Process by which at least one stripe of one material is incorporated in a layer of another material

Abstract

A process in which a support is moved in a prescribed path and has at least one layer of a material continuously coated on a surface thereof. In a specific embodiment of the invention, several emulsion layers are simultaneously applied to a support. The laminar flow of each different layer forms with the other layers a composite flow in which the layers are in a predetermined order and superposed in contacting relation with each other. A flow of a recording material, such as a hydrophilic colloid having iron oxide particles dispersed therein, is introduced as a stripe within the laminar flow. The composite flow including the stripe is applied to the surface of the moving support and the stripe extends in the direction of movement of the support with the exposed surface of the outermost layer and of the stripe being generally coplanar.

Description

1. Field of the Invention

This invention relates in general to the coating art, and, more particularly, to an article of manufacture and to a process by which at least one stripe of a first composition is applied within a layer of a second composition that is carried on a surface of a support. In a particular embodiment, the invention relates to a process for the manufacture of a photographic element comprising a support and at least one layer of a photosensitive material and a recording stripe coated within the layer.

2. Description of the Prior Art

Various methods have been devised to provide a unitary combination of a recording track and a photosensitive film. One method of providing for such combination has been to apply a stripe of magnetic material relative to the image areas on the film after processing of the latter. The sound is then added to the striped film. Such a system requires that an additional tape be used; namely, to record the sound at the time the photographic image is exposed on the film. Such a system also requires that the recorded sound be synchronized with the exposure that will produce the ultimate visual image.

Another method that has been suggested to provide a satisfactory photosensitive film with a sound track comprises cutting a longitudinal groove in the film and then depositing a magnetic sound recording material in the groove. This method is relatively expensive due to the precision with which the groove must be cut not only in relation to the thickness of the film but also in relation to the film image area.

Another method by which a sound track has been added to a strip of photosensitive film is the application of a stripe of magnetic material to the back of the film and relative to the image area. The shortcoming of this method is that the stripe is necessarily added to the antihalation layer on the back surface of the support, which is removed during processing of the film with alkaline photographic developer solutions. As a result, the magnetic stripe is completely, or at least partially, removed along with the antihalation layer. This problem was overcome by the method disclosed in U.S. Pat. No. 3,050,758, wherein the antihalation layer is removed before applying the magnetic stripe, thereby permitting the stripe to be adhered directly to the film support.

Magnetic stripes have also been attached to photosensitive film using an adhesive. For example, the stripe is deposited on its own support which, in turn, is adhered to the film. A stripe added in this way is easily abraded and subject to removal or loosening with respect to the support. In addition, it has been found the support on which the magnetic stripe is coated becomes brittle and can have different expansion characteristics from that of the film base. Hence, there is a possibility the magnetic stripe will crack and break away from the film support.

With all of the methods described hereinabove, the primary disadvantage is that the photosensitive film is thicker at the edge along which the stripe is located. As a result, uniform winding of the film is very difficult. In U.S. Pat. No. 3,220,843, this disadvantage was deemed to be overcome by applying a balance stripe along the opposite edge of the film. However, with photosensitive films that are relatively narrow, such as an 8mm film, the use of such a balance stripe is not only impractical but impossible.

While the prior art does disclose methods by which a photosensitive film can be striped with spectrally different emulsions, the stripes are not applied within the outermost emulsion layer nor are they applied at the same time and simultaneously with the application of one or a number of emulsion layers to the support.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a process wherein at least one layer of a material of a first composition is continuously applied to at least one surface of a support simultaneously with at least one stripe of a material of a second composition arranged within said layer.

It is another object of the invention to provide a process wherein at least one layer of a material of a first composition is continuously applied to one surface of a flexible support simultaneously with a plurality of spaced stripes of a material of a second composition arranged within said layer.

It is still another object of the invention to provide a process wherein a number of layers of material of different composition superposed in contacting relation are continuously and simultaneously applied to one surface of a flexible, transparent support with at least one stripe of a material of a second composition arranged within the outermost layer.

It is yet another object of the invention to provide a process wherein a layer of silver halide emulsion is continuously applied to one surface of a flexible, transparent support with at least one stripe of a compatible sound recording material arranged within said emulsion layer.

These and other objects and advantages will be apparent to those skilled in the art by the description which follows of preferred embodiments of the invention.

