The present invention provides a hydraulic fluid comprising: (a) 40 to 2000 ppm by weight in terms of nitrogen content of a corrosion inhibiting agent which is one or more compounds of formula (I):

##STR00001## and/or tribologically acceptable salts thereof, wherein in formula (I): each R.sup.1 is independently a hydrocarbyl group comprising 1 to 10 carbon atoms, x is 0 to 4, each of R.sup.2 and R.sup.3 is independently hydrogen or a hydrocarbyl group comprising 1 to 20 carbon atoms, R.sup.4 is —NR.sup.5R.sup.6 or —OR.sup.7, each of R.sup.5 and R.sup.6 is independently an aryl group comprising 6 to 14 carbon atoms, optionally substituted with one or more hydrocarbyl groups comprising 1 to 20 carbon atoms, R.sup.7 is a hydrocarbyl group comprising 1 to 20 carbon atoms, and in each of said hydrocarbyl groups containing 2 or more carbon atoms, the carbon chain may, independently, optionally be interrupted by one or more ether groups; (b) 0.1 to 1% by weight of an ashless dispersant; and (c) a major amount of a base oil.

The present invention provides a hydraulic fluid comprising: (a) 40 to 2000 ppm by weight in terms of nitrogen content of a corrosion inhibiting agent which is one or more compounds of formula (I):

##STR00001## and/or tribologically acceptable salts thereof, wherein in formula (I): each R.sup.1 is independently a hydrocarbyl group comprising 1 to 10 carbon atoms, x is 0 to 4, each of R.sup.2 and R.sup.3 is independently hydrogen or a hydrocarbyl group comprising 1 to 20 carbon atoms, R.sup.4 is —NR.sup.5R.sup.6 or —OR.sup.7, each of R.sup.5 and R.sup.6 is independently an aryl group comprising 6 to 14 carbon atoms, optionally substituted with one or more hydrocarbyl groups comprising 1 to 20 carbon atoms, R.sup.7 is a hydrocarbyl group comprising 1 to 20 carbon atoms, and in each of said hydrocarbyl groups containing 2 or more carbon atoms, the carbon chain may, independently, optionally be interrupted by one or more ether groups; (b) 0.1 to 1% by weight of an ashless dispersant; and (c) a major amount of a base oil.

Provided is a lubricating oil composition to be used in an internal combustion engine having a sliding mechanism including a piston ring and a liner, the lubricating oil composition including: a base oil; (A) a poly(meth)acrylate; and (B) an organic molybdenum compound, in which: (A) the poly(meth)acrylate contains a polymer (A1) including a repeating unit derived from a (meth)acrylate represented by the following formula (1) and having a mass-average molecular weight of from 1,000 to 500,000; and a content of (B) the organic molybdenum compound in a total amount of the composition is from 0.01 mass % to 0.2 mass % in terms of a molybdenum atom: wherein R.sup.1 represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, a hydrocarbon group having 1 to 60 carbon atoms, or a functional group-containing hydrocarbon group having 1 to 60 carbon atoms.

The invention relates to a polyalkyl (meth) acrylate for improving lubricating oil properties, which comprises repetition units which are derived from (meth) acrylates having 6 to 22 carbon atoms in the alcohol residues, and repetition units which are derived from amine derivatives of an ethylenically unsaturated monomer. The invention further relates to methods for producing and using the present polyalkyl (meth) acrylate.

The invention relates to a polyalkyl (meth) acrylate for improving lubricating oil properties, which comprises repetition units which are derived from (meth) acrylates having 6 to 22 carbon atoms in the alcohol residues, and repetition units which are derived from amine derivatives of an ethylenically unsaturated monomer. The invention further relates to methods for producing and using the present polyalkyl (meth) acrylate.

This invention relates to malienated derivatives made from maleic anhydride, functionalized monomers, and one or more additional reagents, e.g., an oxygen-containing reagent (e.g., alcohol, polyol), a nitrogen-containing reagent (e.g., amine, polyamine, aminoalcohol), a metal and/or a metal compound. The invention relates to lubricants, functional fluids, fuels, dispersants, detergents and functional compositions (e.g., cleaning solutions, food compositions, etc.)

This invention relates to malienated derivatives made from maleic anhydride, functionalized monomers, and one or more additional reagents, e.g., an oxygen-containing reagent (e.g., alcohol, polyol), a nitrogen-containing reagent (e.g., amine, polyamine, aminoalcohol), a metal and/or a metal compound. The invention relates to lubricants, functional fluids, fuels, dispersants, detergents and functional compositions (e.g., cleaning solutions, food compositions, etc.)

A lubricant composition of an oil of lubricating viscosity; an esterified copolymer with a backbone comprising units derived from (i) an α-olefin monomer of at least about 6 carbon atoms and (ii) an ethylenically unsaturated carboxylic acid in a mole ratio of 1:3 to 3:1; and a polymer comprising olefin monomer units of 3 to 5 carbon atoms, wherein at least 50 percent by weight of such units contain fewer than 6 carbon atoms and wherein less than 5 percent by weight of such units are ethylene monomer units; exhibits good power transfer efficiency and elastohydrodynamic film thickness.

The invention provides a lubricating composition comprising an oil of lubricating viscosity and synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate block polymer having a substantially oil soluble block and a substantially oil insoluble block. The invention also provides a method of lubricating a mechanical device using such a lubricating composition.

The invention provides a lubricating composition comprising an oil of lubricating viscosity and synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate block polymer having a substantially oil soluble block and a substantially oil insoluble block. The invention also provides a method of lubricating a mechanical device using such a lubricating composition.