SU598555A3 - Method of separating chloranthraquinone mixtures - Google Patents

Description

(54) METHOD FOR SEPARATION OF MIXTURES OF CHLORANTRAININES

measures with a purity of from 99.5 to 99.9 ° / o. According to the proposed method, it is also possible to obtain, for example, high-purity 1 dichlorometrachine or binary mixtures of dichloroptraquinones, consisting of 1,5- and 1,8-dichlororanthinones or 1,6- and 1,7-dichlorantrahionov.

Used in the proposed method, the mixture may contain in addition to chlorantrachipon still other substances, such as, for example, anthraquinone, nitroanthraquinones and / or oxyanthraquinones.

Mixtures of chlorantraquinones can be of any composition.

The proposed fractional vacuum distillation is carried out under vacuum in the upper part, equal to 5-50 mm Hg. Art. and reflux ratio of 2: 1-80: 1.

One variant of the proposed method consists in the fact that the melt of chlorotraquinones, whose temperature lies between 20-100 ° C, preferably 30-50 ° C, in the case of l-Chlorantraquinone 90 ° C above the melting point of Chlorantraquinones, is subjected to fractional distillation in a distillation column, the performance of which corresponds to 20-50 theoretical plates with a reflux ratio of 2: 1 80: 1 and with a vacuum in the upper part of the column 550 mm Hg. Art. Because of the high melting points of chloranthranquinones and their strong tendency to sublimate, it is necessary to heat all parts of the apparatus that the product comes into contact with.

For example, the distillation column should preferably be provided with adiabatic heating with an outer jacket. To prevent the high temperatures from the bottom of the column, which lead to the formation of undesirable cracking products, it is recommended to use medium vacuum columns, characterized by small pressure drops, which supply metal sieves or metal nozzles, and energy is supplied in the lower part of the column through film evaporators, preferably falling film evaporators.

It is advisable to subject rectification of such technical chlorotraquinones or mixtures from which, during the synthesis, acids and salts are largely removed by washing and which are preliminarily distilled with a short residence time, for example using a thin-film evaporator, free from untransposed and easily volatile, incondensable contaminants. The purification of technical blends of chloroanthraquinones by distillation can be carried out particularly well in a continuous plant.

This variant of the method is characterized in that, if possible, acid-free mixtures of chlorotraquinones, consisting of 1-chloro, 2-chloro, 1,5-dichloro, 1,6-dichloro, 1,7-dichloro, 1,8-dichlor2, 6-dichloro, 2,7-dichloro and, if necessary, 1,4,5-trichloro- and 1,4,6-trichlorotranquinones, are melted appropriately, for example in a melting screw, then in an evaporator apparatus with a short residence time and a small pressure drop of the melts, they are freed from non-distilled and / or volatile components, the melt thus purified is supplied continuously to the middle Part adiabatically heated medium vacuum distillation column with 20-50 theoretical plates, and there is rectified so that the top of the column at a vacuum of 25 2 mm Hg. Art. and reflux. including 5: 1-50: 1 tap t 2-chlorantraquinone with a minimum content of 94%. The product practically free of 2-chloroanthraquinone from the bottom of the column is continuously fed to the middle part of the second distillation column, from the top of which at least 94 / o-i-I-chloroenthraquinone is taken. The product from the bottom of the second column is fed to the middle part of the third column, at the top of which at least a 94% binary mixture of 1,6- and 1.7-dichlororanthraquinones is withdrawn. The product from the bottom of the third column is served in

the middle part of the fourth column, from the top of which a 94% binary mixture of 1,5- and 1,8-dichlororanthraquinones is taken at least and, if desired, 1,4,5-trichlororanthraquinone is separated from the bottom of the column, for example by feeding into a thin-film evaporator apparatus.

When using chlorantraquinones of a different composition, it is possible to work without one or two of the columns described above. It is recommended that, prior to fractionation in a subsequent column, the corresponding products from the bottom of the column be subjected to intermediate purification, for example, using a filter or thin film evaporator in order to separate the cracking products.

The degree of purity of the fractions obtained by continuous or batch distillation depends on the purity of the starting materials and the requirements for processing chlorantraquinones into dyes.

