DE1422849B1 - Multilayer photographic recording material for the dye developer diffusion process - Google Patents

Description

The invention relates to a photographic, multilayer recording material for the dye developer diffusion process, consisting of a support and variously sensitized silver halide emulsion layers applied to it, as well as optionally intermediate and top layers that are present in the sensitized silver halide emulsion layers or contains subtractively colored dye developers dispersed in underlying layers.

Dye developer diffusion process for the production of multicolored images in which a multilayer Photographic recording material composed of a support with variously sensitized Consists of silver halide emulsion layers and, if applicable, intermediate and top layers, being in these layers, dissolved subtractively in at least one high-boiling organic solvent Colored dye developers are dispersed, exposed and with an alkaline solution in the presence a small amount of an auxiliary developer is developed and in which the non-oxidized Dye developer on an image receiving material in contact with the recording material are known from British patent specification 804,971, for example. The ones in the Dye developer present for the recording materials used to carry out the process are compounds that like the chromophoric system of a dye and a developer function Silver halide developing compounds. Become the latent ones obtained upon exposure Images with an alkaline solution, d. H. brought into contact with an activator solution containing the emulsion layers and the dye developer If it penetrates layers, the latent images are developed into silver images. Simultaneously form Oxidation products of the dye developers in practically the same areas as the silver images. the Oxidation products of the dye developer are relatively non-diffusing, which is at least partially due to a decrease in solubility in the alkaline solution is due. The one in the layers respectively Unoxidized dye developer which remains in an imagewise distribution can be diffused onto a Image-receiving material, whereby a positive dye image is obtained.

If a recording material is used which has several differently sensitized silver halide emulsion layers contains, and are in the corresponding emulsion layers or in adjacent ones If layers of subtractively colored dye developers are present, multicolored images can be created obtain.

The quality of the images that can be produced depends, at least in part, on the degree to which the Dye developers set in the exposed areas of the emulsion layers during development will.

If unoxidized dye developer remains in fully exposed areas, which correspond to the high lights of the captured image object, this is transferred to the image receiving material together with the unconverted dye developer of the positive image areas and leads to high D _mi "values here.

Typical known dye developers, such as 1,4-bis [| S- (2,5-dioxyphenyl) ethylamino] anthraquinone, are relatively weak silver halide developers, even when used at relatively high pH values . They therefore do not develop a silver halide emulsion layer very quickly and vigorously, so that colored images obtained when they are used generally have undesirably high D _mi " values in the areas of high light and low color saturation.
It is therefore known e.g. B. from British patent specification 804 971, to carry out the development in the presence of a so-called silver halide auxiliary developer compound, such as p-methylaminophenol sulfate, in order to accelerate the silver halide development and the fixing of the dye developer in the recording materials. The use of auxiliary developing agents such as p-methylaminophenol sulfate does improve the quality of the images to some extent, but the results have not been really satisfactory.

The object of the invention was therefore to provide a recording material for the known dye developer diffusion process from which images of improved quality, in particular lower M D _mf "values, can be produced. ™

The invention relates to a photographic, multilayer recording material for the dye developer diffusion process, consisting of a support and variously sensitized silver halide emulsion layers applied to it, and, optionally, intermediate and top layers in sensitized silver halide emulsion layers or subtractively colored dye developers are dispersed in underlying layers which is characterized in that it contains an auxiliary developer in the form of a solution of Phenylhydroquinone ^ '- Oxyphenylhydroquinone ^' - Methylphenylhydroquinone, 4-chlorophenylhydroquinone or 2,5-diphenylhydroquinone in a low molecular weight, organic, water-insoluble (so-called "crystalloidal") solvents with a boiling point contains dispersed above 175 ° C.

The invention achieves that multicolored images of improved quality are obtained. Apparently when using the hydroquinones ^

as auxiliary developing complete the dye developer in the individual layers mono-% and more evenly defined is reduced so that the color contamination of the color developer images formed.
The use of solvents to disperse the dye developers prevents the latter from crystallizing out of the hydrophilic organic colloid layers, for example gelatin layers. In addition, less colloid is required for the production of the dye developer layers, which is why very thin layers can be obtained in which the dye developers can be quickly set or from their unexposed areas they can be quickly extracted by the alkaline activator and transferred to the image receiving material.

Particularly good results are obtained when the hydrophilic colloidal binder of the layers of the recording material consists mainly of gelatin.

