A question for the Chemists about Adox Silvermax Developer

runswithsizzers · Oct 25, 2020

I have just started reading "The Film Developing Cookbook" by Bill Troop with Steve Anchell. I have the second edition (2020). So far, I have not found any specific information about the Adox Silvermax developer.

Given the ingredients listed below, can anyone help me classify the Silvermax developer to see how it fits in with the other developers discussed in the book?

1. Is this a PQ developer or PMQ? (the second-to-last ingredient has a name somewhat similar to Metol, but...?).
2. Is Silvermax more of a solvent type, or non-solvent developer?
3. Is Silvermax more likely to be speed-increasing, speed maintaining, or speed decreasing?
4. Is Adox Silvermax developer essentially similar to some other more common commercial developer which may be discussed in The Film Developing Cookbook?
5. <Here> Adox describes Silvermax as being an "equalizing developer" - what does that mean? So far, I have not seen that term used in the "...Cookbook"

It is probably obvious that I am very new to the study of photo chemistry, so if you answer, assume I know nothing.

--- below, copied from the <Adox Silvermax MDS>
- Potassium carbonate: EINECS: 209-529-3; CAS RN: 584-08-7, Percentage: < 5 %
- Diethylene glycol: EINECS: 203-872-2; CAS RN: 111-46-6, Percentage: < 2.5 %
- Trilon C: EINECS: 205-391-3; CAS RN: 140-01-2, Percentage: < 1 %
- Hydroquinone sulfonic acid (potassium salt): EINECS: 244-584-7; CAS RN: 21799-87-1, Percentage: < 2.5 %
- 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone: EINECS: 235-920-3; CAS RN: 13047-13-7, Percentage: < 0.15 %
- 1-Phenyl-3-pyrazolidinone: EINECS: 202-155-1, CAS RN: 92-43-3, Percentage: < 0.1 %
- Sodium Tetraborate Decahydrate: EINECS: 215-540-4; CAS-RN: 1303-96-4, Percentage: < 0.5 %
- Potassium Thiocyanate: EINECS: 206-370-1; CAS RN: 333-20-0 Percentage: < 0.5 %
- 4-Methylaminophenol sulfate: EINECS:200-237-1: CAS RN 55-55-0, Anteil: < 0.05 %
- Hydroquinone (1,4-Dihydroxybenzene): EINECS: 204-617-8; CAS RN: 123-31-9, Percentage: < 1 %
- pH-value at 20° C: 9,9

Anon Ymous · Oct 25, 2020

Blimey, 5 development agents? Lolwut!?

Kino · Oct 25, 2020

Here, let's explore our ignorance together!

- Potassium carbonate = Salt (to avoid swelling emulsion?), Percentage: < 5 %
- Diethylene glycol = Same (preservative?) Percentage: < 2.5 %
- Trilon C = Water Softener? , Percentage: < 1 %
- Hydroquinone sulfonic acid (potassium salt): (???? ph adjustment?), Percentage: < 2.5 %
- 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone: Dimezone developer;, Percentage: < 0.15 %
- 1-Phenyl-3-pyrazolidinone: Phenidone developer, Percentage: < 0.1 %
- Sodium Tetraborate Decahydrate: Borax : 1303-96-4, Percentage: < 0.5 %
- Potassium Thiocyanate: ???? Percentage: < 0.5 %
- 4-Methylaminophenol sulfate: Metol Developer: CAS RN 55-55-0, Anteil: < 0.05 %
- Hydroquinone (1,4-Dihydroxybenzene): Hydroquinone Developer, Percentage: < 1 %
- pH-value at 20° C: 9,9

Anon Ymous · Oct 25, 2020

Kino said:
Here, let's explore our ignorance together!

