Abstract: [Problem] To provide a dust reducer which suppresses blocking against moisture absorption and has a reduced amount of dust generation, without impairing the water absorption physical properties that are required from a water absorbing agent, such as water absorption capacity under load; a method for producing a water absorbing agent using the dust reducer; and a water absorbing agent in which blocking against moisture absorption is suppressed and which has a reduced amount of dust generation. [Solution] A dust reducer for a water absorbing agent containing a surface crosslinked polyacrylic acid (salt)-based water absorbent resin as a main component, wherein the dust reducer is a multi-component metal compound which has a hydrotalcite structure and contains a hydroxyl group and two kinds of metal cations that are divalent and trivalent.

Abstract: [PROBLEM] It is an object of the present invention to enhance and stabilize properties of a water-absorbing resin, for example, damage resistance or water-absorbing speed, by a simple and convenient method without requiring change of raw materials or expensive facility investment, in a large scale production method for the water-absorbing resin. [MEANS FOR SOLVING THE PROBLEM] It is solved by circulation of the water-absorbing resin in a predetermined amount or more in the pulverization step before the surface cross-linking step. That is, at least a part of the classified polymer is supplied again to the same or different pulverization step, before the surface cross-linking step, wherein circulation pulverization ratio in the pulverization step, represented by the following equation is larger than 1.

Abstract: There is provided a production method for a water-absorbing resin for stably and continuously producing the water-absorbing resin with industrially high property, in particular, the water-absorbing resin with high liquid permeation. A method of the present invention relates to a production method for a water-absorbing resin including: a polymerization step of an aqueous solution of an unsaturated monomer; a drying step of the resultant hydrogel polymer; and a surface cross-linking step after drying; characterized by including a pneumatic transportation step for pneumatic transporting the water-absorbing resin powder substance in a pipeline with a surface roughness (Rz) of the inner surface of equal to or smaller than 800 nm, by using gas with a dew point of ?5° C. to ?100° C.

Abstract: In obtaining a water-absorbing resin with high property in high productivity, produced a production method for a water-absorbing resin in high property and stably. Provided is a production method for a water-absorbing resin, comprising: a step for polymerizing an acrylic acid aqueous solution; a step for drying the resultant water-containing gel; a step for pulverizing and classifying the dried substance; and a step for surface cross-linking after classification, wherein a hopper having an inclination angle of a cone part of equal to or larger than 45 degree, and a drawing rate of 30 to 80% is used.

Abstract: To provide a waterborne curable resin composition that is advantageous for environmental protection measures, can be applied without use of a film-forming assistant and can improve the dispersion stability of the emulsion, and also improve physical properties of the coat such as curability, durability, and stain resistance. A waterborne curable resin composition having an acrylic emulsion produced by emulsion polymerization, wherein the acrylic emulsion contains a curable monomer and/or oligomer in emulsion particles.

Abstract: A drying shrinkage-reducing agent which comprises a polymer containing as an essential component at least one structural unit (I) represented by the following formula (1): wherein R1, R2, and R3 independently stand for a hydrogen atom, a methyl group, or a —(CH2)pCOOX group, wherein X stands for a hydrogen atom, a monovalent metal, a divalent metal, an ammonium group, an organic amine group, or a hydrocarbon group, and p is an integer of 0-2; and R4 stands for a hydrocarbon group of 4-30 carbon atoms, and exhibiting surface tension in the range of 25-50 mN/m in a solution containing 0.2 mass % of the polymer in a cement supernatant is provided. The drying shrinkage-reducing agent manifests no dispersibility in an amount capable of attaining necessary drying shrinking-reducing properties and, when used in combination with a dispersing agent, acquires ability to adjust the dispersibility and the drying shrinkage-reducing properties fit for the purpose.

Abstract: The present invention provides: a novel water-absorbing agent, which exhibits an excellent absorption capacity under a load (AAP), gel layer liquid permeation rate under a load (FRUP), saline flow conductivity (SFC), and shape-maintaining property and ball burst strength (BBS) of a swollen water-absorbing agent aggregate, and excellent persistency of these effects for a long time. The water-absorbing agent, which comprises a polymer obtained by a process including the steps of polymerizing and then crosslinking a monomer including acrylic acid and/or a salt thereof, with the water-absorbing agent being characterized by: (1) exhibiting a free swelling capacity of not less than 23 g/g (GV), a gel deformation of not more than 12.5 cm under a short-time load (0.5 hrPT), and a gel deformation deterioration of not more than 3.

Abstract: A method which produces colored minute particles by suspending in an aqueous suspending medium a polymerizable monomer composition obtained by dispersing a coloring agent at least in a polymerizable monomer and polymerizing the resultant suspension is characterized in that the dispersion of the coloring agent in the polymerizable monomer is performed in the presence of a dispersing agent, the polymerizable monomer composition exhibits a viscosity of not more than 300 cP, and the suspension of the polymerizable monomer composition in the aqueous suspending medium exhibits a viscosity of not more than 100 cP. The dispersing agent is at least one resin selected from the group consisting of rosin derivatives, aromatic petroleum resins, pinene type resins, epoxy type resins, cumdrone resins, and styrene-acryl type resins.