DE2417256A1 - Aqs. liq. prepns. of known reactive dyes - for dyeing cotton, wool, silk, etc. black, grey and yellow shades, obviating inconveniences of dry dyestuff prepns. - Google Patents

Abstract

Novel aq. liq. dyeing prepns. of reactive dyes contain (a) 5-35% of a dye (i) 311-carboxy-511-hydroxy-411-(41-(2-(beta-sulphatoethylsulphonyl)-- phenylcarbamoyl)benzene-azo)-111-(4111-sulphonatophenyl)-pyrazole- , (ii) 31-carboxy-51-hydroxy-41-(4-beta-sulphatoethylsulphonyl-benzene)a- zo-pyrazole, (iii) 51-hydroxy-31-methyl-41-(2-methoxy-5-methyl-4-beta-sulphatoethyls- ulphonylbenzene)azopyrazole, (iv) 11-amino-81-hydroxy-21,71-bis(4-beta-sulphatoethylsulphonylbenzen- eazo)-naphthalene-3,6-disulphonic acid, 51-hydroxy-31-methyl-11-(4-beta-sulphatoethylsulphonylphenyl)-41-- (1,3-sulphonatonaphthalene-2-azo)-pyrazole or (v) a copper complex of 11-hydroxy-21-(2-hydroxy-5-methoxy-4-beta-sulphatoethylbenzeneazo- )-71-(3-carboxy-5-hydroxy-1-(p-sulphatophenyl)pyrazole-4-azo)-nap- hthalene-3-sulphonic acid; and (b) 1-5% of buffer not chemically reactive with the reactive gp., the soln. being of pH 3-7. The compsn. is used for dyeing or printing polyamides natural or regenerated cellulose or mixts., black, grey and yellow shades; without disadvantages of the solid dye.

Description

Liquid dye preparations of a reactive dye The present invention relates to liquid aqueous dye preparations of a reactive dye which, in the form of the free acid of the formula (I) is equivalent to. These dye preparations are characterized in that they contain the dye mentioned, preferably as its alkali metal, especially tiatrium salt, in aqueous solution in a concentration of 5 to 35% by weight, preferably 15 to 30% by weight, based on the pure dye of the formula (I), and have a pH between 3 and 7, advantageously between 5.5 and 6.8, and additionally contain 1-5% by weight of buffer substances.

This dye of the formula (1) is from DT-OS 1,804,524, examples 4 and 5, known.

Water-soluble reactive dyes become more common after their synthesis Way isolated so that they are salted out of the aqueous reaction solution, the precipitated salt-dye mixture is suctioned off and the press cake obtained is dried. Another technically common method, the solved one, as a rule Isolating readily water-soluble dye from the synthesis solution is the most direct Drying> for example spray drying of the manufacturing solution.

The salt-containing dye powder is used for the desired dyeing application usually following drying by adding neutral inorganic substances Salts, such as sodium sulphate for example, to a certain dye content one shares.

These conventional powder formulations of reactive dyes show But there are a number of things that arise, in particular, from the development of dust such powdered dye preparations, when worked with them, give them when filling and decanting, when weighing and dosing or when preparing the dye liquor or printing pastes. This dust development is not only a nuisance for the workforce in production or application operations, but they can also in the dyeing or printing works as a result of the settling of the dye dust lead to unpleasant speckled staining of undyed or already dyed goods. On the other hand, there is the dust removal of powdered dyes with the Common dedusting agents based on mineral oil always run the risk of oily deposits in dyeing and printing, resulting in stained and therefore unusable dyeings and Printing leads. Furthermore, such powdery dyes are often the in rationalization measures worth striving for in technology, such as continuous Ferbe processes or automatic dosing and weighing devices, not feasible.

These disadvantages also apply to the powdered dye mentioned above of the formula (1) apply, by the liquid dye preparation according to the invention this dye of formula (I) completely avoided. In addition, for the new preparation for both the dye manufacturer and the dye user thereby advantages over the powdery dye settings that the salt load the wastewater is decisively reduced The new liquid dye preparations of the dyestuff of the formula (I) are namely prepared in the manner according to the invention in such a way that that the clarified dye solution obtained in the synthesis is used directly and if desired, as advantageous, either by concentration, for example by distilling off part of the water under vacuum, or advantageously by Addition of a dried, for example spray-dried, portion thereof the synthesis obtained and clarified dye solution to the desired higher Dye content adjusts, with this dye solution still in all cases Buffer substances are added.

