JP4792898B2 - Thermal transfer image protection sheet - Google Patents

Description

  The present invention relates to a thermal transfer type image protection sheet.

  Conventionally, an image such as a gradation image, a monotonous image such as a character, a symbol, or the like is formed on a base material using a thermal transfer method. As the thermal transfer system, a thermal sublimation transfer system and a thermal melt transfer system are widely used.

  Among these, the thermal sublimation transfer method uses a thermal transfer film in which a dye layer in which a sublimable dye used as a coloring material is melted or dispersed in a binder resin is supported on a base material, and this thermal transfer film is stacked on an image receiving sheet to form a thermal head. By applying energy according to image information to a heating device such as a sublimation dye contained in the dye layer on the thermal transfer film, the image is formed by transferring the dye to the image receiving sheet. This heat-sensitive sublimation transfer method can control the amount of dye transfer in dot units according to the amount of energy applied to the thermal transfer film, and is therefore excellent in the formation of gradation images and has the advantage of easy formation of characters, symbols, etc. Have.

  The gradation image and monotonic image formed by the above heat-sensitive sublimation transfer method, the transferred dye is present on the surface of the transferred material, and the dye is not a pigment but a relatively low molecular weight substance, so it is light resistant. In particular, the light resistance to ultraviolet rays is poor. For this reason, attempts have been made to improve the light resistance of images. For example, a technique has been proposed in which a protective layer containing an ultraviolet absorber is transferred to a transfer target (image receiving sheet) on which an image is formed to improve the light resistance of the image (for example, Patent Document 1).

Such protective layer is ^{generally, 0.1g / m 2 ~5g / m} 2 that may be formed by coating the coating amount ^(after drying) are known in the prior art. As long as the function of the protective layer is maintained, the protective layer is never thin from the viewpoint of resource saving.

However, as the protective layer becomes thinner, rainbow unevenness due to visible light reflection is seen on the image surface due to a slight difference in film thickness. Rainbow irregularities are interference fringes between the image surface and the protective layer. Such rainbow unevenness is noticeable especially when a protective layer is formed on a black solid image. It is.
JP 2000-71626 A

  The present invention has been made in view of the above circumstances, and provides a thermal transfer type image protection sheet capable of providing a protective layer in which rainbow unevenness does not occur even when a protective layer is formed on a transfer target. For the purpose.

  The present invention has a heat transferable protective layer composed of a release layer and an adhesive layer on at least a part of one side of the base sheet, and the release layer and the adhesive layer are made of a resin having a different refractive index. The present invention relates to a thermal transfer type image protection sheet.

The present invention has a heat transferable protective layer composed of a release layer and an adhesive layer on at least a part of one side of the base sheet, and the release layer and the adhesive layer are made of a resin having a different refractive index. This is achieved by a thermal transfer type image protection sheet.
In the present invention, “refractive index” indicates a value measured by the method of JIS K 7142.

  The release layer and the adhesive layer are composed of resins having different refractive indexes, but one layer is composed of a resin having a refractive index of less than 1.5 with a refractive index of 1.5 as a side, and the other resin is A resin having a refractive index of 1.5 or more is used. In order to achieve the object of the present invention, in addition to forming the release layer and the release layer with resins having different refractive indexes, the coating amount of the release layer is also important. From such a viewpoint, the following three aspects of the thermal transfer type image protection sheet are provided.

At least a part of one side of the substrate sheet has a heat transferable protective layer composed of a release layer and an adhesive layer, and the release layer is made of a resin having a refractive index of 1.5 or more, and an adhesive layer Is made of a resin having a refractive index of less than 1.5, and the release layer is formed by coating so that the coating amount after drying is 1.0 to 3.0 g / m ^2. A thermal transfer type image protection sheet formed by coating such that the coating amount after drying of the layer is 0.5 to 2.0 g / m ² (invention of aspect 1).

At least a part of one surface on the base sheet has a heat transferable protective layer composed of a release layer and an adhesive layer, and the release layer is made of a resin having a refractive index of less than 1.5, and the adhesive layer Is made of a resin having a refractive index of 1.5 to less than 1.55, and the release layer is applied and formed so that the coating amount after drying is 2.0 g / m ² or more. The thermal transfer image protective sheet (Aspect 2 invention), wherein the adhesive layer is formed by coating so that the coating amount after drying is 0.5 to 2.0 g / m ² .