The silver halide emulsion layers and the adjoining layers of the for implementation The recording material used in the process of the invention may be those from the French

Patent specification 1 205 755 known emulsion additives, such as noble metal salts, stannous salts, polyamines, optical sensitizing dyes, mercury and azaind stabilizers, quaternary ammonium salts and polyethylene glycols to increase sensitivity, Plasticizers, hardeners, coating aids and colloidal forming agents.

The drawing serves to explain the invention in more detail. In detail are shown in

Fig. 1 shows the implementation of the method of the invention in the scheme,

F i g. 2 a recording material suitable for carrying out the method of the invention,

F i g. 3 shows an apparatus for carrying out the method of the invention.

The in Fig. 1 with A designated recording material consists of the substrate 1, the applied layer 2 with a cyan dye developer, the red-sensitive silver halide emulsion layer 3, the intermediate layer 4, the layer 5 with a magenta dye developer, the green-sensitive silver halide emulsion layer 6, the intermediate layer 7, the layer 8 with a Yellow dye developer, the blue-sensitive silver halide emulsion layer 9 and the overcoat layer 10 containing 4-methylphenylhydroquinone.

The image-receiving material B , which consists of the layer support 13 and the image-receiving layer 12, is arranged above the recording material A. A breakable container 11 with the activator solution is located between recording material A and image receiving material B.

If the container 11 z. B. when passing the sandwich through the gap between two roles in one If the camera is destroyed, its contents spill evenly over the recording material. The activator solution penetrates into the layer 10, dissolves the water-insoluble, alkali-soluble and diffusible 4-methylphenylhydroquinone and leads it to the underlying layers where the latent images of the Layers 3, 6 and 9 are developed into silver images 14, 15 and 16, respectively. The district dye developers 14, 15 and 16 are set. The unreacted dye developers of the layers 2, 5 and 8 then diffuse image-wise and with the correct contours onto the image-receiving layer 12 and form then the dye image (step 2). This consists of the yellow part 17 and the purple part 18 and the blue-green part 19.

The in Fig. 2 shown recording material consists of the layer support 1 ', the red-sensitive, a cyan dye developer-containing silver halide emulsion layer 2 of the green-sensitive, a silver overhalide emulsion layer containing a magenta dye developer 3 ', the blue sensitive containing a yellow dye developer Silver halide emulsion layer 4 'and the 4-methylphenylhydroquinone containing top layer 5 '.

In the in F i g. 3, the exposed recording material 20, wound with the emulsion side inward, of the structure designated by A in FIG. In the trough 23 there is an activator solution which is taken up by the roller 22 and applied to the recording material 20. The recording material passes from rollers 21 and 22 into the roller gap formed by rollers 24 and 25. In the process, it comes into contact with the image receiving material 26. The sandwich 27 formed is pulled out of the device via the roller 28. Recording material 20 and image receiving material 26 are then separated from one another. The image receiving material 26 contains colored images.

The dye developers are in the layers of the recording material using dispersed as little organic solvents as possible. The solvents used are in usually more soluble in water than the dye developer. For dispersing the dye developer can be a high-boiling solvent alone or together with a low-boiling solvent can be used, it being possible for the latter to be removed again from the dispersion by evaporation. Even Mixtures of high-boiling solvents can be used. Also can be a mixture of one high-boiling, practically water-insoluble solvent and a more water-soluble solvent be used.

The dye developers can be placed in the solvent or the mixed solvent by heating be dissolved, whereupon the resulting solution

is added to an aqueous solution of a colloidal binder, for example a gelatin solution. The mixture obtained can then be homogenized in a colloid mill. The dispersion can then be used immediately or quenched and washed first. The dye developer dispersion can finally also be added to a silver halide emulsion.

Crystalloidal water-insoluble solvents which are particularly suitable for dispersing the dye developers are for example: phthalic acid di tetrahydrofurfuryl ester, ß-methoxyethyl phthalate, N, N-din-butylcarbamic acid ethyl ester, o-methoxyphenyl acetate, tetrahydrofurfuryl propionate, triethyl citrate, Acetyl triethyl citrate, tricresyl phosphate, trip-tert-butylphenyl phosphate, Triethyl phosphate, trin-butyl phosphate, triphenyl phosphate, isoamyl acetate, Dimetrahydrofurfuryl succinate, methyl acetate, dimetrahydrofurfuryl adipate, tetrahydrofurfuryl benzoate, N-n-Amylphthalimid, Diethyllauramid, Dibutyllauramid, Lauroylpiperidin, N-n-Butylacetanilid ^ etraäthylphthalamid ^ -n-Amylsuccinimid, 4-methyl-2-pentanol, 2,4-di-n-amylphenol, ethylene glycol monobenzyl ether, methyl isobutyl carbinol, Furfuryl alcohol, cyclohexane and 2- (2-butoxyethoxy) ethyl acetate.