- Potassium carbonate = Same, Percentage: < 5 %
- Diethylene glycol = Same (preservative?) Percentage: < 2.5 %
- Trilon C = Water Softener? , Percentage: < 1 %
- Hydroquinone sulfonic acid (potassium salt): (???? ph adjustment?), Percentage: < 2.5 %
- 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone: Dimezone developer;, Percentage: < 0.15 %
- 1-Phenyl-3-pyrazolidinone: Phenidone developer, Percentage: < 0.1 %
- Sodium Tetraborate Decahydrate: Borax : 1303-96-4, Percentage: < 0.5 %
- Potassium Thiocyanate: Developer Percentage: < 0.5 %
- 4-Methylaminophenol sulfate: Metol Developer: CAS RN 55-55-0, Anteil: < 0.05 %
- Hydroquinone (1,4-Dihydroxybenzene): Hydroquinone Developer, Percentage: < 1 %
- pH-value at 20° C: 9,9

Hydroquinone Sulfonic acid potassium salt (aka Potassium Hydroquinone monosulfonate, HQMS-K) is a hydroquinone derivative that is used in E6 FD and is a milder development agent compared to hydroquinone. Potassium Thiocyanate isn't an agent. Diethylene glycol might be there to help dissolving some agents.

PS I am not a chemist.

Kino · Oct 25, 2020

With a quick glance, it seems like the Solvent-type developers tend to use Potassium Thiocyanate in the FDCB.

PS: I am not a chemist either...just flogging along...

Alessandro Serrao · Oct 25, 2020

Kino said:
Here, let's explore our ignorance together!

- Potassium carbonate = Salt (to avoid swelling emulsion?), Percentage: < 5 %
- Diethylene glycol = Same (preservative?) Percentage: < 2.5 %
- Trilon C = Water Softener? , Percentage: < 1 %
- Hydroquinone sulfonic acid (potassium salt): (???? ph adjustment?), Percentage: < 2.5 %
- 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone: Dimezone developer;, Percentage: < 0.15 %
- 1-Phenyl-3-pyrazolidinone: Phenidone developer, Percentage: < 0.1 %
- Sodium Tetraborate Decahydrate: Borax : 1303-96-4, Percentage: < 0.5 %
- Potassium Thiocyanate: Developer Percentage: < 0.5 %
- 4-Methylaminophenol sulfate: Metol Developer: CAS RN 55-55-0, Anteil: < 0.05 %
- Hydroquinone (1,4-Dihydroxybenzene): Hydroquinone Developer, Percentage: < 1 %
- pH-value at 20° C: 9,9

potassium carbonate is the accelerator
Diethylene glycol is the solvent
Sodium Tetraborate Decahydrate another accelerator / buffer
Potassium Thiocyanate is a silver halide solvent

AgX · Oct 25, 2020

runswithsizzers said:
5. <Here> Adox describes Silvermax as being an "equalizing developer" - what does that mean? So far, I have not seen that term used in the "...Cookbook"

Well, my photo-dictionary says instead "compensating developer", but that will not make you wiser, and indeed I Find tghe Adox term better.

It means that such developer is slow acting, yielding good density at the shadows but still not making lights too dense.

runswithsizzers · Oct 25, 2020

AgX said:
Well, my photo-dictionary says instead "compensating developer", but that will not make you wiser, and indeed I Find tghe Adox term better.

It means that such developer is slow acting, yielding good density at the shadows but still not making lights too dense.

Thanks for confirming what I suspected. The authors of the "...Cookbook" do define the term "compensating developer"

john_s · Oct 25, 2020

Anon Ymous said:
Blimey, 5 development agents? Lolwut!?

Looks to me like an MSDS designed to discourage people from trying to mix it up themselves. Why have two sorts of phenidone, two sorts of hydroquinone?

runswithsizzers · Oct 25, 2020

Can someone confirm or dispute if "4-Methylaminophenol sulfate" is about the same thing as "Metol"?

In the FDCB, the authors show Metol as "monomethyl-para-aminophenol sulfate" or "para-methyl-amino-phenyl sulfate"

On <this page> "para-" is defined as "...a molecule with substituents at the 1 and 4 positions on an aromatic compound. ... The symbol for para is p- or 1,4-" So, I can imagine how these might be three different names for the same thing, but what little I learned about chemical nomenclature was many years ago, so I can't be sure thay are not different.

koraks · Oct 25, 2020

Kino said:
Potassium carbonate = Salt (to avoid swelling emulsion?), Percentage: < 5 %
- Diethylene glycol = Same (preservative?) Percentage: < 2.5 %

The carbonate is part of the pH buffer/accelerator.
The glycol might be there to help keep stuff in solution; I don't think it preserves anything. Might Also play a role in modifying surface tension/preventing bubbles.

runswithsizzers · Oct 25, 2020

Thanks for all the helpful replies. It is good to know more about how some of the bits and pieces work.

