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:
Oct. 04, 2011
Filed:
Jan. 31, 2006
Tsuyoshi Ikeda, Kanagawa, JP;
Koshi Koide, Kanagawa, JP;
Nobuyuki Koike, Kanagawa, JP;
Tadashi Kawabata, Kanagawa, JP;
Takeshi Hirokane, Kanagawa, JP;
Shojiro Kuwahara, Kanagawa, JP;
Tsuyoshi Ikeda, Kanagawa, JP;
Koshi Koide, Kanagawa, JP;
Nobuyuki Koike, Kanagawa, JP;
Tadashi Kawabata, Kanagawa, JP;
Takeshi Hirokane, Kanagawa, JP;
Shojiro Kuwahara, Kanagawa, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
The present invention relates to a polyester film produced by melt-extruding a polyester composed of a dicarboxylic acid unit and a diol unit, wherein 1 to 80 mol % of the diol unit is a unit containing a cyclic acetal skeleton, and the polyester film has an in-plane retardation of 20 nm or less at a wavelength of 550 nm. The polyester film is an optically isotropic polyester film which is easily produced by an extrusion-molding method and has an economical advantage. The polyester film is useful for production of optical members or optical products such as phase difference films, protective films for polarizing plates, light diffusion films, lens sheets, anti-reflection films and optical information recording media.