公开(公告)号：DE59610360D1

公开(公告)日：2003-05-28

申请号：DE59610360

申请日：1996-07-01

Applicant: BASF AG

Inventor： ENGELHARDT DR ,  STUEVEN DR ,  DANIEL THOMAS DR ,  HERFERT DR

IPC: A61L15/34 ,  A61L15/60 ,  C08J3/075 ,  C08J3/12 ,  C08J7/04 ,  C08L1/28 ,  C08L3/08 ,  C08L91/06 ,  C09D123/06 ,  C09D123/30 ,  C09D191/06

Abstract: Hydraulic, highly swellable hydrogel (H)- coated with 0.05 - 2 wt.% unreactive, water-insoluble wax (w.r.t. (H)). Also claimed are: (i) the prepn. of (H) by applying the wax onto the hydrogel; and (ii) a method for preventing hydrogels getting dusty by coating them with 0.05 - 2 wt.% wax. Pref. the wax has a m.pt. or drip temp. of 30-180 degrees C and is pref. grafted montan wax or polyethylene wax (oxidate). The hydrogel is coated with 0.1-0.95 wt% wax. (H) is a polymer comprising (co)polymerised hydrophilic monomers, graft (co)polymer comprising one or more hydrophilic monomers grafted onto a suitable backbone, cross-linked cellulose- or starch ether, or natural substance swellable in aq. liq(s)..