New Application of Phenyl Silicone Oil


Light-emitting diode (LED) is a kind of electroluminescent solid device. With the continuous innovation of technology and the guidance of national policy, the whole LED product develops rapidly, and the LED packaging industry grows synchronously. Among the packaging materials, silicone packaging materials have been recognized by the industry for their excellent performance, and become the fastest growing and most valuable packaging materials, which has shown great market value.


LED silicone packaging adhesive is a new type of high-end liquid silica gel, which is also called optical packaging. It can maintain high transparency in the visible region, has a high absorptivity to 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, the organic silicone packaging glue for LED has become the leader in LED packaging materials because of its excellent physical and chemical properties. With the aggravation of the energy crisis, the LED industry will continue to grow. Therefore, the market potential of LED packaging materials is huge. High power LED packaging materials require high transmittance and refractive index of raw materials. Phenyl silicone oil has become an important component of LED packaging collagen. With the increase of phenyl molar fraction, the high temperature resistance, irradiation resistance and refractive index of silicone materials have been improved, and the importance of phenyl silicone oil for LED packaging has been increasing.


Phenyl silicone oil for LED packaging mainly includes vinyl terminated methyl phenyl silicone oil and phenyl hydrogenated silicone oil. Phenyl silicone oil can be divided into: low phenyl silicone oil (phenyl molar fraction 5% - 10%), medium phenyl silicone oil (phenyl molar fraction 25%) and high phenyl silicone oil (phenyl molar fraction 45%). The requirement for phenyl content of LED packaging adhesives for different purposes is different. High power LED packaging adhesives generally require higher phenyl content in order to achieve high refractive index and reduce the energy loss of light source.


Vinyl capped methyl phenyl silicone oil is a silicone oil with vinyl end group and methyl and phenyl attached to silicon atoms in the main chain. According to the types of phenyl, they can be divided into methyl phenyl, diphenyl and mixed (containing two phenyl chains at the same time). Phenyl hydrogen-containing silicone oil can be divided into hydrogen-terminated phenyl silicone oil and side hydrogen-containing phenyl silicone oil, which have different uses. The former is mainly used as diluent or chain extender when it is added into packaging adhesive, while the latter is mainly used as centralized crosslinking agent of packaging adhesive, playing the role of crosslinking center. The preparation method of phenyl hydrogenated silicone oil is cationic polymerization, and sulfuric acid is generally used. In order to reduce the technological process, acid resin can also be used for catalytic polymerization, which omits the steps of neutralizing catalyst and filters acid resin directly, and acid resin can be reused many times.


Vinyl capped methyl phenyl silicone oil and phenyl hydrogen silicone oil are the basic raw materials of high refractive index LED packaging adhesive. With the rapid development of LED industry, the potential of LED packaging industry is unlimited, and the demand for phenyl silicone oil is huge. In recent years, with the further improvement of domestic production technology of phenyl monomers and intermediates, the research of this kind of products has made some progress, but there is still a certain gap compared with foreign products, which needs to be improved urgently. At present, the preparation technology and market of high refractive index LED packaging adhesive are monopolized by foreign silicone companies, and phenyl material is the development. The key is the key point that needs to be studied urgently.


Source: Silicone Innovation Institute