You need to read things , but I could have given all the Patent No's use the search feature in Adobe Acrobat: Try another US 3765892 this is the one I cut & pasted from. I'm skipping between Patents rather fast looking at it's uses, and the Fuji Patents are interlinked through citations etc.

2nd line states . . . . . . sodium benzenene-sulfonate, ascorbic acid, diethylhydroxylamine, etc are used as antioxidants. Page 3 of the Patent bottom of Column 3.

The fact that Fuji refer to it in at least 4 Patents, and that many other companies/patents refer to it as an antioxidant is rather conclusive that it can be used as such.
Quote Originally Posted by Kirk Keyes View Post
Sulfonic acids, as a class, are often used as detergents/wetting agents. Benzene sulfonic acid is probably not used for that much as it's rather reactive, I thought. But longer chained sulfonic acids are, as you can have an alkane or aromatic on an alkane chain and the sulfonic acid group on the other end, and that's good for detergents.
Sodium Benzenesulfonate may well fall somewhere between what Mason (& Levenson) cal anti-oxidants and wetting agents - which include sodium alkyl sulphonates.

I was more interested in finding a link to it's use by Agfa, I've save some of the other Patents for later reading but didn't think they were of that much interest.