Rubber composition and tire

Patent metadata

Field	Value
Publication number	US-11920022-B2
Application number	US-201917274328-A
Country	US
Kind code	B2
Filing date	Jul 31, 2019
Priority date	Sep 11, 2018
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

Provided is a rubber composition that can achieve excellent breaking resistance while having high operability. A rubber composition comprises: a rubber component containing a multicomponent copolymer that contains a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit; and at least one selected from an ethylene-α olefin copolymer and an ethylene-aromatic vinyl copolymer each having a number-average molecular weight of 500 to 30,000.

First claim

The invention claimed is:

1. A rubber composition comprising:
a rubber component containing a multicomponent copolymer that contains a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit; and
at least one selected from an ethylene-α olefin copolymer and an ethylene-aromatic vinyl copolymer each having a number-average molecular weight (Mn) of 500 to 30,000.

2. The rubber composition according to claim 1 , wherein a content of the at least one selected from the ethylene-α olefin copolymer and the ethylene-aromatic vinyl copolymer is 10 parts to 80 parts by mass with respect to 100 parts by mass of the rubber component.

3. The rubber composition according to claim 1 , wherein a carbon number of an α-olefin in the ethylene-α olefin copolymer is 3 to 20.

4. The rubber composition according to claim 1 , wherein a molecular weight distribution of the at least one selected from the ethylene-α olefin copolymer and the ethylene-aromatic vinyl copolymer is in a range of 1 to 5.

5. The rubber composition according to claim 1 , wherein the rubber composition includes at least the ethylene-α olefin copolymer having a number-average molecular weight (Mn) of 500 to 30,000, and a content of the ethylene-α olefin copolymer is 10 parts to 80 parts by mass with respect to 100 parts by mass of the rubber component.

6. The rubber composition according to claim 1 , wherein the rubber composition includes at least the ethylene-aromatic vinyl copolymer having a number-average molecular weight (Mn) of 500 to 30,000, and a content of the ethylene-aromatic vinyl copolymer is 10 parts to 80 parts by mass with respect to 100 parts by mass of the rubber component.

7. The rubber composition according to claim 1 , wherein an aromatic vinyl in the ethylene-aromatic vinyl copolymer is styrene.

8. The rubber composition according to claim 1 , wherein a content of the multicomponent copolymer in the rubber component is 10 mass % or more.

9. The rubber composition according to claim 1 , wherein in the multicomponent copolymer, a content of the conjugated diene unit is 1 mol % to 50 mol %, a content of the non-conjugated olefin unit is 40 mol % to 97 mol %, and a content of the aromatic vinyl unit is 2 mol % to 35 mol %.

10. The rubber composition according to claim 1 , wherein an endothermic peak energy of the multicomponent copolymer from 0° C. to 120° C. measured by a differential scanning calorimeter (DSC) is 10 J/g to 150 J/g.

11. The rubber composition according to claim 1 , wherein a melting point of the multicomponent copolymer measured by a differential scanning calorimeter (DSC) is 30° C. to 130° C.

12. The rubber composition according to claim 1 , wherein a glass transition temperature of the multicomponent copolymer measured by a differential scanning calorimeter (DSC) is 0° C. or less.

13. The rubber composition according to claim 1 , wherein a degree of crystallinity of the multicomponent copolymer is 0.5% to 50%.

14. The rubber composition according to claim 1 , wherein a main chain of the multicomponent copolymer consists only of an acyclic structure.

15. The rubber composition according to claim 1 , wherein in the multicomponent copolymer, the non-conjugated olefin unit consists only of an ethylene unit.

16. The rubber composition according to claim 1 , wherein in the multicomponent copolymer, the aromatic vinyl unit contains a styrene unit.

17. The rubber composition according to claim 1 , wherein in the multicomponent copolymer, the conjugated diene unit contains one or both of a 1,3-butadiene unit and an isoprene unit.

18. A tire produced using the rubber composition according to claim 1 .

19. The rubber composition according to claim 2 , wherein a carbon number of an α-olefin in the ethylene-α olefin copolymer is 3 to 20.

20. The rubber composition according to claim 2 , wherein a molecular weight distribution of the at least one selected from the ethylene-α olefin copolymer and the ethylene-aromatic vinyl copolymer is in a range of 1 to 5.

Assignees

• Bridgestone Corp

Inventors

• Shoda Yasuhiro
• Tardif Olivier

Classifications

• C08L23/0815 Primary

  with aliphatic 1-olefins containing one carbon-to-carbon double bond · CPC title

• B60C1/00

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

• B60C1/0016

  Compositions of the tread · CPC title

• C08F210/02 Primary

  Ethene · CPC title

• C08F210/16

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