US3265499A - Photographic developing compositions - Google Patents

Description

United States Patent 3,265,499 PHOTOGRAPHIC DEVELOPING COMPOSITIONS Jozef Frans Willems, Wilrijk-Antwerp, and Georges Frans van Veelen, Mortsel-Antwerp, Belgium, assignors to Gevaert Photo-Producten N.V., Mortsel, Belgium, a company of Belgium No Drawing. Filed July 9, 1962, Ser. No. 208,572 Claims priority, application Great Britain, July 10, 1961,

9 Claims. (CI. 96-29) This invention relates to the development of photographic materials, containing exposed silver halide, to new developing combinations, photographic materials and solutions containing such combinations.

It is known that certain developer solutions containing several developing substances in concentrations equal to that of the separate developer solutions of each of these substances, show a higher additive developing activity than the awaited one. This phenomenon is called the superadditive development.

An example of this superadditive development is obtained with the combination of p-monomethylaminophenol hemisulphate and hydroquinone which has been described by G. Pizzighelli, Leitfaden der praktischen Photographic, Auflage 14 (Paul Hanneke), p.177.

Now it has been found that an exceptional super-additive developing activity appears, exceeding that of the mixture of p-monomethylaminophenol hemisulphate and hydroquinone when using in the development of an exposed silver halide emulsion layer a combination of developing agents comprising hydroquinone and a p-aminophenol derivative corresponding to one of the following general formulae:

R represents a member selected from the group consisting of a hydrogen atom, an alkyl radical such as methyl, ethyl, propyl, butyl, pentyl and hexyl, a substituted alkyl radical such as hydroxy methyl, fi-hydroxyethyl, v'y-hydroxypropyl, fi-hydroxybutyl, fi-carboxybutyl, e-ClFbOXYPflHiYl, w-carboxyhexy-l, fi-sulfobutyl, e-sulfopentyl, w-sulfohexyl, fi-sulfoatobutyl, esuilf oatopen'tyl, w sulfoatohexyl and B- acylamino ethyl, each of X and X represents a member selected from the group consisting of a hydrogen atom, a chlorine atom and an electron-donating group such as an alkyl group, an alkoxy group, an amino group, a monoalkyl amino group, a dialkylamino group, an acylamino group and a 'sul-fonamido group, and each of A and A represents a member selected from the group consisting of an ethylene radical, a propylene radical, a substituted ethylene radical and a substituted propylene radical.

More particularly the p-aminophenol derivatives identified hereinafter have been proved to be very suitable for being applied in the process according to the present invention:

( 1 1- (4-hydroxyphenyl) -pyrrolidine (2) 1-(3-chloro-4-hydroxyphenyl)-pyrrolidine (3) 1-(3,5-dimethy1-4-hydroxyphenyl)-pyrrolidine 1-(3-amino-4-hydroxyphenyl)-pyrrolidine (5 1- 3-methoxy-4-hydroxyphenyl) -pyrrolidine (6) 1-(3-methylsulfonamino-4-hydroxyphenyl)-pyrrolidine (7) 1- 3 -acetylamino-4-hydroxyphenyl -pyrrolidine (8) 6-hydroxy- 1 ,2,3 ,4-tetrahydroquinoline (9) l-ethyl-6-hydroxy-l,2,3,4-tetrahydroquinoline (10) 1-(methylsulfonylamino-ethyl)-6-hydroxy-1,2,3 ,4-

tetrahydroquinoline (1 1 1- (Z-hydroxyethyl)-6-hydroxy-1,2 ,3,4-tetrahydroquinoline (12) 1-(4-sulfobutyl)-6-hydroxy-1,2,3 ,4-tetrahydroquinoline.

The following are preparations of some p-aminophenol derivatives used in this invention.

PREPARATION 1 1e(4-hydroxyphenyl-pyrrolidine hydrochloride is prepared as follows:

44 g. (0.25 mol) of l-(p-methoxyphenyl)-pyrrolidine and 200 cm. of a 48% solution of hydrobromic acid are refluxed for 8 hours. The reaction mixture is evaporated and the residue is dissolved in 300 cm. of water. Then it is neutralized with sodium bicarbonate. The precipitate is sucked off and recrystallized from a mixture of dioxan and water (1:2). Melting point: 147 C.

The free base is dissolved in 1000 cm. of ether and hydrogen chloride is passed through the solution. The obtained precipitate is sucked ofi, washed with ether and dried. Melting point: 130 C.

