| 摘要 |
PURPOSE:To remove press working oil sticking to silver or silver plated parts without tarnishing the silver by cleaning the parts with a cleaning solvent having a specified composition. CONSTITUTION:When silver or silver plated parts are press-worked, press working oil sticks to the worked parts. In order to remove the oil, 1,1-difluoro-1,2- dichloroethane (flon 132b) or 1,2-dichloro-1-fluoroethane (flon 141) is used as a cleaning agent. A cleaning agent prepd. by mixing flon 132b or flonw 141 with <=30wt% one or more among ethanol, propanol, isopropanol, butanol, isobutanol, tertiary butanol, acetanitrile, nitromethane, methyl acetate and ethyl acetate may be used. |
