Introduction to Silicone Resin
Silicone resin is a highly cross-linked thermosetting polymer containing difunctional, trifunctional, and tetrafunctional siloxane structural units.
The four structural units that make up silicone resin can form three-dimensional structures, and T or Q units are essential components that can be combined with D and M units to produce various silicone resins.
The influence of different substituents on the properties of silicone resin
1) The organic substituents on the silicon atoms of silicone resin are mainly methyl groups. Introducing phenyl groups can improve thermal elasticity and adhesion, as well as enhance compatibility with organic polymers and pigments;
2) Introducing ethyl, propyl, or long-chain alkyl groups can enhance the affinity for organic compounds and improve hydrophobicity;
3) Introducing vinyl and hydrogen groups can achieve platinum catalyzed addition reactions and peroxide induced crosslinking reactions;
4) Introducing carbon functional groups can react with more organic compounds and improve adhesion to substrates.

The Influence of R/Si Value on the Properties of Silicone Resin
The performance of the final processed product of silicone resin depends on the ratio of organic and inorganic parts in its structure, that is, the value of R/Si.
Generally, silicone resins with practical value have a molecular composition with a ratio of R to Si between 1.0 and 1.6. The general rule is that the smaller the R/Si value, the better the silicone resin can be cured at lower temperatures; The larger the value of R/Si, the longer the baking time at 200-250 ℃ is required for the silicone resin to fully cure. The resulting paint film has poor hardness, but much better thermal elasticity than the former.

The ratio of methyl to phenyl groups in organic groups also has a significant impact on the properties of silicone resins. The lower the content of phenyl groups in organic groups, the softer the resulting paint film and the faster the condensation; The higher the benzene content, the harder and more thermoplastic the resulting paint film. The benzene content is between 20% and 60%, and the paint film has the best bending resistance and heat resistance. In addition, introducing phenyl groups can improve the compatibility of silicone resin with other silicone resins and organic pigments, and enhance the adhesion of silicone resin to various substrates.
When manufacturing silicone resins with various purposes and properties, the first consideration is to choose which monomers and determine their mix proportions.

Application of Silicone Resin
Organic silicon resin is mainly used as insulation paint (including varnish, enamel, color paint, impregnating paint, etc.) to impregnate H-grade motor and transformer coils, as well as to impregnate glass cloth, glass cloth wire, and asbestos cloth to make motor sleeves, electrical insulation windings, etc.
Using organic silicon insulation paint to bond mica can produce large-area mica sheet insulation material, which can be used as the main insulation of high-voltage motors.