Dimezone-S instead of phenidone in Pyrocat-HD?

Discussion in 'B&W: Film, Paper, Chemistry' started by john_s, Sep 14, 2004.

  1. john_s

    john_s Subscriber

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    I have acquired some Dimezone-S which is reputed to be a better-keeping variety of phenidone. I'm interested in knowing if anyone has tried it, and if so any advice about equivalent quantities. Someone on the old pure-silver list suggested that I substitute equivalent molar weights (i.e. multiply the recipe's amount of phenidone by about 1.15). He had also done some tests in a very different developer to compare the two versions and found that this conversion worked for him.

    Leaving aside the potential for weighing inaccuracy with comparatively small amounts of this chemical, how critical is the amount of phenidone in Pyrocat-HD?

    The reason I'm trying this is because I'm using the metol version of Pyrocat-HD since my first attempt with phenidone didn't work at all well. Maybe that batch of phenidone was bad, since all the other ingredients worked very well in the metol batch that I mixed up. The metol version is great, but a little more speed would always come in handy!
     
  2. Jorge

    Jorge Inactive

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    John, I dont know who you got the phenidone from, but you must have had a bad batch. I bought 50 gr of phenidone 3 years ago, I have kept it dry and in a dark place and it is still as good as the day I got it.

    As to your question, beats me, why dont you try and tell us how it went.
     
  3. Tom Hoskinson

    Tom Hoskinson Member

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    I have substituted Phenidone 1:1 (in a Suzuki formulation) for Dimezone-S and had good results.

    The Phenidone I used is around 30 years old, by the way - no change in activity that I can notice. I keep it dry, sealed amber glass container.
     
  4. sanking

    sanking Member

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    The amount of phenidone in the Pyrocat-HD formula is not as critical as one might think. In my own tests I have seen very little difference with amounts ranging from 1.5 g per liter to 2.5 g per liter of Stock Solution A. The minimum amount appears to be about 1.0 g, and the maximum about 3.0. Below 1.0 g there is not as much synergism (= longer development times) and above 3.0 g there is an increase in B+F.

    I have no experience with Dimezone-S. However, as others have suggsted, phenidone in powder form lasts a very long time. And once mixed in the Pyrocat-HD stock solution the useful life is at least six months in a partially full bottle. And if you need more shelf life out of the Stock Solution A consider mixing it in propylene glycol instead of water, which should increase its life to years instead of months.

    Sandy
     
  5. psvensson

    psvensson Member

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    Where do you guys get Dimezone-S?
     
  6. Tom Hoskinson

    Tom Hoskinson Member

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    I have never purchased or used it. I use regular phenidone and am quite happy with it.

    However: http://www.techcheminc.com/Photo_Order.htm
    advertises it ( and other photo chemicals) for sale in small quantities:

    Dimezone - S 4-Hydroxymethyl-4-Methyl-1-Phenyl-3-Pyrazolidone
    DZ00100 100 grams $ 34.64
    DZ01001 1 lb $125.79
     
  7. psvensson

    psvensson Member

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    Very cool, thanks. Didn't know about Tech Chem. Apart from better keeping qualities, I thought one of the advantages of Dimezone was that it dissolves easier in water?
     
  8. john_s

    john_s Subscriber

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    Easier dissolution was one reason I wanted to try it. I'm in Australia, and have found that Sigma-Aldrich, the big chemical company, has stopped listing it. I enquired with an English company which has a local agent. Normally the minimum package size is 25kg (enough for 12500 Litres of Pyrocat-HD stock, enough for 2,500,000 films)

    I was lucky to enquire just when one customer was taking delivery of 25kg, and they arranged for me to take 1kg. Who in Australia would want 25kg of it? I don't know, but maybe it's used for colour processing of some type, perhaps reversal.

    I'll let you know how it goes.

    Incidentally, my failed attempt with phenidone involved my use of a stock solution of phenidone in ethyl alcohol (95% food grade) so maybe something went wrong with the stock. It was only a few days old, though.
     
