| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a temperature-sensitive ink for indicating a temperature history a exceeding a prescribed temperature for a definite period with a clear and irreversible color change, and to provide a simple indicator marked with the ink and enabling the accurate indication of the temperature history and the storage of the result as a record. SOLUTION: The temperature-sensitive ink contains a granular or powdery hot-melt material having a melting point corresponding to the temperature to be recorded, a granular or powdery diffusible pigment dispersible or soluble in the molten material and an ink vehicle diffusing the molten material and colored with a color masking agent having a color complementary to the color of the pigment. The temperature history indicator is produced by applying the temperature-sensitive ink to a substrate.</p> |
