DE814995C - Process for photo reproduction in the dry way - Google Patents

Description

This invention relates to a new method of photographic copying on the dry path.

For the production of photocopies, many processes have been proposed, which in principle can be used the chemicals used as the photosensitive element and the manner in which the color image is developed differentiate. The best known of these methods are those that focus on the photosensitivity of aromatic Diazo compounds, iron salts and bichromates are based.

It is known that light-sensitive anthraquinone sulfonic acids and their salts in the presence of oxidizable compounds to give the corresponding dihydroanthraquinones be reduced when exposed. While it is also possible to use negative silver images produced by exposing paper that is coated with a layer of anthraquinone sulfonic acids and then treated with silver salts, but such a process is not very practical because it Requires four wet treatments of the exposed print.

This invention relates to a new process for the production of photocopies, in which light-sensitive anthraquinone sulfonic acids or their alkali salts are used.

Another object is a new photocopying process which is used to develop the exposed Trigger does not require wet treatment.

It has been found that cupris salts are easily reduced to cupro salts when in the presence of a light-sensitive anthraquinone sulfonic acid or its alkali salt are moistened, and that the formed Cupro salt can be transformed into a metallic copper image by heating to at least 100 ° C.

ίο According to one embodiment of the invention a suitable carrier such as paper or film, preferably a paper provided with a gelatin layer or film, with an aqueous solution of a cupric salt, such as cupriformate, cuprilactate, cuprifluorosilicate, Cupric acetate, cupriaminoacetate, cupric gluconate, cupric sulfate and the like, and a photosensitive Anthraquinone sulfonic acid or one of its salts, such as anthraquinone-2, 6-disulfonic acid, anthraquinone-2,7-disulfonic acid, Anthraquinone-i, 2-disulfonic acid, anthra

ao quinone-2-sulfonic acid and the like, or their alkali salts overdrawn. Of the above-mentioned cupri salts, cupriformate is preferable because it is the easiest to use Cuproformate can be reduced and very easily transformed into metallic copper. After drying the carrier treated in this way is exposed to light in contact with an original to be reproduced. The anthraquinone sulfonic acid is reduced to the corresponding hydroanthraquinone, which in turn is the Cupra salt reduced to cupro salt. The exposed substrate is then brought to a higher temperature, z. B. 100 to 170 "C, creating a metallic Copper picture is created.

In another embodiment, the one with a layer of the photosensitive anthraquinone sulfonic acid and carriers provided with the cupric salt can also be used for reflex copying.

Copies made by the process of this invention are red to brown in color pure white background, good contrast and excellent impermeability to ultraviolet, violet and blue light, so that they leave a wide margin for the copy exposure and therefore can be used as intermediate copies without the risk of overexposure. As a result of the advantage of The process is characterized by its great simplicity in dry development and fixation.

The addition of a mild reducing agent such as glycerin, sorbitol and the like to the coating solution increases the sensitivity and density.

The shelf life of the finished photosensitive paper or film and the durability of the developed one Copy can still be enhanced by using the photosensitive paper or the The film is provided with a water-repellent layer, such as paraffin. The invention is accomplished by the following Examples described in more detail.

example 1

The film provided with a gelatin layer is treated with a solution of

10 g cupriformate and

2 g of anthraquinone-2,6-disulphonic acid sodium in 100 ecm of water

treated and dried. The film is then exposed under a to be reproduced original and the exposed FiJm heated for 3 minutes for 130 to 140 ⁰ C, whereby a dark brown-red negative copy is thus obtained with excellent contrast.

The picture becomes even darker if 6 ecm of glycerine are added to the above solution and that with it treated film is exposed and heated as above.

Example 2

A paper provided with a gelatin layer is treated with a solution of 15 g cupriformate

2 g of anthraquinone-2, 7-disulfonic acid sodium and 20 ecm of glycerine in
100 ecm of water

treated and dried. The paper is exposed under a negative and then 5 minutes on Heated to 130 ° C, creating a brown-black positive is produced with excellent contrast.

Example 3

A film provided with a gelatin layer is treated with a solution of
13 g cupriformate

2 g of anthraquinone-2,6-disulfonic acid sodium and 10 ecm of glycerine in 100 ecm of water

treated and dried. The film is exposed under a positive and then at 170 ° C for 5 seconds heated to give a dark, brownish-red negative with excellent contrast.

Example 4

A paper provided with a gelatin layer is treated with a solution of

6 g cuprilactate

2 g of anthraquinone-2,6-disulfosaurem sodium and '10 cc of glycerol in

100 ecm of water

treated and dried. The finished paper is exposed under a negative and then for 2 hours warmed to 100 ° C. A brown colored copy is obtained.

Example 5

Paper is made with a solution of 15 g cuprifluorosilicate

2 g of anthraquinone-2,6-disulfonic acid sodium and 10 ecm of glycerine in
100 ecm of water

treated and dried. The finished paper is exposed under a negative and then heated ^{to 150 ° C. for 1 minute.} A red-brown image is obtained.

Example 6

A film provided with a gelatin layer is treated with a solution of
15 g cupriaminoacetate

2 g of anthraquinone-2,6-disulfonic acid sodium and 10 ecm of glycerine in 100 ecm of water

treated and dried. This film is exposed under a negative and at 120 ° C. for 15 minutes warmed up. A red-brown colored image is obtained.

Claims (5)

PATENT CLAIMS: 1. A method for producing photocopies by dry means, characterized in that that a suitable substrate, preferably provided with a gelatin layer, such as film or paper, with a solution of a cupric salt and a light-sensitive anthraquinone mono- or polysulfonic acid or one substituted in the 2-position of the anthraquinone nucleus with a sulfonic acid group Derivatives or their alkali salt treated and after drying and exposure in contact with an original to be reproduced is developed so long by heating to temperatures above 100 ° C that red-brown colored Copies are made. 2. The method according to claim 1, characterized in that that the cupric salt, cupric sulfate, cuprilactate, cuprifluorosilicate, cupric acetate, cupriaminoacetate, Cuprigluconate, etc., but preferably cupriformate, is used. 3. The method according to claim 1, characterized in that that as light-sensitive anthraquinone mono- or polysulfonic acid and its derivatives, preferably anthraquinone-2-sulfonic acid, anthraquinone-i, 2-disulfonic acid, anthraquinone-2, 6-disulfonic acid, anthraquinone-2, 7-disulfonic acid or their alkali salts are used. 4. The method according to claim 1 to 3, characterized in that the sensitizing solution is a mild reducing agent such as glycerin, sorbitol o. The like., is added. 5. The method according to claim 1 to 4, characterized in that the copy material according to the Treatment with the aqueous solution and, after drying, with a water-repellent Layer, such as paraffin, is provided. 1556 9.51