JP2000136160A - Purification of bromine compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound having high purity and excellent heat stability by crystallization wherein crystalline concentration in a slurry comprising a good solvent, a poor solvent and crystals of a bromine compound is in a specified range and the solubility of the bromine compound is kept in a specified range. SOLUTION: This compound is obtained by following steps; (A) a crude solution of a bromine compound of the formula [Ar1 and Ar2 are each a 6-10C hydrocarbon group; (m) and (n) are each 1-4; (p) and (q) are each 2 or 4] is fed into a slurry including particles of the above mentioned bromine compound and crystallized the bromine compound in a agitated solvent, wherein (B) the slurry is kept its bromine particle concentration to be 10-50 wt.%, (C) the solvent in the slurry is a mixture consisting of a good solvent (e.g. methylene chloride or chloroform) and a poor solvent (e.g. methanol) for the bromine compound and the solubility of the compound is kept to be 0.1-5 g/100 g-solvent and (D) the slurry is taken out and the solid particles of the bromine compound are separated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 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 thermal stability.

[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 by-products produced during the production process, various types of these by-products adversely affect the thermal stability. Therefore, various purification means have been conventionally proposed.

For example, JP-A-49-125348 discloses 2,2-bis [@ 3,5-dibromo-4-.
There is disclosed a method of dissolving (2,3-dibromopropyloxy) {phenyl] propane (hereinafter sometimes abbreviated as TBA-BE) in a ketone-based solvent, and cooling and precipitating the same.

[0005] Japanese Patent Application Laid-Open No. 55-111429 discloses a method of adding a halogenated aromatic hydrocarbon solution of TBA-BE 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, and after completion of the dropping, TBA-BE is distilled off while distilling the good solvent. A method to recover as fine powder is shown,
In Japanese Patent Application Laid-Open No. 7-316087, a TBA-BE solution dissolved in a good solvent is dropped into a poor solvent having a boiling point higher than that of a good solvent while stirring, and the poor solvent is simultaneously distilled off in the poor solvent. A method of dispersing and collecting TBA-BE crystals is described.

[0006] 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, TBA-BE
Water is added to the organic solvent solution of the above in the presence of a surfactant to form an emulsion, and then the organic solvent is removed to form TB.
A method for recovering A-BE powder is described.

Japanese Patent Application Laid-Open No. 2-286645 discloses a method in which TBA-BE is melted, and unpurified TBA-BE is added thereto.
Further, in Japanese Patent Publication No. 57-289, TBA-B
A method is disclosed in which a non-solvent or a poor solvent is added to a solution of E in a good solvent and stirring with shearing force is performed.

However, these methods require complicated operations and large-scale equipment, and the obtained solids are not always sufficient in purity and thermal stability. Therefore, there is a demand for a purification method for obtaining a bromine compound having higher purity and excellent thermal stability with a simple apparatus.

[0009]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies for the purpose of providing a purification method for obtaining a bromine compound having improved purity and excellent thermal stability. In the method for purifying a bromine compound from a solvent, a good solvent, a poor solvent and a crystal in a slurry comprising crystals of the bromine compound are in a specific ratio, and the solubility of the bromine compound in the solvent in the slurry is in a certain range. The inventors have found that a high-purity bromine compound having excellent thermal stability can be obtained by crystallizing a bromine compound while maintaining the conditions, and arrived at the present invention.

[0010]

That is, according to the present invention, a bromine compound is precipitated as solid particles from a crude solution containing a bromine compound represented by the following general formula (1) to purify the bromine compound. A method comprising: (i) feeding the crude solution into a slurry containing the bromine compound particles to precipitate the bromine compound in the slurry with stirring; (ii) wherein the slurry comprises the bromine compound. (Iii) At that time, the solvent in the slurry is a mixed solvent composed of a good solvent and a poor solvent for the bromine compound, and the mixed solvent has a solubility of the bromine compound. Is maintained at a composition of 0.1 to 5 g / 100 g of solvent, and (iv) removing the slurry and separating solid particles of the bromine compound from the slurry. There is provided.

