Transition metal compound and method of preparing polypropylene using the same

Patent metadata

Field	Value
Publication number	US-12358938-B2
Application number	US-202017264593-A
Country	US
Kind code	B2
Filing date	Jun 10, 2020
Priority date	Jun 13, 2019
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

Provided are a novel transition metal compound of the following Chemical Formula 1 that exhibits excellent catalytic activity, allows formation of a macromonomer which is a polymer in which a double bond is formed at the end of a chain, and improves a melt strength characteristic when used in polymerizing polypropylene, and a method of preparing a polypropylene using the same.wherein A, M, R1 to R10, X1 and X2, Y1 and Y2 and m are described herein.

First claim

The invention claimed is:

1. A transition metal compound represented by Chemical Formula 1:

in Chemical Formula 1,
A is an element of Group 14;
M is a transition metal of Group 4,
R 1 to R 5 are each independently linear C 1-6 alkyl,
R 6 is C 6-20 aryl unsubstituted or substituted with linear or branched C 1-8 alkyl,
R 7 to R 9 are each independently hydrogen, or two adjacent groups of R 7 to R 9 combine with each other to form a cyclopentyl group,
R 10 is each independently hydrogen,
one of X 1 or X 2 is S, and the other is a single bond,
Y 1 and Y 2 are each independently halogen, and
m is an integer of 4.

2. The transition metal compound of claim 1 , wherein A is silicon and M is zirconium.

3. The transition metal compound of claim 1 , wherein all of R 1 to R 5 are methyl.

4. The transition metal compound of claim 1 , wherein R 6 is phenyl or naphthyl, each of which is unsubstituted or substituted with branched C 3-6 alkyl.

5. The transition metal compound of claim 1 , wherein R 6 is phenyl, 4-t-butylphenyl, 3,5-di-t-butylphenyl, or naphthyl.

6. The transition metal compound of claim 1 , wherein the transition metal compound is selected from the group consisting of compounds of the following structures:

7. A catalyst composition comprising the transition metal compound of claim 1 .

8. The catalyst composition of claim 7 , further comprising at least one selected from a carrier, a cocatalyst, or an antistatic agent.

9. The catalyst composition of claim 8 , wherein the carrier comprises silica.

10. The catalyst composition of claim 8 , wherein the cocatalyst comprises one or more of compounds represented by the following Chemical Formulae 4 to 6:
—[Al(R 11 )—O] m —  [Chemical Formula 4]

in Chemical Formula 4,
R 11 is the same as or different from each other, and is each independently halogen; C 1-20 hydrocarbon; or C 1-20 hydrocarbon substituted with halogen; and
m is an integer of 2 or more;
J(R 12 ) 3   [Chemical Formula 5]

in Chemical Formula 5,
R 12 is the same as or different from each other, and is each independently halogen; C 1-20 hydrocarbon; or C 1-20 hydrocarbon substituted with halogen; and
J is aluminum or boron; and
[E-H] + [ZQ 4 ] − or [E] + [ZQ 4 ] −   [Chemical Formula 6]

in Chemical Formula 6,
E is a neutral or cationic Lewis base;
H is a hydrogen atom;
Z is an element of Group 13; and
Q is the same as or different from each other, and is each independently a C 6-20 aryl group or a C 1-20 alkyl group in which one or more hydrogen atoms are unsubstituted or substituted with halogen, C 1-20 hydrocarbon, alkoxy, or phenoxy.

11. The catalyst composition of claim 8 , wherein the cocatalyst is alkylaluminoxane.

12. A method of preparing a homopolypropylene, which comprises polymerizing propylene monomers by adding hydrogen in the presence of the catalyst composition of claim 7 .

13. The method of claim 12 , wherein the hydrogen is added in an amount of 50 ppm to 2000 ppm, based on a total weight of the propylene monomers.

14. The method of claim 12 , wherein the homopolypropylene has a ratio of vinyl end groups (:CH═CH 2 ) of 70% or more, as calculated according to Equation 1, and a ratio of vinylidene end groups (:C═CH 2 ) of 10% or less, as calculated according to Equation 2,
Ratio of vinyl end groups (%)=[( Mn/ 42)×2×([ Vi]/ 1000)]×100  [Equation 1]

Ratio of vinylidene end groups (%)=[( Mn/ 42)×2×([ Vd]/ 1000)]×100  [Equation 2]

in Equations 1 and 2, Mn is a value of a number average molecular weight (g/mol) of homopolypropylene, [Vi] is a number of the vinyl end groups per 1000 carbon atoms, and [Vd] is a number of the vinylidene end groups per 1000 carbon atoms.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Insun
• Kim Seok Hwan
• Kim Byung Seok
• Gwon Donghyeon
• Kim Seyoung

Classifications

• C08F110/06

  Propene · CPC title

• C08F4/16

  of silicon, germanium, tin, lead, titanium, zirconium or hafnium · CPC title

• B01J31/22

  Organic complexes · CPC title

• C08F4/6465

  containing silicium · CPC title

• C08F4/6496

  containing sulfur · CPC title