| 摘要 |
PURPOSE:To especially prevent whitening phenomenon of a copying material by incorporating a combination of a specified coupler of naphtholcarboxylic acid ester or its sodium salt and a naphtholcarboxamide coupler and a diazo compound to form a diazo image. CONSTITUTION:A photosensitive layer formed on a support such as paper or synthetic paper, by coating contains each of the couplers represented by formulae I and II [R1 is 1-3C alkyl or Na, R2 is H, NH2, or (CH2)n-OH, or (CH2)n-Y, n is 1, 2, or 3, Y is a hetero ring or N(R3)2, and R3 is methyl or ethyl] and the diazo compound capable of forming a diazo dye image together with said couplers, preferably, in a proportion of coupler I : coupler : diazo compound of 10-80:50-150:100 by the weight basis. The photosensitive layer may further contain an antioxidant, an acid stabilizer, and so on, thus permitting the obtained photosensitive layer to prevent crystallization of the azo dye by the use of 2 kinds of couplers, and whitening phenomenon of an image. |