The above objects of the invention are attained by a process in which a support is moved in a prescribed path and has at least one layer of a material continuously coated on a surface thereof. In a specific embodiment of the invention, several emulsion layers are simultaneously applied to a support as disclosed in U.S. Pat. Nos. 2,761,791 and 3,508,947. The laminar flow of each different layer forms with the other layers a composite flow in which the layers are in a predetermined order and superposed in contacting relation with each other. A flow of a recording material, such as a hydrophilic colloid having iron oxide particles dispersed therein, is introduced as a stripe within the laminar flow. The composite flow including the stripe is applied to the surface of the moving support and the stripe extends in the direction of movement of the support with the exposed surface of the outermost layer and of the stripe being generally coplanar.

With this arrangement of the recording stripe and the process by which the stripe is arranged within the one emulsion layer, means for recording information or sound is accomplished which is unaffected by photographic processing. Since the stripe is inserted within an emulsion layer during coating, both the stripe and the layer can be coated simultaneously and continuously and provides an element or film strip having a generally coplanar or flat surface that presents no winding problem. With the insertion of a number of such stripes within an emulsion and arranged in predetermined spaced relation transversely of the support, the coated material can be slit longitudinally so as to provide different arrangements of the recording stripe relative to the edge of the film strip. For example, the stripe can be arranged along one or both edges, or centrally of the film strip. In addition, the thickness of the stripe can be controlled to provide a thinner layer for the recording of digital information as compared to the recording of sound.

The present invention is also considered to include within its scope the article of manufacture derived from the process. The article per se can take many forms depending on the material to which the layers are added; for example, a glass sheet or plate, a sheet, strip or web of paper, or a sheet, strip or web of either an opaque or transparent flexible material. In the latter case, a photographic film would not only have to be flexible but also transparent.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying drawings wherein like reference numerals and characters designate like parts and wherein:

FIGS. 1 and 2 are enlarged sections of a photographic element showing a number of layers on a support and the location of several recording stripes for producing film strips of different widths and with different locations of the stripes in accordance with the slitting of the coated support;

FIG. 3 is a schematic, perspective view showing one type of apparatus by which a plurality of layers of a material can be applied to a support together with another material for forming a stripe within the outermost layer;

FIG. 4 is a schematic, perspective view showing a free-falling, vertical curtain formed by the composite flow of several layers of different compositions being applied to a support with at least one stripe of a compatible composition being applied simultaneously therewith; and

FIG. 5 is a schematic, perspective view of still another arrangement by which a single layer of a material is applied to a support with a stripe of another and compatible material being applied simultaneously and continuously therewith.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring particularly to FIGS. 1 and 2, the element 10 comprises a support 11 on one surface 12 of which a plurality of layers are coated. While three layers designated 13, 14 and 15 are disclosed, only one of such layers need be applied to the surface 12 to consummate the invention. As is well-known in the photographic art, the layers 13, 14 and 15 can comprise one or more emulsion layers, sensitizing layers, light filtering layers, as well as other layers; and in the case of a color film, such layers may reach a total of eight or more. Within the outermost layer 15, one or more stripes 16 of a material or composition compatible with that of the other layers is applied, as described hereinafter, continuously and simultaneously with the other layers. In one embodiment of the invention, the stripe 16 comprises a hydrophilic colloid having iron oxide particles in suspension for use as a magnetic sound recording track. As shown in FIG. 1, the stripe 16 has a width w and the exposed or actual surfaces 17 and 18 of the layer 15 and stripe 16, respectively, are generally coplanar so as to provide a surface that is continuous and generally even or flat. The stripes 16 can be spaced transversely of the support 11 by a distance d so that upon slitting of the finally coated support along lines 19, an 8mm or 16mm film strip can be obtained with a stripe arranged along one edge thereof. The distance or dimension d will determine the width of the film strip. In FIG. 2 a stripe 16' is shown that is twice as wide as the stripe 16 in FIG. 1. In this arrangement, the finally coated support can be slit along lines 20 to produce a film strip of width d which can also be either an 8mm or 16mm film strip in accordance with the overall spacing between stripes 16'. By the same token, an alternate width of the film strip can be 35mm, or any other dimension, depending on the predetermined transverse spacing of the stripes 16.

