Note: Descriptions are shown in the official language in which they were submitted.
-
3~5
This invention relates to photogr~phic materials,
their preparation and use. In one aspect, this invention
relates to photographic elements containing a ruthenium
cationic complex having a predominance of ammine or amine
ligands. In another aspect, this invention relates to
photographic elements containing such complexes and further
containing an azaindene.
In one aspect, this invention is comprised of a
photographic element having coated thereon at least one
layer comprising a photographic silver halide emulsion. In
the emulsion layer, or in a second layer adjacent thereto,
i9 incorporated a development accelerating amount of a
ruthenium cationic complex having a predominance of
coordination bonds formed by ligands chosen from the class
con~isting of ammine and amine ligands. In one preferred
form of this invention, the cationic ruthenium complex is
present in a concentration of less than 100 mg per mole of
silver. In another aspect, the pre`sent invention comprises
the above-described photographic element further including
in or adjacent the emulsion layer at least one azaindene.
Cadmium salts have long been employed in the
photographic field for a variety of purposes. For example,
it is stated in Glafkides, "Photographic Chemistry",
Volume 1, 1958, page 151, that cadmium chloride can be
used to increase the contrast in the silver halide emulsion.
U.S. Patent 3,488,709 issued January 6, 1970, to Sidebotham
teaches that cadmium bromide stabilizes silver halide emul-
sions precipitated in the presence of rhodium salts in that
it reduces the loss of contrast and speed change upon
storage and also that cadmium bromide acts to increase the
contrast in a synergistic manner.
~ '
- 2 -
'-13~
Althou~h the concentrations of cadmium br~mide
taught by ~iaebotham are reIatively small, i~e., 2Q to
a~out 60 grams per mole of silver halide, the elimination
or reduction of such cadmium salts appears to be ecologically
advantageous since, during film processing, such cadmium
salts are eventually washed out and may find their way
into the environment.
~ n view of the now-recognized toxicity of cadmium
and other trace metals, concern for the public health and
the maintenance of a more normal ecological balance has led
to a search for new means of achieving good prope~ties in
photographic compositions by utilizing relatively non-toxic
materials or, where necessary, substantially reduced amounts
of toxic materials. One means of achieving this is des-
criaed in Product ~icehsing Index, Vol. 100, August, 1972,
publlcation 10014, wherein at least part of the cadmium salt
i8 replaced by a water-soluble manganou~ salt. Despite the
advantages of this development, however, a need still exists
for improved photographic compositions which do not contaln
cadmlum salts but which exhibit the increased photographic
speed and the development acceleration obtainable with
cadmium salts.
Smith and Trivel'li U.S. Patent 2,448,060 issued
August 31, 1948, teach the use as sensitizers for Photo-
graphlc emulslons of soluble compounds of the general formula:
R2MX6
wherein ~ represents a hydrogen atom, an alkali metal atom
or an ammonium radical; M represents a metal atom ~elected
from group VIII of the periodic arrangement of the elements
having an atomic weight greater than 100, i.e., ruthenium,
rhodium~ palladium, osmium, iridiu~. and platinum; and X ;
..
,; ,~ .
- 3 - ~; '''
.. -
, . . . . .. . ...... .. .... .. .. . . . .. . .
, ` . ... . . -. . , . : . . - . ~ . i . .. ~ ... . . .
~ ~ 3~ 1 ~
represents a halogen atom, e.g., a chlorine or bromine
atom. Smith and Trivelli recognize that these compounds
will fog photographic emulsions and, therefore, suggest
the use of concentrations below that which produces any
substantial fog. Quantities of from o.8 to somewhat less
than 39.4 mg of metal compound for each lO0 grams of silver
in the emulsion are suggested. It is to be noted that
ammonium radicals are Lewis acids, whereas ammonia and
amine compounds are Lewis bases. Further, in the above
Smith and Trivelli compounds, the metal atom is coordinated
in a complex having an overall negative charge.
In my U.S. Patent 3,891,442, issued June 24, 1975,
and having an effective filing date of December 4, 1972, I dis-
closed trivalent cationlc complexes of trivalent metals such as
Ru(III), Co(III) and Cr(III) with ammine or amine ligands
to be useful addenda for lithographic silver chloride emul-
clon~. These trlvalent cationic complexes when incorporated
in concentrations of from 0.2 to 5.0 grams per mole of
sllver are disclosed to promote increased photographic speed
and development acceleration in a manner similar to the
cadmlum salts previously employed for this purpose. However,
the contrast obtained with photographic elements utilizing
ruthenium(III) complexes was noted to be too low for use
in lithographic elements. This is because ruthenium(III)
complexes when employed in the concentration levels investi-
gated produce an elevated level of emulsion fogging.
Based upon further investigations, I have dls-
covered unique and surprising properties for ruthenium
complexes containing a predominance of ruthenium coordination
bonds formed by ammine or amine ligands. First, while
cobalt(III) and chromium(III) complexes in emulsion con-
centrations significantly below 200 mg per mole of silver
~1~
,: . ..... .
~ . ~ ... . . . : .. .
~04~ 5
are su~st-ntially ineffective as sensitizers or development
accelerators, I have found that much lower concentrations of
ruthenium complexes having a predominance of ammine or amine
ligand coordination bonds are surprisingly effective in pro-
viding sensitization and development acceleration. Hence, I
have discovered these ruthenium complexes to be effective in
a distinctly lower concen~ration range than that re~uried for
cobalt (III~ and chromium(III) complexes.
