Nano silica is one of the most important high-tech ultra-fine inorganic materials. Due to its small particle size, it has large specific surface area, strong surface adsorption, large surface energy, high chemical purity, good dispersion performance, thermal resistance and resistance. It has unique characteristics in many disciplines and fields because of its excellent stability, reinforcement, thickening and thixotropy, It plays an irreplaceable role. Nano silica, commonly known as “ultra-fine white carbon black”, is widely used in various industries as additives, catalyst carriers, petrochemical industry, decolorizing agent, matting agent, rubber reinforcing agent, plastic filling agent, ink thickener, metal soft polishing agent, insulation filler, advanced daily cosmetics filler and spraying materials, medicine, environmental protection and other fields. It also provides new material basis and technical guarantee for the development of relevant industrial fields. Compared with conventional materials, it shows special functions in magnetism, catalysis, light absorption, thermal resistance and melting point, so it has attracted great attention.
Electronic packaging material organic electroluminescent device (OELD) is a new type of flat panel display device newly developed at present. It has the advantages of low opening and driving voltage, DC voltage driving, matching with large-scale integrated circuits, easy to realize full-color, high luminous brightness (> 105cd / m2), etc. However, the service life of OELD devices can not meet the application requirements, One of the technical difficulties to be solved is the packaging materials and packaging technology of devices. At present, silicone modified epoxy resin is widely used abroad (Japan, the United States, Europe, etc.), that is, through the blending, copolymerization or grafting reaction between them, it can not only reduce the internal stress of epoxy resin, but also form intramolecular toughening, improve the high temperature resistance, but also improve the waterproof, oil and oxygen resistance of organosilicon, However, it requires a long curing time (several hours to several days). In order to speed up the curing reaction, it needs to be at a higher temperature (above 60 ℃ to 100 ℃) or increase the use of curing agent, which not only increases the cost, but also is difficult to meet the requirements of large-scale device production lines for packaging materials (short time and room temperature packaging). The nano silica after surface activity treatment is fully dispersed in the silicone modified epoxy resin packaging adhesive matrix, which can greatly shorten the curing time of the packaging material (2.0-2.5h), and the curing temperature can be reduced to room temperature, significantly improve the sealing performance of OELD devices and increase the service life of OELD devices.
