Regenerable colour developer

摘要

A development process for bromide-containing colour papers of the EP-2 type which contains a concentrated developer and a separate concentrated addition solution which is used in combination with the concentrated developer. The concentrated developer is formulated in such a way that it, used alone and in a correspondingly concentrated mixture with water, gives a development time which is shorter by a factor of from two to three than the standard. This is achieved in accordance with the most recent prior art by, inter alia, a high concentration of the developer substance CD-4 in combination with a low bromide concentration. The concentrated addition solution is formulated in such a way that, combined with the concentrated developer and appropriate dilution, a slower-working machine developer solution is obtained for use in heated development machines. To this end, the concentrated addition solution contains, in addition to buffering alkalis, at least 50% of the total bromide content of the machine developer solution to be prepared from the two concentrates. A particular advantage of this formulation is that the machine developer solution can be regenerated after exhaustion due to processing conventional amounts of colour paper by addition of concentrated developer.