For the production of such fiction according to dye preparations with Up to 35% by weight of dye, it is advantageous from aqueous, clarified dye solutions assume their content of inert salts, such as sodium sulfate or Sodium chloride, is as low as possible and below 50% by weight of the dye content of this is located in the synthesis of the dye solutions.

In the production of dye preparations that have a lower dye content have, such as those with up to 15% by weight of dye, the inert salt content should of the starting solutions must be lower than their dye content. Usually lies the inert salt content of the aqueous dye solutions obtained during the synthesis under these limits. In order to also use solutions of the reactive dye with the ß-Suifatoäthylsulfonylgruppe, the sulfuric acid concentrated by esterification of the ß-HydroxySthylsulfonylgruppe lait was obtained to keep the inert salt content below these limits, the for Formation of this sulfuric acid half ester group required Schlfefels-Acid excess not with caustic soda or other reagents which lead to easily soluble inert salts lead, be neutralized. Rather, it is recommended here to use the excess sulfuric acid neutralize with calcium carbonate and remove the dye solution by filtration from to separate poorly soluble calcium sulfate, This procedure is among others in the DT-OS 1.955.849, example 1, DT-OS 2.049.664, example 1, and DT-OS 2.060.081, example 2.

The dye solutions of the dye obtained during the synthesis of the formula (I) contain between 5 and 15% by weight of dye and can be added of dried dye or by distilling off water in vacuo up to A dye content of about 30 to 35% by weight can be brought.

In the case of the dye producer, the very salty, partly salt-saturated mother liquors, and also with dye users Salinity of wastewater is considerably reduced because of the need to adjust dye powders amounts of salt used in the preparation of the liquid formulations according to the invention omitted.

For the coloring preparations according to the invention, all of these are buffer substances suitable, which do not lead to any chemical reaction with the ß-Sulfatoäthylsulfonyl group or their vinylsulfonyl analog are capable of how for example atrium 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 Mention sodium hydrogen phosphate.

The mechanism of reaction of reactive dyes of the above The type with cellulose fibers is well known. The formation of the covalent bond between the fiber substrate and the dye molecule according to the reaction (4) of the below given scheme after conversion of the ß-sulfatoäthylsulfonylgruppe in the Vi.oylsulPongruppe in the presence of alkaline agents according to reaction (1), the known ones good fastness properties of dyeings with reactive dyes.

It is also from the use of reactive dyes with the ß-sulfatoethylsulfonyl group known ago 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 competitive reaction to the actual dyeing reaction (4) according to (2) or (3) of the scheme to the R-HydroxySthylsulfonylgruppe, which is only inert with the fiber substrate implements.

Scheme: where F denotes the est of a dye molecule and Cell.-OlI denotes cellulose.

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

For this reason, water-soluble reactive dyes are used in the manufacture As a rule, proceed in such a way that the initially mentioned separation and drying the reactive dyes from the synthesis solution also directly to the synthesis in terms of time is made in order to avoid losses of dye 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 heavy dye (I) over a long period of time without loss of color strength are durable.

Aqueous solutions according to the invention of the dye of the formula (I) provide even after several months, for example 6 months, storage at room temperature or several weeks, for example 8 weeks of storage at 500C stains and Prints with unchanged color strength.

The dye preparations according to the invention are suitable for reactive dyes customary and generally known manner after dilution with water and optionally after the addition of customary dyeing auxiliaries or, accordingly, after the addition of in the printing house Usual thickeners and, if necessary, printing auxiliaries for coloring and printing of 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 10 parts by weight of an aqueous, clarified dye solution of the dye of the above formula (I) having a pH of 6.0 and a dye content of 15% by weight, in the usual manner in the synthesis of the dye by diazotization and coupling of the corresponding starting compounds were obtained with stirring with 24.5 parts by weight of a dry dye powder with 67% by weight of dye content, that by spray drying another portion of the same clarified dye solution was obtained, added. The 124.5 parts by weight of a 25.3% by weight obtained in this way Aqueous solution containing pure dye and having a pH of 6 resulted after addition of 2 parts by weight of disodium hydrogen phosphate an aqueous dye preparation that had a pure dye content of 25% by weight and also a pH of 6.0.

