Patent ID: 6762267
Filing Date: 2004-07-13
Classification: A61K,B29B,B29K,C08J

Abstract:
A granular polyacrylic acid product produced by a process comprising:(a) delivering a fine powder consisting essentially of anhydrous polyacrylic acid to a compaction device; (b) compacting said polyacrylic acid into larger agglomerates and/or aggregates; (c) fracturing said agglomerates and/or aggregates into smaller granules; (d) optionally screening said smaller granules to obtain the desired particle size range by removing or recycling in said process oversized and/or undersized granules, wherein the granular product has the following properties: (i) a flow index of &lE;25, (ii) a bulk density of at least 0.35 g/cc, and (iii) less than 5 wt. % particles are fine enough to pass through a U.S. Standard 325 mesh screen, and, (iv) said polyacrylic acid being a polymer of one or more monomers characterized by having at least 50 mole percent repeating units having a carboxylic acid group or an anhydride of dicarboxylic acid and when dispersed in water and neutralized to a pH of 7 at a concentration of 10 g/L imparting a viscosity of at least 400 centipoise to said water.