Note: Descriptions are shown in the official language in which they were submitted.
TITLE
STABLE PHOTOGRAPHIC DEVELOPER
AND REPLENISHER THEREFOR
'le ~:
Thi~ invention is in the field of
photographic silver halide developer solutions and
replenishers therefor, and is specifically dir~c~ed
to developer~replenisher solutions useful in low
through-put machine processing (developing) of
10 photographic film.
8ao k~ound Ar t:
The use of so-called "automatic processors"
is conventional for developing imagewise exposed
5ilve~r halide elements such as ~-ray f ilms . The
15 exposed ilms are fed into the processor from a
sa~eli~ht area~ i.e. one in whi~h the level of light
is reduced below that which exposes th~ film further~
and is transported through various chambers
containing the developer, the fixer and the water
29 washes. At th end of the processor, the film. is
dried and exits into normal light as a finished
~product ready for use. This is illustrated in U.SO
Pat~nt 3,545,971 "Rapid Proce~sing of Photographic
X-ray Film" (1966). This system is rapid and
25 convenien~ and large numbers of films can be
routinely handled in this manner over long periods of
time without dele~erious effec~s to the finished
image. Of cou~set the processing solutions become
exhausted by the passage of the exposed silver halide
film and replenishmen~ mus~ be made to account for
ingredient loss. Addi~ionally, the processing
flui~s, especially the developer solution, are
degraded aerobic~lly by contact with air and
anerobically when simply left for long periods of
P~-1810 35 inaction.
'~
When large amounts of ~ilm are being
processed (high throughpu'c), exhaustion of ~he
developer is due almost entirely to devalopment s~f
the s ilver hal ide image . The developmen ~ reaction as
5 shown in Mason's "Pho~ographic Processing Ch~mis~xy"
Focal Press (1966~ page 74, is~
2AgBr ~ H2Q + Na2S03 ~ 7Ag ~ ~Br ~ NaBr + ElQS03Na
Thus, some materials, i.e., hydroquinone and sulfite
are lost while bromide, acld, and hydroquinone
19 mono~ulfonate are formed~ Also, no~ shown by this
reaction, antioggant may be los~. Curren~ devPloper
replenishers are formulated based on this reaction as
follows: The replenisher is made higher in pH ~han
developer and contains no bromide t SO as to offset
the acid and bromide released by the development
reaction. ~he other ingredients are se~ at
concentrations whirh allow for ~he ~xpec~ed losses,
the hydroquinone being offset by ~he antifoggants,
without substantially affecting the sensi~ometry. In
20 this situation a replenishment rate can be
co~veniently calculated ba~ed on the approximate area
of film fed into the processor.
The other situation presen~s a more
difficul t problem because when only small amounts of
~ilm are processed (low throughput), the developer
deteriorates primarily from air oxidation and thermal
reactions r and not from development reaction; Mason's
~Photographic Processing Chemistry~ supra at page 73:
2Q a~ 3 2 ~ HQS03Na ~ NaO~ ~ Na2S04.
That is, hydroquinone and sulfite are lost bu~ not
bromide. Also, p~ increases, not decreases as in the
development reaction. Also, since film passage
activates the replenishmen~, low throughput decr~ases
replenishment.
Current practice is to compensate for low
throughput by increasing replenishment rate
significan~ly e.gO~ as much as two-fold. This,
however, can actually accelerate the problems caused
by low throughput processing and cause sensitometric
instability~ ~ does so because the replenisher,
which is being added, in ~xcess, has higher p~I than
the developer and no bromide. The effec~ of this is
to (1) maintain the increasiny p~ of the developer
10 caused by oxid2tion, and (2) dilute the bromide
content to levels so low as ~o cause sensitometric
instability, reflected mainly in fog ~nd speed~ The
presen~ inven~ion provides a replenisher formula~ion
whieh is aimed at compensating for developer changes
caused by nonuse, and not by the development
reaction. Thus, ~he replenisher is characterized by
a p~ lower ~han ~ha~ of ~he developer, and it
contains the maximum amoun~ of bromide consistent
with acceptable sensitometr.y. Now when replenishment
occurs, pH will remain constant or slightly ~ecr~ase,
the bromide will remain essentially constan , and the
o~her changes will compensate as in state of the art
formulations. Thus ~ by maintaining the developer
composition more constant, the developer can maintain
a useful lifetime e~uivalent to the high throughput
processors.