With 2 parts by weight of this pH-stabilized solution were in each case Dye baths, padding liquors and printing pastes produced in a known and customary manner, those applied and fixed to cotton in the usual way for reactive dyes, yellow stains and prints gave as color strength as those that were with the appropriate use of equally concentrated dye baths, padding liquors or Printing pastes with 1 part by weight of a powder formulation containing 50% by weight of pure dye were manufactured.

This color strength of the prints and dyeings was retained unchanged, weml the new aqueous preparation given above for 6 weeks at 50 ° C. in the closed Vessel was kept.

Example 2 200 parts by weight of an aqueous, gelatinized dye solution of the dye of the above formula (I) with a pH of 5.8 and a dye content of about 13% by weight, which is customary in the synthesis of the dye by diazotization and coupling of corresponding starting compounds was obtained with stirring with 34 parts by weight of a dry dye powder with 65% by weight dye content, that by spray drying another portion of the same clarified dye solution was obtained, added. The 734 parts by weight of a 20.5% by weight pure dye obtained in this way containing aqueous solution resulted after addition of 6 parts by weight of disodium hydrogen phosphate An aqueous dye preparation which has a pure dye content of 20% by weight and a pH 6.1.

With 5 parts by weight of this pH-stabilized solution were each Dye baths, Klot zflotten and printing pastes produced in a known and customary manner, those applied and fixed to cotton in the usual way for reactive dyes, gave yellow stains and prints that were just as strong in color as those those with the appropriate use of equally concentrated dye baths, padding liquors or printing pastes with 2 parts by weight of eggs containing 50% by weight of pure dye Powder setting have been made.

This color strength of the prints and dyeings was retained unchanged, if the above-mentioned new aqueous preparation is closed for 3 months at 200C Vessel was kept.

Example 3 200 parts by weight of an aqueous, clarified dye solution of the dye of the above formula (I) with a pH of 6 and a dye content of 13% by weight, in the usual manner in the synthesis of the dye by diazotiares and coupling of corresponding starting compounds were obtained with 3 parts by weight Disodium hydrogen phosphate added. From this dye solution were stirred 73 parts by weight of water were distilled off at 60 ° C. and under a vacuum of 18 torr.

130 parts by weight of an aqueous dye preparation were obtained which had a pure dye content of 20% by weight and a pH of 6.1 at 20 ° C.

With 5 parts by weight of this pH-stabilized solution were each Dye baths, padding liquors and printing pastes produced in a known and customary manner, those, applied and fixed on cotton wool in the usual way for reactive dyes, yellow colorations and prints resulted which were just as strong as dierenigen, The same concentration of dye baths, padding liquors when used appropriately or printing pastes with 2 parts by weight of a 50% by weight pure dye Powder adjustment were made.

This color strength of the prints and dyeings was retained unchanged, when the above new aqueous preparation is closed for 3 months at 200C Vessel was kept.

Example J 100 parts by weight of an aqueous, clarified dye solution of the dye of the above formula (I) with a pH of 6 and a dye content of 15% by weight in the usual manner in the synthesis of the dye by diazotization and coupling of corresponding starting compounds were obtained with stirring with 27 parts by weight of a dry coloring powder with 57 gr. Dye content, that by spray drying another portion of the same clarified dye solution was obtained, added. The 127 parts by weight of a 26.1% by weight obtained in this way Aqueous solution containing pure dye resulted after the addition of 8 parts by weight Sodium borate an aqueous dye preparation which has a pure dye content of 2C Weight 0 and further had a pH of 6.

With 2 parts by weight of this pH-stabilized solution became part Dye baths, Elotzflotten and printing pastes produced in a known and customary manner, which, applied to cotton in the usual way for R.eaktivfarbs'cofoe and fixed, gave yellow stains and prints that were just as strong in color as those the dyebaths, padding liquors, which are equally concentrated when used appropriately or printing pastes with 1 part by weight of a powder formulation containing 50% by weight of pure dye were manufactured.

This color strength of the prints and coloring was retained unchanged, if the above new aqueous preparation is closed for 6 weeks at 500C Vessel was kept.

Claims (2)

Patent claims: 1. Liquid, aqueous dye preparations of a reactive dye peat, characterized by a content of 5 - 35 wt.% Of a dye, which is in the form of the free acid of the general formula corresponds to 1 - 5% by weight of buffer substances and a pH value of 3 to 7, 2. Use of the dyeing preparations according to claim 1 for dyeing and printing Fiber materials made from wool, silk, polyamide and natural or regenerated cellulose or of fiber blends which contain one or more of the fiber types mentioned.