Nano-scale precipitating zinc oxide used e.g. for protecting UV-sensitive organic polymers consists of particles having an average specified primary particle diameter

摘要

Nano-scale precipitating zinc oxide consists of particles having an average primary particle diameter of less than 10 nm and can be re-dispersed in organic solvents (mixtures) as well as in water and mixtures with organic solvents or in mixtures with surface-modified substances to give organic as well as water-based primary particle-dispersed sols. Independent claims are also included for: (a) a process for the production of a precipitating zinc oxide comprising leaving the precipitate to mature after basic hydrolysis, compressing to give a gel and removing the supernatant phase in which the by-products are dissolved in the precipitate; and (b) a process for the production of zinc oxide sols from precipitating zinc oxide comprising converting the precipitating zinc oxide into a colloidal-dispersed state by adding organic solvent (mixture) or water and/or water-alcohol mixture with surface-modifying substances.