Improved version of DS-10 by Ryuji Suzuki?

P C Headland said:

The good thing about PC-TEA is that it seems to have keeping qualities more akin to Rodinal / HC110 than Xtol. Like Rodinal, it darkens once opened, but it's activity seems to stay the same. I'm still working my way through a batch I made almost 5 years ago.

Click to expand...

PC-TEA has little developer in it, so to keep dev-times reasonable, the pH is high. But that boosts fog, and makes grain worse (compared to XTOL or DS-10). But I like the convenience of PC-TEA, and its longevity. Thanks for pointing out the nearly 5-year life you've gotten out of it. Such results are valuable knowledge. Do you know if PC-Glycol has similar longevity?

My approach will be to mix some Instant MYTOL -- organic solution, invented by Jordan and disclosed here: (there was a url link here which no longer exists)
It has all the chemicals (except sulfite) mixed in TEA and propylene glycol. The sulfite is mixed into the working solution separately, so it's not as convenient as PC-TEA, but it's still convenient enough, and the concentrate should last years.

After testing that, I'll try changing the quantities of its developers to match DS-10, and adjust alkali to hit the DS-10 target pH of 8.0.

BTW, I tried mixing sulfite into propylene glycol as a suspension (it won't dissolve), but the sulfite granules are too large and heavy, and sink too quickly for the suspension to be of any use. Also, the sulfite sediment tends to self-glue as a single hard chunk on the bottom, so even a finely ground suspension will probably fail. That means we mix the sulfite separately. Oh well.

Mark Overton

albada said:

BTW, I tried mixing sulfite into propylene glycol as a suspension (it won't dissolve), but the sulfite granules are too large and heavy, and sink too quickly for the suspension to be of any use. Also, the sulfite sediment tends to self-glue as a single hard chunk on the bottom, so even a finely ground suspension will probably fail. That means we mix the sulfite separately. Oh well.

Mark Overton

Click to expand...

Inorganic compounds like sodium sulfite are not usually soluble in organic solvents. Kodak when formulating HC-110 (which contains no water) had to use an organic adduct of an amine and sulfur dioxide in order to get sulfite into the developer. They did the same for bromide using an adduct with hydrogen bromide.

When mixing up a concentrate with TEA or glycols be sure not to get the mixture too hot. Doing so causes some oxidation of the developing agents and results in a dark color. Actually everything will eventually dissolve at room temperature, you just have to be patient. Gentle warming can be used but the solution should never be hotter than what can be comfortably held in the hand.

Don't add any water as this negates the purpose of using a glycol or TEA. Once you add water the concentrate becomes susceptable to air oxidation. This is why HC-110 c0ntains no water and last so long. Water allows oxidation to occur.

Jerry

Gerald C Koch said:

When mixing up a concentrate with TEA or glycols be sure not to get the mixture too hot. Doing so causes some oxidation of the developing agents and results in a dark color. Actually everything will eventually dissolve at room temperature, you just have to be patient. Gentle warming can be used but the solution should never be hotter than what can be comfortably held in the hand.

Click to expand...

Jerry, thanks for the warning, and I wish I'd known that last night! I mixed some Instant Mytol, which is PC-TEA + glycol + sulfite with some proportions changed. My tests showed the pH was too high -- around 9.0 instead of 8.2. And a test-strip was dense as could be expected. I've been pondering since then what happened.

I could have goofed my measurements, but I wonder if heating destroyed some of the ascorbic acid. I heated the TEA+PG mixture in a water-bath up to simmering, so the solution was at 90-95C for around 20 minutes. The Phenidone and ascorbic acid took that long to dissolve, even with constant stirring. Do you think such prolonged heat could destroy some ascorbic acid?

What max temperature would you recommend? I notice that 50C is almost too hot to touch for me, so perhaps that would be a safe limit for these chemicals? I use 50C when dissolving Phenidone into water, but perhaps ascorbic acid is more fragile.

Do you suppose that steam from the hot water-bath could have been absorbed into the solution? An Internet-search tells me that PG is hygroscopic, so having water-saturated air around it for half an hour might have been a poor idea.

BTW, during that 20-minute stir, the solution gradually turned (and remains) a fairly strong yellow. Is PC-TEA or PC-Glycol normally yellow after mixing? Might this be due to the oxidation you warned about above?

