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Publication numberUS3615512 A
Publication typeGrant
Publication dateOct 26, 1971
Filing dateOct 16, 1968
Priority dateMay 7, 1968
Also published asDE1923112A1
Publication numberUS 3615512 A, US 3615512A, US-A-3615512, US3615512 A, US3615512A
InventorsDucrocq Jacques, Gallois Daniel
Original AssigneeEastman Kodak Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Photographic compositions and process for stabilizing image records with said compositions
US 3615512 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

,[73] Assignee United States Patent [54] PHOTOGRAPHIC COMPOSITIONS AND PROCESS FOR STABILIZING IMAGE RECORDS WITH SAID COMPOSITIONS 16 Claims, No Drawings [52] U.S.Cl 96/61, 96/29, 96/95 [51] Int.Cl G03c 5/38, G030 5/30 [50] Field of Search 96/61, 95, 29

[56] References Cited UNITED STATES PATENTS 2,375,740 3/1945 Dearing 96/61 2,230,977 2/1941 Ham 96/61 2,857,275 10/1958 Land et aL. 96/61 2,875,048 2/1959 Haist et al 96/61 3,161,514 12/1964 l-lenn 96/95 3,169,992 2/1965 Henn... 96/61 3,245,793 4/1966 Smith 96/61 OTHER REFERENCES Organic Silver-Complexing Agents for Photographic Monobaths" by Haist et al., Photographic Science and Engineering; Vol. 5; No. 4, July- Aug. 1961 pp. 198 to 203.

Prirnary Examiner-William D. Martin Assistant Examiner-William R. Trenor Attorneys-W. H. J. Kline and Gerald E. Battist ABSTRACT: Photographic compositions comprising (1) a silver halide developing agent, (2) a water-soluble silver halide solvent and (3) a weak silver halide complexing agent. ln one embodiment the above composition can be used to rapidly develop or stabilize image records in silver halide emulsions which contain addenda which lower the rate of dissolution of silver halide in a potassium thiocyanate solution.

PHOTOGRAPHIC COMPOSITIONS AND PROCESS FOR STABILIZING IMAGE RECORDS WITH SAID COMPOSITIONS This invention relates to new processes for obtaining stable images in silver halide compositions. In one aspect this invention relates to new compositions which can be used to obtain stable images in silver halide compositions. In another aspect this invention relates to means for obtaining stable image records in direct-print emulsions. In still another aspect this invention relates to novel monobaths for stabilizing image records in photographic compositions.

It is known in the art to stabilize image records in silver halide compositions and in particular in direct-print silver halide compositions by treating said records with developing solutions. However, in internally sensitive silver halide compositions which have surface latent image specks in the background areas, conventional developing solutions do not discriminate satisfactorily between the latent internal image and the surface latent image. This is especially true when certain halogen acceptors, development modifiers, antifoggants and the like are present in the silver halide composition which lower the development rate of latent internal image in a silver halide composition.

Therefore, it is an object of this invention to provide new means for obtaining stable image records in photographic compositions.

it is another object of this invention to provide new compositions for stabilizing image records in silver halide compositions.

It is another object of this invention to provide new monobath systems.

1t is still another object of this invention to provide means for stabilizing image records in internally sensitive silver halide compositions.

It is still another object to provide means for obtaining stable image records and high discrimination (Dmax-Dmin) in internally sensitive silver halide emulsions.

We have now found that these and other objects of the invention can be accomplished with a developer composition comprising a silver halide solvent and a weak silver complexing agent. It is believed that the silver complexing agent forms a silver ion complex. The weak silver complexing agents of this invention all have the inherent characteristic property of not being capable of reducing silver halide to metallic silver. ln one embodiment the weak silver complexing agent is additionally characterized in that it contains the ethenic group such as benzene, toluene, aniline, etc. In another embodiment the weak silver complexing agent is additionally characterized as being a halogenated hydrocarbon. The complexing agents are also substantially free of mercaptan groups (or tautomers thereof) which would provide other predominant characteristics. In still another embodiment we have found that polyhydric compounds such as lactose, maltose, glucose, and the like can be added to said stabilizing compositions to improve image discrimination when stabilizing a silver halide image record.

