US3485696A - Method and means for copying printed material - Google Patents

Description

Dec. 23, 1969 J. E. HAMMONDS 3,485,696

METHOD AND MEANS FOR COPYING PRINTED MATERIAL Filed May 25, 1966 2 Sheets-Sheet l 'IIIIIIIIIIIIIIIII 1 IIIIIJIIIIIIII VIII/IIIIIIIIIIIIIIII/IIII/q IO Fig. 3

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INVENTOR.

John E, Hommonds Attorney 23, 1969 J. a. HAMMONDS 3,485,696

METHOD AND MEANS FOR COPYING PRINTED MATERIAL 2 Sheets-Sheet 2 Filed May 25, 1966 I 8 30 Q 3 Ill/A'TI/III/III/III/IJ'. III. A

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I I I STRESS I-Y I s'TRAIN DEFORMATION Fig. II

ELONGATION I I /I I INVENTOR. John E. Hummunds Attorney United States Patent 3,485,696 METHOD AND MEANS FOR COPYING PRINTED MATERIAL John E. Hammonds, 37 Pine St., Bedford, Mass. 01730 Filed May 25, 1966, Ser. No. 552,914 Int. Cl. B41c 1/06 US. Cl. 156-249 Claims ABSTRACT OF THE DISCLOSURE Copies of original papers having printed indicia thereon are made by contacting the surface of the original with an impression sheet substrate coated with an elastomeric film layer. The film layer exhibits a differential and adhesive bond strength between the inked and uninked areas of the surface of the original. When the impression sheet is peeled away from the original, the elastomeric film layer is disrupted in the areas of the greater adhesive bond strength, thereby generating in the film layer a mirror image of the indicia.

This invention relates to a novel copying device and method, and more particularly to a device and method for copying indicia without the use of any mechanical equipment.

Over the recent past, considerable attention has been directed to the development and commercialization of machines and systems for duplicating and copying printed material. The systems now in use are based upon several different modes of operation. For example, one system is based upon the effecting of a phemical reaction, which gives rise to a colored end product. The reaction is initiated or effected by heat which is absorbed and transmitted by indicia on the original to be copied. Another system is based upon the electrostatic deposition of pigmented particles and the fixing of these pigmented particles through heat. Other systems depend upon the use of papers which have heat-sensitive or light-sensitive coatings, while yet others contain coatings having electrically-conducting particles such as zinc oxide.

All of the prior art systems require the use of relatively complicated and expensive equipment, and some of this equipment may be bulky. Thus, such copying processes as described are generally limited to being performed in localities where this equipment may be located and can not be made available in remote locations or Where the demand is relatively low. This indicates the need for having available a relatively simple and inexpensive system for copying printed material at points remote from the location of copying equipment. Such a copying system would be particularly helpful where copies are only occasionally needed or where expensive equipment can not be economically justified.

The copying method and device of this invention provides a system for making copies of printed material remote from any complicated or bulky equipment. It is, moreover, flexible enough so that a number of duplicates can be made from a single master copy if this is desired or a master copy in one of several forms can be made and used later with conventional copying equipment remote from the location of the actual printed matter being copied.

It is therefore a primary object of this invention to provide a device and method for copying printed material, the device and method being of such a character that no mechanical equipment is required. It is another object of this invention to provide such a device and method. which are relatively inexpensive and which at the same time are capable of reproducing finely-detailed material as well as half-tones. It is yet another object 3,485,695 Patented Dec. 23, 1969 of this invention to provide a system of the character described which is flexible in its ultimate application and which can be used to produce several duplicates from a single master copy by any one of several methods. Other objects of the invention will in part be obvious and will in part be apparent hereinafter.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the article possessing the features, properties, and the relation of elements, which are exemplified in the following detailed disclosure and the scope of the invention will be indicated in the claims.

