Curable compositions, cured compositions, articles containing the curable or cured compositions, and methods of making the articles are provided. More particularly, the curable compositions contain a (meth)acrylate-based polymer having pendant (meth)acryloyl groups, at least one monomer having a single ethylenically unsaturated group, a photoinitiator that includes an acyl phosphine oxide, and a thixotropic agent. The curable compositions can be printed or dispensed, if desired, and the cured compositions are pressure-sensitive adhesives.

Curable compositions, cured compositions, articles containing the curable or cured compositions, and methods of making the articles are provided. More particularly, the curable compositions contain a (meth)acrylate-based polymer having pendant (meth)acryloyl groups, at least one monomer having a single ethylenically unsaturated group, a photoinitiator that includes an acyl phosphine oxide, and a thixotropic agent. The curable compositions can be printed or dispensed, if desired, and the cured compositions are pressure-sensitive adhesives.

A pressure-sensitive adhesive comprising a polymer (X1) containing 48% by mass or more of a constituent unit derived from at least one monomer (Y) selected from the group consisting of a monomer (A1) represented by the following general formula (1) and a monomer (B1) represented by the following general formula (2), in which a tan δ (23° C.) determined as G″ (23° C.)/G′ (23° C.) is 0.8 to 1.3, wherein a storage elastic modulus and a loss coefficient at 23° C. are respectively represented by G′ (23° C.) and G″ (23° C.). In the formula (1), R.sup.1 represents H or CH.sub.3, R.sup.2 represents —C.sub.nH.sub.2n+1 and n represents an integer of 7 to 14. In the formula (2), R.sup.3 represents —C(═O)C.sub.mH.sub.2m+1 and m represents an integer of 7 to 13. Thus, retention force under high temperature, low-temperature attachability, and adhesiveness to a low-polar adherend are favorable along with a high bio rate.

A pressure-sensitive adhesive comprising a polymer (X1) containing 48% by mass or more of a constituent unit derived from at least one monomer (Y) selected from the group consisting of a monomer (A1) represented by the following general formula (1) and a monomer (B1) represented by the following general formula (2), in which a tan δ (23° C.) determined as G″ (23° C.)/G′ (23° C.) is 0.8 to 1.3, wherein a storage elastic modulus and a loss coefficient at 23° C. are respectively represented by G′ (23° C.) and G″ (23° C.). In the formula (1), R.sup.1 represents H or CH.sub.3, R.sup.2 represents —C.sub.nH.sub.2n+1 and n represents an integer of 7 to 14. In the formula (2), R.sup.3 represents —C(═O)C.sub.mH.sub.2m+1 and m represents an integer of 7 to 13. Thus, retention force under high temperature, low-temperature attachability, and adhesiveness to a low-polar adherend are favorable along with a high bio rate.

A multilayer adhesive tape in which an interface separation between layers does not occur even at in extremely low temperature atmosphere is provided. The multilayer adhesive tape sequentially includes: a first outer adhesive layer; an intermediate adhesive layer; and a second outer adhesive layer, in which attaching force among the first outer adhesive layer, the intermediate adhesive layer, and the second outer adhesive layer is maintained after the multilayer adhesive tape is treated in liquefied nitrogen for 15 seconds.

A mask-integrated surface protective tape, containing: a substrate film; a temporary-adhesive layer provided on the substrate film; and a mask material layer provided on the temporary-adhesive layer; wherein the mask material layer and the temporary-adhesive layer each contain a (meth)acrylic copolymer; and wherein the mask-integrated surface protective tape is used for a method of producing a semiconductor chip utilizing a plasma-dicing.

A display unit that includes an image display part and a light-transmitting protective part arranged on the image display part. A cured resin layer is arranged between the display part and the protective part. The cured resin layer can have a transmittance of 90% or higher in the visible range and a storage modulus at 25° C. of 1×10.sup.7 Pa or less. The cured resin layer can be formed from a resin composition that has a cure shrinkage of 5% or less.

A display unit that includes an image display part and a light-transmitting protective part arranged on the image display part. A cured resin layer is arranged between the display part and the protective part. The cured resin layer can have a transmittance of 90% or higher in the visible range and a storage modulus at 25° C. of 1×10.sup.7 Pa or less. The cured resin layer can be formed from a resin composition that has a cure shrinkage of 5% or less.

Electrically conductive masking tapes include an electrically conductive backing and an electrically conductive pressure sensitive adhesive layer. The pressure sensitive adhesive contains an acrylate-based copolymeric matrix, a crosslinker, an electrically conductive filler, and at least one antioxidant. The acrylate-based copolymeric matrix is the reaction product of a polymerizable mixture including at least one first alkyl(meth)acrylate monomer with a homopolymer Tg of less than −50° C., and at least one hydroxyl-functional alkyl(meth)acrylate with a homopolymer Tg of less than −10° C. The electrically conductive tape is capable of being laminated to and cleanly removed from a substrate surface, after being subjected to harsh conditions such as plasma vapor deposition conditions.

An object of the present invention is to provide a pressure-sensitive adhesive sheet enables a pressure-sensitive adhesive layer to be formed, wherein the pressure-sensitive adhesive layer has a low dielectric constant, is excellent in level difference conformability while maintaining adhesive strength and adhesion reliability at high temperatures, and suitable for laminating a metal mesh film and the like. The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer containing an acrylic polymer (A) and a hydrogenated polyolefinic resin (B) that exhibits liquid flowability at 25° C. The pressure-sensitive adhesive layer has a dielectric constant at a frequency of 1 MHz of from 2.3 to 3.5. The pressure-sensitive adhesive sheet has a 180° peel adhesive strength to a glass plate at a tensile speed of 300 mm/minute at 65° C. of 6 N/20 mm or more. In the pressure-sensitive adhesive sheet, the proportion of the 180° peel adhesive strength to a glass plate at a tensile speed of 300 mm/minute at 65° C. to the 180° peel adhesive strength to a glass plate at a tensile speed of 300 mm/minute at 25° C. (180° peel adhesive strength to a glass plate at a tensile speed of 300 mm/minute at 65° C./180° peel adhesive strength to a glass plate at a tensile speed of 300 mm/minute at 25° C.×100) is 30 or more.