US2653530A

US2653530A - Composite photographic printreceiving sheet

Info

Publication number: US2653530A
Application number: US255995A
Authority: US
Inventors: Jr William J Mccune
Original assignee: Polaroid Corp
Current assignee: Polaroid Corp
Priority date: 1948-10-20
Filing date: 1951-11-13
Publication date: 1953-09-29
Anticipated expiration: 1970-09-29

Description

Sept. 29, 1953 w. J. M CUNE, JR

COMPOSITE PHOTOGRAPHIC PRINT-RECEIVING SHEET Filed NOV. 13, 1951 III II I INVENTOR efiw/w Patented Sept. 29, 1953 COMPOSITE PHOTOGRAPHIC PRINT- RECEIVING SHEET William J. McCune, Jr., South Lincoln, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware.

Application November 13, 1951, Serial No. 255,995 In Canada October 20, 1948 6 Claims. (Cl. 95-88) vide a novel composite print-receiving sheet for use in the performance of transfer processes, said sheet giving a finished framed print at the completion of the process.

Another object of the present invention is to provide a novel composite print-receiving sheet of the above type which includes, as part of the composite structure thereof, all of the reagents, including the liquid, for performing the transfer process.

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

The invention accordingly comprises the product possessing the features, properties and the relation of components which are exemplified in the following detailed disclosure, 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 following detailed description taken in connection with the accompanying drawing wherein:

Figure 1 is an isometric, diagrammatic view of one preferred form of the invention during the use thereof, with parts cut away for clarity of illustration;

Fig. 2 is a diagrammatic, exaggerated, enlarged, sectional view taken along the line 2-4. of Fig. 1; and

Fig. 3 is a diagrammatic, exa gerated, enlarged, sectional view similar to Fig. 2 wherein the operation of removing the processed positive image is shown.

In general, the present invention relates to an improved composite print-receiving sheet for having transfer prints formed thereon. In one preferred form the composite sheet comprises a suitable image-carrying layer on which there is mounted a framing means in the form of a thin paper mask having an aperture therein for defining an image-receiving area on the imagecarrying layer. A section of the image-carrying layer, including this image-receiving area, is detachable from the remainder of the image-receiv- 55 ing layer and is also strippable from the mask.

The mask serves to confine the image formed on the image-carrying layer to the image-receiving area so that when the detachable section is removed it provides a finished print in which the image is bounded by a decorative border.

The product of the present invention also preferably includes a container releasably holding the processing liquid and a trap for trapping excess spread liquid, said container and trap being placed on top of the mask. Thus the liquid, when released from the container and spread, is trapped between the photosensitive layer on the one hand and the mask and image area of the image-carrying layer on the other hand.

Referring now to Fig. 1,-there is shown an isometric, diagrammatic view of one preferred form of the invention with portions thereof cut away for clarity of illustration. In this figure, Ill represents a photosensitive layer having its photosensitive surface extending upwardly. An imagecarrying layer I 2 is shown with a positive image area In on its upper surface. This area l2a is defined by a cut-away portion of a mask l4 secured to the surface of the image-carrying layer. Placed on top of the framing mask i4 is a container l6 having therein a processing liquid 11. This container extends transversely of the imagecarrying layer and is capable of releasin its contained liquid for spreading across area I M. Adjacent the opposite edge of area 12a is a trap comprising a pair of trapping members l8. Extending longitudinally of the image-carrying layer a ong the margins thereof is a pair of spacer strips 20 which, together with marginal portions of the mask l4, predeterminedly separate the photosensitive and image-carrying layers. In a preferred form of the invention, the image-carrying layer I2 is provided with a plurality of perforations 22 to permit tearing out of the image area portion lZa, and a hole 24 may also be provided for assisting in commencing such tearing. As can be seen the hole 24 is preferably positioned under the container l6 and a correspon ing hole 26 is provided in the mask l4, this latter hole being somewhat larger than hole 24.

Referring now to Fig. 2 which is an exaggerated, diagrammatic, enlarged sectional view of the image-carrying layer of Fig. 1 taken along the line 22, there are shown in more detail certain aspects of the present invention. In Fig. 2, like numbers refer to like elements in the other figures. As can be seen from an. examination of Fig. 2, there are two layers 28 and 39 between the mask I 4 and the image-carrying layer I2. Layer 2B is preferably a plastic such as polyvinyl alcohol, while layer 30 is preferably a plastic such ethyl cellulose. These two incompatible plastie layers adhere more strongly to their adjacent paper layers than they adhere to each other, although their adherence to each other is sufficient to hold the mask smoothly on the surface of the image-carrying layer during the manufacture, storage and use of the product.