The proposed method can be obtained preferably the following products: 1-hlorantrahinon; 2-chlorantraquinone; 1,5- and 1,8-dichlororanthraquinone (as a binary mixture); 1,6- and 1,7-dichlororanthraquinone (as a binary mixture) and 1,4,5-trichlororantrahinon.

The resulting binary mixtures, for example, mixtures of 1,5- and 1,8-dichlororanthraquinones, can be enriched and obtained individual components with a concentration of 70-92% by further vacuum rectification and to an even greater concentration, if necessary, by other methods. , for example by fractional crystallization. Opportunity to distil technical

A mixture of chlorantraquinones on the industrial scale with this good yield is unexpected, since, due to high melting points, a high tendency to sublimate and a narrow range of boiling points, one would expect various types of complications. It is therefore not surprising that even the distillation of the pure isomers of chlorantraquinones is not described in the literature.

Example 1. 1500 g of a mixture of chlorantraquinones

of the following composition,%: 22 2-chloroanthraquinone; 22 1-chlorantraquinone; 34 1,6- and 1,7-dichlororanthraquinone; 16 1,5-and 1,8-di. Chloro-tertrahinos; 6 1,4,5-trichlororanthraquinone, is fed into a flat, electrically refractory flask from a batch column. The olives consists of two sections (30 mm in width in the branch, 2 m in height, 2 m in nozzles, rings made of 4x4 mm metal mesh), packed up to compensate for heat loss by the adiabatic electric heating jacket.

The column is equipped with a deflation device, the cooling of which is carried out with a heat-transfer oil with a temperature below the boiling point of the distillate. The distillate is separated into a reverse flow and the product is withdrawn using an electronically controlled divider. The product from the top of the crown is collected in a heated distillate collector and taken as a fraction from the plant. All parts of the equipment that are in contact with the product are equipped with heating jackets through which the temperature-controlled heat transfer oil flows.

At a temperature in the lower part of the column from 280 ° C (beginning) to 320 ° C (end), a vacuum of 10 mm Hg. Art. The following fractions are obtained at the top of the column and with a reflux ratio of 20: 1:

G main fraction (at 235 ° C in the upper part of the column) 220 g of 97% 2-chloroanthraquinone;

G intermediate fraction of 234 g, containing 44 ° / o 2-chloro and 56% 1-hlrrantrahinona;

And the main fraction at 245 ° C is 130 g of 95% 1-chlorantraquinone;

To intermediate fraction 97 g contains 52% of 1-chloro- and 48% of 1.6- (1.7) -dichlororantrahinon;

U1 basic fraction at 263 ° C 241 g of a 9.2% mixture of 1,6- (1,7) -dichlororantrahinon;

A III intermediate fraction of 380 g contains 56% of 1.6- (1.7) -dichloro- and 44% of 1.5- and 1.8-dichlorotraquinone;

IV major fraction at 269 ° C 45 g of a 92% mixture of 1,5- and 1,8-dichloro-transhinone;

remainder 153

The resulting intermediate fractions can be separated by repeated distillation under similar conditions.

FIG. 1 shows a seven-column technological scheme for the separation of mixtures of chlorantraquinone (examples 2-6); in fig. 2 - the same, picolone (example 7).

Example 2. 105 kg / h of a mixture of chlorantraquinone of approximately the following composition, wt.%: About 1 anthraquinone; 3.0 2-chloroanthraquinone; 56.0 1-hlorantrahinona; 1.1 2.7- (2,6) -dichlororanthraquinone; 12.8 1.6- (1.7) -dichl orantrahinin; 11.9 1,8-dichlororanthraquinone; 12.7 1,5-dichlororantrahinon; 2, 3 1,4,5- (1,4,6) -trichlororantrahinon, melted in the melting auger 1 at 260 ° C and continuously through pipe 2 dispensed into thin-film evaporator 3, heated to 340 ° C with oil - coolant. The juice vapors formed in the thin-film evaporator pass through an adiabatically heated concentration column 4 equipped with 5 theoretical plates and are condensed in condenser 5 (boiling point at 20 mm Hg. 280 ° C). With reflux

