Starch compatible polyvinyl acetate latices
AssigneeAir Products and Chemicals, Inc.
InventorsWallace H. Pippin, Wiley E. Daniels
Life of this patent
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Abstract
Aqueous coating compositions comprising latices containing a copolymer of vinyl acetate in the range of about 95-99.9% by weight and maleic anhydride in the range of about 0.1-5% by weight have been found to have improved starch binder compatibility. Vinyl acetate and maleic anhydride are polymerized in an aqueous medium in the presence of a free radical initiator and a surfactant which prevents the vinyl acetate-maleic anhydride copolymer from dissolving in the aqueous medium. The resulting latex coating compositions have a high solids content (greater than about 50% by weight) and a copolymer particle size of under 0.5 microns in addition to the excellent starch compatibility.
Claims17
A coating composition comprising a latex which contains a copolymer of vinyl acetate in the range of about 95 to 99.9% by weight and maleic anhydride in the range of about 5.0 to 0.1% by weight polymerized in an aqueous medium in the presence of a surfactant which prevents the resulting vinyl acetate-maleic anhydride copolymer from becoming solubilized in said aqueous medium and a free radical initiator, said latex being characterized by having a solids content of at least 50% by weight and a copolymer particle size of not more than 0.5 micron.
A coating composition comprising a latex which contains a copolymer of vinyl acetate in the range of about 98 to 99.6% by weight and maleic anhydride in the range of about 2 to 0.4% by weight polymerized in an aqueous medium in the presence of a water soluble anionic surfactant which prevents the resulting vinyl acetate-maleic anhydride copolymer from becoming solubilized in said aqueous medium and a free radical initiator, said coating composition being characterized by having a solids content of at least 55% by weight and a particle size in the range of 0.05 to 0.3 micron.
A coating composition comprising 3.33 to 50 parts by weight of mineral pigments and one part by weight latex which contains a copolymer prepared by copolymerizing vinyl acetate in the range of about 95 to 99.9 parts by weight and maleic anhydride in the range of about 5.0 to 0.1 parts by weight in an aqueous medium in the presence of a surfactant which prevents the resulting vinyl acetate-maleic anhydride copolymer from becoming solubilized in said aqueous medium and a free radical initiator, said coating composition being characterized by having a solids content of at least 50% by weight and a particle size of not more than 0.5 micron.
Dependencies are inferred from the claim text.