An oil composition comprising a first component having pendant groups and a second component but free of a third component and process for making such oil composition, where a single molecule of the third component can form large shearable stable complex structure with two molecules of the first component via van der Waals force between pendant groups and the terminal carbon chains, and a single molecule of the second component is capable of adjoining no more than one molecule of the first type. The oil composition has high shear stability making it suitable for use in lubricants subject to repeated high shear stress events.

The present invention provides a lubricant material for assisting machining process comprising a high molecular weight compound (A) having a weight average molecular weight of 5?10.sup.4 or higher and 1?10.sup.6 or lower, a medium molecular weight compound (B) having a weight average molecular weight of 1?10.sup.3 or higher and lower than 5?10.sup.4, and a carbon (C) having an average particle size of 100 ?m or larger.

Low transition temperature mixtures (LTTMs) comprising a eutectic mixture of a quaternary amine and a polyol such as glycol are provided. The LTTMs can provide various beneficial properties, such as highly desirable viscosity index, low glass transition temperatures, and/or high kinematic viscosities relative to the molecular weight of the mixture components. The mixtures can be advantageously used as co-base stocks in lubricating oil compositions.

Low transition temperature mixtures (LTTMs) comprising a eutectic mixture of a quaternary amine and a polyol such as glycol are provided. The LTTMs can provide various beneficial properties, such as highly desirable viscosity index, low glass transition temperatures, and/or high kinematic viscosities relative to the molecular weight of the mixture components. The mixtures can be advantageously used as co-base stocks in lubricating oil compositions.

An oil composition comprising a first component having pendant groups and a second component but free of a third component and process for making such oil composition, where a single molecule of the third component can form large shearable stable complex structure with two molecules of the first component via van der Waals force between pendant groups and the terminal carbon chains, and a single molecule of the second component is capable of adjoining no more than one molecule of the first type. The oil composition has high shear stability making it suitable for use in lubricants subject to repeated high shear stress events.

A lubricating oil composition may have excellent fuel economy and high shear stability. Such a lubricating oil composition may include: a comb-like polymer (A1) having a weight average molecular weight (Mw) of less than 300,000; and a comb-like polymer (A2) having a Mw of at least 400,000. The (A1)/(A2) mass content ratio of the comb-like polymer (A1) to the comb-like polymer (A2) in terms of resin content may be at least 0.25.

A lubricating oil composition may have excellent fuel economy and high shear stability. Such a lubricating oil composition may include: a comb-like polymer (A1) having a weight average molecular weight (Mw) of less than 300,000; and a comb-like polymer (A2) having a Mw of at least 400,000. The (A1)/(A2) mass content ratio of the comb-like polymer (A1) to the comb-like polymer (A2) in terms of resin content may be at least 0.25.

The present invention provides a fluorine-containing ether compound that can form a lubricating layer which has excellent wear resistance even if the thickness is thin and in which a decrease in film thickness due to spin-off is less likely to occur. The fluorine-containing ether compound is represented by the following formula. R.sup.1R.sup.2OCH.sub.2R.sup.3CH.sub.2OR.sup.4R.sup.5 (R.sup.3 is a perfluoropolyether chain. R.sup.1 and R.sup.5 are either an alkyl group which may have a substituent or a hydrocarbon group having a double bond or triple bond. R.sup.2 and R.sup.4 are each a divalent linking group containing one or more heteroatoms, and have one or more polar groups, and the terminal end on the side bonded to R.sup.1 and R.sup.5 is a heteroatom. At least one of R.sup.2 and R.sup.4 contains one or more secondary amine structures. At least one of R.sup.1R.sup.2 and R.sup.4R.sup.5 contains one or more cyano groups).

The present invention provides a fluorine-containing ether compound that can form a lubricating layer which has excellent wear resistance even if the thickness is thin and in which a decrease in film thickness due to spin-off is less likely to occur. The fluorine-containing ether compound is represented by the following formula. R.sup.1R.sup.2OCH.sub.2R.sup.3CH.sub.2OR.sup.4R.sup.5 (R.sup.3 is a perfluoropolyether chain. R.sup.1 and R.sup.5 are either an alkyl group which may have a substituent or a hydrocarbon group having a double bond or triple bond. R.sup.2 and R.sup.4 are each a divalent linking group containing one or more heteroatoms, and have one or more polar groups, and the terminal end on the side bonded to R.sup.1 and R.sup.5 is a heteroatom. At least one of R.sup.2 and R.sup.4 contains one or more secondary amine structures. At least one of R.sup.1R.sup.2 and R.sup.4R.sup.5 contains one or more cyano groups).

A lubricating oil composition may have excellent fuel economy and high shear stability. Such a lubricating oil composition may include: a comb-like polymer (A1) having a weight average molecular weight (Mw) of less than 300,000; and a comb-like polymer (A2) having a Mw of at least 400,000. The (A1)/(A2) mass content ratio of the comb-like polymer (A1) to the comb-like polymer (A2) in terms of resin content may be at least 0.25.