Light-emitting diode (LED) is an electroluminescent solid-state device. With the continuous innovation of technology and the guidance of national policies, the entire LED product is developing rapidly, and the LED packaging industry is growing simultaneously. Among the packaging materials, organic silicon packaging materials have been recognized by the industry due to their excellent performance and have become the fastest-growing and most valuable packaging materials, which have shown huge market value.

LED silicone encapsulant is a new type of high-end liquid silica gel, which is also called a kind of optical package. It can maintain high transparency in the visible light region, has a high absorption rate of 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 materials have become the leader in LED packaging materials due to their 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 the raw materials of LED packaging glue. With the increase of the mole fraction of phenyl groups, the high temperature resistance, radiation resistance and refractive index of silicone materials have been improved, and the importance of phenyl silicone oil for LED encapsulation has increased.

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 (Phenyl mole fraction 5%-10%); Medium phenyl silicone oil (Phenyl mole fraction 25%); High phenyl silicone oil (Phenyl mole fraction 45%). Different 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 energy loss of the light source.

Vinyl-terminated methyl phenyl silicone oil refers to a silicone oil with a vinyl end group and a methyl group and a phenyl group attached to the silicon atom on the main chain. According to the type of phenyl, it can be divided into methyl phenyl chain link type, diphenyl chain link type and mixed type (contains two phenyl chain links at the same time). Phenyl hydrogen-containing silicone oil is divided into hydrogen-terminated 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, and generally adopts sulfuric acid. In order to reduce the process flow, acidic resin can also be used for catalytic polymerization, eliminating the need to neutralize the catalyst, and directly filtering out the acidic resin, and the acidic resin can be reused many times. Vinyl-terminated methyl phenyl silicone oil and phenyl hydrogen-containing silicone oil are the basic raw materials for high refractive index LED encapsulants. With the rapid development of the LED industry, the LED encapsulation industry has unlimited potential, and there is a huge demand for phenyl silicone oil.