Patent ID: 6586549
Filing Date: 2003-07-01
Classification: A61L,C08J,C08L

Abstract:
A water-absorbing composition, which comprises a mixture of a water-absorbent resin and an excessive-liquid permeation buffer, wherein the water-absorbent resin is a product obtained by a process including the step of further crosslinking the surface vicinity of a crosslinked polymer having an average particle diameter in the range of 200-600 &mgr;m, wherein the ratio of particles having particle diameters smaller than 106 &mgr;m in the crosslinked polymer is not more than 5 weight %, with the water-absorbing composition being characterized by having a liquid permeation buffering index of not less than 0.4 and exhibiting an absorption capacity of not less than 25 g/g in absorbent structures under load, and further having an average particle diameter in the range of 200Ëœ600 &mgr;m, wherein the ratio of particles having particle diameters smaller than 106 &mgr;m in the water-absorbing composition is not more than 5 weight %, wherein:said liquid permeation buffering index is calculated by the following formula: Liquid permeation buffering index=10/{(weight W1 (g))/(weight (g) of water-absorbing composition)}wherein W1 is the weight in grams of a physiological saline solution absorbed by said water-absorbing composition over a period of 60 minutes under a load of 20 g/cm2 (=about 1.9 kPa); andthe conditions for measuring said absorption capacity in absorbent structures under load are that: (i) the load is 20 g/cm2 (=about 1.9 kPa); (ii) the liquid being absorbed is physiological saline solution; and (iii) the absorption quantity is measured over a period of 60 minutes.