JPH11292817A - Purification of bromine compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject high-purity compound excellent in heat stability by adding a bromine compound in melted state, a good solvent to a solid-liquid mixture comprising the good solvent, a poor solvent and seed crystal and mixing these components. SOLUTION: (A) A bromine compound of the formula l (m), (n), (p) and (q) are each 1-6; Ar<1> and Ar<2> are each a 5-16C aromatic hydrocarbon; Y is methylene or the like; R<1> and R<2> are each a 2-6C saturated hydrocarbon] in melted state [e.g. 2,2-bis [3,5-dibromo-4-(2,3-dibromopropyloxy)]phenyl}propane] and (B) a good solvent [a solvent capable of dissolving >=5 wt.% bromine compound at 20 deg.C] (e.g. methylene chloride) are added to (C) a solid-liquid mixture comprising the good solvent, a poor solvent [a solvent incapable of dissolving >=2 wt.% bromine compound at 20 deg.C] (e.g. methanol) and seed crystal and these components are mixed to provide slurry comprising the good solvent, the poor solvent and bromine compound crystal and containing the crystal in a ratio of 0.01-70 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for purifying a specific bromine compound. More specifically, the present invention relates to a method for purifying a specific bromine compound capable of obtaining a bromine compound having high purity and excellent heat stability (without blocking or coloring).

[0002]

2. Description of the Related Art Bromine compounds represented by ether derivatives of tetrabromobisphenol generally exhibit excellent performance as flame retardants for polyolefin resins and styrene resins, and are widely used.

[0003] If such a bromine compound contains a by-product produced in the course of its production, the by-product adversely affects the thermal stability, and various purification means have been conventionally proposed.

For example, Japanese Patent Application Laid-Open No. Sho 49-125348 discloses that 2,2-bis [@ 3,5-dibromo-4-
Disclosed is a method of dissolving (2,3-dibromopropyloxy) {phenyl] propane (hereinafter sometimes abbreviated as TBA-BE) in a ketone-based solvent, cooling and precipitating.

Japanese Patent Application Laid-Open No. 55-111429 discloses a method in which an aromatic hydrocarbon solution of TBA-BE is added to a mixture of methanol and a seed crystal.

In JP-A-4-234337, a poor solvent having a boiling point higher than that of a good solvent is dropped into a solution of TBA-BE dissolved in a good solvent. A method for recovering -BE as a fine powder is shown, and in JP-A-7-316087,
A TBA-BE solution dissolved in a good solvent is dropped into a heated poor solvent having a higher boiling point than the good solvent while stirring, and the TBA-BE crystals are dispersed and collected in the poor solvent while simultaneously distilling the good solvent. The method is described.

[0007] Japanese Patent Application Laid-Open No. Hei 8-113546 discloses TB
A-BE good solvent solution was added to heated methanol in the presence of seed crystals, and at the same time, the good solvent was distilled off and crystallized,
A method for recovering a solid having a large particle size is disclosed.

In Japanese Patent Application Laid-Open No. Hei 7-291883, water is added to an organic solvent solution of TBA-BE in the presence of a surfactant to form an emulsion, and then the organic solvent is removed to remove TBA-BE. A method for recovering powder is described.

Japanese Patent Application Laid-Open No. Hei 2-286645 discloses a method in which TBA-BE is kept in a molten state, and unpurified TBA-BE is added thereto.

Further, Japanese Patent Publication No. 57-289 discloses a method in which a non-solvent or a poor solvent is added to a good solvent solution of TBA-BE and stirring with shearing force is performed.

However, these methods require complicated operations and large-scale equipment, and the purity and thermal stability of the obtained solid are not always sufficient. There is a need for a purification method for obtaining a bromine compound having excellent stability.

[0012]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies with the aim of providing a purification method for obtaining a bromine compound having improved purity and excellent thermal stability. The present inventors have found that a good solvent, a good solvent, a poor solvent and a solid-liquid mixture comprising a seed crystal are added and mixed to obtain a bromine compound having high purity and excellent heat stability, and arrived at the present invention. .