I~ is accordingly an object of thls
invention to provide an improved developer/-
replenisher system for developing exposed silver
30 halide photographic filmO A further object is to
provide a developer/replenisher sys-tem par~icularly
useful for machine processing of X~ray film when low
throughput s~f film is practised.
Summar~ of the Invention:
These and other objects are achieved in this
invention by providing an aqueous processing solution
useful as a photographic developer bath for automatic
processing of silver halide photographic film, parti-
cularly X-ray film, and as a replenisher therefor,
consisting essentially of, per liter:
l-phenyl-3-pyrazolidone
photographic developing
10 agent, or a derivative thereof 0.8 to 2.5 g
Hydroquinone developing agent
or a derivative thereof15 to 35 g
Bromide ion 1 to 7 g
Organic antifoggant and film
speed restrainer 0.01 to 2.66 m mole
Alkaline material and buffer to
provide a pH of 10.0 + 0.3;
with the proviso that the replenisher solution will
not only contain bromide ion but also will have a
lower pH than tha-t of the developer solution.
Developers and replenishers made according
to this invention can be used in processing machines
for low throughput of X-ray film, for example, and
will exhibit excellent stability over long periods
of both use and nonuse. Hence, a further embodiment
of the invention is a process for the automatic
processing of exposed photographic silver halide
X-ray film wherein the imagewise exposed X-ray film
is developed in a photographic developer bath
comprising a photographic developer, bromide ion,
an alkaline material and buffer system to maintain
the pH of the developer bath at a desired value, an
organic antifoggant and film speed restrainer, and
water; the developed X-ray film is fixed, washed and
dried; and the developer bath is replenished by a
~J
replenisher solu~ion ts~ maintain constant the
photographic properties o~ the developer bath during
pro::essing of a large quanti~y o: exposed X~ray film~
characterized in that ~he processing solu~ion
5 described above serves as bo~ch ~he deveïoper ba~h and
the replenisher ss:~lution; with ~he proviso that the
la~ter have a pH lower 'chan ~hat of the developer.
Detailed Di~closure of ~he Xn~7ention:
The processing ~olu~ion of this inventior
10 can be used for both the develQper and the
replenisher therefor~ In the lat~er embodiment,
wherein the replenisher solution has a lower pH than
~hat of the developer, it is only necessary to add a
small amount of acid, acetic acid, for example, to
15 ad~u~t the pH. However, for a commercial pu~-up~ a
small amount of base (alkaline ma~erial~ is added to
~he develop~r to raise the pH of the developer rather
~han adding acid to the replenisher ~o lower its pH.
This will be illustra~ed in Example 1, wherein a
20 ~mall amount of base is added through the starter
sol~ltion ~Part D). The replerlisher is added to the
developer bath as needed, based on ~ime and/or the
amount o film proc:essed, thus compensa~ing for both
forms of developer exhausltion. It is surprising ~hat
25 this particular f ormulation can be used so
successfull5~ for low throughput in automatic
processors ~ince the di~erences b~tween it and the
prior art are so slight. E~owever, as will be seen in
the Examples, the difference in performance between
the formulation of this invention and the prior art
is very la~ge.
As the photographic developing agents in the
processing solution, a combina~ion of
l-phenyl-3-pyrazolidone (sold under the Ilford
trademark Phenidone) or a derivative thereof such as
4-mel:hyl or 4 / 4-dimethyl phenidone, and hydroquinone
or a derivative thereof such as chlorohydroquinone or
bromohydroquir~ne is used. This combin~tion is
parti~ularly suited fs~r automatic p~ocessing of X-ray
5 ilms, These ordinarily comprise a gelatins~-Ag33r,
AgBrI, or AgClE~rI emulsion on a film support such as
polyethylene ~erephthalate.
~ ny alka].ine material may be used to provide
the required pH, such as sodium or potassillm
10 hydroa~ide~ sodium or potassium carbonatel etc. The
buffer sysi:em may be any converlient systemy e.g., the
borate and carbonate bu~fers conventionally used in
X~ray developer baths are both suitable.
