US3113511A - Composite stencil-offset printing blank - Google Patents

Description

Dec. 10, 1963 H. R. DALTON 3,113,511

COMPOSITE STENCIL OFFSET PRINTING BLANK Filed Sept. 27, 1951 2 Sheets-Sheet 1 IN V TOR.

T BY Dec. 10, 1963 H. R. DALTON 3,113,511

COMPOSITE STENCIL OFFSET PRINTING BLANK Filed Sept. 27, 1951 2 Sheets-Sheet 2 Z1 87 g? 22 in 20 AMP] l M 1 1 12 11 ABC RESISTANCE MERSURING INQT? INK ROLLERS WHTER ROLLER PRINTING FORM RUBBER TRANSFER ROLL INVENTOR. HAROLD R DALTON @oy PAPER y%l% IMPRESSlON ROLL ATTO R N EV United States Patent 3,113,511 COMPGdlTE STENtIlL-OFFSET PRINTING BLANK Harold R. Dalton, Rydal Road, lenkingtown, Pa. Filed Feb. 27, B61, Ser. No. 243,5@% 9 Claims. (Cl. 101-1492) This invention relates to duplicating blanks and more especially to electrosensitive blanks which can be used to produce a printing control plate or form, such for example as is used in offset or planographic printing and the like.

The invention is in the nature of an improvement on the blank and process disclosed in my prior application Serial No. 755,263, filed lune 17, 1947, now issued as US. Patent No. 2,664,043.

I have disclosed in said prior application a composite printed record and stencil-forming blank, comprising a smooth-surfaced backing member such for example as smooth-surfaced paper, cardboard or other member, which is attached with a low degree of adhesive ailinity to an electrically conductive plastic film so as to be readily mechanically or manually peeled or stripped therefrom. The said plastic film is a carbon-bearing film which is normally non-porous, substantially non-hygroscopic, and has a smooth continuous surface, as distinguished from the surface of a porous paper, fabric, or the like. When the blank is subjected to the action of stylus-applied electric voltages representing for example subject matter to be reproduced, the said film is finely perforated through its entire thickness at the desired points but without perforating the backing to which it is peelably attached. During the electro-perforation of the plastic layer, there is simultaneously deposited on the surface of the backing in registry with each perforation a certain amount of carbon which thereby produces a carbon record of the signals which have simultaneously perforated the plastic film. Thus, if the signals are those representing printed, graphic or pictorial subject matter, there is simultaneously produced by a single electric recording operation a plastic film record stencil which may be used for duplicating purposes by any well-known stencil-controlled process; and also there is produced on the backing a carbon copy of the stencilled record.

The surface of the paper, cardboard or similar backing member may be rendered smooth and hydrophilic and substantially water insoluble by providing it with a pigmented or non-pigmented coating containing a suitable binder, which binder is not affected by the subsequent application of the plastic film in liquid or semi-liquid form. Thus the paper surfacing may be a pigmented or non-pigmented coating containing starch, casein, polyvinyl alcohol or other similar binder which when dried on to the backing, produces a smooth and substantially water insoluble surface which surface however possesses hydrophilic properties. By reason of the non-porous smoothed surface of the backing, the stencil-forming plastic film can be readily peeled from the backing by a simple manual peeling operation, without distorting, tearing or destroying the said film. I have found that by incorporating a water repellent ingredient for example waxes such as chlorinated paraffin, octadecanoic amide, etc. in small percentage, for example between 3% and of film weight, into the plastic stencil-forming film, that the duplicate transferred carbon record on the surface of the backing is rendered selectively responsive to pick up printers ink such as is used in ofset printing processes for example from a conventional inking roller, the said transferred record being water-repellent or hydrophobic. The backing member from which the stencil film has been stripped can then be used in any well-known offset printing machine or similar process to receive the usual print- "ice ing ink and it thereby serves as a master plate or form for making duplicate copies. Thus, by the single electric recording operation there is simultaneously produced a plastic stencil which can be used in any well-known stencilling apparatus, and the backing from which the stencil is peeled, can be used as a duplicating master printing form or plate.

