JP2008137257A - Heat transfer image receiving sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat transfer image receiving sheet which prevents an image receiving face from being influenced caused by friction of the heat transfer image receiving sheets each other, is excellent in writing suitability and adhesiveness to a stamp or the like, and has mold releasabilities and stain resistance. <P>SOLUTION: The heat transfer image receiving sheet which forms a dye receiving layer on at least one face of a substrate sheet, has the constitution that the face of the substrate sheet on the opposite face of the face which has the dye receiving layer has a back face layer comprising a thermoplastic resin and a cellulose filler. By forming such a constitution as this, the writing suitability and the adhesiveness on the stamp or the like is excellent especially on the back face layer, and the back face layer has such functions as an appropriate slip properties, the mold releasabilities (the mold releasabilities from the heat transfer sheet when the surface and the back face are reversely inserted into a printer by mistake), and the stain resistance. In addition, the influences to the image receiving face caused by scuffing between the back face layer and the dye receiving layer (deterioration in image quality such as generation of stripes and fluctuation) caused by the heat transfer image receiving sheets each other can be prevented from occurring. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal transfer image-receiving sheet, more specifically, in a thermal transfer image-receiving sheet provided with a sublimable dye-receiving layer on at least one surface of a base material sheet, preventing the influence on the image-receiving surface due to friction between thermal transfer image-receiving sheets, The present invention relates to a thermal transfer image-receiving sheet that is excellent in writability and adhesiveness such as stamps, and has appropriate slipperiness, releasability and stain resistance in the back layer.

  Conventionally, in a thermal transfer image receiving sheet, a color material receiving layer is provided on the surface to improve the acceptability and retention of a color material such as a dye, and at the same time, the back side of the thermal transfer image receiving sheet is transported such as automatic paper supply and discharge in a printer. In order to improve the performance, to prevent the thermal transfer sheet and the image-receiving sheet from being fused when the image-receiving sheet is inserted into the printer by mistake, and when the image-receiving sheet after printing is stored in an overlapping manner In addition, for the purpose of preventing dyes, etc. from moving to the back side and lowering the image density on the front side or contaminating the back side, the back side is provided with appropriate slipperiness, releasability and stain resistance. It has been practiced to provide a back surface layer for this purpose.

  In recent years, the need to use the thermal transfer image-receiving sheet as a postcard such as a picture postcard has increased, and on the surface of the image-receiving sheet, for example, a color image such as a photograph is thermally transferred, and on the back surface, in addition to the above performance, In order to write an address, a sent message, or affix a stamp, it has become necessary to add writing ability and adhesiveness to the stamp. As a method for meeting such needs, for example, Patent Document 1 proposes a thermal transfer image-receiving sheet containing polyvinyl butyral resin and hydrophilic porous microsilica as a back layer. Patent Document 2 discloses a thermal transfer image receiving sheet in which the back layer contains nylon resin particles, barium sulfate, and a higher fatty acid salt. Moreover, in patent document 3, it is shown that a back surface layer contains a cellulose acetate resin and micro silica as a main component.

  In these patent documents, an inorganic filler such as silica or barium sulfate is included in the outermost surface of the back surface layer. However, the friction between the heat transfer image receiving sheets is strong due to the paper supply / discharge in the printer, and the influence on the image receiving surface ( Image quality such as streaks and unevenness) is likely to occur. Moreover, in patent document 4, the hydrophilic porous layer which has a thermoplastic resin and a hydrophilic porous particle as a main component as a 1st layer is formed in the back surface side of the base material sheet | seat of a thermal transfer image receiving sheet, and also on it. A layer in which a back coating layer containing a polyvinyl acetal resin, a silicone-modified acrylic resin and nylon resin particles is formed as a second layer has been proposed. However, the thermal transfer image-receiving sheet shown in Patent Document 4 is not satisfactory in writing ability and adhesiveness of stamps, and is manufactured in order to provide two layers containing particles on the back surface of the substrate. There is a problem with low productivity.

JP-A-9-175048 JP 2000-335120 A JP-A-8-244362 JP 2002-337463 A

  Therefore, in order to solve the above problems, the influence on the image receiving surface due to the friction between the thermal transfer image receiving sheets is prevented, the writing property and the adhesiveness such as stamps are excellent, and the moderate slipping property, releasability, An object of the present invention is to provide a thermal transfer image-receiving sheet having a contamination property.

