JP2021133583A - Thermal transfer image receiving sheet - Google Patents

Abstract

To provide a thermal transfer image receiving sheet having a novel designability.SOLUTION: A thermal transfer image receiving sheet includes a multilayer laminate film and a reception layer disposed on one side of the multilayer laminate film. The multilayer laminate film is formed by alternately laminating, in total, 20 or more layers of first polyester layers and second polyester layers with thickness of 0.05 to 0.5 μm, respectively having different refractive indexes. The thermal transfer image receiving sheet further includes an adhesive layer and a release part disposed on the other side of the multilayer laminate film. The release part and a seal part including the reception layer, the multilayer laminate film and the adhesive layer are integrated. The seal part may be peelable from the release part.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a thermal transfer image receiving sheet.

Conventionally, various thermal transfer methods have been proposed. For example, there is known a sublimation thermal transfer method that has excellent transparency, high reproducibility of neutral colors and high gradation, and can easily form a high-quality image equivalent to a conventional full-color photographic image.

For the formation of the thermal transfer image by the sublimation thermal transfer method, a thermal transfer sheet having a dye layer provided on one surface of the base material and a receiving layer provided on one surface of the transferred body, for example, the other base material. A thermal transfer image receiving sheet is used. Then, the receiving layer of the thermal transfer image receiving sheet and the dye layer of the thermal transfer sheet are overlapped with each other, and heat is applied from the back surface side of the thermal transfer sheet by the thermal head to transfer the dye of the dye layer onto the receiving layer. A printed matter in which a thermal transfer image is formed on the layer is obtained.

The thermal transfer image receiving sheet used in such a thermal transfer method has a wide variety of uses, for example, it is used for cards such as ID cards and credit cards having facial photographs, and synthetic photographs in amusement facilities.

In such a diversified application, a thermal transfer image receiving sheet with high design is required.

Japanese Patent No. 4372969 Japanese Patent No. 4372974 Japanese Unexamined Patent Publication No. 2005-59332

An object of the present disclosure is to provide a thermal transfer image receiving sheet having a novel design property.

The heat transfer image receiving sheet of the present disclosure has a multilayer laminated film and a receiving layer provided on one surface of the multilayer laminated film, and the multilayer laminated films have different refractive indexes from each other and have a thickness of 0.05 μm or more and 0.5 μm. The following first polyester layer and second polyester layer are alternately laminated so that the total number of layers is 20 or more.

In one aspect of the present disclosure, an adhesive layer provided on the other surface of the multilayer laminated film and a mold release portion are further provided, and the sealing portion including the receiving layer, the multilayer laminated film and the adhesive layer and the release portion are separated. The mold portion is integrated, and the seal portion can be peeled off from the mold release portion.

In one aspect of the present disclosure, the sealed portion has a minimum transmittance of light in the wavelength range of 400 nm or more and 700 nm, which is 30% or more lower than the average transmittance in the wavelength range of 720 nm or more and 780 nm.

In one aspect of the present disclosure, the sealing portion further comprises a sealing portion base material provided between the multilayer laminated film and the receiving layer.

According to the present disclosure, a novel design can be imparted to the thermal transfer image receiving sheet.

It is schematic cross-sectional view which shows an example of the seal type thermal transfer image receiving sheet which concerns on embodiment of this disclosure. It is schematic cross-sectional view which shows an example of the seal type thermal transfer image receiving sheet which concerns on embodiment of this disclosure. It is schematic cross-sectional view which shows an example of the seal type thermal transfer image receiving sheet which concerns on embodiment of this disclosure. It is schematic cross-sectional view which shows an example of the seal type thermal transfer image receiving sheet which concerns on embodiment of this disclosure. It is schematic cross-sectional view which shows an example of the thermal transfer image receiving sheet which concerns on embodiment of this disclosure.

