IT9019645A1 - ALKALINE PHOTOGRAPHIC DEVELOPER IN BLACK AND WHITE - Google Patents

Description

"Black and White Alkaline Photo Developer".

SUMMARY

Black and white aqueous alkaline photographic developer for the treatment of silver halide radiographic materials comprising (1) a hydroquinone, (2) a 3-pyrazolidone developing agent, (3) a dialdehyde hardener, (4) antifreeze, (5) a sequestering agent, (6) a sulfite antioxidant, and (7) a buffering agent, wherein said sequestering agent is a cycloaminomethane diphosphonic acid compound. Preferably, the antifogens comprise a combination of a benzotriazole type antifreeze, an indazole type antifreeze and a mercaptotetrazole type antifreeze.

FIELD OF THE INVENTION

The present invention relates to a black and white alkaline developer for treating a silver halide photographic material and, more particularly, to a black and white alkaline hardener developer for treating a silver halide radiographic material in developer. automatic. The developer gives improved stability and excellent photographic properties.

STATE OF THE TECHNIQUE

The aqueous black and white developers used to treat silver halide photographic materials include, as major components, hydroquinone and 3-pyrazolidone developing agents, an alkaline agent, an organic antifog and a sulfite.

It is known in the art that when silver halide photographic materials are to be processed rapidly in an automatic developing machine, a hardener of the dialdehyde type is added to the developer to increase the mechanical strength of the photographic material during processing ( see for example the US patents RE 26.601, 3,232,761 and 3,545,971 and the English patent 1,269,268). It is normal practice to subject X-ray silver halide materials to rapid processing in a developer machine using a developer hardener. A problem frequently encountered with such hardener developers is the tendency of the developer agent to degrade during its storage and use. In order to increase the stability of the hardener developer it is normal practice in the photographic art to add a sulfite. The greater the amount of sulfite, the longer the useful life of the developer. However, high concentrations of sulfite in the developer cause reduced activity and dark deposits in the developer vessel. Furthermore, the presence of traces of metal ions (such as Fe ++) in the developer causes the catalytic oxidation of the sulphites. Sequestering agents, such as ethylenediaminetetracetic acid (EDTA), used to avoid the precipitation of calcium salts in developers, in the presence of traces of iron ions cause the self-oxidation of the hydroquinone developing agent at a faster rate than that which occurs without EDTA.

US patent 4,672,025 discloses a black and white developer comprising hydroquinone, a 3-pyrazolidone developing agent, a dialdehyde hardener, an organic antifog and a sequestering agent selected from diethylenetriaminopentacetic acid (DTPA), triethylenetetraminohexacetic acid (TTHA), 1,3-diamino-2-propane itetetraacetic acid (DPTA), glycolic ether of diaminotetraacetic acid, ethylenediaminetetramethylenephosphonic acid (EDTP), aminotrimethylenephosphonic acid and alkali metal salts of these acids. The use of such chelating agents, compared to the previously used ethylenediaminetetraacetic acid (EDTA), increases the stability of the developer and avoids the formation of precipitates in the developer comprising the dialdehyde hardener.

European Patent Application 286,874 describes the use of a dialkylaminomethanbiphosphonic acid sequestering agent (comprising cycloaminomethane diphosphonic acids) in alkaline aqueous photographic developers to increase developer stability and inhibit deposit formation. Said developers do not include hardeners and are intended for manual processing, preferably of silver halide color photographic materials.

U.S. Patent 4,810,622 discloses a black and white developer having a pH of 9.2 to 10 comprising hydroquinone, a 3-pyrazolidone developing agent, a dialdehyde hardener, an organic antifreeze, a chelating agent selected from the group consisting of diethylenetriaminopentacetic acid (DTPA), triethylenetetraminohexacetic acid (TTHA), 1,3-diamino-2-propanoletetraacetic acid (DPTA), ethylenediaminetetramethylenephosphonic acid (EDTP), aminotrimethylenephosphonic acid and alkali metal alkali solvents silver and a sulphite. The developer is suitable for processing black and white negative silver halide materials other than radiographic materials, such as machine negative films, printing papers and microfilms in the developer machine.

