US3424584A - Abrasion of the outer surfaces of film supports and rupturable containers to reduce blocking - Google Patents

Description

Jan. 28, 1969 R. P. COOK 3,424,534

ABRASION OF THE OUTER SURFACES OF FILM SUPPORTS AND RUPTURABLE CONTAINERS TO REDUCE BLOCKING Filed June 10, 1964 PHOTOGRAPHIC SILVER HALIDE GELATIN d I; EMuLs|o- LAYER I/sUPPQRT LAYER z L/ABRADED SURFACE LAYER FIGIY BLUE SENSITIVE SILVER HALIDE GELATIN EMULSION LAYER YELLOW DYE DEVELOPER CONTAINING GELATIN LAYER GREEN SENSITIVE SILVER HALID GELATIN EMULSION LAYER MAGENTA DYE DEVELOPER CONTAINING GELATIN LAYER RED SENSITIVE SILVER HALIDE GELATIN EMULSION LAYER CYAN DYE DEVELOPER CONTAINING GELATIN LAYER SUPPORT LAYER ABRADED SURFACE LAYER FIG. 2

INVENTOR ATTORNEY United States Patent 3,424,584 ABRASION OF THE OUTER SURFACES OF FILM SUPPORTS AND RUPTURABLE CONTAINERS TO REDUCE BLOCKING Russell P. Cook, Marlboro, Mass., assignor to Polaroid Corporation, Cambridge, Mass, a corporation of Delaware Filed June 10, 1964, Ser. No. 374,021 US. Cl. 96-76 11 Claims Int. Cl. G03c 1/48 ABSTRACT OF THE DISCLOSURE Photographic film supports and photographic rupturable containers and the like, which are treated by a process comprising abrading the outer surface thereof to prevent blocking during storage.

The present invention is concerned with photography and, more particularly, with processes for substantially reducing blocking in composite photographic film units.

Usually in commercial practice, composite photographic film elements, X-ray films, etc., are stored as packaged film rolls or film packs for period of months prior to their actual use. During such storage the sheet material is subjected to compressive pressures and, in addition, may be subjected to a wide variety of environmental stresses or extremes, as, for example, varying temperature conditions and relative humidities. Under such conditions the photographic film elements Which usually comprise a support or film base having one or more layers coated thereon, e.g., gelatin layers, must be prevented from blocking or adhering to one another when the film is stacked as in film packs or when the film is rolled upon itself as occurs in roll film.

In the past, attempts have been made to prevent such adhesion or blocking, for example, by the addition to the gelatin layer of relatively large amounts of conventional gelatin-hardening agents, as, for example, inorganic agents providing polyvalent metallic atoms, especially polyvalent aluminum or chromium ions, for example, potash alum [K Al (SO -24H O] and chrome alum [K Cr(SO -24H O], and organic agents of the aldehyde type such as formaldehyde, glyoxal, mucochloric acid, etc., the ketone type such as diacetyl, the quinone type, etc.

The use of large amounts of such hardening agents gives rise to a serious problem of controlling the deposition of such agents, so as to insure that they do not migrate from the layer in which they are deposited and deleteriously contaminate a photosensitive silver halide gelatin layer of the film unit.

Objects of the present invention are therefore to provide photographic films which include a film support which is particularly adapted to alleviate blocking during storage.

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 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 a diagrammatic fragmentary cross-sectional view of a photographic film product of the present invention particularly adapted for employment in monochromatic photographic processes; and

FIG. 2 is a diagrammatic fragmentary cross-secitonal view, similar to FIGURE 1, and illustrates a photographic element of the present invention particularly adapted for employment in multichromatic photographic processes.

It has now been found that blocking, such as occurs in film packs and roll film, may be substantially reduced by abrading the outer surface of the film support. When it is considered that prior to the present invention it was generally felt that abrading would promote rather than reduce the adhesive properties of films, the results obtained are quite unexpected.

The processes of the present invention have been found useful on the various types of material used for film supports. As examples of such materials, mention may be made of cellulose esters such as cellpulose acetate, polyesters such as Mylar (trade name of E. I. du Pont Co. for a polyester film of ethyleneglycol and terephthalic acid), polycarbonates such as those of 4,4-bis-hydroxyphenyl-dimethylmethane (bis-phenol A) and carbonic acid, polystyrenes and polymethyl methacrylates. The processes have been found especially useful on Mylar.

