Electronic packaging material
Organic electroluminescent device (OELD) is a new type of flat display device newly developed. It has low on-drive and low-drive voltage, and can be driven by DC voltage. It can be matched with large-scale integrated circuits, and it is easy to realize full color and brightness. High (>105cd/m2), but the service life of OELD devices can not meet the application requirements. One of the technical difficulties to be solved is the packaging material and packaging technology of the device. At present, foreign countries (Japan, the United States, Europe, etc.) widely use silicone-modified epoxy resin, that is, through the blending, copolymerization or grafting reaction between the two, it can reduce the internal stress of epoxy resin and form molecules. Internal toughening, improve high temperature resistance, and also improve the waterproof, oil and oxygen resistance of silicone, but it requires a longer curing time (a few hours to several days), to accelerate the curing reaction, it needs to be higher Temperature (60 ° C to 100 ° C or higher) or increase the amount of curing agent, which not only increases the cost, but also difficult to meet the requirements of large-scale device production line packaging materials (time is short, room temperature package). The surface-treated gas phase white carbon black [2] is sufficiently dispersed in the silicone-modified epoxy resin encapsulant matrix, which can greatly shorten the curing time of the encapsulating material (2.0-2.5 h), and the curing temperature can be Lowering to room temperature significantly improves the sealing performance of OELD devices and increases the lifetime of OELD devices.

Resin composite
Resin-based composite materials are light, high-strength, and corrosion-resistant. However, in recent years, the material industry and the national economy pillar industries have higher requirements for the performance of resin-based materials. How to synthesize high-performance resin-based composite materials has become An important topic in the current material and business world. The advent of fumed silica has provided a new opportunity for the synthesis of resin-based composites, providing a new way for the modification of traditional resin-based materials, as long as the gas-phase silica particles can be fully and uniformly dispersed into the resin. In the material, the purpose of comprehensively improving the performance of the resin-based material can be fully achieved.
1. Improve strength and elongation. Epoxy resin is the basic resin material. The fumed silica is added to the epoxy resin. The structure is completely different from the epoxy resin-based composite material added by coarse-grained silica (white carbon black, etc.), coarse-grained SiO2. Generally added as a reinforcing agent, it is mainly distributed in the chain of polymer materials, and the gas phase white carbon black is extremely strong due to the serious surface coordination, large specific surface area and surface under oxygen. The activity is easy to bond with the oxygen of the epoxy ring molecule, which improves the bonding force between the molecules. In the same fashion, a part of the vapor phase white carbon black particles are still distributed in the voids of the polymer chain, and the coarse crystal SiO2 particles are phased. Compared with the high flowability, the strength, toughness and ductility of the epoxy resin added by the fumed silica are greatly improved.

2. Improve wear resistance and improve the surface finish of the material. The fumed silica particles are 100-1000 times smaller than SiO2, and are added to the epoxy resin to facilitate the drawing into filaments. Due to the high fluidity and small size effect of the gas phase white carbon black, the surface of the material is more dense and fine, the friction coefficient becomes smaller, and the high strength of the nanoparticles makes the wear resistance of the material greatly enhanced.

3, anti-aging performance. A fatal weakness in the use of epoxy resin matrix composites is the poor anti-aging performance. The main reason is the ultraviolet and long-wave effects of solar radiation in the 280-400 nm band. Its damage to resin-based composites is very serious. The degradation of the polymer chain causes the resin-based composite material to age rapidly. The fumed silica can strongly reflect the ultraviolet rays, and the addition of the epoxy resin can greatly reduce the degradation of the epoxy resin by the ultraviolet rays, thereby achieving the purpose of delaying the aging of the material.