0.2: 1 through pipe 6, approximately 98 kg / h of product is withdrawn from the top of the column in the form of a distillate. The distillate collections and the condenser are heated, and the coolant oil with a temperature of 200 ° C. From the bottom of a thin-film evaporator, about 7 kg / hr of a viscous vat residue, consisting of non-distilled products, cracking products and high-boiling contaminants, pipeline 7 to heated up to 270 ° С

8 for bottoms. The product, preliminarily purified to improve thermal stability and the preliminary stage, enters through pipe 6 into a distillation column 9 with 30 theoretical plates, in which the monochlororanthraquinones are separated from the trichlorometraquinone diium. As a product from the top of this column, approximately 98% monochloranthraquinone, contaminated with anthraquinone and dichloranthraquinone, is condensed in a condenser 10 at 20 mm Hg. Art. in the head part

columns and a boiling point of 255 ° C and fed it at a reflux ratio of 15: 1 through pipe 11 to the next column 12. Condenser 10 and pipe 11 are heated with heat-transfer oil with a temperature of 200 ° C. At 35 m. m. Art. and at a boiling point of about 305 ° C, practically no monochloranthraquinone di- (triororanthraquinone) is withdrawn as a product from the bottom of the column 9 and through tr} baud 13 it is fed to the distillation column 14. The formed 15 is removed from the product 15 in the process

cracking products. The evaporator 16 is heated with a heat carrier oil with a temperature of 340 ° C. The mixture of monochlororanthraquinones fed through pipe 11 is divided in column 12 into 2-chloroanthraquinone and 1-chloroantra-5 quinone.

Adiabatically heated column has a capacity of 48 theoretical plates. As a product from the top of the column, 2.8 kg / h of 97% 2-hlorantrahinonona, contaminated 2% anthraquinone and 1% 1-hlorantrahinona and

0 is discharged through the pipeline 17. C. column 12 operates at a pressure of 20 mm Hg. Art. at the top and boiling point of 252 ° C. The reflux ratio is 100: 1. The condenser 18 and the pipe 17 for distilling the distillate is heated

. up to 220 ° C. The mixture of 1-chloroanthraquinone formed in the lower part of the column through pipe 19 is withdrawn at 45 mm Hg. Art. and a boiling point of 290 ° C from the column. The heating of the evaporator 20 is produced with a heating oil heated to 340 ° C. Get

0 55 kg / h of 99% 1-hlorantrahinonon contaminated with 2-chloroanthraquinone and 2,7- (2,6) -dichlororanthraquinone. from the bottom of the column, they are fed through pipe 19 to a thin-film evaporator 21. The resulting product is distilled at 20 mm Hg. Art. and 264 ° C and condense in condenser 22 at 190 ° C and withdrawn through heated pipeline 23. High-boiling contaminants and cracking products, some of which are removed and part of the cracked products are withdrawn through the pipeline 24 leaving the bottom of the column. The thin-film evaporator is heated with oil heated to 340 ° C. In column 14, isomers of 2.7-2.6-1.6-, 1.7-di. Chloroanthraquinium () are separated from a mixture of 1,5-, 1,8-dichlororanthraquinones and trichlororanthraquinones. The column has 48 theoretical tapej lok. With a pressure of 15 mm Hg. Art. at the head and at the boiling point of 270 ° C, about 12 kg / h of 88% isomers of 1,6- and 1.7-dichlorotranquinones contaminated with about 7% of 2.7- and 2,6-dichlororanthraquinones , 2 ° / about 1-dichlororantrahinonone and 3% 1,8- and 1,5-dichlorantrahininone. The condenser and the pipe for distilling the distillate are heated to 230 ° C. The reflux ratio is 30: 1. A mixture of 1,8- and 1,5-dichloro- (trichlorotranquinone), which is mostly free of 1,6- and 1,7-dichlororanthraquinones, is withdrawn from the bottom of the column through line 26. The boiling point at the bottom of the column is approximately 310 ° C at 40 mm Hg. Art. The evaporator is heated to 340 ° C. The product from the bottom of column 14 is fed through pipe 26 into the first column of the cascade, consisting of two columns connected in series 27, 28. In these two columns, the isomers 1,5 and 1 are separated from each other. , 8-dichloranthraquinones. Both columns operate at a pressure of 20 mm Hg. Art. and a temperature of 288 ° C in the head parts. Condensers 29 and 30 and pipelines 31, 32 for distillate removal are heated to 220 ° C. Pipeline 32 yields approximately 11 kg / h 91 / o-tion 1.8-dichlororanthraquinone contaminated with -8% 1,5-di.chlorotraquinone and 17 ° 1.6- and 1.7-dich; 10-ratrahinonones, with reflux 4Hc: ie 40. Distillate from column 27 is fed through pipe 31 to the bottom of column 28. Product from the bottom of column 28 is returned to column 27 through pipe 33. Both columns

