申请人:——
公开号:US20030096905A1
公开(公告)日:2003-05-22
The invention relates to aqueous dispersions and aqueous electrodepositable primers made with the aqueous dispersions of the invention. The aqueous dispersion of the invention requires the use of a polymer (a) comprising one or more water dispersible groups per molecule and one or more functional groups (f), and at least one crosslinking agent (b) comprising one or more blocked functional groups (f
b
) reactive with polymer (a) after unblocking. Crosslinking agent (b) has a T
g
of from 40 to 70° C./105 to 158° F. and is a solid at 23.9° C./75° F. when at 100% by weight solids. Crosslinking agent (b) is melt mixed into acrylic polymer (a) to provide a first dispersion and said first dispersion is emulsified in water to provide an aqueous dispersion. In a preferred embodiment, the aqueous electrodepositable primers comprise at least 50% by weight water and an acrylic polymer (a) having one or more salted sites per molecule.
本发明涉及水性分散体和使用本发明水性分散体制成的水性电沉积底漆。本发明的水性分散体需要使用一种聚合物(a),该聚合物每个分子包含一个或多个水分散基团和一个或多个官能团(f),以及至少一种交联剂(b),该交联剂包含一个或多个封端官能团(f
b
) 与解封后的聚合物 (a) 起反应。交联剂(b)的 T
g
为 40 至 70 摄氏度/105 至 158 华氏度,在 23.9 摄氏度/75 华氏度时为固体(按重量计为 100%)。将交联剂(b)熔融混入丙烯酸聚合物(a)中,得到第一分散体,然后将第一分散体乳化在水中,得到水分散体。在一个优选的实施方案中,水性电沉积底层涂料包括至少 50% 重量的水和丙烯酸聚合物 (a),丙烯酸聚合物 (a) 每个分子有一个或多个盐渍位点。