JP7659744B2 - Laminated Sheet - Google Patents

Description

This disclosure relates to a laminated sheet.

Skin design sheets that are applied to the skin are known (see, for example, Patent Document 1). Examples of skin design sheets include tattoo stickers and skin concealing sheets. Tattoo stickers are sheets with various designs printed on a base material. Tattoo stickers are sold, for example, at variety stores, sporting and music event venues, amusement parks, and the like, and are used to liven up the atmosphere. Skin concealing sheets are sheets with a base material that has been pre-colored with a specific color by screen printing or the like. Skin concealing sheets are used, for example, to conceal discolored areas such as scratches or blemishes on the skin. Users choose a skin design sheet that matches their own skin color.

The skin design sheet, for example, comprises a release sheet, an adhesive layer, a base layer, and a protective sheet in that order in the thickness direction. The skin design sheet is applied to the user's skin by peeling the release sheet from the adhesive layer, attaching the adhesive layer to the skin, and then peeling the protective sheet from the base layer.

Patent No. 6147874

Conventional skin design sheets have a film-like feel, which does not adequately provide the moist feel of skin and is not necessarily close to the feel of skin. The objective of this disclosure is to provide a laminated sheet that can be used as a skin design sheet that has a feel closer to skin.

The laminate sheet of the present disclosure comprises an adhesive layer and a surface resin layer, and the surface resin layer has a dynamic friction coefficient of 0.35 or more as measured using a static and dynamic friction measuring device equipped with a finger model tactile contact, and has a maximum valley depth (Sv) of 30 μm or more as specified in ISO25178-2:2012.

This disclosure provides a laminated sheet that can be used as a skin-design sheet that feels similar to the skin.

FIG. 1 is a cross-sectional view of a laminate sheet. FIG. 2 is a cross-sectional view of a laminated sheet. FIG. 3 is a cross-sectional view of a laminated sheet. FIG. 4 is a schematic diagram of the surface shape indicated by Ssk. FIG. 5 is a schematic diagram of the surface profile shown by Sku.

The following describes in detail the embodiments of the present disclosure. The present disclosure can be implemented in many different forms, and is not to be construed as being limited to the description of the embodiments exemplified below. In the drawings, the width, thickness, shape, etc. of each layer may be shown diagrammatically compared to the embodiments in order to make the explanation clearer, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each figure, elements similar to those already explained with respect to the previous figures are given the same reference numerals, and detailed explanations may be omitted as appropriate.

In the present disclosure, when multiple upper limit candidates and multiple lower limit candidates are listed for a certain parameter, the numerical range of the parameter may be constructed by combining any one of the upper limit candidates and any one of the lower limit candidates. Examples of the above parameters include physical property values, component content ratios, and layer thicknesses. As an example, the description "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." will be explained. 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.

In this specification, each of the components (e.g., resin materials and additives such as colorants) appearing in the following description may be used alone or in combination of two or more types.

[Laminated sheet]
The laminate sheet of the present disclosure includes an adhesive layer and a surface resin layer.

Specific examples of the laminate sheet of the present disclosure will be described below with reference to the drawings.
The laminated sheet 1 shown in FIG. 1 includes an adhesive layer 20 and a surface resin layer 10. The surface resin layer 10 has a first surface 1a and a second surface 1b opposite to the first surface 1a. The second surface 1b faces the adhesive layer 20. The first surface 1a is the surface opposite to the second surface 1b. In this example, the surface resin layer 10 is a substrate layer. In this example, one or both of the adhesive layer 20 and the surface resin layer 10 may be colored with a colorant to a desired color, such as skin color. A printing layer may be provided on either one or both surfaces of the substrate layer.

The laminate sheet 1 shown in FIG. 2 includes an adhesive layer 20, a base layer 30, and a surface resin layer 10. Thus, the laminate sheet 1 may include the adhesive layer 20, the base layer 30, and the surface resin layer 10 in this order in the thickness direction. In this example, at least one layer selected from the adhesive layer 20, the base layer 30, and the surface resin layer 10 may be colored with a colorant to a desired color, such as skin color. A printing layer may be provided on either one or both surfaces of the base layer.

The laminate sheet 1 shown in FIG. 3 further includes a release sheet 40 on the surface of the adhesive layer 20 opposite the surface facing the base layer 30. In this way, the laminate sheet 1 may include the release sheet 40, the adhesive layer 20, the base layer 30, and the surface resin layer 10 in this order in the thickness direction.

The laminate sheet may further include a protective sheet (not shown) on the surface (first surface) of the surface resin layer opposite to the surface (second surface) facing the adhesive layer. The laminate sheet may include an adhesive layer, a base layer as needed, a surface resin layer, and a protective sheet in this order in the thickness direction, or may include a release sheet, an adhesive layer, an optional base layer, a surface resin layer, and a protective sheet in this order in the thickness direction.

The laminate sheet may include, in this order, a release sheet, an adhesive layer, a base layer, a receiving layer on which an image is formed, and, in this order, a protective sheet, if necessary. In this example, the receiving layer corresponds to the surface resin layer. The laminate sheet may include, in this order, a release sheet, an adhesive layer, a base layer, a receiving layer on which an image is formed, a protective layer, and, in this example, a protective sheet, if necessary. In this example, the protective layer corresponds to the surface resin layer. In these examples, an image of a desired color, such as skin color, is formed on the receiving layer using a coloring agent such as a dye.

In one embodiment, the laminate sheet of the present disclosure is in the form of a long strip, and Figures 1 to 3 are cross-sectional views perpendicular to the longitudinal direction of, for example, laminate sheet 1.

<Surface resin layer>
The laminate sheet of the present disclosure includes a surface resin layer.
The surface resin layer constitutes the surface layer located farthest from the adherend when the laminate sheet is attached to the adherend. When the laminate sheet is provided with a protective sheet, the protective sheet is peeled off.

The surface resin layer has a first surface and a second surface opposite to the first surface. The second surface is the surface of the surface resin layer that faces the adhesive layer, and the first surface is the surface of the surface resin layer opposite to the surface that faces the adhesive layer.

The surface resin layer has a dynamic friction coefficient of 0.35 or more.
In this specification, the dynamic friction coefficient is measured using a static/dynamic friction measuring instrument (i-tester TL201Ts, Trinity Lab Co., Ltd.) equipped with a finger model tactile contactor (Trinity Lab Co., Ltd.). The dynamic friction coefficient is measured for the first surface of the surface resin layer by attaching and fixing the laminated sheet to a Bioskin plate (Beaulux Co., Ltd., product number P001-001) having an uneven surface so that the adhesive layer is in contact with the plate. This allows the dynamic friction coefficient to be measured under conditions similar to those when the laminated sheet is attached to the skin and under conditions where the contactor is close to the pad of the finger. Details of the measurement conditions for the dynamic friction coefficient are described in the Examples section.

A surface resin layer with a low dynamic friction coefficient measured under the above conditions tends to have a smooth feel. A surface resin layer with a high dynamic friction coefficient measured under the above conditions tends to have a moist feel. A smooth feel specifically refers to the feel felt when touching a non-moist smooth surface with the pad of a finger. A moist feel specifically refers to the feel felt when touching a moist surface with the pad of a finger.

The dynamic friction coefficient of the surface resin layer is 0.35 or more, preferably 0.36 or more, and more preferably 0.37 or more. The dynamic friction coefficient of the surface resin layer is preferably 1.5 or less, more preferably 1.3 or less, even more preferably 1.0 or less, even more preferably 0.8 or less, and particularly preferably 0.7 or less, 0.65 or less, 0.6 or less, or 0.55 or less. The dynamic friction coefficient of the surface resin layer is, for example, 0.35 or more and 1.5 or less. The feel of a surface resin layer with a dynamic friction coefficient of 0.35 or more tends to be close to the feel of skin. If the dynamic friction coefficient is too high, the feel may be too moist compared to skin, which may cause discomfort, but a surface resin layer with a dynamic friction coefficient of the above upper limit or less, particularly 1.0 or less, shows a moderately moist feel that is closer to the feel of skin.

The surface resin layer has a maximum valley depth (Sv) of 30 μm or more. Sv is specified in ISO25178-2:2012. Sv refers to the absolute value of the maximum depth from the average surface of the surface.

The Sv of the surface resin layer is preferably 70 μm or less, more preferably 65 μm or less, even more preferably 60 μm or less, even more preferably 55 μm or less, and particularly preferably 50 μm or less, 45 μm or less, or 40 μm or less. The Sv of the surface resin layer is, for example, 30 μm or more and 70 μm or less. A surface resin layer with a large Sv has a high cushioning property, and when checking the feel of the surface resin layer, the surface resin layer has a high ability to follow the pad of the finger, and therefore tends to have a strong moist feel.

The present inventors have found that even when the kinetic friction coefficient of the surface resin layer is 0.35 or more, the moist feel may not be sufficient, and even when the Sv of the surface resin layer is 30 μm or more, the moist feel may not be sufficient. The present inventors have found that when the kinetic friction coefficient of the surface resin layer is 0.35 or more and the Sv is 30 μm or more, the surface resin layer has a highly moist feel and a feel close to skin, and that when the kinetic friction coefficient of the surface resin layer is 0.35 or more and 1.0 or less and the Sv is 30 μm or more, the surface resin layer has a feel closer to skin.

It is preferable that the surface resin layer has the three-dimensional surface properties described below.

The surface resin layer preferably has an Ssk (skewness) of 0.0 or less and an Sku (kurtosis) of 2.6 or more. Ssk and Sku are each specified in ISO25178-2:2012.

Ssk is one of the three-dimensional surface texture parameters defined by the ISO, and is an index indicating the degree of deviation of the height distribution from the average plane. When Ssk is 0, the surface shape is symmetrical with respect to the average plane, when Ssk exceeds 0, the surface shape is biased downward from the average plane, i.e., toward the lower side, and the vicinity of the top of the convex portion tends to be sharp and thin, and when Ssk is less than 0, the surface shape is biased upward from the average plane, i.e., toward the higher side, and the vicinity of the top of the convex portion tends to be blunt and thick. "Symmetrical with respect to the average plane" can also be called "normal distribution". The tendency of the shape exhibited by the surface shape indicated by Ssk will be explained using FIG. 4. FIG. 4 is a schematic diagram of when Ssk exceeds 0 (1-1) and when Ssk is less than 0 (1-2). When Ssk is less than 0, it means that the surface shape of the surface resin layer is biased upward from the average plane, and the vicinity of the top of the convex portion tends to be blunt and thick. In Figure 4, the "average plane" is the average level plane that corresponds to the horizontal line, and "above the average plane" is also the upper side in Figure 4.

Sku is one of the three-dimensional surface quality parameters defined by the ISO, and is an index that indicates the degree of peaking of the height distribution from the average plane. When Sku is 3, the surface shape is symmetrical (normal distribution) with respect to the average plane, when Sku is less than 3, the height distribution tends to have a flat shape, and when Sku is more than 3, the height distribution tends to have a sharp shape. The tendency of the shape exhibited by the surface shape indicated by Sku will be explained using FIG. 5. FIG. 5 is a schematic diagram of when Sku is less than 3 (2-1) and when Sku is more than 3 (2-2). When Sku is 2.6 or more, it means that the height distribution of the surface resin layer tends to have a shape that is not too flattened. In FIG. 5, the "average plane" is the average level plane corresponding to the horizontal line, and "upper side of the average plane" is also the upper side in FIG. 5.

The Ssk of the surface resin layer is preferably -1.5 or more, more preferably -1.0 or more, even more preferably -0.8 or more, even more preferably -0.65 or more, and particularly preferably -0.5 or more. The Ssk of the surface resin layer is preferably less than 0.0, more preferably -0.05 or less, even more preferably -0.1 or less, even more preferably -0.13 or less, and particularly preferably -0.15 or less. The Ssk of the surface resin layer is, for example, -1.5 or more and 0.0 or less.

The Sku of the surface resin layer is preferably 2.6 or more. The Sku of the surface resin layer is preferably 6.0 or less, more preferably 5.0 or less, even more preferably 4.0 or less, even more preferably 3.7 or less, and particularly preferably 3.4 or less. The Sku of the surface resin layer is, for example, 2.6 or more and 6.0 or less.

In addition to the dynamic friction coefficient and Sv being within the above ranges, a surface resin layer with Ssk of 0.0 or less and Sku of 2.6 or more tends to have a stronger moist feel and tends to have a feel closer to that of skin. A surface resin layer with Ssk and Sku in the preferred ranges described above has, for example, a moderately crushed and rounded shape near the top of the convex portion present above the average surface, and a gently pointed shape near the lowest surface of the concave portion below, which is thought to contribute to a feel close to that of skin.

In this specification, Sv, Ssk, and Sku are measured using a shape analysis laser microscope. Sv, Ssk, and Sku are measured by attaching and fixing the laminated sheet to a Bioskin plate (manufactured by Viewlux Co., Ltd., product number P001-001) having an uneven surface so that the adhesive layer is in contact with the plate, and scanning the surface shape of the first side of the surface resin layer using a shape analysis laser microscope. This allows Sv, Ssk, and Sku to be measured under conditions similar to those when the laminated sheet is attached to the skin. Details of the measurement conditions for Sv, Ssk, and Sku are described in the Examples section.

The dynamic friction coefficients Sv, Ssk and Sku can be adjusted, for example, by appropriately selecting and using the materials described below as the materials constituting the surface resin layer, and by subjecting the surface resin layer to a shaping process such as embossing. Specifically, the dynamic friction coefficient and the like can be adjusted by the surface shape of the embossing plate and shaping sheet used in the embossing process, and the pressure, temperature and time during the embossing process.

The surface resin layer may be a layer formed by thermal transfer, such as the protective layer or receiving layer described below, that is, a transfer layer transferred by a thermal transfer process from a thermal transfer sheet having a transfer layer such as a protective layer and a receiving layer.