At least a part of one surface on the base sheet has a heat transferable protective layer composed of a release layer and an adhesive layer, and the release layer is made of a resin having a refractive index of less than 1.5, and the adhesive layer Is made of a resin having a refractive index of 1.55 or more, the release layer is formed by coating so that the coating amount after drying is 2.5 g / m ² or more, and the adhesive layer is A thermal transfer type image protective sheet (invention of aspect 3), characterized in that it is formed by coating so that the coating amount after drying is 0.5 to 2.0 g / m ² .

A schematic cross-sectional view of an example of the thermal transfer type image protection sheet of the present invention is shown in FIG. In the figure, the thermal transfer type image protection sheet 1 has a protective layer 2 composed of a release layer 3 and an adhesive layer 4 formed on one surface of a substrate sheet 1.
Hereinafter, the invention will be sequentially described from the aspect 1 invention.

  The base material sheet 1 can be the same base material sheet widely used in this field, and is not particularly limited. Specific examples of the base sheet include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone and other highly heat-resistant polyesters; polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, Examples thereof include plastic films such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, and ionomer, and laminates thereof. The plastic film may be stretched or unstretched. Although the thickness of a base material sheet can be suitably selected in consideration of strength, heat resistance and the like, it is usually about 1 to 100 μm.

In the aspect 1 invention, the protective layer 2 provided on the base sheet is composed of a resin having a release layer having a refractive index of 1.5 or higher, and an adhesive layer having a refractive index of less than 1.5. The release layer is formed by coating so that the coating amount after drying is 1.0 to 3.0 g / m ^2, and the coating amount after drying the adhesive layer is 0.5. It is formed by coating so as to be ˜2.0 g / m ² .

  Examples of the resin having a refractive index of 1.5 to less than 1.55 include polyacrylonitrile, polyethylene, nylon 6, polyester, vinyl chloride-vinyl acetate copolymer) and the like. Examples of the resin having a refractive index of 1.55 or more include resins such as polyester, polyamideimide, styrene-acrylonitrile copolymer, polystyrene, and polyethylene terephthalate.

  As the polyester resin, those having a polar group such as a sulfonic acid group, amino group, carboxylic acid group, and phosphonic acid group at the terminal or side chain of the polyester resin are electrically compared with the polyester resin homopolymer. The polarizability representing strain is high, and the refractive index is also improved. Specifically, the refractive index of the polyester resin having a polar group is about 1.52 to 1.59. The refractive indexes in the present invention are all measured according to the method described in JIS K 7124. The polyester resin having this polar group has a glass transition temperature of about 60 to 100 ° C. When the glass transition temperature is less than 60 ° C., bleeding of the thermal transfer image tends to occur when the printed material is stored at a high temperature. On the other hand, when the glass transition temperature exceeds 120 ° C., the foil breakability during thermal transfer is lowered.

  The polyamideimide resin preferably has a molecular weight of about 5000 to 30,000, and preferably has a glass transition temperature of about 200 to 350 ° C. Such a polyamide resin can be obtained from the market under the trade name Viromax HR11NN, HR12N2, HR13NX, HR14ET, HR15ET, HR16NN, etc., manufactured by Toyobo Co., Ltd. When the glass transition temperature is too high, the solubility in a solvent is deteriorated and coating becomes difficult. On the other hand, when the glass transition temperature is too low, durability such as plasticizer resistance is deteriorated. In addition, since the release layer containing the polyamideimide resin is used after being transferred to a print as a protective layer, it is required to be colorless and transparent. Therefore, HR14ET and HR15ET of trade names Viromax are particularly preferably used. .

  Examples of the resin having a refractive index of less than 1.5 include polytetrafluoroethylene, vinylidene fluoride, polyvinyl acetate, acrylic resin, (meth) acrylate resin (meaning both acrylate resin and methacrylate resin), etc. Resins can be exemplified.

  It is also possible to use a mixture of resins having different refractive indexes. In such a case, the value derived from Σ (refractive index × weight ratio) only needs to belong to the above refractive index range.

