Borated oxazolines as varnish inhibiting dispersants in lubricating oils

A composition comprising a major amount of an oil of lubricating viscosity and a minor but dispersing amount of an oil-soluble, borated derivative of the oxazoline reaction product of a substantially saturated aliphatic hydrocarbyl, substituted C.sub.4 -C.sub.10 mono-unsaturated dicarboxylic acid material, said hydrocarbyl group having a number average molecular weight ranging from about 700 to about 140,000 with from at least 1 to about 2 mole equivalent, per mole equivalent of said dicarboxylic acid material, of a 2,2-disubstituted-2-amino-1-alkanol having 2 to 3 hydroxy groups and containing a total of 4 to 8 carbons, and which is represented by the formula:

• ##STR15## wherein X is an alkyl or hydroxyl alkyl group, with at least one of the X substituents being a hydroxyl alkyl group of the structure --(CH.sub.2).sub.n OH wherein n is 1 to 3, said reaction conditions being at a temperature of from about 140.degree. C. to 240.degree. C. for from 1/2 to 24 hours whereby at least one carboxylic acyl group is converted into an oxazoline ring, said reaction product being borated by condensation with a boron compound selected from the class consisting of boron oxide, boron acids and esters of boron acids in an amount to provide from about 0.1 to 2.0 wt. % boron based on the total weight of said borated ester derivative.

A lubricant composition comprising a major proportion of a lubricant oil and from about 0.01 to 20% by weight of the oil-soluble borated oxazoline reaction product, of one mole equivalent alkenyl succinic acid or anhydride wherein said alkenyl substituent contains a chain of at least 50 carbons, with from at least 1 to about 2 mole equivalent tris-hydroxymethylaminomethane, further condensed by reaction with from 1 to 3 moles of a boron reactant selected from the group consisting of boron oxides, boron oxide hydrates, boron acids and esters of boron acids.

A lubricating oil composition comprising:

• a major amount of lubricating oil and 0.01 to 20 wt. % of an oil-soluble, borated lactone oxazoline reaction product obtained from heating together a molar proportion of a hydrocarbon substituted lactone acid material and one molar proportion of a 2,2-disubstituted-2-amino-1-alkanol having 1 to 3 hydroxy groups and containing a total of 4 to 8 carbons at a temperature of from 100.degree.-240.degree. C. until cessation of water evolution indicating completion of the oxazoline reaction and thereafter condensing said product with a boron compound selected from the class consisting of boron oxides, boron oxide hydrates, boron acids and esters of boron acids in an amount to provide from about 0.1 to 2.0 wt. % boron based on the total weight of said borated reaction product, wherein said lactone acid material is formed by converting one of the carboxy groups of a hydrocarbyl substituted C.sub.4 to C.sub.10 dicarboxylic acid or anhydride to a lactone, said hydrocarbyl substituent being a polymer of a C.sub.2 to C.sub.5 monoolefin, said polymer having a molecular weight of about 900 to 10,000.

An oil-soluble borated oxazoline material containing from about 0.1 to 2.0 wt. % boron, wherein

• said oxazoline material is formed by the reaction of (A) a hydrocarbyl substituted C.sub.4 to C.sub.10 dicarboxylic acid or anhydride, wherein said hydrocarbyl group is a polymer of C.sub.2 to C.sub.5 monoolefin, said polymer having a molecular weight of about 900 and 10,000;
• and (B) a 2,2-disubstituted-2-amino-1-alkanol having 2 to 3 hydroxy groups and containing a total of 4 to 8 carbons and represented by the formula:
• ##STR16## wherein X is an alkyl, or hydroxy alkyl group, with at least one of the X substituents being a hydroxy alkyl group of the structure --(CH.sub.2).sub.n OH, said oxazoline material having one to two oxazoline rings.

A borated oxazoline material which is a borated derivative of the oxazoline reaction product of a substantially saturated aliphatic hydrocarbyl, substituted C.sub.4 -C.sub.10 mono-unsaturated dicarboxylic acid material, said hydrocarbyl group having a number average molecular weight ranging from about 700 to about 140,000 with from at least 1 to about 2 mole equivalent, per mole equivalent of said dicarboxylic acid material, of a 2,2-disubstituted-2-amino-1-alkanol having 2 to 3 hydroxy groups and containing a total of 4 to 8 carbons, and which is represented by the formula:

• ##STR17## wherein X is an alkyl or hydroxyl alkyl group, with at least one of the X substituents being a hydroxyl alkyl group of the structure --(CH.sub.2).sub.n OH wherein n is 1 to 3, said reaction conditions being at a temperature of from about 140.degree. C. to 240.degree. C. for from 1/2 to 24 hours whereby at least one carboxylic acyl group is converted into an oxazoline ring, said oxazoline reaction product being borated by condensation with a boron compound selected from the class consisting of boron oxides, boron oxide hydrates, boron acids and esters of boron acids in an amount to provide from about 0.1 to 2.0 wt. % boron based on the total weight of said borated ester derivative.