Second, although cobalt complexes are effective only
where the cobalt is in its trivalent oxidation state, it is
surprising that the effectiveness of ruthenium is not dependent
on its being in its trivalent oxidation state. Additionally,
whereas cobalt(III) and chromium(III) complexes are sensitizers
and development accelerators only for silver halide emulsions
in which the halide consists of at least 50 mole percent
chloride, the ruthenium complexes of m~ present invention are
effective in sen~itizing and development of silver halide
emulsions generally. Whereas cobalt~III) and chromium(III)
complexes were disclosed in my earlier filed patent application
only in high-contrast lith-type silver halide emulsions, I
have discovered that the ruthenium complexes as herein disclosed
are useful in proper concentration ranges in improving both
high and low contrast emulsions. Still further, the ruthenium
complexes are distinctly superior to cobalt(III) and chromium-
(III) complexes when employed in high contrast emulsions
lacking alkylene oxide development restrainers. Additionally,
the emulsions containing the ruthenium complexes of this
invention are useful with a wider ranqe of developers than
cobalt(III~ or chromiumCIII) complexes. It is, accordingly,
apparent that the ruthenium complexes are considerably more
versatile in providing sensitization and development ac-
celeration than cobalt(III) and chromium(III) complexes.
5- ~
. .:
:. , ~ : -. - .
104~
~ Ihe ruthenium complexes hereln disclosed also
exhi~itunique and surprising properties as regards the ligands
associated therewith. In working with cobalt(III) and chromium-
(III) complexes, I have observed that the inclusion of ligands
other than ammine or amine lig~nds, such as halogen, water,
etc., render these complexes ineffective as sensitizers and
development accelerators. While I have found ruthenium com-
plexes comtaining only ammine or amine ligands to be distinctly
superior, I have further observed that ruthenium complexes
containing one or two ruthenium coordination bonds formed by
ligands other than ammine or amine ligands afford substantial
sensitizatiOn and development acceleration improvement and are
superior to corresponding cobalt(III) and chromium(III) complexes,
even when differences in effective concentrations are ignored.
The ruthenium complexes herein employed not only act
as sensitizers and development accelerators, but they also
act to reduce the development time dependence of the charac-
teristic H and D curves of the photographic elements in which
they are incorporated. As is well appreciated by those skilled
in the art, H & D characteristic curves are translated along
the log E axis as a function of development time. Shorter
development times show the photographic elements to be of slower
speed while longer development periods show the same photo-
graphic elements to be faster. Since some variation in dev-
elopment times occurs as a practical matter in photographic
element processing, it is desirable to manufacture photographic
elements which can tolerate a substantial latitude in processing
times. If a pair of identical photographic elements lacking
the ruthenium complexes of this invention are processed at
3n differing development times, they will exhibit a substantial
difference in their log E values at a reference density. If
an additional pair of photographic elements, including the -
- . . . -
. .. .. . . , ~ - . ~...... . . .. ~ j
` 1(~4~6~LS
ruthenium comple~es empl~yed in the practice of this invention,
but otherwise i~entical, are processed similarly, I have dis-
covered that a dramatically lower difference in their log E
Values at the reference density will be observed. Thus, the
spacing between the H and D curves for the ruthenium complex
containing photographic elements is compressed. This performance
improvement for the photographic elements is typically referred
to in the art as H & D curve compression or simply curve
compre~sion.
The cationic ruthenium complexes employed in the
practice of this invention include a predominance of ammine or
amine ligand coordination bonds. The amine ligands include
primary, secondary and tertiary amine ligands as well as diamine
ligands. The amine ligands are preferably aliphatic amines and
are most preferably comprised of alkyl, alkylene and alkanol
aliphatic moieties. Each aliphatic moiety preferably includes
6 or fewer carbon atoms. Dialkanol amines have been found
particularly useful in forming bidentate ligands as have
alkylene diamines. Bidentate ligands which form with the
ruthenium atom 5 to 8 membered rings have been found to produce
particularly stable complexes. Exemplary preferred ammine and
amine ligand-forming compounds include ammonia, ethylene diamine,
trimethylene diamine, diethanol amine, dipropanol amine, di-
ethylene triamine, alkyltetramines, etc.
A minor proportion of the coordination bonds making
up the cationic ruthenium complex can be provided by ligand~
other than ammine or amine ligands. A ruthenium(II) and ~III)
complex can contain 1 or 2 mondentate ligands, such as water,
halogen, thiocyanate, etc., or a single bidentate ligand. I
These and other unique and advantageous features of 1--
my inVentiOn will ~ecome further apparent in the following --
description of certain preferred embodiments: ¦
,
_ 7 -
''. ',:
Th~ cat~on~c ruthenium complexes employed in the
practice of t~s-~nvention comprise a ruthenium ion surrounded
by ~ertain other molecules which are re~erred to as ligands.
The ruthenium ion is a Lewis acid; the ligands are Lewis bases.
Werner complexes are well-known examples of these complexes. As
is wellunderstood by those skilled in the art, ruthenium can
exhibit a variety of valences. Because of their availability,
ruthenium complexes incorporating ruthenium(II) and ruthenium-
(III) are preferred, although the effectiveness of the cationic
ruthenium complexes has not been observed to depend on the
oxidation state of the ruthenium. While it is possible to form
ruthenium complexes that are neutral (i.e., carry no net charge)
or are negatively charged, such as the ruthenium complexes
disclosed by Smith and Trivelli, only ruthenium complexes exhib-
iting a net positive charge, i.e., cationic complexes, are
employed in the practice of this invention.
Exemplary cationic ruthenium complexes useful in the
practice of my invention are set forth below:
TABLE I
E emplary Cationic Ruthenium Complexes
RU-l hexammine ruthenium(III)
RU-2 tris~ethylenediamine) ruthenium(III)
RU-3 bis~diethanolamine) ruthenium(lII)
RU-4 bis(dipropanolamine) ruthenium(III)
RU-S tris(trimethylenediamine) ruthenium(III)
RU-6 ethylenediaminebis(trimethylenediamine)
ruthenium (III)
RV-7 bis(ethylenediamine trimethylenediamine)
; ruthenium(III)
RU-8 monochlor~pentammine ~ruthenium(III)
RU~9 monoaquopentammine ruthenium(III)
RU-10 bromopentammine ruthenium(III)
RU-ll aquochlorotetrammine ruthenium(III)
RU-12 bis(ethylenediamine) ruthenium(II)
RU-13 bisCtrimethylenediamine) ruthenium(II)
- . ., , . - : , .
