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.

To provide a fluorinated elastic copolymer composition such that solubility of a fluorinated elastic copolymer in a solvent is excellent, the solvent is easily removed, and the solvent is easily available. A fluorinated elastic copolymer composition comprising a fluorinated elastic copolymer having units based tetrafluoroethylene and units based on CF.sub.2=CFOR.sup.f1 (wherein R.sup.f1 is a C.sub.1-10 perfluoroalkyl group), and a fluorinated solvent having a perfluorohydrocarbon group, wherein the perfluorohydrocarbon group having the largest number of carbon atoms in the fluorinated solvent has from 3 to 7 carbon atoms, the fluorinated solvent has a boiling point of from 50 to 160° C., and the fluorinated solvent has a fluorine atom content (fluorine atom content (mass %)=(19× number of fluorine atoms in the fluorinated solvent/molecular weight of the fluorinated solvent)×100) of from 69 to 80 mass %.

The present disclosure provides a hydrophobic low-dielectric-constant film and a preparation method therefor. The low-dielectric-constant film is formed from one or more fluorine-containing compounds A by means of a plasma enhanced chemical vapor deposition method, and the one or more fluorine-containing compounds comprise a compound having the general formula C.sub.xSi.sub.yO.sub.mH.sub.nF.sub.2x+2y−n+2 or C.sub.xSi.sub.yO.sub.mH.sub.nF.sub.2x+2y−n, x being an integer from 1 to 20, y being an integer from 0 to 8, m being an integer from 0 to 6, and n being 0, 3, 6, 7, 9, 10, 12, 13, 15, 16, 17 and 19. Thus, a nano-film having a low dielectric constant and good hydrophobicity is formed on the surface of a substrate.

The present disclosure provides a hydrophobic low-dielectric-constant film and a preparation method therefor. The low-dielectric-constant film is formed from one or more fluorine-containing compounds A by means of a plasma enhanced chemical vapor deposition method, and the one or more fluorine-containing compounds comprise a compound having the general formula C.sub.xSi.sub.yO.sub.mH.sub.nF.sub.2x+2y−n+2 or C.sub.xSi.sub.yO.sub.mH.sub.nF.sub.2x+2y−n, x being an integer from 1 to 20, y being an integer from 0 to 8, m being an integer from 0 to 6, and n being 0, 3, 6, 7, 9, 10, 12, 13, 15, 16, 17 and 19. Thus, a nano-film having a low dielectric constant and good hydrophobicity is formed on the surface of a substrate.

A resin composition for a circuit board, containing a melt-fabricable fluororesin and a particulate boron nitride. The particulate boron nitride has a ratio (b)/(a) of 1.0 or higher, wherein (a) represents a proportion of particles having a particle size of 14.6 to 20.6 μm and (b) represents a proportion of particles having a particle size of 24.6 to 29.4 μm. Also disclosed is a molded article for a circuit board obtained from the resin composition, a laminate for a circuit board including a metal layer (A1) and a layer (B) obtained from the resin composition, and a circuit board including a metal layer (A2) and a layer (B) obtained from the resin composition.

To provide a liquid composition whereby a resin powder can be uniformly dispersed in a resin or the like without being scattered, and a method for producing a film, a laminate or the like by using the liquid composition. The liquid composition comprises a liquid medium and a resin powder dispersed in the liquid medium, and characterized in that the average particle size of the resin powder is from 0.3 to 6 μm, the volume-based cumulative 90% diameter of the resin powder is at most 8 μm, and the resin powder is a resin containing a fluorinated copolymer having a specific functional group. And, the method is a method for producing a film, a laminate or the like by using the liquid composition.

To provide a method for producing modified polytetrafluoroethylene, in which formation of a fluorinated oligomer as a by-product is little. A method for producing modified polytetrafluoroethylene which contains substantially no C.sub.6-34 fluorinated oligomer containing hydrophilic functional groups and which contains substantially no fluorinated surfactant, the method comprising conducting copolymerization of tetrafluoroethylene and a monomer having a polar group, in a liquid dispersion 1 comprising a polymer containing units derived from a non-fluorinated monomer and an aqueous medium, or in a solution 2 obtainable by mixing at least one member selected from the group consisting of a polyalkylene oxide compound and a hydrocarbon-containing surfactant, with an oxidizing agent, in an aqueous medium, under such a condition that the amount of the monomer having a polar group to be used, is at most 0.150 mass % to the whole amount of tetrafluoroethylene, to obtain modified polytetrafluoroethylene.

To provide a method for producing modified polytetrafluoroethylene, in which formation of a fluorinated oligomer as a by-product is little. A method for producing modified polytetrafluoroethylene which contains substantially no C.sub.6-34 fluorinated oligomer containing hydrophilic functional groups and which contains substantially no fluorinated surfactant, the method comprising conducting copolymerization of tetrafluoroethylene and a monomer having a polar group, in a liquid dispersion 1 comprising a polymer containing units derived from a non-fluorinated monomer and an aqueous medium, or in a solution 2 obtainable by mixing at least one member selected from the group consisting of a polyalkylene oxide compound and a hydrocarbon-containing surfactant, with an oxidizing agent, in an aqueous medium, under such a condition that the amount of the monomer having a polar group to be used, is at most 0.150 mass % to the whole amount of tetrafluoroethylene, to obtain modified polytetrafluoroethylene.

A molded article containing a crystal of a fluoropolymer. The fluoropolymer contains at least one selected from vinylidene fluoride/tetrafluoroethylene copolymer, polychlorotrifluoroethylene, an ethylene/tetrafluoroethylene copolymer, a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer and a tetrafluoroethylene/hexafluoropropylene copolymer. Further, the crystal is a nano-oriented crystal having a size of 300 nm or smaller.