TEA Developers

I wouldn't normally cross post on LFPF and APUG but the knowledge base is different and maybe someone will have some thoughts.

Is TEA a suitable base for a Metol/Hydroquinone developer? Does anyone have a formula as such? From the MSDS of 99% TEA it states a 1% TEA solution [in water] has a pH of approx 10.
Is TEA inert as such until added to water? Would Metol or Hydroqinone dissolve in sufficient concentration?
I don't have Phenidone but do have Metol hence my desire to use this combination.
I know Pat gainer and Jay have made TEA based developers in the past. Both of which use Phenidone. Any thoughts would be good.

Apart from PC-TEA and 510 Pyro does anyone know of any other TEA developers?

Steve

The only commercial product I aware of is Agfa Studional (Rodical Special). It uses a phenidone and hydroquinone. You must use potassium sulfite and not the sodium salt to make the concentrate as the sodium salt has a lower solubility.

One has to be careful with TEA since the are two grades. The technical grade contains about 15% DEA and has a higher pH enough higher to throw things off if you use the wrong grade. .

The following formula is said to produce negatives identical to the Agfa developer. Formula from a German website.

Agfa Studional

Distilled water (50°C) …………………………………………… 500 ml
Potassium sulfite (anhy) ……………………………………… 225 g
Hydroquinone ……………………………………………………………………… 40.0 g
Phenidone ……………………………………………………………………………… 5.0 g
Triethanolamine …………………………………………………………… 400 ml
Potassium bromide ………………………………………………………… 15.0 g
EDTA, Na2 ……………………………………………………………………………… 25.0 g
Distilled water to make ………………………………………… 1.0 l

Hydroquinone and metol should both dissolve in TEA. However I don't know if metol will dissolve in sufficient quantity to be useful. Not much posted about this type of developer at present. I think because the results of these home brew developers were just so-so. Using TEA or glycol as a solvent instead of water results in too many limitations as to what chemicals can be used. For example, neither potassium bromide nor sodium sulfite can be used since they are not soluble. Kodak had to resort to some novel chemistry in order to come up with HC-110.

Thanks Gerald that is a great answer and helps me with my pursuit. If I have any luck I will post back.

QP-TEA gives a long development time:
(there was a url link here which no longer exists)
Likely QM-TEA would be still longer.If there is no sulfite the oxidation product of Q is not removed and tans gelatin,

To provide more detail: if HQ reduces a silver ion, it turns into a semiquinone which is very reactive. Lith developers take advantage of this fact. All normal developers with HQ contain a healthy dose of Sulfite, because the semiquinone reacts with Sulfite to form HQMS (Hydroquinonemonosulfonate). This is what Pat Gainer referred to when he mentions "Sulfite is necessary to the superadditivity beteen the P and the Q. A very small amount will sufice, but some is necessary. I appears that the formation of hydroquinone monosulfonate is a necessary step in that synergism." in that thread.

Kodak found a way to get Sulfite into TEA, but from what I read this isn't something you can or should do in your home lab or dark room.

On this page Sandy King gives a formula for Pyro-Metol/TEA (PM-TEA):
(there was a url link here which no longer exists)
Hydroquinone-Metol/TEA (QM-TEA) has not been tried AFAIK, this too is a rather hazardous preparation.

There is a way around the sulfite problem in making waterless TEA developers. Potassium and sodium bisulfite can be thought of as containers for sulfur dioxide. By using technical grade TEA (~15% DEA) and adding a calculated amount of the bisulfite you can make the addition product of DEA and sulfur dioxide which Kodak uses. The TEA and bisulfite will react leaving an insoluble potassium or sodium sulfite behind. The adduct TEA mixture can be decanted from the solid byproduct. This may be an exothermic reaction so go slowly and be careful and make allowances to cool the mixture. This gets around the rather problematical need to use sulfur dioxide directly. Haven't tried this but it should work.

Benzotriazole can be used to replace bromide in TEA based developers instead of potassium bromide. The working pH can be adjusted by using a TEA and glycol mixture. The more glycol in the mixture the lower the pH. I suggested this on one of the long threads on these developers. Some people advocate heating the TEA to dissolve the other ingredients. But this causes some decomposition of the developing agents and really is not necessary. All hat is required is a bit of patience and agitation to get everything into solution.