PREPARATION 2 1 (3-chloro-4-hydroxyphenyl)-pyrrolidine is prepared as follows:

To a mixture of 14.35 g. of 2-chloro-4-amir1ophenol, dissolved in cm. of ethanol and 13.8 g. of potassium carbonate, 21.6 g. of 1,4-dibromobutane are dropwise added while stirring and introducing nitrogen. The mixture is refluxed .for 8 hours. Then the solid substance is filtered while being warm, twice extracted with boiling ethanol and once again'filtered 01f. Both filtrates are evaporated and the resulting viscous mass is treated with sodium hydroxide. The obtained solution is neutralized with hydrochloric acid which gives a precipitate that is separated. The precipitate is recrystallized from ethanol/ water (1:1). Melting point: 114116 C.

PERPARATION 3 1-(3,5-dimethyl-4-hydroxyphenyl)-pyrrolidine is prepared as follows:

8 g. of 2,6-dimethyl-4-aminophenol, 12.5 g. of 1,4-dibromobutane, 8 g. of potassium carbonate and 100 cm. of absolute ethanol are refluxed for 10 hrs. The solid substance is filtered off while being warm, twice extracted with boiling ethanol and once again filtered off. The filtrates are evaporated and the residue is treated with ether. The ether extract is evaporated and the residue is recrystallized from ethyl acetate. The filtrate of this recrystallization is evaporated and the residue recrystallized from water/ethanol. Melting point: 94 C.

PREPARATION 4 1-(3-amino-4-hydroxyphenyl)-pyrrolidine dihydrobrobromide is prepared as follows:

A solution 9 g. of 3-acetylamino-4-methoxyaniline, prepared as described in J. Am. Chem. Soc. 69 (1947) 586, 6.9 g. of potassium carbonate and 10.8 g. of 1,4-dibromobutane in 100 cm. of absolute ethanol is refluxed for 8 hrs. The formed precipitate is sucked off and treated with boiling ethanol. The filtrates are allowed to cool whereby a precipitate is formed which is also sucked off. The remaining filtrate is evaporated till the half of its volume and then once again allowed to cool. The formed precipitate is sucked off and then together with the above precipitate recrystallized from ethanol. Melting point: 170 C.

Then 23.4 g. of the thus obtained 1-(3-acetamino-4- methoxyphenyl)-pyrrolidine is refluxed together with a 48% solution hydrobromic acid. The reaction mixture is evaporated and the residue treated with ether. The precipitate is then sucked off and dried. Melting point: 190 C.

PREPARATION 5 1-(3-methoxy-4-hydroxyphenyl)-pyrrolidine is prepared as follows:

13.9 g. of 2-methoxy-4-aminophenol, 21.6 g. of 1,4- dibromobutane, 13.8 g. of potassium carbonate and 120 cm. of absolute ethanol are refluxed for hrs. While introducing nitrogen. The formed precipitate is filtered off while being warm and then washed twice with ethanol.

The filtrates are evaporated and the residue extracted with ether. The ether extract is evaporated and the formed oil becomes solid after a certain time. substance is recrystallized from petroleum naphtha (boiling range: 90-120 C.) in the presence of decolourising carbon. Melting point: 72 C.

PREPARATION 6 1-( 3 methylsulfonylamino-4-hydroxyphenyl) pyrrolidine is prepared under an oxygen-free nitrogen atmosphere in a continuous liquid extraction apparatus, using ether as extraction liquid.

From the hydrobromide of 1-(3-amino-4-hydroxyphenyl)-pyrrolidine the base is set free by adding sodium bicarbonate. This free base immediately reacts with the added methane sulfonyl chloride.

The formed 1-(3=methylsul-fonylamino-4-hydroxyphenyl)-pyrrolidine is finally separated from the ether. Melting point: 180 C.

PREPARATION 7 1-(3-acetylamino-4-hydroxyphenyl)-pyrrolidine is prepared under an oxygen-free nitrogen atmosphere, in continuous liquid extraction apparatus, using ether as extraction liquid.

From the hydrobromide of 1-(3-amino-4-hydroxyphenyl) pyrrolidine the base is set free by adding sodium carbonate.

The thus obtained free base immediately reacts with the added acetic acid anhydride.

The formed 1-(3-acetylamino-4-hydroxyphenyl)-pyrrolidine is finally separated from the ether. Melting point: 244-246 C. Y

The solid 4 PREPARATION s 6-hydroxy-1,2,3,4-tetrahydroquinoline is prepared according to the method described in the German patent specification No. 42,871. Melting point: 148 C.

