A metal working fluid having increased resistance to bacterial growth. The metal working fluid includes a cross-linked polymeric ester emulsifier; and an amine represented by the formula (H.sub.2N).sub.a-Q-(NH.sub.2).sub.b, where a and b are each integers, and Q is at least one carbon atom. Q may also be represented by XYZ, where a+b2; X is a cyclic ring system including 3 to 24 carbon atoms; and Y and Z are groups that include at least one carbon atom directly attached to the cyclic ring system. The metal working fluid may also include a biocide, and may also include an amide that is formed by reacting the amine with a carboxylic acid.

The invention provides a lubricant composition for an eccentric oscillating planetary gear type speed reducer comprising the following components (a) to (d): (a) a base oil containing a synthetic oil; (b) at least one calcium salt selected from the group consisting of calcium salts of petroleum sulfonic acids, calcium salts of alkyl aromatic sulfonic acids, calcium salts of salicylates, calcium salts of phenates, calcium salts of oxidized waxes, overbased calcium salts of petroleum sulfonic acids, overbased calcium salts of alkyl aromatic sulfonic acids, overbased calcium salts of salicylates, overbased calcium salts of phenates, and overbased calcium salts of oxidized waxes; (c) an antioxidant; and (d) a glycerin fatty acid ester.

Provided is a lubricating oil composition for use in internal-combustion engines, containing a base oil (A), an ashless dispersant (B) containing a non-boronated alkenylsuccinic acid imide (B1) and a boronated alkenylsuccinic acid imide (B2), a thiadiazole compound (C), and an aromatic carboxylate (D) having one or more hydroxy groups, wherein the content of the component (C) is 0.2 to 1.2% by mass based on the total amount of the lubricating oil composition, the content of a zinc dithiophosphate is, as calculated in terms of zinc atoms, less than 500 ppm by mass based on the total amount of the lubricating oil composition, and the content of a metal-based detergent is, as calculated in terms of metal atoms, less than 600 ppm by mass based on the total amount of the lubricating oil composition.

Disclosed herein is a process for lubricating an internal combustion engine with a lubricant composition that may be substantially ash free. The ashless lubricant composition described herein may comprise primary antioxidants, such as aminic diphenyl amines, alkylated phenyl-naphthyl amines, and phenolic antioxidants. The ashless lubricant composition described herein may also comprise sulfur containing products that may work as secondary antioxidants. Other components such as ashless antiwear components, dispersants, pour point depressants, friction modifiers, and metal deactivators may also be used to formulate an ashless lubricant composition according to an embodiment.

The disclosed technology relates to a lubricant composition for automotive gears, axles and bearings, the lubricant composition containing an oil of lubricating viscosity and a metal thiophosphate compound, such as zinc dialkyldithiophosphate, as well as a method of obtaining extreme pressure performance in automotive gears, axles and bearings at lower sulfur content than is typical, by lubricating such automotive gears, axles and bearings with a lubricant composition containing a metal thiophosphate compound, such as zinc dialkyldithiophosphate.

The invention provides a lubricant composition for an eccentric oscillating planetary gear type speed reducer comprising the following components (a) to (d): (a) a base oil containing a synthetic oil; (b) at least one calcium salt selected from the group consisting of calcium salts of petroleum sulfonic acids, calcium salts of alkyl aromatic sulfonic acids, calcium salts of salicylates, calcium salts of phenates, calcium salts of oxidized waxes, overbased calcium salts of petroleum sulfonic acids, overbased calcium salts of alkyl aromatic sulfonic acids, overbased calcium salts of salicylates, overbased calcium salts of phenates, and overbased calcium salts of oxidized waxes; (c) an antioxidant; and (d) a glycerin fatty acid ester.

A lubricant composition comprising an oil of lubricating viscosity and 0.01 to 5 percent by weight of a substantially sulfur-free alkyl phosphate amine salt, where at least 30 mole percent of the phosphorus atoms are in an alkyl pyrophosphate salt structure, exhibits good antiwear performance. In the phosphate amine salt, at least 25 mole percent of the alkyl groups are primary alkyl groups of 3 to 12 carbon atoms.

A metal working fluid having increased resistance to bacterial growth. The metal working fluid includes a cross-linked polymeric ester emulsifier; and an amine represented by the formula (H.sub.2N).sub.a-Q-(NH.sub.2).sub.b, where a and b are each integers, and Q is at least one carbon atom. Q may also be represented by XYZ, where a+b2; X is a cyclic ring system including 3 to 24 carbon atoms; and Y and Z are groups that include at least one carbon atom directly attached to the cyclic ring system. The metal working fluid may also include a biocide, and may also include an amide that is formed by reacting the amine with a carboxylic acid.

Provided are; a lubricating oil composition excellent in fuel saving performance, seizure resistance, wear resistance, fatigue lifetime and shear stability, which contains a base oil (A), an olefin polymer (B) having a number average molecular weight of 1,000 or more and 12,000 or less, and a specific sulfur compound (C) and wherein the content of all sulfur atoms based on the total amount of the composition is 1.2% by mass or more and 2.5% by mass or less; and a lubrication method using the lubricating oil composition.

The present invention provides a mineral base oil having a kinetic viscosity at 100 C. of 7 mm.sup.2/s or more and less than 10 mm.sup.2/s, a viscosity index of 100 or more, and a temperature gradient |*| complex viscosity between two temperature points of 5 C. and 15 C. of 240 mPa.Math.s/ C. or less as measured with a rotary rheometer at an angular velocity of 6.3 rad/s. The use of the mineral base oil enables easy preparation of a lubricating oil composition and a grease composition having excellent oxidation stability while ensuring the freedom of selection of additives.