[0011]

Embedded image (Wherein, Ar ¹ and Ar ² are the same or different aromatic hydrocarbon groups having 6 to 10 carbon atoms; Y is 1 to 3 carbon atoms)
R ¹ and R ² are the same or different and have ^{2 to} 5 carbon atoms; m and n are the same or different integers of 1 to 4; p and q are the same Alternatively, it represents a different integer of 2 or 4. )

According to the purification method of the present invention, when the obtained bromine compound is used as a flame retardant for a resin, a high-purity bromine compound which does not reduce the thermal stability of the resin and does not cause coloring of the resin. Is obtained. In particular, according to the purification method of the present invention, impurities having an undesired effect when mixed with a resin are separated into a mixed solvent, and the desired bromine compound can be obtained as a high-purity solid in good yield. . Further, the purification method of the present invention is industrially excellent because continuous operation is easy and can be carried out with a simple apparatus and under mild conditions.

Hereinafter, the present invention will be described in more detail. The bromine compound to be purified in the present invention is represented by the general formula (1). In the general formula (1), Ar ¹ and Ar ² have the same or different carbon atoms of 6 to
10 aromatic hydrocarbon groups, specifically, benzene,
Monomethyl-substituted benzene, dimethyl-substituted benzene or naphthalene, preferably benzene. Y is A
a bonding valve or group for bonding r ¹ and Ar ² , specifically, an alkylene group having 1 to 3 carbon atoms, a single bond,
It is a sulfone group or a ketone group, preferably a methylene group or an isopropylidene group. R ¹ and R ² are the same or different monohydrogen groups having 2 to 5 carbon atoms,
Specifically, it is an ethyl group, a propyl group, an isopropyl group, a butyl group or an isobutyl group, and preferably has 2 carbon atoms.
Or 3 ethyl or propyl groups. m and n represent the same or different integers of 1 to 4, preferably 1 or 2. p and q represent the same or different integers of 2 or 4, preferably 2.

As the bromine compound represented by the general formula (1), 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.

The purification method of the present invention is carried out by precipitating a high-purity solid bromine compound from a crude solution containing the bromine compound represented by the general formula (1).
The crude solution is, specifically, a solution containing a bromine compound produced by an addition reaction of bromine (Br ₂ ).
This addition reaction is a reaction for brominating an unsaturated bromine compound represented by the following general formula (2), and the purification method of the present invention is advantageously applied to a solution obtained by this reaction.

[0016]

Embedded image (Wherein, the definitions of Ar ¹ , Ar ² , Y, m and n mean the same as those in the general formula (1). Q ¹ and Q ² are the same or different unsaturated groups by one or It represents a hydrocarbon group having 2 to 2 carbon atoms and having 2 to 5 carbon atoms.)

In the general formula (2), Ar ¹ , A
The definitions of r ² , Y, m and n have the same meanings as in the general formula (1), and the preferred definitions also mean the same. Specific examples of the hydrocarbon group for Q ¹ and Q ² include a vinyl group, an allyl group and an isobutenyl group, and preferably an allyl group.

As the unsaturated bromine compound represented by the general formula (2), specifically, 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane, 2,2
-Bis {(3,5-dibromo-4-isobutenyloxy) phenyl} propane, bis {(3,5-dibromo-
4-allyloxy) phenyl {methane, bis} (3.5
-Dibromo-4-isobutenyloxy) phenyl} methane, (3,3 ', 5,5'-tetrabromo-4,4'-diallyloxy) biphenyl, (3,3', 5,5'-tetrabromo- 4,4'-divinyloxy) biphenyl, bis {(3,5-dibromo-4-allyloxy) phenyl}
Sulfone and bis {(3,5-dibromo-4-isobutenyloxy) phenyl} sulfone, and the like,
Among them, 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane, 2,2-bis} (3,5
-Dibromo-4-isobutenyloxy) phenyl {propane, bis} (3,5-dibromo-4-allyloxy)
Phenyl {methane, bis {(3,5-dibromo-4-isobutenyloxy) phenyl} methane, (3,3 ′, 5,
5′-tetrabromo-4,4′-diallyloxy) biphenyl and (3,3 ′, 5,5′-tetrabromo-4,
4'-divinyloxy) biphenyl is preferable, and 2,2-bis {(3,5-dibromo-4-allyloxy) is more preferable.
Phenyl {propane, 2,2-bis {(3,5-dibromo-4-isobutenyloxy) phenyl} propane, bis {(3,5-dibromo-4-allyloxy) phenyl}
Methane and bis {(3,5-dibromo-4-isobutenyloxy) phenyl} methane are more preferred, especially 2,2-bis {(3,5-dibromo-4-allyloxy)
Phenyldipropane is preferably used.

