Study On The Preparation Of Photocured Polyurethane Acrylate Ink

Flexible printed circuit board from the initial application in the field of aerospace to now used in electronic watches,portable audio and other small devices,its application products towards miniaturization,portable rapid development,this also insulation protection ink requirements are becoming higher and higher,UV ink due to its printing convenience,fast curing speed,low cost,wide range of applications and other advantages into the public’s vision,Become a hot research direction.In this paper,a series of oligomers of organosilica-modified polyurethane acrylate were synthesized by bulk polymerization with two steps of raw materials such as HMDI,PTMEG,PDMS and HEA,and the influence of catalyst dosage and temperature on the reaction was studied.Din-butylamine titration was used to determine the amount of catalyst used in the synthesis process of oligomer reaction was 0.2wt%,and the reaction temperature of the first step was 60℃,and the second step was 70℃.The properties of the cured film were tested by DSC,TGA,SEM,water absorption rate,n-hexane absorption rate and water contact Angle.The results showed that the introduction of silicone significantly improved the water resistance of oligomers.The water contact Angle of the cured film increased from 75.2°to 110.1°,and the water absorption rate decreased from 11%to 4%.The absorption rate of n-hexane increased from 5.9%to 7.9%.The thermal stability of T₅ increased from 325.08℃to 340.35℃,and T₅₀ increased from 412.74℃to 416.51℃.Adhesion test and flexural resistance test prove that a small amount of silicone can increase the dispersion of the hard segment region,reduce the degree of phase separation,and the material has better mechanical properties,and when the amount of silicone is 4 wt%,the mechanical properties of the material reach the best.By using single factor optimization method,by adjusting the type of active diluent and the amount of oligomers,diluent and photoinitiator,and studying their influence on the properties of curing film,the mass ratio of single functional group diluent and bifunctional group diluent was finally determined to be 3:2.The optimal usage interval of oligomer is 35 wt%～40 wt%,the optimal usage interval of diluent is 30 wt%～35 wt%,and the optimal usage interval of photoinitiator is 4 wt%～6 wt%.In order to set the factor level table,design orthogonal experiment scheme,comprehensive analysis of ink curing film adhesion,flexural resistance and photocuring time,finally determine the formula of the ink,and all aspects of the performance have reached the expectations.