A method of preparing a superabsorbent polymer includes preparing a base resin in which an acrylic acid-based monomer having acidic groups which are at least partially neutralized and an internal crosslinking agent are crosslinked in the presence of a sodium polycarboxylate surfactant; and heating the base resin in the presence of a surface crosslinking agent to carry out surface modification of the base resin, wherein the internal crosslinking agent includes a first epoxy crosslinking agent having an epoxy equivalent weight of 100 g/eq or more to less than 130 g/eq, and a second epoxy crosslinking agent having an epoxy equivalent weight of 130 g/eq or more. The superabsorbent polymer provides improved rewetting property and liquid permeability.

A method of preparing a superabsorbent polymer includes preparing a base resin in which an acrylic acid-based monomer having acidic groups which are at least partially neutralized and an internal crosslinking agent are crosslinked in the presence of a sodium polycarboxylate surfactant; and heating the base resin in the presence of a surface crosslinking agent to carry out surface modification of the base resin, wherein the internal crosslinking agent includes a first epoxy crosslinking agent having an epoxy equivalent weight of 100 g/eq or more to less than 130 g/eq, and a second epoxy crosslinking agent having an epoxy equivalent weight of 130 g/eq or more. The superabsorbent polymer provides improved rewetting property and liquid permeability.

A method for treating an aqueous fluid resulting from a fluorine-containing polymer production step, the method comprising: separating the aqueous fluid into a solid component and a filtrate using a filter aid.

A method for treating an aqueous fluid resulting from a fluorine-containing polymer production step, the method comprising: separating the aqueous fluid into a solid component and a filtrate using a filter aid.

Fluoropolymers, specifically polyvinylidene fluoride (PVDF) polymers stabilized against color degradation due to high thermal exposure. The fluoropolymers are produced with free-radical initiators in the presence of surfactants containing acid end groups. The fluoropolymer resins are melt processed into final articles at high temperatures, above the melting point of the polymer. While the fluoropolymer is stable, residual acid surfactant causes discoloration during thermal processing. Stabilization is achieved by the addition of small amounts of ammonium or phosphonium cations to the fluoropolymer composition. It is believed the cations react with any residual acid to form a less reactive salt. These salts do not adversely affect the color of a melt processed product. The phosphonium or ammonium ions can be added to the fluoropolymer at any point from the polymerization step up to the thermal processing step. A preferred family of salts are quaternary alkyl ammonium halides.

A coextruded biaxially oriented composite film comprising a polyester substrate layer and disposed on one or both surfaces thereof a strippable sacrificial layer, wherein said strippable sacrificial layer comprises an ethylene-methacrylic acid (EMAA) copolymer.

A coextruded biaxially oriented composite film comprising a polyester substrate layer and disposed on one or both surfaces thereof a strippable sacrificial layer, wherein said strippable sacrificial layer comprises an ethylene-methacrylic acid (EMAA) copolymer.

The present invention provides polyacrylic acid (salt)-based water-absorbing resin powder having an excellent fluid retention capacity under pressure, an excellent water absorption speed, and an excellent liquid permeability and a method for producing the polyacrylic acid (salt)-based water-absorbing resin powder. The earlier-described objects are attained by: a method for producing water-absorbing resin powder which includes adding an inorganic compound to a crosslinked hydrogel polymer obtained in a polymerization step of polymerizing a polyacrylic acid (salt) and performing crushing in specific gel-crushing conditions; and the resultant water-absorbing resin powder.

The present invention provides polyacrylic acid (salt)-based water-absorbing resin powder having an excellent fluid retention capacity under pressure, an excellent water absorption speed, and an excellent liquid permeability and a method for producing the polyacrylic acid (salt)-based water-absorbing resin powder. The earlier-described objects are attained by: a method for producing water-absorbing resin powder which includes adding an inorganic compound to a crosslinked hydrogel polymer obtained in a polymerization step of polymerizing a polyacrylic acid (salt) and performing crushing in specific gel-crushing conditions; and the resultant water-absorbing resin powder.

Provided are a superabsorbent polymer and a preparation method thereof. According to the present invention, a superabsorbent polymer having high centrifuge retention capacity and absorption rate may be prepared by using a specific foam stabilizer.