US1484346A - Process for producing negatives from nontransparent originals for use in preparing printing plates - Google Patents

Description

Patented Feb. 19, 1924.

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MAX ULLNANN-,or ZWIGKAU, GERMANY, ASSIGNOR r KARL wnrvrn, or THE HAGUE,

. Nnrnnn-LANns.

rnoonss For, rn-onUoINe NEGATIVES rnoivi NoNrnANsrennN'r ORIGINALS For. use I INrRnranINs- PRINTING rrn'rns.

No Drawing.

Application filed April 14, 1921. Serial No. 461,454.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. I1. 1313.) i I To aZZ whom it may concern:-

Be it known that 1, MAX ULLMANN, re-

' siding at 16 Talstrasse, Zwiclrau, Saxony,

Germany, have invented certain new and useful Improvements in Processes for Produoing Negatives Originals for Use in Preparing Printing Plates (for which I havefiled applications in various countries foreign to the United States as follows: Germany, filed Jan. 7, 1920, patented Dec. Belgium, filed Dec. 2, 1920, application No. 253,982; Bohemia, filed Nov. 20, 1920; Denmark, filed Oct. 28, 1920, patented June 23, 1922, No. 29,873; Finland, filed Nov. 2, 1920, patented Sept. 2, 1921, No. 8,693; France, filed Nov. 2, 1920, patented July 8, 1921, No. 526,835; Holland, filed Nov. 27, 1920; Italy, filed Oct. 20, 1920, patented J an. 31, 1922, No. 542/185; Luxemburg, filed Oct. 23, 1920, patented Oct. 23, 1920, N 0. 11,985; Norway, filed Nov. 2, 1920, patented Aug. 22, 1921, No. 33,301; Austria, filed Oct. 21, 1920, application No. Oct. 28, 1920, application No. 14,994; Sweden, filed Nov. 16, 1920, application No. 5432/20; Switzerland, filed Oct. 22, 1920, patented Sept. 15, 1921, No. 91,898; Hungary, filed Oct. 29, 1920, patented Feb. 14, 1921, No. 14,667; England, filed Jan. 7, 1921, application No. 725/21; Portugal, filed Feb. 26, 1921, patented Dec. 19, 1921, No. 12,104; Rumania, filed March 17, 1921, application No. 6,854; Spain, filed Nov. 22, 1920, patented Nov. 23, 1920, No. 76,313; Turkey, filed March 12, 1921, patented March 12, 1921, No. 3,178), of which the following is a specification. V

Negatives for use in preparing printing plates may be prepared from originals which are adapted to reflect light from a portion of their surfaces by the method more fully described in my Patent 1,436,125, dated Nov. 21, 1922, which embodies rendering a photographic image produced on a film of chromate colloid impervious to light by dyeing the same with suitable soluble coal tar dyestufis. The preferred process there described may be briefly summarized as follows. The translucent film of chromated colloid such as bichromated gelatin is laid on the original which is to be copied with from Nontransparent 5873 20; Poland, filed opposite the white portions of the original are thus rendered insolublefby the reflected light. The negative is then washed in water or dilute acid to remove the portionsjwhich have not been so rendered insoluble and after the washing the plate is dipped in one or more suitable coloring or dyeing baths, for example, a bath of soluble analin dye such as methyl violet, and the parts of the colloid layer remaining are thus colored and adapted to intercept light of an objectionably actinic character In the practical utilization of this process .a-drawback is found in the fact that the image fades or bleeds when left in water. This results in indistinct pictures and re-coloring becomes necessary. Furthermore, some difficulty is encountered when the negative after drying is coated with an aqueous preparation, such, for instance, as a gelatin solution, because of the danger that the coating will absorb the dyestuffs- These difiiculties are obviated by the present invention which provides for the conversion of the dyestuffs, whether basic or acid, into compounds insoluble in water. Y

It is known that basic or acid dyestufis may be rendered insoluble in water by certain salts and acid or basic bodies accord-v ing to the character of the particular dyestuff, usually an acid agentbeing adapted for use with a basic dyestufl, and vice versa. Thus diamido stilbene disulphoacid-diphe- 1101 in an aqueous solution reacts with a dilute aqueous solution of pentamethyl-prosaniline to produce a precipitate that is insoluble in water.

As a specific example of the manner in which my process may be carried out I may mention the following. The negatives are produced in the manner described in my Patent 1,436,125 above referred to and the image colored by placing them in a dilute solution of pentamethyl-p-rosaniline. colored negatives are then washed in a dilute aqueous solution of diamido-stilbenedisulphoaoiddiphenolt A. colored lake The Y which is insoluble in Water is formed in the layer of chromate colloid so that no fading takes place While the negative is immersed in Water and if a Warm solution of gelatin is poured on to the negative no coloring of this solution takes place.

The process herein disclosed is also disclosed in my copendin-g application constituting a continuation of this present application, Serial No. 573,660, filed July 8, 1922, which has eventuat'ed in Patent 1,436,629, dated Nov. 24, 1922, in which application the transfer negative as an article is claimed.

Having thus described in detail the par ticular embodiment of my invention here described, What I claim and desire to secure by Letters Patent is ,1. That method of producing negatives for use in the preparation of printing plates 1 from originals which are adapted to reflect 2. That method of producing negatives for use in the preparation of printing plates from originals Which are adapted to. reflect light from a portion of their surfaces characterized by rendering the photographic image resistant to objectionably actinic light by treatment with a dilute solution of pentalnethyl-p-rosaniline and thereafter Washing it in a dilute aqueous solution of diamido-stilbene-disulphoacid-diphenol.

In testimony whereof I have signed my name to this specification.

MAX ULLMANN.