Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
-
1064307
This invention relates to a process for the pro-
duction of photographic images by dye diffusion transfer,
and to a photographic material containing new diffusion-
resistant dye-giving compounds suitable for use in this
process.
Among conventional processes for the production of
colored photographic images by dye diffusion transfer, in-
creasing significance is being attached to those based on
the use of dye-giving compounds incorporated in diffusion-
resistant form, from which diffusible dyes or dye pre-
cursor products are split off image-wise during development
and transferred to an image-receiving layer.
Dye-giving compounds suitable for this purpose include,
for example the non-diffusing color couplers described in
e~ O ~en~
l ~ DT PS 1,095,115. During development, these couplers release
,~ 15 in diffusible form a preformed dye or a dye produced during
coupling by reacting with the oxidation product of a color
developer compounds which consists of a primary aromatic
amine. The choice of the developer compound required is,
of course, limited to color developers.
In addition, reference is made in this connection
to the non-dif~usible dye-giving compounds described in
~e~ 0~5
~i DT OS 1,930,215 which contain a preformed, latently diffusible
dye radical attached to a diffusion-inhibi-ting radical
through a cleavable hydrazone group. These compounds cannot
be regarded as color couplers, and it has also been found
; that the choice of the developer compounds required for
liberating the diffusible dye radical is by no means limited
to conventional color developers, but black-and-whitede-
A-G 121Z - 2 -
.
:
.. .
10643~7
velopers, for example pyrocatechols, can also be effectively
used.
G~f?/~an f~/ S
In addition, ~ 1,772,929 discloses non-di~fusible
colored compounds with a special group which, during
development, enter into an oxidizing ring-closing reaction
and, in doing so, release a preformed dye radical in
diffusible form.The compounds discussed in that Offenle-
gungsschrift can be divided into two groups. For develop-
ment, the compounds of the one group require a conventional
color developer compound with whose oxidation product they
couple and , in a subsequent ring-closing reaction, liberate
the preformed dye radical in diffusible form. The compounds of
the other group represent silver halide developers which in
the oxidized form, are able to enter the aforementioned ring-
` 15 closing reaction releasing the diffusible dyes, even in the absence of other developer compounds.
`~ Finally, reference is made to the non-diffusible dye-
n~ OL S
giving compounds disclosed in ~ 2,242,762. These com-
pounds are sulfonamidophenols and sulfonamidoanilines which,
2c after being oxidized during development, are split under the
effect of the developer alkali to release diffusing dyes.
~; The dye-giving compounds referred to above all work
negatively. In other words, in cases where conventional (ne-
gatively working) silver halide emulsions are used, the
diffusing dye released is distributed imagewise in consistency
with the negative silver image produced during development.
To produce positive dye images, therefore, it is necessary
to use directpositive silver halide emulsions or, alternative-
`' ly 7 to apply a suitable reversal process.
A-G 1212 - 3 -
-
, .
~o64307
The object of the present invention is to provide new
non-diffusing dye-giving compounds for the dye diffusion
transfer process which, when used in the same quantity as
conventional compounds in the layer, give an increased dye
yield or, conversely, which enable a smaller quantity of
dye-giving compound and a smaller quantity of silver halide to
be required for producing the same dye density.
It has now unexpectedly been found that liberation
of the sulfonamide group on completion of oxidation is by
no means confined to compounds of the kind which contain a
hydroxyl group, amino group or alkylamino group in the ~-
position to the sulfonamide group on the aromatic ring. In-
~ stead, also a sulfonamide group or carbonamide group in the
- o- or P-position has an adequate activating effect upon the
` 15 ring system.
The present invention relates to a photographic dye
diffusion transfer process for the production of colored
images, in which a photographic material with at least one
photosensitive silver halide emulsion layer and, associated with
that layer, a non-diffusing dye-giving sulfonamidoaryl com-
pound which, in oxidized form, is able to release a diffusing
dye in an alkaline developer medium, is exposed imagewise
and developed with a silver halide developing agent, the
silver halide developing agent in oxidized form oxidizing
the dye-giving sulfonamidoaryl compound which, as a result
of being oxidized, is split by the developer alkali to pro-
duce an imagewise distribution of the diffusing dye liberated,
distinguished by the fact that the non-diffusing sulfon-
amidoaryl compound corresponds to the following formula:
;1 30 ~I) Y - NH - Ar - NH - S02 - X
~ A-G 1212 - 4 -
.. ..
.. , :
.. ~
106~3~7
in which:
Ar represents an arylene radical such that the group
Y-N~- is attached to the group -N~-S02-X through a chain
of n(n = 1,2,3, or 4) vinylene groups which are part of
the arylene radical;
X represents the radical of a dye or dye precursor;
Y represents a --C0~ or -~02X radical; and
R represents an alkyl group, aryl group or heterocyclic
group which may optionally be further substituted.
In the most simple case, the arylene radical Ar
1c represents a phenylene radical, for example a p-phenylene
radical. It can also be a polynuclear aromatic group, for ex-
ample a 4,4'-biphenylene group, a 1,4-naphthylene group, a
1,5-naphthylene group or a 9,10-anthracenylene group. The
arylene groups can, of course, contain one or more other sub-
stituents to facilitate oxidation of the dye-giving compounds,
for example alkyl, alkoxy, aryl or acylamino. Accordingly,
; the vinylene groups referred to above are groups corresponding
to the formula:
- C~'=CR'-
in which the two radicals X~ can be the same or dif~erent and
represent hydrogen or, for example, one of the aforementioned
substituents; alternatively, two radicals R' of the same or
..
different vinyl group can together represent the C-atoms re- -
quired to complete the arylene group.
The radical R can perform different functions within the
scope of the invention. For example, it can be a radical which
imparts adequate diffusion resistance to thed~e-giving compound.
The fact that the radical X is split off during development
together with the -CONH- or -S02-NH- group can also be utilised
A-G 1212 _ 5 _
. .~
1064~0~
for coloring in cases where R represents a dye radical. In
this case, the radical R is, for example, an aryl group which
is further substituted so that it contains a chromophoric
group. R can be the same dye radical as X so that, where Y
represents -~02R, the two radicals, which are split off imagewise
during development, are identical and, hence, coincide in
color. It is clear that, in this case, an increased yield
of diffusing dyes is obtained per equivalent of dye-giving
compound, compared with conventional dye-giving compounds.
