Wiedermann's developers (RSC and other)

thio · Nov 13, 2017

After the 'discovering' of phenidone in the middle of 50s many autors formulated they own developers for film and papers.
A. Wiedermann formulated a few concentrated developers, one of which (RSC) was popular in the Soviet Union.
RSC is a typical one-shot compensating developer with a compromise between fine grain and sharpness.

RSC (Standart concentrated developer)*

Phenidone - 1 g
Hydroquinone - 16 g
Sodium sulfite - 125 g
Sodium carbonate anh. - 60 g
Potassium bromide - 9 g
Benzotriazole - 3 g
Water to make - 1 L

Dilute 1:20 or 1:50 for use. Developing times for ISO 100 are ca. 13 and 17 min respectively. I think it must be corrected for modern films.

Other formulas (PQ with TEA, PQ with glycin, developers for paper and technical films) with sensitometric investigations - see attached original paper (in French).

*A. Wiedermann // Sci. et Ind. Phot, 1961, t.32, №4, 97-107

Gerald C Koch · Nov 14, 2017

The Wiedermann formulas appeared in the Dignan Newsletter some years ago. Opinion at the time was that they did not keep very well due to hydrolysis of the phenidone at the high pH of the concentrates. Keeping properties might be better using one of the Dimezones which are more stable.

thio · Nov 15, 2017

or you can use divided concentrates (alcali in the second bollte), as discussed by autor.
I have not problem with stability of PQ with TEA developer stored in refrigerator up to 1-2 months.

thio · Nov 15, 2017

Interesting note: with a pure 99% chemical grade TEA I have the pH of working solution (1:20) of PQ with TEA is 9.3 instead of 9.8 (described by the author). Obviously Widermann used technical grade TEA with DEA impurities.

thio · Nov 15, 2017

Concentrated PQ developer with TEA (Wiedermann):

Phenidone - 1.2 g
Hydroquinone - 20 g
Sodium Sulfite anh. - 125 g
Triethanolamine - 80 g
Potassium bromide - 7 g*
Water to make - 1 L

Dilution: 1:20 (1+19), pH = 9.3 (pure chemical grade TEA)
Developing times: 10 min for 50 ISO, 13 min for 100 ISO films (reduce for a modern films)

*for technical grade TEA. For the 99% TEA the amount of KBr can be reduced.

Ian Grant · Nov 15, 2017

Gerald C Koch said:
The Wiedermann formulas appeared in the Dignan Newsletter some years ago. Opinion at the time was that they did not keep very well due to hydrolysis of the phenidone at the high pH of the concentrates. Keeping properties might be better using one of the Dimezones which are more stable.

There's always been a difference in opinion on the keeping properties of Phenidone. US books say it keeps poorly even as a dry powder while British books and my own experience is completely different, I have Phenidone that't was made in the early 1960's and it's still as good as modern Phenidone. Of course the difference is the here's more than one version of Phenidone so they aren't comparing like for like. as some are much more stable.

I'm 100% certain that if I made up the Wiedermann RSC (Standart concentrated developer) formula that the OP has listed it would keep well it's not so different to the various PQ developers I've used over the years, it's significantly less alkali as well.

Ian

Ian Grant · Nov 15, 2017

Phenidone was first made in 1890 however it wasn't used as a developing agent in the late 1930's and Patented by Kendall of Ilford in 1940. First commercial production was in 1951 and Ilford reformulated many commercial MQ developers to use it, soon realising after complaints about coulor shifts in printing that Benzotriazole was needed to maintain neutral tones, leading to further reformulation.

Ian

Rudeofus · Nov 15, 2017

One of the commonly reported problems with Phenidone was hydrolysis in alkaline, aqueous solutions, which made it quite unsuitable for concentrates with intended long shelf life. A variant sold under the name Dimezone-S solved this, and every commercial vendor, including Ilford, uses this variant today. Dry powder stability may have depended on impurities of all kinds, and different levels of precaution during Phenidone synthesis may have created products with vastly different stability.

Ian Grant · Nov 15, 2017

Rudeofus said:
One of the commonly reported problems with Phenidone was hydrolysis in alkaline, aqueous solutions, which made it quite unsuitable for concentrates with intended long shelf life. A variant sold under the name Dimezone-S solved this, and every commercial vendor, including Ilford, uses this variant today. Dry powder stability may have depended on impurities of all kinds, and different levels of precaution during Phenidone synthesis may have created products with vastly different stability.

Ilford synthesised stable versions of Phenidone like Phenidone-Z very early on and they've sold huge quantities of concentrated liquid PQ developers with a good shelf life since the early 1950's, so close to 65 years.

The myths come from US work and we don't know what variant of Phenidone they were based on but it's relevant because their conclusions don't match years of commercial reality.

In more recent years when Champion took over Ilford's chemical production some PQ liquid developers were reformulated using Dimezone S, there's no increase in shelf life/keeping properties. The switch was due to cost saving.

Ian

Rudeofus · Nov 15, 2017

Ian Grant said:
Ilford synthesised stable versions of Phenidone like Phenidone-Z very early on and they've sold huge quantities of concentrated liquid PQ developers with a good shelf life since the early 1950's, so close to 65 years.