The indicia which are to be copied by the practice of this invention are those which are in the form of ink deposited on a paper surface, i.e., so-called printed matter. Ink and paper surfaces have different physical and chemical characteristics. By virtue of these different physical and chemical characteristics the overall surface of the printed matter exhibits a variation in adhesion to certain elastomeric materials deposited in essentially transparent film form. This variation can be thought of as representing a pattern in adhesion-non-adhesion with respect to the elastomeric film and can serve as a means for generating an impression of the printed matter by using elastomeric films which exhibit a marked differential in adhesion to the inked surface compared to the non-inked surfaces. Normally, it will be desirable to use elastomeric film which exhibits a greater adhesive bond to the inked areas than to the non-inked areas. The elastomeric film, which is coated on a suitable, normally transparent, substrate, is brought into direct surface-tosurface contact with the printed material to be copied. The contact is then broken and the elastomeric film is stripped from the printed surface. In those areas where printed indicia contacted the elastomeric film, there is generated a pattern on the film surface, provided, of course, that the elastomer formed a stronger adhesive bond to the inked surface areas. This pattern is then in the form of what is hereinafter termed disrupted film areas. These in turn give rise to a mirror image copy of the indicia manifested in cloudy or opaque areas in the otherwise transparent elastomeric film which did not adhere to the unprinted portion of the paper surface and remained undisrupted. Since the elastomeric film may have a certain degree of cold flow, it may be necessary to fix it in the pattern of disrupted-undisrupted areas established in the step of contacting the elastomeric film with the printed material. This fixing, if required, is accomplished by depositing a thin film of a polymeric material on the surface. The amount of such fixing film is preferably no more than that which is sufficient to prevent the cold flow of the elastomeric film. For reasons not clearly understood, the fixing film leaves the disrupted areas forming the mirror image of the indicia in a sufiiciently tacky or rough condition so that these disrupted area patterns can be developed by causing finely divided pigmented material to adhere thereto. If the developed surface is to be used as a permanent copy, then a contrast-color (usually white) substrate is pressed into contact with the fixed elastomeric surface, thus making the uncoated side of the original transparent substrate film the viewing side of the copy. This is possible since the original elastomeric film, although fixed with a polymeric coating, still retains sufiicient mobility and adhesion to cause it permanently to adhere the colored substrate surface. This color of the contrast-color substrate will show through the undisrupted areas of the transparent elastomeric surface to provide a suitable background for the developed areas. Since this requires a reversing of the elastomeric surface for viewing, the final copy will be a true copy of the original material.

Alternatively, the fixed surface may be developed with an ink, such as India ink or a glycol-base ink, rather than a finely divided particulate material, which will adhere to the disrupted areas. Such an ink will adhere to the disrupted areas but may be 'readily wiped off the undisrnpted areas. The thus inked surface may be used to form a final copy as previously described, or it may be used as a master to form several duplicate copies. Other developers may be used as will be described in detail.

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 drawings in which:

FIG. 1 is a partial cross-sectional view of an elastomercoated substrate forming an impression sheet;

FIG. 2 illustrates, partially in cross-section, the contacting of the copy paper with the printed material to be copied;

FIG. 3 is a detailed cross-section through the original to be copied and the impression sheet just prior to their contact;

FIG. 4 is the detailed cross-section of FIG. 3 showing the breaking of the contact;

FIG. 5 is a fragmentary detailed cross-section of FIG. 4 illustrating deposition of the fixing film;

FIG. 6 is the cross-section of FIG. 5 showing the development of the fixed sheet with finely divided particulate material;

FIG. 7 is a partial cross-section of the completed copy showing the contrast-color substrate in position;

FIG. 8 illustrates one embodiment of a copy assembly utilizing the method and copy paper of this invention;

FIG. 9 is a detailed partial cross-section showing the use of an ink as a developer;

FIG. 10 illustrates the making of duplicate copies from a master; and

FIG. 11 is a typical stress-strain plot for an elastomer suitable for forming the elastomeric-film of the impression sheet.

FIGS. 1-7 illustrate, somewhat in simplified crosssectional drawings, the method and device of this invention. It will be appreciated that no attempt has been made to draw these figures to scale and that thicknesses and other features have been considerably exaggerated better to illustrate the invention.

In FIG. 1 there is shown in partial cross-section an assembly 27, hereinafter referred to as the impression sheet, comprising a substrate 10, having one surface coated with an essentially transparent elastomeric film 11. In the impression sheet of FIG. 1 there is provided an impression surface 12 which is the surface of the elastomeric film and a smooth surface 13 which is the uncoated surface of the substrate. In the description of FIGS. 1-7, as well as of FIG. 8, which follows it, it will be assumed that it is desired to make a single copy of a printed sheet and that such copy is to be in the nature of a piece of paper. It is further assumed for the sake of this example that a positive copy is desired. Under these circumstances, the substrate 10 will be a thin, flexible transparent sheet thus giving rise to the term impression sheet; and the elastomer will exhibit a stronger adhesive bond with the inked areas than with the uninked areas. However, it is to be understood that this impression sheet need not be flexible (as in the case of making lantern slides for example) or even transparent (as in the case of making a master for electrostatic printing). Moreover, the differential adhesive bond may be reversed to form a negative impression.