Hereinafter, embodiments of the present disclosure will be described with reference to drawings and the like. It should be noted that the present disclosure can be implemented in many different modes and is not construed as being limited to the description of the embodiments illustrated below. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, etc. of each part as compared with the actual embodiment, but this is merely an example and limits the interpretation of the present disclosure. It's not a thing. Further, in the specification of the present application and each of the drawings, the same elements as those described above with respect to the above-described drawings may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

<< Seal type thermal transfer image receiving sheet >>
As shown in FIGS. 1 to 4, in the seal type thermal transfer image receiving sheet 100 according to the embodiment of the present disclosure, the mold release portion 10 and the seal portion 50 are integrated, and the seal portion 50 is a mold release portion. It is provided so as to be peelable from 10. Further, the seal portion 50 has a laminated structure in which the adhesive layer 51, the multilayer laminated film 52, and the receiving layer 56 capable of receiving the sublimation dye are laminated in this order from the release portion 10 side.

The multilayer laminated film 52 is formed by alternately laminating a large number of layers having a low refractive index and layers having a high refractive index, and selectively reflects or transmits light having a specific wavelength by structural light interference between the layers. By setting a specific wavelength as the visible light region, the color changes depending on, for example, the viewing angle.

In the multilayer laminated film 52, for example, the first polyester layer and the second polyester layer having different refractive indexes and having a thickness of 0.05 μm or more and 0.5 μm or less are alternately laminated so as to have a total number of layers of 20 or more. It is a thing. The desired reflection performance can be obtained by setting the thickness of one layer to 0.05 μm or more and 0.5 μm or less. The thickness of each layer can be measured by embedding the laminate with an epoxy resin and forming a thin film section having a thickness of about 50 nm with a microtome and observing it with a transmission electron microscope. The difference in refractive index between the first polyester layer and the second polyester layer is preferably 0.03 or more, more preferably 0.05 or more. The upper limit of the difference in refractive index is about 0.2.

In the sealing portion 50 including the multilayer laminated film 52, the minimum transmittance of light in the wavelength range of 400 nm or more and 700 nm is preferably 30% or more lower than the average value of the transmittance in the wavelength range of 720 nm or more and 780 nm, preferably 40% or more. It is even more preferable that it is low.

Since the color of the seal portion 50 including the multilayer laminated film 52 changes by changing the tilted viewing angle, it is possible to impart a novel design to the seal portion 50. In addition, it has high anti-counterfeiting properties and is suitable for security purposes.

Hereinafter, each configuration of the seal type thermal transfer image receiving sheet 100 will be specifically described.

<Release part>
The mold release portion 10 is an essential configuration in the seal type thermal transfer image receiving sheet 100. The mold release portion 10 as an example is composed of a base material 11 (hereinafter, may be referred to as a base material for the mold release portion). The release portion 10 may be composed of one member or may be a laminated body of a plurality of members. For example, as shown in FIG. 1, the release portion 10 may be composed of only the base material 11, and as shown in FIG. 2, the release portion 10 is formed as a laminated structure of the base material 11 and the release layer 12. May be good. Further, other configurations may be used.

(Base material for mold release part)
The base material 11 for the release portion includes, for example, a stretched or unstretched base material (film) of polyester such as polyethylene terephthalate and polyethylene naphthalate, polypropylene, polycarbonate, cellulose acetate resin, polyethylene derivative, polyamide, and polymethylpentene. (May be), high-quality paper, coated paper, resin-coated paper, art paper, cast-coated paper, paperboard, emulsion-impregnated paper, synthetic rubber latex-impregnated paper, synthetic resin inner paper, cellulose fiber paper, etc. can. Further, as the base material 11 for the release portion, a base material (film) having a void inside can also be used. As the base material having a void, the base material described in the seal portion base material 54 described later can be appropriately selected and used.

The thickness of the base material 11 for the release portion may be determined in consideration of the thickness of the entire seal type thermal transfer image receiving sheet 100 and the like, and as an example, it is 50 μm or more and 150 μm or less.

As shown in FIG. 2, in order to improve the peelability of the seal portion 50 from the release portion 10, a laminate of the release portion base material 11 and the release layer 12 may be used as the release portion 10. can.

