US2616804A

US2616804A - Sheet material containing a liquid for processing a silver halide layer

Info

Publication number: US2616804A
Application number: US610523A
Authority: US
Inventors: Edwin H Land
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1945-08-13
Filing date: 1945-08-13
Publication date: 1952-11-04
Anticipated expiration: 1969-11-04
Also published as: GB658740A; FR950235A

Description

Nov. 4, 1952 E. H. LAND 2,616,804

SHEET MATERIAL CONTAINING A LIQUID FOR PROCESSING A SILVER HALIDE LAYER Filed Aug. 13, 1945 v 2 SHEETSSHEET l Phoiographic Reqgenf Removable Liquid Remirfing Wal! Liquid Reiaining Wall Base Phoiographic FH Composih Liquid Coniuining ShQ i f IN VE TOR.

E. H. LAND SHEET MATERIAL CONTAINING A LIQUID FOR PROCESSING A SILVER HALIDE LAYER Filed Aug. 13, 1945 2 $HEETS-SHEET 2 4 I ro.|2 22.24

y 5 FIG. 4

FIG. 5

1 INVENT0R. t

Patented Nov. 4, 1952 SHEET MATERIAL CONTAINING A LIQUID FOR PROCESSING A SILVER HALIDE LAYER Edwin H. Land, Cambridge, Mass, assignor to IPolaroid Corporation, Cambridge, Mass., a corporation of Delaware ApplicationAugust .13, 1945, Serial No. 610,523

(oress) '18 Claims.

layer of material such, =for exampla as aphoto' sensitive emulsion, with said reagent.

Anotherobject of theinvention is to provide a novel sheet material of theabove type wherein the liquid reagent is in layer form and is contained in an envelope comprising a removable liquid-retainingmember, said sheet :material beingso .formed that when said retaining member is removed and the remainder of the sheet is brought into face-to-iace contact with a developable photosensitive emulsion containinga latent image said image is developed.

.A- further object is .to:provide a novel composite sheet-material :oithe above character which is adapted to provide a positive print of the subject matter of the latent image.

Still-another object is :to providea novel composite fihn comprising, in combination, a photosensitive layer and the materials required for forming afixed positive image of the subject matter of a :latent image in :said layer.

.Another object .is to provide a novel sheet material comprising a, permeable layer and means containing a liquid material out of contact with said layer, said means being so constructed that said liquid material-may be caused to selectively permeate a. predetermined area of said permeable layer. 1 i

A :still .further object of the invention is to provide a novel multi-ply photographic film comprising a photosensitive layer wherein a latent image may be .formed and a liquid layer coextensive with said photosensitive layer or at least theportion thereof containing said image, and adapted, when brought into .face-to-face contact with .said photosensitive layer, to develop said image.

' Another object of the invention is to provide a novel film or the above type wherein the liquid layer provides a receiving layer for a positive image and contains ingredients which, when permeated through'the photosensitive layer, provide an image-forming component in said .receiving layer.

A further. object is to provide a novel sheet material adapted to serve as a base for a positive image and to act as part of a vapor-impervious envelope for the reagent which is employed to produce said image.

These and other objects of .the invention will in part be obvious'and will in part appear hereinafter.

Theinventionaccordingly comprises the product possessing .the features, properties .and rela- 2 tion of components which are exemplified in the product hereinafter described and the scope of the application of which will "be indicated 'in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be'had to the accompanying drawings wherein:

Figure l is a somewhat diagrammatic, transverse, sectional view of one type of. sheet material comprehended 'by the present invention, the thicknesses .of the several layers of said film means being exaggerated for the purpose of clarity;

.2 is a .view similar to Fig. 1 through a longitudinal section of said sheet material;

Fig. .3 is a view similar to Fig. 1 of a novel composite photographic film embodying the novel sheet material of the invention;

.Fig. 4 is a diagrammatic view of a camera apparatus wherein the novel liquid-containing sheet material of the present invention may be utilized to provide a fixed positive image of subject matter to which a photosensitive film in said camera has been exposed; and

Fig.5 is a view similar to Fig. 4 of a type of camera apparatus which maybe employed in conjunction with the film means of Fig. 3.

