Sumitomo Chemical Company, Limited

Other

Gunze Limited

Keiichi Minakuchi

Koji Higashi

Nobuo Oi

Kazuaki Sakakura

Shunsuke Hirano

Yukio Murakami

Hideki Shimomura

The present invention provides a phase retarder made of a copolymer prepared by polymerizing one non-cyclic olefin monomer (A) selected from ethylene and &agr;-olefin compound having 3 to 20 carbon atoms, one cyclic olefin monomer (B) selected from cyclic olefin compound such as norbornene, and one cyclic vinyl monomer (C) selected from vinyl compound having a cyclic unit made of an aromatic hydrocarbon or an alicyclic hydrocarbon such as styrene or vinylcyclohexane; wherein (1) an amount of the aromatic vinyl monomer is from about 1 to about 20 mol % and a total amount of the non-cyclic olefin monomer (A) and the cyclic olefin monomer (B) is from about 80 to about 99 mol % in case the component (C) is the aromatic vinyl monomer, or (2) an amount of the alicyclic vinyl monomer is from about 80 to about 99 mol % and a total amount of the non-cyclic olefin monomer and the cyclic olefin monomer is from about 1 to about 20 mol % in case the component (C) is the alicyclic vinyl monomer. The present phase retarder makes it possible to conduct uniform polarizing conversion within a wide wavelength range using a single plate.

Phase retarder

Liquid crystal display device

A touch panel is constructed of a top sheet member having a resistive membrane on its inner surface and a base sheet member having a resistive membrane on its inner surface, the top and base sheet members facing each other with dot spacers being located in between. The top sheet member is formed by laminating a bulge-resistant film, a polarizing plate, a quarter wavelength plate, and a light isotropic film in this order from above. A PET film which is not heat-treated so as to have a higher thermal contraction rate than the other members of the top sheet member underneath such as the polarizing plate, is used as the bulge-resistant film. Since the bulge-resistant film contracts more than the polarizing plate under a high ambient temperature, after the ambient temperature returns to normal, the bulge-resistant film does not become slack against the polarizing plate. Accordingly, the top sheet member can be kept from bulging outward.

Glare-resistant touch panel

A process for producing a phase retarder film, which comprises laminating a heat-shrinkable film on at least one side of a uniaxially stretched thermoplastic resin film so that the heat shrinkage axis direction of said heat-shrinkable film becomes perpendicular to the stretching axis direction of said uniaxially stretched thermoplastic resin film, subjecting the resulting laminate to heat shrinkage, and then peeling and removing the heat-shrinkable film. An object of the present invention is to provide a process for providing a phase retarder film having a desired R.sub.40 /R.sub.0 value and a desired retardation value, easily and at a high efficiency.

Process for producing phase retarder film

Growing community of inventors

Niihama, Japan

Keiichi Minakuchi