The components of the release layer 12 include components having releasability, for example, various silicone-modified resins such as waxes, silicone waxes, silicone resins, and silicone-modified acrylic resins, fluororesins, fluorine-modified resins, polyvinyl alcohols, and acrylic resins. , Thermo-curable epoxy-amino copolymer, thermo-curable alkyd-amino copolymer (thermo-curable aminoalkyd resin), melamine resin, cellulose resin, urea resin, polyolefin, acrylic resin and the like. The release layer 12 may contain one kind of component alone, or may contain two or more kinds of components.

The thickness of the release layer 12 is, for example, 0.1 μm or more and 0.4 μm or less.

Further, a back surface layer (not shown) may be provided on the surface of the base material 11 for the mold release portion opposite to the surface on which the release layer 12 is provided. Further, a back surface primer layer can be provided between the release portion base material 11 and the back surface layer. Further, the antistatic layer may be provided on the surface of the back surface opposite to the surface on which the release portion base material 11 is provided. The back surface layer, the back surface primer layer, and the antistatic layer are arbitrary layers constituting the release portion 10.

Examples of the components of the back layer include polyolefins such as polyethylene and polypropylene, polyester, polyacrylic acid ester, polyvinyl acetate, styrene acrylate, polyurethane, polystyrene, polyvinyl chloride, polyether, polyamide, polyimide, polyamideimide, and polycarbonate. Examples thereof include thermoplastic resins such as polyacrylamide, polyvinyl chloride, and polyvinyl acetal, and silicone modified products thereof.

<Seal part>
As shown in FIGS. 1 and 2, a seal portion 50 is provided on the release portion 10 so as to be peelable from the release portion 10. The seal portion 50 has a laminated structure in which an adhesive layer 51, a multilayer laminated film 52, and a receiving layer 56 capable of receiving a sublimation dye are laminated in this order from the release portion 10 side. The sealing portion 50 may be composed of only the adhesive layer 51, the multilayer laminated film 52, and the receiving layer 56, or may include any other layer.

For example, as shown in FIG. 3, the adhesive layer 51, the multilayer laminated film 52, the adhesive layer 53, the base material 54 for the sealing portion, and the receiving layer 56 are laminated in this order from the release portion 10 side of the sealing portion 50. It may be a laminated structure.

Further, as shown in FIG. 4, the seal portion 50 is provided with the adhesive layer 51, the multilayer laminated film 52, the adhesive layer 53, the base material 54 for the seal portion, the primer layer 55, and the receiving layer 56 from the release portion 10 side. It may be a laminated structure which is laminated in order.

(Adhesive layer)
The components of the adhesive layer 51 are not particularly limited, and examples thereof include acrylic resin, vinyl resin, polyester, urethane resin, polyamide, epoxy resin, rubber resin, and ionomer resin. The thickness of the adhesive layer 51 is not particularly limited, but is generally 5 μm or more and 20 μm or less, and preferably 8 μm or more and 10 μm or less.

(Multilayer laminated film)
A multilayer laminated film 52 is provided on the adhesive layer 51. The multilayer laminated film 52 includes a first polyester layer made of a polyester composition having a thickness of 0.05 μm or more and 0.5 μm or less, and a second polyester layer made of a polyester composition having a thickness of 0.05 μm or more and 0.5 μm or less. Are alternately laminated in at least 20 layers. By setting the number of layers to 20 or more, selective reflection due to multiple interference becomes large, and sufficient reflectance can be obtained. The upper limit of the number of layers is preferably about 500 layers from the viewpoint of productivity and the like.

The polyesters constituting the first polyester layer and the second polyester layer of the multilayer laminated film 52 are crystalline polyesters, respectively, and the proportion of the ethylene terephthalate component is 80 mol% or more based on the total repeating unit of the polyester. As a result, the adhesion between the layers of the first polyester layer and the second polyester layer is improved.