Consequently, although many compounds have been proposed as sequestering agents for use in photographic developers, compounds capable of increasing the stability of photographic hardener developers are still required for the rapid processing of silver halide photographic materials, especially materials. silver halide radiographs, in automatic developing machines, especially at high processing temperatures, and to give excellent photographic properties.

SUMMARY OF THE INVENTION Black and white alkaline aqueous photographic developers for processing silver halide radiographic materials include (1) a hydroquinone, (2) a 3-pyrazolidone developing agent, (3) a dialdehyde hardener, (4) antifog, (5) a sequestering agent, (6) a sulfite antioxidant, and (7) a buffering agent, wherein said sequestering agent is a cycloaminomethane diphosphonic acid compound. Preferably, the antifogens comprise a combination of a benzotriazole type antifreeze, an indazole type antifreeze and a mercaptotetrazole type antifreeze.

The developer is stable for long periods of time and can give excellent photographic properties when used in automatic developing machines. The developer allows to control the photographic characteristics (veil and degradation) even if used at the high temperatures of the rapid treatment.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a black and white alkaline aqueous photographic developer, for processing a silver halide photographic material, in particular a silver halide radiographic material, comprising (1) at least one of the hydroquinones, (2) at least one of the 3-pyrazolidone developing agents, (3) at least one of the dialdehyde hardeners, (4) at least one antifog, (5) a sequestering agent, (6) a sulfite antioxidant, and (7 ) a buffering agent, characterized in that said sequestering agent is a compound of diphosphonic cycloaminomethane acid.

In one aspect referred to, the present invention relates to an alkaline developer as described above, wherein the antifreeze comprises a combination of a benzotriazole type antifreeze, an indazole type antifog and a mercaptotetrazole type antifreeze.

The diphosphonic cycloaminomethane acid compounds used in the developer of the present invention are those described in European patent application 286,874. Preferably, said compounds of diphosphonic cycloaminomethane acid correspond to the following formula:

, 'CH2

Q \ -C I-R

/ I

CH-in which Rj_, R2 and R3, equal or different, each represent a hydrogen atom or a P03M'M "group, in which M 'and M" represent a hydrogen atom, an alkali metal such as Li, Na or K or a quaternary ammonium group such as ammonium, pyridinium, triethanolammonium or triethylammonium, and Q represents the atoms or chemical bonds necessary to complete a three- to six-membered ring, such as aziridine, pyrrolidine, imidazolidine, piperidino, isoindolino or morpholino, provided that at least two of the substituents, R2 and R3 represent the P03M'M "group.

Typical examples of sequestering agents within the above general formula are:

CH2-CH2 PO3H2 CH2-CH2 PO3H2 / \ I

(1) O / \ N-CI-H (2) HN N- C-H

\ / I \ / I CH2-CH2 P03h2 CH2-CH2 P03h2 CH2 "ch2? ° 3h2 CH2-ch2 PO3IHn2 / \ / \ I

(3) N-C I-H (4) H2C N- C-H

\ CH2-CH2 /

2 PI / I

1O3H2 \ CH2-CH2 PO3H2

CH2-CH2 PO3H2 CH2-CH; PO3H2 / \ I (5) H2C (6) N-C-H \

H- / YL! / I

-C PO3H2 CH2-CH2 PO3H2

CH2-CH2 PO3H2 CH— CH- PO3H2

\ I \ I

(7) N-C-H (8) N-C-H / I

NH— CH2 P03H2 CH— CH- / PIO3H2 CH— CH PO.H2 CH— CH2 P03H2 // \ I J \

(9) HC (10) N N-C-H / I \

CH2-CH2 PO3H2 CH2-CH2 / P IO3H2 CH2 PO3H2

\

(11) N-C-H

CH2 / P IO3H2

Said sequestering agents can be advantageously used in quantities from about 0.0005 to about 0.5 moles per liter, preferably from about 0.008 to about 0.1 moles per liter of developer.

The above sequestering agents can be used in combination with other sequestering agents known in the art, such as for example aminopolycarboxylic acids (ethylenediaminetetraacetic acid, diethylenetriaminopentacetic, nitrilotriacetic, diaminopropanoletetraacetic, etc.), aminopolyphosphonic acids (methylenediaminophosphonic acids) Disclosure 18837 of December 1979, phosphonic acids described in US patent 4,596,764, etc.), polyphosphate compounds (sodium hexametaphosphate, etc.), α-hydroxy carboxylic acid compounds (lactic acid, tartaric acid, etc.), compounds of dicarboxylic acid (mayionic acid, etc.), compounds of α-ketocarboxylic acid (pyruvic acid, etc.), compounds of alkanolamine (diethanolamine, etc.), etc.

