image receiving sheet. The point average roughness (Rz) is 5 μm or more and 30 μm or less, the ten-point average roughness (Rz) of the surface of the cooling roller B is 0 μm or more and 3.0 μm or less, and measured by a durometer (type A), The rubber hardness of the rubber roller A is 60 or more and 95 or less, and the rubber hardness of the rubber roller B measured by a durometer (type A) is 50 or more and 80 or less.

The ten-point average roughness (Rz) is a value measured according to JIS B0660: 1998. Measurement with a durometer (type A) is performed at a measurement temperature of 23 ± 2 ° C. according to JIS K6253-3: 2012.

In one embodiment of the present invention, the thickness of the first resin layer is 10 μm or more and 50 μm or less, and the thickness of the second resin layer is 5 μm or more and 30 μm or less.

In one embodiment of the present invention, the thickness of the porous film layer is 10 μm or more and 100 μm or less.

In one embodiment of the present invention, the first resin layer is formed after corona treatment of one surface of the substrate.

In one embodiment of the present invention, the surface of the base material on which the first resin layer is not formed is subjected to corona treatment, and then the second resin layer is formed.

In one aspect of the present invention, the cooling roller A is in contact with the first resin layer, the rubber roller A is in contact with the surface of the substrate on which the first resin layer is not formed, and the cooling roller B is in contact with the porous film layer, and the rubber roller B is in contact with the first resin layer.

The method for producing a thermal transfer image-receiving sheet according to the present invention comprises forming a colorant receiving layer via an intermediate layer on the porous film of the thermal transfer image-receiving sheet support thus produced.

In one embodiment of the present invention, the intermediate layer is a primer layer containing a binder resin.

In the thermal transfer image-receiving sheet support and thermal transfer image-receiving sheet produced by the method of the present invention, the cooling roller A (12) has a high surface roughness and the rubber roller A (13) has a high rubber hardness. Thus, the first resin layer formed on one surface of the substrate has a high surface roughness, and the thermal transfer image receiving sheet support and the thermal transfer image receiving sheet supportability (multiple thermal transfer image receiving sheet supports) Or, when the thermal transfer image receiving sheets are superposed on each other, they are less likely to adhere to each other and are easy to handle (spread).

In the present invention, by reducing the surface roughness of the cooling roller B (22) for bonding the porous film to the other surface of the substrate, the surface of the bonded porous film becomes smooth. In addition, the smoothness of the colorant receiving layer formed thereon via the intermediate layer is also improved. As a result, the glossiness is improved. Further, by lowering the rubber hardness of the rubber roller B (23) at this time, bubbles are prevented from entering into the second resin layer (including suppression, the same applies hereinafter), and also, other than that, Occurrence of unevenness in appearance is also prevented.

When the first resin layer is formed on one surface of the substrate and the second resin layer is formed on the other surface, the affinity between the resin and the substrate is improved by corona treatment of the substrate surface. In addition, the adhesion strength of the resin to the base material is increased, and the molten resin is easily cast uniformly on the surface of the base material, thereby improving the uniformity of the resin layer.

1a to 1d are schematic cross-sectional views in the thickness direction of a thermal transfer image receiving sheet support, for explaining a method for producing the thermal transfer image receiving sheet support according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a first step in the method for producing a thermal transfer image receiving sheet support according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a second step in the method for producing a thermal transfer image receiving sheet support according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view illustrating a first step in the method for producing a thermal transfer image receiving sheet support according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view illustrating a second step in the method for producing a thermal transfer image receiving sheet support according to an embodiment of the present invention.

≪Manufacturing process of thermal transfer image receiving sheet support / thermal transfer image receiving sheet≫
1a to 1d show an example of a method for producing a thermal transfer image-receiving sheet support according to the present invention.

After corona treatment on one surface of the base material 1 shown in FIG. 1a, a first resin layer 2 is deposited and formed as shown in FIG. 1b (hereinafter sometimes referred to as the first step), and then the other side of the base material 1 is formed. After the corona treatment on the surface, as shown in FIG. 1 c, the porous film 4 is bonded via the second resin layer 3 to manufacture the thermal transfer image receiving sheet support 5 (hereinafter sometimes referred to as a second step). ).

A thermal transfer image receiving sheet 8 is produced by laminating a colorant receiving layer 7 via an intermediate layer 6 on the porous film 4 of the thermal transfer image receiving sheet support 5 as shown in FIG. Sometimes referred to as the third step.)

In the second step, the surface of the first resin layer 2 (the surface opposite to the substrate 1) may be corona treated. A writing layer (not shown) is attached to the surface of the corona-treated resin layer 2 in a separate step.

[First Embodiment]
[First step]
As shown in FIG. 2, in the first step in the first embodiment, after corona discharge treatment machine 11 corona-treats one surface of substrate 1 while continuously feeding substrate 1 by a transport mechanism (not shown). The one surface is set as the cooling roller (chill roller) A (12) side, and the sheet is fed between the cooling roller A (12) and the rubber roller (press roller) A (13). Further, the die 14 melts in the form of a curtain on the most sandwiched portion between the cooling roller A (12) and the rubber roller A (13) or slightly on the rubber roller A (13) side or slightly on the cooling roller A (12) side. The extruded first resin 15 is supplied, and the base material 1 and the first resin 15 are overlapped and passed between the cooling roller A (12) and the rubber roller A (13) in a pinched state. Thereby, the 1st laminated body 16 with which the base material 1 and the 1st resin layer 2 formed by casting the resin 15 were bonded together is obtained.

At this time, the die 14 is on the rubber roller A (13) side or slightly to the cooling roller A (12) side from the most sandwiched portion between the cooling roller A (12) and the rubber roller A (13). By installing and melt-extruding the first resin 15, it is possible to obtain a support for a thermal transfer image-receiving sheet having a good printed material formation and good adhesion between the substrate 1 and the first resin.

