Functionalized coating materials based on inorganic-organic polymers

Abstract ORMOCER ® s (ORMOCER ® Trademark of Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V.) as inorganic-organic polymers synthesized by a two-step sol-gel processing method can be applied as thin transparent coatings on various substrates (polymers, metals, ceramics). The curing of ORMOCER ® s is performed thermally (at temperatures below 200°C) or by UV-radiation. Their high abrasion resistance and good chemical stability led to several actual industrial applications. Beside mechanical protection functions (e.g. for sensitive polymer substrates) additional functionalities of ORMOCER ® surfaces are investigated to find new application areas. This paper presents two additional surface functions of abrasion resistant ORMOCER ® coatings: Antiadhesive and antistatic properties. Incorporation of perfluorinated alkoxysilane compounds via sol-gel processing decreases the surface energy of the cured layer. Water as well as non-polar substances lose their adhesion to the surface, wetting is reduced, solutions are drained off and particles can be removed easily. By addition of polar and/or ionic compounds bearing hydrolyzable alkoxysilyl groups a scratch resistant antistatic coating for polycarbonate was developed. Compared to the uncoated substrate, the specific surface resistance was decreased from 10 15 to 10 8 Ω. Electrostatic charging is decreased and attraction of particles inhibited or reduced. The coatings are abrasion resistant and show very good adhesion even in a wet climate.