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:
Nov. 27, 2012
Filed:
May. 09, 2008
Masaaki Otoshi, Minami-Ashigara, JP;
Masaaki Otoshi, Minami-Ashigara, JP;
FUJIFILM Corporation, Tokyo, JP;
Abstract
One embodiment of the present invention provides a method for producing a stretched cellulose acylate film with an in-plane retardation, Re, of 100 nm or more and a relationship between the thickness direction retardation, Rth, and Re which satisfies Rth<(Re/2), by longitudinally stretching an unstretched cellulose acylate film in a longitudinal direction by pulling by means of a difference in circumferential velocity between a pair of rollers, wherein the method is characterized in that the cellulose acylate film is subjected to free-end uniaxial stretching to a longitudinal stretch ratio of 1 to 2 while the film is being heated in a heating oven installed between the pair of rollers at a stretching temperature in the range of Tc−10° C. to Tc+70° C., Tc being the crystallization temperature of the film, and with the temperature difference in the film width direction maintained within 10° C.