DE2417256B2 - LIQUID DYE PREPARATIONS OF A REACTIVE DYE - Google Patents

Description

SO ₃ H

is equivalent to. These dye preparations are characterized in that they contain the dye mentioned, preferably as its alkali, in particular sodium, salt in an aqueous solution in a concentration of 5 to 35 Percent by weight, preferably 15 to 30 percent by weight, based on the pure dye of the formula (I), and have a pH value between 3 and 7, advantageously between 5.5 and 6.8 and additionally I to 5 percent by weight of buffer substances that are not chemically reactive with the reactive group are able to contain.

This dye of the formula (I) is known from DT-OS 18 04 524, Examples 4 and 5.

Water-soluble reactive dyes are isolated after their synthesis in the usual way so that they can from the aqueous reaction solution are salted out, the »precipitated salt-dye mixture is filtered off with suction and the press cake obtained is dried. Another technically common method, the solved one, in the Usually, to isolate easily water-soluble dye from the synthesis solution is direct drying, for example the spray drying of the manufacturing solution.

For the desired dyeing application, the salt-containing dye powder is usually added afterwards drying by adding neutral inorganic salts such as sodium sulfate, adjusted to a certain dye content.

However, these conventional powder formulations of reactive dyestuffs have a number of disadvantages which result in particular from the formation of dust in such pulverulent coloring preparations when SO ₂ —CH ₂ —CH ₂ —OSO ₃ H

you work with them, such as when filling and decanting, when weighing and dosing or when preparing the Dye liquors or printing pastes. This dust development is not only a nuisance for them Workers in production or application operations, but can also work in the Dyeing or printing works lead to unpleasant speckled staining as a result of the settling of the dye dust lead undyed or already dyed goods. On the other hand, there is the dust removal of powdery Dyes with the common dedusting agents based on mineral oil always run the risk oily deposits during dyeing and printing, resulting in stained and therefore unusable dyeings and Printing leads. Furthermore, such pulverulent dyes are often those that are desirable in technology Rationalization measures, such as continuous dyeing processes or automatic dosing and weighing equipment, not feasible.

These disadvantages, which also apply to the above-mentioned powdery dye of the formula (I), become completely avoided by the liquid dye preparation according to the invention of this dye of the formula (i). In addition, the new preparation results from both the dye manufacturer and the dye user this has advantages over the powdery dye settings, that is, the exposure to salt the wastewater is significantly reduced.

The new liquid dye preparations of the dye of the formula (1) are namely in accordance with the invention Way made so that one at the

Synthesized, clarified dye solution used directly and, if desired, as advantageous, either by concentration, for example by distilling off part of the water under vacuum, or advantageously by adding a dried, for example spray-dried, portion thereof the synthesis obtained and clarified dyestuff topping adjusts to the desired higher dyestuff content, In all cases, buffer substances are also added to this dye solution.

For the production of such inventive coloring preparations with up to 35 percent by weight of dye it is advantageous to start from aqueous, clarified dye solutions whose content of inert salts, such as for example sodium sulfate or sodium chloride, as low as possible and below 50 percent by weight of the The dye content of these dye solutions obtained during the synthesis lies. In the manufacture of Dye preparations which have a lower dye content, such as those with up to 15 percent by weight Dye, the inert salt content of the starting solutions should be lower than their dye content. In the As a rule, the inert salt content of the aqueous dye solutions obtained during the synthesis is below this Limits. To also with solutions of the reactive dye with the j? -Sulfatoäthylsulfonylgruppe, which by esterification the j3-Hydroxyäthylsulfonylgruppe was obtained with concentrated sulfuric acid, the inert salt content The amount required for the formation of this sulfuric acid half-ester group can be kept below these limits Do not use excess sulfuric acid with caustic soda or other reagents that are too easily soluble Inertsaken lead, be neutralized. Rather, it is advisable here to use the excess sulfuric acid To neutralize calcium carbonate and the dye flotation by filtration of the poorly soluble calcium sulfate to separate. This procedure is, inter alia, in DT-OS 19 55 849,. Example 1, DT-OS 2049 664, example 1, and DT-OS 20 60 081, example 2.

The dye solutions of the dye of the formula (I) obtained during the synthesis contain between 5 and

40 15 percent by weight of dye and can be brought to a dye content of about 30 to 35 percent by weight by adding dried dye or by distilling off water in vacuo.

