| SILRES® HP 1250 is is a glycidoxy functional silicone polymer, which is used as a binder to increase UV resistance and corrosion resistance of coating formulations. This patented technology combines the chemical resistance and adhesion of an epoxy resin with the UV and high temperature resistance of a silicone polymer into one product. The incorporation of phenyl substituents on the silicon atom increases high temperature resistance and chemical resistance of the polymer. The phenyl substituent increases the compatibility of the silicone with organic polymers such as acrylics, fluorocarbons, and polyesters. The use of difunctional dimethyl groups increases the flexibility of the coating which increases the resistance of the polymer to cracking. The ratio of tri-functional (T-units) silicon to di-functional (D-units) silicon is balanced to maximize the amount of high energy Si-OSi concentration without sacrificing flexibility. The high level of T units increases the polymers ability to form adurable, chemical resistant coating. The incorporation of D units increase the polymers flexibility. The epoxy functionality on the SILRES® HP 1250 make it ideal for developing low VOC (volatile organic compounds), room temperature curable coatings, which have little to no film shrinkage (see figure 2). The incorporation of a glycidoxy group directly to the silicon atom through a Si-C bond increases stability and makes the polymer resistant to hydrolysis. Application: SILRES® HP 1250 can be used as a binder to make high solids or solvent-free exterior durable coatings for the Marine, Architectural, and Industrial Protective Coatings Market. Coatings made using this product can be applied directly to zinc-rich coatings, bare steel or aluminum substrates. SILRES® HP 1250 has a weight per epoxy between 660-680 grams of polymer per moles of epoxy, which makes it highly reactive with nucleophiles such as phosphoric acid, acid functional acrylics, amine and amino functional curing agents. The degree of replacement of organic binder should be determined through laboratory evaluations. SILRES® HP 1250 will increase the UV resistance of the coating. The silicone-epoxy polymer is only a portion of the coating formulation, and therefore to make a exterior durable coating, ceramic pigments, extenders and hardeners designed for exterior applications should be used. The additives and hardeners used should also be UV and corrosion resistant. The silicone-epoxy polymer has a relatively low viscosity and has a high functionality, which enable formulators the ability to develop low VOC coatings. Information provided by Wacker Chemie AG. |
