Colorless and Transparent Epoxy Adhesive for LED Lights Embedding

The colorless andtransparent bisphenol A epoxy resin was used as matrix resin, methyl hexahydrophthalic anhydride and methyl tetrahydrophthalic anhydride were used as curing agents. 8 component epoxy adhesives were prepared by adjusting the ratio of curing agent and epoxy resin. Using 135℃/1 h +150℃/4 h of curing on the curing process, the water absorption, bending strength and modulus, light transmittance and glass transition temperature of the cured product were investigated. Through comparative analysis, a better performance ratio of the curing system was obtained. The results showed that the viscosity of the epoxy resin system decreased with the increase in the amount of curing agent, when m(MeHHPA):m(EP)=1:1, the viscosity was 570 mPa·s, and the hardness was 25.50 HBa, the bending strength was 93.3 MPa, the flexural modulus was 2.4 GPa, the water absorption was 0.20%, and the light transmittance was 86.68%. Its overall performance is better than that of the market products.