FerricOxaCitrate a different sensitizer ?

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Harald Leban
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Joined: Fri Apr 08, 2016 7:22 am
Location: Hainburg/Austria

FerricOxaCitrate a different sensitizer ?

Post by Harald Leban » Fri Apr 22, 2016 1:55 am

Some of the old Ferric processes always used ferric salts of citric acid, mainly a Ammonia double salt for advanced solubility.

Knowing that with the FerricAmmonium-salt you always had a printing-out process!

When a developing-out process was needed, it was always that Ferric(III)oxalate was the sensitizer of choice. Nobody wanted to use Ferric(III)citrate because it´s low solubility in water (4g/l = 0,4% ) was useless for this purposes.

I was thinking about a possibility of creating a kind of Ferric(III)citrate like I make my own Ferric(III)Oxalate from Fe(II) salts in a simple reaction.

I make my sensitizer for Pt/Pd printing from Ferrous(II)oxalate +oxalic acid and oxidation through Nitric acid (HNO3)

I switched the formula to Ferrous(II)oxalate +citric acid and oxidation through Nitric acid and got a solution that I named FerricOxaCitrate.

I write this because this happend around 8 years ago but I didt had the time for extensive tests on pt/pd - I found the bottle in my freezer few weeks ago and wanted to throw it away but when I checked the mix it still looked clear and free of precipitation (never got Ferricoxalate solutions so stable).

For me it´s a good sign that this mixture must be very stable and maybe worth to try again for these old processes - remember, its a kind of pure Ferric(III)citrate.

More when I have checked it´s properties in printing.

Harald Leban

Paul Cunningham
Posts: 1
Joined: Tue Mar 01, 2016 3:57 pm

FerricOxaCitrate a different sensitizer ?

Post by Paul Cunningham » Thu Oct 20, 2016 12:57 pm

You've made me curious, any results?

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