As the copolymerization component other than the ethylene terephthalate component, a 2,6-naphthalenedicarboxylic acid or an isophthalic acid component is preferable because the melting point can be easily lowered. Based on all repeating units, 1.5 mol% or more and 20 mol% or less are 2,6-naphthalenedicarboxylic acid or isophthalic acid components. As a result, it is possible to maintain a sufficient difference in refractive index between the first polyester layer and the second polyester layer, and to achieve both adhesion between layers.

In the resin constituting the first polyester layer, it is preferable that the main repeating unit is an ethylene terephthalate component. Since the melting point can be maintained higher than that of the polyester constituting the second polyester layer described later, it is preferable that 95 mol% or more of the repeating unit is composed of an ethylene terephthalate component. Among these, homopolyethylene terephthalate in which 100 mol% of the repeating unit is an ethylene terephthalate component is preferable because the melting point can be maintained at a high level. Copolymerization components other than the ethylene terephthalate component include other aromatic carboxylic acids such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid; adipic acid, azelaic acid, sebacic acid, and decandicarboxylic acid. An aliphatic dicarboxylic acid such as an acid; an acid component such as an alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, an aliphatic diol such as butanediol or hexanediol; a glycol component such as an alicyclic diol such as cyclohexanedimethanol. Can be preferably mentioned.

In the resin constituting the second polyester layer, it is preferable that the main repeating unit is an ethylene terephthalate component. Particularly, it is preferably crystalline polyester. Further, since the melting point can be lower than that of the polyester constituting the first polyester layer described above, 75 mol% or more and 97 mol% or less of the repeating unit is composed of an ethylene terephthalate component, and 3 mol% or more and 25 mol% or less is other than that. Copolymerized polyethylene terephthalate composed of a copolymerization component is preferable. Copolymerization components other than the ethylene terephthalate component include other aromatic carboxylic acids such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid; adipic acid, azelaic acid, sebacic acid, and decandicarboxylic acid. An aliphatic dicarboxylic acid such as an acid; an acid component such as an alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, an aliphatic diol such as butanediol or hexanediol; a glycol component such as an alicyclic diol such as cyclohexanedimethanol. Can be preferably mentioned.

The multilayer laminated film 52 is obtained by alternately laminating 20 or more layers of the polyester for the first polyester layer and the polyester for the second polyester layer in a molten state.

(Receptive layer)
There is no particular limitation on the components of the receiving layer 56. For example, a polyolefin resin such as polypropylene, a halogenated resin such as polyvinyl chloride or polyvinylidene chloride, a vinyl resin such as polyvinyl acetate, a vinyl chloride-vinyl acetate copolymer, an ethylene-vinyl acetate copolymer or a polyacrylic acid ester. , Polyester such as polyethylene terephthalate or polybutylene terephthalate, copolymer of polyolefin such as ethylene or propylene and other vinyl polymer, cellulose resin such as ionomer or cellulose diacetate, solvent system such as polycarbonate, polystyrene, polyamide, acrylic resin Resin can be mentioned. One of these materials may be used alone, or two or more of these materials may be used in combination. The thickness of the receiving layer 56 is not particularly limited, but is preferably 0.5 μm or more and 10 μm or less, and more preferably 2 μm or more and 5 μm or less.

Sublimation transfer of a dye is a suitable image forming method because it can form an image having excellent transparency, but the image forming method is not limited to this, and is used in melt transfer using a pigment as a coloring material, inkjet printing, gravure printing, etc. There may be.

(Base material for seal part)
As shown in FIG. 3, when forming an image on the receiving layer 56, for the sealing portion under the receiving layer 55 in order to suppress the loss of energy applied from the heating member and to support the sealing portion 50. The base material 54 can be provided.

Examples of the base material 54 for the sealing portion include stretched or unstretched base materials (films) of polyesters such as polyethylene terephthalate and polyethylene naphthalate, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyamides, and plastics such as polymethylpentene. May be) and the like. The base material 54 for the sealing portion may have a single-layer structure or may be a composite base material in which two or more are laminated.