The point of many TEA developers is that they provide an anhydrous environment so that the stock solutions last longer. Sandy King's formulas illustrate the approach, dissolving the developing agents in rather hot TEA to form a very concentrated anhydrous solution. There were a series of fairly long threads on APUG about this a few years ago. Unfortunately, sodium sulfite does not dissolve well in pure TEA, and substitutes are hard to come by. The workaround is to add the sulfite when you make up the working solution. Sulfite solutions are fairly stable and quite cheap, so you can dissolve the TEA-developer concentrate is a bottle of sulfite solution (of the appropriate strength) for a quick and easy working solution of developer.

Gerald,

I copied information from a German-language site years ago (FotoLabor); the author gave this as his "self-made" Rodinal Special -- it's consistent with your formula though I think the potassium differ slightly. Note yours is for a liter, this one is for 100ml (of concentrate). As translated by Google Translate from the German:

Rodinal Special SB:
Distilled water. 15 ml
Potassium bromide 1.5 g
Potassium - 45% soln 35 ml.
40 ml of triethanolamine
Hydroquinone 4.0g
Phenidone 0.5 g
EDTA Na2 2.5 g
Fill up with water to 100 ml
pH - value concentrate from 10.3 to 10.4
pH - value solution from 9.40 to 9.50
The recipe describes the concentrate. It is diluted for use 1 + 15.

Hello,
it is quite unusual that EDTA Na2 is used here, usually EDTA Na4 is used. Is this true or a mistake in the interesting formula for a Studional type developer? Since the EDTA Na2 has 2acid groups, there could be an influence on the pH value.

The two posted formulas are the result of back engineering the Agfa product. In this respect every effort was made to make the formula respond exactly as the commercial product. This also includes the pH of the concentrate. So there is no problem using the disodium salt.

Thank you Gerald,
in the chemical laboratory the disodium salt is very common as analytical reagent (Titriplex III in Germany) for complexometric titrations, e.d. of the water hardness. The tetrasodium salt, technical grade (Trilon B from BASF) is mostly used to reduce water hardness.

If you want to have some fun and play around with a metol/HQ dev in TEA, you can take the Pyrocat-HDC formula and substitute HQ for the catechol (50g HQ/2.5g Metol/4g Ascorbic Acid for one liter). Somewhere in the archives, P. Gainer suggested it for when catechol was difficult to get. I had some of this HQ version already mixed up in glycol and when in the darkroom, I added 99% TEA for part 'B' at 1:1:100. The film was 35mm ultrafine xtreme 100 at EI 100, 30C for 6min. It had decent grain, good shadows, but I have not tried to print it. As others have said, I don't think the ph of TEA is ideal for this combo, but it does with work w/similar times to Pyrocat-HD when you use sodium carbonate at 200g/L as part 'B' in 1:1:100. You will get a reddish stain.

One of the purposes of PC-TEA was to see wheter a usable developer could be made without the need for any sodium sulfite. I made up a few batches and heated the TEA with a hot water bath using a metal measurng cup. I was never able to get times as short as others with the 1:50 dilution but the stuff did work and lasted a long time. If you have metol and sodium sulfite handy and don't need to make up a huge batch at one time then why not just make up some D-23. It's very similar in use to D-76 but does not seem to suffer from the PH change that can affect regular (home mixed) D-76. The biggest benefit of TEA or glycol is shelf life. If you can mix up a batch of D-23 any time you like, it should last long enough for your needs.

dynachrome said:

The biggest benefit of TEA or glycol is shelf life. If you can mix up a batch of D-23 any time you like, it should last long enough for your needs.

Click to expand...

This nicely skewers the idea that you need to mix up your own waterless developer concentrates. Since the shelf life of most developers in measured in months why bother. Waterless developers just place too many restrictions on what ingredients can successfully used. There are a large number of conventional developers that can be easily mixed from a few chemicals.

Agfa Studional represents a good compromise in providing a concentrate that yields fine grain.