In a preferred form of the invention the photosensitive layer I comprises a paper base upon which is coated a layer ll (shown in Fig. 3) of a silver halide emulsion and preferably a gelatino silver iodobromide emulsion. The imagecarrying layer l2 preferably comprises a sheet of baryta paper which has been treated as set forth in the following nonlimiting example:

Example 1 A sheet of single-weight baryta paper is run through a bath containing by weight 11 grams of cadmium acetate, .37 gram of lead acetate end 11 grams of zinc nitrate per 100 cc. of water, the sheet being in contact with the bath for about seconds.

Solution A is prepared by adding 60 grams of cadmium acetate, 2 grams of lead acetate and 60 grams of zinc nitrate to'200 cc. of water. Solution B is prepared by adding 28 grams of sodium sulfide and 300 grams of silica aerogel to 2800 cc. of water. Solution C is prepared by adding 160 cc. of solution A to 500 cc. of solution B and thoroughly mixing. The resulting mixture is then applied to the surface of the previously coated baryta paper by dipping the sheet into a bath of the mix and removing the excess mix from the sheet, as it leaves the bath, by

means of a soft rubber bufling roll which rotates in a direction opposite to the direction of travel of the sheet. Thereafter the sheet is coated with a 0.5% water solution of gelatin to provide a surface to which the mask adheres well. Al-

ternatively, the sheet may be coated with a so- Example 2 Layer 28 is applied by passing the sheet through a water solution of the plastic; such as a 10% water solution of polyvinyl alcohol, and removing the excess by means of a doctor blade and roller, the resulting coating being thick enough to give a'shiny smoothsurface'tothe mask. After drying the polyvinyl alcohol'coat, layer 30 is similarly applied by use of a solution containing 80 grams of ethyl cell ulose,13' cc. of diethyl phthalate', 320 cc. oftoluene and 80 0'0. of denatured alcohol. In a preferredform of the invention, about 3.24 cc'. per square foot of polyvinyl alcohol solution andabout 754"00. per'square foot ofethyl "cellulose solution are applied to the tissue paper. The ethyl'cellulose coating, together with the polyvinyl alcohol coating, increases thethickness ofthe tissue paper to about .0025 to .003 inch. Other organic solvents such, for example, as isopropyl acetate may be used.

The coated tissue paper, after drying, is next cut to the shape shown in Fig. 1, the image area portion and the hole 26 being stamped out by a suitable die. Thereafter the mask is bonded to the previously prepared baryta paper, the ethyl cellulose coating of the mask being next to the baryta surface. This bonding may be accomplished, for example, by passing the two sheets between a pair of 4-inch steel rolls under an 18 pound load and having surface temperatures of between 250 and 300F. With such temperatures and pressures the paper speed may be about 9 inches per minute.

In still another method of preparing and adhering the mask, the steps set forth in the following nonlimiting example are followed:

Example 3 The mask, comprising a .0015 inch thick calendered condenser tissue paper is coated in a polyvinyl alcohol bath of the type set forth in Exemple 2. "Then an ethyl cellulose coating is applied from a bath containing 500 cc. of isopropyl alcohol, 60 grams of ethyl cellulose and 12 grams of triphenyl phosphate. After the mask has been cut to shape, it is secured to the imagecarrying layer by placing the two sheets between platens, the platen adjacent the mask being heated to about 320 F. The platens are then squeezed together under a one ton pressure for less than second.

The edge spacer strips 20 are then applied to the mask prepared in accordance with Example 1 or 2, these spacer strips 20 preferably comprising kraft paper, or cellophane, about .001 to .0015 inch thick and having a suitable pressuresensitive adhesive such as a blend of unvulcanized rubber and a tack-producing resin. The strips preferably raise the total thickness of strips and mask, at the marginal portions of the image-carrying layer, to about .004 inch. The containers are formed of a paper-backed metal foil having an alkali-inert inner coating of polyvinyl butyral and a strip of ethyl cellulose along the sealed edge as described in the copending application of Edwin H. Land, Serial No. 652,612, filed March 7, 1946.

The transversely tapered trapping members 18 are preferably made of a semi-crepe paper tape about .15 inch thick secured to the mask by means of a suitable adhesive.

The container is preferably secured to the image-carrying layer by means of a strip of an adhesive, for example, polyvinyl butyral, applied to the bottom of the leading edge thereof. The leadingv edge is then flattened and sealed to the image-carrying layer by pressing downwardly with a heated narrow iron, for example.

In one preferred form of the invention, the photosensitive layer I0 comprises a suitable paper base upon which is coated a fast gelatino silver iodobromide photosensitive emulsion. For use with such an emulsion and an imagecarrying layer as prepared in Example 1, a preferred liquid composition includes the following ingredients in the relative proportions given be- Example 4 Grams Water 1860 Sodium carboxymethyl cellulose 93 Sodium sulfite '78 Sodium hydroxide 74.6 Sodium thiosulfate 14.5 Citric acid 38.5 Hydroquinone 52.0 Chlorobenzotriazole 1.5

In the use of the novel product described above, the photosensitive emulsion I l of the photosensitive layer I0 is suitably exposed in the camera,

, the two layers Ill-l2 constituting the preferred product of the invention being suitably disposed within the camera So that they may be advanced past a processing means in the camera with the exposed area of the photosensitive layer in coincident superposed relation to the positive image area I20. of the image-carrying layer. In a. preferred type of camera the processing means comprises a pair of pressure rolls indicated at 40 in Fig. 1. As the two layers Ill-l2 pass between these rolls. the container I6 is positioned therebetween and the liquid I! is forced therefrom by the increased hydraulic pressure created by the rolls 40. Continued movement of the two layers causes the released liouid to be spread in a uniform thin lay r between the two outer layers I0l 2. the thickness of the spread layer of liquid being determined by the thickness of the s acer strips and mask [4 (including coatings 28 and This layer of spread processing liouid I1 is shown in Fig. 3, it bein seen that the thickness of the spread layer of liquid 11 adjacent area 12a is about eoual to the total thickness of the spacer 20 and the composite mask M. Licuid s read beyond the end of area iZa is trapped due to the separation of the pressure rolls, with conseouent decrease in hydraulic pressure on the liquid. by the trapping members I8. Motion of the product is then preferably stopped and the composite lamination is maintained in the dark for about 1 minute. A door provided in the camera may then be opened and the positive image area 12a. can be removed from the lamination by inserting a fingernail through hole 24 (shown in Fig. 1) and tearing the image-carrying layer along perforations 22. Since the mask I4 is cut away at 20 in the neighborhood of hole 24. the stripping of the image-carryin layer from the mask at the same time is facilitated. As can be seen from Fig. 3,

that portion of the ethyl cellulose layer 30 on tho image area 12a is stripped away from its adjacent polyvinyl alcohol layer 28. The portion of ethyl cellulose 30 adhering to image area lZa thus forms a border for the positive image formed in or under layer !1 of the processing liquid. It should also be noted that the portions of liquid I! spread between the mask [4 and the photosensitive layer 10 are trapped between these layers when image area Ila is removed.

It should be pointed out. in connection with the diagrammatic representation of Fig. 3, that the layer of spread liouid quickly dries out, during and after the processing, to form a film of about .0002 inch thick. Thus, when the time occurs for the image area i2a to be torn out, the film ll formed by the spread liquid is considerably thinner than shown, although it is usually not completely dry within a minute of spreading. The latter portion of the drying is accomplished by evaporation of the water from the surface thereof exposed as a result of removal of area 12a.

When the product, prepared as set forth in ac cordance with Examples 1 and 2, is processed by spreading the liquid between the photosensitive and image-carrying layers, the developer develops exposed silver halide grains and the sodium thiosulfate, concurrently with the development, forms soluble silver complexes with unexposed silver halide grains. These complexes migrate to the image-carrying layer where they are converted to a positive image comprising silver, the sulfide slowly released from the surface of the image-carrying layer forming silver sulfide specks around which large silver grains are formed. The cadmium acetate and zinc nitrate are slowly released to lower the alkalinity of the liquid toa point where oxidation of the excess developer does not occur. Meanwhile, the sodium carboxymethyl cellulose is forming a dimensionally stable film which adheres to the surface of the imagecarrying layer. The above-described reactions (with the exception of the lowering of the pH) are completed in about 1 minute and the positive image area is then separated from the lamina tion comprising the photosensitive and imagecarrying layers. As explained above, this sepa* ration is preferably accomplished by opening the door, inserting a fingernail through hole 24 and tearing the image-carrying layer along lines 22, thus revealing the final stable positive image.

