A polymer comprising units having the structure (I): ##STR00001##
wherein x is 2 or 3, wherein L is (CH.sub.2).sub.y, where y is an integer from 1 to 10, or wherein L is CH(CH.sub.3)CH.sub.2S(CH.sub.2).sub.z, where z is an integer from 1 to 5; wherein [Q] is absent or is a polymerised moiety consisting of units having the structure (II): ##STR00002##
wherein R is a hydrocarbyl group, or a hydrocarbyl group containing one or more heteroatoms, wherein R may be linear, branched or cyclic, saturated or unsaturated, and wherein R has from 1 to 30 carbon atoms; wherein [Q] either consists of identical units of structure (II), or wherein [Q] consists of more than one different units of structure (II), differing in group R; and wherein X is a halogen or another chain terminating group. The polymers may find use as additives in lubricating compositions where they provide friction improvement and wear reduction.

A polymer comprising units having the structure (I): ##STR00001##
wherein x is 2 or 3, wherein L is (CH.sub.2).sub.y, where y is an integer from 1 to 10, or wherein L is CH(CH.sub.3)CH.sub.2S(CH.sub.2).sub.z, where z is an integer from 1 to 5; wherein [Q] is absent or is a polymerised moiety consisting of units having the structure (II): ##STR00002##
wherein R is a hydrocarbyl group, or a hydrocarbyl group containing one or more heteroatoms, wherein R may be linear, branched or cyclic, saturated or unsaturated, and wherein R has from 1 to 30 carbon atoms; wherein [Q] either consists of identical units of structure (II), or wherein [Q] consists of more than one different units of structure (II), differing in group R; and wherein X is a halogen or another chain terminating group. The polymers may find use as additives in lubricating compositions where they provide friction improvement and wear reduction.

A lubricating composition comprises an oil-soluble poly(2-oxazoline) additive having the repeat unit:

—N(COR.sup.1)CH.sub.2CH.sub.2— where the number of repeat units (n) is an integer between 4 and 1000; where the polymer carries an inorganic or organic nucleophilic polymerization terminating group t, and a linear, branched or cyclic hydrocarbyl polymerization initiator group (i); and where R.sup.1 comprises a single or a mixture of linear branched or cyclic hydrocarbyl groups having 1-100 carbon atoms, some or all having 12-100 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms provided that when the polymer is a homopolymer and R.sup.1 lacks any hetero atoms; (A) i has a molecular weight of less than 250 g/mol, and R.sup.1 has an average number of carbon atoms of 12 to 50; or (B) n is greater than 15.

The polymer may provide the composition, in the form of a lubricant, with friction modifier, and with low impact on lubricant viscosity.

The polymer may be a homopolymer, a block copolymer or a star polymer.

A lubricating composition includes an oil of lubricating viscosity and an oil-soluble dispersant viscosity modifier. The dispersant viscosity modifier includes an olefin-based polymer backbone and at least one pendent group derived from a functionalized aliphatic amine. Each pendent group is independently attached to the olefin-based polymer backbone. The pendent group is non-ionic, non-basic, and non-acidic and includes a functional group which includes at least one heteroatom other than nitrogen.

A lubricating oil composition comprising at least 50 percent by mass, based on the mass of the composition of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of a polymer comprising units (a) and one or both units (b) and (c):
—N(COR.sup.1)(CH.sub.2).sub.x—  (a)
—NH(CH.sub.2).sub.y—  (b)
—N(CH.sub.2CH.sub.2-k(CH.sub.3).sub.kCOOR.sup.2)(CH.sub.2).sub.z   (c) where the total number (n) of units (a), (b) and (c) is an integer between 4 and 500; wherein x, y and z are independently 2 or 3; wherein k is zero or 1. The polymer shows good solubility in the lubricating oil and provides friction modification. A method of synthesising a polymer is also disclosed.

The disclosed technology provides a lubricating composition and a method of lubricating an internal combustion engine where the lubricating composition contains an oil of lubricating viscosity, one or more metal-containing, sulfur-free, alkyl-phenol based detergents, an alkaline earth metal sulfonate detergent, a polyisobutenyl succinimide dispersant, and a dispersant viscosity modifier having a number average molecular weight of at least 20,000.

The lubricating composition of the present invention can be formulated to have lower HTHS viscosity, and reduced phosphorous content, while providing protection against adhesive wear.

The disclosed technology provides a lubricating composition and a method of lubricating an internal combustion engine where the lubricating composition contains an oil of lubricating viscosity, one or more metal-containing, sulfur-free, alkyl-phenol based detergents, an alkaline earth metal sulfonate detergent, a polyisobutenyl succinimide dispersant, and a dispersant viscosity modifier having a number average molecular weight of at least 20,000.

The lubricating composition of the present invention can be formulated to have lower HTHS viscosity, and reduced phosphorous content, while providing protection against adhesive wear.

A lubricating composition comprises at least 50 percent by mass, based on the mass of the composition of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble poly(2-oxazine) polymer. The polymer has the repeat unit: ##STR00001##
where the number (n) of repeat units is an integer between 4 and 500, such as between 4 and 400. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. R.sup.1 comprises a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

A lubricating composition comprises at least 50 percent by mass, based on the mass of the composition of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble poly(2-oxazine) polymer. The polymer has the repeat unit: ##STR00001##
where the number (n) of repeat units is an integer between 4 and 500, such as between 4 and 400. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. R.sup.1 comprises a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

A polyisobutylene-substituted hydroxyaromatic compound and derivatives thereof which are suitable for use as additives in lubricating compositions. The polyisobutylene-substituted hydroxyaromatic compound may include the reaction product of a hydroxyaromatic compound with a polyisobutylene having a number average molecular weight of 150 to 800.