The silver halide compositions which can be stabilized or developed according to this invention are those which are internally sensitive to electromagnetic radiation, i.e., light, X- rays, electrons, etc. Suitable silver halides include internally sensitive silver bromide, silver bromoiodide, silver chlorobromide, silver chlorobromoiodide, and the like. The preferred emulsions are those wherein the silver halide is predominantly silver bromide. 1n a typical embodiment preferred emulsions according to this invention have higher internal sensitivity than surface sensitivity. Typical suitable emulsions are disclosed in Davey et al., U.S. Pat. No. 2,592,250 issued Apr. 8, 1952; U.S. Pat. No. 3,206,316; Porter et al., U.S. Pat. No. 3,206,313, Glafkides, Photographic Chemistry, Vol. 1. pp.

31-32, Fountain Press, London; McBride, U.S. Pat. No. 3,271,157 issued Sept. 6, 1966, McBride, U.S. Pat. No. 3,287,137 issued Nov. 22, 1966, and Hunt, Photographic Science and Engineering, Vol. 5, No. 2, Mar.Apr., 1961, pp. 104-108.

The so-called intemal image" emulsions can be used in the invention, such having silver halide grains wherein a predominant amount of the sensitivity is internal to the grains. Such internal image emulsions are those which, when measured according to normal photographic techniques by coating a test portion of the emulsion on a transparent support, exposing to a light intensity scale having a fixed time between 1X10" and l second, bleaching 5 minutes in a 0.3 percent potassium ferricyanide solution at 65 F. in Developer B below (an internal-type developer), have a sensitivity, measured at a density of 0.1 above fog, greater than the sensitivity of an identical test portion which has been exposed in the same way and developed for 6 minutes at 68 F. in developer A below (a surface-type" developer).

Sodium thiosulfate 10.0 g. Water to make 1 liter The stabilizing or developing baths of this invention provide unexpected increases in the stabilizing or development rate of silver halide compositions which contain addenda which lower the dissolution rate of silver halides in potassium thiocyanate. In one embodiment of this invention direct-print compositions containing a halogen acceptor which lowers the rate of dissolution of silver halide in potassium thiocyanate can be effectively and quickly stabilized to form permanent image records having high image discrimination. Typical direct-print emulsions which are preferably stabilized according to this invention contain halogen acceptors such as l-n-butyl-l,2,5-6- tetrachydro-l ,3,5-triazine-4-thiol, 2,2,4-trimethyl-6-mercapto-metadiazine, 5-methyl-2-mercapto-oxazoline, phenyl thiosemicarbazide and dithiomalonamide.

The photographic elements processed according to the present invention can contain only latent images or they can contain visible image records, such as in the instance of a photodeveloped direct-print element. A permanent visible substantially uniform image record having good image discrimination will be obtained regardless of whether film is entirely photodeveloped to a visible image record or contains no visible image record.

The stabilizing or developing bath can contain a wide variety of compounds which reduce silver halide to silver. Typical developers include N-methyl-p-aminophenol sulfate, hydroquinone, 1-phenyl-3-pyrazolidone, l-phenyl-4methyl-4 '-hydroxymethyl-3-pyrazolidone, ascorbic acids, and the like or mixtures of the same. In a preferred embodiment the developing agent comprises 1-phenyl-3pyrazolidone/hydro quinone I or l-phenyl-3-pyrazolidone/ascorbic acid. The developing compositions also can contain agents such as anhydrous sodium sulfite, stabilizing agents such as, for example, sodium or potassium carbonate amines or amino and S clathrates and other agents such as antifoggant agents commonly used in developer compositions.

