Replace PPD by CD-3

Gerald C Koch · Oct 14, 2010

When used alone PPD causes a severe loss of film speed and acutance. Because of this another developing agent was added to most formulas, metol, glycin, ... Of course this sort of negates the use of PPD in the first place because the grain is increased again.

Kodak published a formula for a special B/W developer based on CD-3 or CD-4. Its name began with SD rather than just D. Can't remember the number, SD-4?

Probably the best starting point for a CD-3 developer would be the Crawley FX-10 formula.

FX-10 Super Fine-Grain Developer

Diethyl-p-phenylenediamine bisulfite 6.0 g
Sodium sulfite, anhydrous 100 g
Hydroquinone 6.0 g
Borax 4.0 g
Boric acid 4.0 g
Water tp make 1 l

Use full strength
The BJ says develop for 8 min @ 65 F

I would adjust for the difference in MW's, you might have to make a small adjustment in the ratio of borax to boric acid.

Photo Engineer · Oct 14, 2010

Jerry;

You do not have to lose speed though with the right formula.

And, since the above formula uses the bisulfite salt of CD2, the pH will have to be tweaked if you change developers say by using the Sulfate salt of CD2. This is the fundamental problem here. Without pH values, the formulas are vague. Without the same salt, same thing applies.

I'm not saying it cannot be done, just that the level of difficulty goes up and the tinkering goes up!

PE

Gerald C Koch · Oct 14, 2010

Ian Grant said:
So there's a vast number that never made the cut archived away. Sometimes other companies beat them to it with Patents, I'm fairly sure that's what delayed Xtol (or an Xtol type developer) as there was an early 60's US Patent held by a Swedish company and Xtol only appeared after that had expired.

According to Mason, ascorbic acid was identified as a developing agent by Ohle in 1932, BP 430,264. I think the use of ascorbic acid as a practical developing agent depended more on the availability of a cheap method of synthesis.

Gerald C Koch · Oct 14, 2010

Photo Engineer said:
Jerry;

You do not have to lose speed though with the right formula.

Granted, but loss of speed is the reason for using an additional developing agent which causes the loss of much of the fine grain character of a PPD developer.

Probably the best combination of speed, grain, and acutance is given by an ascorbate developer such as Xtol.

Photo Engineer · Oct 14, 2010

Vitamin C was first synthesized in 1934.

PE

patrickjames · Oct 15, 2010

eclarke said:
Are you in the US? I just got 2 pounds of ppd from Formulary (as an aside, I use a lot of this and the stuff I just got from them is the best I ever bought, finely milled and dissolves very well)...Evan Clarke

What? Every time I get PPD from them it is in big chunks and is a pain to use.

Athiril · Oct 15, 2010

I can definately recommend giving CD-2 a go, I havent had any problem dissolving it a little methylated spirits @ working solution.

It dissolves very well in HCl which I am using for a 2 part concentrate.

In a document I collected from an APUG member and posted here - http://athiril.blogspot.com/2010/04/colour-photographic-formulae.html

There was a substitution table for amounts in it. Obviously thats for colour... but it still works via developing the silver halide on colour films.. so, may be a starting point?

Table is as:
What you have, formula specifies, multiply by this number to get 'equivalent'.
CD-2 CD-3/CD-4 0.50/0.82
CD-3 CD-2/CD-4 2.00/1.79
CD-4 CD-2/CD-3 1.21/0.56

Relayer · Oct 18, 2010

As I know PPD base is easily oxidized. But I have PPD chloride. I as can understand if mix PPD chloride with NaOH we obtain PPD base. It's correct? if yes - how many NaOH must be added?

Photo Engineer · Oct 18, 2010

I have seen several acid salts of PPD as well as the free base.

If you have the PPD.HCl then 1 mole of NaOH should be added but if you have the PPD.2HCl then 2 moles should be added. If you have the sulfate salt, then 2 moles are usually added. So, it is difficult to say and you must know which salt you have. Most sellers of these will specify.

PE

Relayer · Oct 19, 2010

Photo Engineer said:
If you have the PPD.HCl then 1 mole of NaOH should be added but if you have the PPD.2HCl then 2 moles should be added. If you have the sulfate salt, then 2 moles are usually added. So, it is difficult to say and you must know which salt you have. Most sellers of these will specify.

I have PPD.2HCl. but where I can find molecular weight of it?

Gerald C Koch · Oct 19, 2010

"If you give a man a fish he will eat for a day ..."

google phenylenediamine hydrochloride

Photo Engineer · Oct 19, 2010

The problem is that searching gives you the monohydrochloride. If you have the dihydrochloride, and you are sure of it, then you have to add the MW of HCl to the molecular weight again.

PE

Gerald C Koch · Oct 19, 2010

Photo Engineer said:
The problem is that searching gives you the monohydrochloride. If you have the dihydrochloride, and you are sure of it, then you have to add the MW of HCl to the molecular weight again.