  9. Jorge

    Jorge Inactive

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    Most likely that was your problem, once diluted, even in alcohol, phenidone goes bad pretty quick. BTW, why dont you try Artcraftchemicals in the US? Michael ships to me in Mexico and he always does an excellent job. It might be cheaper even with the shipping than buying 25 Kg. No?
     
  10. Tom Hoskinson

    Tom Hoskinson Member

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    Suzuki implies that Dimezone-S is easier to dissolve in water than Phenidone. I have no problem dissolving Phenidone in water if I first dissolve it in a small amount of alcohol. This should be done as an integral part of a developer mixing sequence. Pyrocat-HD "A" solution, prepared this way, will last for months.

    An alcohol or alcohol/water Phenidone stock solution will start oxidizing almost immediately - with no appreciable color change.

    To prepare a stable Phenidone stock solution, dissolve the Phenidone in propylene glycol.
     
  11. psvensson

    psvensson Member

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    How about dissolving the phenidone in alcohol with salicylic acid, as Ryuji recommends? Anyone tried that?
     
  12. Tom Hoskinson

    Tom Hoskinson Member

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    That Suzuki recommendation was in the context of mixing stable ascorbic acid/phenidone developers.

    I have looked through his postings and could not find any references to mixing phenidone/salicylic acid stock solutions.
     
  13. Tom Hoskinson

    Tom Hoskinson Member

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    Here are 2 formulations, based on Suzuki developers, that I modified to produce concentrated TEA stock solutions.

    I have not yet tested these developers!

    DS–14 Modified, (Neutral Black Tone Paper Developer)

    Triethanolamine---------------------------350 ml
    Ascorbic Acid------------------------------68 grams
    Phenidone ---------------------------------2.3 grams
    Triethanolamine to make-----------------500 ml

    To make 1 liter of working developer, take 50 ml of DS-14A, add 850ml water, 12 grams sulfite and 30 grams carbonate and mix. Then add water to make 1 liter.

    Add 0.2% Benzotriazole as needed to achieve desired tone
    ---------------------------------------------------------------------------


    DS–15 Modified, (Warm Tone Soft Working Paper Developer)

    Triethanolamine--------------------------350 ml
    Ascorbic Acid------------------------------47 grams
    Metol---------------------------------------5.8 grams
    Triethanolamine to make----------------500 ml

    To make 1 liter of working developer, take 50 ml DS–15A, add 850ml water, 5 grams sulfite, 8 grams carbonate and mix. Then add water to make 1 liter.

    Add 2% solution of KBr as needed to achieve desired tone
     
  14. psvensson

    psvensson Member

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    Tom, on this page, Suzuki says:

    Phenidone may be substituted for Dimezone S, but the solution should be used soon after mixing. Phenidone B or Dimezone may also be substituted for Dimezone S with no loss of stability, but it is best to dissolve it in alcohol first together with salicylic acid. ​

    So he's talking about Phenidone B or Dimezone, not Phenidone A, but it implies that the salicylic acid is good for more than preserving ascorbate.
     
  15. Tom Hoskinson

    Tom Hoskinson Member

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    Yes, that is the same page I'm refering to. The context of that section is the mixing of an ascorbic acid developer.

    In another post (I can't find the URL) Suzuki goes into great detail about the the beneficial effects of salicylic acid for the preservation of the ascorbates in ascorbic acid developers.

    Suzuki advocates the use of salicylic acid in both his DS-14 (Dimezone-S/Ascorbic acid) and Ds-15 (Metol/Ascorbic acid) developers.
     
  16. mts

    mts Subscriber

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    I use Dimezone S in formulation for a T-Max developer clone. There was considerable discussion about this agent versus Phenidone in a series of privately published photo bulletins that ran in the early 1980's, way before Internet communications. It is better than Phenidone in the T-Max formulation, but I doubt it will make much difference in your Pyrocat formula.

    Dimezone S is also preferred in E-6 first developer formulae that are MPQ solutions. Here is the note I have in my formulary:

    1% Dimezone-S solution with 2% Sod. Sulfite can be used in place of Phenidone base. See D. Neville SuperBulletin #37 for a discussion of the advantages of Dimezone S versus Phenidone. Multiply phenidone by 1.27 to give the Dimezone S substitution amount.