The stabilizers or developers of this invention contain a silver halide solvent or fixing agent such as for example, watersoluble thiocyanates. ln one embodiment the thiocyanates are used in combination with organic thioethers. Suitable organic thioethers include those which when utilized in aqueous solutions (60 C.) at 0.02 molar concentrations, are capable of dissolving more than twice the amount (by weight) of silver chloride than that which can be dissolved by water at 60 C. Typical preferred organic thioethers which can be used according to this invention contain at least one moiety wherein oxygen and sulfur are separated by an ethylene radical (e.g., -0Cl-l CH- .S). Generally, the subject thioethers have one to three thioether atoms (-8- although thioether compounds having more than three thioether atoms can be used. Typical thioethers are disclosed in McBride, U.S. Pat. No. 3,271,157 issued Sept. 6, 1966. These organic thioethers play also the part of weak complexing agents such as defined hereinafter. Typical thiocyanates useful according to the invention include potassium thiacyanate, sodium thiocyanate, ammonium thiocyanate, and the like. Generally, the watersoluble thiocyanate is present in concentrations of about 25 grams to about 500 grams per liter and preferably from about 150 grams to about 450 grams per liter. Other suitable fixing agents can also be used within the scope of the invention; however, the thiocyanates are the preferred fixing agents.

The weak silver complexing agents are all characterized by the common property of not being capable of reducing silver halide to metallic silver. The weak complexing agents are generally incorporated in the stabilizing or developer compositions in concentrations of about 1 gram/liter to about 150 grams/liter and preferably from about 10 grams/liter to about 100 grams/liter Preferably the weak silver complexing agents are those compounds which can be additionally characterized as hydrocarbons having an ethenic group halogen groups or combinations of these groups in the compound. In a preferred embodiment the weak silver complexing agents contain at least one halogen group and more preferably at least one halogen group and at least one ethenic group. In another embodiment the weak silver complexing agents contain at least two ethenic groups and more preferably at least three ethenic groups. Typical compounds useful in the invention which have the above characteristic properties are acyclic ethylene compounds such as trichloroethylene and the like; cyclic ethylene compounds such as dicyclopentadiene and the like; aromatic compounds such as benzene, toluene, maminophenol, aniline, anisol, benzoic acid, benzylamine, benzylic alcohol, benzylic aldehyde, chlorobenzene,

1 bromobenzene, m-cresol, dimethyl benzylamine, xylenes,

ethylbenzene, N-methyl aniline, m-phenylene diamine, resorcinol, salicylic aldehyde, o-toluidine, primary phenylethyl alcohol, l-methyl-B-phenylpropylamine, phenylethlamine, and the like; unsaturated heterocyclic compounds such as lutidines, 2-Bphenylethyl isoquinolinium bromide and the like; halogenated compounds such as disclosed by l... J. Andrews and R. W. Keefer in J.A.C.S. Review 71, 3644-3647, 1949; 72, 3113-3116, 1950; 72, 5034-5037, 1950; 73, 5733-5736, 1951, which include halomethanes such as methyl iodide, diiodomethane, chloroform and the like; dihaloethylenes such as diiodoethylenes, dichloroethylenes and the like; halobenzenes such as chlorobenzene, diiodebenzenes and the like.

We have also found that polyhydroxy compounds can be effectively added to the above developing or stabilizing baths of this invention to increase the discrimination (Dmax-Dmin) of the image record. In a preferred embodiment carbohydrates are employed such as lactose, maltose, levulose, glucose, mannitol, dextrose and the like.

The essential ingredients of the stabilizing or developing composition according to this invention, namely the developers, the weak silver complexing agents and the silver halide solvent can be prepackaged in a kit in diluted, concentrated, or powder form and can be either mixed together or packaged individually for use in making the permanizing composition of this invention. Either one or all of the essential ingredients can also be coated in a separate layer on the photographic element which can subsequently be activated by an aqueous solution. The respective compositions are generally prepackaged individually and can be readily added to water to form a bath. Therefore, it is understood that kits prepared for making stabilizing or developing compositions comprising the essential ingredients of this invention are contemplated to be within the scope of this invention.

