Patent ID: 7943789

Claim:
A method for making a sizing composition comprising the sequential steps of: (a) emulsifying components consisting of alkenylsuccinic anhydride, a first starch component, wherein the first starch component is an aqueous starch solution consisting of water and a starch selected from the group consisting of non-ionic starches, anionic starches, and mixtures thereof, and optionally, a surfactant component consisting of a surfactant selected from the group consisting of anionic surfactants and nonionic surfactants to form an emulsion consisting of the alkenylsuccinic anhydride, the first starch component, and, optionally, the surfactant component; and (b) combining the emulsion with a second starch component selected from the group consisting of non-ionic starches, ionic starches, and mixtures thereof, and thereby forming a sizing composition; wherein the alkenylsuccinic anhydride and the starch in the emulsion and the second starch component are present at a starch:alkenylsuccinic anhydride weight ratio that is sufficiently high to enable the sizing composition to impart useful sizing properties to a fibrous substrate when the sizing composition contacts the-fibrous substrate; and wherein the starch component of the starch:alkenylsuccinic anhydride weight ratio is the total weight of the first starch component and the second starch component.