The reaction between the unsaturated bromine compound and bromine is as follows:
The reaction is carried out in the presence of a solvent, which is inert without adversely affecting the reaction. The higher the solubility of the solvent for the unsaturated bromine compound is, the more preferable it is, but the solvent may be partially soluble. Further, it is preferable that the bromine compound generated by the bromination reaction of the unsaturated bromine compound is substantially dissolved in the solvent.

The solvent in the bromination reaction is not only used as a mere solvent for performing the reaction uniformly, but also preferably functions as a solvent for effectively removing the reaction heat to the outside of the system. Have. Therefore, it is advantageous that the solvent has a normal pressure boiling point in the range of 0 to 100 ° C, preferably 20 to 90 ° C. In particular, when the reaction heat is substantially removed by the heat of vaporization of the solvent, the normal pressure boiling point is 20 ° C. ~ 80 ° C, especially 20 ~
A range of 60 ° C. is desirable.

Examples of such a solvent include halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethane, bromoethane, butyl chloride, chloropropane, diethyl ether, ethyl isopropyl ether, tetrahydrofuran, dioxane and the like. Examples thereof include ether hydrocarbon compounds and aromatic hydrocarbon compounds such as toluene. Also, bromine can be used as a solvent.

Among these solvents, halogenated hydrocarbons are preferable, and methylene chloride and chloroform are particularly preferably used as the solvent. These solvents are used alone or in combination of two or more. These halogenated hydrocarbons can also be used as a mixed solvent with dioxane.

The amount of bromine used in the bromination is as follows:
In order to obtain a desired bromine compound, it is sufficient that the molar ratio is sufficient with respect to the unsaturated bromine compound.For one unsaturated group in the unsaturated bromine compound, bromine is preferably in a range of 1 molecule to 5 molecules. , Bromine is more preferably in the range of 1.1 to 3 molecules.

In the bromination, bromine itself or a bromine solution is used. As the solvent used in the bromine solution, the same solvent as described above is used, and in this case, the concentration of bromine is preferably in the range of 10 to 90% by weight.

In the above bromination method, as a specific means, a solution of an unsaturated bond compound dissolved in a solvent inert to the reaction and bromine or a bromine solution are mixed to form an unsaturated compound and bromine. Is reacted. At the time of this bromination reaction, it is preferable to remove a substantial amount of the heat of the bromination reaction by a solvent or the heat of vaporization of bromine. The substantial amount of the heat of reaction means at least 80%, preferably at least 85% of the theoretical calorific value generated by the desired bromination reaction.

As described above, the reaction temperature in the bromination reaction is preferably such that the substantial amount of the heat of the bromination reaction is removed by the heat of vaporization of bromine or the solvent, and the bromination reaction is limited to normal pressure. Instead, it can be performed under pressure or under reduced pressure. The reaction temperature can be controlled by operating pressure, depending on the type of solvent used (boiling point) and the amount of bromine. Usually, the reaction temperature is in the range of 0 to 60 ° C, preferably in the range of 5 to 55 ° C, particularly preferably 10 to 55 ° C.
A range of ５０50 ° C. is advantageous.

The purification method of the present invention is advantageously applied to the separation of a purified bromine compound from a reaction mixture obtained by the above-mentioned bromination reaction. Since the reaction mixture is obtained as a crude solution containing a bromine compound, the solution can be directly subjected to the purification treatment of the present invention. However, in the reaction mixture described above, unreacted bromine (B
r ₂ ) remains, and the residual bromine adversely affects the purification step and the recovery step. Therefore, it is desirable that the compound be subjected to chemical treatment to be converted to another compound.

This chemical treatment employs a method in which residual bromine in the reaction mixture is treated with a reducing agent, bromine is once converted into hydrobromic acid, and then hydrobromic acid is neutralized with an alkaline neutralizing agent. Is done. The method is carried out by adding a reducing agent and a neutralizing agent to the reaction mixture.

The reducing agent used in this treatment method is a reducing agent used in a usual reduction reaction, and specifically, sodium hydrogen sulfite, sodium dithionite, sodium sulfite, oxalic acid, hydrogen sulfide , Sodium nitrite, potassium nitrite, hydroxylamine sulfate,
Examples include tin, stannous oxide, and hydrazine. Of these, sodium bisulfite, sodium dithionite, sodium sulfite, oxalic acid, and sodium nitrite are preferably used. These reducing agents can also be used as an aqueous solution. These reducing agents are used alone or in combination of two or more.