[0013]

According to the present invention, there is provided a method for purifying a bromine compound from a molten bromine compound represented by the following formula (1): , A good solvent, a poor solvent, and a seed crystal, and added to and mixed with the solid-liquid mixture to form a slurry composed of the good solvent, the poor solvent, and the crystal of the bromine compound. A method for purifying a bromine compound, which is characterized in that the amount is from 01 to 70% by weight.

[0014]

Embedded image

(Where m, n, p, and q are integers of 1 to 6, Ar ¹ and Ar ² may be the same or different, and are aromatic hydrocarbon groups having 5 to 16 carbon atoms.) Y is a kind selected from methylene, propylene, isopropylidene, isopropylidene, cyclohexylidene, sulfone, ketone and a single bond, and R ¹ and R ² are each a saturated hydrocarbon group having 2 to 6 carbon atoms. )

The bromine compound used in the present invention is represented by the above formula (1), wherein m, n, p and q are integers of 1 to 6, preferably 1 to 2, and Ar ¹ and Ar ² may be the same or different and is an aromatic hydrocarbon group having 5 to 16 carbon atoms, preferably a phenyl group, a tolyl group, a xylyl group or a naphthyl group, and Y is methylene, propylene, isopropylidene, isobutylidene, cyclohexyl. Siliden,
It is one kind selected from sulfone, ketone and single bond, preferably one kind selected from methylene, isopropylidene, isobutylidene, cyclohexylidene, sulfone and single bond, and R ¹ and R ² each have 2 carbon atoms.
To 6 saturated hydrocarbon groups, preferably an ethyl group, a propyl group, an isopropyl group, a butyl group and an isobutyl group.

As such a bromine compound, specifically,
2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane, 2,2
-Bis [{3,5-dibromo-4- (2,3-dibromo-2-methylpropyloxy)} phenyl] propane,
Bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] methane, bis [{3,5-
Dibromo-4- (2,3-dibromo-2-methylpropyloxy) {phenyl] methane, bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] sulfone, bis [} 3,5-dibromo-4-
(2,3-dibromo-2-methylpropyloxy) @phenyl] sulfone, {3,3 ', 5,5'-tetrabromo-4,4'-(2,3-dibromopropyloxy)} biphenyl, {3 , 3 ', 5,5'-Tetrabromo-4,4'-(2,3-dibromo-2-methylpropyloxy)} biphenyl and {3,3 ', 5,5'-
Tetrabromo-4,4 '-(1,2-dibromoethyloxy) {biphenyl and the like, and among them, 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)}. [Phenyl] propane is preferably used.

In the purification method of the present invention, a bromine compound in a molten state is used. The melting temperature differs depending on the bromine compound used. For example, when the bromine compound is 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane, it is preferable. Is 110 ° C to 150 ° C, more preferably 115 ° C to 145.
It is desirable to use what is heated to 120 ° C, particularly preferably 120 ° C to 140 ° C. The bromine compound is bis [｛3
In the case of 5-dibromo-4- (2,3-dibromopropyloxy) {phenyl] methane, the temperature is preferably from 90C to
It is desirable to use one heated to 130 ° C, more preferably 95 ° C to 125 ° C, particularly preferably 100 ° C to 120 ° C. Bis [｛3,5-dibromo-4- (2,
In the case of 3-dibromopropyloxy) {phenyl] sulfone, it is preferably 170C to 210C, more preferably 175C to 205C, and particularly preferably 180C to 2C.
It is desirable to use one heated to 00 ° C. Melting the bromine compound within a range not exceeding a temperature higher by 30 ° C. than the melting point of the bromine compound is preferably employed because there is no risk of decomposition of the bromine compound.

