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 has developed rapidly, and the LED packaging industry has grown synchronously. Among packaging materials, organic silicon packaging materials have been recognized by the industry for their excellent performance and have become the fastest developing and most valuable packaging materials, demonstrating enormous market value.

LED organic silicon encapsulation adhesive is a new type of high-end liquid silicone and also a type of optical encapsulation. It can maintain high transparency in the visible light range, has a high absorption rate for ultraviolet rays, and can improve the light output rate and service life of lighting devices.

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 adhesive has become a leader in LED packaging materials due to its excellent physical and chemical properties. With the worsening energy crisis, the LED industry will continue to grow, therefore, the market potential for LED packaging materials is enormous. High power LED packaging materials require high transmittance and refractive index of the raw materials, and phenyl silicone oil has become an important component of LED packaging adhesive raw materials. With the increase of phenyl mole fraction, the high temperature resistance, radiation resistance, and refractive index of organic silicon materials are all improved, and the importance of phenyl silicone oil for LED packaging adhesive is increasing day by day.

The phenyl silicone oil used for LED packaging mainly includes two types: vinyl terminated methyl phenyl silicone oil and phenyl hydrogen containing silicone oil. Phenyl silicone oil can be divided into: low phenyl silicone oil (phenyl mole fraction of 5% -10%); Medium phenyl silicone oil (phenyl mole fraction 25%); High phenyl silicone oil (phenyl mole fraction 45%). The requirements for the phenyl content of LED packaging adhesives for different purposes vary. High power LED packaging adhesives generally require a higher phenyl content in order to achieve a high refractive index and reduce the loss of light source energy.

Vinyl terminated methylphenyl silicone oil refers to silicone oil with vinyl groups at the end groups and methyl and phenyl groups attached to the silicon atoms on the main chain. According to the type of phenyl group, it can be divided into methylphenyl chain type, diphenyl chain type, and mixed type (containing both types of phenyl chains). 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 encapsulation adhesive, while the latter is mainly used as a concentrated crosslinking agent for the encapsulation adhesive, serving as a crosslinking center. The preparation method of phenyl hydrogenated silicone oil adopts cationic polymerization method, generally using sulfuric acid. In order to reduce the process flow, acidic resin can also be used for catalytic polymerization, eliminating the step of neutralizing the catalyst, directly filtering out the acidic resin, and the acidic resin can be reused multiple times.

Vinyl terminated methyl phenyl 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 potential of the LED packaging industry is unlimited, and there is a huge demand for phenyl silicone oil. In recent years, with the further improvement of domestic production technology for phenyl monomers and intermediates, research on this type of product has made certain progress. However, there is still a certain gap compared to foreign products, which urgently needs to be improved. Currently, the preparation technology and market of high refractive index LED packaging adhesive are monopolized by foreign organic silicon companies, and phenyl materials are the key to development and the focus of urgent research.

Phenyl tris (dimethylsiloxyalkyl) silane，plz check MY 235