According to the present invention, there is provided a novel composite sheet material comprising a layer of liquid reagent, 1. e., a layer of a liquid mixture or solution of materials useful particularly for the treatment of photosensitive emulsions, said layer of reagent being coextensive with a predetermined area of said sheet and substantially coextensive in area with the area of the photosensitive emulsion to be treated thereby. The liquid reagent contains a filmforming substance in solution or in dispersion so that upon removal of the liquid content of said layer, as .by evaporation or permeation into another layer, .a layer of solid material coextensive with the area .of said liquid'layer is obtained. The layer of solid material may be opaque or transparent, depending upon the composition of the reagent mixture .orsolution. The film-forming material also acts to impart a desired high viscosity to the reagent, the viscosity of said reagent being preferably in excess of 5,000 centipoises.

In a preferred .iorm, .the liquid reagent comprises as a film-forming substance ahigh molecular weight polymeric plastic or protein, prei- 3 solid layer formed by incorporating in the reagent mixture a suitable pigment such as titanium dioxide or a metallic flake such as aluminum fiake.

The layer of liquid material or reagent preferably has a suificient concentration of the filmforming material and is sufficiently thin so that when it is brought into contact with a layer of relatively permeable material such as a layer of developable photosensitive emulsion the latter layer may, by absorption of the liquid in the reagent, cause a substantially solid film to be formed in the place of said liquid layer, said solid film being sufficiently stable dimensionally to receive. an image-forming component. The layer of liquid reagent also preferably contains in solution one or more substances which, upon permeation of a photosensitive emulsion containing a latent image, are adapted to provide a component for forming an image of said latent image in an adjacent receiving layer. The image-forming component may be a complex soluble in the reagent and adapted to be transported at least in part by the reagent to the receiving layer and reduced in the latter layer to give an insoluble product which forms the desired image. The component may also be a dye which is more substantive to the receiving layer than to the unexposed, undeveloped portions ofv the photosensitive layer and more substantive to the developed portions of the photosensitive layer than to the receiving layer. The component may be the oxidized developer and may act as a bleach to selectively bleach a dye with which the receiving layer is stained, said dye being initially incorporated in the reagent so as to form a uniformly dyed receiving layer.

One form of the novel sheet material of the invention is shown by way of example in the drawings, the thicknesses of the several layers of the composite sheet material being greatly exaggerated for the purpose of clarity. As shown, said composite sheet material comprises a suitable base It preferably of paper, as for example a kraft paper, upon which there is mounted a container IZ'in the form of an envelope which is substantially coextensive with said base and which has contained therein a relatively thin layer of the photographic reagent. Envelope 12 preferably comprises a pair of liquid-retaining walls IS an [8, upper wall l8 being readily removable from lower wall It. By removing upper wall IS, the layer of liquid reagent is exposed and may be brought into contact, for example, with the photosensitive layer of a photographic film to provide an image-receiving layer adjacent said photosensitive layer and to form in said receiving layer a fixed image of the subject matter of any latent image contained in the area of said photosensitive layer in contact with said liquid reagent.

In order to normally retain the liquid reagent in the envelope without loss of the solvent of, the reagent, as by evaporation, and without oxidation of the reagent if the latter is susceptible to oxidation, it is preferable to form liquid-retaining walls I6 and E8 of materials which are substantially impervious to the liquid of the reagent, to the vapor of said liquid, and to oxygen. Where the solvent material in the reagent is water, the material of walls l6 and I8 may be a relatively water-vapor-impervious plastic such as polyethylene or ethyl cellulose, or may be formed of a metal foil or a. metal foil coated with paraffin. In a preferred form, each of walls 16 and I8 is formed of a sheet of metal foil I 621, 18a, respectively, for example of lead or silver, provided on the inside surfaces thereof, 1. e., the surfaces adjoining the liquid reagent, with coatings 16b and [8b, respectively, of a material inert to an alkali as, for example, ethyl cellulose or a mixture of ethyl cellulose and parafiln. Other satisfactory materials for coatings I61) and I8?) are the polyvinyl acetals such as the polyvinyl acetal commercially identified by the trade name Alvar, the polyvinyl butyral commercially identified as Butvar, and the polyvinyl formal commercially identified as Formvar.

In the event that the liquid reagent layer I4 is adapted upon drying to form a solid film which is transparent, as for example when the filmforming substance in said reagent is a transparent plastic such as sodium carboxymethyl cellulose, it is desirable to incorporate in coating liib a suitable pigment such as titanium dioxide or a metallic fiake such as aluminum flake which is adapted to provide a white background against which an image formed of silver or a dye in said transparent film may be visible.

