摘要 |
<p>Ziegler-type hydrocarbon-soluble catalyst systems for the polymerization of conjugated diolefins, or mixtures thereof, to obtain high molecular weight polymers possessing varying proportions of trans-1,4 units, in the range of 50-90%. The catalyst systems are based on a nonreduced salt of titanium, an organometallic compound, and an iodine-containing compound, or iodine corresponding to the generalized formula Ti(halide)4-MnIm-AlRaX3- a. M is aluminum or tetravalent tin, n is 0 or 1, m is the valence of M and when n is 0, m is 2, X is Cl, Br or I, a is 2 to 3, R is alkyl, halide is Cl, Br or I and when halide is I, MnIm is omitted.</p> |