In the invention of aspect 1, the release layer is formed by coating so that the coating amount after drying is 1.0 to 3.0 g / m ² . If the coating amount of the release layer is less than 1.0 g / m ² , the problem of rainbow unevenness cannot be solved. If the total coating amount of the release layer and the adhesive layer is too large, the protective layer will be cut off at the time of transfer, and problems such as the protective layer being unable to transfer a predetermined dimension to the transfer medium will occur.

In the invention of aspect 1, the adhesive layer is formed by coating so that the coating amount after drying is 0.5 to 2.0 g / m ² .

  For the release layer and adhesive layer that form the protective layer, inorganic fine particles such as silica filler, alumina filler, and titanium oxide, organic fine particles such as polyethylene wax and acrylic filler, phenol-based, phosphorus-based, and sulfur-based antioxidants as required. An additive such as a light stabilizer such as an agent, a hindered amine, a fluorescent whitening agent, and an ultraviolet absorber may be contained.

  The release layer and adhesive layer that form the protective layer use gravure printing, screen printing, and gravure printing, using resin and, if desired, other resins dissolved or decomposed in a solvent such as water or organic solvent. It is formed by applying and drying in accordance with a normal coating method such as a reverse roll coating method.

The invention of aspect 2 will be described. In the second aspect of the invention, the release layer is made of a resin having a refractive index of less than 1.5, and the adhesive layer is made of a resin having a refractive index of 1.5 to less than 1.55. , the release layer, the coating amount after drying is to be applied and formed so that 2.0 g / ^{m 2} or more, the adhesive layer, the coating amount after drying of 0.5 to 2.0 g / ^{m 2} Thus, it is formed by coating.

  As the base sheet, the resin having a refractive index of 1.5 or more and less than 1.55, and the resin having a refractive index of less than 1.5, the same ones as those of the invention of aspect 1 can be used.

  The adhesive layer in the invention of aspect 2 is applied in the same manner as in the invention of the first aspect except that the refractive indexes of the constituent resins are different.

The release layer in the invention of aspect 2 is formed by coating so that the coating amount after drying is 2.0 g / m ² or more, preferably 2.4 g / m ² or more. If the coating amount is too thin, the problem of rainbow unevenness cannot be solved. If the total coating amount of the release layer and the adhesive layer is too large, the protective layer will be cut off at the time of transfer, and problems such as the protective layer being unable to transfer a predetermined dimension to the transfer medium will occur.

  The release layer and the adhesive may contain an additive in the same manner as in the first aspect, and the method for forming each layer may be the same as in the first aspect.

The invention of aspect 3 will be described. In the invention of aspect 3, the release layer is made of a resin having a refractive index of less than 1.5, the adhesive layer is made of a resin having a refractive index of 1.55 or more, and the release layer is The coating amount is formed so that the coating amount after drying is 2.5 g / m ² or more, and the adhesive layer is coated and formed so that the coating amount after drying is 0.5 to 2.0 g / m ^2. It becomes.

  As the base sheet and the resin having a refractive index of 1.55 or more, the same resin as that of the first aspect can be used.

  The adhesive layer in the invention of aspect 3 is applied in the same manner as in the invention of the first aspect except that the refractive indexes of the constituent resins are different.

The release layer in the invention of aspect 3 is formed by coating so that the coating amount after drying is 2.5 g / m ² or more, preferably 2.9 g / m ² or more. If the coating amount is too thin, the problem of rainbow unevenness cannot be solved. If the total coating amount of the release layer and the adhesive layer is too large, the protective layer will be cut off at the time of transfer, and problems such as the protective layer being unable to transfer a predetermined dimension to the transfer medium will occur.

  The release layer and the adhesive may contain an additive in the same manner as in the first aspect, and the method for forming each layer may be the same as in the first aspect.

  In the present invention, a release layer may be provided between the base sheet and the protective layer. When the peelability between the base film and the protective layer is not appropriate, the release layer is provided as necessary to adjust the adhesiveness between the base film and the protective layer and to peel the protective layer satisfactorily. . When a release layer is provided, the protective layer is peeled off from the protective layer by transfer, and the release layer itself is formed so as to remain on the base film side.

  The release layer is, for example, various waxes such as silicone wax or silicone oil, silicone resin, fluorine resin, (meth) acrylic resin (used to include both acrylic resin and methacrylic resin), It is formed from various resins such as silicone-modified (meth) acrylic resins, water-soluble resins, cellulose derivative resins, urethane resins, acetic acid vinyl resins, acrylic vinyl ether resins, maleic anhydride resins, and the like, and mixtures thereof.

  The release layer may contain additives such as a curing agent and an ultraviolet absorber, and the release layer contains at least one selected from the group consisting of the above waxes and / or resins, and optionally an additive. It can form by apply | coating the containing coating liquid on a base film by well-known coating methods, such as a wire-coating method, hardening as needed, and drying. The thickness of the release layer is usually about 0.5 to 5.0 μm.

  In the present invention, a back layer may be formed on the other surface of the base sheet. The back layer is provided for the purpose of preventing thermal fusion between a heating device such as a thermal head and the base sheet 1 and smooth running. Examples of the resin used for the back layer include cellulose resins such as ethyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose butyrate, and nitrocellulose; polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl Vinyl resins such as pyrrolidone; Acrylic resins such as polymethyl methacrylate, polyethyl acrylate, polyacrylamide, and acrylonitrile-styrene copolymers; polyamide resins; polyvinyl toluene resins; coumarone indene resins; polyester resins; A simple substance or a mixture of natural or synthetic resins such as silicone-modified or fluorine-modified urethane is used. Of the above resins, a resin having a hydroxyl group reactive group (for example, butyral resin, acetal resin, etc.) is used in order to further increase the heat resistance of the back layer, and polyisocyanate is used in combination as a crosslinking agent. Thus, a crosslinked resin layer is preferable.

  Further, in order to impart slidability with the thermal head, a solid or liquid release agent or lubricant may be added to the back layer to provide heat-resistant lubricity. Examples of release agents or lubricants include various waxes such as polyethylene wax and paraffin wax; higher aliphatic alcohols, organopolysiloxanes, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants Various surfactants such as an activator and a fluorine-based surfactant; fine particles of inorganic compounds such as organic carboxylic acids and derivatives thereof, fluorine-based resins, silicone-based resins, talc, and silica can be used. The amount of lubricant contained in the back layer is about 5 to 50% by weight, preferably about 10 to 30% by weight in the back surface.

  The back layer is a gravure printing method, a screen printing method, a reverse coating method using a gravure plate, or the like obtained by dissolving or dispersing the above resin and other additives in a solvent such as water or an organic solvent on a base sheet. It is formed by applying and drying according to the usual coating method. The thickness of the back layer is usually about 0.1 to 10 μm, preferably about 0.5 to 5 μm.

The thermal transfer type image protection sheet of the present invention is not limited to the above-described embodiment, and is a composite type thermal transfer type image protection sheet comprising a thermal transferable protective layer and a thermal sublimation colorant layer, a thermal transferable protective layer, and It can be arbitrarily set according to the purpose of use, such as a composite type thermal transfer image protective sheet with a heat-meltable color material layer. In the case of a composite type thermal transfer type image protection sheet, if a transfer material has a dye receiving layer, image formation by the thermal transfer method and transfer of the protection layer to the transfer material can be performed simultaneously.
As another example of the heat transfer type image protection sheet, at least one color material selected from the group consisting of a heat transfer protection layer, a heat sublimation color material layer, and a heat melt color material layer is provided on one surface of the base sheet. Examples thereof include a thermal transfer type image protection sheet in which layers are provided in a surface sequential manner.

FIG. 2 is a schematic cross-sectional view showing another example of the thermal transfer type image protection sheet of the present invention. In FIG. 2, the thermal transfer type image protection sheet 21 of the present invention has a heat sublimation colorant layer Y, a heat sublimation colorant layer M, a heat sublimation colorant layer C, a heat sublimation on one surface of a substrate sheet 22. The colorant material layer B and the heat transferable protective layer are formed in the surface order, and the back layer 27 is formed on the other surface of the base sheet 22. The thermal transferable protective layer is composed of the protective layer 2 described above.
The heat-sublimable color material layers Y, M, C, and B in FIG. 2 may be heat-meltable color material layers Y, M, C, and B, and are configured by mixing these layers. Also good.

There is no restriction | limiting in particular as a to-be-transferred body which transfers a protective layer using this invention heat transfer type image protection sheet.
The transfer target may be, for example, a sheet made of any base material such as plain paper, high-quality paper, tracing paper, and plastic film. Further, the transfer object may have any shape such as a card, a postcard, a passport, a notepaper, a report sheet, a notebook, a catalog, and the like.

