A fluorinated polymer suitable for deposition and capable of favorable metal patterning, is provided. A resin film containing such a fluorinated polymer as a material is provided. Further, a photoelectronic element having such a resin film in its structure is provided.

A fluorinated polymer which satisfies the following requirements (1) to (3): (1) the melting point is less than 200° C., or no melting point is observed, (2) the thermogravimetric loss rate when the temperature is increased at a temperature-increasing rate of 2° C./min under a pressure of 1×10.sup.−3 Pa, substantially reaches 100% at 400° C. or lower, (3) when the temperature is increased at a temperature-increasing rate of 2° C./min under a pressure of 1×10.sup.−3 Pa, the temperature width from a temperature at which the thermogravimetric loss rate is 10% to a temperature at which it is 90%, is within 200° C.

A fluorinated polymer suitable for deposition and capable of favorable metal patterning, is provided. A resin film containing such a fluorinated polymer as a material is provided. Further, a photoelectronic element having such a resin film in its structure is provided.

A fluorinated polymer which satisfies the following requirements (1) to (3): (1) the melting point is less than 200° C., or no melting point is observed, (2) the thermogravimetric loss rate when the temperature is increased at a temperature-increasing rate of 2° C./min under a pressure of 1×10.sup.−3 Pa, substantially reaches 100% at 400° C. or lower, (3) when the temperature is increased at a temperature-increasing rate of 2° C./min under a pressure of 1×10.sup.−3 Pa, the temperature width from a temperature at which the thermogravimetric loss rate is 10% to a temperature at which it is 90%, is within 200° C.

To provide a liquid composition with which a catalyst layer and a polymer electrolyte membrane will hardly be broken at the time of their formation and a method for producing the liquid composition; and a method for producing a membrane/electrode assembly by which a catalyst layer and a polymer electrolyte membrane will hardly be broken at the time of their formation. A liquid composition comprising a polymer having ion exchange groups, water and an organic solvent, wherein the average secondary particle size of the polymer having ion exchange groups is from 100 to 3,000 nm, and the primary particle size parameter represented by the product of the average primary particle size (nm) and the ion exchange capacity (meq/g dry resin) of the polymer having ion exchange groups, is from 12 to 20.

To provide a liquid composition with which a catalyst layer and a polymer electrolyte membrane will hardly be broken at the time of their formation and a method for producing the liquid composition; and a method for producing a membrane/electrode assembly by which a catalyst layer and a polymer electrolyte membrane will hardly be broken at the time of their formation. A liquid composition comprising a polymer having ion exchange groups, water and an organic solvent, wherein the average secondary particle size of the polymer having ion exchange groups is from 100 to 3,000 nm, and the primary particle size parameter represented by the product of the average primary particle size (nm) and the ion exchange capacity (meq/g dry resin) of the polymer having ion exchange groups, is from 12 to 20.

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.

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.

Fluorinated photoinitiators and polymerizable compositions including such fluorinated photoinitiators and at least one free-radically polymerizable monomer, oligomer, or mixture thereof. Multilayer films including a substrate and at least a first layer overlaying a surface of the substrate also are described, in which the at least first layer includes a (co)polymer obtained by polymerizing the foregoing polymerizable compositions. Processes for making a multilayer film using the polymerizable composition also are taught. Articles including the multilayer film also are disclosed, in which the article preferably is selected from a photovoltaic device, a display evice, a solid-state lighting device, a sensor, a medical or biological diagnostic device, an electrochromic device, light control device, or a combination thereof.

Fluorinated photoinitiators and polymerizable compositions including such fluorinated photoinitiators and at least one free-radically polymerizable monomer, oligomer, or mixture thereof. Multilayer films including a substrate and at least a first layer overlaying a surface of the substrate also are described, in which the at least first layer includes a (co)polymer obtained by polymerizing the foregoing polymerizable compositions. Processes for making a multilayer film using the polymerizable composition also are taught. Articles including the multilayer film also are disclosed, in which the article preferably is selected from a photovoltaic device, a display evice, a solid-state lighting device, a sensor, a medical or biological diagnostic device, an electrochromic device, light control device, or a combination thereof.

A method for producing a fluorosulfonyl group-containing compound to obtain a compound represented by the following formula 5 from a compound represented by the following formula 1 as a starting material and a method for producing a fluorosulfonyl group-containing monomer in which the fluorosulfonyl group-containing compound is used: ##STR00001##
wherein R.sup.1 and R.sup.2 are a C.sub.1-3 alkylene group, and R.sup.F1 and R.sup.F2 are a C.sub.1-3 perfluoroalkylene group.

The present invention is a low dielectric resin substrate, which is a composite including an annealed quartz glass cloth and an organic resin, where the annealed quartz glass cloth has a dielectric loss tangent of less than 0.0010 at 10 GHz, and tensile strength of 1.0 N/25 mm or more per cloth weight (g/m.sup.2). This provides a resin substrate that includes a quartz glass cloth which has a low dielectric loss tangent and which is also excellent in tensile strength.