Alkai-soluble, water-resistant binders for non-woven materials

Claim 1

A cellulosic non-woven material containing from 2% to 25% by dry weight of the alkali-soluble, water-resistant in neutral to weakly acidic solutions, binder for cellulosic non-woven material consisting essentially of an aqueous vinyl acetate copolymer dispersion having a solids content of from 10% to 60% by weight and the following range of monomeric units: (1) 50% to 70% by weight of the monomer units of vinyl acetate units, (2) 20% to 35% by weight of the monomer units of higher molecular weight ethylenically-unsaturated ester units selected from the group consisting of vinyl esters of alkanoic acids having from 8 to 18 carbon atoms, alkyl esters having from 4 to 18 carbon atoms in the alkyl of acrylic acid, alkyl esters having from 4 to 18 carbon atoms in the alkyl of methacrylic acid, and mixtures thereof, and (3) 3% to 15% by weight of the monomer units of ethylenically-unsaturated acid units selected from the group consisting of alkenoic acids having 3 to 4 carbon atoms, alkendioic acids having 4 carbon atoms, alkyl monoesters having from 1 to 18 carbon atoms in the alkyl of alkenedioic acids having 4 carbon atoms, alkenyl monoesters having from 3 to 6 carbon atoms in the alkenyl of alkanedioic acids having 2 to 6 carbon atoms, and mixtures thereof, and containing from 0.5% to 10% by weight, based on the monomer units, of protective colloids and from 0 to 6% by weight, based on the monomer units of emulsifiers, said binder being applied to said cellulosic non-woven material as an aqueous dispersion and subsequently dried.