US3438776A - Non-aqueous silver halide photographic process - Google Patents

Description

April 15, 1969 J YUDELSQN 3,438,776

NONAQUEOUS SILVER HALI DE PHOTOGRAPHIC PROCESS Filed Dec. 28, 1964 5 U PPORT l7 l6 l7 K n SILVER'HALIDE EMULSION WNON-AQUEOUS SOLVENT mseme LAYER SUPPORT dbs c ahs ildelsow INVENTZR. BY g .ATTOR s25 United States Patent 0 ABSTRACT OF THE DISCLOSURE Dry processing of exposed photographic elements is carried out using a nonaqueous material which is solid at about room temperature but which becomes a nonaqueous liquid containing a photographic processing agent upon heating. Such nonaqueous material can be a component of the photographic element or can be contacted therewith to effect dry processing.

This invention relates to dry methods of photographic processing, more particularly to dry methods of processing in diffusion transfer and colloid transfer photographic systems.

In the conventional photographic processing systems, a light sensitive silver halide emulsion is exposed to light and processed by imbibing into the emulsion an alkaline reducing agent which reduces the silver halide to silver to form a negative image. In the photographic system, known as diffusion transfer as described in Rott US. Patent 2,352,014, the exposed silver halide emulsion during the developing stage is contacted against a receiving layer containing nuclei in the presence of a silver halide solvent. The undeveloped silver halide is complexed with the silver halide solvent, diffused to the receiving layer and reduced on the nuclei to form a positive image.

The colloid transfer photographic system, as described in Yutzy et al. U.S. Patents 2,596,756 and 2,716,059, uses an unhardened silver halide emulsion and a tanning silver halide developer, so that the exposed areas become tanned or hardened during the developing stage and the unexposed or unhardened areas of the emulsion are transferred to a receiving support when pressed in contact with the emulsion.

It has been desirable to discover a dry method of processing photographic emulsions which would avoid the inherent disadvantages of aqueous solutions particularly in ofiice copying devices wherein spillage and splattering from the solutions result in handling problems.

Various methods have been suggested for accomplishing so called dry processing such as incorporating hydroscopic materials in the emulsion which collect water from the atmosphere which can 'be released by heating, but these systems depend upon a certain level of moisture in the atmosphere and may not operate satisfactorily under extremely dry conditions. Another method which has been suggested is to provide a material which, when heated, releases ammonia or an amine on heating. However, the amines or ammonia do not cause development in the emulsion in the dry state, but in the presence of water. Still another proposed method involves the use of a viscous developer containing a minimum of moisture in which heat is employed to drive off the small amount of moisture in the developer after it has been imbibed in the photographic emulsion while effecting development.

Light-sensitive silver halide emulsions are noted for being extremely sensitive to various addenda which may cause desensitization, fogging, spotting, and the like, so that any agents which are added to the emulsion or to the developer solution must be compatible with the emulsion 3,438,776 Patented Apr. 15, 1969 and avoid any deleterious elfects. Moreover, conventional components of silver halide developing solutions have customarily required either water or water vapor. For these reasons, it has been diflicult to devise methods of dry or relatively dry processing silver halide emulsions.

I have discovered a method of dry processing which incorporates a material which is solid at room temperature butbecomes a solvent for the silver halide reducing agents and developing agents when heated. This material is also compatible with silver halide emulsions.

One object of this invention is to provide a dry method of processing silver halide emulsions particularly when used with the diffusion transfer and colloid transfer systems. Another object is to provide organic materials which are solid at room temperature but which act as solvents for silver halide reducing agents when in a molten state. A further object is to provide nonaqueous molten solvents for silver halide developers which are compatible with silver halide emulsions. An additional object is to provide a diffusion transfer system employing a dry developing process carried out by the application of heat. A still further object is to provide a dry colloid transfer system. Other objects will be apparent from the following disclosure.

The above objects are attained by the use of nonaqueous solvents which are solid at room temperature and preferably have melting points below 140 C. These nonaqueous solvents may be specific compounds, complexes, eutectics or mixtures of two or more compounds. Particularly useful materials for these nonaqueous solvents are polar compounds having high dielectric constants containing the electron withdrawing groups -SO and CO and may be represented by the following formulas:

(I) XCONRR (II) YSO NH 111 Reno CHZO where X may be chosen from the group consisting of H, alkyl groups of 1 to 4 carbon atoms, R'NI-I, R"O- and -(CH CONRR', where n is 1 to 4, R may be chosen from the group consisting of H, CH and HOCH CH R may be chosen from the group consisting of H and CH R" may be lower alkyl of l to 4 carbon atoms, X and R together may be a diradical chosen from the group consisting of -(CH ),CO and -(CH where a is 2 to 3 and b is 3 to 5, R and R taken together and with N of XCONRR may complete a heterocyclic ring such as morpholine or piperidine, Y may be chosen from the group consisting of alkyl groups of 1 to 4 carbon atoms, NH R"O, aryl and substituted aryl. The following are some examples of specific compounds included in these generic formulas: forma mide, acetamide, propionamide, valeramide, N-methyl acetamide, N,N-dirnethylacetamide, N-lt2-hydroxyethyl) acetamide, N,N'-bis(2-hydroxyethyl)malonamide, N,N'- bis 2-hydroxyethyl) adipamide, N,N-bis (Z-hydroxyethyl N,N-dimethylsuccinamide, succinimide, glutarimide, 2- pyrrolidinone, 2-oxohexamethylenimine, ethyl carbamate, urea, N-methylurea, N,N'-dimethylurea, sulfamide, methyl sulfamate, ethyl sulfamate, methylsulfonamide, ethylsulfonamide, p-toluenesulfonamide, ethylene carbonate, and propylene carbonate.