The bacldng member with the simultaneously recorded carbon record thereon is then used in any well-known offset printing apparatus whereby the carbon record on the backing takes up the ink from the inking element of the printing machine, thus enabling the inked backing to be used as an offset or planographic printing form or plate. This avoids the necessity of forcing ink through the stencil openings while unpeeled from the backing, to form the printing plate or form as proposed in another modification of the invention covered by the claims of my co-pending application Serial No. 292,700, filed June 10, 1952, now abandoned.

Other features and advantages not particularly enumerated, will be apparent from a consideration of the following detailed descriptions and the appended claims.

In the drawing,

FIG. 1 is a plan view of the novel blank containing a manually peelable plastic layer prior to performation thereof by received facsimile signals.

FIG. 1a is a cross-sectional view of a modification of FIG. 1.

FIG. 2 is a view of the blank of FIG. 1 after perforation of the plastic layer.

FIG. 3 is a sectional View of FIG. 2, taken along the line 33 thereof.

FIG. 4 is a view of the perforated plastic layer blank showing it in the act of being peeled from its backing.

FIG. 5 is a blank similar to that of FIGS. 1 to 4, and having a reinforcing and stripping band at one end.

FIG. 6 is a cross-sectional view of FIG. 5, taken along the line 66 thereof.

FIG. 7 is a view showing the blank of FIGS. 5 and 6, with the plastic layer partially peeled from its backing.

PEG. 8 is a diagrammatic view of a facsimile transmit-ting and reproducing system for producing the facsimile stencil and printing form or plate according to the invention.

PEG. 9 is a diagrammatic View showing the blank of FIGS. 1 to 7 attached to the drum of a conventional mirneograph machine.

FIG. 10 shows schematically a modified manner of using the recorded blank of FIG. 3 to produce an inked duplicate record on the backing member prior to peeling the plastic layer. 1

FIG. 11 shows the plastic layer of FIG. 10, partially stripped from the backing to exhibit the said inked record thereon.

FIG. 12 is a schematic diagram of one typical method of measuring the surface resistance of the blank according to the invention.

FIG. 13 is a diagrammatic view showing how the duplicate record on the backing is used in any well-known offset printing process.

FIG. 14 is a modification of FIG. 5.

FIG. 15 shows in magnified form or enlarged scale, a portion of the finished offset printing plate produced according to the invention.

Referring to FIG. 1, the composite stencil and printing form according to the invention, comprises one or more integrally bonded layers of a film-forming resin, plastic, or elastomer 3%, into the body of which is incorporated a predetermined amount of a powdered elec trically-conducting material, such as electrically-conductive carbon black, for the purpose of controlling the electric conductivity of the layer it This layer it) is distinguished from ordinary carbon paper, since such ordinary carbon paper is electrically non-conductive for all practical electro-recording purposes, whereas the layer according to the present invention has substantial electric conductivity which is used for the purpose of enabling the layer 10 alone to be perforated through its thickness in response to stylus-applied electric signals. The layer 10 is of a film-forming resin or plastic, such for example as the following: Vinyl ester polymers, or reaction products of polyvinyl alcohol and aldehydes, cellulose esters, ethers or the like; i.e., any one of the well-known filmforming resins or elastomers such as vinyl chloride polymers, vinylidine chloride polymers, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral polymers, styrene polymers, cellulose nitrate, cellulose acetate, ethyl cellulose, etc. In any event, the plastic film or layer is substantially non-porous with a relatively smooth continuous surface as distinguished from fibrous material such as paper, fabric or the like. The layer 14 is applied or deposited on a backing 11 of relatively stiff paper, cardboard, or the like, and is applied for example by casting, roll coating, spraying, dipping, or brushing, so that it is directly but peelably attached with a low adhesive afiinity to the said backing 12. Preferably the backing "ill consists of any smooth-surfaced paper or cardboard such as that known as high-finish paper, machine glazed paper, or certain coated paper. The coating of paper 11 should consist of a pigmented or non-pigmented coating and a binder chosen so as not to be affected by the subsequent application of the stencil coating lil. As examples of such binders may be mentioned, starch, casein, polyvinyl alcohol and the like. This coating material applied to the surface of the paper backing should also contain a substance which will make the coating water-insoluble after it is dried, but still allow it to retain its desired hydrophilic properties. For instance in the case of starch binder, urea formaldehyde resin may be used. In the case of casein binder, formaldehyde can be used. Any other well-known method of rendering the pigmented or non-pigmented coating water insoluble can be used so long as the said coating after it has become. dried will still retain its hydrophilic properties. The backing member can be a flexible metal plate, having its surface prepared to make it hydrophilic, for example by mechanical abrasion or other methods well-known in the art and as described for example in Gfifset Duplicator Techniques, by Richard Caruzzi, published by Harold L. Taylor Incorporated. If desired, the backing 11 may take the form of a cloth having a suitable smooth-surfaced finish comparable to the papers described above. In other words, the backing or carrier 11 may be of any sheet material which will easily release the plastic coating or layer 10 after the latter has been perforated by the received facsimile signals. The plastic coating 19 is, in accordance with the invention, attached to the backing 11 so that it can be peeled or stripped therefrom by simple stripping action, and without any destruction or deformation of the stripped film.

