Preparation of Dam Glue Used in COB Light Source Module and Research of Its Thixotropism

A dam glue used in COB light source module was prepared by methylvinylsilicone fluid,methylvinylsilicone resin and methylhydrosilicone fluid as main polymer,CaCO3 as filler and fumed silica as thixotropic agent.This research studies the effect of Surface modification nano fumed silica on thickening and thixotropy.The results showed that the surface modification nano fumed silica is a good thixotropic agent for the dam glue system.The thixotropy of the dam glue can be greatly promoted by silylation due to the enhancement of the surface hydrophobicity of the nano fumed silica.