Polyolefin catalyst and method for preparing polyolefin by using same

Patent metadata

Field	Value
Publication number	US-11359040-B2
Application number	US-201716463325-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	Nov 23, 2016
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

Disclosed are a polyolefin having a high molecular weight by using a novel metallocene catalyst; a method for preparing the polyolefin by using the same; and a method for preparing an ethylene-propylene random copolymer having high molecular weight, high syndiotacticity and small crystal size, thereby providing injection molded articles with improved transparency. The present invention provides a transition metal compound represented by chemical formula 1:

First claim

The invention claimed is:

1. A transition metal compound for preparing a polypropylene represented by the following chemical formula 1:

in chemical formula 1,
M is a transition metal of group 4,
Q 1 and Q 2 are each independently a halogen;
R 2 and R 4 are hydrogen;
R 1 and R 3 are each independently (C 1 -C 20 )alkyl;
R 5 , R 6 , and R 7 are methyl;
R 8 , R 9 , R 10 , R 12 , R 13 , R 14 , R 15 and R 16 are hydrogen; and
R 11 is tert-butyl.

2. A transition metal catalyst composition, comprising:
the transition metal compound according to claim 1 ; and
one or more co-catalyst compounds selected from the group consisting of an aluminum compound represented by chemical formula 2 below, an alkyl metal compound represented by chemical formula 3 below and a boron compound represented by chemical formula 4 below:
—[Al(R 17 )—O] n -  [Chemical formula 2]

in chemical formula 2, R 17 is a halogen radical, or a hydrocarbyl radical of 1 to 20 carbon atoms, which is substituted or unsubstituted with halogen; and n is an integer of 2 or more,
A(R 18 ) 3   [Chemical formula 3]

in chemical formula 3, A is aluminum or boron; R 18 groups are the same or different, and are each independently a halogen radical, or a hydrocarbyl radical of 1 to 20 carbon atoms, which is substituted or unsubstituted with halogen,
[L-H] + [Z(B) 4 ] − or [L] + [Z(B) 4 ] −   [Chemical formula 4]

in chemical formula 4, L is a neutral or cationic Lewis acid; H is a hydrogen atom;
Z is an element of group 13; and B is each independently an aryl or alkyl radical of 6 to 20 carbon atoms, of which one or more hydrogen atoms are substituted with halogen, hydrocarbyl of 1 to 20 carbon atoms, alkoxy or a phenoxy radicals.

3. The transition metal catalyst composition according to claim 2 , wherein the aluminum compound co-catalyst is one selected from an alkylaluminoxane or an organic aluminum, or a mixture of two or more thereof, and is a single one selected among methylaluminoxane, modified methylaluminoxane, tetraisobutylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum and trioctylaluminum, or a mixture of two or more thereof, and the boron compound co-catalyst is a single one selected among tris(pentafluorophenyl)borane, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and triphenylmethylinium tetrakis(pentafluorophenyl)borate, or a mixture thereof.

4. A method for preparing a polyolefin, comprising a step of polymerizing propylene or ethylene in the presence of the transition metal catalyst composition of claim 2 .

5. A method for preparing an ethylene-propylene random copolymer, comprising a step of polymerizing propylene and ethylene in the presence of the transition metal catalyst composition of claim 2 , the ethylene-propylene random copolymer having a syndiotacticity of 0.91 or more, a melting point of 147° C. or less, a weight average molecular weight of 200,000-1,000,000, molecular weight distribution (Mw/Mn) of 2.0-5.0, a melt index (230° C., 2.16 kg load) of 0.5-10.0 g/10 min, and a haze of 10-25.

6. The method for preparing an ethylene-propylene random copolymer according to claim 5 , wherein the ethylene is added in 0.5 to 5 parts by weight with respect to 100 parts by weight of the propylene.

Assignees

• Lotte Chemical Corp

Inventors

• Chae Byung Hun
• Min Joon Keun
• Jung Sung Won
• Hong Youn Jin
• Woo Hyun Yul

Classifications

• C08F4/65916

  supported on a carrier, e.g. silica, MgCl2, polymer · CPC title

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C07F19/00

  Metal compounds according to more than one of main groups C07F1/00 - C07F17/00 · CPC title

• C08F4/642

  Component covered by group C08F4/64 with an organo-aluminium compound {(C08F4/64003 - C08F4/64196 take precedence)} · CPC title

• C08F2420/01

  Cp or analog bridged to a non-Cp X neutral donor · CPC title