Abstract: In a production process for a water-absorbent resin, comprising the steps of: blending a liquid material and a water-absorbent resin; and heating the resultant mixture in order to produce a modified water-absorbent resin, the present invention is to provide: a method for uniformly and efficiently treating a water-absorbent resin favorably in view of industry, and as a result, a good-balanced water-absorbent resin having various excellent properties, such absorption capacity without a load, absorption capacity under a load, and single-layer absorption capacity under a load in contact with an aqueous liquid. The production process comprises the step of spray-blending a water-absorbent resin (A) and a liquid material (B) with a blending apparatus equipped with a spray nozzle (C), wherein the liquid material (B) is sprayed from the spray nozzle (C) and its spray pattern is a circular and hollow cone shape or a double-convex-lens and elliptic cone shape.

Abstract: In the production of an acrylate polymer by the steps of preparing a water-soluble unsaturated monomer having a ratio of neutralization in the range of 30 to 100 mol % and containing 50 to 100 mol % of an acrylate and then polymerizing the monomer, a method for the production of a hydrophilic resin which comprises using a water-soluble unsaturated monomer having a &bgr;-hydroxy propionic acid (salt) content of not more than 1,000 ppm. The hydrophilic resin obtained by this method exhibits excellent physical properties and has only a small residual monomer content. Further, a residual monomer content neither occurs nor increases in any using conditions.

Abstract: The present invention provides a production process for a water-absorbent resin powder which is excellent in particle diameter distribution and properties, wherein the production process not only inhibits adhesion and aggregation in the production steps, but also is excellent in energy efficiency, drying efficiency, and productivity.

Abstract: A manufacturing method of absorbent resin of the present invention includes, in addition to a drying step of drying hydrogel of a crosslinked polymer to obtain a dried product and a pulverizing step of pulverizing the dried product, a separating step of separating a incompletely dried product contained in the dried product therefrom. Since particles of the incompletely dried product are larger than those of the dried product, the former can be readily separated from the latter in the separating step by classifying the dried product to particles of a particle size within a predetermined range. Consequently, the incompletely dried product is never delivered to the pulverizing step, and therefore, it has become possible to prevent inconveniences, such as causing a trouble in pulverizing the dried product, and the incompletely dried product being mixed into the absorbent resin.

Abstract: The present invention provides: a process for treating a particulate water-absorbent resin, which enables to carry out pulverization stably in a process for producing a particulate water-absorbent resin, and transportation or storage of the particulate water-absorbent resin stably during or after producing the particulate water-absorbent resin, and to prevent contamination of cohered matters of the particulate water-absorbent resin; and involves no or little deterioration of properties. The process for treating a particulate water-absorbent resin is characterized by carrying out at least one selected from the group consisting of: (1) heating at least one portion of a surface getting contact with the particulate water-absorbent resin from the outside, (2) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin at 30 to 150° C.

Abstract: A method for the continuous production of a shaped hydrogel of absorbent resin is disclosed. This invention accomplishes the continuous production by continuously supplying in the form of a layer a monomer mixture capable of forming an absorbent resin by polymerization and polymerizing the layer of the monomer mixture. This method is characterized by retaining the rate of change of the thickness in the direction of width of the layer of hydrogel of absorbent resin at the time of formation of gel at a level of not more than 20%.

Abstract: The invention provides: a water-absorbent resin granule-containing composition with resolution of various problems, as caused by water-absorbent resin fine powders, and with high granulation strength, and with no physical property deterioration due to granulation, and, if anything, with improvement of the absorption capacity under a load by granulation; and a process for producing the above granule. A water-absorbent resin primary particle and a water-absorbent resin granule are separately surface-crosslinked and then mixed, or mixed and then surface-crosslinked. The granulation is carried out by mixing a preheated aqueous liquid and a water-absorbent resin powder at a high speed or by supplying a water-absorbent resin powder downstream of an aqueous liquid with a continuous extrusion mixer.

Abstract: A method for producing a cross-linked polymer manifesting a high absorption capacity and having a small content of soluble component by a convenient and expeditious process with high productivity is provided. An absorbent resin such that disposable diapers and other products incorporating the absorbent resin manifest outstanding qualities and a method for the production of the absorbent resin are proposed.

Abstract: A method for producing a cross-linked polymer manifesting a high absorption capacity and having a small content of soluble component by a convenient and expeditious process with high productivity is provided. An absorbent resin such that disposable diapers and other products incorporating the absorbent resin manifest outstanding qualities and a method for the production of the absorbent resin are proposed.

Abstract: The present invention provides a production process, in which hydrophilic crosslinked polymers can be dried uniformly with good efficiency, and the deterioration during the drying is little. The production process of a hydrophilic crosslinked polymer comprises the steps of polymerizing an aqueous solution including a hydrophilic monomer and a crosslinking agent to obtain a hydrogel crosslinked polymer, and drying the hydrogel crosslinked polymer, thus obtaining the hydrophilic crosslinked polymer, and is characterized in that: the hydrogel crosslinked polymer is dried in a static state until it becomes possible to disintegrate an aggregate of the hydrogel crosslinked polymer; the dried hydrogel crosslinked polymer is disintegrated into a particle size of 20 mm or less; and the disintegrated hydrogel crosslinked polymer is dried in a stirred state and/or a fluidized state.

