Thermosetting size press composition

摘要

A thermosetting size applyable to paper in a size press and curable at a temperature not in excess of about 280 DEG F. for 10 seconds is disclosed. This size comprises an aqueous emulsion comprising water having suspended therein aqueous emulsion copolymer particles of monoethylenically unsaturated monomers comprising hydroxy-functional monomer having an hydroxy number of at least about 20, and the balance of the monomers provides a water insoluble polymer having a glass transition temperature of from about -20 DEG C. to about 50 DEG C. The emulsion has a pH greater than about 2.5, preferably from 4.0 to 7.0, and a stoichiometric deficiency of an aminoplast cross-linking agent is used for cure. An acid curing catalyst is uniformly distributed in the size to speed the cure.