Note: Descriptions are shown in the official language in which they were submitted.
PHOT~GRAPHIC COUPLER DISPERSIONS
This invention relates to dispersions of
couplers useful in silver halide color photc~raphic
materials.
It is well known to incorporate dye-forming
couplers into photographic silver halide emulsion
layers, or adjacent hydrophilic colloid layers, so
that an imagewise distribution of oxidized color
developing agent obtained by developing silver halide
in the emulsion layer reacts with the coupler to form
a dye image. In a color photographic material having
red-, green- and blue-sensitive emulsion layers for
providing, respectively, cyan9 magenta and yellow dye
images, it is necessary, in order to prevent conta-
mination of each dye image with one or both of theother dyes, to ensure that the cyan, magenta and
yellow couplers cannot diffuse from their positions
in or near their respective emulsion layers. A
common me~hod of preventing coupler diffusion com-
prises providing the coupler with a water-insoluble
"ballast" group and, before mixing the coupler with
the relevant coating composition, dispersing the
coupler as a uniform mixture with a water-insoluble
high-boiling organic solvent, termed a coupler
solvent or an "oil-former", in an aqueous gelatin
solution. A surface-active agent is used to facili-
tate the dispersion process and to help stabilize the
dispersion obtained.
A great variety of surface active agents
have been made available and many types have been
suggested for use in photographic materials. How-
ever, relatively hydrophobic surface ative agents
have been suggested for this purpose much less
frequently than surfactants of other classes.
Instances concerning the preparation of dispersion~
of water-insoluble addenda, such as color couplers 9
``` ~.~6~
are to be found in U.S. Patents 3,676,141 and
3,912,517. Both of these patents propose use of an
anionic ~urfactant containing a sul~onate or sulphate
group and a hydrophobie radical o~ 8 to 30 carbon
atoms with a non-ionic surface active compound for
aiding disper~ion by a conventional high-speed mi~ing
process.
Many photographic coupler dispersions
contain compounds with phenolic or naphtholic groups
of which the acidity i~ enhanced by the presence of
electron-withdrawing substituents in the ortho and/or
para positions relative to the hydroxyl group.
Well-known compounds of this kind are certain
phenolic and naphtholic cyan dye-forming couplers,
but couplers ~or producing dyes of other colors are
known which contain such acidic groups. It has been
found that the dark stability of the dyes formed by
color development of photographic materials contain-
ing dispersions o~ phenolic or naphtholic compounds
with enhanced acidity i~ not as good as is desir-
able. The present invention is ba~ed upon the
discovery that the adverse e~fect on dye stability
o~ the phenolic or naphtholic compound can be
mitigated to a ùseful extent by the use of certain
lipophilic anionic surfactants in preparing the
relevant dispersions. Additional anionic ~urfactants
of more conventional type can be used to aid the
dispersion process but non-ionic surfactants have
been found to reduce the beneficial effect of the
lipophilic surfactant and so are excluded.
In accord with the present invention a
photographic element is provided comprising a support
bearing at least one hydrophilic layer, preferably at
least one hydrophilic photographic silver halide
emulsion layer and/or at least one hydrophilic layer
that is not photosensitive. The hydrophilic layer
~ 3
--3--
comprises at least one photographic coupler and an
oil-former in the pre6ence of an anionic surfactant.
In this photographic element according to the inven-
tion
A. at least one of the photographic coupler and
oil-former comprise a phenolic or naphtholic
moiety having a least one electron-
withdrawing group at a position ortho or
para to the phenolic hydroxyl group; and
B. the anionic surfactant iæ a lipGphilic
anionic surfactant that comprises a sulfatP
or sulfonate group as the sole hydrophilic
group and comprises either a single
aliphatic hydrocarbon group having at least
15 carbon atoms or at least two aliphatic
hydrocarbon groups tha~ together contain at
least 17 carbon atoms.
The photographic element of the invention contains no
non-ionic surfactant.
