Patent ID: 7498391

Claim:
A process for preparing cationic polyvinyl acetals, comprising copolymerizing one or more cationic N-alkyldiallylammonium salt monomers with one or more vinyl esters of branched or unbranched carboxylic acids having 1 to 15 carbon atoms to form a vinyl ester copolymer; hydrolyzing the vinyl ester copolymer to a hydrolyzed copolymer containing >50 mol % vinyl alcohol units; and acetalizing vinyl alcohol units with one or more aliphatic aldehydes having 1 to 15 carbon atoms, their acetals, hemiacetals, or mixtures thereof, wherein copolymerizating takes place in a mixture of water and monovalent aliphatic alcohol having a water fraction of 2% to 35% by weight, and the cationic polyvinyl acetal product is isolated as a suspension or dispersion in water, or as a solid from aqueous dispersion or suspension.