  The invention according to claim 1 is a thermal transfer image-receiving sheet in which a dye-receiving layer is formed on at least one surface of a substrate sheet, on the surface of the substrate sheet opposite to the surface on which the dye-receiving layer is formed, A back layer containing a thermoplastic resin and a cellulose filler is formed. The invention according to claim 2 is characterized in that a back surface intermediate layer is formed between the base material sheet according to claim 1 and the back surface layer.

  The invention according to claim 3 is characterized in that the back layer according to claim 1 or 2 further contains a filler selected from polyolefin resin, polyamide resin, zinc stearate, calcium carbonate, and kaolin. As for invention of Claim 4, the average particle diameter of the cellulose filler in the back surface layer in any one of Claims 1-3 is 5-20 micrometers, and mass ratio of the cellulose filler / thermoplastic resin in a back surface layer is. It is 0.5-3.0.

  In the thermal transfer image-receiving sheet of the present invention, a dye-receiving layer is formed on at least one surface of the substrate sheet, and a thermoplastic resin and a cellulose filler are formed on the surface of the substrate sheet opposite to the surface on which the dye-receiving layer is formed. By having a configuration in which the back layer is formed, it is particularly excellent in writing ability and adhesiveness such as stamps in the back layer, and also has moderate slipperiness and releasability in the back layer (printing the wrong side of the thermal transfer image receiving sheet by mistake) (Releasability from the thermal transfer sheet when inserted in the resin) and anti-contamination function. Furthermore, the friction between the thermal transfer image receiving sheets affects the image receiving surface due to rubbing between the back surface layer and the dye receiving layer (streak, It was possible to prevent deterioration in image quality such as unevenness.

Hereinafter, each layer constituting the thermal transfer image receiving sheet of the present invention will be described in detail.
(Substrate sheet)
As the base sheet used in the present invention, synthetic paper (polyolefin, polystyrene, etc.), fine paper, art paper, coated paper, cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex Various plastic films or sheets such as impregnated paper, synthetic resin internal paper, cellulose fiber paper such as paperboard, polyolefin (polyethylene, polypropylene, etc.), polystyrene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, polymethacrylate, etc. can be used. In addition, a white opaque film formed by adding a white pigment or a filler to these synthetic resins, or a film having fine voids (microvoids) inside the substrate can be used, and is not particularly limited. Moreover, the laminated body by the arbitrary combinations of the said base material sheet can also be used.

  Examples of typical laminates include a laminate of cellulose fiber paper and synthetic paper, or cellulose fiber paper and a plastic film or sheet. The thickness of these base material sheets may be arbitrary, for example, the thickness of about 10-300 micrometers is common. When the base sheet as described above has poor adhesion to the receiving layer formed on the surface thereof, it is preferable to subject the surface to easy adhesion treatment such as primer treatment, corona discharge treatment or plasma treatment. Further, the thermal transfer image receiving sheet of the present invention can be applied to various uses such as a thermal transfer sheet capable of thermal transfer recording, cards, and a transmissive original document sheet by appropriately selecting a substrate sheet.

(Dye-receiving layer)
The dye receiving layer in the thermal transfer image receiving sheet of the present invention is for receiving the sublimation dye transferred from the thermal transfer sheet and maintaining the formed image. As the resin for forming the receiving layer, polycarbonate resin, polyester resin, polyamide resin, acrylic resin, cellulose resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-acetic acid Examples thereof include vinyl copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyurethane resins, polystyrene resins, polypropylene resins, polyethylene resins, ethylene-vinyl acetate copolymer resins, and epoxy resins.

  The thermal transfer image-receiving sheet of the present invention can contain a release agent in the receiving layer in order to improve the releasability from the thermal transfer sheet. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder, fluorine-based or phosphate-based surfactant, silicone oil, various silicone resins, and the like. Silicone oil is preferable. . An oily oil can be used as the silicone oil, but a curable oil is preferred. Examples of the curable silicone oil include a reaction curable type, a photo curable type, and a catalyst curable type, and a reaction curable type and a catalyst curable type silicone oil are particularly preferable.