27, 28 have 32 theoretical plates each. The temperatures in the lower parts of the columns are approximately 310 ° C at 35 mm Hg. Art. Evaporators 34, 35 are heated with oil-coolant heated to 340 ° C. A mixture of 1,5-dichloro- (trichloro) anthraquinone, contaminated with 8% of 1,8-dichlororanthraquinone, is supplied through conduit 36 to column 37. Using filter 38, the cracking products formed during the process are removed. In column 37 with 28 theoretical plates, about 10 kg / h of 90%, 1,5-dichlororanthraquinone, 9% of 1,8-dichlororanthraone, and 1% trichlororanthraquone, which is discharged through a pipeline, is obtained as product from the top of the column. 39. At a pressure of 15 mm Hg. Art. a boiling point of 283 ° C is set at the top. A reflux ratio is 5: 1. Condenser 40 and pipe 39 for distilling the distillate are heated to 260 ° C. The bottom product, which contains mainly trichlororanthraquinone and dichlororanthraquinone, is withdrawn through line 41. The temperature at the bottom of the column is approximately 310 ° C at 30 mm Hg. Art. The evaporator 42 is heated with a heat-transfer oil heated to 340 ° C. The general rectification unit consists mainly of 6 columns, equipped with adiabatically heated external scrubs. All parts in contact with the product are heated to temperatures above the melting points of the products.

Example 3. From 1400 g of a mixture of chlorothraquinone of the following composition, wt. ° / o: 93 1-chloroanthraquinone; 0.5 Anthraquinone, 2.0 1.6-, and 1.7-dichlororanthraquinone; 2.5 1,5- and 1,8-dichlororanthraquinones and 2.0 other components, with a vacuum of 20 mm Hg. Art. at the head of the column and with a reflux ratio of 4: 1, high-purity 1-chlorantraquinone is obtained (99%):

the first shoulder strap at 260 ° C in the head in the amount of 105 g;

the main line at 264 ° С in the head part in the amount of 1067 g of 99% 1-hlorantrahinonona.

The balance in the amount of 228 g

Temperatures at the bottom of the column rise from 286 at 40 mm Hg. Art. (start of distillation) to 300 ° C (end of distillation).

Example 4. 40 kg / h of a mixture of chlorograconinone of the following composition, wt.%: 1.5 1-chloroanthraquinone; 1.5 1,8-dichlororanthraquone; 95.0 1,5-dichloranthraquinone; 1.0 trichlororantrahinone; 1.0 insoluble components are melted in a melting screw 1 at 270 ° C and are continuously metered into the thin-film evaporator 3 through line 2. At the bottom of the thin-film evaporator, approximately 3.0 kg / h of high-boiling soils and residues are concentrated. through pipe 7 and collector 8. The pre-purified product through pipe 6, bypassing column 9, is fed directly to column 12. Condenser 5 and pipe 6 are heated to 260 ° C. The thin-film evaporator operates at a pressure of 20 mm Hg. Art. in the head part corresponding to a temperature of 290 ° C. The temperature of the heat transfer medium is 340 ° C. In column 12, volatile contaminants of 1-chloroanthraquinone and 1,8-dichloroanthraquinone are concentrated in the head, they are collected through conduit 17 (approximately 3 kg / h). The condenser 18 and the pipeline 17 are heated with heat-transfer oil with a temperature of 220 ° C. The column operates at a vacuum of 20 mm Hg. Art., a temperature of 280 ° in the head part and a reflux number 12b. From the bottom of the column, 1,5-dichlororanthraquinone, freed from low-boiling contaminants, is withdrawn through conduit 19 and in a thin-film evaporator 21, it is freed from high-boiling contaminants and cracking products, which are withdrawn from the thin-film evaporator through conduit 24. Thin-film evaporation The apparatus 21 and the evaporator 20 of the column 12 are heated with oil-coolant heated to 340 ° C. Through conduit 23 for removal of the distillate after condensation in condenser 22, 32 kg / h of 99 / o-th 1,5-dichlororantrahinon are obtained. The thin-film evaporator 21 operates at a vacuum of 20 mm Hg. Art. and a boiling point of 290 ° C. The heating of the condenser 22 and the pipeline 23 occurs above the melting point at 260 ° C.