Film l0, I2 may be employed for forming a positive print of the subject matter of a latent image contained in a photosensitive layer by having retaining wall l8 removed and liquid layer It brought into face-to-face contact with that portion of the photosensitive layer which contains the latent image to be reproduced. The contact between the permeable photosensitive layer and the liquid reagent causes the liquid content of layer M to permeate into at least the surface portions of the photosensitive layer adjacent said liquid layer and thus provides an image-forming component which is adapted to migrate from the photosensitive layer to the remainder of layer It to form a positive image in the latter layer. The permeation of the liquid content of layer I4 into the photosensitive layer also acts to dry layer l4 and to form said layer into a dimensionally stable film so that the image obtained in said layer from the image-forming component is an accurate reproduction of the latent image in the photosensitive layer. At the termination of the period required for the formation and migration of the image-forming components, the remainder of layer [4 is separated from the photosensitive layer and substantially fully dried in the atmosphere to provide a solid film containing a fixed image. Composite sheet l0, [2 may be provided for use in conjunction with a single frame of a photosensitive film as by having layer I4 formed of an area corresponding substantially to the area of the film frame.

In this form, said composite sheet is particularly adapted for use with cut film either in a camera or in a dark room. Sheet I0, l2 may also be provided in a strip of sufficient length to form fixed images of the latent images contained in a plural-,

ity of frames of a photographic film. In the latter form, the composite sheet material of the invention may have the liquid layer extend contmuously from frame to frame, or the liquid layer for each frame may be contained in a separate envelope mounted. on a single base strip or a.

adapted to handle a plurality of image frames,

and as shown envelope walls l6, l8 are provided with a plurality of transverse seals 20 at spaced intervals separated by a'distance equal approxistream mately to the'leng'th of each ertn'e image irames with which the reagent layer is to coast. Each of seals 20 may be obtained by adhering together coatings I62) and 18b throughout-the width-of the sheet and along a predetermined length of said sheet preferably equal to the spacing between the film frames of the photographic film with which the composite sheet is to be u'ltimately employed.

To form the novel composite sheet material 'of the invention, itispossible, for'exampl'e, to se= cure retaining wall l6 to base and to thereafter coat the surface of said retaining wallwitha layer of reagent of "the desired thickness. The reagent layer'is'then covered with retaining wall 18 and the latter adhered to retaining wall It longitudinally and transversely as by the applieation of ressure and heat orpressure alone, the seal being effected along the longitudinal edges of the sheet, and transversely where "desired. The reagent is sufficiently "viscous to permit spreading thereof on the surface of retaining wall IE to the desired thickness as by the'use of a doctor blade. It is also possible to 'emboss the area of wall l-S which receives layer M to provide a shallow trough for receiving and retaining the reagent during assembly of the composit'e sheet. The thicknessof layer I4 need not exceed .002 mm. and is preferably between 1002 ahd-.0l1nm.thick. a

A reagent which is particularly suitable for use as layer Min the composite sheet material of the invention where the latter material is to'be employed in conjunction 'with photosensitive films comprising a silver halideemulslon is one which contains, in addition to the 'film for'ming agent, a developer and-a substance for forming asoluble silver complex withsilver halide. When the reagent is broughtinto contact with a photosensitive emulsion comprising a silver halide and containing a latent image, the developer and the complex-forming substance permeate said emul sion, reducing the exposed silver halide of thelatent image to silver and reacting with "the unexposed'silverhalide to provide-a soluble silver complex. -At the same time, the film-forming component of thereagent provides'a'permeable layer or sheet adjacent the emulsion'to which the reagent transports at leasta part of the soluble silver complex and in which said complex is re= duced to an insoluble product comprising silver to give the desired positive image.

Examples of suitable reagents of this type are given below, but itis to "be expressly understood that the examples are illustrative only, and that the invention is not limited to the ma'terials Or the proportions set out therein:

, rrhe sodium sulfiteflhydroquinone, and sodium thiosulfate are dissolved in the water, and the sodium carboxymethyl cellulose solution is then added and thoroughly mixed therewith. The solution thus obtained is cooledto a temperature between 65 and 75 and thereaiterthe'sodium hydrexide solution is added thereto,

' 6 alternative method of obtaining the above reagent "is to first dilute the sodium .carboxymethyl cellulose solution with the water and thereafter add the sodium sulfite, hydroquinone, and sodium thiosulfate. The mixing of these ingredients may be carried out at a temperature between and F. and after the components are thoroughly mixed, the mixture may be cooled to a temperature of approximately 65 to 75 F. and the specified quantity of sodium hydroxide solution added thereto. I

The proportions of "the ingredients set out above may be varied within relatively wide limits as, for example, quantities of hydroquinone up to 6.6 grams may be used. Similarly, the quantity of sodium thiosulfate may be Varied from 1.4 to 2.8 grams, and the amount of sodium hydroxide solution from '11 to 44 cc. While it preferred to omit the restrainer from the novel reagents of the invention, satisfactory results may be obtained by including, for example, 2.2 to 6.6 grams of potassium bromide in the solution of the above example.

