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Патент USA US2404774

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Patented July 30, 1946
2,404,774
"UNITED STATES PATENT OFFICE
2,404,774
PHOTOGRAPHIC DEVELOPING PROCESS
Fritz Dersch, Binghamton, and Newton Helm
bach, Johnson City, N. Y., assignors to General
Aniline & Film Corporation, New York, N. Y., a
corporation of Delaware
No Drawing. Application July 2, 1943,
. Serial No. 493.254
19 Claims.
(CI. 95-88)
1
2
This invention pertains to a process for in
a given degree of contrast or, if normal develop
ing time is employed, produces the effect of higher
speed and better contrast on the developed ?lm.
These results are accomplished by adding such‘
"compounds to the developing solution used for
creasing the speed of development of a silver hal
ideemulsion.
Photographic ?lms having silver halide emul
sions of sufficiently high speed and, when devel
oped with ordinary developers, yielding negatives
with silver grains that are not objectionably large
for ordinary photographic purposes, have been
development of the exposed gelatino silver halide
emulsion. Without in any way limiting our in
vention to any particular theory as to the mecha
developed and are now well known to the art.
nism of the action of said compounds in the de
It has been observed that some difficulty is often 10 veloping process it is suggested that they have a
encountered in obtaining proper gradation upon
softening or swelling action which‘ permits the
development of such ?lms especially during opti
developer to reach the silver halide grain in a
mum developing time. The principal develop
shorter time or permits the developer to pene
ment appears to be at the surface of the exposed
trate more deeply in a given length of time into
layer due probably to the resistance of the gela
the emulsion and thus produce greater contrast.
tin emulsion to penetration by the developer solu
Other materials, such as substantial amounts
tion. Increasing the developing time in order to
of sodium hydroxide and substantial amounts of
promote deeper penetration into the exposed layer
thiourea or thiocyanates are known to have a
increases the fog characteristic. Accordingly, it
marked softening effect on gelatin, ‘but their
is an object of this invention to provide a process
for increasing the speed of development or im
function in the presence of a gelatin medium is
proving the gradation or contrast of known ‘gela
tine silver halide ?lms. It is a further object to
provide a developer which will effect this result.
somewhat obscure due to the lack of sufficient
knowledge of the chemical structure of the gela
tin itself. It is believed, however, that at least
a temporary chemical alteration of the gelatin
It is well known that there is a loss of activity
structure occurs which is accompanied. by a
on the part of developing agents commonly used
in the development of photographic ?lms during
continued use of the developing solution. As the
activity of the developer decreases on approach
marked change in the physical properties such‘
as lowering of the melting point and setting point,
and such softening agents also have undesirable
speci?c effects on the photographic emulsion.
Sodium hydroxide, for instance, has a, tendency
to fog the emulsion. Thiourea or thiocyanates,
being silver halide solvents, also fog the photo
ing exhaustion, the time of development and
hence the fog characteristics become the greater.
Accordingly, it is still another object of this in
vention to provide a process for revivifying or
increasing the activity of a partially exhausted
developer.
It is often a disadvantage to carry out the de
graphic emulsion. Urea and the other com
pounds used in accordance with the present in-_
vention are free from these undesirable effects.
The swelling or softening eifect, which they exert
velopment with commonly used developers at
their required developing temperature of 65° F.
(18° C.). It is, therefore, a further object of this
occurs only during the time of contact of the de
veloping solution with the gelatin. There is no
permanent swelling effect and upon ‘removal of
invention to provide a process for development 40 the emulsion from the developing solution and
with all common developers at lower tempera
Washing, the original physical properties of the
tures.
gelatin are substantially restored.
