Patent ID: 7393908
Filing Date: 2008-07-01
Classification: C08F

Abstract:
1. Crosslinked water-swellable addition polymer consisting of polymerized units of a) a water-soluble monoethylenically unsaturated monomer selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid, α-chloroacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid. aconitic acid, fumaric acid, an alkali metal salt or ammonium salt of these acids, acrylamide, methacrylamide, crotonamide, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminopropyl acrylate, diethylaminopropyl acrylate, dimethylaminobutyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoneopentyl acrylate, dimethylaminoneopentyl methacrylate, and mixtures thereof, b) from 0.001 to 5 mol % based on the monomers a) of a crosslinker combination the molar ratio of b1) to b2) being in the range from 3:2 to 5:1, and c) and up to 20 mol %, based on the monomers a), of a monomer selected from the group consisting of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylonitrile, methacrylonitrile, an ether of acrylic acid or methacrylic acid with a monohydric alcohol having 1 to 18 carbon atoms, diethyl fumarate, diethyl maleate, dimethyl maleate, dibutyl maleate, vinyl acetate, and vinyl propionate.