Toyo Tire Rubber Co., Ltd.

Toyo Boseki Kabushiki Kaisha

Masayuki Tsutsumi

Koichi A Ono

Tetsuo Shimomura

Takatoshi Yamada

Masahiko Nakamori

Shigeru Komai

Keizo Kawahara

Kazutake Okamoto

Akinobu Nagara

Satoshi Maeda

Naonobu Oda

Hisato Kobayashi

Noriko Takahashi

Kazumoto Imai

Shoichi Uemura

Shigeto Yoshida

Akira Takahashi

Takefumi Yoshida

Shinsuke Yamaguchi

Eiji Kumagai

Morio Morino

Yoshiko Akitomo

Hiroko Oyama

Shunji Kurahara

Jun Yasui

This polyimide film is superior in heat resistance, rigidity and high frequency properties, is free of inconveniences due to curling even when various functional layers are laminated by heating, and is preferable as a substrate film superior in thermal degradation stability for electronic parts. This polyimide film has a planar orientation coefficient of 0.79-0.89 as measured by an X-ray diffraction method, a difference in the surface planar orientation degree between one surface thereof and the other surface thereof of not more than 2 and a curling degree of not more than 5%, which is obtained by imidation of a polyimide precursor film having a particular imidation rate.

Polyimide film

A polishing pad includes a polishing layer having abrasive grains dispersed in a resin and is characterized in that the resin is a resin containing ionic groups in the range of 20 to 1500 eq/ton.

Polishing pad and cushion layer for polishing pad

A polishing pad includes at least a polishing layer and a cushion layer and is characterized in that the difference in hardness in Shore D hardness between the polishing layer and the cushion layer is 3 or more.

An oriented syndiotactic polystyrene-based film composed of an oriented film made of a syndiotactic styrene polymer and an adhesiveness-improving layer formed from a specific water-dispersible resin on at least one surface of the oriented film, which is excellent in the tight adhesion between the oriented film and the adhesiveness-improving layer, the adhesion between the adhesiveness-improving layer and an ink layer or laminate layer applied thereon, economical efficiency, recyclability, and environmental compatibility in production. It is particularly preferable that the film be produced by applying the aqueous dispersion of the water-dispersible resin on unstretched or uniaxially stretched film to form the adhesiveness-improving layer, stretching the obtained laminate uni- or bi-axially at least one time, and then heat-treating the resulting laminate.

Oriented syndiotactic polystyrene-base film

A method of producing a polishing pad having a polishing layer is characterized in that the polishing layer is produced by a photolithographic method including: forming a sheet molding from a curing composition containing at least an initiator and an energy ray-reactive compound to be cured with energy rays; exposing the sheet molding to energy rays to induce modification thereof, to change the solubility of the sheet molding in a solvent; and developing the sheet molding after irradiation with energy rays, to partially remove the curing composition with a solvent thereby forming a concave and convex pattern at least one surface.

Method of producing polishing pad

The polishing pad of this invention is a polishing pad effecting stable planarizing processing, at high polishing rate, materials requiring surface flatness at high level, such as a silicon wafer for semiconductor devices, a magnetic disk, an optical lens etc. This invention provides a polishing pad which can be subjected to surface processing to form a sheet or grooves, is excellent in thickness accuracy, attains a high polishing rate, achieves a uniform polishing rate, and also provides a polishing pad which is free of quality variations resulting from an individual variation, easily enables a change the surface patterns, enables fine surface pattern, is compatible with various materials to be polished, is free of burrs upon forming the pattern. This invention provides a polishing pad which can have abrasive grains mixed at very high density without using slurry, and generates few scratches by preventing aggregation of abrasive grains dispersed therein. The polishing pad of this invention has a polishing layer formed from a curing composition to be cured with energy rays, the polishing layer being formed surface pattern thereon by photolithography. The polishing pad of this invention comprises a polishing layer resin having abrasive grains dispersed therein, the resin containing ionic groups in the range of 20 to 1500 eq/ton.

Polishing pad, method of producing the same, and cushion layer for polishing pad

Growing community of inventors

Ohtsu, Japan

Masayuki Tsutsumi