These materials may be used alone or in combination with other materials, either as mixtures, complexes or eutectics. By the proper choice of mixtures of these compounds or mixtures of these compounds with many other compounds, many variables in nonaqueous processing such as processing temperature, rate of processing, maximum density, fog level, gamma, etc., can be adjusted as desired. Some compounds included in the generic formulas are liquid at room temperature and while satisfactory for use in liquid nonaqueous processing baths would not be satisfactory in coatings of photographic elements. These compounds, on mixture with either other compounds covered by the generic formulas or many other types of compounds, will form mixtures which are solid at room temperature. Also some compounds with desirable solvent properties but with melting points too high for practical operating conditions can be incorporated into nonaqueous solvents by mixture with other substances which will lower their melting points. Mixtures illustrating some of these points are shown in the following table:

Percent addi- Additive M.P. i additivo range to tive (deg) obtain M.P. of

100 or less To succinimide, M.P. 123 0.:

Formamide 2 -100 Triethanolamine 21 -100 N -Methylacetamide 25 22-100 Ethyl carbamate. 49 25-100 Acetanu'de 79 16-100 N, N -dimethylu.re 100 25-95 N,N-bis(2- ydroxyethyl)- adipamide 130 48-70 To urea, M.P. 132:

N-(2-hydroxyethyl) acetamide 25 44-100 N-methylacetamide 25 40-100 2-arnino-2-methyl-l-propauoL 25 57-100 1,6-hexanediol 42 71-100 Ethyl carbamate 49 61-100 2,2,2-trichloro-1-ethoxyethanol 51 -100 n-butyl carbamate. 53 86-100 n-propionamide..- 78 40-100 Acetarnide 79 30-100 Imidaz0le 88 -100 Methylurea 99 30-100 n-valeramide 102 72-95 2-amino-2-methy1-1,3-propanediol. 109 8-95 Suceinnm'de 123 1 None N ,N-bis (2-hydroxyethyl) adipamide 130 -80 Thiourea 171 30-45 Lithium nitrate 255 13-23 1 At 30%, forms a eutectic with M.P. 111 0.

As an alternative procedure, the nonaqueous solvent may be used to form a complex with hydroquinone by heating the nonaqueous solvent with hydroquinone and using the complex wherever the nonaqueous solvent is used by itself. This is a particularly advantageous method 4 of incorporating the material, since materials which are liquid at room temperature but which form complexes which are solid at room temperature can be used. Liquids which can be used include N-methyl-pyrrolidinone, acetylmorpholine, etc. The complex releases hydroquinone and provides the nonaqueous solvent upon heating sufiiciently to melt the complex.

In a preferred embodiment the solid material is coated in a thin layer of about 0.001 to 0.003-inch thickness on a support which is to be contacted against the silver halide emulsion. A preferred coverage for the nonaqueous solvent is about 1-2 -g./ft. but a larger amount may be used provided the nonaqueous solvent to binder ratio is from about 2:1 to 8: 1. When used with the diffusion transfer process, this layer is coated over a nucleated receiving support, whereas, when used in the colloid transfer process, it is coated over an untreated receiver sheet or one which has thereon a fogging agent to increase the density of the transferred image.

In carrying out the nonaqueous diffusion transfer process, the exposed silver halide emulsion is contacted against a nucleated receiving sheet having the overcoat of this invention and containing therein a silver halide developer and a silver halide solvent. This sandwich is then heated to a temperature sufiicient to melt the nonaqueous solvent material for a sufiicient time for the emulsion to develop and the positive image to form in the nucleated layer. Supercooling occurs so that the nonaqueous solvent remains liquid for some time after the melted layer has been cooled back to room temperature, facilitating removal of the receiving sheet from the emulsion layer. After transfer occurs, the receiving sheet is separated from the emulsion revealing a positive image.

In carrying out my process with a colloid transfer type emulsion, the tanning silver halide developer is preferably incorporated in the unhardened silver halide emulsion and contacted against the overcoated receiving sheet of this invention. The sandwich is heated to a temperature suf- -ficient to melt the nonaqueous material causing tanning development to occur in the silver halide emulsion. Upon removal from the heating source, the sandwich is separated, revealing a transferred stratum of unhardened emulsion on the receiving support. Successive copies can then be made.

The colloidal material which may be used in the diffusion transfer process as a vehicle for the light sensitive silver halide may be any of those capable of swelling, which can be used in photographic emulsions such as gelatin, polyvinyl alcohol, methyl cellulose, polyacrylamide, copolymer of ethylacrylate and acrylic acid, cellulose ether phthalate, albumin, collodion, etc. The vehicle used in the colloid transfer process is a colloid which can be hardened by a tanning silver halide developer.

The nonaqueous solvent is preferably coated together on the support with a suitable film-forming binder to provide suitable adhesion to the support. Although a wide number of binders may be used, those which are particularly useful are flexible binders including those described above as suitable as vehicles for photographic emulsions, but also including binders, such as for example, a copolymer of ethylene and maleic acid, cellulose ethers such as ethyl cellulose, cellulose esters such as cellulose acetate butyra-te and cellulose acetate containing approximately 33% acetyl, poly-N,N-diethylacrylamide, a copolymer of vinyl pyrrolidone and vinyl acetate, a copolymer of styrene and butadiene, proteins, such as casein and the like, etc., providing the binders are permeable to the molten form of the nonaqueous solvents.

The silver halide developing agents which may be used are not critical but include those commonly known as silver halide reducing agents such as, for example, N- methyl-p-aminophenol sulfate, ascorbic acid, hydroquinones, 3-pyrazolidones, including l-phenyl-3-pyrazolidone, l-phenyl-4,4-dimethyl-3-pyrazolidone, etc., p-phenylene diamine, catechol, stannous octoate, dextrine, 3,5- diaminophenol, etc.

The silver halide solvents or silver complexing agents which are useful include, for example, thioureas, thiocyanates, thiosulfates, mercapto containing compounds such as mercapto acetic acid, polyamines such as tetraethylene pentamine, etc.

The silver halide emulsion is preferably silver chloride, but other conventional developing out emulsions may be used such as silver bromochloride, bromoiodide, chloroiodide, chlorobromoiodide, etc.

It is preferable to use a paper receiving sheet but other supports may be used such as cellulose acetate, glass, wood, metal, polymeric materials such as polyesters, polyolefins, and the like.

