Abstract: A method for producing particles of a fluorinated polymer (A) which has either one or both of structural units (u1) derived from tetrafluoroethylene and structural units (u2) having no sulfonic acid type functional group and having a cyclic structure and fluorine atoms, and which has structural units (u3) having a sulfonic acid type functional group, wherein the proportion of the structural units (u1) is from 0 to 82 mol % in all structural units in the fluorinated polymer (A), the method including: (i) preparing solution or dispersion of the fluorinated polymer (A) having the fluorinated polymer (A) dissolved or dispersed in a solvent (B); and (ii) mixing the solution or dispersion of the fluorinated polymer (A) and a solvent (C) to aggregate the fluorinated polymer (A) to form particles of the fluorinated polymer (A).

Abstract: To provide a polymerization initiator composition for a fluorinated polymer which will not destroy ozone layer and which has less influence over polymerization of a monomer for a fluorinated polymer, and a method for producing a fluorinated polymer by which a fluorinated polymer having a sufficient molecular weight can be obtained. An initiator composition for a fluorinated polymer, which comprises an organic peroxide, and a saturated hydrocarbon compound having at least one tertiary or quaternary carbon atom, and a method for producing a fluorinated polymer using the polymerization initiator composition, and a polymerization method comprising a step of recovering a polymerization solvent and a step of separating the saturated hydrocarbon compound from the recovered polymerization solvent.

Abstract: To provide a method capable of producing fluorinated polymer particles in which formation of fine particles or formation of large aggregates is sufficiently suppressed even in the case of a fluorinated polymer having high solubility in a solvent.

Abstract: To provide a method for recovering, from a liquid to be treated containing a fluorinated polymer and a fluorinated emulsifier, the fluorinated emulsifier easily and efficiently. A liquid to be treated containing a fluorinated polymer and a fluorinated emulsifier, and a strongly basic anion exchange resin having an ion exchange capacity of at most 1.0 eq/L and a water content of at least 60 mass %, are brought into contact with each other, so that the fluorinated emulsifier is adsorbed on the strongly basic anion exchange resin, whereby the fluorinated emulsifier is recovered from the liquid to be treated.

Abstract: To provide a method for recovering, from a liquid to be treated containing a fluorinated polymer and a fluorinated emulsifier, the fluorinated emulsifier easily and efficiently. A liquid to be treated containing a fluorinated polymer and a fluorinated emulsifier, and a strongly basic anion exchange resin having an ion exchange capacity of at most 1.0 eq/L and a water content of at least 60 mass %, are brought into contact with each other, so that the fluorinated emulsifier is adsorbed on the strongly basic anion exchange resin, whereby the fluorinated emulsifier is recovered from the liquid to be treated.

Abstract: Provided is a treatment method for fluororesin pellets to remove hydrofluoric acid released from fluororesin pellets obtained by melt-molding a melt-moldable fluororesin. The treatment method comprises bringing a hydrofluoric acid-removing medium selected from warm water of from 30 to 200° C., steam of from 100 to 200° C. and warm wind of from 40 to 200° C. into contact with fluororesin pellets obtained by melt-molding a melt-moldable fluororesin, and thereby treating the fluororesin pellets so that the amount of hydrofluoric acid released per kg of the resulting fluororesin pellets would be at most 5 ?g as determined after the storage of the resulting fluororesin pellets at 35° C. for 15 days.

Abstract: A mold release film, which is adapted to be disposed on the cavity surface of a mold to form a resin-encapsulated portion by encapsulating a semiconductor element of a semiconductor device with a curable encapsulation resin, has a tensile modulus of elasticity of from 10 to 24 MPa at 132° C. as measured in accordance with JIS K 7127, and a peak peel resistance of at most 0.8 N/25 mm.

Abstract: A mold release film, which is adapted to be disposed on the cavity surface of a mold to form a resin-encapsulated portion by encapsulating a semiconductor element of a semiconductor device with a curable encapsulation resin, has a tensile modulus of elasticity of from 10 to 24 MPa at 132° C. as measured in accordance with JIS K 7127, and a peak peel resistance of at most 0.8 N/25 mm.

Abstract: Provided is a treatment method for fluororesin pellets to remove hydrofluoric acid released from fluororesin pellets obtained by melt-molding a melt-moldable fluororesin. The treatment method comprises bringing a hydrofluoric acid-removing medium selected from warm water of from 30 to 200° C., steam of from 100 to 200° C. and warm wind of from 40 to 200° C. into contact with fluororesin pellets obtained by melt-molding a melt-moldable fluororesin, and thereby treating the fluororesin pellets so that the amount of hydrofluoric acid released per kg of the resulting fluororesin pellets would be at most 5 ?g as determined after the storage of the resulting fluororesin pellets at 35° C. for 15 days.