US 2409564 A
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Description (OCR text may contain errors)
TRANSFER MATERIAL Filed lay 28, 1941 )van mons Tneuoppnslc .Anneslvs moms Tnznuppusnc .massive moan (ummA cELLuLosE) y o@ 151946 Y l w. Helm-:CKE :TAL 2,409,554`
@atente @i I5, i946 William Meinecke and Frieda Meinecke, "Verona, N. li., assignors to The Iii-"tice ltfanufaetnring Company, ieveiant'l, miic, a
corporation cui @Mmmm i? im mi, sean at. estaria (iii. o)
The present invention relates to a transfer process, and it particularly relates to a transfer process for applying photographically sensitive emulsions to various surfaces and particularly to metal plates.
Although the present invention will be particularly described in the application of photographically sensitive emulsions to metallic plates, it is to be understood that it has a broad application to the transfer of any types of films from carrier sheets to other sheets 'upon which said materials are to be permanently mounted or utilized, as, for example, in the application of decorative sheets to furniture, or signs to glasswindows, or decalcomanias to light bulbs for advertising o r decorative purposes, trade-marks to various articles, etc.
In the application of these sheets of photographically sensitive emulsions, it has been custernary to coat the emulsion directly upon the surface to .which it is finally to be applied or on whichit is finally to be utilized.
For example, in the making of various types of printing or reproduction plates, whether of metal or of other materials, the photographic i emulsion is coated upon the metal surface or other surface and then is exposed to light and the unexposed and exposed portions are differentiated so that the metal or other surface corresponding to one may be eroded or eaten away as by an acid, While the surface corresponding to the other will be protected against acid erosion or destruction.
However, the coating of such light sensitive emulsions upon metal surfaces or upon other surfaces which are to be exposed and developed is quite diiiicult and involves skillfwl manipulation, also the handling of 'relatively expensive or weighty or cumbersome backing plates, and it is among the objects of the present invention to provide an .improved procedure which will enable more inexpensive and less dimcult manufacture of photographic emulsions in layer form with subsequent application to the surface which is to be subjected to photographic development vor which is to be utilized or treated when carrying a photographic emulsion.
Another object is toprovide an improved carrier for photographic emulsions upon which photographic emulsions may be realily applied as coatings and from which photographic emulsions may be readily transferred on to metal or other surfaces upon which they are to be utilized.
Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only, and not by way of limitation, .since various changes therein may be made by those skilled in the art, without depart- In accomplishing the above objects, it has been found most suitable according to one embodi' ment of the present invention, to utilize a 'flexible sheet, particularly a paper sheet, to carry a photographic emulsion and to provide on either side of said photographic emulsion layers of material or surfaces which will enable the photographic emulsion to be readily transferred from the carrier sheet or paper sheet on to a metal surface.
In one preferred construction as shown in Fig. 1, the paper carrier or other thin flexible sheet material I0 is first provided with a weak adhesive coating or surfacing l i which will preferably have a smooth upper face and then to this coating or surface is applied a second coating or surfacing consisting of the photographic emulsion I2 which, for example, will consist of gelatin-silver halide composition or, if desired, a gelatine-bichrpmate composition.
On top of this photographicemulsion is then applied a third coating I3, preferably `consisting of a thermoplastic material or some other adhesive material which will have much greater adhesion for both the photographic emulsion and the metal surface to which the photographic emulsion is applied than the adhesion between the first coating Il and the photographic emulsion. Although the adhesiveness of the third coating or upper face of the laminated structure may be developed by heat where a thermoplastic material is employed, it is also possible, less preferably, to utilize an adhesive, the adhesiveness of which may readily be developed by pressure without application oi heat, or the adhesiveness of which maybe readily developed by molstening.' Furthermore, the iirst coating of an adhesive connection between the photographic film and the carrier or the paper sheet may also be of such a nature as to be released by pressure alone or by heat or by moisture and, if desired, the entire carrier sheet may be of 'a nature that will be disintegrated and be readily removable from the phctographically sensitive layer upon heating, moistening, pressure or other means.
In all cases, however, it is an essential feature of the present invention that the development of the adhesiveness of the third or top coating will always result in a decreaseddevelopment of adhesiveness of the rst coating, so that the photographic emulsion will always tenti to adhere and to be transferred to the face 'upon which the third or uppermost adhesive layer is applied.
In order to achieve the first coating face or to cause the paper to be treated to receive thephotographically sensitive lm, the paper is impregnated or coated with materials which will either out the aid of solvents, or which will permit detachment of the sensitized layer upon meistening with suitable solvents, or which will permit ready detachment either upon pressure or upon heating or both. In all cases the carrier should be so coated in a manner to give a smooth surface which will in turn permit the face of the gelatine layer or photographic emulsion upon transfer to be similarly smooth and uniformly be affected by the light used for exposure purposes.
