| 摘要 |
PURPOSE:To contrive to enhance dynamic developed color density in using an organic color developer in combination with a basic inorganic dye and to stabilize a developed color image, by incorporating a specified hydroxyphenylsulfonate compound as an organic color developer. CONSTITUTION:A hydroxyphenylsulfonate compound of the formula, wherein X is hydrogen, halogen, carboxyl, lower alkyl, lower alkoxy, hydroxyl or nitro, and R is 1-12C alkyl, cycloalkyl, group (a), group (b), group (c) or group (d), wherein A is hydrogen, halogen, nitro, lower alkyl, lower alkoxy or hydroxyl, and each of (n) and (m) which may be equal is an integer of 0-3, is used as an organic color developer. The color developer and a basic colorless dye are pulverized to a particle diameter of not larger than several mum by an attrition mill such as a ball mill or an appropriate emulsifier, and various additives are added to the resultant material as required to obtain a coating liquid. The coating liquid is applied to a base to obtain a thermal recording paper. Accordingly, it is possible to clearly record with high color density even in recording at high speed or in high density, and the developed color image is made to be stable to adhesion of hair treatment toiletries, oils and fats. The groups (A)n and (A)m in the substituent groups may be combined with each other. |
