Nippon Shokubai Co., Ltd.

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Yoshihiko Masuda

Kinya Nagasuna

Nobuyuki Harada

Yoshio Irie

Katsuyuki Wada

Yorimichi Dairoku

Kunihiko Ishizaki

Shin-Ichi Fujino

Yoshihiro Motono

Kenji Kadonaga

Tadao Shimomura

Katsuhiro Kajikawa

Tsuneo Tsubakimoto

Hiroyuki Ikeuchi

Takumi Hatsuda

Masazumi Sasabe

Masatoshi Nakamura

Kazumasa Kimura

Seiji Kato

Hideaki Nagano

Toru Yanase

Yohei Murakami

Akira Hattori

Atsushi Tachibana

Kazutaka Yano

Shigeru Oka

Kouichi Okamoto

Kohichi Hirota

Hideyuki Kubo

An object of the present invention is to provide a waste solution solidifying agent which can solidify a waste solution, particularly, a waste solution containing blood or body fluid at a low cost, uniformly, and in a short time; in particular, to provide a waste solution solidifying agent which can solidify a waste solution uniformly and in a short time in a vertically oriented waste solution equipment. As a means of achieving this object, a waste solution solidifying agent of the present invention is a particulate treating agent used in a method of treating a waste solution which solidifies a waste solution into a gel by placing a treating agent in a waste solution, and is characterized in that said agent contains, as an essential component, a water-absorbent resin having a crosslinked structure obtained by polymerizing a water-soluble ethylenic unsaturated monomer and, when flowing-placed at once into a 0.90 mass % aqueous sodium chloride solution, 20 to 95 mass % of the agent is floated, and 80 to 5 mass % is settled. And a process for preparing a waste solution solidifying agent of the present invention is a process for preparing a particulate waste solution solidifying agent containing, as an essential component, a water-absorbent resin having a crosslinked structure obtained by polymerizing a water-soluble ethylenic unsaturated monomer, and comprises a step of mixing a hydrophobic substance having a methanol index of 20 or more after polymerization.

Waste solution solidifying agent, process for preparing the same and use of the same

A method for the production of a water-absorbent agent comprises mixing an absorbent resin containing a carboxyl group with an additive soluble in the aqueous solution of at least one member selected from the group consisting of inorganic acids, organic acids, and polyamino acids and a cross-linking agent capable of reacting with the carboxyl group. A water-absorbent agent obtained by adding from 0.005 to 8 parts by weight of an epoxy compound to 100 parts by weight of a water-absorbent resin, exhibiting an absorption capacity without load of at least 45 (g/g), an absorption capacity under load of 20 g/cmof not less than 30 (ml/g) and having a residue amount of an epoxy compound of not more than 2 ppm. A water-absorbent composition comprises a polyamino acid (salt) and a water-absorbent resin containing a carboxyl group.

Absorbent resin composition

Water-absorbent agent, method for production thereof, and water-absorbent composition

The present invention provides: a process for producing a water-absorbing agent at low temperature in a short time, wherein the water-absorbing agent has excellent balance between the absorption capacity without load and the absorption capacity under a load, high fluidity under a hygroscopic atmosphere, and excellent safety; and a novel water-absorbing agent and a novel crosslinking agent particularly suitable for crosslinking water-absorbent resins. The water-absorbing agent, having excellent balance between the absorption capacity without load and the absorption capacity under a load, high fluidity under a hygroscopic atmosphere, and excellent safety, can be obtained by using an oxetane compound and/or an imidazolidinone compound for a water-absorbent resin.

Water-absorbing agent and process for producing the same

A hydrophilic polymer is denatured with a gaseous denaturant or a powdery denaturant substance made from a liquid denaturant substance. The liquid denaturant substance is made into powders by, for example, a method of mixing the liquid denaturant substance with a water-insoluble compound, a method of cooling the liquid denaturant substance to or below its melting point to turn the same into a solid state. Consequently, the hydrophilic polymer can be denatured uniformly. In case that the hydrophilic polymer is denatured with a gaseous denaturant, the hydrophilic polymer and denaturant react with each other efficiently in a safe manner regardless of the size or shape of the hydrophilic polymer. In case that the hydrophilic polymer is denatured with the powdery denaturant substance, not only the liquid denaturant substance which is substantially in the solid state can be mixed with the hydrophilic polymer, but also the denaturation timing can be readily controlled.