It has now been found that the development of
For simplicity of expression the following gen
exposed gelatino silver halide emulsions in thc
eral description of the invention will be made in
presence of a compound of the general formula 45 connection with urea‘ as a speci?c embodiment,
and it is to be understood that any of the other
compounds falling within the above general for
mula may be employed in place thereof. When
the urea is added to the developer for the devel
opment of any ordinary gelatino silver halide
wherein Y'represents‘a member of the group con
emulsion, it is preferable to make the addition
sisting of oxygen and NH, X represents a mem
just prior to use of the developer. This is par
ber of a group consisting of hydrogen, methyl,
ticularly so when using those developers which
and allyl radicals and cyanogen, but cyanogen
are high‘ in alkalinity and low in sul?te since the
only when Y represents NH, considerably de 55 stability of such developers is impaired by long
creases the developing time required for reaching
contact with urea. Developers which contain
2,404,774
3
4
the least possible amount of alkali and the high
est possible amount of sul?te are rather stable
Example I
in ‘the presence of urea and hence are not so apt
to be subject to this decomposition.
The increase in speed of development and
greater contrast obtained by developing a, gela
tino silver halide emulsion in the presence of
urea are not dependent upon the use of any par
ticular type of developer.
The developers may
A developing solution was made up as follows:
Hot water (125° F. or 52° C.) _________ __cc__ ‘750
Metol (p-methylaminophenol)__;_______g__ 3.5
Sodium sul?te, anhydrous ____________ __g__
60
Hydroquinone _______________________ __g__
' 9
Sodium carbonate, monohydrated_______g__ 40
Potassium bromide_____________________g__ 2
liters"
1
be simple hydroquinone developers which contain 1O Water to make
hydroquinone, potassium metabisul?te and po
Two separate batches of this developer were
tassium bromide, or they may be the metol-hy
made up, one being used without further addi
droquinone type of developer‘ which contain
tions or dilution as a “blank.” To the other
p-methylaminoyahenol, sodium sul?te, sodium bi
there was added 300 g. of urea. Exposed X-ray
sul?te, hydroquinone, sodium carbonate, and po
?lms having the same degree of exposure were
tassium bromide or they may have a composition
of a so-called borax developer which contains
p-methylaminophenol, sodium sul?te, hydroqui
none, borax and potassium bromide. In short,
‘the effect is obtainable with practically all types
of’ developers used for developing the latent image
developed in each of the solutions.
In the case of
the “blank” solution, development was carried out
at 65° F. (18.34" 0.). In the case of the, solution
having the addition of 300 g. of urea, develop
ment was carried out at 45° F. (722° C.). The
time of development was the same in both cases.
of an exposed silver halide emulsion. The devel
It was observed that the ?lm developed at the
oping time of any such developer can be decreased
lower temperature in the developer containing
from 20 to 30% by the addition of'from 50 to 150
the urea was developed to the same contrast as
grams of the urea to 1 liter of the developing solu 25
the ?lm, which was developed at the normal tem
tion.
perature in the “blank” developer.
The retarded speed of development or decrease
of gradation obtainable in a given time for a par
tially exhausted developing solution can be in
creased by the addition of urea to such a devel
oper.
Replenishment or revivi?cation of a par
tially, exhausted developer where normal grada
tion and developing speed have gradually de
creased with the exhaustion is thereby effected.
For revivifying partially exhausted developer so
Example II
.
A developing solution was made up as follows:
Hot water (125° F. or 52° C.) ______ __,___cc__ 750
Metol (p-methylaminophenol) ________ __g__ 0.8
Sodium sul?te, anhydrous____________ _-g__
45
Hydroquinone _______________________ __g__
1.2
Sodium carbonate, monohydrated_______g__
8
lutions, from 50 to 150 grams of the urea’ per
Potassium metabisul?te ______________ __g__
4
liter of the exhausted developer solution may be
Potassium bromide ____________ __ _____ __g__
1.5
Water to make ___________________ __liters__
1
added, or as little as 40 grams dicyandiamide may
be added. A substantial prolonging of the nor
Two separate batches of this developer were
mal life of the developer is obtained and it is pos 40 made up; one of these was used without further
sible to develop almost as many photographic
additions or dilution to develop an exposed silver
?lms in such a revived developer as were devel
halide high-speed ?lm having a high orthochro
oped in the original solution before it became
exhausted. In the case of such exhausted de_
velopers, the decrease in developer activity is be
matic sensitization (the “blank” solution). To
lieved to. be at least partially due to the tanning
ther dilution to develop an exposed silver halide
?lm of the same type.
