Polyazo dyestuffs having high UV absorption

Compounds of the formula EQU (B--L.sub.m --A--L'--B'.sub.n, (1) in which A is the radical of a bisazo or trisazo dye, L and L' are organic radicals and B and B' are cyclic organic radicals and at least one of the radicals B and B' has spectral absorption in the UV region and one of the radicals B and B' is different from 2,4-dihydroxyphenyl, m is 1 or 2 and n is 0, 1 or 2. The compounds are suitable for use as image dyes in photographic silver dye bleach materials.

The present invention relates to UV-absorbent compounds, a process for 
their preparation and their use as image dyes in photographic materials 
for the silver dye bleach process. 
UV-absorbent compounds which can be used as image dyes in photographic 
materials for the silver dye bleach process permit the use of these 
materials wherever exposure to UV light or light having a high UV content 
plays a part. For example, diazotype materials are imagewise exposed by 
means of mercury vapour lamps whose light has a high and intensive UV 
content. If the original which is to be transferred to such diazotype 
materials is an original prepared from silver dye bleach material, the 
image dyes contained in this silver dye bleach material should thus have 
high absorption not only in the visible region but also in the ultraviolet 
region. To allow visual assessment of the images it is of advantage for 
the image dyes to be dark, i.e. to absorb across a very large portion of 
the visible spectrum. 
The present invention thus has for its object the provision of compounds 
which have spectral absorption in the UV region as well as in virtually 
the entire region of the visible spectrum and which are suitable for use 
in photographic silver dye bleach material. 
It has now been found that the compounds of the formula (1) below 
substantially meet these requirements. 
The present invention accordingly provides compounds of the formula 
EQU (B-L.sub.m -A-L'-B').sub.n ( 1) 
in which A is the radical of a bisazo or trisazo dye, L and L' are 
identical or different from each other and denote bridge members, B and B' 
are identical or different from each other and denote aromatic radicals, 
at least one of the radicals B and B' having spectral absorption in the UV 
region and one of the radicals B and B' being different from 
2,4-dihydroxyphenyl, and m is 1 or 2 and n is 0, 1 or 2. 
The present invention also provides the preparation of the novel compounds 
of the formula (1), their use as image dyes in photographic silver dye 
bleach materials, the photographic silver dye bleach materials containing 
these image dyes, in particular monochromic silver dye bleach materials, 
and the use of images prepared from these materials as originals in the 
exposure of diazotype material. 
In the compounds of the formula (1), A is the radical (chromophore) of a 
bisazo or trisazo dye. Preferably A can be represented by the formulae 
(2) --E--N.dbd.N--D--N.dbd.N--E', 
(3) --E--N.dbd.N--D--N.dbd.N--E'--, 
(4) --E--N.dbd.N--D--N.dbd.N--D'--N.dbd.N--E' or 
(5) --E--N.dbd.N--D--N.dbd.N--D'--N.dbd.N--E'-- 
The radicals E, E', D and D' can be identical or different and are 
preferably aromatic radicals. Examples of suitable aromatic radicals are 
those of the formula 
##STR1## 
in which R.sub.1 is hydrogen or alkyl, alkoxy, alkylthio, alkylamino or 
dialkylamino, it being possible for the stated radicals to contain 1 to 4 
carbon atoms each, or amino, aryl, for example phenyl, halogen, in 
particular fluorine, chlorine or bromine, nitro, cyano, hydroxyl, 
mercapto, acylamido (C.sub.1-4 -alkyl-CONH--), sulfo, amidosulfonyl 
(H.sub.2 N--SO.sub.2 --, (C.sub.1-4)alkyl.sub.2 N--SO.sub.2--), carboxyl 
or amidocarbonyl (H.sub.2 N--CO--, (C.sub.1-4 -alkyl).sub.2 N--CO--). G is 
a straight-chain or branched or heterocyclic, organic divalent radical, a 
hetero atom, for example --O-- or --S--, or a group of the formula 
##STR2## 
Suitable heterocyclic divalent organic radicals are preferably 5- to 
6-membered unsaturated radicals in which the hetero atoms are nitrogen, 
oxygen and/or sulfur atoms, for example pyrrolediyl, furandiyl, 
thiophenediyl, thiophenedioxidediyl, imidazolediyl, thiazolediyl, 
oxazolediyl, oxadiazolediyl, thiadiazolediyl and triazolediyl, and also 
pyridinediyl, pyrazinediyl, pyrandily, triazinediyl, thiopyrandiyl and 
oxazinediyl. 
Examples of straight-chain or branched organic radicals G are alkylene, for 
example methylene, ethylene, n-propylene, sec.-proylene or isopropylene 
##STR3## 
alkenylene, preferably ethenylene or butadienylene, and also --O--, --S--, 
--SO.sub.2 --, --CH.sub.2 SO.sub.2 --, --NH--, --N--alkyl having 
preferably 1 to 4 carbon atoms, --CH.sub.2 NH--, --NHCO--, --NHSO.sub.2 
--, --NHCONH-- --NHCSNH--, --N.dbd.N-- or 
##STR4## 
q can be 0 or 1. 
The stated cyclic radicals E, E', D and D' can contain 1 to 3 substituents 
R.sub.1. If 2 or 3 substituents R.sub.1 are present, these can be 
identical or different from one another. 
The bridge members L and L' can be identical or different from each other. 
They are preferably radicals such as alkylene having 1 to 4 carbon atoms, 
arylene such as phenylene and naphthylene, acylamide (--CONH--), 
carboxylene (--COO--), --O--, --S--, --NH--, --SO.sub.2 -- or --N.dbd.N--. 
