Denka Company Limited

Denki Kagaku Kogyo Kabushiki Kaisha

Masashi Kume

Atsushi Takei

Atsushi Horihata

Tomomichi Takatsu

Masamichi Kanaoka

Masanobu Kutsumi

Takuya Akahane

Masamich Kanaoka

A fiber for artificial hair, the fiber containing 50 parts by mass or more and 95 parts by mass or less of a vinyl chloride-based resin and 5 parts by mass or more and 50 parts by mass or less of a vinyl-based copolymer resin, in which the vinyl-based copolymer resin contains 60% by mass or more and less than 70% by mass of a styrene-based monomer unit and more than 30% by mass and 40% by mass or less of an acrylonitrile-based monomer unit on the basis of the entire vinyl-based copolymer resin.

Fiber for artificial hair and hair accessory product

The present invention provides a fiber for artificial hair and a hair decorating product having superior combing property. A fiber for artificial hair includes vinyl chloride based resin, vinyl based copolymer, and vinyl chloride based acrylic graft copolymer.

Fiber for artificial hair and hair decorating product

A polyvinyl chloride-based fiber for artificial hair that has excellent low glossiness and grip performance when woven and can be stably spun. Configuring a fiber for artificial hair using a polyvinyl chloride-based resin composition, wherein the polyvinyl chloride-based resin includes, at predetermined blending amounts, a polyvinyl chloride-based resin (A) having a viscosity-average polymerization degree of 450-1,700 and a crosslinked vinyl chloride-based resin (B) in which the viscosity-average polymerization degree of a component that dissolves in tetrahydrofuran is 1,800-2,300, the difference between the viscosity-average polymerization degree of the polyvinyl chloride-based resin (A) and the viscosity-average polymerization degree of the THF-soluble component of the crosslinked vinyl chloride-based resin (B) is in a predetermined range, and the cross-sectional shape of the fiber for artificial hair has a first projection, a second projection, and a third projection and the lengths and widths thereof satisfy predetermined conditions.

Artificial hair fiber

After an adhesive sheet is pasted on a semiconductor wafer, an adhesive of the sheet increases tight attachment to the semiconductor wafer because wetting spreads over time. Due to this, at the time of peeling the adhesive sheet from the ground semiconductor wafer, the semiconductor wafer used to be damaged. This phenomenon is likely to occur for a thinner semiconductor wafer. The present invention resides in an adhesive sheet including a substrate and an adhesive layer disposed on the substrate. The substrate is formed of an ethylene/vinyl acetate copolymer having a vinyl acetate content of 10% by mass or less. The adhesive layer contains 100 parts by mass of a (meth)acrylate ester copolymer, 1 to 10 parts by mass of a cross-linker, 0.05 to 5 parts by mass of a silicone compound. The (meth)acrylate ester copolymer is formed of a copolymer produced by polymerizing a (meth)acrylate ester monomer and a functional-group-containing monomer.

Adhesive sheet and method of backgrinding semiconductor wafer

Provided is a adhesive and an adhesive sheet which exhibit excellent chip-holding properties during dicing and from which chips can be easily stripped during pick up, even when considering changes over time. It is a adhesive composition which contains both (A) a (meth)acrylic acid ester copolymer component that has functional-group containing monomer units and a weight average molecular weight of less than 350,000 and (B) a (meth)acrylic ester copolymer component that has functional-group containing monomer units and a weight average molecular weight of 350,000 to 2,000,000 at a weight ratio of 10:90 to 90:10, and further contains 0.5 to 20 parts by mass of a crosslinking agent per 100 parts by mass of components (A) and (B) in total, the crosslinking agent being a crosslinking agent that reacts with both the functional groups of the component (A) and the functional groups of the component (B).

Adhesive and adhesive sheet

An adhesive sheet comprising a sheetlike base material and, superimposed on one major surface thereof, an adhesive layer, wherein the average surface roughness on one major surface of the base material is in the range of 0.1 to 3.5 &#x3bc;m and on the other major surface thereof is in the range of 0.05 to 0.7 &#x3bc;m. In this structure, the average surface roughness values on both the major surfaces of the base material as a constituent of the adhesive sheet are regulated so as to fall within respective specified ranges, so that not only can any blocking occurring in backwinding of reeled adhesive sheet be inhibited but also any occurrence of minute unevenness (waving) on the wafer surface after grinding can be inhibited, and further that the transparency of the adhesive sheet can be maintained.

Growing community of inventors

Shibukawa, Japan

Masashi Kume