Seal-type thermal transfer receiving sheet

Abstract

To provide a seal-type thermal transfer receiving sheet usable as a seal for application onto human skin and exhibiting superior print quality.SOLUTION: The seal-type thermal transfer receiving sheet of the present disclosure comprises: a release sheet; and a seal portion having an adhesive layer and a base sheet in this order from the release sheet side, the seal portion being provided so as to be peelable from the release sheet. An arithmetic mean height Sa on a surface of the release sheet on the seal portion side, measured in accordance with ISO 25178, is 0.01 or more and 0.30 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a seal-type thermal transfer image-receiving sheet. [Background technology]

[0002] There are stickers for human skin that are applied to the skin to exhibit design features or other functions, such as nail stickers, body paint stickers, skin stickers, etc. Sticker-type thermal transfer image-receiving sheets are used as such stickers for application to the skin (see, for example, Patent Document 1).

[0003] The sticker-type thermal transfer image receiving sheet disclosed in Patent Document 1 comprises, for example, a release sheet portion and a seal portion comprising, from the release sheet side, an adhesive layer, a base layer, a primer layer, and a receptor layer in this order. When the sticker-type thermal transfer image receiving sheet is used as a seal to be attached to human skin, the seal portion, which has a pattern printed on the receptor layer, is peeled off from the release sheet, and then the adhesive layer is attached to the skin, so that the seal portion is attached to the user's skin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-136748 Summary of the Invention [Problem to be solved by the invention]

[0005] The sticker-type thermal transfer image receiving sheet disclosed in Patent Document 1 has the advantage that highly designed stickers can be created on demand using a thermal transfer printer, but there is a demand for a natural feel (bare skin feel) when applied to human skin. Therefore, studies are being conducted to reduce the thickness of the sticker part that is applied to the user in sticker-type thermal transfer image receiving sheets. This will achieve a natural feel when the sticker part with a printed image is applied to human skin.

[0006] However, if the seal portion of a conventional seal-type thermal transfer image receiving sheet is made thinner, printing using the thermal transfer recording method results in print voids with a rough texture, making it difficult to maintain print quality.

[0007] An object of the present disclosure is to provide a sticker-type thermal transfer image-receiving sheet that can be used as a sticker to be attached to human skin and has excellent print quality. [Means for solving the problem]

[0008] The seal-type thermal transfer image receiving sheet of the present disclosure comprises a release sheet and a seal portion having an adhesive layer and a base sheet in this order from the release sheet side, the seal portion being releasable from the release sheet, and the arithmetic mean height Sa of the surface of the release sheet on the seal portion side, measured in accordance with ISO 25178, is 0.01 or more and 0.30 or less. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a sticker-type thermal transfer image-receiving sheet that can be used as a sticker to be attached to human skin and has excellent print quality. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a seal-type thermal transfer image-receiving sheet according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram illustrating an embodiment of the seal type thermal transfer image receiving sheet of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the following exemplary embodiments. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each layer more schematically than in the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those already described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0012] In the present disclosure, when multiple upper limit candidates and multiple lower limit candidate values ​​are listed for a parameter, the numerical range of the parameter may be constructed by combining any one of the upper limit candidate values ​​with any one of the lower limit candidate values. The parameters include, for example, physical property values, component content ratios, and layer thicknesses. As an example, the following description will be explained: "Parameter B is preferably A1 or more, more preferably A2 or more, and even more preferably A3 or more. Parameter B is preferably A4 or less, more preferably A5 or less, and even more preferably A6 or less." In this example, the numerical range of parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

[0013] In this specification, each of the components (for example, resin materials and additives such as mold release agents) appearing in the following description may be used alone or in combination of two or more types.

[0014] [Stick-on thermal transfer image receiving sheet] The seal-type thermal transfer image receiving sheet of the present disclosure includes a release sheet and a seal portion, and the seal portion is provided so as to be releasable from the release sheet. The seal portion includes, from the release sheet side, an adhesive layer and a base sheet in this order.

[0015] Specific examples of the seal-type thermal transfer image-receiving sheet of the present disclosure will be described below with reference to the drawings. The seal-type thermal transfer image receiving sheet 1 shown in Fig. 1 comprises a release sheet 10, an adhesive layer 21, and a base sheet 22, in this order in the thickness direction. In this example, the adhesive layer 21 and the base sheet 22 constitute the seal portion 20. An image of a desired color, such as flesh color, may be formed on the base sheet 22 using a coloring agent such as a dye.

[0016] The seal-type thermal transfer image receiving sheet may further include a receiving layer (not shown) on the surface of the base sheet. The seal-type thermal transfer image receiving sheet may include a release sheet, an adhesive layer, a base sheet, and a receiving layer in this order in the thickness direction. The seal-type thermal transfer image receiving sheet may further include an adhesive layer, a masking layer, and a protective layer (not shown). The seal-type thermal transfer image receiving sheet may include a release sheet, a pressure-sensitive adhesive layer, a substrate sheet, an adhesive layer, a masking layer, a receiving layer, and a protective layer in this order in the thickness direction. In these examples, an image of a desired color, such as flesh color, may be formed on the receptor layer using a colorant such as a dye.

[0017] In one embodiment, the seal type thermal transfer image receiving sheet of the present disclosure is in the form of a long strip, and FIG. 1 is a cross-sectional view of, for example, a seal type thermal transfer image receiving sheet 1 taken perpendicular to the longitudinal direction.

[0018] <Base sheet> The seal-type thermal transfer image-receiving sheet of the present disclosure includes a substrate sheet, which constitutes a seal portion.

[0019] Examples of the substrate sheet include resin films formed from resin materials. Examples of resin materials include polyurethane, polyester, polyamide, polyimide, polyolefin, vinyl resin, styrene resin, acrylic resin, and cellulose resin. Among the above resin films, polyvinyl chloride (PVC) film, urethane film, and polyethylene film are preferred. The substrate sheet may consist of or contain one type of resin, or may consist of a mixture of two or more types of resin.