The development in both cases was at 68° F.
(20° C.) and under usual conditions of agitation.
The time of development in the case of the
“blank” developer was seven minutes and in the
case of the developer containing the urea, six
minutes. The two ?lms were washed, ?xed and
dried in the usual manner and under the same
conditions.
The ?lm developed in the developer solution
containing urea showed a better contrast than
that developed in the‘ solution which did not con
tain urea. A saving of from 15 to 20% in devel
effect of the oxidation products of the organic
compounds used in the developers. This tanning
elfect of said oxidation products is believed to be
counteracted by the presence of the urea and the
penetration of the developer chemicals into the
emulsion layer is facilitated.
It is the general practice to develop silver halide
emulsions at temperatures of not less than 65° F.
(18.34" C.) since development at lower temper
atures with commonly used developing agents
cannot be carried out successfully. However, it is
often necessary to carry out the development un
der adverse atmospheric conditions or other in
the other batch there were added 100 g. of urea
and the resulting developer was used Without fur
?uencing factors which make di?icult the mainte 60 oping time is therefore apparent as well as an
nance of the optimum developing temperature.
improved result when developing in the presence
When adding as much as 300 grams of urea to a
of urea.
liter of developing solution, developing temper
ature of as low as 45° F. (722° C.) can be used
without any impairment of the developed image.
Smaller amounts of ureacan be used, depending
upon the developing temperature desired. Thus
EaiampleIII
A developing solution was made up as follows:
Hot water (125° F. or 52° C.) _________ __cc__ 750
Metol
_
g
1.5
an addition of 150 grams of urea per liter of de
.Sodium sul?te, anhydrous__________‘____g__ 80
veloping solution gives the same development at
Hydroquinone _______________________ __g__
55° F. as is obtained without addition of urea at
65° F.
Borax ______________________________ __g__
3
Potassium bromide _____________ __' ____ __g__
0.5
The following examples may serve to illustrate
the invention which, however, is not limited
thereto. The parts are by weight unless other
wise ‘indicated.
'
'
-
3
Two separate batches of this developer were
made up, one being used as a “blank” as in the
case of Example I. _7 To the other there was added
150 g. of methyl urea. The same type of ex
aeogvve
5
‘ Exposed strips of . silver halide high-speed ?lm
posed ?lm and the‘ same procedure or develop
ment as recited in Example I were used.‘ ‘The
development time in the case of the “blank” of
this developing solution was seven minutes and
in the case of the developing solution containing
methyl urea, ?ve minutes. A better contrast‘was
again obtained when developing in the presence
of methyl urea. The saving in developing time
achieved was from 25 to 30%.
Example IV
having a high orthochromatic sensitization were
developed in this developer for seven minutes each
at 68° F. (20° C.). When the solution began to
lose strength and the desired degree of develop
ment was no longer obtained in the same devel
oping time 40 g. of dicyandiamide were added to
the solution. The resulting developing solution‘
was then reused-to develop the same number of‘
‘10. ?lms exposed under the same conditions as were
developed in the original developer. The same
developing time was used for the ?lms developed
after addition of the dicyandiamide and the same
' A developing solution‘of the following compo
sition was made up:
.
Hot water (125° F. or 52? C.) ________ _-cc__ ‘750
Metol ______________________________ __g__ 3.5
Sodium sul?te, anhydrous ____________ __g__
to exhaustion of the original developer.
Having now fully set forth and described an
60
Hydroquinone _______________________ __g__
9
Sodium carbonate, monohydrated _____ __g__
40
Potassium bromide r _________________ __g__
Water to make ___________________ __liters__ ~
degree of development was obtained as was ob
15 tained in the case of the ?lms developed prior‘
2
1
invention and having illustrated the best man
ner in which to perform it by speci?c examples,
20 what we claim as new and desire to have secured
by Letters Patent is:
Two separate batches of this developer were
made up, one being used without further addi
_
.
