Synthesis of High Refractive Index Epoxy Modified Methyl Phenyl Silicone Resin and Amine Phenyl Silicone Resin for LEDs Packaging

Abstract

A series of epoxy modified methyl phenyl silicone resins with different epoxy values were prepared by an approach of combination of hydrolytic sol-gel and non-hydrolytic sol-gel process. Then, in order to solve poor compatibility between epoxy modified silicone resins and commercial amine curing agents, amine phenyl silicone resin curing agent was synthesized by non-hydrolytic sol-gel method. The test results exhibited that the process of combination of hydrolytic sol-gel and non-hydrolytic sol-gel process had a significant effect on the elimination of hydroxyl groups. A lot of experiments and mechanism analysis exhibited that the activity and content of hydroxyl groups are two important factors for ring-opening of epoxy groups and gelation of product. So, epoxy groups can be stably and efficiently introduced in the terminal of product in the course of non-hydrolytic sol-gel process, which hugely avoided ring-opening of epoxy groups. Subsequently, epoxy modified silicone materials were obtained by thermal curing reaction between epoxy modified silicone resins with different epoxy values and amine phenyl silicone resin. And the curing reaction can be completed at 80 °C for 2 h. Transmittance of light, thermogravimetric (TG) analysis, differential scanning calorimetry (DSC) and reliability test were used to analyze performance of epoxy modified silicone materials. The results exhibited that prepared silicone materials had a high transmittance (>90%), strong adhesive strength, good thermal stability and mechanical performance. Therefore, epoxy modified silicone material can be applied in high-power LEDs packaging.