Provided herein is a composition for improving performance of waxless skis, in particular skin skis, more particularly of skin strips, on snow, the composition comprising (a) C.sub.1-6-alcohol(s); and (b) lubricant(s) selected from a group consisting of (c) perfluoropolyethers, (d) polydi(C.sub.1-3-alkyl)siloxanes, and mixtures thereof.

A heat and mass transfer component comprises a lubricant-impregnated surface including hydrophobic surface features, which comprise nanostructured surface protrusions having a hydrophobic species attached thereto. The hydrophobic surface features are impregnated with a fluorinated lubricant having a viscosity in a range from about 400 mPa.Math.s to about 6000 mPa.Math.s. A method of fabricating a lubricant-impregnated surface on a heat and mass transfer component comprises: cleaning a thermally conductive substrate to form a cleaned substrate; exposing the cleaned substrate to a hot water or hot alkaline solution to form a thermally conductive substrate having nanostructured surface protrusions; depositing a hydrophobic species on the nanostructured surface protrusions to form hydrophobic surface features; and coating the hydrophobic surface features with a fluorinated lubricant having a viscosity in a range from 400 mPa.Math.s to 6000 mPa.Math.s. The heat and mass transfer component may exhibit a substantial increase in heat transfer coefficient during hydrocarbon condensation.

Provided is a fluorine-containing ether compound capable of forming a lubricant layer having excellent wear resistance even when the thickness is thin, and suitable as a material of a lubricant for a magnetic recording medium. The fluorine-containing ether compound is a compound represented by the following formula (1): R.sup.1R.sup.2CH.sub.2R.sup.3CH.sub.2R.sup.4R.sup.5; wherein R.sup.3 is a perfluoropolyether chain; R.sup.1 is a terminal group bonded to R.sup.2; R.sup.5 is a terminal group bonded to R.sup.4; R.sup.1 is an alkenyl group or an alkynyl group; R.sup.5 is a group containing a heterocyclic ring; R.sup.2 is represented by the following formula (2); R.sup.4 is represented by the following formula (3); and a in the formula (2) and b in the formula (3) are each independently an integer of 1 to 3.

##STR00001##

A grease of the invention contains a fluorine synthetic oil as a base oil and an inorganic acid salt that is at least one selected from phosphate, tungstate, sulfate and sulfite. The grease of the invention is suitably usable in a bearing, a gear and the like because of an excellent wear resistance and a low environmental burden.

A composition comprising a heat transfer portion and a lubricating portion, wherein the lubricating portion comprises one or more compounds according to formula (I): wherein W is independently selected from the group consisting of H, F, Cl, Br and I; Y is independently selected from the group consisting of F, Cl, Br and I; Z is independently selected from the group consisting of H, OH, (CW.sub.2).sub.PCW.sub.3, CY.sub.3, OCW.sub.3, 0(CW.sub.2).sub.pCW.sub.3, OCW((CY.sub.2).sub.mCY.sub.3)CWCW.sub.2, polyalkylene glycol and polyolester; n is an integer from 2 to 250; m is an integer from 0 to 3; and p is an integer from 0 to 9.

One embodiment of the present invention is a fullerene derivative represented by general formula (1) ##STR00001##
(wherein FLN is a fullerene backbone; each A is independently a monovalent group including a divalent perfluoropolyether group; each R is each independently a hydrogen atom, a hydrocarbon group, or an alkoxycarbonyl group including a divalent perfluoropolyether group; at least one of the 2m R is a hydrocarbon group or an alkoxycarbonyl group including a divalent perfluoropolyether group; m is an integer from 1 to 5; and n is an integer from 1 to 6).

Low-friction fluorinated coatings are disclosed herein. A preferred low-friction material contains a low-surface-energy fluoropolymer having a surface energy between about 5 mJ/m.sup.2 to about 50 mJ/m.sup.2, and a hygroscopic material that is covalently connected to the fluoropolymer in a triblock copolymer, such as PEG-PFPE-PEG. The material forms a lubricating surface layer in the presence of humidity. An exemplary copolymer comprises fluoropolymers with average molecular weight from 500 g/mol to 20,000 g/mol, wherein the fluoropolymers are (,)-hydroxyl-terminated and/or (,)-amine-terminated, and wherein the fluoropolymers are present in the triblock structure T-(CH.sub.2CH.sub.2O)CH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.nCF.sub.2CH.sub.2(OCH.sub.2CH.sub.2).sub.p-T where T is a hydroxyl or amine terminal group, p=1 to 50, m=1 to 100, and n=1 to 100. The copolymer also contains isocyanate species and polyol or polyamine chain extenders or crosslinkers possessing a functionality of preferably 3 or greater. These durable, solvent-resistant, and transparent coatings reduce insect debris following impact.

Low-friction fluorinated coatings are disclosed herein. A preferred low-friction material contains a low-surface-energy fluoropolymer having a surface energy between about 5 mJ/m.sup.2 to about 50 mJ/m.sup.2, and a hygroscopic material that is covalently connected to the fluoropolymer in a triblock copolymer, such as PEG-PFPE-PEG. The material forms a lubricating surface layer in the presence of humidity. An exemplary copolymer comprises fluoropolymers with average molecular weight from 500 g/mol to 20,000 g/mol, wherein the fluoropolymers are (,)-hydroxyl-terminated and/or (,)-amine-terminated, and wherein the fluoropolymers are present in the triblock structure T-(CH.sub.2CH.sub.2O)CH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.nCF.sub.2CH.sub.2(OCH.sub.2CH.sub.2).sub.p-T where T is a hydroxyl or amine terminal group, p=1 to 50, m=1 to 100, and n=1 to 100. The copolymer also contains isocyanate species and polyol or polyamine chain extenders or crosslinkers possessing a functionality of preferably 3 or greater. These durable, solvent-resistant, and transparent coatings reduce insect debris following impact.

There are provided a solvent composition containing tDCE, which does not exert an adverse effect on the global environment, has high solubility and incombustibility, and can maintain initial incombustibility even in use accompanied by a phase change, a cleaning method using the solvent composition, a coating film-forming composition including the solvent composition, and a method of forming a homogeneous coating film using the coating film-forming composition. A solvent composition includes: tDCE; at least one HFE (A) selected from HFE-347pc-f, HFE-365mf-c, and HFE-467sc-f; and at least one HFC (X) selected from cHFC-447, and HFC-76-13sf, in which a ratio of tDCE with respect to a total amount of tDCE, HFE (A), and HFC (X) is 65 to 80 mass %, a ratio of HFE (A) with respect to the total amount is 5 to 25 mass %, and a ratio of HFC (X) with respect to the total amount is 5 to 25 mass %.

A vacuum pump may include a rotor and a stator, wherein the rotor is supported by metal bearings (such as steel bearings) to allow relative rotation of the rotor with respect to the stator. A liquid PFPE lubricant compound is provided to lubricate the bearings, wherein the lubricant further comprises a solid lubricant that is in suspension in the liquid lubricant. The solid lubricant can comprise any of graphite, graphene and molybdenum disulphide. In other words, the inventive concept encompasses a lubricated bearing arranged to support a rotating shaft in a body under sub-atmospheric conditions, wherein a lubricant used to lubricate the bearing comprises liquid PFPE lubricant having a low vapour pressure, and a solid lubricant that is held in suspension in the liquid lubricant. The solid lubricant may comprise any of graphite, graphene and molybdenum disulphide.