Nippon Shokubai Co., Ltd.

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Nippon Shokubai Kagaku Kabushiki Kaisha

Kinya Nagasuna

Katsuyuki Wada

Yoshihiko Masuda

Kunihiko Ishizaki

Kenji Kadonaga

Koji Miyake

Kazumasa Kimura

Nobuyuki Harada

Hirotama Fujimaru

Yorimichi Dairoku

Takumi Hatsuda

Tadao Shimomura

Katsuhiro Kajikawa

Shin-Ichi Fujino

Yoshio Irie

Hiroko Ueda

Takashi Namba

Naoko Takahashi

Yasuhiro Fujita

Masatoshi Nakamura

Kenji Minami

Yoshihiro Motono

Kozo Nogi

Shinichi Fujino

Masazumi Sasabe

Akito Yano

Toru Yanase

Kazutaka Yano

Hiroshi Yamazaki

Kazuki Kimura

Motohiro Imura

Hiroki Inoue

Toshimasa Kitayama

Teruaki Fujiwara

Katsuhiko Sakamoto

Hideaki Nagano

Akiko Mitsuhashi

Koichi Yonemura

Takanori Murakami

Yoshiniko Masuda

Kohichi Hirota

Hideyuki Kubo

Takuni Hatsuda

The present invention provides: an absorbent structure and an absorbent article, which are excellent in both liquid diffusion ability and liquid storage ability, and which are excellent in the dry feeling and the amount of wet back of the aqueous liquid, and which can realize the thinning and lightening more; and a water-absorbent resin fitly usable for the above absorbent structure and absorbent article. The absorbent structure, according to the present invention, comprises a liquid-diffusing member and a water-absorbent resin, with the absorbent structure being characterized in that when the capillary absorption index of the liquid-diffusing member at a height of 40 cm is referred to as A (A&#x2267;0.10), the capillary absorption index B of the water-absorbent resin at a height of 40 cm satisfies the following equation: B/A&#x2267;0.7 (equation 1).

Absorbent structure, absorbent article, water-absorbent resin, and its production process and evaluation method

The present invention provides: a water-absorbing agent which has excellent urine resistance; a water-absorbing agent which has not only excellent urine resistance, but also excellent absorption properties that are stable to any composition of urine and show little change with time; and production processes and uses for these water-absorbing agents. The present invention water-absorbing agent exhibits a specific or larger value of absorption capacity under a load in a process in which the absorption capacity under a load is measured in a new manner using a specific liquid to be absorbed, and the present invention provides an absorbent matter and an absorbent article which display a specific or larger value of new absorption index as is, for example, led from the absorption capacity under a load or from the resin concentration using the above water-absorbing agent. The present invention further provides a production process for a water-absorbing agent having the above specific parameter.

Water-absorbing agent production process with surface crosslinking and ion blocking

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

Water-absorbing agent and its production process and use

A method for producing a porous material excelling in stability of preservation is produced. A method for the production of a porous material comprising a step for obtaining a porous polymer by polymerizing an HIPE containing a polymerizable monomer is disclosed, which method comprises a step for adding a compound capable of reacting with a polymerization initiator and/or a compound capable of reacting with an unsaturated double bond to said emulsion, said porous polymer and/or said porous material having a conversion of not less than 70%. According to this invention, it is made possible to produce a porous material excelling in stability in storage and to decrease the polymerization initiator and the residual monomer very simply.

Method for production of porous material

A method of production is provided which is capable of efficiently producing in a very short period of time a porous polymer possessing a uniform foam structure and truly excelling in absorption properties and physical properties. It is a method for the production of a porous polymer, characterized by comprising (a) an emulsifying step for forming a water-in-oil type high internal phase emulsion (HIPE) by mixing and stirring an oil phase containing a polymerizing monomer component and a surfactant as essential components, (b) a shaping step for shaping the HIPE in a specific form, and (c) a polymerizing step for polymerizing the shaped HIPE and controlling the temperatures of the emulsion at the component steps (a)-(c) so that they may not produce a change exceeding 10&deg; C. or controlling all the component steps so that they may proceed at temperatures of not lower than 80&deg; C.