[Second step]
As shown in FIG. 3, in the second step in the first embodiment, while the first laminate 16 is continuously fed by a transport mechanism (not shown), the other surface of the substrate 1 ( The surface opposite to the resin layer 2) is subjected to corona treatment. The surface of the resin layer 2 (the surface opposite to the substrate 1) may be corona treated by the corona discharge treatment machine 21. Next, the first laminated body 16 is fed between the cooling roller (chill roller) B (22) and the rubber roller B (23) with the first resin layer 2 as the rubber roller (press roller) B (23) side. Further, the porous film 4 fed by a transport mechanism (not shown) is supplied between the cooling roller B (22) and the rubber roller B (23). Further, a second resin 25 melt-extruded in a curtain shape from a die 24 is supplied between the porous film 4 and the base material 1 of the first laminate 16, and the porous film 4 and the second film 16 are supplied. The resin 25 and the first laminated body 16 are overlapped and passed between the cooling roller B (22) and the rubber roller B (23) in a pinched state. As a result, the thermal transfer image receiving sheet support 5 in which the first laminate 16, the second resin layer 3 formed by casting the second resin 25, and the porous film 4 are bonded together is obtained. It is done.

At this time, the die 24 is set slightly closer to the cooling roller B (22) side than the most sandwiched portion between the cooling roller B (22) and the rubber roller B (23) to melt and extrude the second resin 25. Thus, it is possible to obtain a support for a thermal transfer image-receiving sheet having a good printed material formation and good adhesion between the substrate 1 and the second resin.

[Third step]
In the third step in the first embodiment, an intermediate layer 6 is formed on the thermal transfer image receiving sheet support 5 by a coating method, and a colorant receiving layer 7 is formed thereon by a coating method, whereby the thermal transfer image receiving sheet 8. Is obtained. Although illustration is omitted, a release layer may be provided on at least a part of the outer surface (the surface opposite to the intermediate layer 6) of the color material receiving layer 7. As described above, a writing layer may be provided via the first resin layer 2.

In the first embodiment, in the second step, the thermal transfer image receiving sheet 8 can be obtained by using the porous film 4 in which the intermediate layer 6 and the colorant receiving layer 7 are previously formed by a coating method.

[Second Embodiment]
[First step]
In the first step in the second embodiment, as shown in FIG. 4, the corona discharge treatment machine 20 corona-treats one surface of the substrate 1 while continuously feeding the substrate 1 by the transport mechanism, With the surface set as the cooling roller (chill roller) B (22) side, the sheet is fed between the cooling roller B (22) and the rubber roller (press roller) B (23). Further, the porous film 4 fed by the transport mechanism is supplied between the cooling roller B (22) and the rubber roller B (23). Further, a second resin 25 melt-extruded in a curtain shape from the die 24 is supplied between the porous film 4 and the base material 1, and the porous film 4, the second resin 25, and the base material 1 are supplied. And the cooling roller B (22) and the rubber roller B (23) are passed under pressure. Thereby, the 2nd laminated body 17 by which the base material 1, the 2nd resin layer 3 formed by casting the 2nd resin 25, and the porous film 4 were bonded together is obtained.

At this time, the die 24 is placed on the side of the cooling roller B (22), about 0 to 20 mm, slightly from the most sandwiched portion between the cooling roller B (22) and the rubber roller B (23). By melt-extruding 25, it is possible to obtain a support for a thermal transfer image-receiving sheet having a good printed material formation and good adhesion between the substrate 1 and the second resin.

[Second step]
In the second step in the second embodiment, as shown in FIG. 5, while the second laminate 17 is continuously fed by the transport mechanism, the other surface (second resin) of the base material 1 by the corona discharge treatment machine 11. After the corona treatment of the surface opposite to the layer 3), the other surface is set as the cooling roller (chill roller) A (12) side and fed between the cooling roller A (12) and the rubber roller (press roller) A (13). . Further, the die 14 melts in the form of a curtain on the most sandwiched portion between the cooling roller A (12) and the rubber roller A (13) or slightly on the rubber roller A (13) side or slightly on the cooling roller A (12) side. The extruded first resin 15 is supplied, and the base material 1 and the first resin 15 are overlapped and passed between the cooling roller A (12) and the rubber roller A (13) in a pinched state. As a result, the thermal transfer image receiving sheet support 5 in which the second laminated body 17, the first resin layer 2 formed by casting the first resin 15, and the porous film 4 are bonded together is obtained. It is done. The surface of the resin layer 2 (the surface opposite to the substrate 1) may be corona treated by the corona discharge treatment machine 21.

At this time, the die 14 is placed slightly closer to the cooling roller A (12) side than the most sandwiched portion between the cooling roller A (12) and the rubber roller A (13) to melt and extrude the first resin 15. Thus, it is possible to obtain a support for a thermal transfer image-receiving sheet having a good printed material formation and good adhesion between the substrate 1 and the first resin.

[Third step]
In the third step in the second embodiment, the intermediate layer 6 is formed on the thermal transfer image receiving sheet support 5 by a coating method, and the colorant receiving layer 7 is formed thereon by the coating method, whereby the thermal transfer image receiving sheet 8. Is obtained. Although illustration is omitted, a release layer may be provided on at least a part of the outer surface (the surface opposite to the intermediate layer 6) of the color material receiving layer 7. As described above, a writing layer may be provided via the first resin layer 2.

In the second embodiment, in the first step, the thermal transfer image receiving sheet 8 can be obtained by using the porous film 4 in which the intermediate layer 6 and the colorant receiving layer 7 are previously formed by a coating method.

Thereafter, the thermal transfer image receiving sheet 8 is subjected to a so-called ear removal process in which both sides along the feeding direction are cut and removed. The cutting residue generated by this cutting is preferably recovered after being cut into a short length (for example, about several tens of cm or less).

Hereinafter, the suitable physical properties of each roller will be described in detail.

