US915666A - Process for producing printing-surfaces. - Google Patents

Description

I To. ell whom it may concern:

' ner.

f UNITED STATES PATENT OFFICE.

. ozms DODGE, oF NORWICH, CONNECTICUT.

PROCESS FOR PBODUCING PBINTING SURFAOES;

. Be. it known that I, OZIAS Dopon, a citizen of the United States, and a resldent of Norwich, in the county of New London and State of' Connecticut, have. invented certain new and useful Improvements in Processes for Producing Printin -Su-rfaces, of which the following is a speci cation.

Myinvention relates to the product on of printing surfaces, more especially printing plates, v It maybe briefly said to consists in forming the picture or desi n on the surface of the plate by methods of photography and buildmg up the exposed surface of the plate by electrol tic action forming either an intaglio v or relie plate as may be desired.

I will-describe the invention for the pro duction of copper plates for printing pur .20

poses.

The copper plate is thoroughly cleaned and coated with a sensitive solution. I have found extremely useful for this purpose the following method of coating the plate. The plate, being thoroughly cleaned, is first coated with the following'solution Albumen from fresh eggs 4. 2% ounces. Water 1 Chlorid of sodium l tion Le: Pages-liquid as. 2 ounces. Double chromate of po-. tassium' and ammo- For. putting onsolution number one the plate is erfectly clean and .wet with cold water. t is then placed in a machine by which it may be rapidly whirled. The plate being held in the pro er position the solution is poured upon it an drained off at one cor- It is again poured upon the late and drained off at the opposite corner. he plate is then whirled, at first slowly and then more rapidly, until there is a thin film nearly dry uponthe' plate. lathe same manner solution number two is then placed upon the plate and the 'late whirled until dry over a gentle heat. he plate thus sensitized than c kept from Specification of Letters Patent.- Application filed Febrnary 19, 1904:. Serial No. 194 886.

I -meated the negative.

three to four days in a dar Patented March 16, 1909'.

room, growing more sensitive the longer it is'lrep't.

If a relief plate and half-tone is desired, 1- take a transparent negative and place the sensitized plate and the negative face to face in the printing-frame, giving it an exposure to dry sunlight of from one to three minutes, or if an electric light is used from four to six minutes. The copper plate is then [placed in a bath of eosin which gives it a bright scarlet color and allows the development of the picture to be watched. The plate is then held under cold water running from the tap and the image will rapidly begin to appear, and it will be observed that the picture will have a. grain which will vary in size in proportion to the amount of light which the plate has received; that is, if the negative from which the plate was made was a half-tone negative the grain will vary according to the protection afforded tothe plate by the negative. The plate is washed untilthe copper is clean in the deepest shadows. The plate is then flowed with wood alcohol and burned off and then held under-a strong heat (380 F.) until the picture turns to a dark brown color. The icture is now insoluble in water and aci in exact proportion to the amount of light that per- 1 then place the plate in a weak solution of chromic acid and etch it slightly; The only object of the etching is to roughen the surface of the plate so that the copper de osited to form the plate in the bath wil adhere firmly thereto. The margins and other parts that appear white may be painted over with asphaltum varnish. lythe'n lace the plate in the electrotyping bath. he copper will be built up on the exposed surface of the plate. As the electro de osition proceeds the coating of varying so ubility will give way in grains in the same proportion, and the lace is supplied with copper, for, as has een said,'the coating of the plate is insoluble in direct proportion to the amount of light that has permeated the negative. Therefore, the-plate will vary in height andin size 01} grain from the highest flat surface which will print black to the lowest point of the original surface of the copper, which will remain white. After the plate'conies from theg bath it is cleaned in boiling water and lye and is then ready for printing in the ordinary press. i

Albumen 2% oz.

Le Pages liquid glue- 2 Bichromate ammonia 70 rains. Ammonia 7 rops.

The plate is coated in the manner heretofore described. I use 'now a transparent positive instead of' a negative. Printing and development. are the same as heretofore described! It will be seen therefore that the cop ipr plate after cleaning will be exposed w ere the-black lines of-the positive were and consequently when laced in the wa s, eit or with an al electrolytic bath copper will e deposited u on those lines thus making a relief printing p ate. The solutionused in this process does not have the grain. To produce an intaglio plate a transparent negative'would be used. Instead of these methods of producin the design upon the pla I-may photograph them upon the late irect.

If a rehef plateis desired, prepare a copper plate as reviously described and coat it with theso utions first described. After drying, the plate is coated with a solution of benzin and pure rubber being flowed and whirled as described until dry, when there will be left upon the surface of the plate a thin transparent film insoluble in. water. This surface then receives a coating of gelatino-bromid emulsion containing, A

Potassium iodid- 3 gr.

bromid 8.7 Nitrate of silver; 11.4 Gelatin- 18 even creamy white color and will keep in-' definitely in a dry atmosphere. The outer coating u on the late is exceedingly sensitive to hg t and t e speed of the plate may be made as high as any 'of'the dry plates now sold to cphotographers. Upon the plate so prepare the picture can be taken in an ordinary camera by the ordinary photographic methods. After the proper exposure the late is develo ed in a variety of Ealine developer or wit a ferrous oxalate developer, the object spread on the bottom. of a box being to -develop a dense negative with and then dried to the extent 'of removing surface water. taken from the dark room and exposed with The plate being still moist is the film side toward direct sunlight for about 1% minutes or with electric light about seven minutes. The plate is then placed in a tray of warm water (about 100 F), and as soon as the outer film begins to loosen the plate is otassium or h osulfateliftedfrom the tray and the 'film taken off.

