iv compounds for example dibutyl tin oxide dibutyl tin dichloride dibutyl tin diacetates dibutyl tin dilaurate dibutyl tin maleate or dioctyl tin diacetate all the above mentioned catalysts can of course be used as mixtures combinations of organic metal compounds in particular metal salts of carboxylic acids for example the pb salt of 2 ethyl hexanic acid with amine catalysts such as diazabicyclo octane are of particular interest catalyst combinations of this type lead to coating compositions having a particularly long pot life at room temperature but still having a short curing time when heated for example three minutes at 100 u00b0 c other examples of catalysts which can be used according to the invention and details about the mode of operation of the catalysts are described in kunststoff handbuch volume vii edited by vieweg and hochtlen carl hanserverlag munich 1966 for example on pages 96 to 102 surface active additives such as emulsifiers can also be used according to the invention suitable emulsifiers include for example the sodium salts of castor oil sulphonates or salts of fatty acids with amines such as oleic acid diethyl amine or stearic acid diethanol amine alkali or ammonium salts of sulphonic acids such as those of dodecyl benzene sulphonic acid.