| 摘要 |
Improvement methods of fuel oil compositions and fuel oil compositions are provided to contain detergent species and be susceptible to the formation of wax at low temperatures, wherein low temperature properties of the fuel containing a wax anti-settling additive and a polyamine detergent can be restored by the additional presence of a third co-additive species. As a method of improving low temperature properties of a fuel oil composition comprising a major amount of a fuel oil and minor amounts of (a) at least one polar nitrogen compound effective as a wax anti-settling additive and (b) at least one polyamine detergent, the method comprises adding (c) at least one acidic organic species to the composition. The at least one polar nitrogen compound comprises an oil-soluble polar nitrogen compound having one or more, preferably two or more, substituents of the formula >NR^13, where R^13 represents a hydrocarbyl group containing 8 to 40 atoms, wherein the substituent or one or more of the substituents may be formed in the form of a cation derived therefrom. The at least one polar nitrogen compound comprises an amide-amine salt formed by reacting one molar proportion of phthalic anhydride with one molar proportion of dihydrogenated tallow amine. The at least one polyamine detergent comprises a reaction product of a poly(isobutene) substituted succinic anhydride acylating agent and a polyamine or a mixture of polyamines. The acidic organic species comprises an unsaturated monocarboxylic acid having 8 to 30 carbon atoms, preferably 12 to 22 carbon atoms. |
