Alright, show's over.
Some ground rules for the two of you (and anyone else, for that matter), @JunoChan and @czygeorge:
1: Treat each other, and basically everyone else too, with respect on this forum.
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Thank you for your consideration.
Thanks a lot Koraks!Alright, show's over.
Some ground rules for the two of you (and anyone else, for that matter), @JunoChan and @czygeorge:
1: Treat each other, and basically everyone else too, with respect on this forum.
2: The main language of communication on this forum is English. This helps all of us to get the most out of your knowledge exchange, and it helps us (moderators) to spot it when things get out of hand.
Thank you for your consideration.
Would you mind to remove the conversation above(all non-English part)?
What are the advantages of using potassium salt of hydroquinone sulfonic acid over hydroquinone in the first e6 developer or any other formula ? I can’t find anything specific. Is it an environmental concern? Thanx.
If HQ gets oxidized by silver ions, it then reacts with sulfite to form HQMS, which is again a developer. If HQMS gets oxidized by silver ion, it reacts with sulfite to form the disulfonate HQDS, which does not develop silver. Therefore HQMS is somewhat selfrestraining (it takes some time for the HQDS to go away from the development center), and this creates sharpness effects.
Therefore HQMS will produce sharper results than HQ, and sharpness was always a big thing for Kodak (and most people looking at pics).
Thank you. That makes sense. I have both in my forum art but can also make it from hq, sulfite and h2O2.
If HQ gets oxidized by silver ions, it then reacts with sulfite to form HQMS, which is again a developer. If HQMS gets oxidized by silver ion, it reacts with sulfite to form the disulfonate HQDS, which does not develop silver. Therefore HQMS is somewhat selfrestraining (it takes some time for the HQDS to go away from the development center), and this creates sharpness effects.
Therefore HQMS will produce sharper results than HQ, and sharpness was always a big thing for Kodak (and most people looking at pics).
If HQ gets oxidized by silver ions, it then reacts with sulfite to form HQMS, which is again a developer. If HQMS gets oxidized by silver ion, it reacts with sulfite to form the disulfonate HQDS, which does not develop silver. Therefore HQMS is somewhat selfrestraining (it takes some time for the HQDS to go away from the development center), and this creates sharpness effects.
Therefore HQMS will produce sharper results than HQ, and sharpness was always a big thing for Kodak (and most people looking at pics).
According to the literature I read, the earliest E-6 FD should use a mixture of hydroquinone and a small amount of HQMS. Now it has become only HQMS
There are several ancient reversal formulas with HQ, so obviously HQ works. Watkin's factor E-6 also uses the much easier to obtain HQ, and many folks seem to be happy with its results. However, Kodak must have arrived at the conclusion, that HQMS yields nicer slides, so here we are. Even to the mighty Kodak HQMS must have been more expensive than HQ, so they certainly didn't pick it just to annoy Fuji&Agfa.
Sharpness may be much less of an issue today, because modern lenses are sharper, modern film is sharper, and even amateur doofuses like me run around with at least 6x6 or larger cameras. Sadly until today I haven't seen side by side comparisons between Watkin's factor and regular E-6 sides.
Hi all friends
I am sorry that I have not been able to understand the communication between you guys before, because I am not particularly familiar with the English names of these chemicals
I'm just now realizing that the DTOD you're talking about is (5244-34-8)
, the price I bought for this ingredient is around 100g/26usds
Because this ingredient needs very little (same as p-aminophenol)
When I told the salesperson to only buy 100g, she was probably not want to care about it
If you want to buy it i'll ask for her email.
And also DTPA5Na(40%),ATMP and ATMPA here is like 2-3usds/500g(But have to be aware that DTPA and ATMPAView attachment 347774View attachment 347775 is liquid may hard to international transport)
Below is some photos which were possessed by my firend using this patent E-6(Thanks to Kodak)recently
(upper two was processed by me)
I have only read some literature on the effect of the principle of E6 potion on each ingredient, may not as good as you in the research on its substitutes. It's just luck that sourcing these chemicals is easy in our country. If anything i can help you configure this Kodak masterpiece, feel free to ask me
(processed by my friends)
View attachment 347771View attachment 347772
In dilute sulfuric acid, a certain amount of sulfur trioxide (SO₃) or HSO₃⁺ ion is formed, which is the active sulfonating agent.
Hydroquinone (as an activated benzene ring due to the –OH groups) reacts with the sulfonating agent.
Typically, the sulfonic group (-SO₃H) is attached in the para-position (if hydroquinone is not in excess) or in the ortho-position (under certain conditions).
The main product is hydroquinone-4-sulfonic acid.
C6H4(OH)2+H2SO4→C6H4(OH)2SO3H+H2O
Hello,
Dissolve hydroquinone in 10-20% glacial acetic acid
According to the bot, it is almost insoluble in water, so adding water will quickly precipitate it, as a purification method.
The last phase is neutralization with KOH to potassium salt.
C6H4(OH)2+H2SO4→C6H4(OH)2SO3H
I am left with the following impressions:
- the choice of glacial acetic acid is for several reasons, but one of them is that hydroquinone is poorly soluble in water, but in an acidic environment it becomes highly soluble. Is this true?
At first I didn't understand. It was a question of using directly concentrated acetic acid, but IF it is too thick due to the low temperature - dilute it with a little water (up to 10-20% water, not acetic acid).What is "10-20% glacial acetic acid" supposed to be? Either it's glacial Acetic Acid, or it's 10-20% Acetic Acid, but not both.