The abrading of the fihn support may be carried out by any suitable means, e.g., sandblasting; rubbing with abrasive materials such as emery cloth, sandpaper; etc. Especially useful results have been obtained by sandblasting using salt as the abrasive material. Usually, the amount of abrading may be varied to suit particular needs. Generally, abrading to a depth of about 1 mil will provide satisfactory results.

FIGURE 1 of the accompanying drawing illustrates a composite photographic element embodying the present invention which comprises a support layer 2, bearing on one surface a photographic silver halide gelatin emulsion layer 1 and on the other surface an abraded surface layer 3.

A multilayer subtractive multicolor film unit particularly adapted for use in the photographic processes of US. Patent No. 2,983,606, issued May 9, 1961 and embodying the present invention, is illustrated in FIG. 2 of the accompanying drawing. The illustrated photosensitive element comprises: a support layer 2, bearing on one surface a gelatin layer 10 containing cyan dye developer, a red-sensitive silver halide gelatin emulsion layer 9, a gelatin layer 8 containing magenta dye developer, a greensensitive silver halide gelatin emulsion layer 7, a gelatin layer 6 containing yellow dye developer, and a blue-sensitive silver halide gelatin emulsion layer 5, and on the other surface an abraded surface layer 3. As examples of dye developers useful in such photographic elements, mention may be made of: 1,4-bis-(u-methyl-fi-hydroquinonylethylamino)-5,8-dihydroxyanthraquinone (a cyan dye developer); Z-(p-[2',5'-dihydroxyphenethyl]-phenylazo)-4-isopropoxy-1-naphthol (a magenta dye developer); and l-phenyl-3-n-hexyl carboxamidol-(p-[hydroquinonylethyl]-phenylazo-4-pyrazolone (a yellow dye developer). The last-mentioned yellow and magenta dye developers are disclosed in the copending US. application of Blout et al., Ser. No. 145,978, filed Oct. 18, 1961, and the cyan dye developer is disclosed in the copending US. application of Blout et al., Ser. No. 233,461, filed Oct. 26, 1962.

The following nonlimiting examples illustrate the processes of the present invention:

EXAMPLE 1 The Mylar film supports of photosensitive elements such as shown in FIGS. 1 and 2 were blasted with sodium chloride under 20 pounds per square inch air pressure at an angle of impingement of 30. The photosensitive elements were placed on one another (gelatin layer to Mylar layer) and subjected to 204 grams per square inch pressure for 24 hours at 100 F. and 80% relative humidity. At the end of the 24-hour period the photosensitive elements were examined for blocking using the following rating system: (1) no blocking; (2) slight blocking (the surfaces do not slide freely but separate at touch); (3) critical blocking I (the surfaces do not slide freely and show slight evidence of marring); (4) critical blocking II (surfaces do not slide freely and show more than slight evidence of marring but no peeling); and (5) critical blocking III (peeling). The photosensitive elements, treated according to the processes of the present invention, exhibited no blocking; whereas the controls (untreated) exhibited critical blocking I.

EXAMPLE 2 Film support Untreated Treated Polystyrene Critical III Critical I.

. Sliglg blocking. o.

The processes of the present invention are particularly useful in film packs, such as disclosed in US. Patent No. 3,002,437. In general, such film packs or assembly comprise a container or magazine having therein a plurality of film units which are adapted to be successively and individually withdrawn from said container. Each film unit comprises a film support which is in stacked, contiguous relationship with the film supports of the other film units and which is adapted to be moved relative to the other film supports. More particularly, each film unit comprises a photosensitive element comprising a film support bearing a photosensitive layer, the photosensitive elements of each unit being in stacked (planar surface to planar surface), contiguous relationship with the photosensitive elements of the other units; an image-receiving sheet adapted to be superposed on the photosensitive element; a rupturable pod, preferably positioned adjacent the edge of one of the photosensitive element or the image-receiving sheet, and containing a photographic processing solution which is adapted to be distributed between the superposed photosensitive element and the image-receiving sheet; and leader means, preferably coupled to the photosensitive element and the image-receiving sheet, for bringing the photosensitive element and image-receiving sheet into superposition and in engagement with means for rupturing the pod and distributing the processing solution.

