| abstract |
A composition consists of an ethylene-propylene copolymer having an amorphous structure, a number average molecular weight of 10,000 to 40,000 a propylene content of 20 to 70 mole per cent and a #M w /#M n of less than 5. The copolymers may be prepared by saturating an inert solvent with ethylene, propylene and hydrogen, and contacting this feed with a solvent soluble Ziegler-Wutla catalyst, preferably a two component catalyst system such as a mixture of tri-n-butyl orthovanadate and ethyl aluminium dichloride, diethyl aluminium chloride or ethylaluminium sesquichloride. In the examples, carbon tetrachloride or cyclohexane are saturated with ethylene, propylene and hydrogen, and contacted with heptane solutions of diethyl aluminium chloride and tri-n-butylvanadate. The polymer solution is washed with hydrochloric acid and stripped of solvent. |