In the description thus far, the stripes 16 have been considered as being spaced far enough apart so the layer 15 is divided by the stripes into widths sufficient to be slit into strips of film. However, the stripes 16 can be spaced such that the layer 15 is as wide as the stripe, or even narrower than the stripe. In these latter cases, the outermost layer would comprise, in effect, a plurality of stripes, every other stripe being of the same composition. It is also possible to provide a repetitive series of stripes, that is a number of stripes each of a different composition and in a particular order and repeated across the support; e.g. ABC, ABC, ABC, etc., A, B and C being different compositions and of the same or different widths. Also, the stripes A, B and C can be coated directly on a support or simultaneously and contiguously with a layer of a composition that is applied to the support. The terms "stripe" and "layer" can, therefore, be considered as being synonomous. Also, the term "within a layer" is meant to include side by side when the stripe and divided layer are applied directly to a support or when the stripe and a divided layer are applied simultaneously with one or more other layers to a support.

As will be evident from the examples set forth hereinbelow, the support 11, as well as the layers and stripes applied to the support, can be of different materials other than a photosensitive film. Consequently, the invention is applicable to the production of a single or multiple striped element for use in fields other than that of photography, e.g. elements usable in the field of graphic and digital data storage, of data processing, of medicine, etc.

With reference to FIG. 3, a three-slide hopper designated by the numeral 30 is disclosed. This type of hopper is more fully disclosed and described in U.S. Pat. No. 2,761,791 to T. A. Russell and relates to a method for coating multiple layers on a support. However, in order to fully understand the present invention, a short description of this apparatus follows. In this coating device, the first coating composition is continuously moved by a pump 31 into a cavity 32 from which it is extruded through a narrow, vertical slot 33 onto a downwardly inclined slide surface 34. Likewise, other coating compositions are continuously pumped into cavities 35 and 36 by pumps 37 and 38, respectively. These latter compositions are extruded through slots 39 and 40 onto respective slide surfaces 41 and 42. Each composition forms a laminar flow which extends lengthwise relative to a drum 43 and flows by gravity toward the drum. The slide surfaces 34, 41 and 42 are coplanar so that as each laminar flow of each composition moves along its respective slide surface, it ultimately flows over the succeeding laminar flow together with one or more preceding laminar flows. The laminar flows are contiguous to one another and, when the last flow is joined, a composite flow is applied to the surface of a support 44 at a line 45 relative to drum 43. This composite flow is picked up by the support 44 and carried along with the rotation of the drum 43. The layers are maintained in their distinct relationship in superposed, contiguous relation throughout their travel and on being picked up by the support 44 at line 45.

The composition to be introduced as a stripe 50 within the outermost layer of the composite flow is contained within a receptacle 51 that is mounted relative to hopper 30 so as to provide a continuous flow via a tube 52 at one or more predetermined locations along the outermost layer in a direction extending parallel to line 45. The introduction of this flow as a stripe separates the laminar flow of the outermost layer and moves therewith throughout its flow from the point of formation to the point of application and carry away by the support 44 at a line 45. There is relatively little, if any, intermixture of the stripe composition with that of the outer layer. While only a single, narrow stripe is shown as being applied to the outer layer in FIG. 3, it should be obvious that the number of stripes can vary in number, can be of different widths, can be spaced at different distances, etc., as shown and described hereinabove with respect to FIGS. 1 and 2. However, as these factors vary, other parameters will be dependent on such variations, e.g. surfactant balance, coated speed, etc.

In FIG. 4, a system is disclosed which is similar to that disclosed in U.S. Pat. No. 3,508,947 to D. J. Hughes and relates to a method for simultaneously applying to a support a plurality of coating layers which are first formed into a stable, multi-layer, free-falling, vertical curtain. In this embodiment of an apparatus for carrying out the invention, two coating compositions are disclosed as being applied to a moving web 60. As in the apparatus disclosed in FIG. 3, the coating compositions are moved into cavities 61 and 62 by pumps 63 and 64, respectively. The compositions flow through respective narrow, vertical slots 65 and 66, and, thence, onto downwardly inclined slide surfaces 67 and 68. The outermost layer flows onto the top of the lower layer to form a composite flow which moves by gravity along the slide surface 68 without intermixing. The composite flow leaves the lip 69 as a free-falling, vertical curtain 70. Impingement of curtain 70 on the moving web or support 60 takes place without intermixing of the layers and deposits on the support a coating comprising distinct, contiguously superposed layers. As in FIG. 3, the material or composition for forming one or more stripes 71 in the outermost layer of the composite flow is moved into a receptacle 73 by a pump 74 and applied to the layer via a tube 75 in a close proximity to the slot 66. Such flow of the stripe composition or material divides the outermost layer without intermixing and forms at least one requisite stripe. Again, the number, width, spacing, etc., of the stripes can be varied in accordance with the element size and use and the width of the support on which the compositions are being applied or coated.

