CPC C08F 210/02 (2013.01) [B60C 1/00 (2013.01); C08K 5/0025 (2013.01); C08F 210/16 (2013.01); C08F 236/045 (2013.01); C08F 2420/00 (2013.01); C08L 23/083 (2013.01)] | 19 Claims |
1. A process for the preparation of a copolymer of ethylene and of a 1,3-diene of formula (I) which comprises ethylene units and units of the 1,3-diene, the ethylene units representing between 50 mol % and 95 mol % of the ethylene units and of the units of the 1,3-diene, and the units of the 1,3-diene of 1,2 and 3,4 configuration representing more than 50 mol % of the units of the 1,3-diene,
CH2=CR−CH=CH2 (I)
the symbol R representing a hydrocarbon chain having from 3 to 20 carbon atoms, wherein the process comprises the polymerization of ethylene and of the 1,3-diene in the presence of a catalytic system based at least on a metallocene of formula (II) and on an organomagnesium compound of formula (III)
P(Cp1Cp2)Nd(BH4)(1-y)-Ly-Nx (II)
MgR1R2 (III)
Cp1 and Cp2, which are identical or different, being selected from the group consisting of substituted fluorenyl groups and the unsubstituted fluorenyl group of formula C13H8,
P being a group bridging the two Cp1 and Cp2 groups and representing a ZR3R4 group, Z representing a silicon or carbon atom, R3 and R4, 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,
R1 and R2, which are identical or different, representing a carbon group.
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