CS226894B1 - Method of preparing disperse anthraquinone dyes - Google Patents

Description

The present invention relates to a process for the production of disperse anthraquinone dyes for dyeing synthetic fibers, in particular polyester, polyamide and cellulose triacetate fibers, consisting of mixtures of aminohydroxy, aminodihydroxy, diaminodihydroxy and diaminohydroxyantraquinones.

Approximately 65 to 70% of the reacted anthraquinone can be used practically for sulphonation of anthraquinone. The remaining amount is formed by the by-products of the sulfonation reaction, i.e. isomeric disulfo acids, 2-sulfoacids and 1-sulfoacids, which, in the current process for the production of anthraquinone-1-sulfoacids, are discharged to waste water. These are biodegradable compounds. The proportion of individual sulfoisomers is to some extent variable. The approximate weight composition of wastewater is as follows:

Sodium anthraquinone-1-sulfonate .............. 10 to 15% Sodium anthraquinone-2-sunfonate ............... 25 to 35%

1.5 and 1,8-anthraquinone disulfonate sodium ... 50 to 60%

1.6 to 1.7 sodium anthraquinone disulfonate ... 4 to 8%

The treatment of a mixture of sulfo and disulfoacids of anthraquinone from wastewater by sequential chlorination, nitration, reduction and bromination to form a disperse dye is known from the Swiss. No. 589,690. The product produced in this way is a dispersion dye of a greenish-blue shade, which is, however, very difficult to use for the preparation of mixed blacks.

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This disadvantage is overcome by a process for the production of disperse anthraquinone dyes, consisting of a mixture of aminohydroxy, aminodihydroxy, diaminodihydroxy and diaminohydroxyantraquinones, suitable for the preparation of commercial dyes such as Ostacet blue, gray, black, from sewage after isolation of sodium anthraquinone-1-sulfonate contain a mixture of sulfo and disulfoacids of anthraquinone according to the invention. It is an object of the present invention that this mixture contained in the wastewater is subjected to a chlorination and phenoxylation stepwise. nitration, hydrolysis, reduction and bromination.

Chlorination can be carried out by conventional methods, e.g., by using free chlorine, by NaClO _; in the presence of Cl ^- ions, Na-ClO, etc. The use of NaClO is particularly advantageous in view of technological simplicity.

Phenoxylation can be accomplished by known methods used in the synthesis of 1,5- and 1,8-diphenoxyanthraquinone, ie, by reacting a mixture of chloranthraquinones with phenol in the presence of alkali, wherein the phenol is used in multiple excess and serves simultaneously as a solvent or org, solvents. Advantageously, the phenoxylation can be carried out according to the newly developed procedure according to the author's certificate No. 216 639, where the reaction is carried out in a heterogeneous phenol-aqueous solution of KgCO3, a mixture of chlorantrachiones. After isolation and drying, the phenoxy anthraquinone mixture is subjected to nitration with conc. nitric and sulfuric acids. Nitration proceeds smoothly at 20 to 40 ° C in a few hours. After washing with water, the obtained product is further processed as an aqueous paste. Hydrolysis of the thus prepared nitrophenoxy compounds is carried out in an aqueous alkaline medium at a temperature of about 90 to 100 ° C. in the same reaction apparatus, the resulting nitrohydroxyantraquinones are reduced with an aqueous solution of sodium sulfide or glucose to a mixture of aminohydroxyantraquinones. This mixture is treated with bromination.

The bromination can be carried out by known methods in various environments, e.g. sulfuric acid, nitrobenzene, hydrochloric acid and the like. Sulfuric acid, which is not only a good solvent for the treated aminohydroxyantraquinones, but also partially regenerates the resulting hydrogen bromide back to bromine. By not diluting the reaction mixture with water, a blue reddish dispersion dye is obtained. The bromine content of the dye, which is a varied mixture of differently brominated aminohydroxy and diaminodihydroxyantraquinones, is 20 to 30%. The dye thus prepared can already be used for dyeing synthetic fibers, in particular polyester, polyamide and cellulose triacetate fibers. The colorant is generally characterized by good stability. The opaque blue dispersion dye obtained by the process of the invention can be used to mix new brands of black, gray, blue and the like by adding relatively small amounts of nucleating components more advantageously than using a dye prepared from pure 1,5- and 1,8-dichloroanthraquinone. The method according to the invention utilizes waste not yet utilized, the purity of waste water is increased, and the raw material - anthraquinone is saved.

In order that the invention may be more fully understood, the following examples are provided.