The three isomeric methylcyclohexanones are special suitable low-boiling solvents for joint use with those listed high-boiling solvents.

Dye developers suitable for practicing the process of the invention are known. You let represented by the following general formula:

40

45

55

60 MN = ND

wherein M denotes an aromatic or heterocyclic ring or a ring system, e.g. B. a Benzene, naphthalene, tetralin, anthracene, anthraquinone, pyrazole or quinoline ring, the optionally can be substituted, for example by oxy, amino, keto, nitro, alkoxy, aryloxy, acyl, Alkylamido- .arylamido- .AlkyKAryKCarboxamido-,

Sulfonamides), carboxyl or sulfo radicals and D one Remainder which gives the dye developer a silver halide developing activity, for example a hydroquinone radical, optionally replaced by amino, alkylamino, alkyl, oxy or alkoxy radicals or halogen atoms may be substituted.

For example, dye developers suitable for practicing the process of the invention are known from Australian patent specification 220 276, German patent specification 1 036 640, British patents 804 971, 804974, 804973 and 804975, French Patent 1,168,292, Canadian Patent specifications 579 038 and 577 021 and Belgian patent 568 344.

The dye developers can be present in the recording materials in the silver halide emulsion layers be present themselves or in these adjacent hydrophilic colloid layers.

Particularly favorable results are obtained when the dye developers are in layers are contained immediately below the emulsion layers, their sensitivity to the colors of the corresponding Dye developers are complementary as shown in FIG.

In multilayer recording materials of the type shown in FIG. 1 shown can be the order the arrangement of the differently sensitized silver halide emulsion layers on the support to be different. That is, the blue-sensitive silver halide emulsion layer, for example can be arranged directly on the support, while the red-sensitive silver halide emulsion layer can be located on the very outside. With such an arrangement of the layers, the sensitivities of the individual silver halide emulsion layers are appropriately matched so that the recording of unwanted blue light images in the silver halide emulsion layers which are primarily sensitive to the red and green regions of the spectrum is prevented. For example, a silver bromide emulsion for the production of the blue-sensitive layer, while silver chloride emulsions are used for the preparation the other layers can be used.

It has proven particularly advantageous to use the recording material according to the invention in the presence to develop an onium compound. The beneficial effect of the onium compounds is based presumably that they react with the dye developers to form salts and that the salt formation has a favorable influence on the solubility properties and the diffusibility the dye developer has. Obviously, the onium compounds temporarily delay the migration of the Dye developer, so that the original diffusion rate of the dye developer is reduced is, with less exposed areas more dye developer under enlargement of the Density is transferred to the image receiving material.

The use of onium compounds in photographic processes is known per se. For example, US Pat. No. 2,648,604 discloses the use of non-surface-active substances quaternary ammonium compounds known as development accelerators. From the USA patents 2 271 622, 2 271 623 and 2 275 727 are also the use of quaternary ammonium, quaternary phosphonium and tertiary sulfonium compounds as sensitizers for silver halide emulsions known.

In the processes known from the stated USA patents, as a result of the use of the onium compounds increases the silver density in the exposed areas of the negatives. When performing a diffusion transfer method using a recording material according to In contrast to this, an increase in density occurs in the positive; i.e., it is primary the result of greater transfer of the dye developer from the unexposed areas of the negative.

Quaternary ammonium compounds have proven to be particularly advantageous onium compounds. According to the invention, usable quaternary ammonium compounds can be, for example represented by the following formulas:

, ι

RN ⁺ -R

Y "

Z-,

N ⁺

where R is an organic radical and Y is an anion and Z represents the atoms necessary to complete a heterocyclic ring. Particularly advantageous heterocyclic quaternary ammonium compounds are those which are in alkaline Solution form diffusible methylene bases and correspond to the following general formula:

—CH) _n = C-CH ₂ R '

X ^e

Here, D denotes the atoms necessary to complete a heterocyclic ring which contains one or more reactive —CH ₂ R 'groups and the remaining ring hydrogen atoms of which can optionally be substituted, for example those to complete a pyridine, quinoline, benzoquinoline, benzoxazole Benzimidazole or isoquinoline ring, benzselenazole, thiazole, benzothiazole, naphthothiazole; R is an optionally substituted alkyl, aryl or aralkyl radical of the benzene series, preferably an alkyl radical having 1 to 4 carbon atoms; R 'is a hydrogen atom or a radical as defined for R; X a

Hydroxylation or an acid anion, for example a Br-, CH ₃ SO ₄ T- or

-SOHon

and η O or 1.