The radials B and B', which are identical (except that B and B' are not 
both 2,4-dihydroxyphenyl) or different from each other, are aromatic 
organic radicals, at least one of the radicals B and B' having very marked 
UV-absorbent properties. B and B' can be for example phenyl, naphthyl or 
one of the aromatic 5- or 6-membered heterocyclic structures mentioned for 
G, or a derivative of benzophenone, benzothiazole, benzotriazole, 
quinoxaline, triazine, phenyl salicylate, 2,4-dihydroxyphenyl or pyrone, 
which are all considered suitable for use as radical B and B', having very 
high absorption in the ultraviolet spectrum. The aromatic organic radicals 
B and B' can contain the substituents customary in dye chemistry. Suitable 
substituents are the radicals enumerated in the definition of R.sub.1. 
Preferred compounds of the formula (1) are those in which A is a radical of 
the formula 
--E--N.dbd.N--D--N.dbd.N--E', 
--E--N.dbd.N--D--N.dbd.N--E'--, 
--E--N.dbd.N--D--N.dbd.N--D'--N.dbd.N--E' or 
--E--N.dbd.N--D--N.dbd.N--D'--N.dbd.N--E'-- 
in which E, E', D and D', independently of one another, are a radical of 
the formula 
##STR5## 
in which R.sub.1 is hydrogen, alkyl, alkoxy, alkythio, alkylamino, 
dialkylamino, amino, aryl, halogen, nitro, cyano, hydroxyl, mercapto, 
acylamido, sulfo, amidosulfonyl, carboxyl or amidocarbonyl, p is 0, 1, 2 
or 3, G is a straight-chain or branched or heterocyclic organic radical or 
--O--, --S--, --SO.sub.2 --, --NH--, --N.dbd.N-- or 
##STR6## 
and q is 0 or 1. 
Preferably in these compounds R.sub.1 is alkyl, alkoxy, alkylthio, 
alkylamino or dialkylamino each having 1 to 4 carbon atoms, phenyl, amino, 
chlorine, nitro, cyano, hydroxyl, mercapto, acylamido, sulfo, 
amidosulfonyl, carboxyl or amidocarbonyl, or in particular alkoxy having 1 
to 4 carbon atoms, amino, hydroxyl or sulfo. 
In particularly suitable compounds, G is alkylene, alkenylene, 
alkylsulfonylene or alkylimino each having 1 to 4 carbon atoms, --NHCO--, 
--NHSO.sub.2 --, --NHCONH--, --NHCSNH--, --O--, --S--, --SO.sub.2 --, 
--NH--, --N.dbd.N-- or 
##STR7## 
or preferably alkylene or alkylimino each having 1 to 4 carbon atoms, 
--NH-- or --N.dbd.N--. 
In a further group of preferred compounds, G is a radical of the formula 
##STR8## 
The chromophore A has, in particularly preferred compounds, the formula 
##STR9## 
In suitable compounds of the formula (1), L and L', independently ofeach 
other, are alkylene having 1 to 4 carbon atoms, phenylene, naphthylene, 
--O--, --S--, --NH--, --SO.sub.2 --, --N.dbd.N--, --CO--NH-- or 
##STR10## 
Preferred compounds of the formula (1) have radicals B and B' which, 
independently of each other, are phenyl, naphthyl, pyridinyl, pyrazinyl, 
thiophenyl, furanyl, pyrrolyl, thiazolyl, benzophenyl, benzothiazolyl, 
benzotriazolyl, triazinyl, quinoxalinyl, phenylsalicyl, resorcinyl or 
pyronyl, in particular independently of each other, benzophenyl, 
benzotriazolyl, benzothiazolyl, quinoxalinyl or 2,4-dihydroxyphenyl. 
2,4-Dihydroxyphenyl is a particularly preferred radical B or B'. 
Particular preference is given to those compounds in which B and B', 
independently of each other, are a radical of the formula 
##STR11## 
in which R.sub.3 hydrogen, hydroxyl, methoxy, chlorine, fluorine, 
carboxyl, or sulfo, r.sub.1 is 1, 2 or 3, R.sub.4 is hydroxyl, amino or 
alkoxy, sulfoalkyloxy or acylamino each having 1 to 4 carbon atoms, 
R.sub.5 is hydrogen, chlorine or sulfo, R.sub.6 is hydrogen, alkyl having 
1 to 4 carbon atoms, carboxyalkyl having 1 to 4 carbon atoms or amino, and 
r2 is 1 or 2 and especially, independently of each other, a radical of the 
formula 
##STR12## 
The compounds according to the invention absorb not only in large portions 
of the visible spectrum but also to a high degree in the ultraviolet 
region. The molar extinction coefficients of these compounds at 
wavelengths below 400 nm are distinctly higher than those of corresponding 
compounds without UV-absorbent groups. Furthermore, the compounds 
according to the invention all have a dark colour, for example dark brown, 
dark blue, dark green or black. The black compounds can for example also 
be used for preparing black and white images from silver dye bleach 
material. All compounds of the formula (1) are readily bleached under the 
conditions customary for the processing of exposed silver dye bleach 
materials. 
The novel compounds of the formula (1) are prepared by customary methods. 
