The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 12, 2008
Filed:
Aug. 26, 2004
Hideyoshi Fujisawa, Saitama, JP;
Kouichi Tanaka, Kita-ku, JP;
Hideyoshi Fujisawa, Saitama, JP;
Kouichi Tanaka, Kita-ku, JP;
Nippon Kayaku Kabushiki Kaisha, Tokyo, JP;
Polatechno Co., Ltd., Niigata, JP;
Abstract
The present invention relates to a retardation film obtained by subjecting a film formed from a cellulose derivative to an orientation treatment, wherein a hydroxyl group of cellulose is substituted by at least one kind of aliphatic acyl group having 5 to 20 carbon atoms, and a degree of substitution by said hydroxyl group is 1 to 3. According to the present invention, a retardation film having various wavelength dispersion characteristics, positiveness or negativeness in birefringence and viewing angle characteristics, in particular, an achromatic retardation film and a retardation film having a high birefringent property and the like can be obtained by preparing a retardation film using a properly selected said cellulose derivative as a raw material of the film.