When the nonaqueous solvent is used in a developing solution, the solution is preferably made above the melting temperature of the nonaqueous solvent and can be stored in a solid condition upon cooling. When the solution is used for developing an exposed silver halide emulsion, the solution is used in the molten condition at a temperature above the melting point of the solution. It will be appreciated that various components used in conventional silver halide developing solutions can be incorporated.

The quantities of nonaqueous solvent are not critical but may be used in an amount suflicient to provide solubility for the components in the developing solution.

When the developing solution and/or the nonaqueous solvent are used as overcoats on silver halide emulsions, they may be used in a manner similar to that used with the colloid and/or the diffusion transfer silver halide emulsions. A barrier coat may be used if desired, to prevent migration of the developer from the nonaqueous solvent layer into the silver halide emulsion prior to thermal processing of the exposed emulsion. The nonaqueous solvent and/or developer may be incorporated in the silver halide emulsion for some purposes.

The nonaqueous solvent must be used in amounts sufiicient to act as a solvent for the developer and other materials present in the coatings. When incorporated in a silver halide emulsion, the nonaqueous solvent should be present at a concentration of at least 0.1 g. per millimole of silver halide. When used in a layer over or under a silver halide emulsion, it is necessary to have a higher concentration of at least 0.4 g. per millimole of silver halide.

The temperatures at which development takes place must be above the melting point of the nonaqueous solvent. However, in some instances the temperature may be considerably higher depending upon the speed of development desired, hardness of the emulsion, type of developer used, etc. The upper limit is dependent upon these same factors.

The attached drawing shows two embodiments of my invention.

FIG. 1 illustrates the use of the nonaqueous solvent layer in a diffusion transfer system. A support 11 carries thereon an exposed silver halide emulsion 12 having areas 17 exposed to light and areas 16 unexposed to light. The exposed silver halide emulsion 12 is contacted against the nonaqueous solvent layer 13 coated over the nucleated layer 14 which is coated on the support 15. The nonaqueous solvent layer 13 contains a silver halide developer and a silver halide solvent or complexing agent. Heat is supplied sufiicient to melt the solid nonaqueous solvent whereby development of the exposed areas 17 of the silver halide emulsion 12 takes place. Unexposed silver halide from areas 16 are dissolved by the silver halide solvent or complexing agent and migrate to the nucleated layer 14 where the silver complex is reduced to form a positive image.

FIG. 2 illustrates a colloid transfer embodiment of the invention in which support 11 carrying an unhardened silver halide emulsion 12 which is contacted against a nonaqueous solvent layer 13 containing a tanning silver halide developer coated over a fogging layer 14 which is, in turn, coated on support 15. Heat is applied to the sandwich to cause the nonaqueous solvent 13 to melt whereby the exposed areas 17 of the silver halide emulsion are developed and hardened. The unexposed areas 16 remain unhardened and adhere to the fogging layer 14 on the support as shown in the area of the figure which shows the separation of the receiver sheet from the developed silver halide emulsion.

The following examples are intended to illustrate my invention but not to limit it in any Way.

EXAMPLE 1 The following layers were coated on a poly(ethylene terephthalate) support subbed with a copolymer of ethyl acrylate and acrylic acid.

Polyvinyl alcohol, 7 percent 50.0 Acetamide 3.5 Poly(ethylene imine) (aqueous), 50 percent 3.5

Polyvinyl alcohol, 7 percent 50.0 Acetamide 20.0 Thiourea. 1.5

This mixture was coated in a 0.016-inch wet thickness. As a negative material, a silver chloride photographic emulsion on a paper support was used. Half of its surface was exposed to light and the entire sheet developed in D-72 developer, washed, and dried under a red safety light. Sandwiches were made of the negative strips and the receiver sheet. The sandwich was heated in a print mounting press for two minutes at 114 C. The sandwich was separated, and the receiving sheet was found to contain the positive image. Thus, the silver halide diffusion transfer and its subsequent reduction in the receiving sheet was achieved in a single operation.

EXAMPLE 2 The following layers were coated on single weight partially acetylated fiber paper which contained a gelatin baryta layer such as is commonly used in photographic printing paper.

G. Polyvinyl alcohol, 7 percent 50.0 Acetamide 3.5 Yellow dextrine 7.0

This was coated to give a 0.5 mil dry thickness. After drying it was then overcoated with a solution made up as follows:

G. Polyvinyl alcohol, 7 percent 50.0 Acetamide 21.0 Tetraethylene pentamine 2.5

EXAMPLE 3 The following layers were coated on a single weight partially acetylated fiber paper as in Example 2.

G. Polyvinyl alcohol, 7 percent 50.0 Acetamide 3.5 Stannous octoate 2.0

This was coated to give a 0.5 mil dry thickness. It was then overcoated with a solution made up as follows:

G. 7 percent polyvinyl alcohol 1 50.0 N-methylacetamide 28.0 Tetraethylene pentamine 2.5

1 The solvent for the polyvinyl alcohol consisted of /45 water/isopropanol by Weight.

This was coated in a 0.024 wet thickness. This receiving sheet was placed in face-to-face contact with a negative as in the preceding examples. It was heated with an electric iron at C. for two minutes. This caused the receiver to contain the positive image of the negative. Analysis revealed the silver coverage in the receiver sheet to be mg./ft. indicating a substantial amount of silver diffusing to the receiver sheet. In this example, the stannous octoate was present in the coating composition as a well-dispersed emulsion. The polyvinyl alcohol acts as the dispersing agent in addition to being the binder.

Since mixtures of N-methylacetamide and acetamide form solid solutions over a wide range of composition, it is possible to lower the heat requirements by using a blend of the two nonaqueous solvents. Table I describes the melting points of mixtures of N-methylaceamide and acetamide.

Table I Percent N-methylacetamide: Melting point, C. 80.0

The following layers were coated on single weight paper as in Example 3.