[Cooling roller A (12) and rubber roller A (13)]
The cooling roller A (12) cools the melt-extruded resin, and is preferably made of metal. The temperature of the cooling roller A (12) is preferably 10 ° C. or higher and 40 ° C. or lower, particularly 25 ° C. or higher and 30 ° C. or lower. The ten-point average roughness (Rz) of the surface of the cooling roller A (12) is preferably 5 μm to 30 μm, particularly preferably 10 μm to 20 μm. As the surface roughness becomes smaller, the resin melt-extruded to the cooling roller A (12) becomes easier to be wrapped (resin generation occurs), and the process stability is not good. As the surface roughness increases, non-uniformity of the back surface of the thermal transfer image-receiving sheet support 5 tends to occur.

The diameter of the cooling roller A (12) is preferably 300 mm to 1000 mm, particularly preferably about 400 mm to 800 mm.

The rubber hardness of the rubber roller A (13) measured by a durometer (type A) is preferably 60 or more and 95 or less, particularly preferably 80 or more and 90 or less. When this value is lowered, unevenness in the adhesion between the first resin and the base material is likely to occur, and the wear resistance is lowered. The diameter of the rubber roller A (13) is preferably from 100 mm to 400 mm, particularly preferably from 200 mm to 300 mm.

The rubber roller A (13) preferably has conductivity from the viewpoint of preventing adhesion of dust and foreign matters. For this purpose, a conductive material such as carbon is kneaded into the rubber material. It is preferable to use a material.

This rubber roller preferably has releasability in order to prevent adhesion of the first resin 15 that is normally melt-extruded widely to the outside of the end portion of the base material 1 in order to prevent resin buildup due to so-called neck-in. For this reason, the rubber roller is preferably made of silicone rubber (FMQ, FVMQ, MQ, PMQ, PVMQ, VMQ, hardness 30 to 90) or FKM (fluoro rubber: hardness 50 to 90).

However, silicone rubber usually has poor adhesion to the roller core. Silicone rubber is harder than ordinary NBR (nitrile rubber: hardness 10 to 95), EPT (ethylene / propylene rubber: hardness 40 to 80), and SBR (styrene rubber: hardness 30 to 95). Therefore, it is preferable that the structure of the rubber roller is roller core / normal rubber / conductive silicone rubber.

NBR, EPT, CR (chloroprene rubber: hardness 30 to 85), IIR (butyl rubber: hardness 20 to 80), U (urethane rubber: hardness 10 to 95), CSM (chlorosulfonated), which is the base of silicone rubber A normal rubber such as polyethylene (having a hardness of 50 or more and 85 or less) is preferable because the linear pressure at the nip with the cooling roller can be increased by setting the hardness to the same or higher than that of silicone rubber. Therefore, for example, a structure in which the hardness of each of ordinary rubber / conductive silicone rubber is 95/90, 95/85, 90/85, 85/80 is preferable.

The thickness of these rubbers is preferably about 10 μm to 30 μm, more preferably about 15 μm to 20 μm. The thinner the thickness, the higher the linear pressure at the nip with the cooling roller, which is preferable. However, when the thickness is too thin, the number of times of polishing regeneration decreases.

The surface roughness Ra (μm) of the rubber roller A (13) is 0 or more and 5 or less, preferably 0.01 or more and 3 or less, more preferably 0.05 or more and 2 or less. This Ra is a value measured according to JIS B 0601: 2013. Rz (μm) is 0 or more and 30 or less, preferably 0.05 or more and 20 or less, and more preferably 0.1 or more and 3 or less.

Thus, by increasing the surface roughness of the cooling roller A (12) and increasing the rubber hardness of the rubber roller A (13), the surface of the surface of the first resin layer 2 (the surface opposite to the substrate 1) is increased. The roughness is increased, and the thermal transfer image receiving sheet support 5 and the thermal transfer image receiving sheet 8 are improved in sprinkling properties, and the adhesion between the substrate 1 and the resin is improved, thereby preventing the occurrence of unevenness. The nip pressure between the cooling roller A (12) and the rubber roller A (13) is preferably about 4 to 6 MPa, particularly about 4.2 to 5 MPa. Moreover, the feed rate of the base material in the first step is preferably 20 m / min or more and 300 m / min or less.

[Cooling roller B (22) and rubber roller B (23)]
The cooling roller B (22) is also preferably made of metal. The temperature of the cooling roller B (22) is preferably 10 ° C. or higher and 40 ° C. or lower, particularly preferably 20 ° C. or higher and 30 ° C. or lower. The ten-point average roughness (Rz) of the surface of the cooling roller B (22) is preferably 0 to 3.0 μm, particularly preferably 0.5 to 2.0 μm. When it is smaller than 0.5 μm, the resin melt-extruded to the cooling roller B (22) is easily wound (resin is taken out), and the process stability is not good. However, the process stability can be improved by devising the extrusion width of the resin to be narrower than the porous film width. When it is larger than 3.0 μm, nonuniformity of the surface of the porous film tends to occur. This non-uniformity is often observed like surface irregularities.

Since the cooling roller B (22) is used for bonding the porous film 4 to the surface, the cooling roller B (22) is compared with the bonding of the first resin 15 to the cooling roller A (12). Since the sticking of the second resin 25 to the side is easy to be suppressed, the roughness of the cooling roller B (22) is made smaller than that of the cooling roller A (12). This also has an effect of improving the gloss of the surface of the thermal transfer image receiving sheet.

The diameter of the cooling roller B (22) is preferably 300 mm to 1000 mm, particularly preferably about 400 mm to 800 mm.

The rubber hardness of the rubber roller B (23) is preferably 50 or more and 80 or less, and particularly preferably 60 or more and 70 or less. The diameter of the rubber roller B (23) is preferably from 100 mm to 500 mm, particularly preferably from 200 mm to 400 mm.

The surface roughness Ra (μm) of the rubber roller B (23) is 0 or more and 5 or less, preferably 0.01 or more and 3 or less, more preferably 0.05 or more and 2 or less. Rz (μm) is 0 or more and 30 or less, preferably 0.05 or more and 20 or less, and more preferably 0.1 or more and 3 or less.

