Patent ID: 8440053

Claim:
A method comprising the following steps of: (a) providing a paper surface sizing composition comprising one or more surface sizing starches in an amount which provides at least about 10% starch solids and which liberates at least about 300 ppm C 16 or higher saturated fatty acids in the paper surface sizing composition when the one or more surface sizing starches are cooked; (b) contacting the paper surface sizing compostition comprising liberated C 16 or higher saturated fatty acids and/or monovalent salts of the liberated C 16 or higher saturated fatty acids with a source of multivalent cations sufficient to provide a level of at least about 1000 ppm of the multivalent cations; and (c) prior to step (b), adding a C 16 or higher saturated fatty acid solubilizing and dispersing surfactant having a Krafft temperature to the paper surface sizing composition in an amount effective to solubilize and disperse the liberated C 16 or higher saturated fatty acids and/or monovalent salts thereof when present in the paper surface sizing composition, wherein the paper surface sizing composition is raised to a temperature above the Krafft temperature to thereby solubilize and disperse the liberated C 16 or higher saturated fatty acids and/or monovalent salts thereof in the paper surface sizing composition and thus inhibit the deposition of multivalent C 16 or higher saturated fatty acid salts on paper surface sizing equipment.