In accordance with the present invention, the plastic layer 10 is rendered electrically conductive so that when electric facsimile signals are stylus-applied thereto, the plastic layer is perforated through its entire thickness at each point underneath the stylus, but without any perforation of the backing member 11. This results in the decomposition of the plastic with the concomitant deposition of the said decomposition products mainly as carbon on the backing. Such carbon is inherently substantially hydrophobic. The electrical conductivity of the plastic layer It can be regulated by incorporating therein a suitable quantity of colloidal electrically-conductive carbon. In order to intensify the said deposited decomposition products there may be incorporated in the plastic layer a small percentage, for example up to 10%, of a record intensifying material. Typical of such materials are certain waxes, for example chlorinated parafiin, octadecanoic amide, etc., or any other well known high molecular weight oleophilic material. The addition of these record intensify materials does not afiect the electrical conductivity of the plastic layer to an undesirable extent. The purpose of adding these record intensifying materials is to cause the carbon record that is simultaneously deposited on the surface of the backing member to be intensified as compared with its deposition in the absence of such materials, while being ink receptive and water repellent.

The invention is not limited to the formation of the plastic layer 19 as a single homogeneous layer. For example, it may be formed of one or more layers or films of polyv nyl film-forming resin with each layer containing different electrical conductivity characteristics. Thus as shown in FIG. 1a, if the backing 111 is of smooth-surfaced non-conductive paper, cloth, or cardboard, the plastic layer m can be made of two superposed coatings Illa, lilb, of the above-mentioned film-forrning materials in which the coating lilo adjacent to the backing 11 is designed to have the same or higher electric conductivity, in order to carry the recording current with as little loss in energy as possible to the grounding strip or metal drum of the facsimile receiving machine. Where two such superposed coatings are employed in the plastic layer, special methods are used for keeping the two coatings from intermingling. For example, a resin may be selected for the first coating lilo so that the solvent used for the resin of the second coating 19b does not have any effect upon the first coating. Instead of using different solvents for that purpose, the two coatings ltla, ltlb, may be cast as separate superposed films, the first film being cast and dried before superposing thereon the second film. It will be understood, of course, that the invention is not limited to a plastic layer lit of di ferent or graduated electrical resistance transversely of its thickness, and a singlelayer homogeneous film of uniform or homogeneous transverse resistance may be employed. If desired, the backing 11 may be rendered electrically conducting itself, or it may be in the form of a metal foil such as aluminum foil or electrically-conducting paper, in which event a correspondingly lower electrical conductivity may be employed in the plastic layer 10.

Preferably the exposed surface of the plastic film It (FIG. 1), or the layer 2% (FIG. la), is provided with a whitish masking coating 12 of extreme thinness, just sufiiciently thick to mask the dark color of the plastic coating id. For typical examples of such masking coatlugs and their preparation, reference may be had to said US. Patent No. 2,398,779, issued April 23, 1946. In any event, the plastic film or coating 16 is so designed that when it is acted upon by the electrical signals stylusapplied thereto, it results only in perforation of the plastic film and its masking coating 12, and without any perforation of the backing 11. This relation is shown in FIGS. 2 and 3 of the drawing.