The stabilizing or developing baths of this invention are particularly useful to stabilize the image record in silver halide compositions containing addenda which lower the rate of dissolution of silver halides in potassium thiocyanate. For example, when a common silver halide emulsion is dipped into a 15/100 in mass of aqueous solution of potassium thiocyanate, at 20 C., for 1 minute, the proportion of dissolved silver halide is 94/100, as will be seen in the following example 1. By operating in the same manner, but with a silver halide emulsion, useful according to the invention, which contains l-nbutyl-l,2-5,6-tetrahydro-l,3,5-triazine-4-thiol at a concentration of 3.63 moles per moles of silver halide, one notes that only 70/100 of silver halides are dissolved.

However, this decrease in the speed of dissolution of the silver halides due to the addenda in the emulsion (i.e. for example, halogen acceptor in a direct-print emulsion), is inhibited by the presence of a weak silver complexing agent, such as previously defined, in the silver halide solvent solution. As will be seen in the following example 1, it suffices to add 15 ml. of a weak silver complexing agent such as benzylamine to 1 l. ofa 15/100 potassium thiocyanate solution in order to pick up the 70/100 to 92/100 92/100 mass proportion of dissolved silver halides.

The invention can be further illustrated by the following examples of preferred embodiments thereof, although it will be understood that the examples are included merely for purposes of illustration and are not intended to limit the scope of the invention unless otherwise indicated.

EXAMPLE 1 Two photodevelopable photographic products are prepared such as samples No. 1 and No. 3 of example 6 of French Pat. No. 1,450,983 Sample No. 1 serves as a control (product 1). Another product is also prepared from sample No. l to which, one adds Z-mercapto-imidazole to the amount of 3.63Xl0 mole per silver gram/atom (product ll). Sample No. 3 (product 111 contains l-n-butyl-l ,2,5,6-tetrahydro-l,3,5- triazinethiol in the emulsion of sample 1 with a concentration of 3.7Xl0 mole per mole of silver. A sample of the three preceding unexposed photographic products are dipped for 1 minute, respectively, into the following solutions I and another sample of the same products into the following solution 11:

Solution I Potassium Thincyanate Water (sufficient quantity to obtain Solution 11 150 g. 15 ml.

Potassium Thiocyanate Benzylumine water (sufficient quantity to obtain) TABLE I Product 1 Product Product (Control) ll lll Solution l Undissolved silver after treatment (1 in mass) 6 5 30 Solution ll Undissolved silver after treatment ('1 in mass) 6 1 8 EXAMPLE 2 Two series of three samples are prepared of photographic products such as those that are described in example i.

The six samples are exposed through a 0.30 neutral density step tablet for l under a lighting of approximately l000 1x, they are then photodeveloped for minutes under a lighting of 540 lx, and finally, a first series of samples is treated in a control stabilizing developer such as developer F:

Developer F (control) Water 500 ml.

Celon E (tetrasodium salt of tetracetic ethylenediamine acid) I g. Anhydrous sodium sulfite 40 40 Methylaminoethanol -S0, S0,) 70 g. l-phenyl-4-metjyl-4-hydroxymethyl-3- pyrazolidone 22 g. Ascorbic acid [2 gr Potassium thiocyanate I50 g.

Water (Sufficient quantity to obtain) l l.

The second series of samples is treated separately in a treatment monobath according to the invention (developer G) with the formula:

Water 500 ml Celon E l g. Anhydrous sodium sulfite 40 g. Methylarninoeihanol --SO,(201' S0,) 70 g. l-phenyl-4-rnethyl-4-hydroxymethyl-3- pyruzolidone 2.2 g Ascorbic acid l2 g Potassium thiocyanate 150 g Benzylamine [5 ml.

Wutcr (sufficient quantity to obtain) The maximum density and the minimum density obtained with the product Ill according to the invention in developers F and G are the following: 7

TABLE II Monobuth Dmax Dmin AD Developer F 0.79 0.56 023 Developer G 0.69 0. 25 0.44

It is noted that Product lll treated in the new monobath embodied in the process according to the invention displays a more sizeable discrimination (AD=Dmax -Dmin) in spite of slight diminution of the Dmax.