Process for producing porous polymer

This invention concerns a method for the production of a porous polymer from a water-in-oil type high internal phase emulsion (HIPE). By using an oil-soluble polymerization initiator as the polymerization initiator, the method for producing a porous polymer with outstanding characteristics in a very short period even when the porous polymer is produced from an HIPE exhibiting a viscosity of not more than 500 mPa second at the emulsion formation temperature or when the porous polymer to be produced possesses a number-average pore diameter of not less than 80 &mgr;m is provided.

Water-absorbing agents containing polycarboxylic amine chelating agents. The water-absorbing agents are obtained by a process including the step of adding to a water-absorbent resin at least one chelating agent selected from the group consisting of polycarboxylic amines and maleic hydrophilic polymers. The polycarboxylic amine may be selected from a class that includes N-carboxymethyl-aspartic acid as one of its members or selected from a class that includes N,N&prime;-bis(1,2-dicarboxyethyl)-ethylenediamine as one of its members. The water-absorbing agents have not only excellent urine resistance, but also excellent absorption properties that are stable to any composition of urine and show little change with time.

Water-absorbent agents containing polycarboxylic amine chelating agents

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

An object of this invention is to provide a method for the production of a porous cross-linked polymer, which permits the polymerization (curing) of a water in oil type high internal phase emulsion (HIPE) in such an exceptionally brief time as not more than 30 minutes, preferably not more than 10 minutes without impairing the stability of the HIPE. The object of this invention mentioned above can be accomplished by a method for the production of a porous cross-linked polymer which comprises steps of mixing an oil phase containing a polymerizing monomer, a cross-linking monomer, and a surfactant as essential components with a water phase containing water as an essential component thereby obtaining a water in oil type high internal phase emulsion and heating said emulsion to a prescribed curing temperature thereby polymerizing the emulsion, wherein said emulsion is formed in a thickness of not more than 50 mm and the temperature-increasing rate of the emulsion is not less than 5&deg; C./minute.

Method for production of porous cross-linked poymer

A method for the production of (D) an absorbent resin excelling in durability, which method comprises polymerizing (A) 30% by weight to saturated concentration of (A) an aqueous water-soluble ethylenically unsaturated monomer solution containing (B) 0.005 to 5 mol % of a cross-linking agent and (C) 0.001 to 1 mol % of a water-soluble chain transfer agent, both based on the amount of said monomer (A), and if necessary, the surface region of the resultant absorbent resin (D) is cross-linked with (E) a hydrophilic cross-linking agent capable of reacting with the functional group of the absorbent resin and an absorbent resin obtained by such method.

Method for production of absorbent resin excelling in durability

The present invention provides: a process for producing a water-absorbing agent by using a crosslinking agent of high safety, wherein the water-absorbing agent is excellent in the absorption capacities under no load and under a load and further in the blocking ratio under a load, and can display excellent absorption properties even if the weight percentage of the water-absorbent resin (resin concentration) is high when the water-absorbent resin is used for materials such as sanitary materials; and such a water-absorbing agent. The water-absorbent resin is mixed and treated with an oxazoline compound, wherein the oxazoline compound has at least three structural units of general formula (1) below:

Water-absorbing agent and production process therefor

This invention is targeted at providing a method for producing a porous cross-linked polymer material excelling in absorption properties and mechanical strength in a short period of time. In the production of a porous cross-linked polymer material from an HIPE, the method of this invention is characterized by comprising a step of polymerizing the HIPE till the bromine value thereof falls to not more than 25% of the value existing prior to the polymerization and a subsequent step of after curing the porous cross-linked polymer material by means of an active energy ray or a temperature higher than the polymerization temperature.

Method for production of porous cross-linked polymer material

Production process for water-absorbing agent

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Himeji, Japan

Kinya Nagasuna