| 摘要 |
1,146,189. Olefin copolymers. J. R. GEIGY A.G. 12 Aug., 1966 [13 Aug., 1965(2)], No. 36244/66. Heading C3P. [Also in Division C5] Olefin polymers suitable as viscosity index improvers for mineral oils and prepared by random stereospecific copolymerization of at least two α-olefins M 1 and M 2 , M 1 having the lower number of carbon atoms, M 1 and M 2 containing together at least 6 and at most 11 carbon atoms; and optionally one or more further α-olefins M 3 containing at least as many carbon atoms as M 2 , the polymer containing 10 to 70 per cent of structural units derived from M 2 and 0 to 10 per cent of structural units derived from M 3 , the sum of M 2 and M 3 structural units not exceeding 70 per cent, all by weight of the polymer, having a viscosity average molecular weight of 200,000 to 1,000,000, at most 0À5 weight per cent of hexane insoluble material at 60‹ C., an X-ray crystallinity of 5 to 50 per cent, a viscosity index improving efficiency of at least 1À2 and having a viscosity as a solution of 1 part by weight in 9 parts of naphthenic oil not exceeding 20,000 cps at 60‹ C; may be prepared by feeding at constant rate to the reaction zone M 1 , M 2 and optionally M 3 , together with a diluent and stereospecific catalyst, maintaining the reaction zone at a constant pressure of 100-1000 psig and a temperature of 50 to 120‹ C. until 20 to 90 weight per cent of M 1 is copolymerized, the composition of monomer feed, temperature t and conversion c being interrelated by the formula with the proviso that bl # x # b h , where X is the weight per cent of M 1 in the monomer feed, and a l , a h , b l and b h are chosen from -6, 10, 10 and 30 when M 1 is ethylene and 20, 36, 24 and 85 respectively when M 1 is a higher olefin, the amount of M 3 in the feed being 0 to 15 weight per cent, continuously removing polymer and unreacted monomer from the reaction zone at such a rate as to maintain equilibrium, deactivating the catalyst and if necessary aftertreating the polymer solution to reduce the viscosity average molecular weight to the required value and removing heptane-insoluble material. Many suitable ingredients are specified and examples describe the copolymerization with catalysts comprising aluminium trichloride, activated titanium trichloride or vanadium trichloride, optionally activated with an α-olefin such as octene-1 or C 12-16 α-olefins, of olefin mixtures comprising propylene, butene-1 and (1, 5-7, 12 and 16) C 12-16 α-olefins, (2) C 16-20 α-olefins, (3, 8-11) octene-1, (13, 14 and 17- 20) C 6-10 α-olefins and (15) C 14-16 α-olefins; and mixtures comprising (21) propylene and octene- 1, (22) propylene and butene-1 and (23-30) ethylene and butene-1. |
