RU96108784A - POWDER-POLYMERS ABSORBING WATER LIQUIDS, THE METHOD FOR PRODUCING THEM AND THEIR APPLICATION AS ABSORBENTS - Google Patents

Claims (15)

1. A powdery, insoluble, water-swellable, crosslinked, water-absorbing, aqueous or serous liquid polymerizate formed from a) 55.0 to 99.9 wt.% Polymerized unsaturated, containing polymerizable acid groups of monomers, which are at least 25 mol. % neutralized; b) 0 to 40 wt.% polymerized unsaturated copolymerizable with a) monomers; c) 0.1 to 5.0% by weight of a crosslinking agent; and d) 0 to 30% by weight of a water-soluble polymer, mass amounts from a) to d) given in terms of an anhydrous polymer, and the polymerised powder is heat treated with a compound which can react with acid groups and has at least two functional groups, at 150 - 250 ^o C when crosslinking on the surface, characterized in that the polymerizate in the powder is recycled by surface crosslinking using 0.1 to 5.0 wt.% compounds with at least two functional groups that can react with acid groups, at 150 - 250 ^o C. 2. The absorbent polymer according to claim 1, characterized in that it has a retention of at least 34 g of a 0.9% sodium chloride solution per g of resin, an absorption of at least 18 g, preferably at least 20 g of 0, 9% sodium chloride solution per 1 g of resin at a pressure of 60 g / cm ² and absorption of at least 12 g of a 0.9% sodium chloride solution per 1 g of resin with a surface content exceeding 90 mg of resin per 1 cm ² and a swelling pressure of at least 600 g.  3. The absorbent polymer according to paragraphs. 1 and 2, characterized in that it is formed from acrylic, methacrylic and / or 2-acrylic-amido-2-methylpropanesulfonic acid as monomers containing acidic groups.  4. The absorbent polymerizate according to one of claims 1 to 3, characterized in that the monomers containing acid groups are neutralized by at least 50 mol%.  5. The water-absorbing polymerizate according to one of claims 1 to 4, characterized in that it is formed from acrylic acid, which is neutralized by 50 - 80 mol.%.  6. Water-absorbing polymerizate according to one of claims 1 to 5, characterized in that it contains water-soluble polymers in concentrations of 1 to 5 wt.%.  7. Water-absorbing polymerizate according to one of claims 1 to 6, characterized in that it contains starch and / or polyvinyl alcohol as water-soluble polymers.  8. The absorbent polymerizate according to one of claims 1 to 7, characterized in that the acid groups of the polymer represent carboxyl groups and the secondary surface crosslinking treatment is carried out with the same crosslinking agent as in the first processing step.  9. The absorbent polymerizate according to claims 1 to 7, characterized in that the acid groups of the polymer represent carboxyl groups and the secondary surface crosslinking treatment is carried out with a crosslinking agent other than the first stage of treatment or with mixtures of such agents.  10. The absorbent polymer according to claims 1 to 9, characterized in that the crosslinking agent on the surface are polyhydric alcohols, polyamines, alkylene carbonates.  11. The absorbent polymer of claim 10, wherein the surface crosslinking agents are ethylene carbonate, glycerin, dimethylolpropionic acid, polyethylene glycol and triethanolamine, and these agents are, if necessary, used in the form of aqueous solutions. 12. A method of obtaining a powder of water-insoluble, crosslinked absorbent aqueous and serous liquids polymerizate, which is formed from a) 55.0 - 99.9 wt.% Polymerized unsaturated, containing polymerizable acid groups of monomers, which are at least 25 mol. % neutralized; b) 0 to 40 wt.% polymerized unsaturated copolymerizable with a) monomers; c) 0.1 to 5.0% by weight of crosslinking agent; and d) 0 to 30% by weight of a water-soluble polymer, and the mass amounts of a) to d) are given in terms of the anhydrous polymer (by heat treatment at 150 - 250 ^o C ) a polymerizate in powder with a compound with at least two functional groups that can react with acidic groups, characterized in that the polymerizate in powder is secondly subjected to surface crosslinking using 0.1 to 5.0 wt.% of the compound with at least two functional groups that can react with an acid group and, at 150 - 250 ^o C.  13. Water-absorbing polymers according to paragraphs. 1 to 11, used as absorbents for water and aqueous fluids, especially in products for absorbing body fluids.  14. The polymerizes according to claims 1 to 11, used in absorbent products of water and aqueous liquids that contain hydrophilic fibers and 2 to 80 wt.% Powdered polymerizate, calculated on the total weight.  15. The polymerizes according to claims 1 to 11, used as components that absorb water or aqueous liquids in current- or light-conducting cables as a component of packaging materials, as a means of improving the soil, and as an artificial nutrient medium for growing plants.