PREPARATION 9 1-ethyl-6-hydroxy-1,2,3,4 tetrahydroquinoline hydrochloride is prepared as follows:

A solution of 37 g. of 6-hydroxy-1,2,3,4-tetrahydroquinoline, 26.2 g. of ethyl bromide and 17.2 g. of potassium carbonate dissolved in 250 cm. of absolute ethanol is refluxed for 5 hrs. while stirring. The reaction mixture is cooled till room temperature and the formed potassium bromide is sucked off. The alcoholic solution is acidified with alcoholic hydrochloric acid whereby a precipitate is formed, which is sucked off and dried. Melting point: 214 C.

PREPARATION 10 1-(methylsulfonylarnino-ethyl)-6-hydroxy-1,2,3,4-tetrahydroquinoline hydrochloride is prepared as follows:

7.45 g. of G-hydroxy-1,2,3,4-tetrahydroquinoline, 10.1 g. of 1-bromo-2-methylsulfonamide-ethane, 3.45 g. of potassium carbonate and 50 cm. of absolute ethanol are refluxed for 10 hrs. While stirring. The solution is filtered while being warm and the solid substance is twice extracted with boiling ethanol. Both filtrates are evaporated till a viscous mass remains and then cm. of N hydrochloric acid are added. The solution is heated for 15 min. on a water-bath whereupon it is evaporated. The residue is rescrystallized from ethylene glycol monomethyl ether. Melting point: 175 C.

PREPARATION 11 1 (2 hydroxyethyl) 6 hydroxy l,2,3,4 tetrahydroquinoline hydrochloride is prepared as follows:

10.5 g. of 6-hydroxy-1,2,3,4-tetrahydroquinoline and 8.75 g. of bromo-ethanol are heated for 2 hr. on a water bath whilst stirring. Then the solid substance is stirred for 15 min. with 50 cm. of a 10% solution of potassium hydroxide and 5 cm. of benzyl chloride. The reaction-mass is then extracted with ether and the ether extract treated with 5 N hydrochloric acid. The aqueous layer is evaporated and the residue boiled with absolute ethanol. The formed precipitate is filtered off and the filtrate is allowed to cool. The formed crystals are sucked off and dried. Melting point: 168 C.

PREPARATION 12 1 (4 sulfobutyl) 6 hydroxy 1,2,3,4 tetrahydroquinoline is prepared as follows:

8.1 g. of 6-hydroxy-1,2,3,4-tetrahydroquinoline and 7.3 g. of butane sultone are heated for 2 hr. on a water-bath. A solid substance is formed. Then, heating is continued for another 12 hr. on an oil-bath at 150 C. After cooling, the solid substance is mixed with ether while pulverizing in a mortar and then dried. Melting point: C.

In the preparation of a developing bath or a photographic material according to this invention, the p-aminophenol derivatives used in this invention are normally added in the form of their salts (e.g., in the form of their hydrochloride).

From the theoretical point of view it is noteworthy that the superadditive effect of a developing combination according to the present invention increases with the number and the length of the'alkyl groups on the p-nitrogen atom of the p-aminophenol derivatives according to the general formulae. An exceptionally strong increase of the superadditive eifect has been observed when using a p-aminophenol derivative according to the above general formulae having a pyrrolidine nucleus in p-position of the hydroxyl group. A same important increase is observed if a compound is used according to the above general formulae having fused rings as in 6-hydroxy- 1,2,3,4-tetrahydroquinoline and 9-hydroxyjulolidine.

The strong superadditive effect of these compounds can probably be ascribed to the planar structure of their molecules whereby sterical hindering is restricted to a minimum. A possible proof in this direction is the fact that no superadditive effect has been observed if, e.g., the pyrrolidine nucleus is replaced by a non-planar piperidine nucleus.

Besides the devoloping composition of hydroquinone and compounds according to the present invention, the

developing bath can contain the usual ingredients, e.g., buffer compositions which may comprise salts such as carbonates, borates, phosphates, bisulphites, sulphites, metabisulphites and acids such as boric acid and citric acid. Further, the developing bath may contain potassium bromide and water-softening agents such as polyphosphates and derivatives of ethylene diamine tetraacetic acid, antifogging agents and wetting agents as well as other compounds known in the photographic development technique.

The pH of the baths may vary within wide limits, preferably between 8 and 11 so that a quick and hard development or a slow and soft development can be obtained at will.