~owever, the dye radicals X and R can also be different in
10 structure and~ hence, different in color as well. By
suitably selecting the two dye radicals, it is possible in
this way to adjust the color and hence obtain any required
color. In addition, the radic&l ~ can be any group which,
if present in diffusing form after splitting off, has a certain
activity and whose action is required imagewise, for example as
a development inhibitor, stabilizer silver-salt solvent and
the like.
-~!
i It is pointed out that the dyet~ing compounds according
to the invention as intact molecules are not intended to diffuse
to the layers of the photographic material. To this end,
,
~ they contain a radical which makes them resistant to diffusion,
- for example in the radical R. Another method of introducing a
diffusion-inhibiting radical into the molecule of the dye-giving
compound is to select as the arylene group Ar groups which
have already been suitably substituted by a diffusion-inhibiting
radical. Whether the dirfusion-inhibiting radical is split
off during development is not critical, because a quinoid comp-
~i
ound with an extremely low tendency towards diffusion is
obviously formed from the arylene group.
Dye-giving compounds particularly suitable for the
purposes of the invention correspond to the following formula:
; A-G 1212 - 6 -
.
-,''
1064307
b b
(Il) Y-NH ~ N~-SOz-X
Z
in which
X and Y are as already defined;
YJ represents hydrogen or one or more identical or different
substituents, for example alkyl, alkoxy, mono- or
di-alkylamino, the alkyl radicals optionally containing
~ up to 20 carbon atoms; aryl, for example phenyl; aroxy,
- ~or example phenoxy; acylamino, the acyl radicals being
derived from aliphatic or aromatic earboxylie or sulfonic-
aeids; and
1 b represents hydrogen or one of the radieals mentioned in
~ the definition of Z, or the two radicals b together form
;il
the radical required to complete a fused aromatic ring
system.
It is particularly preferred to use dye-g~fing compounds
~ 15 corresponding to the following formula: :
,, (111) R~-S02NR- ~-NII-S02_X
OR3
:,~
~,l in whieh X is as defined above;
Rl represents a diffusion-inhibi$ing radieal or the
i,l
radical of a dye or dye precursor, for example the
radical X; and
A-G 1212 _ 7 _
'S1
a,
.!
10643(~,7
X2 and R3 are identical or different radicals, i.e. alkyl with
up to 20 carbon atoms, preferably with up to 4 carbon
atoms.
The dye-gi~g compounds can themselves be sufficiently
resistant to diffusion in cases where Y or ~l represents a dye
radical, even when Z (for~ula II) or R2 and R3 (formula III) do
not contain relatively long chain alkyl radicals, because in
that case the molecule can be sufficiently large, depending
upon the particular dye radical. Alternatively, the dye-giving
compounds can be made adequately resistant to diffusion by
selecting radicals Z or R2 and R3 of a suitable size.
In the context of the invention, diffusion-inhibiting
radicals are radicals of the kind which enable the compounds
according to the invention to be incorporated in diffusion-
resistant form in the hydrophilic colloids normally used inphotographic materials. Preferred radicals of this kind are
organic radicals which generally contain linear or branched
aliphatic groups and, optionally, isocyclic or heterocyclic
aro~atic groups with, in general from 8 to 20 carbon atoms as
well. These radicals are attached either directly or indirectly,
to the rest of the molecule for example through one of the fol-
lowing groups: -NHC0-, -NHS02-, -NR-, R representing hydrogen
or alkyl, -0- or -S-. In additiont the diffusion-inhibiting
radical can also contain water-solubilising groups, for
example sulfo groups or carboxyl groups which can also be
present in anionic form. Since the diffusion properties are
governed by the size of the molecule of the whole compound
used, it is sufficient in certain cases, for example in cases
where the whole molecule used is large enough, to use even
shorter-chain radicals as "diffusion-inhibiting radicals".
A-G 1212 - 8 -
~o64307
Basically, suitable dye radicals are the radicals of dyes
of any class, providing they are diffusible enough to be able
- to diffuse through the layers of the photosensitive material
into the image-receiving layer. To this end, the dye radicals
`~ 5 can be provided with one or more water- solubilizinggroups.
Suitable water-solubilizing groups are inter alia carboxyl
groups, sulfo groups, sulfonamide groups and aliphatic or
aromatic hydroxyl groups. ~owever, the sulfonamide group
remaining in the dye after splitting itself imparts to the
dye molecule a con~iderable tendency towards diffusion in the
alkaline medium, with the result that the presence of additional
water-solubilizin~ groups is not absolutely essential~ -
Examples of dyes particularly suitable for use in the process
according to the invention are azo dyes, anthraquinone dyes,
phthalocyanine dyes, indigo dyes and triphenylmethane dyes,
In the context of the invention, the radicals of dye
.~
' precursors are the radicals of compounds of the kind which are
converted into dyes during photographic processing by conven-
~, tional or additional processing stages, whether by oxidation,
by coupling or by liberating an auxochromic group in a
chromophoric system, for example by hydrolysis. Dye precursors
in accordance with this definition can be leuco dyes, couplers
~.,
or even dyes that are converted into other dyes during proces-
sing. Where it is not crucial to distinguish between dye
radicals and the radicals of dye precursors, dye precursors
are also referred to hereinafter as dye radicals.
The following compounds are examples of dye-giving
`i compounds according to the invention:
~, A-G 1212 - 9 -
. ~
. ~,
..~
,: .-. ,~ , . , - : . .. ..
- : - , - .: .. .- ., . . .
~.o64307
Transfer Color
Compound No. 1
~CH3
n-C16H33-S02-NH- </ ~ -NH-so2-x1
-~ 6CH3 yellow
~ ~ 3
:
. Compound No. 2
. OCH3
_c16H33_so2_NH_ ~ -NH-S02-X2 cyan
; O H3
OCH
X2 = ~ -NH S03H
L 11
,~
~ (CH3)2CH-NH O
. .
; ~
A-G 1212 . - 10 -
', :
10643~7
Compound No. 3 Transfer Color
OCH3
n-c1 6H33-S02-NH_ ~ -NH-S02-X3
magenta
. OCH3
OH
OCH
OCH ( CH3 )2
.~:
Compound No. 4 magenta
C2H5
CO-NH- ~ -NH-S02-X3
C2H5
.-
-. Compound No. 5 magenta
X3-52-NH- 8 - NH-S02-X~;
.