  As the reactive silicone oil, those obtained by reaction-curing amino-modified silicone oil and epoxy-modified silicone oil are preferable. As amino-modified silicone oil, KF-393, KF-857, KF-858, X-22-3680 are used. X-22-3801C (above, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like, and epoxy-modified silicone oils such as KF-100T, KF-101, KF-60-164, KF-103 (above, Shin-Etsu Chemical) Etc.). Examples of the catalyst curable silicone oil include KS-705, FKS-770, and X-22-1212 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  The addition amount of these curable silicone oils is preferably 0.5 to 30% by mass of the resin constituting the receiving layer. Alternatively, the release agent layer may be provided by partially dissolving and dispersing the release agent in a suitable solvent on the surface of the receptor layer and then drying. As the release agent constituting the release agent layer, the reaction cured product of the amino-modified silicone oil and the epoxy-modified silicone oil described above is particularly preferable, and the thickness of the release agent layer is 0.01 to 5.0 μm, particularly 0.05-2.0 micrometers is preferable. When forming the receptor layer by adding silicone oil, the release agent layer can be formed even if the silicone oil bleed out on the surface after application is cured. In the formation of the receiving layer, pigments such as titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, fine powder silica and the like are used for the purpose of improving the whiteness of the receiving layer and further enhancing the clarity of the transferred image. Fillers can be added. Further, a plasticizer such as a phthalic acid ester compound, a sebacic acid ester compound, or a phosphoric acid ester compound may be added.

The thermal transfer image-receiving sheet of the present invention has a thermoplastic resin as described above and other necessary additives such as a mold release agent, a plasticizer, a filler, a crosslinking agent, and a curing agent on at least one surface of the base sheet. , A catalyst, a heat release agent, an ultraviolet absorber, an antioxidant, a light stabilizer, and the like are dissolved in a suitable organic solvent, or a dispersion dispersed in an organic solvent or water is used, for example, a gravure printing method It is obtained by applying and drying by a forming means such as a screen printing method or a reverse roll coating method using a gravure plate to form a dye receiving layer. Application of an intermediate layer, a back surface layer, a back surface intermediate layer, and the like, which will be described later, is also performed by the same method as that for forming the dye receiving layer. The coating amount of the thus formed are dye-receiving layer, usually, 0.5 to 50 g / m ² approximately in the dry state, preferably 2 to 10 g / m ^2. Such a dye-receiving layer is preferably a continuous coating, but may be formed as a discontinuous coating.

(Middle layer)
Between the receiving layer and the substrate sheet, any conventionally known intermediate is used to provide adhesion, whiteness, cushioning, concealing property, antistatic property, anti-curling property, etc. between the receiving layer and the substrate sheet. A layer can be provided. The binder resin used for the intermediate layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl chloride- Examples include vinyl acetate copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, epoxy resins, cellulose resins, ethylene-vinyl acetate copolymer resins, polyethylene resins, polypropylene resins, and the like. Of these, those having an active hydroxyl group can further be used as a cured product thereof.

Moreover, it is preferable to add fillers such as titanium oxide, zinc oxide, magnesium carbonate, and calcium carbonate in order to impart whiteness and concealability. In addition, stilbene compounds, benzimidazole compounds, benzoxazole compounds, etc. are added as fluorescent brighteners to enhance whiteness, and hindered amine compounds, hindered phenol compounds to enhance the light resistance of printed materials. Benzotriazole compounds, benzophenone compounds, etc. may be added as UV absorbers or antioxidants, or cationic acrylic resins, polyaniline resins, various conductive fillers, etc. may be added to impart antistatic properties. it can. The coating amount of the intermediate layer is preferably about 0.5 to 30 g / m ^{2 in} a dry state.

(Back layer)
In the thermal transfer image receiving sheet of the present invention, a back layer is provided on the surface of the base sheet opposite to the surface on which the dye receiving layer is provided. The back layer of the present invention has writing ability and adhesiveness such as stamps, and also has moderate slipperiness and releasability (releasability from the heat transfer sheet when the front and back sides of the heat transfer image-receiving sheet are mistakenly inserted into the printer). It has the function of stain resistance (dye contamination from the dye image formed on the dye receiving layer), and furthermore, the friction between the thermal transfer image receiving sheets affects the image receiving surface due to rubbing between the back layer and the dye receiving layer ( (Deterioration in image quality such as stripes and unevenness) is prevented. The structure of the back surface layer exhibiting this function contains a thermoplastic resin, a cellulose filler, and a thermoplastic resin as a binder resin.