Method of producing a hydrophilic resin

To prevent adhesion of a support body and a hardened body of a hydraulic composition, the hydraulic composition being used for a soil structure such as a retaining wall built in a soil excavating work in the civil engineering and construction fields, a composition (A) composed of at least an alkaline-water-soluble resin with an acid value of not less than 15 mgKOH/g and a water-absorbent material is provided so as to intervene between the support body and the hardened body of the hydraulic composition, either by applying the composition (A) on a surface of the support body, or by covering the support body with a sheet-like member on which the composition (A) is applied. The alkaline-water-soluble resin dissolves in alkaline water upon contact with the same contained in the hydraulic composition. As the alkaline-water-soluble resin dissolves, the water-absorbent material swells absorbing the alkaline water, whereby a layer of the water-absorbent material which has swollen is formed between the hardened body of the hydraulic composition and the support body, preventing the adhesion therebetween.

Adhesion preventing method and support body extracting method

An absorbing agent has a diffusing absorbency under pressure of not less than 25 g/g when 60 minutes elapsed after absorption is started, and a water-soluble content is above 0 percent by weight and not more than 7 percent by weight. The absorbing agent is prepared by surface-crosslinking a precursor of the absorbing agent obtained by performing an aqueous solution polymerization of a hydrophilic unsaturated monomer having not less than 50 mole percent neutralized acrylic acid as a main component using a specific crosslinking agent having a main component composed of an ester compound of a specific polyhydroxy alcohol and an unsatuated carboxylic acid, and a high-boiling component having at least two alcohol structures in a molecule as a specific ratio. As a result, an absorbing agent having excellent properties such as the diffusing absorbency under pressure is high, the water soluble content is small, and the amount of wet back of the aqueous liquid after a long period of time is small, water absorbency under pressure can be stably maintained for a long period of time can be achieved.

Process for manufacturing an absorbing agent and absorbent material

Process of manufacturing precursor of an absorbing agent

A method for the production of an absorbent resin having a very small residual monomer content either by adding to an absorbent resin powder a substance capable of reacting with the residual monomer in the absorbent resin powder thereby forming an absorbent resin composition having a water content in the range of 10 to 70% by weight and heat-treating the absorbent resin composition at a temperature in the range of 100.degree. to 200 .degree. C. while retaining the water content of the absorbent resin or by adding to an absorbent resin powder a substance capable of reacting with the residual monomer in the absorbent resin powder thereby forming an absorbent resin composition having a water content in the range of 25 to 55% by weight, heat-treating the absorbent resin composition at a temperature in the range of 120.degree. to 200 .degree. C. while retaining the water content of the absorbent resin composition in the range mentioned above, and then drying the absorbent resin composition at a temperature not exceeding 120.degree. C.

Absorbent and method for production of absorbent resin

Absorbing agent, process of manufacturing same, and absorbent product

A method for the production of a water-absorbent agent comprises mixing an absorbent resin containing a carboxyl group with an additive soluble in the aqueous solution of at least one member selected from the group consisting of inorganic acids, organic acids, and polyamino acids and a cross-linking agent capable of reacting with the carboxyl group. A water-absorbent agent obtained by adding from 0.005 to 8 parts by weight of an epoxy compound to 100 parts by weight of a water-absorbent resin, exhibiting an absorption capacity without load of at least 45 (g/g), an absorption capacity under load of 20 g/cm.sup.2 of not less than 30 (ml/g) and having a residue amount of an epoxy compound of not more than 2 ppm. A water-absorbent composition comprises a polyamino acid (salt) and a water-absorbent resin containing a carboxyl group.