Example 5. In an appropriate way, you can clean the mixture of hlorantrahinonona of approximately the following composition, wt.%: 2 1-hlorantrahinona; 95 1,8-dichlorantrahinon; 1 1,5-dichloranthraquinone; 1 trichlororantrahinone; 1 insoluble components. At the same time, 80 kg / h is melted at 240 ° C in the melting screw 1 and is continuously metered through pipe 2 into a thin-film evaporator 3. In the lower part of the thin-film evaporator, approximately 6 kg / h of high-boiling soils and residues are concentrated. through line 7 and collector 8. The pre-purified distillate is fed through line 6 directly to column 12. Condenser 5 and line 6 for distilling the distillate are heated to 220 ° C. The thin-film evaporator operates at a pressure of 20 mmHg. Art. at the head and boiling point of 288 ° C. At the head of the column 12, the volatile components of 1-chloroanthraquinone are concentrated to approximately 30%, they are discharged through conduit 17 (6 kg / h). The condenser 18 and the pipe 17 for distilling the distillate are heated with oil at a temperature of 220 ° C. The column operates at a pressure of 20 mm Hg. Art. at the head, with a boiling point of 275 ° C and a reflux ratio of 50: 1. From the bottom of the column, 1,8-dichloranthraquinone, freed from low-boiling contaminants, is withdrawn through conduit 19 and in a thin-film Parboiler 21 it is freed from high-boiling contaminants and cracking products. The thin-film evaporator 21 and the evaporator 20 of the column 12 are heated with oil heated to 340 ° C. At the bottom of the column, a boiling point of 312 ° C is established at 45 mm Hg. Art. Separated in a thin-film evaporator 21, contamination (6 kg / h) is withdrawn through conduit 24. After condensation at condenser 22 at 220 ° C through conduit 23, 62 kg / h of pure 99% 1,8-dichloro entraquinone are withdrawn. Example 6. 80 kg / h of a mixture of hlorantrahinona approximately the following composition, wt.%: Anthraquinone; 95 2-chloroanthraquinone; 1 1-Chlorantraquinone; 1 of insoluble components, melt continuously in the melting screw 1 at 240 ° C and metered into the thin-film evaporator 3 through pipeline 2. 4 kg / h of insoluble components and high-boiling contaminants are concentrated and discharged through pipeline 7 and collection 8. Pre-cleaned The distillate is fed through line 6 to column 9. The thin-film evaporator operates at a pressure of 30 mm Hg. C., corresponding to a boiling point of 265 ° C. Heating of a thin-film evaporator takes place with the help of a heat-transfer oil heated to 320 ° C. Condenser 5 and pipeline 6 are heated to 220 ° C. In the lower part of column 9, 1-chloro-trehraquinone is concentrated 15%, pipe 13 is discharged through the pipe (kg / h), 2-chloro-anthraquinone and anthraquinone are led through pipe 11 into the next column 12 . Column 9 operation em at a pressure of 30 mm Hg. Art. at the head of the corresponding boiling point of 266 ° C and a reflux ratio of 15: 1. The condenser 10 pipe 11 is heated to 220 ° C. In the lower part of the column 9 at 45 mm Hg. Art. boiling point is established. 285 ° C. The evaporator 16 is heated with a heat carrier heated to 40 ° C. In column 12, low boiling point contamination — anthraquinone is concentrated to about 30% and removed via conduit 17 (8 kg / h). The column operates at a speed of 30 mmHg. Art. in the head part. This sets the temperature to 260 ° C. The condenser 18 and the pipe 17 is heated to 240 ° C. The reflux number is 40. The 2-chlorantraquinone released from anthraquinone is withdrawn from the bottom of the column through line 19. At the bottom of the column at 55 mm Hg. Art. boiling point is set at 286 ° C. The evaporator is heated with oil heated to 340 ° C. In thin-film evaporation apparatus 21, 2-chloroanthraquinone is freed from other high-boiling contaminants and cracking products, which are removed through conduit 24. 59 kg / h of pure 99% 2-chloroanthraquinone are condensed in a condenser 22 at 220 ° C and drained t through pipeline 23. The heating of the thin-film evaporator is carried out with a heating oil heated to 340 ° C. Example 7. a) 530 g / h of a mixture of chloroanthraquinones of the following composition, weight. Vo: 15 2-.Hlorantrahinona; 13 1-chlorantraquinone; 32 1.6- (1.7) -di.chlorotraquinones; 30 1,5- (l, 8) -dichropanters; 7 1,4,5-tri-chloro trathraquinone, melted with a melter puff 43 at 260 ° C and continuously metered through conduit 44 into a thin-film evaporator 45 (clear width 50 mm, length 200 mm) heated to 300 ° C oil heat carrier. The juice vapors formed in the thin-film evaporator flow into the concentration column 46 (50 mm wide, 500 mm nozzle, 500 mm packed nozzles, metal rings 4X4 mm) equipped with a jacket for adiabatic heating, and completely condensed in a condenser 47 (t. Kip. 275 ° C at 20 mm Hg. Art.). With a reflux ratio of 1: 1, approximately 500 g / h of product is obtained from the top of the column, which as a distillate is discharged through conduit 48. The collector for the distillate and the condenser are heated with an oil-heated with 230 ° C. From the bottom of the thin-film evaporator, approximately 30 g / h of a viscous residue is withdrawn through conduit 49 to a collection 50 heated to 270 ° C for bottoms. b) 500 g / h of the distillate obtained from the preliminary purification stage in the liquid state is continuously metered through conduit 48 to column 51 consisting of distant and concentration parts (column: clear 50, distant part: nozzle height 2 m, 4X4 - metal mesh rings, concentration part: nozzle height 1.5 m, 4X4 metal mesh rings). The design of the column is basically the same as that described in Example 1. Heating of the bottom is achieved using an evaporator.