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Example 1 - Wastewater chlorination after isolation of sodium anthraquinone-1-sulfonate

To 1500 ml of the filtrate after isolation of sodium anthraquinone-1-sulfonate at 95-100 ° C was added 180-225 ml of a 20% NaClO 3 solution over a period of 4-6 hours. 2 to 4 hours Ghloration can be considered complete when 1-sulfoacid or cC, <C ¹ - disulfoacid is absent. Check by thin-layer or paper chromatography. The product was filtered off with suction, washed with hot water until neutral and dried. 30 to 80 g of a mixture of chloro- and dichloroanthraquinones are obtained. According to the analysis, the representation of individual iaomers is as follows:

1-chloranthraquinone 12 to 18 2-chloroanthraquinone 5 to 8 1,5- + 1,8-dichloroanthraquinones 55 to 65 1,6- + 1,7-dichloroanthraquinones 7 to 9

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Example 2 - Phenoxylation of a mixture of chloro and dichloroanthraquinones

a) Dissolve 48.9 g KOH in 82 g phenol at 50-60 ° C. After dissolution, 115 ml of water and 183 g of K2CO3 are added. After thorough mixing, 100 g of the chloranthraquinone mixture, prepared according to Example 1, are slowly metered in. The reaction mixture was heated to 118-125 ° C. After 4 hours the reaction is complete. The reaction can be monitored by thin layer chromatography. After completion of the reaction, the reaction mixture is distilled with steam to remove excess phenol. 50 g of a 10% solution of rosin and 20 g of solid sodium acetate are added to the reaction mixture before the start of the distillation.

After distillation, the product is filtered, washed with water until neutral and dried. 120-130 g of a product which is a mixture of phenoxy and diphenoxyanthraquinones are obtained.

b) In 545 g of phenol, 37.3 g of NaOH are dissolved at 80 ° C. After dissolution, 100 g of the chloranthraquinone mixture prepared according to Example 1 are introduced. The reaction mixture is heated to 160 DEG C. for 0.5 h. the temperature of the water present is lowered to 150 ° C and maintained at this temperature for 4 h. When the reaction is complete, the temperature is lowered to 60-65 ° C and 410 g of ethanol are added dropwise to the reaction mixture with stirring over 2 h. The reaction mixture was then cooled to 25 ° C. The precipitated product is filtered, washed with ethanol to clear filtrates and 400 ml of 1% NaOH solution. Finally, a hot water wash is performed until neutral. The aqueous paste is dried. The ethanolic filtrates were distilled off. The distillation residue (return phenol) is reused after the addition of phenol in the next batch. 90 to 120 g of product are obtained which is a mixture of phenoxy- and diphenoxyanthraquinones.

Example 3 - nitration of a mixture of phenoxy and diphenoxy anthraquinones

100 g of a mixture of phenoxy and diphenoxy anthraquinones prepared according to Example 2 are introduced at a temperature of max. 20 ° C with stirring, which gives a mixture of 352 g of mixed nitrating acid and 503 g of 100% sulfuric acid. After complete dissolution, the reaction mixture was stirred at 30-40 ° C for 12 h. The reaction mixture is then poured into 2000-4000 ml of cold water. The precipitated product is filtered and washed with water until neutral. It is further processed in aqueous form

226 694 paste. 150-160 g (calculated on dry product) are obtained. '

Example 4 - Hydrolysis and Reduction of Nitrophenoxyanthraquinones

The mixture of nitrophenoxy anthraquinones, prepared according to Example 3, corresponding to 100 g of dry substance, is stirred in 2000 ml of water. After stirring, 82 g of 50% NaOH solution are added. The reaction slurry is heated to 90-95 ° C. It is kept at this temperature for 0.5 to 1 hour. Then it is cooled to about 70 ° C and 136 g of Na ₂ S is added in the form of an approximately 15% solution. The reaction mixture is reheated to 90-95 ° C and maintained at this temperature for 1 h. After this time the reduction of the nitro groups is complete. The reaction suspension is cooled to about 50 ° C, filtered and the product is washed with water until neutral. Dry at approx. 70 ° C. 27 to 32 g of product are obtained, which is a mixture of aminohydroxy- and diaminodihydroxyantraquinones.

Example 5 - Bromination of a mixture of aminohydroxyantraquinones

100 g of a mixture of aminohydroxyantraquinones. prepared according to Example 4 is dissolved in 930 g of 100% industrial sulfuric acid in which 37 g of HgBO4 is previously dissolved. After complete dissolution, 1 g of NaNO2 and 54.9 g of bromine are added. The reaction mixture was heated to 60 ° C over 2 h and to 80 ° C over a further 2 h. The reaction mixture was stirred at 80 ° C for 4 h. After this time, the reaction was complete. The reaction mixture is cooled to about 35 ° C, 4 g of nitrobenzene, 10 g of Kartamol SS dispersant (as a 30% substance) are added and poured into a mixture of 1000 g of ice and 6000 ml H ₂ O containing 13 g of Kartamol SS ( 30%). Unreacted bromine is removed by the action of Na ₂ S ₂ O 4. The product is filtered and washed with water until neutral. 800 g of a paste containing 120 to 140 g of dry substance are obtained. The bromine content is 20 to 30%.

The raw dye produced as described above is ground on a bead mill together with dispersants so that the particle size corresponds to the prescribed values and operational application in dyeing polyester yarn.

The commercial type is prepared by mixing the so-called basic type with the nuance components to the commercial type Ostacet black, gray and navy blue.

Claims (1)

SUBJECT OF THE INVENTION Processes for the production of disperse anthraquinone dyes, consisting of mixtures of aminohydroxy, aminodihydroxy, diaminodihydroxy and diaminohydroxyantraquinones, suitable for the preparation of commercial dyes such as marine blue, gray, black, from waste water after isolation of anthraquinonal sodium sulphonate containing sulphora disulphonic acid mixture characterized in that the mixture contained in the waste water is subjected to successive chlorination, phenoxylation, nitration, hydrolysis, reduction and bromination.