It has been found that the sequestering agents incorporated in the black and white hardener hours of the present invention increase the stability of the developer over a long period.

The composition of the developer of the present invention is suitable for obtaining black and white images for the development of silver halide photographic materials exposed to light, in particular radiographic materials. Typically, it includes a black and white developing agent, a dialdehyde hardener, a sulfite antioxidant, an antifreeze agent, a buffering agent and alkaline agents.

Black and white developing agents for use in the present invention include hydroquinone and hydroquinone derivatives (e.g., t-butylhydroquinone, methylhydroquinone, dimethylhydroquinone, chlorohydroquinone, dichlorohydroquinone, bromohydroquinone, 1,4-dihydroquinone, methoxyhydroquinone, ethoxyhydroquinone, hydroquinone, hydroquinone disulfonate, etc.). L <1> hydroquinone, however, is preferred. Said black and white developing agents are generally used in quantities from 0.075 to 0.75 moles per liter, preferably from 0.10 to 0.50 moles per liter of developer.

Said black and white developing agents are used in combination with auxiliary developing agents which have a superadditive developing effect, such as p-aminophenol and derivatives of p-aminophenol (such as N-methyl-p-aminophenol and 2,4-diaminophenol ) and pyrazolidone compounds (such as 1-phenyl-3-pyrazolidone) and pyrazolidone derivatives (such as 4-methyl-1-phenyl-3-pyrazolidone and 4,4'-dimethyl-1-phenyl-3-pyrazolidone). 1-phenyl-3-pyrazolidone, however, is preferred. Said auxiliary developing agents are generally used in quantities from 0.0003 to 0.15 moles per liter, preferably from 0.003 to 0.1 moles per liter of developer.

The dialdehyde hardeners used in the developer of the present invention include, for example, glutaraldehyde, α-methylglutaraldehyde, β-methylglutaraldehyde, maleic dialdehyde, succinic dialdehyde, methoxysuccinic dialdehyde, 1 'a-methoxy-3-ethoxyglutaraldehyde , Α-n-butoxyglutaraldehyde, α-dialdehyde, α-dimethoxysuccinic dialdehyde, β-isopropylsuccinic dialdehyde, α-dialdehyde, α-diethylsuccinic, butylmaleic dialdehyde and bisulfite adducts of these aldehydes. Of the above compounds glutaraldehyde and its bisulfite adducts are the most preferred. Such dialdehyde hardeners are generally used in amounts from 0.001 to 0.3 moles per liter, preferably from 0.01 to 0.1 moles per liter of developer.

Antioxidants are typically sulphites. By sulphites we mean those compounds known in the art which are capable of generating sulphite ions (S03) in aqueous solutions and include sulphites, bisulfites, metabisulfites (1 mol of metabisulfite forming 2 moles of bisulfite in aqueous solution) and adducts bisulfite aldehyde. Examples of sulfites, bisulfites, metabisulfites include sodium sulfite, sodium bisulfite, potassium sulfite, potassium bisulfite and ammonium metabisulfite. The total amount of the sulphite ions is preferably not less than 0.05 moles, more preferably it is from 0.1 to 1.25 moles and even more preferably from 0.3 to 0.9 moles per liter of developer. The amount of the sulphite ions with respect to the hydroquinone preferably exceeds a molar ratio of 2: 1 and, more preferably, is in the range from 2.5: 1 to 4: 1.

Anti-veils known in the art for controlling haze formation in the photographic materials handled and useful in the developer of the present invention include benzimidazole, benzotriazole, mercaptoazole, indazole and mercaptothiadiazole. Preferred anti-veils include 5-nitroindazole or benzimidazole nitrate, 5-methyl-benzotriazole and 1-phenyl-5-mercaptotetrazole. Said compounds are used alone or in combination in amounts of from about 1 x 10-6 to about 5x10 "* moles per liter, preferably from about 5 x 10" ^ to about 1 x 10-* moles per liter of developer.

