Патент USA US2137725код для вставки
Nov. 2z, 193s; R, R I_Ewlg 2,137,725 TRANSFER DEVICE Filed NOV. 27, 1954 1ra/ees» myn? \ Mg, B“ INVÈNTOR. , MWL ATTORNEYS 2,137,125 Patented Nov. 22, 1938 . UNITED STATES PATENT ori-‘ICE l ' ~ 2,137,725 e ' TRANSFER nevica Robert n; Lewis, Baldwin, N. Y.. -assignor to vul - can Proofing Company, -New York, N. Y.; a eor- _ poration? of New York 'Application November 27, 1934, Serial No. 754,993 y.z claims. LMy invention relates to a new and improved transfer device, to be used vfor the photomechan ical reproduction ofy printing plates. One ofthe objects ofmy invention- is to pro ` 5 vide a device which can `be used in 'connection with the method of making printing plates which is disclosed in U. S. Patent No. >1,382,613 issued on (Cl. 411-46) , which’is coated with athin layer of substantially pure rubber.. 1 - " . ' yReferring to the annexed diagrammatic draw ing, the inner surface of the transparent or trans-f lucent sheet 3, which is made of cellulose acetate, is especially prepared in order to enable the rubber coating 2 to adhere thereto. Said inner surface June 28, 1921,-and ,in Canadian Patent No. 325,250l 4 of the sheet 3 may be so prepared, so as to give ~it a sufficiently rough surface, by means of em issued, on August _23, 1932. Another object of my invention is to provide bossing, or by any other process.« Likewise, said an improved device for mechanically producing a inner surface of the sheet 3 couldbe roughened by photographictnegative‘ from a photo-engraving.> coating the same with a mixture containing crys ' Another object of my invention is to provide a .device having a tacky material, and which can >be'conveniently manufactured and shipped and handled, said transfer device having means for protecting said tacky material until the device is to be used. l _, - . talline substances. Such a mixture could consist of gelatine having mineral crystals. The sheet 3 remains light-permeable and substantially 16 transparent or translucent, after it has been pro vided with' a rough inner surface. ' - The roughenedsurface which is thus secured,4 is provided with a'coating or-layer 2. This coat-- Other objects of my invention will be set . ing or layer 2 consists substantially of pure rubber. 20 À2o. forth in the following description and drawing. the It may consist of 95 _parts of the whitest obtain-l able grade «of first latex crepe, and 5 parts of ft has heretofore been well known to make a white petrolatum. -T’his rubber mixture: is milled to give it satisfactory calendering -qualities and Fig. 1 is a diagrammatic cross section of improved device. , Fig. 2 is a diagrammatic plan view. 25 printing plate from a relief plate'of the subject. rli‘his relief plate may be made of metal, and it may be etched. Accordingfto this well-known method, as disclosed in the above mentioned 'United States patent and the Cabove- mentioned 30 Canadian patent, the plate is first cleaned, and this mixture of rubber and petrolatum is then 25 applied to the base i, by means of a calender. The thickness of the coating 2 can be from two thousandths of an inch to three thousandths of an inch. It will be noted that I do not use av coating or so layer which is a solvent for the cellulose acetate, then a suitable opaque pigment is applied to the printing surface of the plate, >so that the pigment - and thatl use a tacky rubber layer which is` ap plied in iinal form to the base sheet 3. I do not Vfiller fills up the etched or relief portions of the - plate, to a level with the printing surface of -35 said plate. ` » ` ' This plate, so prepared, is then pressed against the surface of a suitable base sheet made of Celluloid or other suitable cellulose material. Ac - cording to said U. S. Patent No. 1,382,613 the sur 40 face of the base sheet of Celluloid is coated with Wish to- be limited to the use of cellulose acetate, as I can use other suitable opaque or transparent 35 or translucent material. I prefer to use cellulose »acetate because l have discovered that it holds its dimensions more accurately than similar material, during the photographic printing operation. ~ However I could use sheets of cellulose nitrate -material or any other light permeable material. an adhesive which is a solvent of Celluloid, just The coated sheet 3 is now covered with a third before' the transfer is made. _ According to said Canadian patent, a sheet of g paper or tracing cloth of Celluloid or “Cellopha‘ne” 4 or 'covering sheet l, which is also preferably made of cellulose acetate. The covering sheet l is preferably provided with a smooth inner surface, 45 or gelatin, is coated with a thin layer of rubber in solution, in order to form an adhesive film on the transparent or translucent sheet, just before the transfer is made, and the rubber solution is used and it is applied to the coating 2 of Ásheet 3, im mediately as the coated sheet 3 comes from the I 50 for removing the pigment from the metal relief of material'which are thus secured, are then >cut printing plate. , e According to my. invention, the metal relief plate, prepared, in the >manner previously de scribed, or in any other manner, is used for print 55 ing a'negative- upon a sheet of cellulose acetate, calender. , .