Very particularly advantageous heterocyclic quaternary ammonium compounds of the formula given are pyridinium salts of the formula given with one to three active groups of the formula —CH ₂ R 'in the 2-, 4- and / or 6-position of the pyridinium nucleus; z. B. lower alkyl groups, for example methyl, ethyl or propyl groups or substituted lower alkyl groups, for example oxyalkyl groups, e.g. B. Oxyäthylgruppen, the alkyl groups in question are responsible for the formation of a methylene base. Positions 3 and 5 of the pyridinium nucleus may or may not be substituted, the substituents being e.g. B. of halogen atoms, such as chlorine atoms or lower alkyl or haloalkyl groups, such as methyl, ethyl, propyl and chloroethyl groups.

Typical advantageous salts of the formula given are, for. B. 1-benzyl-2-picolinium bromide; 1- (3-bromopropyl) -2-picolinium-p-toluenesulfonate; 1-phenethyl-2-picolinium bromide; 1- γ- phenylpropyl-2-picolinium bromide; 2,4-dimethyl-1-phenethylpyridinium bromide; 2,6-dimethyl-1-phenethylpyridinium bromide; 5-ethyl-2-methyl-1-phenethylpyridinium bromide; 2 - ethyl 1 - phenethylpyridinium bromide; 1 - [3 - (N - ρ - pyridinium bromide) propyl] -2-picolinium p-toluene sulfonate; Anhydro -1 - (4 - sulfobutyl) -2 - picolinium hydroxide; l - (/ 3-naphthoylmethyl) -2-picolinium bromide; l- (ß- phenyl - carbamoyloxyethyl) - 2-picolinium bromide; 1 - methyl - 2 - picolinium - ρ - toluenesulfonate; 1 - phenethyl 2,4,6 - trimethylpyridinium bromide; 1 - phenethyl 4-n-propylpyridinium bromide; 4-y-oxypropyl-1-phenethylpyridinium bromide and ln-heptyl-2-picolinium bromide.

Suitable tertiary sulfonium and quaternary phosphonium compounds can be expressed by the following formula:

(R) ₃ S ⁺ X "
(R) ₄ P ⁺ X "

wherein R is an organic radical, e.g. B. an alkyl, aralkyl or aryl radical, and X is an anion, ζ. B. a hydroxyl, bromide, chloride or toluenesulfonate anion.

Examples of suitable tertiary sulfonium and quaternary phosphonium compounds are: lauryl dimethyl sulfonium p-toluenesulfonate; Nonyldimethylsulfonium p-toluenesulfonate; Octyldimethylsulfonium p-toluenesulfonate; Butyldimethylsulfonium bromide; Triethylsulfonium bromide; Tetraethylphosphonium bromide, Dimethylsulfonium p-toluenesulfonate; Dodecyldimethylsulfonium p-toluenesulfonate; Decyl dimethyl sulfonium p-toluenesulfonate and ethylene-bis-oxymethyltriethylphosphonium bromide.

The onium compounds can be in either the activator solution and / or the image receiving material be accommodated, but optionally also, although not preferably, in the photosensitive Recording material itself.

The onium compounds can be used in various concentrations.

Advantageous results can be obtained, for example, if the alkaline activator solution is 0.2 contains up to 15% onium compound.

The hydroquinones used according to the invention are characterized in that they are practically colorless, practically insoluble in water, soluble in alkaline solution and covered by organic colloid layers, e.g. B.

ίο gelatin layers that are diffusible.

The hydroquinone derivatives can be in each of the layers of the recording material, for example an overcoat, silver halide emulsion, dye developer or intermediate layer, may be present.

The hydroquinone is preferably in a water-insoluble organic, so-called crystalloidal Low molecular weight solvent compared to the alkaline activator solution is permeable and has a boiling point above 175 ° C, e.g. dibutyl phthalate, diethyl lauramide or diethyl phosphate, after which the solution is added to an aqueous gelatin solution. The dispersion obtained can then be homogenized in a ball mill.

If necessary, a so-called organic solvent can also be used together with the crystalloidal solvent Co-solvents can be used, for example one that has greater solubility in Has water as the crystalloidal solvent.

The co-solvent can therefore be washed out of a quenched gelatin dispersion. Suitable auxiliary solvents are solvents with a boiling point of at least about 25 ° C below the boiling point of the crystalloidal solvent.

