Provided is a fluoroelastomer crosslinkable composition, containing a polyol-crosslinkable fluoroelastomer (a) and a cross-linking agent (b), wherein the cross-linking agent (b) is at least one selected from the group consisting of a compound represented by the general formula (b) set forth in the description and a salt of the compound with an alkali metal, an alkaline earth metal, or an onium compound.

A fluororesin material containing a fluororesin. The fluororesin has a carbonyl group, the total number of carbonyl groups is 1 or more and less than 800 per 10.sup.6 main-chain carbon atoms, and the fluororesin contains ethylene unit and tetrafluoroethylene unit. When the fluororesin material is heated at a rate of 10° C./minute, the initial pyrolysis temperature when the mass reduction of the fluororesin material reaches 1% by mass is 390° C. or more.

A fluororesin material containing a fluororesin. The fluororesin has a carbonyl group, the total number of carbonyl groups is 1 or more and less than 800 per 10.sup.6 main-chain carbon atoms, and the fluororesin contains ethylene unit and tetrafluoroethylene unit. When the fluororesin material is heated at a rate of 10° C./minute, the initial pyrolysis temperature when the mass reduction of the fluororesin material reaches 1% by mass is 390° C. or more.

Provided are a composite that can be suitably used as an electrolyte in polymer-based solid-state batteries, and various electrochemical devices using the composite. The composite includes a fluorine-containing elastomer and an alkali metal salt as essential components, wherein the fluorine-containing elastomer is an amorphous fluorine-containing elastomer having a glass transition temperature of 25° C. or less, and the composite has a volatile content of 0.1 mass % or less with respect to the entire composite.

Provided are a composite that can be suitably used as an electrolyte in polymer-based solid-state batteries, and various electrochemical devices using the composite. The composite includes a fluorine-containing elastomer and an alkali metal salt as essential components, wherein the fluorine-containing elastomer is an amorphous fluorine-containing elastomer having a glass transition temperature of 25° C. or less, and the composite has a volatile content of 0.1 mass % or less with respect to the entire composite.

A film containing a resin composition containing an aromatic polyetherketone resin (I) and a fluorine-containing copolymer (II). The fluorine-containing copolymer (II) defines a dispersed phase at an average dispersed particle size of 5 .Math.m or smaller. The aromatic polyetherketone resin (I) has a crystallinity of lower than 6%.

A film containing a resin composition containing an aromatic polyetherketone resin (I) and a fluorine-containing copolymer (II). The fluorine-containing copolymer (II) defines a dispersed phase at an average dispersed particle size of 5 .Math.m or smaller. The aromatic polyetherketone resin (I) has a crystallinity of lower than 6%.

A method for producing an aqueous dispersion of a fluorine-containing elastomer, which includes polymerizing a fluorine-containing monomer in the presence of a fluorine-free compound (1) represented by general formula (1): CR.sup.1X.sup.1═CX.sup.2—R.sup.2—COOM and an aqueous medium, to produce an aqueous dispersion of the fluorine-containing elastomer containing —CH.sub.2— in a main chain. Also disclosed is an aqueous dispersion of the fluorine-containing elastomer and a composition containing the fluorine-containing elastomer.

A method for producing an aqueous dispersion of a fluorine-containing elastomer, which includes polymerizing a fluorine-containing monomer in the presence of a fluorine-free compound (1) represented by general formula (1): CR.sup.1X.sup.1═CX.sup.2—R.sup.2—COOM and an aqueous medium, to produce an aqueous dispersion of the fluorine-containing elastomer containing —CH.sub.2— in a main chain. Also disclosed is an aqueous dispersion of the fluorine-containing elastomer and a composition containing the fluorine-containing elastomer.

Provided is a method for producing an aqueous dispersion of a fluorine-containing elastomer, comprising polymerizing a fluorine-containing monomer in the presence of a compound (1) having a triple bond and a hydrophilic group and an aqueous medium to produce an aqueous dispersion of a fluorine-containing elastomer.