Hydroquinone derivatives, their preparation and use in photographic materials.

摘要

Substituted hydroquinone compounds of the formula
<Chemistry id="chema01" num="0001"><Image id="ia01" he="22" wi="54" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>wherein R<Sub>1</Sub> to R<Sub>4</Sub> are hydrogen or alkyl and Z is an aromatic ring or a group of the formula -X-Y-X-, wherein X is an aromatic ring and Y is an electron withdrawing group, are incorporated as developers into photographic materials. These materials are suitable for activation processings.