Catalytic system for conjugated diene polymerisation, polymerisation method and functional polymer obtained

Abstract

The present invention relates to a novel catalytic system for polymerisation and, specifically, for preparing conjugated diene polymers with a polar function at the chain end. Said catalytic system is made up of a metal salt of a rare earth metal and, as an alkylating agent, an organometallic compound based on a metal from the second or thirteenth column of the periodic table, capable of transferring a polar function to the diene elastomer during the conjugated diene polymerisation step. The novel catalytic system reduces the steps required for synthesising a functional diene elastomer at the chain end, while guaranteeing optimal functionalisation, advantageously near or equal to 100%.

Description

technical field [0001] The present invention relates to a novel catalytic system based on rare earth elements, a process for the preparation of this catalytic system, a process for the preparation of functionalized conjugated diene polymers consisting in the use of said catalytic system, and such polymers. The present invention also relates to novel organometallic compounds based on divalent metals belonging to the second column of the periodic table for use as cocatalysts in catalytic systems based on rare earth elements and to processes for their preparation. Background technique [0002] Since the need to save fuel and protect the environment has become a matter of priority, there is a need to prepare a mixture with excellent mechanical properties and as low a hysteresis as possible in order to be able to use the mixture in the form of a rubber composition which can be used in the manufacture of tires contained in various semi-finished products, such as innerliners, sidew...

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Problems solved by technology

[0010] However, a drawback is that the synthesis process involves several steps, which can lead to relatively complex production of such polymers on an industrial scale (for example, it involves the use of a larger number of reactors and thus complex auxiliary equipment). high cost

[0011] Another drawback lies in the control of the purity of the functionalizing agent which, depending on the circumstances, can lead to inactivation or termination reactions at the ends of the growing polymer chains, which lead to a higher or lower proportion of unfunctionalized elastomeric chains

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