DE469326C - Process for dyeing leuco ester compounds from dyes of the indigo series and other dyes in the dipping cup - Google Patents

Description

Process for dyeing leuco ester compounds from dyes of the indigo vat and other vat dyes in the dipping vat It has been shown that the use of leuco ester compounds from dyes of the indigo series and other vat dyes can very effectively replace the old indigo dipping vat preparation. So Uelingt z. B. according to the development methods mentioned in patent 410 972 z # Z, e.g. with the leuco ester of Inäigo in the time necessary for one puff in the indigo vat, for which with indigo, depending on the concentration of the vat, 8 to 10 and more puffs, so at least 8 to 10 of the time and work is necessary. However, since the leuco ester compounds of indigo and other vat dyes are usually very easily soluble, they have the unpleasant property of concentrating on drying the soaked goods stretched on the so-called star hoop after the tighter, more open tissue parts that dry faster. This gives streaky colorations during development.

The important fact has now been found that this defective drying can be avoided by adding dextrin, glue, starch paste or similar substances to their vats - which reduce the mobility of the dye in the drying solution. - In this way, completely uniform colors are obtained when the dried goods are developed in sulfuric acid. A further advantage has been found that these additives significantly reduce the disruptive development of nitrous acid. The procedure is illustrated by the following example. EXAMPLE A dye bath is prepared from 100 g leuco ester of indigo, 100 g dextrin, ro g Glauber's salt, crystalline. 3 g of formaldehyde -lo () / o, 16 g of sodium nitrite, 1 1 water.

The '# Vare stretched on the star hoop is hung in the cold bath for 10 minutes to 1/1-hour. After pulling out the star tire, it may be turned over and allowed to drain, then dried in the air or in a moderately heated drying room. Then one dips the star hoop for about ll /. Minute in a bath with 30 1- sulfuric acid 66'B6 in the liter of water, rinse well and dry. The development of the indigoleuco ester compound can also be carried out continuously in the broad state after the dried goods have been removed from the star tire.

Claims (1)

PATENT CLAIM: Process for coloring leuco ester compounds Dyes of the indigo series and other vat dyes in the immersion cap, thereby characterized in that you have their Eüpen, dextrin, glue, starch paste and similar acting Adding substances that cause the uneven drying of the dye on the with the Prevent dye solution soaked goods.