A method of making a coating solution includes the steps of polymerising an initial monomer feed comprising an N-vinyl pyrrolidone and an acrylate, preferably methacrylate, salt in water to synthesise a copolymer thereof, acidifying the resulting copolymer-water mixture to give free carboxylic acid groups along the copolymer backbone, diluting the aqueous solution down with alcohol, and adding a cross-linking agent which is capable of reacting with the carboxylic acid groups and curing the copolymer at a later stage after the coating solution has been applied to a substrate and the copolymer coated thereon. Also disclosed are a coating solution in storage, a method of coating a substrate which is on, or is part of, a medical device or other article, a substrate, article or medical device having a coating so applied, and a coated medical device packaged in a hydration solution. The aqueous-alcoholic coating solution may be stored for an extended period, suitably for at least one month and desirably for substantially longer, without deteriorating.

An additive for a lubricating composition includes an ionic tetrahedral borate compound which includes a cation and a tetrahedral borate anion having a boron atom, the boron atom has at least one aliphatic bidentate di-oxo ligand. The cation may be selected to provide detergent and/or dispersant and/or antioxidant properties to a lubricating composition.

An additive for a lubricating composition includes an ionic tetrahedral borate compound which includes a cation and a tetrahedral borate anion having a boron atom, the boron atom has at least one aliphatic bidentate di-oxo ligand. The cation may be selected to provide detergent and/or dispersant and/or antioxidant properties to a lubricating composition.

Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.

Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.

A lubricating oil composition for an internal combustion engine has a HTHS viscosity at 150° C. of 2.25 to <2.55 mPa.Math.s and includes: (A) a lubricating base oil including (a) mineral base oil(s) and/or (a) synthetic base oil(s), and having a kinematic viscosity at 100° C. of 3.8-4.6 mm.sup.2/s; (B) 1000-2000 mass ppm, in terms of metal content, of a metallic detergent including (a) metal salicylate detergent(s), and delivering ≥10 mmol/kg of total salicylate soap base per kilogram of the composition; (C) 1.0 to 4.0 mass % of a comb-shaped poly(meth)acrylate having a Mw of 350,000-1,000,000 and a PDI of ≤4.0; and (D) 100-1000 mass ppm, in terms of nitrogen, of a succinimide dispersant including (i) (a) non-modified succinimide dispersant(s) and/or (ii) (a) boric acid-modified succinimide dispersant(s), wherein the (i) and the (ii), in total, deliver 70 mass % of total nitrogen content of the component (D).

A lubricating oil composition for an internal combustion engine has a HTHS viscosity at 150° C. of 2.25 to <2.55 mPa.Math.s and includes: (A) a lubricating base oil including (a) mineral base oil(s) and/or (a) synthetic base oil(s), and having a kinematic viscosity at 100° C. of 3.8-4.6 mm.sup.2/s; (B) 1000-2000 mass ppm, in terms of metal content, of a metallic detergent including (a) metal salicylate detergent(s), and delivering ≥10 mmol/kg of total salicylate soap base per kilogram of the composition; (C) 1.0 to 4.0 mass % of a comb-shaped poly(meth)acrylate having a Mw of 350,000-1,000,000 and a PDI of ≤4.0; and (D) 100-1000 mass ppm, in terms of nitrogen, of a succinimide dispersant including (i) (a) non-modified succinimide dispersant(s) and/or (ii) (a) boric acid-modified succinimide dispersant(s), wherein the (i) and the (ii), in total, deliver 70 mass % of total nitrogen content of the component (D).

The present invention relates to a composition suitable to be used as working fluid, said composition being in the form of a solution and comprising at least one (per)fluoropolyether polymer [polymer (P)] and at least one amorphous polymer [polymer (F)].

The present invention is to provide a refrigeration cycle apparatus that has a low GWP of 750 or less and low flammability and that maintains performance and safety for an extended period of time. The refrigeration cycle apparatus includes a compressor (300) that compresses a refrigerant, a condenser that condenses the refrigerant compressed by the compressor (300), a pressure reducer that reduces a pressure of the refrigerant condensed by the condenser, and an evaporator that evaporates the refrigerant reduced in pressure by the pressure reducer. The refrigerant is a mixed refrigerant which contains difluoromethane, pentafluoroethane, and trifluoroiodomethane and which has a global warming potential of 750 or less and a vapor pressure at 25° C. of 1.1 MPa or more and 1.8 MPa or less. The compressor (300) is a sealed electric compressor in which a refrigerator oil to lubricate a sliding portion is charged. The refrigerator oil is polyol ester oil and has a water content of 300 ppm by weight or less.

A viscosity index improver comprising a reaction product of (i) an acylated copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having an Mn of 3,000 to 250,000 g/mol; and (ii) a compound of the formulae (I)-(V): ##STR00001##
wherein R.sub.1, R.sub.6, R.sub.8, R.sub.9, R.sub.10, R.sub.12 and R.sub.15 are independently selected from a hydrogen and an optionally substituted linear or branched alkyl or alkenyl group, and R.sub.2, R.sub.3, R.sub.4, and R.sub.5 R.sub.7, R.sub.11, R.sub.13, R.sub.14, R.sub.16, and R.sub.17 are independent selected from an optionally substituted linear or branched alkyl or alkenyl group, and a sum of the number of carbon atoms in each compound of the formulae (I)-(V) is from 6 to 31.