For example, the carrier sheet or paper may be impregnated with a waxy or resinous substance such as 'paraine Wax, or a brittle resin such as sandarac resin, or a synthetic resin such as a' urea formaldehyde` resin, a cyclop'arafne resin, or a coumarone-indene resin, or a synthetic cellulose plastic material such as ethyl cellulose. A surfacing of this sort will permit ready detachment of the emulsion layer without moistening or use of solvents.
Where also desired, the support may be impregnated or coated with solutions of water soluble alkyl, cellulose or albuminoids or water soluble urea formaldehyde, or vinyl alcohol resins which upon application to moistening agents of aqueous nature will permit a ready release of the photographic emulsion.
The supporting paper film may also be, for example, impregnated with castor oil and alcohol, following which there is applied a glossy coating of an albuminoid or alcohol soluble resin or resinous material. Such a material will permit ready penetration of the solvent, whether` it be an aqueous solvent or an alcoholic solvent, and at the same time will not cause any disadvantageous effect upon the light sensitive photographic emulsion or its thermoplastic binder.
However, in the preferred construction, the transfer sheet is first coated with a cellulose ether, and then a silver-halide emulsion is coated upon such cellulose ether. The cellulose ether preferably is so plasticized with glycols or alcohols or with the addition of cellulose nitrate toA control the adhesion thereof, so that it will hold the light sensitive emulsion or layer against accidental displacement without overcoming the adhesion of the uppermost surfacing or main adhesive layer.
If desired, the paper, before application of the ethyl cellulose, may be treated to prevent penetration of the cellulose ether or other cellulose derivative thereinto, or it may be coated with a surfacing material such as albumen before the light sensitive emulsion is applied thereto.
After the light sensitive emulsion is applied, a thermoplastic and preferably non-tacky adhesive is applied over the light sensitive layer to serve as a binder between the same and the final support to which said light sensitive layer is to be transferred. f
Although not specifically limited thereto, the following examples are given of various compositions which may be employed and the manners in which they may be applied.
EXAMPLE I In treating the paper material which is used as the temporary carrier base, such paper material may be treated or impregnated or coated with or without prior impregnation with a solution of ethyl cellulose in an organic solvent. For example, a suitable solution is one containing 2 to 8% of ethyl cellulose, 46 to 42% of ethyl acetate, 47 to 43% of ethyl alcohol and 5% of toluol.
This coating has two functions, one to provide a smooth glossy and non-absorbent surface for coating with the photographic emulsion, and the other function is to hold the light sensitive 5 layer in sufficiently rm adhesion to prevent its spontaneous release under ordinary handling when a certain amount of force is applied, and yet to permit ready release when the transfer is to be effected.
Some or all of the ethyl cellulose may be replaced by other cellulose ethers, esters, rubber compounds and/or natural or synthetic resins or waxes, and the ethyl cellulose may be also provided with a suitable amount of plasticizer or other modifying agent to control the readiness of the release.
If desired, there also may be applied under or over coats upon this rst surfacing coat for the paper carrier to enable readier control of the adhesion and of the removal of the light sensitive emulsion such as, for example, various water soluble surfacings of casein, albumen, water soluble alkyl cellulose, water soluble vinyl alcohol, or Water soluble urea formaldehyde resins, or even various types of glycerol or glycol modified resins.
Although the rst layer or impregnations to be applied may be caused to be readily soluble or to lose its adhesiveness upon being moistened with water or organic solvents, it is preferable to provide a base layer of such a nature that the photographically sensitive material will be removed therefrom by pressure and/or heating 1alone after moistening or treatment with organic solvents. It is of course important to select materials for this under coat or paper surfacing coat which will not affect the light sensi-- tive qualities 0f the photographic emulsion.
EXAMPLE II After the photographically sensitive emulsion has been applied, various types of thermoplastic surfacings may readily be employed on the top thereof. Specific examples of two different materials which may be employed are the following compositions:
Per cent Balata resin, precipitated 15-18 Rubber resin 5--9 Coumarone-indene resin 5--9 Parafline wax 1 3 Petroleum solvents and/or aromatic solvents r1'4-61 Per een?. Sucrose cota-acetate l0-lfi Toluene and acetone 'I0-65 Ester gum 1.5-10 Ethyl cellulose 5-l0 Plasticizers To suit Vinylite resins also of course may be employed.
The resultant sheet then may be applied upon being warmed or by means of a hot roller to a sheet of heated metal Iface down and then by means of an adhesive tape the backing may be ripped away from one corner, leaving the photographic emulsion firmly adhering to the surface to which the sheet has been applied.
The photographic layer then on the final surface may be photographically developed or treated to enable etching or other reproduction of a shape, imprint or cul-line upon the surface -to be etched, and the process may be used both able number of steps and labor.
for decoration or in the manufacture of etching or printing plates, to enable reproduction in re-y duced, exact or enlarged. scale of original drawings upon metal or other surfaces.
Instead of using a sensitized combination o gelatine including silver-halide, it is also possible to use other sensitive material which may be acted upon and/or developed by chemicals or by light such as, for example, azo dye forming material, which may be developed by ammonia fumes without aid of Water. With such azo sen-l sitized films, a base with a smooth sheet would be utilized and then would be coated with a thin layer of gelatine sensitized by the azo compound and then the entire sheet would be covered by an adhesive top coating. The sensitized layer of gelatine may, if necessary, be reinforced by a thin backing or supporting coat positioned between the sensitized layer and theadhesive layer.