Preferably, according to the present invention, the developer comprises a combination of antifog of the benzotriazole, indazole and mercaptoazole type, more preferably a combination of 5-methylbenzotriazole, 5-nitroindazole and 1-phenyl-5-mercaptotetrazole. Preferably, said combination comprises from 7 x 10 to 0.04 moles per liter of said benzotriazole antifreeze, from 6x10 "to 0.03 moles per liter of said indazole type antifreeze and from 6 x 10 to 0.02 moles. per liter of said antifog of mercaptoazole type. Examples of mercaptoazoles are described in US patent 3,576,633, and examples of indazole type antifreeze are described in US patent 2,271,229. The developer, comprising said combination of antifreeze, is used advantageously in a developing machine with continuous transport for high temperature treatments (above 35 “C) suitable for the treatment of radiographic materials, without changing the sensitometric properties of the material, in particular without substantially increasing the veil of the developed material.

Accordingly, in a preferred aspect the present invention relates to a black and white aqueous alkaline photographic developer for processing a silver halide photographic material, in particular a silver halide radiographic material, comprising (1) at least a hydroquinone, (2) at least one 3-pyrazolidone developing agent, (3) at least one dialdehyde hardener, (4) at least one antifog, (5) a sequestering agent, (6) a sulfite antioxidant, and (7) a buffering agent, characterized in that said sequestering agent is a compound of diphosphonic cycloaminomethane acid and the anti-veil comprises a combination of a benzotriazole type antifreeze, an indazole type antifreeze and a mercaptotetrazole type antifreeze.

According to the present invention, the developer further contains a buffering agent (e.g. carbonic acid salts of phosphoric acid polyphosphates, metaborates, boric acid and salts of boric acid). The amount of buffering agent with respect to the sulphite preferably is greater than a molar ratio of 0.5: 1, more preferably it is in the range of 1: 1 to 2: 1.

Inorganic alkaline agents are used in the developer composition to obtain the preferred pH which is generally higher than 10. Said alkaline inorganic agents include KOH, NaOH, LiOH, sodium and potassium carbonate, etc.

Other adjuvants well known to the developer formulation expert may be added to the developer of the present invention. These include retarders, such as soluble halides (e.g., KBr), solvents (e.g., polyethylene glycols and their esters), development accelerators (e.g., polyethylene glycols and pyridinium compounds), preservatives, surfactants, and the like.

The developer of the present invention is prepared by dissolving the ingredients in water and bringing the pH to the desired value. The developer can also be prepared in concentrated form and then diluted to the working grade before being used. The developer can be prepared in two or more concentrated parts to be combined and diluted with water to the desired degree of work and then placed in the developing vessel of the developing machine.

The developer of the present invention is particularly useful when the processing is done in automatic developing machines. Such machines may be of the type described in US patent 3,545,971, such as the "X-OMAT Processor", produced by Eastman Kodak Co., of the "TRIMATIC" series produced by 3M Company and of the "Model RK" type produced by Fuji. Photo Film Company. The temperature and the development time are related to each other and depend on the total treatment time. In general, they range from 20 to 50 ° C, as far as the temperature is concerned, and from 10 seconds to 1.5 minutes.

After development in the developer of the present invention, the silver halide material is fixed, preferably in an acid fixer, and washed and dried in the usual way. In the developing machine, these steps are determined by the machine.

The silver halide photographic materials that can be used in the present invention comprise a support and at least one silver halide emulsion layer coated on the support. The silver halide emulsion layer can be spread on one side of the support or on both sides. The silver halide photographic element may comprise other non-light sensitive layers, such as back layers, anti-halo layers, intermediate layers, filter layers, protective layers. Silver halide emulsions include dispersed silver halide grains (such as silver chloride, silver bromide, silver chloro-bromide, silver bromo-iodide, silver chloro-bromo-iodide) in a hydrophilic colloid (such as gelatin, modified gelatins, albumin, casein, sodium alginate, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone and their mixtures). The emulsion may contain cubic, octahedral, spherical and / or tabular silver halide grains. The emulsion can be chemically and optically sensitized and added, during its production or before laying, with various additions, such as stabilizers, antifreeze, hardeners, paving aids, etc. The silver halide emulsion is coated on a support, such as a cellulose acetate, polyethylene terephthalate film, using coating methods well known in the art, and dried. The silver halide materials to be used in the present invention are preferably black and white radiographic materials of high gradation (contrast) and preferably materials giving a gradation of 1.5 to 4.0.