The myths come from US work and we don't know what variant of Phenidone they were based on but it's relevant because their conclusions don't match years of commercial reality.

Allow me to quote an article by L. F. A. Mason, The Journal of Photographic Science, 1965, vol 13, p 205ff. Mason still worked for Ilford's Research Labs in Essex when he wrote and published this article:

On the other hand, perhaps the biggest disadvantage of Phenidone is its instability in alkaline solution.This is particularly a problem in the supply of liquid concentrates in which the pH will be fairly high.

There may have been variants of Phenidone besides Kodak's Dimezone-S, which also overcame this issue, but the original Phenidone compound does AFAIK not. If this is a Kodak conspiracy, then Mason must have bought into it. Note, that the problem is unrelated to oxidation, so glass bottles, protective gas and glass pebbles, which work great in many other situations, will not help one bit in this case.

I write this not to rip on Ilford or the English, but to warn folks from putting too much trust in a concentrate formula like the one posted here. Since Phenidone is more available and cheaper than its more stable variants, it would be quite tempting to do just that - and face disappointment.

Alan Johnson · Nov 15, 2017

LFA Mason, "Photographic Processing Chemistry" 1975 p85:
"...the 4-methyl derivative is marketed by Ilford under the name "Phenidone Z", whilst the 4,4-dimethyl derivative is marketed by Eastman Kodak Co. under the name "Dimezone". "
Mason does not specifically say that Phenidone Z was in Ilford proprietary chemicals at that time but it seems a possibility.

Rudeofus · Nov 15, 2017

Dimezone-S is 4-(Hydroxymethyl)-4-Methyl-Phenidone, and the patent covering it was published in 1967, well after Mason published his article in The Journal of Photographic Science. Kendall's original "Phenidone as photographic developer and how to make it" patent covers Phenidone-Z, but gives it no particular attention.

Ian Grant · Nov 15, 2017

Rudeofus said:
I write this not to rip on Ilford or the English, but to warn folks from putting too much trust in a concentrate formula like the one posted here. Since Phenidone is more available and cheaper than its more stable variants, it would be quite tempting to do just that - and face disappointment.

You entirely missed that Mason mentions Ilford's more stable Phenidone Z and Kodak's Dimezone S. Maybe in the US they were selling the original Phenidone but in Europe what was sold was Phenidone Z or one of Ilford's other stable derivatives under the generic "Phenidone" name. There may well have been a level of commercial secrecy on Ilford's part to not divulge the exact variant of Phenidone they were using.

I'll state quite clearly once again the formula the OP has posted is stable using commercial photographic Phenidone, I've been making up similar PQ developers and with more Carbonate (& hydroxide) so a higher pH for about 40 years never with any issues, my concentrated developers last at least 2 years. That's the reality.

Ian

Alan Johnson · Nov 15, 2017

By Ilford's trade mark, "Phenidone" refers both to Phenidone A, which is the formula normally given for this substance name and also to the 4-methyl derivative Phenidone B aka Phenidone Z.
http://cameo.mfa.org/wiki/Phenidone

Rudeofus · Nov 15, 2017

Mason must have been aware of singly 4-substituted Phenidone derivatives in 1965, since these, and a procedure to synthesize them, was described in the original Kendall patent. If a single 4-substitution would have solved the hydrolysis issue, this would have been prominently mentioned in an article, which raves about Phenidone and lists hydrolysis as the one single shortcoming. However, there is no such mention of this. Either Mason was not aware of the improved stability of singly 4-substituted Phenidone variants, or it is not as stable as some claim here.

And even if Phenidone B, or Phenidone Z as some call it here, is infinitely more stable, cheap and reliable than any other product out there: nobody seems to carry it these days. Formulary sells Phenidone A under the Phenidone name, so does Suvatlar and Artcraft. Silverprint doesn't explicitly mention which version they carry, but I guess they would state Phenidone B or something if that was what they sold. Sigma Aldrich has Phenidone B in their product list but can't quote a price - sounds like a high cost tiny quantity custom synthesis item to me.

For all these reasons I stick with my original assertion: don't mix Wiedermann's developer concentrate as listed and expect year long shelf life, unless you can locate that one source of Phenidone B that I was not able to find. And even then it will only work, if Phenidone B does indeed solve the problem that Mason himself described for Phenidone A.

AgX · Nov 15, 2017

But if there was a stable version as Ian asserts, why has it gone under?

Gerald C Koch · Nov 16, 2017

I have a glass bottle of phenidone that is decades old and still good. However a plastic jar turned to tar in about 6 months. So how the solid is stored is critical.

There are four 'phenidones': phenidone, phenidone B (or Z), dimezone and dimezone S. The relative stabilities depend on whether the 4 position on the heterocyclic ring is substituted and the nature of the particular group.

Rudeofus · Nov 16, 2017

AgX said:
But if there was a stable version as Ian asserts, why has it gone under?