But for now, my broader goal is to try to put the Silvermax developer into one of six broad classifications. The Cookbook authors show a table of Solvent Developers which can be eiither Speed Decreasing, Speed Maintaining, or Speed Increasing, and then a row of Non-Solvent Developers in the same three 'Speed' categories.

Apparently, it's not quite that simple, because a "Solvent" developer can become a "Non-Solvent" developer at higher dilutions, but ignoring that for the moment - can we say, because Silvermax developer contains Potassium Thiocyanate - "a silver halide solvent" (thanks Alessandro Serrao), it is a Solvent developer (?)

Does knowing what developing agents are present allow for informed speculation about how this developer might decrease or increase film speed?

Kino · Oct 25, 2020

Take it for what it is worth, my understanding of it is that as a general rule, solvent developers trend toward reducing speed because of the reduction of the silver of the image.

However, with the other developers and ingredients, that might be mitigated in some way.

Not really helpful, I know...

runswithsizzers · Oct 25, 2020

Anon Ymous said:
Hydroquinone Sulfonic acid potassium salt (aka Potassium Hydroquinone monosulfonate, HQMS-K) is a hydroquinone derivative that is used in E6 FD and is a milder development agent compared to hydroquinone. [...].

john_s said:
Looks to me like an MSDS designed to discourage people from trying to mix it up themselves. Why have two sorts of phenidone, two sorts of hydroquinone?

I just found this passage on p.28 of the FDCB, vol.2 (underlining and typos are mine):

"Hydroquinone monosulfonate [HQMS] is an important oxidation product of HQ that is formed as a natural part of development. However, employed as a separate chemical, it is in itself a developer, though typically requiring at least ten times more HQMS than HQ. It's primary use in photography has been as a constituent of the first developer in some of the last versions of the E6 process where HQ itself was found to be too active at the high desired processing temperatures (100F/38C), because HQ activity rises greatly with temperature increase.

It has been speculated that a phenidone/HQMS developer can produce more desirable images than a PQ developer, because the lower activity and different regeneration kinetics produce better controlled microcontrast and adjacency effects. We know of only one black and white developer which has ever been formulated with it. In Acurol-Ng, HQ, HQMS, Phenidone, Dimezone, and metol are employed for a grandiloquent total of five separate developing agents. At first glance, such a promiscuous, or rather polygamous, feat has not been recorded in photographic literature since the heady 1930s when Harry Champlin's developers were popular. However, in fairness to the formulator, using lesser quantities of more ingredients means fewer regulatory headaches in EU countries. In such a formulation, it is difficult to see how HQMS could be having much overall effect on the developer kinetics. Using HQ along with HQMS defeats the main chemical purpose of using HQMS."

As described, it sounds like Silvermax may be similar to Acurol-Ng (whatever that is), and possibly, a relatively uncommon formulation? So far, I have not seen any other references to Acurol-Ng in the FDCB.

@john_s, I don't understand how "using lesser quantities of more ingredients means fewer regulatory headaches in EU countries." but maybe after I have mastered chemisty, I will study law.

AgX · Oct 25, 2020

runswithsizzers said:
In the FDCB, the authors show Metol as "monomethyl-para-aminophenol sulfate" or "para-methyl-amino-phenyl sulfate"

Both terms designate the same chemical.

Pixophrenic · Oct 25, 2020

runswithsizzers said:
I have just started reading "The Film Developing Cookbook" by Bill Troop with Steve Anchell. I have the second edition (2020). So far, I have not found any specific information about the Adox Silvermax developer.

Given the ingredients listed below, can anyone help me classify the Silvermax developer to see how it fits in with the other developers discussed in the book?]

