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. 01, 2001
Filed:
Jun. 04, 1997
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
A polypropylene block copolymer obtained by producing an ethylene-propylene copolymer moiety as a component A having an ethylene content of 1.5 to 6.0% by weight in an amount of 40 to 85% by weight based on the total weight of components A and B in the absence of an inert solvent, substantially, in a first step, with a Ziegler-Natta catalyst, and then producing an ethylene-propylene copolymer moiety as a component B having an ethylene content of 7 to 17% by weight in an amount of 15 to 60% by weight based on an amount of the whole polymer in a gas phase in a second step, wherein an intrinsic viscosity ([&eegr;]B) of the component B is from 2.0 to 5.0 dl/g and the ratio of the intrinsic viscosity ([&eegr;]B) of the component B to an intrinsic viscosity ([&eegr;]A) of the component A is within the range of 0.5 to 1.8.