  The cellulose filler contained in the back layer is a kind of carbohydrate, which is a main component of plant cells and fibers, and is a powder of cellulose, which is a natural polymer substance. It does not dissolve in water or hot water. The cellulose filler used in the present invention preferably has an average particle size of 5 to 20 μm. When the particle size is too small, the drying property in writing of water-based ink or the like is lowered, and the slipping property and the release property are likely to be lowered. On the other hand, if the particle size is too large, bleeding tends to occur at the time of writing, or the influence of image quality degradation such as streaks or unevenness on the image receiving surface due to rubbing between the back surface layer and the dye receiving layer tends to occur. Regarding the average particle size of the cellulose filler in the present invention, the average particle size was calculated on the basis of a volume based on a laser diffraction scattering method (microtrack method), and specifically measured with a microtrack particle size distribution measuring device manufactured by Nikkiso Co., Ltd. Is.

  The ratio of adding the cellulose filler in the back layer is preferably 0.5 to 3.0 in terms of the weight ratio of cellulose filler / thermoplastic resin to the thermoplastic resin of the binder resin in the back layer. When the addition ratio of the cellulose filler is too small, the drying property in writing of water-based ink or the like is lowered, and the slipping property and the release property are likely to be lowered. On the other hand, if the cellulose filler is added too much, the film strength of the back layer is lowered, the fixability of the ink to be written is lowered, or the ink to be written is liable to spread.

  The thermoplastic resin that is the binder resin in the back layer includes resins such as polyvinyl acetal, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl butyral, cellulose acetate, nitrile cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, starch, gelatin, and water-soluble Examples thereof include acrylic resins, water-soluble polyester resins, water-soluble urethane resins, mixtures and copolymers thereof, and vinyl acetate resin emulsions and vinyl chloride-vinyl acetate copolymer resin emulsions. In the back layer of the present invention, among the above binder resins, polyvinyl alcohol, water-soluble acrylic resin, water-soluble polyester resin, and water-soluble urethane resin are preferable because they easily exhibit the functions of the back layer such as writing suitability.

  In addition, in the back layer, in addition to the cellulose filler and thermoplastic resin described above, a filler selected from polyolefin resin, polyamide resin, zinc stearate, calcium carbonate, and kaolin is further included, thereby automatically feeding and discharging paper in the printer. Thus, it is possible to improve the slipperiness such as the thermal transfer sheet when the front and back sides of the thermal transfer image receiving sheet are erroneously inserted into the printer. Examples of the polyolefin resin filler include polyethylene wax filler and polypropylene wax filler, which can be used. When the back surface layer contains a filler selected from the above polyolefin resin, polyamide resin, zinc stearate, calcium carbonate, and kaolin, only one type of the various fillers described above, or each filler of polyethylene wax and polyamide resin It is also possible to contain two or more different types of fillers.

  Among the various fillers described above, the filler of polyethylene wax and the filler of zinc stearate are particularly excellent in releasability from the thermal transfer sheet when the front and back sides of the thermal transfer image-receiving sheet are mistakenly inserted into the printer. In addition, each filler of polyamide resin, calcium carbonate, and kaolin is excellent in slipperiness such as automatic paper supply / discharge in a printer.

(Back layer)
In the thermal transfer image-receiving sheet of the present invention, a back surface intermediate layer can be provided between the base material sheet and the back surface layer, if necessary, when the adhesion between the both is low. Any conventionally known intermediate layer can be provided for the purpose of imparting adhesiveness, whiteness, cushioning property, concealing property, antistatic property, anticurling property, etc. between the back surface layer and the substrate sheet. The binder resin used for the intermediate layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl chloride- Examples thereof include vinyl acetate copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, epoxy resins, cellulose resins, ethylene-vinyl acetate copolymer resins, polyethylene resins, and polypropylene resins.

Among the binder resins described above, for the binder resin having an active hydroxyl group, an isocyanate can be further added to use the cured isocyanate as a binder. The coating amount of the back surface intermediate layer is preferably about 0.5 to 30 g / m ^{2 in} a dry state.

