METHOD FOR PRODUCING WATER-ABSORBENT RESIN
First Claim
1. A method for producing a water-absorbent resin comprising mixing a monomer composition, which contains at least a monomer and a pyrolytic polymerization initiator, with an organic solvent,wherein a temperature of the organic solvent is not lower than 70°
- C. at time of mixing, andwherein, when a mass per unit time of the monomer in the monomer composition that is mixed with the organic solvent per unit time is expressed as an amount per unit volume of the organic solvent, a lower limit is 0.01 g/ml/min and an upper limit is 0.2 g/ml/min.
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Accused Products
Abstract
[Object] To provide a method for stably producing a water-absorbent resin in powder form or particle form, which has excellent physical properties such as water absorption performance and the like, without any production trouble.
[Solution] A method for producing a water-absorbent resin includes mixing a monomer composition, which contains at least a monomer and a pyrolytic polymerization initiator, with an organic solvent, a temperature of the organic solvent is not lower than 70° C. at time of mixing, and when a mass per unit time of the monomer in the monomer composition to be mixed with the organic solvent is expressed as an amount per unit volume of the organic solvent, a lower limit is 0.01 g/ml/min, and an upper limit is 0.2 g/ml/min.
9 Citations
13 Claims
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1. A method for producing a water-absorbent resin comprising mixing a monomer composition, which contains at least a monomer and a pyrolytic polymerization initiator, with an organic solvent,
wherein a temperature of the organic solvent is not lower than 70° - C. at time of mixing, and
wherein, when a mass per unit time of the monomer in the monomer composition that is mixed with the organic solvent per unit time is expressed as an amount per unit volume of the organic solvent, a lower limit is 0.01 g/ml/min and an upper limit is 0.2 g/ml/min. - View Dependent Claims (2, 3, 4, 5, 6, 7, 11)
- C. at time of mixing, and
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8. A reaction device for a water-absorbent resin comprising a supply portion, a reaction portion and a discharge portion,
wherein the supply portion has at least one supply port for a monomer composition, and at least one supply port for an organic solvent composition, and wherein the discharge portion has at least one or more discharge ports through which a reaction solvent and a hydrous gel in particle form are discharged.
Specification