Methyl phenyl silicone resin is the mainstream variety of silicone resin, mainly including electrical insulating paint, heat resistant paint, glass fiber cloth impregnation material, silicone varnish for laminated materials, silicone molding plastics, semiconductor device packaging materials, modified intermediates and so on.Methyl phenyl silicone resins are also used as flame retardant additives for organic polymers, giving plastic products flame retardant properties, and as a normal support component for thermal sensitive phase change materials, such as heat-shrinkable silicone rubber products.

　　A methyl phenyl silicone resin synthesized from chlorosilane

　　1、methyl phenyl silicone resin varnish: is made of a variety of methyl chlorosilane, phenyl chlorosilane co-hydrolysis condensation system.

　　In the first step, a certain proportion of methyl chlorosilane and phenyl chlorosilane were co-hydrolyzed. After the reactants were stratified, the acid water layer was separated. The low molar mass polysiloxane toluene solution was washed with water to neutral, and then filtered.(The low molar mass polysiloxane toluene solution prepared at this time can be used as the intermediate of weather-resistant paint varnish or modified silicone resin)

　　To be used as a laminate or heat resistant varnish, further condensation is required.Part of toluene was first steamed, and the polymer mass fraction was adjusted to 50-60%, and then polycondensated to a certain viscosity at reflux temperature or in the presence of a catalyst.The water generated in the polycondensation reaction is carried out by toluene, and gelation should be prevented during the reaction.

　　2、solvent-free methyl phenyl silicone resin: at room temperature for liquid or softening temperature is low solvent-free methyl phenyl silicone resin, mainly used as electrical insulating paint, heat resistant coating, semiconductor packaging materials and thermal softening materials.

　　3、Difunctional organochlorosilane and trifunctional organochlorosilane were hydrolyzed, condensed and recopolymerized to prepare block copolymerized methylphenyl silicone resin.(Methyl phenyl silicone resin varnish prepared by this method, solvent volatilized pre-poly silicone resin as a non-sticky solid, used for glass fiber fabric treatment, air dried surface is non-sticky, can improve the laminating process, the preparation of laminated materials with good flexibility.This silicone varnish, used as a high temperature resistant coating, can withstand 1200℃. The resin itself does not decompose at 600℃, slowly decompose above 600℃ and melt into a whole with the metal oxide pigment in the high temperature coating.

　　4、alcoholysis and hydrolytic condensation of methyl phenyl silicone resin method: without solvent, the first alcoholysis of organochlorosilane, hydrolytic condensation of methyl phenyl silicone resin, can simplify the process.The prepolymer silicone resin can be used as modified intermediate of alkyd resin and polyester resin.

　　5、glass cloth pipe silicone varnish and silicone molding plastic

　　(1) Silicone varnish for glass cloth tube: glass cloth tube treated with silicone varnish is mainly used for covering and protecting the wiring of heating and heating parts of household appliances, automobiles, motors and transformers. It is a heat-resistant electrical insulation material with large demand.Silicone varnish for glass cloth tube is a kind of methyl phenyl silicone product that can form soft paint film, with higher D link content.

　　(2) plastic with methyl phenyl silicone resin: silicone resin molding plastic is methyl phenyl pre-poly silicone resin as the base material, with appropriate quartz powder, silica black, diatomite, calcium stearate and other fillers, by mixing into a mixture of thermosetting correction molding or injection molding.The forming products have excellent electric arc, electrical insulation, high and low temperature characteristics and good weight and mechanical properties.It can be used to make arc cover, switchboard, commutation switch and connectors of various electrical appliances and instruments.The methyl phenyl silicone resin used has a high T link content and R/Si value between 1.0 and 1.4.