The concentration of the hydroquinone in one or more layers of the recording material can be about 10 to 100 mg or more per 0.09 m ^{2 of support} surface. The most favorable concentration in each individual case depends in part on the concentration of the silver halide, the layer in which the hydroquinone derivative is contained, the concentration of the dye developer and, if appropriate, the concentration of an onium salt in the recording material or in the activator solution.

If necessary, a complex compound can be produced from the hydroquinone by reaction with sulfur dioxide in a known manner, whereupon this complex can be incorporated into the top layer, the outer emulsion layer or another layer of the recording material. This complex is more soluble and more stable than the hydroquinone derivative itself.
Various hydrophilic organic colloids can be used as binders to produce the layers of the recording material, for example gelatin, gelatin derivatives, e.g. B. esters of gelatin with dibasic acids, polyvinyl alcohol and cellulose acetate hydrogen phthalates or mixtures thereof. The most favorable results are obtained when gelatin is used as the binder in all layers of the recording material. If the recording material has gelatin intermediate layers, as shown in FIG. 1, these should have a thickness which is at least 75% of the measured thickness of the yellow dye developer layer. The intermediate layers should also contain at least about twice as much gelatin as

009 528/246

is present in the yellow dye developer layer to prevent the dye developer and whose development products migrate from layer to layer.

The activator solution used to develop the recording material should be strongly alkaline, in order to accelerate the developer activity of the dye developer as much as possible. Suitable alkaline Reactive compounds for the preparation of the activator solutions are z. B. alkali metal hydroxides, for example sodium hydroxide or alkaline salts, for example sodium carbonate. Suitable but are also quaternary ammonium hydroxides and volatile amines, for example diethylamine, which have the advantage of evaporating from the produced images and therefore none Leaving alkali residue on it.

The recording material can optionally be developed in a camera, if a sandwich of the stage 1 of FIG. 1 is used. In this case it may be useful to use an activator solution that, in addition to a strongly alkaline compound a thickening agent such as high viscosity carboxymethyl cellulose or oxyethyl cellulose contains.

Optionally, the alkaline activator solution by water or an aqueous solution with a pH 7.5 or below can be replaced if the image receiving material used is alkali or a Contains compound from which alkali can be set free.

Photographic cameras for practicing the method of the invention are e.g. B. from the USA patent 2435117 known.

However, the development of the recording material according to the invention can also be carried out with one in one usual camera exposed recording material outside the camera, e.g. B. in a device, as shown in FIG. 3 is shown.

The image receiving layer of the image receiving material can consist of various substances, for example from linear polyamides, proteins, e.g. B. gelatin, polyvinylpyrrolidones, poly (4-vinylpyridine). Polyvinyl acetate, polyvinyl alcohol, cellulose acetate, polyvinyl salicylal, partially hydrolyzed polyvinyl acetate, Methyl cellulose, regenerated cellulose, carboxymethyl cellulose and oxyethyl cellulose. Of the Layer support of the image receiving material can, for example, made of paper, a transparent film or consist of a white pigmented cellulose ester carrier.

About the deterioration of the developed images due to the effects of heat, light and moisture to avoid, it is advisable to post-treat the pictures, for example with solutions of tannic acid, a condensation product of naphthalenesulfonic acid with formaldehyde or polyvinylpyrrolidone. A solution of polyvinyl alcohol that contains a sugar, such as, for example, has proven to be particularly advantageous Laevulose, avabinose, maltose or mannose or a sugar alcohol, for example mannitol, contains, proven.

It can optionally be advantageous to add an antifoggant to the recording material of the alkaline activator solution and / or to the image receiving material. It can also be advantageous to add a development-interrupting compound to the image receiving material. When used in the image-receiving material, the latter only become effective when they have been dissolved from the activator solution and have penetrated to the recording material under development. As a result, the latent image can develop very quickly, and the development interruption is delayed until the development of the exposed areas has practically ended. This means that development is practically prevented only in the unexposed areas and the amount of dye developer transferred is increased.
It has proven to be particularly advantageous if a compound which interrupts development is present in the image-receiving layer and if a quaternary ammonium salt is also present in the activator solution and / or the image-receiving layer.

Suitable development interrupters are e.g. B. heterocyclic mercaptans, for example mercaptotetrazoles and mercaptobenzothiazoles, for example 1-phenyl-5-mercaptotetrazole and 2-mercaptobenzolthiazole.
Optionally, the image receiving material and / or the alkaline activator solution can contain a small amount of a silver halide solvent, for example an alkali or ammonium thiosulfate or an alkali or ammonium thiosulfate, whereby the effective photographic sensitivity can be increased.

The recording material and the image receiving material can optionally form a whole. So that Image receiving material easily stripped from the recording material after diffusion transfer can be between the image-receiving layer and the layers of the recording material a stripping layer may be present.