The following table Ill mentions, on the other hand, the quantities of developed silver and the covering power obtained with the six preceding samples.

Product I, treated in developer G (developer containing benzylamine) displays a quantity of developed silver clearly increased compared to that obtained in developer F.

Product ll gives comparable results. The covering power, which remains high, is slightly diminished by the presence of benzylamine.

Product lll displays results opposite to those obtained with products I and II. The treatment according to the invention provides a diminution of the quantity of developed silver. On the other hand, the quantity of silver developed in developer F (usual stabilizing developer) is clearly higher to that obtained with product ll treated in the same bath. This result can be explained by the fact that l-n-butyl-l,2,5,6-tetrahydro-l,3,5- triazine-4-thiol reduces considerably the fixing speed of the silver bromide through the potassium thiocyanate by forming a complex with the silver halide, as was seen in example 1. The role of the weak complexing silver agent such as the benzylamine of developer G is to inhibit this diminution of the dissolving speed of the silver halides in the potassium thiocyanate, as shown by example 1.

Similar results are obtained when utilizing l-n-butyl- 1,2,5 ,-tetrahydrol ,3 ,5 ,-triazine-4-thiol and 2,2,4- triamethyl-6-mercaptometadiazine in Product lll.

Example 3 This example shows that the association of an emulsion addenda, such as a halogen acceptor, and a weak complexing silver agent useful according to the invention makes it possible to inhibit the development of a surface image in a surface developer.

A photographic product is prepared comprising a silver bromide photographic emulsion layer applied on a paper support, it is then exposed through a 0.15 neutral density step tablet for a microsecond by means ofa flash bulb placed at 1 meter from the original (lighting of approximately 1 lumen per second). The photographic product exposed in this manner contains an internal image.

The photographic product is divided into five samples TABLE IV AD L54 Dmin Dmax

Sample No. Developer l (H) CONTROL 2 (H )+0.2 3. of l-phcnyl- -mercupto-tetrazole per liter 3 (H)+0.03 g. of 2.2.4-

trimethyl-6-mercaptometadiazine per liter 4 (H )+N-methylnniline to the point of saturation 5 (H)+N-methylaniline to the point of saturation +0.03 g. of 2,2,4-trimethyl--rnercaptometadiazine per liter With sample No. 2 which contains a usual antifogging agent which is also an inhibitor of nonselective development, a total inhibition of the development is noted. With sample No. 4, no inhibiting reaction of the development is noted due to N- methylaniline, weak complexing silver agent useful according to the invention. With sample No. 5, it is noted that the joint action of the compound of sample 3 and the N-methylaniline inhibits any development. Developer H being essentially a surface-image developer, the result obtained with sample No. 5 shows that the development ofa surface image is inhibited.

Similar results are obtained by replacing in the preceding baths Nos. 3 and 5 the 2,2,4-trimethyl-6-mercaptometadiazine with l-n-butyll ,2,5,6-tetrahydrol ,3,5-triazine-4-thiol or other halogen acceptor useful according to the invention.

Example 4 This example shows that the association of certain addenda and a weak complexing silver agent useful according to the invention make it possible to develop an internal image in a solvent developer, without development ofa surface image.

A photographic paper, such as that of example 3, is divided into five samples which are exposed as in example 4 and which are treated, respectively, in one of the developers mentioned in the following table V. These developers are prepared from developer l which develops at the same time both the internal and surface images; the other developers used for treating the various samples being derived from developer 1 to which the compounds mentioned in the following table V have been added.

2 l+0.2 g. of lphenyl-S-mercaptotetrazole per liter 3 l+0.03 g. of 2,2,

4-trimethyl-6-mercaptometadiazine per liter 4 1+ N-methylaniline to point of saturation With sample No. 2, which contains a nonselective development inhibitor, a total inhibition of the development is noted, i.e., development inhibition of both the surface andinternal image. With sample No. 3, an emulsion containing an adden'da (halogen acceptor) used in small quantity makes it possible to obtain an image record very close to the control image record. With sample No. 5, no inhibition of the internal development is noted when the developer used contains a halogen acceptor and a weak silver complexing agent, useful according to the invention such as previously defined.