Another embodiment of the invention com
prises a method of making a photographic coupler
dispersion by dispersing a mixture containing the
coupler and an oil-former in an aqueous hydrophilic
colloid solution in the presence of an anionic
surfactant, the coupler and/or the oil-former com-
prising a phenolic or naphtholic moiety of which the
acidity is enhanced by the presence of at least one
electron-withdrawing group at a position ortho or
para to the phenolic hydroxyl group, wherein there is
added at any stage a lipophilic anionic surfactant
which comprises a sulphate or sulfonate group as the
sole hydrophilic group and either a single aliphatic
hydrocarbon group having at least 15 carbon atoms or
~wo or more aliphatic hydrocarbon groups which
together contain at least 17 carbon atoms, but where-
in no non-ionic 6urfactant is used.
--4--
The anionic surfactant defined above is
referred to herein as the lipophilic anionic surfact-
ant.
The coupler dispersions according to the
invention contain in the oily, dispersed~ phase, at
least one compound comprising a phenolic or naph-
~holic moiety, each such compound having at least one
electron-withdrawing substituent in a position ortho
or para to the phenolic hydroxyl group which enhances
the acidity of that group. As is well known, many
substituents have an electron-withdrawing effect and
the following are listed as examples:
cyano -COORl
nitro -CONRlR 2
halogen -SO2NRlR 2
(especially F, Cl or Br) -SO2R
-CCl3 or -C F2 +1l -SO3M
-COR -OSO3M
-OCOR -N=N-R 3
wherein R is an alkyl or aryl group, each of Rl and
R 2 iS hydrogen or an alkyl or aryl group, R 3 iS
- an aryl or heterocyclic group and M is a cation, any
group R, Rl, R2 and R3 possibly being itself
substituted with such substituents as alkyl, alkoxy,
aryl, aryloxy a halogen, nitro, and carboxylic acid,
ester and amide groups. A suitable substituent for
the phenolic or naphtholic moiety has a Hammett
p-Substituent Constant greater than zero: See, for
instance, the article by Exner in the book "Advances
in Linear Free Energy Relationships", edited by
Chapman and Shorter, Plenum Pre6s (London) 1972.
The compound comprislng ~he acidic phenolic,
or naphtholic, moiety can be the coupler itself, in
which case it can be a substituted member of one of
``` .~.~6
--5--
the various classes of cyan dye-~orming coupler.
Such coupler3 are described in, for example:
U.K. Patent 562,205 825,311
~86,211843,497
627,~141,077,873
649,6601,165,563
737,1041,377,233
797,1411,541,075
Alternatively the compound comprising the
acidic phenolic or naphtholic moiety can be a coupler
giving, on color development, a magenta or yellow
dye, coupling taking place preferentially at a
pyrazolone or active methylene coupling position
rather than at a position para to the hydroxyl group
of the phenolic or naphtholic moiety. Couplers of
this kind are described in, for instance, U.K. Patent
Specification 1,474,128.
Another alternative i8 for the compound
comprising the acidic phenolic or naphtholic ~oiety
to be a coupler solvent, in which case the coupler
itself need not contain such a moiety. Coupler
solvents having acidic phenolic or naphtholic
moieties are described in, for instance, U.S. Patent
4,207,393 and 4,228,235.
Any coupler æolvents known to be useful in
photographic materials are useful as the oil-~ormer
in a dispersion of the invention. Useful solvents
are inert high-boiling liquids or low-melting solids,
well-known examples being dibutyl phthalate and
tricresyl phosphate. Numerous other coupler solvents
are described in U.K. Patent Specification 541,589.
