CS253074B1 - Diazographic material on paper backing - Google Patents

Abstract

The invention concerns a diazographic material on a paper substrate which, in addition to the substances common in diazography, contains as a stabilizing and solubilizing additive dimethylbenzenesulfonic acid or its alkaline salts, preferably a product formed by sulfonation of further undivided dimethylbenzene isomers. The material is used in the entire field of reprography for making copies by contact method or optical transfer.

Description

The present invention relates to diazographic material on a paper backing. This material is intended for production of copies in the whole area of information systems, especially in reprography. In principle, this method consists in breaking the diazonium compound at places not covered by the drawing of the pattern, so that it is not capable of color reaction with the color forming components. In the non-illuminated areas, the non-decomposed diazo compound then reacts with the coupling agents to form an azo dye.

It is known to use a variety of diazo compounds for mono- and bi-component diazographic material and combinations thereof to achieve the desired sensitivity, density and contrast, as well as color-forming coupling agents used alone or in mixtures to achieve the desired hue. In addition to these basic substances, the diazographic assemblies used so far are supplemented with organic or inorganic acids, which act as acid stabilizers, further stabilizing substances, metallizing substances, anti-healing substances and many others are used.

The basic problem is the stability of the diazo compound itself, which is very susceptible to decomposition, resulting in poor shelf life of the material and formation of colored veils, resulting from the reaction of decomposition products with other substances contained in the assembly or more often in the paperboard itself. the need to use low dissolution temperatures due to the thermolability of diazosols.

Substances such as thiourea and its derivatives, naphthalene mono-, di- or trisulfonic acid or its alkali salts, some types of alkaloids and the like are described and used to increase stability and possibly to increase solubility.

A diazographic material has now been found on a paper backing, which is based on the fact that, in addition to the diazography of conventional metallizing, surface-active substances, etc., the diazographic assembly comprises dimethylbenzenesulfonic acid or its alkali salt as the basic stabilizing and hydrotropic substance.

SO ₃ X wherein X is hydrogen, sodium or potassium.

The use of a substance of this type is particularly important in single component materials, where, due to their hydrotropic effect, the dissolution temperature of the diazo compound can be greatly reduced, so that its thermal decomposition and taring are virtually eliminated. In terms of stabilizing effects compared to, for example, naphthalene di- or trisulphonic acid stabilizers or their alkali salts, the effect of dimethylbenzene sulphonates is at least equivalent. In general, the use of this substance increases operational reliability in the manufacture of diazographic materials and there is no need to use dissolution aids such as alcohols, glycols, etc., which are not optimal in terms of health or fire safety, or are costly.

The advantage is also the possibility of using reaction products of sulfonation of further non-separated isomers of dimethylbenzene with possible admixture of the resulting disulfoderivatives. The following substances are functional using diazo compounds of the general formulas:

^R 1

Ν, -Χ '7 - Q ^ ₂ ^ n - wherein X is a is a is a is hydrogen, alkyl, alkoxy, aryl, aryloxy, haloaryl or halogenoaryloxy group, hydrogen, alkyl, alkoxy or halo, hydrogen, alkyl, hydroxyalkyl, cycloalkyl, hydrogen, alkyl, hydroxyalkyl, morpholine, pyrrolidine, aryl, substituted aryl, hydrogen, alkyl, hydrogen, alkyl, chloride, fluoroborate, sulfate, zinc chloride.

In the production it is advantageous to use auxiliary and paper-modifying layers, for example according to U.S. Pat. AO 206 396. It is not inconsistent with our invention to use, for example, pseudo-prepreparation, supplementing the assembly with polymer dispersions, using optical bleaches, colored antioxidants and the like.

Example 1 - single component diazographic material

Prepare a solution of the following composition:

water 900 ml oxalic acid 17 g

2.4 Sodium dimethylbenzenesulfonate 20 g Aluminum sulphate 4 g

4-Diazo-2,5-dibutoxyphenylene morpholine sulfate 22 g

They are dried after application on paper. The induction is carried out in an developer with an alkaline reaction (pH greater than 10) containing floroglucin and a balancing yellow component of the N, N ¹ -ethylenediamine-bis-acetoacetamide type. The azo dye is black.

Example 2 - single component diazographic material

Prepare a solution:

water 900 ml citric acid 25 g

Sodium 2,5-dimethylbenzenesulfonate. 18 g aluminum sulphate 3 g

4-Diazo-1-tolylmercapto-2,5-diethoxybenzene.

. 1/2 ZnCl ₂ 12 g

They are dried after application on paper. The development is performed in a developer at pH 6-7 containing fluoroglucine and resorcin. The color tone is black.

Example 3 - single component diazographic material water 900 ml citric acid 18 g tartaric acid 7 g

Sodium 3,4-dimethylbenzenesulfonate 20 g

4-Diazo-1-tolylmercapto-2,5-diethoxybenzene. 1/2 ZnCl ₂ 2 g

4-diethyleneamine-3- (4'-chlorophenoxy) -6-chlorobenzenediazonium chloride. 1/2 ZnCl ₂ 14 g aluminum sulphate 4 g saponin 0.2 g

They are dried after being spilled on paper. The call is performed in the developer type according to Example 2.

Example 4 - Two-component diazographic material water 850 ml citric acid 27 g

Sodium 2,5-dimethylbenzenesulfonate 18 g 4-bromo-3,5-dihydroxybenzoic acid methylamide 10 g zinc chloride 8 g

4-diazo-2,5-dimethoxyphenylmorpholine. 1/2 ZnCl ₂ 12 g

They are dried after being applied to a paper backing. The development is carried out in ammonia vapors and the red color of the drawing is obtained.

Example 5 - two-component diazographic material water 850 ml citric acid 22 g tartaric acid 3 g itaconic acid 2 g

Sodium 3,4-dimethylbenzenesulfonate 20 g of 2-hydroxy-3-naphthoic acid morpholinopropylamide. 10 g

4-diazo-N, N ' -diethylaniline. ZnCl ₂ 12 g aluminum sulphate 9 g zinc chloride 6 g

The paper is dried after deposition. The development of the azo image is carried out in ammonia vapors and the blue color of the image is obtained.

Claims (1)

Diazographic material on a paper support, characterized in that the diazographic assembly comprises as a solubilizing agent dimethylbenzenesulfonic acid or an alkali salt thereof of the formula wherein X is hydrogen, sodium or potassium, preferably comprising the reaction product of the sulfonation of undivided dimethylbenzene isomers with optional admixture coupling with diazonium salts of the general formulas «2 wherein R R R _n 6- ^S 'X ^ -N ₂ -> ^NH - (N ₂ -) is hydrogen, alkyl, alkoxy, aryl, aryloxy, haloaryl or haloaryloxy, is hydrogen, alkyl, alkoxy or halogen, R 6 is hydrogen, alkyl, hydroxyalkyl, cycloalkyl, R 4 is hydrogen, alkyl, hydroxyalkyl, R $ is morpholine, pyrrolidine, R 8 is aryl, substituted aryl, R? is hydrogen, alkyl, R 8 is hydrogen, alkyl, X is chloride, fluoroborate, sulfate, zinc chloride either alone or in mixtures in an amount of 1.5-56% by weight.