The following examples more specifically illustrate the aqueous alkaline black and white developer of the present invention. However, it is understood that the present invention is not limited to such examples,

EXAMPLE 1

Developers 1 to 4 were prepared for silver halide radiographic materials having the compositions shown in Table 1.

Table 1

Developer

1 2 3 4

£ DTA.4Na.2H20 g

DTPA. 5Na 40% (w / W) g

Compound 1 g

5-Methylbenzotriazole g 0.06 0.06 0.0

5-Nitroindazole g 0.1 0.1 0.1

KOH 35% (w / w) g 110 110 110 110 Na2S205 - g 45 45 45 45 Κ200β g 13.2 13.2 13.2 13.2 H3BO3 g 1.7 1.7 1.7 1.7 Hydroquinone g 20 20 20 20 l-Phenyl-3-pyrazolidone g 1.45 1.45 1.45 1.45 Diethylene glycol g 4.9 4.9 4.9 4.9 Glutaraldehyde 50% (w / w) g 7.2 7.2 7.2 7.2 Sodium bromide g 5 5 5 5 CH3COOH to bring pH to 10.30 10.30 10.30 10.30 Water to make 1 1 1 1 1

Twenty five cc of each developer were placed in a 50 cc open plastic container and allowed to stand at 40 ° C for seven days. Their ability to chelate Fe ++ ions was then examined and the time in which the developer changed color, from colorless (or pale yellow) to dark brown, was measured, corresponding to the developer time. The results are summarized in Table 2, where the time (in hours) of the useful time and the sequestering power (in parts per million) are reported in comparison to Fe <++> ions.

Table 2

Developer

1 2 3 4

Time (hours) 110 98 130 150 Sequestering power (ppm) 560 4 300 1650

EXAMPLE 2

Concentrated parts of the developers were prepared, to be combined and diluted with water to the desired degree of work having the compositions shown in Table 3.

Table 3

Set off

At A2

Water cc 500 500 EDTA.4Na.2H20 g 8.77

5-Methyl-benzotriazole g 0.321 0.24 KOH 35% (w / w) g 427 434 NaS205 g 132 164 K2C03 g 52.8 53 H3BO3 g 6.85 6.85 Hydroquinone g 114.7 80 Water to make 1 1 1

Set off

B1 B2

Acetic acid 99% (w / w) g 362 586 l-Phenyl-3-pyrazolidone g 58,1 116,2 5-nitro-indazole g 6,34 8 Ethylene glycol to make 11 g "708 Diethylene glycol to make 11 g -" 394 Parties

CI C2

Water cc 690 690 Na2S20e} g 137 160 Glutaraldehyde 50% (w / w) g 144 288 Acetic acid g 11 13,2 Water to make 1 1 1

Part

D.

Water cc 600

Sodium bromide g 200

Water to make 1 1

The two developers (5 and 6) were prepared by combining the concentrated parts following Table 4.

Table 4

Developer

Water cc 650 680 Part Al cc 250

Part A2 cc 250 Compound 1 g 3 Part B1 cc 25

Part B2 cc 12.5 Part Cl. cc 50

Part C2 cc 25 Part D cc 25 25 Water to make 1 1 1 pH at 20 ° C 10.10 10.35 Seizure power. (ppm Fe <++>) 540 1700 Seizure power (ppm Ca <++>) 250 750

Two liters of developers 5 and 6 were placed in an open evaporation dish and allowed to stand at room temperature for ten days (oxidized developer). The pH, color at 400 nm and the most important developer components were then determined. The results are summarized in the following Table 5.

Table 5

Developer

pH F 10.10 10.35 **

pH O 10.57 10.20 Color F 1.11 0.53 **

Color O 2.27 0.67 Hydroquinone F g / i 26.00 17.00 A

Hydroquinone 0 g / i traces 8.00 Hydroquinone monosulfonate F * g / i 4.00 4.50

**

Hydroquinone monosulfonate 0 g / i 61.30 23.40 l-phenyl-3-pyrazolidone F g / i 1.26 1.33 **

l-phenyl-3-pyrazolidone 0 g / i 1.12 1.28 S03 "F * g / i 34.3 38

_ **

S03⁄4 O g / i 9.7 21.2 F: Fresh developer

O **: Oxidized developer

A 3M XD-A double layer X-ray film and a 3M MS-3 single layer X-ray film were processed using fresh and oxidized developers 5 and 6 for 20 seconds at 35 ° C and then fixed in 3M fixation XAF / 3 for 24 seconds at 30 ° C, washed in running water for 22 seconds at 35 ° C and dried for 22 seconds at 35 ° C. The results are summarized in the following Table 6.