apparatus 52 with a falling film. With a pressure of 15 mm Hg. at a temperature of 245 ° C. of the upper part and a reflux ratio of 15: 1 in condenser 53, approximately 75 g / h of 97% 2-chloro-trathivone, mainly contaminated with 1-chloro-anthraquinone, is obtained. The condenser and the pipelines 54 heat up to about 220 ° C 425 g / h of the product from the bottom of the column containing less than 0, 2-chloroanthraquinone, is fed through the pipe 55 and the filter 56 into the next column 57. The filter 56 removes from the product 56 cracking products.

c) In column 57, fundamentally equal to the column in which 2-chlorantraquinone was previously obtained, at about 250 ° C, approximately 425 g / h of the product obtained is introduced from the bottom of the column in liquid form. Instead of the required height of the nozzle in 2 m, only a nozzle 1 m high is needed as a distant part. With a pressure of 20 mm Hg. Art. at the head end, a boiling point of 263 ° C and a reflux ratio of 12: 1 yields approximately 65 fjM of 97% 1-chloroanthraquinone. contaminated with 2-chlorantraquinone and 13 alomers of 1,6-, 1,7-dichlorantrahinin. The condenser 58 and the pipe 59 for distilling the distillate are heated with a heating oil heated to about 180 ° C. The column is heated using an evaporator 60. As the product from the bottom of the column, approximately 360 g / h is withdrawn through pipe 61 at 30 mm Hg. Art. and a temperature of 300 ° C in the lower part and at the stage of intermediate purification (thin-film evaporator 62) are freed from high-boiling and non-distilled products. The product, consisting mainly of isomers of dichlororanthraquinone with 0.5% 1-chloroanthraquinone, is fed as a low-boiling contaminant through conduit 63 into the next column 64.

