| 摘要 |
<p>The sensitivity of photographic emulsions, particularly silver halide gelatine emulsions, is increased by adding to the emulsion at the start of chemical ripening a dithioester of formula: R-CS-SR1 where R is alkyl including cycloalkyl, alpha-hydroxyalkyl, alpha-hydroxyaralkyl, condensed aryl, or phenyl or alpha-naphthyl opt. substd. in the ortho or para positions by F, OH, dialkylamino, sulpho, phenyl, phenylazo, or anilidocarbonyl and R1 is alkyl or aralkyl. The sensitivity of silver halide gelatin emulsions is nearly double that of emulsions sensitised only by gold.</p> |