In FIG. 5 a device is shown for applying a single layer of a composition to a support 80 carried by a drum 81. Such device is a modification of one of the embodiments disclosed in the above-mentioned Russell patent. In this arrangement the material or composition to be coated on the support 80 is introduced into a chamber 82 via a number of inlets 83 which are spaced lengthwise of the chamber 82 so as to form a laminar flow which is extruded from chamber 82 via a slot 84 extending generally parallel to the axis of drum 81 and onto the surface of the support 80 at a line indicated by 85. The material or composition for providing one or more stripes 86 is also introduced into chamber 82 at the requisite location of the stripe or stripes via a corresponding number of inlets 87. The stripe is extruded at slot 84 with the laminar flow of the other composition and does not intermix therewith. Since the composition of the layer is introduced at a number of locations through inlets 83, when more than one stripe 86 is to be applied to the support, best results are obtained if the layer composition is introduced on each side of the stripe material. In this way, the layer composition can flow, upon introduction into chamber 82, toward and against the stripe composition to insure edge contact therewith before extrusion from the hopper.

A number of examples are set forth hereinbelow and are illustrative of different compositions that can be utilized in practicing the invention. However, the scope of the invention is not to be defined by the structures and variations shown and described herein. As pointed out hereinafter, the invention can be practiced with many different types of compositions and can have many different uses in accordance with the support and the compositions that are combined to form the requisite element.

EXAMPLE 1

Three clear gelatin layers were simultaneously coated on a cellulose acetate support using a multiple slide hopper such as that as disclosed in FIG. 3. The gelatin layers comprised a first layer of 4% aqueous gelatin solution at 6 g/ft.sup.2 ; a second layer of 6% aqueous gelatin solution at 2 g/ft.sup.2 ; and a third 8% aqueous gelatin solution containing 0.2 g/l Triton X-200 surfactant at 1 g/ft.sup.2. The gelatin layers were coated at 40.degree.C and at 40 ft/min from the slide hopper. An iron oxide stripe comprising as 6% aqueous gelatin solution containing 25 g/l of an iron oxide (magnetite, Fe.sub.3 O.sub.4) dispersion and 8.8 g/liter of a water soluble blue dye was expelled from a syringe with an aimed coverage at 1 g/ft.sup.2. The iron oxide stripe was applied by means of the syringe to the top of the slide surface 42 at the point where the composition emerges from the slot 40 and flows onto the surface 42. The resulting coating was of clear gel of approximately 5.mu.m thickness. The dye appeared in a photomicrograph of the striped area to be equally distributed in the coating from the support to the surface. The stripe was about 1mm wide with some further diffusion of the water soluble dyes. The surface was smooth except where the iron oxide particles (2-3.5.mu.m in size) protruded to some extent. At the 25 mg/ft.sup.2 level of the magnetite, the stripe was capable of recording a 100 Hertz saturated signal at a 20-30 decibel signal/noise ratio, a level adequate for recording digital information. The extent to which the stripe penetrates the other layers is dependent on the degree of control that can be accomplished by surfactant balance.

With respect to the above Example, Triton X-200 is a registered trademark of Rohm and Haas for sodium p-tert-octylphenoxyethoxy-ethylsulfonate. The water soluble dye is Bis [3-methyl-1p-sulfophenyl-2-pyrazolin-5-one(4)]pentamethineoxonol.

EXAMPLE 2

An iron oxide stripe was coated within the outermost layer of a two-layer, free-falling curtain on a polyester support, substantially as disclosed in FIG. 4. The bottom layer, which contacts the surface of the support, was coated at 420 cc/min and was composed of a 10% gelatin solution containing approximately 2 g/l Carey Lea silver. The outermost layer was coated at 210 cc/min and was composed of a 10% gelatin solution. Both layers contained 1.3 g/l Triton X-200 surfactant. The layers were coated on the support as the latter was moved at 150 ft/min. An iron oxide dispersion in poly(vinyl alcohol) was diluted with an equal volume of water (to 12.5% solids) and was injected by means of a syringe into the upper layer at a point where the flow exits from slot 66 for flow along surface 67. The resulting stripe was 0.3mm in width and contained about 400 mg/ft.sup.2 of iron oxide. At 4 in/sec and a recording frequency of 1000 Hz, the maximum signal/noise ratio was 35 dB.