This film may be preserved as a negative to print from by simply placing it flat upon a suitable glass support. The plate is then given a bath of benzinwhich dissolves the rubber coating and leaves the first coating upon the'plate itself exposed and ready to be developed by cold water. The development and the subsequent steps of the process are the same as heretofore described, the result. being a relief plate in half-tone suitable for printing in an ordinary press.

A stillfurther method of using a plate on which-the picture may be directly hoto: graphed is as follows,-A.copper p ate is first etched in a solution of- Chlorateof potash 20 parts. H drochloric acid 100 I ater 880 It is then washed in warm water and placed in an ele'ctroty ing bath.of silver and given a thin coating 0' silver. The plate on "being taken fromthe bath should have a bright frosted appearance showing a grained surface under t e glass. The silver surface is then covered with silver bromo iodin containing aslight excess of iodin and becomes exceedingly sensitive to light. I now owdered iodin, and above the powdered iodin I place a piece of cardboard. The iodi'n will volatillze upon the cardboard. The cardboard is then turned over and the silvered plate is placed above it at a distance of about 1% inches the silvered surface of the late-facing the side of the cardboard whic was exposed to the iodin. The plate will graduall receive a thin coating of iodin and the co or will change. a It should be taken out before it begins to turn gray. I then place the plate in a box in the bottom of which there is a mixture of bromin and calcium hydrate. The bromin. acting'upon the iodid on the surface of the late converts it into bromoiodid. The co or now'changes to steel gray and violet and the late should be taken out and again subjecte to the action of iodin as heretofore described for about one-third the original time. The plate is now ready for perature is now raised to 150 F and the vapor of mercury converts the parts acted 1 the right stage, when the highest on by light into an amalgam of mercury while the arts unaffected by light remain iodid of si ver. The plate having reached ights are perfectly white, is at once laced inthe electrotyping bath when it wil be found that the copper will deposit u on the amalgam or mercury while the i0 id will remain unaffected'. When the late is sufficiently built up it is cleaned an the result is an intaglio grain plate suitable for printing.

Asthe methods of producing pictures by rinting fromnegatives or positives or by direct hotographs are those used in photograp y, I have selected as generically descriptive of them all for use in the claims the term methods of photography.

What I claim and desire to secure ters Patent is 1. The process of producing printing surfaces, which consists in producing a picture or design on the surface of the plate by hotography and building up the surface 0 the plate upon or about the photographed lines on the plate by electrolytic action, forming by Leteither an intaglio or relief printing plate, substantially as and for the urpose set forth.

2. The process of pro ucing printing surfaces, which consists in forming a picture or design on the surface of the plate by sensitizing the plate, exposing the plate to the object to be re roduced, developing the same, and then bu' ding up the surface of the plate u on or about the photographed-lines by e ectrolytic action, to form eit er an intaglio or relief printing plate as may be desired, substantially as and for the purpose set forth.

3. The process of producing a printing surface which consists in coating the copper plate with a photographic sensitive solution, exposing the plate as sensitized to the object to be reproduced, developing the same, exposing the developed late to electrolytic action, whereby an lntag io or relief printing upon y lig surface is formed substantially as and for, the purpose set forth.

4. The process of producing a rinting surface which consists incoating t e plate with a photographic sensitive solution, exposing t e sensitive late to the object'to be reproduced, developing the plate after it is exposed, immersing the plate in an electrotypin bath containing a copper solution, where y an intaglio orv relief printing plate is formed, substantially as and for the purpose set forth.

,5. The process of producing a rinting surface which consists in coatin t e plate with a hotographic sensitive so ution containing i-chromate of potassium, exposing the sensitive plate, thereby rendering the parts of the coating that are acted upon by ight insoluble, developing the plate after it is exposed, and then building up the exposed surface of .the plate by electrolytic action to form either an intaglio or.relief plate as may be desired, substantially as and for the purpose set forth.

6. The process of printing surface, whic consists in coating the plate with a photographic sensitive solution containing bichromate of potassium and common salt, exposing the sensitized plate to the object to be re roduced, thereby renderin the arts "of t e coat that are acted I fit insoluble, develo ing the plate after it is ex osed, thereby ma ing a grained surface, an then building up the exposed surface of the plate by electrolytic action, whereby an intaglio or relief is formed, substantially as an for the purpose set forth.

roducing a, grained printing plate 7. The method of forming a picture or design on the surface of the plate, which consists in producing the said picture or design on the plate by photographv, and by electrolytic action building up t e exposed surface of the plate to var ing heights, from the highest flat surface w 'ch will print black,

to the lowest original surface of the copper,

whichwill remain white, forming either an intaglio or relief printing plate, substantially as and for the purpose set forth.

In witness whereof, I have hereunto set my hand at Norwich in the county of New London and State of Connecticut, this 17th day of February, 1904. ()ZIAS DODGE.

In presence of WILLIs A. Bmscon,

JOHN P. HUNTINGTON.