US1911955A - Phototransfer process - Google Patents

Description

PHOTOTRANSFER PROCES S Filed Sept. 24, 1927 MAY CONTAIN SUBSTANCE RENDERING CORTING NON-ACTINIC INK IMPENETRHBLE COATING SENSITIZED EMULSION SH E ET BASE NON-A GTIN I 0 GOAT! N 6 ff dimm flea/woke fikkda f/gagagvelyer Patented May 30, 1933 UNITED STATES:

PATENT OFFICE 'rnororimivsrnn PROCESS I Application filed September 24, 1327. Serial No. 221,853.

This invention relates to aphototransfer process for use in printing or photography. In the co-pending application of William Heinecke, Serial No. 189,458, filed May 6, 1927, .there is described a method of making negatives, or positives, for printing or photographic purposes, Comprising pulling an inked impression from lithographic stone, copper plate, type, or the like on the sensitive side of a sensitized sheet or photographic film, plate, or the like, developing the impression,- washing oflf, the ink,.and fixing;

The present invention differs from the former in that the impression is pulled on the non-light sensitive side of a sensitized sheet of paper, film, or the like, and the sheet then exposed with the printed side toward the light. After or before being de- 9 veloped the ink impression is removed and the sheet or film fixed in a suitable 'bath, washed and dried.

The present invention provides a simpler and more economical method in that a cheaper grade of sensitized material may be used. We have furtherprovided a specialv protective coating for the material toprevent actinic action upon the sensitizing agent so that the process may be carried out 0 in daylight or under artificial light, using ordinary or even high-speed sensitiveemulsions.

Furthermore, the present invention obvi-' ates the necessity of reversing the negative when using the negative for printing on sensitized zinc plate for offset'printing. 'Our invention insures closer contact between the negative proper and sensitized side of the zinc plate, thereby resulting in a clearer and more sharply defined print.

. to provide a method applicable to offset light in the course of operations.

printing, commercial photography and the photographing of finger prints that will repended claims.

Our invention in its preferred form is illustrated on this accompanying sheet of drawing.

The sensitized material that is suitable for our process includes sensitized paper, film or stripfilm, glass and the like, but we prefor to use a paper of fairly cheap stock that 55 is white, or translucent or semi-translucent, closely formed and hard, of about 0.002 to 0.003 inch in thickness. The sensitive coating is comprised of known emulsions of silver halides, ferric compounds, bichromates and other substances, but is preferably an extremely low speed emulsion to enable the operation to be carried out in daylight or" artificial bright light.

We can, however, use ordinary or high speed emulsionsby employing non-actinic coatings or desensitizers or both to prevent chemical action by ordinary exposure to If a fast emulsion, that is, a highly light sensitive one, is used, the sensitized material isprotected against light during operations by a coating of a red-colored solution that will readily dissolve in the developing solution and on the paper side of the sheet by a coating of yellow colored gelatine solution or other suitable material.

Our process has thus obvious advantages over the usual photographic processes which require dark rooms, since the printing and It is therefore an object of this invention proof presses, from which the impressions will be frequently pulled, cannot be installed in dark rooms nor can the usual press rooms be readily converted'into dark 'sensitizer for use in connection with ordinary or high speed emulsions is phenosafranine.

In order to prevent the ink from penetrating into the paper used for pulling the impressions, we prefer to employ a suitable coating, which may be prepared from sodium silicate, lacquer, wax or the like.

There are, however, certain special inks available for our purpose that do not require any such coating. By inks, in general, we intend to include all inks of a fatty or greasy nature or fats and greases opaque in character that are suitable for our purpose.

The ink, of course, prevents any chemical action on the parts of the sensitized sheet or film covered by the ink, and after the ink has been removed by a proper solvent, such as potassium bicarbonate, the free silver is washed out of said parts to produce a perfect'negative.

Other solvents, such as benzine, ether, spirits of turpentine and the like may alsobe used, but we prefer potassium bicarbonate because it readily saponifies the greases or fats of the ink, thereby rendering the operation clean, while other solvents will soil trays and the hands of the operator with ink and will form a film on the fixing bath.

Without limiting our invention to any particular procedure the following. method will serve to illustrate our preferred mode of operation.

We start with a sensitized paper such as above described, the unsensitized side of which has been previously coated with a suitable coating to prevent the ink from penetrating the paper and affecting the light sens1tive emulsion. Such a coating may be comprised of the following ingredients:

Beesw x 15 grains Rosin 30 grains Gum dammar I 10 grains Benzine 5 ounces 7 Spirits of turpentine 5 ounces For the developer, We preferably use the following formula:

Ounces Water 32 Sodium sulphite (dry) 5 Hydrochinone 1 Formalin 1 fixing bath,

preferably of the following composition.

- Ounces Water 64 Hypo 16 Stock hardener 8 When the'fixing operation, requiring about one to two minutes, has been completed, the negative is thoroughly washed in several changes of water of medium temperature and is then ready for use.

It will be appreciated that according to our present invention, the non-sensitive side of the paper having received the inked impression, the negative thus produced will show the type in the same order or arrangement as it occurs on the press. Naturally, if our process is to be used in offset printing, the regular, or non-readable, arrangement of type on the press will be employed so that it will not be necessary to reverse the negative in its subsequent application to a sensitized zinc plate. This is unimportant feature, as heretofore described, because it results in clearer and more sharply defined print.

Our process is obviously well adapted not only to offset printing, photo-engraving, and kindred arts, but to commercial photography and to the recording of finger prints.

We are aware that many changes may be made and numerous details of our process maybe varied through a wide range without departing from the principles of this invention, and we therefore do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior art.

We claim as our invention:

1., As a new article of manufacture, a sensitized sheet having a non-actinic coating on its light sensitive side and a nonactinic and ink impenetrable coating on its non-sensitized side.

2. As a new article of -manufacture, photo-sensitized sheet material comprising a translucent base having a sensitive coating and an outer non-actinic water soluble coating on one side and a non-actinic and ink impenetrable coating on its reverse side.

3. As a new article of manufacture, a sensitized sheet having a non-actinic coating on its light sensitive side and a yellow, ink impenetrable coating on its non-sensitized side.

4. As a new article of manufacture, a translucent paper having a low speed light sensitive coating on one side and a transparent coating comprising Wax, gum dammar, and rosin on the reverse side.

In testimony whereof, We have hereunto subscribed our names at Chicago, Cook County, Illinois.

WILLIAM HEINECKE. FRIEDA HUNSPERGER.

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