Abstract:

The effects of different epoxy resin, curing agent and pigment/binder ratio on the adhesion, pencil hardness, impact resistance and acid resistance of the coating on the surface of hot-dip galvanized tube substrate were investigated. The result shows that the epoxy E-20-polyamide 125 system can reduce the drying time of the coating. The impact resistance of the coating on the surface of the hot-dip galvanized pipe can be improved up to 123.5 cm, meanwhile, it still can reach 95.5 cm after the acid resistance test. When the pigment/binder ratio of the coating is controlled at 1.8∶1, the overall performance of the coating reaches the best. Before and after the acid resistance test, the performance has not declined, the adhesion still reaches 0 level and the impact resistance still reaches 162.5 cm. Thus, the protective coating for hot-dip galvanized gas pipeline is prepared by using epoxy resin E-20 as the base resin, polyamide 125 as the curing agent and the coating pigment/binder ratio 1.8∶1. The performance of the coating is significantly better than the technical requirements for the epoxy resin coatings and film thereof as described by “CGAS001—2016 wide-edge pipe connection coating gas pipeline technical regulations”.

Key words: epoxy resin, hot-dip galvanizing, polyamide, acid resistance, impact resistance

摘要：

探讨了不同种类的环氧树脂、不同种类的胺固化剂以及颜基比对热镀锌管基材涂层附着力、铅笔硬度、耐冲击性、耐酸性等性能的影响。研究表明:环氧树脂E-20-聚酰胺125体系可以降低涂层干燥时间,提高涂层在热镀锌管表面耐冲击性能至123.5 cm,同时耐酸试验后耐冲击性能仍达到95.5 cm;当涂层颜基比控制在1.8∶1时,涂层的综合性能达到最佳,耐酸试验前后各项性能均未下降,附着力均达到0级,耐冲击性能均达到162.5 cm。最终选用环氧树脂E-20为基体树脂,聚酰胺125作为固化剂,以1.8∶1的颜基比制备了一种适用于热镀锌燃气管道外用防护涂料,该涂料各项性能均明显优于CGAS001—2016《宽边管件连接涂覆燃气管道技术规程》中对环氧树脂涂料及涂层的技术要求。

关键词: 环氧树脂, 热镀锌, 聚酰胺, 耐酸性, 耐冲击性

CLC Number: 

• TQ635.2