ELASTOMERIC COMPOSITION HAVING A VERY GOOD DISPERSION OF THE FILLER IN THE ELASTOMERIC MATRIX

• US 20140378575A1
• Filed: 12/12/2012
• Published: 12/25/2014
• Est. Priority Date: 12/12/2011
• Status: Active Grant

• Current Assignee: Compagnie générale des établissements Michelin
• Original Assignee: Compagnie générale des établissements Michelin, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Sevignon, Marc, Belin, Ccile
• Granted Patent: US 9,751,992 B2
• Time in Patent Office: Days
• US Class Current: 523/156
• CPC Class Codes: B60C 1/0016 Compositions of the tread
• CPC Class Codes: C08J 2307/02 Latex
• CPC Class Codes: C08J 2321/00 Characterised by the use of unspecified rubbers
• CPC Class Codes: C08J 3/22 using masterbatch techniques
• CPC Class Codes: C08K 2201/006 Additives being defined by their surface area
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 5/0016 Plasticisers

Abstract

The invention relates to a rubber composition based on at least one diene elastomer, a reinforcing filler comprising at least carbon black having a CTAB specific surface of greater than or equal to 130 m²/g, a plasticizing oil and also a crosslinking system, the dispersion of the filler in the elastomeric matrix having a Z score of greater than or equal to 70.

Claims

1. A rubber composition based on at least one diene elastomer, a reinforcing filler comprising at least carbon black having a CTAB specific surface of greater than or equal to 130 m²/g, a plasticizing oil and also a cros slinking system, wherein dispersion of the filler in the elastomeric matrix has a Z score of greater than or equal to 70.

2. The rubber composition according to claim 1, obtained from a first masterbatch comprising at least the diene elastomer and the carbon black, and exhibiting wherein a dispersion of the carbon black in the elastomeric matrix having has a Z score of greater than or equal to 80.

4. The rubber composition according to claim 1, wherein the content of plasticizing oil varies from 2 to 50 parts per hundred parts by weight of elastomer.

7. The rubber composition according to any one of claim 1, wherein the diene elastomer is selected from the group consisting of polybutadienes, natural rubber, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers and the mixtures of these elastomers.

8. The rubber composition according to claim 7, wherein the diene elastomer is a natural rubber.

9. The rubber composition according to any one of claim 1, which further comprises at least one inorganic filler, or at least one second elastomer identical to or different from the first elastomer, or both.

10. The rubber composition according to claim 1, wherein the content of all of the filler varies from 30 to 150 phr.

11. The rubber composition according to claim 9, wherein an inorganic filler is added to the first masterbatch and wherein the content of carbon black varies from 20 to 80 phr and the content of inorganic filler varies from 5 to 50 phr.

29. A finished or semi-finished article comprising a composition according to claim 1.

30. A tire tread comprising a composition according to claim 1.

31. A tire or semi-finished product comprising at least one composition according to claim 1.

32. A tire according to claim 31, adapted to equip vehicles carrying heavy loads and running at sustained speed.

3. A rubber composition based on at least one diene elastomer, a reinforcing filler comprising at least carbon black having a CTAB specific surface of greater than or equal to 130 m²/g, a plasticizing oil and also a crosslinking system, obtained from a first masterbatch comprising at least the diene elastomer and the carbon black, and exhibiting a dispersion of the carbon black in the elastomeric matrix having a Z score of greater than or equal to 80.

5. The rubber composition according to claim 3, wherein the first masterbatch is obtained by liquid-phase compounding starting from a diene elastomer latex and an aqueous dispersion of carbon black.

6. The rubber composition according to claim 5, wherein the first masterbatch is obtained according to a process comprising:

feeding a continuous stream of a diene elastomer latex to a mixing region of a coagulation reactor defining an elongated coagulation region extending between the mixing region and an outlet,

feeding a continuous stream of a fluid comprising a filler under pressure to the mixing region of a coagulation reactor in order to form a coagulated mixture,

drying the coagulum obtained above in order to recover the first masterbatch.

