Quote Originally Posted by Photo Engineer View Post
I tried a search of USP 3765892 and find no reference to benzene sulfonates. The "find" utility in the PDF file does not find it, but it is found in the search of the text version. It becomes clear though that there are errors such as the claim of an antioxidant called potassium fulfite!

Errors do happen. The point is that we do not know for sure in spite of that patent.

I might add, in support of my comments, that diethy hydroxyl amine, which is claimed as an antioxidant, would be a very poor one for B&W developing agents, especially at that pH.

The Text part is OCRed which is why Text usually not there for old poor quality photocopied Patents.

Patents are waffle full of irrelevances hiding facts, ascorbic acid won't work at that high pH (examples) as an antioxidant either.

Kodak's ppd/Benzenesulphonate Patent is more interesting as the citation is to a an anti-oxidant Patent.