The present invention provides aqueous coating compositions comprising one or more emulsion copolymer made from itaconic acid, a sulfonic acid or sulfonate ester monomer and an additional acid monomer which is a carboxylic acid and having a glass transition temperature of from -45°C to -10°C, and one or more pigment, opacifier, filler, extender, or mixture of any of these at a %PVC of from 20 to 55, preferably 30 to 50, wherein coatings made from the coating compositions provide improved resistance to water swelling and dirt pickup resistance. The improvements are observed regardless of whether the compositions contain or are substantially free of zinc or divalent metal ions, or salts or compounds containing them. The present invention also provides roofing substrates coated with the aqueous compositions.
本发明提供了
水性涂料组合物,该组合物包含一种或多种由
衣康酸、
磺酸或
磺酸酯单体和另外一种
羧酸单体制成的乳液共聚物,该单体的
玻璃化转变温度为-45℃至-10℃,还包含一种或多种
颜料、不透明剂、填料、扩展剂或其中任何一种的混合物,其P
VC%为20至55,最好为30至50,其中由该涂料组合物制成的涂料具有更好的抗
水膨胀性和抗污性。无论组合物中是否含有
锌或二价
金属离子或含有它们的盐或化合物,或基本上不含有它们,都能观察到这些改进。本发明还提供了涂有
水性组合物的屋顶基材。