As the good solvent used in the present invention, 20
The compound is capable of dissolving the bromine compound at a concentration of 5% or more by weight at a temperature of 0 ° C., for example, methylene chloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethane, acetone, methyl isobutyl ketone, diethyl ketone, cyclohexanone , Dioxane, ethyl acetate, butyl acetate, toluene, xylene, benzene, dimethylformamide, dimethylacetamide, dimethylsulfoxide and the like, methylene chloride, chloroform,
1,2-Dichloroethane, 1,1-dichloroethane, cyclohexanone, ethyl acetate, toluene and dimethylformamide are preferred, methylene chloride, chloroform, 1,2-dichloroethane and 1,1-dichloroethane are more preferred, and methylene chloride is particularly preferred. Can be These good solvents are used alone or in combination of two or more.

The solid-liquid mixture of the present invention is before the addition of the bromine compound in the molten state, and comprises a good solvent, a poor solvent and a seed crystal. Such a good solvent is the same as the above-mentioned good solvent.

The poor solvent is one which cannot dissolve the bromine compound at a concentration of 2% or more by weight at 20 ° C., for example, a solvent having 1 to 5 carbon atoms such as water, methanol, ethanol and i-propanol. Saturated monohydric alcohol, ethylene glycol, glycerin, diethyl ether, dipropyl ether, diisopropyl ether and n-
5 to 5 carbon atoms such as pentane, n-hexane and n-octane
10 saturated hydrocarbons and the like, water, methanol, ethanol, i-propanol and diisopropyl ether are preferred, water, methanol, ethanol and i-propanol are more preferred, and methanol is particularly preferably used. These poor solvents are used alone or in combination of two or more.

The seed crystal preferably has a purity of 90% or more. As such a seed crystal, the same bromine compound as the bromine compound in a molten state to be used is preferably used. By using a seed crystal, the generation of bromine compound crystals from the molten bromine compound is smoothed, a high-purity bromine compound with less impurities is obtained, and the generation of microcrystals is suppressed. The crystals of the bromine compound have a uniform particle size.

In the solid-liquid mixture, the proportion of the seed crystal in the solid-liquid mixture is preferably 0.01 to 50% by weight.
0.1-40 weight% is more preferable, 1-30 weight% is still more preferable, 5-20 weight% is especially preferable. When the ratio of the seed crystal is lower than 0.01% by weight, the seed crystal does not function sufficiently, which is not preferable. When the ratio is higher than 50% by weight, the production efficiency of the bromine compound is lowered, which is not preferable.

In the present invention, the bromine compound and the good solvent in a molten state are added to the solid-liquid mixture and mixed to crystallize the bromine compound. Here, the molten bromine compound and good solvent are added to a solid-liquid mixture, and the mixture is referred to as a slurry. The slurry is composed of crystals of a good solvent, a poor solvent and a bromine compound.
It is composed of a solution portion in which impurities and an uncrystallized bromine compound are dissolved in a good solvent and a poor solvent, and a crystal portion of a bromine compound containing some impurities. Such good and poor solvents are the same as the good and poor solvents in the solid-liquid mixture described above. Further, such a bromine compound crystal includes both a seed crystal in the solid-liquid mixture and a bromine compound crystal generated from the molten bromine compound. In addition, a part of the generated crystal of the bromine compound itself has a function as a seed crystal.

In the slurry comprising the good solvent, the poor solvent and the bromine compound crystals, the ratio of the bromine compound crystals in the slurry is 0.01 to 70% by weight.
It is preferably from 1 to 60% by weight, more preferably from 1 to 55% by weight, even more preferably from 5 to 50% by weight. Here, the ratio of the crystals of the bromine compound is a ratio to the weight of the entire slurry (including the good solvent, the poor solvent, the crystals of the bromine compound, the bromine compound dissolved in the solvent, and the impurities, as described above). is there. If the ratio of such crystals is lower than 0.01% by weight, the production efficiency of the bromine compound is lowered, which is not preferable. It is difficult to obtain a compound, which is not preferable. Further, regarding the ratio of the crystal of the bromine compound in the slurry, the bromine compound in a molten state and the good solvent were added to the solid-liquid mixture, and mixing was started. This means that the above ratio is maintained until the addition of the good solvent is completed.

