The invention relates to the use of silane-functional polyvinyl alcohols in priming agents for separating papers and films, comprising I) at least one silane-containing polyvinyl alcohol made from fully saponified or partially saponified vinyl ester copolymers with a degree of hydrolysis of 75 to 100 mol %, obtainable by radical polymerisation of a) one or more vinyl esters of straight or branched chain alkyl carboxylic acids with 1 to 18 C atoms, of which a proportion of 1 to 30 mol %, based on the total polymer, are one or several 1-alkylvinyl esters with alkyl groups having 1 to 6 C atoms and carboxylic acids with 1 to 6 C atoms, b) 0.01 to 10 mol % of one or more silane-containing ethylenically-unsaturated monomers and, optionally, c) further comonomers which may be copolymerised with the above and saponification of the polymer thus obtained.