While in the preceding examples the mask M has been shown as strippably secured to the image-carrying layer [2 by the use of two layers of incompatible plastics which provide a strippable bend, it will be appreciated that other bonding means or structures may be employed. For example, the mask may be coated on one surface with a layer of a single material possessing adhesive properties and having a greater affinity for the material of the mask than for the material of the receiving sheet. In this regard, a water-soap solution may be utilized, for example a 5 to 40% water-soap solution made of Ivory soap. Alternatively, the mask may be coated with a thin layer of a fatty substance or soap which is insoluble in water and then may be covered after drying with a layer of hardened gelatin or collodion. In regard to soap, or soap and hardened gelatin, reference is made to Photography, Theory and Practice by L. P. Clerc, second edi tion, Pitman Publishing Corp, New York, New York, page 159, footnote 3, and also to the copending application of Edwin H. Land, Serial No. 708,007, filed November 6, 1946, for Photographic Product and Process (now Patent No. 2,647,055, issued July 28, 1953) and Patent No. 2,563,342, issued to Edwin H. Land on August 7, 1951, for Photographic Product and Process. Additionally, the mask surface to be adhered to the imagecarrying layer may be coated with gelatin to which has been added an appropriate amount of glycerin whereby to suitably control the bond strength of the gelatin, as is well understood by the art. In lieu of these practices, the mask may be coated with a suitable pressure-bondable rubber cement. These and other procedures for forming a strippable bond between the mask and the image-carrying layer are employable in carrying out the invention. A mask coated with any. of the just-described stripping layers is intended to be adhered to the image-carrying layer in the manner described in Example 2 hereof by passing the finished mask and the receiving sheet layer between pressure rolls.

While preferred forms of the invention have been described above, numerous other modifications thereof are possible without departing from the scope thereof. For example, the mask l4 (plus layers 28 and 30) may be made thicker than the .0025 to .003 inch mentioned above. In this case, the spacing strips may be eliminated since the mask will give sufiicient thickness to allow for proper spread of the liquid.

With either of the above modifications of the invention, the top surface of the mask (and the spacing strip 20) may be coated with a Watersoluble adhesive to increase the adhesion of the mask to the emulsion layer l I. Such an adhesive may comprise gum arabic coated from a water solution thereof onto that side of the mask opposite to

coatings

28 and 30.

In addition to the above modifications, the containers and traps of the present invention may be secured to the photosensitive rather than the image-carrying layer. Also, the spacing strips may be eliminated in several other preferred forms of the invention. In one of these forms, the mask thickness (including layers 28 and 30) is about the thickness desired for the layer of spread liquid. In another preferred form, the mask thickness is as described previously and one of the pressure rolls of the camera has thickened shoulder portions engaging the margins of the lamination formed by the pressure rolls. Such shoulders may have a, radius greater, by about .001 to .002 inch, than the other part of the roll, depending upon the thickness of the mask and the desired thickness of spread liquid. Equally, numerous other processing liquids may be employed with numerous types of photosensitive materials and image-carrying layers of the type described, for example, in the copending application of Edwin H. Land, Serial No. 729,578, filed February 19, 1947.

When a slow silver bromide or silver chloride emulsion is used, the image-carrying layer I! may comprise a sheet of plain baryta paper to which the mask of Example 2 or 3 is laminated as described therein. With such a photosensitive layer and image-carrying layer, the liquid of Example 4 may be used, preferably without the chlorobenzotriazole.

The liquid in the container may carry only a part of the processing reagents and others may be included in solid form in the sheets. For example, the developer may be included in the photosensitive emulsion.