~, Compound No. 6 magenta
:1 <_=~/ 2 3
....
. '.1,
.":
''I
: A-G 1212 - 11 -
:
-:,
.. . .. , . . :- :. ,
~064307
Compound No. 7 Transfer color
~ 3 . -
X3-S2-NH- ~ ~ -NH-SO2-X3 magenta
OCH3
Compound No. 8 magenta
OC2H5
X3-S2-NH- <~ ~ -NH-S02-X3
OC2H5
:;:
Compound No. 9 magenta
IOC4H9-n
X3-S2-NH- ~-NH-S02-X3
;~ OC H n
' '
- . Compound No. 10 magenta
` C12H25 n
X3-S02-NH- ~ - NH-S02-X3
C1 2H25-n
.
Compound No. 11 magenta
3 2 ~ H-SO2-X3
~\
, , OC2H5
Compound No. 12 magenta
r--~ C2H5 and yellow
X3-S2-NH- ~ NH SO2 X
OC2H5
A-G 1212 ~ - 12 -
;
.
.~,
~Q643~7
. `
Compound No. 13
/OC2H5
n-C16H33-SO2-NH- ~ -NH-SO2-X1 yellow
OC2H5
:'~
Compound No. 14
, ~OC2H5
C16 33 2 ~ -NH-SO2-X2 cyan
.:~ OC2H5
CompoUnd No- 15 OC2H5
:,n-C16H33-S2-NH- ~ -NH-S02 X magenta
OC2H5
Compound No. 16
;, ~
16 33 2 ~ -NH-SO2 X4 =
OCH3
; N = N ~ ~ co-NH-c6H13(n) yellow
OCH3 H ~ N
N
'~ ~
1:
..
A-G 1212 ~ - 12 a -
. ' `' '~ " ;. ' , ' ,: ,' :
1o64307.
Compound No. 17
OCH3
n-C H33-SO2-NH- ~ NH SO2 X5 =
OCH3
: ~ =N- ~ -NO2
52CH3 cyan
OH
Compound No. 18
OCH3
16 33 SO2 NH ~ -NH-S02 X
; 3
~ -NHCOCH3
.~ ~ -OH
magenta
N=N~
H3
,.,~
` .
A-G 1212 - 12 b - ~
.
' - . . ..
1064307
Preparation of the ~ye-g~ing com~ ds accordin~ to the
nvention
General Procedure
The corresponding arylamine or arylenediamine (or salts
thereof, for example the HCl salt) is dissolved or suspended in
5 to 50 times the quantity of anhydrous pyridine. Somewhat
more than the $heoretically required quantity of the sulfo-
chloride or sulfobromide o~ the corresponding dye or dye
precursor is introduced with stirring at room temperature, a
pyridine complex of the sulfohalide being precipitated in
some cases. On completion of the reaction, which generally
takes a few hours, any undissolved constituents are isolated
by filtration under suction and water is slowly added with
stirring to the pyridine solution in such a quantity (the
volume of water added is generally approximately equal to
the volume of pyridine) that the required sulfonamidoaryl
compound is precipitated, whilst the sulfonicaid of the dye or
dye precursor formed as secondary product remains in solution.
After cooling in an ice bath~ the product is filtered under
suction, washed with pyridine/water and dried, or suspended
with a suitable low-boiling water-miscible organic solvent such
; as9 for example, acetonitrile, filtered under suction again
and then dried.
If the reaction is followed by thin-layer chromatography,
it can be seen that ~he two amino groups of arylene diamines
react one after another. As a result, it is possible to in-
-i troduce two different radicals into the compound.
Example: Preparation of compound No. 12.
11.2 g of the dye sulfochloride A are added in portions
with thorough stirring to 3.9 g of 2,5-diethoxy-1,4-phenylene
diamine in 50 ml of dry pyridine. The mixture is stirred for a
~ few hours, filtered under suction and water is added with stirring
- A-G 1212 -13-
:,
. .
1~64307
to the clenr filtrate in such a quantity that the intermediate
product B is precipitated. The precipitate is filtered under
suction, washed with water and dried. Yield 8.8 g, Mp. 233 -
235C (decomposition).
3.4 g of the dye sulfochloride C are added in portions
with thorough stirring to 3.2 g of B in 50 ml of dry pyridine.
After stirring for several hours, water is added with stirring
to the reaction solution in such a quantity that compound No.12
is precipitated. This compound is filtered under suction,
washed with water and dried. Yield: 4.3 g, Mp. 265 - 266OC
(decomposition). Compound No. 12 can be purified by column
chromatography using Merck's silica gel 60 (grain size o.o63 -
0.200 mm); eluent chloroform.
; There is no need to isolate the intermediate product B
as described above. In this case, the dye sulfochloride C is
directly added to the filtered pyridine reaction solution of
the dye sulfochloride A with 2,5-diethoxy-1,4-phenylene diamine.
';
H3NNCO~ N = 11 ~ 2-
' _~C2~5
CN3NNCO~ON ~S2 - NN- ~N2
:. C~ O
. A_G 1212 --14--
r~d~ Lrlc
, . . ~ . , , " . . - - , :
OH 106430 7
~U;N ~O ~Cl
( C~3 ) 2CH- O
Preparation of 2-amino-5-hexadecylsulfonamido-1~4-dimeth
benzene (intermediate product for compounds 1 to ~).
Sta~e 1: 2-acetamido-5-hexadecylsulfonamido-1~4-dimeth
benzene-65 g of hexadecylsulfochloride are added at room
temperature to a solution of 42 g of 2-acetamido-5-amino-1,4-
dimethoxybenzene in 250 ml of anhydrous pyridine, and the
mixture is stirred for 1 hour. After dilution with a little
water, the mixture is poured out onto ice and acidified with
concentrated hydrochloric acid. The deposit is filtered under
suction, poured with stirring mto a ~tt1~ ac~nib~le,~d under
-~ suction, washed with acetonitrile and dried.
. . .
Yield: 79.4 g, Mp: 139-140C.
- Sta~e 2: 2-amino-5-hexadecylsulfonamido-1,4-dimethoxybenzene
74.3 g of the product of Stage 1 are boiled u~der reflux
with 24.8 ml of concentrated hydrochloric acid in 500 ml of
ethanol until no more starting material can be detected
(approximately 4 to 6 hours). The product precipitates on
cooling. It is filtered under suction and dried in vacuo over
potassium hydroxide.