[0020] The substrate sheet may contain a plasticizer, such as a phthalate ester compound, a sebacate ester compound, or a phosphate ester compound. Phthalate esters such as DBP (dibutyl phthalate), DOP (di-2-ethylhexyl phthalate, DEHP), n-DOP (dioctyl phthalate), BLP (butyl lauryl phthalate), DLP (dilauryl phthalate), and BBP (butyl benzyl phthalate) are known. However, they are subject to regulation due to concerns about endocrine disruption. Therefore, diethyl phthalate, dipropyl phthalate, and di-n-heptyl phthalate are preferred. Also, adipic acid derivatives such as DOA (dioctyl adipate), azelaic acid derivatives such as DOZ (dioctyl azelate), sebacic acid derivatives such as DOS (dioctyl sebacate), phosphate esters such as TCP (tricresyl phosphate), TXP (trixylenyl phosphate), Santicizer 141 (monoctyl diphenyl phosphate), B-2-X (monobutyl dixylenyl phosphate), TOF (trioctyl phosphate), methyl acetyl ricinoleate, methyl cellosolve ricinoleate epoxidized vegetable oils such as Paraplex G-60, Paraplex G-62, and Monoplex S-71; tri- or tetraethylene glycol esters of C6 to C10 fatty acids; ethylene glycol derivatives such as butylphthalyl butyl glycolate; polyester-based plasticizers such as Paraplex G-25 and Paraplez G-50; chlorinated paraffins and chlorinated compounds such as pentachlorobutyl stearate; petroleum-based auxiliary plasticizers such as Savaloid C and Dutrex 25; and nitrile-based synthetic rubbers such as NBR. The base sheet may contain one type of plasticizer, or may contain two or more types of lubricants.

[0021] The content of the plasticizer in the substrate sheet is preferably 20 parts by mass or more and 100 parts by mass or less, more preferably 30 parts by mass or more and 80 parts by mass or less, per 100 parts by mass of the resin material.

[0022] The base sheet preferably has an elongation rate of 100% or more, and even 250% or more. For example, in the case of a PVC sheet, a base sheet with such an elongation rate can be adjusted to a moderate elongation rate by internal plasticization through copolymerization with vinyl acetate or copolymerization with acrylic resin, or external plasticization with various additives. For example, the elongation rate can be adjusted by adjusting the amount of dioctyl phthalate, a plasticizer. In the case of standard PVC, when the amount of dioctyl phthalate is 10 parts or 30 parts per 100 parts of PVC, the elongation rate can be adjusted to 200% or 300%.

[0023] The substrate sheet may contain additives other than plasticizers. Examples of other additives include ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents. The substrate sheet may contain a colorant as needed. The substrate sheet may contain a colorant to match the color tone of the seal portion to a desired color, such as skin color. Examples of colorants include pigments and dyes.

[0024] The substrate sheet may contain additives other than plasticizers. Examples of other additives include ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents. The substrate sheet may also contain a colorant, if necessary. The substrate sheet may also contain a colorant to match the color tone of the seal portion to a desired color, such as skin color. Examples of colorants include pigments and dyes. When thermal transfer images are directly formed on the substrate sheet, adding a release agent to the substrate sheet is preferable, as it allows for particularly high-density printing, high-speed printing, and printing in high-temperature, high-humidity environments. Furthermore, by considering the compatibility with the substrate sheet, it is possible to effectively adjust the elongation and release properties of the substrate sheet.

[0025] Examples of such release agents include solid waxes such as polyethylene wax, amide wax, and fluororesin powder; fluorine-based or phosphate ester-based surfactants; various modified silicone oils such as silicone oil, reactive silicone oil, and cured silicone oil; and various silicone resins. While oily silicone oils can be used, modified silicone oils are preferred. Preferred modified silicone oils include amino-modified silicone oil, epoxy-modified silicone oil, aralkyl-modified silicone oil, epoxy-aralkyl-modified silicone oil, alcohol-modified silicone oil, vinyl-modified silicone oil, and urethane-modified silicone oil, with epoxy-modified silicone oil, aralkyl-modified silicone oil, and epoxy-aralkyl-modified silicone oil being particularly preferred. It is also preferred to use two or more of these release agents in combination. The amount of these modified silicone oils added is preferably 0.5% by mass or more and 30% by mass or less of the resin material constituting the substrate sheet.

[0026] The elongation percentage of the substrate sheet is preferably in the range of 100% or more and 10,000% or less, more preferably 150% or more and 5,000% or less, and even more preferably 250% or more and 1,000% or less. The elongation of the substrate sheet is determined by a test method conforming to JIS-K-7127 (1999). The elongation can be calculated using the following formula (1). Elongation (%) = 100 × (L - L0) / L0 Equation (1)

[0027] Here, L in formula (1) is the length at which the stretchable sheet breaks (ruptures) when pulled at a speed of 200 mm / min using a tensile tester. L0 in formula (1) is the length of the recorded portion before being pulled by the tensile tester. The tensile tester may be a Tensilon universal material testing machine or the like. By using a base sheet with such elongation, it is possible to produce a seal-type thermal transfer image-receiving sheet that is comfortable to wear, does not feel tight when applied within the range of motion, and allows for natural movement, and is also suitable for print transport when printed using a thermal transfer printer.

[0028] Known examples of substrates having such elongation include polyester film (PET) as a substrate having an elongation of about 50% to 200%, polypropylene as a substrate having an elongation of about 100% to 600%, soft polyvinyl chloride (PVC) as a substrate having an elongation of about 150% to 500%, high-density polyethylene as a substrate having an elongation of about 10% to 300%, medium-density polyethylene as a substrate having an elongation of about 100% to 700%, low-density polyethylene as a substrate having an elongation of about 100% to 1000%, and polyurethane as a substrate having an elongation of about 100 to 10,000%. These materials can be used alone or in combination of two or more. In addition to the resin materials not exemplified here, pigments and other additives can also be included to adjust the elongation percentage of the base sheet within this range, thereby making it possible to produce a sheet that meets the objectives of the present invention.

[0029] The base sheet is made of a material with a thickness of 1000g / (m 2 It is preferable that the material has a moisture permeability of at least 24 hours.