PE

If you google and read the information correctly you will get what you desire and perhaps learn a few things. The answers to many of the questions asked on APUG can be found by a simple search of the internet. That was the intent of my post hence the maxim on fishing.

neelin · Oct 19, 2010

Gerald C Koch said:
"If you give a man a fish he will eat for a day ..."

"If you build a man a fire you warm him for a day,
If you set a man on fire you warm him for a lifetime"
Sorry, way OT.

Relayer · Oct 19, 2010

Photo Engineer said:
The problem is that searching gives you the monohydrochloride. If you have the dihydrochloride, and you are sure of it, then you have to add the MW of HCl to the molecular weight again.

yes, you right. google search give me monohydrochloride. but I found that PPD.2HCl is the C6H8N2*2(HCl) and MW calculator give me MW 181.06 g/m. I think its correct. so MW of NaOH is 40 and we need mix 18.1 gr of PPD.2HCl with 8 gr NaOH for recovery PPD base

Photo Engineer · Oct 19, 2010

Gerald C Koch said:
If you google and read the information correctly you will get what you desire and perhaps learn a few things. The answers to many of the questions asked on APUG can be found by a simple search of the internet. That was the intent of my post hence the maxim on fishing.

Jerry;

I understand, but with some examples the results can be misleading and that is why I said what I did in my post. Chemistry is not a "do it yourself" proposition that works for many people. Organic chemistry can be a difficult topic to wade through for a novice.

The internet results can be misleading to a novice at Organic Chemistry. The nature of the emails and PMs that I get are abundant proof of that. So, I err on the side of caution.

PE

nworth · Oct 19, 2010

We've been discussing the necessity for tweaking the pH depending on whether you are using PPD (or a derivative like CD2 or CD4) or one of its acid salts. The real problem, as has been often mentioned, is that the formulas for PPD developers seldom tell us whether the base or the salt was used, and they almost never give a target pH. Fortunately, most of the formulas seem to work over a range of pH and concentrations of the PPD compound. For careful work, however, these problems will call for some experimentation.

Ian Grant · Oct 19, 2010

Every formulae I've ever seen is very clear on the exact PPD derivative or equivalent, or sometimes the free base. I can't think of one that hasn't. I've seen some dubious nonsense in more recent books but then I have the original data the books used

ian

Athiril · Oct 19, 2010

There's so much ppd in common products.. I wonder how much exposure the average person has to it.

Photo Engineer · Oct 19, 2010

Well, the CD series from 1 - 6 are designed in approximate order of decreasing toxicity and increasing dye stability, but this is only a rough approximation as the stability is based on coupler as well and the toxicity is based on many environmental factors such as method of contact and etc. The bottom line though is that in-general, PPD is considered more toxic than the CD series.

And yet, PPD is used in many hair dyes and other preparations. It is rather perplexing when one considers the current antagonism to photographic developers in comparison to the hair dyes.

PE

Gerald C Koch · Oct 19, 2010

Photo Engineer said:
And yet, PPD is used in many hair dyes and other preparations. It is rather perplexing when one considers the current antagonism to photographic developers in comparison to the hair dyes.

PE

I read on one website that current government regulations say that hair dyes may be applied to the hair but cannot be applied to the scalp. Seems like a good trick if one can do it.

Black hair dye seems to be the real offender since it contains the most PPD or derivatives thereof.

The CD series is a good choice if one insists on experimenting with PPD developers.

Photo Engineer · Oct 19, 2010

Don't forget that the couplers in PPD hair dyes are analogs of Kodachrome couplers, themselves chosen for purity and dye stability. Since no one is expected to handle the couplers when processing Kodahcrome film, nothing much is said about them, but they do contact people in the hair dressing business, and the customers who have their hair dyed.

PE

Gerald C Koch · Oct 19, 2010

Photo Engineer said:
Don't forget that the couplers in PPD hair dyes are analogs of Kodachrome couplers, themselves chosen for purity and dye stability. Since no one is expected to handle the couplers when processing Kodahcrome film, nothing much is said about them, but they do contact people in the hair dressing business, and the customers who have their hair dyed.

PE

Good point. I wonder if the FDA is considering these chemicals too?

Alan Johnson · Oct 20, 2010

Sease No.1 with CD-4

CD-4..............................10g
Sodium Sulfite..................90g
Water to..........................1L
pH~7
Develop 100 T-max ~25m 68F

I did try this but it loses about 2/3 stop cf Xtol 1+0 and the grain is not as fine.
The crops are 2.5mm square sections of negative, sharpened identically.
Back to the drawing board.

Photo Engineer · Oct 20, 2010

This is an exceptionally low pH for using CD-4 or indeed any of the CD series. You should get better results than what I see here.

PE

Replace PPD by CD-3

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