The vinylidene-fluoride-based polymer composition according to the present invention comprises a vinylidene-fluoride-based polymer and a specific surfactant and contains no fluorinated surfactant, wherein the specific surfactant is contained in an amount of 10 ppm or larger but less than 100 ppm in terms of mass ppm of the solid components of the composition and has an HLB value of 10 or greater. The method for producing a vinylidene-fluoride-based polymer according to the present invention comprises emulsion-polymerizing specific monomers in an aqueous medium in the presence of a specific emulsifier and an initiator without using any fluorinated surfactant, the use amount of the emulsifier being 8.5 ppm or larger but less than 100 ppm in terms of mass ppm of the monomers.

An inorganic solid electrolyte-containing composition contains an inorganic solid electrolyte having an ion conductivity of a metal belonging to Group 1 or Group 2 in the periodic table, a polymer binder, and a dispersion medium, where the polymer binder includes a polymer binder of which an adsorption rate with respect to the inorganic solid electrolyte in the dispersion medium is less than 60%.

An inorganic solid electrolyte-containing composition contains an inorganic solid electrolyte having an ion conductivity of a metal belonging to Group 1 or Group 2 in the periodic table, a polymer binder, and a dispersion medium, where the polymer binder includes a polymer binder of which an adsorption rate with respect to the inorganic solid electrolyte in the dispersion medium is less than 60%.

A fluorine-containing polymer for a metal-clad laminated sheet, containing: a polymerized unit based on a fluorine-containing vinyl monomer; and a polymerized unit based on a vinyl ester monomer other than the fluorine-containing vinyl monomer. The fluorine-containing polymer contains not more than 1 mol % in total of a polymerized unit based on a monomer containing a hydroxy group and a polymerized unit based on a monomer containing a carboxy group, of all polymerized units. Also disclosed is a composition containing the fluorine-containing polymer, a curable composition containing the fluorine-containing polymer and an epoxy resin, a metal-clad laminated sheet including a metal foil and a resin layer provided on the metal foil and being formed of the curable composition, and a printed substrate including a patterned circuit formed by etching the metal foil of the metal-clad laminated sheet.

A fluorine-containing polymer for a metal-clad laminated sheet, containing: a polymerized unit based on a fluorine-containing vinyl monomer; and a polymerized unit based on a vinyl ester monomer other than the fluorine-containing vinyl monomer. The fluorine-containing polymer contains not more than 1 mol % in total of a polymerized unit based on a monomer containing a hydroxy group and a polymerized unit based on a monomer containing a carboxy group, of all polymerized units. Also disclosed is a composition containing the fluorine-containing polymer, a curable composition containing the fluorine-containing polymer and an epoxy resin, a metal-clad laminated sheet including a metal foil and a resin layer provided on the metal foil and being formed of the curable composition, and a printed substrate including a patterned circuit formed by etching the metal foil of the metal-clad laminated sheet.

A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a fluorine-containing diacyl peroxide represented by the formula (1): XRf.sup.aC(═O)OOC(═O)Rf.sup.bY (wherein X and Y are each independently H or F; and Rf.sup.a and Rf.sup.b are each independently a C1-C6 linear or branched perfluoroalkylene group optionally containing an ether bond) and a fluorine-containing carboxylic acid represented by the following formula (2): Z.sup.2Rf.sup.cCOOH (wherein Z.sup.2 is H or F; and Rf.sup.c is a C1-C3 linear or branched perfluoroalkylene group optionally containing an ether bond when Z.sup.2 is H, and Rf.sup.c is a C1 or C2 linear or branched perfluoroalkylene group optionally containing an ether bond when Z.sup.2 is F) to provide a fluoropolymer.

A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a fluorine-containing diacyl peroxide represented by the formula (1): XRf.sup.aC(═O)OOC(═O)Rf.sup.bY (wherein X and Y are each independently H or F; and Rf.sup.a and Rf.sup.b are each independently a C1-C6 linear or branched perfluoroalkylene group optionally containing an ether bond) and a fluorine-containing carboxylic acid represented by the following formula (2): Z.sup.2Rf.sup.cCOOH (wherein Z.sup.2 is H or F; and Rf.sup.c is a C1-C3 linear or branched perfluoroalkylene group optionally containing an ether bond when Z.sup.2 is H, and Rf.sup.c is a C1 or C2 linear or branched perfluoroalkylene group optionally containing an ether bond when Z.sup.2 is F) to provide a fluoropolymer.

A water/oil repellent composition which can provide an article with high and durable water repellency is provided. A water/oil repellent composition comprising units based on a fluoroolefin represented by the formula (1): CH.sub.2═CH—R.sup.f (wherein R.sup.f is a C.sub.1-8 perfluoroalkyl group), units based on a vinyl carboxylate (b1) having a C.sub.12 or higher alkyl group and units based on a vinyl carboxylate (b2) having a C.sub.1-6 alkyl group, wherein the ratio of units based on the fluoroolefin is from 20 to 35 mol %, the ratio of units based on the vinyl carboxylate (b1) is from 30 to 70 mol %, and the ratio of units based on the vinyl carboxylate (b2) is from 5 to 50 mol %, relative to all the units in the fluorinated polymer.

A water/oil repellent composition which can provide an article with high and durable water repellency is provided. A water/oil repellent composition comprising units based on a fluoroolefin represented by the formula (1): CH.sub.2═CH—R.sup.f (wherein R.sup.f is a C.sub.1-8 perfluoroalkyl group), units based on a vinyl carboxylate having a C.sub.12 or higher alkyl group, and units based on a haloolefin other than the fluoroolefin or a derivative thereof, wherein the ratio of units based on the fluoroolefin is from 15 to 35 mol %, the ratio of units based on the vinyl carboxylate is from 30 to 60 mol %, and the ratio of units based on the haloolefin or derivative thereof is from 5 to 55 mol %, relative to all the units constituting the fluorinated polymer:

Described herein is method of making branched perfluorinated compounds, specifically (CF.sub.3).sub.2CFCF(CF.sub.3)OCF(CF.sub.3)C(═O)F and (CF.sub.3).sub.2CFCF(CF.sub.3)OCF═CF.sub.2. Also disclosed herein is a fluoropolymer derived from the branched perfluorovinyl ether monomer and methods of making the fluoropolymer.