Лако-красочные материалы — производство

In keeping with the global trend, waterbased silicone resins are also commercially available for the coating industry. Some important com­mercial categories of waterbased silicone resins are primary emulsi­ons, secondary emulsions, and waterborne silicone modified resins.

Primary emulsions are prepared by polymerization of low MW cyclic siloxanes in combination with branched silicone resins or often with multifunctional alkoxy silanes. All the components are

first emulsified using a suitable emulsifier to give a stable aque­ous dispersion, followed by base catalyzed condensation of alkoxy silane groups. Secondary emulsions are of more significance in the coating industry. They are prepared by emulsifying solvent — based silicone resins as well as silicone modified resins in water with subsequent removal of solvent by distillation. Some residual amount of solvent (up to 10 %) is not removed to assist film formation through coalescence of dispersed resin particles. Waterborne sili­cone modified resins are prepared from silicone modified water — reducible acrylic or polyester resins, where ionic groups in acrylics or polyesters ensure water dispersibility of the final polymer.