Silicone resin is a cross-linked semi-inorganic high polymer with Si-O-Si as the main chain and organic groups connected to the silicon atom. In the presence of a catalyst, it can be further transformed into an insoluble and infusible thermosetting resin with a three-dimensional structure. The outstanding properties of silicone resin are high and low temperature resistance, weather resistance, chemical resistance and dielectric properties, so silicone resin as the base material for electrical insulating paints, coatings, molding compounds, laminates, mold release agents, etc. Various products are becoming more and more popular in electrical and electronic, aerospace, building materials, cultural relics protection and interior and exterior of automobiles.

Silicone resin coatings use pure silicone resins or modified silicone resins as film-forming substances, so the structure of silicone resins determines the basic properties of silicone resin coatings.

The bond energy of the Si-O bond (422.5kJ/mol) is very high, and it is embedded in the resin by the substituent R in the form of a network. The shielding effect of the substituent R makes the main chain less susceptible to the attack of impurities, and the SiO that forms a network structure increases the activation energy of the main chain breaking, so the thermal stability of the silicone resin is very good, and it can be continuous at 180~200 °C. use.

The Si-O bond has a long bond length (1.64A) and a large si-o-si bond angle (143°), which makes it easy to rotate between Si, and its molecular chain is generally a helical structure, which is very soft, and the interaction between The force is very weak, so the surface energy of the silicone resin is very low.

The electronegativity (1.8) of the Si element in the Si-O bond is very different from the electronegativity (3.5) between the elements, and the Si atom is easily polarized to form a positive Si ion (si-o), and the positive Si ion can The hydrocarbyl group to which it is attached is stabilized, so the silicone resin is not prone to oxidation reactions.

The dissociation energy of the Si-O bond (460.5kJ/mo1) is higher than the light energy (300~400kJ/mo1) generated by the near-ultraviolet light wave irradiated on the ground, and it is difficult for ultraviolet rays to generate free radicals. Strong weather resistance.