EP-4741449-A1 - DECORATIVE SHEET AND METHOD FOR PRODUCING SAME

Abstract

An object of the present invention is to provide a decorative sheet having all of processability in three-dimensional molding, adhesiveness to a substrate, and scratch resistance of a surface. The decorative sheet is a three-dimensionally moldable decorative sheet having at least a resin base material layer and a surface protective layer, in which the surface protective layer consists of a cured product of a resin composition including an ultraviolet-curable resin (A) and a thermosetting resin (B) at a mass ratio of 30:70 to 60:40, the ultraviolet-curable resin (A) is one or more urethane (meth)acrylates selected from a polyester-based urethane (meth)acrylate, a polyether-based urethane (meth)acrylate, and a polycarbonate-based urethane (meth)acrylate, each of which has 2 to 3 functional groups and yields a cured product of a pencil hardness of HB to 4B, and the thermosetting resin (B) consists of an acrylic polyol-based resin and a polyisocyanate compound that is a curing agent.

Inventors

• TAKEMURA, MAKOTO

Assignees

• Eiwakako Co., Ltd.

Dates

Publication Date

20260513

Application Date

20251111

Claims (10)

1. A three-dimensionally moldable decorative sheet comprising at least: a resin base material layer; and a surface protective layer, wherein the surface protective layer consists of a cured product of a resin composition including an ultraviolet-curable resin (A) and a thermosetting resin (B) at a mass ratio of 30:70 to 60:40, the ultraviolet-curable resin (A) is one or more urethane (meth)acrylates selected from a polyester-based urethane (meth)acrylate, a polyether-based urethane (meth)acrylate, and a polycarbonate-based urethane (meth)acrylate, each of which has 2 to 3 functional groups and yields a cured product of a pencil hardness of HB to 4B, and the thermosetting resin (B) consists of an acrylic polyol-based resin and a polyisocyanate compound that is a curing agent.
2. The decorative sheet according to Claim 1, wherein the resin base material layer consists of a polyester-based sheet or a polypropylene-based sheet having a tensile elongation of 200% or more at 90°C and a load of 4.0 to 9.0 N/cm at the tensile elongation in a range of 50% to 200%, and the resin base material layer has a thickness of 120 to 300 µm.
3. The decorative sheet according to Claim 2, wherein the polyester-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polyester-based sheet.
4. The decorative sheet according to Claim 2, wherein the polypropylene-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polypropylene-based sheet in which an olefin-based elastomer and a polyethylene resin are blended.
5. The decorative sheet according to any one of Claims 1 to 4, wherein the resin base material layer is a three-layer structure including two kinds of components or a three-layer structure including three kinds of components, in which a recycled polyethylene terephthalate resin or a recycled polypropylene resin is used in an interlayer of the resin base material layer.
6. A method for producing a three-dimensionally moldable decorative sheet having at least a resin base material layer and a surface protective layer, the method comprising: applying the following resin composition including an ultraviolet-curable resin (A) and a thermosetting resin (B), each described below, at a mass ratio of 30:70 to 60:40 onto a surface of a long sheet that forms the resin base material layer; and curing the ultraviolet-curable resin (A) by ultraviolet irradiation, followed by winding into a roll, and then completely curing the thermosetting resin (B) by aging at 35°C to 55°C to form a surface protective layer, wherein the ultraviolet-curable resin (A) is one or more urethane (meth)acrylates selected from a polyester-based urethane (meth)acrylate, a polyether-based urethane (meth)acrylate, and a polycarbonate-based urethane (meth)acrylate, each of which has 2 to 3 functional groups, and yields a cured product of a pencil hardness of HB to 4B, and the thermosetting resin (B) consists of an acrylic polyol-based resin and a polyisocyanate compound that is a curing agent.
7. The method for producing a decorative sheet according to Claim 6, wherein the resin base material layer consists of a polyester-based sheet or a polypropylene-based sheet having a tensile elongation of 200% or more at 90°C and a load of 4.0 to 9.0 N/cm at the tensile elongation in a range of 50% to 200%, and the resin base material layer has a thickness of 120 to 250 µm.
8. The method for producing a decorative sheet according to Claim 7, wherein the polyester-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polyester-based sheet.
9. The method for producing a decorative sheet according to Claim 7, wherein the polypropylene-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polypropylene-based sheet in which an olefin-based elastomer and a polyethylene resin are blended.