Water-absorbent agent, method for production thereof, and

A process for preparing an absorbent resin includes the steps of: preparing a first crosslinking agent (A) including at least two polymerizable unsaturated bonds; preparing a second crosslinking agent (B) including at least two polymerizable unsaturated bonds and hydroxyl groups; preparing a crosslinking agent including (A) and (B) with a ratio of (A) to (B) ranging from 95/5 to 50/50; and polymerizing a hydrophilic unsaturated monomer having at least one carboxyl group using the crosslinking agent. The crosslinking agent includes a crosslinking agent which includes a main component at least 90 percent by weight, the main component being an ester having at least two polymerizable unsaturated bonds, wherein the ester is composed of a polyhydroxy alcohol (C) having not more than six carbon atoms and at least three hydroxy groups, and an unsaturated carboxylic acid (D); and a molecular weight ratio of the main component to a standard compound (E) is in the range of from 0.7/1 to less than 1.3/1, (E) being an ester composed of (C) that composes the main component, and (D) that composes the main component, in which all the hydroxy groups in (C) are ester-linked with (D).

Process for preparing an absorbent resin crosslinked with a mixture of

A method for the production of an absorbent resin, which method comprises mixing 100 parts by weight of (A) a hydrated gel of absorbent resin which is resulted from aqueous solution polymerization having a polymerization ratio in the range of from 60 to 99%, an average particle diameter in the range of from 0.1 to 200 mm, a water content in the range of from 30 to 90% by weight, and a temperature in the range of from 40.degree. to 110.degree. C., with from 1 to 50 parts by weight of (B) a substantially dry fine absorbent resin powder having an average particle diameter smaller than the average particle diameter assumed by said hydrated gel of absorbent resin (A) while in a dried state, then raising the polymerization ratio of said hydrated gel of absorbent resin (A) to a level higher than the polymerization ratio of said hydrated gel when being mixed.

Method for production of absorbent resin

A method for the production of an absorbent resin retaining at a high level an absorption capacity without load, one of the basic physical properties of absorbent resin, and excelling in an absorption capacity under load is provided. The production is attained by mixing an absorbent resin as a base polymer possessing a carboxyl group with a first cross-linking agent possessing a solubility parameter (SP value) of not less than 12.5 (cal/cm.sup.3).sup.1/2 and exhibiting reactivity with the carboxyl group and a second cross-linking agent possessing a solubility parameter (SP value) of less than 12.5 (cal/cm.sup.3).sup.1/2 and exhibiting reactivity with the carboxyl group and then subjecting the resultant mixture to a heat treatment at a temperature not less than 160.degree. C.

The invention provides [I] a water-absorbing agent composed of a water-absorbing resin powder having the molecular chains near its surface being crosslinked, said powder being obtained by mixing 100 parts by weight of a powder of a carboxyl-containing water-absorbing resin selected from the group consisting of a hydrolyzate of a starch-acrylonitrile graft polymer, a partially neutralized product of a starch-acrylic acid graft polymer, a saponification product of a vinyl acetate-acrylic ester copolymer, a hydrolyzate of an acrylonitrile copolymer, a crosslinked product of a hydrolyzate of an acrylonitrile copolymer, a hydrolyzate of an acrylamide copolymer, a crosslinked product of a hydrolyzate of an acrylamide copolymer, a partially neutralized product of polyacrylic acid, and a crosslinked product of partially neutralized polyacrylic acid with 0.001 to 10 parts by weight of a polyhydric alcohol, 0.01 to 8 parts by weight of a hydrophilic organic solvent and 0 to 8 parts by weight of water, and heating the mixture at a temperature of at least 90.degree. C. to react the water-absorbing resin powder with the polyhydric alcohol; [II] a water-absorbing agent composed of a mixture of the water-absorbing agent [I] with finely divided silica; [III] a water-absorbing agent obtained by pulverizing and granulating a mixture of the water-absorbing agent [I] with an aqueous liquid; and [IV] a water-absorbing agent composed of a mixture of the water-absorbing agent [III] with finely divided silica.

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Takarazuka, Japan

Yoshihiko Masuda