The thickness of the base material 54 for the sealing portion is preferably 50 μm or more and 100 μm or less.

(Adhesive layer)
The adhesive layer 53 is not particularly limited as long as it has a function of adhering the multilayer laminated film 52 and the base material 54 for the sealing portion. Examples of the adhesive component used for the adhesive layer 53 include polyolefins such as polyurethane and α-olefin-maleic anhydride resin, polyesters, acrylic resins, epoxy resins, uria resins, melamine resins, phenol resins, vinyl acetate resins, and cyanoacrylates. Resin and the like can be mentioned. Among them, a reactive type of acrylic resin, a modified type, or the like can be preferably used. Further, when the adhesive is cured by using a curing agent, the adhesive strength is improved and the heat resistance is also increased, which is preferable. As the curing agent, an isocyanate compound is generally used, but an aliphatic amine, a cyclic aliphatic amine, an aromatic amine, an acid anhydride and the like can also be used.

The thickness of the adhesive layer 53 is 0.5 μm or more and 6 μm or less, preferably 1 μm or more and 5 μm or less.

(Primer layer)
In order to improve the interlayer adhesion, a primer layer 56 can be provided between the base material 54 for the sealing portion and the receiving layer 56.

Examples of the components of the primer layer 55 include polyester, polyvinyl acetate, polyvinyl acetate, polyurethane, styrene acrylate, polyacrylamide, polyamide, polyether, polystyrene, polyethylene, polypropylene, polyvinyl chloride, polyvinyl alcohol, polyvinylpyrrolidone and the like. Vinyl resin, polyvinyl acetal such as polyvinyl acetacetal and polyvinyl butyral, inorganic particles and the like can be mentioned.

The thickness of the primer layer 55 is not particularly limited, but is preferably 0.6 μm or more, and more preferably 1 μm or more. The upper limit is not particularly limited, but is about 2.5 μm.

The thickness of the entire seal-type thermal transfer image receiving sheet 100 is not particularly limited, but is generally 150 μm or more and 300 μm or less, preferably 175 μm or more and 250 μm or less.

When the sealing portion 50 includes the multilayer laminated film 52, a novel design can be imparted to the sealing portion 50.

The position of the multilayer laminated film 52 on the sealing portion 50 is not particularly limited, but it is preferable to provide the multilayer laminated film 52 at a position away from the receiving layer 56 in order to suppress the influence of heating on the receiving layer 56 at the time of image formation.

The receiving layer may be provided on the seal portion having the adhesive layer, or may be provided on the release portion having the release layer. For example, a seal-type thermal transfer image receiving sheet in which the first base material, the adhesive layer, the release layer, the multilayer laminated film, the second base material, and the receiving layer are laminated in this order may be used. In this case, the first base material and the adhesive layer serve as the sealing portion, and the release layer, the multilayer laminated film, the second base material and the receiving layer serve as the release portion.

Further, instead of the adhesive layer, a pseudo-adhesive layer may be provided, which reduces the re-adhesiveness once it is peeled off.

In the above embodiment, the configuration of the seal type thermal transfer image receiving sheet having the release portion and the sealing portion has been described, but a thermal transfer image receiving sheet containing a multilayer laminated film which is not a seal type may be used. For example, as shown in FIG. 5, the thermal transfer image receiving sheet 110 having the base material 54, the adhesive layer 53, the multilayer laminated film 52, and the receiving layer 56 which are laminated in this order may be used.

Next, the present disclosure will be described in more detail with reference to examples. Hereinafter, unless otherwise specified, parts or% are based on mass and are values before conversion to solid content.

(Example 1)
A polyethylene terephthalate film (S100 # 75 Mitsubishi Chemical Corporation) having a thickness of 75 μm was used as the base material for the release part, and a coating liquid for the release layer having the following composition was applied to one surface of the base material for the release part. Was applied and dried so that the thickness at the time of drying was 0.25 μm, and a release layer was formed on the base material for the release portion.