Thanks,

Mark Overton

Hi Mark,

Ethylene and propyl glycols are hydroscopic and will readily absorb water. I would mix everything in a glass bottle to avoid this problem. Keep the bottle lossely capped. Alkalis like TEa increase the rate of oxidation of ascorbic acid. What i did was to dissolve the ascorbic acid and phenidone in the glycol and once dissolved and cool add the TEA. Using glycol would also lower the pH. I used half of the total volume as glycol and half as TEA. If the pH is too low try 40 parts glycol to 60 parts TEA. You can add a small amount of TEA to the glycol to neutraiize the acidity of the ascorbic acid to help dissolve the AA. My final solution was yellow but not a strong yellow and did not darken as much as my first attempt using a lot of heat. So keeping things as cool as possible does seem to work. I used Dimezone instead of Phenidone as it is more stable in basic solutions.

If your working developer is producing too much fog you can add some bromide. Potassium bromide will not dissolve in glycol or TEA but ammonium bromide will dissolve in TEA. This allows you to get some bromide restrainer into the concentrate. This will reduce any fog. Benzotriazole will also dissolve in the concentrate and also reduces fog. With either first find how much is needed for working strength developer to determine just how much to add to the concentrate. Years ago people would improve D-76 by adding 0.5 g/l of potassium bromide. This prevents one having to season the replenished developer. Hope all this helps.

Jerry

Jerry;

Ammonium ion can cause fog in some emulsions. I would stick with Benzotriazole. Also, there is the chance that AA will dissolve more easily in TEA as you are mixing acid with base. I would be careful here though as it might not be "friendly". I have not tried this, so beware.

PE

Hi Ron,

I heated the TEA to drive off any ammonia. This was the only way short of using hydrogen bromide that I could think of for getting bromide into the concentrate. I didn't experience any fog with the amount of ammonium bromide that I was using. I originally mixed up the PC-TEA formula and did not experience any problems. But I added the AA slowly with stirring.

It was fun to see what could be done to improve the PC-TEA formula. But, getting lazy in my old age I now use HC-110 for what little developing I now do.

Jerry

Very good idea. Wow, you drove off the Ammonia and effectively made the adduct! Now I think I can do that with Ammonium Sulfite. I have a pound of it. What do you think?

If it works, that is the route to all kinds of HC-110 / PC TEA takeoffs.

PE

A second experiment done this afternoon makes me suspect that the Instant Mytol formula is incorrect. I created a small 50 ml working solution (not concentrate) with the correct proportions of all ingredients except that I omitted Phenidone. I simultaneously dipped pH test-strips into this test-solution and fresh XTOL, and compared their colors with each other and with the color-charts. I did this with two brands of pH-strips. Both showed XTOL at 8.0 and the test-solution at 8.7. These numbers are approximate, but the conclusion is clear: The pH of Instant Mytol is too high.

I'll reduce the TEA in Instant Mytol to get the pH correct (matching colors with XTOL). Or maybe I'll skip this stepping-stone and move onto modifying this formula to mimic DS-10. Let's see, DS-10, that was the goal of all this, wasn't it?

Jerry, like you, I don't shoot that much, maybe a roll a month. And some of that is C-41. So the desire is for a developer that gives XTOL-quality but that keeps a long time, and is tolerably convenient. Mixing two things such as concentrate and sulfite is fine, but having to mix everything from scratch just to dev one roll is too much effort.

PE: Thanks for the warning about Ammonium bromide and fog. I've entered that into my file of chemistry notes. You have an enormous amount of knowledge of tidbits like this, not to mention principles of operation for all kinds of processes. Have you considering putting all this into a book? If so, sign me up to buy a copy!

Mark Overton

Mark;

Right now I am in the final stages of writing the Photographic Emulsion Making and Coating book. Bill Troop and I have discussed writing what you say and there are some interviews on tape with Scott Sheppard on this topic somewhere. Unfortunately, the book you envision will take several years to produce and cost a bit. Also we need to get rights to portions of Anchell and Troop to kick start the project.

PE

Ron I would say give it a try. Since there would be much more ammonium sulfite and hence more ammonia I would do it outside. I sometimes miss having a hood. Jerry

So far, my experiments show that about 6.8 ml/L is the correct amount of TEA to add to Instant Mytol to hit the target pH of 8.2, instead of the 13.4 ml/L given in the formula.

Question 1: What alkalis will dissolve in propylene glycol?
Obviously TEA will, as will borax. Sodium carbonate contains carbon, so perhaps it'll dissolve also? I don't have much hope for sodium metaborate, but I'll have to check whether it's considered organic. Other alkalis? I'd like to experiment with the effects of alkalis on image-quality. The grain from TEA looks rougher than I like.

Question 2: What halide-solvents will dissolve in propylene glycol?
Sodium chloride or ammonium chloride? I suspect PPD will, but its toxicity concerns me, and it's a developer also.
It would be convenient to not have to dissolve sodium sulfite separately from the concentrate.

