DE513358C - Process for the production of colorings and prints with ester salts of Kuepen dyes - Google Patents

Description

Process for the production of dyeings and prints with ester salts of vat dyes Addition to Patent 418487 dyeings with vat dyes be made by a textile fiber with an ester salt of a leuco vat dye (see patent 424981) impregnated and afterwards the coloration through a suitable oxidizing effect, z. B. by means of ferric chloride + acid, nitrite -f- acid or bichromate -f- acid (see patent 418 487, 410 972).

Give the oxidizing agents previously used for the stated purpose not always satisfactory results, as they sometimes seem too energetic, which can lead to overoxidation. So z. B. the ester salt of Leuko-N-Dihydro-i, 2, 1 ', 2'-anthraquinone azine on the fiber easily over due to excessive oxidation the normal level: dihydroanthraquinone azine converted into dianthraquinone azine, whose nuance is worthless.

The oxidizing agent used must meet the following requirements fulfill. It should rapidly and completely develop the color, i. H. the regression effect of the vat dye from the ester salt on the fiber without this beforehand Ester salt is partially dissolved away from the fiber and passes into the bath. The oxidant should not, however, act so forcefully that over-oxidation occurs. It was now found that in many cases iron ammonium alums, generally iron alums, are considered mild Oxidizing agents meet these requirements to a high degree. It becomes one Oxidizing agents can be used to advantage in all cases where the There is a risk of over-oxidation.

On animal fiber (wool, silk, etc.), to which the sulfuric acid ester of the leuco vat dyes show affinity without exception (see patent 431 g01), iron alum is readily applicable.

In the case of vegetable fiber, this oxidizing agent is only used in such Ester salts come into consideration, which once show affinity for the fiber, so that this after the ester salt has been absorbed and before the development of the color due to oxidation can be rinsed without the ester salt being dissolved away, and furthermore easily are oxidizable (i.e. can be developed with a mild oxidizing agent). It is a coincidence that the ester salts, which show affinity for vegetable fibers, are generally also easily oxidizable.

In the case of vegetable fiber, however, the use of iron alum has excepted the avoidance of overoxidation, still another advantage. The ones that have been used so far Oxidizing agent, such as ferric chloride, nitrite, bichromate, etc., must used in the presence of free acid, otherwise it will not work at all or too slowly works. In general, this can be done safely, provided that: after dyeing the acid can be thoroughly removed from the fiber by rinsing. But it can There are cases where flushing water is not available in any quantity, such as B. in the Orient, and there is the risk of fiber damage from incompletely rinsed Acid not excluded.

The slightly acidic reacting iron alum now offers the great advantage that it can be used in the developing bath without the use of free acid can. This significantly reduces the risk of acid damage to the fibers. Much less water is also required to rinse the dyed goods.

The process is illustrated by the following examples: I. Wool is made from a bath which, based on the weight of the wool, contains 1/2% ester salt of leuco-N-dihydro-1,2,1 ', 2'-anthraquinone azine Contains 100% formaldehyde sulphoxylate, 100% ammonium sulphate and 2% acetic acid, colored at the boil for about one-quarter hour, until the bath is exhausted. The coloring is then in. a bath which contains 2½% iron ammonium alum and 7 g sulfuric acid per liter, developed at the boil for 179 hours.

In the same way, silk or any other animal fiber can be dyed will.

II. The ester salt of Leukodimethoxydibenzanthron is made from neutral, A bath containing glauber's salt is allowed to soak on cotton at about 7o to 8o'C. After a cold intermediate rinse, the orange-brown pre-dye is in a solution of iron ammonium alum z: ioo in water that does not require any further additives, developed quickly and smoothly to the vivid green shade at ordinary temperature.

Instead of iron ammonium alum, similar examples can be used in these examples Other iron alums can also be used as a result.

Claims (1)

PATENT CLAIM: Further training of the manufacturing process of true dyeings and prints using ester salts of leukokipene dyes according to the main patent, characterized in that in order to obtain a suitable tint to achieve the oxidizing effect and to reduce the risk of fiber damage, Iron alum used as an oxidizing agent.