The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

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.

A fuel additive for fuel formulations comprising calcium sulfonates in an amount effective to limit or eliminate valve seat recession in engines utilizing such fuel formulations. The fuel additive may also include a detergent, particularly in an amount to enhance the VSR limiting effect of the calcium sulfonates. Also included are fuel formulations containing calcium sulfonates in a concentration effective to limit vale seat recession in engines utilizing the fuel formulations. Methods for treating VSR in piston engines are also provided.

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 present disclosure relates to a composition for corrosion inhibition in a fuel mixture. The present disclosure also relates to a method for preparing a composition for corrosion inhibition in a fuel mixture. The corrosion inhibitor of the present invention delivered excellent corrosion resistance, minimum dosage levels & good stability and miscibility which can be used for mitigating corrosion issues in neat Ethanol and Gasohol.

Methods of making antidegradant compounds are disclosed in which a p-phenylenediamine is reacted with a diol to obtain mixtures comprising the antidegradant compounds.

A compound represented by the formula:

##STR00001## wherein R is selected from the group consisting of (i) substituted or unsubstituted alkyl with C=0 to 12 inclusive; (ii) substituted or unsubstituted aryl; and (iii) substituted and unsubstituted alkylaryl; wherein X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are each selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen; wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are each selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen and R.sup.2 and R.sup.3 may optionally be bridged by a polymethylene group; wherein when C=0 in R, the combined group R.sup.1 R.sup.2 is the same as the combined group R.sup.3 R.sup.4; and wherein when C=1 in R, each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are hydrogen.

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.

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 invention relates to functional fluid compositions containing antioxidants, and specifically stable compositions containing antioxidants with limited solubility in and/or limited compatibility with the functional fluids with which they are used. In particular the present invention deals with functional fluids used in internal combustion engines, such as engine oils, and antioxidants containing a phenolic or benzoic group, where the antioxidant is present in the functional fluid composition at levels that would otherwise cause the composition to be unstable and/or hazy.