Teijin Limited

Other

Bayer Aktiengesellschaft

Michio Yamaura

Kaoru Iwata

Kiyonari Hashidzume

Toshiaki Yatabe

Hiroshi Matsuzawa

Hideaki Nitta

Masaki Takeuchi

Shunichi Matsumura

Takashi Tomie

Akihiko Uchiyama

Nobuaki Kido

Takeshi Sasaki

Takashi Kushida

Tsuneo Hagiwara

Kazuhiko Sato

A film which is a single polymer film and has a smaller phase difference as the wavelength becomes shorter. This film is made from an olefin-based polymer which has an alicyclic group in the side chain, such as hydrogenated polystyrene, the amount of the alicyclic group in the side chain being 60 to 90 wt % based on the whole polymer, and satisfies the following expression:(450)/(550)&#x3c;1wherein R(450) and R(550) are phase differences on the film plane at a wavelength of 450 nm and a wavelength of 550 nm, respectively.

Optical film

A cyclic olefin polymer having a small content of a catalyst residue, a production process for the same and use of the same as an optical material. Catalysts used for polymerization and/or hydrogenation reaction for forming the cyclic olefin polymer are decomposed efficiently by adding at least one compound selected from the group consisting of an &agr;-oxyacid and &bgr;-oxyacid having one hydroxyl group and one carboxyl group in the molecule and derivatives obtained by substituting hydroxyl group thereof by an alkoxyl group, and the decomposition products are removed by rendering them insoluble in a reaction solvent used for the polymerization and/or hydrogenation reaction and precipitating them efficiently.

Cyclic olefin polymer containing little catalyst residue

Process for producing a hydrogenated &agr;-olefin-dicyclopentadiene copolymer. The process includes a step of distilling of unreacted dicyclopentadiene or tetrahydrodicyclopentadiene which is a hydrogenated product of unreacted dicyclopentadiene from a mixture containing &agr;-olefin-dicyclopentadiene copolymer or its hydrogenated product in the presence of a high-boiling hydrocarbon solvent having a boiling point of 195 to 300&deg; C. and an ignition point of 260&deg; C. or more. Method for melt molding the hydrogenated &agr;-olefin-dicyclopentadiene copolymer is also proposed.

Process for producing hydrogenated &agr;-olefin-dicyclopentadiene copolymer, method for molding the same and optical material

Polypyrrole shaped material, process for production thereof, and

A thin film type magnetic recording medium having a durability close to that of the coating type magneting recording medium is provided by a metal oxide protective layer which is formed by a physical vapor deposition.

Method of producing a magnetic recording medium

Magnetic recording medium method for producing the same, and method for

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Hachioji, Japan

Michio Yamaura