The ratio of hydroquinone to a p-aminophenol derivative used in the present invention can be chosen in such a way that the combination is suited for the development of all kinds of materials including materials having little sensitive silver chloride emulsion layers as well as mate- :rials having highly sensitive silver bromo-iodide emulsion layers.

veloping agent described hereinbefore to an amount of 5 g. of hydroquinone per litre. Of course, larger amounts of said p-aminophenol derivatives can be used, although the superadditive effect obtained with higher concentrations is not more considerable. Preferably, 50 mg. to 2 g. of p-arninophenol derivative and from 5 to 20 g. of hydroquinone per litre are used.

Combinations of developing agents used in this invention may also be applied in the baths and/ or in the lightsensitive material and/or in the image-receiving material used in the application of the silver complex diffusion transfer process, the principle of which is described in the British patent specifications 614,155 and 654,630 and in the German patent specification 887,733. For more details concerning the silver complex diffusion transfer process, the different embodiments of the materials and apparatus used therein, there can be referred to Progress in Photography 1955-1958, pp. 2436, and the patent literature cited therein.

According to a special embodiment both hydroquinone and at least one of the p-aminophenol derivatives according to the general formulae are incorporated in the imagereceiving material, preferably in the image-receiving layer in an amount of preferably 0.2 g. to 20 g. of hydroquinone and 20 mg. to 2 g. of p-aminophenol derivative per sq. m.

Such an image-receiving material is normally used in that type of silver complex diffusion transfer process wherein a processing liquid is used comprising an aqueous alkaline solution.

Accordingly, the present invention includes any mate rial in which an image can be formed by diffusion transfer from an image-wise exposed silver halide emulsion layer according to the silver-salt diffusion transfer process, said material incorporating development nuclei for promoting development of diffused silver-salt to metallic silver or incorporating a compound or compounds capable of reacting with another compound or compounds to form such nuclei in situ, and the said material incorporating hydroquinone and at least one compound cor-responding to the above general formulae. Preferably the image-receiving material also incorporates a compound or compounds for complexing or solubilizing silver halide, e.g., sodium thiosulphate or sodium thiocyanate.

In the silver complex diffusion transfer process, a silver image can be formed on an image-receiving material according to the invention, by pressing it into contact with an image-wise exposed light-sensitive material in the presence of a processing liquid comprising an aqueous alkaline solution; neither this solution nor the light-sensitive material need contain photographic developers.

Suitable processing liquids for such a process are solutions of basic compounds, e.g., solutions of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate and trisodium phosphate. The amount of dissolved salt required depends on its power to impart alkalinity. For a compound which is weak in this respect, e.g., trisodium phosphate, it is appropriate to use an amount of the anhydrous salt of from 50 to 200 g. per liter. In the case of a compound which imparts a high degree of alkalinity, e.g., sodium hydroxide, an amount of from 5 to 20 g. will suffice.

Anhydrous sodium sulphite may be incorporated into the processing liquid, e.g., in an amount of from 10 g. to 40 g. per liter.

The processing liquid may further contain other usual ingredients such as sodium bromide, calcium sequestering compounds and substances which favourably influence the image-tone, e.g., 1-phenyl-5-mercaptotetrazole or similar products, e.g., those described in the British patent specification 561,875 and the Belgian patent specification 502,525.

The image-receiving material may incorporate further compounds which are useful ingredients for image-receiving materials to be used in the diffusion transfer process, e.g., sodium sulphite as known per se or potassium metabisulphite as described and claimed in the French patent specification 1,296,888.

An image-receiving material according to the invention may, e.g., consist of a support which is impregnated with development nuclei or a substance or substances for forming such nuclei in situ. As an alternative such nuclei or nuclei-forming substances may be incorporated in an image-receiving layer applied onto such support. An image-receiving material according to the invention preferably comprises a non-light-sensitive colloid layer, e.g.,

a water permeable organic colloid layer, e.g., a gelatin layer, on a paper or other support, the colloid layer incorporating the development nuclei or nuclei forming component(s) and the hydroquinone/p-aminophenol derivative developing combination. By way of example an image-receiving material can be manufactured by applying a thin layer on a support from an aqueous suspension containing developing nuclei and comprising per liter of suspension 20 to g. of gelatin, 2 to 50 g. of hydroquinone, 3 to 12 g. of p-aminophenol derivative (preferably in salt form) 10 to 60 g. of anhydrous sodium thiosulphate, :5 to 40 g. of anhydrous sodium sulphite and 5 to 40 g. if potassium metabisulphite.