Examples of the alkaline neutralizer include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides and alkaline earth metal carbonates. Sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, calcium hydroxide, calcium carbonate, and the like are preferable, and sodium hydroxide is particularly preferably used. These alkaline neutralizing agents are preferably used as an aqueous solution. Also,
These alkaline neutralizing agents are used alone or in combination of two or more.

In the above treatment method, 2 mol or more, preferably 2 to 3 mol, per mol of residual bromine in the reaction mixture.
0 mol, more preferably 2.2 to 15 mol, even more preferably 2.5 to 10 mol of reducing agent are added to the reaction mixture. When less than 2 mol of reducing agent is added,
Bromine remains in the mixture, and a low-purity brown colored bromine compound is obtained, which is not preferable. Further, 2 mol or more, preferably 2 to 50 mol, more preferably 2.2 to 30 mol, and still more preferably 2.5 to 20 mol of an alkaline neutralizing agent per 1 mol of the residual bromine in the reaction mixture. Is added to the reaction mixture. When the amount of the neutralizing agent to be added is less than 2 mol, hydrogen bromide remains in the aqueous solution, and this strong acid aqueous solution cannot be discarded as it is. In addition, some hydrogen bromide remains in the mixture, which easily corrodes metals. Furthermore, this hydrogen bromide has a strong irritating odor, which is not preferable in a working environment.

The reducing agent and the alkaline neutralizing agent are as follows:
The bromine compound and the bromine-containing reaction mixture are added simultaneously or separately. Such a reducing agent and a neutralizing agent may be added separately or in advance, but it is preferable to add them separately since there is no possibility that the reducing agent may cause a side reaction due to alkali. As the addition method, a method in which a reducing agent is added followed by a neutralizing agent is preferably adopted.

In the treatment method, the reaction mixture to which the reducing agent and the alkaline neutralizing agent are added is mixed so that the reducing and neutralizing reactions proceed smoothly.

The weight ratio of the reaction mixture to the aqueous phase at the time of performing the reduction and neutralization reactions is from 20:80 to 80:
20 is preferable, 30:70 to 70:30 is more preferable, and 40:60 to 60:40 is particularly preferable. Within this range, the reduction and neutralization reactions proceed efficiently, and bromine is removed in a short time. Therefore, when performing reduction and neutralization reactions,
It is preferable to add water or a solvent to the reaction mixture so as to fall within the above range.

The time required for the reduction and neutralization of bromine in the reaction mixture is preferably 2 minutes or more, more preferably 2 to 90 minutes, still more preferably 5 to 60 minutes, and more preferably 10 to 45 minutes.
Minutes are particularly preferred.

After the above-mentioned reduction treatment and neutralization treatment, the reaction mixture (organic phase) is separated from the aqueous phase, and this organic phase can be used as a crude solution in the purification method of the present invention. The crude solution to which the purification method of the present invention is applied contains 10 to 80% by weight, preferably 20 to 65% by weight of the bromine compound (1).
%, Particularly preferably 25 to 55% by weight.

The solvent forming the crude solution of the bromine compound (1) is a good solvent for the bromine compound (1). Such a good solvent has a solubility of the bromine compound (1) at 25 ° C. of 1 g / solvent 1
What is 00 g or more, preferably 2 g / solvent 100 g or more is preferable. Examples of good solvents include methylene chloride,
Chloroform, 1,2-dichloroethane, 1,1-dichloroethane, cyclohexanone, ethyl acetate and toluene are preferred, and these may be one kind or a mixture of two or more kinds. Of these, more preferred are halogenated hydrocarbons such as methylene chloride and chloroform, with methylene chloride being most preferred.

As mentioned above, the crude solution of the bromine compound (1) can be the reaction mixture produced by the bromination or a solution derived from the mixture, in which case it is used for the bromination. The solution is a solution of the reaction solvent as it is or a solution subjected to additional chemical treatment.

