Metal oxide sol, film and molded articles made therefrom

A process for preparing a binder-free metal oxide sol, comprising the steps of: a) providing a metal oxide dispersion, wherein the metal oxide powder in the dispersion has an average, number-related aggregate diameter of less than 200 nm, and b1) adding a metal alkoxide M (OR) b2) adding a starting sol, which is by hydrolysis of a metal alkoxide M OR) and the weight-related ratio of metal oxide from the hydrolysis to metal oxide in the dispersion is 0.01 to 1. By this method available metal oxide sol. By means of the metal oxide sol coated substrate producible and moldings.