Concentrates and Working Solution for E-6 Color Developer Based on Kodak's US5948604A

[Rudeofus]

Rudeofus submitted a new resource:

Concentrates and Working Solution for E-6 Color Developer Based on Kodak's US5948604A - E-6 color developer formula derived from patent US5948604A

Kodak provided a "teaching patent", i.e. a publication for preservation of knowledge, for their 5 liter E-6 home processing kit. The original patent text can be seen here. While anyone with access to these formulas and ingredients could start mixing and using, this article tries to make these formulas more accessible to amateurs. Please note, that all liquid ingredients except for dilute aqueous solutions and water are given in...

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[Anon Ymous]

Hello Rudi

I have bought ATMP-5Na solution from Axelcolor and they told me that it's a 40% w/w solution.

 

[Rudeofus]

Yes, that's Dequest 2006. If you get Dequest 2000, then that's the free acid without the sodium, and you get 50% w/w solution. You should be able to convert the formula, if you can only buy Dequest 2006.

 

[lamerko]

Hello

One question about phosphoric acid. In the direct formula, there is "H3PO4 75% solution". This makes it a bit difficult for me - here it is easy to get this acid, but all its variants (for analysis, food grade, pharma grade, pure...) are 85%. I accept that this is the normal distribution, but the 75% of the formula in question is based on what - 75% of that 85%, or?
About trisodium phosphate (Na3PO4) - what form is it in? Here it is mostly present as the dodecahydrate (.12H2O).

 

[Rudeofus]

For some reason chemical industry keeps w/w versus w/v top secret in their data sheets, but I have found out, that searching for "phosphoric acid 75% w/w" yields much better results than "phosphoric acid 75% w/v", and this allows me to conclude: Phosphoric Acid is sold as w/w solution.

1kg (not 1 liter!! ) of Phosphoric Acid 85% w/w solution would therefore contain 850g H3PO4 and 150g water. You'd have to add it to 133.3g water (not the other way round!! ) in order to obtain 1133.3g Phosphoric Acid 75% w/w.