(Base layer)
In one embodiment, the surface resin layer is a substrate layer.
The substrate layer may be, for example, a resin film formed from a resin material, such as polyurethane, polyester, polyamide, polyimide, polyolefin, vinyl resin, styrene resin, acrylic resin, or cellulose resin.

As the substrate layer, for example, a stretchable substrate is preferably used. Examples of the stretchable substrate include the above-mentioned resin films, and among the above-mentioned resin films, urethane films are preferred.

The stretchable substrate preferably has an elongation percentage of 30% or more and 100% or less in order to follow the expansion and contraction of the adherend when the laminate sheet is attached to the adherend. The elongation percentage of the stretchable substrate is the elongation percentage obtained by a test method in accordance with JIS K 7127:1999. The elongation percentage is expressed by the following formula (1).
Elongation (%)=100×(L−L ₀ )/L ₀ (1)

In formula (1), L is the length of the elastic substrate when it is pulled at a speed of 200 mm/min using a tensile tester and the elastic substrate breaks. L ₀ in formula (1) is the length of the elastic substrate before being pulled by the tensile tester. A Tensilon universal material testing machine can be used as the tensile tester.

The substrate layer may contain an additive. Examples of additives include ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents. The substrate layer may contain a colorant, as necessary. The substrate 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.

The thickness of the substrate layer is preferably 3 μm or more, more preferably 5 μm or more. A laminate sheet having such a substrate layer can, for example, suppress the occurrence of wrinkles when the sheet is applied, and can also improve workability. The thickness of the substrate layer is preferably 80 μm or less, more preferably 60 μm or less, even more preferably 40 μm or less, and particularly preferably 30 μm or less. A laminate sheet having such a substrate layer can, for example, suppress the user's discomfort after the sheet is applied.

A printing layer may be provided on the base layer. The printing layer may be a layer for adjusting the color tone of the laminated sheet to a desired color, such as skin color. The printing layer contains a colorant. Examples of colorants include pigments and dyes.

In one embodiment, the laminate sheet of the present disclosure may include the above-mentioned base layer between the adhesive layer and the surface resin layer. In this case, the surface resin layer may be, for example, a protective layer or a receiving layer described below.

(Protective Layer)
In one embodiment, the surface resin layer is a protective layer. The laminate sheet of the present disclosure may, for example, include an adhesive layer, a base layer, and a protective layer in this order, or may include an adhesive layer, a base layer, a receiving layer on which an image is formed, and a protective layer in this order. The receiving layer will be described later.

The material that can be used to form the protective layer is, for example, a resin material. Examples of the resin material include 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.

Examples of polyesters include polyethylene terephthalate and polyethylene naphthalate. Examples of vinyl resins include vinyl chloride-vinyl acetate copolymers, polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, and polyvinylpyrrolidone. Examples of cellulose resins include ethyl cellulose, hydroxyethyl cellulose, ethylhydroxycellulose, methyl cellulose, and cellulose acetate.

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. Specifically, examples include resins obtained by adding a photopolymerization initiator to a radical polymerizable polymer or a radical polymerizable oligomer as necessary, and polymerizing and crosslinking the polymer by irradiating it with an electron beam or ultraviolet light.

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. This can provide, for example, sufficient durability to the protective layer.

The protective layer may contain an additive. 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.

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, based on 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.

The thickness of the protective layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more, and is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. Such a protective layer can, for example, provide a sufficient protective function to the laminate sheet. The thickness of the protective layer is, for example, 0.1 μm or more and 20 μm or less.

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

The protective layer can be formed, for example, by preparing a thermal transfer sheet with a protective layer, superimposing the thermal transfer sheet on a base film or the like that corresponds to the base layer, and transferring the protective layer onto the base film or the receiving layer on which the image is formed by a thermal transfer process.

(Receptive layer)
In one embodiment, the surface resin layer is a receiving layer on which an image is formed. The laminate sheet of the present disclosure may include, for example, an adhesive layer, a base layer, and a receiving layer on which an image is formed, in this order. The receiving layer is a layer for receiving dyes and the like transferred from a thermal transfer sheet. For example, when forming an image using a thermal transfer printer, it is desirable to provide a receiving layer on the base layer. The image may be, for example, an image for matching the color tone of the laminate sheet to a desired color, such as skin color.

As a material constituting the receiving layer, for example, a resin material can be used. 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. As a resin material constituting the receiving layer, vinyl resin is preferable, and vinyl chloride-vinyl acetate copolymer is more preferable.

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, based on the total mass of the receiving layer. This can, for example, impart sufficient durability to the receiving layer.

The receiving layer may contain additives. Examples of additives include ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents.

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.

