| 摘要 |
PURPOSE:To obtain a sufficient achromatic effect even with less heat energy in coloring at high temperature by providing achromatic agents the melting points of which are different from each from each other (one in the upper layer is higher than the other by a specific value) in the upper and middle layers of two heat sensitive coloring layers. CONSTITUTION:Two heat sensitive coloring layers the coloring temperatures and color tones of which are different from aeach other respectively (coloring component in the upper layer contans colorless or light color leuco dyestuff and phenolic or acidic material) are overlapped, the melting point of the achromatic agent in the upper layer is made higher than that of the other in the middle layer by 20 deg.C or more. A sufficiently colored picture can be obtained without affection to the achromatic agent in coloring at low temperature, a remakable achromatic effect is developed even with less heat energy in coloring at high temperature, a greatly clear contrast can be obtained. |