I guess from the above confusion.I'd be very surprised, if HQMS free acid was "almost insoluble" in water. If this was the case, it would also be almost insoluble in "10-20% acetic acid"
I also see a small difference in the formula, but at the end of the chat, when you calculated the weights, the molar weight of this formula is very close to the one given by Maersk (difference of 2-3 hundredths)This is certainly not the sum formula of HQMS - it should be C6H3(OH)2SO3H, since one -H was replaced with -SO3H.
I guess the salt is many times more soluble than the free acid. And again - it's about the maximum possible concentration of acetic acid at 5 degrees.If HQMS is only soluble in 10-20% Acetic Acid, then how would it be soluble in alkaline E-6 FD? There are close to 100 g/l HQMS-K in E-6 FD concentrate ...
Honestly, I have seen procedures to make HQMS-K, I know a guy who made them work in practice, and none of the procedures looked like this. I am a big fan of AI, but this doesn't seem to be one of its prime time results.
The sulfonation of HQ, without further purification is described in the attached patent. I have followed it successfully at molar scales. For b/w developers, the stoichiometric sulfate present can be accounted for and does not present a problem.
Just curious. Which B&W developer(s) makes use of HQMS other than a reversal first developer described in Agfa-Gevaert patent?
@lamerko , I have to agree with Rudi that the procedure, as outlined by the AI, is broadly unclear, and will not result in any meaningful yield of the sulfonate.
Glacial acetic acid is a pretty good polar, protic solvent and is used in substitutions reactions, most notably in aromatic nitrations, since it tolerates nitric acid and forms the active nitration species in that case. The solubility of HQ in GAA is not mentioned in the CRC databooks, but I was able to quickly find a reference(https://pubs.acs.org/doi/pdf/10.1021/ja01333a057), where it is stated that 60g dissolved in 250g of solvent on heating, so that may be a reason to use it. However, the solubility of HQ in water at room temperature is about 70g/L, so not orders of magnitude difference. HQ-sulfonic acid is very water soluble, in fact it hydrolyzes on standing as an aqueous solution, so it is only prepared to then be converted to a salt (sodium, potassium, calcium are the most common).
I think the silicon mind was thinking about nitration and not sulfonation. Nitrations are usually carried out at low temperatures and slowly to prevent side products and increase yield. Sulfonations are much harder to effect in practice. For example, to prepare benzenesulfonic acid, benzene must be treated at boiling point with oleum, which is sulfuric acid with added sulfur trioxide - basically the anhydride of H2SO4. HQ is a bit easier, the two hydroxyl groups activate the ring quite well, so regular concentrated acid will do the trick. In both cases, the reason for the high concentration of H2SO4 is to act as a dehydrating agent - the sulfonation is an equilibrium reaction and the resulting HQ-sulfonic acid can hydrolyze back to HQ and sulfuric acid in the presence of water, so an excess of H2SO4 is used to sequester the water (or the reaction is carried out under vacuum to remove water as it forms). This is well known and the earliest preparations of HQ sulfonates (Seyda, 1880s), outline the procedure in sufficient detail. Even the 10-20% water suggested would represent a stoichiometric excess to the amount of HQ that can be dissolved, even at reflux. At room temp or near the ice point, you will end up with an acidic slurry of HQ, water and acid, the activation energy is much higher. There are only two (reasonable, non-esoteric) methods to obtain HQMS at room temperature, either by reductive sulfonation of the quinone with tight pH control, or by anodic sulfonation at a platinum or carbon electrode, with a bit looser pH dependence.
The two above points make preparation of HQ-sulfonates difficult, because both the free acid and its salts are very water soluble. You can use the common ion effect to precipitate them out of solution (prepare a concentrated solution, then add sulfate salts and sulfuric acid), but the usual recrystallization yields are in the 10-20% range. Another unfortunate complication is that sulfates are almost always produced as a byproduct and have almost identical physical properties to the sulfonates, regarding solubility. Weissberger, et al, to prepare about 100g of HQMS-Na, use 7 liters (2 gal) of boiling hot methanol, to extract the salt from a reaction mix. Only the calcium salt (also known as calcium dobesilate) has reasonable solubility in simple alcohols, and can be separated out more easily (but converting it back to the more useful K or Na salt is a pain).
The sulfonation of HQ, without further purification is described in the attached patent. I have followed it successfully at molar scales. For b/w developers, the stoichiometric sulfate present can be accounted for and does not present a problem. For color work, the product has to be purified by extraction.
There are many black and white developers that use HQMS. In fact, there are quite complex formulations - with 4 or 5 developing agents, often combining hydroquinone with HQMS. These are usually commercial and not very cheap developers.
Ok, I guess you're talking about Spur developers, Adotech, Silvermax etc. I don't know if anyone synthesising HQMS for personal use have been able to create effective substitutes for these developers. Other than these, is there anything from the distant or not so distant past in the public domain?
Moersch as well. Absent any other technical disclosures, it seems reasonable to surmise that they caught wind of E-6 FD and knowledge about electron transfer developer models, but did not have easy access to the big data that has informed developer formulation at the major manufacturers since the 1980s (i.e. PQ or possibly PA will do just about all the things you need (outwith very specific cases where development inhibition effects are actively not desirable), with possible side excursions into further modifying Phenidones) - but which seems to demand sufficiently precise formulation accuracy that fall-backs to various more arcane sources of semi-quinones are used by smaller players. HQMS-Na will effectively start to form in-situ in an HQ containing developer using sodium sulphite after mixing, but there are specific reasons for preferably wanting the potassium salt as a discrete ingredient in colour systems.
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