If L and L' are azo groups, the compound of the formula 
EQU (H.sub.2 N.sub.m -A-NH.sub.2).sub.n ( 6) 
is turned into the corresponding tetrazo compound, A, m and n being defined 
as above. This compound is then converted by coupling with the compound of 
the formula 
EQU B--H (7) 
or 
EQU B'--H (7a) 
in which B and B' are as defined above, into the corresponding compound of 
the formula 
EQU (B--N.dbd.N.sub.m -A-N.dbd.N--B').sub.n (ia) 
If L and L' are as defined above save azo groups, it is advantageous to 
proceed from the compound of the formula 
EQU (H.sub.m -A-H).sub.n ( 8) 
and react this compound with the compound of the formula 
EQU B-L-halogen (9) 
or 
EQU B'-L'-halogen (9a) 
to give the compound of the formula 
EQU (B--L.sub.m -A-L'--B').sub.n ( 1b) 
The incorporation of the compounds according to the invention and also of 
those compounds of the formula (1) in which the radicals B and B' are both 
2,4-dihydroxyphenyl groups in photographic silver dye bleach materials is 
carried out as follows: 
The stated compounds, preferably as solution in water or in a 
water-miscible solvent, are added with stirring at room temperature or 
elevated temperature to an aqueous gelatin solution. Subsequently this 
mixture is brought together with a binder containing silver halide and/or 
other materials for producing photographic images, and the resulting 
mixture is cast in conventional manner on a substrate to form a layer 
which can, if desired, be dried. 
The solution of these compounds can also be added directly to a binder 
containing silver halide and/or other materials for producing photographic 
images. It is possible, for instance, to meter in the solution only 
immediately before casting. Instead of simply stirring, it is also 
possible to use the customary methods of dispersion which rely on kneading 
and/or shearing forces or ultrasound. It is also possible to add the 
compounds according to the invention not as solution but in solid form or 
as paste. 
Suitable silver halide emulsions can contain silver bromide or silver 
iodobromide but also silver chloride or silver chlorobromide or silver 
chloroiodobromide. The silver halide emulsions can be spectrally 
sensitised and contain stabilisers and anti-fogging agents. Such silver 
halide emulsions are described for example in Research Disclosure No. 17, 
643 (December 1978), No. 18, 155 (May 1979) and No. 22, 534 (January 
1983). The choice of a specific emulsion is determined especially by the 
sensitivity required for the material. 
The gelatin used in the photographic material according to the invention as 
a binder for the compounds of the formula (1) used as image dye, for 
silver halide and, if present, filter dyes can contain additives, for 
example polyvinyl alcohol or polyvinylpyrrolidone. Furthermore, a portion 
of the gelatin can be replaced by dispersions of water--insoluble, 
high-molecular substances, for example dispersion polymers of 
.alpha.,.beta.-unsaturated compounds such as acrylate esters, vinyl esters 
and vinyl ethers, vinyl chloride and also vinylidene chloride. The 
gelatins are preferably crosslinked by means of the triazine derivatives 
described in Swiss Patent Publication No. 574,980. However, it is also 
possible to use other curing agents, for example aldehydes, vinyl 
sulfones, diimines and the like. 
The substrate for the material used according to the invention can be a 
customary transparent material, for example a material made of cellulose 
triacetate or polyester. 
Preferably the material according to the invention contains a transparent 
substrate, a silver halide emulsion layer containing a compound of the 
formula (1), and if desired a protective layer. In addition, the material 
according to the invention can also have a layer containing a bleachable 
image dye. 
The processing of the exposed silver dye bleach materials is generally 
carried out in four successive steps: silver development, dye bleach, 
silver bleach and fixing. 
The first step consists of the development of the latent silver image 
formed in the course of exposure. The second step consists in bleaching 
out the image dye which is associated with the silver in correspondence 
with the present imagewise distribution of the silver. The third step is 
necessary to reoxidise the excess image silver which is still present 
after the dye bleach. In the fourth step, the silver, all of which is then 
present in the form of halides, is removed by dissolving out with a 
complexing agent, in particular with a salt of thiosulfuric acid, in order 
to render the completed image insensitive to further exposure and to free 
the pure dye image of clouding. 
The second process step, namely the dye bleach, takes place in the 
customary known processes in a strongly acid medium and in the presence of 
a catalyst for speeding up the dye bleach. The bleach baths additionally 
contain a silver-complexing agent or ligand. Both components, that is to 
say catalyst and ligand, are necessary in order to transmit the reducing 
action of the metallic, non-diffusible image silver to the similarly 
non-diffusible dye. The reduced form of the catalyst formed by reduction 
at the image silver in this step serves as an intercarrier which, after 
covering a certain diffusion length, irreversibly reduces and hence 
bleaches the dye and thereby is itself reoxidised to the original form. 
The ability of the reduced form of the bleach catalyst to diffuse freely 
between image silver and dye to be bleached makes it possible to keep 
silver and image dye spatially separate from each other to a certain 
degree; that is, to arrange the bleachable dye and the associated silver 
halide emulsion to be not or only partially in the same layer but in 
adjacent layers. Such silver dye bleach materials are described for 
example in No. DE-A-2,036,918, No. DE-A-2,132,835 and No. DE-A-2,132,836. 
A simplified form of the process, wherein the dye bleach and the silver 
bleach are combined in a single process step, is described in No. 
DE-A-2,488,433. 
The combined dye and silver bleach baths (preparations) for processing the 
exposed silver dye bleach material contain components (a) to (e) and can, 
if desired, also contain (f): (a) strong acid, (b) water-soluble iodide, 
(c) water-soluble oxidising agent, (d) oxidation inhibitor, (e) bleach 
catalyst, (f) bleach accelerant. 
