A method of cleaning up internal diesel injector deposits in a severely fouled engine, the method including combusting in the engine a diesel fuel composition having (a) a quaternary ammonium salt additive; and (b) one or more further nitrogen-containing detergents; in which the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; in which each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

A method of cleaning up internal diesel injector deposits in a severely fouled engine, the method including combusting in the engine a diesel fuel composition having (a) a quaternary ammonium salt additive; and (b) one or more further nitrogen-containing detergents; in which the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; in which each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

Additive composition mixtures and methods for synergistically maintaining low surface voltages of distillate fuels that include a synergistic conductivity improver additive composition for a distillate fuel. The additive composition includes: A) a mixture of (i) alkenyl polysulfone polymer, (ii) C16-C24 substituted maleic/polyamine copolymer, (iii) sulfonic acid, and (iv) aromatic solvent; and B) a mixture of (i) alkenyl polysulfone polymer, (v) polymeric reaction product of a C8-C18 aliphatic amine or diamine with epichlorohydrin; (iii) sulfonic acid, (iv) aromatic solvent; and optionally (vi) a quaternary ammonium compound. The additive composition contains from 30 to 60 wt. % component (A) and from 30 to 60 wt. % component (B) based on a total weight of the additive composition.

Polyisobutylenes (PIBs) containing a high proportion of vinylidene end groups are generally favored over conventional PIBs because of their higher reactivity in reactions that are needed to prepare fuel and lubricant additives. However, detergent additives that have been prepared from conventional PIBs actually perform better than detergent additives prepared from high reactive PIBs. Specifically, detergent additives that were prepared from conventional PIB that was then enriched with tri- and tetra-PIB resulted in altered thermal stability and improved detergency of the resulting compound as compared to the structures which were created using a high proportion of vinylidene end groups.

A synergistic mixture comprising from 1 to 99.9% by weight of compounds having structural elements (I) ##STR00001##
in which the free valencies on the oxygen atom and on the nitrogen atom may be combined to form a five-, six- or seven-membered ring and the benzene ring may also bear substituents at one or more of the free positions, and from 0.1 to 99% by weight of sulfur-containing organic compounds with antioxidant action. This synergistic mixture is suitable as a stabilizer for stabilizing inanimate organic material, especially mineral oil products and fuels, against the action of light, oxygen and heat.

A diesel fuel composition including (a) a quaternary ammonium salt additive; and (b) one or more nitrogen-free detergents; wherein the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; wherein each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

A method of removing deposits in a direct injection spark ignition engine, the method including combusting in the engine a gasoline fuel composition having a quaternary ammonium salt additive wherein the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; in which each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

The present disclosure relates to the use of at least one modified alkylphenol-aldehyde resin as additive for improving the oxidation and/or storage stability of a motor fuel or liquid hydrocarbon-containing fuel composition. The modified alkylphenol-aldehyde resin can be obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with at least one aldehyde and/or one ketone having from 1 to 8 carbon atoms, preferably from 1 to 4 carbon atoms; and at least one hydrocarbon-containing compound having at least one alkylmonoamine or alkylpolyamine (alkylamine) group, having between 1 and 30 carbon atoms. The alkylphenol-aldehyde condensation resin itself can be obtained by condensation of at least one alkylphenol substituted with at least one linear or branched alkyl group having from 1 to 30 carbon atoms, preferably a monoalkylphenol, with at least one aldehyde and/or one ketone having from 1 to 8 carbon atoms, preferably from 1 to 4 carbon atoms.

The present disclosure relates to the use of at least one modified alkylphenol-aldehyde resin as additive for improving the oxidation and/or storage stability of a motor fuel or liquid hydrocarbon-containing fuel composition. The modified alkylphenol-aldehyde resin can be obtained by Mannich reaction of an alkylphenol-aldehyde condensation resin with at least one aldehyde and/or one ketone having from 1 to 8 carbon atoms, preferably from 1 to 4 carbon atoms; and at least one hydrocarbon-containing compound having at least one alkylmonoamine or alkylpolyamine (alkylamine) group, having between 1 and 30 carbon atoms. The alkylphenol-aldehyde condensation resin itself can be obtained by condensation of at least one alkylphenol substituted with at least one linear or branched alkyl group having from 1 to 30 carbon atoms, preferably a monoalkylphenol, with at least one aldehyde and/or one ketone having from 1 to 8 carbon atoms, preferably from 1 to 4 carbon atoms.

Modified alkylphenol-aldehyde resins include one or more alkylamines, having preferably at least one primary amine type group as well as their use for improving the flow properties of motor fuels and hydrocarbon fuels, such as in particular jet fuel, gas oil, fuel oil domestic, heavy fuel oil.