G. Polyvinyl alcohol, 7.4 percent solution in /45 (water isopropyl alcohol) 47.0 Acetamide 5.0 Stannous octoate 2.5

This was coated to give a 0.5-mil dry thickness. It was then overcoated with a solution made up as follows:

G. Acetamide 42.0 Cellulose acetate 2 7.0 Tetraethylene pentamine 4.0

32.7 percent acetylcorresponds to 1.3 acetyl/anhydro glucose.

This was coated at 90-95 C. with a 0.0l2-inch knife. The receiving sheet was placed in face-to-face contact with a negative and heated with an electric iron at 110 C. for 15 seconds. Upon separation, the receiving sheet contained the positive image of the negative.

The receiving sheet containing the positive image of Example 4 was placed into an oven at approximately 130 C. for about two minutes. The image became darker leaving the silver image in what is now an essentially pure cellulose acetate binder.

EXAMPLE 5 This example deals with a reducing agent which is mobile. The preceding examples dealt with polymeric reducing agents such as polyethylene imine and dextrine, and a reducing agent which was dispersed in a binder in which it was insoluble. A mobile reducing agent will, of course, migrate to the negative material and cause reduction of the silver halide there in addition to reduction in the receiving sheet. The following layers were coated on single weight partially acetyated fiber paper.

G. Gelatin (water solution), 7 percent 50.0 Dimethylamine-borane 20.0

This was coated to give a 0.5-mil dry thickness. It was then overcoated with a melt made up of the following:

G. Acetamide 42.0 Cellulose acetate 7.0 Tetraethylene pentamine 4.0

This was coated at -95 C. with a 0.012-inch knife. The receiving sheet was placed in face-to-face contact with a silver chloride negative for 60 seconds as in the preceding examples at C. Upon separation, the receiving sheet contained the positive image of the negative. The image was also black in color as compared with the brown images obtained in the preceding examples.

EXAMPLE 6 The following illustrates methods of forming hydroquinone nonaqueous solvent complexes:

(A) Hydroquinone-formamide complex.One hundred and ten grams of hydroquinone and 91 grams of formamide were placed in 250 ml. of ethyl acetate. This mixture was heated on a steam bath until complete solution occurred. While hot, the solution was filtered and then allowed to cool to room temperature to obtain the crystalline complex. It was collected by filtration and dried to give grams of solid, M.P. 77.

(B) Hydroquinone-acetarnide complex.One mole of hydroquinone and 1 mole of acetamide were warmed in 700 ml. of acetone until a homogeneous solution was obtained. This solution was evaporated to dryness, triturated with ether, filtered and dried to yield 148 grams of white crystalline solid, M.P. 105.

(C) Hydroquinone-N-methylpyrrolidinone complex. One mole of hydroquinone was dissolved in 250 ml. of warm isopropanol to which was added 200 grams of N- rnethylpyrrolidinone. After the solution was cooled overnight, the product was collected by filtration and recrystallized from 250 ml. of isopropanol to obtain 212 grams of complex, M.P. about 70.

(D) Hydroquinone-acetylmorph'oline complex.One mole of hydroquinone was dissolved in 250 ml. of warm isopropanol to which was added 260 grams of acetylmorpholine. The resulting solution was filtered, cooled and the crystalline complex which precipitated was collected by vacuum filtration to give 336 grams of product, M.P. 88-90.

EXAMPLE 7 A solution of 15 grams of hydroquinone-acetylmorpholine complex, 10 grams of l-phenyl-3-pyrazolidone and 100 ml. methanol was imbibed into Corinth white paper in 0.25 and 0.5 gram per square foot amounts and dried. Samples of the two coatings were placed in close contact with an exposed silver halide emulsion and heated with a hot iron sufficiently to cause the complex to melt and release hydroquinone. After one minute the sandwich was separated. The silver halide emulsion was found to have been developed in the image areas. Similar coatings were made with the other complexes of Example 6 and were found to develop a silver halide emulsion.

The process described in the preceding examples demonstrates many advantages over existing aqueous processes. The use of a solvent which is solid at room temperature means that there is very little loss of such solvent on stor age of the photographic materials. In existing diffusion transfer processes where water is used as the solvent medium, elaborate precautions must be taken to prevent its loss due to evaporation. Use of a hydrate such as Na PO -12H O as a method of storing water which would be released on heating are not practical under conditions of low relative humidity. Also, when heat is applied to a hydrate, much of the water is evaporated and it is thus unavailable to the silver halide complex as a diffusion medium. The systems described in this invention provide a stable diffusion medium for high temperature processing. Elevated temperatures enable photographic processing to be greatly accelerated.

Since acetamide will dissolve hydrophobic binders such as cellulose acetate, silver images can be obtained in matrices that are not water soluble. Such matrices would be very stable under a wide variety of conditions in which conventional materials such as gelatin or paper would deteriorate.

The images obtained in this invention were based on silver. It is also possible to make use of color forming reactions in which oxidized developer reacts with a conpler. An example of such a system would be p-phenylene diamine (as developer) and naphthalene glycol (as coupler). Heat causes the exposed silver halide image to be developed, and the oxidized developer diffuses to the receiver sheet where it reacts with the coupler thus forming an image. Nonaqueous solvents which are solids at room temperature make such a high temperature process feasible. It is also possible to use this oxidized developer process to provide dry ofiice copying employing heat.

EXAMPLE 8 The following solution was made up:

G. Succinimide 25.0 Urea 5.0 Water 25.0

This was dispersed in 125 grams of 3.5% ethyl cellulose.

The dispersion was coated over a silver chloride emulsion containing 4-pheny1 catech'ol, of the type described in Yutzy et al. US. Patent 2,716,059, using a 0.006-inch coating knife. After drying it was exposed to a line copy negative for seconds using a #2 photofiood at a distance of 24 inches. It was then heated for 5 seconds at 140 C. and an excellent black-and-white positive image appeared. The coating was dipped in water, causing the 'overcoat to slough off and exposing the tanned image layer. The wet matrix was pressed against an absorbent sheet and the white non-tanned areas transferred to the receiving sheet, leaving the tanned-developed areas on the matrix.