Th~ organic antifog~ant may be any organic
antifoggant and film speed restrainer. Such organic
antifoggants are commonly employed in X-ray developer
baths and include compounds of the benzimidazole,
benzotriazole~ benzothiazole, indazole~ ~etrazole,
and thiazole groupJ as well as anthraquinone sulfonic
acid salts. Two or more organic antifoggant~ may be
used9 ~t is preferred to use a mixture of ~wo
antifoggan~s such as 5 nitroindazole and
benzo~riazole.
A range of bromide ion can be used
successfully in this inven~ion and provides excellent
stability. 1 to 10 g/liter of KBr, for example, will
provide sufficient bromide ion. NaBr may also be
employed. Optimum amounts depend on replenishment
rate and specific formula.
These essential ingredients, when dissolved
in water at the concentrations se~ f orth above,
enable the photographic solution of ~he invention to
function as a developer bath and a shelf-stable
replenisher .
3S
.
Other materials may be included in the
processing solution, such as gelatin hardening
agen~s, aerial oxidation res~rainers, sequestering
agents, surfactants, dyes, etc., as well known in the
art. See, e.g., U~S~ Patent 3,545,971 and
~Photographic Processiny Chemistry", supra, page 149
et seq~
Conventionally, all of ~he inyredients of
the developer are prepared in con entrated form in
water. Separate portions of the concentrates are
furnished users so that interaction between
ingredients is lessened while in ~hiq concentra~ed
state. Then, the user makes up the developer
solution by measuring various amounts from each part
15 and diluting with water to achieve the desired
~olu~:ion. The pH is then adjusted, e.g~, to
10~0 + 0. 3, and the soluticn charged ~o the.
p~ocessing tank~ e.gI, of the type described in U.S.
Patent No. 3,545,971, such as an "X Omat Processor"~
in the amount reguired by the system. Developm nt
time is determined empirically or by the processor.
Replenishment will be carried out al: a rate per unit
area of exposed ilm to provide processing of a large
quantity of exposed film without change in
~5 sensi~ometric properties of the fi.~m, ~nd will be
determined empirically, as is known. As a guide,
when using an X~Omat Processor to process X-ray film,
a suitable replenishment rate will be about 55 ml per
240 square inches o exposed ~ilm for development to
normal radiographic density, usiny the processin~
solution o the invention.
Some processors have a standby replenishment
mode. This works as follows: if no film is passed in
a given time, the proc:essor goes into a standby mode
which deactivates the drive train and dryer and
reduces water supply. After a given time, it comes
back on for several minu~es and then shuts off
ayain. After a specified number of cycles, it
replenishes a predetermined amount, This
S replenishment is not effective with current
developerfreplenisher formula~ions but very effective
with this invention since more of the correc~
replenisher is used.
After development in the processing solution
of the invention, the silver halide film is fixed,
preerably in an acid fixer, and washed and dried in
the usual manner~ If a processing maohine is used,
these steps will be de~ermined by the machine.
The following examples are illustrative of
lS the inventionr wi~h Example 1 being the bes~ mode
contemplated by the inventor of oarrying out the
invention .
EXAMPLE 1
_
The following solutions were prepared in
order to formula e a developer/replenisher ~I~
according to the present invention, and to sompare it
wi h a conve~ional developer~replenisher
In~redients ~g~
Part A
~ist. Water 250
Ethylenediaminetetraacetic 8
Acid (EDTA)
Sodium Bisulfite (43% aq.) 333
30 ~ydroquinone 100
K~r 13
K0~ ~45% aq.) 323
~2C3 (47% aq.) 116
Distilled Water to1 liter
g
Part B
__
Acetic Acid 560
Triethylene Glycol 240
5 Phenidone 60
5-nitroindazole 6.4
2.66 m moles
Benzotriazole 8.0
~odium Bisul~ite (anhydr.~ 5
~ Part C
~ist. Water 500
Glutaraldehyde (50~ aq.)300
Sodium Bisulfi~e (anhydrO) 106
Water.to 1 liter
Part ~
Dist~ Water 500
2~ RO~ (45% a~O) 200
RBr 171
Water to 1 li~er
To make developer Ir 2~0cc A
25cc B pH 10.2
25cc C
Water to 1 liter
23.4cc D
To make replenisher 250cc A pH 10.0
25cc B
30~5c~ C
Water to 1 liter
For comparison, a conventional high throughput
medical X-ray developer II was prepared. The most
significan~ difference was that Part ~' ~of developer
II) contained no K3r, and Par~ Dl contained 130 g
acetic acid~liter instead of 200 y KO~(45% aq)/li~er.