Thus, by reducing the surface roughness of the cooling roller B (22) and reducing the rubber hardness of the rubber roller B (23), the surface smoothness of the porous film 4 is improved and the second Air bubbles are prevented from entering the resin layer 3 and the uniformity of the second resin layer 3 is improved. The nip pressure between the cooling roller B (22) and the rubber roller B (23) is preferably about 2 MPa to 4 MPa, particularly about 2.5 MPa to 3.5 MPa. Moreover, the feed rate of the base material in the second step is preferably 20 m / min or more and 300 m / min or less.

Hereinafter, the preferred composition, preferred physical properties, preferred conditions for corona treatment, etc. of the substrate, each resin and the porous film will be described in detail.

[Base material]
Since the substrate 1 of the thermal transfer image receiving sheet is heated during thermal transfer, it is preferable to use a material having a mechanical strength that does not hinder handling even in a heated state. As such a base material, a paper base material is preferably used. As the paper substrate, either coated paper or non-coated paper can be used. For example, base paper, photographic base paper, high-quality paper, and the like can be used. For example, high-quality paper or art paper having a basis weight of 78 g / m ² or more and 400 g / m ² or less, preferably 100 g / m ² or more and 200 g / m ² or less can be used. In the present invention, by using uncoated paper as the base material, the cost can be reduced compared to when coated paper is used.

The thickness of the substrate is not particularly limited, but is preferably 50 μm or more and 300 μm or less, more preferably 100 μm or more and 250 μm or less, and further preferably 130 μm or more and 175 μm or less. If the thickness of the substrate is within the above range, the adhesion between the substrate and the porous film is improved without crushing the voids of the porous film, and the texture of the printed surface of the obtained thermal transfer image-receiving sheet is improved. Can be made.

The surface roughness Ra (μm) of the substrate is 0 or more and 10 or less, preferably 0.1 or more and 5 or less, and more preferably 0.1 or more and 3 or less. Rz (μm) is 0 or more and 50 or less, preferably 0.1 or more and 30 or less, and more preferably 1 or more and 20 or less.

[First and second resin layers]
The second resin layer 3 of the thermal transfer image receiving sheet is provided for bonding the substrate 1 and the porous film 4 together. The first resin layer 2 is provided for adjusting the curl balance of the thermal transfer image receiving sheet, and a writing layer may be provided for further providing writing properties. Each resin layer is formed of the melt-extruded resins 15 and 25 as described above. This resin is preferably a thermoplastic resin. Specifically, as a thermoplastic resin, a low density polyethylene resin, a medium density polyethylene resin, a high density polyethylene resin, a linear low density polyethylene resin, a copolymer of ethylene / α-olefin polymerized using a metallocene catalyst Resin, ethylene / polypropylene copolymer resin, ethylene / vinyl acetate copolymer resin, ethylene / acrylic acid copolymer resin, ethylene / ethyl acrylate copolymer resin, ethylene / methacrylic acid copolymer resin, ethylene / methacrylic acid resin Methyl acid copolymer resin, ethylene / maleic acid copolymer resin, ionomer resin, polyolefin resin are graft-polymerized or copolymerized with ester-forming monomers such as unsaturated carboxylic acid and unsaturated carboxylic acid anhydride Resin, for example, maleic anhydride graft modified with polyolefin resin And the like can be used. These materials can be used alone or in combination.

In the present invention, the melt-extruded resin is preferably a polyolefin resin having a melting point measured by JIS K7121 of 100 ° C. or higher and 170 ° C. or lower, and the first resin 15 is 115 ° C. or higher, more preferably 118 ° C. 167 ° C. or lower and the second resin 25 has a temperature of 105 ° C. or higher, more preferably 106 ° C. or higher and 120 ° C. or lower. preferable. From the viewpoint of improving the curl stability of the printed material and the texture of the surface of the printed material, the polyolefin resin used for the first resin 15 has a density measured by JIS K6760 of 0.89 g / cm ³ or more and 0.97 g / cm. ³ or less, preferably 0.930 g / cm ³ or more 0.965 g / cm ³ or less, more preferably preferably not more than 0.940 g / cm ³ or more 0.960 g / cm ^3, used for the second resin 25 polyolefin resins, the density measured by JIS K6760 is 0.89 g / cm ³ or more 0.93 g / cm ³ or less, preferably 0.90 g / cm ³ or more 0.93 g / cm ³ or less, more preferably 0. it is preferred 915 g / cm ³ or more 0.925 g / cm ³ or less.

A resin may be mixed and used so as to have these melting points and densities.

The thickness of the first resin layer 2 is preferably 10 μm or more and 50 μm or less, particularly preferably 20 μm or more and 30 μm or less, and the thickness of the second resin layer 3 is preferably 5 μm or more and 30 μm or less, particularly preferably 10 μm or more and 20 μm or less.

[Porous film]
The porous film 4 is preferably a porous film containing a polypropylene resin as a base resin and having fine voids inside. By providing a porous film layer made of a porous film having a thickness of the following range and containing a polypropylene resin, the adhesion between the substrate and the porous film can be improved without crushing the voids of the porous film. In addition, it is possible to improve the texture of the surface of the printed product of the obtained thermal transfer image-receiving sheet.

The thickness of the four porous film layers is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 80 μm or less, and further preferably 20 μm or more and 50 μm or less. The porous film preferably has a density measured by JIS K6922 of 0.1 g / cm ³ or more and 1.5 g / cm ³ or less, and 0.3 g / cm ³ or more and 1.0 g / cm ³ or less. Is more preferable.

As a method for generating fine voids in the film, a compound is prepared by kneading organic fine particles or inorganic fine particles (one kind or plural kinds) incompatible with the resin as the base of the film. Microscopically, this compound forms a fine sea-island structure with the base resin and fine particles incompatible with the base resin, and the compound is formed into a film and stretched to form the sea-island interface. The fine voids as described above are generated by the peeling of the film or the large deformation of the region forming the island.

As a method for forming the fine voids, for example, there is a method of adding polyester or acrylic resin mainly composed of polypropylene and having a melting point higher than that of polypropylene. In this case, polyester or acrylic resin serves as a nucleating agent that forms fine voids. In any case, the content of the polyester and acrylic resin is preferably 2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of polypropylene. When the content is 2 parts by mass or more, fine voids can be sufficiently generated, and the printing sensitivity can be further improved. Moreover, when content is 10 mass parts or less, the heat resistance of a porous film can fully be ensured.

