Paper wet-strength improvement with cellulose reactive size and amine functional poly(vinyl alcohol)

摘要

The wet strength of cellulosic paper is improved by adding the combination of an amine-functional poly(vinyl alcohol) and a cellulose reactive size which is a 4 or 5 membered cyclic ester or anhydride having alkyl or alkenyl substituents of 4 or more carbon atoms. The amine-functional polymer is preferably a hydrolyzed copolymer of vinyl acetate and N-vinylformamide in which about 1-25 mole % of the monomer units are incorporated N-vinylformamide, and the cellulose reactive size is preferably an alkyl ketene dimer or an alkenyl succinic anhydride. A paper product is provided having improved wet-strength and containing normally 0.05 to 4.0 wt % based on the dry pulp of the additive amine-functional polymer and cellulose reactive size. The particular compounds which represent the polymer and the size cooperate to provide improvements in wet-tensile strength for paper which could not have been foreseen from the effects of either material acting alone.