Rubber composition comprising a 1,3-dipolar compound additive bearing an imidazole functional group

Patent metadata

Field	Value
Publication number	US-2016263943-A1
Application number	US-201415031407-A
Country	US
Kind code	A1
Filing date	Oct 24, 2014
Priority date	Oct 25, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

A rubber composition is based on at least one diene elastomer, a reinforcing filler and a 1,3-dipolar compound bearing an imidazole functional group. Such a composition exhibits an improved compromise in certain properties such as stiffness in the cured state and hysteresis.

First claim

1 .- 37 . (canceled)

38 . A rubber composition based on:
at least one diene elastomer; a reinforcing filler; and a 1,3-dipolar compound of formula (I):
Q-A-B  (I)

wherein Q comprises a dipole containing at least one nitrogen atom, wherein A is an atom or a group of atoms connecting Q to B, wherein B comprises a ring of formula (II):

and
wherein three of the four symbols Z, Y, R and R′, which are identical or different, each represent an atom or a group of atoms, it being possible for Z and Y to form, together with the carbon atoms to which they are attached, a ring, and the fourth symbol Z, Y, R or R′ denotes a direct attachment to A.

39 . The rubber composition according to claim 38 , wherein R′ denotes a direct attachment to A.

40 . The rubber composition according to claim 39 , wherein Z and Y are each a hydrogen atom.

41 . The rubber composition according to claim 39 , wherein Z and Y form, together with the carbon atoms to which they are attached, a ring.

42 . The rubber composition according to claim 38 , wherein R represents a hydrogen atom or a carbon-based group which can contain at least one heteroatom.

43 . The rubber composition according to claim 42 , wherein R is an alkyl group that contains from 1 to 12 carbon atoms.

44 . The rubber composition according to claim 38 , wherein A is an aliphatic group or an aromatic group.

45 . The rubber composition according to claim 44 , wherein A is an alkylene group containing from 1 to 20 carbon atoms or an arylene group.

46 . The rubber composition according to claim 38 , wherein the 1,3-dipolar compound is selected from the group consisting of nitrile oxides, nitrile imines and nitrones.

47 . The rubber composition according to claim 46 , wherein Q contains a —C≡N→O unit.

48 . The rubber composition according to claim 47 , wherein Q comprises a unit of formula (III):

wherein four of the five symbols R 1 to R 5 , which are identical or different, are each an atom or a group of atoms, and the fifth symbol denotes a direct attachment to A, and
wherein R 1 and R 5 are not H.

49 . The rubber composition according to claim 48 , wherein R 1 , R 3 and R 5 are each an alkyl group of 1 to 6 carbon atoms.

50 . The rubber composition according to claim 49 , wherein the 1,3-dipolar compound is 2,4,6-trimethyl-3-((2-methyl-1H-imidazol-1-yl)methyl)benzonitrile oxide or 2,4,6-triethyl-3-((2-methyl-1H-imidazol-1-yl)methyl)benzonitrile oxide.

51 . The rubber composition according to claim 46 , wherein Q contains a —C≡N(→O)— unit.

52 . The rubber composition according to claim 51 , wherein Q comprises a unit of formula (IV) or (V):

wherein Y 1 is an aliphatic group or an aromatic group containing from 6 to 20 carbon atoms, and
wherein Y 2 , comprising a direct attachment to A, is an aliphatic group or an aromatic group comprising, on its benzene nucleus, the direct attachment to A.

53 . The rubber composition according to claim 52 , wherein the 1,3-dipolar compound is of formula (IVa), (IVb), (Va) or (Vb):

54 . The rubber composition according to claim 38 , wherein an amount of 1,3-dipolar compound is between 0 and 3 molar equivalents of imidazole ring per 100 moles of monomer units constituting the diene elastomer.

55 . The rubber composition according to claim 38 , wherein the diene elastomer is an essentially unsaturated elastomer selected from the group consisting of polybutadienes, polyisoprenes, butadiene copolymers, isoprene copolymers and mixtures thereof.

56 . The rubber composition according to claim 38 , wherein the reinforcing filler comprises an organic filler.

57 . The rubber composition according to claim 38 , wherein the reinforcing filler comprises a reinforcing inorganic filler.

58 . The rubber composition according to claim 57 , wherein the reinforcing inorganic filler is a silica.

59 . The rubber composition according to claim 57 , wherein the rubber composition further comprises a silane coupling agent for bonding the reinforcing inorganic filler to the diene elastomer.

60 . The rubber composition according to claim 38 , wherein the rubber composition further comprises a crosslinking system.

61 . A process for preparing a rubber composition according to claim 60 , said process comprising the steps of:
adding, during a first non-productive stage, to the diene elastomer, the 1,3-dipolar compound, the reinforcing filler and, if appropriate, a coupling agent, by kneading 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 crosslinking system; and kneading up to a maximum temperature of less than 120° C.

62 . A tread which comprises a rubber composition according to claim 38 .

63 . A tire comprising a rubber composition according to claim 38 .

Assignees

• Michelin & Cie
• Michelin Rech Tech

Inventors

• Gander Sophie
• Salit Anne-Frédérique
• Seeboth Nicolas

Classifications

• C08K3/36

  Silica · CPC title

• B60C2011/0025

  Modulus or tan delta · CPC title

• C08K5/3447

  condensed with carbocyclic rings · CPC title

• B60C1/0016 Primary

  Compositions of the tread · CPC title

• C08K5/3445

  Five-membered rings · CPC title