[0030] The thickness of the substrate sheet is preferably 10 μm or more, more preferably 30 μm or more. A seal-type thermal transfer image receiving sheet having a substrate sheet with a thickness of 10 μm or more can, for example, suppress the occurrence of wrinkles when the seal is applied. Furthermore, a seal-type thermal transfer image receiving sheet having a substrate sheet with a thickness of 30 μm or more can easily peel off the release sheet from the seal portion and apply it without the substrate sheet (seal portion) becoming distorted, thereby improving workability. When trying to create a thermal transfer image receiving sheet that is highly stretchable and not stiff or stiff when applied to the skin, it is necessary to eliminate the void film, which contributes greatly to flexibility and heat insulation. This results in a significant deterioration in image uniformity compared to conventional thermal transfer image receiving seal structures. The thickness of the substrate sheet is preferably 100 μm or less, more preferably 80 μm or less. A sticker-type thermal transfer image receiving sheet including such a substrate sheet can, for example, suppress the discomfort felt by the user after the sticker is applied. As described above, by setting the thickness of the base sheet within this range, it is possible to adjust the thickness and surface properties of the release sheet. The thickness of the substrate sheet is preferably 100 μm or less, more preferably 80 μm or less. A sticker-type thermal transfer image receiving sheet including such a substrate sheet can, for example, suppress the discomfort felt by the user after the sticker is applied.

[0031] A thermal transfer image may be provided directly on the surface of the base sheet, which allows the total thickness of the seal portion to be reduced, thereby preventing, for example, discomfort felt by the user after the seal is applied.

[0032] A printed layer may be provided on the surface of the substrate sheet. The printed layer may be a layer for adjusting the color tone of the laminated sheet to a desired color, such as skin color. The printed layer contains a colorant. Examples of the colorant include pigments and dyes.

[0033] <Adhesive layer> The seal-type thermal transfer image receiving sheet of the present disclosure includes an adhesive layer, which constitutes a seal portion.

[0034] The adhesive layer is formed using, for example, a pressure-sensitive adhesive. A pressure-sensitive adhesive is a material that has adhesive properties at room temperature and can be attached to an adherend by applying pressure. For example, even when an adherend attached to the adhesive layer is peeled off, the adhesive layer retains practical adhesive strength.

[0035] Examples of adhesives include acrylic adhesives, urethane adhesives, silicone adhesives, rubber adhesives, vinyl alkyl ether adhesives, polyester adhesives, polyamide adhesives, and fluorine-based adhesives. The adhesive may contain a solvent. For example, either a water-based or solvent-based solvent can be used. For medical use, it is preferable to select an adhesive that causes little skin rash or irritation to the skin, and for example, acrylic adhesives and urethane adhesives are preferred.

[0036] The adhesive layer may contain additives. Examples of additives include ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents. The adhesive layer may also contain colorants as needed. The adhesive layer may also contain solvents and plasticizers. Examples of solvents that can be used include both water-based and solvent-based solvents. Examples of plasticizers include phthalate-based plasticizers such as dioctyl phthalate, diisononyl phthalate, octyldecyl phthalate, and diisodecyl phthalate; adipic acid-based plasticizers such as di-2-ethylhexyl adipate, diisononyl adipate, and diisodecyl adipate; di-2-ethylhexyl azelate; di-2-ethylhexyl sebacate; tricresyl phosphate; trixylyl phosphate; tributyl phosphate; tri-2-ethylhexyl phosphate; octyldiphenyl phosphate; chlorinated paraffin; chlorinated fatty acid ester; and epoxidized soybean oil. The adhesive layer may contain a colorant to match the color tone of the laminated sheet to a desired color, such as skin color, etc. Examples of colorants include pigments and dyes.

[0037] The adhesive strength of the adhesive layer is preferably 100 gf / 50 mm or more and 10,000 gf / 50 mm or less, more preferably 500 gf / 50 mm or more and 5,000 gf / 50 mm or less, and even more preferably 1,000 gf / 50 mm or more and 3,000 gf / 50 mm or less. If the adhesive strength is 10,000 gf / 50 mm or less, there is little risk of damaging the adherend (particularly human or animal skin) when the sheet is applied incorrectly or removed during replacement. If the adhesive strength is 100 gf / 50 mm or more, for example, adhesive strength to the adherend (particularly human or animal skin) can be ensured, and peeling of the sheet due to sweating, movement, etc. can be prevented.

[0038] The thickness of the adhesive layer is preferably 3 μm or more, more preferably 5 μm or more, and preferably 40 μm or less, more preferably 30 μm or less. The thickness of the adhesive layer is, for example, 10 μm or more and 20 μm or less.

[0039] <Release sheet> The seal-type thermal transfer image-receiving sheet of the present disclosure includes a release sheet. The release sheet constituting the seal-type thermal transfer image receiving sheet of the present disclosure has an arithmetic mean height Sa of 0.01 or more and 0.30 or less on the surface of the release sheet on the seal side (symbol 10a in Figure 1) measured in accordance with ISO 25178. If the arithmetic mean height Sa is 0.30 or less, when a thermal transfer image is formed on a seal-type thermal transfer image receiving sheet using a thermal transfer printer, even if the sheet is sandwiched between rollers including a thermal transfer roller in the thermal transfer printer and a load is applied, the uneven shape of the seal side of the release sheet is not reflected on the surface of the seal portion, thereby ensuring excellent printing quality. The upper limit of the arithmetic mean height Sa is preferably 0.25 or less, and more preferably 0.21 or less.

[0040] Examples of release sheets include release paper with at least one release-treated surface of a paper substrate and resin films with at least one release-treated surface of a resin film. Examples of release treatments include treatments using release agents such as silicone resin-based release agents, alkyd resin-based release agents, long-chain alkyl compound-based release agents, and fluororesin-based release agents. Examples of resin films include resin films formed from resin materials such as polyolefin, vinyl resin, styrene resin, acrylic resin, fluororesin, polyester, and polyamide. Among these, polyesters such as polyethylene terephthalate (PET) are preferred from the standpoints of smoothness, rigidity, and cost. Furthermore, these release sheets have been treated with an antistatic agent to reduce the surface resistance to 1×10 14 It is preferable that the resistance is treated to be Ω / □ or less. Furthermore, it is preferable that the back surface of these release sheets is matte-finished.