12. A process for the preparation of a composition comprising at least one diene elastomer, a reinforcing filler comprising at least carbon black having a CTAB specific surface of greater than or equal to 130 m²/g, a plasticizing oil and also a cros slinking system, wherein dispersion of the filler in the elastomeric matrix has a Z score of greater than or equal to 70, which comprises the following stages:

incorporating all of the constituents of the composition, with the exception of the crosslinking system, in a mixer, and kneading everything thermomechanically until a maximum temperature of between 130°

C. and 200°

C. is reached,

cooling the combined mixture to a temperature of less than 100°

C.,

subsequently incorporating the cros slinking system,

kneading everything up to a maximum temperature of less than 120°

C.

13. The process according to claim 12, wherein a first masterbatch comprising at least the diene elastomer and the carbon black, and exhibiting a dispersion of the carbon black in the elastomeric matrix having a Z score of greater than or equal to 80, is prepared prior to the incorporation of all of the constituents of the composition in the mixer.

17. The process according to claim 12, wherein the diene elastomer is selected from the group consisting of polybutadienes, natural rubber, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers and the mixtures of these elastomers.

18. The process according to claim 17, wherein the diene elastomer is a natural rubber.

19. The process according to claim 12, wherein the content of carbon black is varies from 20 to 80.

20. The process according claim 12, wherein the content of plasticizing oil varies from 2 to 50 parts per hundred parts by weight of elastomer.

21. The process according to claim 12, further comprising introducing an inorganic filler, a second elastomer, or both into the composition simultaneously with the other constituents.

22. The process according to claim 21, wherein an inorganic filler and a second elastomer are introduced into the composition in the form of a specific masterbatch prepared beforehand.

23. The process according to any one of claim 12, wherein an inorganic filler and a second elastomer are introduced separately into the composition, the inorganic filler being introduced before or after the second elastomer.

24. The process according to claim 23, wherein the introduction of the inorganic filler and/or of the second elastomer is offset in time from a few tens of seconds to a few minutes with respect to the introduction of the first masterbatch into the mixer.

14. A process for the preparation of a composition comprising at least one diene elastomer, a reinforcing filler comprising at least carbon black having a CTAB specific surface of greater than or equal to 130 m²/g, a plasticizing oil and also a crosslinking system, which comprises the following stages:

preparing a first masterbatch comprising the diene elastomer and the carbon black, this first masterbatch exhibiting a dispersion of the filler in the elastomeric matrix having a Z score of greater than or equal to 80,

incorporating the other constituents of the composition, with the exception of the crosslinking system, in the first masterbatch in a mixer, and kneading everything thermomechanically until a maximum temperature of between 130°

C. and 200°

C. is reached,

cooling the combined mixture to a temperature of less than 100°

C.,

subsequently incorporating the cros slinking system,

kneading everything up to a maximum temperature of less than 120°

C.

15. The process according to claim 14, wherein the masterbatch is produced in the liquid phase from at least one elastomer latex and a dispersion of carbon black.

16. The process according to claim 15, wherein the masterbatch is produced according to the following successive stages:

feeding a continuous stream of a diene elastomer latex to a mixing region of a coagulation reactor defining an elongated coagulation region extending between the mixing region and an outlet orifice,

feeding a continuous stream of a fluid comprising a filler under pressure to the mixing region of a coagulation reactor in order to form a coagulated mixture,

drying the coagulum obtained above in order to recover the first masterbatch.

25. A masterbatch based on at least one diene elastomer, a reinforcing filler comprising at least carbon black having a CTAB specific surface of greater than or equal to 130 m²/g, and a plasticizing oil, the dispersion of the filler in the elastomeric matrix having a Z score of greater than or equal to 70.

26. The masterbatch according to claim 25, obtained from a first masterbatch comprising at least the diene elastomer and the carbon black, and exhibiting a dispersion of the carbon black in the elastomeric matrix having a Z score of greater than or equal to 80.

27. A masterbatch based on at least one diene elastomer, a reinforcing filler comprising at least carbon black having a CTAB specific surface of greater than or equal to 130 m²/g, and a plasticizing oil, obtained from a first masterbatch comprising at least the diene elastomer and the carbon black, and exhibiting a dispersion of the carbon black in the elastomeric matrix having a Z score of greater than or equal to 80.

28. The masterbatch according to claim 27, wherein the first masterbatch is obtained by liquid-phase compounding starting from a diene elastomer latex and an aqueous dispersion of carbon black.