FIGS. 2-4 illustrate the contact of the impression sheet with printed material 14. FIG. 2 shows the general assembly of components, while FIGS. 3 and 4 are detailed cross-sections just prior to contact and during the breaking of the contact, respectively. The elastomer surface 12 of the impression sheet is brought into surface-to-surface .4 contact with the printed material such that it makes contact with both the unprinted portion 15 and the printed indicia 16. When the contact is broken and the impression sheet is separated from the original printed sheet (FIG. 4), it will be seen that there is generated in the elastomer film surface 12 a disrupted area 18 which is a mirror image of the indicia 16 of the printed material. Although FIG. 4 does not show the uninked surface 19 making actual contact with the elastomeric film surface 12, it does in fact make such contact. This contact is not ilustrated so that the contact with the inked areas may be more clearly shown and emphasized. FIG. 5 shows the application of a transparent fixing film coating 20 applied to form a thin, flexible, more-or-less continuous film over the elastomeric film 11. Whatever fixing film adheres to the disruptive area pattern 18 does not essentially affect its tackiness or roughness. Both films 10 and 11 are transparent, but the disrupted areas 18 are converted to a surface configuration which scatters light. The visual result is an opaque indicia, in a mirror image, on a transparent background.

With the application of a finely-divided particulate material as developer 22 to the surface of FIG. 5, there results the surface illustrated in cross-section in FIG. 6. The developer 22 adheres to the disrupted areas 18 giving use now to a colored mirror image on the otherwise transparent impression sheet. This is because the developer does not adhere to that portion of the surface of the fixing film 20 which corresponds in area to the original uninked surfaces of the original; but the developer does adhere to the disrupted areas corresponding to the inked surfaces of the original.

The final step in making the copy by the embodiment illustrated in FIGS. 1-7 is the application of the contrastcolor substrate to convert the transparent background to a desired contrasting color, e.g., white if a black or colored developer is used. In the cross-sectional drawing of FIG. 7 the impression sheet is shown in an inverted position. The elastomeric film coated side (originally surface 12 of FIG. 1) is pressed into permanent contact with the contrast-color substrate 24. Although the elastomeric film 11 was covered with a thin polymeric fixing film 20 (FIG. 5), it is still possible with a small amount of pressure to cause the contrast-color substrate 24 to permanently adhere to this side of the copy paper. By viewing the uncoated side 13 of the impression sheet, there now appears a properly oriented copy of the original indicia on the printed matter. As will be seen from FIG. 7, the visual image 26 is that which is seen through transparent substrate 10 and transparent elastomeric film 11. The contrast-color substrate serving as the background of the copy is viewed through the substrate 10, the elastomeric film 11 and fixing film 20, all of which are transparent in this embodiment.

In the use of this copying method the impression sheet and the contrast-color substrate may be handled as an assembly such as shown in FIG. 8. The impression sheet 27 (constructed as shown in partial cross-section in FIG. 1) is bound along one edge 23 to a contrast-color substrate 24. For handling and shipping, it is desirable to place a readily removable release sheet 28 between the impression sheet 27 and the contrast-color substrate 24 since these will be asembled with the elastomeric tacky film facing the contrast-color substrate. Many suitable release coatings are available for making the release sheet 28. In using the assembly'of FIG. 8 it will only be necessary to fold back the contrast-color substrate 24, such as on fold line 29, remove the release sheet 28 and follow through the steps as discussed in connection with FIGS. 2-6. The step of FIG. 7 then requires only the folding back of the contrast-color substrate 24 into its original position and applying sufiicient pressure to form the copy as shown in FIG. 7.

The developer may also be a suitable liquid ink such as an India or a glycol-base stamp pad ink, or a spirit duplicating ink, the latter two being suitable for making duplicate copies. In using inks, the method may be the same through the step of depositing the fixing film 20 as shown in cross-section in FIG. 5. However, it will normally not be necessary to use a fixing film, and therefore none is shown in FIG. 9. The ink is applied by wiping it across over the entire surface with suitable means such as a sequeegee. In this wiping action, the ink adheres to the disrupted areas 18 corresponding to the mirror image of the indicia being copied, but does not adhere to the fixing film 20 where it forms a layer over that portion of the elastomeric layer 11 which has not been disrupted. The result is shown in partial cross-section in FIG. 9 where the ink 30 is seen to adhere to the disrupted indicia area 18.

The developed copy sheet shown in FIG. 9 may then be treated in the same manner as the sheet developed with carbon black. That is, it may have a contrast-color substrate 24 placed in contact with the surface and adhered thereto with some pressure. The ink surface shown in FIG. 9 may also be used as a means for making several duplicate copies as illustrated in FIG. 10. Ink is first transferred to the surface as in FIG. 9 so that it adheres to the disrupted areas. The surface is then brought into contact with a glossy transfer paper 31 which picks up the ink from the intermediate copy sheet. The ink is rapidly absorbed in the surface of the transfer paper to produce the indicia 32 in the transfer paper as it appeared on the original which was to be copied. A master, such as that of FIG. 9, may be used to make several duplicate copies by the process illustrated in FIG. 10.

In like manner, other finely-divided particulate matter may be used for developmental purposes. As one example, magnetic particles such as Fe O may be used and the resulting copy employed as a master in an electromagnetic device. As another example, finely divided particles of gentian violet may be used to make a spirit duplicating master. The process using these developers is identical to that by which an ink is used. In such cases, however, it is normally not necessary to employ a transparent substrate, e.g., substrate of FIG. 1.

The method and means of this invention offer the possibility of making a wide variety of products including copies, slides transparent to light, and masters for duplieating. For this reason, there exists a wide choice of subtrates on which the elastomeric film coating can be deposited. For making regular copies the substrate is preferably a thin transparent film such as a polymeric film. As an example, 3-rnil polyvinyl chloride has been found to be particularly suitable. However, other transparent films of cellulose acetate, Mylar, cellulose triacetate, and the like may be used. In the formation of lantern slides, for example, rigid transparent materials such as one of the polyacrylates, sheets of polyvinyl chloride, polytetrafiuoroethylene, glass, and the like may be used. In some special applications, e.g., where the developing is done with a magnetic powder to form an offset master, or a dye to form a spirit master, the substrate need not be transparent.

It may be necessary in some cases to pretreat the surface of the substrate in order to efiect a good bond between the surface and the elastomeric material. Such treatments are well known in the art. For example, synthetic resin surfaces may be treated with flash-dried casein. As another example, cellulose triacetate film may be treated with caustic solution. The treatment will, of course, depend both upon the surface of the substrate and the elastomeric material which is to be applied.

The elastomeric material which is used to form the elastomeric layer of the impression sheet must exhibit a differential in adhesive bond strength between the inked and uninked areas of the surface of the original printed matter which is to be copied. This differential should be of a magnitude such that the greater of the adhesive bond strengths is sufficient to effect at least a temporary disruption in the surface of the elastomer film; while the lesser of the adhesive bond strengths is insufficient to effect such a disruption in the surface of the elastomer film. The greater of the adhesive bond strengths must, however, be limited in its bond strength so that it is less than that which will effect any appreciable alteration of the surface structure of the original being copied. That is, if the adhesive bond strength of the elastomer film is greater for the inked areas, it must be somewhat less than the adhesive bond strength existing at the interface between the ink and the paper surface. If the adhesive bond strength of the film is greater for the uninked areas, it must be less than the bond which exists between the fibers forming the surface of the paper of the original printed matter. This is necessary since it is, of course, not desirable to remove the ink from the printed matter in the first case or to roughen the surface of the paper of the printed matter in the second case. Finally, the adhesive bond in either case should be less than the cohesive strength of the elastomeric film so that essentially no film residue is left on the surface of the printed matter being copied.

The physical properties of the elastomer film may be further described with reference to FIGS. 3, 4 and 11, which cover the case where the elastomer film has a greater bond strength for the inked surfaces. As illustrated in FIGS. 3 and 4, it Will be seen that subsequent to the contact of the impression sheet with the original to be copied the contact must be broken by pulling the two sheets apart. As pointed out in connection with the description of FIG. 4, the elastomer surface actually makes contact with both the inked and uninked areas. (It may or may not, however, wet both surfaces-cg, the intimacy of contact may not be equivalent in both cases.) Since the elastomer film exhibits a differential adhesive bond strength, it will part readily from uninked area 19 of the original but will adhere temporarily to the inked surfaces 16. Since the film is visco-elastic in character and has an adhesive bond strength for the inked areas, there will be a short period of time during the separation of the two sheets when the adherence between the elastomer film and the inked surfaces is sufficiently strong to stretch the elastomer surface before contact is broken and the elastomer film partially returns to its original state.

Turning now to FIG. 11, which is a plot of a somewhat stylized stress-strain curve for an elastomer, it will be seen that in applying the stress necessary to separate the two sheets the elastomer film will follow the loading curve represented by the solid line. It is, of course, necessary to stay within the area in which the response of the film material to stress is predominantly elastic as indicated as being to the left of the vertical-dashed line in FIG. 11. With the separation of the inked surface and the elastomer film surface the elastomer returns along the unloading curve represented by the dotted line. However, in keeping with a typical release curve, it will be seen that the elastomer returns to a point on the strain or elongation axis which does not coincide with the original zero-stress point and thereby it exhibits a small, but marked, degree of hysteresis Which is visually observed by a marked increase in opacity in the elastomer film. It is this hysteresis which apparently gives rise to the required deformation or disruption in the elastomer film surface.

As noted above, it is of course necessary that the adhesive bond strength of the elastomer be somewhat less with respect to the inked surface area than the adhesive bond strength between the inked indicia 16 and the printed page surface 15 (see FIG. 3). If this is not the case, then in the process of separating the two sheets the elastomer film will take with it at least a portion of the ink from the original which is being copied. Normally, of course, this is undesirable.

If the greater adhesive bond strength exists between the elastomer film surface and the uninked surface of the original, then the process Will of course be reversed with the disruption being established in those areas in the elastomer film corresponding to the uninked surface areas of the original.

A large number of elastomer materials are available commercially which are suitable for the practice of this invention. Generally, these may be referred to as the synthetic rubbers. They include the styrene-butadiene rubbers (hot and cold polymerized, solvent polymerized and oil extended); the nitrile-butadiene rubbers and modified (e.g., carboxylated) nitrile-butadiene rubbers; the polyisobutylenes (molecular weights in the tens to hundred thousands); the modified polyisobutylenes such as those which contain a few mol percent of a diene such as isoprene or cyclopentadiene and the chloroprenes; the polyurethanes; the polyisoprene rubbers; the ethylenepropylene copolymer and terpolymer rubbers; and the polybutadienes. Among those elastomers which have been found to be particularly well suited for the practice of this invention are 1,4-polybutadiene (98% cis and 2% trans), polyisobutylene having molecular weight in excess of about 100,000, and chlorobutyl rubber.

The elastomeric film coating is conveniently deposited upon the substrate from a solution in a suitable organic solvent such as hexane, the volatile hydrocarbons, whether aliphatic or aromatic, (e.g., toluene and xylene), and the oxygenated solvents such as ketones and ether. These latter are required for some of the acrylonitrile-butadienes which are generally not soluble in hydrocarbons. A preferred solvent, where usable, is hexane.

The solvent is chosen with regard to the elastomeric material, as well as the substrate. Obviously, it can not be a liquid which is to any extent reactive with the substrate. The concentrations of the solutions used will depend upon the elastomer, the solvent and the coating method employed. Normally, such concentrations will range from a few (e.g., 2 or 3) percent to 20%, with a normal range being between 8 to 10%. Above about 20%, many solutions become too viscous to work with.

In applying the elastomer coating solutions or dispersions, any well known technique may be used. Such techniques include, among others, the use of wire wound rods, rolls, knife coaters, and the like.

The quantity of the elastomeric film coating on the substrate is not critical, although for practical reasons, it is desirable to keep it low to minimize cost and weight. Preferably, the amount of elastomeric film coating should range between 0.1 pound and 4 pounds per thousand square feet of substrate surface. The coating thickness should be such that the film is substantially transparent for making normal copies.

The elastomeric film material may contain one or more modifiers to regulate its physical properties. For example, tackifiers may be added to increase tack, or a material such as calcium stearate may be added to decrease tack. In like manner, plasticizers, antioxidants, dyes, pigments, and the like may also be incorporated into the elastomeric film.

The fixing material must be one which is capable of forming a thin, essentially continuous film over the undisrupted areas in the tacky layer of the impression sheet. It is preferably alcohol or water soluble and may be applied by spraying or dipping. The solvents used in applying the fixing films should not be a solvent for the elastomer. To form a thin fixing film over the undisrupted areas while permitting the disruptive areas to retain a degree of tackiness for the developer, it is preferable to use water or alcohol solutions of relatively low concentrations. Thus, concentrations in excess of about 10% by weight of the fixing film material are undesirable; and it is preferable to use concentrations of about 26%. The fixing film should preferably be relatively thin such that with some pressure the elastomeric film can be made to adhere through the fixing film to the contrast-color substrate if one is used. Where, however, the purpose of the fixing film is to permanently prevent cold flow and completely cover the elastomeric film as in the case of making a latern slide, then its thickness is not particularly important.

Among these materials which have been found to form satisfactory fixing films are polyvinylpyrollidone in methyl alcohol, polyvinyl alcohol in water, carboxymethyl cellulose and methyl cellulose in water solutions and shellac in an alcohol-ammoniated water solvent. Small quantities of a wetting agent may be added as well as plasticizers to prevent cracking of the fixing film. The choice of the developer will depend upon the color desired and the preferred method or developing, i.e., with a dry powder or liquid ink. Normally, for black on white copies a preferred dry developer is carbon black, although it may be a black-dyed finely ground resinous material. However, any finely divided pigment, including metallic (e.g., aluminum) powders may be used. The powders are applied by dusting or brushing on and then rubbing the surface with a soft cloth or brush to remove the particulate matter from the undisrupted areas.

The developer may also be an ink which adheres to the disrupted areas but which does not adhere, or adheres only slightly, to the surface of the elastomer film, or to the fixing film if one is used. Stamp pad inks which have a glycol base are suitable for such developers where a master for duplicating is desired; for permanent copies, India is suitable. The ink is applied by wiping it across the surface of the impression sheet, preferably with a squeegee-type applicator.

The contrast-color substrate may be any material which provides a suitably colored surface to contrast with the color of the developer. For making a regular copy, it is preferably a white or near white paper having a surface which will adhere to the elastomeric material through the fixing film layer. Where ink is used as a developer, the contrast-color substrate should be capable of rapidly absorbing the ink to produce a clear copy without lateral ink spreading.

