Abstract
The influence of liquid cleaners on the inner wall coating of aluminum bottle cans was examined by a combination of 20 cleaners and 21 bottles. The bottle cans were classified into three types by their inner resin coatings. The coatings were an epoxy resin, another type of epoxy resin and a polyester resin. After a small portion of liquid cleaners were dropped on the epoxy resin inner coatings of bottles, one of the cleaners generated hydrogen bubbles but the other 19 cleaners caused no effect. This phenomenon was not observed even after about twenty hours when using other liquid cleaners. A mixture of alkalis (NaOH and KOH) and a solvent (diethylene glycol mono-n-butyl ether) in the components of the liquid cleaner in question brought the same phenomenon, and the concentration of the solvent and the time taken to start bubbling were correlated. Therefore, we concluded that because the solvent denatured the inner resin coating of aluminum bottle cans, the alkalis were made accessible to aluminum and generated hydrogen bubbles as a result.
