| 摘要 |
PURPOSE:To attain high heat sensitivity and storage stability of a photo-fixing type thermal recording medium containing mainly diazonium salt and coupler, by incorporating aluminium tripolyphosphate as a pre-coupling preventing agent. CONSTITUTION:With a thermal recording layer coating liquid containing diazonium salt, coupler, basic material or coupler having a basic residue is incorporated tripolyphosphate containing more than 0.1wt% (on the solid basis) of the basic material or coupler having a basic residue. Conventional diazonium salt can be used, and a storage stability at a high humidity may be attained by making the salt insoluble in water and difficultly soluble in water by addition of such anions as BF4<->, arylsulfonate ion, organoboron ion, etc. Known coupler and basic substance can also be used, and those which are insoluble or difficulty soluble in water can also be used. A substance having two functions of coupler as well as basic substance can also be used. |
