The present invention relates to a sulphur-containing polyester capable of being obtained by a process comprising esterification reactions between a polyol and a carboxylic acid and a thiolactic acid, or by a process comprising an esterification reaction between a partially esterified polyol and a thiolactic acid. It also concerns its use as a multiproperty additive, and compositions comprising it.

The present invention relates to a sulphur-containing polyester capable of being obtained by a process comprising esterification reactions between a polyol and a carboxylic acid and a thiolactic acid, or by a process comprising an esterification reaction between a partially esterified polyol and a thiolactic acid. It also concerns its use as a multiproperty additive, and compositions comprising it.

Disclosed herein is a process for lubricating an internal combustion engine with a lubricant composition that may be substantially ash free. The ashless lubricant composition described herein may comprise primary antioxidants, such as aminic diphenyl amines, alkylated phenyl-naphthyl amines, and phenolic antioxidants. The ashless lubricant composition described herein may also comprise sulfur containing products that may work as secondary antioxidants. Other components such as ashless antiwear components, dispersants, pour point depressants, friction modifiers, and metal deactivators may also be used to formulate an ashless lubricant composition according to an embodiment.

Disclosed herein is a process for lubricating an internal combustion engine with a lubricant composition that may be substantially ash free. The ashless lubricant composition described herein may comprise primary antioxidants, such as aminic diphenyl amines, alkylated phenyl-naphthyl amines, and phenolic antioxidants. The ashless lubricant composition described herein may also comprise sulfur containing products that may work as secondary antioxidants. Other components such as ashless antiwear components, dispersants, pour point depressants, friction modifiers, and metal deactivators may also be used to formulate an ashless lubricant composition according to an embodiment.

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.

An antioxidant package composition including a combination of: (i) at least one aromatic amine, and (ii) at least one polyether sulphide; a lubricant composition including: (a) the above antioxidant package and (b) at least one base oil; a process for preparing the antioxidant package; and a process for preparing the lubricant composition.

An antioxidant package composition including a combination of: (i) at least one aromatic amine, and (ii) at least one polyether sulphide; a lubricant composition including: (a) the above antioxidant package and (b) at least one base oil; a process for preparing the antioxidant package; and a process for preparing the lubricant composition.

The invention relates to a method for preparing lignin derivative-based lubricating greases thickened by a polyurea thickener, lubricating greases thus prepared, and the use of such lubricant greases, inter alia, in transmissions, constant-velocity driveshafts and sealed roller bearings.

The invention relates to a method for preparing lignin derivative-based lubricating greases thickened by a polyurea thickener, lubricating greases thus prepared, and the use of such lubricant greases, inter alia, in transmissions, constant-velocity driveshafts and sealed roller bearings.

A polymer having the structure (I):

##STR00001##

L is a linking group, R is a hydrocarbon group or a substituted-hydrocarbon group, and x is 2 or more, preferably from 2 to 100, more preferably from 2 to 50. Each {Q} is (a) an identical polymer block composed of 3 or more monomer units, or (b) contains a plurality of polymer blocks, each polymer block being composed of 3 or more monomer units, such that the moiety {Q}-L-{Q} has the structure {P.sub.n . . . P.sub.2P.sub.1}-L-{P.sub.1P.sub.2 . . . P.sub.n} where each P.sub.n is an individual polymer block, the number of polymer blocks n in each {Q} being the same; wherein for each value of n the polymer blocks are identical; and wherein n is an integer of 2 or more, preferably from 2 to 100, more preferably from 2 to 50.