The invention relates to a method for preparing aqueous dispersions, especially electrodepositable aqueous dispersions. 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 mixed into polymer (a) at a temperature at or above the melting temperatures of both polymer (a) and compound (b) but below the temperature at which blocked functional groups (f
b
) unblock. Sufficient water is added to the resulting melt-mixture (ii) to provide an aqueous dispersion.
本发明涉及一种制备
水性分散体,特别是可电沉积
水性分散体的方法。本发明要求使用一种聚合物 (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)在聚合物(a)和化合物(b)的熔融温度或高于熔融温度但低于封端官能团(f
b
) 解封的温度以下。向得到的熔融混合物 (ii) 中加入足量的
水,以形成
水性分散体。