The receiving layer may be a white receiving layer. The white receiving layer may, for example, comprise a primer layer containing a white pigment and a transparent receiving layer in this order. Examples of white pigments include silica, titanium oxide, titanium dioxide, zinc oxide, cerium oxide, titanium mica, muscovite, white carbon, calcium carbonate, barium sulfate, alumina white, and talc. By using a white receiving layer, it is possible to suppress reflected light from discolored areas on the adherend, increase the concealment of the discolored areas, and improve the reproducibility of the desired skin color. The transparent receiving layer may contain particles that scatter light.

A concealing layer may be further provided on the primer layer containing the white pigment. The concealing layer may contain a metal pigment. Examples of metal pigments include particles of aluminum, nickel, chromium, brass, tin, brass, bronze, zinc, silver, platinum, gold, and oxides thereof, as well as glass and the like that have been subjected to metal deposition. Among these, aluminum pigments are preferred from the viewpoint of the transferability and glossiness of the concealing layer. The aluminum pigment may be of the leafing type or non-leafing type, but non-leafing type is preferred from the viewpoint of the transferability and glossiness of the concealing layer.

The thickness of the receiving layer is preferably 0.5 μm or more, more preferably 1 μm or more, and is preferably 20 μm or less, more preferably 10 μm or less. This can improve, for example, the density of the thermal transfer image formed on the receiving layer. The thickness of the receiving layer is, for example, 0.5 μm or more and 20 μm or less.

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

When providing a receiving layer on a substrate layer, the substrate layer may be melted and damaged, or may be denatured or deformed by the solvent contained in the coating liquid during the process of applying and drying the coating liquid for the receiving layer on the substrate layer. In this case, it is preferable to transfer the receiving layer onto the substrate layer by thermal transfer. The receiving layer may be provided on the substrate layer in advance, or may be provided by thermal transfer onto the substrate layer during image formation.

<Adhesive layer>
The laminated sheet of the present disclosure includes an adhesive layer.
The adhesive layer is formed, for example, using an adhesive. An adhesive is also called a pressure-sensitive adhesive, and refers to a material that has adhesiveness 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 a practical adhesive strength.

Examples of adhesives include acrylic adhesives, urethane adhesives, silicone adhesives, rubber adhesives, vinyl alkyl ether adhesives, polyester adhesives, polyamide adhesives, and fluorine adhesives. The adhesive may contain a solvent. For example, either water-based or solvent-based solvents 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.

The adhesive layer may contain an additive. Examples of additives include ultraviolet absorbers, light stabilizers, antioxidants, colorants, fillers, and release agents. The adhesive layer may contain a colorant, as necessary. The adhesive 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.

The adhesive strength of the adhesive layer is preferably 5000 gf/50 mm or less, more preferably 100 gf/50 mm or more and 5000 gf/50 mm or less. If the adhesive strength is 5000 gf/50 mm or less, for example, there is little risk of damaging the adherend (particularly the skin of a human body or an animal) when the sheet is applied incorrectly or peeled off when replacing it. If the adhesive strength is 100 gf/50 mm or more, for example, adhesive strength to the adherend (particularly the skin of a human body or an animal) can be ensured, and peeling of the sheet due to sweating or movement of the skin can be suppressed.

The adhesive strength between the release sheet and the adhesive layer may be, for example, 2 gf/50 mm or more, 4 gf/50 mm or more, or 50 gf/50 mm or less, or 30 gf/50 mm or less. If the adhesive strength is 2 gf/50 mm or more, peeling of the release sheet during storage or transportation of the laminated sheet can be suppressed, for example. If the adhesive strength is 50 gf/50 mm or less, the release sheet can be easily peeled off, for example, when using the skin design sheet. The adhesive strength is measured in accordance with the method (180° peeling) described in JIS Z 0237:2009.

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

<Release sheet>
The laminated sheet of the present disclosure may include a release sheet releasably provided on the adhesive layer. Examples of the release sheet include release paper with at least one side of a paper substrate being release-treated, and resin film with at least one side of a resin film being release-treated. Examples of the release treatment include release treatment using a release agent such as a silicone resin-based release agent, an alkyd resin-based release agent, a long-chain alkyl compound-based release agent, and a fluororesin-based release agent. Examples of the resin film include resin films formed from resin materials such as polyolefin, vinyl resin, styrene resin, acrylic resin, fluororesin, polyester, and polyamide.

The thickness of the release sheet is preferably 50 μm or more, more preferably 100 μm or more, and is preferably 300 μm or less, more preferably 200 μm or less. The thickness of the release sheet is, for example, 50 μm or more and 300 μm or less.

