Quote Originally Posted by keesbran View Post
I looked this up in Kosar's Light-Sensitive Systems and found on page 331 of my 1965 copy, in the section about aromatic azides, a reference to a (Fr. ?) patent (886,716/1942) by Kalle A.G.
In this reference Kosar states that with gum arabic, dichromates can be replaced by DAS. I wasn't able to track this patent yet, but I have the impression Kosar did not check this himself. As far as I know Kalle A.G. was a German company. It was also active in the production of light sensitive papers, mostly for diazotype, which are not the same as aromatic azides. Kosar states in a note (75) that the patent is french, which is somewhat strange for a german company.

-k

I just had a look at FR 886,716. Gum is not mentioned there. The colloids listed in that patent are: gelatin, methyl cellulose and PVA/methyl cellulose.