. . . , - - .:
r~,
There will, of course, be anions associated with the
foregoing complex cations. Any anion which does not exert un-
desirable effects upon the finished photographic element may be
employed. Among those anions which will be found useful may be
listed chloride, bromide, sulfite, sulfate, perchlorate, nitrite,
nitrate, zinc bromide, tetrafluoroborate, hexafluorophosphate,
thiocyanate, dithionate, methyl sulfonate, tolyl sulfonate, and
the like.
The ruthenium complexes e~p~Dyed in the practice of
this invention are incorporated within a sllver halide emulsion
or in a layer adjacent to a silver halide emulsion layer. The
silver halide emulsions can comprise, for example, silver
chloride, silver bromide, silver bromoiodide, silver chlorobromide,
silver chloroiodide, silver chlorobromoiodide crystals or mixtures
thereof. The emulsions can be coarse or fine grain emulsions and
can be prepared by a variety of techniques, e.g., single jet
emulsions such as those described in Trivelli and Smith, The
Photographic Journal, Vol. LXXIX, May, 1939 ~pages 330-338), double
~et emulsion8, sUch as Lippmann emulsions, ammoniacal emulsions,
¦ thiocyanate or thioether ripened emulsions, such as those des-
cribed in Nietz et al U.S. Patent 2,222,264 issued November 19,
1940; Illingsworth U.S. Patent 3,320,069 issued May 16, 1967 and
McBride U.S. Patent 3,271,157 issued September 6, 1966. Silver
halide emulsions can form latent images predominantly on the sur-
face of the silver halide grains, or predominant1y on the interior
of the silver halide grains, such as those described in Davey et
; al U.S. Patent 2,592,250 issued May 8, 1952; Porter et al U.S.
Patent 3,206,313 issued September 14, 1965; Berriman U.S. Patent
3,367,778 issued February 6, 1968 and Bacon et al U.S. Patent
3,447,927 issued June 3, 1969. If desired, mixture of such sur-
face and internal image-forming emulsions can be made, such being
described in Luckey et al U.S. Patent 2,996,382 issued August 15,
1961. Silver halide
_ 9 _
emulsions can be regular grain emulsions, such as the type des-
cribed in Klein and Moisar, J. Phot. Sci., Vol. 12, No. 5, Sept/
Oct, 1964, pages 242-251, and German Patent 2,107,118. Negative
type emulsions can be made, as well as direct positive emulsions
as described in Leermakers U.S. Patent 2,184,013 issued December
19, 1939; Kendall et al U.S. Patent 2,541,472 issued February
13, 1951; Schouwenaars British Patent 723,019 issued February
2, 1955; Illingsworth et al French Patent 1,520,821 issued March
4, 1968; Illingsworth U.S. Patent 3,501,307 issued March 17,
1970; Ives U.S.
-- 10 --
~ . ' '' - , ~ - .
- : .
Patent 2, 563,785 issued August 7, 1951; Knott et al U.S.
Patent 2,456,g53 issued December 21, 1948, and Land U.S.
Patent 2,861,885 issued November 25, 1958.
The ruthenium complexes employed in the practice
of this invention will produce sensitization and develop-
ment acceleration when incorporated in a photographic
element in one or more silver halide emulsion layers or
in a layer immediately ad~acent thereto in a concentration
of as much as 5.0 grams per mole of silver, as indicated
in my above-noted U.S. Patent 3,891,442.
However, since fogging increases dramatically at higher
concentration levels, concentrations of the ruthenium
complexes below 1.0 gram per mole silver are presently
contemplated.
I have made the surprising discovery that the
ruthenium complexes remain hlghly effective as sensitizers
and development accelerators in concentratlon ranges of
from 100 to 0.1 mg of ruthenium complex per mole of sllver
while their emulsion fogging characteristic ls dramatically
reduced. Accordingly, at concentrations below 100 mg per
mole of silver, the ruthenium complexes can be employed ~-
in silver halide emulsions generally, including particularly
those requiring hlgh contrast. For most applications, I
prefer to incorporate from 50 to 0.5 milligrams ruthenium
complex per mole of silver. Generally, concentrations of
from about 20 to 1 milligram per mole silver have been
observed to be optimum concentration ranges in photographic
elements.
In one preferred form, the photographic silver ;
halide emulsions employed in the practice of this invention
are lithographic silver halide emulsions in which the halide
--11-- . .
A~
-- ~0436~5
generally comprlses at least about 50 mole percent
chloride, up to about 10 mole percent iodide and any
re~aining halide being bromide. Fcr convenience, these
emulsions are referred to herein as lithographic silver
halide emulsions. These hi8h contrast emulsions preferably
contain at least 60 mole percent chloride, less than 40
mole percent bromide and less than 5 mole percent iodide.
If desired, the silver halides employed in the
practice of this invention can be precipitated in the
presence of a rhodium salt, as disclosed in Sidebotham
U.S. Patent 3,488,709, cited above and British Patent
775,197. Typical useful rhodium salts are, for example,
rhodium chloride, rhodium trichloride, rhodium ammonium
chloride, etc. The rhodlum salts can be employed in any
concentratlon whlch ls effectlve for the lntended purpose.
~speclally good results are obtalned when the concentration
ls from sbout 0.01 to about 0.35 milligram per mole of
silver hslide.