The concentration of alkali in the processing liquid and the concentration in the image-receiving layer of the products identified above are not critical and other concentrations than those referred to may be used.

By adding a p-aminophenol derivative as aforesaid to an image-receiving layer which contains hydroquinone an image-receiving material is obtained which even when used in a diffusion transfer process with a light-sensitive material and a processing liquid neither of which contains developer, is found to cause the primary and secondary development stages to proceed so rapidly, that in the most .modern developing apparatus for quick treatment very good images are obtained. This is surprising, since the primary and secondary development stages can only start when the image-receiving and light-sensitive materials are pressed together.

An image-receiving material according to the invention can be used in conjunction with a light-sensitive material having a silverhalide emulsion as known per se or conventionally used in the art of diffusion transfer. The emulsion composition is not critical, provided its silver salt(s) is (are) capable of development and diffusion in the exposed and non-exposed areas respectively with the rapidity required in diffusion transfer processes. Silver chloride emulsions, which may contain silver bromide or silver iodide, and to which other ingredients have been added so as to impart the desired emulsion characteristics are preferably used. The emulsion is normally cast in such a way that 0.5 to 2 g. of silver are applied per sq. m., of support. Any such emulsion can be hardened or slightly hardened.

Development nuclei for silver halide complexes suitable for promoting the formation of the silver-containing image in the image-receiving layer are the sulphides of heavy metals, e.g., of antimony, bismuth, cadmium, cobalt, lead, nickel, silver and zinc. Selenides, polysulphides, polyselenides, mercaptanes, stannous halides, heavy metals or their salts and fogged silver halides are also suitable for this purpose.

The image-receiving layer of an image-receiving material according to the invention may comprise one or more water-insoluble metal alginates or a chromium salt of carboxy-methyl cellulose as described and claimed in the Belgian patent specifications Nos. 609,394 and 609,- 395.

According to another special embodiment, the hydroquinone can be present in the image-receiving material and at least one of the aforesaid p-aminophenol derivatives in the light-sensitive material. The p-aminophenol derivatives, when incorporated in the light-sensitive material, e.g., in the silver halide emulsion layer, or in a water-permeable layer which is in effective contact with said emulsion layer, cause practically no fog since, in then absence of hydroquinone, they only possess a very weak developing activity. An image-receiving material containing hydroquinone is more particularly described in the French patent specification 1,296,888. By an effective contact there is meant that developing agents can diffuse from said water-permeable layer, e.g., a nonlight-sensitive colloid layer adjacent to the light-sensitive emulsion layer to the latter layer.

Lightsensitive silver chloride emulsions, which may also comprise silver bormide and silver iodide, are preferably used. The emulsion is generally coated in such a way that 0.5 to 2 g. of silver is present per sq. m. and that 12 sq. m. are covered per litre of emulsion.

The emulsion, ready for coating, contains per kg. prefera'bly from 2 to g. of the above p-aminophenol derivative.

In the last embodiment too, a processing liquid comprising an aqueous alkaline solution can be used. The last embodiment is also especially suited for rapid processing.

With regard to the combination p-amonomethylaminophenol hemisulphate/hydroquinone the combinations of developers used in the present invention show the advantage that by the use of smaller concentrations an equivalent and mostly a higher developing activity is obtained. The developing compositions according to this invention are not sensitive to hydrolysis even in strong alkaline solution, whereas compositions with 1-pheny1-3-pyrazolidone hydrolyse in strong alkaline baths.

The following examples illustrate the present invention.

sensitive silver halide emulsion layer, coated onto a cellulose triacetate support, are exposed through a grey filter with a light-quantity (E) which corresponds to the shoulder part of the density/log E curve.

Each of these film strips are developed at 20 C. in separate developing baths. One of them is developed in a bath A containing as developing agent only hydroquinone and having the following composition:

Sodium carbonate g 20 Sodium hexametaphosphate g 1 Sodium sulfite g 20 Potassium bromide g 0.5 Hydroquinone g 4.4

Water till 1 l.

The other strips are respectively developed in baths, having the same composition as bath A but containing moreover an equivalent amount of a developing agent as listed in Table I given hereinafter. The densities are determined respectively after a developing time of 30, 60, and 120 sec.