The processes of the present invention are also useful in composite roll film intended for use in a Polaroid Land Camera, sold by Polaroid Corporation, Cambridge 39, Mass, or a similar camera structure such, for example, as the camera forming the subject matter of US. Patent No. 2,435,717, issued to Edwin H. Land on Feb. 10, 1948. In general. such composite roll films comprise a photosensitive roll, rolled upon itself, and bearing a plurality of photosensitive elements, a roll of image-receiving material and a plurality of pods containing photographic processing solution. The rolls and pods are so associated with each other that, upon processing, the photosensitive element may be superposed on the image-receiving material and the pods may be ruptured to spread the processing solution between the superposed elements. The nature and construction of the pods used in such units are well known to the art. See, for example, US. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land and US. Patents Nos. 3,056,491 and 3,056,492, issued to John E. Campbell.

The processes of the present invention may also be used to treat the outer surfaces of the films, used to form the outer walls of the pods to prevent unwanted adhesion of such pods to other elements in the film packs and rolls such as the image-receiving elements and the photosensitive elements.

EXAMPLE 3 Mylar coated pods for use in film packs and rolls such as described above were blasted at an angle of 30 using sodium chloride and powdered polyvinyl chloride as the abrasives. The treated pods along with controls were placed in film packs against image-receiving sheets for 16 hours at 100 F. and relative humidity. The pods treated according to the processes of the present invention showed no blocking, whereas the controls exhibited critical level I blocking (defined above).

Since certain changes may be made in the above products and processes 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. A photographic product which consists of a plurality of layers including a support layer, a silver halide gelatin emulsion layer located on one surface of said support layer and the other surface of said support layer being abraded.

2. A photographic product as defined in claim 1 wherein said support layer comprises a polyester polymer.

3. A photographic product as defined in claim 2 wherein said support layer comprises a polycarbonate polymer.

4. A photographic product as defined in claim 3 wherein said support layer comprises a polystyrene polymer.

5. A photographic product as defined in claim 2 wherein said support layer comprises a cellulose acetate polymer.

6. A photographic product as defined in claim 2 wherein said polyester polymer is formed from ethyleneglycol and terephthalic acid.

7. A photographic product which consists of a plurality of layers including a support layer having located on one side of said support layer a cyan dye developer-containing layer, a red-sensitive silver halide gelatin emulsion layer, a magenta dye developer-containing layer, a greensensitive silver halide gelatin emulsion layer, a yellow dye developer-containing layer, and a blue-sensitive silver halide gelatin emulsion layer, and the opposite surface of said support being abraded.

8. In a rupturable pod for use in photographic film packs and rolls having therein a photographic processing solution and having outer walls of a film-forming material, the feature of having the outer surface of said filmforming material abraded.

9. A photographic roll film unit consisting of a film support rolled upon itself, said film support bearing on one side a photosensitive layer and having the outer surface of the other side abraded.

10. In a film pack consisting of a plurality of film units which are adapted to be successively and individually withdrawn from said pack, each film unit comprising a film support which is in stacked, contiguous relationship with the film supports of the other units and is adapted to be moved relative to the film supports of the other units, the improvement of having the surface layer of said film support abraded.

11. In a film pack consisting of a plurality of film units, each film unit comprising (1) a photosensitive element which comprises a film support bearing on one side a photosensitive layer, the photosensitive elements of each unit being in stacked contiguous relationship with one another; (2) an image-receiving sheet adapted to be superposed on the photosensitive element; (3) a rupturable pod containing a processing solution which is adapted to be distributed between the superposed photosensitive element and image-receiving sheet; and (4) leader means for 5 6 bringing the photosensitive element and the image-receiv- 2,647,055 7/1953 Land 9684 X ing sheet into superposition and in engagement with means 2,983,606 5/ 1961 Rodgers 9629 for rupturing the pod and distributing the processing solution, the feature of having the surface of the second side OTHER REFERENCES of said fil support abraded. wgglsgy, Pulp and Paper, Second Ed., col. 3, 1961, pp. g afg if NT NORMAN G. TORCHIN, Primary Examiner.

E S R. E. MARTIN, Assistant Examiner. 676,272 6/1901 Plagwitz 9684 10 1,929,254 10/1933 Narath 9684 as CL X,R

2,333,809 11/1943 Nadean et al. 9684 96 87

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