A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by weight, based on the weight of the composition, of a poly(2-oxazoline) polymer. The polymer has the repeat unit:
N(COR.sup.1)CH.sub.2CH.sub.2
wherein the number of repeat units (n) in the polymer is an integer between 4 and 1000, such as between 4 and 500. 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. At least 5% of the total number of the groups R.sup.1 in the polymer comprise alkenyl groups having between 15 and 20 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.

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.

A lubricating oil composition having greater than 50 wt % of a base oil and 0.1 wt % to 20 wt %, both based on the total weight of the lubricating oil composition, of a dispersant viscosity modifier obtainable by: A) reacting: a) at least one of a lactone of formula (I) or a derivative thereof: ##STR00001##
wherein X is oxygen, and R is an optionally substituted hydrocarbylene group having from 1 to 20 carbon atoms; and b) at least one compound selected from amines, alcohols and oxazolines; and B) reacting the reaction product of step A) onto an acylated olefin copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having a number average molecular weight of 5,000 to 200,000 g/mol as measured by GPC, with an acylating agent. Methods employing the lubricating oil compositions and uses of the lubricating compositions as engine oils are also described.

The present disclosure relates to viscosity index modifiers that have dispersant properties and lubricating oil compositions comprising said viscosity index modifiers. The viscosity index modifier is the reaction product of an acylated olefin copolymer, a polyamine, and a dicarboxylic acid or anhydride thereof that can react with a free primary amine of the polyamine to form a ring moiety. The disclosure also relates to the use of lubricant compositions comprising the viscosity index improvers of the disclosure for improving the soot or sludge handling characteristics of an engine lubricant composition, while minimizing the deterioration of engine seals.

The present disclosure relates to viscosity index modifiers that have dispersant properties and lubricating oil compositions comprising said viscosity index modifiers. The viscosity index modifier is the reaction product of an acylated olefin copolymer, a polyamine, and a dicarboxylic acid or anhydride thereof that can react with a free primary amine of the polyamine to form a ring moiety. The disclosure also relates to the use of lubricant compositions comprising the viscosity index improvers of the disclosure for improving the soot or sludge handling characteristics of an engine lubricant composition, while minimizing the deterioration of engine seals.

The present disclosure relates to lubricant additives such as dispersants and dispersant viscosity modifiers including acyl peptide grafted polymers and lubricating oil compositions comprising such additives. The disclosure also relates to the use of lubricant compositions comprising the additives herein for improving the soot or sludge handling characteristics of an engine lubricant composition and while minimizing the deterioration of engine's elastomer compatibility.

A lubricating oil composition having greater than 50 wt % of a base oil and 0.1 wt % to 20 wt %, both based on the total weight of the lubricating oil composition, of a dispersant viscosity modifier obtainable by: A) reacting: a) at least one of a lactone of formula (I) or a derivative thereof:

##STR00001##

wherein X is oxygen, and R is an optionally substituted hydrocarbylene group having from 1 to 20 carbon atoms; and b) at least one compound selected from amines, alcohols and oxazolines; and B) reacting the reaction product of step A) onto an acylated olefin copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having a number average molecular weight of 5,000 to 200,000 g/mol as measured by GPC, with an acylating agent. Methods employing the lubricating oil compositions and uses of the lubricating compositions as engine oils are also described.

A multiphase composite lubricant for a railway lubricant stick that can be used in both low and high temperature applications. The composition of the multiphase composite lubricant includes an amount of a lubricant, an amount of a thermoplastic lattice components that forms a lattice structure, and a polymer extender.

A multiphase composite lubricant for a railway lubricant stick that can be used in both low and high temperature applications. The composition of the multiphase composite lubricant includes an amount of a lubricant, an amount of a thermoplastic lattice components that forms a lattice structure, and a polymer extender.