US 9,518,180 B2 · Method for producing polyacrylic acid (salt)-based water absorbing agent, and water absorbing agent

Abstract

The present invention relates to an absorbent suitable for use in a thin sanitary material/absorbent article having a high absorbent content and not prone to gel blocking, the absorbent having excellent liquid diffusibility (e.g. SFC) and minimal decrease in absorption ratio under pressure (e.g., AAP or PUP) even when a liquid permeation enhancer is added, and to a method for manufacturing the high-performance absorbent stably during actual production. The method is a method for manufacturing a polyacrylic acid (salt)-based absorbent, having a surface-crosslinking agent addition step for adding a solution of a surface-crosslinking agent, and a liquid permeation enhancer addition step for adding a liquid permeation enhancer, the liquid permeation enhancer addition step being performed after and/or at the same time as the surface-crosslinking agent addition step, the method characterized in that a surface crosslinking step for performing heat treatment in an atmosphere having a dew point of 45° C. to 100° C. is performed after or at the same time as the surface-crosslinking agent addition step.

Claims4

Dependent claims

A polyacrylic acid (salt)-based water absorbing agent having a surface, a periphery of which surface is cross-linked by an organic surface crosslinking agent and is provided with a liquid permeability enhancer, the polyacrylic acid(salt)-based water absorbing agent satisfying the following requirements (A) through (D):

(A) CRC is 25 g/g to 35 g/g;
(B) SFC is not less than 10(×10−7 cm3·sec/g);
(C) soluble component is 5 mass % to 20 mass %;
and
(D) surface-crosslinked layer strength index is not more than 40 provided that surface-crosslinked layer strength index is defined by the following equation:
surface-crosslinked layer strength index=surface soluble component (%)/soluble component (%)×100.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application

14/426,539Filed 20 Aug 2013

Priority

JP 2012-19992311 Sep 2012

Published

US 2015/0210843 A130 Jul 2015

Granted

13 Dec 2016

Term ends

Not estimatedThe source records don’t support an estimate.

Classification13 codes

C08J 3/245
Crosslinking, e.g. vulcanising, of macromolecules: differential crosslinking of one polymer with one crosslinking type, e.g. surface crosslinking
A61L 15/24
Containing macromolecular materials: macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives…
A61L 15/60
Use of materials characterised by their function or physical properties: liquid-swellable gel-forming materials, e.g. super-absorbents
B01J 20/267
Modified or post-treated polymers: cross-linked polymers

Method for producing polyacrylic acid (salt)-based water absorbing agent, and water absorbing agent

Life of this patent

Method for producing polyacrylic acid (salt)-based water absorbing agent, and water absorbing agent

Life of this patent

Abstract

Claims4