| 摘要 |
PURPOSE:To widen the a transparency-change temperature range by using fatty acid, higher fatty acid and aliphatic saturated dicarboxylic acid, melting points of which are kept within specific ranges, as low molecular compounds in a recording material, in which an organic low molecular compound is dispersed into a high molecular resin base material and the base material is changed reversibly into transparency and opacity by heat. CONSTITUTION:A reflecting layer 2, a recording material layer 3, a protective layer 4 and a printed layer 5 for forming a visible recording display window 6 are laminated on a synthetic-resin base material sheet 1, and a magnetic recording layer 7 is formed on the rear. Fatty acid A, the melting point of which is lower than 60 deg.C, higher fatty acid or higher ketone B having the melting point of 60-100 deg.C and aliphatic saturated dicarboxylic acid C having the melting point of 100 deg.C or higher are dispersed into the high molecular resin base material of the recording material layer 3 respectively. A temperature range changed into transparency can be altered by varying the mixing ratio of these A, B, C, B:C=90:10-50:50, and (B+C):A=90:10-60:40 are favorable as the mixing ratio of each component, and 10-80 pts.wt. is preferable to the 100 pts.wt. base material as the total amount of A, B and C. |
