US2354121A - Matrix film for the production of colored copies - Google Patents

Description

Patented July 18,

MATRIX FILM FOR THE PRODUCTION OF COLORED COPIES Gard Heymer, Wolfen, Krels Bitterield, Germany,

assignor to General Aniline & Film Corporation, New York. N. Y.. a corporation of Delaware 1% Drawing. Application September 14,1940, Se- 'rlal No. 356,835. In Germany May 5, 1939 6 Claims.

This invention relates to matrix film for the production of colored copies.

The matrix films which are destined for the I production of printing reliefs are generally .exposed through the emulsion carrier, developed with a hardening developer and washed out in warm water, so that after the washing process a relief'remains on those places only, where silver was present. The relief may be also obtained by developing with an ordinary developer and after treating with bichromate. However, without special precautions the relief becomes too high and the gradation consequently too steep. In order to prevent this, there is ordinarily added to the emulsion layer a yellow or red dyestufi' ..vide a method for the preparation of colored reproductions with the aid of matrix films.

1 color tinge which absorbsblue.

Other and more specific objects will appear from the following disclosure.

The matrix films hitherto known were destined to be exposed under black and white originals and consequently they were not specially sensitized. The new material on the other hand is designed for obtaining the three. separation pictures from the colored originals directly on the matrix film.

The following two ways are possible:

(1) One sort of film is used for all three separation pictures. The emulsion is dyed with a black dyestuff in a suitable density. The emulsion carrier also is tinged with a neutral gray dyestufi in such a manner, that it possesses a transparency of about 70%. In this way one avoids the halation by reflection which always happens, when a film is exposed through the emulsion carrier. Besides being sensitized for blue light the film is sensitized for green and red light, while insuring that the sensitizing maxima in the green and in the red correspond as much as possible to the absorption maxima of the purremoved either by the treating baths or by a special bath. If for the development of the matrix films there is used a developer which hardens the gelatin at the place of the photographic image, also colloidal silver may be added to the emulsion in place of the black dyestufi. This, however, is not possible, when films are afterwards hardened with the aid of bichromate, sinceunder these circumstances the silver added to the emulsion would harden the entire emulsion layer.

(2) Three different types of films are used for the separation pictures.

(a) Blue separation picture.-Matrix films similar to the material hitherto used possessing a Emulsion not sensitized. Dyeing of the emulsion carrier'with grey or blue absorbing dyestuif.

(b) Green separation picture.Dyeing of the green sensitized emulsion with a green absorbing dyestuilf, for instance purple, the maximum of which corresponds to the sensitizing, maximum. Dyeing of the emulsion carrier with a neutral gray or green absorbing, for instance purple dyestufi. Y

(0) Red separation picture.--Emulsion red sensitized and'dyed with a red absorbing dyestuil, for instance blue-green. Antihalation layer which must be located between the emulsion layer and the original, for instance, between the carrier and the emulsion or nn'the non-emulsified side of the film. The copying must be done with a point-light source, in order to insure sharpness in spite of the distance between original and copying material. Another possibility is to copy (enlarge) optically. For the dyeing of the emulsionpreferablysuch dyestuffs are to be used which are easily dissolved or destroyed in the treating baths. Naturally also such dyestuffs can be. employed which have tobe destroyed by a special bath.

The matrix films thus obtained from them!- ored originals are dyed in a known manner and are transferred in an accurately registered form" on blanks according to the known imbibition process. v Y

It is also possible to remove the colored reliefs from their carrier and to arrange them firmly and in accurate registration one on top of the other; on another final transparent or reflecting carrier. In this case there may be used for the dyeing of the emulsion besides the aforementioned dyestufls also'such substances which are not destroyed, but remain in the relief andserv for the building up of the color image. a

What I claim is: 1. A process of producing colored copies on matrix film which comprises exposing three ma,-

trix films each comprising an emulsion carrier I and a single photographic emulsion layer thereon which is panchromatically sensitized and contains a readily removable from gray to black fllter dyestufl to the different primary color lights 1 proceeding directly from three-color separation originals and processing the-exposed films in the manner usual with matrix film.

2. The process as defined in claim 1 wherein the emulsion carrier 01' each matrix film contains as an antihalation agent a neutral gray dy estun.

3. The process as defined in claim 1 w the emulsion carrier of each matrix 'nlm cone tains as an antihalation agent a neutral gm dyestufl at a transparency of from 0.5 to ;0.9. s

4..The process as defined in claim lvwherein' the exposureoi each matrix fllm 'to the origlnal three-color separations is effected by means or separation filters transmitting-narrow spectral regions.

5. The process as defined in claim 1 wherein the maxima of the green and red-sensitivities of each emulsion correspond to-the absorption maxlma oi the purple and blue-"green dyestuils oi