The amount of bleach catalysts which is used in the preferably aqueous 
treatment baths can vary within wide limits and is about 0.05 to 10 g/l of 
bleach bath. 
The temperature of the bleach bath is generally between 20.degree. and 
90.degree. C., preferably between 20.degree. and 60.degree. C., the 
necessary duration of treatment at a relatively high temperature being of 
course shorter than at a relatively low temperature. The bleach baths are 
stable within the specified temperature ranges. The aqueous bleach 
preparations required for processing are generally used in the form of 
dilute aqueous solutions which contain the stated components. However, 
there are other possible methods, for example the use in paste form. 
This temperature range also applies to the other processing steps. The 
aqueous bleach preparation according to the present invention can be 
prepared for example from liquid, in particular aqueous, concentrates of 
individual or all components (a) to (f). Advantageously use is made of, 
for example, two liquid concentrates, one of which contains the strong 
acid (a) and the oxidising agent (c) and the other of which contains the 
other components (b), (d), (e) and if desired (f), this latter concentrate 
also containing an additional solvent for improving the solubility, in 
particular of component (e), such as ethyl or propyl alcohol, benzyl 
alcohol, or ethylene glycol methyl or ethyl ether. The aqueous bleach 
preparations which are used generally contain the components (a) to (f) in 
the following amounts: (a) strong acid: 10 to 220 g/l; (b) water-soluble 
iodide: 2 to 50 g/l, preferably 5 to 25 g/l; (c) water-soluble oxidising 
agent: 1 to 30 g/l; (d) oxidation inhibitor: 0.5 to 10 g/l; (e) bleach 
catalyst: 0.05 to 10 g/l, and if desired (f) bleach accelerant: 1 to 20 
g/l. 
The strong acids (component (a)) in the combined dye and silver bleach 
baths can be alkylsulfonic or arylsulfonic acids and in particular 
p-toluenesulfonic acid, sulfuric acid, sulfamic acid or trichloroacetic 
acid. If desired it is also possible to use mixtures of these acids. The 
pH of the bleach bath is in particular not higher than 2 and preferably 
not higher than 1. 
The water-soluble iodides (component (b)) are generally alkali metal 
iodides, in particular sodium iodide or potassium iodide. 
The oxidising agents (c) used are advantageously water-soluble aromatic 
mononitro or dinitro compounds or anthraquinonesulfonic acid derivatives. 
The use of such oxidising agents serves to influence the dye equilibrium 
and the contrast of the images prepared in the dye bleach process and is 
known from German Pat. No. 735,672, British Pat. Nos. 539,190 and 539,509 
and Japanese Patent Publication No. 22673/69. 
The mononitro and dinitro compounds are preferably mononitrobenzenesulfonic 
and dinitrobenzenesulfonic acids, o-nitrobenzenesulfonic acid, 
m-nitrobenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, 
3,5-dinitrobenzenesulfonic acid, 3-nitro-4-chlorobenzenesulfonic acid, 
2-chloro-5-nitrobenzenesulfonic acid, 4-methyl-3,5-dinitrobenzenesulfonic 
acid, 3-chloro-2,5-dinitrobenzenesulfonic acid, 
2-amino-4-nitrobenzenesulfonic acid, 
2-amino-4-nitro-5-methoxybenzenesulfonic acid and 4-nitrophenol-2-sulfonic 
acid. 
The compounds of component (c) serve not only as silver bleach agents but 
also for flattening gradations. 
The oxidation inhibitors (corrosion inhibitors) (d) used are advantageously 
reductones or water-soluble mercapto compounds. Suitable reductones are in 
particular acireductones having a 3-carbonyl-1,2-diol grouping, such as 
reductone, triosereductone or preferably ascorbic acid. Suitable mercapto 
compounds are for example thioglycerol, but in particular the compounds of 
the formulae HS--C.sub.q H.sub.2q --B or preferably HS--(CH.sub.2).sub.m 
--COOH, in which q is an integer from 2 to 12, B is a sulfo or carboxyl 
group and m is one of the numbers 3 and 4. Mercapto compounds which can be 
used as oxidation inhibitors are described in No. DE-A-2,258,076 and No. 
DE-A-2,423,814. Further suitable oxidation inhibitors are alkali metal, 
alkaline earth metal and ammonium bisulfite adducts of organic carbonyl 
compounds, preferably alkali metal or ammonium bisulfite adducts of 
monoaldehydes having 1 to 4 or dialdehydes having 2 to 5 carbon atoms (No. 
DE-A-2,737,142). 
Examples are the particularly preferred formaldehyde bisulfite adduct and 
also the corresponding adducts of acetaldehyde, propionaldehyde, 
butyraldehyde or isobutyraldehyde, of glyoxal, malondialdehyde or 
glutardialdehyde. If desired, the tertiary water-soluble phosphines given 
below as bleach accelerants can also be used at the same time as oxidation 
inhibitors. 
Examples of suitable bleach accelerants (f) are quaternary ammonium salts 
of the type known from Nos. DE-A-2,139,401 and 2,716,136. These salts are 
preferably quaternary, substituted or unsubstituted piperidine, 
piperazine, pyrazine, quinoline or pyridine compounds, the latter being 
preferred. It is also possible to use tetraalkylammonium compounds (alkyl 
having 1 to 4 carbon atoms) and alkylenediammonium compounds (alkylene 
having 2 to 6 carbon atoms). Specific examples are: tetraethylammonium 
iodide; (CH.sub.3).sub.3 N.sup..sym. (CH.sub.2).sub.2 N.sup..sym. 
