喷涂型汽车油箱点焊密封胶的研制

从油箱喷塑固化工艺条件出发,以环氧树脂(EP)和小分子聚酰胺为主要原料,制备了两种不同配方的汽车油箱用点焊密封胶。测试了点焊胶在90#汽油和0#柴油中的耐油性和粘接强度,并对三种不同连接接头(胶接、点焊、胶焊)的粘接强度进行了对比和分析。结果表明:点焊胶的固化工艺与汽车镀锌板类油箱表面漆层的固化工艺相同,故不必增加点焊胶的固化设备和工序;两种点焊胶具有较好的粘接性能,其T型剥离强度分别为89.0kN/m和92.0kN/m,拉伸剪切强度分别为13.3MPa和12.9MPa;两种点焊胶在90#汽油和0#柴油中浸泡360d后,试样的粘接强度降幅不明显,说明其具有一定程度的耐油性;将两种点焊胶用于汽车油箱的密封中,既具有良好的粘接密封性能,又解决了镀锌板类油箱渗漏油等问题。

Study on preparing sprayable spot-welding sealant for automobile fuel tank

With epoxy resin(EP) and polyamide with small molecule as main materials,so two types of sprayable spot-welding sealants with different formula for automobile fuel tank were prepared based on curing process conditions of fuel tank surface coat spurted by plastic. The oil-resistance and bonding strength in 90# gasoline or 0# diesel oil were tested for spot-welding sealants,and the bonding strength of three different joints(such as bonding,spot-welding and bond-welding) were respectively compared and analysed. The results showed that the spot-welding sealants need not add curing equipment and process because the curing process conditions between spot-welding sealant and automobile fuel tank surface(namely galvanized plate's surface) coat spurted by plastic were same. Two types of spot-welding sealants had better bonding performances and oil-resistance because their T-peeling strengths were 89.0 kN/m and 92.0 kN/m respectively,and tensile shear strengths were 13.3 MPa and 12.9 MPa respectively,the decrease of bonding strength weren't obvious after marinating in 90# gasoline or 0# diesel oil for 360 d. Two types of spot-welding sealants,which were used as sealants of automobile fuel tank,had well bonding airproofing performance,and could solve the problem of leaking oil from galvanized plate's gap of fuel tank.