A coupler dispersion of the invention
contains an anionic surfactant which comprises, as
the sole hydrophilic group, a group of formula
--6--
-S03M or -OS03M (where M i9 any convenient
cation, ~uch as sodium or potassium cations) and
either a single aliphatic hydrocarbon group having at
least 15 carbon atoms os two or more aliphatic hydro-
carbon groups wh;ch together contain at least 17carbon atoms. The aliphatic hydrocarbon group or
groups can contain unsaturation and the surfactant
molecule can contain such non-hydrophilic features as
ether, amide or sulfonamide linkages and ester
groups. Classes of surfactant having at least some
members in accordance with these requirements include:
i) alkane sulfonates,
ii) alcohol sulphates,
iii) ether alcohol sulphates,
iv) sulphated polyol esters,
v) sulpha~ed alkanolamides,
vi) sulphated amides
vii) æulphated esters
viii) sulfonated esters,
2C ix) al~ylarylsulfonates,
x) olefin sulfonates,
~i) sulfopolycarbo~ylic esters,
xii) sulfonalkylesters of fatty acids,
xiii) sulfoalkylamides of fatty acids, and
xiv) petroleum sulfonates.
Pre$erred surfactants from these classes are
alkane sulfonates (class i) of formula: R'S03M and
alkylphenol sulfonates (class ix) of formula:
~-\ /SO3M
HO ~ -~--R
~0/
wherein R' is a straight chain alkyl or alkenyl
group of at least 15 carbon atoms, and dialkyl~ulfo-
succinates (class xi) of formula:
CH2COOCmH
MO3S-CHCOOCnH2n+~
wherein m + n is at least 17~ m and n being the same
or different. M in the above formula~ is a hydrogen
ion, an alkali metal ion or any other useful cation.
Optionally, a mixture of two or more com-
pounds can be used. Thus two or more couplers,
coupler solvents or lipophilic surfactants can be
employed, it being necessary for only one of these
compounds to comprise an acidic phenolic or naph-
tholic moiety.
The dispersing agent used in a method of the
invention can also include a second, and less llpo-
philic, anionic surfactant. This can be from the
classes (i~ to (xiii) listed above, the reduced
lipophilic character being achieved through the
presence of fewer carbon atoms in the allphatic
hydrocarbon group or groups present or through the
presence of more than one hydrophilic group, any
additional group belng~ for instance, an hydroxyl, or
a carboxylic acid or salt, group. Thus, a second
anionic surfactant can contain a single group -S03M
or -OS03M and either a single aliphatic hydrocarbon
group having fewer than 15 carbon atoms or two or
more aliphatic hydrocarbon group~ which together
contain fewer than 17 carbon atoms. Alternatively, a
second anionic surfactant can be of some other clasæ
such as a sulphated monoglyceride, a ~ulphated fat or
oil having a free carboxyl group, an ~-sulfocar-
boxylic acid, an alkyl glyceryl ether sulfonate or anN-acylated-amino acid.
The coupler-coupler solvent solution or
mixture is dispersed, with the aid of a surfactant or
surfactant mixture, in an aqueous hydrophilic colloid
solution. The colloid is preferably gelatin or a
simple derivative such as phthalated gelatin.
This dispersion step in a method of the
invention can be effected conventionally using any
high-speed mixing device. A water-miscible or
volatile water-immiscible "auxiliary solvent" can be
present, being removed by washing with water from the
set dispersion or when volatile, by evaporation under
reduced pressure. Auxiliary solvents and their use
are described in, for example, U.S. Patent 2,801,171.
In carrying out a method of the invention,
the compound comprising a phenolic or naphtholic
moiety of enhanced acidity, or mixture of such com-
pounds, preferably constitutes at least 5% by weight
of the oil phase (i.e. the coupler, water-immiscible
solvent and lipophilic anionic surfactant) and the
lipophilic anionic surfactant preferably cons~itutes
at least 1% by weight of the oil phaseO Relative to
the weight of the coupler, the weight of lipophilic
surfartant is usually present at a concentration of
from 1 to 100~/o by weight, the preferred range being 3
to 20%
A coupler dispersion made by a method of thP
invention is employed conventionally in the manu-
facture of incorporated-coupler silver halide color
photographic materials, bo~h negative and positive
materials. Numerous references to patent specifica-
~ions and other publications relating to silver
halide photographic materials, including color
ma~erials and their processing, are given in Research
Disclosure, December 1978, Item 17643 (see especially
.~Z~ ~ ~9
_9_
sections ~II, XI, XIV and XI~) published by Kenneth
Mason Publications, Ltd., The Old ~arbourmaster's,
B North Street, Emsworth, Hampshire PO10 7DD,
ENGLAND. Thus, the dispersion is mixed with the
appropriate coating composition, usually a gelatino-
silver halide photographic emul~ion, prior to coating.