TABLE I Density (D) Time of development 30 sec. 60 sec. 90 sec. 120 see Bath A 0. 04 0. 04 0. 10 0. 18 Bath A+45 mg. of p-aminophen0l--. 0. 04 0. 06 0. 12 0.30 Bath A+53 mg. of p-monomethyl aminophenol hemisulphate 0.06 0.20 0.75 1. 40 Bath A+60 mg. of 4-(N,N-dimethyl aminophenoD-oxalate O. 06 0. 18 0. 74 1. 40 Bath A+66 111g. of 4-(N,N-diethylaminophenol)-hemisulphate 0. 06 0.20 0. 76 1. 41 Bath A+61 mg. of 1-(4-hydroxyphenyD-pyrrolidine hydrochloride- 0. 11 1. 10 2. 50 Bath A+68 mg. of 1-(3-acetylamino- 4-hydroxyphenyl)-pyrrolidine 0.10 0.73 1. 85 Bath A+66 mg. of 1-(4-hydroxyphenyhpiperidine hydrochloride... 0. 04 0. 04 0. 08 0. 15 Bath A+46 mg. of 6-hydroxy-1,2,3,4-

tetrahydroquinoline 0. 18 1. 35 2. 10 Bath A+66 mg. of l-ethyl-fi-hydroxy-l,2,3,4-tetrahydroquinoline hydrochloride 0. 20 l. 48 2. 37 Bath A+61 mg. of 1-(3-ehloro-4- hydroxyphenyl)-pyrrolidine 0. 08 0. 62 1. 75 Bath A+60 mg. of 1-(3-methoxy-4- hydroxyphenyl)-pyrrolidlne 0. 23 0.90 1. 52 Bath A+60 mg. of 1-(3,5-dimethyl- 4-hydroxyphenyl)-pyrrolidine 0. 12 1.00 2. 10 Bath A+ mg. of 1- (methylsulfonylaminoethyl)-6-hydroxy-1,2,3,4-

tetrahydroquinoline hydrochloride. 0.10 0.99 2.01

Example 2 none and having the following composition:

Boric acid g 5 Borax g 10 Sodium hexametaphosphate g 1 Sodium sulfite g Hydroquinone g 4.4

Water up to 1000 cm.

The other strips are respectively developed in baths having the same composition as bath B but moreover containing an equivalent amount of a developing agent as listed in Table II given hereinafter. The densities are determined respectively after a developing time of 2, 4, 6, 8 and 10 min.

TABLE II Density (D) Time of development 2 4 g 10 mm. mm. mm. mm. mm.

BathB 0.04 0.04 0.04 0.04 0.04 Bath B+45 mg. of p-aminophenol 0.04 0.04 0.04 0.04 0.04 Bath B+53 mg. of p-monomethyl aminophenol hemisulphate 0.04 0.04 0.10 0.25 0.45 Bath B+60 mg. of 4N,N-dimethylaminophenoloxalate 0.04 0.08 0. 22 0.52 0.91 Bath B+66 mg. of 4-N,N-diethylaminophenolhemisulphate 0.04 0.17 0.60 1.13 1.66 Bath B+61 mg. of 1-(4-hydroxyphenyl)-pyrrolidine hydr0chlor1de. 0.35 1.43 2.12

Example 3 Strips of a photographic material comprising a lightsensitive silver halide emulsion layer, coated onto a cellulose triacetate support, are exposed through a grey filter with a light-quantity (E) which corresponds to the shoulder part of the density/ log E curve.

Each of these exposed film strips are developed at 20 C. in separate developing baths. One of them is developed in a bath C, containing as developing agent only hydroquinone and having the following composition:

Boric acid g Borax g Sodium hexametaphosphate g 1 Sodium sulfite g- Hydroquinone g 4.4

Water up to 1000 cm.

The other film strips are respectively developed in developing baths having the same composition as bath C, but containing moreover an equivalent amount of a developing agent as listed in Table III given hereinafter.

TABLE III Density (D) Time of development 2 4 0 s 10 mm. mm. mm. mm min.

BathC 0.04 0.04 0.04 0.04 0.04 Bath C+53 mg. of p-monomethyl aminophenol hemisulphate 0.04 0.04 0.08 0.18 0.32 Bath O+61 mg. of 1-(4-hydroxyphenyl)-pyrrolidine hydrochloride... 0.21 0.99 1.82 Bath C+62 mg. of l-(3-chloro-4- hydroxyphenyl)-pyrrolidine 0.74 2.20 Bath C+71 mg. 0f1-(2-hydroxyethyD- line hydrochloride 0.22 1.07 1.89 Bath C+95 mg. of l-(rnethylsulfonylaminoethyD-G-hydroxy-l,2,3,4-tetrahydroquinoline hydrochloride 0.24 1.11 1.88 Bath O+60 mg. of l-(3,5,dimethyl-4- hydroxyphenyl)-pyrrolidine 0.14 0.41 0.70 0.98 1.25

Example 4 A light-sensitive material for the silver complex diffusion transfer process is prepared by coating onto a paper support a gelatino silverchloro-iodide emulsion (0.5% of iodide). i1 kg. of flowable emulsion has been prepared starting from 45 g. of silver nitrate. The emulsion is sensitized for light of 500 to 570 m wavelength and is cast in such a Way that the silver content amounts to 1.5 g./sq. m. of paper.