Sodiumthiosul-f M. g 1o Aqueous solution of medium viscosity'sodium earboxymethyl cellulose consistingof '20 g. of the latter compound in cc. of water mesa-"rang" 100 sodium hydroxide s rll i-i -i ;g 5.6

Example II I Watera--- l ah H- l -ra l ccs 100 Sodium sulfite 4.5 4.5 2.5 4.9

boxymethyl cellulose, sodium salt, medium viscosity, consisting of 35 g. of the latter compound in 100 cc. of waterernahlgh 30 Era'mple IV 7 Water any. l-l -l vrecs. 100 Sodium sulfite-. a-.. -g 6 Hydroquinone r. l. g 6 Sodium thiosulfate l -g 3.3 Sodium hydroxide g c 3.6

Aqueous solution of Hercules or Dow carboxymethyl cellulose, sodium salt, medium viscosity, consisting of 35- g. of thelatter compound in 100 cc. of water g 13.3

"Sodium alginate may beused instead of sodium carboxymethyl cellulose in any of the above ex-' amples in the same relative amounts as sodium carboxymethyl cellulose. Many of the starches, as for example Mercks starch, Argo starch, Maine potato starch and Brazilian starch may also be used, and it is preferable when using these starches to employ a concentration approximately twice that of the sodium carboxymethyl cellulosesuggested above. It is also possible to utilize such other cellulosic ethers as hydroxyethyl cellulose, the latter being preferably provided in the reagent in somewhat higher concentration than the sodium 'carboxymethyl cellulose. If a relatively'white and nontransparent film is to be formed by the reagent, "there may beincorporated in said reagent 9. suitable pigment such as titanium dioxide or. mixtures of titanium dioxide and magnesium oxide or magnesium carbonate. The addition of titanium dioxide equivalent to from to 20% by weight of the reagent has given good results. These pigments also serve as fillersfor increasing the viscosity of the reagent.

Examples of other developers which may be used in the reagent are p-aminophenol hydrochloride (Kodelon), p-hydroxyphenylaminoacetic acid (Athenon, Glycin), p-phenylenediamine, pyrocatechin, diaminophenolhydrochloride (Amidol), pyrogallol, o-phenylenediamine and bromohydroquinone.

Examples of other materials which may be used in the reagent for the purpose of forming a soluble silver complex with the undeveloped silver halide of the photosensitive layer are ammonium thiosulfate and ammonia. For obvious reasons, it is preferable that the complex-forming substance be one which does not desensitize the silver halide emulsion and one which is not toxic. For example, a compound such as sodium cyanide which will give satisfactory photographic results when used in the reagent in accordance with the methods of the invention is generally not desirable because of its toxic character.

The liquid reagent may also contain other accelerators, as for example potassium hydroxide, sodium carbonate, borax, sodium metaborate, paraformaldehyde, trisodium phosphate or Triton B. In certain modifications of the reagent composition, the restrainer as well as the preservative may be omitted.

With the reagents set out in the above examples, satisfactory results are obtained if layer I4 has a thickness of approximately .005 mm.

The novel composite sheet material of the present invention may comprise part of a unitary film structure which also includes a layer of photosensitive material. Referring to Fig. 3, there is illustrated by way of example one form of film means of this type, and as shown, said film means comprises a suitable transparent film base 22, for example, a cellulosic film base such as cellulose acetate, cellulose nitrate, cellulose acetate butyrate, or cellulose acetate propionate, which serves as a support for a photosensitive emulsion 24 comprising a silver halide. It is to be understood that the term photosensitive emulsion comprising a silver halide as used herein is intended to include within its scope an emulsion of a single. silver halide salt, an emulsion of mixed silver halide salts, an emulsion of a silver mixed halide salt, or an emulsion of a mixture of the last-named salt with any of the others.

Photographic film

22, 24 is mounted on composite sheet l0, I2 with retaining wall 18 adjoining photosensitive layer 24.