Yield: 67 g, decomposition at about 178-180C.
Preparation of 2,5-diamino-1,4-didodecyloxybenzene (intermediate
product ior compound No. 10)
Sta~e 1: 2-nitro-1,4-didodecyloxybenzene
11.7 ml Or nitric acid o~ density 1.39 are added dropwise
with stirring at room temperature to a suspension o~ 67 g of
hydroquinone didodecyl ether (described in US-PS 2,067,960) in
1000 ml of glacial acetic acid. The hydroquinone ether enters
into solution, and it~ nitro compound is precipitated. After
A-G 1212 -15-
,
.,
. . . : .
1064307
stirring overnight, the product is filtered under suction, the
filtrate is concentrated in vacuo to around 1/4 of its volume~
refiltered under suction and the combined filter residues are
dried in vacuo over potassium hydroxide. Yield: 69 g, Mp:
34-36C.
Sta~e 2: 2-amino-1,4-didodecyloxybenzene
24.6 g of the product of Stage 1 are catalytically
hydrogenated in 200 ml of tetrahydrofuran in the presence of
Haney nickel at 30-35C/50 atms pressure. The hydrogenation
solution ~iltered off from the nickel is directly used for
Stage 3. When concentrated by evaporation, a small sample of
the solution leaves behind a solid residue melting at 54C.
Sta~e ~: 2-acetamido-1,4-didodecyloxyben~ene
6.3 ml of acetanhydride are added to the filtered
, ~ .
hydrogenation solution of Stage 2 which is then left to stand
for a few hours, being occasionally shaken in the meantime.
The product is precipitated with 1 to 2 times the volume of
^ acetonitrile~filtered under suction and dried. Yield: 22.8 g,
Mp:68-690C.
Sta~e 4: 5-nitro-2-acetamido-1,4-didodecyloxybenzene
The product of Stage 3 (22.8 ~) i9 suspe~ded in 250 ml of
glacial acetic acid. 4.9 ml of nitric acid of density 1.39 are
added dropwise with stirring at room temperature, the mixture
;; becoming pasty. Following the addition of another 50 ml of
glacial acetic acid, the mixture is stirred for a few hours and
~, filtered under suction. The filtered residue is suspended twice
with acetonitrile, filtered under suction and dried. Yield:
20.5 g, Mp: 70-71C.
Sta~ : 5-nitro-2-amino-l~4-didodecyloxybenzene
4.6g af the product of Stage 4 are boiled under reflux for
a few hours with 1.5 ml o~ concentrated hydrochloric acid in
eth~nol until no more starting material can be detected. The
A-G 1212 -16-
~064307.
- mixture is then adjusted to neutral to alkaline with strong
sodium hydroxid~? solution and precipitated with plenty of water.
The deposit is filtered under suction, washed with water, stirr~d
with acetonitrile, refiltered under suction and dried.
Yield: 4.0 g, Mp: 85-86~C.
~ta~e 6: 2,5-diamino-1,4-didodecyloxybenzene
; The product of Stage 5 (4.0 g) is dissolved with heating
in 250 ml of ethanol and catalytically hydrogenated with Raney
nickel at 50~C/50 atms pressure. Concentration of the
hydrogenation solution after the nickel has been filtered off
under suction gives 2.8 g of a product melting at 75-760C.
The dye-gi~g compounds according to the invention are
incorporated in the casting solutions for the layers of the
photographic material by any one of the usual methods. The
quantity of dye-giv~g compound used per litre o~ casting solution
varies within relatively wide limits, the most favourable
concentration being determined by simple tests. For example,
from 5 to 80 g and preferably from 20 to 40 g of dye-giving
compound are used per litre of casting solution.
.~
The association between the dif~usion-resistant dye-giving
compound and the silver halide required to obtain the required
effect can be established, for example, by introducing the
` diffusion-resistant compounds into the casting solutions from
aqueous-alkaline solutions using any water-solubilizing groups
- 25 present. However, the non-diffusing dye-g~ng compounds can also
`1 be introduced into the layers by any of the known emulsifying
processes. Processes of this kind are described, for example,
` in British Patent Specifications Nos 791,219 and 1,099,414 to
'!' 1,099,417. In another embodiment, it can be desirable for example
to incorporate the dye-giv~g compounds together with silver
~ halide and, optionally, developer substances into the layer in
- the form of so-called microcapsules. In this case, two or
A-G 1212 -17-
L
~064307
more differently sensitized photosensi-tive silver halide emul-
sions and the corresponding diffusion-resistant compounds are
also combined in a single layer in the form of so-called mixed-
grain emulsions, as described, for example, in American
Patent Specification No. 2,698,794. The non-diffusing dye-givin,
compounds can be accommodated in a photosensitive layer itself
or in an adjacent layer. For example, a compound liberating
a cyan dye is associated with the red-sensitive layer,
a compound liberating a m~nta dye is associated with the
green~sensitive layer and a compound liberating a yellow dye is
associated with the blue-sensitive layer.
During development of the silver image, the dye-giving
compounds according to the invention are oxidized imagewise
by developer oxidation products and subsequently undergo a
cleavage reaction under the effect of the developer or activator
alkali, in which the dye radicals are liberated in dif~usible
form as dye sulfonamides. The usual photographic developer
compounds can be used for development providing they are able
in oxidized form to oxidiæ the dye-giv~ compounds according
to the invention. The following are examples of suitable de-
velopers:
hydroquinone
N-methylaminophenol
l-phenyl-3-pyrazolidone
1-phenyl-4,4-dimethyl-3-pyrazolidone
ascorbic acid
aminophenols
N,N-diethyl-p-phenylenediamine
N-ethyl-N-hydroxyethyl-P-phenylenediamine and
3-methyl-N,N-diethyl-p-phenylenediamine
It is expressly pointed out that the choice of developer
substances suitable ~or use in the process according to the
A-G 1212 -18-
~'
- . . . -, . . . . .
1(~6430~7
inventi~n is not confined to color developers, but instead
conventional black-and-white developers can also be used,
whi~h can he regarded as advantageous on account of their lower
tendency towards discoloration. 'l'he developers can actually
be present in the layers of the color photographic material
where they are activated by the alkaline activator liqui~, or
in the alkaline processing liquid or paste.