The image-receiving material is prepared as follows:

A paper support is coated with an image-receiving layer from a suspension consisting of:

Water cm. 274

Gelatin g 10 Sodium thiosulfate g 12 Sodium sulfide mol 7.7 -10' Cobaltous nitrate =6 aq. mol 1.l l0 1% solution of 1-phenyl-5-mercapto 1,2,3,-4-

tetrazole in ethanol cm. 1

so that 13 sq. m. of paper can be coated with 1 1. After drying, this layer is coated in its turn with a layer from a solution consisting of:

t. Cm. 4% aqueous carboxymethylcellulose 45 Water 155 Sandozol (trademark for a sulfonated organic oil marketed by Sandoz, A. G., Basel, S\vitzerland) 0.6

The image-receiving material obtained, in close contact with the silver halide emulsion layer of the lightsensitive material which has been exposed to a line original, is carried through a developing apparatus containing the following composition:

Water cm. 1000 Sodium sulfite g 75 Sodium hydroxide g '10 Potassium bromide g '1 Hydroquinone g 16 1-(4-hydroxyphenyl)-pyyrolidine hydrochloride I After squeezing the image-receiving layer and the lightsensitive layer between the rubber rollers of the developing apparatus, the image-receiving material and the lightsensitive material are separated from each other after 10 to 20 seconds of contact and a strong positive image of the original is obtained in the receiving layer.

Example 5 A light-sensitive material for the silver complex diffusion transfer process, is prepared by coating onto a paper support of 90 g./sq. m. a gelatino silver chloride emulsion containing per litre 0.126 mol of silver chloride, 50 g. of gelatin, 2 cm. of a 40% aqueous solution of saponine and 2 cm. of a 40% aqueous solution of formaldehyde.

The emulsion is coated in such a Way that l g. of silver is applied per sq. In.

An image-receiving material is prepared by coating onto a paper support of 90 g./sq. m., a thin layer from a suspension of the following composition:

Water cm. 837 Gelatin g 40 Sodium thi-osulfate 5 aq g 48 10% aqueous solution of sodium sulfide cm. 2.5 10% aqueous solution of cobalt nitrate cm. .13 I-lydroquinone g" 6.5 Potassium metabisul fite g 12.8 5% solution of 1-(4-hydroxypheny1)-pyrrolidine in ethanol cm. 40

This suspension is coated in such a way that with 1 litre, 12 sq. m. of the support are covered.

The light-sensitive material is now image-wise exposed and together with the image-receiving material passed through a diffusion transfer developing apparatus containing a solution of the following composition:

Water cm. 1000 Trisodium phosphate g 100 Sodium sulfite (anhydrous) g 20 In the preparation of a light-sensitive material for the silver complex diffusion transfer process, a gelatino silver chloride emulsion is coated onto a paper support of g./sq. m. in such a way that 1 g. of silver and 0.1 g. of 1-(4-hydroxyphenyl)pyrrolidine are present per sq. m.

An image-receiving material is prepared by coating onto a SllS- Water cm. 877.2 Gelatin g 40 10% aqueous solution of sodium sulfide cm. 2.4 10% aqueous solution of cobalt nitrate cm. 13.2 Potassium metabisulfite g 12.8 Hydroquinone g 6.4 Sodium thiosulfate aq. g 48 This suspension is coated in such a way that with 1 litre 12 sq. m. of the support are covered.

The light-sensitive material is now image-wise exposed and together with the image-receiving material passed through a diflusion transfer developing apparatus containing a solution of the following composition:

Water cm. 1000 Trisodium phosphate g 100 Sodium sulfite (anhydrous) g 20 After squeezing between the rubber rollers of the developing apparatus and after seconds of contact both materials are separated from each other.

A positive print of the original is apparent in the imagereceiving material.