[0041] The thickness of the release sheet is preferably 50 μm or more, more preferably 100 μm or more, even more preferably 120 μm or more, and is preferably 250 μm or less, more preferably 200 μm or less, even more preferably 180 μm or less. The thickness of the release sheet is, for example, 50 μm or more and 300 μm or less.

[0042] (Concealment layer) The seal type thermal transfer image receiving sheet of the present disclosure may be provided with a hiding layer. The hiding layer may be a white primer layer containing a white pigment and a resin material. Examples of white pigments include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, and calcium carbonate. Among these, titanium oxide is preferred from the viewpoint of whiteness. The hiding layer may contain one or more white pigments.

[0043] The content of the white pigment in the hiding layer is preferably 40% by mass or more and 85% by mass or less, more preferably 50% by mass or more and 80% by mass or less. By increasing or decreasing the content of the white pigment in the hiding layer, the hiding ratio of the hiding layer can be adjusted to a desired value.

[0044] Examples of resin materials include (meth)acrylic resins, polyolefins, styrene resins, vinyl resins such as ethylene-vinyl acetate copolymers and vinyl chloride-vinyl acetate copolymers, polyesters, polyamides, imide resins, cellulose resins, polyol resins, polycarbonates, and ionomer resins. The hiding layer can contain one or more resin materials.

[0045] The content of the resin material in the hiding layer is preferably 10% by mass to 70% by mass, more preferably 10% by mass to 50% by mass, which can prevent re-aggregation of the white pigment and provide high hiding power.

[0046] The hiding layer may contain additives. Examples of additives include fillers, plasticizers, antistatic agents, UV absorbers, release agents, and dispersants. The hiding layer can contain one or more additives.

[0047] The thickness of the hiding layer is preferably 0.6 μm or more, more preferably 0.8 μm or more, and even more preferably 1.0 μm or more. The thickness of the hiding layer is preferably 6 μm or less, more preferably 5 μm or less, and even more preferably 4 μm or less. Here, increasing the thickness of the hiding layer can hide the color of the base. On the other hand, decreasing the thickness of the hiding layer can reduce the hiding rate of the hiding layer.

[0048] The concealing layer can be formed, for example, by dispersing or dissolving the components described above in a suitable solvent to prepare a coating liquid, which is then applied to any layer to be provided on the base sheet of the sealing portion using the known coating method described above, and then dried.

[0049] (adhesive layer) The seal type thermal transfer image receiving sheet of the present disclosure may have an adhesive layer. In one embodiment, the seal-type thermal transfer image-receiving sheet may have an adhesive layer between the substrate sheet and the concealing layer, thereby improving the adhesion between the substrate sheet and the concealing layer.

[0050] The adhesive layer preferably contains a resin material. Examples of the resin material include (meth)acrylic resin, vinyl resin, polyolefin, polyester, polyurethane, epoxy resin, urea resin, melamine resin, and phenol resin. The adhesive layer can contain one or more resin materials.

[0051] The content of the resin material in the adhesive layer is preferably 70% by mass or more and 100% by mass or less, and more preferably 80% by mass or more and 100% by mass or less.

[0052] The adhesive layer may be a layer obtained by curing a resin material with a curing agent, such as an isocyanate compound, an aliphatic amine, a cyclic aliphatic amine, an aromatic amine, or an acid anhydride.

[0053] The thickness of the adhesive layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and preferably 10 μm or less, more preferably 2 μm or less. The thickness of the adhesive layer is, for example, 0.1 μm or more and 10 μm or less.

[0054] The adhesive layer can be formed, for example, by dispersing or dissolving the components described above in a suitable solvent to prepare a coating liquid, which is then applied onto the hiding layer by the known coating method described above and dried.

[0055] (receptor layer) The seal-type thermal transfer image-receiving sheet of the present disclosure may include a receptor layer, which is located on the surface of the substrate sheet opposite the adhesive layer in the seal portion. The receiving layer is a layer for receiving dyes and the like transferred from the thermal transfer sheet. For example, when forming an image (thermal transfer image) using a printer, the image may be formed on a receiving layer previously provided on a substrate sheet, or a concealing layer may be formed on a transfer sheet, and the receiving layer may be provided on the concealing layer. The image may be, for example, an image for adjusting the color tone of the seal portion to a desired color, such as skin color.

[0056] The material constituting the receiving layer may be, for example, a resin material. Examples of the resin material include polyolefin, vinyl resin, styrene resin, acrylic resin, polyester, polyamide, polyimide, polyurethane, polycarbonate, cellulose resin, and ionomer resin. Examples of the polyolefin include polyethylene and polypropylene. Examples of the vinyl resin include polyvinyl chloride, polyvinyl acetate, and vinyl chloride-vinyl acetate copolymer. Examples of the polyester include polyethylene terephthalate and polyethylene naphthalate. The resin material constituting the receiving layer is preferably a vinyl resin, and more preferably a vinyl chloride-vinyl acetate copolymer.

[0057] The content of the resin material in the receiving layer is preferably 70% by mass or more, and more preferably 80% by mass or more, relative to the total mass of the receiving layer, which can provide the receiving layer with sufficient durability, for example.

[0058] The receiving layer may contain additives such as ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents.

[0059] The content of the additive in the receiving layer is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, based on the total mass of the receiving layer. The content of the additive in the receiving layer is, for example, 1% by mass or more and 30% by mass or less.

[0060] The thickness of the receptor layer is preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.8 μm or more. The thickness of the receptor layer is preferably 6.0 μm or less, more preferably 4.0 μm or less, and even more preferably 3.0 μm or less. Here, if the thickness of the receptor layer is above the lower limit, sufficient print density cannot be obtained. On the other hand, if the thickness of the receptor layer is below the upper limit, the conformability when applied to the skin is insufficient, and a sense of unity with the skin cannot be obtained.

[0061] When a receiving layer is provided on a substrate sheet in advance, the solvent contained in the coating liquid may melt and damage the substrate sheet, or cause denaturation or deformation during the process of applying and drying a coating liquid for the receiving layer on the hiding layer. In this case, it is preferable to transfer the receiving layer onto the substrate sheet by thermal transfer. The receiving layer may be provided on the substrate sheet in advance, or may be provided by thermal transfer onto the substrate sheet during image formation.

