| 摘要 |
1,237,632. Dewaxing oils; pour point depressants. ESSO RESEARCH & ENG. CO. 4 March, 1969 [1 April, 1968], No. 11513/69. Headings C5E and C5G. [Also in Division C3] Copolymers particularly useful as wax crystal modifiers for dewaxing or depressing the pour point of petroleum oils, have a M.W. of 1000- 50,000, comprise at least 80 mole per cent of a mixture of ethylene and acrylate in a relative mole ratio of 4 to 40 molar proportions of ethylene per molar proportion of acrylate of the formula CH 2 = C(X)Y wherein X is hydrogen or methyl and Y is-COOR wherein R is a C 1 to C 16 alkyl group, and are prepared by copolymerizing ethylene and the acrylate in an inert hydrocarbon solvent with a free radical type polymerization catalyst, under a pressure above 2000 p.s.i.g., and up to 50,000 p.s.i.g. The copolymer may include up to 20 mole per cent of a third or even a fourth monomer (specified). Examples are directed to the preparation of copolymers of ethylene and ethyl or isobutyl acrylate using di-t-butyl peroxide or di-lauroyl peroxide as catalyst and benzene (or hexane) as solvent. 0À001-2À0% by weight of the copolymer is added to petroleum distillate oil boiling in the range of 250-750‹ F. such as heating oil and diesel fuel oil as a pour depressant. 0À05% by weight of an ethylene-ethyl acrylate copolymer was added at 150‹ F. to hexane/oil (ratio 3À5/l) and the resulting mixture was chilled at the rate of 2‹ F. per minute down to -30‹ F. Wax was then removed from the chilled mixture by filtering through a leaf filter. The oil containing the 0À05 wt. per cent polymer was found to filter faster than the untreated oil. |
