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Method for producing water-absorbing resin

A technology of water absorption and resin, which is applied in the direction of absorbent pads, medical science, bandages, etc., can solve the problems of high water absorption and less dissolved components, and achieve the effect of less dissolved components, fast water absorption and high water absorption

Active Publication Date: 2007-01-17
SUMITOMO SEIKA CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the water-absorbent resins prepared by these methods do not fully satisfy the performance requirements of high water retention capacity and high water absorption under pressure, and at the same time, fast water absorption speed and low dissolved components, and there is room for further improvement.

Method used

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  • Method for producing water-absorbing resin

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] Add 340 g of n-heptane and 0.92 g of sucrose fatty acid ester [manufactured by Mitsubishi Chemical Co., Ltd., Trade name: S-370], after dispersing, heating and dissolving, cool to 55°C.

[0062] In addition, 92 g (1.02 mol) of 80 wt % acrylic acid aqueous solution was added to a 500 ml Erlenmeyer flask, and then 102.2 g (0.77 mol) of 30 wt % sodium hydroxide aqueous solution was added dropwise while cooling from the outside to neutralize 75 mol % of acrylic acid. , and further added 50.2 g of water, 0.11 g (0.00041 mol) of potassium persulfate and 8.3 mg (0.000047 mol) of ethylene glycol diglycidyl ether to prepare an aqueous monomer solution for the first step of polymerization.

[0063] Add all the monomer aqueous solution used in the first step of polymerization into the aforementioned round bottom flask under stirring to disperse it, and after fully replacing the system with nitrogen, raise the liquid temperature of the content liquid to 70°C. After the polymerizat...

Embodiment 2

[0068] 222.5 g of a water absorbent resin having a mass average particle diameter of 370 μm was obtained in the same manner as in Example 1 except that the amount of disodium phosphite pentahydrate was changed to 0.36 g (0.0017 mol).

Embodiment 3

[0070] Add 340 g of n-heptane, 0.92 g of sucrose fatty acid ester [manufactured by Mitsubishi Chemical Co., Ltd., Product name: S-370], disperse, heat up and dissolve, then cool to 55°C.

[0071] Separately, 92 g (1.02 mol) of an 80% by weight acrylic acid aqueous solution was placed in a 500-ml Erlenmeyer flask. Then, cooling from the outside, 102.2 g (0.77 mol) of 30 weight% sodium hydroxide aqueous solution was dripped, and 75 mol% of acrylic acid was neutralized. Further, 50.2 g of water, 0.11 g (0.00041 mol) of potassium persulfate and 8.3 mg (0.000047 mol) of ethylene glycol diglycidyl ether were added to prepare an aqueous monomer solution for the first-step polymerization.

[0072] Add all the monomer aqueous solution used in the first step of polymerization into the aforementioned round-bottomed flask to disperse under stirring, fully replace the inside of the system with nitrogen, and then raise the temperature of the liquid to 70°C. After the polymerization was ca...

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Abstract

A method for producing a water-absorbing resin wherein a water-soluble ethylenically unsaturated monomer is subjected to a reversed phase suspension polymerization process having multi polymerization stages of two or more, characterized in that in at least one polymerization stage of the second or later stages, a phosphorus compound is added and the polymerization is carried out in the presence of the phosphorus compound. A water-absorbing resin produced by the above method can be suitably used for manufacturing a hygienic material, such as a disposable diaper, an adult incontinence pad or a sanitary napkin, in particular, a disposable diaper.

Description

technical field [0001] The present invention relates to the preparation method of water-absorbent resin. More specifically, it relates to a method for producing a water-absorbent resin suitable for use in hygienic materials such as incontinence pads and sanitary napkins, especially disposable diapers. Background technique [0002] In the past, water-absorbent resins have been widely used in sanitary materials such as paper diapers and sanitary napkins, and industrial materials such as waterproof materials for cables. As water-absorbent resins, for example, hydrolyzate of starch-acrylonitrile graft copolymer, neutralized product of starch-acrylic acid graft copolymer, saponified product of vinyl ester-acrylic acid ester copolymer, partially neutralized product of polyacrylic acid Wait. [0003] In recent years, hygienic materials such as disposable diapers and sanitary napkins tend to have thinner absorbent bodies from the viewpoint of comfort during use. When the absorben...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F2/20C08F2/38C08F2/32
CPCC08F2/32A61L15/60C08F2/18C08F2/20C08K3/32
Inventor 宇田新一川北知纪绳田康博
Owner SUMITOMO SEIKA CHEM CO LTD