Thanks,

Mark Overton

Most inorganic compounds will not dissove in glycols. You are really restricted to using an amine TEA, DEA, or MEA and a few others. Kodak uses sulfur dioxide adduct as a halide solvent and preservstive in HC-110.

albada said:

Thanks for the suggestion. Coincidentally, the TEA arrived in the mail today, so you can guess what I'll be doing this weekend.
A few postings in apug.org have noted that PC-TEA is a little grainier than XTOL, probably due to having no solvent in the soup. Adding Sodium Sulfite creates Jordan's "Instant Mytol", described here: (there was a url link here which no longer exists)
So I'm thinking of trying some of that Instant Mytol.

Mark Overton

Click to expand...

hi mark

why don't you contact ryuji himself ( he has a website and is accessible )
rather than ask people who may or may not have any idea of what his changes might have been ?

good luck !

Gerry: I was afraid of that. PG is a good carrier (I guess that's a good word for it) because oxidation isn't a problem, but few things will dissolve in it.

Jnanian: That's a good idea! It hadn't occurred to me to contact Ryuji. It's winter, so his freelance photo business is probably slow now, and maybe he'll have time to talk about his work. BTW, did he simply lose interest in film? It seems he hasn't posted in a few years now.

Anyway, I'll be shooting a roll of Tri-X today at a company-luncheon. The camera will be a Minolta V2. Gotta love those classic cameras.

Mark Overton

albada said:

Gerry: I was afraid of that. PG is a good carrier (I guess that's a good word for it) because oxidation isn't a problem, but few things will dissolve in it.

Jnanian: That's a good idea! It hadn't occurred to me to contact Ryuji. It's winter, so his freelance photo business is probably slow now, and maybe he'll have time to talk about his work. BTW, did he simply lose interest in film? It seems he hasn't posted in a few years now.

Anyway, I'll be shooting a roll of Tri-X today at a company-luncheon. The camera will be a Minolta V2. Gotta love those classic cameras.

Mark Overton

Click to expand...

hi mark

i am not sure if he lost interest in film or traditional photography: i doubt it.
he not only was involved with creating photochemistry, but he also
was very involved in making photo emulsions.

you can probably look up his threads / posts when he was here
to see what was going on " politically " when he was here ...

good luck !
john

All right Mark, your email got me curious and googled and found this. It's kinda surprising I remembered the login u and pw.

First, I recommend you to get a better way to measure pH than test strips. You'll notice that pH difference of 0.2 would make a significant difference in the development time required to attain a target contrast index.

Triethanolamine is a good alkaline agent in fine grain developers. If you are making an accutance developer or more rapid action developer, you can mix diethanolamine as well. Some of the derivatives of TEA and DEA are also good alkaline agents (some names were given in my old posts - please find them). You can get a range of buffering systems with them. But, if you are a casual darkroom hobbyist, don't go there.

Borax is a really good buffer for pH 9 range, but not really for 8 or 10. It's easy to use, and cheap, but that's about it.

Small quantity of ammonium salt would probably do little harm at pH of 8.2. But I'd rather not use them, unless you know what it affects and carefully control for it. I recall trying using ammonia in small quantities, but I vaguely recall the results varied a lot depending on the film. That was actually somewhat expected. Also, I'd definitely not use ammonium salt in developers of pH any higher than that.

I actually have an improved version of fine grain developer as well as high accutance developer, but never commercialized.

Regarding the silver halide complexing agent for fine grain effects, I also played around with a few pyrimidine derivatives. Some are interesting because they are also a very mild developing agent when used alone. But after all, sulfite was easier to use and a lot cheaper.

Another thing I never posted before is that I have a developer stabilizing additive. This actually improves the shelf life and tray life of the developers. It was used in print developers that had silvergrain label and sold in F-style jugs but not any other bottle shape or label. This thing actually works well in film dev as well, but the additive looks brown color and a lot of users would get confused with the color of stale developers. So that was another concern for me and I didn't want to go ahead without a colorless stabilizer additive. But I was using it for routine processing in my lab.

Another challenge is that if you try to make a highly concentrated film developer (as I was doing) you'll sooner or later face a problem with phase separation. Some of the compounds in the concentrated developers do not mix with water rich of inorganic salts. So, you'll get sulfite-rich water phase and "oily" look phase containing amines, Dimezone S, etc. There are some solvents you can use to blend them, but they're not particularly safe. Certainly not the kind of stuff I'd put in if I were to sell the product as low toxicity. Well, that was a part of the reasons why I was looking for something to partially replace sulfite with.

Alright, I think I shouldn't write much more frmo memory - any more would risk being incorrect.

