The present invention provides a composition based on the reaction at least of the following components: (i) a glycidyloxypropylalkoxysilane, (ii) an aqueous silica sol having an SiO2 content of >20% by weight, (iii) an organic acid hydrolysis catalyst, and (iv) n-propyl zirconate, butyl titanate or titanium acetylacetonate as crosslinker, a process for its preparation, and the use thereof, particularly as a composition for scratch resistant coatings, and also provides articles thus coated.