Patent ID: 7838569
Filing Date: 2010-11-23
Classification: A61L,C08J

Abstract:
1. A method of surface cross-linking superabsorbent polymer particles which comprises the steps of a) providing superabsorbent polymer particles having a surface and a core and having a degree of neutralization of more than 60 mol-%; b) applying one or more Brønsted acids in a concentration of 0.005-10% by weight of the superabsorbent polymer particles onto the surface of the superabsorbent polymer particles; and either c1) exposing said superabsorbent polymer particles to irradiation with vacuum UV radiation having a wavelength from 100 nm to 200 nm or c2) exposing said superabsorbent polymer particles to irradiation with UV radiation having a wavelength from 201 nm to 400 nm and wherein further to the Brønsted acids, a radical former molecule is applied to the surface of the superabsorbent polymer particles, to form surface cross-linked superabsorbent polymer particles; wherein the surface cross-linked superabsorbent polymer particles have a higher absorbency against pressure of 4.83 kPa than the superabsorbent polymer particles prior to being subjected to the method.