In the present invention, the method of adding the bromine compound and the good solvent in the molten state to the solid-liquid mixture is not particularly limited, but the bromine compound and the good solvent in the molten state can be added to a pump or a dropping funnel. , And a method of continuously adding a fixed amount at a time is preferably used. Also,
A part of the slurry in the container can be extracted and circulated.

In the method of the present invention, the bromine compound and the good solvent in a molten state are added to the solid-liquid mixture,
When crystallizing the bromine compound, it is preferable to control the solvent so that the solvent does not evaporate and scatter outside the container. The temperature at which the bromine compound is crystallized is not particularly limited,
The reaction is preferably performed at a temperature not exceeding the boiling point of the solvent (mixed solvent of a good solvent and a poor solvent) in the slurry, and a range of 5 to 50 ° C, more preferably a range of 25 to 50 ° C can be adopted. When methylene chloride, which is suitable as a good solvent, is used, it is preferably in the range of 5 to 40C, more preferably 25 to 40C.
A range of 40 ° C. is employed. When such a method is adopted,
A good solvent is present in the slurry, and the crystallization proceeds gradually, so that a high-purity bromine compound is easily obtained,
Further, there is an advantage that the control of the form (particle size) of the crystal becomes easy. Furthermore, by setting the crystallization temperature higher, a bromine compound with a reduced residual solvent can be easily obtained, and a high purity bromine compound can be obtained because the solubility of the impurities in the mixed solvent in the slurry increases. It is preferably adopted because it becomes easy.

When a good solvent solution known in the prior art is added to a mixture of a seed crystal and a poor solvent, a bromine compound precipitates rapidly, it is difficult to remove impurities, and the obtained bromine compound has low purity. On the other hand, in the purification method of the present invention, since the bromine compound in the molten state comes into contact with the slurry containing the good solvent from the beginning, the ratio of the good solvent to the poor solvent sharply increases. It is considered that the crystallization progressed slowly without changing, and thus the impurities were efficiently removed.

In a preferred embodiment of the present invention, the bromine compound is 2,2-bis [@ 3,5-dibromo-4- (2,3
-Dibromopropyloxy) {phenyl] propane, where the good solvent in the slurry is methylene chloride and the poor solvent is methanol, the chloride in the slurry after the addition of the molten bromine compound and methylene chloride. The ratio of methylene to methanol is 30:70 to 7 by weight.
It is preferably 0:30.

Crystals precipitated by the method of the present invention are:
Separation by filtration, centrifugation, or the like, and drying by a known method can give a purified bromine compound.

The bromine compound obtained in the present invention has an average particle diameter on a weight basis of preferably from 0.1 to 0.9 mm, more preferably from 0.1 to 0.8 mm, and preferably from 0.2 to 0.8 mm.
A range of .about.0.7 mm is preferred. When the average particle size is smaller than 0.1 mm, the handleability becomes poor, and the working environment is deteriorated due to scattering of dust, which is not preferable.
If the average particle size is larger than 0.9 mm, the dispersibility of the bromine compound as a flame retardant in a resin is poor, which is not preferable.

The bromine compound obtained by the purification method of the present invention is useful as a flame retardant for resins, and particularly, ABS.
It is suitable as a flame retardant for resins, styrene resins and polyolefin resins.

[0033]

The present invention will be described below in detail with reference to examples. The following methods were used for measuring the purity, the average particle size, and the ratio of the crystals in the slurry. (1) Purity analysis Purity was measured by high performance liquid chromatography.
It carried out by the method of detecting the absorption of 80 nm. (2) Average particle size Samples were prepared at 200, 100, 60, 20, 16, 10,
After sieving using a 5,3.5 mesh sieve, a cumulative particle size distribution graph based on weight was created to determine the average particle size. (3) Ratio of Crystals in Slurry A certain amount of the slurry was filtered to take out crystals,
After drying at 5 mmHg at 3 ° C. for 3 hours, the weight of the crystal was measured, and the weight ratio of the crystal to the slurry was calculated.