Further, a primer layer coating liquid having the following composition was applied and dried on the other surface of the base material for the mold release portion so that the thickness at the time of drying was 1.5 μm to form a primer layer. Then, the coating liquid for the back surface layer having the following composition was applied and dried on the primer layer so that the thickness at the time of drying was 0.7 μm to form the back surface layer. Then, an antistatic layer coating liquid having the same composition as that of the primer layer is applied and dried on the back surface layer so that the thickness at the time of drying is 0.1 μm, and the antistatic layer is formed to be charged. A mold release portion was obtained in which the prevention layer, the back surface layer, the primer layer, the base material for the mold release portion, and the release layer were laminated in this order.

Further, a polyethylene terephthalate film (S100 # 75 Mitsubishi Chemical Corporation) having a thickness of 75 μm is used as the base material for the seal part, and one surface of the base material for the seal part is used for a primer layer having the same composition as the above primer layer. The coating liquid is applied and dried so that the thickness at the time of drying is 1.5 μm to form a primer layer, and the coating liquid for the receiving layer having the following composition is applied on the primer layer so that the thickness at the time of drying is 1.5 μm. It was applied and dried to a thickness of 4.2 μm to form a receiving layer.

Further, an adhesive layer coating liquid having the following composition was applied and dried on the other surface of the base material for the sealing portion so that the thickness at the time of drying was 4.5 μm to form an adhesive layer.

The 101 layer of the first polyester layer having a thickness of 0.065 μm made of polyethylene terephthalate and the 100 layer of the second polyester layer having a thickness of 0.065 μm made of polyethylene terephthalate copolymerized with 12 mol% of isophthalic acid were alternately laminated. A multilayer laminated film having a thickness of 13 μm was prepared and provided on the adhesive layer. Then, the coating liquid for the adhesive layer is applied and dried on the multilayer laminated film so that the thickness at the time of drying is 9 μm to form the adhesive layer, thereby forming a primer on one surface of the base material for the sealing portion. A sealing portion was obtained in which a layer and a receiving layer were provided in this order, and an adhesive layer, a multilayer laminated film, and an adhesive layer were provided in this order on the other surface of the base material for the sealing portion.

Next, an embodiment in which the release portion and the seal portion are integrated by sticking the release portion and the seal portion so that the release layer of the release portion and the adhesive layer of the seal portion face each other. A seal type thermal transfer image receiving sheet of No. 1 was obtained.

(Coating liquid for release layer)
・ Addition Polymerizer Silicone (KS847H Shin-Etsu Chemical Co., Ltd.) 100 parts ・ Toluene 200 parts

(Coating liquid for primer layer)
・ Polyurethane (N-5199 Nippon Polyurethane Industry Co., Ltd.) 15 parts ・ Hardener (Takenate (registered trademark) A-14 Mitsui Chemicals Co., Ltd.) 6 parts ・ Toluene 38.5 parts ・ Methyl ethyl ketone 38.5 parts

(Coating liquid for back layer)
・ 10 parts of polyvinyl butyral (Denka Butyral 3000-1 Denka Co., Ltd.)
・ Nylon filler (average particle size 7.5 μm) 2 parts (MW330 Shinto Paint Co., Ltd.)
-Pt catalyst 0.44 part (CAT-PL-50T Shin-Etsu Chemical Co., Ltd.)
・ Reaction delay agent 0.36 parts (CAT-PLR-5 Shin-Etsu Chemical Co., Ltd.)
・ Titanium chelate 2.4 parts (AT chelate agent Denka Polymer Co., Ltd.)
・ 30 parts of toluene ・ 30 parts of isopropyl alcohol

(Coating liquid for receiving layer)
・ 12 parts of vinyl chloride-vinyl acetate copolymer (Solvine (registered trademark) C Nissin Chemical Industry Co., Ltd.)
・ Epoxy-modified silicone (X-22-3000T Shin-Etsu Chemical Co., Ltd.) 0.8 parts ・ Amino-modified silicone 0.24 parts (X-22-1660B-3 Shin-Etsu Chemical Co., Ltd.)
・ 30 parts of toluene ・ 30 parts of methyl ethyl ketone