When producing a porous film having polypropylene as the base resin, it is preferable to add polyisoprene in order to generate finer and dense voids. Thereby, higher printing sensitivity can be obtained. For example, a porous film having high printing sensitivity can be obtained by preparing a compound composed mainly of polypropylene, blended with acrylic resin or polyester, and polyisoprene, forming a compound, and stretching.

[Middle layer]
The intermediate layer 6 of the thermal transfer image-receiving sheet is provided between the color material receiving layer 7 and the porous film 4, and the adhesiveness, whiteness, cushioning, and concealment between the color material receiving layer 7 and the porous film 4. For the purpose of imparting properties, antistatic properties, anti-curling properties and the like. As the intermediate layer 6, various primer layers can be provided. The binder resin used in the primer layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl chloride- One or two kinds of vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, epoxy resin, cellulose resin, ethylene-vinyl acetate copolymer resin, polyethylene resin, polypropylene resin, etc. The above can be mentioned, and those having an active hydroxyl group among these resins can further be used as a cured product thereof.

It is preferable to add fillers such as titanium oxide, zinc oxide, magnesium carbonate, and calcium carbonate in order to impart whiteness and hiding properties. Furthermore, stilbene compounds, benzimidazole compounds, and benzoxazole compounds are added as fluorescent brightening agents to enhance whiteness, and hindered amine compounds and hindered phenol compounds are used to increase the light fastness of printed materials. Add compounds, benzotriazole compounds, benzophenone compounds, etc. as UV absorbers or antioxidants, or add cationic acrylic resins, polyaniline resins, and various conductive fillers to impart antistatic properties can do. The coating amount of the primer layer is preferably about 0.5 g / m ² or more and 5 g / m ² or less in a dry state. The primer layer and the like may be applied by the same method as that for forming the colorant receiving layer.

[Color material receiving layer]
The color material receiving layer 7 of the thermal transfer image receiving sheet is for receiving the sublimation dye transferred from the thermal transfer ink sheet and maintaining the formed image. Examples of the resin for forming the colorant receiving layer 7 include polycarbonate resin, polyester resin, polyamide resin, acrylic resin, cellulose resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, and chloride. One kind of vinyl-vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyurethane resin, polystyrene resin, polypropylene resin, polyethylene resin, ethylene-vinyl acetate copolymer resin, and epoxy resin, or the like Two or more types can be mentioned.

In order to improve releasability from the thermal transfer ink sheet, a release agent may be included in the colorant receiving layer 7. As release agents, solid waxes such as polyethylene wax, amide wax, fluororesin powder, fluorine or phosphate ester surfactants, various modified silicone oils such as silicone oil, reactive silicone oil, curable silicone oil, And various silicone resins. Silicone oil is preferred. An oily oil can be used as the silicone oil, but a modified silicone oil is preferred. As the modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, aralkyl-modified silicone oil, epoxy-aralkyl-modified silicone oil, alcohol-modified silicone oil, vinyl-modified silicone oil, urethane-modified silicone oil, etc. can be preferably used. Epoxy-modified silicone oil, aralkyl-modified silicone oil, and epoxy-aralkyl-modified silicone oil are particularly preferred. It is also preferable to use a combination of two or more of these release agents. The addition amount of these modified silicone oils is preferably 0.5% by mass or more and 30% by mass or less of the resin constituting the colorant receiving layer.

In forming the color material receiving layer 7, titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, fine powder silica, etc. are used for the purpose of improving the whiteness of the color material receiving layer and further enhancing the clarity of the transferred image. Pigments and fillers can be added. Plasticizers such as phthalic acid ester compounds, sebacic acid ester compounds, and phosphoric acid ester compounds may be added.

The colorant receiving layer 7 is composed of a thermoplastic resin and other necessary additives such as a mold release agent, a plasticizer, a filler, a crosslinking agent, a curing agent, a catalyst, a heat release agent, an ultraviolet absorber, and an antioxidant. And a coating solution in which a light stabilizer or the like is dissolved or dispersed in an organic solvent or water is applied and dried by a forming means such as a gravure printing method, a screen printing method, and a reverse roll coating method using a gravure plate. Can be formed. The coating amount of the thus colorant receiving layer thus formed is usually extent 0.5 g / ^{m 2} or more 50 g / ^{m 2} or less in the dry state, preferably 2 g / ^{m 2} or more 10 g / ^{m 2} or less. Such a colorant-receiving layer is preferably a continuous coating, but may be formed as a discontinuous coating.

[Release layer]
The thermal transfer image receiving sheet may further have a release layer on at least a part of the surface of the color material receiving layer 7. The release layer can be formed by applying the above release agent dissolved or dispersed in an appropriate solvent and then drying. Although it does not specifically limit as a mold release agent used for a mold release layer, The reaction hardened | cured material of an amino modified silicone oil and an epoxy modified silicone oil is preferable. The thickness of the release layer is preferably 0.01 μm or more and 5.0 μm or less, and more preferably 0.05 μm or more and 2.0 μm or less. The release layer can also be formed by using silicone oil when forming the colorant receiving layer and curing the silicone oil bleed out on the surface after application.

[Corona treatment conditions]
When the surfaces of the substrate 1 and the surface of the first resin layer 2 are processed by the corona discharge treatment machines 11, 20, and 21, the corona treatment conditions are 5 W / m ² · min to 50 W / m ² · min in particular. 10 W / ^{m 2} · min or more 30 W / ^m about ² · min is preferred. Incidentally, the corona treatment conditions is less than 5W / m 2 ^· min, corona treatment is insufficient, it is impossible to obtain improved effects of adhesion of the resin sufficiently, when higher than 50 W / m 2 ^· min Corona may become unstable.

