Ethylene and isoprene copolymer

Patent metadata

Field	Value
Publication number	US-12043680-B2
Application number	US-201916972360-A
Country	US
Kind code	B2
Filing date	May 27, 2019
Priority date	Jun 6, 2018
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

A copolymer of ethylene and of isoprene, which comprises from 10 to 35 mol % of isoprene units, at least 70% of which are in the 3,4 configuration and a portion of which is in the 1,2 configuration is provided. A copolymer of this type with a reduced crystallinity is synthesized with a much higher productivity than its homologues of ethylene and of butadiene, and also confers improved curing properties on rubber compositions.

First claim

The invention claimed is:

1. A copolymer of ethylene and of isoprene, the copolymer comprising from 15 to 30 mol % of isoprene units, at least 70% of which are in the 3,4 configuration and a portion of which is in the 1,2 configuration, the copolymer being a statistical copolymer and having a glass transition temperature of less than −35° C.

2. The copolymer according to claim 1 , in which the isoprene units in the 3,4 configuration and the isoprene units in the 1,2 configuration represent at least 75 mol % of the isoprene units of the copolymer.

3. The copolymer according to claim 1 , which copolymer contains isoprene units in the 1,4-trans configuration.

4. The copolymer according to claim 1 , wherein the copolymer includes at least 65 mol % ethylene units.

5. The copolymer according to claim 1 , which copolymer has a glass transition temperature of between −60° C. and −35° C.

6. The copolymer according to claim 1 , which copolymer is an elastomer.

7. A process for the preparation of a copolymer of ethylene and of isoprene defined in claim 1 , which comprises the copolymerization of ethylene and of isoprene in the presence of a catalytic system based at least on a metallocene of formula (I) and on an organomagnesium compound of formula (II)
P(Cp 1 )(Cp 2 )Nd(BH 4 ) (1+y) L y -N x   (I)

MgR 1 R 2   (II)

Cp 1 and Cp 2 , which are identical or different, being selected from the group consisting of substituted fluorenyl groups and the unsubstituted fluorenyl group of formula C 13 H 8 , P being a group bridging the two Cp 1 and Cp 2 groups and representing a ZR 3 R 4 group, Z representing a silicon or carbon atom, R 3 and R 4 , which are identical or different, each representing an alkyl group comprising from 1 to 20 carbon atoms,
y, which is an integer, being equal to or greater than 0,
x, which is or is not an integer, being equal to or greater than 0,
L representing an alkali metal selected from the group consisting of lithium, sodium and potassium,
N representing a molecule of an ether,
R 1 and R 2 , which are identical or different, representing a carbon group.

8. The process according to claim 7 , in which the metallocene is of formula (Ia), (Ib), (Ic), (Id) or (Ie)
[{Me 2 SiFlu 2 Nd(μ-BH 4 ) 2 Li(THF)} 2 ]  (Ia)

[Me 2 SiFlu 2 Nd(μ-BH 4 ) 2 Li(THF)]  (Ib)

[Me 2 SiFlu 2 Nd(μ-BH 4 )(THF)]  (Ic)

[{Me 2 SiFlu 2 Nd(μ-BH 4 )(THF)} 2 ]  (Id)

[Me 2 SiFlu 2 Nd(μ-BH 4 )]  (Ie)

the symbol Flu presenting the fluorenyl group of formula C 13 H 8 .

9. The process according to claim 7 , in which Wand R 2 contain from 2 to 10 carbon atoms.

10. The process according to claim 7 , in which Wand R 2 each represent an alkyl.

11. The process according to claim 7 , in which the organomagnesium compound is a dialkylmagnesium compound.

12. The process according to claim 7 , in which the ethylene and the isoprene are added continuously during the copolymerization.

13. A rubber composition which comprises the elastomer defined in claim 6 .

14. The rubber composition according to claim 13 , which rubber composition comprises a crosslinking system.

15. The rubber composition according to claim 13 , which rubber composition comprises a reinforcing filler.

16. A tire which comprises the rubber composition defined in claim 13 .

17. The copolymer according to claim 5 , which copolymer has a glass transition temperature of between −55° C. and −40° C.

18. The process according to claim 11 , in which the organomagnesium compound is butylethylmagnesium or butyloctylmagnesium.

Assignees

• Michelin & Cie

Inventors

• Araujo Da Silva José-Carlos
• Lafaquiere Vincent
• Moreso Emma
• Thuilliez Julien
• Triguel Aurélie

Classifications

• C08L23/083

  with aliphatic polyenes, i.e. containing two or more carbon-to-carbon double bonds · CPC title

• C08L9/00

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

• C08F210/02

  Ethene · CPC title

• C08F4/545

  rare earths being present, e.g. triethylaluminium + neodymium octanoate · CPC title

• B60C1/00 Primary

  Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition · CPC title