Method for obtaining a rubber composition including a thermoplastic filler

1. A process for preparing a rubber composition usable in manufacturing tyres, the composition being based on one or more diene elastomers, one or more reinforcing fillers, and a crosslinking system, the composition further including particles of one or more thermoplastic materials chosen from amorphous thermoplastic materials and semicrystalline thermoplastic materials, with a glass transition temperature of the one or more amorphous thermoplastic materials and a melting point of the one or more semicrystalline thermoplastic materials being in a range of from 80° C. to 300° C., and with the particles exhibiting a volume-average diameter of less than or equal to 200 μm, the process comprising:

incorporating in at least one diene elastomer, during a non-productive stage, at least one reinforcing filler to form a first mixture, and thermomechanically kneading the first mixture in one or more kneading events until a maximum temperature of between 130° C. and 200° C. is reached;

cooling the first mixture to a temperature of less than 60° C.;

subsequently incorporating in the first mixture, during a productive stage, a crosslinking system, particles of at least one amorphous thermoplastic material having a glass transition temperature of less than 200° C., and particles of at least one semicrystalline thermoplastic material having a melting point less than 200° C. to form a combined mixture; and

kneading the combined mixture up to a maximum temperature of less than 80° C.,

wherein particles of at least one amorphous thermoplastic material having a glass transition temperature greater than or equal to 200° C. and particles of at least one semicrystalline thermoplastic material having a melting point greater than or equal to 200° C. are introduced during the non-productive stage or during the productive stage or during both the non-productive stage and the productive stage.

2. The process according to claim 1 , wherein the at least one thermoplastic material is or are chosen from a group that includes: polypropylenes, polyethylenes, polystyrenes, acrylonitrile/butadiene/styrene copolymers, polymethyl methacrylates, polyamides, polyphenylene ethers, polycarbonates, polyacetals, thermoplastic polyurethanes, thermoplastic fluoropolymers, and polyesters.

3. The process according to claim 2 , wherein the polyesters are chosen from a group that includes: polyethylene terephthalates, polybutylene terephthalates, and polyethylene naphthoates.

4. The process according to claim 2 , wherein the fluoropolymers are chosen from a group that includes: copolymers of tetrafluoroethylene and hexafluoropropene, copolymers of tetrafluoroethylene and perfluorovinyl ether, copolymers of tetrafluoroethylene and ethylene, and polyvinylidene fluoride.

5. The process according to claim 1 , wherein the glass transition temperature of the at least one amorphous thermoplastic material and the melting point of the at least one semicrystalline thermoplastic material are in a range of from 80° C. to 200° C.

6. The process according to claim 1 , wherein the particles exhibit a volume-average diameter of between 50 and 100 μm.

7. The process according to claim 1 , wherein the particles of the at least one thermoplastic material are present at a content of from 10 to 50 phr.

8. The process according to claim 1 , wherein the particles of the at least one thermoplastic material are present at a content of from 20 to 40 phr.

9. The process according to claim 1 , wherein the at least one diene elastomer is or are chosen from a group that includes: polybutadienes, natural rubber, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers, and mixtures thereof.

10. The process according to claim 9 , wherein the at least one diene elastomer is a butadiene/styrene copolymer.

11. The process according to claim 1 , wherein the at least one reinforcing filler is or are chosen from a group that includes: silica, carbon black, and mixtures thereof.

12. The process according to claim 1 , wherein the at least one reinforcing filler is or are present at a content of between 20 and 200 phr.

13. The process according to claim 1 , wherein the at least one reinforcing filler is or are present at a content of between 30 and 150 phr.