DE709074C - Process for making diazotypes - Google Patents

Description

Method of making diazotypes The main pursuit: in, the modern - diazotypes is aimed at contrasting black lines to be achieved on a white background. One brought. mainly diazo compounds the group of p-diamines in application, which is substituted in various ways could be. In p-diamines, for example, one or both of the hydrogen atoms in one of the amino groups substituted by alkyl groups or other aliphatic or aromatic radicals; one could also substitute these p-diamines in their B; enzene nucleus and then they use in the semi-dry process as well as in the dry process. The general However, application failed because of the question of price, because in principle, to the extreme Cheaper blueprints to be stored are by no means expensive prepping furniture in: Asks come.

When using diazo anhydrides, it is also known. the diazo connection de; Amido-naphthol-sulfonic acid through the addition of metal salts: e.g. B. Manganese salts, to make water resistant. The use of manganese salts with inorganic acid residues led to a deepening of the color shade on the breaks, but at the same time on a very bad, slightly colored, brownish or greenish background the tracing paper, making the latter unsaleable. A pure white background could not be achieved because the one used to develop the exposed Diazo layer necessary alkaline substances, such as ammonia and others, the added: Metal salts decompose into the corresponding metal hydroxides or carbonates, which Decomposition products discolor the ground in the manner indicated until it is unusable.

On the other hand: one has the diazo compounds of the r, z or: z, z amdonaphthol sulfoic acids organic acids have also been added to achieve a white background.

If manganese salts and organic acids are added at the same time, the effect is: according to the invention, it is significantly increased because, in addition to the manganese salts and the. organic 'acids. excessive addition of . Sulfur compounds, e.g. B. thiourea oer thiosanamine, - is used, whereby .the -blackness of the lines produced is significantly improved and the formation of black dye after development 'is accelerated quite significantly. Accordingly, instead of the usual amount of 3% thiourea, at least double that amount, optionally - 10 to 20%, is added to the preparation solution.

In addition, the color contrast is increased and it is achieved that the background, which from the start shows a more pronounced white color, too retains its white color longer.

When executing the new process, the use of manganese salts organic acids with a double carbon bond in the acid residue z. B. of maleinsaurem Manganese found to be particularly useful.

The acceleration of the development aimed at according to the invention The dull black dye can also be removed by adding water-attracting substances Increase salts.

The reducing agents which are otherwise known can also be used here with advantage can be added. The application of the organic manganese salts can depend on the chosen Diazo compound take place in such a way that the manganese salt and the azo dye component containing diazo solution is added, or that the manganese salt, optionally together with other reducing agents. applies separately to the layer side. The latter is recommended, if to achieve a special dye strength high concentrations must be chosen.

The following list may serve as an example of preparation mixtures and solutions serve: zoo ccm of water, q. g i-Diazo-2-Naphtholq.-SulfOsäuxe, 3 g dichlororesorcinol, q. g maleic manganese, 15 g thioharristof% I12 g gum arabic. This solution is applied to absorbent paper.

Particularly .Beautiful caused blue-black breaks with this mixture, and the formation w l # blue-black image is more rapidly # e -I than it otherwise: is the case, the Be-.säÜeunigung the deep blue-black hue nor by. an addition of water-attracting salts, such as. B. Magnesium chloride, capillary syrup, etc., can be increased: According to the above example, a pause developed in ammonia becomes blue-violet. After the ammonia has evaporated when the pause is in the air, it becomes red-brown. Then the color effect changes to blue-black with a normal thiourea content only in the course of about 20 hours, while with the addition of larger amounts of about 15 g to 30 g of sulfourea the blue-black color occurs after about 6 hours. A further acceleration is then achieved by the aforementioned addition of water-attracting salts.

Claims (3)

PATENT CLAIMS: i. Method for making diazotypes with a Mixture of D2azo compounds of 1, 2- or 2, 1-amidonaphtholsulfonic acids, of Manganese salts and organic acids; characterized in that, moreover, an excessive Addition of sulfo compounds, e.g. B. thiourea is used. 2. Procedure according to claim i, characterized in that da.ß manganese salts of organic acids with double carbon bond can be used, e.g. B. Maleic Manganese. 3. Procedure according to claim 1 or 2, characterized in that the light-sensitive layer Turn added water-attracting salts.