Design And Synthesis Of Functionalized Silicone Resin And Application In Conductive Inks

In recent years,with the continuous development of electronic products towards light,thin and flexible direction,flexible circuits that are both light,thin and flexible have also been highly valued.As a key material for preparing flexible circuits,the development of conductive ink has attracted much attention.Conductive ink plays the role of wires and electronic devices when printed on the substrate,greatly improving the utilization of ma-terials and showing significant advantages over traditional manufacturing methods.Silver conductive ink is considered to be the most suitable high-performance conductive ink for flexible electronic manufacturing.However,due to the high density of silver（10.49g/cm3）,it is easy to sink in the ink and the high sintering temperature of silver（more than200℃）is not friendly to the substrate material.Therefore,the performance of silver con-ductive ink is often improved by adding resin bonding phase.However,with the addition of resin bonding phase,the conductivity of silver conductive ink decreases and silver nanoparticles tend to aggregate.Therefore,how to solve the problem of uniform disper-sion of silver in conductive ink and reduce sintering temperature of silver conductive ink is currently a challenging issue in research.In this study,a functionalized silicon resin was designed and synthesized as the resin binder for silver conductive ink.The silicon resin used methylphenylamino silicon oil（N75）and epoxy-modified silicone oil（SE35）designed and synthesized as the main raw materials,and N,N-dimethylformamide（DMF）as the solvent,with the addition of differ-ent proportions of nano-Si O₂（1～5 wt%）to prepare different types of silicon resin.The silicon resin with 2 wt%nano-Si O₂ content,named 1030H silicone resin,exhibited ex-cellent properties.Using 1030H silicon resin as the resin binder,and nano silver powder as the conductive filler,silver conductive ink with different silver contents was prepared uniformly dispersed in DMF solvent.The prepared silver conductive ink exhibited excel-lent dispersion performance.The storage stability of the silver conductive ink was tested,and the results showed that the prepared silver conductive ink had excellent storage sta-bility,with no obvious delamination after 2 months of storage.In the evaluation of the application performance of silver conductive inks,using1030H silicon resin as the resin binder and nano silver powder as the conductive filler,silver conductive ink was uniformly dispersed in DMF solvent,proprylene glycol monomethyl ether（PM）solvent,and a mixed solvent of DMF and PM to prepare silver conductive ink with different solvent systems.Among them,the silver conductive ink using DMF:PM（1:1）as the solvent was more suitable for printing,with better dispersion performance,the surface tension of 35.329 m N/m,and the peak particle size of 50.748nm.The ink was printed on the proprylene glycol monomethyl ether（PET）film and cured at a low temperature（160℃）to obtain a conductive pattern.The resistivity of conductive pattern was 0.564×10^-6Ω·m,and the resistance change rate of conductive pattern after100 bending cycles was 1.23%.The low-temperature cured silver conductive ink we pre-pared can be used for printing flexible circuits and has potential for practical application.