Abstract: An absorbent member and a method for making such an absorbent member. The absorbent member includes a modified water absorbent resin having good production efficiency, absorbency against pressure, absorption speed, gel strength, and liquid permeability. The modified water absorbent resin may be made by mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer to obtain a water absorbent resin composition, and irradiating the water absorbent resin composition with active energy rays. During irradiation, the surface water content of the water absorbent resin is at least 3.0 wt %.

Abstract: [Problem] To obtain a particulate water absorbent having excellent and stabilized physical properties.

Abstract: An object of the present invention is to provide a water absorbent having excellent gel properties and showing excellent properties when used in a water-absorbing material of a sanitary/hygienic material such as paper diaper. Moreover, another object of the present invention is to provide a water absorbent which is safe and excellent in liquid permeability, and in which an amount of liquid permeability improver for improving the liquid permeability is reduced. The water absorbent is made from a water-absorbing resin prepared by a specific polymerization method and having a high degree of cross-linking, a high liquid holding property and a high gel strength (its swelling pressure of gel layer of is 35 kdyne/cm2 or more). This water absorbent is further processed to have a particular particle size distribution (95 wt % or more of its particles are less than 850ƒÊm but not less than 106ƒÊm, and logarithmic standard deviation (ƒĐƒÄ) is in a range of 0.25 to 0.

Abstract: An absorbent member and a method for making such an absorbent member. The absorbent member includes a modified water absorbent resin having good production efficiency, absorbency against pressure, absorption speed, gel strength, and liquid permeability. The modified water absorbent resin may be made by mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer to obtain a water absorbent resin composition, and irradiating the water absorbent resin composition with active energy rays. During irradiation, the surface water content of the water absorbent resin is at least 3.0 wt %.

Abstract: The present invention relates to a method of surface cross-linking superabsorbent polymer particles using UV irradiation. The superabsorbent polymer particles for use in the method of the present invention have a relatively high degree of neutralization. Bronsted acids are selectively applied onto the surface of the superabsorbent polymer particles to selectively facilitate a relatively high number of protonated carboxyl groups at the surface of the superabsorbent polymer particles while the relatively high degree of neutralization in the core of the superabsorbent polymer particles remains substantially unaffected.

Abstract: The subject invention provides a hydrophilic polymer (water-absorbing resin) which is superior in performance and productivity. According to the production method of the present invention, a hydrophilichigh-molecular-weight compound is dispersed in an aqueous solution containing a hydrophilic monomer. The dispersed hydrophilic high-molecular-weight compound is dissolved by heat of neutralization (heat of hydration) and/or heat of polymerization generated in the process of producing a hydrophilic polymer.

Abstract: Provided is a surface treatment method for a water-absorbent resin having excellent production efficiency, absorption capacity against pressure, fluid permeability or the like. Provided is a method for the surface treatment of a water-absorbent resin which comprises a) a step for mixing 0.1 to 20 parts by weight of an acid group-containing radically polymerizable compound and 5 to 20 parts by weight of water, relative to 100 parts by weight of a water-absorbent resin; and b) a step for polymerizing the acid group-containing radically polymerizable compound, wherein neutralization ratio of the acid group-containing radically polymerizable compound is 0 to 60% by mol, and is lower than neutralization ratio of the water-absorbent resin.

Abstract: An object of the present invention is to provide a water absorbent having excellent gel properties and showing excellent properties when used in a water-absorbing material of a sanitary/hygienic material such as paper diaper. Moreover, another object of the present invention is to provide a water absorbent which is safe and excellent in liquid permeability, and in which an amount of liquid permeability improver for improving the liquid permeability is reduced. The water absorbent is made from a water-absorbing resin prepared by a specific polymerization method and having a high degree of cross-linking, a high liquid holding property and a high gel strength (its swelling pressure of gel layer of is 35 kdyne/cm2 or more). This water absorbent is further processed to have a particular particle size distribution (95 wt % or more of its particles are less than 850ƒÊm but not less than 106ƒÊm, and logarithmic standard deviation (ƒĐƒÄ) is in a range of 0.25 to 0.

Abstract: The present invention provides a method for producing a water absorbing agent which excels in water absorption properties. In detail, the present invention provides a method for the production of a water absorbing agent, comprising a) a step of mixing a water absorbing resin, water, and a mixing aid without adding a water-soluble radical polymerization initiator and an ethylenically unsaturated monomer and b) a step of irradiating the resultant mixture with ultraviolet rays while keeping the mixture with flowed state.

Abstract: This invention is to provide an absorbent member and a method for making such an absorbent member. The absorbent member comprises modified water absorbent having good production efficiency, good absorbency against pressure, good absorption speed, gel strength, good liquid permeability, and the like. The modified water absorbent resin is made by a method, which comprises (i) a mixing step comprising mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer, to obtain a water absorbent resin composition, and (ii) an irradiating step comprising irradiating said water absorbent resin composition obtained in the mixing step with active energy rays, wherein the surface water content of said water absorbent resin in said water absorbent resin composition at least at any point of time in the irradiating step (ii) is controlled to a level of not lower than 3.0% by weight based on 100% by weight of the water absorbent resin.

