Hartwig, A.A.HartwigTrautmann, J.J.TrautmannSebald, M.M.SebaldRischka, K.K.Rischka2022-03-082022-03-082006https://publica.fraunhofer.de/handle/publica/307624(C1)(B3) Es wird ein Verfahren zur Herstellung von Nanokompositen aus agglomeriert vorliegenden Nanopulvern und organischen Bindemitteln vorgestellt. Durch Oberflaechenmodifikation der Nanofuellstoffe in einem organischen Medium gelingt es die Agglomerate dauerhaft soweit zu zerteilen, dass transparente Nanokomposite erhalten werden koennen. Das modifizierte Nanopulver wird bevorzugt als trockenes Zwischenprodukt isoliert. Die Herstellung der vorgestellten Nanokomposite ist einfacher als die Herstellung von Nanokompositen nach der Sol-Gel-Technik und ist zusaetzlich flexibler und breiter einsetzbar. Eine wichtige Anwendung fuer die Nanokomposite sind kratzfeste Lacke.DE 102006039638 B3 UPAB: 20080615 NOVELTY - A method (M1) for the production of nano-composites (I) from organic binders (II) and surface-modified fillers (III) by surface-modifying a nano-filler in an organic medium with a silane, titanate and/or zirconate in presence of a base (IV), and then mixing (III) with a binder (II), in which the medium is a polar solvent and (IV) is a non-ionic base, namely an acyclic base or a cyclic base with a pKBH plus minus value of not less than 19 or not less than 15 respectively (measured in acetonitrile). DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for (1) a method (M2) for the production of (I) as above in which the organic medium is the binder (II) (2) nano-composites (I) obtained by these methods (3) a method (M3) as described above for the production of modified nano-fillers (III) (4) surface-modified nano-fillers (III) obtained by M3 . USE - Nano-composites obtained by this method are used in paint, adhesives, casting compounds and coating materials, as matrix resins for fibre-reinforced plastics, polymer foam or plastic moldings, or for the production of such products, especially in aircraft construction and electronics, for painting cars, transparent plastics and parquet flooring, as dental materials, for coating optical glass, as base material for optical glass, more especially for varnishing polycarbonate car windows, for coating spectacles or as base materials for spectacle lenses (claimed). ADVANTAGE - The use of a strong organic base as catalyst for the surface-modification enables the production of nano-scale fillers with a high content of functional surface groups which can undergo chemical bonding or other strong interactions (van der Waals bonds or hydrogen bonds) with the binder matrix, resulting in nano-composites with improved mechanical properties, thermal properties and transparency. This method avoids the problems associated with prior-art basic catalysts, e.g. hydrolysis and condensation of silanes.de620660671patent102006039638