Лако-красочные материалы — производство

Most silicone resins are copolymers of methyl and phenyl substi­tuted monomers. Based on the type of organic substitution, the two main types of pure silicone resins are high-methyl silicone resins and high-phenyl silicone resins.

High-methyl silicone resins are polymethylsiloxanes that have methyl groups as the predominant organic substitution and hence have the lowest carbon content. Pigmentation of these binders is difficult, and their incompatibility with other resins limits their use in blends with

conventional organic binders. They are normally supplied as solu­tions in aromatic hydrocarbons (50 to 80 % solids). They are mainly used as binders for high temperature coatings, water repellents and co-binders for breathable and weather resistant exterior coatings.

High-phenyl silicone resins are a group of silicone resins with phe­nyl content greater than 20 %, with the rest being predominantly methyl and occasionally other alkyl groups. Silicones with only phenyl substitution do not have significance in coatings, as they pro­duce brittle films. Phenyl groups increase their heat resistance and improve compatibility with co-binders. Some important properties of pure silicone resins are summarized in Table 2.10.