The silver halide emulsion layers of the recording material according to the invention can usual silver halides or mixtures thereof, e.g. B. silver bromide, silver bromide iodide or Silver chloride bromide.

The activator solutions used in the following examples had the following compositions:

Activator solution I

Aqueous 3.5% oxyethyl cellulose containing high viscosity, 4.5% NaOH and 2% benzotriazole Solution.

Activator solution II

Activator solution I + 2.0% 1-phenethyl-2-picolinium bromide.

Activator solution III

Activator solution I + 2.0% l-benzyl-2-picolinium bromide.

Activator solution IV

Activator solution III + 1.0% sodium thiosulphate.

Activator solution V

Activator solution I + 1.0% sodium thiosulphate.
Activator solution VI

Aqueous 4% carboxymethyl cellulose, 4%

NaOH, 1% sodium thiosulfate, 0.2% 5-nitrobenzimidazole, and 5% hexamethylenetetramine containing solution.

Activator solution VII

Activator solution VI + 2% 1-phenethyl-3-picolinium bromide.

Activator solution VIII

Activator solution VI + 2% 1-phenethylpyridinium bromide.

Activator solution IX

Aqueous 2.5% carboxymethyl cellulose, 3.5% NaOH, 0.2% 6-nitrobenzimidazole, 1% sodium thiosulphate, 0.4% 2,5-bis-ethyleneiminohydroquinone, 0.6% l-phenyl-3-pyrazolidone and 10% Solution containing ethylene glycol.

Activator solution X

Activator solution IX 4- 0.4% cetyltrimethylammonium bromide.

Activator solution XI

Activator solution IX + 0.6% tetradecyldimethylsulfonium-p-toluenesulfonate.

example 1

First, a photosensitive recording material of the type described in step 1 of FIG. 1 shown Structure made. For this purpose, the following were applied to a layer support in the following order Layers applied:

1. A gelatin layer containing the cyan dye developer 5,8-dihydroxy -1,4- "bis - [(ß - hydroquinonyl - a - methyl) ethylamino] anthraquinone. For this purpose, a mixture of an aqueous gelatin solution and a solution of the dye developer in a mixture of Nn-butyl acetanilide, 4-methylcyclohexanone and sodium triisopropylnaphthalene sulfonate as a dispersant repeatedly passed through a colloid mill.

The resulting emulsion was then applied to the support and volatilized of the methylcyclohexanone dried up.

2. A red sensitive gelatin-silver bromide iodide emulsion layer.

3. An intermediate gelatin layer.

4. One of the magenta dye developer 2- [p- (2 ', 5'-dihydroxyphenethyl) - phenylazo] - 4 - η - propoxy-1-naphthol containing gelatin layer. For this purpose, a mixture of an aqueous gelatin solution and a solution of the dye developer was used in a mixture of N-n-butyl acetanilide, cyclohexanone and sodium triisopropylnaphthalene sulfonate ? 's dispersant passed through a colloid mill repeatedly. the The resulting emulsion was then applied to the gelatin interlayer and allowed to volatilize of the cyclohexanone dried up.

5. A green sensitive gelatin-silver bromideiodide emulsion layer.

6. An intermediate gelatin layer.

7. One of the yellow dye developer 1-phenyl-3-N-n-hexylcarboxamido-4-Γjp- (2 ', 5'-dihydroxyphenethyl) -phenylazo] -5-pyrazolone containing gelatin layer. For this purpose, a mixture of an aqueous gelatin solution and a solution was used of the dye developer in a mixture of adipic acid tetra-hydrofurfuryl ester, ethylene glycol monobenzyl ether and sodium triisopropylnaphthalene sulfonate as a dispersant repeatedly passed through a colloid mill. the The resulting dispersion was then quenched and the ethylene glycol monobenzyl ether was removed washed with water. The dispersion was then applied to the gelatin interlayer applied and dried.

8. A blue sensitive gelatin-silver bromideiodide emulsion layer.

9. An overcoat containing 4-methylphenylhydroquinone. To produce the cover layer a coating composition was prepared as follows initially: 136 g 4-methylphenylhydroquinone were dissolved with heating at 70 ⁰ C in a mixture of 136 ml of methyl alcohol and 272 ml of di-n-butyl phthalate. The resulting solution (solution A) was then cooled to 40 ⁰ C.

1,360 g of a 10 ° / _o by weight gelatin solution, with heating at 40 ⁰ C with 1,360 ml of water and 136 ml of a 5% aqueous solution of sodium diluted (solution B).