After the recording has been effected by perforating the plastic layer and its masking layer 12, said layer together with its contrasting masking coating is then peeled from the backing 11, as indicated in FIGS. 4 and 7. Because of the low adhesive affinity between the plastic film and the backing 11, this stripping or peeling action can be effected without any special tools, and without any damage to the perforated plastic film. This perforated plastic film containing the recorded subject matter can then be mounted on the drum of any well-known stencilcontrolled machine to produce any desired number of copies. Since the perforated plastic record blank is of non-porous material, it does not lose its surface characteristics even after a great number of copies have been made. Furthermore, since it is of plastic, it can be smoothly and family attached to the drum of the duplicatmg machine and without crinkling or bulging, as is likely with conventional paper or similar stencil sheets.

In order to facilitate the peeling of the perforated record plastic layer 16 from the backing 11, that layer may have attached integrally to the exposed surface thereof, at one end, a reinforcing strip 13 of heavy paper, cardboard, or other material, or if desired, the plastic layer itself may be doubled or thickened at this portion so as to provide a reinforcement and gripping edge to facilitate peeling, as illustrated in FIG. 7 of the drawing. It has been found that when the stripped plastic stencil has been mounted on the usual stencil-controlled printing drum or the like, after continued rotation the stencil sheet tends to skew itself on the drum, or to become distorted at one or both longitudinal edges. I have found that these objections can be overcome by applying to either or both longitudinal edges of the stencil blank, prior to re cording thereon, strips 13a, 13b, as shown in FIG. 14. If desired, when the strips 13a, 13b, are used, the end strip 13 may be omitted.

Referring to FIG. 8, there is shown in schematic form a typical method of perforating the blank of FIG. 1 in accordance with electric signals. Thus there is shown in the left-hand portion of FIG. 8 a conventional facsimile transmitter comprising a scanning drum 14- which is adapted to be rotated at a suitable speed by a motor 15, and also simultaneously fed longitudinally of its axis, for example by a lead screw 16 and split nut 17. The fac simile subject matter in the form of a sheet or film 18 is wrapped around drum 14. Associated with the drum is a scanning head of any well-known construction comprising a scanning light source 19 and a photoelectric cell 20 for translating the shades of the successive elemental areas of subject 18 into corresponding electric signals. For a detailed disclosure of one form of scanning drum and associated mechanism, reference may be had to US. Patent No. 2,138,784, granted November 29, 1939. These signals are then applied to modulate an audio frequency carrier from the carrier source 21 through the amplifier modulator unit 22. At the receiving station shown in the right-hand portion of FIG. 8, there is provided a metal and electrically-grounded scanning drum 2.: which may be similar to drum 14. Drum 23 is arranged to be driven in rotational and longitudinal synchronisrn with drum 14 by means of a motor 24 and a lead screw 25. The recording blank such as the blank of FIGS. 17 is wrapped around drum 23, and cooperating with this blank is a recording conductive stylus 26 which is supplied with electrical energy from the receiving amplifier 27, preferably, although not necessarily, through a transformer 28 whose secondary winding energizes stylus 26. By reason of the character of the recording blank on the drum 23, these electric signals cause the 10 to be perforated in localized areas corresponding to the original subject matter on the transmitting blank 13 but without perforation of the paper backing 11. When the recording has been completed, the blank is removed from drum 23, and the stenciled film or strip 10 is stripped from its backing 11. This stenciled strip can then be used to duplicate the recording by any well-known duplicating process. Because of the porous nature of the stencil only at the areas where the recording takes place, duplication by ordinary stencil-controlled printing processes can be employed. Since the blank is only perforated at the regions where the recording takes place, its over-all strength is not greatly reduced, and therefore it may be handled with ease.

