新型非离子型水性环氧固化剂的制备

以苯酚、甲醛、二乙烯三胺为原料制备曼尼希胺(Man - A1),然后以聚乙二醇与液体环氧树脂的反应物(P)为改性剂对Man - A1进行改性,再用苯基缩水甘油醚封端,制得具有自乳性的改性曼尼希胺(Man - A2),最后采用相反转法制得了非离子型水性环氧固化剂.讨论了聚乙二醇相对分子质量、聚乙二醇与环氧树脂物质的量之比以及端羟基环氧聚合物P的含量对乳液的稳定性和粒径的影响.结果表明:以聚乙二醇4 000为原料制备端羟基环氧聚合物P,当聚乙二醇4 000与环氧树脂物质的量之比为3:4,P的添加量为20％时,所得的水性环氧固化剂体系的稳定性最佳,在3 000 r/min的离心机中20 min不分层,平均粒径最小,为0.43 μm,固含量约为50％,胺值为160 mgKOH/g.室温固化后,涂膜硬度4H,耐冲击性50 cm,柔韧性1mm,附着力0～1级,适用期5～6h,耐水性优异.

Preparation of Novel Nonionic Waterborne Epoxy Curing Agent

Mannich Amine(Man-A1) was synthesized by using phenol,formaldehyde and diethylenetriamine(DETA),which was then modified with the reaction product(P) of liquid epoxy resin and polyethylene glycol(PEG) and terminated with pheugl glycidyl ether(PGE) to obtain the self-emulsified Man-A2.A nonionic waterborne Mannich epoxy curing agent was obtained by phase inversion method.The influences of molecular weight of PEG,PEG/CYD-128 ratio and OH terminated epoxy content on the stability and particle size of the dispersion were discussed.It was found that the dispersion of waterborne epoxy curing agent,which was prepared using PEG 4 000 and PEG epoxy at 3∶4 molar ratios,optimal stability and following properties: particle size 0.43 μm,solid content 50%,and amine value 160 mgKOH/g,with no separation under 3 000 rpm centrifugalization.The coating cured at room temperature showed a hardness 4H,impact strength 50 cm,flexibility 1 mm,adhesion 0-1 grade,potlife 5-6 h and excellent water resistance.