[0062] (protective layer) The seal type thermal transfer image receiving sheet of the present disclosure may be provided with a protective layer. The seal-type thermal transfer image receiving sheet of the present disclosure may have a seal portion that includes, for example, an adhesive layer, a base sheet, a concealing layer, a receiving layer, and a protective layer in this order, or may have an adhesive layer, a base sheet, a concealing layer, a receiving layer on which an image is formed, and a protective layer in this order.

[0063] The protective layer may be made of a resin material, such as polyester, polyamide, polyurethane, polycarbonate, vinyl resin, styrene resin, acrylic resin, acrylic polyol resin, cellulose resin, phenoxy resin, epoxy resin, silicone-modified versions of these resins, ultraviolet-absorbing resins, and ionizing radiation-curable resins.

[0064] Examples of polyesters include polyethylene terephthalate and polyethylene naphthalate. Examples of vinyl resins include vinyl chloride-vinyl acetate copolymer, polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, and polyvinyl pyrrolidone. Examples of cellulose resins include ethyl cellulose, hydroxyethyl cellulose, ethylhydroxycellulose, methyl cellulose, and cellulose acetate.

[0065] Examples of ionizing radiation curable resins include resins obtained by crosslinking and curing a radical polymerizable polymer or a radical polymerizable oligomer by irradiating it with ionizing radiation. Specific examples include resins obtained by adding a photopolymerization initiator to a radical polymerizable polymer or a radical polymerizable oligomer as needed, and polymerizing and crosslinking the resulting polymer or oligomer by irradiating it with an electron beam or ultraviolet light.

[0066] The content of the resin material in the protective layer is preferably 80% by mass or more, and more preferably 85% by mass or more, relative to the total mass of the protective layer, which can provide, for example, sufficient durability to the protective layer.

[0067] The protective layer may contain additives. Examples of additives include ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents. The protective layer may contain a colorant, if necessary. The protective layer may contain a colorant to match the color tone of the laminated sheet to a desired color, such as skin color. Examples of colorants include pigments and dyes.

[0068] The content of the additive in the protective layer is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, relative to the total mass of the protective layer. The content of the additive in the protective layer is, for example, 1% by mass or more and 20% by mass or less.

[0069] The thickness of the protective layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, even more preferably 1 μm or more, and preferably 20 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less. Such a protective layer can, for example, impart sufficient protective function to the seal-type thermal transfer image-receiving sheet. The thickness of the protective layer is, for example, 0.1 μm or more and 20 μm or less.

[0070] The protective layer can be formed, for example, by applying a coating liquid containing the above-mentioned materials to a receiving layer or the like by a known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, or rod coating, and then drying the coating.

[0071] The protective layer can be formed, for example, by preparing a thermal transfer sheet having a protective layer, superimposing the thermal transfer sheet on a substrate film or the like corresponding to the substrate sheet, and transferring the protective layer onto the receiving layer or the receiving layer on which an image is formed by a thermal transfer process.

[0072] <Sticker-type thermal transfer image receiving sheet> The total thickness of the seal-type thermal transfer image receiving sheet of the present disclosure, which is composed of a release sheet, an adhesive layer, and a substrate sheet, is preferably 100 μm or more, more preferably 120 μm or more, even more preferably 150 μm or more, and preferably 300 μm or less, more preferably 250 μm or less, and even more preferably 220 μm or less. The total thickness of the seal-type thermal transfer image receiving sheet is, for example, 100 μm or more and 300 μm or less. When the total thickness of the seal-type thermal transfer image receiving sheet is within the above range, when a thermal transfer image is formed directly on the surface of the substrate sheet of the seal portion or on the receiving layer, the unevenness of the surface of the release sheet is less likely to be reflected on the surface of the substrate sheet or the surface of the receiving layer, making it easier to ensure smoothness, resulting in excellent print quality. Furthermore, when the thermal transfer image is formed and the sheet is used as a seal to be applied to human skin, the discomfort felt by the user after application of the seal can be reduced.

[0073] (Mechanism of action) When printing a thermal transfer sheet using a thermal transfer printer, the thermal transfer sheet receives the dye while being affected by external factors such as heat, pressure, and tensile stress. For example, sticker-type thermal transfer image receiving sheets used for applications that are attached to human skin, such as nail stickers, body paint stickers, and skin stickers, are becoming thinner in the seal area, making them more susceptible to changes in external factors such as the thermal transfer printer. Furthermore, if the release sheet has significant irregularities on the surface of the seal area, the uneven shape will be reflected on the surface of the base sheet, adversely affecting the print. In particular, sticker-type thermal transfer image receiving sheets that do not have a receptor layer have a thinner overall sheet thickness, and therefore may be more susceptible to the three-dimensional shape of the release sheet surface than ordinary image receiving sheets.

[0074] Therefore, the inventors of the present invention conducted extensive research and found that the arithmetic mean height Sa of the surface on the sealed side of the release sheet affects print quality. Specifically, they found that if a release sheet with large irregularities on the sealed side of the release sheet is used, the irregularities are reflected on the surface of the base sheet when a thermal transfer image is formed using a thermal transfer printer, adversely affecting the print. In contrast, they found that if a release sheet with small irregularities on the sealed side of the release sheet is used, the smoothness of the surface of the base sheet is more easily ensured when a thermal transfer image is formed using a thermal transfer printer, thereby suppressing adverse effects on the print.

[0075] The inventors then used the arithmetic mean height Sa measured in accordance with ISO 25178 as an indicator of the uneven shape of the surface on the seal side of the release sheet, and found that if this arithmetic mean height Sa is 0.01 or more and 0.30 or less, a seal-type thermal transfer image-receiving sheet with excellent printing quality can be obtained.

[0076] (Application) An example of the use of the seal-type thermal transfer image-receiving sheet of the present disclosure will be described below. In one embodiment, the sticker-type thermal transfer image receiving sheet can be used as a skin design sheet (a sticker for application to human skin; a skin sheet) by forming an image (thermal transfer image) on the surface of the base sheet, or by forming an image on the receiving layer if the sheet has one. Examples of skin design sheets include nail stickers, body paint stickers, and tattoo stickers.

