| abstract |
Hydroquinones of the formula .wherein X is the residue of a 5- or 6-membered ring, R<sub>1</sub> is hydrogen, alkyl or aryl, R<sub>1</sub>,R<sub>3</sub>, R<sub>4</sub> and R<sub>5</sub> are hydrogen or alkyl and R<sub>6</sub> is hydrogen or a group of the formulawherein X and R<sub>1</sub> are as defined above, are of use as protected developing agents in photographic silver halide material. |