Rubber composition comprising a specific hydrocarbon resin

Patent metadata

Field	Value
Publication number	US-11220591-B2
Application number	US-201716472736-A
Country	US
Kind code	B2
Filing date	Dec 5, 2017
Priority date	Dec 22, 2016
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A rubber composition based on at least: from 50 to 100 phr of one or more diene elastomers, referred to as very low glass transition temperature (Tg) diene elastomers, having a Tg within a range of from −110° C. to −70° C., selected from butadiene homopolymers, copolymers of butadiene and of a vinylaromatic monomer, having a content of vinylaromatic units of between 0 and 5% by weight, and mixtures thereof a reinforcing filler a crosslinking system; and from 40 to 150 phr of at least one hydrogenated hydrocarbon resin predominantly composed of units derived from C9 monomers, the resin having a content of aromatic protons of less than 25% and a content of ethylenic protons of less than 1%.

First claim

The invention claimed is:

1. A rubber composition based on at least:
from 50 to 100 phr of at least one diene elastomer,
wherein the at least one diene elastomer is a very low glass transition temperature Tg diene elastomer consisting of a copolymer of butadiene and of a vinylaromatic monomer, wherein the copolymer of butadiene and of a vinylaromatic monomer has a Tg within a range of from −110° C. to −70° C. and has a content of vinylaromatic units of between 0 and 5% by weight relative to the total weight of the at least one diene elastomer;

a reinforcing filler;
a crosslinking system; and
from 40 to 150 phr of at least one hydrogenated hydrocarbon resin predominantly composed of units derived from C 9 monomers, the resin having a content of aromatic protons of less than 25% and a content of ethylenic protons of less than 1%.

2. The rubber composition according to claim 1 , wherein the very low glass transition temperature Tg diene elastomer is present at a total content of from 75 to 100 phr.

3. The rubber composition according to claim 1 , wherein the very low glass transition temperature Tg diene elastomer has a Tg within a range of from −100° C. to −80° C.

4. The rubber composition according to claim 1 , wherein the very low glass transition temperature Tg diene elastomer has a Mooney viscosity within a range of from 50 to 80.

5. The rubber composition according to claim 1 , wherein the very low glass transition temperature Tg diene elastomer has a content of 1,2-bonds relative to a diene portion ranging from 8% to 15% by weight.

6. The rubber composition according to claim 5 , wherein at least 70% by weight of the copolymer of butadiene and of a vinylaromatic monomer is functionalized.

7. The rubber composition according to claim 6 , wherein the copolymer of butadiene and of a vinylaromatic monomer is functionalized with an alkoxysilane group, optionally partially or completely hydrolyzed to give silanol, the alkoxysilane group optionally bearing another function capable of interacting with a reinforcing filler, the alkoxysilane group being bonded to the diene elastomer by means of the silicon atom.

8. The rubber composition according to claim 6 , wherein the copolymer of butadiene and of a vinylaromatic monomer is functionalized predominantly in the middle of the chain.

9. The rubber composition according to claim 5 , wherein the copolymer of butadiene and of a vinylaromatic monomer comprises more than 0 and up to 30% by weight, relative to the total weight of the copolymer of butadiene and of a vinylaromatic monomer, of a star-branched copolymer of butadiene and of a vinylaromatic monomer.

10. The rubber composition according to claim 9 , wherein the copolymer of butadiene and of a vinylaromatic monomer comprises between 0 and 20% by weight of a star-branched copolymer of butadiene and of a vinylaromatic monomer.

11. The rubber composition according to claim 1 , wherein the copolymer of butadiene and of a vinylaromatic monomer is present at a content within a range of from 50 to 100 phr.

12. The rubber composition according to claim 11 , wherein the copolymer of butadiene and of a vinylaromatic monomer is present at a content within a range of from 90 to 100 phr.

13. The rubber composition according to claim 1 , wherein a content of the hydrocarbon resin is within a range of from 45 to 120 phr.

14. The rubber composition according to claim 1 , wherein the hydrocarbon resin has a content of aromatic protons of less than 10%.

15. The rubber composition according to claim 1 , wherein the hydrocarbon resin has a content of aromatic protons of less than 5%.

16. The rubber composition according to claim 1 , wherein the hydrocarbon resin has a glass transition temperature Tg of greater than 60° C.

17. The rubber composition according to claim 1 , wherein the hydrocarbon resin has a content of ethylenic protons of less than 0.5%.

18. The rubber composition according to claim 1 , wherein the hydrocarbon resin does not comprise any ethylenic units.

19. The rubber composition according to claim 1 , wherein the hydrocarbon resin has an Mn of greater than 600 g/mol.

20. The rubber composition according to claim 1 , wherein the hydrocarbon resin has a polydispersity index of less than 2.

21. The rubber composition according to claim 1 , wherein the reinforcing filler is selected from the group consisting of silicas, carbon blacks, and mixtures thereof.

22. The rubber composition according to claim 1 , wherein a content of reinforcing filler is within a range of from 5 to 200 phr.

23. The rubber composition according to claim 1 , wherein a predominant reinforcing filler is silica at a content within a range of from 40 to 150 phr.

24. The rubber composition according to claim 23 further comprising a minority amount of carbon black at a content within a range of from 0.1 to 10 phr.

25. A tire comprising the rubber composition according to claim 1 .

26. The tire according to claim 25 , wherein the rubber composition constitutes all or part of a tread of the tire.

Assignees

• Michelin & Cie

Inventors

• De Gaudemaris Benoit
• Labrunie Philippe

Classifications

• C08L9/06 Primary

  Copolymers with styrene · CPC title

• C08K2003/2296

  of zinc · CPC title

• B60C1/0016

  Compositions of the tread · CPC title

• C08L9/00 Primary

  Compositions of homopolymers or copolymers of conjugated diene hydrocarbons · CPC title

• C08F236/06

  Butadiene · CPC title