The invention is illustrated by the ~ollow-
ing examples.
Example 1
Dispersions of coupler I having the
structure:
OH C2~5 lsHll t
I~ ~ N~COCHO \ ~D - C~El1-t
C ~ ~/
3 1
Cl
were prepared by di~solving the coupler, 0.60 g, in
di-n-butyl phthalate, 0.60g, and mechanically dis-
persing the resulting oily solution in 9.4 ml of
6.6% w/v gelatin aolution to which had been added
surfactant as in Table 1. The result wa~ an oil-in-
water dispersion having an average droplet diameter
of less than l ~m.
Photographic coating~ were prepared by
combining together, under sa~elight conditions, 1.5 g
of coupler dispersion, 1.5 g of 12 l/2 % w/v aqueous
gelatin ~olution, 0.20 ml of photographic paper type
silver chlorobromide emulsion (approximately 1.0 M in
silver halide) and 5.5 ml water. 5% w/v chromic
sulphate solution, 0.30 ml, was added immediately
prior to coating on photographic film base at a wet
thickness of approximately 0.1 mm.
~'
~Z6~
--10--
Portions of dried coating were exposed to
room light for 5 s and then developed for 210 B in a
-phenylene-diamine developer (KODAK-"Ektaprint 2ll,
trademark of Eastman Kodak Company, U.S.A.) at 31C,
bleach-fixed.for 120 ~ in a bleach-fix solution
(KODAK "Ektaprint", trademark of Ea~tman Kodak
Company, U.S.A.), washed for 30 minutes in running
water, and dried.
The resulting cyan dye density of each
sample was measured with a transmission densitometer
through a red filter. The ~amples were then incub-
ated in an oven at 60C and 70% relative humidity and
the dye density measured from time to time. The
initial optical density (Di) and the percentage
density loss at the various times are recorded in
Table 1.
TABLE 1
% density 10BS at
stated time/days
Surfactant added (sodium salt)Di 7 14 28 42
Control:
tri-isopropylnaphthalene
sulfonate
0.03 g ~.56 5.8 12 26 37
0.06 g 1.85 6.3 12 26 39
0.12 g 1.9~ 7.3 15 30 43
Invention:
bis (tridecyl) sulfosuccinate
0.04 g 1.37 1.5 5.1 11 18
0.08 g 1.57 0.6 4.0 10 ~8
pentadecylphenolsulfonate
0.06 g 1.26 2.~ 5.5 12 20
0.12 g 1.70 1.2 4.1 11 19
35 .
D~
It will be see~ that the image dyes from
dispersions made accordlng to the inven~ion faded at
less than half the rate of the dyes from the prior
art dispersions (sodium tri-isopropylnaphthalene
sulfonate peptized) in this accelerated dsrk keeping
test.
Example 2
This example illustrates the use of a com~
bination of hydrophilic and hydrophobic surfactants
according to the the invention.
A coupler dispersion was prepared by dis-
solving coupler I, S.0 g, in di-n-butyl phthalate,
2.8 g together with 2 - (2 - butoxyethoxy~ ethyl
acetate, 0.4 g, and mechanically dispersing the
resulting oily solution in 11.5% w/v gelatin 601u-
tion, 42 g, containing sodium triisopropylnaphthalene
sulfonate, 0.18 g. Portions of 10 g were withdrawn,
and 10% w/v solutions of sodium bis (tridecyl~ sulfo-
succinate in 1:~ methanol:water were added a~ in
Table 2 and mechanically dispersed into the disper-
sion.
