Erforschung von Systemloesungen fuer transparente Verschleissschutzschichten auf Kunststoffen fuer die Optik. Teilvorhaben: Organische Schichten und organische Haftvermittlungsschichten mit kovalenter Anbindung Abschlussbericht

Abstract

All of the scheduled investigations have been terminated. Only covalent linkages to protective coatings are promising. That fact came out from rather diverse experiments aimed to improve the adhesion. Particular problems were encountered with the chosen materials PC, CR29, PU 161, and PMMA due to their photolability during plasma CVD and due to corrosion by ubiquitous gases such as ammonia, methylamine, chlorine, nitrogen dioxide. AFM shows that gaseous amines even destroy the common hard coatings. Purposeful exposure to reactive gases under AFM control gives functionalization with recoiling of the polymer chains at the surface. Chain fissions are not tolerable. Highly cross-linked CR39 enables the direct PVD connection to SiO_2 coatings. Side-group hydrolysis without destruction of the optical surfaces is particularly attractive in the case of PMMA. Covalently attached Al_2O_3/SiO_2-coatings exhibit rather high long-term stability towards hydrolysis. The carboxylic groups that are generated should be prone to lasting covalent attachments of stress-relieving polyurethane coatings by reaction with diisocyanates. That branch was halted for reasons of capacity in favor of covalent attachment of CR39 via plasma induced grafting, even though numerous covalent attachments succeeded by simple chemical gas/solid reactions. (orig.)SIGLEAvailable from TIB Hannover: F98B80+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman