US3844789A

US3844789A - Composite film elements

Info

Publication number: US3844789A
Application number: US00068560A
Authority: US
Inventors: J Bates; F Farren; J Sklute
Original assignee: GAF Corp
Current assignee: GAF Corp
Priority date: 1967-03-06
Filing date: 1970-08-31
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29
Also published as: CH507535A; BE711674A; GB1184063A; DE1622933A1; FR1556083A

Abstract

Composite film elements comprising a base, a light-sensitive layer capable of providing an image directly upon exposure to light and a further light-sensitive layer adapted to yield an image upon photographic development.

Description

United States Patent [191 Bates et al.

[ Oct. 29, 1974 COMPOSITE FILM ELEMENTS [75] Inventors: James E. Bates, Binghamton;

Francis J. Farren, Vestal; Jerome Sklute, Corning, all of N.Y.

[73] Assignee: GAF Corporation, Wayne, NJ.

[22] Filed: Aug. 31, 1970 [21] Appl. No.: 68,560

Related US. Application Data [63] Continuation of Ser. No. 621,033, March 6, 1967,

abandoned.

[52] US. Cl. 96/68, 96/71, 96/119 PO [5]] Int. Cl G03c 1/76, G03c 3/00 [58] Field of Search 96/68, 69, 71, 119 PD [56] References Cited UNITED STATES PATENTS 4/1936 Sirnjian ..96/68 6/1970 Giaimo 3,253,918 5/1966 Condax 96/5 3,51 1,658 5/1970 Manko 96/68 OTHER PUBLICATIONS Photographic Chemistry, Pierre Glafkides, Vol. 1, 1958, Pp- 32, 33.

Primary Examiner-Norman G. Torchin Assistant Examiner-Richard L. Schilling Attorney, Agent, or Firm-Walter C. Kehm; Samson B. Leavitt [5 7] ABSTRACT 2 Claims, 9 Drawing Figures PATENTEU sum 1 a 2 Develop out Emulsion Base 3 Stripping Layer 4 Print ouf Emulsion Fig. 1.

Fig. 5.

Fig.5.

INVENTORS m aw b 0| VI 0 M E B |K N .2 .m 6m T mum A are JFJ PATENTEUMZI 2 I974 SHEETBNZ Exposure -4 Print out Erhulsion Film Bose Fig. 6A.

Develop out Emulsion IN VENTORS m. r m1... OHM B k EJS mm ec 2% are JFJ ATTORNEY COMPOSITE FILM ELEMENTS This application is a continuation of application Ser. No. 621,033 filed Mar. 6, 1967 and now abandoned.

The present invention relates in general to photography and in particular to composite film elements and process for using same beneficially adapted for use in photo reproduction applications involving the formation of images of both print-out and developing-out types.

A considerable number of photo reproduction techniques currently enjoying widespread use involves as an essential step the initial formation of a visually comprehensible image photolytically, i.e., image formation results, substantially, immediately, from the direct effects of the exposure radiation. Such processes are commonly referred to as print-out techniques in contradistinction to the so-called developing-out techniques, the latter requiring treatment of the latent-imagebearing exposed element with a photographic devel oper composition in order to provide the visible image. Print-out image reproduction processes have found particularly beneficial application in photographic reproduction systems connected with the reproduction,

fabrication, etc., of engineering drawings, or other diagrams involving the recording of letters, symbols, or other similar indicia, one such process in this regard being the well known Mergenthaler method. In essence, the apparatus employed in carrying out the latter technique comprises a punch-key type device provided with a plurality of keys each being correlated with a distinct form of image character. When a particular key is activated by the operator, the image character represented thereby appears in the form of a corresponding light image, the positioning and focussing of which may be readily controlled by the operator, suitable means being provided for such purposes. Thus, engineering drawings for example, can be readily composed photographically in typewriter fashion by merely activating the particular key in question and fcussing the corresponding light image upon a suitable photo-sensitive material. Accurate positioning of the characters to be produced is made possible by the use of a print-out type emulsion wherein the particular image character focussed thereupon is substantially im-' mediately reproduced. The operator is thereby afforded with ready means for visually comprehending the progress of the reproduction and thus can ascertain at a glance the relative positioning of the next succeeding character to be reproduced. As previously mentioned, the apparatus is provided with means whereby the operator is capable of precisely positioning the light sensitive material employed for reproduction in its proper physical relationship to thereby permit the drawing in question to be accurately copied. As will be recognized. such a process depends vitally for its efficacy upon the use of a photo-sensitive material adapted specifically to yield immediately upon actinic exposure a visible image which can be readily comprehended visually by the operator. Pursuant thereto, there has been provided in the art a wide variety of photographic film materials whose actinic response includes the immediate generation of visible species, i.e., those which depend solely upon the photolytic action of light for image reproduction. Purportedly, such materials may be employed to advantage in systems of the aforedescribed type. However, one of the primary objects of such reproduction methods resides in the obtention of permanent image copy having the required stability against the image-degrading effects of heat, humidity, etc. This has been somewhat problematical since the print-out materials currently promulgated in the art for such purposes are uniformly characterized in that the images obtainable therewith fail, to a great extent, to satisfy commercial requirements. Thus, it has been found that such materials invariably are deleteriously affected by even moderate conditions of environment such effects often being manifested in the form of background discoloration, loss of contrast, image fading and the like. Moreover, since such image bearing materials are often contemplated for use as photographic masters and thus, in all likelihood, will be subjected to repeated photographic exposures, it is of utmost importance that they possess a high order of stability over a relatively protracted period of time. Accomplishment of the latter objective has thus proved highly problematical in view of the speed requirements of the process involved. As will be readily evident, it is of extreme importance that the print-out material be possessed of a high order of actinic response, i.e., speed, in order to be capable of providing a visual image immediately upon exposure to actinic radiation and absent any necessity for ancillary operations, treatments, etc., designed to augment image quality, ease of visual comprehension and the like. Attempts to impart the required speed characteristics to the print-out material have tended to correspondingly aggravate the problems associated with image stability, i.e., it has been found in general that significant increases in print-out speed are invariably attended by intolerable increase in fog characteristics, loss of density, contrast, etc. Despite the efforts of prior art investigators to overcome or otherwise mitigate deficiencies of the aforenoted type, e.g., the utilization of special speed increasing additives, stabilizers, antifoggants, etc., the improvements heretofore realized thereby have, in the main, been marginal only. Moreover, the disadvantages from an economic standpoint alone have tended to militate against further commercialization of such procedures.

The utility of print-out materials extends, in general, to most any photo reproduction technique requiring as an essential operative step the formation of proof-copy, Le, a copy which may be visually examined substantially immediately upon exposure in order to assess reproduction quality, accuracy, etc. With the use of such materials, the processor may evaluate the sensitometric characteristics of one or more of the exposure parameters, ,e.g., intensity, exposure duration, etc., in order to assure the attainment of optimum reproduction characteristics in the image. With many industrial applications, due to the high cost involved, such as in the manufacture of offset printing plates, e.g., intaglio, gravure and the like, it is imperative that proof copy be obtained prior to the final plate forming exposure step. Manifestly, the prohibitive cost of materials employed in commercial plate making severely limits the latitude of the processor as regards the determination of optimum exposure parameters. The latter situation correspondingly enhances the importance of the function served by the proof copy since in the final analysis such copy will provide the final means for determining the propriety of proceeding with the plate-forming exposure. In view of the pivotal function served by the printout material at such a critical phase in the processing, any departure from optimum sensitometric characteristics can be disastrous and require that the entire plate forming process be repeated. In addition, since plate making is usually associated with high quality photomechanical reproduction, even slight variations in reproduction detail are unacceptable.

In accordance with the discovery forming the basis of the present invention, it has been ascertained that the utilization of light sensitive print-out layers of the silver halide type in combination with the more conventional emulsions of the developing-out type, the latter term being intended to encompass those materials wherein visible image formation is not coincident with actinic exposure but is brought about by a post exposure development operation of a chemical nature, makes possible the realization of the advantages peculiarly characteristic of print-out materials in general while simultaneously providing a permanent image copy of outstanding reproduction characteristics and stability, and being advantageously adapted to repetitive use.

Thus, a primary object of the present invention resides in the provision of a composite photographic film element capable or producing images of both the printout and developing-out type wherein the aforedescribed disadvantages are eliminated or at least mitigated to a substantial extent.

Another object of the present invention resides in the provision of a composite photographic film element and method for employing same which permits the obtention with a single exposure of. both a visible image and a latent image, the latter being readily capable of forming a permanent visible image by subsequent development.

A further object of the present invention resides in the provision of a composite photographic element comprising developing-out and print-out light layers capable of providing permanent image copy characterized by superior reproduction quality, i.e., density, contrast and the like.

A still further object of the present invention resides in the provision of a composite photographic film element which can be readily processed to provide a permanent image having outstanding stability and useful life.

Other objects of the present invention will become more apparent hereinafter as the description thereof proceeds.

The attainment of the foregoing and related objects is made possible in accordance with the present invention which in its broader aspects includes the provision of a composite film element comprising a base and having disposed thereupon two light sensitive layers one of said layers comprising a light sensitive print-out silver halide composition capable of yielding, photolytically, a visible image immediately upon exposure to actinic radiation, said other layer comprising a light sensitive substance which forms a latent image of the develop ing-out type upon exposure to actinic radiation, said image being capable of being rendered visible by treatment with a photographic developer composition.

A further aspect of the present invention includes the method of processing such materials whereby to obtain permanent image copy of exceptional reproduction quality.

The light sensitive print-out emulsions contemplated for use in accordance with the present invention comprise in general those of the silver halide type and within this delimited classification encompass a relatively wide range of materials. Such silver halide emulsion materials are well known in the art, the connotation print-out" being art-recognized nomenclature, and generically includes those silver halides whose photolytic reaction includes the substantially immediate formation of visible species. Thus, such materials when subjected to an image-wise illumination, i.e., photographic exposure, are capable of forming visible deposits in the light affected areas absent the necessity of further treatment, i.e., photographic development. However, it has been ascertained that the improvements contemplated herein may be realized to optimum advantage by the use of silver halide emulsions of the ammoniacal type with exceptional improvement being noted with emulsions of the ammoniacal-bromoiodide type. Surprisingly, print-out silver halide emulsions of the aforedescribed type and in particular ammoniacal silver bromoiodide emulsions obtained through the reprecipitation of silver chlorobromide emulsions during the after-ripening step are found to the exclusion of other silver halide types not only to readily deposit photolytic silver upon subjection to actinic radiation but, in addition, to provide print-out image reproductions having an exceptional degree of photographic quality as well as stability.

The present invention will now be explained in greater detail reference being made to FIGS. 1 to 6 of the accompanying drawings which represent several structural arrangements of the print-out and developing-out layers found to be highly effective for use herein and wherein like reference numerals and letters designate like parts.

FIG. 1 illustrates a relatively simple structural arrangement wherein the oppositely disposed surfaces of a suitable film base material 1 are provided respectively with a developing-out or negative emulsion 2 and a stripping layer 3, the latter being overcoated with a print-out emulsion 4. In this particular embodiment, it is of course necessary that the base material and stripping layer be transparent to the exposure radiation in order to permit the latter to impinge image-wise upon each of the print-out and developing-out emulsions. The stripping layer 3 may be prepared with any of the conventional materials promulgated in the art for such purposes and usually comprises a film forming organic colloid, polymeric material, etc., soluble at neutral and- /or alkaline pH with typical representatives including, for example, and without necessary limitation gelatin, PVP (polyvinyl pyrrolidone), PVA (polyvinyl alcohol), carboxymethyl cellulose, gum arabic and the like. The nature of the base material selected for use is likewise not a critical factor in the practice of the present invention and again, may be any of the customary materials described in the art for such use including, for example, film forming synthetic polymeric materials such as polycarbonate, polyester, etc., cellulose, cellulose acetate, cellulose acetate butyrate, etc., as well as transparentized fibrous supports in which the transparentizing is achieved by mechanical treatment such as extended heating or a chemical treatment for instance impregnation with mineral spirits which are high boiling solvents of the petroleum family; or with solutions of polypropylene. As indicated hereinbefore, the-printout material preferred for use herein comprises in general silver halide emulsions of the ammoniacal type with ammoniacal reprecipitated bromoiodide emulsions being particularly preferred. Emulsions of this type are well known in the art and can be readily prepared according to well known techniques. in this regard, reference is made to the emulsion materials described in U.S. Pat. Nos. 3,039,871; 3,047,392; 3,109,737 and 3,123,474.

One of the particularly valuable aspects of the present invention relates to the fact that the use of print-out silver halide emulsions of the aforedescribed type permits the exercise of a wide area of discretion as regards the selection of the developing-out material 2. Selection of the latter material will be influenced to a great extent by the nature of the process contemplated for the composite film element. Thus, if a wash-out relief image is desired, developing-out layer 4 may comprise a dichromate sensitized gelatin which may include as optional ingredients a suitable pigment for purposes of enhancing contrast in the final relief image or alternatively, may include minor quantities of a silver halide emulsion material. Wash-out emulsions of this type are described for example on pages 669-671 of Dierre Glaflrides book Photographic Chemistry (Fountain Press, London 195 8-1 960) and on pages 225-230 of E. .1. Wall & F. l. Jordans book Photographic Facts and Formulae (American Photographic Publishing Co.; Boston; 1940). As a further embodiment developingout layer 4 may comprise a photosensitive polymer or polymer-forming composition, i.e., one which undergoes a photolytically induced polymerication or hardening reaction when subjected to actinic radiation. It should be mentioned at this point that the language developing-out as used herein is intended to connote in general those photographic systems wherein a distinct operation is necessary for the obtention of the desired image and supplemental to the exposure step. Thus, the developing operation may be physical, chemical, etc., in nature, i.e., such emulsion may be of the tanning type wherein image formation results from a light-induced change in solubility characteristics and thus a mere wash-out operation suffices for purposes of defining the ultimate image, as with the dichromate type of emulsion systems. In any event, whether the light sensitive system be of the gelatin-tanning ning type or photopolymer type or, for that matter, any other emulsion system which relies for operability upon the utilization of a solvent-removal step, such elements may be processed simply by treating the exposed emulsion layer following exposure with a substance which exhibits a selective solvent action for either the exposed or unexposed areas. The image thus obtained is defined in terms of raised and non-raised areas. In general, suitable photopolymer systems are comprised of one or more monomeric substances commonly referred to in the art as vinyl-type monomers further containing a substance which is capable of liberating polymerization-initiating species when subjected to the photolytic effects of exposure radiation. Light sensitive photopolymer systems found to be highly efficacious in this regard are those described, for example, in U.S. Pat. Nos. 3,101,270; 3,041,172; 3,234,021 and 3,050,390.

Further embodiments of the present invention envisage the use of light sensitive diazo compounds as the developing-out layer. The light sensitive diazo system may be adapted to either wet or dry processing. As is well known in the art, wet processing diazotype materials encompass those wherein the diazo coupling component is included as an ingredient in the developer 6 composition; in contradistinction, dry processing diazotype materials encompass those wherein each of the diazo and coupling components is present in the emulsion composition, image formation being brought about by subjecting the exposed element to an alkaline environment.

The developing-out layer 2 may be adapted to provide either a positive or negative reproduction of the original, i.e., may be either a negative-working or positive-working emulsion. In this regard, beneficial results may be readily obtained with the use of autopositive emulsions such as those which utilize the Herschel effect for reversal. Representative emulsions of this type are described for example in U.S. Pat. No. 2,857,273 and on page 216 of Glafkides book Photographic Chemistry.

The present invention may likewise be implemented to exceptional advantage by the employment of a light sensitized, electrostatic composition as the developingout layer 2. Representative of the light sensitive electrostatic compositions contemplated for use herein are those comprising a photoconductor material, e.g., zinc oxide dispersed uniformly throughout a suitable resin binder. In this connection reference is made-to the electrostatic layer compositions described in U.S. Pat. Nos. 3,248,216; 3,002,835; 2,986,467; 3,095,301 and 2,81 1,465. Composite film elements of this type can be readily processed by imparting an electrical charge to the electrostatic layer prior to actinic exposure. When subjected to an image-wise light pattern, the electrostatic layer undergoes an image-wise attrition, i.e., charge decay in accordance with the point to point intensity of the incident exposure radiation. Visible image formation is thereafter obtained by treating the thus exposed element with a suitable toner powder or other coloring agent. The processing materials incident to the use of electrostatic layer compositions of the aforedescribed type are well known in the art being extensively described in the published literature both patent and otherwise. i

The developing-out and print-out emulsions may likewise be coated on the same side of the base support, said layers being separated by and in contact with a stripping layer in order to expedite physical removal, i.e., stripping of the print-out emulsion layer 4 from the composite film element. Such a structural arrangement is illustrated in FIG. 2. It will be understood, of course, that such an embodiment obviates the necessity of employing a base material which is transparent to the exposure radiation, i.e., such material may contain a pigment, dye or other colorant.

As previously mentioned, the composite film elements of the present invention may be employed to particular advantage in connection with the photocomposing drafting procedure, colloquially known as the so-called Mergenthaler Method, the latter method providing exceptional means for the reproduction of engineering drawings or other structural illustrations involving representation of various image characters, designs, indicia and the like. According to such processing, a film element of the type described herein would be suitably positioned in the exposure apparatus to receive the imaging radiation. In accordance with the information to be reproduced the operator successively activates as required one of the punch keys whereby a light pattern corresponding to the image character represented by such punch key is focussed upon print-out emulsion 4. Such image appears substantially immediately in the form of a visible deposit of photolytic silver. The exposure light energy simultaneously impinges upon the corresponding subjacent portions of developing-out emulsion 2 whereby to form a latent image therein. Since the operator can thus visually discern the photographic reproduction of the image character, he is readily able to precisely determine relative to such image, the exact situs of the next succeeding image character. This sequence of operations is, of course, repeated until such time as all of the required information is reproduced in print-out emulsion 4. A permanent image is then obtained in developing-out emulsion 2 by subjecting same to the required developing operation; i.e., solvent removal of nonexposed areas in the case of photopolymer or tanning emulsion systems, treatment with a suitable toner or other coloring agent in the case of an electrostatic layer, etc. The print-out emulsion layer 4 can be physically removed from the composite film element either prior to or subsequent to the developing operation as desired. However, it is to be understood that the physical removal of the print-out layer is optional. In either case, the remaining developed-out emulsion'layer provides the dominant and permanent image copy.

A still further embodiment of the present invention eliminates entirely any necessity for the use of a stripping layer positioned so as to physically separate the print-out and developing-out layers. These structural embodiments are illustrated in FIGS. 3, 4, and 5. As will be recognized, in many industrial applications, the print-out image layer may be dispensed with subsequent to formation of the permanent image in developing-out layer 2. This, of course, can be accomplished in the manner described i.e., by physically stripping the print-out layer from the composite film element. However, this correspondingly circumscribes possible variations in the relative physical arrangement of layers since the requirement is imposed that each of the printout and stripping layers be positioned outwardly of the developing-out layer. This, of course, allows the permanent, i.e., developing-out image to be retained intact upon the base support. Furthermore, in some instances it is found that following physical removal of the printout layer the element carrying the permanent image layer lacks to a substantial extent the requisite structural stability and exhibits a distinct tendency to curl or otherwise assume an arcuate configuration along its length, interfering with ease of processing. In contradistinction, the ammoniacal type silver halide emulsions contemplated for use herein possess the singular advantage that the photolytic silver images deposited therein may be readily removed after fixing and washing by a simple silver bleaching treatment. This can be readily and easily accomplished, for example, by treating the print-out silver halide emulsion in question subsequent to permanent image development, fixing and washing with a suitable silver bleaching solution, including a potassium ferricyanide, potassium bichromate or any of the conventional silver bleach solutions promulgated in the art for such purposes. This bleach treatment does not impair the quality of the permanent developed-out image which has a much higher image density. Thus, the gelatin layer which earlier contained the print-out image may be retained without any risk of image distortion. This circumstance proves to be particularly advantageous since the bleached print-out layer serves to promote structural stability of the composite film element by serving as an anti-curl layer and thus to offset substantially any curling tendency exhibited by the developing-out image layer. Thus, the unique advantage presented in view of the dual function served by the print-out layer that any requirement for resorting to ancillary procedure for purposes of augmenting the structural stability of the composite film element e.g., the application of an anti-curl layer to the film base, is eliminated.

The present invention can perhaps best be illustrated by reference to the accompanying drawing and particularly FIGS. 6A, 6B, 6C and 6D. FIG. 6A depicts a relatively simple arrangement of developing-out and print out emulsions disposed on opposite sides of a translucent film base. This particular film base corresponds to that illustrated in FIG. 3. FIG. 6A represents the appearance of the film element at the outset of the exposure, the latter being effected by means of light source 5 through a light slit 7 provided in a metal shield 6. As illustrated in FIG. 6B, the exposure radiation produces a relatively low-density image 7a of the slit 7 in printout emulsion layer 4 and a latent image 7b of slit 7 in developing-out emulsion layer 2. Print-out image 7a is readily visible by reflected light. FIG. 6C represents the exposed element following development and fixing whereby to provide a visible image 7b of slit 7 in layer 2. As will be noted, the light-sensitive element does not include a stripping layer. As described previously, this particular structural embodiment is preferred since it leads to the provision of a final photographic film element characterized by improved structural integrity. This is illustrated in FIG. 6D which depicts the element subsequent to treatment with a chemical reducer which functions to bleach print-out image 7a thus rendering same nonvisible. Following chemical reducer treatment, i.e., bleaching, there is obtained only developedout image 7b which represents a strong transmission image of light slit 7. As a result of the fixing treatment employed either as a post-development operation or as a combined fixing-development operation, the light sensitivity of the element is destroyed thus rendering developing-out layer 2 and print-out layer 4 incapable of further-recording. It will be understood of course that in practice, the developing-fixing operation will be utilized only upon completion of the desired exposure sequence. Until such time, the print-out images produced in layer 4 afford the processor with means to visually comprehend the extent of reproduction and thus the relative positioning of subsequent image characters to be reproduced. As described hereinbefore, the salient advantage of photographic elements devoid of stripping layers relates to the fact that upon bleaching of the print-out emulsion layer, such layer is retained in its entire physical extent as an integral part of the photographic element and functions as an anti-halation layer thereby promoting structural stability of the film element.

The following example is given for purposes of illustration only and is not to be considered as necessarily constituting a limitation on the present invention.

EXAMPLE A film corresponding to FIG. 3 is prepared by first coating a subbed polyester film base on one side with a developing-out emulsion prepared in the following manner. The following solutions are provided.

Part I H 104 liters Gelatin 20.0 grams Part 1A H O 250.0 ml

CdCL, 16.0 grams Sulfuric Acid 16.0 ml NaCl 160 grams Kl 10% 2.0 ml

Part 18 CuNO;,) 1% 10.0 ml

Part [C Rhodium trichloride 32.0 ml

Part "A H 0 310.0 ml

AgNO; 31.0 grams Part "B H O 310.0 ml

AgNO 31.0 grams Part VI Gelatin 40.5 grams PROCEDURE:

Solution 1A is added to solution I followed by solution 18 temperatures at 48C. After a short pause, solutions IC, 11A, and 11B are added and the resultant emulsion digested for 30 minutes at 48C. The resultant silver halide emulsion is precipitated with a 50 percent aqueous ammonium sulfate solution washed 3 times with a 1.8 liters of water and cooled to 25C. The gelatin (V1) is now added. The emulsion is warmed to 42C and the following ingredients added in succession:

10% Citric Acid 32.0 ml l0'7r Sodium Chloride 20.0 ml 1'72 Potassium Iodide 3.0 ml CdCl- 1071 10.0 ml

The emulsion is ripened for 6 minutes at 48C. At the end of the ripening period, 30 ml of a 10% CdCl are added.

, After the addition of suitable hardening and spreading agents, the emulsion is coated at sufficient thickness to yield a silver coating weight of about 3.5 grams per square meter.

The opposite side of the base is thereafter coated with a print-out emulsion formulated as follows:

Part 1 H O 1.35 liters KBr 84.0 grams NuCl 140.0 grams Gelatin 30.0 grams Part "A H 0 1.4 liters AgNO; 380.0 grams HNO (1071) 40.0 ml NH OH 420.0 ml

Part lll H O 600.0 ml

KBr 200.0 grams Solution A is added within 2 minutes to solution 1. After a pause of about 5 minutes, solution 111 is dumped into the mixture. After minutes holding, the emulsion is precipitated with 3 liters of a 50% ammonium sulfate solution and cooled to 25C and decanted to 4 liters, after which it is washed twice with 8.0 liters water and decanted to 4 liters.

250 grams of gelatin are added, the emulsion heated to 55C, cooled to 40C and digested for 15 minutes. Ripening took place for 30 minutes at 405C and cooled to 40C.

230 ml of 10% sulfamic acid and 50 ml of 10% potassium iodide are then added. After standing 10 minutes. 350 ml of a 10% KBr solution is added.

After the addition of suitable hardener and spreading agents, this print-out emulsion is coated so as to provide a silver coverage of about 3.2 grams per square meter. Since neither the print-out emulsion nor the develop-out emulsion is optically sensitized, all manufacturing operations as well as coating are carried out under bright red safelight conditions.

The aforedescribed coated element is arranged in a suitable holder. An opaque metal shield bearing a narrow slit is positioned against and in contact with the print-out emulsion layer. Exposure is effected by means of a Hanovia No. r-P-ll high intensity mercury arc lamp, the latter being positioned approximately 1 inch from the print-out emulsion surface. With an exposure duration of about 2 seconds a strong negative print-out image corresponding to light passing through the slit is readily visible on the print-out emulsion. This print image is measured by reflection with a GAF Micro Densitometer and found to have a maximum reflection density of 1.20 in the area where the line is exposed compared to a reflection density of about 0.50 for the print-out emulsion in unexposed areas. There thus resulted a line image with a net reflection density of about 0.70 which is readily visible even when viewed through a red safelight. Additional line or character images could then be exposed on the same sheet in any pattern required to yield a photo drawing. These line images exposures produced no visible effect on the develop-out emulsion.

Following exposure, the entire film is developed for 2 minutes at 68E in GAF Reprodol" Developer, fixed 5 minutes in GAF Surfix fixer, washed 10 minutes, and dried. This development produced a strong negative image in the develop-out layer. When measured by the microdensitometer, the line image shows a maximum transmission density in excess of 3.5 and with a fog density of approximately 0.05. The developing step also produces a weak negative transmission density of about 0.10 in the print-out image on the opposite side of the base. Fog density of the unexposed but developed and fixed print-out emulsion is very low (i.e., less than 0.05).

The developed and fixed film, thus, yields a very high contrast, high quality, permanent silver image in the develop-out emulsion.

Under conditions where the slight developed image on the print-out side is not desired, it is removed by treating in a typical reducing solution prepared as follows:

Part A Potassium Ferricyanide 1.0 g

Water 25.0 ml

Part B Sodium Thiosulfate 24.0 g

Water 900.0 ml

Mix Part A and B immediately before use. Treat complete film for 3 to 4 minutes, then wash and dry.

This treatment is found to remove all but traces of the image in the developed print-out layer, but does not visibly degrade the high density of the image on the develop-out side. The transmission density of this image remains in excess of 3.0.

If it is desired to totally remove the print-out image, this can be done by coating a soft gelatin stripping layer between the film base and the print-out layer as in FIG. 1. A gel stripping layer is prepared as follows:

Water 1.0 liter Gelatin 25.0 grams Urea 1.0 gram Saponin l()'/: 3.0 ml

The above solution is coated over the film base with sufficient coverage to provide a dry thickness of l to 2 microns. When dry, the print-out emulsion may be directly applied.

