The co-condesation polymer of cyanurotriamide and nitrogenous base S with formaldehyde as the coupler and a capping agnt can be used as a good retanning agent.

• 以三聚氰胺及含氮碱S为基本原料,辅以适当的偶联剂与封端剂进行缩合共聚,缩聚产物可用作复鞣剂。