金在铱内敏的直接正像乳剂中的作用  

THE FUNCTION OF GOLD IN DIRECT-POSITIVE PROCESS WITH AN INTERNALLY 1RIDIUM SENSITIZED EMULSION

作　　者：符玉华[1] 季素雪 周本茂[1] 任新民[1] 

机构地区：[1]中国科学院感光化学研究所,北京100101

出　　处：《感光科学与光化学》1992年第2期103-108,共6页Photographic Science and Photochemistry

摘　　要：制备依内敏的AgBr立方体乳剂,乳剂被二氧化硫脲和三氯化金灰化。实验表明:有金存在时灰化乳剂,灰化中心优先在颗粒表面形成;金不存在时,则灰化中心优先在颗粒内部形成。用Na_1S_2O_3溶液刻蚀乳剂,得到了灰化中心在乳剂颗粒体相中的分布曲线。当二氧化硫脲量小,加金灰化时,灰化中心分布在颗粒表面和次表面;当二氧化硫脲量大,加金灰化时,灰化中心分布在颗粒体相中,但由表到里,灰化中心越来越少;当二氧化硫脲量大,不加金灰化时,灰化中心主要分布在颗粒中层部分。对加金灰化的乳剂来说,由于颗粒内部没有灰化中心竞争光生空穴,有大量的光生空穴破坏颗粒表面的灰化中心,因而可以获得高感直接正像乳剂。Silver bromide emulsions with monodisperse cubic grains, which were sensitized internally by iridium, were prepared. The emulsions were fogged by thiourea dioxide and gold salt. It was found that if the fogging proceeds with gold, fog centers may form predominantly on the grain surface, and if fogging proceeds without gold salt, fog centers may form predominantly in the interior of the grain. The emulsion grains were etched with Na2S2O2 solution for different times and spatial distribution curves of fog centers were obtained. When emulsions were fogged by (1) a small amount of thiourea dioxide and gold salt, fog centers distributed on the grain surface and sub-surface; (2) a more amount of thiourea dioxide and a small amount of gold salt, fog centers distributed on the grain surface and interior, but from the surface to the center, fog centers became less and less; (3) a more amount of thiourea dioxide, fog centers mainly distributed in the grain interior. It is clear that the function of gold in the direct-positive process is to suppress the internal fogging which in turn to eliminate the competition in hole trapping and to increase the reversal efficiency.

关 键 词：光漂白 乳剂 金 铱内敏 直接正像 

分 类 号：TQ575.147[化学工程—精细化工]