(CH.sub.3).sub.3.2I.sup..crclbar. ; (CH.sub.3).sub.3 N.sup..sym. 
(CH.sub.2).sub.6 N.sup..sym. (CH.sub.3).sub.3.2I.sup..crclbar. ; 
N-methylpyridinium iodide, N-methylquinolinium iodide; 
N-hydroxyethylpyridinium chloride; N-hydroxypropylpyridinium bromide; 
N-methyl-2-hydroxymethylpyridinium iodide; N,N-dimethylpiperidinium 
iodide; N,N'-dimethylpyrazinium fluorosulfate; and .gamma.-picolinium 
hydrogensulfate. 
Further bleach accelerants are the water-soluble tertiary phosphines which 
are known from No. DE-A-2,651,969 and which preferably contain at least 
one cyanoethyl group, for example 
bi-(.beta.-cyanoethyl)-2-sulfoethylphosphine (sodium salt), 
bis-(.beta.-cyanoethyl)-3-sulfopropylphosphine sodium salt), 
bis-(.beta.-cyanoethyl)-4-sulfobutylphosphine (sodium salt), 
bis-(.beta.-cyanoethyl)-2-methoxyethylphosphine, 
bis-(2-methoxyethyl)-(.beta.-cyanoethyl)-phosphine, 
(.beta.-cyanoethyl)-phenyl-3-sulfopropylphosphine (sodium salt), 
(.beta.-cyanoethyl)-phenyl-2-methoxyethylphosphine and 
bis-(2-methoxyethyl)-phenylphosphine. 
To develop the silver it is possible to use baths of customary composition, 
for example those which contain, as developer substance, hydroquinone and 
can, if desired, also contain 1-phenyl-3-pyrazolidinone. If desired, the 
silver development bath already contains a bleach catalyst. 
The silver-fixing bath can be composed in known and conventional manner. 
The fixing agent used can be for example sodium thiosulfate or, 
advantageously, ammonium thiosulfate, if desired together with additives 
such as sodium bisulfite and/or sodium metabisulfate. 
The images prepared from the material according to the invention are 
distinguished by good reproduction and legibility of the depicted details. 
The image dyes also have the required high absorption in the ultraviolet 
spectrum. These properties make it possible to use the images as originals 
for preparing, for example, copies by the diazotype method. For example, 
the images prepared with the material according to the invention can be 
present in the form of microfiches. The information contained thereon can 
then be magnified and copied on to diazotype material. Examples of 
suitable diazotype materials are described in German Pat. No. 1,285,874 
and German Pat. No. 2,166,264. 
The material according to the invention can however also be used for 
preparing high-quality black and white images.

PREATION EXAMPLES 
EXAMPLE 1: 
Dye of the formula 
##STR13## 
A mixture of 12.2 g (0.05 m) of o-dianisidine in 50 ml of water and 11.5 ml 
of concentrated hydrochloric acid (39%) is heated at 80.degree. C and is 
cooled down, and a further 11.5 ml of hydrochloric acid (39%) are added. 
The solution is tetrazotised with 8.0 g (0.115 m) of sodium nitrite while 
cooling with ice and, after destruction of the excess nitrite with 
sulfamic acid, is coupled on to 22.0 g of H acid (72.7%) (0.05 m) under 
acid conditions. 4.4 g (0.047 m) of aniline are then diazotised and added 
to the intermediate. Coupling is effected by raising the pH to 9 by means 
of sodium carbonate. After 1 hour the pH is raised to 10 by means of 
sodium carbonate and an aqueous solution of 11.8 g (0.005 m) of 
2,4-dihydroxybenzophenone, adjusted to pH 10 with aquesous sodium 
hydroxide solution, is added dropwise. After 1 hour at 10.degree. C. the 
reaction mixture is heated to 50.degree. C. and cooled down again. On 
acidifying with hydrochloric acid to pH 1 the dye of the formula (102) 
precipitates. It is purified by repeated suspension in warm pyridine and 
ethanol. This gives 12.6 g of dye (55.7% yield). 
EXAMPLE 2: 
Dye of the formula 
##STR14## 
Example 1 is repeated, except that dihydroxybenzophenone is replaced by an 
equivalent amount of 4-amino-2-hydroxybenzophenone which is coupled on to 
the diazo intermediate at pH 8.2, affording 6.9 of the trisazo dye of the 
formula (103) (30.5% yield). 
EXAMPLE 3: 
Dye of the formula 
##STR15## 
Example 1 is repeated, except that dihydroxybenzophenone is replaced by an 
equivalent amount of 2-(4-amino-2-hydroxy)-phenylbenzotriazole-5-sulfonic 
acid which is coupled on to the diazo intermediate at pH 8.2, affording 
17.9 g of the dye of the formula (104) (7.8% yield). 
