- 专利标题: DUAL CATALYST SYSTEM FOR PRODUCING POLYETHYLENE WITH LONG CHAIN BRANCHING FOR BLOW MOLDING APPLICATIONS
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申请号: US16898502申请日: 2020-06-11
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公开(公告)号: US20210388130A1公开(公告)日: 2021-12-16
- 发明人: Jeremy M. Praetorius , Alfred E. Brown, JR. , Yongwoo Inn , Youlu Yu , Qing Yang , Ashish M. Sukhadia
- 申请人: Chevron Phillips Chemical Company LP
- 申请人地址: US TX The Woodlands
- 专利权人: Chevron Phillips Chemical Company LP
- 当前专利权人: Chevron Phillips Chemical Company LP
- 当前专利权人地址: US TX The Woodlands
- 主分类号: C08F210/16
- IPC分类号: C08F210/16 ; B29C49/00 ; C08F4/6592
摘要:
Ethylene-based polymers are characterized by a melt index less than 1 g/10 min, a density from 0.94 to 0.965 g/cm3, a Mw from 100,000 to 250,000 g/mol, a relaxation time from 0.5 to 3 sec, and an average number of long chain branches (LCBs) per 1,000,000 total carbon atoms in a molecular weight range of 300,000 to 900,000 g/mol that is greater than that in a molecular weight range of 1,000,000 to 2,000,000 g/mol, or an average number of LCBs per 1,000,000 total carbon atoms in a molecular weight range of 1,000,000 to 2,000,000 g/mol of less than or equal to about 5 and a maximum ratio of ηE/3η at an extensional rate of 0.1 sec−1 from 1.2 to 10. These polymers have substantially no long chain branching in the high molecular weight fraction of the polymer, but instead have significant long chain branching in a lower molecular weight fraction, such that polymer melt strength and parison stability are maintained for the fabrication of blow molded products and other articles of manufacture. These ethylene polymers can be produced using a dual catalyst system containing a single or two atom bridged metallocene compound with two indenyl groups, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.