Next, an Example and a comparative example are given and this invention is explained in full detail. In the text, “part” or “%” is based on mass unless otherwise specified. As a base material sheet, on a transparent polyethylene terephthalate film (Lumirror T60, # 25, manufactured by Toray Industries, Inc.), an intermediate layer coating solution having the following composition is wire bar coated to a dry coating amount of 2.0 g / m ² . The intermediate layer was formed by coating and drying. On the intermediate layer, a dye receptive layer coating solution having the following composition was applied by wire bar coating so that the dry coating amount was 4.0 g / m ² and dried to form a dye receptive layer.

<Intermediate layer coating solution>
Polyurethane resin (Nippon Polyurethane Industry Co., Ltd., NIPPON 5199) 25.0 parts Titanium oxide (Tochem Products, TCA-888) 75.0 parts Methyl ethyl ketone / toluene (mass ratio 1: 1) 400.0 parts

<Dye-receiving layer coating solution>
Vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Industry Co., Ltd., Solvein C) 100.0 parts Epoxy-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd., X-22-3000T) 5.0 parts methyl ethyl ketone / Toluene (mass ratio 1: 1) 400.0 parts

On the other surface of the base sheet on which the intermediate layer and the dye receiving layer are formed, a back surface intermediate layer coating solution having the following composition is coated by wire bar so that the dry coating amount is 2.0 g / m ^2. Application and drying were carried out to form a back surface intermediate layer. On the back surface intermediate layer, a back surface layer coating solution having the following composition was applied by wire bar coating to a dry coating amount of 3.0 g / m ² and dried to form a back surface layer. 1 thermal transfer image-receiving sheet was prepared.

<Back surface intermediate layer coating solution>
Polyurethane resin (Nippon Polyurethane Industry Co., Ltd., Nippon Run 5199) 5 parts Isocyanate curing agent (Takeda Pharmaceutical Co., Ltd., Takenate A-14) 10 parts Methyl ethyl ketone / toluene / isopropyl alcohol (mass ratio 2: 2: 1) 70 copies

<Back layer coating solution 1>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) ), W10MG, average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts The average particle size of the above polyethylene wax filler is measured by the Coulter counter method. The average particle diameters of the polyethylene wax filler and the polypropylene wax filler described below are all measured by the Coulter counter method.

A thermal transfer image receiving sheet of Example 2 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 2>
Acrylic polyol resin (Nippon Pure Chemicals Co., Ltd., Jurimer AT613) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) ), W10MG, average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 3 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 3>
Styrene-butadiene rubber (manufactured by Nippon Zeon Co., Ltd., LX407F8B) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) Manufactured, W10MG, average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 4 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 4>
Polyester resin (Toyobo Co., Ltd., Vylonal MD1480) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) W10MG, average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 5 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 5>
Urethane-modified copolymer polyester resin (Dainippon Ink Chemical Co., Ltd., AP40) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Japan) Paper Manufacturing Chemical Co., Ltd., W10MG, average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 6 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 6>
Urethane-modified copolyester resin (manufactured by Nikka Chemical Co., Ltd., Neo Sticker 1200) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Japan) Paper Manufacturing Chemical Co., Ltd., W10MG, average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image-receiving sheet of Example 7 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 7>
Vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Industry Co., Ltd., ViniBran 601) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose Filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 10.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

In the thermal transfer image receiving sheet produced in Example 1, the thermal transfer image receiving sheet of Example 8 was produced in the same manner as in Example 1 except that the back layer had the following composition.
<Back layer coating solution 8>
Polyvinyl alcohol resin (manufactured by Otsuka Kogyo Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W100, average particle size 3 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) ), W10MG, average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 9 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 9>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Zinc stearate filler (manufactured by Chukyo Yushi Co., Ltd., F930) 10.0 parts Cellulose filler (manufactured by Nippon Paper Chemicals Co., Ltd., W10MG) (Average particle size 10 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

The thermal transfer image receiving sheet of Example 10 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back layer coating solution 10>
Polyvinyl alcohol resin (manufactured by Oil & Fat Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Nylon 12 filler (Shinto Chemical Co., Ltd.) MW330) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 10.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 290.0 parts

A thermal transfer image receiving sheet of Example 11 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 11>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Calcium carbonate filler (manufactured by PMMA Tech, FMT100) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 10.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 290.0 parts

A thermal transfer image receiving sheet of Example 12 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 12>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Firing kaolin filler (Takehara Chemical Industries ( Co., Ltd., Santeton 5) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 10.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 290.0 parts

