Aqueous coating compositions having low or zero VOCs and comprising encapsulated or polymer adsorbed pigments and letdown binders
申请人:Rohm and Haas Company
公开号:US10703928B2
公开(公告)日:2020-07-07
The present invention provides aqueous compositions useful as zero VOC coating compositions having a % opacifying pigment volume concentration (% OPVC) of from 2 to 25 and comprising (i) an opacifier composition of an at least partially polymer encapsulated opacifying pigment, a polymer opacifying pigment composite or their mixtures, with the opacifying pigment, encapsulated in and/or as a composite with at least one soft polymer having a measured glass transition temperature (measured Tg) of 5° C. or less, and (ii) a hard binder polymer having a measured Tg of at least 30° C. and a weight average particle size of 120 nm or less, wherein the ratio of the weight average particle size of the opacifier composition to that of the hard binder polymer is from 2:1 to 12:1 and the volume ratio of the opacifying pigment to the soft polymer solids in the opacifier composition is from 2:5 to 1:1.
本发明提供了可用作零 VOC 涂料组合物的水性组合物,其不透明颜料体积浓度 (OPVC) 为 2 至 25%,包含 (i) 至少部分由聚合物包覆的不透明颜料、聚合物不透明颜料复合体或它们的混合物组成的不透明剂组合物,其中不透明颜料包覆在至少一种软聚合物中和/或与至少一种软聚合物复合,该软聚合物的测量玻璃化转变温度 (Tg) 为 5 摄氏度或更低,以及 (ii) 测量 Tg 至少为 30 摄氏度且重量平均粒径为 120 纳米或更小的硬粘结剂聚合物。或更低,以及(ii) 硬粘合剂聚合物,其测量 Tg 至少为 30°C,重量平均粒径为 120nm 或更小,其中不透明剂组合物的重量平均粒径与硬粘合剂聚合物的重量平均粒径之比为 2:1 至 12:1,不透明剂组合物中不透明颜料与软聚合物固体的体积比为 2:5 至 1:1。