It is preferret that the photographic elements
of thl~ lnvention further comprise at lesst one szaindene,
locatet either in the photographic silver halide emulslon layer
or ln a layer lmmedlately ad~acent thereto. The azalndene
can be lncorporated for the purpose of reduclng fog
formstion ~lthln the photographic element attributable to
the presence of the catlonic ruthenium complex. The
azalndene also has a sensltlzlng effect. ' The azalndene
wlll generally be present ln a concentratlon of from about
0.2 to about 5.0 grams per mole of silver, preferably from
about 0.3 to about 3.0 grams per mole of silver and, most
preferably, from about 0.5 to about 1.0 gram per mole of
sllver. Among these azaindenes which may be employed in
the practlce of thls inventlon can be llsted, for example,
4-hydroxy,6~alkyl-1,3,3a,7-tetrazaindenes, such as,
-12_
3~
,, ,
4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene, 5-carboxy-4-
hydroxy-1,3,3a,7-tetrazaindene, 6-methyl-1,3,3a,7-tetraza-
indene-4-thiol, 5,7-dimethyl-4, 6-dioxo-4, 5,6,7-tetrahydro-
1,2,3,5,7-pentazaindene, 6-phenyl-1,3,3a,7-tetrazaindene-
4-thiol, 5-bromo-4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene-
4-thiol, 2,6-dimethyl-1,3,3a,7-tetrazaindene-4-thiol,
6-methyl-2-methylthio-1,3,3a,7-tetrazaindene-4-thiol,
5-ethyl 6-methyl-1,3,3a,7-tetrazaindene-4-thiol, 5-iso-
butyl-6-methyl-1,3,3a,7-tetrazaindene-4-thiol, S-phenyl-
1,2,3a, 4-tetrazaindene-7-thiol, 6-ethyl-5-methyl-1,2,3a,4-
tetrazaindene-7-thiol, 5-methyl-1,2,3a,4-tetrazaindene-7-
thiol, 1,2-bis(4-hydroxy-6-methyl-1,3,3a,7-tetrazainden-2-
yl)-1,2-dihydroxyethane, 1,6-bis(4-hydroxy-6-methyl-1,3,3a,7-
tetrazainden-2-yl)-2,5-dioxahexane, 1,2-bis(4-hydroxy-6-
methyl-1,3,3a,7-tetrazainden-2-yl)ethane, 1,4-bis(4-hydroxy-
6-methyl-1,3,3a,7-tetrazainden-2-yl)butane, 1,2,3,4-
tetraki~4-hydroxy-6-methyl-1,3,3a,7-tetrazainden-2-yl)-
butane, S-amino-7-hydroxy-2-phenyl-1,2,3,4,6-pentazaindene,
7-amino-5-mercapto-2-p-sulfophenyl-1,2,3,4,6-pentazaindene
5-~mino-2 p-carboxyphenyl-7-hydroxy-1,2,3,4,6-pentazaindene, ;
5, 7-diamino-2-phenyl-1,2,3,4,6-pentazaindene, 7-amino-5-
dimethylamino-2-phenyl-1,2,3,4,6-pentazaindene, 5-dimethyl-
amino-7-hydroxy-2-phenyl-1,2,3,4,6-pentazaindene, 2-p-
aminophenyl-5-amino-7-hydroxy-1,2,3,4,6-pentazaindene,
5-amino-7-hydroxy-2-p-methoxyphenyl-1,2,3,4,6-pentazaindene,
5-amino-2-p-chlorophenyl-7-hydroxy-1,2,3,4,6-pentazaindene, j
5-amino-2-hydro-7-hydroxy-1,2,3,4,6-pentazaindene, 5,7-
dihydroxy-1,2,3,4,6-pentazaindene, 7-hydroxy-5-methyl- .
1,2,3,4,6-Pentazaindene, 7-hydroxy-1,2,3,4,6-pentazaindene,
7-hydroxy-5-mercapto-1,2,3,4,6-pentazaindene, 7-amino-5-
carboxy-methylmercapto-1,2,3,4,6-pentazaindene, 7-mercapto
"~ .
- 13 -
,.,., ,- . . -
- ~043~
1,2,3,4,6-pentazaindene, 5,7-dimercapto-1,2,3,4,6-
pentazaindene, 5-ethylmercapto-7-hydroxy-1,2,3,4,6-
pentazaindene, 5-hydroxy-1,2,3,4,6-pentazaindene, 5-
hydroxy-7-mercapto-1,2,3,4,6-pentazaindene, 5-hydroxy-7-
methyl-1,2,3,4,6-pentazaindene, 2,4-dihydroxy-6-methyl-
1,3a,7-triazaindene, 4-hydroxy-5-chloro-1,3,3a,7-tetraza-
indene, 4-hydroxy-5-iodo-1,3,3a,7-tetrazaindene, 2-methyl-
4-hydroxy-6-methyl-3,3a,7_triazaindene and the like.
These azaindenes, as well as others which can be employed in
~he practice of this inventlon, are known in the art and
have been described, for example, in ~eimbach et al U.S.
Patent 2,444,605 issued July 6, 1948; Allen et al U.S.
Patent 2~713,541 issued July 19, 1955; Carroll et al U.S.
Patent 2,716,062 issued August 23, 1955; Allen et al U.S,
Patent 2,735,769 lssued February 21, 1956; Allen et al
U.S. Patent 2,743,181 issued April 24, 1956; Tinker et al
U.S. Patent 2,835~581 issued May 20, 1958~ Reynolds U.S.
Patent 2,756,147 issued July 24, 1956~ Tlnker U.S. Patent
2~852,375 lssued September 16, 1958; Carroll et al U.S.
Patent 2,743,180 issued April 24~ 1956~ Knott U.S. Patent
2,933~388 is~ued April 19, 1960; Carroll et al U.S. Patent
2,944,900 issued July 12, 1960; &leck et al U.S. Patent
3~432,304 issued March 11~ 1969; Ishikawa et al U.S. Patent
3~526~507 issued September 1, 1970; Baldock et al U.S.
Patent 3~573,056 lssued March 30, 1971; British Specifica-
tlon 1,270,734 to Konishlroku Photo Industry Company,
Llmltet, publlshet April.12, 1972 ant Zeitschrift Fur Wiss.
Phot. 47, 2-28 (1952) ant Piper U.S. Patent 2,886,437
issudd May 12, 1959.
