What other chemicals are put in developer packs?

[jsmithphoto1]

Hey, everyone! I am just curious as to what other chemicals Kodak puts in their powder developer packs, if any, to prevent the individual chemicals from acting upon each other? I want to make some in bulk because getting the scale out and mixing containers, hydroquinone, borax, metol, phenidone, etc each time i want to make a fresh liter is beginning to become a good bit of trouble. I love mixing them, but it takes more time to put a batch together than to develop them film haha. Thanks in advance for any and all input!

 

[railwayman3]

You can't do that at home. Kodak developed special coatings which "wrap" the the particles and prevent them from reacting. In addition, the order of dissolution is important in some cases.

Kodak's single packet developer packaging technologies are not trivial.

Oddly enough, I've never realised that before in all the time I've used powder chemicals ! I suppose I assumed they were just preweighed and mixed together!

 

[jsmithphoto1]

So, basically like foma? Have the metol and quinone in one pouch and the borax and sulfite in the other? Now for paper developer, could the bromide be mixed in with the alkali and preservative?

 

[Gerald C Koch]

Years ago I had to something similar. I was working with some organo-metallic compounds that were destroyed by only a few seconds exposure to humid air. It wasn't easy and I had the advantage of working in a fully equipped lab.

I seriously doubt whether you can duplicate anything like Kodak's packaging methods. First all the chemicals must be anhydrous and not just sold as anhydrous. The chemicals must also be rendered anhydrous. Then you need a waterless working environment. Something like a glove box with a tank of nitrogen gas.. And on, and on, ...

You can try using Ilford's method of just separating the developing agents from the alkali ingredients and putting them in separate bottles. But here again there are pitfalls. There is always the possibility of chemical interactions. Do what chefs do, mise en place, assemble everything that you will need before you start. I can make up something like D-76 in 15 min. So I see no overall real time savings.

 

[jsmithphoto1]

So, I have a bottle of OLD D-76 and there is one chemical listed on the back of it that is p-....... something. I don't have it on me right now so I can't check, but I wonder if that chemical is one of the "encapsulators"? Or did D-76 use that chemical about 30-40 years ago as an active agent in the developer?

 

[Gerald C Koch]

AFAIK, the encapsulation technology was proprietary and would not appear on the label or on a MSDS. One of the chemicals used was rather ordinary boric anhydride. A small amount was included in the mix as a very fine powder. The developing agents were coated with this. The boric anhydride would react with any moisture to form boric acid and protect developing agents from alkaline substances.

 

[jsmithphoto1]

hmmm... Very interesting!

 

[fdonadio]

So, I have a bottle of OLD D-76 and there is one chemical listed on the back of it that is p-....... something.

If it's p-aminophenol methyl sulphate (or something like that), it's Metol. Metol is a commercial name, a trademark...