Light-emitting diode (LED) is a kind of electroluminescent solid devices. With the continuous innovation of technology and the guidance of national policies, the whole LED products are developing rapidly, and the LED packaging industry is growing synchronously. Among packaging materials, silicone packaging materials have been recognized by the industry because of their excellent performance, becoming the fastest developing and most valuable packaging materials, has shown great market value.
LED silicone packaging adhesive is a new type of high-end liquid silicone, is also a kind of optical packaging called, can maintain high transparency in the visible light area, has a high absorption rate of ultraviolet light, can improve the light output rate and service life of lighting devices.
In recent years, due to the rapid development of LED industry, the demand for LED packaging materials increases, among which LED silicone packaging adhesive has become a leader in LED packaging materials with its excellent physical and chemical characteristics. With the aggravation of energy crisis, LED industry will maintain continuous growth, therefore, LED packaging materials market potential 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 rubber raw materials. With the increase of the mole fraction of phenyl, the high temperature resistance, irradiation resistance and refractive index of organic silicon materials are improved, and the importance of phenyl silicone oil for LED packaging adhesives is increasing.
Phenyl silicone oil for LED packaging mainly includes vinyl capped methyl phenyl silicone oil and phenyl hydrogen containing silicone oil. Phenyl silicone oil according to the content of phenyl can be divided into: low phenyl silicone oil (phenyl mole fraction 5%-10%); Medium phenyl silicone oil (25% phenyl mole fraction); High phenyl silicone oil (45% phenyl mole fraction). LED packaging adhesives of different uses have different requirements for phenyl content. High-power LED packaging adhesives generally require higher phenyl content in order to achieve high refractive index and reduce the loss of light source energy.
Vinyl capped methyl phenyl silicone oil is a kind of silicone oil containing vinyl at the finger end and methyl and phenyl groups in the silicon atom of the backbone. According to the type of phenyl group, it can be divided into methyl phenyl chain segment, diphenyl chain segment and mixed type (containing both phenyl chain segments). Phenyl containing hydrogen silicone oil is divided into hydrogen capped phenyl silicone oil and side hydrogen containing phenyl silicone oil, both uses are different. The former is mainly used as diluent or chain extender in the packaging rubber, while the latter is mainly used as a concentrated cross-linking agent to play the role of cross-linking center. The preparation method of phenyl hydrogen containing silicone oil is cationic polymerization, generally sulfuric acid. In order to reduce the process flow, acid resin can also be used for catalytic polymerization, eliminating the step of neutralizing the catalyst, the acid resin is directly filtered out, and the acid resin can be reused many times.
Vinyl capped 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 LED industry, LED packaging industry has unlimited potential, and there is a huge demand for phenyl silicone oil. In recent years, with the domestic phenyl monomer, further improving intermediates production technology, the research of this kind of product has made certain progress, but there are still a certain gap compared with foreign products, need to be improved, the current high refractive index LED encapsulation adhesive preparation technology and market are monopolized by foreign silicone company, phenyl is the key to the development of the material, is in urgent need of research focus.
From: Global Silicone network
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