[Preparation Example 1] Recrystallization of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane having a purity of 93% was performed using ethyl acetate. Was. As a result, 2,2-bis [@ 3,5-dibromo-4-] having a purity of 94% and an average particle diameter of 0.2 mm was obtained.
Crystals of (2,3-dibromopropyloxy) {phenyl] propane were obtained (hereinafter, abbreviated as seed crystal A).
Furthermore, recrystallization was performed in the same manner twice, and 2,2-bis [｛3,5-dibromo- having a purity of 99% and an average particle diameter of 0.2 mm was used.
4- (2,3-dibromopropyloxy) @phenyl]
Propane crystals were obtained (hereinafter, abbreviated as seed crystals B).

Preparation Example 2 Hot air circulating drying of 130% of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane having a purity of 90%. The mixture was heated for 1 hour by a machine to be melted.

Example 1 A flask equipped with a thermometer, a stirrer and a reflux tube was charged with 60 g of methylene chloride, 120 g of methanol and 20 g of the seed crystal B obtained in Preparation Example 1.
(The ratio of the seed crystal B in the solid-liquid mixture was 1
0% by weight). While stirring the solid-liquid mixture, at a temperature of 25 ° C, the melted 2,2-bis [｛3,5-dibromo-4- (2,3-dibromopropyloxy) obtained in Preparation Example 2 was obtained. [Phenyl] propane (60 g) and methylene chloride (60 g) were added from separate dropping funnels over 30 minutes. After completion of the addition, stirring was continued for another 30 minutes (at this time, the ratio of crystals in the slurry was 24% by weight, and the weight ratio of methylene chloride to methanol in the slurry was 50: 5).
0). Thereafter, the slurry was filtered to remove a crystal, which was dried at 80 ° C. for 3 hours under reduced pressure of 5 mmHg to obtain 2,2-bis [｛3,5-dibromo-4- (2,3
[Dibromopropyloxy) {phenyl] propane crystals were obtained. The obtained crystals had a purity of 96%, an average particle diameter of 0.7 mm, and a recovery of 97%.

Example 2 Seed crystal B used in Example 1
Was replaced with seed crystal A, and a crystal of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane was obtained in the same manner as in Example 1. . The obtained crystals have a purity of 95% and an average particle diameter of 0.6.
mm, and the recovery was 97%.

Example 3 A flask equipped with a thermometer, a stirrer and a reflux tube was charged with 60 g of methylene chloride, 120 g of methanol and 20 g of the seed crystal B obtained in Preparation Example 1.
(The ratio of the seed crystal B in the solid-liquid mixture was 1
0% by weight). While stirring the solid-liquid mixture, at a temperature of 25 ° C, the melted 2,2-bis [｛3,5-dibromo-4- (2,3-dibromopropyloxy) obtained in Preparation Example 2 was obtained. [Phenyl] propane (30 g) and methylene chloride (90 g) were added from respective dropping funnels over 30 minutes. After completion of the addition, stirring was further continued for 30 minutes (at this time, the ratio of crystals in the slurry was 15% by weight, and the weight ratio of methylene chloride to methanol in the slurry was 56: 4.
4). Thereafter, the slurry was filtered to remove a crystal, which was dried at 80 ° C. for 3 hours under reduced pressure of 5 mmHg to obtain 2,2-bis [｛3,5-dibromo-4- (2,3
[Dibromopropyloxy) {phenyl] propane crystals were obtained. The obtained crystals had a purity of 96%, an average particle diameter of 0.6 mm, and a recovery of 96%.