≪Thermal transfer ink sheet≫
The thermal transfer image receiving sheet obtained by the production method of the present invention is used together with a thermal transfer ink sheet to form an image. The thermal transfer ink sheet preferably has a layer structure in which a heat transferable color material layer is provided on one surface of a base sheet and a heat resistant slipping layer is provided on the other surface of the base sheet. Hereinafter, each layer constituting the thermal transfer ink sheet will be described.

<Base material sheet>
As the material of the base sheet constituting the thermal transfer ink sheet, conventionally known materials can be used, and even other materials can be used as long as they have a certain degree of heat resistance and strength. be able to. For example, polyesters such as polyethylene terephthalate, polypropylene, polycarbonate, polyethylene, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyimide, nylon, cellulose acetate, resin films such as ionomer, paper such as condenser paper, paraffin paper, Nonwoven fabric etc. are mentioned. These may be used alone, or a laminate in which these are arbitrarily combined may be used. Among these, polyethylene terephthalate, which is an inexpensive general-purpose plastic that can be thinned, is preferable.

The thickness of the base sheet can be appropriately selected according to the material so that the strength, heat resistance and the like are appropriate, but usually it is preferably about 0.5 μm to 50 μm, more preferably 1 μm to 20 μm. More preferably, it is 1 μm or more and 10 μm or less.

The base sheet may be subjected to a surface treatment in order to improve adhesion with an adjacent layer. As the surface treatment, known resin surface modification techniques such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, plasma treatment, and grafting treatment are applied. can do. Only one type of the surface treatment may be applied, or two or more types may be applied.

It is also possible to apply and form an adhesive layer on the base sheet as an adhesive treatment of the base sheet. An adhesion layer can be formed from the following organic materials and inorganic materials, for example. Examples of the organic material include polyester resins, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylamide resins, polyamide resins, polyether resins, polystyrene resins, Examples thereof include polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinyl alcohol resins, polyvinyl pyrrolidone and vinyl resins such as modified products thereof, and polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral. Examples of the inorganic material include silica (colloidal silica), alumina or alumina hydrate (alumina sol, colloidal alumina, cationic aluminum oxide or hydrate, suspicion bakumaite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, oxidation Examples thereof include ultrafine particles of colloidal inorganic pigments such as magnesium and titanium oxide.

As the surface treatment, when a plastic film is stretched and manufactured, the primer solution can be applied to the unstretched film and then stretched.

<Heat transferable colorant layer>
The thermal transfer ink sheet is provided with a thermal transfer color material layer on one surface of a base sheet. When the thermal transfer ink sheet is a sublimation type thermal transfer ink sheet, a layer containing a sublimation dye is formed as the thermal transferable color material layer, and when the thermal transfer type thermal transfer ink sheet is a hot melt composition containing a colorant A layer containing a heat-meltable ink is formed. A layer region containing a sublimable dye and a layer region containing a heat-meltable ink composed of a heat-melting composition containing a colorant are provided in a surface sequence on a continuous base sheet. Also good.

As the material of the heat transferable color material layer, conventionally known dyes can be used, but those having good characteristics as a printing material, for example, having a sufficient coloring density and changing color due to light, heat, temperature, etc. Preferred are diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, indoaniline dyes, acetophenone azomethine, pyrazoloazomethine, imidazolazomethine, imidazoazomethine, pyridone Azomethine dyes such as azomethine, xanthene dyes, oxazine dyes, cyanostyrene dyes such as dicyanostyrene and tricyanostyrene, thiazine dyes, azine dyes, acridine dyes, benzeneazo dyes, pyridoneazo, thiophenazo, iso Thiazoleazo, pi Azo dyes such as azo azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, disazo, etc. And dyes. Specifically, red dye such as Disperse Red 60, Disperse Violet 26, CeresRed 7B, Samaron Red F3BS, yellow dyes such as Disperse Yellow 231, PTY-52, Macrolex Yellow 6G, Solvent Blue 63, Waxolin Blue AP-FW, Holon Brilliant Blue SR, MS Blue 100, C.I. I. And blue dyes such as Solvent Blue 22. In addition, the dye contained in the ribbon used by the sublimation type thermal transfer system marketed can also be used.

Examples of the binder resin for supporting the dye include cellulose resins such as ethyl cellulose resin, hydroxyethyl cellulose resin, ethyl hydroxy cellulose resin, methyl cellulose resin, and cellulose acetate resin, polyvinyl alcohol resin, polyvinyl acetate resin, and polyvinyl butyral resin. And vinyl resins such as polyvinyl acetal resin and polyvinyl pyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, and polyester resins. Among these, cellulose-based, vinyl-based, acrylic-based, polyurethane-based, and polyester-based resins are preferable from the viewpoints of heat resistance, dye transferability, and the like.

Examples of the method for forming the heat transferable color material layer include the following methods. For the heat-transferable colorant layer obtained by adding additives such as a release agent to the dye and binder resin as necessary, dissolving in an appropriate organic solvent such as toluene and methyl ethyl ketone, or dispersing in water. A coating solution (dissolved solution or dispersion) is applied to one surface of a substrate sheet by, for example, a gravure printing method, a reverse roll coating method using a gravure plate, a roll coater, a bar coater, etc., and dried. Let The heat transferable color material layer has a thickness of about 0.2 μm or more and 5.0 μm or less, and the content of the sublimable dye in the heat transferable color material layer is preferably 5% by mass or more and 90% by mass or less. 5 mass% or more and 70 mass% or less are more preferable.

<Protective layer>
The thermal transfer ink sheet may be provided with a protective layer in the surface order on the same side as the thermal transferable color material layer. After the color material is transferred to the thermal transfer image-receiving sheet, the protective layer is transferred to cover the image, whereby the image can be protected from light, gas, liquid, abrasion and the like. Other layers such as an adhesive layer, a release layer, or an undercoat layer may be provided as a protective layer.

<Heat resistant slip layer>
A heat resistant slipping layer is formed on the surface of the base sheet opposite to the heat transferable color material layer.