<Protective sheet>
The laminated sheet of the present disclosure may include a protective sheet releasably provided on the surface resin layer. Examples of the protective sheet include a low-density polyethylene (LDPE) sheet and a polypropylene (PP) sheet. The protective sheet includes, for example, a weak adhesive layer. An acrylic weak adhesive and a urethane weak adhesive can be used to form the weak adhesive layer.
The thickness of the protective sheet is, for example, not less than 10 μm and not more than 200 μm.

[Applications of laminated sheets]
An example of the use of the laminate sheet of the present disclosure will now be described.
In one embodiment, the laminate sheet can be used as a skin design sheet (skin sheet) to be attached to the skin. Examples of skin design sheets include skin concealing sheets and tattoo stickers.

In one embodiment, a skin design sheet can be produced from the laminate sheet. For example, multiple skin design sheets can be produced from the laminate sheet. For example, a roll of the laminate sheet can be cut to produce a sheet of laminate sheet in the product form.

By attaching the skin design sheet to skin that has, for example, spots, birthmarks, freckles, wrinkles, sagging skin, pores, scars, acne scars, burn scars, or discoloration due to skin disease, with the adhesive layer in contact with the skin, these can be concealed and made less noticeable.

[Method of manufacturing laminated sheet]
Laminated sheets of the present disclosure can be made, for example, by a thermal transfer process.
A long base film corresponding to the base layer is prepared. The base film and the thermal transfer sheet are set in a thermal transfer printer. As the thermal transfer printer, a dye-sublimation type thermal transfer printer, which has excellent color reproducibility and gradation, is suitable.

The thermal transfer sheet comprises a substrate, a transfer-type receiving layer, a dye layer, and an optional protective layer, which are provided in surface order on one side of the substrate. The receiving layer is a layer that receives the dye transferred from the thermal transfer sheet, and is transparent. 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. If a receiving layer is provided on the substrate film in advance, it is not necessary for the thermal transfer sheet to have a receiving layer, and it is not necessary to transfer the receiving layer as described below.

The thermal transfer printer has a thermal head and a platen roll that sandwich the base film and the thermal transfer sheet, and heats the thermal transfer sheet. The thermal head heats the transfer type receptive layer to transfer the receptive layer onto the base film. The thermal head then heats the yellow dye layer, magenta dye layer, and cyan dye layer in order, for example, based on the data of the skin design sheet, and transfers the dye to the receptive layer transferred onto the base film to form an image. This makes it easy to match the color of the laminated sheet to the color of the user's skin. If necessary, the protective layer of the thermal transfer sheet is then heated and transferred onto the receptive layer on which the image has been formed. Here, the receptive layer or (if a protective layer is provided) the protective layer corresponds to the surface resin layer described above.

If necessary, the surface resin layer is subjected to a shaping process such as embossing to form an uneven shape in the surface resin layer. The above-mentioned dynamic friction coefficients Sv, Ssk, and Sku in the surface resin layer can be adjusted by the shaping process. In the embossing process, for example, an embossing plate or a shaping sheet can be used. The embossing plate and the shaping sheet can be used without any particular restrictions as long as they can impart the above-mentioned surface shape. The surface shape of the embossing plate and the shaping sheet and the surface shape shaped by them are almost the opposite shapes.

The long laminate sheet is cut parallel to the width direction of the laminate sheet using a cutter in the thermal transfer printer to obtain a single laminate sheet. If necessary, a protective sheet may be attached to the surface resin layer of the single laminate sheet.

Then, using a known cutting device, the laminated sheet is cut into the shape of the product form of the skin design sheet. For example, when the laminated sheet is viewed in a plan view, the laminated sheet is punched into a circular shape. The shape is not particularly limited.

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 film before the thermal transfer process. In this case, it is preferable to provide a release sheet on the adhesive layer. Alternatively, the adhesive layer may be provided on the substrate film after the thermal transfer process.

Although a method for manufacturing a laminate sheet by a thermal transfer process has been described, the manufacturing method of the laminate sheet of the present disclosure is not limited to the above method. For example, the laminate sheet may be manufactured by forming each layer in sequence.

