Process for polymerizing conjugated dienes
AssigneeThe Firestone Tire & Rubber Company
InventorsAdel Farhan Halasa, Richard Gutierrez
Life of this patent
Estimating the term…
Abstract
Conjugated dienes and alpha-olefins, such as butadiene and propylene, are copolymerized by a new catalyst system which gives copolymers containing a high proportion of the alpha-olefin with accompanying desired properties. This catalyst system comprises: (1) A titanium or vanadium halide, preferably chloride, (2) an aluminum hydrocarbon compound which also has Cl, Br or H attached to the Al atom and preferably the hydrocarbon group or groups are alkyl groups which have 1-8 carbon atoms in each of said alkyl groups and (3) CS.sub.2. The copolymers produced by this process have molecular weights in the range of 100,000-5,000,000; referably 250,000-500,000, and other desirable properties.
Claims19
A process for the hydrocarbon solution polymerization of a monomer composition consisting essentially of 10-95 percent by weight of a conjugated diene and 5-90 percent by weight of an alpha olefin having 2-8 carbon atoms to produce a copolymer having 5-90 percent of the alpha olefine in the resultant copolymer comprising the steps of maintaining said monomer composition at a temperature of -10.degree. to 70.degree. C. in intimate contact with a catalyst composition consisting essentially of:
- a. A metal halide compound having the formula TiBr.sub.n Cl.sub.4-n or VBr.sub.m Cl.sub.5-m wherein n has a value of 0-4 and m has a value of 0-5;
- b. An aluminum hydrocarbon compound having the formula R.sub.2 AlX or RAlX.sub.2 wherein X is Cl, Br or H, and R is a hydrocarbon group having 1-8 carbon atoms selected from alkyl, aryl and cycloalkyl groups, and
- c. CS.sub.2 ;
- the proportion of said metal halide compound being 1-10 millimoles per 100 grams of said monomer composition;
- the proportion of said aluminum compound being 0.9-3 moles per mole of metal halide compound;
- and the proportion of said CS.sub.2 being 0.01-0.5 mole per mole of said metal halide compound, said polymerization being conducted for a period of at least 1 hour.
Dependencies are inferred from the claim text.