is a polyorganosiloxane with a highly cross-linked network structure with silicon and oxygen as the main chain. Usually methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, and diphenyl are used. Various mixtures of dichlorosilane or methylphenyldichlorosilane are hydrolyzed in organic solvents and lower temperatures to obtain acid hydrolysates. The initial product of the hydrolysis is a mixture of cyclic, linear and cross-linked polymers, usually containing a considerable number of hydroxyl groups. The hydrolysate is washed with water to remove the acid, and the neutral primary polycondensate is thermally oxidized in the air or further polycondensed in the presence of a catalyst, and finally forms a highly cross-linked three-dimensional network structure.
Silicone resin is a thermosetting plastic, one of its most outstanding properties is excellent thermal oxidation stability. After heating at 250°C for 24 hours, the weight loss of silicone resin is only 2-8%. Another outstanding performance of silicone resin is its excellent electrical insulation properties, which can maintain its good insulation properties in a wide range of temperature and frequency.
According to the source of raw materials, silicone resin adhesives can be divided into: silicone resin-based adhesives and silicone rubber-based adhesives. The former is mainly used for bonding metals and heat-resistant silicone resins. It has good bonding performance to metals such as iron, aluminum and tin, and is easy to bond to glass and ceramics, but has poor adhesion to copper.
Silicone adhesive silicone resin coatings
based on pure silicone resin have many disadvantages: poor film-forming properties, including high curing temperature, long time, inconvenient large-area construction, and poor adhesion of the coating to the bottom layer.
Modification with fluorination is mainly to increase the solvent resistance, oil repellency (anti-sticking) of the silicone resin and reduce the surface energy. The critical surface tension of silicone resin is lower than that of other resins, but higher than that of fluororesin.
In view of the above characteristics, silicone resin is mainly used as insulating varnish (including varnish, enamel, colored paint, impregnating varnish, etc.) to impregnate H-class motors and transformer coils, and to impregnate glass cloth, glass cloth silk and asbestos cloth to make motor covers Tube, electrical insulation winding, etc. Using organic silicon insulating varnish to bond mica can make a large area of mica sheet insulating material, which can be used as the main insulation of high-voltage motors.
In addition, silicone resin can also be used as heat-resistant, weather-resistant anti-corrosion coatings, metal protective coatings, waterproof and moisture-proof coatings for construction projects, release agents, adhesives and secondary processing into silicone plastics for electronics, electrical and defense industries Above, as semiconductor packaging materials and insulating materials for electronic and electrical parts.
According to its main purpose and cross-linking method, silicone resins can be roughly divided into silicone insulating paints, silicone coatings, silicone plastics and silicone adhesives.Top Win is one of the leading & professional manufacturers with more than 20 years' experience, have domestic top-level engineers in silicone surfactant industry. We specialized in producing all kinds of SILICONE BASED new materials and specialized in research, production, sales and marketing in silicone-based performance materials. Provide good OEM&ODM service. Our products are mainly used in polyurethane foam, Agriculture,Coatings and Inks, Leather & Textiles, Pulp and Paper, Cosmetic industry, etc.