FIG. 9 shows, in diagrammatic form, a portion of a typical stencil-controlled printing machine comprising the usual drum 29 having the usual blank-clamping member 30 and supporting screen under the stencil. The perforated record blank above described is partially peeled at one end, as shown in FIGS. 4 and 7, and the peeled plastic film at its reinforced end is clamped to the drum 29. The backing member 11 can then be completely peeled away from the plastic film, as indicated in FIG. 9. The reinforcing strip 13 above described, prevents distortion of the plastic film during this peeling process, and also prevents the clamping means 30 from harming the said plastic film during the clamping thereof to the mimeograph drum. While as mentioned hereinabove with the blank of FIGS. 1 to 7, when the plastic layer is perforated by the signals, it results in the production of a corresponding positive copy on the surface of the backing 11. This copy consists of the carbon particles which have been transferred to the surface of backing 11 during the recording process. If desired, this record on the backing 11 can be made into an inked record, as indicated schematically in FIG. 10, by applying a layer of ink 31 to the recorded blank, and by means of a squeegee or similar device 32 the ink 31 can be forced through the recorded perforations in the plastic layer to form a corresponding positive inked record on the backing 11, so that when the plastic layer is stripped therefrom, as shown in FIG. 11, a corresponding permanent inked record appears on the backing 11. This backing 11 may then be used as an offset printing plate for use in any well-known offset printing machine, or hectograph machine.

I have found that by treating the surface of the backing member 11 so as to render it hydrophilic while rendering it Water insoluble and by incorporating the said waxes in the plastic film, the carbon record which is deposited on the backing member during the electrorecording operation is of sufficient intensity so that the backing member with the carbon record can be used directly as an offset printing form without the necessity of squeegeeing ink through the perforations of the stenciled film. In other words, the stenciled film can be stripped from the backing and used as a stencil and the backing with the carbon record can also be used as a separate offset printing form, as indicated in FIG. 13.

While the invention is not limited to any particular thickness for the plastic film and its masking coating, since the blank must respond to conventional facsimile signals, and since these signals are for practical purposes of limited voltage range, it is important that the masking coating 12 be of the minimum thickness consonant with its masking qualities for the darkened plastic film 10. I have found the best results to be obtained when the combined thickness of the plastic film 1% with its masking coating 12, or the combined thickness of the films 10a, 10b, with the masking coating 12, does not exceed approximately 0.006 inch, and preferably should be between 0.001 inch and 0.003 inch. Preferably also,

the blank should have a surface resistance of approximately 1,000 to 8,000 ohms before the top coating is applied. With this relation of resistance and thickness, conventional facsimile signals can be stylus-applied to the blank, to perforate it Without burning or perforating the cardboard backing 11. Furthermore, as the plastic layer 19 is thus perforated, it results in the deposition of carbon on the surface of the backing 11 beneath each perforation, thus producing a direct duplicate and permanent record in the form of deposited carbon on the surface of the said backing 11. In other words, by this process there are produced at the same time, a perforated plastic sheet record of the facsimile subject matter, and also a carbon-deposited record on the surface of the backing 11. One convenient way of measuring this resistance is shown in FIG. 12. A strip of the record blank, for example nine centimeters long by three centimeters Wide, has clamped thereto a pair of flat electrodes, each one centimeter in length and spaced apart by one centimeter, and located at the central region of the strip. These electrodes are connected to a suitable resistance-measuring instrument, such for example as a Wheatstone bridge or ohmmeter.

While certain particular embodiments have been disclosed herein, it will be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention.

This application is a continuation-in-part of application Serial No. 755,263, filed June 17, 1947, and of application Serial No. 188,702, filed October 6, 1950, now abandoned.

The term plastic is employed in the claims in a generic sense to include film-forming resins and elastorners.

For a typical formulation for the conductive plastic coating reference may be had to Patent 2,664,043; and for a typical formulation for the lithographic coating on the backing, reference may be had to US. Patent 614,029.

By the expression intensifying ingredient as used herein is meant a material which when incorporated together with powdered carbon in the perforatable stratum attached to the backing, produces on said backing decomposition products when said stratum is subjected to a perforating electric discharge, which products have a more intense blackness than is produced by the perforation of said stratum containing powdered carbon without such ingredient. In either case the carbon deposit is ink-receptive and hydrophobic except that in one case, namely with the intensifying ingredient in the plastic, it is blacker and more intense, and is a more effective ink receptor.

