SU48934A1 - The method of obtaining vat dyes - Google Patents

Description

Vat dyes, due to the exceptional strength of their color on fabrics, are becoming more and more common.

 There is a wide variety of colored vat dyes. Black and gray dyes are represented by units only.

Of the few known gray dyes (german. Pat. Nos. 213501 and 157685) such as, for example, indanthrene gray 6B (german. Pat. Nos. 216224, 252771, 239673, 240805, 241910) are distinguished by the complexity of the synthesis, and for black color , e is known only one representative.

This black dye (Germ. Pat. Nos. 185222, 226215 and 402641), is ush; dinitroviolantron itself (indanthrene black B, 2 Schultz tab. No. 1267, 1268) has the disadvantage that it gives black color only after oxidation, usually achieved by passing the colored fabric through an oxidizing bath, which introduces, thus, a well-known complication in the dyeing technique (germ. pat. No. 448908.).

The proposed method makes it possible to obtain vat dyes, free from the specified disadvantage; these dyes dye the fabric directly, without additional oxidation, in colors from deep black to deep blue.

Possessing all the inherent properties of cubic dyes for light, washing, etc., these new dyes can also be used to obtain gray tones.

The starting material for producing the proposed dyes is the oxidant product of violantron (dibenzantron); and the process of obtaining them consists in heating the product of the above oxidant product of volantron in a dry form in the presence of air — a black dye is formed (germ. Pat. No. 259370 and amer. Pat. No. 1910603).

If heating is carried out without air, a dark blue dye is formed. By varying the duration of the initial heating without access for air followed by heating with the access of air, it is possible to obtain, if desired, a black dye with any degree of blue, up to deep blue, i.e., to obtain particularly valuable black shades.

Example 1. Heated with the access of air in a dry form. The oxidation product of violantrone (according to Germ. Pat. No. 259370

or amer. pat No. 1910603) at a temperature of 350 ° - 380 °, until the trial of vygraska does not show the complete disappearance of greenness. The resulting product, without any further processing, can be used as a black vat dye or as a gray dye at low concentrations.

PRI mme R 2. Heat the same product as in example 1 at the same temperature, but without air.

Get dark blue vat dye.

Example 3. Heated the same product as in examples 1 and 2 and at the same temperature, but initially without air access, and then with air access, get a black dye with the desired degree of blue.

The subject matter of the invention.

1. A method for producing vat dyes from dark blue to black, characterized in that the oxidation product of dibenzantron (vyolantron), obtained, for example, from germs. pat No. 259370, is heated at 350-380 ° until the desired shade of color is achieved, in the absence of air in order to obtain dark blue dyes and in the presence of it in order to achieve black tones.

2. Acceptance of the method mentioned in claim 1, characterized in that the initial oxidation product of the violantrone mentioned in claim 1 is heated first without air and then in the presence of it.