PE has noted on multiple occasions, that Phenidone and its variants are one trick ponies: photographic development is pretty much all they are used for. If any variant falls out of favor with photographic suppliers, it's gone. Whatever caused Ilford to switch to Dimezone-S was the final nail in the coffin for Phenidone B.

Ian Grant · Nov 16, 2017

The major issue here is all these negative comments are based on very old here-say and not reality.You've only got to look at how many PQ liquid concentrated developers have been sold by Ilford, May & Baker (Champion), Agfa, Orwo, Foma etc as well as other eastern block countries to realise that the few reports from the US aren't backed up by anyone's current experiences.

Also note that Kodak themselves still use Phenidone in some film developers rather then Dimezone-S, as do Ilford.

Ian

Rudeofus · Nov 16, 2017

Ian, there is no room for conspiracy theories, if Mason himself describes the poor stability of Phenidone A in an article which raves about the benefits of Phenidone. Phenidone B or Z may have been an improvement, but this is irrelevant today when it isn't available any longer. Homebrewers have the choice between Phenidone A and Dimezone S, and if longevity is an issue I would recommend the latter.

PS: I just checked MSDS of Kodak's most popular film developers. Almost all of them (TMAX, TMAX RS, Xtol) list Dimezone-S or Metol. HC-110 is listed with Phenidone B in some older MSDS, but that's not an aqueous concentrate, and its working solution has no keeping properties to speak of.

Ian Grant · Nov 16, 2017

Rudeofus said:
Ian, there is no room for conspiracy theories, if Mason himself describes the poor stability of Phenidone A in an article which raves about the benefits of Phenidone. Phenidone B or Z may have been an improvement, but this is irrelevant today when it isn't available any longer. Homebrewers have the choice between Phenidone A and Dimezone S, and if longevity is an issue I would recommend the latter.

PS: I just checked MSDS of Kodak's most popular film developers. Almost all of them (TMAX, TMAX RS, Xtol) list Dimezone-S or Metol. HC-110 is listed with Phenidone B in some older MSDS, but that's not an aqueous concentrate, and its working solution has no keeping properties to speak of.

Again you entirely miss the point that the Phenidone available today (at least in Europe) is stable in concentrated alkali developers, and that all the writings you refer to are from 50+ years ago. as to longevity it appears that the liquid developers which switch from Dimezone-S from Phenidone may actually have a slightly shorter lifespan so the opposite to the expected.

I'm talking about real world use, not old literature, I have concentrated PQ developers made up in my darkroom which are my only print developers and the shelf life is equally as good as the commercial equivalents now using Dimezone-S. I can't complain when developer s last 2+ years and that's often in partially filled bottles.

So something really doesn't add up between fact and fiction, actual decades of production and use of concentrated PQ developers by many companies and in different countries.

Ian

dE fENDER · Nov 16, 2017

Rudeofus said:
Phenidone B or Z may have been an improvement, but this is irrelevant today when it isn't available any longer.

It still very available in Russia, even more than Phenidone A, while the Dimezones are not available here at all.
I've got old soviet Phenidone A (produced at 1966), it still has excellent quality, as fresh Phenidone B, but I trust the books regarding its stability and avoid using it in color developers - it should quickly oxidized at high temperatures (100 F), and shouldn't oxydize at room temperature at all.

thio · Nov 16, 2017

My dry old soviet Phenidone A has excellent quality too.

About the phenidone stability in alcaline solutions: I read a few research paper of the NIKFI (Cinema and Photo Research Institute, Moscow) that discovers of various properties of phenidone and a lot of its derivatives (V.L. Abritalin, 1960s). Short conclusions:
1. MQ and PQ developers (with the same pH and buffer capacity) in the open trays lost of activity with the same rates. Measured for pH 8.6 and 9.2.
2. High pH phenidone-A-based ID-62 developer do not change a photographic activity if stored for a 8 month in full filled stoped jars. High speed panchomatic film has a sensitivity S(0.2) = 190 in the fresh developer (dilution 1:5, developing time 8 min) and 200 in the stored developer (with the same conditions). Fog D0 was equal 0.16 for the both.

See attechment for details: the paper "Keepeng properties of phenidone developers", in Russian, from the "Soviet Photo" journal, 1968, N5.

Gerald C Koch · Nov 16, 2017

At one time it was popular to add the phenidone as an isopropyl alcohol or aqueous solution (phenidone plus a bit of sodium sulfite to protect it from oxidation). However the solution would soon turn pink. When in alcohol or other organic solution the color change is much more rapid.Glycols are slower in this respect. One of the hydrolysis products is a red free radical. Anyone is free to perform this test.

As to the relative stability of phenidone and dimezone I don'tt think that it was a coincidence the Kodak chose dimezone for several of its developers HC-110 and Xtol among them.

Alan Johnson · Nov 16, 2017

My phenidone in the UK from Silverprint is labelled 1-phenyl etc, ie,it is apparently Phenidone A.

y
Maybe the phenidone powder sold to hobbyists was and is Phenidone A, at least in the UK, and that which used to be in proprietary developers Phenidone B.

Wiedermann's developers (RSC and other)

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