[0077] In one embodiment, a skin design sheet can be produced from a seal-type thermal transfer image receiving sheet. For example, a plurality of skin design sheets may be produced from a seal-type thermal transfer image receiving sheet. For example, a roll of seal-type thermal transfer image receiving sheet may be cut to produce individual seal-type thermal transfer image receiving sheets in the product form.

[0078] By attaching the skin-design sheet to the user's skin with the adhesive layer in contact with the skin, users can easily enjoy body painting, etc. Also, stickers made by printing images of personal favorite animals, pets, theme park characters, etc. can be attached to any location of their choice, such as the arm or cheek, for enjoyment. Furthermore, photos of favorite places, favorite idols, favorite athletes, buildings, landscapes, etc. can be printed and enjoyed at any time at any location, such as an event venue, theme park, or concert venue.

[0079] In addition, by producing a skin design sheet by on-demand printing from a photographed image of the user onto a sticker-type thermal transfer image receiving sheet, the color of the skin design sheet can be matched to the natural skin color of the user, thereby reducing the discomfort felt when the skin design sheet is applied to the user's skin.

[0080] [Manufacturing method of skin design sheet] According to the seal-type thermal transfer image-receiving sheet of the present disclosure, for example, a skin-design sheet can be produced by a thermal transfer process. A long substrate sheet corresponding to the seal-type thermal transfer image receiving sheet of the present disclosure is prepared. The substrate sheet may be provided with an adhesive layer and a release sheet. This substrate sheet and thermal transfer sheet are set in a thermal transfer printer.

[0081] The thermal transfer sheet comprises a substrate sheet and a transfer-type receiving layer, a dye layer, and optionally a protective layer, which are provided in surface order on one side of the substrate sheet. The transfer-type receiving layer is a transparent layer that receives the dye transferred from the thermal transfer sheet. Examples of the dye layer include a yellow dye layer, a magenta dye layer, and a cyan dye layer. The dye layer contains a binder resin and a sublimable dye. Known materials can be used for the yellow dye layer, the magenta dye layer, and the cyan dye layer. Details of the receiving layer and the protective layer are as described above. When printing directly on the surface of the substrate sheet or when a receiving layer is previously provided on the substrate sheet, it is not necessary for the thermal transfer sheet to have a receiving layer or to transfer the receiving layer as described below.

[0082] The thermal transfer printer includes a thermal head and a platen roll that sandwich the substrate sheet and heat the thermal transfer sheet. The thermal head heats the receptor layer of the transfer mold, transferring the receptor layer onto the substrate sheet. Next, the thermal head sequentially heats the yellow dye layer, magenta dye layer, and cyan dye layer, for example, based on the data of the skin design sheet, transferring the dyes to the receptor layer transferred onto the substrate sheet to form an image. If necessary, the protective layer of the thermal transfer sheet is then heated, transferring the protective layer onto the receptor layer on which the image has been formed.

[0083] If necessary, the surface of the base sheet may be subjected to a shaping process such as embossing to form a concave-convex shape. For example, an embossing plate or a shaping sheet may be used in the embossing process. The embossing plate and the shaping sheet may be used without any particular restrictions. The surface shapes of the embossing plate and the shaping sheet and the surface shapes shaped by them are almost the inverse of each other.

[0084] The long seal-type thermal transfer image-receiving sheet is cut parallel to the width direction of the sheet using a cutter in a thermal transfer printer to obtain a sheet-like seal-type thermal transfer image-receiving sheet. If necessary, a protective sheet may be attached to the seal surface of the sheet-like seal-type thermal transfer image-receiving sheet.

[0085] Next, using a known cutting device, the sticker-type thermal transfer image receiving sheet is cut into the shape of the product form of the skin design sheet. For example, when the sticker-type thermal transfer image receiving sheet is viewed in a plane, the sticker-type thermal transfer image receiving sheet is punched out into a circular shape. The shape is not particularly limited, and it is possible to cut out not only geometric patterns such as rectangles, diamonds, hearts, and ellipses, but also patterns matching the print design, such as animal shapes, human shapes, building shapes, and vehicle shapes. Furthermore, since the sticker-type thermal transfer image receiving sheet of the present invention does not peel off at the leading edge during printing, it can be printed using a thermal transfer printer as a sticker-type thermal transfer image receiving sheet with pre-cut "frames."

[0086] Furthermore, since the seal-type thermal transfer image-receiving sheet of the present invention has a sufficient separator thickness, it is possible to easily adjust the depth of the half cut when half-cutting with a conventionally known half-cutting blade before printing. As a result, half-cut seals can be produced as soon as they are ejected from the printer, and seals with desired designs can be easily obtained on demand without the need for a process of cutting the sheet again after printing.

[0087] In this manner, a skin design sheet having a desired shape can be produced. In the above method, the adhesive layer may be provided on the substrate sheet after the thermal transfer process. In this case, it is preferable to provide a release sheet after the adhesive layer is formed.

[0088] In one embodiment of the seal-type thermal transfer image-receiving sheet of the present disclosure, a method for producing a skin design sheet by a thermal transfer process has been described, but the method for producing a skin design sheet is not limited to the above method.

[0089] Furthermore, in one embodiment of the seal-type thermal transfer image-receiving sheet of the present disclosure, a mode in which a thermal transfer printer (thermal printer) is used in the method for producing a skin-design sheet has been described, but the present invention is not limited to this. The printer may be a thermal transfer printer, an inkjet printer, etc. Among these, a thermal transfer printer is preferable. As a thermal transfer printer for use with the seal-type thermal transfer image-receiving sheet of the present disclosure, a dye-sublimation thermal transfer printer, which has excellent color reproducibility and gradation, is suitable.