EXAMPLE 3

A single layer of a photographic emulsion with a single continuous iron oxide stripe was coated on a polyester support from an extrusion hopper of the type shown in FIG. 5. The emulsion, a high speed, panchromatically sensitized silver bromoiodide in a 6.5% gelatin solution containing saponin, 560 mg/ft.sup.2 silver and 1025 mg/ft.sup.2 gelatin was pumped into a hopper through a pair of spaced inlets 83. The iron oxide composition described in Example 1 was dispersed in a 5% gelatin solution containing saponin and was introduced into the hopper through inlet 87 which was arranged between the inlets 83. There was no separation in the hopper between the inlets and the stripe 86 applied to the support within the emulsion layer, straight and sharply defined, was 4.5mm wide and contained 990 mg/ft.sup.2 of iron oxide. At 4 in/sec, the stripe was capable of recording sound of a frequency of 1000 Hz at a signal/noise ratio of 65 dB. This compares to a signal/noise ratio of 62 dB for commercially available 16mm sound recording film.

EXAMPLE 4

A stripe of high speed, panchromatically sensitized, silver halide emulsion was coated within a layer of the same but not spectrally sensitized emulsion from an extrusion hopper of the type shown in FIG. 5. Both emulsion samples contained 6.5% gelatin and saponin and were coated to provide substantially the same coverage as in Example 3.

The dried coating was exposed to a tungsten light source in a sensitometer through a portion of a continuous step wedge with exposure channels perpendicular to the stripe. The five exposure channels had (1) no filter, (2) a blue filter combination, (3) a green filter, (4) a red filter, and (5) a yellow (minus blue) filter. The film was developed, fixed, washed and dried in a conventional manner. In the clear and blue channels, where both emulsions were sensitive, there was essentially no discontinuity in the exposed channels in the vicinity of the stripe, except for an expected slight density difference within the striped area due to spectral sensitization. The light from the other three channels exposed only the stripe, the edge of which showed a sharp demarcation from the adjacent unsensitized emulsion at the border of the stripe. In the unexposed areas, the stripe could be distinguished only by a very slight increase in fog. The stripe appeared homogeneous across its width both in the exposed and background areas.

EXAMPLE 5

A single gelatin layer with a stripe coating a scintillator was coated on a polyester support from an extrusion hopper of the type shown in FIG. 5. The stripe, about 8mm in width, showed a bright fluorescence when illuminated by an ultraviolet source. The stripe was coated within a yellow dyed gelatin layer containing 40 g/l (4%) gelatin and 6.8 g/l bis[3-methyl-1-p-sulfophenyl-2-pyrazolin-5-one(4)]methineoxonol. The stripe contained 29.4 g/l gelatin in which was dispersed 59 g/l copolymer of butyl acrylate and styrene, 5.3 g/l of 2,5-diphenyloxazole ("PPO") and 0.3 g/l of 2,2'-phenylenebis (5-phenyloxazole) ("POPOP").

A stripe of this type within a silver halide layer will provide means for monitoring a direct electron or ultraviolet exposure for readout of information as disclosed in U.S. Pat. No. 3,403,387 to Boblett and entitled ELECTRON BEAM INFORMATION REPRODUCING APPARATUS.

EXAMPLE 6

An iron oxide stripe in a cellulose nitrate binder was coated within a clear cellulose nitrate layer by means of an extrusion hopper of the type shown in FIG. 5. The stripe composition contained 48.8 g gamma ferric oxide (Fe.sub.2 O.sub.3), 11.8 g cellulose nitrate binder and 8.8 g tricresyl phosphate as a plasticizer in 300 g of a mixture of pentyl acetate, 2-ethoxyethanol and methyl ethyl ketone (MEK) solvents. The clear layer within which the stripe was applied was composed of 27.3 g cellulose nitrate in 500 g of a mixture of phenyl acetate and MEK. The mixtures wee coated at 980 mg/dm.sup.2 (9.1 g/ft.sup.2), the iron oxide composition through the inlet 87 and the cellulose nitrate composition through the inlets 83, one each side of inlet 87, at a relative rate such that a sharply defined stripe 4mm wide was obtained. The total iron oxide in the stripe was 161 mg/dm.sup.2 (1500 mg/ft.sup.2). At 18.3 cm/sec (7.2 in/sec), the stripe was capable of recording a frequency of 100-1000 Hz at a signal/noise ratio of 61 dB. This compares to 63 dB for commercially available, prestriped 16mm movie film.