Gerald C Koch said:

Saying that a formula has too many ingredients is like saying that Mozart's music has too many notes.

Click to expand...

Good quotable statement.

nworth said:

I wonder what a little bit of EDTA-Na would do for stability.

Click to expand...

If you are talking about DS-10, don't. You add a little EDTA, and the keeping property worsens. You add a LOT, and it gets a little bit better. It's not a matter of stability constants. It's something else. If it were that simple it would be all solved back then.

Gerald C Koch said:

As I stated before EDTA cannot be used since it actually catalyses the Fenton reaction. Don't know about NTA. This was the problem that Ryuji encountered. Which agents can be used and which cannot.

Click to expand...

That is correct. I am not 100% sure if it is Fenton reaction per se, or something like that but different. But frmo the macroscopic systems view, it is the same problem.

The outcome should be somewhat predicted from the redox properties of the chelated iron complex. The goal is to keep the chelated ferrous ion in the form not readily oxidized. An alternate approach would be go bind iron to some bulky molecules so that any reaction it engages in will be slowed down.

Ryuji said:

The outcome should be somewhat predicted from the redox properties of the chelated iron complex. The goal is to keep the chelated ferrous ion in the form not readily oxidized.

Click to expand...

Hi Ryuji,

Good to see you again on APUG. I tried unsuccessfully a few weeks ago to get such information for iron chelates. Lots of information but not what I wanted.

Jerry

Jerry;

Try the DEQUEST series of chelating agents. They have one of the highest complexation constants with Iron of any such agent. It is so strong it can redissolve Ferric and Ferrous hydroxide and that is saying a lont.

PE

Gerald C Koch said:

Hi Ryuji,
Good to see you again on APUG. I tried unsuccessfully a few weeks ago to get such information for iron chelates. Lots of information but not what I wanted.
Jerry

Click to expand...

Yes! I hope you stay and continue to contribute.
I am new to developer-chemistry, but I've read many of your past postings, and value your knowledge.

Mark Overton

Gerald C Koch said:

I tried unsuccessfully a few weeks ago to get such information for iron chelates. Lots of information but not what I wanted.

Click to expand...

That sounds right. I couldn't find that data tabulated anywhere back then using traditional as well as electronic libraries at MIT and Harvard. Met a bunch of industrial chemists, electrochemists, ..., no one had idea of where to look. That's why I started doing own experimentation to find some empirical laws that could guide me in finding the right compound. Meanwhile, a list of chelating agents that don't help or worsen the oxidation problem grew. A lot of people threw names of their favorite chelating agents at me but they had no idea. There is no one universal scale by which usefulness of chelating agents can be measured, for this particular problem.

Ryuji said:

First, I recommend you to get a better way to measure pH than test strips.

Click to expand...

I thought I was being clever by matching the color against XTOL. I put two strips into the test-developer and fresh XTOL at the same time, and compared. When colors match, pH should be equal. Not so! A liquid indicator gave a large mismatch when the strips agreed. And when the strips agreed, activity was lower than expected. Now I distrust the strips. Time to buy a pH meter! I'm planning to get a Hanna pHep-5.

Ryuji said:

Another challenge is that if you try to make a highly concentrated film developer (as I was doing) you'll sooner or later face a problem with phase separation.

Click to expand...

A google search just told me what "phase separation" is. That problem never occurred to me.

Here's an idea: Can we make a dual concentrate? That is, have two concentrated solutions, one using propylene glycol, and the other using water. The developers would go in the PG (as with PC-Glycol), and everything else in the water-based concentrate. I think the big problem here is that it's not possible to concentrate sodium sulfite enough due to its solubility limit. So we must find another more powerful halide-solvent. Perhaps ammonium chloride? Anyway, I wouldn't mind mixing two concentrates 1+1+10 or similar, as long as both concentrates would last years.

Another idea: Mix in the (powdered) sodium sulfite separately. Then add the concentrate. That would solve the sulfite-problem nicely. Comments on these ideas?

Mark Overton

Mark,

I can no longer point to my website but be very careful about pH meter. Cheap pH testers are not good enough for photographic processing chemicals. Processing chemicals will damage the electrode easily, as they are using silver electrode inside. You need refillable double junction electrode for the reference potential. A classic reference electrode for photographic work was calomel, which is still one of the best choice, but it's just too much mercury to have around. Most cheap electrodes are gel-filled single junction. Don't waste your time or money with those.

One concentrate with powder is not a bad idea. Such a formulation would not be desirable if you were making products but acceptable for private darkrooms.

Ammonium chloride would actually make the image grainier than having nothing at all. It'll give opposite effects to sulfite. You can't just round them all up with a categorical label "silver halide solvent."