出版社：The Society of Photographic Science and Technolgy of Japan
摘要：Cations of Cu, Pb and Cd were added to tabular AgBr emulsions when the emulsions were coated. Although Pb++ and Cd++ did not show significant desensitization, Cu++ and Cu+ caused considerable decrease of both surface and internal speeds of the emulsions. Since the desensitization caused by Cu++ was in competition with that caused by phenosafranine which is known to act as electron trape, it has been suggested that Cu++ also act as electron traps at the grain surface. It has been suggested that the desensitization observed when Cu+ was added to the emulsions result from the formation of Cu++ as a result of oxidation of Cu+ in the emulsions. By introducing Cu++ to the emulsions before or after exposure by bathing the coated emulsions in Cu++ solutions, it has been found that the desensitization caused by Cu++ arises from its retardations of both development and latent image formation. The action of Cu++ as electron traps is supported by the fact that the redox potential of Cu++ is the most positive among Cu++, Cd++ and Pb++.
