Production of a new type of butadiene polymer

1,138,299. Stereoblock butadiene polymers. BADISCHE ANILIN- & SODA-FABRIK A.G. 3 May, 1966 [4 May, 1965], No. 19366/66. Heading C3P. Stereoblock polymers are made by polymerizing butadiene with a Ziegler-Natta type catalyst comprising an alkyl metal compound and a compound of a transition metal of Groups IV to VIII, and whilst unreacted butadiene is still present in the polymerization mixture adding a catalyst of the same type but which converts butadiene into a polymer whose configuration is different to the configuration of the polybutadiene first prepared, and continuing the polymerization. In examples, effected in solvents, the following catalysts are used: (1) (C 2 H 5 ) 3 Al, AlBr 3 , and TiI 4 , followed by (C 2 H 5 ) 3 Al and VCl 3 , (2) as (1) but VCl 3 replaced by VCl 4 , (3) (C 4 H 9 ) 3 Al and TiCl 3 , followed by (C 2 H 5 ) 2 AlI and TiCl 3 , (4) (C 4 H 9 ) 2 AlCl and TiCl 3 , followed by (C 2 H 5 ) 2 AlI and TiCl 3 , (5) (C 2 H 5 ) 3 Al and TiCl 4 , followed by (C 2 H 5 ) 2 AlI and TiCl 3 , (6) (C 4 H 9 ) 3 Al and Ti(-OC 4 H 9 ) 4 , followed by (C 2 H 5 ) 3 Al and VCl 3 , (7) Cr triacetylacetonate and (C 4 H 9 ) 3 Al followed by (C 4 H 9 ) 3 Al, (8) Sn(C 4 H 9 ) 4 and ZrCl 4 , followed by amyl Na and TiCl 3 . The polymers may be sulphur vulcanized.