Ilfochrome processing for the home/photoclub amateur

[Rudeofus]

The MSDS and many other descriptions I found online claim that 2,3,6-trimethyl-quinoxaline are used by Ilford. This substance, however, seems to be difficult to get, at least Sigma Aldrich doesn't seem to carry it. The Ciba patent mentions that very good results are obtained if a mix of two catalysts are used which have different redox potential, and based on that patent a combo of 2,3-dimethyl-quinoxaline and 2-hydroxy-3,6,7-trimethylquinoxaline could be very promising. I have, unfortunately not delved into this deeply enough, but the Ciba patent does mention patents which could provide useful recipes.

About paper support: could bleached and fixed b&w paper do the job? I have tons of b&w prints that only highlight my poor photographic skills which could be repurposed for this.

 

[Photo Engineer]

Someone has described elsewhere on APUG, how these quinoxalines may be easily made by simpler chemicals. Unfortunately, the scheme uses p-Phenylene Diamines and the real synthesis uses o-Phenylene Diamines. Mix the right one with Diacetyl, and in one step you have the Quinoxlaine. Easy one step.

Not explosive, nor very corrosive.

FB papers are not a good idea here. RC would work.

PE

 

[Rudeofus]

Since I can get quinoxaline and some variations of it at reasonable cost (compared to cost of Ilfochrome paper and given that it is used only in small amounts), I think I will just plunk down money for the real thing.

Here is my home brew strategy:

• Replace Ilfochrome fixer with OlepH 6.5, which is based on Ole's quick fix but has pH adjusted to 6.5
• Replace developer with Dr. Beer's developer and make sure that color balance can be restored. Experiment with different contrasts.
• Once this is all figured out, play with dye bleach. I guess I'll start with sulfamic acid for pH of 1, various amounts of 2,3-dimethyl-quinoxaline and 2-hydroxy-3,6,7-trimethylquinoxaline and 50g/l of NH4Br. You also list thiourea, can you tell me what that is supposed to do in the dye bleach?

One thing which honestly surprises me about the process is the extremely relaxed attitude towards fixing. Although it is supposedly archival, they use sodium thiosulfate for two minutes without much fuss, compare this to the complex procedure recommended even for plain b&w RC paper!

 

[Photo Engineer]

Thiourea is a fixing agent that helps accelerate the dye bleach reaction.

Since the "paper" is really plastic, the wash will proceed rapidly in the fully swollen emulsion. But, be careful. There are known cases of browning of Dye Transfer prints due to under fixing and/or under washing.

I do not recommend storing chromogenic and dye bleach prints together. You will notice a strong odor from the dye bleach prints after a few years. IDK what the reason is.

PE

 

[Rudeofus]

Thiourea is a fixing agent that helps accelerate the dye bleach reaction.

Any hints about recommended concentration of thiourea in such a dye bleach?

 

[Photo Engineer]

Guesstimate would be 100 g/l. There are hundreds of EK and Ciba patents with formulas if you care to do a search and then a "comparative anatomy" on them. It is very educational and useful.

PE

 

[Rudeofus]

Just a short comment for the general public: in the recent past I tried reducing the need for Ilfochrome chems. With these steps I could increase the amount of paper processed with a given quantity of Ilfochrome soup at least by a factor of 3 or 4:

• I replaced the developer with home brew Dr. Beer's developer. Note that the choice of dev (Dr. Beer's offers 8 choices from very soft to extra hard) had no impact on the final image. I added 2g/l KSCN to this dev to make it work with the Ilfochrome process.
• I made a bunch of experiment with reuse of Ilfochrome dye bleach. So far I was unable to exhaust the bleach. It could be reused over and over again with no visible change in the images. I also reused working solution dye bleach after storage for over a month in the basement with no visible effect on image appearance.
• I replaced the fixer with Agfa 304 fixer with addition of 20g/l Borax, which puts the pH close to 6.5. Note, that standard rapid fixer can not be used for this. The dye bleach bath is extremely acidic and will cause sulfur precipitation in any fixer that is not sufficiently well buffered. Remember, there is no wash step between dye bleach and fixer. If your processor supports more than 4 liquids kept at proper temperature, a wash step between dye bleach and fixer might make rapid fixer work.

 

[sheremey]

As the owner of one of the last Ilfochrome labs on earth I can confirm that Ilfochrome is a far simpler process than Kodachrome and it would be very viable and easy to make the chemistry from scratch. Ilfochrome as long as the chemistry is kept in stringent control is a very very very simple process.

The huge hurdle for it will be getting fresh material to expose....

Hello,

What a promising statement! Would you please point me to the right direction to make the chemistry from scratch? Thanks!!

 

[Wayne]

Developer is just B&W with a touch of hypo. Easy. For fix you can just use rapid fix. Easy Peasy. For Bleach, well to my knowledge nobody has made it at home consistently because its not so easy. And now that the print material is gone except for what is stashed away turning magenta in freezers like mine, nobody is even trying.