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:
Jan. 23, 1996
Filed:
Dec. 01, 1994
Takashi Fujita, Yokkaichi, JP;
Toshihiko Sugano, Yokkaichi, JP;
Mitsubishi Chemical Corporation, Tokyo, JP;
Abstract
A process for preparing propylene block copolymers, comprising a preceding polymerization step in which a crystalline homopolymer of propylene, or a propylene-ethylene copolymer containing 7 wt. % or less of ethylene is produced in the presence of a catalyst comprising the following components (A) and (B), and a succeeding polymerization step in which the polymerization is continued in the presence of at least part of the homopolymer or copolymer, and of the following component (C) further added to give a copolymer with a polymerization ratio (weight ratio) of propylene to ethylene of from 0/100 to 90/10; the polymerization amount at the preceding polymerization step being from 30 to 95 wt. % of the total polymerization amount at the preceding and succeeding polymerization steps;