DE1139021B - Process for making hectographic prints and photographic material therefor - Google Patents

Description

The invention relates to an improvement in the main patent application G 19595 IXa / 57 d (German Auslegeschrift 1016127) described method for the production of numerous hectographic prints of one obtained by photographic means hectographic printing form.

Using the main patent application procedure, numerous Copies are made when one

1. this original reproduced photographically on a light-sensitive material, its Halogen silver emulsion preferably has a non-colored or only slightly colored water-insoluble dye component containing the image formed by tanning development selectively on the support of the photographic material allowed to adhere while removing the rest of the emulsion,

2. then the remaining tanned image containing the dye component as Brings printing form with the copy paper in contact, the printing form and / or the Copying liquid either separately or in combination means for converting the dye component included in dye, and finally

3. Repeatedly replace the printing form with new copy paper in the presence of the copying liquid brings in contact.

For the production of this printing form or this relief image are in the main patent application as well in the German Auslegeschrift 1 084 570 various execution methods are described.

According to the embodiments of the main patent application, the copy paper and / or the Copy liquid contain an agent that quickly and at room temperature the dye component converts into dye. If the emulsion contains a leuco base, the paper and / or the copying liquid must contain an oxidizing agent. Particularly suitable for this are: high-quality cerium, Vanadium, manganese compounds, dichromates, etc. Next, the layer of copy paper can be products to increase the lightfastness of the organic dye, such as heteropoly acids.

Finally, the copying liquid must ensure that either the dye component in the emulsion or the dye formed is dissolved and can diffuse over to the copy paper.

An aqueous solution of an acid, preferably an organic acid such as oxalic acid, lemon method for the production

hectographic prints

and photographic material therefor

Addition to patent application G 19595 IXa / 57 d
(Interpretation document 1016 127)

Applicant:

Gevaert Photo-Products NV,
Mortsel, Antwerp (Belgium)

Representative: Dr. W. Muller-Bore

and Dipl.-Ing. H. Gralfs, patent attorneys,

Braunschweig, Am Bürgerpark 8

Claimed priority:
Netherlands of 8 October 1959 (no.244 134)

Albert Emiel van Hoof, Berchem, Antwerp

(Belgium),
has been named as the inventor

acid, tartaric acid, etc., is particularly satisfactory as a copying liquid when using leuco bases.

In example 3 of the main patent application, a method is described, according to which a gelatin relief, the containing a leuco base and an oxidizing agent, in the presence of an aqueous acid solution with ordinary Paper is brought into contact, whereby the leuco base is converted into dye at the same time, this dye diffuses over to the paper and thus provides a colored print of the original.

Maintaining the printing form in contact with the paper can be carried out in a copier of the alcohol duplicator type take place. If an aqueous acid solution is used as the copying liquid in this process

there is a risk that the material of the duplicator will be attacked. In addition, the paper moistened with an aqueous solution easily adheres to the image relief serving as the printing form.
In order to avoid these disadvantages, after the image relief, which contains the leuco base of a triphenylmethane dye, has been produced, this leuco base can only be mixed with one or more bath treatments

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convert an oxidizing agent and a dilute acid into a dye and then with this printing form in an ordinary alcohol duplicator with the help of the usual alcohol duplicator copying liquid, which usually contains one or more lower aliphatic alcohols, make prints.

But the disadvantage of this process is that it rinses out the dye that has formed during the conversion of the leuco base into dye necessary treatment, so that only a small number of fairly blurred copies are obtained will.

In contrast, the subject of the invention is a further development of the process of the main patent application, according to which one can make numerous sharp copies of the original. This further Training is characterized in that the mirror image formed in the positive relief of the printing form Dye due to the action of di- or trichloroacetic acid in a hardly soluble or water-soluble Dye is reacted, whereupon the resulting colored printing form with a copy paper in the presence a lower aliphatic alcohol is brought into contact.

The new process offers the significant advantage that the use of acidic solutions in the Alcohol duplicator is omitted, so that the corrosive effect on individual metal parts is avoided will.

Another important advantage is that in this way the dissolution of the Dye former is strongly counteracted in the acidic bath.

Particularly suitable oxidizing agents for using the method according to the invention are the same which are used in the main patent.

In principle, the treatment of the washed-out image relief is carried out according to the method according to the invention carried out in stages as follows: The printing form can only be made through an oxidation bath from a dilute aqueous potassium permanganate solution, and then through an acid bath consisting of an aqueous solution containing di- or trichloroacetic acid are passed. This di- or trichloroacetic acid however, it can also be dissolved in the oxidation bath. Of course, the Dioder must then Trichloroacetic acid compatible with the oxidizing agent for at least a certain period of time be,

After this treatment, the formed printing form can after removal of the excess liquid can easily be used to produce numerous prints on paper that is printed with a Copying liquid was moistened, mainly composed of a lower aliphatic alcohol, such as Methanol, ethanol or isopropanol or a mixture of such alcohols with one another or with Water. This copying liquid can of course also contain the usual ingredients for the Composition of duplicator fluids included. Such compositions are under described, inter alia, in J. Chem. Education, 32, pp. 200-202 (1955) and in the USA patents 2,228,108, 2,262,488, 2,294,711.

The following examples serve to illustrate the invention without, however, restricting it thereto.

example 1

A according to the main patent application G19595 IXa / 57 d (German Auslegeschrift 1016 127) produced material is reflectographic behind an original exposed. After tanning development, as described in German Auslegeschrift 1 084 570, the undeveloped and consequently not hardened parts of the gelatin emulsion layer were washed away. The image relief obtained in this way is immersed in a 1% strength aqueous potassium permanganate solution for 5 seconds dipped, whereupon the excess solution is removed by squeezing it between two rubber rollers will.

The treated image relief is then immersed in 10% aqueous trichloroacetic acid for 5 seconds. The excess liquid is removed by squeezing it between two rubber rollers, whereupon the obtained printing form is attached to a duplicator containing isopropanol as a copying liquid. With this printing form numerous sharp copies of the original to be reproduced can be produced will.

Example 2

A gelatin relief image produced according to Example 1 is immersed in a solution of the following composition for 30 seconds submerged:

10% aqueous ammonium

dichromate solution 4 cm ³

20% aqueous dichloroacetic acid

solution 50 cm ³

The procedure is as in Example 1, with the difference, however, that ethanol is used as the copying liquid is used.

Example 3

A gelatin relief image produced according to Example 1 is immersed for 3 seconds in a mixture of 20 cm ^{3 of} a 20% aqueous trichloroacetic acid ^{solution and 50 cm 3 of} a solution of the following composition:

Ceris sulfate _t 41 g

Concentrated sulfuric acid ... 28 cm ³ water 500 cm ³

The further treatment takes place as described in Example 1.

Claims (1)

PATENT CLAIM: Process for the production of hectographic prints according to the main patent application G19595 IX a / 57 d (German Auslegeschrift 1016127), characterized in that the dye formed in the positive relief mirror image of the printing form is converted by the action of di- or trichloroacetic acid into a dye that is barely or insoluble in water , whereupon the obtained colored printing form is brought into contact with a copy paper in the presence of a lower aliphatic alcohol. © 203 679/182 10.62