车灯密封用反应型聚氨酯热熔胶的制备及性能研究

Preparation and properties of reactive polyurethane hot melt adhesive for vehicle lamp sealing

用结晶性聚酯多元醇、液体聚醚多元醇和多异氰酸酯为主要原料,合成了反应型聚氨酯预聚体;同时复配丙烯酸树脂粉体、固化剂、触变剂等助剂,制备了用于车灯粘接密封的反应型聚氨酯热熔胶。探讨了反应型聚氨酯热熔胶黏度、黏度热稳定性、剪切强度等性能指标的主要影响因素,并对所制备的反应型聚氨酯热熔胶的分子结构、热性能和机械性能进行表征。研究结果表明:当两种结晶性聚酯即聚酯多元醇n(HJ-3500)∶n(7380)=1∶1,异氰酸酯指数(R)=1.5~1.9,m(聚酯多元醇)∶m(聚醚多元醇)=1∶2,并使用丙烯酸树脂粉体、固化剂、触变剂等助剂进行复配时,制备的反应型聚氨酯热熔胶具备良好的耐高低温性能。该车灯密封用反应型聚氨酯热熔胶能解决对低极性的塑料材质粘接性能较差的问题,并且开放时间较短、定位速度快,可满足车灯行业车灯样件打胶施工后能及时移动、装配的流水线操作要求。另外,该自主研发的产品剪切性能指标基本达到进口的产品标准,且优胜于某些国内产品,可以替代某些进口产品使用。

Reactive polyurethane prepolymer was synthesized by using crystalline polyester polyols,liquid polyether polyols and polyisocyanates as the main raw materials.At the same time,reactive polyurethane hot melt adhesive for lamp bonding and sealing was prepared by compounding with acrylic resin powder,curing agent,thixotropic agent and other additives.The main influencing factors of reactive polyurethane hot melt adhesive such as viscosity,viscosity thermal stability,shear strength and so on were explored,and the molecular structure,thermal properties and mechanical properties of the prepared reactive polyurethane hot melt adhesive were characterized.The research results showed that when two crystalline polyesters,namely polyester polyols n(HJ-3500)∶n(7380)=1∶1,the isocyanate index R=1.5-1.9,m(polyester polyol)∶m(polyether polyol)=1∶2,and acrylic resin powder,curing agent,thixotropic agent and other additives were used for compounding,the prepared reactive polyurethane hot melt adhesive had good resistance to high and low temperatures.The reactive polyurethane hot melt adhesive for vehicle lamp sealing could solve the problem of poor bonding performance to low polarity plastic materials,the open time was short and the positioning speed was fast,which could meet the production line operation requirements of timely movement and assembly of vehicle lamp samples in the vehicle lamp industry after gluing construction.In addition,the shear performance indicators of the self-developed product basically met the standards of imported products and were superior to some domestic products,which could replace certain imported products.