1. A process for the development of a gelatino
silver halide emulsion which comprises develop.
tions or dilution as a “blank.” ‘To the other there
was added 100 g. of urea. Exposed X-ray ?lms
having the same degree of exposure were devel
ing such an emulsion in a developer solution con‘
taining at least 50 grams urea per liter.
oped in each of the solutions; The development
silver halide emulsion which‘ comprises develop
in both cases was at 65° F. (18.340 C.).
ing such an emulsion in a developer containing a -
. 2. A process for the development of a gelatino
The time
of development in the case of the “blank” de
compound of the general formula
veloper was ?ve minutes and in the case of the _
NHX
developer containing urea, four minutes. This
represents a saving in developing time of from
20 to 25%. It was also observed that the ?lm
=Y
D‘IHz
developed in the developer solution containing
wherein Y represents a member of the group cone
sisting of oxygen and NH, X represents a mem-’
ber of a group consisting of hydrogen, methyl,‘
and allyl radicals and cyanogen, but cyanogen
urea showed a better contrast than that devel
oped in the “blank” solution.
‘
’
Example V
only when Y represents NH, in ‘a concentration
A developing solution having the following com
position was made up:
of from about 50 to 150 grams to 1 liter of develop
Hot water (125° F. or 52° C.)-‘ _______ _rcc__ 750
ing solution.
Metol ________________ _..‘_ __________ __‘_g__
1.5
Sodium sul?te, anhydrous ____________ __g__
45
Sodium bisul?te _________ __- __________ __g‘_'_
1
Hydroquinone _______________ __‘______ __g__
3
Sodium carbonate ___________________ __g__
6
Potassium bromide __________________ __g__ 0.8
Exposed strips of silver halide high-speed ?lm
3. A process for the development of a gelatino
silver halide emulsion which comprises develop
ing such an emulsion in a developer containing
urea in the proportion of from about 50 to 150
‘ grams to 1 liter of developing solution.
4. A process for the development of a gelatino‘
silver halide emulsion which comprises develop
having a high orthochromatic sensitization were
ing such an emulsion in a developer containing
150 grams of methyl urea to 1 liter of developing
developed in the above developing solution for
solution.
‘
seven minutes each at 68° F. (20° C.). When the
5. A process of revivifying a partially exhausted
solution began to lose strength and the desired
photographic developing solution which comprises
adding to the partially exhausted developing so
lution a compound of the general formula
degree of development was no longer obtained
in the said developing time, 100 g. of urea were
added to the solution. The resulting develop
ing solution was then reused to develop the same
number of ?lms exposed under the same condi
tions as were developed in the original developing
solution. The same developing time of seven min
utes was used on the ?lms developed after ad
dition of’ the urea and the same degree of de
velopment was obtained as was obtained in the
case of the ?lms developed prior to exhaustion
’
NHX
==Y
NH:
wherein Y represents a member of the group con
sisting of oxygen and NH, X represents amem
ber of a group consisting of hydrogen. methyl,‘
and allyl radicals and cyanogen, but cyanogen
only when Y represents NH in the proportion of
65 at least 40 grams per liter of developing solution
Example VI
when the compound is dicyandiamide and at least
A developing solution having the following com
50 grams per liter of developing solution when the
position was made up:
compound is any other member of the group.
6. A process of revivifying a partially exhausted
Hot water (125° F. or 52° C.) ________ __cci__ 750
Metol ______________________________ __g__ 3.5 70 photographic developing solution which comprises
adding urea to the partially exhausted develop
Sodium sul?te, anhydrous ____________ __g__ 60
ing solution in the proportion of from about 50
Hydroquinone _______________________ __g__
9
of the original solution.
Sodium carbonate, monohydrated_____ __g__
40
Potassium bromide __________________ __g__
Water to make ___________________ __liters__
2
1
to 150 grams of urea per liter of solution.
'
7. A process of revivifying a partially exhaust
75 ed photographic developing solution which com
2,404,774
.
