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:
Jun. 30, 2015
Filed:
Jan. 21, 2011
Wenbo Song, Beijing, CN;
Meifang Guo, Beijing, CN;
Shijun Zhang, Beijing, CN;
Wenjun Wei, Beijing, CN;
Honghong Huang, Beijing, CN;
Luqiang Yu, Beijing, CN;
Tao Liu, Beijing, CN;
Huijie HU, Beijing, CN;
Huan Xu, Beijing, CN;
Peiqian Yu, Beijing, CN;
Xiaomeng Zhang, Beijing, CN;
Wenbo Song, Beijing, CN;
Meifang Guo, Beijing, CN;
Shijun Zhang, Beijing, CN;
Wenjun Wei, Beijing, CN;
Honghong Huang, Beijing, CN;
Luqiang Yu, Beijing, CN;
Tao Liu, Beijing, CN;
Huijie Hu, Beijing, CN;
Huan Xu, Beijing, CN;
Peiqian Yu, Beijing, CN;
Xiaomeng Zhang, Beijing, CN;
Abstract
The present invention provides a process for preparing high melt strength propylene polymer by direct polymerization, comprising that a propylene polymer with wide molecular weight distribution and containing 'very high molecular weight fraction' can be prepared by controlling the species and ratios of the external electron donors in the Ziegler-Natta catalyst system at different reaction stages according to the requirement for different molecular weight fractions in the different propylene polymerization stage of the series operation, and said polymer has excellent mechanical properties, especially with very high melt strength. The present invention also provides a propylene homopolymer with high melt strength, comprising the following features: (1) the MFR is 0.2-10 g/10 min at 230° C. with a load of 2.16 kg; (2) the molecular weight distribution M/Mis 6-20; (3) the content of the fraction with a molecular weight higher than 5,000,000 is higher than or equal to 0.8 wt %; (4) M/Mis higher than or equal to 70. Said homopolymer can be used in the preparation of foam products, thermoforming products, biaxial stretching films, blown films and blow-molded products.