| 摘要 |
<p>Bis substd. azabenzimidazolate anti-fog agents. Formation of fog during conventional photographic development is prevented by developing in the presence of an anti-fog precursor of formula (I), which can be hydrolysed by the compsn. A - X - A (I) (where each A is an anti-fog nucleus of formula (II), (III) or (IV), Z is N or CR, R is H or lower alkyl, F is the non-metallic ions required to complete the heterocyclic ring, and X is Cu, Zn, Hg, Pb, Sn, Ni, Cd, Co, Mn, Ca or Fe, the metal being joined to each anti-fog nucleus at posns. preventing an anti-fog action during fixing). Pref. the agent is a bis(substd azabenzimidazolate).</p> |