7
V
,
t
prises adding dicyandiamide to the partially ex
hausted developing solution in the proportion of
,
8
V
,
15. A photographic developer comprising p
at least 40 grams of dicyandiamide per liter of
methylaminophenol, hydroquinone and urea in
the proportion of 300 grams of urea to 1 liter of
solution.
developing solution.
8. A process for the development of a gelatino
16. The process which comprises developing a
gelatino silver halide emulsion .in a solution con
taining a, developer, an alkali metal sul?te in a
silver halide emulsion Which comprises develop
ing such an emulsion at temperatures below 65°
F. in a developer containing 50 to 300 grams per
liter of a compound of the general formula
>
NHX
concentration greater than 45 grams per liter
and an alkali equivalent to not greater than 40
10 grams per liter sodium carbonate and at least 50
grams 'per liter of a compound of the general
=Y
formula
11TH:
_
;
V
wherein Y represents a member of the group
consisting of oxygen and NH, X represents a
member of a group consisting of hydrogen, meth
yl, and allyl radicals and cyanogen, but cyanogen
only when Y represents NH.
9. A process for the development of a gelatino
silver halide emulsion which comprises develop
NHX
NHz
wherein Y represents a member of the group con
sisting of oxygen and NH, X represents a mem
ber of the group consisting of hydrogen, the
methyl and allyl radicals and cyanogen, but
V cyanogen only when Y represents NH.
ing such an emulsion at a temperature of 45° F.
17. The process which comprises developing a
gelatino silver halide emulsion in a solution com
10. A photographic developer composition com-' prising a developer, at least 45 grams sodium
prising hydroquinone and 50 to 300 grams per liter 25 sul?te per liter, an alkali equivalent to notgreater
than 8 grams per liter sodium carbonate, and at
of a compound of the general formula
least 50 grams per liter of a compound of the
NHX
in a developer containing 300'grams per liter of
urea.
'
‘
general formula
>
-=Y
IlTHa
30
wherein Y represents a. member of the group
consisting of oxygen and NH, X represents a
member of a group consisting of hydrogen, meth
yl, and allyl radicals and cyanogen, but cyanogen
only when Y represents NH.
11. A photographic developer comprising p
wherein Y represents a member of the group con
sisting of oxygen and NH, X represents a mem
35 ber of the group consisting of hydrogen, the
methyl and allyl radicalsv and cyanogen, but
cyanogen only when Y, represents NH.
methylaminophenol, hydroquinone and a com
1
18. The process which comprises developing a
gelatino silver halide emulsion in a developer
40 solution containing a developer, an alkali metal
sul?te in a concentration greater than 45 grams
pound of the general formula
‘ per liter and an alkali equivalent to not greater
than 40 grams per liter sodium carbonate and at
wherein Y represents a member of the group con
least 50 grams per liter of urea.
sisting of oxygen and NH, X represents a mem 45
19. The process which comprises developing
ber of a group consisting of hydrogen, methyl,
an exposed photographic ?lm in a solution com
and ‘allyl radicals and cyanogen, but cyanogen
only when Y represents NH, in the proportion of
from 50’to-150‘ grams per liter of developing so
lution.
1
,
1'2. A photographic developer comprising p
methylaminophenol, hydroquinone and urea in
prising a developer, at least 45 grams sodium
sul?te per liter, an alkali equivalent to not greater
than 8 grams per liter sodium carbonate, and at
50 least 50 grams per liter of a compound of ‘the
theiproportion of from 50 to 150 grams urea to 1
liter of developing solution.
general formula
NHX
I
13. A photographic developer comprising p 55
methylaminophenol, hydroquinone, and methyl
urea in the proportion of from 50 to 150 grams
methyl urea to 1 liter of developing solution.
wherein Y represents a member of the group con
sisting of oxygen and NH, X represents a mem
ber of the group consisting of hydrogen, the meth
yl and allyl radicals and cyanogen, but cyanogen
methylaminophenol, hydroquinone and dieyandL 60 only when Y represents NH.
amide in the proportion of about 50 grams of di
‘
FRITZ DERSCH.
cyandiamide to 1 liter of developing solution.
NEWTON HEIMBACH.
14. A photographic developer comprising p
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