Polyester-starch sized paper, sizing composition, and process therefor

摘要

There is disclosed a cellulosic material such as paper or paperboard surface-sized with an aqueous dispersion of a combination of degraded starch or a starch derivative and a branched-chain, water-dispersible polyester condensation product. Said polyester is derived from the reaction of a dicarboxylic reactant, a diol or polyoxyalkylene glycol, and a phosphorus acid reactant wherein said polyester has a carboxylic acid number of about 5 to about 15 and an average molecular weight of about 4,000 to about 11,000. Mixtures of said starch and said polyester when used to surface-size cellulosic materials impart water resistance thereto.