DE748974C - Process for printing cellulose fibers - Google Patents

Description

Process for printing cellulosic fibers There are already printing processes known, according to which one vat dyes as unlinked pigments without the addition of Printing reducing agents onto the fiber with the help of suitable thickening compounds. then developed and fixed.

The development can be done in such a way that the printed goods are in one Bath paddles or blocks, which in addition to sodium hydrosulfite still caustic alkalis, z. B. \ Ta O H or K O H, contains. Because of the implementation (of this procedure resulting difficulties (short shelf life of the pad bath, inaccurate pressure, fluctuating color loss), this process could not be used on a technical scale can be carried out in a satisfactory manner.

One can: but also carry out the development in such a way that one follows the Klotzbade sodium formaldehyde sulfoxylate and alkali, carbonate, z. B. soda or potash, clogs.

In general, one works in a bath which contains roo to 1509 sodium formal, dehydsulphoxylate and 80 to zoo g potash per liter of liquor. In addition, hygroscopic substances are added, for example glycerine, in amounts between 50 and aoo - / l, the amount depending on the type of continuous damper.

Processes are also already known by which it is possible is to save on reducing agents, the addition of hygroscolic substances reduce or omit at all or the otherwise usual intermediate drying to drop the log bath.

The surprising finding was now made that one ate Better through-printing gets deeper and brighter colors, if you have that up to now applied carbonic acid alkali rder the sodium formaldehyde sulfoxylate liquor wholly or partially replaced by caustic alkalis. with the proviso that the total alkali content of the reducing solution, calculated on Na O H, exceeds 1 o g ini liter.

The aforementioned advantages are to-recycle that, in your novel process, the fixation of the colors is faster and better, they @da almost quantitatively be absorbed by the fiber.

It was also found that after yours. -.Verfahren of the present invention can also use such viable dyes. which, due to their difficult fixability, have so far not been considered suitable for carrying out the above-described method. . Example z A cotton and rayon mixed fabric is printed with a printing paste of the following composition: So g of indanthrene blue GCD (Schultz, Dye Tables, 7th Edition, No. 1234) are mixed with 30 g of a highly effective wetting and distributing agent, for example highly sulfonated oil.

The paste is diluted with 320 g of water, whereupon 60o g of a thickener is added, made from 20 g of carob seed flour, 0.5 g of NaOH 35 % Be and ro6og water.

The printed goods are padded with the following solution: rooog water, 3og sodium formaldehyde, sulfoxylate, suction sodium sulfate anhydrous, 20 g sodium carbonate anhydrous, 709 NaOH 35'B # = 20 ° NaOH solid.

In this block bath you go with the dried goods, squeeze then down to about 100% block fluid and steam in the mattress for 5 to 6 minutes.

EXAMPLE 2 Instead of the mixture of 20 g anhydrous sodium carbonate and 709 NaOH 35 ° Be given in the preceding example, 80 g NaOH 35 ° Be = 23 g solid NaOH can be added to the pad bath.

Claims (1)

PATENT CLAIM: Process for printing cellulose fibers by printing printing pastes containing vat dyes and thickeners which can be precipitated by alkalis, padding with alkaline sodium formaldehyde sulfoxylate solutions after intermediate drying, steaming and reoxidation, characterized; that sodium formaldehyde, ifoxyl: at solutions are used which contain alkali hydroxide alone or in combination with alkali bicarbonate and whose total potassium content, calculated on NaOH, exceeds ro g per liter. To differentiate: the subject of the application from the state of the art, the following documents were considered in the grant procedure: French patents. No. 783 455, 642 99 1 , 36 498, addition to 642 99 1 .