If the inked impression sheet is to be used to make several duplicate copies, then the copy sheet should preferably have a glossy surface which readily absorbs the ink transferred to it.

If a release sheet such as sheet 28 of FIG. 8 is used, there are available a number of known release coatings which can be applied to that surface of sheet 28 which contacts the elastomeric film on the impression sheet 27. These release coatings must prevent any substantial migration of the elastomeric coating which would affect its impression-forming characteristics. Suitable release coatings on films include, but are not limited to, polytetra fluoroethylene, cellulose acetate, polypropylene and polyvinylidenechloride.

The device and means of this invention may be further decsribed with reference to the following examples which are meant to be illustrative and not limiting.

EXAMPLE 1 A 3-mil transparent film of polyuslfone was coated by means of a No. 40 wire-wound rod with an 8% by weight solution of 1,4-p0lybutadiene (98% cis and 2% trans) in hexane. The resulting coated film was dried to form an impression sheet. The elastomer-coated surface of the impression sheet was then brought into contact with a printed magazine page, pressed down to form contact with it and then pulled ofi. A mirror image of the printed characters, in the form of a somewhat opaque pattern on a transparent background, was formed in the polybutadiene surface. This surface was then wiped with stamp pad ink with a squeegee. The ink adhered to the opaque pattern but not to the transparent background areas. A piece of glossy white paper was then pressed into contact with the inked surface to form a final black-on-white copy when viewed through the original film of polysulfone.

9 EXAMPLE 2 The polybutadienecoated film of Example 1 was contacted with a printed magazine page and then the impression was fixed by spraying with a 3% water solution of polyvinyl alcohol. The fixed impression sheet was then mounted on a black contrast-color substrate to form a white image on black background, the image being generated by the disruptions in the elastomeric layer surface.

EXAMPLE 3 A 3-mil transparent polysulfone film was coated with a 10% by weight solution of polyisobutylene (molecular weight about 200,000) in heptane and used as the impression sheet. It was contacted with a printed magazine page, and then permanently afiixed to a black paper as a contrast-color substrate to form a white copy on a black background. This elastomeric material required no fixing.

EXAMPLE 4 The impression sheet of Example 1 was contacted with a printed magazine page as in Example 1 and after the image was formed in the elastomeric film layer, it was wiped with India ink which adhered only to the disrupted areas. A gloss white paper was then applied as the contrast-color substrate to complete the copy.

EXAMPLE 5 A master was made by the same method as the inktreated elastomeric film surface of Example 1 using a black stamp pad ink. Final copies were made from this master by bringing pieces of coated paper in contact with the inked surface and separating it therefrom. The ink was transferred to the paper surface to make a clear black copy.

EXAMPLE 6 Impression sheets were made as in Example 1 using 8% by weight solutions of chlorobutyl rubber and polyisobutylene (molecular weight about 200,000). After forming the disrupted patterns by contact with a printed page in the elastomeric film layers, they were developed by wiping with stamp pad ink and with India ink. The copies were completed by laminating with white contrastcolor sheets.

EXAMPLE 7 An impression sheet was prepared as in Example 1. After contacting with the printed sheet of a magazine page, the elastomeric film layer surface was dipped in a 1% by weight water solution of polyvinyl alcohol. The removal of the water by air drying left a thin fixing film of polyvinyl alcohol on the film surface which was then developed by dusting with carbon black using a camels hair brush. The copy was completed by afiixing a white backing substrate to the elastomeric film surface to give a black-on-white copy.

EXAMPLE 8 Samples of a transparent film previously coated with a thin film of low-tack acrylic resin as a pretreatment were coated with various different elastomeric film ma terials dissolved in hexane (concentrations ranging from 5 to 10% by weight). The elastomeric film materials were as follows:

solution-polymerized styrene-butadiene rubber (SBR) oil-extended hot polymerized SBR cold polymerized SBR oil-extended cold polymerized SBR carboxylated acrylonitrile-butadiene rubber polyisobutylene rubber containing 5 mole percent of a diene (isoprene and cyclopentadiene) polyisoprene rubber ethylene-propylene oopolymer rubber etheylene-propylene terpolymer rubber acrylonitrile-butadiene rubber (in toluene) silicone rubber (in toluene).

Impression sheets were made using these coating solutions as described in Example 1. Developing was accomplished with inks as in Examples 1 and 2. In addition, samples of the exposed film surfaces were dipped in a low concentration water/methyl alcohol (25/75) solution of polyvinyl alcohol, while others were sprayed with a 2% methanol solution of polyvinylpyrollidone as fixing films. Development was with carbon black as in Example 7.

