Aqueous compositions comprising a blend of emulsion vinyl copolymer and polyurethane dispersion

摘要

The present invention provides an aqueous composition comprising: a) a plurality of polymer particles (A) comprising one or more copolymer, pA, having a glass transition temperature, Tg, of 20°C or higher, as measured by differential scanning calorimetry, DSC; b) a plurality of polymer particles (B) in aqueous dispersion comprising one or more polyurethane copolymer, pB, comprising at least 40 wt%, based on the weight of polyurethane solids, of: (i) a first polyol having a molecular weight of at least 850, wherein the first polyol is a polyether polyol, or (ii) a second polyol chosen from a polyester, a polycaprolactam, a polycarbonate and a combination thereof, wherein the second polyol has a molecular weight of at least 1,500, or (iii) a combination of one or more first polyol and one or more second polyol; and c) one or more additive to improve film formation chosen from: a coalescent having a normal boiling point of 150°C to no greater than 300°C present in an amount of at least 4%, based on the total weight of solids of the copolymers pA and pB.