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. 28, 2020
Filed:
May. 12, 2015
China Petroleum & Chemical Corporation, Beijing, CN;
Beijing Research Institute of Chemical Industry, China Petroleum & Chemical Corporation, Beijing, CN;
Wenbo Song, Beijing, CN;
Meifang Guo, Beijing, CN;
Jinliang Qiao, Beijing, CN;
Zhichao Yang, Beijing, CN;
Shijun Zhang, Beijing, CN;
Luqiang Yu, Beijing, CN;
China Petroleum & Chemical Corporation and Beijing Research Institute of Chemical Industry, Chaoyang District, Beijing, CN;
China Petroleum & Chemical Corporation, Chaoyang District, Beijing, CN;
Abstract
The invention discloses a process for preparing high-performance propylene polymers, the process utilizing a high activity, highly stereoselective Ziegler-Natta catalyst and two or more stages of polymerization carried out under different hydrogen concentrations to prepare propylene polymers having broad molecular weight distribution, wherein non-uniformness of isotacticity of molecular chains of the final propylene polymers is improved by adjusting or controlling stereoselectivity of catalytic active sites under different hydrogen concentrations, namely, making the low molecular weight fraction of the polymers having a higher isotacticity and making the high molecular weight fraction of the polymers having a lower isotacticity, thereby overcoming the drawbacks of the propylene polymers having broad molecular weight distribution known in the art. The resulting final polymers have excellent combined properties, in particular, remarkably improved mechanical properties.