10. The method for producing a decorative sheet according to any one of Claims 6 to 9, wherein the resin base material layer is a three-layer structure including two kinds of components or a three-layer structure including three kinds of components, in which a recycled polyethylene terephthalate resin or a recycled polypropylene resin is used in an interlayer of the resin base material layer.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a decorative sheet and a method for producing the same. Priority is claimed on Japanese Patent Application No. 2024-197364 filed November 12, 2024. Description of Related Art For example, as an interior or exterior member used in building materials, it is widely practiced to attach a decorative sheet to a surface of a three-dimensionally shaped substrate to impart designability. As the decorative sheet, for example, a decorative sheet having a base material, a colored ink layer, a primer layer, and a surface protective layer in this order, in which the base material is a polyester-based film that is particularly biaxially stretched and has a thickness of 20 µm or more and 95 µm or less, and the surface protective layer consists of a cured product of a resin composition including an ionizing radiation-curable resin and a thermosetting resin at a mass ratio of 95:5 to 50:50, has been proposed (Japanese Patent No. 5949053). Since the biaxially stretched polyester-based film is aligned and crystallized in the biaxial direction, the film does not have elongation at around 100°C, making it impossible to perform three-dimensional molding. SUMMARY OF THE INVENTION However, in the related art such as Japanese Patent No. 5949053, it is difficult to obtain a decorative sheet having all of processability in three-dimensional molding, adhesiveness to a substrate, and scratch resistance of a surface. An object of the present invention is to provide a decorative sheet having all of processability in three-dimensional molding, adhesiveness to a substrate, and scratch resistance of a surface; and a method for producing the same. The present invention includes the following configurations. [1]: A three-dimensionally moldable decorative sheet having at least: a resin base material layer; anda surface protective layer, in which the surface protective layer consists of a cured product of a resin composition including an ultraviolet-curable resin (A) and a thermosetting resin (B) at a mass ratio of 30:70 to 60:40, the ultraviolet-curable resin (A) is one or more urethane (meth)acrylates selected from a polyester-based urethane (meth)acrylate, a polyether-based urethane (meth)acrylate, and a polycarbonate-based urethane (meth)acrylate, each of which has 2 to 3 functional groups and yields a cured product of a pencil hardness of HB to 4B, and the thermosetting resin (B) consists of an acrylic polyol-based resin and a polyisocyanate compound that is a curing agent.[2]: The decorative sheet according to [1], in which the resin base material layer consists of a polyester-based sheet or a polypropylene-based sheet having a tensile elongation of 200% or more at 90°C and a load of 4.0 to 9.0 N/cm at the tensile elongation in a range of 50% to 200%, and the resin base material layer has a thickness of 120 to 300 µm.[3]: The decorative sheet according to [2], in which the polyester-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polyester-based sheet.[4]: The decorative sheet according to [2], in which the polypropylene-based sheet having a tensile elongation of 200% or more at 90°C is an amorphous polypropylene-based sheet in which an olefin-based elastomer and a polyethylene resin are blended.[5]: The decorative sheet according to any one of [1] to [4], in which the resin base material layer is a three-layer structure including two kinds of components or a three-layer structure including three kinds of components, in which a recycled polyethylene terephthalate resin or a recycled polypropylene resin is used in an interlayer of the resin base material layer.[6]: A method for producing a three-dimensionally moldable decorative sheet having at least a resin base material layer and a surface protective layer, the method including: applying the following resin composition including an ultraviolet-curable resin (A) and a thermosetting resin (B), each described below, at a mass ratio of 30:70 to 60:40 onto a surface of a long sheet that forms the resin base material layer; and curing the ultraviolet-curable resin (A) by ultraviolet irradiation, followed by winding into a roll, and then completely curing the thermosetting resin (B) by aging at 35°C to 55°C to form a surface protective layer,in which the ultraviolet-curable resin (A) is one or more urethane (meth)acrylates selected from a polyester-based urethane (meth)acrylate, a polyether-based urethane (meth)acrylate, and a polycarbonate-based urethane (meth)acrylate, each of which has 2 to 3 functional groups, and yields a cured product of a pencil hardness of HB to 4B, and the thermosetting resin (B) consists of an acrylic polyol-based resin and a polyisocyanate compound that is a curing agent.[7]: The method for producing a decorative sheet according to [6], in which the resin base material layer consists of a polyester-based sheet or a polypropylene-based sheet having a tens