Sizing agents for cellulosic products

Claim 1

A process for preparing a sizing composition having improved sizing characteristics, which process comprises combining (A) a first component comprising a material which provides both ammonia and ammonium salt when combined with the other sizing composition components, said ammonia-ammonium salt-providing material being selected from the group consisting of ammonia or precursor thereof; ammonium salts or precursor thereof; the reaction product of urea and at least one Lewis acid selected from sulfuryl chloride, chlorosulfonic acid, thionyl chloride, benzenesulfonyl chloride, benzenesulfonic acid, ortho-toluenesulfonic acid, para-toluenesulfonic acid, ortho-toluenesulfonyl chloride, and para-toluenesulfonyl chloride; and mixtures of these materials; and (B) a second component comprising a saponified, partly saponified or unsaponified rosin which is modified with an organic acidic material selected from α,β-unsaturated aliphatic carboxylic acids containing from about 3 to 10 carbon atoms, anhydrides thereof, and mixtures of said acids and anhydrides; said combining of said first component and said second component being effected by forming sprays of said first component and said second component, wherein each component is formed into particles having an average diameter of about 10 to about 1000 microns, and allowing said sprays to contact each other to thereby provide a sizing composition or precursor thereof, which sizing composition or precursor thereof comprises sizing-effective amounts of said modified rosin, and sizing enhancing amounts of said ammonia and ammonium salt, the amount of said modified rosin, ammonia and ammonium salt being sufficient to provide a sizing composition with a total acidity of at least about 1,000 parts per million.