The silver halide emulsion can contain a~y of
the hydrophllic water-permeable binding materials known
in the art to be suitable for this purpose. Suitable
-14-
. .
.. ,. : - . .:
43~5
.
materials include gelatin, colloidal albumin, polyvinyl com-
pounds, cellulose derivatives, acrylamide polymers, etc.
Mixtures of these binding agents can also be used. The
binding agents for the emulsion layer of the photographic
element can also contain dispersed polymerized vinyl compounds.
Typical synthetic polymers include those described in Nottorf --
U.S. Patent 3,142,568 issued July 28, 1964; White U.S. Patent
3,193,386 issued July 6, 1965; Houck et al U.S. Patent
3,062,674 issued November 6, 1962; Houck et al U.S. Paten~
3,220,844 issued November 30, 1965; Ream et al U.S. Patent
3,287,289 issued November 22, 1966; and Dykstra U.S. Patent
3,411,911 issued November 19, 1968. Other vehicle materials
include those water-insoluble polymers of alkyl acrylates and
methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates,;
those which have crosslinking sites which facilitate hardening
or curing as described in Smith U.S. Patent 3,488,708 issued
~anuary 6, 1970, and those having recurring sulfobetaine units
as described in Dykstra Canadian Patent 774,054. The vinyl
polymers are generally employed in concentrations in the range
of about 20 to about 80 percent, most often concentrations at
least 50 percent, by weight, based on the weight of the binding
agent. Silver halide emulsions wherein the binding agent -
contains dispersed polymerized vinyl compound provide part-
icularly good results in eliminating drag streaks and dot
distortions in lithographic materials.
The silver halide emulsions can be sensitized using
any of the well-known techniques in emulsion making, for
example, by digesting with naturally active gelatin or various
suI$ur, selenium, tellurium compounds and/or gold compounds.
; 30 The emulsions can be sensitized with salts of noble metals of
Group VIII o$ the Periodic Table which have an atomic weight
--
~ - 15 -
:. :.
r^
greater than 100. The emulsions can also contain addenda
which increase speed and/or contrast such as quaternary ammonium
salts, thioether sensitizers or combinations thereof.
The silver halide emulsions of this invention can
conveniently be ortho-sensitized or pan-sensitized with spectral
sensitizing dyes. Sensitizing dyes useful in sensiti~ing
these silver halide emulsions are described, for example, in
Brooker et al U.S. Patent 2,526,632 issued October 24, 1950;
Sprague U.S. Patent 2,503,776 issued April 11, 1950; Brooker
et al U.S. Patent 2,493,748 issued January 10, 1950; and
Taber et al U.S. Patent 3,384,486 issued May 21, 1968. Spectral
sensitizers which can be used include the cyanines, merocyanines,
complex (tri- or tetranuclear) cyanines, holopolar cyanines,
styryls, hemicyanines (e.g., enamine cyanines), oxonols and
hemioxonols.
In one preferred form, the silver halide emulsion
can contain de~elopment ~odifiers that function as restrainers
in silver halide emulsions requiring high contrast, such as
lithographic silver halide emulsions. It is preferred to
employ alkylene oxides in the emulsion for this purpose.
Typical useful alkylene oxides include polyethylene glycol,
polyethylene glycol oleyl ether, polyethylene glycol cetyl
ether, polyethylene oxide derivatives, block copolymers,
such as those comprising blocks of polyoxypropylene,
polyoxyethylene and the like, water-soluble organosilicone
polyalkylenoxide polymers and the like. The alkylene oxide
polymer can be used in any concentration effective for the
intended purpose. When the alkylene oxide polymer is
present in the photographic element, good results are
obtained when the concentration is less than about 2 grams
- 16 -
~ 36 ~ ~
per mole of silver in the silver halide emulsion. A
preferred concentration range for the polymer in this
embodiment is from about lO to about 800 mg per mole of s
silver in the silver halide emulsion.
Where it is desired to incorporate the cationic
ruthenium complex in a lithographic silver halide emulsion,
it is, of course, recognized that one or more cobalt(III)
or chromium(III) cationic complexes can additionally be
incorporated into the emulsion to supplement the action
10 of the cationic ruthenium complex in sensitizing or
accelerating development. These cobalt(III) and chromium-
(III) cationic complexes are fully described in my
U.S. Patent 3,891,442, noted above. The
cobalt(III) and chromium(III) complexes are octahedral
complexes formed by the metal atom acting as a Lewis acid
with other associaJced molecule~ or ligands acting aR Lewis
bases. These complexeR have coordination numbers of 6.
The cobalt(III) and chromium(III) cationic complexes useful
in the practice of this invention in combination with
cationic ruthenium complexes are formed entirely of ammine
or amlne ligands, which can be identical to those previously
described as useful in the ruthenium complexes. The
cobalt(III) and chromium(III) cationic complexes are
useful in concentration ranges of from 0.2 to 5 0 grams
per mole of silver, preferably from about 0.3 to about
3 0 grams per mole of silver, and most preferably from
about 0.5 to about l.0 gram per mole silver The cobalt(III)
and chromium(III) complexes can be located directly within
an emulsion layer or layers or in one or more layers
3 immediately ad~acent thereto, similarly as the ruthenium
complexes. ;
A~
,. .. ~ - .
1(~43~5
The silver halide emulsions of this invention can
also c~ntain conventional addenda such as gelatin plasticizers,
coating aids, antifoggants and hardeners as described in Product
Licensing Index, Vol. 92, December, 1971, publication 9232, pages
107-110.
As is well understood by those skilled in the art,
the photographic emulsions above described can be coated onto
a photographic support to form one or more silver halide emulsion
la~ers. One or more nonimaging layers can also be coated onto
the support along with the silver halide emulsion layer or
layers. The nonimaging layers can take the form of subbing layers
interlayers and/or overlayers of conventional character. Where
the.cationic ruthenium complex is to be incorporated in a non-
imaging layer adjacent to a silver halide emulsion layer, it
i~ pxeferred that the nonimaging layer be comprised of a
.hydrophilic, water-permeable binding material similar to those
aescribed in connection with the silver halide emulsions.
