A fluororesin having a tensile strength retention ratio of 50% or more, the tensile strength retention ratio being calculated by the following formula from the tensile strength of the fluororesin after a heat treatment obtained by conducting a heat treatment at 130° C. for 40,000 hours, and the tensile strength of the fluororesin before the heat treatment. Tensile strength retention ratio (%)=(tensile strength of fluororesin after heat treatment (MPa))/(tensile strength of fluororesin before heat treatment (MPa))×100.

A partially-fluorinated resin having a storage elastic modulus G′ of 0.1 Pa or more at a measurement temperature of 230° C. and an angular frequency of 0.0025 rad/second in dynamic viscoelasticity measurement. Also disclosed is a laminate including a partially-fluorinated resin layer containing the partially-fluorinated resin and a non-fluororesin layer containing a non-fluororesin.

A partially-fluorinated resin having a storage elastic modulus G′ of 0.1 Pa or more at a measurement temperature of 230° C. and an angular frequency of 0.0025 rad/second in dynamic viscoelasticity measurement. Also disclosed is a laminate including a partially-fluorinated resin layer containing the partially-fluorinated resin and a non-fluororesin layer containing a non-fluororesin.

A fluororesin having a reactive functional group, wherein the difference between the loss elastic modulus at 270° C. of the fluororesin (G″.sub.270) and the loss elastic modulus at 280° C. of the fluororesin (G″.sub.280) (G″.sub.270-G″.sub.280) is 2,500 Pa or more. Also disclosed is a fluororesin layer containing the fluororesin; and a non-fluororesin layer containing a non-fluororesin.

A fluororesin having a reactive functional group, wherein the difference between the loss elastic modulus at 270° C. of the fluororesin (G″.sub.270) and the loss elastic modulus at 280° C. of the fluororesin (G″.sub.280) (G″.sub.270-G″.sub.280) is 2,500 Pa or more. Also disclosed is a fluororesin layer containing the fluororesin; and a non-fluororesin layer containing a non-fluororesin.

The present invention provides 1,3,3,3-tetrafluoropropene (HFO-1234ze) copolymers comprising 1,3,3,3-tetrafluoropropene and one or more comonomers selected from the group consisting of vinyl fluoride (VF), vinylidene fluoride (VF.sub.2), tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), and perfluoro(alkyl vinyl ether) (PAVE), wherein said alkyl contains 1 to 5 carbon atoms, the copolymers being a fluoroplastic or a fluoroelastomer, depending upon monomer content.

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.

The invention relates to aqueous dispersions of fluoropolymers comprising recurring units derived from vinylidene fluoride (VDF) in an amount of from 60% to 82% in moles and recurring units derived from trifluoroethylene (TrFE) in an amount of from 18% to 40% in moles, with respect to the total moles of recurring units, said fluoropolymers possessing an improved thermodynamic ordered structure in the ferroelectric phase.

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 fluorine-containing compound (1) represented by general formula (1) and an aqueous medium to produce an aqueous dispersion of a fluorine-containing elastomer:

CX.sup.1X.sup.2═CX.sup.3—Z  General formula (1):

wherein X.sup.1 to X.sup.3 are each independently H, F, or a fluorine-containing alkyl group; when X.sup.1 and X.sup.2 are both H, X.sup.3 is F or a fluorine-containing alkyl group; Z is a group represented by —COOM, —SO.sub.3M, —OSO.sub.3M, —PO(OM).sub.2, —OPO(OM).sub.2, —BO(OM).sub.2, or —OBO(OM).sub.2; M is H, a metal atom, NR.sup.1.sub.4, optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium; and R.sup.1 is independently H or an organic group, and any two R.sup.1 are optionally bonded to each other to form a ring.