The present disclosure relates to, for example, the following [1] to [8].
[1] A laminated sheet comprising an adhesive layer and a surface resin layer, wherein the surface resin layer has a dynamic friction coefficient of 0.35 or more as measured using a static and dynamic friction measuring device equipped with a finger model tactile contactor, and has an Sv (maximum valley depth) of 30 μm or more as defined in ISO25178-2:2012.
[2] The laminate sheet according to [1], wherein the dynamic friction coefficient is 0.35 or more and 1.5 or less.
[3] The laminate sheet according to [1], wherein the dynamic friction coefficient is 0.35 or more and 1.0 or less.
[4] The laminate sheet according to any one of [1] to [3], wherein the surface resin layer has an Ssk (skewness) of 0.0 or less and an Sku (kurtosis) of 2.6 or more as defined in ISO25178-2:2012.
[5] The laminate sheet according to any one of [1] to [4], wherein the laminate sheet comprises a base material layer as the surface resin layer, or the laminate sheet further comprises a base material layer between the adhesive layer and the surface resin layer.
[6] The laminate sheet according to any one of [1] to [5], wherein the surface resin layer is a layer formed by thermal transfer.
[7] The laminate sheet according to any one of [1] to [6], further comprising a protective sheet releasably provided on the surface resin layer, and/or a release sheet releasably provided on the adhesive layer.
[8] The laminate sheet according to any one of [1] to [7], which is a skin design sheet.

The laminate sheet of the present disclosure will be described in more detail with reference to examples, but the laminate sheet of the present disclosure is not limited to these examples.

[Example 1]
An acrylic adhesive was applied onto a release paper (Sumika Kakoshi Co., Ltd., SLB-110WT, thickness 170 μm) and dried to form an adhesive layer with a thickness of 10 μm. A urethane film with a thickness of 20 μm (Okura Kogyo Co., Ltd., NES85, elastic substrate) was attached to the adhesive layer. In this way, a sheet having a release paper, an adhesive layer, and a urethane film in this order was produced.

A thermal transfer sheet was prepared having a 2 μm thick transfer layer made of vinyl chloride-vinyl acetate copolymer (Nissin Chemical Industry Co., Ltd., Solvine (registered trademark) CNL) on a 4.5 μm thick polyethylene terephthalate film (Toray Industries, Inc.). The transfer layer from this thermal transfer sheet was thermally transferred onto the urethane film of the above sheet under the following transfer conditions. Synthetic leather release paper "DN-TP (registered trademark) DE-43" (Dai Nippon Printing Co., Ltd.) was prepared. After thermal transfer, the synthetic leather release paper was layered on the transfer layer and heated at a temperature of 150 ° C. with a laminating machine "Fujipla LPD3226N" (Hisago Co., Ltd.) to form irregularities on the surface of the transfer layer. In this way, a laminated sheet was obtained that had a release paper, an adhesive layer, a urethane film, and a transfer layer.
(Transfer conditions)
Thermal head: KGT-217-12MPL20 (Kyocera Corporation)
Heating element average resistance: 31915Ω
- Print density in the main scanning direction: 300 dpi
Sub-scanning direction print density: 300 dpi
・Applied power: 0.12W/dot
・1 line period: 5 msec.
・Printing start temperature: 40℃

[Examples 2 to 4]
The laminated sheets of Examples 2 to 4 were obtained by forming projections and recesses on the surface of the transfer layer in the same manner as in Example 1, except that the release paper for synthetic leather was changed to DE-73M (Example 2), DE-89 (Example 3), or DE-145 (Example 4) of the DE series of "DN-TP (registered trademark)" (Dai Nippon Printing Co., Ltd.).

[Example 5]
A thermal transfer sheet was prepared having a 2 μm thick protective layer made of 20 parts by mass of polyester (Elitel (registered trademark) UE-3380, Unitika Co., Ltd.) and 6 parts by mass of polyester (Elitel (registered trademark) UE-3210, Unitika Co., Ltd.) on a 4.5 μm thick polyethylene terephthalate film (Toray Co., Ltd.). The protective layer from this thermal transfer sheet was thermally transferred onto the urethane film of the sheet prepared in Example 1 under the above transfer conditions. Synthetic leather release paper "DN-TP (registered trademark) DE-43" (Dai Nippon Printing Co., Ltd.) was prepared. After thermal transfer, the synthetic leather release paper was layered on the protective layer and heated at a temperature of 150 ° C. in the laminating machine to form irregularities on the surface of the protective layer. In this way, a laminated sheet was obtained that had a release paper, an adhesive layer, a urethane film, and a protective layer.

[Examples 6 to 8]
In Examples 1 to 3, the synthetic leather release paper was overlaid on the transfer layer and heated at a temperature of 130°C in the laminator, and the same procedures were followed as in Examples 1 to 3 to form irregularities on the surface of the transfer layer, thereby obtaining a laminate sheet of Example 6 corresponding to Example 1, a laminate sheet of Example 7 corresponding to Example 2, and a laminate sheet of Example 8 corresponding to Example 3, respectively.

[Examples 9 to 12]
The release paper for synthetic leather used in Examples 1 to 4 was overlaid on the urethane film of the sheet comprising the release paper, adhesive layer and urethane film prepared in Example 1 in this order, and heated at a temperature of 150° C. in the laminating machine to form irregularities on the surface of the urethane film. In this way, a laminate sheet of Example 9 corresponding to Example 1, a laminate sheet of Example 10 corresponding to Example 2, a laminate sheet of Example 11 corresponding to Example 3, and a laminate sheet of Example 12 corresponding to Example 4 were obtained.