The layers coated onto the photographic supports can
be coated by various coating procedures including dip coating,
air knife coating, curtain coating, or extrusion coating using
hoppers of the type described in Beguin U.S. Patent 2,681,294
issued June 15, 1954. If desired, two or more layers can be
coated simultaneously by the procedures described in Russell
U.S. Patent 2,761,791 issued September 4, 1956; Hughes U.S.
Patent 3,508,947 i88ued April 28, 1970;. Wynn British Patent
837,095 published June 9, 1960; and Herzhof et al British Patent
1,208,809 published October 14, 1970. Also, silver halide layers
can be coated by vacuum evaporation as described in British
Patent 968,453 published September 2, 1964, and LuValle et al
U.S. Patent 3,219,451 issued November 23, 1965.
The photographic layers, including silver halide ~ -
emulsion layers and other layers of-.the Dhotographic element
- 18 -
-
1(~43~5
can be coated on a wide variety of supports. Typical supports
include cellulose nitrate film oe llulose acetate film, poly-
(vinyl acetal) film, polystyrene film, poly(ethylene terephthalate
film, polycarbonate film and related films or resinous materials,
as well as glass, paper, metal and the like. Typically, a flex-
ible support is empolyed, especially a paper support, which can
be partially acetylated or coated with baryta and/or an alpha-
olefin polymer, particularly a polymer of an-alpha-olefin con-
taining 2 to lO carbon atoms~ such as polyethylene, polypropylene,
stnylenebutene copolymers and the like.
The ruthenium complexes, azaindenes and other addenda
employed in the practice of this invention can be incorporated
into the compositions forming the layer prior to coating or can
be incorporated in a suitable solvent and added to the photo-
graphic element after coating. In most instances, water is the
preferred ~olvent. The addenda can be added using various pro-
cedure~, including those de~cribed in Collin~ et al V.S. Patent
2,912,343 is~ued November 10, 1959; McCros~en et al U.S. Patent
3,342,605 issued September 19, 1967; Audran U.S. Patent 2,996,287
issued Augu~t lS, 1961, and Johnson et al U.S. Patent 3,425,83S
issued February 4, 1969.
In addition to photograph~c imaging, including forming
images of high contrast of the type used for exposing lithographic
printing plates, the silver halide photographic elements of this
invention can be used for making lithographic printing plates such
a8 by the colloid transfer of undeveloped and unhardened area~ ;
of an exposed and developed emulsion to a suitable support as
described in Clark et al U.S. Patent 2,763,SS3 issued September
18, 1956; to provide a relief image as described in Woodward U.S.
Patent 3,402,045 issued September 17, 1968, or Spencer U.S. Patent
3,053,658 issued September 11, 1962; to prepare a relief printing
plate as described in Baxter et al U.S. Patent 3,271,150 issued
September 6, 1966; to prepare a silver salt diffusion transfer
plate as de~cribed in Hepher et al British Patent 934,691 issued
-- 19 --
43~
August 21, 1963, and AGfa British Patent 883,846 issued December
6, 1961; to provide an element which does not require washing or
etching as described in Yackel et al U.S. Patent 3,146,104,
reissue 25,885.
Although not critical to the present invention, it
will be very convenient, and thus preferred, if a continuous
method is employed for processing the exposed high contrast
photographic elements. In such a method, the element is processed
in one continuous motion by transporting it into and out of at
least one processing solution in the manner sho~n, for example,
by U.S. Patents 3,025,779 of Russell and Kunz issued March 20,
1962; 3,078,024 of Sardeson issued February 19, 1963; 3,122,086
of Fitch issued February 25, 1964; 3,149,551 of Cramer issued
February 22, 1964; 3,156,173 of Meyer issued November 10, 1964;
and 3,224,356 of Fleisher and Hixon issued February 21, 1965.
It is preferred, where the photographic elements are
intended to produce high contrast images upon expo~ure, that
they be developed ln developers containing one or more amines
and/or amine derivatives. A particularly desirable developer
composition is described in Masseth U.S. Patent 3,573,914 which
comprises a developing agent, a carbonyl bisulfite-amine con-
densation product, and at least about 0.075 mole of free amine
per liter of developer composition.
The developing agents which can be employed in these
developer compositions can be any of those suitable for the in-
tended purpose. Suitable silver halide developing agents, for
example, include the dihydroxybenzenes, such as hydroquinone,
chlorohydroquinone, bromohydroquinone, isopropylhydroquinone,
toluhydroquinone, methylhydroquinone, 2,3-dichlorohydroquinone,
2,5-dimethylhydroquinone, 2,3-dibromohydroquinone, 1,4-dihydroxy
-2-acetophenone-2,5-dimethylhydroguinone,2,5-diethylhydroquinone,
2,5-di-p-phenethylhydroquinone, 2,5-dibenzoylaminohydroquinone,
- 20 -
1(~43~
2,5-diacetaminohydroquinone, etc. Esters of such compounds,
e.g., formates and acetates, can also be employed. These dev-
eloping agents can be used alone or in any combination and can
be employed in any concentration which is effective for develop- -
ment. A suitable concentration for the developing agent is from -
about 0 05 to about 0.50 mole per liter of deveIoper composition
and is preferably from about 0.10 to about 0.30 mole per liter
of developer composition.