Since the imagewise distribution of the diffusing dye
liberated during development coincides with the developed
1~ silver image, it is necessary to use direct-positive silver hal-
ide emulsions or, if conventional negative e~ulsions are used,
to apply a suitable revers~l process to produce positive colored
transfer images.
The silver salt diffusion process provides one such
reversal process Photographic reversal by the silver salt
diffusion process for producing positive coloured images using
conventional colour couplers is described, for example, in
US-PS 2,763,800. ~y exchanging the color couplers for the
aforementioned dye-gi~g compounds, it is possible to obtain
a photosensitive element which is suitable for the dye diffusion
transfer process. A photosensitive element of this kind
comprises, for example, at least one combination of a photo-
sensitive silver halide emulsion layer and, associated with
that silver halide emulsion layer, a binder layer containing
development nuclei for physical development and a dye-giving
compound.
During development, the~xposed part of the silver halide
is chemically developed in the photosensitive silver halide
emulsion layer. The une~posed part is transferred to the
3 associated binder layer containing development nuclei by means
of a silver halide solvent, and is physically developed there.
In cases where physical development is carried out with a develo-
per which, in oxidized form is capable of releasing a diffusiLle
A-G 1212 -19-
~,
1064307
dye by reaction with the dye-giv~g compound present in that layer
diffusible dyes are distributed imagewise and can be transferred
to, and form a positive colored~ image on, an image-receiving
layer.
In cases where reversal is carried out with compounds
releasing development inhibitors imagewise, the photosensitive
element consists of at least one layer combination of a
photosensitive silver halide emulsion layer and a second emul-
sion layer containing the dye-giv~g compound which can be de-
veloped without exposure. The photosensitive silver halide
emulsion layer is developed with, for example, color developers
in the presence of certain compounds which release development-
inhibiting substances during the reaction with oxidized color
; developers. The development-inhibiting substances liberated
imagewise in the photosensitive layer diffuse into the adjacent
emulsion layer which can be developed without exposure, where
they inhibit development imagewise. ln this case, the
; uninhibi~d(positive) parts of the emulsion layer which can
be developed without exposure are developed by the remaining
developer, the oxidation products of which subsequently react
with the non- dif~using dye~ ~ ~g compounds according to the
i~vention to release diffusible dyes which are transferred image-
wise to the image-receiving element. Suitable compounds which
release development-inhibiting substances by reaction with
color developer oxidation products nre, for example, the known
DIR couplers (DIH = development inhibitor releasing), which
are color couplers containing a releasable inhibitor radical
in the coupling position. DIR couplers of this kind are
described, for example in US-PS 3,227,554.
Another group of compounds which release development-
inhibiting substances by reaction with color developer oxidation
products is described in US-PS 3,632,345. These compounds
A-G 1212 -20-
~064307
~re not color couplers. Accordingly, no dyes are formed
during release of the development-inhibitin g substances.
0~
Finally, it is also possible, according to~h~-~ 1,a2~,389, to
use in a ~rocess of this kind suitable substituted non-diffusible
hydro~iuinone compounds which, by reacting with developer
oxidation products, are oxidized into the corresponding quinones,
thereby liberating development-inhibiting meroaptans.
Suitable direct-positive silver halide emulsions are,
in principle, any direct-positive silver halide emulsions of
the kind which, when subjected to straightforward development
produce a positive silver image and an imagewise distribution
of developer oxidation products corresponding to that silver
image. E~amples include silver halide emulsions of the kind
in which exposure or chemical treatment has produced a
developable fog which can be destroyed imagewise during image-
wise exposure under certain conditions. The fog remains intact
at the unexposed areas, so that subsequent development gives a
direct-positive silver image and, in consistency with that
image, an imagewise distribution of di~fusing dye when a
dye-gi~ compound according to the invention is associated
with the direct-positive silver halide emulsion.
Another group of direct-positive silver halide emulsions
which can be used with advantage in the process according to
the invention are the so-called unfogged direct-positive silver
halide emulsions which show photosensitivity predominantly
inside the silver halide grainæ. Imagewise exposure of these
emulsions produces a latent image predominantly inside the silver
halide grains. However, unfogged direct-positive silver halide
emulsions of this kind are developed under fogging conditions,
a fog being produced predominantly in the unexposed areas,
whilst a positive silver image is developed during development.
-The unfogged direct~positive silver halide emulsions are
A-G 1212 -21-
.
~064307
distinguished by the fact that, when developed with a typical
surface developer of the following composition
p-hydroxyphenylglycine 10 g
sodium carbonate (crystallised) 100 g
make up with water to 1000 ml
exposed samples preferably do not give a silver image, or only
produce a low-density silver image, whereas in cases where an
internal developer of the following composition is used
hydroquinone 15 g
monomethyl-p-aminophenolsulphate 15 g
sodium sulphite (anhydrous) 50 g
potassium bromide 10 g
sodium hydroxide 25 g
sodium thiosulphate (crystallised) 20 g
make up with water to1000 ml
a silver image of adequate density is formed.
Selective fogging of the unfogged direct-positive emulsions
,
which have been exposed imagewise can be carried out before or
during development by treatment with a fogging agent. Suitable
fogging agents are reducing agents such as hydrazine or
substituted hydrazines~ cf. for example US-PS 3,227,552.
Unfogged direct-positive emulsions are, for example those
which show faults inside the silver halide grains (US-PS
.
`~ 2,592, 250) or silver-halide emusions of laminar grain structure
/~r~an 0~5
` 25 -e4L4~2,308,239)
In the context of the invention, the words ~'association"
and "associated" are intended to mean that the arrangement of
silver halide emuls~n and dye~u~ compound is such that they
can interact to allow imagewise consistency between the silver
image formed and the imagewise distribution of the diffusing
dye liberated. The associated dye-gi~ compound is best
- incorporated in the silver halide emulsion itself or in a
layer adjacent to the silver halide emulsion layer, this adjacent
A-G 1212 -22-
~064307
. .
layer preferably lying behind the silver halide emulsion layer
(looking in the direction of the incident light during ex-
posure).
The dye diffusion transfer process according to the in-
vention is carried out with a photosensitive element which
contains one or more silver halide emulsion layers and,
associated with those layers, non-diffusing dy~giving com-
pounds, and with an image-receiving element in which the re-
quired dye image is produced by the diffusible dyes transfer-
red imagewise. To this end, the photosensitive element and
the image-receiving element must be in firm contact with one ~-
- another for at least a finite period within the developing
time, so that the imagewise distribution of diffusing dyes
produced in the photosensitive element as a result of develop-
ment can be transferred to the image-receiving element.