What is claimed is:

1. A blank of the kind described, comprising a flexible backing having its surface treated to make it a lithographic surface which is water insoluble and hydrophilic, and a layer of plastic adhesively attached to said surface, said layer containing powdered carbon to render it an electric conductor and being attached to said backing with a low degree of adhesive aflinity to facilitate its manual peeling therefrom without tearing and Without permanent deformation.

2. A blank for producing a facsimile lithographic record under control of electric voltages applied to the blank comprising, in combination, a backing member having a smooth, Water insoluble, hydrophilic, lithographic surface, a plastic film adherently attached to said lithographic surface of the backing with a low degree of adhesive affinity so as to be readily strippable therefrom manually when dry, the plastic of said film being normally a non-conductor but having incorporated therein prior to attachment to said backing a quantity of conductive carbon to render the film perforatable by said applied electric voltages and to simultaneously deposit on said lithographic surface corresponding ink-receptive areas consisting of the decomposition products of the perforated plastic.

3. A blank according to claim 2, in which said litho- 9 graphic surface on the backing contains a filler and a binder which does not have its hydrophilic character affected by the subsequent adherent application of said plastic film thereon, nor by the subsequent stripping of the plastic film therefrom.

4. A blank according to claim 2, in which said plastic film is comprised of at least two strata of different electric conductivity with the stratum of higher conductivity adjacent the said backing.

5. A blank according to claim 2, in which said plastic film has incorporated therein a wax constituting up to 10% of the Weight of the film but Without substantially affecting the electrical conductivity of said film.

6. A blank according to claim 2, in which said plastic film has also incorporated therein with said carbon a decomposition product intensifying ingredient to intensify the said deposition products on the backing when said plastic film is perforated by an electric discharge.

7. A blank according to claim 6, in which said intensifying ingredient is in the form of a high molecular weight oleophilic material.

8. A blank according to claim 7, in which said oleophilic material is a chlorinated paraflin.

9. A blank according to claim 7, in which said oleophilic material is octadecanoic amide.

References (Iited in the file of this patent UNITED STATES PATENTS 915,680 Kosters et al Mar. 16, 1909 1,221,780 Wald Apr. 13, 1917 1,656,338 Ranger Jan. 17, 1928 2,140,483 Schutte Dec. 13, 1938 2,142,250 Neidich Jan. 3, 1939 2,156,100 Simons Apr. 25, 1939 2,230,981 Toland et al Feb. 4, 1941 2,294,146 Wise Aug. 25, 1942 2,342,713 Wescott Feb. 29, 1944 2,346,812 Bradner Apr. 18, 1944 2,351,696 Nichols June 30, 1944 2,385,562 Baczewski Sept. 25, 1945 2,398,779 Dalton et al Apr. 23, 1946 2,402,469 Tuland et al June 18, 1946 2,419,206 Fischer Apr. 22, 1947 2,500,617 Meigs Mar. 14, 1950 2,503,679 Newman Apr. 11, 1950 2,540,125 Van Dusen Mar. 13, 1951 2,664,043 Dalton Dec. 29, 1953 2,713,822 Newman July 26, 1955

Claims (1)

1. A BLANK OF THE OF THE KIND DESCRIBED, COMPRISING A FLEXIBLE BACKING HAVING ITS SURFACE TREATED TO MAKE IT A LIGHOGRAPHIC SURFACE WHICH IS WATER INSOLUBLE AND HYDROPHILIC, AND A LAYER OF PLASTIC ADHESIVELY ATTACHED TO SAID SURFACE, SAID LAYER CONTAINING POWDERED CARBON TO RENDER IT AN ELECTRIC CONDUCTOR AND BEING ATTACHED TO SAID BACKING WITH A LOW DEGREE OF ADHESIVE AFFINITY TO FACILITATE ITS MANUAL PEELING THEREFROM WITHOUT TEARING AND WITHOUT PERMANENT DEFORMATION.

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