US2903964A - Photographic spirit duplicating process - Google Patents

Description

Sept. 15, 1959 J. B. TAYLOR 2,903,964

' 'PHOTOGRAPHIC SPIRIT DUPLICATING PROCESS Filed Jan. 24, 1955 EXPOSUR TANN/NG DEVELOPMENT AND TRANSFER T 0 PAPER LA7ERALL) RE VERSE!) GELAfl/V-AgX Sfage 2, 4 WAGE I 4% PAPER SOUEEGEE r0 COLORED SP/R/T f .ou L/cAn/va MASTER SHEET l HEAT AND STR/P ATTORNEY 8 AGENT 2,903,964 THOTOGRAPHIC SPIRIT DUPLICATING PROCESS Joseph B. Taylor, Rochester, N. assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Application January 24, 1955, Serial No. 483,466 1 Claim. to]. 101-4494 This invention relates to a duplicating'process employing certain features of the well known spirit or direct duplicating process wherein a duplicating master is prepared by typing, drawing or otherwise forming a design on a sheet of paper while the sheet is in contact with the inked or colored surface of a spirit duplicating States Patent i It will be apparent that this process lends itself readily to the reproduction of printed or typed subject matter and that for the reproduction of designs such as mechanical drawings, graphs, musical scores, etc., it is necessary to draw or otherwise impress the design on the master sheet while it is in contact with the inked or colored surface of the spirit duplicating master sheet.

I have discovered a process which dispenses with typing and other manual operations for the reproduction of subject matter of all kinds in the spirit or direct duplicating process. In the process of the invention the subject to be copied is recorded photographically so as to obtain a laterally reversed image on a light-sensitive hydrophilic organic colloid layer capable of being differentially tanned or hardened under influence of light such as an unhardened gelatino-silver halide emulsion layer. Thereafter the unhardened areas of the light-sensitive layer are transferred to paper by merely placing the differentially hardened layer while moist against the paper to leave a thin stratum of the unhardened areas of the lightsensitive element adhering to the paper in the form of a relief image after the sheets have been separated. Shortly thereafter while the relief image is still moist the paper is squeegeed against a spirit duplicating master sheet of a type well known in the art carrying a layer of coloring material, preferably a water and alcohol soluble dye, with the result that the coloring matter adheres to the relief image when the sheets are separated. The resulting colored printing element is then used as a duplicating master in a spirit or direct process duplicating machine by merely moistening the duplicating master sheet with a water miscible alcoholic solution and printing onto paper.

A preferred embodiment of my process is illustrated in the accompanying drawing wherein Stage 1 shows in greatly enlarged cross-sectional view, a sensitive element comprising a paper support 10 carrying an unhardened gelatino-silver halide emulsion layer 11 which preferably contains a gelatin tanning silver halide developing agent, being exposed to a translucent subject 12 containing the opaque characters 13. The exposure of emulsion 11 is made through the transparent subject as shown so as Patented Sept. 15, 1959 'halide' developing agent simply by means of an alkaline solution in case a gelatin-tanning silver halide developing agent had originally been incorporated in the emulsion layer. Accordingly, development tans or hardens emulsion layer 11 in the regions of exposure and the remaining regions underlying images 13 remain substantially undeveloped and unhardened. The element while still moistened with the alkaline solution is then squeegeed onto an absorbent sheet such as paper and shortly thereafter stripped oif the paper leaving a stratum of unhardened laterally reversed gelatin and silver halide relief image 14 on the paper 15 as shown in Stage 2 of the drawings.

While relief image 14 is still moist with developer solution, as shown in Stage 3, it is squeegeed into intimate contact with a spirit duplicating master sheet of a well known type having a layer 17 of water and alcohol soluble dye or coloring material on a paper support 16. It is now desirable, but not absolutely necessary, to heat the elements, while the relief image and spirit duplicating master sheet are in contact as shown in Stage 3, apparently to set the coloring matter absorbed by image 14 from the colored layer 17. The amount and means of heating is not especiallycritical. A convenient method is to place the sandwich in an enclosure at a temperature of about C. or more for about 1 minute. Thereafter, the sandwich is stripped apart leaving a duplicating master unit having an appreciable amount of coloring matter 18 adhering to or absorbed by image 14 as shown in Stage 4 of the drawing. The duplicating master is then affixed to the drum of a conventional spirit duplicating machine and the desired number of copies printed in a well known manner using solvent such as aqueous ethyl alcohol solution. By repeated application of solvent to the duplicating master as many as 100 to 200 copies may be obtained. After printing a limited number of copies the duplicating master may be stored away for later use in printing additional copies on the duplicating machine in the same manner. I

The advantages of my process illustrated above will now be apparent. As mentioned, in the usual spirit duplicating processes it is customary to type or otherwise impress a design to be reproduced, on a blank sheet in contact with an inked duplicating master sheet to obtain a laterally reversed duplicating master. In my process once a subject is available, either a line or half-tone subject (a so-called two-tone subject) the image is recorded photographically in one operation as in Stage 1 of the drawing and it is not necessary to retype or again draw the design to be reproduced with the concomitant chance of error. Thus, for example, in the case of the reproduction of mechanical drawings, parts lists, music scores, etc. no retyping or drawing is necessary. In other cases such as in the duplication of parts lists, stock cards, musical scores, etc. usually carrying rulings, it will be apparent that the rulings as Well as the other characters of the subject will be conveniently reproduced in one operation Whereas in conventional spirit duplicating processes it is necessary to print in register on a suitably ruled printed form.