Solution A was slowly added to solution B with mechanical stirring. The received Solution was then passed through a colloid mill 5 times. The dispersion obtained was brought to a total of 3775 g by adding water, quenched and all in one Stored in the refrigerator.

Before further processing, the dispersion was heated to 40 ° C with 2225 ml Diluted water (Part I). Furthermore, 3180 g

diluted a 10% gelatin solution while warming to 40 ⁰ C with 12000 ml of water. The pH of the solution was adjusted to 5.5. Then, 515 of a 2.7% strength aqueous ^en Mucochlorsäurelö solution was added (Part II) were ml. Parts I and II were then combined with one another, whereupon the mixture was diluted with water to a total volume of 22.7 liters. The obtained coating material was applied to the blue-sensitive gelatin-silver bromide iodide emulsion layer in such a way that

that on a layer area of 0.09 m ² 120 mg

Gelatin and 40 mg 4-methylphenylhydroquinone were omitted.

Furthermore, an image receiving material made of a white pigmented cellulose ester support was used with an image receiving layer made of gelatine and l-phenyl-5-mercaptotetrazole and poly (4-vinylpyridine) produced as a mordant (image receiving material A).

Sections of the recording material obtained and sections of a corresponding recording material, however, which did not contain 4'-methylphenylhydroquinone, became the same subject matter exposed and after exposure in contact with the image receiving material with the Activator solutions I, II and III moistened. This made the silver halide in the exposed areas 14, 15 and 16 (Fig. 1). The dye developers were set in the neighboring districts as a result of the development. Not in response Stepped dye developer diffused imagewise and with correct contours onto the image receiving material, with a colored positive image, which is made up of the partial

images 17, 18 and 19, as in stage 2 of FIG. 1 shown, consisted, was obtained.

The images obtained with the recording material according to the invention showed in comparison with those of the comparison material cleaner districts of high borrowing ter, d. H. Districts of lower minimum densities as well as improved color separation and reduced Color fall off.

The test results compiled in the following table show that when the comparison material without 4-methylphenylhydroquinone was processed with activator solutions II and III (tests 2 and 3), the D _mi “values of the neutral scale read in the red and green light were reduced compared to Experiment 1. In addition, a visual inspection of the color copies from Runs 2 and 3 showed that color contamination was reduced and that "color fall-off" was significantly improved.

It can be seen from the results of experiments 4 to 6 that, although the 4-methylphenylhydroquinone per se reduces the minimum density (experiment 4), an additional reduction in D _{min is} achieved when a quaternary compound is present (experiments 5 and 6) .

attempt Recording Activator Red D "" " green material solution 0.69 blue 1.72 1 Comparison I. 1.15 material 0.45 1.76 -) Comparison II 0.55 material 0.53 2.00 3 Comparison III 0.68 material 0.55 0.95 4th after I. 0.69 invention 0.32 0.26 5 after II 0.25 invention 0.31 0.41 6th after III 0.28 invention

Example 2

A recording material of the structure described in Example 1 was produced, but this time 45 mg of 4-methylphenylhydroquinone per 0.09 m ^{2 of support} area were accommodated in the blue-sensitive silver halide emulsion layer instead of in the top layer. Sections of the recording material were then developed using Activator Solutions I, II and III and the described image recording material. The results compiled in the following table were obtained:

Recording Activator Red D _mi " green attempt material solution 0.48 blue 0.69 1 after I. 0.58 invention 0.25 0.32 2 after II 0.27 invention 0.29 0.37 3 after III 0.29 invention

Example 3

Four further recording materials A, B, C and D of the structure described in Example 1 were produced. Recording material A contained no 4'-methylphenylhydroquinone. Recording material B f contained 40 mg of 4'-methylphenylhydroquinone per 0.09 m ² of support surface in the top layer. Recording material C contained 40 mg of 4-methylphenyl

hydroquinone per ^ 09 m ^{2 of support} surface in the intermediate layer between the yellow dye developer layer and the green-sensitive silver halide emulsion layer. Recording material D contained 40 mg of 4'-methylphenylhydroquinone per 0.09 m ^{2 of support area} in the intermediate layer between the magenta dye developer layer and the red-sensitive silver halide emulsion layer.

Sections of the recording materials were developed with the aid of activator solutions IV and V.