The dyestuff producers do not have the very salty, sometimes salt-saturated mother liquors, and the salt content of the wastewater is also considerably reduced by dye users because the for adjusting the amounts of salt used in the preparation of the dye powders according to the invention Liquid settings are not required.

For the dyeing preparations according to the invention, all those buffer substances are suitable that are not related to any of the Chemical reaction with the jS-sulfatoethylsulfonyl group or its vinylsulfonyl analogue, which reduces the color yield capable, such as sodium and potassium acetate, sodium and potassium oxalate, the acidic sodium and potassium salts of phosphoric acid, mixtures of the various sodium or potassium salts of phosphoric acid and sodium borate. Of these, sodium borate and sodium hydrogen phosphate are preferred to call.

The mechanism of reaction of reactive dyes of the above type with cellulose fibers is well known. The formation of the covalent bond between the fiber substrate and the dye molecule according to reaction (4) of the scheme given below after conversion of the S-sulfatoethylsulfonyl group into the vinyl sulfone group in the presence of alkaline agents according to the reaction (1) causes the well-known good fastness properties of dyeings with reactive dyes.

It is also known from the use of reactive dyes with the] 3-sulfatoethylsulfonyl group, that this reactive group as well as in the form of its vinylsulfonyl group with water, not only in the presence of alkalis, but also in the acidic range, in a reaction that competes with the actual coloring reaction (4) According to (2) or (3) of the scheme for the j9-hydroxyethylsulfonyl group which is only inert with the fiber substrate implements.

Scheme:

F-SO, -CH ₇ -CH ₁ -O-CcIl.

F-SO ₂ -CH ₂ -CH ₂ -O- SO ₁ H

(4)

+ Cell. — OH

- F-SO ₃ -CH = CH,

+ H ₂ O
- H ₂ SO ₄

- H, SO ₄

(2)

(3)

F-SO ₁ -CH, CH, OH

H ₁ O

where F is the remainder of a dye molecule and Cell.-OH is the cellulose.

The hydrolysis (2) and the addition of water (3) are practically irreversible under dyeing conditions and thus reduce the color yield.

For this reason, this is usually the case in the manufacture of water-soluble reactive dyes process that the initially mentioned separation and drying of the reactive dyes from the synthesis solution also immediately to the Swiihese is made in order to avoid losses of dyeing strength for the reasons mentioned above.

It was therefore all the more surprising to find that neutral to weakly acidic aqueous, buffered

Solutions of the reactive dye (I) can be kept for a long time without loss of color strength. According to the invention aqueous solutions of the dye of formula (I) also provide, after several months, such as 6 months of storage at room temperature or for several weeks, for example at 8wöciiiger storage at 50 ⁰ C dyeings and prints unchanged color strength.

The dyeing preparations according to the invention are suitable for those customary and general for reactive dyes known manner after dilution with water and optionally after the addition of customary dyeing auxiliaries or correspondingly after the addition of thickeners customary in the printing company and, if necessary Printing auxiliaries for dyeing and printing fiber materials made of wool, silk, polyamide and natural or regenerated cellulose or fiber blends containing one or more of the above Type of fiber included.

The following examples serve to illustrate the invention.

example 1

100 parts by weight of an aqueous, clarified dye solution of the dye of the above formula (I) with a pH of 6.0 and a dye content of 15 percent by weight, which in the usual manner at the Synthesis of the dye obtained by diazotizing and coupling the appropriate starting compounds were added with stirring to 24.5 parts by weight a dry dye powder with 67 percent by weight dye content, which by spray drying another portion of the same clarified dye solution was added. The 124.5 thus obtained Parts by weight of an aqueous solution containing 25.3 percent by weight of pure dye and having a pH of 6 after the addition of 2 parts by weight of disodium hydrogen phosphate resulted in an aqueous coloring preparation which had a pure dye content of 25 percent by weight and also a pH of 6.0.

With 2 parts by weight of this pH-stabilized solution dyebaths, padding liquors and printing pastes were each prepared in a known and customary manner, in applied to cotton in the usual way for reactive dyes and fixed, yellow dyeings and prints resulted that were just as strong in color as those that were equally concentrated with the appropriate use Dye baths, padding liquors or printing pastes with 1 part by weight of a 50 percent by weight pure dye containing powder formulation.

