CS202185B1 - Method of dyeing fibre forming polymers containing quaternary ammonium groups - Google Patents

Description

The invention relates to a method for dyeing modified cellulose fibers with reactive dyes.

When dyeing cellulose fibers with reactive dyes, a chemical reaction occurs between the dye reactive group and the hydroxyl groups of the cellulose. The reaction proceeds either as nucleophilic substitution or nucleophilic addition. In order to form a bond, the reaction must be carried out in an alkaline medium. The degree of alkalinity of the medium is governed by the reactivity of the dye used and the method of application. Dyeing with sufficient nouns is used in the pull-out dyeing process. However, a high amount of electrolyte needs to be metered in order to achieve an acceptable dye utilization.

The electrolyte doses are in the range of 50-100 g / l bath. The alkali dosages required to fix the dye are controlled by the reactivity of the respective dye, respectively. reactive group. Usually sodium carbonate is used in an amount of 5-30 g / l, target. sodium phosphate in equal amounts or sodium hydroxide or a combination thereof with sodium carbonate. The dyeing temperature again depends on the type of dye reactive group and is in the range of 20 to 95 ° C. Despite the high electrolyte dosing and the choice of the optimum dyeing mode, high dye losses occur due to the dye reacting simultaneously with water in the presence of alkali. Dye losses due to hydrolysis range from 30 to 70%. In addition, considerable amounts of hydrolyzed dye have to be laboriously removed, requiring high amounts of water and increased energy requirements. This increases the total dyeing time. Incomplete removal of the hydrolyzed dye results in impaired color fastnesses.

In impregnation dyeing processes, the use of dye is usually higher. Even here, however, there is hydrolysis and thus loss of color.

In dyeing with reactive dyes, it is very difficult to achieve deeper shades of color, especially on unercerated cotton. In such cases, it is necessary to select such high amounts of dye that the overall dyeing process appears economically disadvantageous.

The nature of the existing reactive dyes shows that they are not universally applicable to all applications. Dyes intended for drawing processes are generally not suitable for printing and, conversely, dyes for printing are not suitable for long bath applications.

All of the aforementioned drawbacks of the prior art dyeing processes are largely eliminated by the process of the invention.

Recently, the problem of modification of cellulose fibers by cationic means has been solved at several workplaces. It has been found that the fibers thus modified exhibit an increased affinity for anionic dyes. Among the many products recommended for modification are compounds of the type

202 185

202 185

R _a -N-CH-CH _O-CH-O '-III έ

Cl

R ₃ OH Cl where R 1, R ₂ , R ₃ denotes alkyl or hydroxyalkyl having a carbon number of 1 to 4. These substances react with cellulose in an alkaline medium to form a chemical bond.

It has now been found that the modified fibers can be dyed not only by conventional methods, but also in the case of reactive dyes by a completely unconventional technique, in which the necessary alkali is not required to dispense the dye for classical fibers. At the same time, it has been shown that a high degree of fixation can be achieved on the modified fibers in pull-out dyeing processes without the addition of an electrolyte.

The dyeing of the cationized cellulose with the reactive dyes according to the invention can therefore take place not only in a neutral, but even in an acidic environment. Fixation of the dye to the fiber is mediated by the basic group of the modifying agent. This dyeing method has a number of other advantages in addition to the advantages already mentioned, i.e. the savings of electrolyte and alkali. One of the greatest benefits is the surprisingly high - almost 100% utilization of the dye, which will also be economically reflected in subsequent finishing operations. The dyeing process itself is considerably simplified and shortened compared to commonly used technology. Finishing operations will also be significantly shorter than usual long-term washing and soap, and the water consumption requirements will be significantly reduced.

The new dyeing process allows entertainers to utilize and combine virtually all known groups of reactive dyes, regardless of the mode of application. Thus, for example, low-constant dyeing and low-reactivity dyeing can be dyeed at low temperatures, even for very saturated stitches.

The following examples illustrate the advantages of the invention:

Example 1:

The pretreated cotton cord is impregnated onto a bath fulary containing 50 g / l of a compound of the formula [(CH ₃ ) ₃ N - CH _{2 -} CH (OH) - ch ₂ ci] ⁺ ci20 g / l anhydrous sodium carbonate 60 g / l urea g / 1 surfactants based on alkyl sulfosuccinate.

This is followed by drying to hotflue and heat fixing for 2 min at 150 ° C. The fabric is further washed on the jug to neutralize the reaction and dyed in the bath (bath ratio 1: 3j 2% by weight of the material Reactive Blue Cl 2 Formic acid to pH 3

The first two passages are stained at 30 ° C, then the temperature is raised to 70 ° C and is then dyed for 45 minutes at this temperature. This is followed by a short wash and boiling soap.

The result is a deep blue color equivalent to approximately twice the saturation achievable by conventional dyeing on the original fabric.

Example 2:

Working twill of a mixture of 67% cotton and 33% viscose staple is cationized according to Example 1.

It is washed by passing through a wide-working machine and then dried.

Next, the bath fulary containing g / l Reactive Red Cl 2 acetic acid is soaked up to pH 6.

The bath temperature is 20 ° C, the rinse is 80%. After resting for 4 hours, the usual washing and soaping is followed by passing through a wide machine.

The result is a red coloring which shows a dye utilization of approximately 40% higher than that of dyeing by cold flinching (on the original fabric).

Example 3:

The cotton loop fabric is cationized according to Example 1, washed on a wide-screen machine, dried and impregnated with a bath containing 10 g / l Reactive Yellow Cl 2 g / L Reactive Blue Cl 95 Acetic acid glacial to pH 4

The bath temperature is 60 ° C, the addition weight is 100 ° / o. Passing through the infrazone followed by wrapping in the thermal chamber. Postponing at 85 ° C for 50 minutes followed by washing on a wide-ranging machine.

The result is a deep green color.

The washing water consumption for all three examples is at most half that of the conventional dyeing method of the same saturated shade. This is also associated with a considerably reduced amount of dye in the waste water and at the same time a reduced salinity.

Claims (1)

A method for dyeing fibrous polymers containing quaternary ammonium groups of the type wherein R 1, R ₂ and R 3 are alkyls or hydroxyalkyls having a carbon number of 1 to 4 reactive dyes, characterized by dyeing the reactive dye in an acid-reacting bath at pH 0-6, 5 for 30 s to 24 hours at 15 to 180 ° C.