Disclosed herein is a method for pretreatment of a metallic substrate for a subsequent metal cold forming process, said method , and contacting at least one surface of the substrate with an aqueous lubricant composition (B). The aqueous lubricant composition (B) has a pH value in the range of from 0.1 to 6.0, and includes water in an amount of at least 40 wt.-%, based on the total weight of the composition (B), at least one film-forming polymer, at least one wax, at least one corrosion inhibitor , and oxalate and/or phosphate anions. Further disclosed herein are a pretreated metallic substrate obtainable by the aforementioned inventive method, a method of cold forming of a metallic substrate including a step of subjecting the inventive pretreated metallic substrate to a cold forming process, an aqueous lubricant composition (B), and a master batch for preparing the aqueous composition (B).

A lubricating oil composition including a base oil (X) having a tertiary carbon atom at a content of 8.0 at % or more based on the total carbon of hydrocarbons and an antioxidant (Y) having an amine-based antioxidant (A), a phenol-based antioxidant (B), and a phosphor-based antioxidant (C). The amine-based antioxidant (A) includes a diphenylamine compound (A1) represented by the following general formula (a1):

##STR00001##

where R.sup.a1 and R.sup.a2, na1 and na2 are defined in the disclosure.

The present disclosure discloses a crosslinked polymer for dewaxing the lubricating oils, the polymer derived from (a) 70-77 weight percentage of at least one alkyl acrylate; (b) 23-28 weight percentage of at least one vinyl aromatic hydrocarbon; (c) 0.1-2.5 weight percentage of at least one crosslinker; and (d) 0.75-2.5 weight percentage of at least one initiator and wherein the polymer has a number average molecular weight in the range of 5000-15000. The present disclosure discloses a convenient process for preparing the crosslinked polymer. The present disclosure further reveals a method for dewaxing the lubricating oil.

The present disclosure discloses a crosslinked polymer for dewaxing the lubricating oils, the polymer derived from (a) 70-77 weight percentage of at least one alkyl acrylate; (b) 23-28 weight percentage of at least one vinyl aromatic hydrocarbon; (c) 0.1-2.5 weight percentage of at least one crosslinker; and (d) 0.75-2.5 weight percentage of at least one initiator and wherein the polymer has a number average molecular weight in the range of 5000-15000. The present disclosure discloses a convenient process for preparing the crosslinked polymer. The present disclosure further reveals a method for dewaxing the lubricating oil.

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 %.

Provided herein are hydrocarbon compositions suitable for use as a lubricant comprising sulfur between about 30 ppm to about 220 ppm, and aromatics between about 0.2 wt. % to about 3 wt. %. The present hydrocarbon compositions comprise a blend of one or more base stocks and a high-sulfur containing material and can demonstrate an improved oxidation performance as a lubricant in weighted piston deposit merits and/or by viscosity increase.

An aspect of the present invention provides a refrigerating machine oil containing a mixed base oil of a first hydrocarbon base oil having a kinematic viscosity at 40° C. of less than 6 mm.sup.2/s and a second hydrocarbon base oil having a kinematic viscosity at 40° C. of 6 mm.sup.2/s or more, wherein a (A)/(B) ratio is more than 1 and 1.5 or less, wherein (A) is a kinematic viscosity at 40° C. of the mixed base oil, and (B) is the kinematic viscosity at 40° C. of the first hydrocarbon base oil.

An aspect of the present invention provides a refrigerating machine oil containing a mixed base oil of a first hydrocarbon base oil having a kinematic viscosity at 40° C. of less than 6 mm.sup.2/s and a second hydrocarbon base oil having a kinematic viscosity at 40° C. of 6 mm.sup.2/s or more, wherein a (A)/(B) ratio is more than 1 and 1.5 or less, wherein (A) is a kinematic viscosity at 40° C. of the mixed base oil, and (B) is the kinematic viscosity at 40° C. of the first hydrocarbon base oil.

A lubricating oil composition for an internal combustion engine including: (A) a lubricant base oil having a kinematic viscosity at 100° C. of 2 to 5 mm.sup.2/s; (B) a metallic detergent in an amount of 500 to 2500 mass ppm in terms of Ca and 100 to 1000 mass ppm in terms of Mg, on the basis of the total mass of the composition, the metallic detergent including both (B1) a Ca-containing metallic detergent and (B2) a Mg-containing metallic detergent; (C) a boron-containing additive in an amount of 50 to 1000 mass ppm in terms of boron on the basis of the total mass of the composition, wherein the boron-containing additive is oil-soluble or oil-dispersible and is stable in oil, and wherein the boron-containing additive may compose at least a part of the component (B); and (D) an oil-soluble organic Mo compound in an amount of 100 to 2000 mass ppm in terms of Mo on the basis of the total mass of the composition, wherein a mass ratio (MB/Mg) of boron content of the composition (MB) to Mg content of the composition (Mg) is 0.5 to 10.

A lubricating oil composition for an internal combustion engine including: (A) a lubricant base oil having a kinematic viscosity at 100° C. of 2 to 5 mm.sup.2/s; (B) a metallic detergent in an amount of 500 to 2500 mass ppm in terms of Ca and 100 to 1000 mass ppm in terms of Mg, on the basis of the total mass of the composition, the metallic detergent including both (B1) a Ca-containing metallic detergent and (B2) a Mg-containing metallic detergent; (C) a boron-containing additive in an amount of 50 to 1000 mass ppm in terms of boron on the basis of the total mass of the composition, wherein the boron-containing additive is oil-soluble or oil-dispersible and is stable in oil, and wherein the boron-containing additive may compose at least a part of the component (B); and (D) an oil-soluble organic Mo compound in an amount of 100 to 2000 mass ppm in terms of Mo on the basis of the total mass of the composition, wherein a mass ratio (MB/Mg) of boron content of the composition (MB) to Mg content of the composition (Mg) is 0.5 to 10.