This color strength of the prints and dyeings was retained unchanged when the new one indicated above aqueous preparation was stored for 6 weeks at 50 ° C in a closed vessel.

Example 2

200 parts by weight of an aqueous, clarified dye solution of the dye of the above formula (I) with a pH of 5.8 and a dye content of about 13 percent by weight, in the usual manner in the synthesis of the dye by diazotization and Coupling of corresponding starting compounds was obtained with stirring at 34 parts by weight of a dry dye powder with 65 percent by weight dye content, which is obtained by spray drying a other portion of the same clarified dye solution was added. The 234 Parts by weight of an aqueous solution containing 20.5 percent by weight of pure dye resulted after addition of 6 parts by weight of disodium hydrogen phosphai an aqueous dye preparation which has a pure dye content of 20 percent by weight and a pH of 6.1.

Dye baths, padding liquors and printing pastes were each mixed with 5 parts by weight of this pH-stabilized solution produced in a known and customary manner, in the manner customary for reactive dyes on cotton applied and fixed, yellow dyeings and prints

ίο revealed that were just as strong in color as those with the appropriate use of dyebaths, padding liquors or printing pastes of the same concentration 2 parts by weight of a powder formulation containing 50% by weight of pure dye were prepared.

This is color strength of the prints and staining was unchanged when the above mentioned novel aqueous preparation three months was stored at 2O ⁰ C in a closed vessel length.

Example 3

^V

200 parts by weight of an aqueous, clarified dye solution of the dye of the above form! (I) with a pH of 6 and a dye content of 13 Weight percent used in the usual way in the synthesis

the dye was obtained by diazotizing and coupling corresponding starting compounds, 3 parts by weight of disodium hydrogen phosphate were added. Of this dye solution were under Stirring at 60 ° C. and under a vacuum of 18 torr, 73 parts by weight of water were distilled off. 130 parts by weight

an aqueous dye preparation were obtained which

had a pure dye content of 20 percent by weight and a pH of 6.1 at 20 ° C.

Dye baths, padding liquors and printing pastes were each mixed with 5 parts by weight of this pH-stabilized solution produced in a known and customary manner, in the manner customary for reactive dyes on cotton applied and fixed, resulted in yellow dyeings and prints that were just as strong in color as those with the appropriate use of dyebaths, padding liquors or printing pastes of the same concentration 2 parts by weight of a 50 weight percent pure dye containing powder formulation were prepared. This color strength of the prints and dyeings was retained unchanged when the new one indicated above aqueous preparation was stored for 3 months at 20 ° C in a closed vessel.

Example 4

100 parts by weight of an aqueous, clarified dye solution of the dye of the above formula (I) with eir.em pH value of 6 and a dye content of 15 Percentage by weight used in the usual manner in the synthesis of the dye by diazotization and coupling corresponding starting compounds was obtained, with stirring with 27 parts by weight of a dry dye powder with 67 percent by weight dye content, which by spray drying, one other part of the same clarified dye solution

to was received. The 127 parts by weight of a 26.1 percent by weight pure dye obtained in this way containing aqueous solution gave an aqueous solution after the addition of 8 parts by weight of sodium borate Dye preparation with a pure dye content of 20 percent by weight and a pH of 6 exhibited.

With 2 parts by weight of this pH-stabilized solution, dye baths, padding liquors and printing pa-

24

most produced in a known and customary manner, in the usual manner for reactive dyes on cotton applied and fixed, resulted in yellow dyeings and prints that were just as strong in color as those with the appropriate use of dyebaths, padding liquors or printing pastes of the same concentration

256

1 part by weight of a powder formulation containing 50 percent by weight of Reir was produced
was kept in a closed vessel.

Claims (2)

Patent claims: I. Liquid, aqueous dye preparations of a reactive dye, characterized by a Content of 5 to 35 percent by weight of a dye in the form of the free acid of the formula SO, H HO, S SO, -CH, -CH, -OSO ₃ H corresponds to, and 1 to 5 percent by weight of buffer substances that do not lead to any chemical reaction with the Reactive groups are capable, as well as by a pH value of 3 to 7. 2. Use of the dyeing preparations according to claim 1 for dyeing and printing fiber materials made of wool, silk, polyamide and natural or regenerated cellulose or of fiber blends, the one or contain more of the types of fiber mentioned. The invention relates to liquid, aqueous dye preparations of a reactive dye, which is in the form of the free Acid of formula (1)