Abstract: A composition that includes: a first perfluoropolymer having a glass transition temperature of 10° C. or lower; and a second fluoropolymer that contains a tetrafluoroethylene-based constituent unit and a perfluoro (alkyl vinyl ether)-based constituent unit, and is different from the first perfluoropolymer, the content of the perfluoro (alkyl vinyl ether)-based constituent unit, with respect to the total content of all the constituent units of the first perfluoropolymer and the second fluoropolymer, being from 0.1 to 10.0 mol %.

Abstract: A composition that contains a first perfluoropolymer having a glass transition temperature of 10° C. or lower, and a second fluoropolymer that contains tetrafluoroethylene and a constitutional unit ascribed to a compound represented by Formula (1) below, and is different from the first perfluoropolymer, the content of a perfluoro (alkyl vinyl ether)-based constitutional unit, with respect to the total content of all the constitutional units of the first perfluoropolymer and the second fluoropolymer, is 0.05 to 5.0 mol %: CF2?CF—CF2—O—Rf . . . (1), in Formula (1), Rf represents a perfluoroalkyl group having 1 to 10 carbon atoms, and optionally having an etheric oxygen atom between carbon atoms in the perfluoroalkyl group.

Abstract: To provide a method for producing a fluorinated elastomer, by which a fluorinated polymer excellent in water dispersion stability can be efficiently produced without using an emulsifier, while an aqueous medium with a small environmental impact is used. A method for producing a fluorinated elastomer, which comprises, in an aqueous dispersion that contains substantially no water-soluble emulsifier, and contains a first fluorinated polymer having TFE units and PAVE units and an aqueous medium, polymerizing a monomer containing TFE and PAVE to produce a second fluorinated polymer, wherein in the first fluorinated polymer, a content of the PAVE units is 20 to 95 mol % to a total content of the TFE units and the PAVE units, in the second fluorinated polymer, a content of the PAVE units is 20 to 95 mol % to a total content of the TFE units and the PAVE units, and before start of the polymerization of the monomer, a content of the first fluorinated polymer is 0.01 to 4.

Abstract: To provide a composition containing a siloxane block-containing diol compound that is easy to manufacture industrially.

Abstract: Provided is: a thermoplastic resin having excellent properties for optical applications and the like, including, for example, properties such as refractive index and chromatic aberration; and a molded article and the like containing such a thermoplastic resin. As a means for solving the above problem, the present invention provides a thermoplastic resin comprising: a silane constituent unit (S) having a prescribed structure; an ester constituent unit (I) represented by formula (I); and a diol constituent unit (A).

Abstract: A method for producing a fluororesin composition comprising: a first fluororesin having a thermal history of having been heated to a melting point or higher; and a second fluororesin having no thermal history of having been heated to a melting point or higher, wherein the first fluororesin and the second fluororesin are non-melt-formable fluororesins, the method comprising washing a crushed product containing the first fluororesin, and mixing the crushed product after washing and the second fluororesin, wherein a thermogravimetric weight loss rate when the washed crushed product is heated from 30 to 280° C. at a rate of 10° C./min is 3% or less as calculated by formula I below: thermogravimetric ? weight ? loss ? rate = ( W B ? 1 - W A ? 1 ) / W B ? 1 × 100 , Formula ? I wherein WB1 is a mass of the crushed product at 30° C., and WA1 is A mass of the crushed product at 280° C.

Abstract: A molded body obtained by compression-molding and sintering a fluororesin composition comprising: a first fluororesin having a thermal history of having been heated to a melting point or higher; and a second fluororesin having no thermal history of having been heated to a melting point or higher, wherein the first fluororesin is a non-melt-formable fluororesin, the second fluororesin is a non-melt-formable fluororesin produced by emulsion polymerization, an amount of the first fluororesin with respect to a total mass of the first fluororesin and the second fluororesin is 40% by mass or more, and a gloss of the molded body at an incident angle of 60° is 15% or more.

Abstract: A fluororesin composition contains a first fluororesin having a thermal history of having been heated to a melting point or higher and a second fluororesin having no thermal history of having been heated to a melting point or higher, in which the first fluororesin and the second fluororesin are non-melt-formable fluororesins, and in a case where a test piece is obtained by compression-molding the fluororesin composition to obtain a preliminary molded body and sintering the preliminary molded body at 380° C. for 2 hours or longer to be formed into a micro-dumbbell shape having a thickness of 0.5 mm and a size of 16 mm×45 mm, a metal elution amount with respect to a total mass of the test piece when the test piece is left to stand in 3.6% by mass hydrochloric acid at 23° C. for 24 hours is 5 ng/g or less.

Abstract: The present invention addresses the problem of providing: a thermoplastic resin which has excellent properties, moldability and the like in optical applications; and a molded article containing such a thermoplastic resin. The solution of the problem may include a thermoplastic resin containing: a silane constituent unit (S) which is a constituent unit derived from at least one silane compound selected from among a predetermined dialkoxysilane compound, a diaryloxysilane compound, and a monoalkoxymonoaryloxysilane compound; a fluorene constituent unit (F) which is a constituent unit derived from a fluorene ring-containing dihydroxy compound; and a dinaphthalene constituent unit (N) which is a constituent unit derived from a dinaphthalene-containing dihydroxy compound.

Abstract: Provided are a thermoplastic resin excellent in terms of properties for optical uses, such as refractive index and chromatic aberration, and a molded article including such thermoplastic resin. This thermoplastic resin has: a silane constituent unit (S) which is a constituent unit represented by general formula (1) and is the —OSi(R1R2)O— moiety; and a diol constituent unit (A) derived from a dihydroxy compound and is represented by M. (In general formula (1), R1 and/or R2 represents an optionally substituted C10-C30 polycyclic aryl group.

Abstract: To provide a copolymer from which a molded product excellent in tensile strength after chemical resistance test, tensile strength after heat aging test and tensile elongation after heat aging test can be formed, a composition and a molded product. The copolymer of the present invention is a copolymer containing units based on tetrafluoroethylene, units based on ethylene, and one or both of units based on a compound represented by the formula (1) and units based on a compound represented by the formula (2), wherein the total content of the units based on tetrafluoroethylene and the units based on ethylene is 80.0 to 98.1 mol % to all units contained in the copolymer; the content of the units based on tetrafluoroethylene is 49.0 mol % or more and less than 56.0 mol % to the total content of the units based on tetrafluoroethylene and the units based on ethylene; the content of the units based on the compound represented by the formula (1) or the compound represented by the formula (2) is 1.

Abstract: To provide a method for producing a fluorinated polymer, by which the fluorinated polymer can be efficiently produced without using an emulsifier while using an aqueous medium with less environmental burden; an aqueous dispersion; and a solid composition. The method for producing a fluorinated polymer of the present invention is a method for producing a fluorinated polymer, which comprises polymerizing a monomer containing tetrafluoroethylene in an aqueous dispersion containing a first fluorinated polymer having a glass transition temperature of 10° C. or lower and an aqueous medium, to produce a second fluorinated polymer that is different from the first fluorinated polymer; wherein before start of the polymerization of the monomer, the content of the first fluorinated polymer is 0.01 to 4.

Abstract: To provide an aqueous dispersion which is excellent in storage stability and from which a coating film excellent in water resistance can be formed. The aqueous dispersion of the present invention is an aqueous dispersion containing a fluorinated polymer having TFE units and PAVE units, and an aqueous medium, wherein the proportion of the PAVE units is 20 to 60 mol % to the total amount of the TFE units and the PAVE units, the content of the fluorinated polymer is 0.1 to 40 mass % to the total mass of the aqueous dispersion, the average particle size of the fluorinated polymer is 1 to 150 nm, the concentration of fluoride ions and the concentration of sulfate ions are each 50 mass ppm or less to the total mass of the aqueous medium in the aqueous dispersion, and the concentration of a hydrocarbon-based emulsifier is 100 mass ppm or less to the total mass of the fluorinated polymer.