' A novel arrangement of elements whereby sheet material l0, l2 may be used in conjunction with a photographic film comprising a plurality of film frames, each of which is adapted to be exposed and to have a latent image formed therein, is shown diagrammatically in Fig. 4. In the form illustrated, said apparatus comprises asuit: able mechanism for removing the liquid-retaining wall 18 froma roll 30 of sheet material 10, i2 as, for example, an idler roll 32 and a take-up roll 34, the latter being drivably connected by a suitabl friction drive (not shown) to a pair of pressure rollers 36. Rollers 36 are preferably provided adjacent to idler roll 32 and composite sheet l0, l2, without the portion of retaining wall l8 which has been removed by the above mechanism, is adapted to be fed between said pressure rollers and brought into face-to-face contact with an exposed frame of the photosensitive layer of a photographic film 31. It will be understood that the above-described apparatus may be provided in a dark room or used in a suitable light-tight housing. In the form illustrated, the several elements comprising said mechanism are embodied in an attachment A for a camera, ,0 wherein photographic film 31 may be fed between rollers 36 as it is metered from exposure position E by the film driving mechanism of said camera.

It is desirable to embody within or connect to said attachment suitable means wherein the assembly obtained between rollers 36 is retained in darkness after it passes through said rollers and from which said assemply may be removed without exposing the interior of the camera to light. To this end, chamber 38 is preferably provided adjacent to the pressure-rollers and is connected to the interior of the camera by a suitable light-tight recess 40 lined, for example, with a material such as felt. The assembly which is formed between rollers 36 is metered therefrom into said chamber through said opening, and is retained in said chamber during th formation of the positive image. One wall 42 of said chamber is preferably pivotally mounted to serve as a closure and in closed position does not admit any light into the chamber. However, said wall 42 may be opened to permit the severance and the removal of the frame of film retained in the chamber. In operation, therefore, the film assembly which is formed between rollers 36 passes through opening 40 into chamber 38 and after the entire frame has passed into said chamber it is retained therein in the absence of actinic light for such time as is necessary to effect the formation of the positive image as, for example, thirty seconds. Thereafter, wall 42 is pivoted outwardly to open the interior of the chamber and the assembly of said materials is severed and removed from the chamber.

A form of camera apparatus wherein the novel composite film means of Fig. 3 may be utilized is shown diagrammatically in Fig. 5 as comprising means for mounting roll 50 of said film, from which said film may be fed to exposure position E. After being exposed, the film is metered over a roll 52 and is so threaded that liquid-retaining wall [8 thereof is adapted to be Wound upon a take-up roll 54 which is connected by means of a friction drive to a pair of pressure rollers 56. Take-up roll 54 is preferably located to one side of th path of travel of th remainder of liquidcontaining sheet l0, l2 (identified as 58 in Fig. 5), as the latter moves from the point at which layer I8 is stripped therefrom to the point at which photosensitive layer 24 of

film

22, 24 is brought into contact therewith. As a result of this arrangement, liquid-containing sheet [0, l2, once placed in condition for release of the liquid, does not contact any material except the photosensitive layer of

film

22, 24. It is desirable to provide suitable guide means such as a plurality of rollers 60 for

film

22, 24 as the later travels from roller 52 to rollers 56, avoiding take-up rollers 54.

After the separated portions I0, l2 and 22, 24 of the composite film are brought into face-toface contact between pressure rollers 56, the assembly thus formed passes from the main chamber of the camera into a suitable light-tight chamber formed, for example, of a flat, rectangular container 62 detachably secured to the camera. The passage of the sheet materials from the main; camera chamber into container 62 is effected through an opening which connects said chamber and said container and which has its walls suitably lined to prevent admission oflight into said main chamber whenever said container is removed. After the assembly formed by the separated portions of the film is fed through pressure rollers 56 into container 62, and a sufficient length of time has elapsed to form the fixed positive image in the receiving layer, container 62 is removed from the camera, exposing the assembly. The latter may then be severed from the remainder of the film. and the receiving layer formed from layer It and supported on envelope wall l6 and base I!) may be separated from, the photosensitive layer 24 of

film

22, 24.

Since certain changes may be made in the above product and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

The term liquid as used herein is intended toinclude material in a relatively plastic state, i. e., materials capable of being deformed continuously and permanently in any direction without rupture under a stress exceeding the yield value.