(Coating liquid for adhesive layer)
・ 30 parts of polyfunctional polyol (Takelac (registered trademark) A-969-V Mitsui Chemicals, Inc.)
・ Isocyanate (Takenate (registered trademark) A-5 Mitsui Chemicals, Inc.) 10 parts ・ Ethyl acetate 60 parts

(Coating liquid for adhesive layer)
・ Acrylic copolymer (SK Dyne 1251 Soken Chemical Co., Ltd.) 15 parts ・ Hardener (L-45 Soken Chemical Co., Ltd.) 0.33 parts ・ Hardener (E-AX Soken Chemical Co., Ltd.) 0.1 Part ・ Ethyl acetate 16.14 part

(Example 2)
Example 2 in the same manner as in Example 1 except that a multilayer laminated film having a thickness of the first polyester layer of 0.08 μm, a thickness of the second polyester layer of 0.08 μm, and a thickness of 16.5 μm was used. A seal-type thermal transfer image receiving sheet was obtained.

(Example 3)
The seal of Example 3 is the same as that of Example 1 except that a multilayer laminated film having a thickness of the first polyester layer of 0.095 μm, a thickness of the second polyester layer of 0.095 μm, and a thickness of 19 μm is used. A mold thermal transfer image receiving sheet was obtained.

(Comparative Example 1)
A seal-type thermal transfer image receiving sheet of Comparative Example 1 was obtained in the same manner as in Example 1 except that the adhesive layer and the multilayer laminated film were omitted from the seal portion.

(Measurement of transmission spectrum)
The transmittance of the seal portion of each example and the comparative example in the wavelength range of 400 to 780 nm was measured with an ultraviolet visible near infrared spectrophotometer (UV-3100, Shimadzu Corporation). The difference between the average transmittance in the wavelength range of 720 nm or more and 780 nm and the minimum transmittance of light in the wavelength range of 400 nm or more and 700 nm was determined. The results are shown in Table 1.

(Evaluation of discoloration)
The seal-type thermal transfer image receiving sheets of each Example and Comparative Example were held by hand, and the appearance was visually observed from the seal portion side while changing the inclination. The color of the seal portion of the seal type thermal transfer image receiving sheet of Examples 1 to 3 changed when the viewing angle was changed. The color of the seal portion of the seal type thermal transfer image receiving sheet of Comparative Example 1 did not change even if the viewing angle was changed.

10 Release part 11 Base material for release part 12 Release layer 50 Seal part 51 Adhesive layer 52 Multilayer laminated film 53 Adhesive layer 54 Base material for seal part 55 Primer layer 56 Receiving layer 100 Seal type thermal transfer image receiving sheet

Claims (4)

It has a multilayer laminated film and a receiving layer provided on one surface of the multilayer laminated film.
The multilayer laminated film is formed by alternately laminating a first polyester layer and a second polyester layer having a thickness of 0.05 μm or more and 0.5 μm or less, which have different refractive indexes, so as to have a total of 20 layers or more. A thermal transfer image receiving sheet characterized by this. An adhesive layer provided on the other surface of the multilayer laminated film and a mold release portion are further provided.
The claim is characterized in that the seal portion including the receiving layer, the multilayer laminated film and the adhesive layer and the mold release portion are integrated, and the seal portion can be peeled off from the mold release portion. The thermal transfer image receiving sheet according to 1. The thermal transfer image receiving sheet according to claim 2, wherein the sealing portion has a minimum transmittance of light in a wavelength range of 400 nm or more and 700 nm, which is 30% or more lower than an average transmittance in a wavelength range of 720 nm or more and 780 nm. The thermal transfer image receiving sheet according to claim 2 or 3, wherein the sealing portion further has a base material for the sealing portion provided between the multilayer laminated film and the receiving layer.

Images