Contact can be established after development has been
started, or it can already have been established before
development begins. The latter occurs, for example, where
the dye diffusion transfer process is carried out with a mater-
ial in which the photosensitive element and the image-receiving
element form an lntegral unit, aleo rererred to hereinafter as
a one-sheet material, which remains intact on completion of
development. In other words the photosensitive element is not
separated from the image-receiving element, even after dye
;~ 25 transfer. An embodiment of this kind is described, for example,
~cr~a~ O~S
- Al in DT-0~ 2,019,430.
A one-sheet material suitable for carrying out the dye
diffusion transfer process according to the invention comprises,
for example the following layer elements:
1) a transparent layer substrate
2) an image-receiving layer
3) a light-impermeable layer
A-G 1212 -23-
.. . .
~0643~7
4) a photosensitive element with at least one photo-
sensitive silver halide emulsion layer and at least
one ~on-diffusing dye-giving compound associated with
that emulsion layer,
5) a retarding layer
6) an acid polymer layer
7) a transparent layer substrate
The one-sheet material can be composed in such a way that
two different parts, namely the photosensitive part (layer
elements 1 to 4) and the cover sheet (layer elements 5 to 7),
are prepared separately from one another, subsequently placed -
one on top of the other (layer side) and joined together,
optionally with spacer strips in between, so that a space for
receiving an accurately measured quantity of a processing liquid
is formed between the two parts. The layer elements 5 and 6
which together form the neutralisation system can also be
arranged in the opposite sequence between the layer substrate
- and the image-receiving layer of the photosensitive part.
Means can be provided for introducing a processing liquid
~ 20 between the photoæensitive part and the coYer sheet~ for example
in the form of a laterally arranged rupturable container which
under the efiect of mechanical forces, releases its contents
between two adjacent layers of the one-sheet material,
` An important part of the photographic material according
~ 25 to the invention i9 the photosensitive element which, in the!~' case of a one-dye transfer process, contains a photosensitive
silver halide emulsion layer and, associated with this layer,
: a non-diffusing dye-giving compound.The non-diffusing compound
can be accommodated in a layer adjacent to the silver halide
emulsion layer or in the silver halide emulsion layer itself,
. in which case the color of the image dye is preferably selected
in such a way th~t the predominant absorption range of the
A-G 1212 -24-
.
~.0643G7
dye-giving compound does not coincide with the predominant
sensitivity range of the silver halide emulsion layer. However,
to produce multicolor transfer images in natural colors, the
photosensitive element contains three such associations of
dye-giving compound and photosensitive silver halide emulsion
layer, the absorption range of the dye-giving compound gene-
rally coinciding to a large extent with the spectral sensi-
tivity range of the associated silver halide emulsion layer.
In this case, however, the dye-giving combination must be
accomodated in a separate binder layer behind the silver
halide emulsion layer (looking in the direction of the
incident light during exposure) if high sensitivity is to
be obtained.
The developer oxidation products formed during the
development of a silver halide emulsion should, of course only
act on the associated dye-giving compound. Accordingly,sepa-
- rating layers are generally present in the photosensitive
element, effectively preventing the developer oxidation pro-
ducts from diffusing into other non-associated layers. These
;~ 20 separating layers can contain, for example, suitable substanceswhich react with the developer oxidation products, for example
non-diffusible hydroquinone derivatives, or, if the developer
is a color developer substance, non-diffusible color couplers.
In one preferred embodiment, therefore, the photosensitive
element has the following structure (from top to bottom):
blue-sensitive silver halide emulsion layer,
layer with non-diffusing compound capable of liberating
a diffusing yellow dye,
` separating layer,
green-sensitised silver halide emulsion layer,
layer with non-diffusing compound capable of liberating
i:,
a diffusing magenta dye,
separating layer
-~ A-G 1212 - 25 -
~0~430~
red-sensitive silver halide emulsion layer,
layer with non-diffusing compound capable of liberating
a diffusing cyan dye.
The silver halide emulsion layers can, of courset also
be arranged in a different order, although in this case the
associated layers must also be changed together with the col-
oring systems so that the association remains intact.
The light-impermeable layer under the photosensitive ele-
ment is permeable to aqueous alkaline treatment solutions and,
hence, to the diffusing dyes. It performs essentially two
functions. Firstly, it is used to mask the image silver left
after development in the originally photosensitive element,
and the coloring compounds left behind as color negative, so
that only the positive dye transfer Image is visible to the
,,
eye through the transparent layer substrate of the photosensi-
tive part. Secondly, it shields the photosensitive element
on the side of the image-receiving layer (downwards) against
light, which is of particular importance in cases where, after
exposure, the one-sheet material is brought into contact with
the alkaline processing composition inside the camera, removed
from the camera and then developed outside the camera.
Layers sufficiently impermeable to light, but sufficiently
; permeable to difiusible dyes can be prepared, for example, with
suspensions of inorganic or organic dark, preierably black
pigments, for example with suspensions of carbon black in
suitable binders, for example in gelatin solutions. In general,
0.5 to 2 ~ thick layers containing from 10 to 90% by weight
(based on the total dry weight) of carbon black in gelatin are
-~ generally sufficient for keeping out light to an adequate
extent during development. The particle size o~ the pigments
used is not particularly critical, providing it does not
exceed 0.5 ~ to any appreciable extent.
A-G 1212 -26-
.,
, ~ .
~.o64307
In addition to the black pigment layer, the light-
impermeable layer also comprises a white pigment layer below
the black pigment layer. The object of this white pigment
layer is to mask the black layer and to provide a white
background for the image. Any white pigments can be used for
the white pigment layer providing they do not have to be used
- in excessive layer thicknesses to provide adequate covering
power. Examples of suitable white pigments include barium
sulfate, oxides of zinc titanium, silicon, aluminium and zirco-
nium and also barium stearate or kaolin. Titanium dioxide is
preferably used as the white pigment. The parameters relating
to binder, concentration and particle size specified in re-
ference to the black pigments apply to the white pigments as
well. The thickness of the white pigment layer can be varied
` 15 according to the required whiteness of the back ground.
Thicknesses of 2 to 10 lu are preferably used.