Table 6

Svii, 3M XD-A Film 3M MS-3 Film

Velo Dmax Sensib. Γ Velo Dmax Sensib. Γ medium medium

5 F * 0.19 3.67 1.85 2.98 0.165 3.25 2.06 2.55 5 O ** 0.18 3.32 .1.58 2.10 0.16 2.79 1, 70 1.20

6% -5.3 -9.5 -14.6 -29.5 -3.0 -14.0 -17.5 -52.9

6 F * 0.19 3.72 1.85 3.05 0.165 3.33 2.08 2.65 6 O ** 0.1853.55 1.74 2.68 0.16 3.17 1.94 1 , 89

6% -2.6 -4.6 -5.9 -12.0 -3.0 -4.8 -6.7 -28.6

F *: Fresh developer

OR ; Oxidized developer

6%: Passage of the developer from fresh to oxidized

EXAMPLE 3

Developers 7 to 11 were prepared having the compositions reported in Table 7 for silver halide radiographic materials.

Table 7

Developer

7 8 9 10 11

EDTA.4Na.2H20 g 5

DTPA.5Na 40% (w / w) g 6.85

Compound 1 g 3 3 5-Methylbenzotriazole g 0.06 0.06 0.06 0.06 0.06 5-Nitroindazole g 0.1 0.1 0.1 0.1 0.1 KOH 35% (w / w ) g 110 110 110 110 110

Na2S2 ° 5 8 45 45 45 45 45 K2CO3 g 13.2 13.2 13.2 13.2 70 H3BO3 g 1.7 1.7 1.7 1.7 1.7 Hydroquinone g 20 20 20 20 20 l- phenyl-3-pyrazolidone g 1.45 1.45 1.45 1, 45 1, 45 Diethylene glycol g 4.9 4.9 4.9 4.9 4.9 Glutaraldehyde

50% (w / w) g 7, 2 7,2 7, 2 7,2 7,2 Sodium bromide g 5 5 5 5 5 CH3C00H for pH 10.20 10.20 10, 20 10.20 10.20 Water to make 1 1 1 1 1 1 Molar ratio

Hydr. ÌSO ^ 1: 2.36 1: 2.36 1: 2.36 1: 2.36 1: 2.36 Molar ratio

SO ^ rCO ^ - "1: 0.2 1: 0.2 1: 0.2 1: 0.2 1: 1.2 One hundred cc of the developers were placed in an open 1 liter flask and allowed to stand at room temperature environment for a period of 1 to 6 days. During this time, the pH of each developer and the Draax of 3M XD-A type X-ray film samples developed for 60 seconds at room temperature in each developer were measured. The following table 8 shows the pH and Dmax values

Table 8

Developer

10 11

pH after: 24 h 10.80 10.50 10.50 10.48 10.41

"48 h 11.28 10.84 10.85 10.81 10.49" 72 h 11.62 11.19 11.25 11.16 10.59 "96 h 11.67 11.25 11.35 11, 25 10.65 "120 h 11.37 10.25 10.51 11.00 10.74" 144 h 10.94 Dmax after: 24 h. 3.39 3.58 3.49 3.49 3.52

"48 h 3.34 3.49 3.42 3.46 3.50" 72 h 2.82 3.15 3.10 3.10 3.45 "96 h 2.42 1.90 2.00 3, 30 "120 h - 3.20" 144 h - 2.73 Useful life 58 h 75 h 80 h 90 h 139 h (*) Time in hours to have a Dmax lower than 3.00, an unacceptable sensitometric value.

EXAMPLE 4

Developers 12 to 15 were prepared for silver halide radiographic materials, having the compositions reported in Table 9 below.