Photographic coatings were prepared by
combining together, under safelight condltions, 1.~ g
of coupler dispersion, 1.5 g of 12 1/2~/o w/v aqueous
gelatin solution, 0.20 ml of photographic paper type
silver chlorobromide emulsion (approximately 1.0 M in
silver halide), and 6.0 ml water. 5~/O w/v chromic
sulphate solution, 0.30 ml, was added immediately
prior to coating on photographic film base at a wet
thickness of approximately 0.1 mm.
Portions of dried coating were exposed 3
processed and tested as in Example 1: the results
are given in Table 2. A low humidity accelerated
keeping ~est was also carried out by placing pro-
cessed strips in an oven at 77C with no addedhumidity, and measuring the dye density at intervals
as before. These results are given in Table 3.
-12-
TABLE 2
60C 7070 R~ H. ~esults
5 10% sodium bis (tridecyl) ~/O density loss
sulfosuccinate solution at stated time
added Di 7 14 2~ days
None 1.71 8.2 19 36
1~ 0.1 ml 1.80 6.1 12 26
0.2 1.52 4.6 10 23
0.4 1.08 1.9 6.5 18
0.8 1.95 *3.5 0 9.7
*increase
TABLE 3
77C low humidity results
10% sodium bis (tridecyl) % density 106s
sulfosuccina~e solution at stated time
added Di 3 7 1~ days
.
None 1.78 13 30 55
- 0.1 ml 1.79 9.5 23 4
0.~ 1.48 10 22 ~7
0.4 1.~2 6.6 17 43
0.8 1.91 4.7 14 39
Example 3
This example illustrates another combination
of hydrophilic and hydrophobic surfactants according
to the invention.
1 ~6~ l~V
-13-
Coupler dispersions were prepared by dis-
solving together 1.0 g of coupler I, 0.6 g of
tricresyl phosphate, and 0.10 g of sodium ~is
~tridecyl) sulfosuccinate, and mechanically dispers-
S ing the resulting oily solution into 5.0 g of a
12 1/2% w/v aqueous gelatin solution mixed with
3.0 ml wa~er and 10% w¦v aqueous sodium dioctyl
sulfosuccinate as stated in Table 4. The dispersion
prepared for Example 2 was used for this control.
Coatings were prepared as in Example 2,
except that 0.9 ml of dispersion and ~.1 ml of water
were added. Testing was as in Example 2, and results
are given in Tablas 4 and 5.
TABLE 4
60C 70% R. H. results
10% sodium dioctylsulfo- % density loss
20 succinate solution added a~ stated time
to coupler dispersion Di 6 14 days
(control)
None (dispersion as Example 2) 2.62 S.0 13
0.60 ml 1.49 2.0 5.4
0.75 ml 2.17 1.4 4.6
1.0 ml 2.63 1.2 1.9
~ Z~ 3
-14-
TABLE 5
77C low humidity results
5 10% sodium dioctylsulfo- % density loss
succinate solution added at stated time
to coupler dispersion Di 3 6 days
(control)
None 2.55 5.9 15
0.60 ml l.SO 2.0 6.
0.75 ml 2.18 2.7 7.~
1.0 ml 2.61 1.1 4.6
Example 4
A dispersion of coupler II having the
formula:
OH CsHll~t
~ . ! .
~ ONH(CH 2) 40~ C sH 1 l-t
was prepared by dissolving 3.5 g of coupler into a
2s mixture of 2.0 g of di-n-butyl phthalate and 8.0 g of
2-(2-butoxyethoxy) ethyl acPtate, and mechanically
dispersing the resulting oily solution into 40 g of
9~0V/o w/v gelatin solution to which had been added
0.5 g of sodîum tri iso-propylnaphthalene sulfonate.