EXAMPLE 7

Two compositions which are intended to provide a substrate for chemical spot tests were simultaneously coated side by side, the second as a stripe between two parts of the first. The first composition contained for each 100 g of composition 14.8 g of silver chromate, Ag.sub.2 CrO.sub.4, 0.2 g of a non-ionic surfactant and sufficient 5% aqueous gelatin to make 100 g of mixture. The second composition contained for each 100 g of composition 117 mg copper sulfate, 0.50 g neocuproine 0.12 g 2-amino-2-methylpropanol, and 0.2 g of a non-ionic surfactant and sufficient 4% aqueous poly(vinylalcohol) to make 100 g of the mixture. The compositions were coated from a hopper of the type disclosed in FIG. 5 at 108 mg/dm.sup.2 (10 g/ft.sup.2). Stripes 8-25mm wide were coated by varying the relative amounts of the first and second compositions which were pumped into the outside (83) and center (87) inlets, respectively. Under these coating conditions, some of the neocuporine precipitated on the surface of the clear poly (vinyl alcohol) layer. There appeared to be only a slight mixing of the two compositions at the interface between the coated areas. The silver chromate areas and the neocuproine areas can be used for the detection of chloride and uric acid in solutions spotted on the dried coating.

The term "photographic" normally refers to a radiation sensitive material but not all of the layers necessarily applied to a support in the formation of a photographic element are, in themselves, radiation sensitive. For example, subbing layers, filter layers, antihalation layers, etc. are often applied in combination with emulsion layers but are not radiation sensitive. The present invention relates to the application of such layers as well as other types of layers and the term "composition" as used herein is intended to include compatible compositions from which layers such as those described herein can be formed. Moreover, the invention includes within its scope all radiation sensitive materials including electrophotographic materials and materials sensitive to invisible radiation, as well as those sensitive to visible radiation. As mentioned hereinbefore, other liquid vehicles can be coated in the manufacture of an element other than a photographic element, for example, to provide a digital tape or a video tape; diagnostic test strips, etc. In the practice of the invention, various types of supports can be used other than those used strictly as a photographic film base; for example, cellulose nitrate, cellulose acetate, polyester, paper, glass, cloth, and the like. The support can be in the form of a continuous web, a strip, a plate, or a discrete sheet, but in commercial practice it will most frequently take the form of a continuous web that can be slit into strips. It should also be noted that a series of stripes of different composition can be coated in spaced or contiguous as well as repetitive relation across a support or a layer on a support.

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

Claims

We claim:

1. A process for applying to at least one surface of a support at least one stripe of a first composition within a flow comprising at least one second and compatible composition, which comprises the steps of:

moving the support in a prescribed path;

forming a flow of said second composition directed toward said support;

while forming said flow, introducing at least one flow of said first composition as a stripe within said flow to form a composite flow; and

applying continuously said composite flow to the one surface of said moving support;

whereby said stripe extends in the direction of movement of said support and the exposed surfaces of said flow and stripe are generally coplanar.

2. A process in accordance with claim 1 wherein said applying step comprises continuously extruding said composite flow onto the one surface of said support.

3. A process in accordance with claim 1 wherein said applying step comprises continuously applying said composite flow as a free-falling curtain to said surface.

4. A process in accordance with claim 1 wherein said first composition comprises a hydrophilic colloid having a substance in suspension and said second composition comprises a hydrophilic colloid.

5. A process in accordance with claim 4 wherein said hydrophilic colloid comprises an aqueous gelatin solution and the substance in suspension comprises iron oxide particles.

6. A process in accordance with claim 1 wherein said first and second compositions are non-aqueous solutions.

7. A process in accordance with claim 6 wherein said first composition comprises cellulose nitrate and particles of iron oxide and said second composition comprises clear cellulose nitrate.

8. A process in accordance with claim 1 wherein said first composition and said second compositions are aqueous solutions.

9. A process in accordance with claim 8 wherein said first composition comprises a neocuproine solution and said second material comprises a silver chromate solution.

10. A process for applying to at least one surface of a generally transparent, flexible support at least one stripe of a first composition within at least the outermost layer of a number of layers of different compositions superposed in contacting relation, which comprises the steps of

moving the support in a prescribed path;

forming a laminar flow of each different composition into a composite flow directed toward said support in which the laminar flows are in a predetermined order and superposed in contacting relation with each other;

while forming said composite flow, introducing at least one flow of said first composition as a stripe within the laminar flow constituting the outermost layer relative to said support;

applying continuously said composite flow to the one surface of said moving support;

whereby said stripe extends in the direction of movement of said support and the exposed surface of said outermost layer and stripe are generally coplanar.

11. A process in accordance with claim 10 wherein said composite flow is applied to the one surface of said moving support as a free-falling vertical curtain.