Diazidostilbine (DAS) (4,4'-diazido-2,2'-stilbenedisulfonic acid disodium tetrahydrate(?) for sale ---wjere?

I can fine nothing current about a source of bulk chemical DAS for use in carbon printing 9alternative methods). The indexing in Photrio shows 2007 and 2008 inquiries and replies (with incorrect response in one case) as 2022. I don't know how the database is updated, but the dates are misleading. So, who knows a current source that isn't for material at say $5 pr $6 per gram? It was about 20-25 cents/gram a decade ago. Any lead would be very appreciated. I don't want to use my dicrhromates (which date to the 1950s or earlier, from my father, and are finally getting exhausted.) Thanks, Paul

I have yet to purchase any DAS so I cannot vouch for the usefulness of this info, but I have the following in my notes...


I would be glad to hear if this source, or any other works out for you.

Regarding the price, it is worth remembering that the world is a very different place than it was a decade ago. Thus, I would not be surprised if the current price has risen dramatically.

From the name this sounds like an optical brightener, correct?

If yes, then Fototechnik Suvatlar sells "optical brightener", which might be the compound you are after.

Not quite. See here:


But as a optical brightener it is an photo-chemical in the most literal sense.

If I remember right Calvin Grier in Spain offered DAS.
But his complete site on his printing is off.

Rudeofus said:

From the name this sounds like an optical brightener, correct?

Click to expand...

No, it's a sensitizer that induces protein crosslinking under UV exposure, at least that's how it's used in carbon transfer. I don't think it's also used as a brightener. It's used as a low-toxicity alternative to dichromate.

I wonder if any of the common screen printing sensitizers might work for carbon transfer. https://www.dickblick.com/items/speedball-diazo-sensitizer-2-oz/
Active compound is CAS 71550-45-3, so certainly not DAS.
This thread contains information on experiments with similar substances; worthwhile to go through it I think.

For getting DAS at a reasonable price, I think the best option is to contact one of the several Chinese sellers and see what options there are to buy a 'small' amount like 1 to 5kg and then split it out/resell it to others. It takes some work and a little investment, but you might get a good price per gram this way.

fgorga said:

I have yet to purchase any DAS so I cannot vouch for the usefulness of this info, but I have the following in my notes...

Source in the US for DAS, CAS 2718-90-3.

groups.io

I would be glad to hear if this source, or any other works out for you.

Regarding the price, it is worth remembering that the world is a very different place than it was a decade ago. Thus, I would not be surprised if the current price has risen dramatically.

Click to expand...

I have found a manufacturer and received a quote (without a delivery time stated yet, but the note that it was in-stock.) I'm looking for others with whom to share it, for I wouldn't need a whole kg of it, I'd say, and if others were interested in 50-100 gm bottles at something like $1/gm, I would do it. I just need to round up people who would also like some right away, for I'm not going into the stock chemicals resale business, just saying. I recall this stuff being $0.20/gm US 10-20 years ago when it was still used in printing lines inside CRTs, but who's making many CRTs today? More recently, I'd seen it as high as about 12.50/gm, so the realm of $400/kilo looks good to me, even while I don't need that much. Paul 7/18/2022