Process for preparing blends of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene

Patent metadata

Field	Value
Publication number	US-9982115-B2
Application number	US-201415101310-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Dec 3, 2013
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

A process for preparing a blend of cis-1,4-polybutadiene and syndiotactic 1,2 polybutadiene, the process comprising the steps of (i) polymerizing 1,3-butadiene in the presence of a lanthanide-based catalyst to form a polymerization mixture including cis-1,4-polybutadiene, and (ii) polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst within the polymerization mixture including cis-1,4-polybutadiene to form syndiotactic 1,2-polybutadiene and thereby produce a blend of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene.

First claim

What is claimed is:

1. A process for preparing a blend of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene, the process comprising the steps of:
(i) polymerizing 1,3-butadiene in the presence of a lanthanide-based catalyst to form a polymerization mixture including cis-1,4-polybutadiene that includes less than 20 percent by weight solvent based upon the total weight of the polymerization mixture, and
(ii) polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst within the polymerization mixture including cis-1,4-polybutadiene that includes less than 20 percent by weight solvent based upon the total weight of the polymerization mixture to form syndiotactic 1,2-polybutadiene and thereby produce a blend of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene.

2. The process of claim 1 , where the lanthanide-based catalyst includes (a) a lanthanide-containing compound, (b) an alkylating agent, and (c) a halogen source.

3. The process of claim 2 , where said step of polymerizing 1,3-butadiene in the presence of a lanthanide-based catalyst takes place in the presence of a polymerization modulator.

4. The process of claim 3 , where the halogen source includes a bromine-containing compound.

5. The process of claim 4 , where the polymerization modulator includes an amine compound.

6. The process of claim 1 , where the cobalt-based catalyst includes (a) a cobalt-containing compound, (b) carbon disulfide, and (c) an organoaluminum compound.

7. The process of claim 2 , where the cobalt-based catalyst includes (a) a cobalt-containing compound, (b) carbon disulfide, and (c) an organoaluminum compound, and where said step of polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst employs from about 1 to about 10 mmol cobalt-containing compound per mmol of lanthanide compound.

8. The process of claim 3 , where the cobalt-based catalyst includes (a) a cobalt-containing compound, (b) carbon disulfide, and (c) an organoaluminum compound, and where said step of polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst employs from about 2 to about 100 mmol cobalt-containing compound per mmol of lanthanide compound.

9. The process of claim 1 , where said step of polymerizing 1,3-butadiene in the presence of a lanthanide-based catalyst takes place within a polymerization mixture that includes less than 5 percent by weight solvent based upon the total weight of the polymerization mixture.

10. The process of claim 3 , where said step of polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst takes place within a polymerization mixture that includes less than 5 percent by weight solvent based upon the total weight of the polymerization mixture.

11. The process of claim 1 , where said step of polymerizing 1,3-butadiene in the presence of a lanthanide-based catalyst takes place within a first vessel, and where said step of polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst takes place within a second vessel.

12. The process of claim 1 , where said step of polymerizing 1,3-butadiene in the presence of a lanthanide-based catalyst and said step of polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst takes place within a single vessel.

13. The process of claim 1 , where said step of polymerizing 1,3-butadiene in the presence of a lanthanide-based catalyst takes place within a first zone of a reactor, and where said step of polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst takes place within a second zone of the reactor.

14. A process for preparing a blend of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene, the process comprising:
(i) introducing a lanthanide-based catalyst and 1,3-butadiene monomer to form a polymerization mixture that includes less than 20 percent by weight solvent based upon the total weight of the polymerization mixture;
(ii) allowing the 1,3-butadiene monomer to polymerize to form cis-1,4-polybutadiene and thereby form a polymerization mixture including cis-1,4-polybutadiene and further includes less than 20 percent by weight solvent based upon the total weight of the polymerization mixture;
(iii) introducing a cobalt-based catalyst to the polymerization mixture including the cis-1,4-polybutadiene; and
(iv) allowing the 1,3-butadiene monomer to polymerize to form syndiotactic 1,2-polybutadiene within the polymerization mixture including the cis-1,4-polybutadiene.

15. The process of claim 14 , where said step of introducing a cobalt-based catalyst takes place after the conversion of 1,3-butadiene monomer to cis-1,4-polybutadiene reaches at least 5% and before the conversion of 1,3-butadiene to cis-1,4-polybutadiene reaches at most 90%.

16. A process for preparing a blend of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene, the process comprising:
(i) providing an active polymerization mixture including a propagating cis-1,4-polybutadiene polymer that includes less than 20 percent by weight solvent based upon the total weight of the polymerization mixture; and
(ii) adding a cobalt-based catalyst to the active polymerization mixture including the propagating cis-1,4-polybutadiene polymer.

17. The process of claim 16 , further comprising the step of adding 1,3-butadiene monomer to the active polymerization mixture.

18. The process of claim 16 , where the polymerization mixture includes less than 5 percent by weight solvent based on the total weight of the polymerization mixture.

19. The process of claim 1 , further comprising preparing a vulcanizable composition by combining the blend of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene, a filler, and a curing agent.

20. The process of claim 1 , further comprising preparing a tire component employing the blend of cis-1,4-polybutadiene and syndiotactic 1,2-polybutadiene.

Assignees

• Bridgestone Corp

Inventors

• Mccauley Kevin M
• Luo Steven

Classifications

• C08F2410/04

  Dual catalyst, i.e. use of two different catalysts, where none of the catalysts is a metallocene · CPC title

• F16F9/0409

  characterised by the wall structure · CPC title

• F16F2224/025

  Elastomers · CPC title

• C08F136/06

  Butadiene · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title