半结晶聚酯树脂的合成及其低温固化超耐候粉末涂料的应用

Synthesis of Semi-crystalline Polyester Resin and Application in Low Temperature Curing Super Weather Resistant Powder Coatings

分别采用一步法合成了羧基封端的半结晶聚酯树脂和低温固化超耐候聚酯树脂,并将其制备成粉末涂料。采用差示扫描量热仪(DSC)、X射线衍射仪(XRD)、傅立叶变换红外光谱(FTIR)和紫外光试验箱(QUVB)对聚酯树脂物理和化学结构及低温固化超耐候粉末涂料性能进行了研究,最后比较了不同结构的半结晶聚酯树脂在低温和常规固化超耐候粉末涂料的性能区别。结果表明:与常规固化相比,半结晶聚酯CP的加入,对低温固化超耐候基本无影响,当CP使用量为树脂总量的10%~15%时,能够显著提高低温固化超耐候聚酯粉末涂料的机械性能和耐丙酮擦拭性能,降低体系的黏度,提高粉末涂层的流平,但会少量降低耐候性;与CP相比,低残羟的半结晶聚酯CP0的耐中性盐雾性更好。

Carboxyl terminated semi-crystalline polyester resin and low temperature curable super weather resistant polyester resin were synthesized by one-step method,which were further used to prepare the powder coatings.The physical and chemical structure of polyester resin and the performance of low temperature curing super weather resistant powder coatings were characterized by differential scanning calorimetry(DSC),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR) and QUV(QUVB).Finally,the differences between the performance of semi-crystalline polyester resins with different structures in low temperature curing and conventional curing super weathering powder coatings were compared.The results showed that compared with conventional curing system,the incorporation of semi-crystalline polyester CP presented no effect on the low temperature curing super weather resistant system.When the amount of CP was 10%~15%of the total amount of resin,the mechanical property and acetone rubbing resistance of the low temperature curing super weatherable polyester powder coatings could be significantly improved,as well as the reduction of viscosity of the system and enhancement of the leveling of the powder coatings,but the weatherability could be slightly reduced.Compared with CP,the semi-crystalline polyester CP0 with low residual hydroxyl value showed better resistance to neutral salt spray.