EXAMPLE 9 The following emulsion was made up:

G. Gelatin (7% aqueous solution) 100.0 Silver chloride coagulum (53% solids) 15.0 Succinimide 21.0 Urea 3.0 Pyrocatechol 2.0

This was coated on gelatin baryta paper using a 0.006-inch knife. A smooth coating resulted. This was exposed to the same source as described in Example 6 and heated at 140 C. for 5 seconds. Good development occurred. A receiving sheet was pressed tightly against the surface of the developed matrix and a good transfer of the untanned areas resulted.

EXAMPLE 10 This example deals with receiving sheets which contain a developing agent so that they can be used to develop the exposed negative material in addition to effecting transfer and subsequent reduction of silver halide in the receiving sheet.

The following layers were coated on single weight partially acetylated fiber paper as in Example 2.

G. Polyvinyl alcohol, 7 percent 50.0 Acetamide 3.5 Stannous octoate 2.0

This was overcoated to give a 0.5-mil dry thickness. After drying, it was overcoated with a solution made up as follows:

G. Acetamide 42.0 Cellulose acetate 7.0 Tetraethylene pentamine 4.0 1-phenyl-3-pyrazolidone 0.5

It was coated at 90 C. with a 0.0l2-inch knife.

This was placed in face-to-face contact with an exposed silver chloride negative and heated at 140 C. for 3 minutes. Upon separation, the receiving sheet contained the reversed image of the negative.

EXAMPLE 11 Sheet I A solution was made as follows:

G. Sulfamide 30.0 N-hydroxyethyl-N-ethyl-p-phenylenediamine 8.0 Ammonium sulfite 2.0

Water 20.0

This solution was dispersed in 125 ml. of a 7% ethyl cellulose solution in toluene. The solution was coated to give a dry coverage of 2 gm./ft. on a gelatin-silver halide emulsion and dried.

Sheet II A solution was made as follows:

Polyvinyl alcohol -g 5.0 Ethanol ml 75.0 Water g 25.0 l-naphthol g 15.0 Ammonium sulfite g 2.0

This solution was coated on a light weight gel sized paper at 1 gm./ft.

The negative (sheet I) was exposed to a line copy negative and then placed in face-to-face contact With the receiving sheet (sheet II) and heated at C. for 1 second. When separated, each had an image. Sheet I had a developed silver image of the negative, and sheet II had an image, blue in color, which was the mirror image of sheet I. The image on sheet II was due to the reaction of the oxidized color developer and the coupling agent in the receiving sheet.

Another sheet of (II) was pressed against the developed image (I) and heated in close contact for one second. Upon separation (II) had a blue mirror image of (I). This was repeated again until four legible copies were obtained on (II) from the original (1).

EXAMPLE 12 Sheet I The following silver halide emulsion was made:

. G. Gelatin (7% solution) 100.0 Silver chloride coagulum (52% AgCl,

47.5% water, 0.5% gelatin) 6.1 Sodium isoascorbate 4.0 l-phenyl-3-pyraz0lidone 1.0 Succinimide 15.0

This was coated on baryta coated 27 lbs/1000 ft. paper stock (I) with a 0.006-inch knife to give a dry coverage of 2 gm./ft.

Sheet II A solution was made as follows:

G. Sulfamide 30.0 Ammonium thiosulfate 4.0 Water 10.0

This was coated over a receiving sheet (II) used in a silver diffusion document copying process (Apeco) at a dry coverage of 1.0 gm./ft.

Sheet I was exposed under a photofiood to a line copy negative (White letters on a black background) for /2 minute. It was then pressed against sheet II in face-toface contact and heated from the back side of sheet I for 30 seconds at 110 C. A positive image appeared on the receiving sheet (11). The receiving sheet used here contained a small amount of development nuclei in a hydrophilic polymer. Nuclei which can be used are, for example, nickel or zinc sulfide, finely dispersed silver 1 1 (Carey Lea Silver), etc. A useful concentration of nuclei is in the range of 10-20 mg./ft.

EXAMPLE l3 Sheet I of Example 11 is exposed on a 3M Thermo-Fax Secretary. The exposed sheet I is then contacted against sheet II with the exposed emulsion in contact with the nucleated surface of the receiving sheet and passed through the heated rollers at a No. 4 setting and the two sheets separated to provide a positive image on the receiving sheet.

EXAMPLE 14 A photographic emulsion coating Was made with the nonaqueous solvent as well as developing agent incorporated in it.

Developing dispersion:

1-phenyl-3 -pyrazolidne -g- 1 20 n-butylacetanilide -cc- 480 Ascorbic acid g 40 Potassium bromide g 5 aqueous gelatin g 18 60 Emulsion:

Silver chloride gelatin emulsion g 3 7 Developer dispersion g 5 0 Succinimide g- 13 The photographic emulsion was coated (0.003" knife) on 0.004 Estar (polyethylene terephthalate) film base. Exposure through a high contrast negative followed by heating on a hot shoe at about 300 F. resulted in development of the image.

EXAMPLE 15 A developing solution was made up as follows:

G. l-phenyl-S-methyl-pyrazolidone 4.0 Potassium bromide 0.1

Acetamide 20.0

Formamide 20.0

EXAMPLE 16 A developing solution was made up as follows:

G. Succinimide 30.0 Ferrous (ethylene diamine tetracetic acid) 5.0 Water 40.0

This solution was dispersed in 125 grams of a 7% ethyl cellulose solution in toluene. It was coated with a 0.006" knife on the emulsion side of photographic papers having emulsions which were predominantly silver chloride. The coated papers were exposed to a continuous tone negative and developed at 140 C. for 15 seconds to give a good image.

