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US 5,494,967 AGranted
Oil additives and compositions
AssigneeExxon Chemical Patents Inc.
InventorsRamah J. Brod, Brian W. Davies, Tuncel Ibrahim
Life of this patent
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Abstract
Compositions comprising two or more re-esterified ethylene-unsaturated ester copolymers, for example ethylene-vinyl acetate copolymers, improve the low temperature properties of fuel oils.
Claims6
A fuel oil composition comprising 0.0005 to 1% by weight of at least two different oil soluble re-esterified ethylene-vinyl ester copolymers, wherein each copolymer has been saponified and then re-esterified by:
- a) at least partial hydrolysis to remove acid groups, and
- b) treatment with the same acid to restore at least partially the ester groups, such that the long chain branches of the copolymer are removed and the linearity of the final re-esterified copolymer is greater than that of the precursor copolymer and wherein each re-esterified copolymer contains units derived from ethylene and units of the formula
- --CH.sub.2 CROOCR.sup.1 -- (I)
- wherein R represents H or CH.sub.3 and R.sup.1 represents a hydrocarbyl group, and the molar proportion of ester units of the formula (I) of each copolymer is from 0.3 to 35 molar percent.
1 more element
A composition as claimed in 1 or 2, wherein both polymers are re-esterified ethylene-vinyl acetate copolymers.
Dependencies are inferred from the claim text.