~eveloper II had a pH of lO.lS, and replenisher II a
p~ of 10.35 (compared to pH lO.0 for replenisher I).
In an ac'cual hospital situation, samples of
5 exposed, high speed medical X-ray film we.e proce~sed
tca. 15-20 sheets of 8" x 10'i film/day) using
developers I and II, ~hich were charged to a C~ONEX~
QC-l Medical X-ray Automatic Processor (E. I. du Pont
de Nemol~rs and Company, Wilmington, DE). The
respective replenisher solutions were supplied to the
replenisher tank thereofO The activities of the
systems wer~ checked by processing control strips of
X-ray ilm exposed through a ~ 21-step wedge on
Crone~ ~le~troluminescent (ELS) Sensitometer
(E. ~. du Pont de Nemours and Company, Wi~mington,
DE). Two st~ips per day (one in the morning and one
in the afternoon) were processed and the sensitometry
checked to see whether the processor and its
solutions were performing well. Processing time
(dry ~o-dry) w~s about 2-1~2 minutes at ~2~F. The
processor was equipped with a conventional ammonium
thiosulfate fixer solution.
In the case of developer/replenisher II,
~ above, high fog and lower speed was noted after about
2 weeks of use and the machine was shut-down and the
solutions drained therefrom. In the case of
developer/replenisher I, above, the fog and speed
remained constant after more than 4 weeks of
continued, low throughput use, demonstrating good
long life performance.
EXAMPLE 2
Developer/replenisher I of Example l was
operated for more th~n thirteen weeks at low
throughpu~ at St. Josephls Hospital in Phoenix,
Arizona in a Cronex QC-l processor under essentially
1~
~he same conditions as Example lo The same formula
was also run over four weeks at high throughpu~, thus
demonstrating that developer/replenishers of this
invention exhibit excellent stability over long
periods of time in both high and low throughput7
~AMPLE 3
In order to differentiate this invention
over another prior art developer/replenisher
formulation, the example given in Mertz, U.S~ Patent
No. 4,04~,571 "Processing Solution For Us~ As
Photographic Developer Bath and Replenisher Therefor"
(1977), Col~. 3, 4 and 5 was repeated. In this
reference, the organic antifoggant and film speed
restrainer is defined as being betw~en
7-26 m mole/liter of solution; which compares to
2.66 m mole/liter in Part B of Example 1.
Corresponding Part B of th~ Mertz example containing
3.6 g/liter of 5-chlorobenzotriazole and 5 g/liter of
5-nitroberlzimidaæole was diffi~ult to prepare and
required heating to ca. 120F. Preparatian of the
working strength developer/replenisher as described
was also difficult and required constant heating to
keep all the solids dissolved. For this reason the
solutions could not be tested in a commercial,
automatic processor. Instead, control strips of
X-ray film were tray processed in this developer and
took about 3 times as long to process as those
processed in developer solution I of Example 1, above.
EXAMæLE 4
The following solutions were prepared:
:L~
~ mt . ~g )
Par t A
___
Dist~ WatercaO 3785 (1 gal3
EDT~ 75
Sodium Bisulfite 1428
EEydroquinone 946
KOH (45~ aq.~ 3075
KOEI (solid) 1383
Sodium ~icarbonate 315
~Br 113
Dist. Water to 9. 46 li~ers
(2.5 gals)
Part B
Triethylen~ Glycol 402
~cetic Acid 270
20 Phenidone 60
5-nitroinidazole 6
Benzotr iazole 8
Dist. Water to 1 liter
2S
Par t C
Water 50 0
Glutaraldehyde ~ 50% A~. )267
50dium Bisul~ite (anhydr . ) 106
Dis'c. Water to 1 liter
A developer solution was made up as follows.
Dist. Water 26. 5 1.
( 7 ~a~ . )
NaBr 120 g
Sodium Bisulfite (anhydr.) 270 g
Potassium Carbonate (anhydr O ~ 312 g
Sodium Carbonate 200 g
~?art A, above 4 . 75 1.
(5 quartsJ
Part B, a~ve . ~5 1.
(1 quar~)
Par~ C, above O95 1.
