A binder includes a cross-linked product of at least a first polymer, a second polymer, and a third polymer, wherein the cross-linked product is cross-linked by at least two ester bonds; the first polymer includes polyimide, polyamic acid, a copolymer thereof, or a combination thereof, wherein the first polymer includes a structural unit including an alkali metal and a structural unit including at least one hydroxyl functional group; the second polymer includes poly(acrylic acid), poly(methacrylic acid), a copolymer thereof, or a combination thereof; and the third polymer includes polyvinyl alcohol, polyacrylamide, polymethacrylamide, a copolymer thereof, or a combination thereof.

Disclosed is water-absorbent resin particles, in which a value of non-pressurization DW after 3 minutes is 14 ml/g or more, and a value of liquid suction power after 3 minutes measured by the following method is 11 ml/g or more. A liquid suction power measurement method: 0.3 g of the water-absorbent resin particles is uniformly dispersed in a cylindrical container having a mesh-like bottom and having an inner diameter of 26 mm; the cylindrical container is placed in a container containing 40 g of a physiological saline solution, the water-absorbent resin particles are caused to absorb the physiological saline solution for 30 minutes from the bottom of the cylindrical container, and thereby a swollen gel is obtained; and non-pressurization DW, which is measured in a state where another 0.3 g of the water-absorbent resin particles is uniformly dispersed on the swollen gel in the cylindrical container, is defined as liquid suction power.

The present invention is a method for producing a water absorbent resin which method is a method for producing surface cross-linked water absorbent resin particles, the method including the successive steps of: (a) adding a surface cross-linking agent and water to a particulate water absorbent resin in a mixer; and (b) reacting the resulting water absorbent resin mixture taken out from the mixer with the surface cross-linking agent in a reactor by heating or active energy ray irradiation, water vapor being used as part or all of the water added in the mixer. This makes it possible to provide a method for producing a water absorbent resin in which method a surface cross-linked water absorbent resin that has excellent properties can be obtained efficiently at low cost with high productivity.

The present invention relates to a method which allows quick and effective hydration of associative polymers, in particular those intended for use in the field of oil drilling. This method uses a specific solid formulation, which can be easily hydrated, including, in a pre-mixture, said associative polymers and surfactants capable of improving the hydration of these polymers.

The present disclosure relates to a method for producing polymer microparticles, this method including a step for polymerizing vinyl monomers in a hydrophilic solvent, which dissolves the vinyl monomers and a dispersion stabilizer but does not dissolve a polymer formed, in the presence of the dispersion stabilizer. The present disclosure is a method for producing these polymer microparticles, wherein the dispersion stabilizer contains a macromonomer having carboxyl groups and ethylenically unsaturated groups at an intermediate location in a molecular chain thereof, the macromonomer has, on average, 1.4 to 2.5 ethylenically unsaturated groups per molecule, and an average value of a carboxyl group content in the macromonomer is 0.5 meq/g to 2.5 meq/g.

Provided is a method of preparing a superabsorbent polymer. In the method of preparing the superabsorbent polymer according to the present disclosure, a polymer resulting from polymerization of ethylene-based unsaturated monomers is subjected to a reassembling process by mixing with a compound of a particular Chemical Formula and water. According to the preparation method of the present disclosure, provided is a method of preparing a superabsorbent polymer having improved water holding capacity and a reduced content of residual monomers, thereby improving quality of final polymer products.

A process for producing water-absorbing polymer particles, comprising the steps of thermal cracking of bionaphtha in the presence of steam, removing propene and at least some of the propane, gas phase oxidation to give acrylic acid and polymerization to give water-absorbing polymer particles.

A process for producing water-absorbing polymer particles having high free swell rate and high centrifuge retention capacity with simultaneously high permeability of the swollen gel bed by polymerization of an aqueous monomer solution in a polymerization reactor having at least two shafts (kneaders) which rotate in an axially parallel manner, subsequent extrusion at high temperatures and thermal surface postcrosslinking.

A karst channel type water inrush efficient-blocking ultra-high expansion grouting material, preparation, methods and application thereof, the grouting material includes macromolecule polymer particles A and a cross-linking solidifying fluid B, wherein the macromolecule polymer particles A are an inlaid type core-shell structure, primary macromolecule water-absorbent resin serves as an inner core, part of a gelling catalyzer is attached to an the inner core surface forming a shell, and the gelling catalyzer permeates the inner core forming an inlaid structure; before use, the macromolecule polymer particle A and the cross-linking solidifying fluid B are stirred; and then obtained mixed liquid is used as the grouting material to be injected into a fracture of a rock mass fracture zone. By means of the grouting material, high-pressure large-flow karst water inrush can be efficiently treated, the blocking efficiency of water inrush is improved, and major underground engineering construction of China is further facilitated.

A particulate water absorbing agent of the present invention is a water absorbing agent containing a water absorbing resin as a main component, the particulate water absorbing agent containing a polyvalent metal cation and satisfying: (1) the polyvalent metal cation is contained in an amount between 0.001 wt % and 5 wt % relative to the amount of the water absorbing agent; (2) an absorbency without pressure (CRC) is not less than 28 (g/g) and an absorbency against pressure (AAP 4.83 kPa) is not less than 10 (g/g); (3) the absorbency against pressure and the absorbency without pressure satisfy 77 ≦AAP (4.83 kPa)+1.8×CRC≦100; and (4) a moisture content of the water absorbing agent is between 5 wt % and 20 wt %. This provides a water absorbing agent which has blocking resistance after moisture absorption, is excellent in stability to shock and suppresses Re-Wet when used in a diaper.