Europaisches Patentamt
19
European Patent Office
Office europeen des brevets
EUROPEAN
12
© Publication number: 0 5 9 3
619
B1
PATENT S P E C I F I C A T I O N
© int. ci.6: G03C 1/09, C07C 3 2 3 / 5 8 ,
C07D 295/135, C07D 2 7 7 / 0 4
@ Date of publication of patent specification
22.02.95 Bulletin 95/08
© Application number: 92915135.5
© Date of filing : 02.07.92
© International application number :
PCT/US92/05444
@ International publication number :
WO 93/01520 21.01.93 Gazette 93/03
@ SILVER HALIDE ELEMENTS WITH IMPROVED SPEED AND LOW FOG.
© Priority : 05.07.91 US 726331
@ Proprietor : E.I. DU PONT DE NEMOURS AND
COMPANY
1007 Market Street
Wilmington Delaware 19898 (US)
@ Date of publication of application :
27.04.94 Bulletin 94/17
© Inventor : CHAN, Dominic, Ming-Tak
1506 Delwood Road
Wilmington, DE 19803 (US)
Inventor : LESTRANGE, Raymond, Joseph
1720 Hummingbird Lane
Hendersonville, NC 28792 (US)
(45) Publication of the grant of the patent :
22.02.95 Bulletin 95/08
@) Designated Contracting States :
DE FR IT
(74) Representative : von Kreisler, Alek,
Dipl.-Chem. et al
Patentanwalte
von Kreisler-Selting-Werner
Bahnhofsvorplatz 1 (Deichmannhaus)
D-50667 Koln (DE)
© References cited :
EP-A- 0 279 417
US-A- 2 449 153
US-A- 4 267 254
S
CO
O)
If)
Q_
LLI
1
Note : Within nine months from the publication of the mention of the grant of the European patent, any
person may give notice to the European Patent Office of opposition to the European patent granted.
Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been
filed until the opposition fee has been paid (Art. 99(1) European patent convention).
Jouve, 18, rue Saint-Denis, 75001 PARIS
EP 0 593 619 B1
Description
BACKGROUND OF THE INVENTION
5
10
15
20
25
30
1. Field of the Invention:
This invention relates to the field of silver halide elements and more particularly to silver halide elements
with improved speed and low fog. Still more particularly, this invention relates to a novel group of silver halide
sensitizers useful in said elements.
2. Discussion of the Prior Art:
Silver halide elements useful in recording photographic images are well-known in the prior art and this
entire art field has been well-described. In an effort to increase the usefulness of these elements, there have
been numerous attempts to increase the speed of the film elements made from these silver halide elements.
Many of these attempts have been made by adding various adjuvants to the silver halide during the emulsion
making step. These additives are usually sulfur compounds as it is well-known that the addition of compounds
that contain labile sulfur will indeed act as a speed increasing adjuvant. However, most of these adjuvants also
cause an undesirable increase in emulsion fog. So, the user must take care that not too much of the speed
increasing compound is added.
Various cysteine compounds have been tried in silver halide emulsions to get the increased speed effect.
Although some of these have been successful, fog is also a problem with these compounds. From US-A- 2
449 153 photographic silver bromide emulsions are known which contain cysteine or cysteine hydrochloride.
SUMMARY OF THE INVENTION
It is an object of these invention to provide a novel composition for increasing speed within a gelatino, silver
halide emulsion system without a subsequent, deleterious increase in fog. These and yet other objects can be
achieved in a photosensitive element having at least one gelatino silver halide emulsion coated thereon wherein
the improvement comprises said emulsion containing a sensitizing amount of a substituted diaminedithio-containing compound of the formula selected from the group consisting of:
(a)
35
40
45
50
55
or a photographically suitable salt thereof wherein:
each of RrRi2 individually is selected from the group consisting of H, alkyl of 1-10 carbon atoms, -COOR
and -A-COOR wherein A is a straight or branched chain alkylene of 1-5 carbon atoms, and R is (a) H, (b)
alkyl of 1-10 carbon atoms, (c) phenyl or benzyl optionally substituted with up to 5 ring substituents each
selected from alkyl of 1-4 carbon atoms; each of R13 and R14 individually is selected from the group consisting of H and alkyl of 1-10 carbon atoms containing zero or 1 heteroatoms selected from N, O or S and
(b)
2
EP 0 593 619 B1
or a photographically suitable salt thereof wherein:
each of RrRi2 individually is selected from the group consisting of H, alkyl of 1-10 carbon atoms, -COOR
and -A-COOR wherein A is a straight or branched chain alkylene of 1-5 carbon atoms, and R is (a) H, (b)
alkyl of 1-10 carbon atoms, (c) phenyl or benzyl optionally substituted with up to 5 ring substituents each
selected from alkyl of 1-4 carbon atoms.