EXAMPLE 9 A solution of the polyisobutylene rubber of Example 6 was coated on a glass lantern slide blank which had been pretreated with flashdried casein to provide good adherence thereto. After the hexane solvent had been removed by vaporization, the elastomeric film layer was contacted with a typed original and then separated therefrom. A methanol solution of polyvinylpyrrolidone was sprayed on the patterned surface. The resulting slide, when exposed to a light source to transmit light therethrough, produced a pattern of the original area on a screen. Where the disruptions had occurred, the light was scattered; and, hence, these disrupted areas were in effect opaque to the transmitted light.

EXAMPLE 10 An optical gage was made from an India inked original. An impression sheet made as in Example 1 was contacted with the inked drawing, and after being separated therefrom a 0.050 inch-thick rigid vinyl transparent (or translucent if desired) sheet was afiixed to the exposed side to form a rigid assembly which could be placed in an optical comparator for projection in the usual manner of employing an optical gage.

EXAMPLE 11 Impression sheets were made and exposed as in Example 7. They were developed using a finely divided aluminum powder, and powdered gentian violet. The sample developed with the aluminum powder had a black contrast-color substrate afiixed thereto, while the sample developed with gentian violet did not require an additional substrate.

EXAMPLE 12 A copy paper assembly was formed as shown in FIG. 8 by binding together at one edge an impression sheet made as in Example 1 and a glossy white sheet of paper. Interposed between was a thin sheet of cellulose acetate as a release sheet. A sheet of paper having a thin polytetrafluoroethylene film coating facing the elastomeric film layer of the impression sheet was also used as a release sheet.

The method and device of this invention provide a novel technique for making copies of printed matter without the use of complicated equipment. It is, of course, possible to perform the exposing step (and fixing step, if needed) at a point where the printed matter is located and complete the developing and application of the contrast-color substrate or making of duplicates at a location remote therefrom. The method is also usable in copying halftones and large printed areas, for it presents no particular problems in handling these types of materials.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efiiciently attained; and, since certain changes may be made in carrying out the above method and in the articles set forth without departing from the scope of the invention, it is intended that all matter contained in the above description (or shown in the accompanying drawings) shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A method of making a copy of an original having printed indicia thereon comprising the steps of (a) contacting the surface of said original with an impression sheet which comprises an elastomeric film layer aflixed to one surface of a substrate, said elastomeric film layer being one which exhibits a differential in adhesive bond strength between the inked and uninked areas of the surface of said original, the differential being of a magnitude such that the greater of the adhesive bond strengths is sufficient to effect at least a temporary disruption in the surface of said elastomeric film but insufficient to effect any appreciable alteration of the surface structure of said original, while the lesser of the adhesive bond strengths is insufficient to effect a disruption in the surface of said elastomeric film; and

(b) separating the impression sheet from the surface contact with said original whereby there is generated in said elastomeric film layer a mirror image of said indicia manifested in a pattern of disrupted and undisrupted areas in said elastomeric film layer.

2. A method in accordance with claim 1 wherein said substrate and said elastomeric film layer are transparent whereby when said impression sheet is viewed from the uncoated side there is contained therein a copy of said original.

3. A method in accordance with claim 1 wherein said elastomeric film layer exhibits a greater adhesive bond strength for said printed indicia than for the unprinted surface of said original.

4. A method in accordance with claim 1 wherein said elastomeric film layer is a styrene-butadiene rubber.

5. A method in accordance with claim 1 wherein said elastomeric film layer is a nitrile-butadiene rubber.

6. A method in accordance with claim 1 wherein said elastomeric film layer is a polyisobutylene having an average molecular weight in excess of 80,000.

7. A method in accordance with claim 1 wherein said elastomeric film layer is 1,4-polybutadiene (98% cis, 2% trans).

8. A method in accordance with claim 1 wherein said elastomeric film layer is a chlorobutyl rubber.

9. A method in accordance with claim 1 including the step of applying to said elastomeric film layer a developer thereby to cause said developer to adhere only to said disrupted areas.

10. A method in accordance with claim 9 wherein said developer is a finely-divided particulate material.

11. A method in accordance with claim 10 wherein said finely-divided particulate material is carbon black.

12. A method in accordance with claim 10 wherein said finely-divided particulate material is a dye suitable for use in spirit duplicating.

13. A method in accordance with claim 9 wherein said developer is a liquid ink.

14. A method in accordance with claim 13 wherein said ink is India ink.

15. A method in accordance with claim 13 wherein said ink is a glycol-base ink.

16. A method in accordance with claim 15 further characterized by transferring said glycol-base ink to at least one copy sheet.

17. A method in accordance with claim 1 including the step of affixing a second substrate to said elastomeric film layer subsequent to said separating step.

18. A method in accordance with claim 1 including the step of applying to said elastomeric film layer subsequent to said separating a thin film of a fixing material from a dilute solution, the solvent of which is a nonsolvent for said elastomeric film layer.