With this sample No. 5, a very legible image record is obtained which displays, compared with the control, only a slight diminution of the maximum density due to. the surface development inhibition.

When N-methylaniline is replaced with other weak silver complexing agents, useful according to the invention and previously mentioned, a good inhibition of the surface image is noticed, while the internal image is well developed.

Similar results are obtained by replacing in the preceding baths nos. 3 and 5, the 2,2,4-trimethyl-6-mercaptometadiazine with l-n-butyll ,2,5 ,o-tetrahydrol ,3 ,5 triazine-4-thiol or any other halogen acceptor useful according to the invention.

The following example illustrates the application of the present invention to stabilizing treatment of photodevelopable copying papers which have been photodeveloped. Direct-print emulsions which have been exposed and photodeveloped, generally comprise two distinct images: an image essentially internal which displays the exposed part, i.e., image of interest, since it represents the sought information (it is also often called trace) and a background image due to the photodevelopment of the previously unexposed crystals. This background image is undesirable because an exposed and photodeveloped paper treated in a conventional internal developer develops the surface image or background image and reduces the discrimination (AD=Dmax-Dmin).

The present invention makes it possible to inhibit the development of the background image. Stabilizing developers according to the invention are used which develop the internal image without developing the background image. The use of this stabilizing developer also makes it possible to reduce treatment time necessary to stabilize aphotographic element.

Example 5 four samples which are treated for 1 minute respectively with one of the following treatment baths (developers J, C, D. E). Exposed but not photodeveloped samples are also treated with these developers.

Developer J has the following composition:

Developer J l-phenyl-3-pyrazolidone L6 g. Hydroquinone 12 g. Anhydrous Sodium Sulfite 40 g. Z-methyI-aminoethanol. SO, (20% of S0,) 70 g. Potassium thiocyanate I50 g. Potassium iodide 0.4 g. Water (sufficient quantity to obtain) 1 l. Developer C l-phenyl-3-pyrazolidone 1.6 g Hydroquinone 12 g Sodium sulfite anhydrous 40 g. Z-methyl-aminoethanol, SO (20% of S0,) 70 g. Potassium thiocyanate 150 g. Potassium iodide 0.4 g. Benzylamine 15 ml. Water to make I l. Developer D l-phenyl-Il-pyrazolidone 1.6 g. Hydroquinone 12 g. Sodium Sullite anhydrous 40 g. Z-methylaminoethanol SO, (20% of S0,) 70 g. Potassium thiocyanate 150 3. Potassium iodide 014 5. Potassium bromide 4 :1 l6 g. Benzylamine 15 ml. Water to make I l. Developer E l-phenyl-3-pyrazolidone l.6;g. Hydroquinone 12 g. Sodium Sulfite anhydrous 40 g. Z-methylaminoethanol, S (20% of S0,) 70 g. Potassium thiocyunate I50 g. Potassium iodide 0.4 g. Sodium thiosult'ate 2 a 4 g. Benzylumirie l5 ml.

Water to make I l.

Developer .l is a usual developer for the internal image. if an exposed but not photodeveloped sample of the previously mentioned photographic product is developed chemically by such a developer, a copy is obtained with low Dmin and relatively high Dmax.

When the sample is photodeveloped, the Dmin increases due to the development of the surface image formed during the photodevelopment.

The stabilizing developers C, D, E according to the invention, when used on a photodeveloped sample, provide an image record identical to that obtained with a nonphotodeveloped sample (low Dmin and relatively high Dmax). The development of the surface image is apparently suppressed by the stabilizing developers.

Photodeveloped samples can be stabilized in developer .I when benzylamine is added to obtain permanent images having density levels similar to those obtained with nonphotodeveloped samples treated by developer .l above (usual internal developer).

