A defoaming agent including a polymer, the polymer including a repeating unit represented by the following general formula (1); and a repeating unit represented by the following general formula (3): ##STR00001##
wherein in the general formula (1), X.sup.1 is a repeating unit obtainable by polymerization of a first ethylenic unsaturated group; Y.sup.1 is a side chain including a linear or branched polysiloxane structure, the polysiloxane structure having a polymerization degree of 5 to 300; and Z.sup.1 is a linking group linking the repeating unit X.sup.1 and the side chain Y.sup.1; ##STR00002##
wherein in the general formula (3), X.sup.2 is a repeating unit obtainable by polymerization of a second ethylenic unsaturated group, Y.sup.2 is a C.sub.1-30 hydrocarbyl side chain; and Z.sup.2 is a linking group linking the repeating unit X.sup.2 and the side chain Y.sup.2.

A defoaming agent comprising: a polymer comprising a repeating unit represented by the following general formula (1): ##STR00001##
where in the general formula (1), X.sup.1 is a repeating unit obtainable by polymerization of an ethylenic unsaturated group; Y.sup.1 is a side chain comprising a linear or branched polysiloxane structure, the polysiloxane structure comprising a repeating unit represented by the following general formula (2) and having a polymerization degree of 5 to 300; and Z.sup.1 is a linking group linking the repeating unit X.sup.1 and the side chain Y.sup.1; ##STR00002##
wherein in the general formula (2), R.sup.1 and R.sup.2 are each independently an organic group having a carbon number of 1 to 18.

A defoaming agent comprising: a polymer comprising a repeating unit represented by the following general formula (1): ##STR00001##
where in the general formula (1), X.sup.1 is a repeating unit obtainable by polymerization of an ethylenic unsaturated group; Y.sup.1 is a side chain comprising a linear or branched polysiloxane structure, the polysiloxane structure comprising a repeating unit represented by the following general formula (2) and having a polymerization degree of 5 to 300; and Z.sup.1 is a linking group linking the repeating unit X.sup.1 and the side chain Y.sup.1; ##STR00002##
wherein in the general formula (2), R.sup.1 and R.sup.2 are each independently an organic group having a carbon number of 1 to 18.

A lubricating oil composition including greater than 50 wt. % of a base oil; a reaction product of a hydrocarbyl acid phosphate and a nitrogen containing compound; and an oil soluble hydrocarbyl borate. A method for reducing gear scuffing in a transmission including a step of lubricating the transmission with the above-mentioned lubricating oil composition and a method of operating a transmission including steps of lubricating said transmission with the lubricating oil composition described above and operating the transmission, are also described.

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

A lubricant composition of an oil of lubricating viscosity and a phosphite ester reaction product of a monomeric phosphorous acid or an ester thereof with a first alkylene diol having two hydroxy groups in a 1,4 or 1,5 or 1,6 relationship and a second, alkyl-substituted, diol being a substituted 1,3-propylene diol, exhibits good wear and frictional performance.

Ethylene-C.sub.3-C.sub.10 alpha olefin copolymers, dispersants and lubricating oils/fuel compositions incorporating dispersants, and related methods are generally described herein. The copolymer may comprise ethylene-derived units and C.sub.3-C.sub.10 alpha-olefin-derived units. The C.sub.3-C.sub.10 alpha-olefin-derived units may have a carbon number from three to ten. For example, the C.sub.3-C.sub.10 alpha-olefin-derived units may be propylene-derived units.

Ethylene-C.sub.3-C.sub.10 alpha olefin copolymers, dispersants and lubricating oils/fuel compositions incorporating dispersants, and related methods are generally described herein. The copolymer may comprise ethylene-derived units and C.sub.3-C.sub.10 alpha-olefin-derived units. The C.sub.3-C.sub.10 alpha-olefin-derived units may have a carbon number from three to ten. For example, the C.sub.3-C.sub.10 alpha-olefin-derived units may be propylene-derived units.

An aqueous composition comprising: (a) at least one 3-isothiazolone; and (b) at least one tertiary amine having three C.sub.2-C.sub.6 hydroxyalkyl groups, wherein at least one of the hydroxyalkyl groups has a secondary hydroxyl group.