The present invention provides an engine oil composition including 70 to 95 percent by weight of a base oil and 0.01 to 15 percent by weight of a dispersant comb polymer, based on the overall weight of the engine oil composition. The dispersant comb polymer consists of 13.7% by weight of a macromonomer, which is an ester of methacrylic acid and a hydroxylated hydrogenated polybutadiene with Mn of 4750 g/mol; 51.5% by weight of n-butyl methacrylate; 17.3% by weight of LMA; 11.2% by weight of styrene; 0.2% by weight of methyl methacrylate; and 6.10% by weight of N,N-dimethylaminoethyl methacrylate. The modified dispersant inhibitor package contains 30 wt % or less of succinimide type dispersant based on the overall weight of the modified dispersant inhibitor additive package, and the engine oil composition has an SAE viscosity grade of 0W-X, wherein X is 30 or less.

The present invention provides an engine oil composition including 70 to 95 percent by weight of a base oil and 0.01 to 15 percent by weight of a dispersant comb polymer, based on the overall weight of the engine oil composition. The dispersant comb polymer consists of 13.7% by weight of a macromonomer, which is an ester of methacrylic acid and a hydroxylated hydrogenated polybutadiene with Mn of 4750 g/mol; 51.5% by weight of n-butyl methacrylate; 17.3% by weight of LMA; 11.2% by weight of styrene; 0.2% by weight of methyl methacrylate; and 6.10% by weight of N,N-dimethylaminoethyl methacrylate. The modified dispersant inhibitor package contains 30 wt % or less of succinimide type dispersant based on the overall weight of the modified dispersant inhibitor additive package, and the engine oil composition has an SAE viscosity grade of 0W-X, wherein X is 30 or less.

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.

The invention relates to polymeric-inorganic nanoparticle compositions and preparation processes thereof. The invention also relates to an additive and lubricant composition comprising these polymeric-inorganic nanoparticle compositions, as well as to the use of these polymeric-inorganic nanoparticle compositions in an oil lubricant formulation to improve tribological performance, in particular to improve anti-friction performance on metal parts.

The invention relates to polymeric-inorganic nanoparticle compositions and preparation processes thereof. The invention also relates to an additive and lubricant composition comprising these polymeric-inorganic nanoparticle compositions, as well as to the use of these polymeric-inorganic nanoparticle compositions in an oil lubricant formulation to improve tribological performance, in particular to improve anti-friction performance on metal parts.

Selected comb polymers contain specified amounts of macromonomer and nitrogen-containing (meth)acrylates. Lubricant compositions can contain such comb polymers. The selected comb polymers can be used as solubilizers in lubricant compositions, especially in engine oil (EO) compositions.

Selected comb polymers contain specified amounts of macromonomer and nitrogen-containing (meth)acrylates. Lubricant compositions can contain such comb polymers. The selected comb polymers can be used as solubilizers in lubricant compositions, especially in engine oil (EO) compositions.

The invention relates to polymeric-inorganic nanoparticle compositions and preparation processes thereof. The invention also relates to an additive and lubricant compositions comprising these polymeric-inorganic nanoparticle compositions, as well as to the use of these polymeric-inorganic nanoparticle compositions in an oil lubricant formulation to improve tribological performance, in particular to improve extreme pressure performance and friction reduction on metal parts.

The invention relates to polymeric-inorganic nanoparticle compositions and preparation processes thereof. The invention also relates to an additive and lubricant compositions comprising these polymeric-inorganic nanoparticle compositions, as well as to the use of these polymeric-inorganic nanoparticle compositions in an oil lubricant formulation to improve tribological performance, in particular to improve extreme pressure performance and friction reduction on metal parts.

A lubricant system for reducing frictional noise includes: a textile fabric at least partially embedded in a lubricant, the lubricant including a comb polymer having a main polymer chain and a plurality of side chains covalently bonded to the main polymer chain. At least one of the side chains has a molecular weight of at least 60 g/mol and/or at least 5 repeat units.