Other inventions which are related to the invention set forth herein and which, like the present invention, are the property of a common assignee are applications of Edwin H. Land, Serial No. 64,870, filed December 11, 1948, now Patent No. 2,543,181; Edwin H. Land, Serial No. 700,931, filed October 3, 1946; and Edwin E. Land, Serial No. 728,983, filed February 1'7, 1947.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

'What' is claimed is:

1. A" storable, externally dry product for developing a photosensitive silver halide element, said product comprising a liquid layer including a liquid having dispersed therein a "thickening agent for substantially increasing the viscosity thereof and at least one photographic reagent from the class consisting of the silver halide developers and the silver halide solvents, said liquid layer containing in each unit area thereof an amountof liquid suflicient to render said reagent effective for processing an equivalent unit area oi? a photosensitive silver halide element, a pair of solid layers impervious to the liquid of. said liquid layer and superposed on opposite sides thereof, said liquid-impervious solid layers extending beyond the margins of said liquid layer and being sealed together adjacent said margins to. form an envelope for said liquid layer, said envelope: having a cavity for said liquid layer which is very thin in relation to its length and breadth and which is continuous in a direction perpendicular to its thickness throughout an area at least equal to the area of the silver halide element to be processed, one of said liquid-impervious layers being strippable from the remainder of said product to expose substantially the entire area of said thin layer for direct contact with a photosensitive silver halide element, said cavity maintaining said liquid layer distrib- 0 uted as a thin layer so that no redistribution of the liquid mass of said liquid layer, either lengthwise or breadthwise, is required to render said liquid layer efiective to process said element upon the removal of said strippable layer.

2. The product of claim 1 wherein said liquid layer is arranged to provide an image-receiving layer by providing, as said thickening agent, a solid material which gives a solid residual film upon removal of the liquid content of said liquid layer.

3. The product of claim 1 wherein said thickening agent comprises an alkali-inert high molecular weight polymer and said liquid includes a silver halide developer, a silver halide solvent and an akali.

4. The product of claim 1 wherein said liquid layer is arranged to provide an image-receiving layer by providing, as said thickening agent, a film-forming material which dries to a solid film upon removal of the liquid contents thereof, said liquid layer including a pigment for rendering said image-receiving layer white and opaque.

5. The product of claim 1 wherein said liquid includes an organic colloid, a silver halide solvent, an alkali and a white pigment.

6. The product of claim 1 wherein each of said liquid-impervious layers includes a stratum of metallic foil.

7. The product of claim 1 wherein said two liquid-impervious layers are sealed together transversely thereof along a plurality of longitudinally spaced lines so as to provide a series of said envelopes, each envelope confining a portion of said liquid layer which is spaced, by a pair of said transverse seals, from its adjacent portions of said liquid layer.

8. A storable, externally dry product comprising a photosensitive silver halide element and means for processing said element, said means comp-rising a liquid layer having dissolved therein a thickening agent for substantially increasing the viscosity thereof, a silver halide solvent and a silver halide developer, said liquid layer being homogeneous throughout its depth and containing in each unit area thereof an amount of liquid sufficient to render said developer effective for developing an equivalent unit area of the photosensitive layer of said photosensitive silver halide element, a pair of solid layers impervious to the liquid of said liquid layer and superposed on opposite sides thereof, said liquidimpervious solid layers extending beyond the margins of said liquid layer and being sealed together adjacent said margins to form an envelope for said liquid layer, one of said liquidimpervious layers being strippable from the remainder of said means to expose the liquid layer for direct contact with said silver halide element, said silver halide element being connected to said means so as to be superposable with said liquid layer after removal of said strippable layer.

9. The product of claim 8 wherein the portion of said means to which the photosensitive element is connected includes a white pigment for forming a background for a positive transfer image in silver formed in said liquid layer.

10. A photographic product comprising a photographic photosensitive silver halide element, a liquid layer superposed with respect to said photosensitiveelement, said liquid layer extending over a predetermined area of said photosensitive element, and a pair of solid layers impervious to the liquid of said liquid layer superposed on each side thereof, said impervious layers being sealed together adjacent the margins of said liquid layer to form an envelope for said liquid layer, one of said impervious layers being located between said liquid layer and said photosensitive element and being strippable from both said photosensitive element and said liquid layer so that said one impervious layer can be removed to permit said liquid layer to contact said photo sensitive element and transfer liquid thereto, said product having positioned therein at least one photographic processing material from the class consisting of the silver halide developers and the silver halide fixers, said processing material being rendered effective upon transfer of liquid from said liquid layer to said photosensitive element to carry out said transformation in said photosensitive element.