The dispersion was then cooled, and when set was cut
into small cubes of approximately 0.5 cm edge. The
chopped dispersion was washed for S hours in chilled
(5C) demineralized water which was maintained at
approximately pH 5.5 by addition of a small quantity
of propionic acid. The washed dispersion was melted
at 40C and to a 5.0 g portion was added 0.2 g of a
-15-
70% w/w solution of sodium bis (tridecyl) sulfosucc-
inate ("Aerosol TR 70" - trademark - supplied by
Cyanamid of Great Britain Limited). I'his solution
was mechanically dispersed into the dispersion sample.
Coatings were prepared as in Example ~,
except that 1.3 g of dispersion and 4.9 ml of water
were used for each coating. Testing was carried out
as in Example 2, and the results are shown in Table 6.
TABLE 6
Condition A: 60C, 70% R. H.
Condi~ion B: 77C, low humidity
Fading 70% sodium bis (tridecyl) % density loss
15 Condition sulfosuccinate added Diafter
7 14 days
A - 1~901.6 4.2
A 0.1 g 20100 1.9
B _ 1~882.1 6.4
B 0.1 g 2.150.5 2.3
Example 5
This is a comparative example in which no
acidic phenol or naphthol was present.
Dispersions of coupler were prepared by
dissolving coupler, 1.5 g, in di-n-butyl phthalate,
0.9 g, and ethyl acetate, 0.9 g, and mechanically
dispersing the resultant solution in 15 g of 9.~a/0 w/w
gela~in to which had been added 10% sodium tri-
isopropyl naphthalene sulfonate, 0.6 ml.
1.0 g portions of dispersion were taken and
0.3 ml of water or of a solution of hydrophobic
surfactant added (see Table 7) and the mixture held
for 20 minutes at 40C.
-16
Photographic coatings were prepared by
combining to~ether, under safelight conditions, the
treated portion of coupler dispersion, 1.5 g of
12 1/2% w/v aqueous gelatin solution, 0.25 ml of
photographic pPper type silver chlorobromide emulsion
(approximately 1.0 M in silver halide) and 5.7 ml
water.
5% w/v chromic sulphate soluti~n, 0.30 ml,
was added immediately prior to coating on photo
graphic film base at a wet thickness of approximately
0.1 mm.
Portions of dried coating were exposed to
room light for 5 s and then developed for 21U s at
31C, bleach-fixed for 60 s, washed for 10 minutes in
running water, and dried. The processing solutions
used were as for Example 1.
The resulting dye density of each sample was
measured with a ~ransmission densitometer through an
appropriate filter: green for a magenta image, blue
for a yellow image. The samples were then incubated
in the dark in an oven at 60C and 70% relative
humidity for four weeks and the dye densities again
measured. The percentage fades which had occurred
are listed in Table 7. It will be seen that the
presence of the surfactants did not improve the dark
- stability.
-17-
TABLE 7
Image Original % Fade
Coupler Addition Hue _ Density (4 we~ks~
s
III Water Yellow1.11 0.0
A 1.14 0.6
IY Water Magenta1.63 0.6
A 1.65 1.
V Water Magenta1.80 2.8
~ 6 9.7
-
Notes: Addition : 0.3 ml of water or
A : 7% Aerosol TR70
(Sodium bis-tridecyl sulfo-
succinate)
(Aerosol TR7Q is a trademark for
a surfactant manufactured by the
American Cyanamid Company,
U.S.A.)
Couplers III to V had the structures:
Coupler III
Cl\ ~\ C(CH2~30 ~ - CsHll-t
(CH 3) 3CCCHCNH
o
~!
i!
~,./
S02
.~ \.
!~ I!
OCH~
-18-
Coupler IV
Cl Cl
\.~ \./
11
~ / \
0 NH~ -NHC~HO ~ C4Hg
Cl2H2s
Coupler VQ Cl . Cl
./
!