DETAILS OF THE INVENTION
Typical substituted diaminodithio containing compounds suitable herein useful within the ambit of this invention include those described by Blondeau et al., Can. J. Chem., 45, 49 (1967). Also procedures disclosed
by Burns etal. European Patent Application 163,119 and Kung European Patent Application 200,211 can be
employed. Compounds especially useful include:
(also referred to herein as Compound A)
(also referred to herein as Compound B)
EP 0 593 619 B1
5
10
15
(also referred to herein as Compound C)
20
25
30
35
40
45
so
55
(also referred to herein as Compound D).
These sensitizers may be added to a gelatino, silver halide emulsion during the sensitization step or they
may be added just prior to coating. They may be added in amounts easily determined by one of normal skill
in the art. Preferably, they are added in amounts of 0.1 to 40 mg/1.5 mole of silver halide and most preferably
in amounts of 1 to 10 mg/1 .5 mole of silver halide. They may be added as a dilute solution made up in water,
preferably made slightly acid, or other emulsion compatible solvents.
Gelatino, silver halide elements useful within the ambit of this invention are legion in number and include
silver bromide, silver iodide, silver chloride or mixtures of two or more of these halides. These silver halides
may be made by any of the conventional processes to yield any of the conventional crystal shapes such as
cubic, rhombic, tabular, etc. These elements are useful as negative or positive-working systems for the recording of images thereon. Particularly useful systems are those used to record medical X-ray information,
for example.
These silver halide emulsions may contain other sensitizers including those described in this invention.
These sensitizers include labile sulfur compounds such as sodium thiosulfate and thionex, for example, as well
as metal salts such as gold thiocyanate. Other adjuvants such as antifoggants, stabilizers, dyes, wetting and
coating agents, antistatic agents, hardeners, etc. may also be present within these systems.
The emulsions prepared according to the teachings of this invention may be coated by any of the standard,
well-known coating procedures (e.g. skim, bar, slide, etc.) on any of the conventional supports (e.g. paper,
films, etc.). Particularly preferred supports include dimensionally stable polyethylene terephthalate on which
thin, substratums of resins and gel layers have been previously coated in order to enhance the coating of the
aqueous emulsions. After the emulsion layer or layers have been applied, thin, hardened gelatin protective
layers may be applied supra thereto.
A particularly preferred system would be a high speed, gelatino silver iodobromide system especially useful for recording medical X-ray images and double-side coated on a polyethylene terephthalate film support,
said support containing sufficient dye to impart a blue color to the support, and having hardened, gelatin layers
overcoated on the emulsion layer. The sensitizers of this invention are then added to the emulsion after said
emulsion has been fully digested with gold and sulfur to achieve an optimum sensitivity.
This invention will now be illustrated by the following specific examples of which Example 2 is considered
to be the best mode. All parts and percentages are by weight unless otherwise indicated.
Preparation of Compounds A, B, C and D
Compound A and B were prepared according to published procedures by Blondeau et al., Can. J. Chem.,
49
45,
(1967).
4
EP 0 593 619 B1
5
Compound Cwas prepared by a procedure similarto the one that was disclosed by Burns etal. in European
Patent Application 163,119 or Kung et al. in European Patent Application 200,211.
Compound D was prepared by the following procedure. To a suspension of 3.0 g of Compound B in 60 ml
of water was added 2.5 ml of a 37% aqueous formaldehyde solution. After stirring for a total of 84 hr., the white
solid was collected by filtration and washed with acetone and dried to 2.8 g of Compound D (m.p. 195-196 C).
EXAMPLE 1
10
15
A standard, large grain, gelatino, silver halide emulsion containing ca. 98 mol percent bromide and ca. 2
mol percent iodide was prepared and sensitized fully with gold and sulfur as well-known to those skilled in the
art. This emulsion was eminently suitable for the preparation of high speed medical X-ray films. The emulsion
was then split into several portions and further sensitized with the compounds of this invention as shown. Each
portion was further treated with conventional antifoggants, stabilizers, wetting and coating aids and coated
on 7 mil blue tinted polyethylene terephthalate film base which had previously been coated with a resin sublayer
followed by a thin gelatin layer. Samples from each coating were then exposed through a V2 step wedge and
developed, fixed, washed and dried as is well-known. Sensitometric results follow:
Added
Amount
Sample
20
Speed
mol
(mg/1.5
Control
(avg.
No A d d ' l .
of
+ Fog
AgX)
0.17
Sens
247
3)
Cysteine
Base
20
303
0.18
Compound
A
20
292
0.18
Compound
B
20
312
0.19
Compound
C
20
296
0.18
This example shows that the addition of the diaminodithio-containing compounds of this invention will produce
excellent speed over controls with no additional sensitizer and equivalent speeds to that of cysteine alone. Little
or no increase in fog was noted over the control.