In this procedure, the aqueous developing, fixing and washing procedures might be replaced by a dry process which will eliminate a consider- If desired, it is also possible to use layers of materials or other means to protect the sensitized layer against the light when the material is being x handled before exposure. This may be accomplished by providing non-actinic colorings of a base and top layer on either side of the sensitized layer. If desired, the layers already applied t0 the transfer sheet may alsobe colored to prevent the penetration of certain light values which will affect the sensitized gelatine layer. Where a paper bas@ is used, the paper base, of course, may be impregnated with a coloring material which will prevent the passage of the actinic light while the adhesive top layer may suitably be impregnated or colored. When the paper base is removed, the top surface of the sensitized gelatine layer will then be exposed andwill be acted upon by light, to get thedesired effect.
Since the sensitized gelatine emulsion layer I2 has a tendency to float oi the thermoplastic layer I3, it has been found desirable to coat on top of the emulsion a substratum i4, as shown in Fig. 2, which acts as a permanent binder between the emulsion and the adhesive. This substratuln, for example, may be a nitrocellulose-resin solution, which Will effectively prevent theemulsion from separating or detaching itself from the adhesive layer during development,L fixing and Washing.
If desired, the order ofthe layers of the nal transfer sheet may be reversed so that there Will be a liner or base upon which there will be coated the adhesive. Then, upon the adhesive will be coated the nitrocellulose or cellulose acetate resin combination, and finally, the gelatine emulsion may be placed upon the cellulosic surfacing of the adhesive. When the liner or base is strippd o, the adhesive layer then is available and the sheet may be used in photo-odset procedures.
As stated above, instead. of using silver halides, it is also possible to use sensitive diazo dyes which may be applied by impregnation after or before coating of the base material. i
For example, the base may be coated with ethyl cellulose to give a smooth surface and then with a coating of a thin layer of a colloid, such as an 'albuminoid or with cellulose acetate, which may be impregnated with the diazo dye. Then a protective coat of gelatin is applied and nally a thermoplastic coating is applied.
It is also possible to apply to one side of a transparent or opaque sheet a coating of thermoplastic material and to impregnate the other side of the sheet with a diazo dye, which is sensitive and may be developed.
If desired, it is also possible to utilize direct 5 positive emulsions for application to the material in lieu of the usual standard type of negative emulsions.
As many changes could be made in the features and details, and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.
What is claimed is: t
1. A composite transfer sheet comprising in combination a bottom base sheet of paper; a sheet of ethyl cellulose coated on the upper face of said base sheet; a photosensitive layeron the upper face of said sheet of ethyl lcellulose, and a top layer of vinyl resin.
2. A transfer sheet as inclaim 1 and a substantially water-impervious binder layer in contact with and between said photosensitive and resin layers.
3. A composite transfer sheet comprising in combination a bottom base sheet of fibrous material; a sheet of ethyl cellulose coated on the upper |face of said base sheet; a photosensitive layer on the upper face of said sheet of ethyl cellulose, and a top layer of vinyl resin, whereby the sheet may be exposed by causing light to pass through the resin and act on the emulsion, then the resin adhered to a plate, then the base sheet dry-stripped and the emulsion developed while adhered to the plate.
4. A composite transfer sheet comprising in combination a bottom base sheet of paper; a sheet containing ethyl cellulose coated on the upper face of said base sheet; a coating of photosensitive gelatinous emulsion on the upper face of said sheet of ethyl cellulose; a coating of nitro-cell lulose-resin on the upper face of said emulsion; and a top layer of adhesive on the upper face of the nitro-cellulose coating, said nitro cellulose coating binding the adhesive tothe emulsion duringV washing, and binding the adhesive to the emulsion more strongly than does ethyl cellulose bind the base sheet to the emulsion during stripping.
5. A transfer sheet as in claim 4, said adhesive comprising 15 to 18 parts precipitated balata resin: 5 to 9 parts rubber-resin; 5 to 9 vparts coumarone wax; and 1 to 3 parts paraflin wax.
6. A transfer sheet as in claim 4; said adhesive comprising sucrose cota-acetate; ester` gum; and ethyl cellulose.
"1. A composite transfer'sheet comprising in combination a. bottom base layer of paper; a sheet containing ethyl cellulose coated-on the upper face of said base layer; a coating of photosensitive gelatin emulsion coated on the upper face of said sheet of ethyl cellulose; a coating of nitrocellulose on the upper face of said emulsion; and
a. top layer of thermo plastic adhesive on the upper face of the nitro-cellulose coating, said sheet containing ethyl cellulose to enable dry stripping of the paper and to be Water permeable at points where portions of the sheet may adhere to the emulsion thereby enabling even development of the emulsion.
WILLIAM HEINECKE. FRIEDA HEINECKE.