Block copolymer, method for producing same, rubber composition using said block copolymer, and tire

Patent metadata

Field	Value
Publication number	US-11976190-B2
Application number	US-201917040829-A
Country	US
Kind code	B2
Filing date	Mar 28, 2019
Priority date	Mar 29, 2018
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

The present invention relates to a block copolymer that contains a polymer block A containing a farnesene-derived monomer unit (a1) and a random copolymer block B containing a C12 or lower conjugated diene-derived monomer unit (b1) and an aromatic vinyl compound-derived monomer unit (b2), the block copolymer having a ratio by mass of the polymer block A to the random copolymer block B (A/B) of 30/70 to 0.5/99.5, a content of the aromatic vinyl compound-derived monomer unit (b2) in the random copolymer block B of 1 to 50% by mass, and a weight average molecular weight (Mw) of 100,000 to 5,000,000.

First claim

The invention claimed is:

1. A block copolymer, comprising:
a polymer block A comprising a farnesene-derived monomer unit (a1); and
a random copolymer block comprising a C12 or lower conjugated diene-derived monomer unit (b1) and an aromatic vinyl compound-derived monomer unit (b2),
wherein the block copolymer has an A/B mass ratio of the polymer block A to the random copolymer block B in a range of from 30170 to 0.5/99.5,
wherein the block copolymer has a content of the aromatic vinyl compound-derived monomer unit (b2) in the random copolymer block B in a range of from 1 to 50% by mass,
wherein the block copolymer has a weight average molecular weight as determined by gel permeation chromatography based on polystyrene in a range of from 100,000 to 5,000,000,
wherein at least a part of the block copolymer is a block copolymer in which terminals of linear block copolymer chains are bonded to one another via a coupling agent, and
wherein the coupling ratio is 40% by mass or less.

2. The block copolymer of claim 1 , having a content of the farnesene-derived monomer unit (a1) in the polymer block A of 60% by mass or more.

3. The block copolymer of claim 1 , having a total content of the C12 or lower conjugated diene-derived monomer unit (b1) and the aromatic vinyl compound-derived monomer unit (b2) in the random copolymer block B of 60% by mass or more.

4. The block copolymer of claim 1 , wherein
the coupling ratio is in a range of from 1 to 40% by mass.

5. The block copolymer of claim 1 , wherein at least a part of the block copolymer is a branched block copolymer in which terminals of linear block copolymer chains are bonded to one another via a coupling agent.

6. The block copolymer of claim 1 , wherein the block copolymer has the polymer block A at a terminus of a molecular chain of the block copolymer.

7. A method for producing a block copolymer, the method comprising:
polymerizing a monomer comprising farnesene in the presence of an organic metal initiator to produce a living polymer comprising the polymer block A; and
polymerizing monomers comprising a C12 or lower conjugated diene and an aromatic vinyl compound in the presence of the living polymer comprising the polymer block A to produce a living block copolymer comprising the polymer block A and a random copolymer block B,
wherein the block copolymer comprises a polymer block A comprising a farnesene-derived monomer unit (a1) and the random copolymer block B comprising a C12 or lower conjugated diene-derived monomer unit (b1) and an aromatic vinyl compound-derived monomer unit (b2),
wherein at least a part of the block copolymer is a block copolymer in which terminals of linear block copolymer chains are bonded to one another via a coupling agent, and
wherein the coupling ratio is 40% by mass or less.

8. The method of claim 7 , further comprising:
coupling at least a part of the living block copolymer comprising the polymer block A and the random copolymer block B with a coupling, agent.

9. A method for producing a block copolymer, the method comprising:
polymerizing monomers comprising a C12 or lower conjugated diene and an aromatic vinyl compound in the presence am organic metal initiator to produce a living polymer comprising a random copolymer block B; and
polymerizing a monomer comprising farnesene in the presence of the living polymer comprising the random copolymer block B to produce a living block copolymer comprising a polymer block A and the random copolymer block B,
wherein the block copolymer comprises the polymer block A comprising a farnesene-derived monomer unit (a1) and the random copolymer block B comprising a C12 or lower conjugated diene-derived monomer unit (b1) and an aromatic vinyl compound-derived monomer unit (b2),
wherein at least a part of the block copolymer is a block copolymer in which terminals of linear block copolymer chains are bonded to one another via a coupling agent, and
wherein the coupling, ratio is 40% by mass or less.

10. The method of claim 9 , further comprising:
coupling at least a part of the living block copolymer comprising the polymer block A and the random copolymer block B with a coupling agent.

11. A rubber composition, comprising:
a rubber component (I) comprising the block copolymer of claim 1 ; and
a filler (II),
wherein the rubber composition has a content of the block copolymer in the total amount of the rubber component (I) in a range of from 0.1 to 99.9% by mass, and
wherein the rubber composition comprises the filler (II) in an amount in a range of from 20 to 150 parts by mass, relative to 100 parts by mass of the rubber component (I).

12. A tire, comprising,
the rubber composition of claim 11 .

13. The block copolymer of claim 1 , wherein the coupling ratio is in a range of from 1 to 30% by mass.

14. The block copolymer of claim 1 , wherein the coupling ratio is in a range of from 5 to 28% by mass.

15. The block copolymer of claim 1 , wherein the coup mg ratio is in a range of from 10 to 25% by mass.

16. The block copolymer of claim 1 , wherein the A/B mass ratio of the block copolymer is in a range of from 23/73 to 0.7/99.3.

17. The block copolymer of claim 1 , having a glass transition temperature in a range of from −90 to −10° C.

18. The block copolymer of claim 1 , having a total content of the C12 or lower conjugated diene-derived monomer unit (b1) and the aromatic vinyl compound-derived monomer unit (b2) in the random copolymer block B in a range of from 80 to 100% by mass.

19. The block copolymer of claim 1 , having a total content of the C12 or lower conjugated diene-derived monomer unit (b1) and the aromatic vinyl compound-derived monomer unit (b2) in the random copolymer block B in a range of from 90 to 100% by mass.

20. The block copolymer of claim 1 , having a total content of the C12 lower conjugated diene-derived monomer unit (b1) and the aromatic vinyl compound-derived monomer unit (b2) in the random copolymer block B in a range of from 98 to 100% by mass.

Assignees

• Kuraray Co
• Amyris Inc

Inventors

• Koda Daisuke

Classifications

• C08L53/02 Primary

  of vinyl-aromatic monomers and conjugated dienes · CPC title

• B60C1/00

  Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition · CPC title

• C08F212/08

  Styrene · CPC title

• C08F236/06

  Butadiene · CPC title

• C08F236/22

  the radical having three or more carbon-to-carbon double bonds · CPC title