19. A method in accordance with claim 18 wherein said elastomeric film layer exhibits a greater bond strength for the indicia in said original than for the uninked surface of said original.

20. A method in accordance with claim- 18 wherein said fixing material is polyvinylpyrollidone.

21. A method in accordance with claim 18 wherein said fixing material is polyvinyl alcohol.

22. A method in accordance with claim 18 wherein said fixing material is a methyl cellulose.

23. A method in accordance with claim 18 including the step of applying a developer to the fixed elastomer film layer.

24. A method of making a copy of an original having printed indicia thereon, comprising the steps of (a) contacting the surface of said original with an impression sheet which comprises a transparent elastomeric film layer affixed to one surface of a transparent substrate, said elastomeric film layer being one which exhibits a differential in adhesive bond strength between the inked and uninked areas of the surface of said original, the differential being of a magnitude such that the greater of the adhesive bond strengths is sufficient to effect at least a temporary disruption in the surface of said elastomeric film but insufficient to effect any appreciable alteration of the surface structure of said original, while the lesser of the adhesive bond strengths is insufficient of effect a disruption in the surface of said elastomer film;

(b) separating the impression sheet from the surface contact with said original whereby there is generated in said elastomeric film layer a mirror image of said indicia manifested in a pattern of disrupted and undisrupted areas in said elastomeric film layer;

(c) applying to said elastomeric film layer a thin film of a fixing material from a dilute solution, the solven of which is a nonsolvent for said elastomeric film layer;

((1) applying to said elastomeric film layer a developer thereby to cause said developer to adhere only to said disrupted areas; and

(e) afiixing to said elastomeric film layer a contrastcolor substrate of a color different from that of said developer whereby when said resulting assembly is viewed from the uncoated side of said transparent substrate there is within said assembly a copy of said original.

25. A method in accordnace with claim 24 wherein said elastomeric film layer exhibits a greater adhesive bond strength for said indicia than for the unprinted surface of said original.

26. A method in accordance with claim 24 wherein said elastomeric film layer is a styrene-butadiene rubber.

27. A method in accordance with claim 24 wherein said elastomeric film layer is a nitrile-butadiene rubber.

28. A method in accordance with claim 24 wherein said elastomeric film layer is a polyisobutyl butadiene having an average molecular weight in excess of 80,000.

29. A method in accordance with claim 24 wherein said elastomeric film layer is a 1,4-polybutadiene (98% cis, 2% trans).

30. A process in accordance with claim 24 wherein said developer is carbon black.

31. A process in accordance with claim 30 wherein said contrast-color substrate is white and the resulting copy is black-on-white.

32. A copy paper assembly comprising in combination (a) an impression sheet which comprises a transparent elastomeric film layer affixed to one surface of a transparent substrate, said elastomeric film layer being one which exhibits a differential in adhesive bond strength between the inked and uninked areas of the surface of said original, the differential being of a magnitude such that the greater of the adhesive bond strengths is sufficient to effect at least a temporary disruption in the surface of said elastomeric film but insufficient to effect any appreciable altertion of the surface structure of said original, while the lesser of the adhesive bond strengths is insufficient to effect a disruption in the surface of said elastomeric film;

13 (b) a contrast-color substrate aflixed along one edge of said impression sheet and facing said elastomeric film layer; and

(c) a removable release sheet interposed between said impression sheet and said contrast-color substrate.

33. A copy paper assembly in accordance with claim 32 wherein said elastomeric film layer exhibits a greater adhesive bond strength for said indicia than for the surface of said original.

34. A copy paper assembly in accordance with claim 32 wherein said elastomeric film layer is styrene-butadiene rubber.

35. A copy paper assembly in accordance with claim 32 wherein said elastomeric film layer is a nitrile-butadiene rubber.

36. A copy paper assembly in accordance with claim 32 wherein said elastomeric film layer is a polyisobutyl butadiene having an average molecular weight in excess of 80,000.

37. A copy paper assembly in accordance with claim 32 wherein said elastomeric film layer is 1,4-polybutadiene (98% cis, 2% trans).

38. A copy paper assembly in accordance with claim 32 wherein said elastomeric film layer is a chlorobutyl rubber.

39 A copy paper assembly in accordance with claim 32 wherein said release sheet is coated with polytetrafiuoroethylene.

40. A copy paper assembly in accordance with claim 32 wherein said release sheet is cellulose acetate.

References Cited UNITED STATES PATENTS 3,294,612 12/1966 Pail et al 156236 X 3,311,521 3/1967 Hofrichter 156-234 3,376,182 4/1968 Borell et al 156-236 HAROLD ANSHER, Primary Examiner T. R. SAVOIE, Assistant Examiner US. Cl. X.R.

10l-40l.l; l56234, 235; 161-189, 247, 255

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