Patent ID: 7285599
Filing Date: 2007-10-23
Classification: A61L,C08F,C08J,C08L

Abstract:
1. A pulverulent polymer which absorbs water, aqueous or serous liquids as well as blood, which is post-cross-linked on the surface and is synthesized from a) from about 55 to about 99.9 wt. % polymerized, ethylenically unsaturated, acid group-containing monomers which are at least about 25 mol % neutralized, b) from 0 to about 40 wt. % polymerized, ethylenically unsaturated monomers which are copolymerizable with a), c) from about 0.1 to about 5.0 wt. % of one or more polymerized cross-linking agents, d) from 0 to about 30 wt. % of a water-soluble polymer, wherein the sum of the quantities by weight a) to d) is 100 wt. %, wherein the polymer is formed into polymer particles that are coated and post-cross-linked, with heating, with e) from about 0.01 to about 5 wt. %, in relation to the polymer, of an organic surface post-cross-linking agent, with the exception of polyols, in the form of an aqueous solution and with f) from about 0.001 to about 1.0 wt. %, in relation to the polymer, of a trivalent or a higher-valent cation in the form of a salt dissolved in an aqueous solution, g) the polymer particles coated with elements e) and f) are heat treated at a temperature from at least 150 to 250° C. to form the pulverulent polymer, and wherein the total quantity of water of the coating solution is from about 0.5 to about 10 wt %, in relation to the polymer, and the ratio by weight of the salt to the post-cross-linking agent is within the range from about 1:0.8 to about 1:4 wherein the pulverulent polymer has a retention (TB) of at least about 25 g/g and a saline flow permeability (SFC) of about 45×10