What is claimed is:

1. Photographic developing method comprising developing an exposed silver halide emulsion layer of a photographic material with hydroquinone and a derivative of p-aminophenol having one of the following general formulae:

wherein: 1

R is a member selected from the group consisting of a hydrogen atom and a lower alkyl radical, each of X and X is a member selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkyl amido group and an alkyl sulfonamido group, wherein alkyl is lower alkyl, and A is -(CH where n is an integer of 23 and A is a propylene radical. 2. Photographic developing solution for developing an exposed silver halide emulsion layer of a photographic material comprising in addition. to. hydroquinone a derivative 1 2 of p-aminophenol having one of the following general formulae:

I. HZC(IJH2 Hz0\ /CH: N

II. A)- R1I\T g III. -(A') ,.(A')- a K 5 wherein:

R is a member selected from the group consisting of a hydrogen atom and a lower alkyl radical, each of X and X is a member selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkyl amido group and an alkyl sulfonamido group, wherein alkyl is lower alkyl, and A is (CH where n is an integer of 2-3 and A is a propylene radical.

3. Photographic developing solution according to claim 2 containing from 5 to 20 g. of hydroquinone and from 50 mg. to 2 g, of said p-aminophenol derivative.

4. Photographic image-receiving material for use in the silver complex diffusion transfer process containing in addition to hydroquinone a derivative of p-aminophenol having one of the following general formulae:

III.

13 wherein:

R is a member selected from the group consisting of a hydrogen atom and a lower alkyl radical,

each of X and X is a member selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an .alkoxy group, an alkyl amido group and an alkyl suilfonamido group, wherein alkyl is lower alkyl, and

A is -(CH where n is an integer of 2-3 and A is a propylene iradical.

5. Photographic image-receiving material according to claim 4 containing in its image-receiving layer from 0.2 to 20 g. of hydroquinone and from 20 mg. to 2 g. of said p-aminophenol derivative per sq. m.

6. Photographic light-sensitive material having a lightsensitive silver-halide emulsion layer and containing a p-aminophenol derivative having one of the following general formulae:

R is a member selected from the group consisting of a hydrogen atom and a lower alkyl radical,

each of X and X is a member selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an .alkoxy group, an alkyl amido group and an alkyl suil-fonamido group, wherein alkyl is lower alkyl, and

A is -(CH where n is an integer of 2-3 and A is a propylene radical.

7. In a photographic copying method of the diffusion transfer type which includes the steps of image-wise exposing a supported silver halide emulsion layer, and developing said exposed layer while in intimate contact with a supported receiving layer providing development nuclei,

the improvement which comprises carrying out said developing step in the presence of a super additive combination of developing agents com-prised essentially of hydroquinone and a derivative of p-aminophenol having one of the following general formulae: I. Hz(|JCH2 H20 /CH2 11. A)- Rr E III. em- ,(A)\

wherein:

R is a member selected from the group consisting of a hydrogen atom and a lower alkyl radical,

each of X and X is a member selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkyl amido group and an alkyl sulfonamido group, wherein alkyl is lower alkyl, and

A is (CH where n is an integer of 2-3 and A is a propylene radical.

8. A photographic copying method according to claim 7 wherein the developing step is performed using an alkaline developing solution.

9. The material of claim 6 including, in addition to said light-sensitive emulsion layer, a water-permeable layer free of light-sensitive emulsion in effective contact with said emulsion layer, at least one of said layers containing said p-amino phenol derivative.

References Cited by the Examiner UNITED STATES PATENTS 3,072,480 1/1963 Abbott et al. 96-29 OTHER REFERENCES Willems et al.: Photographic Science and Engineering vol. 6, No. 1, pp. 49-54, January-February 1962.

NORMAN G. TORCHIN, Primary Examiner.

I. T. BROWN, Assistant Examiner.

Claims (1)

1. 7. IN A PHOTOGRAPHIC COPYING METHOD OF THE DIFFUSION TRANSFER TYPE WHICH INCLUDES THE STEPS OF IMAGE-WISE EXPOSING A SUPPORTED SILVER HALIDE EMULSION LAYER, AND DEVELOPING SAID EXPOSED LAYER WHILE IN INTIMATE CONTACT WITH A SUPPORTED RECEIVING LAYER PROVIDING DEVELOPMENT NUCLEI, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT SAID DEVELOPING STEP IN THE PRESENCE OF A SUPER ADDITIVE COMBINATION OF DEVELOPING AGENTS COMPRISED ESSENTIALLY OF HYDROQUINONE AND A DERIVATIVE OF P-AMINOPHENOL HAVING ONE OF THE FOLLOWING GENERAL FORMULAE: