Sorry, I've lost the original thread title, but here's Bob Chapman's
response to Shel's ID-11 / D-76 question:
>>>>>>
Dear Mike:
It was good to hear from you. I hope the "Falarfus" cures quickly. So far, I
haven't had a flu, cold or any other malady this winter.
About D-76 vs. ID-11: I went to the Kodak and Ilford websites and found the
MSDS sheets for both. Although I have older formulas for these in my
reference books, I felt that consulting the latest MSDS sheets would better
answer your question. The significant results are abstracted below. Note
that
both formulas list hydroquinone, metol and sodium sulfite. Of course, we
knew
this already. Sodium tetraborate and boric anhydride are listed for D-76,
while simple borax is listed for ID-11; the use of borates in D-76 and ID-11
is also well known. The one, significant difference between the two formulas
is the inclusion of "sodium tripolyphosphate" in ID-11. This compound is a
chelating (or sequestering) agent. These compounds are used to solubilize
hard water minerals (such as calcium and magnesium) so that scum will not
form on film surfaces when processing in hard water.
Substituting metabisulfite for sulfite merely changes the buffer capacity at
a particular pH, i.e., the resistance to pH changes. This may, or may not,
affect the pH drift problem you mentioned. Realize that MSDS sheets are
required to list only hazardous ingredients and/or ingredients > some
percentage on a wt. % basis. This means that other compounds might be
present
in either or both formulas. If so, they would be at low levels and/or be
nonhazardous.
regards ... Bob Chapman
****************************************************
KODAK Developer D-76
MATERIAL SAFETY DATA SHEET
----------------------------------------------------------------------
2. COMPOSITION/INFORMATION ON INGREDIENTS
Weight % - Component - (CAS Registry No.)
Concentrate:
85-90 Sodium sulfite (007757-83-7)
4 Hydroquinone (000123-31-9)
1-5 Sodium tetraborate, pentahydrate (012179-04-3)
1-5 4-(methylamino)phenol sulfate (000055-55-0)
< 1 Boric anhydride (001303-86-2)
Working solution:
85-90 Water (007732-18-5)
5-10 Sodium sulfite (007757-83-7)
1-5 Sodium tetraborate, pentahydrate (012179-04-3)
< 1 Hydroquinone (000123-31-9)
< 1 4-(methylamino)phenol sulfate (000055-55-0)
ID -11 DEVELOPER
Part A
CONTAINS: Hydroquinone (123- 31-9)
Methyl p - amino - phenol Sulfate
(Metol) (55 - 55- 0)
Part B
CONTAINS: Sodium Sulfite ( 7757- 83- 7)
Borax (1303-96- 4)
Sodium Tripolyphosphate (7758- 29- 4)
-
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