| 摘要 |
PURPOSE:To obtain a preservable and stable indicator which is discolored clearly and reversibly in accordance with O2 concentrations by printing or coating with printing inks or paints contg. bis(salicylaldehyde)-3,3'-diiminodipropylamine cobalt or its derivatives on a substrate. CONSTITUTION:In a synthetic resin varnish, a compound expressed by the formula I and its derivatives substituted by F, -OC2H5 or the like at the position there of the benzene ring are dispersed to make inks and paints, which are printed or coated on a supporter such as film made of PE or polyester, paper, metallic foil or the like. In this method, an indicator is obtd. which can be discolored clearly e.g. by the compound shown by the formula in accordance with the O2 concentrations of 0%, 1%, 10%, 20% respectively to yellow, brown, blackbrown, black and used repeatedly due to the reversible discoloration. This indicator is preservable and inexpensive, and can be applied for the comfirmation of the O2 removal at vacuum packagings of packaged foods, clothes, grain or the like, and the detection of the presence or absence of O2 permeation into packagings in a circulation process. |
