摘要 |
<P>PROBLEM TO BE SOLVED: To provide a stationery which makes the reverse color changes between a plurality of colors visually discriminable by a simple means by a hand touch or rubbing, and which is rich in variations of the color change, and has a high commodity value. <P>SOLUTION: A thermal discoloring layer containing reversible thermal discoloring pigments A and B is installed. The pigments A and B are a pigment which envelopes a reversible thermal discoloring composition in a micro-capsule. In this case, the reversible thermal discoloring composition starts coloring when the temperature has reached a coloring starting temperature (t<SB>2</SB>) in a temperature descending process from a colorless state in a temperature-color density curve, and becomes a completely colored state when the temperature has reached a complete coloring temperature (t<SB>1</SB>). Also, the reversible thermal discoloring composition starts fading when the temperature has reached a fading starting temperature (t<SB>3</SB>) in a temperature ascending process from the colored state, and becomes a completely colorless state when the temperature has reached a complete colorless temperature (t<SB>4</SB>). In this case, t<SB>1A</SB>and t<SB>4A</SB>of the pigment A and t<SB>1B</SB>and t<SB>4B</SB>of the pigment B satisfy equations (1) to (4). The equation (1) is 28(°C)≤t<SB>4A</SB>≤36(°C), the equation (2) is t<SB>4A</SB>+2(°C)≤t<SB>4B</SB>≤t<SB>4A</SB>+25(°C), the equation (3) is 10(°C)≤t<SB>1A</SB>≤33(°C), and the equation (4) is 10(°C)≤t<SB>1B</SB>≤40(°C). <P>COPYRIGHT: (C)2008,JPO&INPIT |