A coating composition which contains a fluorinated polymer having a unit (1) represented by [CX.sup.1X.sup.2CY.sup.1(Rf.sup.1COOM.sup.1)] and a fluorinated compound represented by CX.sup.3X.sup.4CY.sup.2(Rf.sup.2COOM.sup.2), wherein the content of the fluorinated compound is from 0.1 to 8.0 parts by mass per 100 parts by mass of the fluorinated polymer. X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are H, F or Cl, Y.sup.1 and Y.sup.2 are H, F, Cl, a methyl group or a trifluoromethyl group, Rf.sup.1 and Rf.sup.2 are a perfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, or an oxyperfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, COOM.sup.1 is COOH or COOZ.sup.1, and COOM.sup.2 is COOH or COOZ.sup.2 (wherein Z.sup.1 and Z.sup.2 are an ammonium ion in which the hydrogen atom may be substituted). The coating composition is suitable for forming a thin antireflection coating layer without increasing its refractive index.

A coating composition which contains a fluorinated polymer having a unit (1) represented by [CX.sup.1X.sup.2CY.sup.1(Rf.sup.1COOM.sup.1)] and a fluorinated compound represented by CX.sup.3X.sup.4CY.sup.2(Rf.sup.2COOM.sup.2), wherein the content of the fluorinated compound is from 0.1 to 8.0 parts by mass per 100 parts by mass of the fluorinated polymer. X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are H, F or Cl, Y.sup.1 and Y.sup.2 are H, F, Cl, a methyl group or a trifluoromethyl group, Rf.sup.1 and Rf.sup.2 are a perfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, or an oxyperfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, COOM.sup.1 is COOH or COOZ.sup.1, and COOM.sup.2 is COOH or COOZ.sup.2 (wherein Z.sup.1 and Z.sup.2 are an ammonium ion in which the hydrogen atom may be substituted). The coating composition is suitable for forming a thin antireflection coating layer without increasing its refractive index.

Composite membranes comprised of at least two layers, one of the layers being a silver ionomer and a second layer which is a fluorinated polymer with certain permeability properties, are especially useful for the separation of alkanes from alkenes, Particularly useful is a three-layer composite membrane in which a porous layer is laminated to the second layer.

Composite membranes comprised of at least two layers, one of the layers being a silver ionomer and a second layer which is a fluorinated polymer with certain permeability properties, are especially useful for the separation of alkanes from alkenes, Particularly useful is a three-layer composite membrane in which a porous layer is laminated to the second layer.

A coating composition has 5-15% by weight of a polymeric binder selected from a polyester polyol, an acrylic polyol, an epoxy, silicone, a silicone hybrid and a fluoropolymer. The composition has 20-40% by weight of microparticles, where the microparticles are made of a polyamide, a polyethylene, a polypropylene, a polyurea, a polyurethane, a polymethyl methacrylate, a polystyrene or mixtures thereof and the microparticles have a mean particle diameter d.sub.50 size ranging from 5 ?m to 60 ?m. The composition has 2-12% by weight of nanoparticles, said nanoparticles are made of inorganic oxides with a primary particle size ranging from 5 nm to 50 nm; 0-15% by weight of a crosslinker having reactivity to the polymeric binder; 0-20% by weight of pigments and/or fillers, and 40-80% by weight of an organic solvent.

A coating composition has 5-15% by weight of a polymeric binder selected from a polyester polyol, an acrylic polyol, an epoxy, silicone, a silicone hybrid and a fluoropolymer. The composition has 20-40% by weight of microparticles, where the microparticles are made of a polyamide, a polyethylene, a polypropylene, a polyurea, a polyurethane, a polymethyl methacrylate, a polystyrene or mixtures thereof and the microparticles have a mean particle diameter d.sub.50 size ranging from 5 ?m to 60 ?m. The composition has 2-12% by weight of nanoparticles, said nanoparticles are made of inorganic oxides with a primary particle size ranging from 5 nm to 50 nm; 0-15% by weight of a crosslinker having reactivity to the polymeric binder; 0-20% by weight of pigments and/or fillers, and 40-80% by weight of an organic solvent.

A composition of matter includes a mixture of styrene derivative monomers and methacrylate and/or acrylate derivative monomers, which have one or more urethane, carbamate, amide, and/or amine functional groups, and initiators, and the compositions are used to achieve composition control of the forming polymer, with the mole fraction of acrylate/methacrylate and styrene moieties in the forming polymer determined by the chemistry and composition of the feeding monomers.

A composition of matter includes a mixture of styrene derivative monomers and methacrylate and/or acrylate derivative monomers, which have one or more urethane, carbamate, amide, and/or amine functional groups, and initiators, and the compositions are used to achieve composition control of the forming polymer, with the mole fraction of acrylate/methacrylate and styrene moieties in the forming polymer determined by the chemistry and composition of the feeding monomers.

An electronic telecommunication article is described comprising a layer of fluoropolymer composition comprising an uncrosslinked fluoropolymer comprising at least 80, 85, or 90% by weight of polymerized units perfluorinated monomers including one or more unsaturated perfluorinated alkyl ethers. In typical embodiments, the uncrosslinked fluoropolymer comprises at least 10, 20, or 30 wt. % of one or more unsaturated perfluorinated alkyl ethers. The uncrosslinked fluoropolymer may be characterized as amorphous. The uncrosslinked fluoropolymer is soluble in fluorinated solvent. Also described are coated (e.g. copper) substrates, methods, and compositions.

An electronic telecommunication article is described comprising a layer of fluoropolymer composition comprising an uncrosslinked fluoropolymer comprising at least 80, 85, or 90% by weight of polymerized units perfluorinated monomers including one or more unsaturated perfluorinated alkyl ethers. In typical embodiments, the uncrosslinked fluoropolymer comprises at least 10, 20, or 30 wt. % of one or more unsaturated perfluorinated alkyl ethers. The uncrosslinked fluoropolymer may be characterized as amorphous. The uncrosslinked fluoropolymer is soluble in fluorinated solvent. Also described are coated (e.g. copper) substrates, methods, and compositions.