| 摘要 |
PURPOSE:To stabilize a copying material at ordinary temp., elongate the shelf life and allow the mqterial to color at a low heating temp. by adding a specified amount of a thermally base releasing agent such as (thio)urea and an ecidic or neutral salt of a specified heat sensitive org. acid as a base releasing accelerator by >=50wt% to the amount of the releasing agent. CONSTITUTION:To a photosensitive layer is added (thio)urea, thiosemicarbazide, carbohydrazide or alkyl-substituted (thio)urea as a thermally base releasing agent by >=30wt% to the total composition of the layer and further added a neutral or acidic salt of a heat sensitive org. acid such as formic acid, acetic acid, propionic acid, lactic acid, malic acid, maleic acid or tartaric acid of Zn, Mg, Ca or Ba as a base releasing accelerator by >=50wt% to the amount of said releasing agent. A heat developing copying material contg. the releasing agent and the accelerator in a single layer together with a diazonium compound and a coupler is applied to a substrate having an under-coat of colloridal silica or starch and polyvinyl alcohol to manufacture copying paper. Thus, a clear image is obtd. on the white ground at about 150 deg.C. This copying material is not colored naturally during storage. |
