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:
Dec. 24, 1996
Filed:
Jun. 30, 1995
Applicant:
Inventors:
Kazunori Akiyoshi, Tsukuba, JP;
Masahiro Niwano, Tsukuba, JP;
Assignee:
Sumitomo Chemical Company, Limited, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ;
U.S. Cl.
CPC ...
528310 ; 528338 ; 528339 ; 528340 ; 528344 ; 528348 ; 528183 ; 528190 ;
Abstract
A process for producing an aromatic polyamide film, which comprises the steps of: (a) forming a thin layer of an optically isotropic dope in which an aromatic polyamide is dissolved in a polar amide, (b) immersing the thin layer dope of aromatic polyamide in a polar solvent, other than said polar amide, kept at a temperature not higher than -20.degree. C. to prepare a film, and (c) drying the film. The aromatic polyamide film thus obtained is excellent in transparency. Said process requires neither a step of dissolving an aromatic polyamide in conc. sulfuric acid nor an acid-resistant equipment, and hence, is inexpensive.