If you look into other creations of the German company SPUR, offered through Rollei and Adox, they are based on a principle that IMHO transcends the Cookbook II universe. Also, Bob Schwalberg would likely have labeled them as an abomination. In my understanding, the concept behind these developers is to achieve a certain characteristic curve for a limited number of films, in most cases for just one film. This is achieved by balancing the development speed of several superadidtive phenidone/hydroquinone or phenidone/HQMS combinations with silver halide solvent action. Without thiocyanate these developers are excessively active, even if used diluted 1:10, and produce rather prominent grain. The entire idea of one film/one developer is alien to what was typically offered in the 20th century. Also, by definition, they are one shot formulations. Disclaimer: no affiliation with SPUR.

grainyvision · Oct 25, 2020

- Potassium carbonate: EINECS: 209-529-3; CAS RN: 584-08-7, Percentage: < 5 % - alkali pH buffer agent
- Diethylene glycol: EINECS: 203-872-2; CAS RN: 111-46-6, Percentage: < 2.5 % - Developer solvent (makes developing agents more soluble) and oxygen reducer (less permeable to oxygen)
- Trilon C: EINECS: 205-391-3; CAS RN: 140-01-2, Percentage: < 1 % - chelating agent. Prevents dissolved iron, copper, etc from causing developer to decay from contaminates etc
- Hydroquinone sulfonic acid (potassium salt): EINECS: 244-584-7; CAS RN: 21799-87-1, Percentage: < 2.5 % - HQMS, similar to HQ but much less active and decays into an inactive byproduct rather than a very active radical byproduct. End result is that this acts more as an agent that restores the other agents, rather than a direct developer itself
- 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone: EINECS: 235-920-3; CAS RN: 13047-13-7, Percentage: < 0.15 % - Dimezone
- 1-Phenyl-3-pyrazolidinone: EINECS: 202-155-1, CAS RN: 92-43-3, Percentage: < 0.1 % - Phenidone
- Sodium Tetraborate Decahydrate: EINECS: 215-540-4; CAS-RN: 1303-96-4, Percentage: < 0.5 % - borax, mildly alkali pH buffer agent (forms the buffer with carbonate for ~9.9pH)
- Potassium Thiocyanate: EINECS: 206-370-1; CAS RN: 333-20-0 Percentage: < 0.5 % - silver solvent. Used often in reversal developers to reach dMax in highly exposed regions. Translates to finer grain and upswept highlights
- 4-Methylaminophenol sulfate: EINECS:200-237-1: CAS RN 55-55-0, Anteil: < 0.05 % - Metol or derivative??
- Hydroquinone (1,4-Dihydroxybenzene): EINECS: 204-617-8; CAS RN: 123-31-9, Percentage: < 1 % - HQ, more active than HQMS. When it decays, it'll make a act almost like a fogging developer, but this behavior depends on sulfite percentage and pH
- pH-value at 20° C: 9,9

grainyvision · Oct 25, 2020

For the actual type of developer, I'd say from what I've heard and seen about it, it's a non-solvent developer EXCLUDING the thiocyanate, but a mildly solvent developer with it, and of unknown speed. That just requires measurement. Non-solvent can be speed reducing (can't develop the "deeper" grains) or maintaining, while solvent developers can be speed reducing (eats away subtle shadows), speed maintaining, or speed increasing (can develop "deeper" grains than a standard developer otherwise could). Developers with thiocyanate are typically very mildly speed increasing, while developers with chloride are typically speed reducing because chloride only is solvent to exposed grains and so in an unbalanced developer could eat at subtle shadows before it has a chance to develop. The total developing agents are:

* Phenidone/Dimezone (these are likely combined due to manufacturing and not specifically by design. ie, they can use lower grade product by compensating for a mixture. Either way they work very similar to each other)
* metol/derivative
* HQMS -- Likely used here solely to regenerate the M and P parts consistently without letting contrast run away and for longer shelf life (HQMS is more stable than HQ and more can be added than HQ to ensure the P and M stays alive). HQMS of sufficient purity is very difficult to source in small amounts today so it is rarely used by hobbyists
* HQ -- used to increase contrast and highlight development most likely

The thiocyanate is a real wild card here as it's a very rarely used component these days because of various problems. Some films can have dichroic fogging with it, and it can often be too solvent or in the wrong ways, and definitely will increase highlight density.

