Preparation of nanoscale titanium dioxide-dispersion, useful in e.g. lacquers, comprises acid-catalyst hydrolysis of nano-titanium dioxide in presence of polar aprotic solvent and reaction of the dispersion with alkyltrialkoxysilane

摘要

Preparation of high concentrated, transparent and long term stable nanoscale titanium dioxide-dispersion (I) comprises: (a) preparing a dispersion of nano-titanium dioxide-dispersion (II) by acid catalyst hydrolysis of titanium alcoholate in presence of emulsifying agent and complex active polar aprotic solvent at room temperature; and (b) reacting (II) with alkyltrialkoxysilane for stabilization to form transparent long term stable (II). Preparation of high concentrated, transparent and long term stable nanoscale titanium dioxide-dispersion (I) with a particle size distribution (2-50 nm) comprises: (a) preparing a dispersion of nano-titanium dioxide (TiO 2)-dispersion (II) in a polar aprotic solvent by a acid catalyst hydrolysis of titanium alcoholate of formula (Ti(OR) 4) in presence of emulsifying agent and a complex active polar aprotic solvent with a E-T-N-value (0.2 (preferably greater than 0.3)) at room temperature; and (b) reacting (II) with alkyltrialkoxysilane for stabilization to form transparent long term stable (II) with a content of up to 25 (preferably 10-20) wt.% of nano-TiO 2. R : 2-4C alkyl. Independent claims are also included for: (1) a method for the processing of (I) comprising removing the solvent and isolating nano-TiO 2 powders stabilized with alkyltrialkoxysilane in the form of crystalline anatase; (2) (I) obtained by the method; (3) a shaped part comprising at least a material of at least a polymer material (preferably polyamide, polyester, copolyester, polyacrylate, polycarbonate, polyethylene, copolymer based on ethylene, polypropylene, copolymers based on polypropylene, polyvinyl chloride, polyacetate, polyketone and polyurethane) comprising nanoscale-TiO 2 or at least a material comprising a material mixture of plastics containing nanoscale-TiO 2; and (4) a foil comprising at least a layer of at least a material of plastics (preferably polyamide, polyester and copolyester, polyacrylate, polycarbonate, polyethylene, copolymer based on ethylene, polypropylene, copolymers based on polypropylene, polyvinyl chloride, polyacetate, polyketone and polyurethane) containing nanoscale-TiO 2 or a material mixture of plastics comprising nanoscale-TiO 2.