It has been found that quaternary onium (e.g., ammonium, sulfonium, and phosphonium) salt group-containing epoxy resins are particularly useful as grinding media in preparing stable pigment disperions useful in water-dispersible coating systems, for example, electrodepositable compositions. The resins are prepared by reacting a material selected from the group consisting of amine salts, phosphine-acid mixtures, and sulfide-acid mixtures with a 1,2-epoxy group containing material wherein a ratio of at least about 0.4 eqivalents of quaternary onium groups are produced per equivalent of epoxy group initially present. Preferably, the system contains at least a small amount of polyoxyalkylene glycol.
已经发现含有季
铵盐(例如
铵盐,磺酰盐和膦盐)基团的环氧
树脂在制备稳定的
颜料分散剂方面特别有用,这些分散剂可用于
水分散性涂层系统,例如电泳涂料。该
树脂是通过将来自胺盐,
膦酸混合物和
硫化物酸混合物的材料与含有1,2-环氧基团的材料反应制备而成,其中至少产生约0.4当量的季
铵基团与最初存在的环氧基团等当量。最好,该系统含有至少少量的聚氧烷基
乙二醇。