EXAMPLE 4 
Dye of the formula 
##STR16## 
12.2 g (0.05 m) of o-dianisidine are tetrazotised as in Example 1. The 
tetrazo solution is added dropwise at 10.degree. C. to a coupling solution 
of 33.6 g (0.10 m) of gamma acid (71.2%) and 4 g of sodium hydroxide in 
350 ml of water, while the pH is maintained between 8 and 9. After 
stirring overnight, the reaction mixture is heated to 60.degree. C. and 
cooled down again. The intermediate isolated by filtration is purified by 
repeated suspension in warm ethanol. 7.9 g (0.01 m) of intermediate 
(calculated as 100% pure) is tetrazotised in aqueous hydrochloric acid 
solution (pH 2) with 1.5 g (0.022 m) of sodium nitrite. After destruction 
of the excess nitrite by means of sulfamic acid, the tetrazo solution is 
coupled on to 5.1 g (0.024 m) of 2,4-dihydroxybenzophenone, which has been 
dissolved in 80 ml of water and brought to pH 10 with aqueous sodium 
hydroxide solution, while pH 10 is maintained by means of sodium 
carbonate. The reaction mixture is stirred at 10.degree. C. for 4 hours, 
is then heated to 40.degree. C., is cooled down again and is filtered. The 
isolated crude product is purified as in Example 1. This gives 8.7 g of 
dye of the formula (202) (70.2% yield). 
EXAMPLE 5 
Dye of the formula 
##STR17## 
Example 4 is repeated, except that dihydroxybenzophenone is replaced by an 
equivalent amount of 4-amino-2-hydroxybenzophenone and coupling is carried 
out at pH 8.5, affording 9.0 g of the tetrakisazo dye of the formula (203) 
(73.1% yield). 
EXAMPLE 6 
##STR18## 
Example 4 is repeated, except that dihydroxybenzophenone is replaced by 
2-(4-amino-2-hydroxy)-phenylbenzotriazole-5-sulfonic acid and coupling is 
carried out at pH 8.5, affording 10.7 g of the tetrakisazo dye of the 
formula (204) (73.2% yield). 
EXAMPLE 7 
Dye of the formula 
##STR19## 
11.2 g (0.4 m) of 4,4'-di-(aminophenyl)-amine-2-sulfonic acid are suspended 
in 1,500 ml of water. After acidification with 140 ml of hydrochloric 
acid, the suspension is tetrazotised at 0.degree. C. with 57 g (0.83 m) of 
sodium nitrite dissolved in 75 ml of water. After one hour the excess 
nitrite is destroyed with sulfamic acid. 215 g (0.9 m) of gamma acid are 
dissolved at pH 7 in 720 ml of water by addition of aqueous sodium 
hydroxide solution. After addition of 1,200 ml of 14% sodium carbonate 
solution, the tetrazo solution is added dropwise at a temperature of at 
most 10.degree. C. in the course of 30 minutes. The resulting suspension 
is stirred for 2 hours and is then heated to 20.degree. C. and finally to 
40.degree. to 50.degree. C. The suspension is filtered at 20.degree. C., 
and the moist crude product is suspended twice in 400 ml of hot ethanol. 
33.8 g (0.4) of this intermediate suspended in 1,100 ml of water and 
acidified with 9.5 ml of concentrated sulfuric acid (93%) are tetrazotised 
at 0.degree. to 5.degree. C. by means of 6.1 g (0.088 m) of sodium 
nitrite. After 4 hours at 0.degree. to 5.degree. C. the excess nitrite is 
destroyed with sulfamic acid. 20.6 g (0.096 m) of 
2,4-dihydroxybenzophenone are dissolved in 320 ml of water by heating in 
the presence of 10 ml of aqueous sodium hydroxide solution (10 m) and 80 
ml of sodium carbonate solution (14%). The coupling is carried out at a 
temperature of at most 10.degree. C. by dropwise addition of the tetrazo 
solution and while the pH is maintained at b10 by means of sodium 
carbonate. After 4 hours of reaction at 10.degree. C., the reaction 
mixture is heated to 30.degree. C. until everything has gone into 
solution. The dye is precipitated by acidifying with sulfuric acid to pH 1 
and filtered off. The moist crude product is purified by suspension in hot 
methanol and subsequently in sulfuric acid (1N). This gives 9.8 g of dye 
of the formula (206) (39.2% yield). 
EXAMPLE 8 
Dye of the formula 
##STR20## 
The tetrazotised intermediate of Example 7 is coupled at pH 5.5, buffered 
with sodium acetate, on to an equivalent amount of 
4-amino-2-hydroxybenzophenone in place of 2,4-dihydroxybenzophenone. The 
dye is purified by suspension in pyridine and ethanol as in Example 1. 
This gives 10.9 g of dye of the formula (207) (42.0% yield). 
EXAMPLE 9 
Dye of the formula 
##STR21## 
Coupling the tetrazotised intermediate of Example 7 at pH 10 on to an 
equivalent amount of 2-(4-amino-2-hydroxy)-phenylbenzotriazole-5-sulfonic 
acid in place of 2,4-dihydroxybenzophenone and purifying the crude dye as 
in Example 1 gives the tetrakisazo dye of the formula (208) in 79.4% yield 
(14.2 g). 
EXAMPLE 10 
Dye of the formula 
##STR22## 
Coupling the tetrazotised intermediate of Example 7 on to an equivalent 
amount of 2-(2,4-dihydroxyphenyl)-benzotriazole, dissolved in acetone, in 
place of 2,4-dihydroxybenzophenone and purifying the crude product as in 
Example 1 gives the tetrakisazo dye of the formula (209) in 78.2% yield 
(13.1 g). 
EXAMPLE 11 
Dye of the formula 
##STR23## 
11.2 g (0.020 m) of the disazo dye 
##STR24## 
are tetrazotised in hydrochloric acid solution with 3.0 g (0.044 m) of 
sodium nitrite, the nitrite excess is destroyed with sulfamic acid, and 
the tetrazonium salt is coupled on to 9.4 g (0.044 m) of 
2,4-dihydroxybenzophenone as in Example 1. The crude dye is purified as in 
Example 1. This gives 10.6 g of the dye of the formula (302) (50.4% 
yield). 