Instead of the light-impermeable layer, the one-sheet
material according to the invention can also contain means for
producing a light-impermeable layer of this kind between the
; 20 photosensitive element and the image-receiving layer, for
.:.
example in the form of a laterally arranged container with a
; pnx~s~gliquid containing an opacifying agent (pigment),which
under the effect of mechanical forces releases its contents
between the aforementioned layers so that a pigment layer is
:,
formed there.
The image-receiving layer consists essentially of binder-
containing dye mordants for fixing the diffusing dyes.
Preferred mordants for acid dyes are long-chain
quaternary ammonium or phosphonium compounds or ternary
sulfonium compounds, for example those described in US
Patent Specifications Nos 3,271,147 and 3,271,148. Certain
metal salts and their hydroxides which form substantially
;~ insoluble compounds with the acid dyes can also be used.
A-G 1212 -27-
~Lo,~4307
:- 'The dye mordants are dispersed in the receiving layer in one
of the usual hydrophilic binders, for e~ample in gelatin,
polyvinylpyrrolidone, completely or partially hydrolysed cellu-
lose esters and the like. Some binders can, of course, also
act as mordants, for example copolymers or polymer mixtures
- of vinylalcohol and N-vinyl-pyrrolidone of the kind described, G~nan Pa7le~?t
B for exa~ple, in DT AS 1,130,284, and also those which repre-
sent polymers of nitrogen-containing quaternary bases, for
example polymers of N-methyl-2-vinyl pyridine of the kind de-
` 10 scribed, for example, in US Patent Specification No.
2,484,430. Other suitable mordant binders are, for example,
~` guanyl hydrazone derivatives of alkylvinyl ketone polymers of
the kind described, for example inl~S Patent Specification
No. 2,882,156 or guanyl hydrazone derivatives of acylstyrene
polymers of the kind described, for example, in DT-O~
2,009,498. In general, however, other binders, for example
'! gelatin, will be added to these mordant binders.
, Suitable transparent layer substrates for the one-sheet
.~
material according to the invention include the transparent
substrate materials normally used in photography, for example
:.~
films of cellulose esters~ polyethylene terephthlate, poly-
.::
carbonate or other film-forming polymers.
The alkaline processing composition produces a relatively
high pH-value (about 11 to 14) in the photosensitive material,
thereby initiating development and imagewise dye diffusion.
It has been found that the dyes and, hence, the images obtained
are not particularly stable at this high pH-value. Accordingly,
the material has to be made almost completely neutral or
.;
weakly acid on completion of development. This can be achieved
in known manner if the material additionally contains an acid
polymer layer which becomes accessible to the alkaline pro-
cessing composition only gradually during development. An
A-G 1212 -28-
.
,
, . . . . : . ... :. .. - . -
307
acid polymer layer is a binder layer which contains polymeric
compounds with acid groups, preferably sulfo or carboxyl
groups. These acid groups react with the cations of the
processing composition to form salts and, in doing so, lower
the pH-value of the composition. The polymeric compounds and,
hence, the acid groups are of course incor~orated in the
aforementioned layer in diffusion-resistan$ form. In many
cases, the acid polymers represent derivatives of cellulose or
derivatives of polyvinyl compounds, although other polymer
compounds can also be used. Examples of suitable acid polymers
include cellulose derivatives with a free carboxyl group, for
example cellulose dicarboxylic acid semiesters with a free
carboxyl group such as cellulose acetate hydrogen phthalate,
cellulose acetate hydrogen glutarate, ethyl cellulose acetate
hydrogen succinate, cellulose acetate hydrogen succinate
hydrogen phthalate, ethers and esters oi cellulose modiiied
with further dicarboxylic acid anhydrides or with sulfonic
acid anhydrides, for example with o-sulfobenzoic acid anhydride,
carboxymethyl cellulose, and also polystyrene sulfonic acid,
polyvinyl hydrogen phthalate, polyvinylacetate hydrogen phthalate,
polyacrylic acid, acetals of ~olyvinylalcohol with aldehydes
substituted by carboxy groups orsulfo groups, such as
o-, m- or p-benzaldehyde sulfonic acid or carboxylic acid,
partially esteri~ied ethylene/maleic acid anhydride copolymers,
partially esterified methylvinyl ether/maleic acid anhydride
copolymers and the like.
This acid polymer layer must contain sufficient acid groups
to reduce the pH-Yalue of the processing composition from its
original level oi 11 to 14 to such an extent that, ultimately,
the material is almost neutral or weakly acid (p~-value 5 to 8).
The delay in the reduction oi the pH-value is obtained
; in conventional manner by coating the acid polymer layer with
; A-G 1212 -29-
1~;43G7~
a so-called retarding layer. This retarding layer is an
alkali-permeable layer which preferably consists of a polymer
inert to alkali, for example of polyvinyl alcohol or a partially
acetal~ polyvinyl alcohol. The delay in the reduction of
the pH-value can be adjusted in the required manner by suitably
selecting the thickness and composition of the retarding layer.
Neutralization systems, i.e. combinations of an acid
polymer layer and a retarding layer, are described, for example,
A ~ G~cr~a~ p~e~7~
in DT-PS-1,285,310. Layer combinations of this kind can be
present in the material according to the invention, for
example in the photosensitive part between the transparent
layer substrate and the image-receiving layer. Another
possibility is to arrange the neutralizationsystem of an acid
polymer layer and a retarding layer on the cover sheet. These
two layers must, of course, be arranged in such an order that
the alkali of the processing composition has first to penet-
rate through the retarding layer to reach the acid polymer
-~ layer.
The dye diffusion transfer process according to the
invention can be carried out with advantage in or by means of
a suitable self-developing camera. This camera can be pro-
vided, for example, with means which, following exposure of the
photosensitive element, distribute a processing solution between
the photosensitive element and the cover sheet, and which
shield the photosensitive material against light. A camera
of this kind is preferably provided with two contacting
squeezing rollers. The one-sheet material is drawn out
between these, splitting open the laterally arranged container
which thus discharges its contents between the layers of the
. .
one-sheet material.
Since, after passing through the squeezing rollers, the
- photosensitive element is protected on both sides against
:'~
A-G 1212 -30-
:~`
' I , , ~ ' ~ ,, ` . . . . .
., : . . . ~
10fci430~
undesirable exposure by light-impermeable layers, the exposed
material can be pulled out o~ the camera immediately after
development has begun.
