Disclosed is a polyurethane hot-melt adhesive including: a thermoplastic polyurethane that is a reactant of a raw material including a polymer polyol, a polyisocyanate, and a chain extender, wherein X−Y≥15, where X represents a temperature (° C.) at which the polyurethane hot-melt adhesive has a melt viscosity of 2.0×10.sup.3 Pa.Math.s, and Y represents a temperature at which the polyurethane hot-melt adhesive has a melt viscosity of 1.0×10.sup.5 Pa.Math.s, and the polyurethane hot-melt adhesive has a 100% modulus of 2.5 MPa or more.

A multilayer adhesive tape is provided, including: a first outer adhesive layer; an intermediate adhesive layer; and a second outer adhesive layer sequentially. At least one of the first outer adhesive layer and the second outer adhesive layer includes a cured product of an outer adhesive composition including a high molecular weight prepolymer having a weight average molecular weight of 100,000 g/mol or more and 1,500,000 g/mol or less and a low molecular weight prepolymer having a weight average molecular weight of 1,000 g/mol or more and 80,000 g/mol or less.

A multilayer adhesive tape is provided, including: a first outer adhesive layer; an intermediate adhesive layer; and a second outer adhesive layer sequentially. At least one of the first outer adhesive layer and the second outer adhesive layer includes a cured product of an outer adhesive composition including a high molecular weight prepolymer having a weight average molecular weight of 100,000 g/mol or more and 1,500,000 g/mol or less and a low molecular weight prepolymer having a weight average molecular weight of 1,000 g/mol or more and 80,000 g/mol or less.

An adhesive sheet including a first release film, a second release film disposed on the first release film, and an adhesive layer disposed between the first release film and the second release film, the adhesive layer including an upper surface facing the second release film, a lower surface facing the first release film, and a side surface extending from an edge of the lower surface to an edge of the upper surface. The side surface of the adhesive layer may be inclined with respect to a direction perpendicular to the upper surface and the lower surface.

An adhesive sheet including a first release film, a second release film disposed on the first release film, and an adhesive layer disposed between the first release film and the second release film, the adhesive layer including an upper surface facing the second release film, a lower surface facing the first release film, and a side surface extending from an edge of the lower surface to an edge of the upper surface. The side surface of the adhesive layer may be inclined with respect to a direction perpendicular to the upper surface and the lower surface.

The present invention relates to a pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer containing a base polymer and a pigment, wherein the light transmittance in the wavelength range of 380 to 500 nm is 25% or less and the light transmittance in the wavelength range of 800 to 2,500 nm is 60% or more.

The present invention aims to provide an adhesive tape that is easily peelable while capable of maintaining high adhesion at high temperature. The present invention also aims to provide a method for fixing an electronic device component or an in-vehicle device component using the adhesive tape and a method for producing an electronic device or an in-vehicle device. Provided is an adhesive tape including an adhesive layer containing: an acrylic copolymer; and 0.01 parts by weight or more and 10 parts by weight or less of a compound having a structure represented by the following formula (A) or (B) relative to 100 parts by weight of the acrylic copolymer:

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The present invention aims to provide an adhesive tape capable of exhibiting excellent adhesion to rough surfaces. The present invention also aims to provide a method for fixing an electronic device component or an in-vehicle device component using the adhesive tape and a method for producing an electronic device or an in-vehicle device. Provided is an adhesive tape including an adhesive layer containing an acrylic copolymer, the acrylic copolymer containing 30% by weight or more of a structural unit derived from n-heptyl (meth)acrylate and 0.01% by weight or more and 30% by weight or less of a structural unit derived from 1-methylheptyl (meth)acrylate.

A double-sided optically clear adhesive is provided. The double-sided optically clear adhesive includes a first adhesive layer and a second adhesive layer. The first adhesive layer includes a first resin and a first thermal-crosslinking agent. The first resin includes a hydroxyl group. The first thermal-crosslinking agent includes a first group. The second adhesive layer includes a second resin and a second thermal-crosslinking agent. The second resin includes a hydroxyl group. The second thermal-crosslinking agent includes a second group. The ratio of the equivalent number of the first group of the first thermal-crosslinking agent to the equivalent number of the hydroxyl group of the first resin is represented by r1. The ratio of the equivalent number of the second group of the second thermal-crosslinking agent to the equivalent number of the hydroxyl group of the second resin is represented by r2, wherein r1<r2≤0.8 and r2−r1≤0.025.

Described are viscoelastic damping materials and constructions which may demonstrate low temperature performance and adhesion and which may be used in making vibration damping composites. Viscoelastic damping materials and constructions may include polymers or copolymers of monomers according to formula I:
CH.sub.2═CHR.sup.1—COOR.sup.2  [I]
wherein R.sup.1 is H, CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a branched alkyl group containing 12 to 32 carbon atoms.