A thermal transfer image receiving sheet of Example 13 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 13>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Wet kaolin filler (Takehara Chemical Industries ( ASP 170) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 10.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 290.0 parts

A thermal transfer image receiving sheet of Example 14 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back layer coating solution 14>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) ), W06MG, average particle size 6 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 15 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 15>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) ), W10MG, average particle size 10 μm) 5.0 parts water / isopropyl alcohol (mass ratio 1: 1) 183.3 parts

A thermal transfer image receiving sheet of Example 16 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 16>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 15.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 183.3 parts

A thermal transfer image receiving sheet of Example 17 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 17>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Cellulose filler (manufactured by Nippon Paper Chemicals Co., Ltd., W10MG, average particle size 10 μm) 20.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 18 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 18>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 30.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 290.0 parts

  A thermal transfer image-receiving sheet of Example 19 was prepared in the same manner as in Example 16 except that the back surface intermediate layer was removed from the thermal transfer image-receiving sheet prepared in Example 16.

  A thermal transfer image receiving sheet of Example 20 was prepared in the same manner as in Example 17 except that the back surface intermediate layer was removed from the thermal transfer image receiving sheet prepared in Example 17.

A thermal transfer image receiving sheet of Example 21 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 19>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 10.0 parts Polypropylene wax filler (Mitsui Chemicals, Chemipearl WP100, average particle size 1 μm) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd.) ), W06MG, average particle size 6 μm) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image receiving sheet of Example 22 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 20>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Cellulose filler (manufactured by Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 40.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

A thermal transfer image-receiving sheet of Example 23 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 21>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Cellulose filler (Nippon Paper Chemical Co., Ltd., W10MG, average particle size 10 μm) 3.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

(Comparative Example 1)
A thermal transfer image receiving sheet of Comparative Example 1 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 22>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Water / isopropyl alcohol (mass ratio 1 : 1) 290.0 parts

(Comparative Example 2)
A thermal transfer image receiving sheet of Comparative Example 2 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 23>
Polyvinyl alcohol resin (manufactured by Oil & Fat Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Nylon 12 filler (Shinto Chemical Co., Ltd.) MW330) 10.0 parts Water / isopropyl alcohol (mass ratio 1: 1) 290.0 parts

(Comparative Example 3)
A thermal transfer image-receiving sheet of Comparative Example 3 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 24>
Polyvinyl alcohol resin (manufactured by Oil and Fat Industries Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Calcium carbonate filler (manufactured by PMMA Tech, FMT100) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

(Comparative Example 4)
A thermal transfer image-receiving sheet of Comparative Example 4 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating solution 25>
Polyvinyl alcohol resin (manufactured by Yushi Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Firing kaolin filler (Takehara Chemical Industries ( Santeton 5) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

(Comparative Example 5)
A thermal transfer image-receiving sheet of Comparative Example 5 was prepared in the same manner as in Example 1 except that the back layer of the thermal transfer image-receiving sheet prepared in Example 1 had the following composition.
<Back surface layer coating liquid 26>
Polyvinyl alcohol resin (manufactured by Yushi Kogyo Co., Ltd., IJC403A) 10.0 parts Polyethylene wax filler (Mitsui Chemicals, Chemipearl W308, average particle size 6 μm) 10.0 parts Wet kaolin filler (Takehara Chemical Industries ( ASP170) 10.0 parts water / isopropyl alcohol (mass ratio 1: 1) 220.0 parts

The following items were tested using the thermal transfer image-receiving sheets of Examples 1 to 23 and Comparative Examples 1 to 5 prepared as described above, and the results are shown in Table 1.
<Writing aptitude>
On the back surface of the thermal transfer image-receiving sheet, letters were handwritten using an oil pen, aqueous pen, pencil, and ballpoint pen, and writing aptitude was evaluated according to the following criteria.
A: Smooth writing with sufficient writing density, no bleeding, and good fixability.
○: Slightly lower than the above evaluation of ◎, but there is no practical problem.
Δ: Written density is slightly light, and bleeding occurs slightly in the writing area.
X: The characters in the writing part cannot be read by lightly rubbing the writing part with a finger. Or writing is difficult.