11. A photographic product comprising a photosensitive silver halide element, a liquid layer superposed with respect to said photosensitive element, said liquid layer providing, upon drying, a solid film arranged to serve as an image-receiving layer, and a pair of layers impervious to the liquid of said liquid layer superposed on each side thereof, said impervious layers being sealed together adjacent the margins of said liquid layer to form an envelope for said liquid layer, one of said impervious layers being located between said liquid layer and said photosensitive element and being strippable from both said photosensitive element and said liquid layer so that said one impervious layer can be removed to permit said liquid layer to contact said photosensitive element and transfer liquid thereto, said product having positioned therein photographic processing material, including a silver halide developer, for developing said photosensitive element and providing an image by transfer on said image-receiving layer, said material being rendered efiective, upon transfer of liquid from said liquid layer to said photosensitive element, to process said photosensitive element, said liquid and said material being suflicient in amount to develop a latent image in the photosensitive element and to provide said imagereceiving layer with a transfer image.

12. The product of claim 11 wherein said liquid includes a solution of said developer and a silver halide solvent.

13. The product of claim 11 wherein said liquid layer is arranged to provide an imagereceiving layer by having therein a solid material which gives a solid residual film upon removal of the liquid content of said liquid layer, said liquid layer including a pigment for rendering said image-receiving layer white and opaque.

14. The product of claim 11 wherein said liquid layer includes an alkali-inert high molecular weight polymer, a silver halide solvent and an alkali.

15. The product of claim 11 wherein said liquid includes an organic colloid, a silver halide solvent, an alkali and a white pigment.

16. The product of claim 11 wherein each of said liquid-impervious layers includes a stratum of metallic foil.

17. The product of claim 11 wherein said two liquid-impervious layers are sealed together transversely thereof along a plurality of longitudinally spaced lines so as to provide a series of flat envelopes, each envelope confining a portion of said liquid layer which is spaced, by a pair of said transverse seals, from its adjacent portions of said liquid layer.

18. The product of claim 11 wherein said liquid includes said silver halide developer, a silver halide solvent, an alkali and sodium carboxymethyl cellulose, said liquid having a viscosity in excess of 5000 centipoises.

EDWIN H. LAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 416,019 Thum Nov. 26, 1889 417,400 Thum Dec. 17, 1889 431,537 Trenner July 1, 1890 447,121 Stecher Feb. 24, 1891 671,961 Heinritz Apr. 16, 1901 693,536 Baker Feb. 18, 1902 740,076 Baker Sept. 29, 1903 786,535 Thornton et a1 Apr. 4, 1905 935,115 Kelly et a1. Sept. 28, 1909 1,207,042 Hochstetter Dec. 5, 1916 1,277,048 Brayer Aug. 27, 1918 1,360,624 Dodge Nov. 30, 1920 2,013,159 Lierg Sept. 3, 1935 2,196,901 Ham Apr. 9, 1940 2,214,446 Albers Sept. 10, 1940 2,315,966 Knott Apr. 6, 1943 2,320,108 Tull May 25, 1943 2,322,005 Fierke et al. June 15, 1943 2,322,006 Fierke et al June 15, 1943 2,322,027 Jelley June 15, 1943 2,323,246 Schneider et al. June 29, 1943 2,328,034 Sease et al. Aug. 31, 1943 2,336,902 Tull Dec. 14, 1943 2,350,380 White June 6, 1944 2,352,014 Rott June 20, 1944 2,365,345 Kirby Dec. 19, 1944 2,369,171 Murray Feb. 13, 1945 FOREIGN PATENTS Number Country Date 1,201 Great Britain Jan. 26, 1888 17,738 Great Britain of 1899 9,248 Great Britain of 1905 26,066 Great Britain Dec. 30, 1905 8,911 Great Britain July 12, 1906 24,667 Great Britain Nov. 3, 1906 13,835 Great Britain 1907 328,762 Great Britain May 8, 1930 370,821 Germany May 25, 1921 115,331