~1 quart3
r~ist. Water to 37. 85 1.
(10 gallons)
p~I ~û.17 ~ 0.05
Five gallons (approxd 19 liters~ of this developer
wer~ charged to the processor described in Example
1. About 60 grams of ace tic acid were added 'co the
20 remaining 19 liters to give a pH of 10. 0 + O . 05 and
this was used as the repl en1sher . The processor was
also charged with standard ammonium thiosulfat~o fixer
and seJc at 92F. Two samples of exposed X-ray f ilm
(high speed CRONEX~4, E. I. du Porlt de alemours and
25 Compan~), 14 x 17 inch size t were processed
(developed) and the sensitometry of ~he system
checked with con rol strips as described in Example
1. The processor was then allowed ~o stand by for
the remainder of the day. About 2, OOOCG of
replenisher was added by the machine during this
time. At the end of the B hour day, the machine was
shutdownO The processor was run for 10 days in this
manner. No substan~ial change was no~ed in the
sensitome~ry of the con~rol strips used to check
developer activity, indicatin~ that this formula was
very sta~le to low throughput of silver halide film
and resistant to anerobic and aerobic degradation.
EXAMPLE 5
The formula of Example 2 (p~ about 10.2)
was used in this example, as both developer and
replenisher, in the processor of Example l. Under
low throughput conditions (7 to 10 sheets of X-ray
film/day) i~ served for more than five weeks. At
the end of this period of time, control strips
processed in this machine showed that the activity
of the developer was well within limits and produced
excellent results. A conventional developer of the
prior art deteriorates badly in less than two weeks
under these conditions and re~uires shut-down and
cleaning of the automatic processor followed by
re-charging with fresh solution.
SUPPLEMENTARY DISCLOSURE
It has been found that in using the
photographic processing solution of the present
invention for automatic processing of X-ray film at
low throu~hput of film and as a replenisher tharefor,
best results, i.e., excellent fog stability and high
control, are achieved when the organic antifoggant
and film speed restrainer is present at a level in
the range of from 0.01 to 6.0 m mole/literO Suppor-t
for a range of 0.01 to 6.0 m mole/liter for the
organic antifoggant and film restrainer is contained
in the following examples, i.e., Examples 6 to 13
inclusive.
EXAMPLE 6
A developer/replenisher solution identical
to that described in Example l was prepared, except
that the level of antifoggant was increased to 5.32 m
mole per liter (0.32 g/l of 5 nitro-indazole and
14
''~,~,.,~
0.40 g/l of benzotriazole). All other ingredierlts
and conditions remained the same as described in
Example 1. The activity of this solution was checked
by processing control strips of medical ~ray pho-to-
graphic film therein. Sensitometric results indica-te
that this developer will perform satisfactorily under
low throughput conditions, i.e., that this solution
will remain stable for long periods of nonuse~
EXAMPLE 7
Example 6 was repeated e~cept that the level
of antifoggan-t was raised to 7.0 m mole per liter
(0.42 g/l of 5-nitroindazole and 0.53 g/l of benzo-
triazole). Although film strips processed in this
solution were satisfactory as regards sensitometry,
solids precipitated from the solution. It was
obvious from this fact that it would be impossible
to keep this solution in an automatic processor.
EXAMPLES 8, 9 and 10
A developer/replenisher solution identical
to that described in Example 1 was prepared except
for the level of antifoggantO Three samples were
prepared from this, and the antifoggant changed in
each one as follows:
Antifoggant Level( )
Example m mole/l g/l
8 0.98 0.16
9 1.96 0.32
30 10 3.92 0.48
(1) 5-nitroindazole
Film strips processed in these solutions were
comparable, sensitometrically, to those processed
1~
in the preferred e~odiment, indicating that -these
three levels of antifoggant will perform within this
invention.
EXAMPLES 11, 12 and 13
A developer/replenisher solution iden-tical
to that described in Example 1 was prepared, except
that the level of antifoggant was changed as follows~
Antifoggant Level( )
10 Example m mole/l g~r~
11 0.05 0.01
12 0.15 0.025
13 0.31 0.05
(2) 1-phenyl-5-mercaptotetrazole
Sensitometric results indicate that this developer
will perform satisfactorily under low throughput
conditions, i.e., that this solution will remain
stable for long periods of nonuse.
16
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9~ ~
