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. 16, 2011
Filed:
Nov. 06, 2008
Tomoyuki Hirayama, Ibaraki, JP;
Toshiyuki Iida, Ibaraki, JP;
Yutaka Ohmori, Ibaraki, JP;
Miyuki Kurogi, Ibaraki, JP;
Hisae Shimizu, Ibaraki, JP;
Tomoyuki Hirayama, Ibaraki, JP;
Toshiyuki Iida, Ibaraki, JP;
Yutaka Ohmori, Ibaraki, JP;
Miyuki Kurogi, Ibaraki, JP;
Hisae Shimizu, Ibaraki, JP;
Nitto Denko Corporation, Ibaraki-shi, Osaka, JP;
Abstract
The invention relates to an optical film containing aromatic polymer which shows high solubility to solvents, and methods for production thereof. Further, the invention also relates to an optical laminate, a polarizing plate, and an image display device each using the optical film. The optical film may be attained by using polyester with a specific structure. The polyester with a specific structure may be obtained by condensation polymerization of bisphenol compound(s) and dicarboxylic acid compound(s) with biphenyl structure, and preferably has no halogen atom in its chemical structure. The optical film of the invention advantageously has not only high solubility in solvents but also a high level of heat resistance and birefringence producing capability. When the content of the biphenyl structure is high, the optical film of the invention can also have large wavelength dispersion of birefringence.