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. 20, 2001
Filed:
Sep. 30, 1998
Manabu Hirakawa, Tsukuba, JP;
Kenichi Ohkawa, Ichihara, JP;
Teruhiko Doi, Konan, JP;
Tetsuya Hisayama, Bartlesville, OK (US);
Yuichi Miyake, Nagoya, JP;
Takeyoshi Nishio, Okazaki, JP;
Other;
Abstract
A high rigidity ethylene-propylene block copolymer which is composed of (I) a crystalline polypropylene portion and (II) an ethylene-propylene random copolymer portion, and in which the crystalline polypropylene portion (I) has a Q value of not more than 5 which is the weight average molecular weight (Mw)/number average molecular weight (Mn) ratio obtained by a gel permeation chromatography (GPC) method, an isotactic pentad fraction of not less than 0.98 as calculated from,C-NMR, and an intrinsic viscosity of 0.6 to 0.88 dl/g as measured at 135° C. in tetralin; the ethylene-propylene random copolymer portion (II) has an intrinsic viscosity of 4.0 to 6.0 dl/g as measured at 135° C. in tetralin and an ethylene/propylene ratio of 25/75 to 35/65 by weight; and when the total of the above polymers ((I)+(II)) is taken as 100% by weight, the content of the ethylene-propylene random copolymer portion (II) is 8 to 22% by weight, and a process for producing the same.