The heat resistant slipping layer is mainly composed of a heat resistant resin. The heat-resistant resin is not particularly limited. For example, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer resin, polyether resin, polybutadiene resin, styrene-butadiene copolymer resin, Acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetate propionate resin, cellulose acetate butyrate resin, cellulose acetate-hydrodiene Phthalate resin, cellulose acetate resin, aromatic polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, Fine chlorinated polyolefin resins.

The heat resistant slipping layer may be formed by blending additives such as a slipperiness imparting agent, a crosslinking agent, a release agent, an organic powder, and an inorganic powder in addition to the above heat resistant resin.

The heat resistant slipping layer is generally a coating solution for the heat resistant slipping layer by adding the above-mentioned heat resistant resin, and optionally adding the above-mentioned slipperiness imparting agent and additives to the solvent and dissolving or dispersing each component. Then, the coating solution for heat resistant slipping layer can be applied on a base sheet and dried. As the solvent in the heat-resistant slipping layer coating solution, the same solvent as the solvent in the heat transferable colorant layer coating solution described above can be used.

Examples of the coating method for the coating solution for the heat resistant slipping layer include wire bar coating, gravure printing, screen printing, reverse roll coating using a gravure plate, and gravure coating is particularly preferable. The heat-resistant slipping layer coating solution may be applied so that the dry coating amount is preferably 0.1 g / m ² or more and 3 g / m ² or less, more preferably 1.5 g / m ² or less.

≪Image formation method≫
In the image forming method using the thermal transfer image receiving sheet obtained by the production method according to the present invention, the thermal transfer image receiving sheet and the thermal transfer ink sheet containing the thermal diffusible dye are superposed and heated according to the recording signal, An image can be formed by transferring the thermal diffusible dye contained in the thermal transfer ink sheet to the thermal transfer image receiving sheet. In the present invention, an image can also be formed by high-speed printing. Here, the high-speed printing is 0.5 msec / line or more and 3.0 msec / line or less. Note that msec / line is the time (msec) required to print one line with the thermal printer.

As the thermal transfer recording apparatus that can be used in such an image forming method, a known apparatus can be used and is not particularly limited. In the present invention, a commercially available thermal transfer recording apparatus can be used, and examples thereof include a sublimation thermal transfer printer (manufactured by ALTECH ADS (model: MEGAPICEL III), manufactured by DNP Photolcio (model: DS40)).

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Example 1]
[Manufacture of support for thermal transfer image-receiving sheet]
White base paper (uncoated paper, thickness 150 μm, manufactured by Mitsubishi Paper Industries Co., Ltd.), which is a paper base material, is prepared as a base material layer, and a porous polypropylene film (thickness) is used as the porous film forming the porous film layer. is 38 [mu] m, was prepared density 0.7g / cm ^3).

As the first resin 15, a polyethylene resin (melting point measured by JISK7121: 120 ° C., density 0.95 g / cm ³ measured by JISK6760) was used. As the second resin, a polyethylene resin (melting point measured by JISK7121: 107 ° C., density measured by JISK6760: 0.919 g / cm ³ ) was used.

The temperature of the resin extruded from the die was 320 ° C. for both the first resin and the second resin.

As the cooling roller A (12), one having a diameter of 600 mm and a surface 10-point average roughness (Rz) of 16 μm was used, and the temperature was set to 28 ° C. As the rubber roller A (13), a normal rubber layer (rubber hardness 85) and a conductive silicone rubber layer (rubber hardness 80) were used. The nip pressure between the cooling roller A (12) and the rubber roller A (13) was 4.0 MPa.

As the cooling roller B (22), one having a diameter of 600 mm and a surface 10-point average roughness (Rz) of 1.7 μm was used, and the temperature was set to 28 ° C. As the rubber roller B (23), a normal rubber layer (rubber hardness 70) and a conductive silicone rubber layer (rubber hardness 70) were used. The nip pressure between the cooling roller B (22) and the rubber roller B (23) was 2.0 MPa.

The substrate transfer speed is 80 m / min, the corona treatment condition is 20 w / m ² · min, and the first and second steps are performed as shown in FIGS. Manufactured. The thickness of the first resin layer 2 of the thermal transfer image-receiving sheet support 5 was 30 μm, and the thickness of the second resin layer 3 was 15 μm.

[Manufacture of thermal transfer image-receiving sheet]
Subsequently, on the porous polypropylene film 4 of the obtained support 5 for the thermal transfer image-receiving sheet, a primer layer coating solution having the following composition was applied with a gravure coater so as to be ² g / m ² after drying, After drying at 110 ° C. for 1 minute, a coating material for a colorant receiving layer having the following composition was applied thereon with a gravure coater so as to be 4 g / m ^2, and dried at 110 ° C. for 1 minute. An intermediate layer 6 and a colorant receiving layer 7 were formed to obtain a thermal transfer image receiving sheet 8.

<Composition of primer layer coating solution>
Polyester resin (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: WR-905): 13.1 parts by mass Titanium oxide (manufactured by Tochem Products, trade name: TCA-888): 26.2 parts by mass Whitening agent (benzimidazole derivative, Ciba Specialty Chemicals Co., Ltd., trade name: Ubitex BAC): 0.39 parts by mass Water / isopropyl alcohol (mass ratio 2/1): 60 parts by mass

<Composition of coating liquid for colorant receiving layer>
Vinyl chloride-vinyl acetate copolymer (manufactured by Nissin Chemical Industry Co., Ltd., trade name: Solvain C): 60 parts by mass Epoxy-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-3000T) : 1.2 parts by mass Methylstill-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: 24-510): 0.6 parts by mass Methyl ethyl ketone / toluene (mass ratio 1/1): 5 parts by mass

[Examples 2 to 8, Comparative Examples 1 to 5]
Table 10 shows the ten-point average roughness (Rz) of the surfaces of the cooling roller A (12) and the cooling roller B (22) and the rubber hardness of the rubber roller B (13) and the rubber roller B (23). A thermal transfer image-receiving sheet was produced under the same conditions as shown in Table 1 except that the following (i) to (iii) were followed. The conditions of the corona discharge treatment machines 11, 20, and 21 are as shown in Table 1.