<Friction between image receiving sheets>
Using the thermal transfer image-receiving sheets of the examples and comparative examples prepared above, 18 thermal transfer image-receiving sheets in each example were placed in the paper feeding section of a Canon photo printer CP710, and a dedicated thermal transfer sheet for the CP710 printer and In combination, thermal transfer recording is performed, and under the following conditions, the influence of the rubbing between the back layer and the dye receiving layer on the image receiving surface, that is, whether there is any image quality defect such as streaks or unevenness in the thermal transfer recording part (image part). Examined. Evaluation was performed according to the following criteria.
A: There is no image quality defect such as streak or unevenness, and it is very good.
○: Although the image quality is slightly lower than the above evaluation of ◎, there is no practical problem.
X: Image quality defects such as streaks and unevenness occur.

<Friction between image-receiving sheets after storage>
The thermal transfer image-receiving sheets of each of the examples and comparative examples prepared above were allowed to stand for 3 days in an environment of 60 ° C. with a load of 20 kg / cm ² in advance, and in each case, 100 In the same manner as in the above evaluation method, except that the single thermal transfer image receiving sheet was placed on the paper feeding unit of Canon photo printer CP710, the influence on the image receiving surface due to rubbing between the back layer and the dye receiving layer, that is, thermal transfer The recording unit (image unit) was examined for the presence of image quality defects such as streaks and unevenness.

<Releasability>
In the dedicated thermal transfer sheet of Canon photo printer CP710, for each color of yellow, magenta, and cyan, the back surfaces of the thermal transfer image receiving sheets of the above examples and comparative examples are overlapped with each dye layer facing each other. Under the conditions, thermal transfer recording was performed using a thermal head, and the releasability, that is, the thermal fusing property between the back surface of the thermal transfer image-receiving sheet and the dye layer of the thermal transfer sheet was examined.

(Printing conditions)
-Thermal head: KGT-217-12MPL20 (manufactured by Kyocera)
-Heating element average resistance value: 3195 (Ω)
・ Print density in the main scanning direction; 300 dpi
・ Print density in the sub-scanning direction; 300 dpi
Applied power: 0.12 (w / dot)
・ One line cycle: 5 (msec.)
・ Printing start temperature: 40 (℃)
Gradation control method Using a multi-pulse test printer that can vary the number of divided pulses from 0 to 255 in one line period with a pulse length obtained by equally dividing one line period into 256, the duty of each divided pulse The ratio was fixed at 60%, the number of pulses was 200, and three-color solid printing of yellow, magenta, and cyan was performed.

Evaluation of releasability was performed according to the following criteria.
(Double-circle): It does not heat-seal at all, light peeling is also very good.
○: Almost no heat fusion, but peeling slightly heavy. However, there is no practical problem.
X: It is heat-sealed and is defective.

(Adhesiveness of stamps)
Tap water was applied to the half of the adhesive surface of the Japanese postage stamp, and the above-mentioned stamp was rubbed onto the back surface of each thermal transfer image-receiving sheet prepared in the examples and comparative examples with an index finger. After leaving in a room at 25 ° C. for 5 hours, the part not coated with tap water was held between the thumb and forefinger, the stamp was peeled off from the thermal transfer image-receiving sheet, and evaluated according to the following criteria.
○: After the stamp is peeled off, a part of the stamp remains on the back surface of the thermal transfer image-receiving sheet, and a trace remains.
X: The stamp is easily peeled off from the back surface of the thermal transfer image receiving sheet, no stamp remains on the back surface of the thermal transfer image receiving sheet, and no trace remains.

The evaluation results of the above tests are shown in Table 1 below.

Claims (4)

  In the thermal transfer image-receiving sheet in which a dye-receiving layer is formed on at least one surface of the base sheet, the surface of the base sheet opposite to the surface on which the dye-receiving layer is formed contains a thermoplastic resin and a cellulose filler. A thermal transfer image receiving sheet, wherein a back layer is formed.   2. The thermal transfer image receiving sheet according to claim 1, wherein a back surface intermediate layer is formed between the base material sheet and the back surface layer.   The thermal transfer image-receiving sheet according to claim 1 or 2, further comprising a filler selected from a polyolefin resin, a polyamide resin, zinc stearate, calcium carbonate, and kaolin in the back layer. The average particle size of the cellulose filler in the back layer is 5 to 20 µm, and the mass ratio of the cellulose filler / thermoplastic resin in the back layer is 0.5 to 3.0. 4. The thermal transfer image receiving sheet described in any one of 3 above.