Method for preparing super absorbent resin with low residual acrylic monomer content

A technology of superabsorbent resin and acrylic acid monomer, which is applied in the field of preparing superabsorbent resin with low residual acrylic acid monomer content, which can solve the problems of reduced drying efficiency, clogged nozzle production, high solution viscosity, etc., and achieve the effect of long drying time

Active Publication Date: 2011-07-20
SHANGHAI HUAYI NEW MATERIAL
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Patent CN1628146A sprays high-molecular-weight ethyleneimine polymer solution into the superabsorbent resin surface cross-linking process to reduce the residual monomer content of acrylic acid in the product, although this method can reduce the residual monomer content of acrylic acid in the product to a certain extent However, due to the addition of polymer additives, on the one hand, the viscosity of the solution is high, and it is easy to cause blockage of the nozzle in the industrial production process, which brings difficulties to production; on the other hand, the color of the polymer will cause The color of the prepared product is accentuated, which is not desired by users of hygienic materials
Patent CN101333261A is to pre-dry the water-containing granular gel at 80-120°C, and then completely dry the gel particles at 130-160°C. The patent example shows that although this method can remove the residual monomer in the final superabsorbent resin product The volume drops to between 120 and 380ppm, which is actually not enough for the production of high-end superabsorbent resin products. In addition, the use of secondary drying will reduce the drying efficiency. For industrial production, energy consumption will increase. Manufacturing enterprises Dry form like this is also not welcome

Method used

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  • Method for preparing super absorbent resin with low residual acrylic monomer content

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Gel preparation:

[0024] at 1m 3 Add 293 kilograms of sodium hydroxide aqueous solution (32wt%) and 272 kilograms of deionized water into the reaction kettle, start the stirring of the reaction kettle, slowly add 225 kilograms of acrylic acid dropwise, keep the temperature of the reaction kettle at 20-30 ° C, and the addition of acrylic acid is completed , add 0.5 kilogram of crosslinking agent N, N-methylenebisacrylamide and 0.25 kilogram of crosslinking agent ethoxytrimethylolpropane triacrylate, then add 0.9 kilogram of initiator potassium persulfate, continue to stir, to reaction The kettle was filled with nitrogen, and the temperature of the reactor was kept at 20-30°C. The above-mentioned mixed material was continuously fed into a continuous conveyor belt with a length of 600cm and a width of 40cm at a flow rate of 48kg / hr for polymerization. The temperature of the conveyor belt was controlled at 85± 5°C, the reaction residence time is 1.5 hours, and the superab...

Embodiment 2

[0028] The preparation of gel is the same as in Example 1, and the disintegrating process of gel is the same as in Example 1. The difference is that the concentration of the initiator potassium persulfate aqueous solution sprayed into the disintegrating process is 1% by weight, and the amount added is 1% by weight. The weight is 3% by weight, and the crosslinking agent is a tripropylene glycol dimethacrylate crosslinking agent solution with a concentration of 0.5% by weight, and the added amount is 5% by weight of the weight of the gel. After 2 minutes of microwave radiation on the disintegrated material, the product obtained by drying, crushing and post-surface cross-linking treatment has been tested. The residual content of acrylic acid monomer is 50ppm, and the absorption rate of normal saline under load pressure is 30.35g / g.

Embodiment 3

[0030] The preparation of the gel is the same as in Example 1, and the disintegrating process of the gel is the same as in Example 1. The difference is that the aqueous solution of initiator potassium persulfate and ascorbic acid is sprayed into the disintegrating process, and the concentration of the aqueous solution is 0.5% by weight. The amount is 5% by weight of gel weight, and the addition type and consumption of crosslinking agent are the same as embodiment 1. After the disintegrated material was irradiated by microwave for 2 minutes, the product obtained by drying, crushing and post-surface crosslinking treatment was tested by performance. The residual content of acrylic acid monomer was 36ppm, and the absorption rate of normal saline under load pressure was 32.08g / g.

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Abstract

The invention discloses a method for preparing super absorbent resin with low residual acrylic monomer content. In the method, initiator solution and crosslinking agent solution are added in the process of making gel particles of the super absorbent resin, the gel particles added with the initiator solution and the crosslinking agent solution are subjected to microwave radiation, and the hydrogel particles are completely dried. The super absorbent resin product prepared by the process has low acrylic monomer content, and the liquid absorbing capacity of the product under load pressure is improved.

Description

technical field [0001] The present invention relates to a method for preparing superabsorbent resin with low residual acrylic acid monomer content. Background technique [0002] Acrylic superabsorbent resin is widely used in hygienic fields such as baby diapers, women's sanitary napkins, and adult incontinence products because of its moderate price, high safety, and good comprehensive performance. [0003] Since acrylic superabsorbent resins are mostly used in places that are in direct contact with human skin, the performance requirements for their products are particularly strict, especially the content of residual acrylic acid monomers in products, because the content of acrylic acid monomers exceeds Certain indicators can produce uncomfortable sensations such as allergies or itching on human skin, which is not desired by inventors, manufacturers of hygiene products or users. [0004] Patent CN1628146A sprays high-molecular-weight ethyleneimine polymer solution into the s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J7/18C08L33/02C08F265/02
Inventor 王月珍连旭罡周柳茵马建学禇小东邵敬铭
Owner SHANGHAI HUAYI NEW MATERIAL
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