Process and catalyst for the preparation of syndiotactic 1,2,-polybutadiene
AssigneeBayer Akteingesellschaft
InventorsJosef Witte, Gerd Sylvester, Bernd Stollfuss
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Abstract
Syndiotactic 1,2-polybutadiene of high quality may be obtained in excellent yield by solution polymerization of butadiene-(1,3) in hydrocarbons, using organometallic mixed catalysts composed of trialkylaluminium, hydrocarbon-soluble chromium-III compounds and a dialkylphosphite corresponding to the formula ##STR1## wherein R denotes straight chained or branched C.sub.1 -C.sub.8 -alkyl and R.sub.1, R.sub.2 and R.sub.3 denote methyl or ethyl or R and R.sub.1 together form a methylene group.
Claims9
Process for the preparation of syndiotactic 1,2-polybutadiene by solution polymerisation of butadiene-(1,3) in hydrocarbons, using organometallic mixed catalysts of trialkylaluminium, chromium-III compounds which are soluble in hydrocarbons, and dialkylphosphites, characterised in that the dialkylphosphites used correspond to the general formula (I) ##STR4## wherein R denotes straight chained or branched C.sub.1 -C.sub.8 -alkyl and R.sub.1, R.sub.2 and R.sub.3 denote methyl or ethyl.
Catalyst based on trialkylaluminium, a hydrocarbon-soluble chromium-III compound and dialkylphosphite, characterised in that the dialkylphosphite is di-neopentylphosphite or neopentylmethylphosphite.
Dependencies are inferred from the claim text.