Abstract: 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: R(450)/R(550)<1 wherein 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.

Abstract: A film which is a single polymer film and has a smaller phase difference as the wavelength becomes shorter.

Abstract: 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.

Abstract: 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° C. and an ignition point of 260° C. or more. Method for melt molding the hydrogenated &agr;-olefin-dicyclopentadiene copolymer is also proposed.

Abstract: A polypyrrole shaped material characterized in that when the polypyrrole shaped material is assembled into a tri-electrode cell comprising the polypyrrole shaped material as a positive electrode, platinum as a negative electrode, a lithium metal as a reference electrode and LiClO.sub.4 or LiBF.sub.4 as an electrolyte and said tri-electrode and cell are subjected to discharging at a current density of 10 mA/cm.sup.2 and controlled-potential charging at 3.6 V, (i) at the completion of the discharging, the concentration of chlorine or fluorine in the polypyrrole shaped material is 30% or below of that at the completion of the charging, and (ii) at the completion of the charging, the distribution of chlorine or fluorine in the thickness direction of the polypyrrole shaped material is 50% or less. This polypyrrole shaped material enables charging and discharging at high current densities and has large charging and discharging capacities, and can therefore be utilized as an electrode for secondary battery.

Abstract: 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.

Abstract: 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.