EXAMPLE 17 A developing solution was made up as follows:

G. Succinimide 40.0 1-phenyl-5-methyl-pyrazolidone 6.0 Ascorbic acid 2.0

Water 15.0

This solution was dispersed in grams of a 7% ethyl cellulose solution in toluene. It was coated on a predominantly silver chloride emulsion on a paper support with a 0.006" knife and dried. The coated paper was exposed to a line copy negative and developed at C. for 3 seconds to give a good image. The paper was then incubated over silica gel at 75 F. for 6 days. It was removed from the desiccator in a room maintained at 15% R.H., 75 F., and exposed to a line copy negative and heated on a mandrel at 140 C. for 3 seconds. The sensitometric data obtained under the two sets of conditions are listed below:

Incubation conditions D... Fog

Fresh coatings, ambient conditions of 75 F.,

40 a R.H 0.8 0.02 Dehydrated coatings, ambient conditions of EXAMPLE 18 G. 1-phenyl-S-methyl-pyrazolidone 6.0 Ascorbic acid 2.0 Acetamide 38.0 Water 10.0

Temperature of solution maintained at 140 F.

A piece of exposed photographic paper having a predominantly silver chloride emulsion was immersed into the solution above and development occurred.

Another sample of the same photographic paper was coated with an ethyl cellulose phthalate (21% phthaloyl, 42% ethoxyl) out of methylene chloride solution to give a 0.3 g./ft. coverage (dry). This coated sample was exposed and immersed in the developer solution for 2 minutes with no development occurring in that time. This indicated that the barrier layer of ethyl cellulose phthalate was impermeable to the developing solution in acetamide-water at 140 F. The temperature of the solution was raised to 200 F. with essentially the same results.

A molten developer solution was made up as follows:

G. 1-phenyl-S-methyl-pyrazolidone 6.0 Ascorbic acid 2.0 Acetamide 38.0

Solution maintained at 205 F.

The photographic paper with its barrier layer was immersed into the molten bath for 5 seconds. Development occurred, indicating that the barrier was permeable to the developing agents in molten acetamide.

EXAMPLE 19 This example covers the simultaneous development and stabilization of a photographic image. The following coatings were made in successive order on predominantly silver chloride emulsion paper under red light.

(a) A 5% solution of ethyl cellulose phthalate (same composition as described in Example 18) in methylene chloride was coated to give a dry coverage of 0.4 g./ft.

(b) The following developer dispersion was made and coated over (a) to give a dry coverage of 2 g./ft.

G. 1-phenyl-3-pyrazolidone 6.0 l-ascorbic acid 2.0 Potassium iodide 0.5 Succinimide 30.0 Water 40.0

The above dispersed in 125 grams of 7% ethyl cellulose in toluene.

(c) The following stabilizer dispersion was made and coated over (b) to give a dry coverage of 2 g./ft.

G. Diethylaminoethananethiol-HCl 8.0 Succinimide 30.0 Water 40.0

The above solution dispersed in 125 grams of 7% ethyl cellulose in toluene.

The sample was exposed for 15 seconds to a line copy negative using a printing box with a 10-watt incandescent lamp. It was heated on a mandrel at 150 C. for 30 seconds. The image appeared after 3 seconds of heating. The developed and stabilized print was exposed to a 20-watt fluorescent lamp at a distance of 6 inches for 24 hours without deterioration of the image or any increase in fog level.

EXAMPLE 20 This example demonstrates the use of a nonaqueous developing solution on a web.

A developing solution was made up as follows:

G. lphenyl-3-pyrazolidone 6.0 1-ascorbic acid 2.0 Acetamide 38.0

Water 10.0

This solution was dispersed in 125 grams of a 7% ethyl cellulose solution in toluene with a Gaulin mill. It was coated on a heavily gel-sized light weight paper base to give a coverage of 3 g./ft. The developer web was now ready for use. A number of strips of photographic paper having a predominantly silver chloride emulsion thereon were exposed to a line copy negative. They were placed in face-to-face contact with the developer web and the sandwich was pressed on a mandrel at 100 C. for 2 to 3 seconds. The same piece of web was used with eight successive samples of the same photographic paper'and gave good developed images in all cases.

This solution was dispersed in 125 grams of 7% ethyl cellulose solution in toluene. It was coated on a print-out paper having thereon a silver chloride silver citrate emulsion to give a dry coverage of 2 g./ft. The coating was exposed to a line copy negative using a photoflood (#2). After a 45 second exposure, a good print-out reversal of the negative appeared on the proof paper. The image was then stabilized by heating on a mandrel at 245 F. for 30 seconds. The stabilization was tested by exposing the sample to the photoflood for minutes with no deterioration of the image.

A sample of the print-out paper was coated with an ethyl cellulose phthalate barrier layer (as described in Example 17) to give a dry coverage of approximately 0.2 g./ft. This was then coated with the above dispersion and exposed and stabilized in the same manner as described above. Good stabilization of the print-out image was obtained with a whiter background than in the case where no barrier layer was used.

EXAMPLE 22 A developing solution was made up as follows:

Water 25.0 Potassium bromide 0.1

This solution was dispersed in 125 grams of a 7% ethyl cellulose solution in toluene. It was coated on photographic paper over a photographic emulsion primarily silver bromide to give 1.5 g./ft. dry coverage. The paper was exposed to a line copy negative using a printing box with a 10-watt incandescent lamp. It was heated on a mandrel at C. for 3 seconds. A black image appeared. In the above example, the nonaqueous solvent is urea-lithium nitrate which forms a eutectic at the composition ratio given above.

This example demonstrates using an ionic salt as the solvent medium. It is possible to use a completely inorganic solvent medium by making use of salt mixtures with sufiiciently low eutectic temperatures. In such a solvent all of the solvent components are ionized. Such media are favorable for the redox reactions of the development process.

It is also possible to use a nonaqueous processing technique for the development of color materials containing incorporated color couplers. Here, one overcoats the film with a dispersion containing a developer such as, for example, p-phenylene diamine. After exposure, the material is heated during which time the developer develops the exposed silver halide and the oxidized developer reacts with the incorporated couplers to give a colored image.

EXAMPLE 23 A developing solution was made up as follows:

G. Ethyl carbamate 18.0 Urea 12.0 1-phe'nyl-3-pyrazolidone 6.0 Ascorbic acid 2.0 Water 10.0

This solution was dispersed in grams of 7% ethyl cellulose solution in toluene. It was coated on photographic paper over a predominantly silver chloride emulsion using a 0.006'inch knife. The paper was exposed to a line copy negative and developed by heating for 1 to 2 seconds on a mandrel at 225 F. A good image appeared.

