Method for making high water absorption resin

Abstract

The invention provides a method for manufacturing a water absorbing resin in a stable manufacturing mode; the method adds a polymerization reaction initiator into water-soluble unsaturated monomers for carrying out polymerization reaction so as to generate an opaque aqueous solution of unsaturated monomers or prepare the water absorbing resin under the polymerization reaction temperature of hydrogel. The obtained water absorbing resin is characterized by good physical property expression and low content of soluble compositions.

Description

technical field [0001] Superabsorbent resins are widely used as water retaining agents in agriculture or gardening, anti-dew condensation agents in building materials and materials for removing moisture from petroleum, or outer waterproof coating agents in cables and hygienic Supplies such as diapers, feminine hygiene products, disposable wipes, etc. [0002] Since the above-mentioned superabsorbent resin comes into direct contact with the human body, the safety of the superabsorbent resin becomes very important. Generally speaking, the physical properties that a superabsorbent resin must possess include absorption rate, absorption force, absorption rate under pressure, and gel force after absorption. An excellent superabsorbent resin not only needs to meet the above physical properties, but more importantly, it must have good safety. Background technique [0003] Well-known component materials of superabsorbent resins include hydrolyzed starch-acrylonitrile (hydrolyzed st...

AI Technical Summary

Problems solved by technology

When there are more soluble components, the absorption rate of the water-absorbent resin and the liquid-through performance of the liquid will be greatly reduced; however, there are problems of high residual unreacted monomer, low retention force and low absorption rate characteristics under higher pressure; However, the superabsorbent resin produced by polymerizing water-soluble unsaturated monomers with a specific neutralization ratio by the post-stage neutralization method (US Patent No. 4,654,039) has the advantages of low soluble components and high absorption rate. However, There are many residual unreacted monomers, and because the production is carried out by the post-stage neutralization method, the operability is not good; US Patent Publication No. 20020086956 provides a suspension polymerization manufacturing method that controls the polymerization reaction temperature, and prepares a low residual Water-absorbent resin with unreacted monomers, low soluble components and high absorption rate, but the problem is that the polymerization reaction is carried out in the form of suspension polymerization, which will cause residual solvents and cause harm to the human body during use, while US Patent No. 6693159 will The reaction temperature during polymerization is controlled within the range of 45-100°C, and the supercritical fluid method with high production cost is used to control the diameter of the pores of the water-absorbent resin. However, the high production cost is the biggest disadvantage of this process

Using a copolymer of acrylic acid and acrylamide, and controlling the reaction temperature during polymerization in the range of 50-110°C (US Patent No. 5,496,890), a water-absorbent resin with high absorption efficiency can be prepared, but its acrylamide residue will cause the use of hazards to the human body