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  1. #61
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    IDK about ethanol. Never done it. Kind of an expensive way to make it IMHO. Drink the ethanol instead!

    I tried bigger batches and different formulations and this baby can get very hot very quickly, so please be careful.

    PE

  2. #62

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    US 4,366,234 in E-6 process

    I have been using the Wheatcroft et al. ( U.S.patent 4,366,234 ) approach of in-situ formation of sodium hydroquinone sulfonate over the last year. This methodology works very well to provide an E-6 first developer with limited run-to-run variability and extended longevity. However, a cursory evaluation of the patent disclosure indicates a potential problem with stoichiometry in the hydroquinone oxidation reaction. The relevant passage is as follows:

    “A first solution was made by dissolving in 150 mls. water, 12.5 g. of sodium sulphite and 5.5 g. of hydroquinone; the pH of the resulting solution was raised to about pH9 and 5 mls. of 40 volumes hydrogen peroxide was then added and the formation of sodium hydroquinone monosulphonate occurred rapidly.
    A second solution was prepared by dissolving in 150 mls. of water the following ingredients:”

    5.5 grams HQ (MW=110)=0.05 moles
    5 ml. 12%H2O2 (1.03 g/ml.)= 5.15 grams (MW=34)=0.15 moles

    Thus, a 3X molar quantity of peroxide over HQ is being used in the presence of excess sodium sulfite.

    As the product has a MW of 212, 10.6 grams of the sodium HQ sulfonate results in the patent procedure. The patent formulation is for 500 ml of developer, which translates to 21.2 grams per liter. This of course is comparable to the liter quantity of the potassium salt found in Fuji patents, and many other locations on the web.

    This VOLUME...... contains this PERCENTAGE
    of hydrogen peroxide
    10 volume or V10 3%
    20 volume or V20 6%
    30 volume or V30 9%
    40 volume or V40 12%

    The specific gravity of 12% H2O2 is found to be 1.03 in an online MSDS
    The specific gravity of 3% H2O2 is found to be 1.01 in an online MSDS

    It is known that the product sulfonate can again be oxidized hydrogen peroxide to produce a di-sulfonate salt of much lower activity in a developer. I thus limited my work to a stoichiometric oxidation of HQ with just 1 mole of 3%(drugstore) peroxide. I was also working with a high-sulfite stock solution from another project which had 12g. HQ, 1 g. phenidone B, 2 g. NaBr, and 50 grams of sulfite per liter.

    250 ml of this stock solution contains 3g. HQ ( .027 mole)

    .027 mole H2O2 via the 3% solution(assumed specific gravity=1)=30.5 ml. I backed off ever so slightly to 30 ml.
    (98mole%), which was added slowly with vigorous stirring. It was also assumed that the excess sulfite present would maintain the slight alkalinity required for the reaction. There is indeed an exotherm here, but it is not at all dangerous. This solution (280 ml.), after stirring for 1 hour, was then treated with restrainer stock solutions, KSCN, and Na2CO3 to make the final developer (285 ml….enough for 1X35mm. In a Nikor).

    Standard E-6 time/temp protocol, along with NaBH4 reversal and a color developer close to Stephan’s (http://www.apug.org/forums/forum40/4...wikipedia.html) gave excellent contrast, with extended gray scale densities, when compared to a PQ substitute developer.

    In the end, I needed less KI than normally indicated, and a lower color developer pH than used by Stephan in order to fine-tune color balance.

  3. #63

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    Brookse,
    In your calculation:

    5 ml. 12%H2O2 (1.03 g/ml.)= 5.15 grams (MW=34)=0.15 moles

    Don't you have to take into account that only 12% of the 5.15 g is H2O2, not the entire amount to calculate how many moles are there? I am assuming the 12% is by weight of H2O2 to H2O.

  4. #64

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    Yes, you are correct..I had some trouble transcribing my notes! The patent is three fold DEFICIENT in peroxide. 5ml. of a 12% solution=0.61 g H2O2=.018 moles..(X3= .054).

  5. #65

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    Is there really a deficient?

    The way I read it, 5 ml of H2O2 40% are needed.
    This will give you a demand of about 16ml H2O2 12% for a total of 500ml developer solution.
    What interests me more is till which degree of completion this reaction will lead and how much time will be needed therefor.

    Assuming reaction goes to 100% (for one Liter developer solution)
    0.2 mol sodium sulfite
    0.1 mol Hydroquinone
    0.15 mol H2O2

    Will give
    0.1 mol Hydroquinonemonosulfonate sodium salt
    0.05 mol Sodium sulfate
    0.05 mol Sodium sulfite residuals
    And an (for my brain) unclear amount of NAOH

    What will be in deficient (in the final solution) is sodium sulfite, which I add normally in the dimension of 0.18 mol (22.7g) per liter…
    Anybody have an idea of this?

    Regards, Stefan
    Last edited by stefan4u; 08-29-2012 at 08:47 AM. Click to view previous post history.

  6. #66
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    Stefan, again I caution all that even with 3% H2O2, this reaction generates quite a bit of heat and can actually boil over if you are not careful!

    PE

  7. #67

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    Dear PE !!

    I’m aware of that, experiments this way should be done with some care, I totally agree!
    But do you have an idea of the expectable completion of the process? It’s hard to believe that in the absence of catalysts all the HQ is transformed to HQMS. I would expect some HQ residuals as well as some unwanted benzoquinones…

    Anyway, going to try it

    Regards Stefan

  8. #68

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    You have been warned. Solutions of hydrogen peroxide above 3% can be dangerous. The slightest speck of dust introduced to the original container can cause the peroxide to explosively decompose. Its solutions should always be kept refrigerated.

    Organic synthesis is complicated, reactions are usually not stoichiometric. You seldom get a pure product.

    There are too many people on APUG playing with chemistry. The most dangerous people are those who think they know what they are doing. The problem with taking precautions is that they only work if you completely understand what you are doing. It is always the unexpected that gets you.
    Last edited by Gerald C Koch; 08-29-2012 at 10:47 AM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  9. #69

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    Oh my god!

    In fact I’ve done that “synthesis” yesterday night with usual precaution.
    Simply haven’t used the solution already, my time is limited. On the other hand I want to make a second batch with prolonged reaction times.

    It get’s warm, as indented by an exothermic reaction, but not over 45-47°C, if enough cold water is used as a basis (400ml).
    This is the most essential part, beside goggles, gloves and clean / well prepared homebrewing.

    Especially the (known) lack of predictable stoichiometric results was the reason for my question… Maybe somebody already has some experiences with this HQMS Homebrew and the use of it, beside Mr. Whetcroft and brooks…

    Regards, Stefan

    p.s. Don’t get me wrong, I honor your warnings clearly, but did you ever bleached your hairs ( preferably to a bluish white) ? Well, I can tell you, THAT is an reaction I would not recommend to anyone…
    Last edited by stefan4u; 08-29-2012 at 11:21 AM. Click to view previous post history.

  10. #70

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    In organic synthesis the yield of a particular product often depends on the temperature of the reaction mixture. Low temperature may favor one product while higher temperature another. So some one else's result may not be useful unless you know the temperature.

    In this particular case my warning was directed primarily at the hydrogen peroxide itself and not the synthesis of the sulfonate.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

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