To process the one-sheet material after imagewise ex-
posure, the photosensitive element is brought into contact
with the aqueous alkaline pr~cessing solution.The sil~er halide
emulsion layers exposed imagewise are developed in the presence
of the developer compound. An imagewise distribution of
oxidation products of the developer compound, which oxidizes
. 10 the associated dye-gi~ compound, is produced in consistency
with the positive silver image formed, followed by reaction
with the alkali in the activator to release the diffusing dye.
EXAMPLE 1
A photosensitive element of a photographic material
according to the invention was produced by successively
applying the following layers to a transparent polyester-film
~ substrate (the quantities quoted are quantities per square
; metre in each case).
1. an image-receiving layer of 3.8 g of octadecyl trimethyl
~ 20 ammonium methylsulfate and 9.5 g of gelatin
2. a reflecting layer of 48.5 g of TiO2 and 4.85 g oi
gelatin
3. a dye layer with 0.77 g of compound 1 (yellow), 0.1 g of
carbon black and 2.56 g of gelatin
4. a silver bromide emulsion layer of 3.15 g of AgBr and
2.65 g of gelatin
: 5. a protective layer of 1.3 g of gelatin
: A transparent cover sheet of cellulose acetate was
applied to the uppermost layer of the photosensitive element.
A rupturable container filled with an alkaline pr~cessing
;~ liquid of the following composition was used for developing
the imagewise exposed photosensitive element:
A-G 1212 -31-
~Oti430~,
20 g of sodium hydroxide
A 30 g of Natrosol HHR 250 (hydroxyethylcellulose)
0.5 g of phenidone
made up with water to lO00 ml.
The image set was passed through a pair of squeezing
rollers which distributed the developer paste between the
photosensitive element and the cover sheet. After development
for 10 minutes at 20C the image element was separated of~
and freed from the paste adhering to it. A negative yellow
dye image of high color quality was visible through the
transparent substrate with the titanium dioxide layer as
image background.
EXAMPLE 2
., .
'I The procedure was as described in Example l, except that
'.! 15 compound l in layer 3 was replaced by compound 2. Processing
.,
` in the same way as in Example 1 produced a negative cyan
dye image oi high color~ quality.
EXAMPLE 3
The procedure was as described in Example 1, except that
~ 20 compound 1 in layer 3 was replaced by compound 3. Processing
3 in the same way as in Example l produced a negative magenta
dye image of high color quality.
~' EXAMPLE 4
The procedure was as described in Example l, except
~l 25 that compound l in layer 3 was replaced by compounds 4 to11,15a~18
:'1
Processing in the same way ns in Example l produced negative
1 magela dye images in each case.
'~ EXAMPLE 5
-', A multilayer multieolored photosensitive recording
material was produced by applying the following layers to a
substrate consisting of a transparent layer substrate, layer l
, (mordant layer) and layer 2 (titanium dioxide layer) o~ Example
A-G l212 -32-
/~
~0643()7
1 (the quantities quoted Mre quantities per square metre in
each case).
3. a gelatin layer with 1 g of compound 2 (cyan) and
~.1 g of carbon black
4. a red-sensitive negative-working gelatin silver bromide
emulsion of 3.15 g of AgBr and 2.65 g o~ gelatin
5. an intermediate layer of 0.25 g of octadecylhydroquinone
sulfoni~ acid and 2,5 g of gelatin as blocking layer for
oxidized auxiliary developer
6. a gelatin layer with 1.4 g of compound 3(magenta )
7. a green-sensitive negative-working gelatin silver bromide
- emulsion of 3.15 g of AgBr and 2.65 g of gelatin
8. a blocking layer for oxidized auxiliary developer,
identical with layer 5
9. a gelatin layer with 0.78 g o~ compound 1 (yellow)
10. a blue-sensitive negative-working gelatin silver bromide
~- emulsion of 3.15 g of AgBr and 2.65 g of gelatin
11. a gelatin protective layer o~ 1.3 g of gelatin.
The photosensitive recording material was exposed
using a color separation wedge and was subsequently pro-
cessed as described in Example 1. A multicolored negative image
of the original with good color separation and Or high c~lGr
quality was obtained.
EXAMPLE 6
(a) positive-working image element
The ~ollowing layers were applied to the same substrate
i (transparent support, layers 19 2 and 3 as in Example 5):
;~ 4. A gelatin layer with a red-sensitizednon-fogged direct-
positive silver chloride bromide emulsion, silver
3o covering 1.8 g
5. a blocking layer as in Example 5
6. a magen~ dye layer as in Example 5
- A-G 1212 -33-
~`
:10643(~7
7. a gelatin layer with a green-sensitised un~ogged
direct-positive silver chloride bromide emulsion, silver
covering 1.8 g
~. a blocking layer as in Example 5
9. a yellow dye layer as in ~xample 5
10. a gelatin layer with a blue-sensitised un~ogged direct-
positive silver chloride bromide emulsion, silver
: covering 1.8 g
11. a gelatin protective layer of 1.3 g of gelatin
(b) A cover sheet consisting of a transparent film of cellulose
triacetate
A strip of the image element (a) was exposed through a
color separation wedge and subsequently joined on the layer
side with the cover sheet (b) to form an image set through two
laterally arranged spacer strips 180~ thick and 0.5 cm wide in
conjunction with a bag of paste at one end of the image strip.
. A paste of the following composition was used as de-
veloper:
~ 25 g of potassium hydroxide
l 20 10 ml of benzylalcohol
5 g of N,N,N~,N~-tetramethyl-p-phenylenediamine
. 1 g of acetylphenylhydrazine
~ 35 g of hydroxyethyl cellulose
:, make up with water to 1 litre.
.l ~5 Processing in the same way as described in Example 1
~ produced a direct-positive multicoiored image of the original9
EXAMPLE 7
,~! The procedure was as described in Example 6, except that
.~ 0.8 g of compound 8 was used in layer 6 instead of 1.4 g Or
compound 3. The photosensitive recording material was then
-`~ exposed and developed in the same way as de~cribed in Example 6. In this way, a direct-positive multicolored image of the
A-& 1212 _34_
`~:
~06430~
original was obtained in the image-receiving layer as in Example
6,
~XAMPL~ 8
The procedure was as described in Example 1, except that
compound 1 in layer 3 was replaced by compound 12. Processing
in the same way as in Example 1 produced a negative red dye
image consisting of yellow and magen~ dyes.
:~'
::`
:`~
:
.
. A-G 1212 -35-
