Process for production of high melt flow propylene-based polymer and product from same

Patent metadata

Field	Value
Publication number	US-10358505-B2
Application number	US-201113993503-A
Country	US
Kind code	B2
Filing date	Dec 20, 2011
Priority date	Dec 21, 2010
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

Disclosed are catalyst compositions having an internal electron donor which includes a 3,6-di-substituted-1,2-phenylene aromatic diester. Ziegler-Natta catalyst compositions containing the present catalyst compositions exhibit very high hydrogen response, high activity, high selectivity and produce propylene-based olefins with high melt flow rate.

First claim

The invention claimed is:

1. A Ziegler-Natta polymerization process for producing a propylene-based polymer comprising:
(A) contacting, under polymerization conditions and in the presence of hydrogen gas (H 2 ), propylene and optionally one or more comonomers with a catalyst composition comprising:
(i) a procatalyst composition comprising a substituted-1,2-phenylene dibenzoate having structure (I),

wherein R 1 -R 14 are the same or different, each of R 1 and R 4 is selected from the group consisting of a C 1 -C 8 alkyl group, a C 2 -C 8 alkenyl group, and combinations thereof, each of R 2 and R 3 is selected from the group consisting of hydrogen and a hydrocarbyl group having 1 to 20 carbon atoms, and each of R 5 -R 14 is selected from hydrogen, a halogen, a hydrocarbyl group having 1 to 20 carbon atoms, and a hydrocarbyloxy group having 1 to 20 carbon atoms,
(ii) a cocatalyst, and
(iii) an external electron donor;
(B) maintaining a H 2 /propylene mole ratio from 0.005 to less than 0.1 during the contacting; and
(C) forming a propylene-based polymer having a melt flow rate greater than 50 g/10 min,
wherein the polymerization process is selected from the group consisting of gas phase, slurry, and a bulk polymerization, operating in one or more than one reactor.

2. The process of claim 1 comprising maintaining a H 2 /propylene mole ratio from 0.03 to less than 0.1 during the contacting; and
forming a propylene-based polymer having a melt flow rate greater than 100 g/10 min.

3. The process of claim 1 wherein at least one of R 1 and R 4 is a methyl group.

4. The process of claim 1 wherein each of R 1 and R 4 is a methyl group.

5. The process of claim 1 wherein R 1 is a methyl group and R 4 is an isopropyl group.

6. The process of claim 1 wherein each of R 1 and R 4 is a methyl group, R 3 is hydrogen, and R 2 is selected from the group consisting of an isopropyl group, a cyclopentyl group, a cyclohexyl group, an aryl group, an alkylaryl group, a tert-butyl group, and a 2,3,3-trimethylbutan-2-yl group.

7. The process of claim 1 wherein each of R 1 and R 4 is a methyl group and R 2 is an isopropyl group.

8. The process of claim 1 comprising forming a propylene homopolymer having a melt flow rate greater than 100 g/10 min.

9. The process of claim 1 wherein the catalyst composition comprises an activity limiting agent selected from the group consisting of a carboxylic acid ester, a diether, a poly(alkene glycol), poly(alkene glycol)ester, a diol ester, and combinations thereof.

10. The process of claim 1 wherein the catalyst composition comprises a first selectivity control agent (SCA1), that is a dimethoxysilane and a second selectivity control agent (SCA2) selected from the group consisting of a diethoxysilane, a triethoxysilane, a tetraethoxysilane, a trimethoxysilane, and a dimethoxysilane containing two linear alkyl or alkenyl groups or hydrogen.

11. The process of claim 1 comprising forming a propylene-based polymer having a xylene solubles content from 1 wt % to 4 wt %.

12. A Ziegler-Natta polymerization process for producing a propylene-based polymer comprising:
(A) contacting, under polymerization conditions and in the presence of hydrogen gas (H 2 ), propylene and optionally one or more comonomers with a catalyst composition comprising:
(i) a procatalyst composition comprising a substituted-1,2-phenylene dibenzoate having structure (I),

wherein R 1 -R 14 are the same or different, each of R 1 and R 4 is selected from the group consisting of a C 1 -C 8 alkyl group, a C 2 -C 8 alkenyl group, and combinations thereof, each of R 2 and R 3 is selected from the group consisting of hydrogen and a hydrocarbyl group having 1 to 20 carbon atoms, and each of R 5 -R 14 is selected from hydrogen, a halogen, a hydrocarbyl group having 1 to 20 carbon atoms, and a hydrocarbyloxy group having 1 to 20 carbon atoms,
(ii) a cocatalyst, and
(iii) an external electron donor;
(B) maintaining a H 2 /propylene mole ratio from 0.005 to less than 0.1 during the contacting; and
(C) forming a propylene-based polymer having a melt flow rate greater than 200 g/10 min
wherein the polymerization process is selected from the group consisting of gas phase, slurry, or a bulk polymerization, operating in one or more than one reactor.

Assignees

• Chen Linfeng
• Leung Tak W
• Tao Tao
• Gao Kuanqiang
• Grace W R & Co

Inventors

• Chen Linfeng
• Leung Tak W
• Tao Tao
• Gao Kuanqiang

Classifications

• C08F4/6094

  containing oxygen · CPC title

• C08F110/06 Primary

  Propene · CPC title

• C08F4/651

  Pretreating with non-metals or metal-free compounds · CPC title

• C08F4/00 Primary

  Polymerisation catalysts · CPC title

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title