(i) Examples 1 to 5 and 8, and Comparative Examples 1 to 5 were produced as in the first embodiment.
(ii) For Example 6, in the second step of the first embodiment, a porous film previously coated with a gravure coater in the order of a primer layer and a colorant receiving layer was used.
(iii) Example 7 was manufactured as in the second embodiment.

[Characteristic evaluation]
Regarding the thermal transfer image-receiving sheets produced in each of the above examples and comparative examples, the glossiness, haulability, presence / absence of bubbles in the resin layer 3, uniformity of the resin layer 3, and surface smoothness of the porous film 4 layers are as follows. Measurement and evaluation were conducted as described above, and the results are shown in Table 1.

Dispersion: 100 natural images were printed using a thermal transfer printer (DNP Photo Lucio DS40). The 100 sheets were bundled, and one side was put on a desk and uniformly arranged.
○: Easily aligned.
X: Not aligned.

Uniformity of first resin layer 2: The surface smoothness of the back surface of the thermal transfer image-receiving sheet was visually observed.
A: A very uniform pattern was observed.
○: A uniform pattern was observed.
Δ: A somewhat uniform pattern was observed.
X: A nonuniform pattern was observed.

Presence / absence of bubbles in the second resin layer 3: In the second step, the porous film 4, the resin 25, and the first laminate 16 are overlapped, and the space between the cooling roller B (22) and the rubber roller B (23) is overlapped. We confirmed the occurrence of wrinkles and air smears when passing under a narrow pressure.
○: Wrinkles and air were not smeared and uniform.
X: Wrinkles and air spots were generated.

Surface smoothness of porous film layer: The surface smoothness of the porous film layer of the manufactured thermal transfer image-receiving sheet was visually evaluated.
○: Uniform.
X: A bumpy protrusion appeared on the surface.

[Discussion]
As shown in Table 1, Examples 1 to 8 are excellent in glossiness and glaring properties, have no bubbles in the resin layer 3, and are excellent in the uniformity of the resin layer 3 and the surface smoothness of the porous film layer. On the other hand, in Comparative Example 1, nonuniformity occurred on the surface of the thermal transfer image receiving sheet.
In Comparative Example 2, air was blown when the second process proceeded, and wrinkles were generated.
In Comparative Example 3, the printability of the printed material was insufficient.
In Comparative Example 4, bumpy protrusions appeared on the surface of the thermal transfer image receiving sheet.
In Comparative Example 5, nonuniformity occurred on the surface of the thermal transfer image receiving sheet.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2015-059675 filed on Mar. 23, 2015 and Japanese Patent Application No. 2016-052520 filed on Mar. 16, 2016, which is incorporated by reference in its entirety. .

DESCRIPTION OF SYMBOLS 1 Base material 2 1st resin layer 3 2nd resin layer 4 Porous film 5 Support body for thermal transfer image receiving sheets 6 Intermediate layer 7 Color material receiving layer 8 Thermal transfer image receiving sheets 11, 20, 21 Corona discharge processor 12, 22 Cooling rollers A and B
13, 23 Rubber roller A, B
14, 24 Die 15 1st resin 16 1st laminated body 25 2nd resin

Claims (8)

1. A method for producing a support for a thermal transfer image receiving sheet, in which a first resin layer is provided on one surface of a substrate and a porous film layer is provided on the other surface via a second resin layer,
   A first step of supplying a first resin to one surface side of the substrate and passing between a cooling roller A and a rubber roller A to form the first resin layer;
   A porous film is superimposed on the other surface of the base material on which the first resin layer is formed via a second resin, and is passed between the cooling roller B and the rubber roller B, and the second resin layer And a method for producing a support for a thermal transfer image-receiving sheet having a second step of forming a porous film layer, or
   A porous film is superimposed on one surface side of the base material via a second resin and passed between the cooling roller B and the rubber roller B to form the second resin layer and the porous film layer. The first resin is supplied to the other surface side of the base material on which the second resin layer and the porous film layer are formed, and is passed between the cooling roller A and the rubber roller A to A second step of forming one resin layer;
   In any of the methods for producing a support for a thermal transfer image receiving sheet having:
   The ten-point average roughness (Rz) of the surface of the cooling roller A is 5 μm or more and 30 μm or less,
   The ten-point average roughness (Rz) of the surface of the cooling roller B is 0 μm or more and 3.0 μm or less,
   The rubber hardness of the rubber roller A measured by a durometer (type A) is 60 or more and 95 or less,
   A method for producing a thermal transfer image-receiving sheet support, wherein the rubber hardness of the rubber roller B is 50 or more and 80 or less as measured by a durometer (type A).
2. 2. The support for a thermal transfer image receiving sheet according to claim 1, wherein the thickness of the first resin layer is 10 μm or more and 50 μm or less, and the thickness of the second resin layer is 5 μm or more and 30 μm or less. Production method.
3. The method for producing a support for a thermal transfer image receiving sheet according to claim 1 or 2, wherein the thickness of the porous film layer is 10 µm or more and 100 µm or less.
4. The method for producing a thermal transfer image-receiving sheet support according to any one of claims 1 to 3, wherein the first resin layer is formed after corona treatment of one surface of the substrate. .
5. The said 2nd resin layer is formed, after corona-treating the surface in which the said 1st resin layer of the said base material is not formed, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. Manufacturing method for thermal transfer image-receiving sheet.
6. The cooling roller A is in contact with the first resin layer;
   The rubber roller A is in contact with the surface of the base material on which the first resin layer is not formed,
   The cooling roller B is in contact with the porous film layer;
   The method for producing a thermal transfer image receiving sheet support according to any one of claims 1 to 5, wherein the rubber roller B is in contact with the first resin layer.
7. A color material receiving layer is further laminated via an intermediate layer on the porous film layer of the support for a thermal transfer image receiving sheet obtained by the production method according to any one of claims 1 to 6. A method for producing a thermal transfer image receiving sheet.
8. The method for producing a thermal transfer image receiving sheet according to claim 7, wherein the intermediate layer is a primer layer containing a binder resin.

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