The carbonyl bisulfite-amine condensation products
lQ which can be used in this developer composition are preferably
formaldehyde bisulfite-amine condensation products, such as
sodium-2-hydroxyethylaminomethane sulfonate, sodium-2-hydroxy-
propylaminomethane sulfonate, sodium-l,l-dimethyl-2-hydroxyl-
aminomethane sulfonate, sodium-},l-bis (hydroxymethyl~ ethyl-
aminomethane sulfonate, sodium-tris (hydroxymethyl) methyl-
~mlnomethane sulfonate, sodium-3-hydroxypropylaminomethane 8ul-
fonate, ~odium bis (2-hydroxyethyl) aminomethane sulfonate, sodium-
N,N-bi~ (2-~1-hydroxylpropyl) amlnomethane sulfonate, sodium-N-
i~opropyl-N-(2-hydroxyethyl) aminomethane sulfonate, sodium-N-
ethyl-N-(2-hydroxyethyl) aminomethane sulfonate,~nd sodium-N-
methyl-N-(2hp~droxyethyl) aminomethane sulfonate. The carbonyl
bisulfite-amine condensation products can be used alone or in
any combinations and can be employed in any concentration which
is effective to provlde a low level of sulfite ion for the
developer composition. A ~uitable concentration for the carbonyl
bisu}U~ff~am~ine condensation product is from about 0.1 to about
1.0 mole per liter of liquid developer composition and is
,~ , .
preferably from about 0.25 to about 0.50 mole per liter of liquid
developer composition.
The~carbonyl bisulfite-amine condensation product can
be added to the developer composition as a separate compound or
formed in situ. Methods for preparing these compounds are dis-
10~ 5
closed, for example, in U.S. Patent 2,388,816 of Bean issued
November 13, 1945.
The free or uncombined amine compounds which can be
employed in these developer compositions include primary and
secondary amines such as 2-aminoethanol, 1-amino-2-propanol,
2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol,
2-amino-2(hydroxymethyl)-1, 3-propanediol, 3-amino-1-propanol,
2-2'-iminodiethanol, di-iso-propanolamine, 2-isopropylaminoethanol,
2-ethylaminoethanol, 2-methylaminoethanol, etc. These amines
can be used alone or in any combination and should be employed
in a concentration of at least about 0.075 mole per liter of
developer composition. A suitable range of concentrations for
the amine compound is from about 0.075 to about 3.0 moles per
liter of developer composi~ion and is preferably from about
0.20 to about 0.90 mole per
~o436~5
liter of developer composition. The free amine present
in the developer compo~ition can be the same amine used
:
to prepare the carbonyl bis~lfite-amine condensation
product or it can be a different amine.
In addition to employing developers of the type
disclosed in the above-citet Masseth patent, it is
recognized that the photographic elements of thls inven~
tion can be developed with conventional photographlc
developers exhibltlng a pH ln the range of from about
9 to 13. These developers are typically rentered basic
by inorganlc ~olute~, such as alkali metal hytroxides,
carbonates, pho~phates, slllcate~, etc. The developer
also preferably contains at least a 0.001 molar concentra-
tion of a stabillzer, such as an alkall metal or amlne
blsulflte. me develop~ng agent can talce the form of`
~corblc acld or a polyhydroxybenzene, such a~ pyrogallol
or any of the hydroqulnones noted above ln the Masseth
dovoloporz. De~eloplng agent concentrations of fro~
0.01 to 0.5 mole of developing agent per liter of
d-voloper r- typlcally preferred. Other conventlonal
developer addenda canj of course, also be incorporated, if
de~ired.
My lnventlon is further lllu~trated by the
following examples.
-23-
i . .. ,..... .. ; .. -. ., , . . ~ ... : " ............... .
1043615
Examples 1 through 6
A fine grain silver chlorobromoiodide gelatin
emulsion containing 90 mole percent chloride, 9 mols percent
bromide and 1 mole percent iodide is chemically sensitized
with sulfur and gold compounds. After the emulsion is heated
to obtain optimum sensitlvity, the e~ulsion ls divided into
equal portions~ and Ru(NH3)6C13 is added in various concen-
tration levels, herein expressed in grams of ruthenium
complex per mole of silver ln the photographic element.
The emulsion samples are then coated on a fllm support at
a coverage of 50.5 mg silver/dm2 and 50.5 mg of gelatlnldm2.
The coated samples are then ldentically exposed and processed
in a Kotak developer, D-85. Table II summarizes the observed
results.
Table II
Example CompountDevelopment ~resh Re 5U lts
Nô. (~/m)Time (Sec.) SPeet Fo~
Control none 60 32.5 .04
Control none 90 129 .04
Control none 120 289 .04
1 0.5 (A) 5 95 .09
2 0.5 ~A) 10 182 .14
3 0.5 (A) 20 234 .23
4 0.1 (A) 10 331 .13
~ 0.1 (A) 15 389 .13
6 0.1 (A) 30 603 .35
Compount A - Ru(NH3)6C13
-24-
~U~3~
From Table II it is apparent that the ruthenium
complex greatly increa~es the speed of the emulsion and
decreases the required time of development. It is
extremely surprising that the use of 100 mg per mole of
silver of ruthenium complex provides even higher speeds
than using 500 mg per mole of silver.
Examples 7 through 10
The procedure of Examples 1 through 6 was
repeated u~ing as an antifoggant an azaindene (Compound B).
The results are summarized in Table III.
Table III
Example CompoundDevelopment Fresh Results
_No. (g/m)Time (Sec.) Speed Fog
Control none 90 100 .05
7 0.05 ~A) 10 331 .04
1.00 ~B)
8 0.05 ~A) 20 891 ,13
1.00 ~B)
9 0.1 ~A) 10 513 .09
1.0 ~B)
0.1 (A) 20 661 .09
1.0 (B)
Compound B - 4-hydroxy-6-methyl-1,3,3a,7-tetra
zaindene
The combination of a ruthenium complex and an
azaindene is beneficial since an improvement is observed
in the fog-speed relationship when compared to coatings in
Table II containing only the ruthenium complex.
- 25 -
iO436~5
Examples 11 throu~h 13
Photographic elements were prepared by the same
general procedures described in Examples 1 through 6,
except that poly(ethylene oxide) as described in U.S.