Table 9

Developer

12 13 14 15

Compound 1 g 3 3 3 3 5-Methylbenzotriazole g 0.06 0.06 0.04 0.04 5-Nitroindazole g 0.10 0.10 0.08 0.08 l-Phenyl-5-mercaptotetrazole g - 0, 04 0.008 0.032 KOH 35% (w / w) g 110 110 110 110 Ν3⁄42®2®5 g 45 45 45 45 K2co3 g 13.2 13.2 13.2 13.2 H3BO3 g 1.7 1.7 1.7 1.7 Hydroquinone g 20 20 20 20 l-Phenyl-3-pyrazolidone g 1.45 1.45 1.45 1.45 Diethylene glycol g 4.9 4.9 4.9 4.9 Glutaraldehyde 50% ( w / w) q 7.2 7.2 7.2 7.2 Sodium bromide g 5 5 5 5 CH3COOH to bring pH to 10.35 10.35 10.35 10.35 Water to make 1 1 1 1 ■ 1

A 3M XD-A green sensitive double layer radiographic film and a 3M R-2 blue sensitive double layer radiographic film were processed using the above developers for 20 seconds at 39 ° C. The films were then fixed for 24 seconds at 30 ° C in a 3M XAF / 3 fixer, washed in running water for 22 seconds at 35 ° C and dried for 22 seconds at 35eC. The results are summarized in Table 10 below.

Table 10

Svii. 3M XD-A Film 3M R-2 Film

Velo Dmax Sens. Sens. Γ Velo Sens. Γ medium medium

12 0.29 3.88 1.95 2.55 0.28 3.36 2.06 2.66 13 0.27 3.92 1.90 2.65 0.25 3.45 2.02 2.88 14 0.29 3.91 1.94 2.55 0.28 3.34 2.05 2.57 15 0.28 3.94 1.93 2.65 0.26 3.43 2.01 2.85

Claims (1)

^ CLAIMS Aqueous alkaline black and white photographic developer comprising (1) a hydroquinone, (2) a 3-pyrazolidone developing agent, (3) a dialdehyde hardener, (4) at least one antifreeze, (5) a sequestering agent, (6) a sulfite antioxidant, e (7) a buffering agent, wherein said sequestering agent is a compound of diphosphonic cycloaminomethane acid. ^ 2?) Aqueous alkaline developer according to claim 1, wherein said cycloaminomethane diphosphonic acid compound corresponds to the following formula: s * v_n ' / THE Q \ N-C i-R- \ 'CH2 / R I3 in which R ^, R2 and R3, the same or different, each represent a hydrogen atom or a PC ^ M'M "group, where M 'and M" represent a hydrogen atom, an alkali metal or an ammonium group quaternary, and Q represents the atoms or chemical bonds necessary to complete a 3 to 6 membered ring, provided that at least two of R ^, R2 and R3 represent a FO3M'M group ". (3⁄4 Aqueous alkaline developer according to claim 1, wherein the sequestering agent corresponds to the formula: .CH2-CH2 PO3H2 O / - - \ N-C I-H \ CH2-CH2 / P IO3H2 Aqueous alkaline developer according to claim 1, wherein the sequestering agent is used in an amount from 5x10-4 to 5x10-1 moles per liter of developer. (Q alkaline aqueous developer according to claim 4, wherein the hydroquinone is present in the developer in an amount of from 0.075 to 0.75 moles per liter, the developing agent 3-pyrazolidone is present in an amount of from 3x1ο "-4 to 0.15 moles per liter, the dialdehyde hardener is present in quantities from lxlO-3 to 0.3 moles per liter, antifloors are present in quantities from lxlO-6 to 0.1 moles per liter, the molar ratio of the antioxidant sulfite to hydroquinone is at least 1.5: 1 and the molar ratio of the buffering agent to the antioxidant is at least 0.5: 1. (? 6?) Aqueous alkaline developer according to claims 1 to 5, wherein the antifogens comprise a combination of antifog such as benzotriazole, indazole and mercaptotetrazole. Aqueous alkaline developer according to claim 6, wherein said combination of antifog comprises between 7x10-5 to 0.04 moles per liter of said benzotriazole-type antifog, from 6x10-6 to 0.03 moles per liter of said indole-type antifog and 6x10 "® at 0.02 moles per liter of said antifreeze of the mercaptotetrazole type.