35
40
EXAMPLE 2
An emulsion similar to that described in Example 1 was prepared and split into four (4) portions. One (1)
sample was kept as a Control. To the other three (3) portions sensitizing compounds representing this invention
were added at 5 mg/1 .5 moles of silver halide just prior to coating. Each portion was coated, overcoated and
dried and samples exposed, developed, fixed, washed and dried as described in Example 1. The following results were obtained:
45
Base
+ Fog
Sample
Speed
Control
242
0.17
Compound
A
261
0.15
Compound
B
355
0.18
Compound
C
263
0.16
EXAMPLE 3
55
An emulsion similar to that described in Example 1 was prepared. This emulsion was split into eight (8)
portions. One (1) portion was kept as a Control (no further additions). To the remainder, cysteine or N,N'-dicysteinyl ethane (Compound B) or combinations of these two compounds were added as shown below. Each
portion was then coated, overcoated, dried, sampled, exposed, developed, fixed, washed and dried as detailed
in Example 1 with the following sensitometric results:
5
EP 0 593 619 B1
Compound
Cysteine
moles
(mg/1.5
5
of
10
15
20
moles
(mg/1.5
of
AgX)
B
Speed
AgX)
+ Fog
Base
None
None
245
0.16
None
10
332
0.22
10
None
284
0.16
10
10
343
0.18
20
None
319
0.17
20
10
362
0.21
40
None
301
0.20
40
10
347
0.24
This table shows that the speed effect of Compound B is additive to cysteine and combinations of the two may
be used for optimum speed.
EXAMPLE 4
25
In this example, a silver halide emulsion similar to that described in Example 1 was prepared and split into
five (5) portions. One (1) portion was kept as control. In the remaining four (4) portions, 10 mg/1.5 moles of
silver halide of the sensitizers described below were added to each sample prior to coating. The overcoat, drying, exposing, fixing, washing and drying steps were the same as described in Example 1 with the following
results:
Compound
None
-
Added
Speed
Control
Compound
B
Thiazolidine
Compound
Acid
Carboxylic
D
Cysteine
40
45
Base
+ Fog
184
0.17
273
0.22
232
0.19
280
0.23
196
0.20
From this example, it can be seen that only the diaminodithiol-containing compounds of this invention serve
to increase the speed over the control and even over prior art sensitizing compounds.
Claims
1.
In a photosensitive element having at least one gelatino silver halide emulsion coated on a support wherein
the improvement comprises said emulsion containing a sensitizing amount of a cysteine derivative selected from the group consisting of:
55
6
EP 0 593 619 B1
(a)
or a photographically suitable salt thereof wherein:
each of R1-R12 individually is selected from the group consisting of H, alkyl of 1-10 carbon atoms,
-COOR and -A-COOR wherein A is a straight or branched chain alkylene of 1-5 carbon atoms, and R
is (a) H, (b) alkyl of 1-10 carbon atoms, (c) phenyl or benzyl optionally substituted with up to 5 ring substituents each selected from alkyl of 1-4 carbon atoms; each of R13 and R14 individually is selected from
the group consisting of H and alkyl of 1-10 carbon atoms containing zero or 1 heteroatoms selected
from N, O or S and
(b)
or a photographically suitable salt thereof wherein:
each of RrRi2 individually is selected from the group consisting of H, alkyl of 1-10 carbon atoms,
-COOR and -A-COOR wherein A is a straight or branched chain alkylene of 1-5 carbon atoms, and R
is (a) H, (b) alkyl of 1-10 carbon atoms, (c) phenyl or benzyl optionally substituted with up to 5 ring substituents each selected from alkyl of 1-4 carbon atoms.
The photosensitive element of Claim 1 wherein said cysteine derivative is present in said emulsion in the
range of 0.1 to 40 mg/1.5 moles of silver halide present.
The photosensitive element of Claim 1 wherein said derivative is
EP 0 593 619 B1
2HCI
'SH
4.
The photosensitive element of Claim 1 wherein said derivative is
H02C,
5.
HS-
r^H
h\j
SH
HS
,C02H
The photosensitive element of Claim 1 wherein said derivative is
2 Oxalic a c i d
6.
The photosensitive element of Claim 1 wherein said derivative is
H02C
r ~ \
,C02H
Patentanspruche
1.
