Catalytic preform system comprising a rare earth metallocene

Patent metadata

Field	Value
Publication number	US-2018355083-A1
Application number	US-201615780233-A
Country	US
Kind code	A1
Filing date	Nov 30, 2016
Priority date	Dec 3, 2015
Publication date	Dec 13, 2018
Grant date	—

Abstract

A catalytic system based at least on a preformation conjugated diene monomer, on an organometallic compound as cocatalyst and on a metallocene of formula {P(Cp 1 )(Cp 2 )Y} is provided. In the formula, Y denotes a group comprising a metal atom which is a rare earth metal, Cp 1 and Cp 2 , which are identical or different, are selected from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted, and P is a group bridging the two Cp 1 and Cp 2 groups and comprising a silicon or carbon atom. Such a catalytic system exhibits an improved stability of the catalytic activity over time, in particular on storage.

First claim

1 . A catalytic system based at least:
on a preformation conjugated diene monomer, on a metallocene of formula (I), on an organometallic compound as cocatalyst,
{P(Cp 1 )(Cp 2 )Y}  (I)

 Y denoting a group comprising a metal atom which is a rare earth metal,  Cp 1 and Cp 2 , which are identical or different, being selected from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted,  P being a group bridging the two Cp 1 and Cp 2 groups and comprising a silicon or carbon atom.

2 . A catalytic system according to claim 1 , in which the cocatalyst is an organomagnesium compound.

3 . A catalytic system according to claim 1 , in which the cocatalyst is an organometallic compound comprising an alkyl group bonded to the metal atom.

4 . A catalytic system according to claim 1 , in which the cocatalyst is a dialkylmagnesium compound or an alkylmagnesium halide.

5 . A catalytic system according to claim 1 , in which Cp 1 and Cp 2 are identical and are selected from the group consisting of substituted fluorenyl groups and the unsubstituted fluorenyl group of formula C 13 H 8 .

6 . A catalytic system according to claim 1 , in which Cp 1 and Cp 2 each represent an unsubstituted fluorenyl group of formula C 13 H 8 .

7 . A catalytic system according to claim 1 , in which the symbol Y represents the group Met-G, with Met denoting a metal atom which is a rare earth metal and G denoting a group comprising the borohydride BH 4 unit or denoting a halogen atom X selected from the group consisting of chlorine, fluorine, bromine and iodine.

8 . A catalytic system according to claim 7 , in which G denotes chlorine or the group of formula (II):
(BH 4 ) (1+y) -L y -N x   (II)
in which:  L represents an alkali metal selected from the group consisting of lithium, sodium and potassium,  N represents a molecule of an ether,  x, which is or is not an integer, is equal to or greater than 0,  y, which is an integer, is equal to or greater than 0.

9 . A catalytic system according to claim 1 , in which the rare earth metal is a lanthanide, the atomic number of which varies from 57 to 71.

10 . A catalytic system according to claim 1 , in which the rare earth metal is neodymium, Nd.

11 . A catalytic system according to claim 1 , in which the bridge P corresponds to the formula ZR 1 R 2 , Z representing a silicon or carbon atom and R 1 and R 2 , which are identical or different, each representing an alkyl group comprising from 1 to 20 carbon atoms.

12 . A catalytic system according to claim 11 , in which Z is Si.

13 . A catalytic system according to claim 1 , in which the metallocene is the (dimethylsilyl)bisfluorenylneodymium borohydride of formula (III):
[Me 2 Si(Flu) 2 Nd( 82 -BH 4 ) 2 Li(THF)]  (III)
Flu representing the C 13 H 8 group.

14 . A catalytic system according to claim 1 , in which the preformation conjugated diene monomer is a 1,3-diene.

15 . A catalytic system according to claim 14 , in which the preformation conjugated diene monomer is 1,3-butadiene.

16 . A catalytic system according to claim 1 , in which the molar ratio of the preformation conjugated diene monomer to the metal of the metallocene has a value ranging from 5 to 1000.

17 . A catalytic system according to claim 1 , in which the molar ratio of cocatalyst to the metal of the metallocene has a value ranging from 0.5 to 20.

18 . A catalytic system according to claim 1 , which catalytic system comprises a hydrocarbon solvent.

19 . A catalytic system according to claim 18 , in which the hydrocarbon solvent is aromatic or aliphatic.

20 . A catalytic system according to claim 18 , in which the molar concentration of metal of the metallocene in the catalytic system has a value ranging from 0.0001 to 0.05 mol/l.

21 . A process for the preparation of a catalytic system defined in claim 1 , which comprises the following stages a) and b):
a) reacting, in a hydrocarbon solvent, the cocatalyst and the metallocene, b) reacting the preformation conjugated diene monomer with the reaction product from stage a).

22 . A process according to claim 21 , in which stage a) takes place at a temperature ranging from 20° C. to 80° C. and stage b) is carried out at a temperature ranging from 40° C. to 100° C.

23 . A process for the preparation of a polymer which comprises the polymerization of a monomer M in the presence of a catalytic system defined in claim 1 .

24 . A process according to claim 23 , in which the monomer M is selected from the group of the monomers consisting of conjugated dienes, ethylene, α-monoolefins and their mixtures.

25 . A process according to claim 23 , in which the monomer M is a 1,3-diene.

26 . A process according to claim 23 , in which the monomer M is 1,3-butadiene or a mixture of 1,3-butadiene and ethylene.

27 . A process according to claim 23 , in which the polymer is an elastomer.

Assignees

• Michelin & Cie

Inventors

• Lafaquiere Vincent
• Thuilliez Julien

Classifications

• C08F2800/10

  as molar percentages · CPC title

• C08F210/02 Primary

  Ethene · CPC title

• C08F2420/01

  Cp or analog bridged to a non-Cp X neutral donor · CPC title