` - The rubber is not vulcanized. The large-sheetsto various sizes and packaged for shipment. I can use any suitable smooth or other material for the covering sheet I. When the device is to be used, the covering sheet is removed and the tacky layer of rubber . ' 2 2,137,725 remains adherlngto the base sheet l, because with. said base material has a rough surface, and the covering material has a smooth surface. Hence the adhesion of the layer 2 to sheet 3, exceeds its sheet would substantially prevent any evapora tion of the solvent, and the transfer device, to gether with its covering sheet, could be packed in adhesion to sheet i. T'his eifect or result can be secured in any suitable manner. Since the layer 2 is very thin and coherent, it remains adhering substantial evaporation of the solvent. However, to the rough surface of the base sheet. This base sheet I, together with its tacky layer, is used in 10 the same manner as thev base sheets which are disclosed in the patents previously mentioned. That is, when a metal relief plate which has been coated with a printing composition in its recesses is pressed against the rubber layer, a reproduc 15 tion- of the plate is formed upon the tacky layer 2. . mula of the rubber layer, without making it un suitable. 'I'he essential characteristics of the rub ber layer are that it shall have a surface of suf iicient tackiness to pull .the particles of pigment from the metal relief plate, and that it shall be as colorless as possible, and as transparent as possible. Likewise, the tacky material should re main unchanged, during moderate periods of storage under average conditions. The base sheet 3 and the protective sheet I, have a thickness of .0075 inch. This thickness can be varied without departing from the inven tion. any suitable wrapper, whichx could prevent any 5 and for the reasons previously described, I prefer to use a dry tacky layer. I have described a preferred embodiment of my \ invention, but it is clear that numerous changes 10 and omissions could be made without departing from its spirit. The thin sheet of cellulose acetate material, used for making the base sheet or the -covering - sheet, is bendable and resilient, so that each said 15 sheet has a predetermined normal shape. « 'I'here can be considerable variation in the for 30 If such a layer were used, the covering ' For convenience, the device may be designated as a “transfer” device, since a replica of the metal plate is transferred to the tacky layer, by means of pressure. Likewise, the tacky layer may be 35 designated as a dry tacky layer, since the tacki ness does not depend upon the addition or use of any solvent. The petrolatum may be omitted or it may be substituted by any other suitable ma terial which can increase the calenderlng proper 40 ties of the rubber. Likewise, I do not wish to ex clude from the scope ofv the invention a tacky rubber layer, which has solvent intermixed there I claim: ` 1. A transfer device for use in photo-mechani cal printing, said device comprising a base sheet made of light-permeable material and having a smooth outer face, said base having a light permeable layer of tacky material at the inner face thereof, and a covering sheet which substan tially covers said layer, of tacky material, said base sheet having a roughened surface directly adjacent said layer of tacky material, said layer having greater' adherence to the base sheet than to the covering sheet, so that said layer adheres to said base sheet -When the covering sheet is 80 removed. 2. A transparent transfer device comprising a base sheet made of transparent and resilient ma terial, said base sheet having a roughened face, a layer of tacky material on said roug'hened face, said tacky material consisting substantially 85 of unvulcanized transparent latex crepe, and a cover sheet applied to said layer of tacky mate rial, said base sheet having sufficient adherence to said layer to retain the same, when the cover 40 sheet'is removed. ROBERT R. LEWIS.