[0090] The present disclosure relates to, for example, the following [1] to [7]. [1] A seal-type thermal transfer image receiving sheet comprising a release sheet and a seal portion having an adhesive layer and a base sheet in this order from the release sheet side, the seal portion being provided so as to be releasable from the release sheet, A seal-type thermal transfer image-receiving sheet, wherein the surface of the release sheet on the seal portion side has an arithmetic mean height Sa of 0.01 or more and 0.30 or less, as measured in accordance with ISO 25178. [2] The seal-type thermal transfer image-receiving sheet according to [1] above, wherein the thickness of the release sheet is 50 μm or more and 250 μm or less. [3] The seal type thermal transfer image receiving sheet according to the above [1] or [2], wherein the thickness of the seal type thermal transfer image receiving sheet is 100 μm or more and 300 μm or less. [4] The seal-type thermal transfer image-receiving sheet according to any one of the above [1] to [3], wherein a thermal transfer image is provided directly on the surface of the base sheet. [5] The sealing portion further comprises a receiving layer, The seal-type thermal transfer image-receiving sheet according to any one of the above [1] to [4], wherein the receiving layer is located on the surface of the base sheet opposite to the adhesive layer. [6] The seal-type thermal transfer image-receiving sheet according to the above [5], wherein a thermal transfer image is provided on the receiving layer. [7] The seal-type thermal transfer image-receiving sheet according to any one of the above [1] to [6], which is for sublimation transfer thermal transfer. [Example]

[0091] The seal-type thermal transfer image-receiving sheet of the present disclosure will be described in more detail with reference to examples, but the seal-type thermal transfer image-receiving sheet of the present disclosure is not limited to these examples. In the following description, "parts" means "parts by mass."

[0092] [Preparation] <Base sheet> Lonseal soft PVC sheet (white), thickness: 70 μm

[0093] <Release sheet> The release sheets used in the preparation of the seal-type thermal transfer image-receiving sheets are as follows. Release sheet 1: Release-treated PET sheet, thickness: 100 μm, Sa 0.15 μm Release sheet 2: Polyester synthetic paper, Thickness: 100 μm, Sa 0.07 μm Release sheet 3: New tack release transparent PET, thickness: 75 μm, Sa 0.03 μm Release sheet 4: Toray T60 release treatment, thickness: 100 μm, Sa 0.02 μm Release sheet 5: New tack release paper, thickness: 75 μm, Sa 0.37 μm Release sheet 6: ADTEC release paper, thickness: 160 μm, Sa 0.36 μm Release sheet 7: Nitto Denko release paper, thickness: 160 μm, Sa 0.37 μm Release sheet 8: Toray T60 release treatment, thickness: 50 μm, Sa 0.02 μm Release sheet 9: Release-treated PET sheet, thickness: 75 μm, Sa 0.19 μm

[0094] Release sheets 1 and 9 were produced by adjusting the surface roughness of the chill roll used in producing the PET sheet. The PET resin was extruded and then biaxially stretched. The release sheets were then produced by surface treatment with the release agent described below. The surface roughness of the release-treated surface was measured, finding Sa 0.15 μm for Release sheet 1 and Sa 0.19 μm for Release sheet 9. (Release layer coating liquid) KS-847H (addition polymerization silicone, manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts CAT-PL-50T (Shin-Etsu Silicone Co., Ltd., Pt catalyst) 1 part 200 parts toluene

[0095] The release sheet 2 was prepared as follows. A release sheet was prepared by coating one side of a 100 μm release substrate (a corona-treated polyethylene terephthalate film, CRISPER G-1212, manufactured by Toyobo Co., Ltd.) with a release layer of the following composition. The surface roughness of the release-treated surface was Ra 0.07 μm. (Release layer coating liquid) KS-847H (addition polymerization silicone, manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts CAT-PL-50T (Shin-Etsu Silicone Co., Ltd., Pt catalyst) 1 part 200 parts toluene

[0096] Release sheets 4 and 8 were prepared by treating one side of a Toray PET sheet (T60) with the release agent described below. The surface roughness of the release-treated surface was measured, and was found to be Sa 0.02 μm for Release Sheet 4 and Sa 0.02 μm for Release Sheet 8. (Release layer coating liquid) KS-847H (addition polymerization silicone, manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts CAT-PL-50T (Shin-Etsu Silicone Co., Ltd., Pt catalyst) 1 part 200 parts toluene

[0097] <Arithmetic mean height Sa> For the above-mentioned release sheets 1 to 9, the arithmetic mean height Sa of the surface on the side to be stuck to the seal portion was measured in accordance with ISO 25178. The results are shown in Table 1. (Evaluation method) Measurements were performed using a 3D surface roughness and shape measuring instrument, Surfcom 570A-3DF, manufactured by Tokyo Seimitsu, under the following conditions. (Measurement conditions) (Length) X: 5.000mm, Y: 5.000mm (Size) X: 2048 points, Y: 202 points (Distance) X: 2443μm, Y: 24.88μm

[0098] <Sticker-type thermal transfer image receiving sheet> Example 1 An adhesive layer having a thickness of 10 μm was formed on the surface of the base sheet using an acrylic adhesive (SK Dyne MD-1, manufactured by Soken Chemical Industries, Ltd.), and was then attached to the surface of the release sheet 1 on which the arithmetic mean height Sa had been measured, to obtain a seal-type thermal transfer image receiving sheet of Example 1.

[0099] (Examples 2 to 5, 7 and Comparative Examples 1 to 3) The seal-type thermal transfer image-receiving sheets of Examples 2 to 5 and 7 and Comparative Examples 1 to 3 were obtained in the same manner as in Example 1, except that the release sheets shown in Table 1 were used instead of Release Sheet 1.

[0100] Example 6 A seal-type thermal transfer image-receiving sheet was prepared by the following procedure, using release sheet 2 instead of release sheet 1 and forming an image-receiving layer on voided PET instead of the base sheet (soft PVC). A 75 μm thick microvoided PET film (FK202, Toyobo Co., Ltd.) was used as the substrate sheet, and an adhesive layer was formed by applying and drying an adhesive layer coating liquid having the following composition to one side of the substrate sheet so that the thickness when dried was 1.5 μm. (Coating liquid for adhesive layer) Polyurethane (Nippolan (registered trademark) 5199 Tosoh Corporation) 14 parts Titanium oxide (TCA-888 Sakai Chemical Industry Co., Ltd.) 28 parts Toluene 13 parts 34 parts methyl ethyl ketone 11 parts isopropyl alcohol