Switzerland June 16, 1926

Claims

1. A STORABLE, EXTERNALLY DRY PRODUCT FOR DEVELOPING A PHOTOSENSITIVE SILVER HALIDE ELEMENT, SAID PRODUCT COMPRISING A LIQUID LAER INCLUDING A LIQUID HAVING DISPERSED THEREIN A THICKENING AGENT FOR SUBSTANTIALLY INCREASING THE VISCOSITY THEREOF AND AT LEAST ONE PHOTOGRAPHIC REAGENT FROM THE CLASS CONSISTING OF THE SILVER HALIDE DEVELOPERS AND THE SILVER HALIDE SOLVENTS, AND LIQUID LAYER CONTAINING IN EACH UNIT AREA THEREOF AN AMOUNT FOR PROCESSING AN EQUIVALENT UNIT AREA EFFECTIVE FOR PROCESSING AN EQUIVALENT UNIT AREA OF A PHOTOSENSITIVE SILVER HALIDE ELEMENT, A P AIR OF SOLID LAYERS HALIDE ELEMENT, A PAIR LIQUID LAYER AND SUPERPOSED ON OPPOSITE SIDES THEREOF, SAID LIQUID IMPERVIOUS SOLOD LAYERS EXTENDING BEYOND THE MARGINS OF SAID LIQUID LAYER AND BEING SEALED TOGETHER ADJACENT SAID MARGINS TO FORM AN ENVELOPE FOR SAID LIQUID LAYER, SAID ENVELOPE HAVING A CAVITY FOR SAID LIQUID LAYER WHICH IS VERY THIN IN RELATION TO ITS LENGTH AND BREADTH AND WHICH IS CONTINUOUS IN A DIRECTION PERPENDICULAR TO ITS THICKNESS THROUGHOUT AN AREA AT LEAST EQUAL TO THE AREA OF THE SILVER HALIDE ELEMENT TO BE PROCESSED, ONE OF SAID LIQUID-IMPERVIOUS LAYERS BEING STRIPPABLE FROM THE REMAINDER OF SAID PRODUCT TO EXPOSE SUBSTANTIALLY THE ENTIRE AREA OF SAID THIN LAYER FOR DIRECT CONTACT WITH A PHOTOSENSITIVE SILVER HALIDE ELEMENT SAID CAVITY MAINTANING SAID LIQUID LAYER DISTRIBTED AS A THIN LAYER SO THAT NO REDISTRIBUTION OF THE LIQUID MASS OF SAID LIQUID LAYER, EITHER LENGTHWISE OR BREADTHWISE, IS REQUIRED TO RENDER SAID LIQUID LAYER EFFECTIVE TO PROCESS SAID ELEMENT. UPON THE REMOVAL OF SAID STRIPPABLE LAYER.

8. A STORABLE, EXTERNALLY DRY PRODUCT COMPRISING A PHOTOSENSITIVE SILVER HALIDE ELEMENT AND MEANS FOR PROCESSING SAID ELEMENT, SAID MEANS COMPRISING A LIQUID LAYER HAVING DISSOLVED THEREING A THICKENING AGENT FOR SUBSTANTIALLY INCREASIN THE THICKENING AGENT FOR SUBSTANTIALLY INCREASAND A SILVER HALIDE DEVELOPER, SAID LIQUID LAYER BEING HOMOGENOUS THROUGHOUT ITS DEPTH AND CONTAINING IN EACH UNIT AREA THEREOF AN AMOUNT OF LIQUID SUFFICIENT TO RENDER SAID DEVELOPER EFFECTIVE FOR DEVELOPING AN EQUIVALENT UNIT AREA OF THE PHOTOSENSITIVE LAYER OF SAID PHOTOSENSITIVE SILVER HALIDE ELEMENT, A PAIR OF SOLID LAYERS IMPERVIOUS TO THE LIQUID OF SAID LIQUID LAYER AND SUPERPOSED ON OPPOSITE SIDES THEREOF, SAID LIQUIDIMPERVIOUS SOLID LAYERS EXTENDING BEYOND THE MARGINS OF SAID LIQUID LAYER AND BEING SEALED TOGETHER ADJACENT SAID MARGINS TO FORM AN ENVELOPE FOR SAID LIQUID LAYER, ONE OF SAID LIQUIDIMPERVIOUS LAYERS BEING STRIPPABLE FROM THE REMAINDER OF SAID MEANS TO EXPOSE THE LIQUID LAYER FOR DIRECT CONTACT WITH SAID SILVER HALIDE ELEMENT, SAID SILVER HALIDE ELEMENT BEING CONNECTED TO SAID MEANS SO AS TO BE SUPERPOSABLE WITH SAID LIQUID LAYER AFTER REMOVAL OF SAID STRIPPABLE LAYER.