An object of the present invention is to improve the piezoelectricity of a PVT having the VDF ratio of 82 to 90% represented by a copolymer, in which copolymerization of vinylidene fluoride VDF and trifluoroethylene TrFe is 85 versus 15 (this is written as PVT85/15, and which is excellent in resistance to deformation, and heat resistance, etc. And therefore, it is also to obtain a piezoelectric film having piezoelectricity exceeding a PVT of less than 82 mol % of VDF represented by a PVT75/25, which conventionally shows the highest piezoelectricity, and a method of producing the same. A piezoelectric film is made of a mixture of two kinds (for example, a first copolymer is PVT85/15 and a second copolymer is PVT75/25) having different polymerization ratios of vinylidene fluoride VDF and trifluoroethylene TrFE.

Co-cured blends of fluoroelastomers of tetrafluoroethylene-propylene copolymer with cure site monomer and terpolymers of Vinylidene fluoride (VDF), Hexafluoropropylene (HFP) and Tetrafluoroethylene (TFE) with peroxide as initiator and coagent TAIC as crosslinker show improved curing performance, improved mechanical properties and improved compression set as well. The co-cured fluoroelastomers show improved chemical resistance to the solvent aging systems and better retention of mechanical properties after aging at high temperature in the solvents system.

Co-cured blends of fluoroelastomers of tetrafluoroethylene-propylene copolymer with cure site monomer and terpolymers of Vinylidene fluoride (VDF), Hexafluoropropylene (HFP) and Tetrafluoroethylene (TFE) with peroxide as initiator and coagent TAIC as crosslinker show improved curing performance, improved mechanical properties and improved compression set as well. The co-cured fluoroelastomers show improved chemical resistance to the solvent aging systems and better retention of mechanical properties after aging at high temperature in the solvents system.

An object is to provide a fluorine-containing copolymer composition that exhibits long-term stability as well as a fluororesin paint or varnish prepared using the composition.

Provided are: a composition comprising a fluorine-containing copolymer synthesized through copolymerization of 0.001 to 50 mol % of particular ethylenically unsaturated organosilicon compound polymerization units relative to 5 to 85 mol % of fluoroolefin polymerization units by a solution polymerization method, a solvent, and an amine compound; a fluororesin paint or varnish prepared using the composition; and a method of producing the fluorine-containing copolymer composition.

An object is to provide a fluorine-containing copolymer composition that exhibits long-term stability as well as a fluororesin paint or varnish prepared using the composition.

Provided are: a composition comprising a fluorine-containing copolymer synthesized through copolymerization of 0.001 to 50 mol % of particular ethylenically unsaturated organosilicon compound polymerization units relative to 5 to 85 mol % of fluoroolefin polymerization units by a solution polymerization method, a solvent, and an amine compound; a fluororesin paint or varnish prepared using the composition; and a method of producing the fluorine-containing copolymer composition.

An object is to provide a fluorine-containing copolymer composition that exhibits long-term stability as well as a fluororesin paint or varnish prepared using the composition.

Provided are: a composition comprising a fluorine-containing copolymer synthesized through copolymerization of 0.001 to 50 mol % of particular ethylenically unsaturated organosilicon compound polymerization units relative to 5 to 85 mol % of fluoroolefin polymerization units by a solution polymerization method, a solvent, and an amine compound; a fluororesin paint or varnish prepared using the composition; and a method of producing the fluorine-containing copolymer composition.

The invention relates to fluoropolymers that have been modified with low molecular weight, polymeric chain transfer agents, and uses of the modified fluoropolymers. The modified fluoropolymers provide enhanced properties to the fluoropolymer, such as increased adhesion, and hydrophilic characteristics. The modified functional fluoropolymers are useful in many applications, including as binders in electrode-forming compositions and separator compositions, for hydrophilic membranes and hollow fiber membranes, as an aqueous and a solvent cast coating for baked decorative and protective coatings, and as a tie layer between a fluoropolymer layer and an incompatible polymer layer.

The present invention pertains to a non-linear, copolymer comprising recurring units derived from vinylidene fluoride (VDF) monomer, at least one functional comonomer and optionally at least one fluorinated ethylenic comonomer. The non-linear fluorinated copolymer comprises from 0.01 to 3.0% by moles of recurring units derived from functional comonomer. The non-linear fluorinated copolymer can be used as electrode binder in batteries.

The invention relates to an extrusion-assisting agent containing low-viscosity thermoplastic fluorinated polymers and preferably not containing a synergist. The invention also relates to the use of the extrusion agent for extrusion in the form of monofilament or multifilament fibres or non-woven materials, and to the extrusion method.

The invention relates to a method of polymerizing at least one monomer comprising a vinylidene fluoride monomer, the method comprising putting in contact the at least one monomer with a polymerization initiator -and an oxidizing agent, the polymerization initiator having the formula (I):

##STR00001##

wherein R.sub.f is a fluoroalkyl group comprising from 1 to 3 carbon atoms; and M.sup.x+ is chosen from a monovalent cation, or a divalent cation, or a trivalent cation, or a tetravalent cation.