Sizing

Abstract

Sizing bath for a non-woven cellulose based substrate in which the bath has a pH of 2 to 12 and contains as sizing agent at least one anionic latex of at least one copolymer of which the vitreous transition temperature is -40.degree. C. to +120.degree. C. and of which the K value is 55 to 130, the copolymer containing in interpolymerised form: A. 35% to 80% by weight of at least one ester of acrylic and/or methacrylic acid with an alcohol containing 1 to 18 carbon atoms and/or at least one vinyl ester of a carboxylic acid containing 1 to 18 carbon atoms, B. 20% to 50% by weight of acrylic, methacrylic, crotonic or itaconic acid, or a mixture thereof, C. 0% to 20% by weight of at least one monomer having an ethylene linkage and at least one polar group or containing several ethylene linkages, D. 0% to 30% by weight of at least one halogenated or nonhalogenated hydrocarbon containing at least one double bond and 2 to 18 carbon atoms, the latex containing 20% to 50% by weight of dry material, having a pH of 2 to 7, and having the property of thickening by treatment with alkali; process for the surface sizing of a non-woven, cellulose-based substrate which comprises impregnating the substrate in such a sizing bath and non-woven cellulose-based substrates sized by this process.

Dependencies are inferred from the claim text.