EXAMPLE 24 The following solution was made up:

G. Succinimide 25.0 Urea 5.0 Water 25.0

This was dispersed in 125 grams of 3.5% ethyl cellulose.

The dispersion was coated on a support and then overcoated with a silver chloride emulsion containing 4-phenyl catechol of the type described in Yutzy et al. U.S. Patent 2,716,059, using a 0.006-inch coating knife. After drying, the element was exposed to a line copy negative for 5 seconds using a #2 photoflood at a distance of 24 inches. It was then heated for 5 seconds at C. and an excellent black-and-white positive image appeared. The coating was dipped in water and the wet matrix was pressed against an absorbent sheet and the entire gelatin layer transferred to the receiving sheet. The non-tanned areas were then removed by washing.

It will be appreciated that this process can be used for making lithographic printing plates either by the diffusion transfer process or by the colloid transfer process. Images prepared according to my invention can be treated to render them oleophilic by methods known in the art.

When images are prepared according to the diffusion transfer process, it is customary to incorporate a toner which is present at the time of transfer of the silver halide to the receiving sheet. These toners may also be used when the diffusion transfer process is carried out using nonaqueous solvents of this invention.

It will also be appreciated that when silver halide emulsions are prepared or exposed, that the customary safelight precautions must be taken. Of course, emulsions of the type which can be handled in roornlight for a short time, such as those customarily used in office copying by the diffusion transfer process or colloid transfer process, can be used in a similar manner in the process of this invention.

The disclosures of US. Patents 2,596,756 and 2,716,059 are incorporated herein by reference.

By room temperature as used herein, is intended 70 to 80 F.

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

I claim:

1. A photographic element comprising a support having thereon at least one layer containing a minor porportion of a film forming colloid binder and a major porportion of a photographically inert, nonfilm-forming, nonaqueous medium, solid at room temperature and having a melting point below about 140 C.; said film forming colloid binder being permeable to the molten form of said nonaqueous medium; said nonaqueous medium comprising a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of -SO and -CO--, and being present in a concentration of at least 0.1 gram per millimole of silver halide to be processed; said nonaqueous medium containing at least one nonaqueous photographic processing chemical in solid solution and providing in the fused state mobility for said processing chemical.

2. A photographic element as in claim 1 in which said binder is selected from the group consisting of film forming proteins, cellulose esters, cellulose ethers and vinyl polymers.

3. A photographic element as in claim 1 also comprising a photo gnaphic silver halide.

4. A photographic element as in claim 1 in which the binder is ethyl cellulose.

5. A photographic element comprising a support having thereon at least one layer comprising a nonaqueous medium, a solid at room temperature and having a melting point below about 140 C.; said medium comprising a nonaqueous, monomeric, high dielectric, polar solid which in the fused state provides mobility for silver halide developing agents; said solid being selected from the group consisting of the formulas:

Cir

wherein X is H-, alkyl groups containing 1 to 4 carbon atoms, R'NH, R"O-, or (CH ),,CONRR; n is 1 to 4; R is -CH or HOCH CH R is H, or CH R" is a lower alkyl group of 1 to 4 carbon atoms; Z and R together represent a divalent radical which is (CH CO, or -(CH a is 2 to 3, b is 3 to 5; Y is an alkyl group of 1 to 4 carbon atoms, NH RO-, or aryl; and W represents remaining members of a heterocyclic ring.

6. A photographic element as in claim 5 also comprising a photographic silver halide.

7. A photographic element as in claim 6 in which said silver halide comprises a silver halide dispersion in a substantally unhardened colloid which can be hardened by a tanning type silver halide developer.

8. A photographic element as in claim 7 in which the said silver halide comprises an unhardened colloid silver halide emulsion containing a tanning silver halide developing agent.

9. A photographic element as in claim 5 also comprising a silver halide solvent.

10. A photographic element as in claim 9 wherein said silver halide solvent is selected from the class consisting of thioureas, thiocyanates, thiosulfates, mercapto containing compounds and polyamines.

11. A method for preparting an image on a receiving sheet comprising contacting an unhardened exposed photographic silver halide emulsion with an absorbent surface in the presence of a tanning silver halide developing agent and a nonaqueous medium being solid at room temperature, having a melting point below about 140 0, comprising a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of SO and -CO, and providing in the fused state mobility for said developing agent; heating to a temperature sufiicient to melt the nonaqueous medium and causing the silver halide emulsion in the exposed areas to become hardened and the unhardened areas of the silver halide emulsion to adhere to the absorbent surface, and separating the silver halide emulsion from the absorbent surface leaving a stratum of the unhardened emulsion adhering to the absorbent surface.

12. A method as in claim 11 wherein said nonaqueous polar solid is selected from the class consisting of the formulas:

( XCONRR' YSO NH (III) E (1V ZCONRR (V) X0 OBIII'KW wherein X is H-, alkyl groups containing 1 to 4 carbon atoms, RNH, RO, or (CH )CONRR; n is 1 to 4; R is H--, CH or HOCH CH R is H-, or CH R" is a lower alkyl group of 1 to 4 carbon atoms; Z and R' together represent a divalent radical which is (CH CO, or (CH a is 2 to 3, b is 3 to 5; Y is an alkyl group of 1 to 4 carbon atoms, NH R"0, or aryl; and W represents remaining members of a heterocyclic ring.

13. A method as in claim 11 in which the tanning silver halide developer is present in the silver halide emul- 14. A method as in claim 11 in which at least one layer comprising said polar solid is present on the silver halide emulsion.

15. A method as in claim 11 in which at least one layer comprising said polar solid is present on the absorbent surface.

16. A method as in claim 11 in which the silver halide emulsion is a gelatino silver halide emulsion.

17. A method for obtaining an image in a layer comprising contacting an exposed photographic silver halide emulsion in the presence of a silver halide developing agent, a silver hadile solvent and at least one layer containing a nonaqueous medium containing a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of --SO;; and CO--, said medium being solid at room temperature and having a melting point below about 140 C., with a nucleated receiving layer, heating sufficiently to melt the nonaqueous medium providing in the fused state mobility for said developing agent whereby the silver halide emulsion is developed in the exposed areas and unexposed silver halide reacts with the silver halide solvent to form a complex which diffuses into the nucleated layer and is reduced to form an image.