Abstract: The invention provides a production process of a water-absorbent resin, by which process the polymerization temperature can be controlled in static aqueous solution polymerization. The production process of a water-absorbent resin comprises the step of polymerizing statically an aqueous solution with a thickness of 10˜50 mm including a hydrophilic monomer, and is characterized in that the polymerization heat is removed using both cooling due to heat conduction transfer and cooling due to the latent heat of vaporization, thereby controlling the maximum attained temperature of the polymerization system in the range of 60˜95°C. or controlling the increase in solid content in the range of 0.2 to 10 weight %.

Abstract: The present invention provides a process for classifying a particulate hydrophilic polymer and a sieving device, which can carry out a classification in a small separation particle diameter with high efficiency and exhibit classification ability inherent in the sieving device. The process comprises the step of classifying a particulate hydrophilic polymer in dry particle size with a sieving device, wherein the sieving device is used in a heated and/or thermally insulated state. The sieving device comprises a thermally insulating means.

Abstract: A method of producing hydrophilic resin by pulverizing and drying a hydrogel polymer, in which, during pulverization of the hydrogel polymer, the hydrogel polymer is sheared between two spiral rotary blades with different respective feed rates, provided opposite one another. Due to the difference in feed rates of the two rotary blades, one rotary blade overtakes the other, and the hydrogel polymer is caught therebetween and sheared. It is preferable if the temperature of the hydrogel polymer at this time is no less than 40.degree. C.

Abstract: An absorbent resin composition which shows high speed of absorption, excels in fluid permeability, and enjoys a high absorption capacity under load comprises primary particles of an absorbent resin and granulated particles of an absorbent resin having an average particle size smaller than the average particle size of the primary particles. An absorbent article contains the composition. The absorbent resin composition is produced by a method which comprises a step of producing granulated particles by granulating particles of absorbent resin having an average particle size in the range of 10 to 100 .mu.m and a step of mixing the resultant granulated particles of the absorbent resin with the primary particles of an absorbent resin having an average particle size in the range of 150 to 800 .mu.m.

Abstract: A method for the production of a water-absorbent resin capable of fast water absorption is disclosed which comprises the steps of dispersing bubbles of an inert gas in an aqueous monomer solution of a mixture of a water-soluble unsaturated monomer and a water-soluble cross-linking monomer and subjecting the mixture to copolymerization under the condition that a volume of the monomer solution wherein the inert gas is dispersed is in the range of 1.02 to 5 times of a volume of non-dispersant state.

Abstract: A blood-absorbable resin composition characterized by having a blood area ratio relative to sheep blood of not less than 30% at a basis weight of 150 g/m.sup.2 and an absorbent article containing the composition. The blood-absorbable resin composition of this invention possesses an excellent ability to absorb blood and, therefore, is highly useful for sanitary napkins, tampons, medical blood-absorbable articles, trauma protectors, trauma healing materials, and reagents for treating liquid refuses from surgical operations.

Abstract: An absorbent material is provided which enjoys suppleness, possesses highly satisfactory absorption qualities (speed of absorption and capacity for absorption), allows section into pieces of desired size and shape, and excels in safety.An absorbent material comprising 100 parts by weight of absorbent resin particles and 15 to 150 parts by weight of water, which absorbent material is in the form of a sheet having a thickness in the approximate range of 0.3 to 5 mm, the form of a sheet resulting from mutual adhesion of the absorbent resin particles.

Abstract: A process for producing a water-absorbing resin, which comprises polymerizing (D) an aqueous solution comprising (A) at least one monomer component selected from the group consisting of an unsaturated carboxylic acid and salts thereof; (B) a compound having two or more unsaturated groups in a molecule; and (C) a compound having two or more functional groups which are capable of reacting with carboxyl groups in a molecule, the polymerization being conducted in such a manner that the following conditions (a) to (c) are simultaneously satisfied: (a) the molar ratio (B)/(C) being in the range of from 2.times.10.sup.-3 to 300, (b) the polymerization being initiated by a redox polymerization initiator, and (c) the maximum reaction temperature being in the range of from 60.degree. to 100.degree. C, and a water-absorbing resin having a degree of reduction in absorption magnification of from 1 to 16, and n absorption magnification under pressure of from 20 to 40.

Abstract: An absorbent material is provided which enjoys suppleness, possesses highly satisfactory absorption qualities (speed of absorption and capacity for absorption), allows section into pieces of desired size and shape, and excels in safety.An absorbent material comprising 100 parts by weight of absorbent resin particles and 15 to 150 parts by weight of water, which absorbent material is in the form of a sheet having a thickness in the approximate range of 0.3 to 5 mm, the form of a sheet resulting from mutual adhesion of the absorbent resin particles.

Abstract: A method for the production of an acrylate by the neutralization reaction of acrylic acid and a basic substance, comprising sequentially (A) a step of supplying acrylic acid and said basic substance to water thereby subjecting them to a neutralization reaction while constantly retaining the neutralization ratio of acrylic acid within the neutralization reaction system in the range of 75 to 100 mol %, (B) a step of adjusting the neutralization ratio of acrylic acid within said neutralization reaction system in the range of 100.1 to 110 mol % by supplying said basic substance to said neutralization reaction system, (C) a step of retaining the neutralization ratio of acrylic acid within said neutralization reaction system in the range of 100.