Ziegler-Natta catalyst composition for preparing polyethylene

Patent metadata

Field	Value
Publication number	US-10344103-B2
Application number	US-201515510665-A
Country	US
Kind code	B2
Filing date	Sep 11, 2015
Priority date	Sep 11, 2014
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

The Zigler-Natta catalyst composition of the present disclosure provides uniform polyethylene having a molecular weight in the range from 1 million g/mol to 12 million g/mol. The Zigler-Natta catalyst composition of the present disclosure comprises external electron donor selected from the group consisting of substituted silanediyl diacetate, trialkyl borate and tetraalkoxysilane.

First claim

What is claimed is:

1. A Ziegler-Natta catalyst composition for preparation of an ultrahigh molecular weight polyolefin, said composition comprising:
i. a pro-catalyst comprising a magnesium component and a titanium component;
ii. an organo-aluminum co-catalyst; and
iii. at least one external electron donor, wherein the at least one external electron donor is a substituted silanediyl diacetate or a trialkyl borate;
wherein the magnesium component is in the form of a spheroidal magnesium alkoxide; and
wherein the pro-catalyst is supported on silica and the mole ratio of the amount of silica to the amount of magnesium component ranges from 1:10 to 1:30,
wherein the substituted silanediyl diacetate is selected from the group consisting of diethyl-2,2′-(dimethylsilanediyl)diacetate; diethyl-2,2′-(phenyl(methyl)silanediyl)diacetate and diethyl-2,2′-(diisopropylsilanediyl)diacetate, and
wherein the trialkyl borate is selected from the group consisting of triethyl borate and trimethyl borate.

2. The catalyst composition as claimed in claim 1 , wherein the organo-aluminum co-catalyst is at least one selected from the group consisting of triethylaluminum, tridecylaluminum, tri-n-butylaluminum, tri-isopropylaluminum, tri-isoprenylaluminum, tri-isobutylaluminum, ethyl aluminum sesquichloride, diethylaluminum chloride, di-isobutyl aluminum chloride, triphenylaluminum, tri-n-octylaluminum and tri-n-decylaluminum.

3. The catalyst composition as claimed in claim 1 , wherein the mole ratio of the amount of the organo-aluminum co-catalyst to the amount of titanium component represented as elemental titanium ranges from 500:1 to 10:1.

4. The Ziegler-Natta catalyst composition as claimed in claim 1 , wherein the mole ratio of the amount of the organo-aluminum co-catalyst to the amount of the external electron donor ranges from 1:1 to 50:1.

5. A process for ethylene polymerization in the presence of the Ziegler-Natta catalyst composition as claimed in claim 1 ; said process comprising preparing a slurry of the Ziegler-Natta catalyst composition in a hydrocarbon solvent in a reactor and introducing ethylene in the reactor to attain a predetermined pressure followed by subjecting ethylene to polymerization at a temperature ranging from 50° C. to 100° C. for a time period ranging from 10 minutes to 120 minutes to obtain polyethylene.

6. The process as claimed in claim 5 , wherein the predetermined pressure of the ethylene ranges from 3 Kg/cm2 to 10 Kg/cm 2 .

7. The process as claimed in claim 5 , wherein the polymerization is carried out in the presence of a chain transfer agent.

8. The process as claimed in claim 7 , wherein said chain transfer agent is hydrogen.

Assignees

• Reliance Industries Ltd

Inventors

• Gupta Virendrakumar
• Bhajiwala Hiren Manojkumar
• Dhamaniya Sunil
• Kalita Amarjyoti
• Joshi Ramesh

Classifications

• C08F4/76

  selected from titanium, zirconium, hafnium, vanadium, niobium or tantalum · CPC title

• B01J31/02

  containing organic compounds or metal hydrides · CPC title

• C08F4/654 Primary

  with magnesium or compounds thereof · CPC title

• C08F4/02

  Carriers therefor · CPC title

• C08F2/14

  Organic medium · CPC title