Similar results are obtained when methyl iodide, benzene N-methyl aniline, trichloroethylene, aminophenol, resorcinol, phenyl ethyl amine and the like are utilized in developer .l for treating photodeveloped and nonphotodeveloped image records. EXAMPLE 6 Two samples are prepared from a photographic product such as described in example 5, which are exposed for one one-thousandths seconds behind a 0.30 neutral density step tablet (the lighting used is approximately 1 lx.s), and which is photodeveloped for 5 minutes at 540 ix. One of the samples is treated for 1 minute in developer F (control developer) of example 2.

The following densities are thus obtained:

Dmin=0.56 -Dmax=0.79 AD=0.23

The second'sample is then treated for 1 minute in a stabilizing developer according to the invention similar to developer G of example 2 in which the benzylamine has been replaced with benzene at the point of saturation.

The results obtained are as follows:

Dmin=0.30 Dmax=0.64 AD=0.34

EXAMPLE 7 This example illustrates the use of a halogenated compound as a weak complexing silver agent for preparing a monobath according to the invention.

A sample according to example 6 is treated with the developer ofe'xample 6 wherein the benzene in the stabilizing developer has been replaced with methyliodide at the point of saturation.

The results obtained are as follows:

Dmin=0.34 Dmax=0.8l AD=0.47

The incorporation of methyl iodide in the treatment monobath according to theinvention makes it possible to increase considerably the (Dm-ax-Dmin) as well as the visual contrast by the diminution of the Dmin.

EXAMPLE 8 Photographic elements are prepared with emulsions made according to French Pat. l,450,983 which contains 3.7Xl0 mole per mole of silver of l-n-butyl-l ,2,5,6-tetrahydro-l ,3,5 -triazinethiol.

Samples of the photographic elements are made by exposure for one one-thousandthof a second behind a 0.30 neutral density step wedge and then photodeveloped for 5 minutes at '54'0lumens.

The samplesa're treated in the following monob'aths.

Water to make I I. l l.

The samples are treated for 1 minute in the respective m'onobaths with the following results:

Dmax Dmin AD Monobuth A 0.73 0.43 0.30 Monobath B, 0.79 0.56 0.23

EXAMPLE 9 Carbohydrates can be used in combination with the ak silver complexingagents in the stabilizing or developing baths of this invention to provide synergistic improvements in the photographic properties of the image record.

Photographic elements are prepared according to example l, exposed for one one-thousandth of a second behind'a 0.30 neutral density step wedge and then photodeveloped for 5 minutes at 540 lux. One of the photographic elements is treated for 1 minute in monobath B having the following composition:

Monobath B,

Water 500 ml. Celon E 1 gr. Sodium Sulfite 40 gr. Z-methyl aminoethanol SO, (20% S0,) 2-methyl 70 gr. l-phenyl-Brpyrazolidone 2.2 gr. Ascorbic Acid 1 12 gr. Potassium thiocyanate 150 gr. Potassium iodide 0.4 gr.

Water to make I l.

A second photographic element, prepared and exposed as above, is treated for 1 minute in a monobath according to monobath B with the addition of 100 grams of saccharose per liter.

A third photographic element, prepared and exposed as above, is treated for 1 minute in a monobath according to monobath B with the addition of 15 ml. of benzylamine per liter.

A fourth photographic element, prepared and exposed as above, is treated for 1 minute in a monobath according to monobath B with the addition of 100 grams of saccharose and 15 ml. of benzylamine per liter.

The following results are obtained on a densitometer:

Dmin Dmax AD Sample 1 0.56 0.79 0.23 Sample 2 0.56 0.79 0.23 Sample 3 0.27 0.58 0.31 Sample 4 0.25 0.63 0.38

EXAMPLE A photographic element, prepared and exposed as in example 9,is treated for 1 minute in a monobath according to monobath B, additionally containing ml. of benzylamine and 100 grams of lactose per liter. The following results are obtained:

Dmin AD Dmax sensitivity ple 5 0.24 0.66 0.42 3.06

Similar results are obtained when maltose, levulose, glucose, amidon, mannitol and dextrine are used in the monobath in combination with the weak silvercomplexing agent.