Example 4 In a flask equipped with a thermometer, a stirrer and a reflux tube, 75 g of methylene chloride, 75 g of methanol and 20 g of the seed crystal B obtained in Preparation Example 1 were mixed and mixed (in the solid-liquid mixture). The ratio of seed crystal B is 12
weight%). While stirring the solid-liquid mixture, at a temperature of 25 ° C, the melted 2,2-bis [｛3,5-dibromo-4- (2,3-dibromopropyloxy) obtained in Preparation Example 2 was obtained. [Phenyl] propane (60 g) and methylene chloride (60 g) were added from separate dropping funnels over 30 minutes. After completion of the addition, stirring was further continued for 30 minutes (at this time, the ratio of crystals in the slurry was 23% by weight, and the weight ratio of methylene chloride to methanol in the slurry was 64: 3.
6). Thereafter, the slurry was filtered to remove a crystal, which was dried at 80 ° C. for 3 hours under reduced pressure of 5 mmHg to obtain 2,2-bis [｛3,5-dibromo-4- (2,3
[Dibromopropyloxy) {phenyl] propane crystals were obtained. The obtained crystals had a purity of 97%, an average particle diameter of 0.7 mm, and a recovery of 79%.

[Example 5] In Example 4, the temperature was changed to 2
Except that the temperature was changed from 5 ° C. to 35 ° C., 2,2-bis [{3,5-dibromo-4- (2,3-
Crystals of dibromopropyloxy) {phenyl] propane were obtained. The obtained crystals have a purity of 97% and an average particle size of 0.
7 mm, and the recovery was 77%.

Example 6 In Example 1, 2,2-bis [５−3,5-dichloromethane was used in the same manner as in Example 1 except that 1,2-dichloroethane was used instead of methylene chloride.
Dibromo-4- (2,3-dibromopropyloxy)
[Phenyl] propane crystals were obtained. The obtained crystals had a purity of 96%, an average particle diameter of 0.4 mm, and a recovery of 97%.

Example 7 2,2-bis [@ 3,5-dibromo-4- (2) was prepared in the same manner as in Example 1 except that cyclohexanone was used in place of methylene chloride. , 3-Dibromopropyloxy) {phenyl] propane. The obtained crystals have a purity of 96.
%, The average particle diameter is 0.6 mm, and the recovery rate is 95%.
Met.

Example 8 Example 1 was repeated except that ethyl acetate was used instead of methylene chloride.
2,2-bis [｛3,5-dibromo-4] in the same manner as described above.
-(2,3-Dibromopropyloxy) {phenyl] propane crystals were obtained. The obtained crystals had a purity of 95%, an average particle diameter of 0.3 mm, and a recovery of 98%.

[Example 9] In the same manner as in Example 1 except that toluene was used instead of methylene chloride, 2,2-bis [@ 3,5-dibromo-4-
Crystals of (2,3-dibromopropyloxy) {phenyl] propane were obtained. The obtained crystals had a purity of 96%, an average particle diameter of 0.8 mm, and a recovery of 98%.

Example 10 The procedure of Example 1 was repeated, except that diisopropyl ether was used instead of methanol.
Dibromo-4- (2,3-dibromopropyloxy)
[Phenyl] propane crystals were obtained. The obtained crystals had a purity of 96%, an average particle diameter of 0.4 mm, and a recovery of 97%.

[Example 11] In the same manner as in Example 1, except that ethyl acetate was used instead of methylene chloride and diisopropyl ether was used instead of methanol, 2,2-bis [ビ ス 3 , 5-dibromo-4-
Crystals of (2,3-dibromopropyloxy) {phenyl] propane were obtained. The obtained crystals had a purity of 95%, an average particle diameter of 0.5 mm, and a recovery of 98%.

