Maleic acid derivatives of 2,5-dimercapto-1,3,4-thiadiazoles and lubricating compositions containing same

Claim 2

A reaction product of a maleic compound and 2,5-dimercapto-1,3,4-­thiadiazole selected from the group of compounds having the structural formulae wherein R represents alkyl, hydroxyalkyl, cycloalkyl, alkyl-substituted cycloalkyl, aryl, alkylthio groups and terpene residues; wherein R′ represents hydrogen, alkyl, hydroxyalkyl, cycloalkyl, alkyl-­substituted cycloalkyl, aryl, alkylthio groups and terpene residues, R² and R³ represent alkyl and cycloalkyl groups and either R² and R³ may be hydrogen; wherein R⁴ and R⁵ represent alkyl and cycloalkyl groups and either R⁴ or R⁵ may be hydrogen; neutralization salts of said compounds and mixtures thereof.

Claim 3

A composition comprising a major amount of oil of lubricating viscosity wherein said oil is a petroleum hydrocarbon oil or a synthetic oil and from about 0.01 to 10 percent by weight of a reaction product of a maleic compound and 2,5-dimercapto-1,3,4-thiadiazole selected from the group of compounds having the structural formulae wherein R represents alkyl, hydroxyalkyl, cycloalkyl, alkyl-substituted cycloalkyl, aryl, alkylthio groups and terpene residues; wherein R′ represents hydrogen, alkyl, hydroxyalkyl, cycloalkyl, alkyl-­substituted cycloalkyl, aryl, alkylthio groups and terpene residues, R² and R³ represent alkyl and cycloalkyl groups and either R² and R³ may be hydrogen; wherein R⁴ and R⁵ represent alkyl and cycloalkyl groups and either R⁴ or R⁵ may be hydrogen; neutralization salts of said compounds and mixtures thereof.

Claim 4

A composition comprising a major amount of oil of lubricating viscosity wherein said oil is a petroleum hydrocarbon oil or a synthetic oil and from about 0.01 to 10 percent by weight of a reaction product of a maleic compound and 2,5-dimercapto-1,3,4-thiadiazole selected from the group of compounds having the structural formulae wherein R represents alkyl, hydroxyalkyl, cycloalkyl, alkyl-substituted cycloalkyl, aryl, alkylthio groups and terpene residues; wherein R′ represents hydrogen, alkyl, hydroxyalkyl, cycloalkyl, alkyl-­substituted cycloalkyl, aryl, alkylthio groups and terpene residues, R² and R³ represent alkyl and cycloalkyl groups and either R² and R³ may be hydrogen; wherein R⁴ and R⁵ represent alkyl and cycloalkyl groups and either R⁴ or R⁵ may be hydrogen; neutralization salts of said compounds and mixtures thereof.

Claim 5

A composition according to claim 2 which further contains up to 1.0 percent by weight of zinc dihydrocarbylphosphorodithioate wherein the hydrocarbyl groups are selected from the group consisting of alkyl, alkenyl, aryl, aralkyl, alkaryl and cycloaliphatic groups.

Claim 6

A composition comprising at least 40 percent by weight of water, from 0 to 15 percent by weight of a petroleum hydrocarbon oil or a synthe­tic oil and from about 0.01 to 10 percent by weight of a reaction product of a maleic compound and 2,5-dimercapto-1,3,4-thiadiazole selected from the group of compounds having the structural formulae wherein R represents alkyl, hydroxyalkyl, cycloalkyl, alkyl-substituted cycloalkyl, aryl, alkylthio groups and terepene residues; wherein R′ represents hydrogen, alkyl, hydroxyalkyl, cycloalkyl, alkyl-­substituted cycloalkyl, aryl, alkylthio groups and terpene residues, R² and R³ represent alkyl and cycloalkyl groups and either R² and R³ may be hydrogen; wherein R⁴ and R⁵ represent alkyl and cycloalkyl groups and either R⁴ or R⁵ may be hydrogen; neutralization salts of said compounds and mixtures there­of.

Claim 7

A composition comprising at least 40 percent by weight of water, from 0 to 15 percent by weight of a petroleum hydrocarbon oil or a synthe­tic oil and from about 0.01 to 10 percent by weight of a reaction product of a maleic compound and 2,5-dimercapto-1,3,4-thiadiazole selected from the group of compounds having the structural formulae wherein R represents alkyl, hydroxyalkyl, cycloalkyl, alkyl-substituted cycloalkyl, aryl, alkylthio groups and terepene residues; wherein R′ represents hydrogen, alkyl, hydroxyalkyl, cycloalkyl, alkyl-­substituted cycloalkyl, aryl, alkylthio groups and terpene residues, R² and R³ represent alkyl and cycloalkyl groups and either R² and R³ may be hydrogen; wherein R⁴ and R⁵ represent alkyl and cycloalkyl groups and either R⁴ or R⁵ may be hydrogen; neutralization salts of said compounds and mixtures there­of.