Lubricating compositions containing a phosphorus-containing salt of an acylated ethylene-α-olefin polymer substituted with an aliphatic polyamine having at least one primary or secondary amine, the lubricating composition having a total phosphorus content in an amount of 200 ppm to 600 ppm by weight of the lubricating composition. The phosphorus-containing salt additive described herein can be used as an anti-wear agent in lubricating composition for diesel engines.

The present disclosure relates to a continuously variable transmission oil composition containing a base oil containing a metallocene polyalpha olefin (mPAO) polymerized with a metallocene catalyst, a viscosity controlling agent containing Polybutadiene hydrogen phosphate Comb Polymethacrylate, and a clean dispersant, and contains mPAO and PHP Comb PMA, which have not been used previously, at a specific ratio to maximize the reduction in low-temperature viscosity while effectively forming an oil film, thereby enhancing fuel efficiency, and at the same time, enhancing durability of a transmission by increasing viscosity.

The present disclosure relates to a continuously variable transmission oil composition containing a base oil containing a metallocene polyalpha olefin (mPAO) polymerized with a metallocene catalyst, a viscosity controlling agent containing Polybutadiene hydrogen phosphate Comb Polymethacrylate, and a clean dispersant, and contains mPAO and PHP Comb PMA, which have not been used previously, at a specific ratio to maximize the reduction in low-temperature viscosity while effectively forming an oil film, thereby enhancing fuel efficiency, and at the same time, enhancing durability of a transmission by increasing viscosity.

The present disclosure relates to a continuously variable transmission oil composition containing a base oil containing a metallocene polyalpha olefin (mPAO) polymerized with a metallocene catalyst, a viscosity controlling agent containing Polybutadiene hydrogen phosphate Comb Polymethacrylate, and a clean dispersant, and contains mPAO and PHP Comb PMA, which have not been used previously, at a specific ratio to maximize the reduction in low-temperature viscosity while effectively forming an oil film, thereby enhancing fuel efficiency, and at the same time, enhancing durability of a transmission by increasing viscosity.

The present disclosure relates to a continuously variable transmission oil composition containing a base oil containing a metallocene polyalpha olefin (mPAO) polymerized with a metallocene catalyst, a viscosity controlling agent containing Polybutadiene hydrogen phosphate Comb Polymethacrylate, and a clean dispersant, and contains mPAO and PHP Comb PMA, which have not been used previously, at a specific ratio to maximize the reduction in low-temperature viscosity while effectively forming an oil film, thereby enhancing fuel efficiency, and at the same time, enhancing durability of a transmission by increasing viscosity.

A viscosity index improver containing a copolymer (A) whose essential constituent monomer is a monomer (a) having a number average molecular weight of 800 to 4,000 represented by the following formula (1), the copolymer (A) having a solubility parameter in the range of 9.00 to 9.40: ##STR00001##
wherein R.sup.1 is a hydrogen atom or a methyl group; —X.sup.1— is a group represented by —O—, —O(AO).sub.m—, or —NH—, AO is a C2-C4 alkyleneoxy group, m is an integer of 1 to 10, each AO may be the same or different when m is 2 or more, and the (AO).sub.m moieties may be randomly bonded or block-bonded; R.sup.2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer whose essential constituent monomer is butadiene in which the butadiene is present in a proportion of 50% by weight or more based on the weight of R.sup.2, or after removal of one hydrogen atom from a polymer formed by partial hydrogenation of the hydrocarbon polymer; and p represents a number of 0 or 1.

A viscosity index improver containing a copolymer (A) whose essential constituent monomer is a monomer (a) having a number average molecular weight of 800 to 4,000 represented by the following formula (1), the copolymer (A) having a solubility parameter in the range of 9.00 to 9.40: ##STR00001##
wherein R.sup.1 is a hydrogen atom or a methyl group; —X.sup.1— is a group represented by —O—, —O(AO).sub.m—, or —NH—, AO is a C2-C4 alkyleneoxy group, m is an integer of 1 to 10, each AO may be the same or different when m is 2 or more, and the (AO).sub.m moieties may be randomly bonded or block-bonded; R.sup.2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer whose essential constituent monomer is butadiene in which the butadiene is present in a proportion of 50% by weight or more based on the weight of R.sup.2, or after removal of one hydrogen atom from a polymer formed by partial hydrogenation of the hydrocarbon polymer; and p represents a number of 0 or 1.

Provided is a lubricity-imparting agent that can impart durable lubricity (in particular, lubricity at the time of wetting) to a substrate. It has been found that a lubricity-imparting agent including a copolymer containing a constitutional unit (A) based on 2-methacryloyloxyethyl phosphorylcholine and a constitutional unit (B) based on a photoreactive functional group-containing monomer, or a copolymer containing a constitutional unit (A) based on 2-methacryloyloxyethyl phosphorylcholine, a constitutional unit (B) based on a photoreactive functional group-containing monomer, and a constitutional unit (C) based on a hydrophobic group-containing monomer can impart durable lubricity to a substrate surface through a simple approach called photoirradiation.

A lubricating oil additive composition that is suitable as a load bearing additive, and is excellent in wear resistance, extreme pressure property, and thermal stability, and a lubricating oil composition containing the lubricating oil additive composition. A lubricating oil additive composition containing a poly(meth)acrylate-based copolymer (X) containing a structural unit (a) derived from a particular alkyl (meth)acrylate (A), a structural unit (b) derived from a particular hydroxy group containing (meth)acrylate (B), and a structural unit (c) derived from a particular phosphorus-containing (meth)acrylate (C).

A lubricating oil additive composition that is suitable as a load bearing additive, and is excellent in wear resistance, extreme pressure property, and thermal stability, and a lubricating oil composition containing the lubricating oil additive composition. A lubricating oil additive composition containing a poly(meth)acrylate-based copolymer (X) containing a structural unit (a) derived from a particular alkyl (meth)acrylate (A), a structural unit (b) derived from a particular hydroxy group containing (meth)acrylate (B), and a structural unit (c) derived from a particular phosphorus-containing (meth)acrylate (C).