Use of zirconium salts to improve the surface sizing efficiency in paper making

摘要

An aqueous surface sizing composition for sizing paper or paperboard having as essential components 50 to 70 pads of a water soluble or water dispersible hydroxylated polymer, an amount of a carboxylated polymer that is present relative to hydroxylated polymer in a ratio of 0.5:99.5 to 4:96 and not exceeding 7 pads carboxylated polymer, 0.3 to 3.0 pads of an alkali salt of a Group IV metal (e.g., zirconium, hafnium, and titanium), and sufficient water to obtain 1.5 to 2.0 percent total solids. The sizing compositions may further include polymeric additives, aqueous alkali, a pigment and a defoamer.