LED silicone encapsulant is a new type of high-end liquid silicone, which is also a kind of optical encapsulation. It can maintain high transparency in the visible light region, has a high absorption rate for ultraviolet rays, and can improve the light output rate and use of lighting devices. life.

In recent years, due to the rapid development of the LED industry, the demand for LED packaging materials has increased. Among them, LED silicone packaging glue has become a leader in LED packaging materials due to its excellent physical and chemical properties. With the aggravation of the energy crisis, the LED industry will maintain continuous growth. Therefore, the market potential of LED packaging materials is huge. High-power LED packaging materials require their raw materials to have high light transmittance and refractive index, and phenyl silicone oil has become an important part of LED packaging rubber raw materials. With the increase of phenyl mole fraction, the high temperature resistance, radiation resistance and refractive index of silicone materials are all improved, and the importance of phenyl silicone oil for LED encapsulation is increasing day by day.

Phenyl silicone oils for LED packaging mainly include vinyl-terminated methyl phenyl silicone oils and phenyl hydrogen-containing silicone oils. According to the phenyl content, phenyl silicone oil can be divided into: low phenyl silicone oil (5% - 10% phenyl mole fraction); medium phenyl silicone oil (25% phenyl mole fraction); high phenyl silicone oil (phenyl mole fraction 45%). Different uses of LED encapsulants have different requirements for phenyl content. High-power LED encapsulants generally require higher phenyl content in order to achieve a high refractive index, thereby reducing the loss of light source energy.

Vinyl-terminated methyl phenyl silicone oil refers to the silicone oil whose terminal group contains vinyl groups, and the silicon atoms on the main chain are connected with methyl groups and phenyl groups. According to the type of phenyl, it can be divided into methyl phenyl chain type, diphenyl chain type and mixed type (contains two kinds of phenyl chains). Phenyl hydrogen-containing silicone oil is divided into hydrogen-blocked phenyl silicone oil and side hydrogen-containing phenyl silicone oil, both of which have different uses. The former is mainly used as a diluent or chain extender when added to the encapsulant, and the latter is mainly used as a concentrated cross-linking agent for the encapsulant, acting as a cross-linking center. The preparation method of phenyl hydrogen-containing silicone oil adopts cationic polymerization method, generally adopts sulfuric acid. In order to reduce the process flow, the acidic resin can also be used for catalytic polymerization, eliminating the step of neutralizing the catalyst, directly filtering the acidic resin, and the acidic resin can be reused many times.

Vinyl-terminated methylphenyl silicone oil and phenyl hydrogen-containing silicone oil are the basic raw materials for high-refractive index LED packaging adhesives. With the rapid development of the LED industry, the LED packaging industry has unlimited potential and there is a huge demand for phenyl silicone oil.