The invention has been described in considerable detail with reference to preferred embodiments thereof, but is will be understood that variations and modification can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim: 1. A photographic monobath composition for developing direct-print photographic compositions comprising (1) a silver halide developing agent, (2) a water soluble thiocyanate silver halide solvent and (3) a weak silver halide complexing agent which is not capable of reducing silver halide to metallic silver.

2. A photographic bath according to claim 1 wherein said weak silver halide complexing agent comprises at least one group or halogen group.

3. A photographic bath according to claim 1 wherein said silver halide solvent is potassium thiocyanate.

4. A photographic bath according to claim 1 wherein said weak silver halide complexing agent is an aromatic compound.

5. A photographic bath according to claim 1 wherein said weak silver halide complexing agent is a halogenated organic compound.

6. A photographic bath according to claim I wherein said weak silver halide complexing agent is an organic thioether.

7. A photographic bath according to claim 6 wherein said organic thioether comprises at least one moiety of the formula OCI-l -CH -S-).

8. A photographic bath according to claim 1 wherein said developing agent comprises l-phenyl-3- pyrazolidone/hydroquinone.

9. A photographic bath according to claim 1 wherein said developing agent comprises l'-phenyl-3- pyrazolidone/ascorbic acid.

10. A photographic bath according to claim 1 wherein said weak silver complexing agent comprises at least two ethenic groups.

11. A photographic bath according to claim 1 wherein said weak silver complexing agent contains a halogen group.

12. A photographic bath according to claim 11 wherein said weak silver complexing agent further agent further contains an ethenic group.

13. A photographic bath according to claim 1 wherein said weak complexing agent comprises at least three ethenic groups.

14. A photographic bath according to claim 1 further comprising a carbohydrate.

15. A photographic bath according to claim 1 wherein said weak silver complexing agent is benzylamine.

16. A photographic composition according to claim 1 wherein said weak silver complexing agent is substantially free of mercaptan groups.

ii i ii i Po-ww UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Potent No. 3, 5,5 2 Dated October 26, 1971 i Jacques Ducrocq and Daniel Gallois 7 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

, e "1 r- Column 2, line 1.2, "1X1O16" should read ---I x! O line L Z, "10.0 g" should be directly under "-5.0 g---; line 56, "tetrachydro" should read ---te,trahydro---. lpColumn 3, line I "sulfite" should read --sulfate---. Column L line 51 after "'1 $50,983", please insert lines 53 and 5h, "3.631210 should w --'--3.63x1 oline 57, "3.7x1o should read --3. 7X1Q Column 5, line I 8, "(produce III)" should read --(Product III)--; line 6, "10 should read ---1o line L "M0 .0" should read -:-L .O Column 8, line 67, -"3.o3X1o should read ---3.63x| o Column 10, lines 33 an 3 "3.7x1o should read -3.7x10" Column 11 line 7;. "70 gr. should be directly under "-14.0 gr.---. Claim 6 should be changed to read as follows:

Claim 7, line 3, O-CH CH -S-)" r'io'dl'd r'o'dd" -Z E GH -cH -SJ- Signed and sealed this 13th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR ROBERT GO'ITSCHALK Attestlng Officer 1 Commissioner of Patents L. I i .J

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3854948 *May 15, 1972Dec 17, 1974Minnesota Mining & MfgNew development composition for radiographic film
US5688635 *May 6, 1996Nov 18, 1997Ilford LimitedToning of photographic print material
US5770351 *Nov 30, 1995Jun 23, 1998Ilford LimitedProcessing of monochrome photographic silver halide print material
WO1996021886A1 *Nov 30, 1995Jul 18, 1996Ilford LimitedProcessing of monochrome photographic silver halide print material
Classifications
U.S. Classification430/456, 430/481, 430/480, 430/486
International ClassificationG03C5/26, G03C5/38
Cooperative ClassificationG03C5/26, G03C5/383
European ClassificationG03C5/26, G03C5/38F