摘要:
Photographic elements containing image-wise developable silver halide are developed in the presence of an oxathioether development activator according to the formula:R.sup.1 --A--(OCH.sub.2 CH.sub.2).sub.n --S--A'--(X--A").sub.m --Y--R.sup.2wherein:R.sup.1 is H, alkyl, hydroxyalkyl, or R.sup.2 --Y--(A"--X).sub.m --A'--S--,A, A', and A" is alkylene, with the proviso that A is a monovalent bond when R.sup.1 is hydrogen or alkyl or hydroxyalkyl,X is --OCO--, --SO.sub.2 --, --CONH--, or Y,Y is ligand or complexing function of the type of --S-- and --N(Q)-- (Q=H or alkyl),R.sup.2 is alkyl, which may be substituted by OH, or when Y is --N(Q)--, R.sup.2 together with Q may represent the atoms needed to complete a nitrogen-containing saturated ring,n is at least 2, and m is 0 or 1.The development activators can be used in black-and-white development or in color development. They can be incorporated in the photographic material or in the developing solution.In reversal processing they can also accomplish the task of the second exposure or of the fogging agent to render the silver halide remaining after the first development developable.
摘要:
An electrodialysis cell intended to be used for the electrolytic rejuvenation of ferricyanide bleach bath into ferricyanide comprises a vessel which is made of carbon and which serves as anode, and a cathode, the space defined by both electrodes being separated by a cationic permeable membrane which is a wall made of asbestos cement which has been treated with a strong acid to remove a substantial part of the cement. The elements of the cell preferably have a cylindrical structure and are concentrically arranged with respect to each other.