[0101] Next, a receiving layer coating solution having the following composition was applied onto the adhesive layer and dried to a dry thickness of 4.5 μm, thereby forming a receiving layer. (Coating liquid for receiving layer) Vinyl chloride-vinyl acetate copolymer 12 parts (Solvine (registered trademark) C, Nissin Chemical Industry Co., Ltd.) Epoxy-modified silicone 0.8 parts (X-22-3000T Shin-Etsu Chemical Co., Ltd.) Amino-modified silicone 0.24 parts (X-22-1660B-3 Shin-Etsu Chemical Co., Ltd.) 30 parts toluene 30 parts methyl ethyl ketone

[0102] Next, a coating liquid for adhesive layer having the following composition was applied to the other surface of the substrate sheet so as to have a dry thickness of 9 μm, followed by drying, to form an adhesive layer. (Coating liquid for adhesive layer) Acrylic copolymer (SK Dyne 1251, Soken Chemical & Engineering Co., Ltd.) 15 parts Curing agent (L-45 Soken Chemical Co., Ltd.) 0.33 parts Hardener (E-AX Soken Chemical Co., Ltd.) 0.1 parts Ethyl acetate 16.14 parts

[0103] As a result, a seal part having a thickness of 90 μm was obtained, which was made by laminating the receiving layer, adhesive layer, base sheet, and pressure-sensitive adhesive layer in this order. The release sheet 2 and the previously prepared seal portion were bonded together so that the release layer of the release portion 2 faced the adhesive layer of the seal portion, thereby obtaining a seal-type thermal transfer image receiving sheet of Example 6 in which the release sheet and the seal portion were integrated.

[0104] [Evaluation method] <Print quality> The seal type thermal transfer image receiving sheets of Examples 1 to 7 and Comparative Examples 1 to 3 were evaluated for roughness of the images formed on the surface of the substrate sheet by the following procedure. The evaluation results are shown in Table 1.

[0105] First, the seal-type thermal transfer image-receiving sheets (width 152 mm) of Examples 1 to 7 and Comparative Examples 1 to 3 were set in a thermal transfer printer (DS620, manufactured by Dai Nippon Printing Co., Ltd.), and images were formed on the surface of each base sheet under the following conditions. (Printing conditions) Solid gray image 127 / 256 shades

[0106] (Evaluation method) The prints created using the above method were visually evaluated by five subjects. The subjects were selected after confirming in advance that their evaluations using a standard sample were consistent. (Evaluation criteria) ◎: All five people rated it as having no roughness and excellent print quality. ○: All five people evaluated that there was a rough feeling, but that there was no problem in actual use. ×: All five people rated it as having a rough texture.

[0107] <Tip peeling> The seal type thermal transfer image receiving sheets of Examples 1 to 7 and Comparative Examples 1 to 3 were evaluated for peeling at the leading edge during printing by the following procedure. The evaluation results are shown in Table 1.

[0108] First, the seal-type thermal transfer image-receiving sheets (width 152 mm) of Examples 1 to 7 and Comparative Examples 1 to 3 were set in a thermal transfer printer (DS620, manufactured by Dai Nippon Printing Co., Ltd.), and images were formed on the surface of each substrate sheet under the following conditions. The resulting prints were then evaluated according to the following evaluation criteria. (Printing conditions) Solid gray image 127 / 256 shades (Evaluation criteria) ◎: Printing was possible in both 40℃ and 25℃ environments without peeling. ○: Printing was possible in a 25℃ environment without peeling. ×: Peeling occurred in an environment of 25°C.

[0109] <Applied feel> The seal type thermal transfer image receiving sheets of Examples 1 to 7 and Comparative Examples 1 to 3 were evaluated for adhesion feeling during printing according to the following evaluation criteria. The evaluation results are shown in Table 1.

[0110] (Preparation of a seal-type thermal transfer image receiving sheet with half cuts) As shown in Figure 2, an image-receiving sheet was produced in which 30 mm wide and 20 mm long frames (31 in Figure 2) were evenly arranged in half cuts, two in the width direction and two in the length direction, for a total of 2 x 2 = 4 frames, within a single screen (30 in Figure 2) with a width of 152 mm and a length of 109 mm. In order to ensure that the position of this half-cut frame matches the image printed by the DS620, a "detection hole (reference number 32 in Figure 2)" for positioning by the DS620 was provided for each image on the thermal transfer image receiving sheet, separate from the frame.

[0111] (Printing conditions) An image of four American flags designed to fit this half-cut frame was printed on a printer. The "American Flag" design piece was peeled off and attached to the wrist, and the adhesion was evaluated according to the following criteria. (Evaluation criteria) ◎: No rough or tight feeling. 〇: It doesn't feel stiff, but there is a slight feeling of tightness. ×: Feels rough and tight.

[0112] [Table 1] [Explanation of symbols]

[0113] 1. Sticker-type thermal transfer image receiving sheet 10 Release sheet 10a surface 20 Seal part 21 Adhesive layer 22 Base sheet 3. Seal-type thermal transfer image receiving sheet with half cut 30 Thermal transfer image receiving sheet 31 30mm wide, 20mm long piece 32 Detection hole

Claims

1. A seal-type thermal transfer image receiving sheet comprising a release sheet and a seal portion having an adhesive layer and a base sheet in this order from the release sheet side, the seal portion being provided so as to be releasable from the release sheet, A seal-type thermal transfer image-receiving sheet, wherein the surface of the release sheet on the seal portion side has an arithmetic mean height Sa of 0.01 or more and 0.30 or less, as measured in accordance with ISO 25178.

2. 2. The seal-type thermal transfer image-receiving sheet according to claim 1, wherein the thickness of the release sheet is 50 [mu]m or more and 250 [mu]m or less.

3. 2. The seal type thermal transfer image receiving sheet according to claim 1, wherein the thickness of the seal type thermal transfer image receiving sheet is 100 [mu]m or more and 300 [mu]m or less.

4. 2. The seal-type thermal transfer image-receiving sheet according to claim 1, wherein a thermal transfer image is provided directly on the surface of the base sheet.

5. The seal portion further comprises a receiving layer, The seal-type thermal transfer image receiving sheet according to claim 1 , wherein the receiving layer is located on the surface of the base sheet opposite to the adhesive layer.

6. 6. The seal type thermal transfer image receiving sheet according to claim 5, wherein the receiving layer is provided with a thermal transfer image.

7. 2. The seal type thermal transfer image receiving sheet according to claim 1, which is for sublimation transfer type thermal transfer.

Images