[pure-silver] Re: ddx vs d76
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Fri, 11 Feb 2005 15:15:08 -0800
----- Original Message -----
From: "titrisol" <titrisol@xxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Friday, February 11, 2005 2:17 PM
Subject: [pure-silver] Re: ddx vs d76
>I thought ID-11 was the phenidone D76
\
ID 11 is the original D-76 formula. Current pacaged D-76
is approximately the buffered formula published as D-76d.
A comparison of the ingredients of DDX and Microphen show
them to be very similar except for the stuff put into DDX to
keep the ingredients in solution. Both are
Phenidone-Hydroquinone developers with a Borax-Boric acid
buffer. Potassium sulfite is used because it probably can
make a more concentrated solution than the sodium salt.
Dielethylene glycol is a solvent. There is also a
sequestering agent for magnesium and calcium salts in the
water. It may also help keep things in solution.
Since the MSDS is for the concentrate the pH will be for
that. I have no idea what happens to the pH when the
concentrate is diluted but, since the solution appears to be
well buffered, perhaps not much.
Microphen is a packaged version of Ilford ID-68
Water, at 125F or 52C 750.0 ml
Sodium Sulfite, dessicated 85.0 grams
Hydroquinone 5.0 grams
Borax 7.0 grams
Boric Acid 2.0 grams
Potassium Bromide 1.0 gram
Phenidone 0.13 gram
Water to make 1.0 liter
Copying from Gerald Koch's post the MSDS for DDX is:
Ingredient CAS # Weight
----------------------------------------------------
Diethyleneglycol ............ 111-46-6 .. 5 - 10%
Hydroquinone ................ 123-31-9 .. 1 - 5%
Phenidone-B ................. 13047-13-7 .. 0 - 1%
Boric acid .................. 10043-35-3 .. 1 - 5%
DTPA Na5 .................... 67-43-6 .. 1 - 5%
Potassium sulfite ........... 10117-38-1 .. 30 - 60%
Sodium tetraborate .......... 1330-43-4 .. 1 - 5%
Water ..................................... 30 - 60%
For reference the buffered version of D-76 is:
D-76d
Water, at 125F or 52C 750.0 ml
Metol 2.0 grams
Sodium Sulfite, dessicated 100.0 grams
Hydroquinone 5.0 grams
Borax, decahydrated 8.0 grams
Boric Acid, crystaline 8.0 grams
Water to make 1.0 liter
The original D-76 and the published formula for ID-11
are:
Water, at 125F or 52C 750.0 ml
Metol 2.0 grams
Sodium Sulfite, dessicated 100.0 grams
Hydroquinone 5.0 grams
Borax, decahydrated 2.0 grams
Water to make 1.0 liter
A version which is closer to being "optimum" according to
Ryuji Suzuki is:
Agfa/Ansco 17
Water, at 125F or 52C 750.0 ml
Metol 1.5 grams
Sodium Sulfite, dessicated 80.0 grams
Hydroquinone 3.0 grams
Borax, granular 3.0 grams
Potassium Bromide 0.5 gram
Water to make 1.0 liter
Note that the reduced sulfite shows up in the Microphen
formula.
In their 1929 paper exploring variations of D-76 Carlton
and Crabtree, of Kodak Labs, found that the addition of 0.5
gram of bromide per liter increased film speed slightly due
to suppression of a small amount of developer fog which is
typical of D-76 type formulas when used _for the first
time_. The buffered formula is also in this paper and is
offered as a cure for the slow rise in activity of D-76 type
developers when not buffered. The cause was not known at the
time but is now thought to be a slow reaction between the
hydroquinone and sulfite which generates some hydroxide
causing a slow rise in pH.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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