| 摘要 |
PURPOSE:To detect easily whether an article preserved by refrigeration or the like is preserved at an adequate temp. or not by forming a titled set in such a way that the coloring material in ink contg. the component to melt at a prescribed temp. colors a sheet contg. a discoloring material under a diaphragm allowing permeation of the ink when the component thereof melts via said diaphragm. CONSTITUTION:Ink 5 prepd. by incorporating a coloring material 1 into a wax-like component 2 which consists of higher alcohol, polyhydric alcohol, polyalkylen eglycol, etc. and melts at a prescribed temp. is coated on a disphragm 4 consisting of paper, a porous film of plastics, a non-woven fabric, etc. and a sheet 6 contg. a discoloring material 3 which discolors when said material contacts with the material 1 is laminated on the opposite side of the film 4. An electron donative colorable org. compd. such as crystal violet lactone is used for the material 1 and a compd. having phenolic OH, org. carboxylic acid, etc. are used for the material 3. If the laminate is stuck to an article preserved by refrigeration, etc., the sheet 6 discolors irreversibly when the thickness, pore size, etc. of the diaphragm 4 are adequately selected and if the laminate is exposed to a prescribed temp. or above for prescribed time or above and therefore the temp. is easily detected. |
