以聚天门冬氨酸酯树脂和聚碳酸酯多元醇作为基料树脂,采用两步法,先用聚己内酯多元醇与异佛尔酮二异氰酸酯制得预聚物,然后和HDI三聚体混合作为固化剂,制备了弹性聚氨酯涂料,其中,聚碳酸酯多元醇和HDI三聚体用以调节涂层回弹性和硬度。讨论了聚己内酯多元醇分子量、预聚物异氰酸酯含量、扩链系数R值对涂膜断裂伸长率、拉伸强度的影响,聚碳酸酯和HDI三聚体的加量对回弹性和硬度的影响,以及涂料体系中主要成分、各类紫外线吸收剂不同加量对耐候性的影响。结果表明:当R=1.05、分子量1000聚己内酯多元醇为软段、PCDL∶NH1420∶PCL预聚物∶N3390=0.3∶0.7∶0.65∶0.4、紫外线吸收剂T249加量为2%时,涂层的综合性能最佳,能够满足橡胶风挡保护涂料的技术指标。

In this paper,polyaspartate resin and polycarbonate polyol were used as the base resin,and the elastic polyurethane coating was prepared by a two-step m ethod.The prepolym er was first prepared by polycaprolactone polyol and isophorone diisocyanate,and then m ixed with HDI tripolym er as curing agent.The polycarbonate polyol and HDI tripolym er were used to adjust the resilience and hardness of the coating.The effects of m olecular weight of polycaprolactone polyol,content of prepolym er isocyanate and chain extension coefficient R on the elongation at break and tensile strength of the coating film,the effects of the dosage of polycarbonate and HDI tripolym er on the resilience and hardness,and the effects of the m ain com ponents of the coating system and the different dosage of various ultraviolet absorbers on the weather resistance were discussed.The results showed that when R value was 1.05,1000 m olecular weight polycaprolactone polyol was soft segm ent,equivalent ratio of PCDL∶NH1420∶PCL prepolym er∶N3390 was0.3∶0.7∶0.65∶0.4,and UV absorber T249 was added 2%,the overall perform ance of the coating was the best,it can m eet the technical indicators of rubber windshield protection coatings.