A lubricating oil composition which may contain a zinc dialkyl dithiophosphate, and whose color deterioration over time is alleviated. Such a lubricating oil composition may contain: a base oil (A); a zinc dialkyl dithiophosphate (B); and a sodium-based detergent (C). In such a lubricating oil composition, a content of zinc atoms may be 100 ppm by mass to 2,000 ppm by mass based on a total amount of the lubricating oil composition, and a content of sodium atoms may be 5 ppm by mass to 1,000 ppm by mass based on the total amount of the lubricating oil composition.

A lubricating oil composition which may contain a zinc dialkyl dithiophosphate, and whose color deterioration over time is alleviated. Such a lubricating oil composition may contain: a base oil (A); a zinc dialkyl dithiophosphate (B); and a sodium-based detergent (C). In such a lubricating oil composition, a content of zinc atoms may be 100 ppm by mass to 2,000 ppm by mass based on a total amount of the lubricating oil composition, and a content of sodium atoms may be 5 ppm by mass to 1,000 ppm by mass based on the total amount of the lubricating oil composition.

In one or more embodiments, this application relates to tribotechnical additive and lubricant compositions based on self-assembled carbon nanoarchitectonics derived through nanoscale modifications of organosilane-functionalized nanocarbon with one or multiple combinations of organo-molybdenum, organo-boron, organo-sulfur, organo-phosphorus, and heterocyclic compounds. The novel lubricant is characterized by having a composition comprising (A) one or more types of the novel additive compositions, (B) Base oil//lubricant, and optionally (C) one or more additives selected from the group including antioxidants, dispersants, detergents, anti-wear additives, extreme pressure additives, friction modifiers, viscosity index modifiers, seal swell additives, defoamers, pour point depressants and corrosion/rust inhibitors. The selfassembled carbon nanoarchitectonics is expected to enhance the surface chemistry, antiwear, antifriction, antioxidancy, electrothermal, and corrosion inhibiting characteristics of the tribotechnical compositions for formulating high-quality solutions in a wide range of applications.

In one or more embodiments, this application relates to tribotechnical additive and lubricant compositions based on self-assembled carbon nanoarchitectonics derived through nanoscale modifications of organosilane-functionalized nanocarbon with one or multiple combinations of organo-molybdenum, organo-boron, organo-sulfur, organo-phosphorus, and heterocyclic compounds. The novel lubricant is characterized by having a composition comprising (A) one or more types of the novel additive compositions, (B) Base oil//lubricant, and optionally (C) one or more additives selected from the group including antioxidants, dispersants, detergents, anti-wear additives, extreme pressure additives, friction modifiers, viscosity index modifiers, seal swell additives, defoamers, pour point depressants and corrosion/rust inhibitors. The selfassembled carbon nanoarchitectonics is expected to enhance the surface chemistry, antiwear, antifriction, antioxidancy, electrothermal, and corrosion inhibiting characteristics of the tribotechnical compositions for formulating high-quality solutions in a wide range of applications.

A lubricant composition according to the present invention contains a fatty acid metal salt, a metal dithiocarbamate, and an additive having an effect of increasing an acid value of the lubricant composition, whereby fretting resistance performances are further improved.

A lubricating oil composition for an internal combustion engine includes: a lubricant base oil including at least one mineral base oil, at least one synthetic base oil, or any combination thereof, and having a kinematic viscosity at 100° C. of 3.0 to 4.0 mm.sup.2/s and a NOACK evaporation loss at 250° C. of no more than 15 mass %; (A) a calcium-containing metallic detergent in an amount of no less than 1000 mass ppm and less than 2000 mass ppm in terms of calcium; (B) a magnesium-containing metallic detergent in an amount of 100 to 1000 mass ppm in terms of magnesium; (G) a zinc dialkyl dithiophosphate in an amount of no less than 600 mass ppm in terms of phosphorus; and optionally (C) a viscosity index improver in an amount of no more than 5 mass %.

The present disclosure relates to methods of improving viscosity shear stability of a lubricating oil and lubricating oil composition comprising: a base oil of lubricating viscosity; an amount of one or more zinc dialkyl dithiophosphate compound(s);
wherein the lubricating oil composition has one or both of the following ratios: a) a ratio of KV40° C..sub.fresh to a weight % of zinc contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 510, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.; and b) a ratio of KV40° C..sub.fresh to a weight % of phosphorus contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 560, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.

The present disclosure relates to methods of improving viscosity shear stability of a lubricating oil and lubricating oil composition comprising: a base oil of lubricating viscosity; an amount of one or more zinc dialkyl dithiophosphate compound(s);
wherein the lubricating oil composition has one or both of the following ratios: a) a ratio of KV40° C..sub.fresh to a weight % of zinc contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 510, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.; and b) a ratio of KV40° C..sub.fresh to a weight % of phosphorus contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 560, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.

This ball screw grease composition for a rack-assisted electric power steering contains a thickener, a base oil, and at least one compound selected from the group consisting of a Ca sulfonates, fatty acids, and triglycerides, wherein the kinematic viscosity of the base oil at 40° C. is 4-100 mm2/s, and the worked penetration of the composition is 265-385.

This ball screw grease composition for a rack-assisted electric power steering contains a thickener, a base oil, and at least one compound selected from the group consisting of a Ca sulfonates, fatty acids, and triglycerides, wherein the kinematic viscosity of the base oil at 40° C. is 4-100 mm2/s, and the worked penetration of the composition is 265-385.