Method for preparing water absorption polymer with high liquid absorption speed, dispersity and dried degree

Abstract

The invention discloses a preparation method of absorbent polymer which is characterized in high speed rate of liquid absorption, good dispersibility and high dry-touch degree. Acrylic acid is added into sodium hydroxide aqueous solution, which is uniformly mixed with acrylamide and then crosslinking agent, and foam stabilizer aqueous solution is added; while being aerated with nitrogen gas, the solution is ordinally added with polymerization initiator azodi (2-amidinopropane hydrochloride) aqueous solution, ammonium persulphate aqueous solution, sodium bisulfite aqueous solution and uniformly mixed; the aeration of nitrogen gas is stopped, and when the temperature of the solution is raised to 35 to 45 DEG C, the solution is added with foamer aqueous solution and uniformly mixed, so that porous gel is obtained; when the temperature is raised to 100 DEG C to 110 DEG C, the porous gel is put in the temperature environment of 80 to 90 DEG C for two the three hours; after being cooled down, the porous gel is taken out of a container, scissored into pieces, dried, crumbled and filtered, and grains are collected; crosslinking treatment agent is sprayed on the surface of grains, and after stirring and heating, the absorbent polymer is obtained. In three minutes, the volume of saline absorbed by the product prepared by the invention can reach 70 ml / gSAP.

Description

technical field [0001] The invention relates to a method for preparing a water-absorbing polymer, in particular to a method for preparing a water-absorbing polymer with high liquid absorption rate, excellent dispersibility and dryness. Background technique [0002] As a superabsorbent polymer (SAP) for hygienic absorbent products such as baby diapers, women's sanitary napkins, mattresses for incontinent patients or the elderly, its liquid absorption rate is a crucial performance indicator. At present, the liquid absorption rate of the SAP made by the mixed aqueous solution polymerization of monomers, crosslinking agents and initiators cannot meet the requirements of sanitary absorbent products. In order to solve this problem, it is usually on the SAP particles obtained above. Surface cross-linking treatment is carried out to make SAP form a shell structure with high cross-linking density on the surface, so as to prevent SAP from quickly forming a layer of adhesive gel barrie...

AI Technical Summary

Problems solved by technology

However, the amount of saline absorbed by the surface-crosslinked SAP is still no more than 50ml / gSAP in three minutes, and there is a certain gap compared with the product SAP of Japan's Sumitomo Seika, (Japan's Sumitomo Seika) The volume of the company's SAP products inhaling physiological saline within three minutes is 70ml / gSAP

[0004] The US5118719 patent disclosed by U.S. Nalco Chemical Company in 1992 is about adding a carbonate foaming agent to the monomer aqueous solution before polymerization to make SAP form a porous structure to improve the water absorption rate, but it has deficiencies in the foaming process Yes, the blowing agent is added 5-15 minutes before adding the polymerization initiator. In fact, the polymerization reaction still needs a period of induction period after adding the initiator. During such a long time, the viscosity of the system is not large, and the generated bubbles will Diffusion rapidly, merging and becoming larger, or even disappearing more than half, the effect of pore formation is very poor