A lubricant, which includes an ionic liquid including a conjugate base and a conjugate acid, wherein the conjugate acid is represented by General Formula (A) below, and wherein a pKa of an acid that is a source of the conjugate base in acetonitrile is 10 or less, ##STR00001##
where, in General Formula (A), R.sub.1, R.sub.2, and R.sub.3 are each independently a group including a hydrocarbon group, with the proviso that at least one of the hydrocarbon groups in R.sub.1, R.sub.2, and R.sub.3 is a straight-chain hydrocarbon group having 6 or greater carbon atoms.

A lubricant, which includes an ionic liquid including a conjugate base and a conjugate acid, wherein the conjugate acid is represented by General Formula (A) below, and wherein a pKa of an acid that is a source of the conjugate base in acetonitrile is 10 or less, ##STR00001##
where, in General Formula (A), R.sub.1, R.sub.2, and R.sub.3 are each independently a group including a hydrocarbon group, with the proviso that at least one of the hydrocarbon groups in R.sub.1, R.sub.2, and R.sub.3 is a straight-chain hydrocarbon group having 6 or greater carbon atoms.

A fluorine-containing ether compound represented by a formula (1) shown below.
R.sup.1(O(CH.sub.2).sub.a).sub.b-[A]-[B]OCH.sub.2R.sup.2CH.sub.2R.sup.3(1)
(In the formula (1), R.sup.1 is an alkyl group which may have a substituent, or an organic group having at least one double bond or triple bond. Further, a represents an integer of 2 to 4, and b is 0 or 1. [A] is represented by a formula (2): (OCH.sub.2CH(OH)CH.sub.2).sub.c (wherein c is 1 or 2). [B] is represented by a formula (3): (O(CH.sub.2).sub.eCH(OH)CH.sub.2).sub.d (wherein d is 0 or 1, and e represents an integer of 2 to 4). However, the sum of c in the formula (2) and d in the formula (3) is 2. R.sup.2 is a perfluoropolyether chain. R.sup.3 is represented by a formula (4): (OCH.sub.2CH(OH)CH.sub.2).sub.2OCH.sub.2(CH.sub.2).sub.fOH (wherein f represents an integer of 2 to 5).

A fluorine-containing ether compound represented by a formula (1) shown below.
R.sup.1(O(CH.sub.2).sub.a).sub.b-[A]-[B]OCH.sub.2R.sup.2CH.sub.2R.sup.3(1)
(In the formula (1), R.sup.1 is an alkyl group which may have a substituent, or an organic group having at least one double bond or triple bond. Further, a represents an integer of 2 to 4, and b is 0 or 1. [A] is represented by a formula (2): (OCH.sub.2CH(OH)CH.sub.2).sub.c (wherein c is 1 or 2). [B] is represented by a formula (3): (O(CH.sub.2).sub.eCH(OH)CH.sub.2).sub.d (wherein d is 0 or 1, and e represents an integer of 2 to 4). However, the sum of c in the formula (2) and d in the formula (3) is 2. R.sup.2 is a perfluoropolyether chain. R.sup.3 is represented by a formula (4): (OCH.sub.2CH(OH)CH.sub.2).sub.2OCH.sub.2(CH.sub.2).sub.fOH (wherein f represents an integer of 2 to 5).

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, which includes an ionic liquid including a conjugate base and a conjugate acid, wherein the conjugate acid has a group including a straight-chain hydrocarbon group having 6 or more carbon atoms, a pKa of an acid that is a source of the conjugate base in acetonitrile is 10 or less, and solubility of the ionic liquid to CF.sub.3(CHF).sub.2CF.sub.2CF.sub.3 is 0.1 parts by mass relative to 100 parts by mass of CF.sub.3(CHF).sub.2CF.sub.2CF.sub.3.

A lubricant, which includes an ionic liquid including a conjugate base and a conjugate acid, wherein the conjugate acid has a group including a straight-chain hydrocarbon group having 6 or more carbon atoms, a pKa of an acid that is a source of the conjugate base in acetonitrile is 10 or less, and solubility of the ionic liquid to CF.sub.3(CHF).sub.2CF.sub.2CF.sub.3 is 0.1 parts by mass relative to 100 parts by mass of CF.sub.3(CHF).sub.2CF.sub.2CF.sub.3.

There is provided a resin composition for a machinable liner of a sliding member. An ultraviolet curable resin composition for a self-lubricating liner contains a (meth)acrylate compound having an isocyanuric acid ring represented by the following formula and PTFE as a solid lubricant. In the formula (1), X is a group which contains an acryloyl group and is composed only of C, H, and O. Y and Z are groups each composed only of C, H, and O. PTFE is contained in an amount of 10 to 50% by weight with respect to a total amount of the ultraviolet curable resin composition. The ultraviolet curable resin composition is suitable for a self-lubricating liner 24 of a spherical bearing 20 having an outer race 22 and an inner race 26. ##STR00001##

There is provided a resin composition for a machinable liner of a sliding member. An ultraviolet curable resin composition for a self-lubricating liner contains a (meth)acrylate compound having an isocyanuric acid ring represented by the following formula and PTFE as a solid lubricant. In the formula (1), X is a group which contains an acryloyl group and is composed only of C, H, and O. Y and Z are groups each composed only of C, H, and O. PTFE is contained in an amount of 10 to 50% by weight with respect to a total amount of the ultraviolet curable resin composition. The ultraviolet curable resin composition is suitable for a self-lubricating liner 24 of a spherical bearing 20 having an outer race 22 and an inner race 26. ##STR00001##