18. A method as in claim 17 in which a silver halide developing agent is present in the silver halide emulsion.

19. A method as in claim 17 in which the silver halide solvent is present in the nonaqueous medium.

20. A method as in claim 17 in which at least one layer containing said nonaqueous medium is on the surface of the silver halide emulsion.

21. A method as in claim 17 in which at least one layer containing said nonaqueous medium is present on the surface of the nucleated receiving layer.

22. A method as in claim 21 in which the silver halide solvent is present in the layer containing said nonaqueous medium on the nucleated receiving layer.

23. A method for obtaining an image in an exposed photographic silver halide emulsion comprising heating a nonaqueous medium being solid at room temperature and having a melting point below about 140 C., said medium comprising a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups se lected from the group consisting of -SO and -'CO- and containing a silver halide developing agent, sufficiently to melt the nonaqueous medium and contacting the silver halide emulsion with the melted medium to form an image in the silver halide emulsion.

24. A nonaqueous photographic developer solution comprising at least one silver halide developing agent and a nonaqueous medium, solid at room temperature and having a melting point below about 140 (3., said nonaqueous medium comprising a non-aqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of SO and CO and providing in the fused state mobility for said developing agent.

2.5. A nonaqueous photographic processing composition comprising a silver halide developing agent and a nonaqueous medium, solid at room temperature and having a melting point below about 140 C., said nonaqueous medium comprising a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of -SO and CO and providing in the fused state mobility for said developing agent.

26. A nonaqueous photographic processing composition comprising a silver halide solvent and a nonaqueous medium, solid at room temperature and having a melting point below about 140 C.; said nonaqueous medium comprising a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of -SO and CO- and providing in the fused state mobility for said silver halide solvent.

27. A nonaqueous photographic processing composition as in claim 25 wherein said polar solid is succinimide.

28. A nonaqueous photographic processing composition as in claim 26 wherein said polar solid is succinimide.

29. A photographic element comprising a support having a coating containing a silver halide developing agent and succinimide, said coating being solid at about room temperature and melting below about 140 C.

30. A photographic element comprising a support having a coating containing a silver halide solvent and succinimide, said coating being solid at about room temperature and melting below about 140 C.

31. A method of obtaining an image in an exposed photographic silver halide layer compirsing heating a nonaqueous photo-graphic processing composition containing a silver halide developing agent and succinimide, said composition being solid at about room temperature and fusible below a temperature of about 140 C., sufficiently to melt said composition, and contacting said photographic silver halide layer with said composition.

32. A photograph element comprising a support containing a print out photographic silver halide layer and a layer containing a nonaqueous photographic processing composition containing a silver halide solvent and a nonaqueous medium, solid at room temperature and having a melting point below about 140 C..; said nonaqueous medium somprising a nonaqueous, monomeric, high dielectric, polar soli-d containing electron withdrawing groups selected from the group consisting of SO and CO and providing in the fused state mobility for said processing composition.

33. A photographic element as in claim 32 containing succinimide, urea and thiourea.

34. A silver halide emulsion comprising a photographic silver halide, at least one photographic processing chemical, and a nonaqueous medium solid at room temperature and having a melting point below about 140 C., said nonaqueous medium comprising a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of SO and CO, providing in the fused state mobility for said processing chemical, and being present at a concentration of at least 0.1 gram per millimole of silver halide.

35. A silver halide emulsion as in claim 34 wherein said photographic processing chemical is a silver halide developing agent.

36. A silver halide emulsion comprising a photographic silver halide, a silver halide developing agent and succinimide.

37. A photographic image receiver comprising a support having thereon a nucleated layer and a nonaqueous medium, solid at room temperature and having a melting point below about 140 C., said nonaqueous medium comprising a nonaqueous, monomeric, high dielectric, polar solid containing electron withdrawing groups selected from the group consisting of SO and -CO-.

38. A photo-graphic image receiver comprising a support having thereon a nucleated layer and succinimide.

References Cited UNITED STATES PATENTS 3,260,604 7/1966 Kalenda 96101 3,348,946 10/1967 Jones 9661 XR 3,038,801 6/1962 Alletag 96-66 3,041,170 6/1962 Haist ct al. 96-66 3,212,896 10/1965 Yudelson et al. 96-63 NORMAN G. TORCHIN, Primary Examiner. .T. R. EVERETT, Assistant Examiner.

US. Cl. X.R.

PO-WSO UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,LIBB, 776 Dated April 15, 1969 Inventor(s) Joseph S. Yudelson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

F In column 3, line 35 (page 5, line 37 of the application)? "8-95 should be --38-95--.

In column 7, line 1 (page 13, line 7 of the application) "N-methylaceamide" should be --N-methylacetamide--.

In column 7, line 67 (page 11 line 26 of the application) "20.0 g" should be --2.0 g--.

In column 15, claim 1, line 31 (page 1, claim 1, line 14. of the amendment) "porpor-" should be -propor--.

In column 15, claim 1, line 32 (page 1, claim 1, line 5 of the amendment) "por" should be --pro---.

In column 16, line 3 (page 3, claim 6, lines 17-18 of the amendment 7/23/68), "R is should be --R is H,--.

In column 16, line lL jpage L claim 8, line 3 of the amendment 7/23/68), "substantally" should be --substantially In column 16, line 26 (page L claim 12, line 1 of the amendment 7/23/68) "pr-eparting" should be --preparing-.

In column 17, line 9 (page 7, claim 18, line L of the amendment 7/23/68) "hadile" should be --halide--.

In column 18, line 25 (page 11, claim 38, line 8 of the amendment 7/23/68) "somprising" should be --comprising-.

SIGNED AN; (.IALEU DELL) Harm) Anew domissionar of Patents

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