Production of elastomer with low glass transition temperature, higher crystallinity peak and good green elasticity

摘要

In the production of (un)saturated elastomers by (co)polymerization of 2-8 C alpha -olefins, open-chain, monocyclic and/or polycyclic 4-15 C dienes and/or styrene, using catalysts that can be activated by cocatalysts, the catalysts are metallocenes of subgroup III, IV, V or VI metals, including the lanthanides and actinides or pi -complex compounds. The process concerns the production of (un)saturated elastomers, which, in addition to the amorphous structure and a low glass transition temperature, Tg, have melt peak(s), including at least one peak maximum at a Tm above +40 deg C, as determined by differential scanning calorimetry (DSC). It involves (co)polymerization of monomers selected from 2-8 C alpha -olefins, open-chain, monocyclic and/or polycyclic 4-15 C dienes and styrene in bulk, solution, high temperature solution, slurry or gas phase in the presence of organometallic catalysts that can be activated by cocatalysts. The novelty is that the organometallic catalysts are metallocene compounds of formula (I) or pi -complex compounds and especially metallocene compounds of formula (II): CpI, CpII = carbanions with structure containing cyclopentadienyl; D = a donor atom; A = an acceptor atom; M = a sub-group III, IV, V or VI transition metal, including the lanthanides and actinides; X = an anion equivalent; n = 0-4, depending on the charge on M; pi I, pi II = charged or electrically neutral pi -systems