Adhesive film having three-dimensional molded shape
An object of the present invention is to provide an adhesive film that can be applied easily to an adherend having a three-dimensional shape. An adhesive film according to the present disclosure is an adhesive film having a three-dimensional molded shape and including: a base layer; an adhesive layer including a fine structure in a surface; and a liner layer covering the adhesive layer. The fine structure of the adhesive layer includes a plurality of convex parts. Each of the plurality of convex parts includes two or more parts joined to each other via an interface. A first part present in a top of the convex part includes a non-adhesive or weak adhesive material, and a second part present below the first part includes a strong adhesive material.
1. An adhesive film having a three-dimensional molded shape, the adhesive film comprising:
a base layer;
an adhesive layer including a fine structure in a surface; and
a liner layer covering the adhesive layer, wherein
the structure of the adhesive layer includes a plurality of convex parts,
each of the plurality of convex parts includes two or more parts joined to each other via an interface,
a first part present in a top of the convex part includes a non-adhesive or weak adhesive material, wherein the weak adhesive material is an adhesive having a storage modulus of elasticity of 3×105 Pa or greater as measured at a frequency of 1 Hz, and
a second part present below the first part includes a strong adhesive material, wherein the strong adhesive material is an adhesive having a storage modulus of elasticity of less than 3×10 5 Pa,
wherein the adhesive film includes portions differing in degree of stretching.
2. The adhesive film according to claim 1 , wherein an angle θ formed by a side surface and a bottom surface of the convex part is 8° or more.
3. The adhesive film according to claim 1 , wherein when a height of the convex part is set at 100%, a height of the first part is in the range of 10% to 90% of the convex part.
4. The adhesive film according to claim 1 , wherein in the structure, the longest distance between centers of two convex parts adjacent to each other is 300 μm or less.
5. The adhesive film according to claim 1 , wherein the convex part is a cone or a frustum, and the number of the cones or the frustums per mm 2 of the surface of the adhesive layer is 16 or more.
6. The adhesive film according to any one of claim 1 , wherein
the first part of the convex part includes polyurethane, poly(meth)acrylate, cellulose, silicone, an amine-based resin, a fluorine-based resin, or polyvinyl chloride.
7. The adhesive film according to claim 1 , wherein the first part of the convex part includes a material having a storage elastic modulus (G′) of 3×10 5 Pa or more as measured at a frequency of 1 Hz at normal temperature.
8. The adhesive film according to claim 1 , wherein a dynamic friction coefficient as tested according to JIS K 7125 is 1.10 or less.
9. The adhesive film according to claim 1 , wherein 180° peel adhesion strength as tested under conditions of a temperature of 23° C. and a tensile speed of 200 mm/minute is 1.0 N/10 mm or more in 48 hours after bonding.
10. The adhesive film according to claim 1 , wherein the adhesive film from which the liner layer is removed has a thickness in the range of 0.1 mm to 10.0 mm.
11. The adhesive film according to claim 1 , wherein the adhesive film from which the liner layer is removed has bending rigidity in the range of 200 mgf to 85000 mgf.
12. An adhesive sheet, comprising:
an adhesive layer including a fine structure in a surface;
a first liner layer covering the adhesive layer; and
a second liner layer covering the first liner layer, wherein
the structure of the adhesive layer includes a plurality of convex parts,
each of the plurality of convex parts includes two or more parts joined to each other via an interface,
a first part present in a top of the convex part includes a non-adhesive or weak adhesive material, wherein the weak adhesive material is an adhesive having a storage modulus of elasticity of 3×105 Pa or greater as measured at a frequency of 1 Hz, and
a second part present below the first part includes a strong adhesive material, wherein the strong adhesive material is an adhesive having a storage modulus of elasticity of less than 3×10 5 Pa,
wherein the adhesive film includes portions differing in degree of stretching.
13. The adhesive sheet according to claim 12 , wherein peel adhesive force between the first liner layer and the second liner layer is 1 N/25 mm or less at 180° peel adhesion strength as tested under conditions of a temperature of 23° C. and a tensile speed of 200 mm/minute.
14. The adhesive sheet according to claim 12 , wherein the second liner layer has hardness greater than hardness of the first liner layer.
15. The adhesive sheet according to claim 12 , wherein the second liner layer has pencil hardness of 8B or more.
16. The adhesive sheet according to claim 12 , wherein the second liner layer has bending rigidity of 50 mgf or more.
17. The adhesive sheet according to claim 12 , wherein the adhesive sheet from which the second liner layer is removed has a maximum degree of stretching of 190% or more.