Comparative Example 1 A flask equipped with a thermometer, a stirrer and a reflux tube was charged with 180 g of methanol and 20 g of the seed crystal B obtained in Preparation Example 1, and mixed. While stirring the inside of the flask, at a temperature of 25 ° C., a purity of 90%
2,2-bis [{3,5-dibromo-4- (2,3-
50 of dibromopropyloxy) {phenyl] propane
120 g of a weight% concentration methylene chloride solution was added from the dropping funnel over 30 minutes. After the addition was completed, stirring was continued for another 30 minutes. Then, the precipitated powder was filtered,
A powder of 2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane was obtained. This was dried under reduced pressure at 5 mmHg at 80 ° C. for 3 hours. However, in this drying under reduced pressure, powder adhered to each other, resulting in a large block and partial coloring. This bromine compound has a purity of 92%,
The recovery was 96%. The results are shown in Tables 1 and 2.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

According to the purification method of the present invention, high purity,
A bromine compound having excellent heat stability can be obtained, and such a bromine compound is suitably used as a flame retardant for a resin.
The industrial effects are extraordinary.

Claims (5)

[Claims] In a method for purifying a bromine compound from a bromine compound in a molten state represented by the following formula (1), the bromine compound in a molten state and a good solvent are mixed with a solid solvent comprising a good solvent, a poor solvent and a seed crystal. Add to the liquid mixture, mix, good solvent,
A slurry comprising crystals of the poor solvent and the bromine compound is used, and the ratio of crystals in the obtained slurry is 0.01 to 7
A method for purifying a bromine compound, which is 0% by weight. Embedded image (Where m, n, p, and q are integers of 1 to 6;
r ¹ and Ar ² may be the same or different, and have 5 to 5 carbon atoms.
16 is an aromatic hydrocarbon group, Y is a kind selected from methylene, propylene, isopropylidene, isobutylidene, cyclohexylidene, sulfone, ketone and a single bond, and R ¹ and R ² each have 2 to 6 carbon atoms. Is a saturated hydrocarbon group. ) 2. A good solvent is methylene chloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethane, acetone, methyl isobutyl ketone, diethyl ketone, cyclohexanone, dioxane, ethyl acetate, butyl acetate, toluene, xylene, benzene. 2. The method for purifying a bromine compound according to claim 1, which is at least one solvent selected from the group consisting of dimethylformamide, dimethylacetamide and dimethylsulfoxide. 3. The poor solvent comprises water, a saturated monohydric alcohol having 1 to 5 carbon atoms, ethylene glycol, glycerin, diethyl ether, diisopropyl ether and 5 to 5 carbon atoms.
The method for purifying a bromine compound according to claim 1, which is at least one solvent selected from the group consisting of 10 saturated hydrocarbons. 4. The method for purifying a bromine compound according to claim 1, wherein the bromine compound is represented by the following formula (2). Embedded image (Where m, n, p, and q are integers of 1 to 2;
r ¹ and Ar ² may be the same or different and are a phenyl group, a tolyl group, a xylyl group or a naphthyl group;
Is a kind selected from methylene, isopropylidene, isobutylidene, cyclohexylidene, sulfone and a single bond, and R ¹ and R ² are a kind selected from an ethyl group, a propyl group, an isopropyl group, a butyl group and an isobutyl group. ) 5. The bromine compound is 2,2-bis [｛3,5
-Dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane, 2,2-bis [{3,5-
Dibromo-4- (2,3-dibromo-2-methylpropyloxy) {phenyl] propane, bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] methane, bis [} 3,5-dibromo-4-
(2,3-dibromo-2-methylpropyloxy) @phenyl] methane, bis [@ 3,5-dibromo-4-
(2,3-dibromopropyloxy) @phenyl] sulfone, bis [{3,5-dibromo-4- (2,3-dibromo-2-methylpropyloxy)} phenyl] sulfone, {3,3 ', 5 , 5'-Tetrabromo-4,
4 '-(2,3-dibromopropyloxy)} biphenyl, {3,3', 5,5'-tetrabromo-4,4'-
(2,3-dibromo-2-methylpropyloxy)} biphenyl and {3,3 ′, 5,5′-tetrabromo-
The method for purifying a bromine compound according to claim 1, which is a kind of compound selected from 4,4 '-(1,2-dibromoethyloxy)｝ biphenyl.