Specific examples of the transfer object of the present invention include, for example, stock certificates, securities, certificates, passbooks, boarding tickets, car horse tickets, stamps, stamps, appreciation tickets, admission tickets, tickets, etc .; cash cards, credit cards , Prepaid cards, members cards, greeting cards, postcards, business cards, driver's licenses, IC cards, optical cards, etc .; cartons, cases such as containers; bags: forms, envelopes, tags, OHP sheets, slide films , Bookmarks, calendars, posters, brochures, menus, passports, POP supplies, coasters, tisplays, nameplates, keyboards, cosmetics, watches, lighters, and other accessories; stationery, report paper, and other stationery; building materials, panels, emblems, Keys, cloth, clothing, footwear, radio, TV, calculator, OA equipment, etc., each Sample book, mention may be made of the album, the output of computer graphics, the medical image output, and the like.
The image on the transfer medium may be formed by any method such as an electrophotographic method, an ink jet recording method, or a thermal transfer recording method.

  In using the thermal transfer type image protection sheet of the present invention, conventionally known methods of using thermal transfer type image protection sheets can be employed as they are. For example, the protective layer surface of the thermal transfer type image protection sheet of the present invention may be superimposed on the transfer target, and the thermal transfer resin layer may be thermally transferred onto the transfer target.

(The invention's effect)
If the thermal transfer type image protection sheet of the present invention is used, a protective layer that does not cause rainbow unevenness can be provided on the transfer target.

  The following examples illustrate the invention. In the examples, “parts” or “%” are based on mass unless otherwise specified.

(Test Examples 1-43)
Production of thermal transfer type image protection sheet (formation of slippery layer)
One surface of a base material (thickness: 4.5 μm, polyethylene terephthalate film (trade name: 4WF597, manufactured by Toray Industries, Inc.) is preliminarily coated with a heat resistant slipping layer coating liquid having the following composition by gravure coating, so that the dry coating amount is 1. A heat resistant slipping layer was formed by applying and drying to 0.0 g / m ^2. Similarly, a release layer coating having the following composition was formed on the surface opposite to the heat resistant slipping layer. The liquid was applied and dried by gravure coating so that the dry coating amount was 1.0 g / m ² .

<Heat resistant slipping layer composition>
Polyvinyl butyral resin (S-REC BX-1 Sekisui Chemical Co., Ltd.) 13.6 parts Polyisocyanate curing agent (Takenate D218 Takeda Pharmaceutical Co., Ltd.) 0.6 parts Phosphate ester (Plysurf A208S Daiichi Kogyo Seiyaku) 0.8 parts Methyl ethyl ketone 42.5 parts Toluene 42.5 parts

On the surface opposite to the printing surface of the heat-resistant slipping layer, a release layer coating solution having the following composition is applied by gravure coating at a dry rate of 1.0 g / m ² and dried in an oven at 110 ° C. for 1 minute. did.

(Formation of release layer)
Release layer coating solution silicone-modified acrylic resin (Cell Top 226, manufactured by Daicel Chemical Industries, Ltd.) 16 parts Silicone-modified acrylic resin (Cell Top 227, manufactured by Daicel Chemical Industries, Ltd.) 8 parts Vinyl chloride-vinyl acetate Polymer resin (Solvine A, manufactured by Nissin Chemical Industry Co., Ltd.) 2.4 parts curing catalyst (Cell Top CAT-A, manufactured by Daicel Chemical Industries, Ltd.) 4.5 parts UV absorber (Ubitex OB, Japan) Ciba Geigy Co., Ltd.) 0.05 parts toluene 9.8 parts methyl ethyl ketone 9.8 parts

(Formation of protective layer)
Next, coating liquid 1, 2, 3, 4 or 5 having the following composition is used on the release layer, and the release layer and coating amount are shown in Tables 1 and 2 below. An adhesive layer was formed. Application was performed by a gravure coating method, and the coating solution was dried in an oven at 110 ° C. for 1 minute to form each layer.