/ \
C s~l l -t
NHCO~ l-NHCOCH20-~ CsHl l-t
Example 6
This Example illustrates the use of the
surfactants of the invention when coupler IV was
dispersed in the presence of an acidic phenol coupler
sOlvent
Coupler IV, 1.0 g; n-dodecyl-R-hydroxybenzo-
ate, 0.33 g; n-octyl-p-hydroxy-benzoate, 0.33 g; and
N,N-diethyl lauramide, 0.33 g) were melted to form an
oily solution. This solution was mechanically
dispersed into 7.6 g of 10.5% w/w gelatln solution,
to which had been added 0.8 g of 10% w/w sodium
dioctyl sulfosuccinate aqueous solution and other
surfactants as stated in Table 9.
Photographic coatings were prepared by
combining together under safelight conditions, 0.8 g
of coupler dispersion, 0.25 g of silver chlorobromide
photographic paper emulsion (approximately 1.0 M in
silver halide, 1.0 g of 12% w/w gelatin aqueous
solution3 and 6.6 ml of water. 5% w/v chromic
sulphate solution, 0.30 ml, was added immediately
prior to coating on photographic film base at a wet
thickness of approximately 0.10 mm.
LZ6~
-19-
Portions of dried coating were exposed,
processed and tested as in Example S: re~ults are
given in Table 9. It will be ~een that in this and
in the previous Example the presence of the sur~act-
ant of the Invention improved the dar~ Rtability ofthe dye in the presence of t~e acidic phenols.
TABLE 8
Coating Surfactant Original % Fade in
Added Density12 weeks
-
- 1.24 6.5
A, 0.10 g 1.29 3.1
A, 0.20 g 1.26 2.4
A, 0.30 g 1.72 -1.2 (density
increase)
Note: surfactant A, 70% sodium bi3 - tridecyl sulfo-
succinate
~xample Z
The coupler used in this Example had an
acidic phenol leaving group. The results 3how how
the dark stability of the image dye wa3 most dimin-
i~hed ln areas of low image density, where most
acidic phenol remained. The stabilizi~g e~ect of
the surfactants of the invention i8 illustrated: the
effects varied with the humidity at which the
accelerated dark fading was carried out.
A coupler di~persion and coatings were
prepared as in Example 5, except that coupler VI was
used. The coatings were expoæed to a photographic
step wedge and processed as in Example 5. The image
densities of the various steps of the image were
measured (blue filter). The strips were incubated
either for 60 days at 60C, 70% R~ or for 28 days at
77C, low R~. Reæults are given in Table 10 :
coating A had 0.3 ml water added, B had 0.3 ml
7% Aerosol TR70, as in Example 5.
-20- ,
Coupler VI: (CH3~3CCCHCN~ N~SO 2 (CH 2~ i sCH 3
O
.
.~ \.
1,
t
S02
!~ ,'!
OH
TABLE 9
. . , _ _ _ _ . . _ _ _ .
_ 60 Days 60C 70 % RH 2~ Days 77C, Low RH
CoatingInitial Step % Initial Step~/O
Density Fade Density Fade
A 0.35 26 0.39 38
0.67 33 0.71 37
0.97 28 1.~2 34
1.37 20 1.42 23
1.76 11 1~82 1~
1.90 7 1.98 3
B 0.47 13 0.46 11
0.78 15 0.76 9
1.10 18 1.08 8
1.52 18 1.49 6
1.90 17 1.87 4
2.02 14 1.95 2
6~
-21-
Example 8
Coatings were prepared and tested as in
Example 5, using the acidic phenol cyan coupler VII.
The surfactant additions were different: these and
other results are given in Table 10.
TABLE 10
.
Surfactant Original (red) /0 Fade
Addition Density (4 weeks~
0.3 ml water 1.64 4.3
0.1 ml A 1.24 1.6
O.Z ml A 1.01 3.0
0.1 ml C 1.09 0.9
0.1 ml ~ 1.69 0.6
Note: Surfactant solution.
A, 7% sodium bis-tridecyl sulfosuccinate.
