低温固化聚酯/环氧粉末涂料研究

Study on Low-temperature Curing Polyester/epoxy Powder Coating

以聚酯树脂P-5127和环氧树脂E-12为固化主体,添加其它的助剂熔融共混制备低温固化聚酯/环氧粉末涂料。用红外光谱和差示扫描量热法(DSC)研究粉末涂料的固化反应,讨论了固化促进剂2-甲基咪唑(2-MI)用量对粉末涂料固化性能及涂膜性能的影响,确定了2-MI的用量;并对该配方进行非等温动力学分析得出了理论最佳固化温度等固化参数,在此基础上将粉末涂料涂装固化确定实际固化条件。结果表明:粉末涂料中聚酯的端羧基和环氧树脂的环氧基发生反应;随着2-MI用量的增加,固化温度先降低后增加,2-MI的较佳用量为0.4 g;最佳固化条件为:140℃、30 min或是150℃、20 min。

A serious of low-temperature polyester/epoxy powder coating made up of polyester （p-5127）, epoxy （E-12） as the main curing body in addition to other additives were prepared by melt blending method. The curing reaction of the powder coating was studied by FT-IR and Differential Scanning Calorimetry, and discussing the dosage of 2-methyl imidazole （2-MI） as curing catalyst effect on the curing properties of powder coating and the film performance and the 2-MI dosage was determined. The curing reaction of the powder coating was studied using non-isothermal differential scanning calorimetry, through kinetic analysis we can obtain the parameters of curing reaction such as theoretical curing temperature, on the basis of theoretical curing temperature, we can obtain optimal curing time and curing temperature by coating the powder coating at different conditions. The experimental results showed that： the end carboxyl of polyester reacted with the epoxy group of epoxy; as the increase of 2-MI dosage, the curing temperature decreased after increasing firstly; the better dosage of curing agent is 0.4 g, curing condition were： 140 ℃, 30 min or 150 ℃, 20 min.