<Coating liquid 1 for protective layer>
Vinyl chloride-vinyl acetate copolymer resin (Solvine CNL, manufactured by Nissin Chemical Industry Co., Ltd.)
(Refractive index 1.52) 4.5 parts UV absorber (UVA635L, manufactured by BASF Japan Ltd.) 15 parts acrylic resin solution (Thermolac LP45M, manufactured by Soken Chemical Co., Ltd., solid content: 40%)
(Refractive index 1.49) 4.69 parts polyethylene WAX (particle size 6 μm) 0.07 parts toluene 10.37 parts methyl ethyl ketone 10.37 parts

<Coating liquid 2 for protective layer>
Polymethyl methacrylate resin (Dianar BR-87, manufactured by Mitsubishi Rayon Co., Ltd.)
(Refractive index 1.49) 10 parts polyester resin (Byron 200, manufactured by Toyobo Co., Ltd.) (refractive index 1.56) 0.01 parts UV absorber (Ubitex OB, manufactured by Ciba Specialty Chemicals Co., Ltd.)
0.02 parts Toluene 10 parts Methyl ethyl ketone 10 parts

<Coating liquid 3 for protective layer>
Polyester resin (Byron 200, manufactured by Toyobo Co., Ltd.) (refractive index 1.56) 19 parts silica (Silicia 310P, manufactured by Fuji Silysia Chemical Co., Ltd.) 0.5 parts Polymer UV absorber (PUVA 50M-40TM, Otsuka Chemical Co., Ltd.) 12 parts Ultraviolet absorber (TINUVIN900, Ciba Specialty Chemicals Co., Ltd.) 2.4 parts Toluene 19 parts Methyl ethyl ketone 19 parts

<Coating liquid 4 for protective layer>
Polyamideimide resin solution 100 parts (Toyobo Co., Ltd., Viromax HR15ET, average molecular weight 10,000, glass transition temperature 260 ° C., solid content 20%, refractive index 1.55)

<Coating liquid 5 for protective layer>
20 parts of polyester resin having sodium sulfonate group (Toyobo Co., Ltd., Byron 885, refractive index 1.55)
Methyl ethyl ketone 40 parts Toluene 40 parts

(Evaluation)
The thermal transfer type image protection sheet obtained in each of the above test examples was cut and pasted on the thermal transfer type image protection sheet portion of the dedicated thermal transfer sheet of MEGAPIXEL-II (manufactured by Altec Co., Ltd.), and MEGAPIXEL-II (Altech Co., Ltd.) was used. A protective layer was formed on a black solid image printed by a sublimation printer MEGAPIXEL-II (manufactured by Altec Co., Ltd.) in combination with a dedicated thermal transfer image receiving paper. The appearance of the transferred material on which the protective layer was formed was visually evaluated, and the rainbow unevenness was ranked as follows. The results are shown in Tables 1 and 2.

3: No rainbow unevenness can be confirmed visually. 2: A slight rainbow unevenness can be confirmed visually. 1: Rainbow unevenness can be confirmed over the entire surface.

(Measurement of refractive index)
The refractive index of the resin of the ink used in the above test example was measured by the method of JIS K7142.

1 is a schematic cross-sectional view of an embodiment of a thermal transfer image protection sheet of the present invention. 1 is a schematic cross-sectional view of an embodiment of a thermal transfer image protection sheet of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 21 Thermal transfer type film 1,22 Base film 2 Thermal transfer protective layer 3 Release layer 4 Adhesive layer 27 Back layer

Claims (3)

A resin having a heat transferable protective layer composed of a release layer and an adhesive layer on at least a part of one side of the base sheet, the release layer having a refractive index of 1.5 or more and less than 1.55. is configured, the adhesive layer is constituted by a resin having a refractive index lower than 1.5, such that the release layer, the coating amount after drying of 1.0 to 3.0 g / m ² it is applied and formed, the thermal transfer image protective sheet adhesive layer is coated amount after drying, characterized in Rukoto such is applied and formed so that 0.5 to 2.0 g / m ^2. Resin having a refractive index lower than 1.5 or higher ～1.55 is poly Akuru nitrile, polyethylene, nylon 6, polyester, vinyl chloride - is selected from vinyl acetate copolymer or Ranaru group, claims 2. The thermal transfer type image protection sheet according to 1. The thermal transfer type image protection sheet according to claim 1 , wherein the resin having a refractive index of less than 1.5 is selected from the group consisting of polytetrafluoroethylene, vinylidene fluoride and polyvinyl acetate.

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