The disazo dye of the formula (302a) is prepared in known manner by, first, 
coupling 1 mole of diazotised p-nitroaniline on to 1 mole of 
1-amino-8-naphthol-3,6-disulfonic acid under acid conditions, then 
coupling on to the resulting monoazo dye a second mole of diazotised 
p-nitroaniline under alkaline conditions, and finally reducing the two 
nitro groups of the disazo dye with sodium sulfide to form amino groups. 
EXAMPLE 12 
Dye of the formula 
##STR25## 
11.2 (0.020 m) of the disazo dye of the formula (302a) are tetrazotised and 
coupled on to 9.4 g (0.044 m) of 4-amino-2-hydroxybenzophenone at pH 8.5, 
both steps being carried out as in Example 11. This gives the dye of the 
formula (303) in a 21.2% yield (4.5 g). 
EXAMPLE 13 
Dye of the formula 
##STR26## 
5.5 g (0.005 m) of the trisazo dye of the formula 
##STR27## 
are tetrazotised in hydrochloric acid solution with 0.8 g (0.011 m) of 
sodium nitrite, the nitrite excess is destroyed with sulfamic acid, and 
the tetrazonium salt is coupled at pH 10 on to 2.6 g (0.012 m) of 
2,4-dihydroxybenzophenone. This gives the pentakisazo dye of the formula 
(402) as a crude product, which is purified as described in Example 1. 
Yield 51.9% (4.0 g). 
The preparation of the trisazo dye of the formula (402a) is described in 
DE-A No. 2,215,081. 
EXAMPLE 14 
Dye of the formula 
##STR28## 
5.5 g (0.005 m) of the trisazo dye of the formula (402a) are tetrazotised 
as in Example 13 and coupled at pH 8.5 on to 2.6 g (0.012 m) of 
4-amino-2-hydroxybenzophenone. This gives 7.5 g of the dye of the formula 
(403) (51.9% yield). 
EXAMPLE 15 
Dye of the formula 
##STR29## 
Tetrazotisation of 5.5 g (0.005 m) of the trisazo dye of the formula (402a) 
and coupling of the tetrazonium salt at pH 8.5 on to 3.7 g (0.012 m) of 
2-(4-amino-2-hydroxy)-phenylbenzotriazole-5-sulfonic acid gives 4.0 g of 
the pentakisazo dye of the formula (404) (44.9% yield). 
EXAMPLE 16 
Dye of the formula 
##STR30## 
Example 13 is repeated, except that the trisazo dye of the formula (402a) 
is replaced by the isomeric starting material of the formula 
##STR31## 
The pentakisazo dye of the formula (405) is obtained in 66.6% yield (8.1 
g). 
EXAMPLE 17 
Dye of the formula 
##STR32## 
Example 14 is repeated except that the trisazo dye of the formula (402a) is 
replaced by that of the formula (402b). 5.9 g of the pentakisazo dye of 
the formula (406) are obtained (63.6% yield). 
EXAMPLE 18 
Dye of the formula 
##STR33## 
38 g (0.04 m) of the disazo dye of the formula 
##STR34## 
are suspended in 1,100 ml of water. The resulting suspension is heated to 
50.degree. C. and is cooled down again to room temperature. 6.1 g (0.088 
m) of sodium nitrite dissolved in 30 ml of water are added. This is 
followed by cooling in ice down to 0.degree. to 5.degree. C. 30 ml (0.35 
m) of concentrated hydrochloric acid are then added, and the suspension is 
stirred at 0.degree. to 5.degree. C. for 4 hours. The nitrite excess is 
then destroyed with sulfamic acid. The tetrazo suspension thus obtained is 
added in the course of 30 minutes to a cooled coupling agent solution at 
0.degree. C. which contains 9.7 g of resorcinol (0.088 m) and 31.8 g (0.30 
m) of sodium carbonate in 100 ml of water. During the dropwise addition of 
the tetrazo suspension to the coupling solution the pH is maintained at 10 
by the simultaneous addition of about 200 ml of sodium carbonate solution 
(14%). The reaction mixture is reacted at a temperature below 10.degree. 
C. for 4 hours and is then allowed to warm up to room temperature. After 
heating the reaction mixture to 40.degree. C. for 1 hour, the crude 
product (200 g) is isolated and suspended in 900 ml of water. The 
suspension is brought to pH 12 with aqueous sodium hydroxide solution 
(30%) and is then stirred at 70.degree. C. until a solution forms. The 
solution is filtered, and the compound of the formula (407) is 
precipitated as crude product by addition of 30 ml of concentrated 
hydrochloric acid. This crude product is purified by boiling in ethanol 
for 30 minutes and drying at 70.degree. C. in vacuo. This gives 32 g 
(71.2% yield) of the compound of the formula (407). 
Table 1 below shows the position of the absorption maximum and the molar 
extinction coefficients of a solution of the dyes according to the 
invention prepared in Examples 1 to 17 in a mixture of dimethylformamide 
(DMF/H.sub.2 O(1:1)). 
