| 摘要 |
PURPOSE:To obtain the positive image having uniform and high quality and sufficient image density in a short developing time with less tendency for generating fog, without using a complex and expensive developing device by incorporating a specific compd. as a nucleus forming agent to a sensitive material. CONSTITUTION:The compd. shown by formula I is used as a uncleus forming agent. In the formula, Z is a non-metal atom group necessary to forming 5-6 membered heterocyclic ring, Z is a substituent which may be substd., R<1> is an aliphatic group, R<2> is hydrogen atom, an aliphatic or an aromatic group, R<1> and R<2> may be substd. At least one of group selected among R<1>, R<2> and Z groups is alkynyl or acyl group, etc., or R<1> and R<2> together with each other forms a six-membered ring such as dihydropyridinium ring. Y is a counter ion for balancing charge, (n) is 0 or 1. |