The following results were obtained:

Record Activator Red A ,,, » green attempt tion 0.70 0.96 material 0.72 blue 1.46 1 A. IV 0.27 0.57 0.57 2 A. V 0.27 1.20 0.25 3 B. V 0.21 0.45 0.90 4th B. IV 0.25 0.21 0.25 'Jl C. V 0.23 0.44 1.29 6th C. IV 0.23 0.20 0.26 7th D. V 0.76 8th D. IV 0.20

As can be seen from the results of experiments 1 to 8, the color values were improved and the color values more favorable D "" "values and lower color impurities are obtained, regardless of the layer of the Material was the hydroquinone, and especially when a pyridinium salt was in the activator solution was present.

B e i s ρ i e 1 4

Further tests were carried out with a different image receiving material.

The image receiving material used consisted of a white pigmented cellulose ester carrier with a Image-receiving layer made of gelatin in which poly (4-vinylpyridine), 1-phenyl-5-mercaptotetrazole and 1-phenethyl-2-picolinium bromide were dispersed.

The following recording materials were used to carry out the experiments:

1. A recording material 1 of the structure described in Example 1 without 4'-methylphenylhydroquinone;

2. A recording material 2 of the structure described in Example 2 with 45 mg of 4'-methylphenylhydroquinone per 0.09 m ^{2 of support area} in the blue-sensitive silver halide emulsion layer and

3. A recording material 3 of the structure described in Example 1 with 40 mg of 4'-methylphenylhydroquinone per 0.09 m ² of support surface in the top layer.

They have been combined in the following table Result received:

attempt

Recording
material

Aclivalor Red O""" green solution 0.53 blue 2.32 I. 0.31 0.89 0.89 I. 0.20 0.41 0.53 I. 0.25

Example 5

Further recording materials of the type described in Example 1 were produced which differed from one another only in that the outer layers contained 5, 10, 20, 40 or 100 mg of 4-methylphenylhydroquinone per 0.09 m ^{2 of} support surface. Activator solution IV was used to develop the recording materials. It was found that excellent results were obtained even with 5 mg of 4-methylphenylhydroquinone per 0.09 m ^{2 of support area} , although optimum results were obtained with 20 to 100 mg of 4-methylphenylhydroquinone per 0.09 m ^{2 of support area} .

Similar results were obtained when the 4-methylphenylhydroquinone in the blue-sensitive silver halide emulsion layer.

B e i s ρ i e 1 6

Further recording materials of the structure described in Example 1 were produced, wherein but once instead of 4-methylphenylhydroquinone corresponding amounts of phenylhydroquinone, 2'-oxyphenylhydroquinone or 2,5-diphenylhydroquinone were used. The same favorable results as described in Example 1 were obtained

obtain. . .

Example/

The procedure described in Example 1 was repeated with the exception, however, that activator solutions VI, VII and VIII were used. It was found that the images developed using activator solutions VII and VIII had lower D _min values than the images developed using activator solution VI containing no quaternary salt.

B e i s ρ i e 1 8

Recording materials of the construction described in Example 1 were produced using the

Activator solutions IX, X and XI processed. The images developed using the activator solutions X and XI containing the quaternary ammonium salt or the tertiary sulfonium salt showed much lower yellow, magenta and cyan Z) _mi "values than corresponding images obtained with the activator IX-, ie in the absence a quaternary ammonium salt or tertiary sulfonium salt.

Example 9

Another recording material of the structure described in Example 1 was produced. at However, this time the 4-methylphenylhydroquinone was used in cyclohexanone for the production of the top layers dissolved in place of methyl alcohol and in diethyl lauramide in place of dibutyl phthalate. That Diethyl lauramide was used in an amount of one tenth the specified amount of di-n-butyl phthalate used. The top layer could be applied much thinner this way. It turned out that the recording material was more quickly penetrable for the developer and that the images obtained exhibited even lower color impurities.

Claims (2)

Patent claims: 1. Photographic multilayer recording material for the dye developer diffusion process, consisting of a support and variously sensitized silver halide emulsion layers coated thereon, as well as optionally intermediate and top layers that are present in the sensitized silver halide emulsion layers or subtractively colored dye developers are dispersed in underlying layers contains, characterized in that there is an auxiliary developer in the form of a solution of phenylhydroquinone, 2-oxyphenylhydroquinone, 4-methylphenyl hydroquinone. 4'-chlorophenylhydroquinone or 2,5-diphenylhydroquinone in a low molecular weight organic water-insoluble (so-called "crystalloidal") solvent with a boiling point above 175 ° C dispersed. 2. Photographic recording material according to claim I, characterized in that it is the Auxiliary developer in the form of a solution in an alkyl phthalate with fewer alkyl radicals than 6 carbon atoms, a phosphoric acid ester, an alkylamide or an acetanilide contains as a solvent. 1 sheet of COPY drawings 009 528/246