| 摘要 |
PURPOSE:To reduce browning after discoloration, by a gas detection agent containing not only basic copper carbonate as a discoloring component but also hydride type gas. CONSTITUTION:When a gas detection agent containing not only basic copper carbonate as a discoloring component but also hydride type gas is contacted with nitrogen gas, hydrogen gas, argon gas, helium gas or air, blue basic copper carbonate sensitively discolors to black and this color is held over a long time. |