Abstract: To provide a method for producing a fluorinated polymer, by which a fluorinated polymer can be efficiently produced without requiring an emulsifier, while an aqueous medium with a small environmental impact is used. The method for producing a fluorinated polymer of the present invention is a method for producing a fluorinated polymer, which comprises polymerizing a monomer comprising a fluorinated monomer in an aqueous dispersion containing a first fluorinated polymer having TFE units and PAVE units, and an aqueous medium, to produce a second fluorinated polymer, wherein in the first fluorinated polymer, the units based on a perfluoro(alkyl vinyl ether) is 20 to 60 mol % to the total amount of the units based on tetrafluoroethylene and the units based on a perfluoro(alkyl vinyl ether), the average particle size of the first fluorinated polymer is 1 to 150 nm, and the content of the first fluorinated polymer before start of the polymerization of the monomer is 0.01 to 4.

Abstract: To provide a modified polytetrafluoroethylene with which a stretched porous body excellent in breaking strength can be produced, a molded product, and a method for producing a stretched porous body. The modified polytetrafluoroethylene of the present invention has units based on tetrafluoroethylene and units based on at least one monomer selected from a perfluoro(alkyl vinyl ether), hexafluoropropylene and a fluoroalkylethylene, wherein the thermal instability index is 0 to 15 and the area ratio S calculated by a predetermined method is 0.70 or less.

Abstract: To provide a method for producing a fluorinated copolymer, whereby it is possible to efficiently produce a fluorinated copolymer in which coloration and foaming are suppressed during heating. A method for producing a fluorinated copolymer, comprising a step of producing a fluorinated copolymer by polymerizing tetrafluoroethylene and other monomer other than the tetrafluoroethylene in the presence of a hydroperoxide, at least one selected from the group consisting of a sulfite, a hydrogen sulfite, a dithionite, and a metabisulfite, at least one selected from the group consisting of an acidic substance and a substance that generates an acid by hydrolysis, and an aqueous medium.

Abstract: To provide a copolymer capable of forming a coated electrical wire excellent in engine oil resistance, a composition, a molded product, and a coated electrical wire. The copolymer of the present invention is a copolymer comprising units based on ethylene, units based on tetrafluoroethylene, and units based on compound A represented by CH?CX(CF2)nY (wherein X and Y are each independently a hydrogen atom or a fluorine atom, and n is an integer of from 2 to 6) or compound B represented by CF2?CF—O—C3F7, wherein the crystal lamella thickness determined by the small angle X-ray scattering method is at most 4.0 nm and the melting point is at least 245° C.

Abstract: The present invention provides, for example, a method for efficiently producing a polysiloxane having a siloxane constituent unit while making it possible to improve safety and reduce environmental burden. The above-mentioned problem is solved by a method comprising a polymerization step of polymerizing a silane-based compound and a diol compound in the presence of a transesterification catalyst including at least a phosphorus compound, in which the silane-based compound is selected from a specific diaryloxysilane compound, a specific dialkoxysilane compound, and a specific silicon compound, and in the polymerization step, a polysiloxane having a siloxane constituent unit represented by any of formula (1-1) to formula (1-4) is produced. (In the formulas, R1-R10, R30-R33, Z1, Z2, J1, K1, A1, A2, L1, L2, and X are as described in the description of the present application.

Abstract: To provide a composition containing a siloxane block-containing diol compound that is easy to manufacture industrially.

Abstract: The problem of the present invention is to provide: a thermoplastic resin having excellent heat resistance and excellent flame retardancy and having a siloxane constituent unit, particularly a thermoplastic resin suitable for optical applications; a composition containing the thermoplastic resin; and others. The problem is solved by a thermoplastic resin containing a structural unit (A) represented by general formula (I).