TABLE 1 
______________________________________ 
Dyes of the 
formula .lambda..sub.max (nm) 
.xi..sub.mol 
______________________________________ 
102 567 35 500 
103 574 37 600 
104 575 41 800 
202 618 69 200 
203 609 81 400 
204 615 81 100 
206 609 61 100 
207 583 58 100 
208 610 60 600 
209 582 67 000 
302 652 67 100 
303 623 26 800 
402 587 49 000 
403 585 52 000 
404 595 65 400 
405 612 63 800 
406 611 55 200 
407 610 56 300 
______________________________________ 
Use Examples 
EXAMPLE 19 
364 mg of the dye of the formula 
##STR35## 
(comparative compound) are dissolved in 50 ml of water and added to a 
mixture of 38 ml of 3.7% aqueous gelatin solution, 1 ml of an 8% solution 
of the sodium salt of dibutylnaphthalenesulfonic acid and 11 g of a 
spectrally non-sensitised gelatin silver chloroiodobromide solution which 
contains about 140 g of silver and 70 g of gelatin per kilogram. This 
mixture is cast together with a protective layer consisting of 37.4 ml of 
3.9% aqueous gelatin solution, 1 ml of a 6% solution of the sodium salt of 
the bis-2-ethylhexyl ester of sulfosuccinic acid, 1 ml of a 3% solution of 
a fatty acid alkanolamide and 0.6 ml of a 10% solution of formaldehyde on 
to 1 m.sup.2 of a polyester substrate and dried. 
Behind a step wedge, the light-sensitive material thus obtained is exposed 
through a blue filter with 10,000 lux/cm.sup.2 for 1 second and is 
processed at 30.degree. C. as follows: 
______________________________________ 
Developing 1.5 minutes 
Washing 0.5 minute 
Silver and dye bleach 1.5 minutes 
Washing 0.5 minute 
Fixing 1.5 minutes 
Washing 3 minutes 
Drying 
______________________________________ 
The developer bath contains the following components per liter of solution: 
______________________________________ 
per liter of solution: 
______________________________________ 
Sodium sulfite 38.0 g 
Potassium sulfite 19.9 g 
Lithium sulfite 0.6 g 
1-Phenyl-3-pyrazolidinone 
1.0 g 
Hydroquinone 12.0 g 
Potassium carbonate 29.1 g 
Potassium bromide 1.5 g 
Benzotriazole 0.5 g 
Ethylenediaminetetraacetic acid 
4.0 g 
(sodium salt) 
______________________________________ 
The silver bleach bath has the following composition per liter of solution: 
______________________________________ 
Concentrated sulfuric acid 
56.2 g 
m-Nitrobenzenesulfonic acid 
6.0 g 
(sodium salt) 
Potassium iodide 8.0 g 
Hydroxyethylpyridinium chloride 
2.4 g 
2,3-Dimethylquinoxaline 2.5 g 
4-Mercaptobutyric acid 1.8 g 
______________________________________ 
The fixing bath contains per liter of solution: 
______________________________________ 
Ammonium thiosulfate 
200 g 
Ammonium metabisulfite 
24 g 
______________________________________ 
The result obtained is a light-fast colour wedge having a deep molecular 
extinction coefficient at 350 nm in the unbleached areas (cf. Table 2). 
The other dyes according to the invention can be incorporated into the 
layers of photographic materials in analogous manner. Table 2 shows the 
amounts of incorporated dye and the corresponding molar extinction 
coefficients in the layer of the photographic material. 
TABLE 2 
______________________________________ 
Dye of the 
formula Amount (mg) 
.xi.(350 nm) 
______________________________________ 
101 364 15 400 
(comparison) 
102 412 25 000 
103 412 28 100 
104 454 36 200 
201 468 22 800 
(comparison) 
202 565 34 200 
203 564 41 800 
204 669 44 700 
205 464 21 000 
(comparison) 
206 591 39 000 
207 590 36 000 
208 645 44 500 
209 617 43 900 
301 383 12 700 
(comparison) 
302 480 20 200 
303 479 23 800 
401 611 28 900 
(comparison) 
402 705 38 400 
403 707 41 900 
404 811 41 900 
405 711 40 200 
406 540 39 900 
407 620 39 100 
______________________________________ 
The table illustrates that the UV absorption of the compounds according to 
the invention in photographic material is significantly higher than that 
of the corresponding comparative compounds without UV-absorbent groups. 
The comparative compounds of the formulae (201), (205), (301) and (401) 
have the following structures: 
##STR36## 
The comparative compounds only differ from the corresponding compounds 
according to the invention in the groups B and B'. 
EXAMPLE 20 
633 mg of dye of the formula (206) are dissolved in 56 ml of water and 
added to a mixture of 42 ml of 3.7% aqueous gelatin solution, 1 ml of an 
8% solution of the sodium salt of dibutylnaphthalenesulfonic acid and 12 g 
of a spectrally non-sensitised gelatin silver chloroiodobromide emulsion 
which contains about 140 g of silver and 70 g of gelatin per kilogram. 
This mixture is cast together with a protective layer consisting of 37.4 ml 
of 3.9% aqueous gelatin solution, 1 ml of a 6% solution of the sodium salt 
of the bis-2-ethylhexyl ester of sulfosuccinic acid, 1 ml of a 3% solution 
of a fatty acid alkanolamide and 0.6 ml of a 10% solution of formaldehyde 
on to 1 m.sup.2 of a polyester substrate and dried. 
A microfiche was exposed on to the light-sensitive material thus obtained 
in a manner known per se and processed as described in Example 19. 
The processed photographic material had a maximum density of 1.70 as 
measured by a UV filter of the Wratten 18 A type. 
Duplication on to a diazo material produced copies of good quality in an 
exposure time of 4 seconds compared with 5 seconds for a commercially 
available silver microfilm.