Modified diene elastomer comprising a diene elastomer coupled by an aminoalkoxysilane compound and having an amine function at the chain end, and rubber composition comprising same

Patent metadata

Field	Value
Publication number	US-2016176992-A1
Application number	US-201414910662-A
Country	US
Kind code	A1
Filing date	Aug 4, 2014
Priority date	Aug 9, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

The invention relates to a modified diene elastomer comprising predominantly the entity functionalized in the middle of the chain by an alkoxysilane group, optionally partially or completely hydrolysed to give silanol, bearing a tertiary amine functional group and the silicon atom of which bonds the two pieces of the chain, the chain ends of the modified diene elastomer being functionalized to at least 70 mol %, with respect to the number of moles of chain end, by an amine functional group.

First claim

1 . A modified diene elastomer comprising predominantly an entity functionalized in the middle of the chain by an alkoxysilane group, optionally partially or completely hydrolysed to give silanol, bearing a tertiary amine functional group and the silicon atom of which bonds the two pieces of the chain, the chain ends of the modified diene elastomer being functionalized to at least 70 mol %, with respect to the number of moles of chain end, by an amine functional group.

2 . A modified diene elastomer according to claim 1 , wherein the entity functionalized in the middle of the chain by the alkoxysilane group, optionally partially or completely hydrolysed to give silanol, bearing a tertiary amine functional group, the silicon atom of which bonds the two pieces of the chain, the chain ends being functionalized to at least 70 mol % by an amine functional group, corresponds to the following formula (I):

in which:
the symbol E denotes a diene elastomer functionalized to at least 70 mol % at the chain end by an amine functional group,
R 1 denotes, as a function of the degree of hydrolysis, a hydrogen atom or a linear or branched C 1 -C 10 ,
R 2 is a saturated or unsaturated, cyclic or non-cyclic, divalent C 1 -C 18 aliphatic hydrocarbon group or C 6 -C 18 aromatic hydrocarbon group,
R 3 and R 4 , which are identical or different, represent a linear or branched C 1 -C 18 , or else R 3 and R 4 form, with N to which they are bonded, a heterocycle comprising a nitrogen atom and at least one carbon atom.

3 . A modified diene elastomer according to claim 2 , wherein R 1 represents a hydrogen atom or a methyl or ethyl radical.

4 . A modified diene elastomer according to claim 2 , wherein R 1 represents a hydrogen atom.

5 . A modified diene elastomer according to claim 2 , wherein R 2 represents the saturated linear divalent C 3 aliphatic hydrocarbon radical.

6 . A modified diene elastomer according to claim 2 , wherein R 3 and R 4 , which are identical or different, represent a methyl or ethyl radical.

7 . A modified diene elastomer according to claim 1 , wherein the modified diene elastomer is a copolymer of butadiene and of a vinylaromatic monomer.

8 . A modified diene elastomer according to claim 1 , comprising at least 70% by weight, with respect to the modified diene elastomer, of the entity functionalized in the middle of the chain by the alkoxysilane group, optionally partially or completely hydrolysed to give silanol, bearing a tertiary amine functional group, the silicon atom of which bonds the two pieces of the chain, the chain ends being functionalized to at least 70 mol % by an amine functional group.

9 . A process for the preparation of a modified diene elastomer as defined in claim 1 , comprising:
anionic polymerization of at least one conjugated diene monomer in the presence of a polymerization initiator having an amine functional group, modification of the living diene elastomer bearing an active site obtained in the preceding stage by a functionalization agent, capable of coupling the elastomer chains, bearing at least one tertiary amine functional group and an alkoxysilane functional group, which can be hydrolysed to give silanol, with a molar ratio of the functionalization agent to the polymerization initiator with a value ranging from 0.35 to 0.65.

10 . A preparation process according to claim 9 , wherein the polymerization initiator comprises an amine functional group chosen from lithium amides obtained from a secondary amine, and from an organolithium compound.

11 . A preparation process according to claim 9 , wherein the functionalization agent corresponds to the formula:

in which:
R 2 is a saturated or unsaturated, cyclic or non-cyclic, divalent C 1 -C 18 aliphatic hydrocarbon group or C 6 -C 18 aromatic hydrocarbon group,
R 3 and R 4 , which are identical or different, represent a linear or branched C 1 -C 18 , or else R 3 and R 4 form, with N to which they are bonded, a heterocycle comprising a nitrogen atom and at least one carbon atom,
the linear or branched R′ radicals, which are identical to or different from one another, represent a C 1 -C 10 .

12 . A reinforced rubber composition based on at least one reinforcing filler and an elastomer matrix comprising at least one modified diene elastomer as defined in of claim 1 .

13 . A rubber composition according to claim 12 , wherein the elastomer matrix predominantly comprises the modified diene elastomer as defined in claim 1 .

14 . A rubber composition according to claim 12 , wherein said reinforcing filler comprises a reinforcing inorganic filler of siliceous type according to a fraction by weight of greater than 50% and ranging up to 100%.

15 . A semi-finished article made of rubber for a tire, comprising a crosslinkable or crosslinked rubber composition according to claim 12 .

16 . A tyre, comprising a semi-finished article as defined in claim 15 .

17 . A modified diene elastomer according to claim 6 , wherein R 3 and R 4 are identical and represent a methyl radical.

18 . A modified diene elastomer according to claim 7 , wherein the modified diene elastomer is an SBR.

19 . A preparation process according to claim 10 , wherein the secondary amine is a cyclic secondary amine.

20 . A preparation process according to claim 11 , wherein R 3 and R 4 represent a C 1 -C 4 alkyl radical, and the linear or branched R′ radicals represent a C 1 -C 4 alkyl group.

Assignees

• Michelin & Cie
• Michelin Rech Tech

Inventors

• Dire Charlotte
• Marechal Jean-Marc
• Seeboth Nicolas

Classifications

• C08F236/10

  with vinyl-aromatic monomers · CPC title

• C08C19/25 Primary

  Incorporating silicon atoms into the molecule · CPC title

• C08C19/44

  of polymers containing metal atoms exclusively at one or both ends of the skeleton · CPC title

• C08K3/36

  Silica · CPC title

• B60C1/0016

  Compositions of the tread · CPC title