汽车用复合底漆的配制、影响主因素及其自动沉积复合层漆膜的性能

Formulation of Composite Paint for Automotive Primer and Performance Evaluation of Its Spontaneously Deposited Coating

为了开发性能更优的汽车底漆自动沉积涂料,配制了热塑型和热固型自动沉积涂料,设计了一种复合自动沉积涂料涂装工艺并制备了自动沉积复合涂层漆膜,研究了自动沉积涂料主要成分乳胶的合成条件对其性能的影响、浸漆时间及沉积方式对漆膜性能的影响。结果表明:乳胶最佳合成条件为0.25%引发剂APS,不同反应阶段应选择不同的搅拌速度(200～350 r/min),乳液聚合温度79～84℃,所制备的乳胶稳定、呈乳白色略带蓝光、无味;复合涂层集热塑型和热固型涂料的优点于一身,抗有机溶剂能力强、与面漆或中涂漆结合能力强、抗腐蚀能力和附着力好,符合汽车用底漆标准;采用先在热塑型自动沉积涂料中浸渍2 min,再在热固型自动沉积涂料中浸渍3 min的复合自动沉积工艺所制备的复合涂层漆膜性能最优。

Thermoplastic and thermosetting paint with spontaneous deposition capability was formulated,and then spontaneously deposited coating of as-formulated composite paint was prepared using a specially designed spontaneous deposition technique.The effect of polymerization condition of latex,which was the main ingredient of the composite paint,on the performance of the spontaneous deposition paint was investigated,while the effects of immersion time and deposition mode on the performance of the spontaneously deposited coating were also examined.It was suggested that the polymerization of the latex conducted at initiator(APS) dosage of 0.25%,stirring speed of 200～350r/min(depending on different polymerization stages),and temperature of 79～84℃.Resultant latex was stable and free of smell,appearing ivorywhite in association with slightly blue.Corresponding composite coating had the advantages of both thermoplastic and thermosetting resins,possessing good resistance against organic solvent,good corrosion resistance as well as strong adhesion to top coating or intermediate coating,meeting with the standard requirements for automotive primer.Typically,the spontaneously deposited coating obtained by immersion in the thermoplastic paint for 2 min and follow-up immersion in the thermosetting paint for 3 min possessed the best performance.