C, 10% Hos~apur SAS 60 (Trademark). (This is a
mixture of C13 - Clg sodium alkyl
sulfonates).
D, 10% sodium pentadecyl phenol sulfonate.
Coupler VII
O OH
Il . I
C3F7CNH \ ~ CsHll-t
il.= i
~HCCHO ~ CsHll~t
C4Hs
Example 9
3 Mllltilayer coatings were made on a paper
support according to the following summary. The
numbers in parenthesis are coverages expressed as
mg/m2. In the case of the silver halide in the
emulsion layers) the coverages relate to the silver
present.
-~2-
Layer 6 - Gelatin (1076~
Layer 5 - Gelatin (1679), red-sensitive silver
çhlorobromide emulsion ~81), cyan
coupler (1076) and hydrophobic surfact-
ant (301), (See Table II)
Layer 4 - Gelatin (1313), UV-absorber (861),
dioctylhydroquinone (5~
Layer 3 - Gelatin (1851), green-sensitive silver
chlorobromide emulsion (41~), mag~nta
coupler IV (522)
Layer ~ - Gelatin (753), dioctylhydroquinone (54)
Layer 1 - Gelatin (1690), blue-sensitive silver
chlorobromide emulsion (403), yellow
coupler III (990~, gelatin hardener
Support - Electron -bombarded polyethylene coated
paper.
The couplers were lncorporated in the layers
as dispersions, being mixed with di n-butyl phthalate
(one half the coupler weight in the case of the cyan
~nd magenta couplers and one quar~er the coupler
` weight ln the case of the yellow coupler) and
dispersed in aqueous gelatin solutions with the aid
of sodium ~ri-isopropyl naphthalene sulfonate. The
UV sbsorber in layer 4 comprised a mixture of ~4.170
(by weight) of 2 (2-hydroxy-3,5-di-tert-pentylphenyl)
benzotriazole, 15% 2-(2-hydroxy-3-tert-butyl-5-
methylphenyl)benzotriazole and 0.9~ dioctylhydro-
quinone dispersed in 2-(2-butoxyethoxy)ethyl
acetate. The gelatin hardener in layer 1 was bis-
(vinylsulfonylmethyl)ether and was added in an amount
equal to 1.75% of the total weight of the gelatin in
~he multilayer coating.
Four different multilayer coatings were made
using two different couplers, each coated with or
wi~hout the lipophilic anionic surfactant sodium
bis~tridecyl) sulfosuccinate. The couplers were
numbers I and VIIT defined by the formula:
q~3~
-23-
OH C2H 5
Cl NHCOCHO ~ CsHll-t
.~-\./ /-=-
!~ ,1! Cs~ t
R
Cl
Coupler I : R = CH3
Coupler VIII : R = C2Hs
Samples of the four coatings were exposed,
processed as described in Example 1 and then used for
determining the stability of the cyan dye image under
incubation test conditions. In all the tests the
loss in red-light reflection density of an ima~e
having an initial value of 1.7 was measured as a
function of the incubation time. Two different test
conditions were used, 77C and 15% relative humidity
for the two week tests and 60~C and 70% humidity for
16 week tests.
The results obtained are given in Table 11.
TABLE 11
Coupler Lipophilic % densi~y loss after
Surfac~ant (weeks incubation):
(mg/m2~ 4 6 8 12 lS 2
I 0 17 32 35 48 ~5 ~8
II 301 10 19 24 3~ 45 25
VIII O 3 4 4 8 9 4
VIII301 0 2 1 5 4 2
3C
These show that the lipophilic surfactant
reduced the densi~y loss of both cyan image dyes for
both incubation test conditions. The stability of
the image dyes to light exposure was unimpaired by
the presence of the lipophilic surfactant.
-24-
The invention has been described in detail
with particular reference to preferred embodiments
thereof, but it will be understood that variatlons
and modifications can be effected within the spirit
and scope of the invention.