[Comparative Examples 1 to 3]
In Examples 1 to 3, the synthetic leather release paper was overlaid on the transfer layer and heated at 100°C in the laminator, and the same procedures were followed as in Examples 1 to 3 to form irregularities on the surface of the transfer layer, thereby obtaining a laminate sheet of Comparative Example 1 corresponding to Example 1, a laminate sheet of Comparative Example 2 corresponding to Example 2, and a laminate sheet of Comparative Example 3 corresponding to Example 3, respectively.

[evaluation]
<Sensory evaluation>
A Bioskin plate (Viewlax Co., Ltd., product number P001-001) was prepared. The laminated sheets obtained in the Examples and Comparative Examples were attached and fixed to the Bioskin plate after removing the release paper, and the feel (moist feel) of the surface of the laminated sheet was evaluated. The evaluation was performed on a 5-point scale, and the average value of the evaluations by 5 people was recorded. The order of feel closest to skin is 3>2>4>1 in the following evaluation.
1: Smooth to the touch 2: Slightly moist to the touch 3: Moist to the touch (similar to the texture of skin)
4. Feels moister than skin

<Dynamic friction coefficient>
The laminated sheets obtained in the Examples and Comparative Examples were attached and fixed to the Bioskin plate after removing the release paper, and a static and dynamic friction measuring device equipped with a tactile contact was attached to measure the dynamic friction coefficient under the following conditions. The dynamic friction coefficient was calculated from the average value of the dynamic friction force/load in the 20-30 mm section.
Static and dynamic friction measuring device: Trinity Lab i-tester TL201Ts
Contact: Trinity Lab's tactile contact, finger model Test environment: 23°C, 50% RH
Load: 10g
Test speed: 10 mm/s
Test range: 30 mm

<Surface shape (Sv, Ssk and Sku)>
The laminated sheets obtained in the Examples and Comparative Examples were attached and fixed to the BIOSKIN plate after removing the release paper, and the surface shape of the laminated sheet, Sv (maximum valley depth), Ssk (skewness) and Sku (kurtosis), were measured under the following conditions using a shape analysis laser microscope in accordance with ISO25178-2: 2012. The surface shape of the attached surface of the laminated sheet on the BIOSKIN plate was Sv: 47.2 μm, Ssk: -0.50, Sku: 2.70.
Shape analysis laser microscope: VK-X150 (control unit) / VK-X160 (measurement unit),
Keyence Corporation Objective lens: 20x Laser wavelength: 658nm
Measurement mode: Surface shape mode Measurement pitch: 0.13 μm
Measurement range: Rectangular (952 μm x 1297 μm)
Measurement quality: High accuracy

1 Laminated sheet 10 Surface resin layer 20 Adhesive layer 30 Base layer 40 Release sheet

Claims (7)

A laminated sheet having an adhesive layer and a surface resin layer, the laminated sheet being used as a skin design sheet to be attached to the skin,
The surface resin layer has a dynamic friction coefficient of 0.35 to 1.5 as measured using a static and dynamic friction measuring device (i-tester TL201Ts, Trinity Lab Co., Ltd.) equipped with a finger model tactile contactor, and has a maximum valley depth (Sv) of 30 μm or more as defined in ISO25178-2:2012.
Laminated sheet. The laminate sheet according to claim 1, wherein the surface resin layer is a layer formed by thermal transfer. A laminated sheet comprising an adhesive layer and a surface resin layer formed by thermal transfer,
The surface resin layer has a dynamic friction coefficient of 0.35 to 1.5 as measured using a static and dynamic friction measuring device (i-tester TL201Ts, Trinity Lab Co., Ltd.) equipped with a finger model tactile contactor, and has a maximum valley depth (Sv) of 30 μm or more as defined in ISO25178-2:2012.
Laminated sheet. The laminate sheet according to any one of claims 1 to 3, wherein the dynamic friction coefficient is 0.35 or more and 1.0 or less. The laminate sheet according to any one of claims 1 to 3, wherein the surface resin layer has an Ssk (skewness) of 0.0 or less and an Sku (kurtosis) of 2.6 or more as defined in ISO25178-2:2012. The laminate sheet according to any one of claims 1 to 3, wherein the laminate sheet comprises a base material layer as the surface resin layer, or the laminate sheet further comprises a base material layer between the adhesive layer and the surface resin layer. a protective sheet releasably provided on the surface resin layer, and/or a release sheet releasably provided on the adhesive layer;
The laminate sheet according to any one of claims 1 to 3, further comprising: