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:
May. 08, 1990
Filed:
Jan. 26, 1989
Akira Sano, Kawasaki, JP;
Shigeki Yokoyama, Yokohama, JP;
Yasunosuke Miyazaki, Machida, JP;
Tetsujiro Kuroishi, Chiba, JP;
Kazuo Matsuura, Tokyo, JP;
Nippon Oil Co., Ltd., Tokyo, US;
Abstract
A process for producing polyethylene of ultrahigh molecular weight having an intrinsic viscosity of 10-30 dl/g at 135.degree. C. in decalin is disclosed which comprises at least the following two stages of polymerization reaction: (a) a first reaction stage where in ethylene is polymerized with use of a catalyst comprising a solid component containing at least Mg, Ti and/or Va and in the absence or presence of hydrogen of reduced concentration to produce 70-99.5 weight parts of polyethylene having an intrinsic viscosity of 12-32 dl/g at 135.degree. C. in decalin; and (b) a second reaction stage wherein a fresh feed of ethylene is polymerized in the presence of hydrogen of higher concentration to produce 30-0.5 weight parts of polyethylene having an intrinsic viscosity of 0.1-5 dl/g at 135.degree. C. in decalin.