Lichtempfindliches Element mit wenigstens einerauf einen Trageraufgetragenen Gelatine-Silberhalogenidemulsion, wobei die Emulsion eine sensibilisierende Menge eines Cysteinderivats enthalt, das aus der
Gruppe ausgewahlt ist, bestehend aus:
8
EP 0 593 619 B1
(a)
odereinem photographisch geeigneten Salz davon, worin:
R1-R12 jeweils einzeln aus der Gruppe ausgewahlt sind, die aus H, Alkyl mit 1-10 Kohlenstoffatomen, -COOR und -A-COOR besteht, worin Aein geradkettiges oder verzweigtes Alkylen mit 1-5
Kohlenstoffatomen ist und R (a) H, (b) Alkyl mit 1-10 Kohlenstoffatomen, (c) Phenyl oder Benzyl, das
gegebenenfalls mit bis zu 5 Ringsubstituenten substituiert ist, die jeweils aus Alkyl mit 1-4 Kohlenstoffatomen ausgewahlt sind, ist; R13 und R14 jeweils einzeln aus der Gruppe ausgewahlt sind, die aus H
und Alkyl mit 1-10 Kohlenstoffatomen, das 0 oder 1 Heteroatom, das aus N, O oder S ausgewahlt ist,
enthalt, besteht, und
(b)
odereinem photographisch geeigneten Salz davon, worin:
R1-R12 jeweils einzeln aus der Gruppe ausgewahlt sind, die aus H, Alkyl mit 1-10 Kohlenstoffatomen, -COOR und -A-COOR besteht, worin Aein geradkettiges oder verzweigtes Alkylen mit 1-5
Kohlenstoffatomen ist und R (a) H, (b) Alkyl mit 1-10 Kohlenstoffatomen, (c) Phenyl oder Benzyl, das
gegebenenfalls mit bis zu 5 Ringsubstituenten substituiert ist, die jeweils aus Alkyl mit 1-4 Kohlenstoffatomen ausgewahlt sind, ist.
Lichtempfindliches Element gemali Anspruch 1, wobeidas Cysteinderivat in der Emulsion im Bereich von
0,1 bis 40 mg/1,5 mol vorhandenes Silberhalogenid vorhanden ist.
Lichtempfindliches Element gemali Anspruch 1, wobei das Derivat
EP 0 593 619 B1
I
.2HCI
ist.
4.
Lichtempfindliches Element gemali Anspruch 1, wobei das Derivat
ist.
5.
Lichtempfindliches Element gemali Anspruch 1, wobei das Derivat
ist.
6.
Lichtempfindliches Element gemali Anspruch 1, wobei das Derivat
ist.
Revendications
1.
Dans un element photosensible comprenant au moins une emulsion gelatineuse a base d'halogenure d'argent deposee sur un support, Amelioration residant en ce que cette emulsion contient une quantite sensibilisatrice d'un derive de cysteine choisi dans le groupe consistant en :
10
EP 0 593 619 B1
(a)
ou d'un sel de celui-ci acceptable du point de vue photographlque,
dans laquelle :
chacun des
a R12 est choisi individuellement dans le groupe consistant en atome d'hydrogene,
de
1
10
atomes de carbone, -COOR et -A-COOR, dans lequel A est un groupe alkylene
a
groupe alkyle
chaTne
droite
ramifiee
de 1 a 5 atomes de carbone, et R est (a) un atome d'hydrogene, (b) un
a
ou
de
1
10
atomes
de carbone, (c) un groupe phenyle ou benzyle dont le cycle porte evena
groupe alkyle
tuellement un maximum de 5 substituants, choisis chacun parmi des groupes alkyles de 1 a 4 atomes
de carbone;
chacun des R13 et R14 est choisi individuellement dans le groupe consistant en atome d'hydrogene, groupe alkyle de 1 a 10 atomes de carbone contenant 0 ou 1 heteroatome choisi parmi les atomes
d'azote, d'oxygene ou de soufre, et
(b)
ou d'un sel de celui-ci acceptable du point de vue photographique,
dans laquelle :
chacun des
a R12 est choisi individuellement dans le groupe consistant en atome d'hydrogene,
de
1
10
atomes de carbone, -COOR et -A-COOR, dans lequel A est un groupe alkylene
a
groupe alkyle
chaTne
droite
ramifiee
de 1 a 5 atomes de carbone, et R est (a) un atome d'hydrogene, (b) un
a
ou
de
1
10
atomes
de carbone, (c) un groupe phenyle ou benzyle dont le cycle porte evena
groupe alkyle
tuellement un maximum de 5 substituants, choisis chacun parmi des groupes alkyles de 1 a 4 atomes
de carbone.
Element photosensible suivant la revendication 1, dans lequel ce derive de cysteine est present dans cette
11
EP 0 593 619 B1
emulsion en une quantite comprise dans la gamme de 0,1 a 40 mg/1 ,5 mole d'halogenure d'argent present.
3.
Element photosensible suivant la revendication 1, dans lequel ce derive est
4.
Element photosensible suivant la revendication 1, dans lequel ce derive est
5.
Element photosensible suivant la revendication 1, dans lequel ce derive est
6.
Element photosensible suivant la revendication 1, dans lequel ce derive est
5
10
15
20
30
35
45
12