SILVER BROMIDE MATERIAL WITH A SURFACE SENSITIVITY AT LEAST EQUAL TO THE INTERNAL SENSITIVITY AS DETERMINED BY A SPECIFIC TESTING PROCEDURE

摘要

Abstract of the DisclosureRadiographic silver halide emulsions are provided com-prising silver halide trains the average silver halide graindiameter of which is at least 250 nm and which consistsubstantially of silver bromide dispersed in a hydrophiliccolloid binder e.g. gelatin wherein the silver halide grainshave high primitive surface sensitivity for direct exposureto penetrating radiation and are substantially regular inshape and wherein the ratio of hydrophilic colloid to silverhalide is at most about 1Ø These emulsions have high sen-sitivity for direct exposure to penetrating radiation and arethemselves substantially insensitive to formation of pressuremarks upon rapid processing.