edit: one important detail about thiocyanate that's not often appreciated because of it's strange behavior is that it actually can act as a restrainer against HQ specifically. There's not much research on this other than a single paper from the 70s, but I've confirmed it myself in lith developers. It's weaker than bromide but stronger than chloride in this respect. It highly depends on formulation as to if it behaves more as a restrainer or an accelerator.

edit2: according to the CAS number, it is metol and not a derivative. Strange way they named the chemical though

john_s · Oct 25, 2020

runswithsizzers said:
@john_s[/USER], I don't understand how "using lesser quantities of more ingredients means fewer regulatory headaches in EU countries." but maybe after I have mastered chemisty, I will study law.

It wasn't me who said this, but I think using more than one ingredient to perform a function can make a list look better. For example, if the list of ingredients on a shampoo bottle have to be listed in declining order of quantity, something can be made less obvious if its percentage is reduced by another similar ingredient. I can't think of a specific example at the moment but I have observed it.

Also, instead of saying Metol or Dimezone-S or glycol a much more complicated (correct) but less recognized name can be used.

grainyvision · Oct 25, 2020

john_s said:
It wasn't me who said this, but I think using more than one ingredient to perform a function can make a list look better. For example, if the list of ingredients on a shampoo bottle have to be listed in declining order of quantity, something can be made less obvious if its percentage is reduced by another similar ingredient. I can't think of a specific example at the moment but I have observed it.

Also, instead of saying Metol or Dimezone-S or glycol a much more complicated (correct) but less recognized name can be used.

This is fairly standard. If the manufacturer is nice, they'll include metol/dimezone in parentheses, but otherwise they stick with the formal chemical name. Use the CAS for easier lookups on this info. Regardless, most manufacturers don't include any chemical that they don't have to so that reverse engineering their trade secret is harder. Carbonate is often not listed, nor is borax. Unsure why its listed here

grainyvision · Oct 25, 2020

Note also that there likely many other components that didn't need to be listed on the MSDS. The obvious one here is the missing entry for sulfite. However, they could've even snuck something like ascorbic acid in there. Anything non-hazardous could have been added to the formula including other glycols that are non-hazardous, sodium chloride, potassium iodide, etc.

Kino · Oct 26, 2020

So, was there ever an consensus on what this developer might be?

I can Google the constituents and read "The Film Developing Cookbook", but I am insufficiently school in chemistry to make a determination.

Anon Ymous · Oct 26, 2020

Kino said:
So, was there ever an consensus on what this developer might be?

Uh, a strange concoction?

Might also be an otherwise fine developer, but strange it definitely is.

Kino · Oct 26, 2020

I like to read The Film Developing Cookbook each night before I go to bed; trying to pound the gist of what is being explained into my head.

While I cannot specifically point to the reasons for my "hunch", I get the vague notion that the "extras" in this developer might be used to manage micro contrast in the highlights, but the interaction of all the various constituents as explained in various sections of the book, are not clear to me in this particular formula.

Like I say, it's only a hunch, but until I hear or learn more, that's what I suspect; that it is neither fish nor fowl...

koraks · Oct 26, 2020

There are really only two weird things with this developer as I see it:
1: The use of effectively two kinds of phenidone (/dimezone S). I don't know the reasoning for this as I understand they're functionally virtually identical.
2: The addition of a very small amount of metol. Its function is also unclear to me as it's unlikely to contribute significantly to the development in the presence of a larger amount of vastly more active phenidone/dimezone.
All this makes me wonder if something couldn't be mixed with just hydroquinone and phenidone that does virtually the same job and does it equally well. Unless someone actually wants to try this, we'll never know, I suppose.

A question for the Chemists about Adox Silvermax Developer

runswithsizzers

Anon Ymous

Kino

Anon Ymous

Kino

Alessandro Serrao

AgX

runswithsizzers

john_s

runswithsizzers

koraks

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Kino

runswithsizzers

AgX

Pixophrenic

grainyvision

grainyvision

john_s

grainyvision

grainyvision

Kino

Anon Ymous

Kino

koraks

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A question for the Chemists about Adox Silvermax Developer

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