In a variation of my process, after the exposure step shown in Stage 1 of the drawings, it is possible to develop the exposed emulsion by means of tanning development then rather than transferring the unhardened image to paper as in Stage 2, the unhardened areas of the exposed element are swelled for example with dilute alcohol or the drawing.

water followed by drying the element until the swollen parts are just moist and then squeegeeing the emulsion directly into contact with a spirit duplicating master sheet. The coloring matter of the latter adheres to the swelled gelatin image and the resulting element can at once be printed in the spirit duplicating machine. This -procedure dispenses with the transfer to paper step of Stage 2 of the drawings; however, as yet the quahty of the copy obtained is inferior to that obtained by the full procedure outlined in the drawing.

The process of my invention exemplified above can be carried out with various light-sensitive elements providing an unhardened hydrophilic colloid. image. For example, a layer of dichromated gelatin or albumin may be employed in the exposure Stage 1 of the drawing and after exposure the unhardened areas of the gelatin or albumin layer can be transferred, colored and printed as described above.

In a preferred procedure the process of the Yutzy and Yackel U.S. Patent 2,596,756, May 13,1952, or Yutzy and Yackel US. application Serial No. 267,447, filed January 21, 1952, now U.S. Patent 2,716,059, granted .August 23, 1955, is employed for providing the laterally developing agents of widely different gelatin tanning ability, prepared as described in the examples of the last- .mentioned Yutzy and Yackel inventions, that is, a mixture of one of the aforesaid compounds with one of the following: N-methyl-p-aminophenyl-x-sulfonic acid, p-hydroxyanilino-methane sulfonic acid, pyrogallol dimethyl ether, 8-hydroxy-u-naphthol and 4-methoxy-m-naphthol.

The sensitive element is exposed and developed under conditions of tanning development then a transfer is made as described above and illustrated in Stages 1 and 2 0f the drawing, followed by squeegeeing or rolling the resulting gelatin-silver halide relief image onto the spirit duplicating master sheet and stripping apart to produce the duplicating master.

The spirit duplicating master sheet or element used in the invention can be a commercially available spirit duplicating master sheet well known in the trade having a layer of water or water and alcohol-soluble dye or other coloring material on its surface. However, it is necessaryfor the best operation of my process that the colered surface of the duplicating master sheet be truly hydrophilic and not carry a layer of Wax or other water repellant substance overlying the coloring material'of the sheet as in the case of certain commercial spirit duplicating master sheets, otherwise the transfer of the coloring material to the gelatin-silver halide image (Stages 3 and 4) is interfered with. For the purpose it is satisfactory to coat a paper, metal, glass or other similar surface with a soft layer of a mixture of a water and alcohol (methyl or ethyl alcohol) soluble dye such as Crystal Violet and a Waxy or viscous hydrophilic binder which may be a partial solvent for the dye such as a soft high molecular weight water-soluble wax, e.g., the polyethylene glycols available under the name Carbowax. If desired, such coatings can contain other polyhydric alcohols such as glycerine, glycol, diethylene glycol, or ether alcohols, e.g., ethylene glycol monomethyl ether, for dispersing the coloring material. Soft soaps can also be used as a binder for the coloring material.

The fluid used in printing from the duplicating master is generally water or a water miscible alcoholic solution the nature of which will depend upon the composition of the coloring matter carried by the relief image of the duplicating master. Generally, aqueous methanol or ethanol solution is satisfactory.

What I claimis:

A duplicating process which comprises exposing to a subject, a substantially unhardened gelatino-silver halide emulsion layer containing a gelatin tanning silver halide developing agent of the class consisting of 3,4-dihydroxy diphenyl, 2,5 -dihydroxy diphenyl, 2,3 -dihydroxy diphenyl, 4-phenoxy catechol, 4(2-cyclopenteny1)catechol, 1,2-diethoxally1-4-phenyl catechol, 1,2,3-triethoxallyl pyrogallol and a developing agent of the class consisting of -N-methyl-p-arninophenol-x-sulfonic acid, p-hydroxyanilino-methane sulfonic acid, pyrogallol dimethyl ether, 8- hydroXy-ct-naphthol and 4-methoxy-ot-naphthol, developing the exposed emulsion layer with an alkaline solution to obtain a hardened gelatin image in the region of exposure to light and an unhardened gelatin image in the remaining region of the emulsion layer, pressing the emulsion layer while moist against a paper sheet to transfer only the moist unhardened gelatin image to the sheet, pressing the resulting transferred moist unhardened gelatin image on the sheet against the surface of a spirit duplicating master sheet having water and alcohol soluble coloring material on the surface free of water repellent substance overlying the coloring material, applying heat to transfer the coloring material to said unhardened gelatin image on the sheet, moistening the resulting colored gelatin image with a solvent for the coloring material, and printing from the moistened colored gelatin image.

References Cited in the file of this patent UNITED STATES PATENTS

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