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

What is claimed is:

1. As a new product, a composite print-receiving sheet comprising, in combination, an imagereceiving layer, a masking layer superposed on and secured to said image-receiving layer and having an aperture therein which leaves an area of said image-receiving layer uncovered for receiving an image by transfer, said image-receiving layer being strippable from said masking layer and being provided with perforations which extend at least partially therethrough and which are located in surrounding relation to said uncovered area at positions outside of the marginal edges of said uncovered area whereby to provide a detachable section which includes the uncovered area and a border surrounding said area, said masking layer overlying said perforations to cover the same, and a rupturable container mounted on said masking layer adjacent one edge of said uncovered area, said container carrying a processing liquid which is spreadable from said container over said uncovered area, the liquid in the container being suflicient in amount to cover said uncovered area, said sheet containing photographic reagents, including a silver halide developer, so located that the release of the liquid from the container over the uncovered area of the image-receiving layer places said reagents in condition to form a transfer print of a latent image contained in a silver halide emulsion superposed on said uncovered area.

2. As a new product, a composite print-receiving sheet comprising, in combination, an imagereceiving layer, a masking layer superposed on and secured to said image-receiving layer and having an aperture therein which leaves an area of said image-receiving layer uncovered for receiving an image by transfer, said image-receiving layer being strippable from said masking layer and being provided with perforation which extend at least partially therethrough and which are located in surrounding relation to said uncovered area at positions outside of the margina1 edges of said uncovered area whereby to provide a detachable section which includes the uncovered area and a border surrounding said area, said image-receiving layer having an aperture adjacent the perforations to facilitate manual detachment of said detachable section along the perforations, said masking layer overlying said perforations to cover the same, and a rupturable container mounted on said masking layer adjacent one edge of said uncovered area, said container carrying a processing liquid which is spreadable from said container over said uncovered area, the liquid in the container being suflicient in amount to cover said uncovered area, said sheet containing photographic reagents, including a silver halide developer, so located that the release of the liquid from the container over the uncovered area of the image-receiving layer places said reagents in condition to form a transfer print of a latent image contained in a silver halide emulsion superposed on said uncovered area.

3. As a. new product, a composite print-receiving sheet comprising, in combination, an imagereceiving layer, a masking layer superposed on and secured to said image-receiving layer and having an aperture therein which leaves an area of said image-receiving layer uncovered for receiving an image by transfer, said image-receiving layer being strippable from said masking layer and being provided with perforations which extend at least partially therethrough and which are located in surrounding relation to said uncovered area at positions outside of the marginal edges of said uncovered area whereby to provide a detachable section which includes the uncovered area and a border surrounding said area, said masking layer overlyin said perforations to cover the same, and a rupturable container mounted on said masking layer adiacent one edge of said uncovered area, said container carrying a processing liquid which is spreadable from said container over said uncovered area, and trapping means mounted on the masking layer adjacent the edge of said uncovered area opposite the container, said trapping means being adapted to confine liquid from the container which spreads beyond said uncovered area, the liquid in the container being suflicient in amount to cover said uncovered area, said sheet containing photographic reagents, including a silver halide developer, so located that the release of the liquid from the container over the uncovered area of the image-receiving layer places said reagents in condition to form a transfer print of a latent image contained in a silver halide emulsion superposed on said uncovered area.

4. The product of claim 1 wherein the reagents include a silver halide solvent in addition to the silver halide developer.

5. The product of claim 4 wherein the silver halide developer and the silver halide solvent are contained in solution in the liquid in the container.

6. A photographic product comprising an elongated, fiexible, composite image-receiving sheet material for use in a photographic transfer process as image-receptive material for receiving a transfer image and comprising an image-receiving layer, a masking layer superposed on and secured to a surface of said image-receiving layer and providing a mask over portions of said image-receiving layer, said masking layer having at least one aperture therein which defines a picture area by leaving an area on said imagereceiving layer uncovered for receiving an image by transfer, said image-receiving layer being strippable from said masking layer and being provided with perforations which extend at least partially therethrough and which are located in adjacent relation to each said uncovered area, at 20 positions outside of marginal edges of said uncovered area whereby to provide a detachable section which includes said uncovered area and a border surrounding the area, said masking layer overlying said perforations to cover the same, and a rupturable container mounted on said masking layer adjacent one edge of each said uncovered area, said container carrying a processing liquid which is spreadable from said container over said uncovered area, the liquid in the container being sufiicient in amount to cover said uncovered area, said product containing photographic reagents, including a silver halide developer, so located that the release of the liquid from the container over an uncovered area of the image-receiving layer places said reagents in condition to form a transfer print of a latent image contained in a silver halide emulsion superposed on said uncovered area.

WILLIAM J. MCCUNE, JR.

No references cited.