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 (??) 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: This invention is to provide a method for producing a modified water absorbent resin excelling in water absorbing properties. This invention relates to a method for producing a modified water absorbent resin, 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: This invention is to provide a method for surface-treatment of a water absorbent resin excelling in water absorption properties. This invention relates to a method for the surface-treatment of a water absorbent resin, which comprises: a) mixing 100 parts by weight of a water absorbent resin, 0.01-20 parts by weight of at least one radical polymerization initiator selected from the group-consisting of persulfates, hydrogen peroxide, and azo compounds, and a radically polymerizing compound and b) irradiating the resultant mixture with active energy rays. The treatment particularly exalts the absorption ratio against pressure and the saline flow conductivity.

Abstract: A method of surface cross-linking superabsorbent polymer particles using UV irradiation is provided. The superabsorbent polymer particles for use in the method have a relatively high degree of neutralization. Brønsted acids are selectively applied onto the surface of the superabsorbent polymer particles to selectively facilitate a relatively high number of protonated carboxyl groups at the surface of the superabsorbent polymer particles while the relatively high degree of neutralization in the core of the superabsorbent polymer particles remains substantially unaffected.

Abstract: A method of surface cross-linking superabsorbent polymer particles using UV irradiation is provided. The method is carried out in a so-called drum reactor, which comprises a hollow drum and an irradiation source. The drum has a longitudinal axis and a cross-section. Superabsorbent polymer particles are fed into the drum and are irradiated while they move within the drum, which is rotated around its longitudinal axis. The irradiation source is provided such that the radiation emitted by the irradiation source is able to reach superabsorbent polymer particles within said drum. The irradiation source for use in the method is able to emit UV radiation of a wavelength between about 100 nm and about 200 nm.

Abstract: The present invention relates to a method of surface cross-linking superabsorbent polymer particles using UV irradiation. The method is carried out in a so-called drum reactor, which comprises a hollow drum and an irradiation source. The drum has a longitudinal axis and a cross-section. Superabsorbent polymer particles are fed into the drum and are irradiated while they move within the drum, which is rotated around its longitudinal axis. The irradiation source is provided such that the radiation emitted by the irradiation source is able to reach superabsorbent polymer particles within said drum. The irradiation source for use in the method of the present invention is able to emit UV radiation of a wavelength between 100 nm and 200 nm.

Abstract: A method of surface cross-linking superabsorbent polymer particles using UV irradiation is provided. The method is carried out in a so-called drum reactor, which comprises a hollow drum and an irradiation source. The drum has a longitudinal axis and a cross-section. Radical former molecules are applied on the surface of superabsorbent polymer particles. These superabsorbent polymer particles are fed into the drum and are irradiated while they move within the drum, which is rotated around its longitudinal axis. The irradiation source is provided such that the radiation emitted by the irradiation source is able to reach superabsorbent polymer particles within said drum. The irradiation source for use in the method is able to emit UV radiation of a wavelength between about 201 nm and about 400 nm.

Abstract: The present invention provides a method for producing a water absorbing agent which excels in water absorption properties. In detail, the present invention provides a method for the production of a water absorbing agent, comprising a) a step of mixing a water absorbing resin, water, and a mixing aid without adding a water-soluble radical polymerization initiator and an ethylenically unsaturated monomer and b) a step of irradiating the resultant mixture with ultraviolet rays while keeping the mixture with flowed state.

Abstract: The present invention relates to a method of surface cross-linking superabsorbent polymer particles using UV irradiation. The method is carried out in a so-called drum reactor, which comprises a hollow drum and an irradiation source. The drum has a longitudinal axis and a cross-section. Radical former molecules are applied on the surface of superabsorbent polymer particles. These superabsorbent polymer particles are fed into the drum and are irradiated while they move within the drum, which is rotated around its longitudinal axis. The irradiation source is provided such that the radiation emitted by the irradiation source is able to reach superabsorbent polymer particles within said drum. The irradiation source for use in the method of the present invention is able to emit UV radiation of a wavelength between 201 nm and 400 nm.

Abstract: The present invention relates to a method of surface cross-linking superabsorbent polymer particles using UV irradiation. The superabsorbent polymer particles for use in the method of the present invention have a relatively high degree of neutralization. Bronsted acids are selectively applied onto the surface of the superabsorbent polymer particles to selectively facilitate a relatively high number of protonated carboxyl groups at the surface of the superabsorbent polymer particles while the relatively high degree of neutralization in the core of the superabsorbent polymer particles remains substantially unaffected.