A crosslinking agent that is an ungelled reaction product of (a) an aminoplast resin and (b) a compound having active hydrogen groups reactive with the aminoplast resin such that the crosslinking agent is essentially free of functional groups reactive with an aminoplast resin and has a glass transition temperature of at least 10° C. is disclosed. Compound (b) is, more specifically, a monofunctional sulfonamide having only one active hydrogen. Methods for preparing crosslinking agents are also disclosed. Further provided is a curable powder coating composition including a polymer having a glass transition temperature of at least 30° C. containing reactive functional groups and the present crosslinking agent; a multilayer composite coating compositions and substrates coated therewith are also disclosed. Methods for modifying aminoplasts are also disclosed.
本发明公开了一种
交联剂,它是(a)
氨基
树脂和(b)具有与
氨基
树脂反应的活性氢基的化合物的未胶化反应产物,这样的
交联剂基本上不含与
氨基
树脂反应的官能团,且
玻璃化转变温度至少为 10 摄氏度。更具体地说,化合物 (b) 是一种只有一个活性氢的单官能度磺酰胺。还公开了制备
交联剂的方法。进一步提供了一种可固化的粉末涂料组合物,包括一种
玻璃化转变温度至少为30℃的含有活性官能团的聚合物和本发明的
交联剂;还公开了一种多层复合涂料组合物和涂覆其的基材。此外,还公开了改性
氨基细胞的方法。