Patent ID: 9708771
Date: 2017-07-18
CPC Classifications: D21H

Claim:
1. A method of preparing an aqueous emulsion of a sizing agent for use in a papermaking process comprising, emulsifying the sizing agent for use in a papermaking process into an aqueous liquid, in which an aqueous dispersion of a water-soluble polymer of N-vinylformamide and/or N-vinylacetamide units is added to either the sizing agent or the aqueous liquid before, during or after emulsification, wherein the dispersion contains, based on 100 parts by weight of water, (A) from 0.1 to 80 parts by weight of the water-soluble polymer containing N-vinylformamide units and/or N-vinylacetamide units, and (B) from 0.02 to 50 parts by weight of at least one polymeric dispersant for the water-soluble polymer (A) selected from the group consisting of polyvinylpyrrolidone, polyvinylpyridine, polyvinylimidazole, polyethyleneimine, and polydiallyl dimethyl ammonium chloride, wherein the N-vinylformamide units and/or N-vinylacetamide units of polymer (A) are hydrolyzed to an extent of 1 to 40 mol %.