Abstract: The production method of a water absorbent resin composition including a particulate water absorbent resin, wherein: 95 wt % or more of particles whose particle diameter is less than 850 ?m and not less, than 106 ?m are contained, and a weight average particle diameter of the particles is less than 500 ?m and not less than 300 ?m and a logarithmic standard deviation (??) of a particle size distribution is 0.45 or less, and a water-soluble component of the water absorbent composition is 35 wt % or less, and a multivalent metal component is contained, and an extraction rate of the multivalent metal component is 5.0 wt % or more and less than 100 wt %, thereby providing the water absorbent resin composition, free from any coagulation of particles in high humidity, which has superior absorbent property in terms of an absorbency and a diffusing absorbency under pressure.

Abstract: The present invention provides a method for manufacturing a particulate water-absorbing agent which has excellent liquid diffusibility and liquid permeability, and whose amount of residual monomers is reduced. The method for manufacturing the particulate water-absorbing agent of the present invention includes a step of surface-crosslinking, in the presence of an organic crosslinking agent, water-absorbing resin particles obtained through at least a step of polymerizing an aqueous solution of unsaturated monomers, and in or after the polymerizing step, a reaction system is mixed with peroxide. Thus, it is possible to obtain the particulate water-absorbing agent which has excellent liquid diffusibility and liquid permeability and whose amount of residual monomers is small, that is, it is possible to obtain the particulate water-absorbing agent which is highly functional and highly safe.

Abstract: A water-absorbing agent according to the present invention includes water-absorbent resin particles having an internal cross-linked structure,.wherein a vicinity of a surface of the water-absorbent resin particle is cross-linked with a surface cross-linking agent, and the water-absorbent resin particle has therein a sea-island structure having (i) part containing a first water-soluble multivalent metal salt such as aluminum sulfate and (ii) part not containing the first water-soluble multivalent metal salt. With this arrangement, it is possible to provide a water-absorbing agent having less water-soluble component content, more excellent liquid permeability, and more excellent water retention under pressure than the conventional water-absorbing agent.

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: There is disclosed a water-absorbing agent which combines both performances of the capillary suction force and the liquid permeability. This water-absorbing agent is a particulate water-absorbing agent comprising water-absorbent resin particles (?) and a liquid-permeability-enhancing agent (?), wherein the water-absorbent resin particles (?) are surface-crosslink-treated particles of a crosslinked polymer of a monomer including acrylic acid and/or its salt; with the water-absorbing agent being characterized in that the particulate water-absorbing agent has: a mass-average particle diameter (D50) in the range of 234 to 394 gm, a logarithmic standard deviation (??Y) of a particle diameter distribution in the range of 0.25 to 0.45, an absorption capacity without load (CRC) of not less than 15 g/g, and a water-extractable component content of not higher than 15 mass %; and further a liquid-permeability-enhancing agent (?) content in the range of 0.

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: An absorbent member for use in disposable diapers, wherein the absorbent member comprises a modified water absorbent resin. The modified water absorbent resin is made according to the method which comprises a) mixing a water absorbent resin and a water-soluble radical polymerization initiator or a heat-degradable radical polymerization initiator without addition of an ethylenically unsaturated monomer and b) irradiating the resultant mixture with active energy rays. The method is particularly capable of exalting the absorbency against pressure and the saline flow conductivity.

Abstract: There are disclosed a water-absorbent resin composition and its production process, wherein the water-absorbent resin composition causes little gel-blocking and is excellent in the liquid permeability and liquid diffusibility and is high also in the absorption performances and further is strong also against the physical damage; and there are further disclosed a water-absorbent resin composition and its production process, wherein the water-absorbent resin composition has the following further advantages, in addition to the above, of involving little segregation of the metal compound and further having a dust prevention effect.

Abstract: The water absorbent resin composition and the production method thereof according to the present invention are characterized by including: water absorbent resin particles having an internal cross-linked structure obtained by polymerizing a water-soluble unsaturated monomer; a nitrogenous ketone compound (A) (containing no carboxyl group) having a structure represented by formula (1); and a bivalent and/or trivalent and/or tetravalent water-soluble metal salt, wherein a total amount of the nitrogenous ketone compound (A) and the bivalent and/or trivalent and/or tetravalent water-soluble metal salt ranges from 0.01 to 100 parts by mass with respect to 100 parts by mass of the water absorbent resin particles, thereby providing a water absorbent resin composition, having an excellent absorption capacity represented by a centrifuge retention capacity (CRC), an absorbency against pressure of 4.83 kPa (AAP) etc.

Abstract: An absorbent article that has a thin, conformable absorbent core where the core has at least two layers, both of which are substantially free of cellulosic fibers is described. The first layer is intended to provide storage for the majority of acquired fluids and has an AAP of at least about 20 g/g and the second layer, which provides temporary capacity for the bulk of the acquired fluid and permanent storage for at least a portion thereof, comprises a second absorbent polymer material which has a Wet Permeability of at least about 400×10?7 (cm3 seconds)/g a ratio of Wet Permeability to SFC of at least about 1.5:1 with respect to the first absorbent polymer material.

Abstract: The present invention provides: a production process for a basic water-absorbent resin to be a main component of a water-absorbing agent which exhibits an excellent water absorption capacity under a load with high productivity; a production process for a water-absorbing agent; and use thereof. The production process for an irregular shape basic water-absorbent resin comprises the step of reacting a basic resin and a crosslinking agent in order to obtain the basic water-absorbent resin, with the process forwarding a crosslinking reaction and pulverizing the resultant product at the same time. The first production process for a water-absorbing agent comprises the step of blending an acidic water-absorbent resin with the basic water-absorbent resin obtained by the above-mentioned process.

Abstract: An object of the present invention is to provide: a water-absorbent resin which can sufficiently overcome the problem of the gel blocking, can manifest sufficient absorption capacity without load and sufficient absorption capacity under load and, at the same time, can also exert excellent liquid permeability under load; and a process for producing the same. As a means of achieving this object, a first production process among the processes according to the present invention for producing a water-absorbent resin having a treated surface is a process comprising: a step of mixing a water-absorbent resin having an internal crosslinked structure obtained by polymerizing a monomer containing acrylic acid and/or a salt thereof as a main component, a complex containing a polyvalent metal atom as a central atom and an organic secondary crosslinking agent in the presence of an aqueous liquid; and a step of crosslinking a surface of the water-absorbent resin with the organic secondary crosslinking agent.

Abstract: The present invention provides: a production process for a basic water-absorbent resin to be a main component of a water-absorbing agent which exhibits an excellent water absorption capacity under a load with high productivity; a production process for a water-absorbing agent; and use thereof. The production process for an irregular shape basic water-absorbent resin comprises the step of reacting a basic resin and a crosslinking agent in order to obtain the basic water-absorbent resin, with the process forwarding a crosslinking reaction and pulverizing the resultant product at the same time. The first production process for a water-absorbing agent comprises the step of blending an acidic water-absorbent resin with the basic water-absorbent resin obtained by the above-mentioned process.

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: The present invention provides: a production process for a basic water-absorbent resin to be a main component of a water-absorbing agent which exhibits an excellent water absorption capacity under a load with high productivity; a production process for a water-absorbing agent; and use thereof. The production process for an irregular shape basic water-absorbent resin comprises the step of reacting a basic resin and a crosslinking agent in order to obtain the basic water-absorbent resin, with the process forwarding a crosslinking reaction and pulverizing the resultant product at the same time. The first production process for a water-absorbing agent comprises the step of blending an acidic water-absorbent resin with the basic water-absorbent resin obtained by the above-mentioned process.