This invention relates to corrosion inhibitor additive combinations giving long acting performance in oxygenated gasoline blends comprising either low carbon number (<3) or high carbon number (greater than or equal to 4) alcohols or mixtures thereof and adapted for use in fuel delivery systems and internal combustion engines. The invention also is concerned with a process for conferring anti-corrosion properties to oxygenates in gasoline fuel mixtures wherein the oxygenate comprises biologically-derived butanol.

This invention relates to corrosion inhibitor additive combinations giving long acting performance in oxygenated gasoline blends comprising either low carbon number (<3) or high carbon number (greater than or equal to 4) alcohols or mixtures thereof and adapted for use in fuel delivery systems and internal combustion engines. The invention also is concerned with a process for conferring anti-corrosion properties to oxygenates in gasoline fuel mixtures wherein the oxygenate comprises biologically-derived butanol.

The invention relates to an oil-in-water emulsion comprising an oil phase and an aqueous phase, and a primary surfactant, wherein the oil phase is dispersed in the aqueous phase, and wherein the oil-in-water emulsion has: an average droplet size distribution (D[4,3]) in the range of from 3 to 15 m and less than 3 wt % of the droplets have a particle size of greater than 125 m; a viscosity of greater than 100 and up to 700 mPas at 50 C.10% and 20 s.sup.110%; and a static stability of less than 5% residue after centrifugation at 50 C.10% and 2000 g=10% for 30 minutes10%. A process for preparing such an oil-in-water emulsion comprises preparing an aqueous phase comprising a primary surfactant, heating a hydrocarbon-containing oil-phase, and blending the hydrocarbon-containing oil and the aqueous phase under conditions sufficient to form an oil-in-water emulsion. The invention also relates to methods for determining the static and dynamic stability of oil-in-water emulsions. Static stability can be determined by a method comprising the steps of: providing an oil-in-water emulsion; centrifuging the oil-in-water emulsion under predetermined conditions for a predetermined period of time; determining the amount of residue deposited from the oil-in-water emulsion after the predetermined period of time; and determining the oil-in-water emulsion's static stability. A method for determining the dynamic stability of an oil-in-water emulsion comprises the steps of: providing an oil-in-water emulsion; analysing the oil-in-water emulsion at a first time; recirculating the oil-in-water emulsion in a recirculation loop; and analysing the oil-in-water emulsion at second time after recirculation has started; in which the oil-in-water emulsion's dynamic stability is determined based on the analysis at the first and second times.

The invention relates to an oil-in-water emulsion comprising an oil phase and an aqueous phase, and a primary surfactant, wherein the oil phase is dispersed in the aqueous phase, and wherein the oil-in-water emulsion has: an average droplet size distribution (D[4,3]) in the range of from 3 to 15 m and less than 3 wt % of the droplets have a particle size of greater than 125 m; a viscosity of greater than 100 and up to 700 mPas at 50 C.10% and 20 s.sup.110%; and a static stability of less than 5% residue after centrifugation at 50 C.10% and 2000 g=10% for 30 minutes10%. A process for preparing such an oil-in-water emulsion comprises preparing an aqueous phase comprising a primary surfactant, heating a hydrocarbon-containing oil-phase, and blending the hydrocarbon-containing oil and the aqueous phase under conditions sufficient to form an oil-in-water emulsion. The invention also relates to methods for determining the static and dynamic stability of oil-in-water emulsions. Static stability can be determined by a method comprising the steps of: providing an oil-in-water emulsion; centrifuging the oil-in-water emulsion under predetermined conditions for a predetermined period of time; determining the amount of residue deposited from the oil-in-water emulsion after the predetermined period of time; and determining the oil-in-water emulsion's static stability. A method for determining the dynamic stability of an oil-in-water emulsion comprises the steps of: providing an oil-in-water emulsion; analysing the oil-in-water emulsion at a first time; recirculating the oil-in-water emulsion in a recirculation loop; and analysing the oil-in-water emulsion at second time after recirculation has started; in which the oil-in-water emulsion's dynamic stability is determined based on the analysis at the first and second times.

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.

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.

Quaternary ammonium salts of formula: wherein each of R.sup.1 and R.sup.2 is independently selected from an optionally substituted alkyl, alkenyl or aryl group having less than 8 carbon atoms, R together with N forms an aliphatic or aromatic heterocycle having less than 12 carbons atoms and R.sup.5 is hydrogen or an optionally substituted hydrocarhyl group. The use of these compounds as fuel or lubricant additives, especially as diesel fuel additives,

The use of tetrahydrobenzoxazines I

##STR00001##

where R.sup.1 is a hydrocarbyl radical and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently hydrogen atoms, hydroxyl groups or hydrocarbyl radicals, and where R.sup.2 to R.sup.5 may also form a second and a third tetrahydrooxazine ring, with the proviso that at least one of the substituents has from 4 to 3000 carbon atoms and the remaining substituents, when they are hydrocarbyl radicals, each have from 1 to 20 carbon atoms, as stabilizers for stabilizing inanimate organic material, especially turbine fuels, against the action of light, oxygen and heat.

The use of tetrahydrobenzoxazines I

##STR00001##

where R.sup.1 is a hydrocarbyl radical and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently hydrogen atoms, hydroxyl groups or hydrocarbyl radicals, and where R.sup.2 to R.sup.5 may also form a second and a third tetrahydrooxazine ring, with the proviso that at least one of the substituents has from 4 to 3000 carbon atoms and the remaining substituents, when they are hydrocarbyl radicals, each have from 1 to 20 carbon atoms, as stabilizers for stabilizing inanimate organic material, especially turbine fuels, against the action of light, oxygen and heat.

The invention relates to quaternary ammonium amide and/or ester salts and their use as additives, including their use in fuels, such as diesel fuel. The invention particularly relates to the use of quaternary ammonium amide and/or ester salts as detergents in diesel fuels.