Patent 2,944,900 was incorporated in the emulsion coatings
in a concentration of 0.25 gram per mole of silver. The
photographic elements were processed in a hydroquinone
developer. Development times of 90 seconds were employed
in each instance to determine speed and fog for~the
emuldons. To determlne the compres~ion of the character-
lstlcs curves additional development timés of 1.0 mlnute
and 2.75 mlnutes were employed and the development pro-
cedures employed were those descrlbed in Masseth U.S.
Patent 3,573,914, Example 1, using Developer A thereof.
The greater the curve compression, of course, the less the
tlfference ln the log E values at the faster and slower
tovolopment tlme8. The results are summsrlzed ln Table IV.
Tsble IV
Exanple Compound Pre~h Tests Corpresslon
No, (~R/mole) SPeed FoR 1~ lo~ E
Control none 57 .03 > 1.3 log e
11 10 (A) 447 .06 0.32 log E
12 10 (C) 112 .04 0.80 log E
13 lO (D) 65 .05 0.80 log E
Compound C - [Ru~NH3)40HC13 C1~2H20
D - ~Ru(NH3)5scn ~CH3S0~ 2
S
To provide a comparison of curve' compression
performance of cobalt(III~ and chromium(III) complexes, four
photographic elements were prepared as described in E~amples
1 through 6, one containing hexammine cobalt~III) chloride, one
containing hexammine chromium(III) perchlorate and two lacking
any cobalt, chromium or ruthenium addenda. These latter were
pr~pared for control purposes. The cobalt(III) and chromium(III)
complexes were both present in concentrations of lOO mg of complex
per mole of silver halide. Employing the development and curve
compression examination procedures described above, the
photographic element containing the cobalt(III) complex exhibited
a curve compression of 1.06 log E, which was identical to that
of the control photographic element processed with it. The
chromium(III) complex similarly processed exhibited a curve
compression of 1.36 log E as compared to a curve compression of ,.
1.26 log E for the control photogxaphic element processed along
wlth it. This illustrated that neither the cobalt(III) nor
chromium(III) complexes were capable of providing significant
curve compression a~ the concentration level of 100 mg per
mole of silver halide, whereas the ruthenium complexes surprisingly
exhibited very significant curve compression capabilities at
one tenth this concentration level.
Example 14
The procedure of Examples 11 through 13 was repeated,
but curve compression comparision was not undertaken. The
results are summarized below in Table V.
- 27 -
,. ,~, , . . . , , ~ . ,
, ............... . . .
10436~5
Table V
Example Compound Fresh Results
No. (m~Lmole) Speed Fo~
Control none 44 NR*
14 10 (E) 57 .Oô
Compound E _LRU(II) (NH2CH2CH2NH2)3~ ZnBr4
*NR - No value recorded
Examples 15 throu~h 18
Ruthenlum complexes were incorporated into a
llthographic silver chloride emulsion containing 200 mg
of oleic ether of polyethylene glycol (molecular weight
1540) per mole of silver halide, with and without
azaindene being present. The excellent speed and
acceleration obtained with these addenda are summarizet
below in Table Vl ln Developer A (containlng a diethanol-
a~ine ant bisulfite addltlon complex) and Developer B
(a typlcal llthographic developer) Kotak Developer D-85.
-28_
~043615
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-29_
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1~;~f~15
Examples 19 and 20
A silver chlorobromoiodide (90:9:1 mole ratio)
emulsion is prepared using the "double jet" technique. The
potassium chloride, potassium bromide and potassium iodide
solution contained 0.15 milligram of rhodium ammonium chloride
per mole of silver halide. The emulsion was sulfur and gold
sensitized and heat finished to optimum sensitivity. The
emulsion was then divided into equal portions and Ru(NH3)6C13
was added to the photographic element in various concentration
levels, herein expressed in milligrams of ruthenium complex
per mole of silver. The emulsion samples were then coated on
a film support at a coverage of 50.5mg of silver/dm2 and 50.5
mg of gelatin/dm2. The coated samples were then identically
exposed and processed for 2 3/4 minutes at room temperature
in Kodak Developer D-85. Table VII summarizes the observed
results:
Table VII
Example Compound Fresh Results
No.(mg/mole) Speed ~ Fog
Controlnone trace 2.8 .04
image
19(A) 2 57 10.1 .03
20(A) 5 100 8.8 .04
From Table VII it is apparent that the
ruthenium complex greatly increases speed and contrast in
rhodium containing silver halide emulsions. When an
azaindene (Compound F) is added to Example~ 19 and 20 a
further increase in speed is observed.
- 30 -
- . : . . . . , - - . .
. .. ........ .. - . . .. .. :.. ~ .. : .
10~361~
Examples 21 and 22
A silver chlorobromoiodide (90:9:1 mole ratio)
emulsion is sulfur and gold sensitized and heat finished to
optimum sensitivity. To the emulsion is added 0.5 gm of
5-bromo-4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene/mole
of silver halide. The emulsion is divided into e~ual portions
and the addenda described in Table VIII is added. The
emulsion samples are then coated on a film support, exposed
and processed as described in Examples 1 through 6. The
development time is 1 minute 45 seconds. Table VIII
summarizes the observed results.
Table VIII
Example Compound Compound Fresh Results
No. (G) gm/mole (A) mg/mole Speed ~ Fog
Control 1.0 -- 100 8.6 .02
-- 7.9 200 6.4 .05
21 0.6 3.2 214 7.5 .03
22 0.4 4.7 234 8.1 .04
Compound G - tris~ethylenediamine)cobalt~III)chloride
From Table VIII it can be seen that a combination
of a cobalt complex and a ruthenium complex provides higher
speed than either complex employed alone.
Example 23
Ammonium hexachloropalladite and potassium
tetrachloropalladite were tested in a similar manner as
deQcribed in Examples 1-6. It was found that they did not
increase speed or development acceleration.
The invention has been described in detail with par-
ticular reference to preferred embodiments thereof, but it will
be understood that variations and modifications can be effected
within the spirit and scope of the invention.
- 31 -
. . , ,: ~ . :... -. . , . . ~ .
