The silicone has a Si-O-Si bond as the main chain. Due to its high bond energy and ionization tendency, Si-O bond has unique weather resistance, heat aging resistance and UV aging resistance. It also has excellent high and low temperature resistance as well as good hydrophobicity, mechanical properties and electricity. Insulation properties, etc., are widely used in electronic and electrical components. However, as a packaging material, silicone has a problem that the refractive index is low and the surface energy is low, and the adhesion to the substrate is poor. In addition, the production of organic silicon monomer is relatively large, the process is complicated, and the production process is long. At present, there are mainly foreign companies such as Dow Corning, Momentive, Wacker, and Shin-Etsu, which can produce silicone monomers on a large scale. The silicone encapsulating materials produced are mainly based on high refractive index (both silicone and silica gel products with a refractive index of more than 1.50), which have an absolute advantage in the domestic high-end market. Domestically, there are mainly silicone monomer manufacturers such as Blue Star Fire, Xin'an Chemical, and Shandong Dongyue. Silicone encapsulating material A number of patent documents have reported high refractive index silicone material systems. Ding Xiaowei et al. hydrolyzed alkoxysilane to form a prepolymer, and then polycondensed with a hydrogen-containing silicone oil to prepare a phenyl-containing hydrogen-containing silicone resin for LED encapsulation with adjustable phenyl content. Its refractive index is up to 1.531, the viscosity and hydrogen content are adjustable, and no by-products that are difficult to recycle are produced in the reaction. ShinjiK and other cured products obtained by two-component hydrosilylation reaction, have high light transmittance, adjustable refractive index between 1.54 and 1.65, and have good mechanical properties; The vinyl group-containing silicone resin is a base polymer, and a Si-H group-containing silicone resin or a hydrogen-containing silicone oil or the like is used as a crosslinking agent, and is cured by crosslinking at room temperature or under heating in the presence of a platinum catalyst. KimJS et al. synthesized the base polymer vinyl phenyl silicone resin by sol-gel method using vinyltrimethoxysilane and diphenylsilyl glycol as raw materials, and then combined with the crosslinker phenyl tris(dimethyl). The siloxane-based silane is cross-linked at a high temperature in the presence of a platinum catalyst to form an encapsulating material. It has a refractive index of 1.56 at 633 nm, good thermal stability and yellowing resistance at 200 ° C, and is ideal for high power LED packaging materials. Various silicone polymers can be prepared by hydrolytic condensation of siloxanes and chlorosilanes. Peng Yinbo et al. obtained the silanol by hydrolysis of a silicone monomer, and then added a phenylhalosilane/vinylhalosilane to carry out polycondensation in the presence of an organometallic catalyst (dibutyltin, zinc naphthenate, cobalt naphthenate, etc.). The reaction was carried out to obtain a silicone resin encapsulating material. It has good heat resistance, moisture resistance and shrinkage, and the light transmittance is more than 98%, and the refractive index is greater than 1.57. Su Junliu et al. obtained the vinyl phenyl silicone resin by acid-catalyzed hydrolysis method and phenyl siloxane as raw material, and used this as the main raw material to form LED potting compound. Its refractive index is 1.53, the light transmittance at 450nm is 99.5%, and the Shore hardness after vulcanization is 40, which is suitable for power LED packaging. KimJS et al. synthesized a phenyl group-containing oligosiloxane resin by using a non-hydrolyzable sol-gel polymerization method using methyldiethoxysilane and diphenylsilyl glycol as precursors in an acidic solution; A phenyl group and a vinyl group-containing oligosiloxane resin were synthesized from trimethoxysilane and diphenylsilyl glycol, and then the two resins were mixed and cured at 150 ° C for 4 hours. The cured resin has a good light transmittance, a light transmittance of 90% at 450 nm, a refractive index of 1.58, and good thermal stability at 440 °C. Liao Yijun et al. used alkoxysilane hydrolysis to synthesize methyl high phenyl vinyl silicone resin, high phenyl hydrogen silicone resin and vinyl high phenyl hydrogen silicone resin. The addition and crosslinking of the silicon vinyl group and the silicon hydrogen group in the presence of a platinum catalyst provide a colorless and transparent silicone encapsulating material. It is found that when the mass fraction of phenyl in the silicone resin is 40%, the refractive index is about 1.51; when the mass fraction of phenyl is 50%, the refractive index of the silicone resin is greater than 1.54. The refractive index of silicone increases with the increase of the mass fraction of phenyl. The refractive index of almost all phenyl silicone can reach 1.57. After the packaged power LED is energized for 1000h, the light decay is within 4%, which is suitable for high power. LED package. Recently, Dow Corning developed a two-component, thermally vulcanized phenyl silicon optical potting compound. The new products OE-6662 and OE-6652 have a Shore hardness of 64 and 59, respectively. The improved gas barrier properties help the potting compound protect the silver-plated electrode from sulfur corrosion while improving light output efficiency and extending service life. At present, the way to increase the refractive index of the silicone material is gradually developed from the method of introducing a high refractive index group structure to the introduction of a high refractive index nano metal oxide. It has been found that the addition of a certain amount of nano metal oxide with a particle size of 10 to 100 nm can greatly increase the refractive index of the material without affecting the light transmittance of the material. At the same time, the nano metal oxide can also absorb ultraviolet rays to act as a light stabilizer, and can act as an inorganic filler to improve the thermal conductivity and mechanical properties of the material. TiO2 and ZrO2 have high refractive index (2.0-2.4), and also have excellent weather resistance and ultraviolet radiation resistance. Their refractive index is similar to that of GaN chip (about 2.2), which is used to fill high refractive index composites. The ideal inorganic material. BasinG et al. studied the effect of filling a certain amount of inorganic particles on the refractive index and luminous efficiency of LEDs. The results show that the introduction of submicron TiO2 and ZrO2 in the silicone encapsulation material can effectively improve the refractive index of the material. When the mass fraction is 2.5% to 5.0%, the luminous efficiency of the GaN-type LED is improved by 5%. ChenWen-chang et al. obtained a phenyl silsesquioxane by hydrolytic condensation of phenyltrimethoxysilane and added it to n-butyl titanate for condensation reaction. The results show that as the mass fraction of TiO2 increases from 0.0% to 54.8%, the refractive index of the optical film also changes from 1.527 to 1.759. This high refractive index inorganic hybrid silicone resin will have a good application prospect in power LED packaging materials. The inorganic component is incorporated into the silicone resin matrix to recombine the inorganic phase with the silicone polymer network at the molecular level. Since the composite material has a relatively large interfacial area, it has many novel physicochemical properties that are not possessed by macroscopic objects. This material combines the advantages of good thermal and thermal shock resistance of silicone, high chemical stability, high refractive index of nano-inorganic oxide, good heat resistance and high hardness. Beverage Refrigerator,Drink Refrigerator,Cold Drink Refrigerator,Commercial Beverage Refrigerator ZHENGZHOU KAIXUE COLD CHAIN CO., LTD. , https://www.supersnowfreezer.com