A lubricating agent including an ionic liquid formed from a Bronsted acid (HX) and a Bronsted base (B), wherein the Bronsted base has a linear hydrocarbon group having 10 or more carbon atoms and the difference between the pKa value of the Bronsted acid in water and the pKa value of the Bronsted base in water is 12 or more.

A lubricating agent including an ionic liquid formed from a Bronsted acid (HX) and a Bronsted base (B), wherein the Bronsted base has a linear hydrocarbon group having 10 or more carbon atoms and the difference between the pKa value of the Bronsted acid in water and the pKa value of the Bronsted base in water is 12 or more.

A lubricant including an ionic liquid, which includes a conjugate acid (B.sup.+) and a conjugate base (X.sup.), and is protic, wherein the conjugate acid includes a straight-chain hydrocarbon group having 10 or more carbon atoms, and wherein the conjugate base is represented by the following general formula (1): ##STR00001##
where n is an integer of from 0 to 6 in the general formula (1).

A lubricant including an ionic liquid, which includes a conjugate acid (B.sup.+) and a conjugate base (X.sup.), and is protic, wherein the conjugate acid includes a straight-chain hydrocarbon group having 10 or more carbon atoms, and wherein the conjugate base is represented by the following general formula (1): ##STR00001##
where n is an integer of from 0 to 6 in the general formula (1).

A carbon dioxide/co-fluid mixture is provided for use in a refrigeration cycle in which the carbon dioxide is alternately absorbed and desorbed from the co-fluid. Suitable co-fluids are selected from the class of alkoxylated carboxylic amides, wherein the amides are cyclic or non-cyclic. It has been discovered that N-2,5,8,11-tetraoxadodecyl-2-pyrrolidinone and its homologs exhibit an advantageous property of a high rate of desorption at lower temperatures.

A carbon dioxide/co-fluid mixture is provided for use in a refrigeration cycle in which the carbon dioxide is alternately absorbed and desorbed from the co-fluid. Suitable co-fluids are selected from the class of alkoxylated carboxylic amides, wherein the amides are cyclic or non-cyclic. It has been discovered that N-2,5,8,11-tetraoxadodecyl-2-pyrrolidinone and its homologs exhibit an advantageous property of a high rate of desorption at lower temperatures.

A lubricant including an ionic liquid, which contains a conjugate acid (B.sup.+) and a conjugate base (X.sup.) and is aprotic, wherein the conjugate acid contains a straight-chain hydrocarbon group having 10 or more carbon atoms, and wherein an acid that is a source of the conjugate base has a pKa in water of 0 or less.

A lubricant including an ionic liquid, which includes a conjugate acid (B.sup.+) and a conjugate base (X.sup.), and is protic, wherein the conjugate acid includes a straight-chain hydrocarbon group having 10 or more carbon atoms, and wherein the conjugate base is represented by the following general formula (1):

##STR00001##

where n is an integer of from 0 to 6 in the general formula (1).

A lubricant including an ionic liquid, which includes a conjugate acid (B.sup.+) and a conjugate base (X.sup.), and is protic, wherein the conjugate acid includes a straight-chain hydrocarbon group having 10 or more carbon atoms, and wherein the conjugate base is represented by the following general formula (1):

##STR00001##

where n is an integer of from 0 to 6 in the general formula (1).

A pre-lubricated stock sheet and a method and system for making the same are described. The pre-lubricated stock is generally in a coil wound form. The stock sheet can have opposing first and second sheet surfaces joined together by opposing side edges and opposing ends. Typically, the first and second sheet surfaces are substantially smooth and planar, wherein the sheet has 3 mg/foot.sup.2/side to about 200 mg/foot.sup.2/side of a solid lubricant having a melting temperature from about 80 to 212 degrees Fahrenheit. Moreover, the opposing side edges usually are substantially free of the solid lubricant. In some configurations, the stock sheet is an aluminum stock sheet, more particularly an aluminum can stock sheet. Furthermore, the lubricant can be in some configurations a food grade lubricant, that is qualifies a low volatile organic compound under one or more of municipal, state and federal governing authorities.