When the material bearing the stripping layer is processed, it is given conventional development as in GAF Reprodol for 2 minutes, then is fixed in GAF Surfix fixer compounded without its hardener additive. After 5 minutes immersion in the non-hardening fixer, the film is placed in warm running water for a few minutes. This will cause the stripping layer to swell and run off but does not harm the develop-out emulsion. After drying the film will be found to bear a developed-out image on the develop-out emulsion with no interfering image on the print-out side.

The present invention has been disclosed with respect to cartain preferred embodiments thereof, and there will become obvious to persons skilled in the art various modifications, equivalents or variations thereof which are intended to be included within the spirit and scope of this invention.

We claim:

1. A composite film element adapted for the recording of images photographically, comprising a base having thereon two light-sensitive layers, one of said layers comprising a light-sensitive print-out silver halide emulsion of the ammoniacal type capable of yielding, photolytically, a visible image immediately upon exposure to actinic radiation, and the other of said layers comprising a light-sensitive developing-out composition capable of forming a latent non-visible image upon exposure to actinic radiation, said image in the latter layer being capable of being rendered visible by a post exposure development operation of a chemical nature, and wherein said print-out layer and said developingout layer are disposed on opposite sides of the film base, and wherein a stripping layer is provided intermediate said print-out layer and said base.

2. A composite film element adapted for the recording of images photographically, comprising a base having thereon two light-sensitive layers, one of said layers comprising a light-sensitive print-out silver halide emulsion of the ammoniacal type capable of yielding, photolytically, a visible image immediately upon exposure to actinic radiation, and the other of said layers comprising a light-sensitive developing-out composition capable of forming a latent non-visible image upon exposure to actinic radiation, said image in the latter layer being capable of being rendered visible by a post exposure development operation of a chemical nature, and wherein said print-out layer and developing layer are disposed on the same side of the film base, said print-out layer being positioned outwardly of said developing-out layer, and wherein a stripping layer is provided intermediate said print-out layer and said developing-out layer.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3, h789 Dated t Qe 29, 197! I Inventor-(S) e r RATFQ' ET A It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below,

In the Title Page, Item (73) for "Assignee: GAF Corporation, Wayne, N.J.", read Assignee: GAF Corporation, New York, N.Y.

Column 5, Line &2, delete "ning";

Column 9, Line 13, for "CuN0 1%", read Cu(N0 1% Column l0, Line 38, for "68 E" read 68F Column ll Line 29, for "certain" read .certain Signed and sea led this 8th day of April 1975.

Attest:

C. I'MRSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks FORM PO-IOSO (10 69) USCOMM-DC UOS'lG-PGD ".5. GOVIIIIIIIIT IIIIII'IIIG OFFICE 1 "ll 0-80-334.

Claims

1. A COMPOSITE FILM ELEMENT ADAPTED FOR THE RECORDING OF IMAGES PHOTOGRAPHICALLY, COMPRISING A BASE HAVING THEREON TWO LIGHT-SENSITIVE LAYERS., ONE OF SAID LAYERS COMPRISING A LIGHT-SENSITIVE PRINT-OUT SILVER HALIDE EMULSION OF THE AMMONOIACAL TYPE CAPABLE OF YIELDING, PHOTOLYTICALLY, A VISIBLE IMAGE IMMEDIATELY UPON EXPOSURE TO ACTINIC RADIATION, AND THE OTHER OF SAID LAYERS COMPRISING A LIGHT-SENSITIVE DEVELOPINF-OUT COMPOSITION CAPABLE OF FORMING A LATEN NON-VISIBLE IMAGE UPON EXPOURE TO ACTINIC RADIATION, SAID IMAGE IN THE LATTER LAYER BEING CAPABLE OF BEING RENDERED VISIBLE BY A POST EXPOSURE DEVELOPMENT OPERATION OF A CHEMICAL NATURE, AND WHEREIN SAID PRINT-OUT LAYER AND SAID DEVELOPING-OUT LAYER ARE DISPOSED ON OPPOSITE SIDES OF THE FILM BASE, AND WHEREIN A STRIPPING LAYER IS PROVIDED INTERMEDIATED SAID PRINT-OUT LAYER AND SAID BASE.