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:
Mar. 30, 1976
Filed:
Apr. 17, 1974
Shigeki Horiie, Yokohama, JA;
Susumu Kurematsu, Zama, JA;
Shinichiro Asai, Machida, JA;
Chiaki Saito, Tokyo, JA;
Denki Kagaku Kogyo K.K., Tokyo, JA;
Abstract
A process for producing a film or sheet of a tapered styrenebutadiene copolymer or mixture thereof, which comprises: Melt extruding and then biaxially stretching a tapered styrenebutadiene copolymer with a molecular weight of 40,000 - 250,000, a total styrene content of 50 - 90 wt. %, and a total butadiene content of 40 - 10 wt. %, wherein said tapered styrene-butadiene copolymer contains: (a) more than 5% of the chain portion having a tapering rate of 0.3 - 4 and a styrene content of 30 - 70 wt. %, (b) more than 35% of the chain portion with a styrene content of more than 80 wt. %, and (c) more than 10% of the chain portion with a styrene content from at least 5 wt. % to less than 50 wt. % between high styrene content chain portions which have a styrene content greater than 80 wt. %.