Nippon Shokubai Co., Ltd.

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Akito Yano

Takumi Hatsuda

Koji Miyake

Yorimichi Dairoku

Nobuyuki Harada

Kinya Nagasuna

Hideyuki Tahara

Yoshihiro Motono

Teruyuki Kanto

Takanori Murakami

Kunihiko Ishizaki

Yoshio Irie

Shigeru Sakamoto

Yasuhiro Fujita

Katsuhiro Kajikawa

Kazuki Kimura

Kazumasa Kimura

Toshimasa Kitayama

Toru Yanase

Yoshinobu Haruna

Teruaki Fujihara

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%. The method is advantageously carried out by the use of an apparatus for the production of a shaped hydrogel of absorbent resin which comprises a movable endless revolving support belt, a monomer mixture supplying device, and a device for discharging the shaped hydrogel of absorbent resin, the apparatus preferably being provided near each of the opposite lateral parts of the movable endless revolving support belt with a lateral weir adapted to move in concert with the belt or being provided near each of the opposite lateral parts of the movable endless revolving support belt with a lateral weir fixed in such a manner as to contact the belt in a sliding state. The method of this invention permits production of a shaped hydrogel of absorbent resin intended to afford an absorbent resin which exhibits high absorption capacity, little water-soluble content and little residual monomer only in small amounts, and enjoys a high productivity rate.

Method for production of shaped hydrogel of absorbent resin

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.

Production process of hydrophilic crosslinked polymer

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.

Method of producing hydrophilic resin

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.

Water-absorbent resin and method for production thereof

Method of production of water-absorbing resin

Water absorbing agent, manufacturing method thereof, and manufacturing

A method of treating the surface of an absorbent resin, which comprises mixing (A) 100 parts by weight of an absorbent resin powder possessing a carboxyl group (B) 0.01 to 30 parts by weight of a cross-linking agent, (C) 0 to 50 parts by weight of water, and (D) 0 to 60 parts by weight of a hydrophilic organic solvent in a high-speed stirring type mixer provided with an inner surface formed substantially of a substrate (I) possessing a contact angle of not less than about 60.degree. with respect to water and a heat distortion point of not lower than about 70.degree. C. and completing reaction of said absorbent resin powder (A) with said cross-linking agent (B).

Method of treating the surface of an absorbent resin

A method for the production of an absorbent polymer by the polymerization of a liquid containing an aqeous hydrophilic monomer solution in a reaction vessel provided with at least one rotary stirring blade, which comprises polymerizing said hydrophilic monomer in a reaction vessel wherein, at least a portion of the inner wall surface of said reaction vessel repeatedly exposed to said aqueous solution or said absorbent polymer and a gas has the surface roughness, R.sub.max, thereof adjusted to not more than 3 .mu.m and at the same time said portion of the inner wall of surface is kept cooled constantly to a temperature of not more than 70.degree. C. from behind said portion with a cooling medium.

Method for production of absorbent polymer

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Himeji, Japan

Akito Yano