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:
Jun. 21, 2022
Filed:
Oct. 27, 2017
Applicant:
Zeon Corporation, Tokyo, JP;
Inventors:
Takao Kobayashi, Tokyo, JP;
Shunsuke Takagi, Tokyo, JP;
Assignee:
ZEON CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 5/30 (2006.01); B32B 7/023 (2019.01); B29D 11/00 (2006.01); B32B 27/08 (2006.01); B32B 7/02 (2019.01); B29C 55/04 (2006.01);
U.S. Cl.
CPC ...
G02B 5/3083 (2013.01); B29C 55/04 (2013.01); B29D 11/00644 (2013.01); B32B 7/02 (2013.01); B32B 7/023 (2019.01); B32B 27/08 (2013.01); G02B 5/30 (2013.01); B32B 2307/42 (2013.01);
Abstract
A method for producing a broadband wavelength film including, in this order: a first step of preparing a layer (A) as a long-length obliquely stretched film; a second step of forming on the layer (A) a layer (B) of a resin having a negative intrinsic birefringence to obtain a multilayer film; and a third step of stretching the multilayer film to obtain a long-length broadband wavelength film including a λ/2 layer and a λ/4 layer.