d) The product obtained in the lower part of the column is then separated in a much longer column 64 (concentration part 2 m, distant part 3 m, diameter, columns 70 mm) into mixtures of isomers 1.6 and 1.7, and also

1,5- and 1,8-dichlororanthraquinones. Approximately 360 g / h of product was introduced into the column at 260 ° C. At a pressure of 10 mm Hg. Art. and a temperature of 262 ° C at the head end and with a reflux number, approximately 168 g / h of a 93% mixture of isomers of 1,6- and 1.7-dichloroetraquinone are obtained. Condenser 65 and pipe 66 for distilling the distillate are heated to approximately 220 ° C, the evaporator is heated to 325 ° C. At 32 mm Hg. Art. and a temperature of 308 ° C in the lower part of the column, approximately 192 g / h of a mixture of isomers of 1,5- and 1,8-dichlororanthraquinones, contaminated with less HT / about 1.6- and 1.7-dichlororanthraquinones and 25% trichlororanthraquinone and high boiling components, are obtained , as the product from the bottom of the column is fed through a pipe 67 (heated to 280 ° C) and a filter 68 to the next column 69.

e) Approximately 192 g / h of the product obtained from the bottom of the column at 270 ° C is fed to column 69, equipped with a concentration part 1 m in length with a distant part 2 m long. At a pressure of 10 mm Hg. Art. in the head

parts and a boiling point of 280 ° C and with a reflux ratio of 0: 0 4: 1, approximately 149 g / h are obtained, a 94% mixture of isomers of 1,5- and 1,8-dichlororanthraquinones. Condenser 70 and pipe 71 for distilling the distillate are heated to 230 ° C. At a pressure of 22 mm Hg. Art. at the bottom of the column and a boiling point of 310 ° C (an evaporator 72 heated to 340 ° C), 43 g / h of the mixture is withdrawn from the bottom of the column, which, along with dichlorotranquinones and high-boiling components, contains approximately 50% 1.4, 6- and 1,4,5-trichlororanthraquinones. Pipeline 73 for removing the product from the bottom of the column is heated to about 280 ° C. From this product, through a thin-film evaporator 74, the concentration column 75 and pipe 76 discharges approximately 20 g / h of distillate, previously condensed in a condenser 77 at a pressure of 10 mm Hg . Art. and a temperature of 285 ° C in the upper part. High boiling contaminants and residues are discharged through conduit 78. The distillate consists of 92% of trichlororanthraquinone isomers and approximately 8% of contaminants in the form of isomers of 1,5- and 1,8-dichlororanthraquinones.

When using a mixture of monochlorine ntrahininone mixture of isomers of dichlororanthraquinones, the crude product previously purified in a thin-film evaporator apparatus 45, bypassing the column 51 and 57, is fed through the pipeline directly to the column 64. The mixture described in example 8 can be used as a starting product. Example 8. 100 g of a mixture of dichlororanthraquinones, consisting of 56% of the 1.6- (1.7-) isomers and 44% of the 1.5- (1.8-) isomers, are fed to the flask of the installation described in Example 1, with the nozzle height extended on 1 m and at vacuum of 5 mm of mercury. Art. in the head part and reflux ratio 30: 1 are rectified.

Get the following products:

I main fraction at 245 ° C in the head

parts - 452 g of a 94% mixture of 1.6- and 1.7-dihydranthranequones;

The intermediate fraction is 210 g of a mixture of 48% of 1.6- and 1.7-dichlorometraquinones and 52% of 1.5- and 1.8-dichloroetraquinones;

The second main fraction is 198 g of a 92% mixture of 1,5- and 1,8-dichlororanthraquinones (residue 140 g).

5 The intermediate fraction can be reused and distilled.

The temperature in the flask rises from 290 ° C at the beginning to 315 ° C at the end of the distillation (at about 25 mmHg).

Claims (1)

1. Patent of Great Britain No. 356728, cl. Since 2 Since 1940.