According to the purification method of the present invention, the crude solution containing the bromine compound (1) as described above is treated with the following (a) to (b)
It is important that the bromine compound (1) is supplied into a slurry containing particles of the bromine compound (1) which satisfies the conditions described above to precipitate the bromine compound in the crude solution. And the solvent in the slurry at that time,
It is a mixed solvent of a bromine compound with a good solvent and a poor solvent as shown in (b) below. (A) The slurry is such that the bromine compound particles are maintained at a slurry concentration of 10 to 50% by weight, preferably 15 to 40% by weight, and (b) the solvent in the slurry is a good solvent and a poor solvent for the bromine compound. And a solvent having a bromine compound solubility of 0.1 to 5 g / solvent 10.
0 g, preferably 0.5 to 4 g / 100 g of solvent,

The purification method of the present invention is carried out by supplying a crude solution containing a bromine compound into a deposition vessel while maintaining the conditions (a) and (b). The particles of the bromine compound forming the slurry act as seed crystals of the bromine compound precipitated from the solution, while the composition of the mixed solvent promotes the precipitation of the bromine compound, suppresses the precipitation of impurities, and reduces the dissolution. It is considered that it has the function of retaining.

Thus, in carrying out the method of the present invention, in addition to supplying the crude solution to the precipitation vessel, the solution is further added to the solution so that the conditions (a) and (b) are maintained in the vessel. A poor solvent, bromine compound particles (seed crystals) or a mixture thereof can be supplied. At this time, if necessary, a good solvent or a mixed solvent of a good solvent and a poor solvent can be supplied.

As the poor solvent for the bromine compound, those having a solubility of the bromine compound (1) of 0.08 g / 100 g or less of the solvent, preferably 0.05 g / 100 g or less of the solvent, particularly preferably 0.01 g / 100 g or less of the solvent. It is advantageous. Here, the solubility is a value measured at a temperature of 25 ° C. The solubility of the good solvent and the mixed solvent also means a value measured at 25 ° C.

Specific examples of the poor solvent include, for example,
Water, methanol, ethanol, saturated monohydric alcohol having 1 to 5 carbon atoms such as i-propanol, ethylene glycol, glycerin, diethyl ether, dipropyl ether, diisopropyl ether and n-pentane;
Examples thereof include saturated hydrocarbons having 5 to 10 carbon atoms such as hexane and n-octane, and water, methanol, ethanol, i-
Propanol and diisopropyl ether are preferred, water, methanol, ethanol and i-propanol are more preferred, and methanol is particularly preferred.
These poor solvents are used alone or in combination of two or more.

The operation of precipitating the bromine compound in the purification method of the present invention does not particularly require cooling or heating.
It is advantageous to work at a temperature in the range of 50 ° C, preferably in the range of 10 to 45 ° C. The average particle diameter of the bromine compound particles in the slurry is preferably in the range of 0.1 to 0.8 mm, more preferably 0.2 to 0.7 mm.

The purification method of the present invention can be carried out by either a batch method or a continuous method. However, since the method of the present invention is a method suitable for a continuous method, the continuous method is industrially advantageous. Next, specific embodiments of the batch method and the continuous method will be described. In order to simplify this description, the following terms have the following meanings, respectively.

Crude solution; Crude solution containing bromine compound Seed crystal; bromine compound particles good solvent; good solvent for bromine compound poor solvent; poor solvent for bromine compound mixed solvent; mixed solvent of good solvent and poor solvent Vessel; Vessel with stirrer for precipitating bromine compounds

First, the mode of the purification operation by the batch method will be described. The batch method can be classified into the following (1) to (4). (1) A method of supplying a crude solution or a crude solution and a poor solvent into a container previously filled with a slurry containing a seed crystal and a mixed solvent. (2) (i) A slurry comprising a crude solution and (ii) a seed crystal and a mixed solvent. Supplying the two liquid streams into the container. (3) A method of supplying three liquid streams of (i) a crude solution, (ii) a slurry comprising a seed crystal and a mixed solvent, and (iii) a poor solvent into a vessel. (4) A method in which (i) a crude solution, (ii) a slurry composed of seed crystals and a poor solvent, and (iii) three liquid streams of a poor solvent are supplied into a vessel.

The methods (1) to (4) are for explanation of the batch method, and slight modifications and additions may be made. For example, in the method (1), a good solvent may be further supplied to the container, or a slurry composed of a seed crystal and a mixed solvent may be supplied to the container. Also (1) ~
In (4), the composition and the supply speed of each liquid stream need not be constant, and may be varied. Furthermore, in the batch method, a method in which a part of the slurry in the container is taken out and circulated and supplied again into the container may be adopted.

In the above methods (1) to (4), it is desirable to mix the slurry in the container well by means such as stirring to enhance the effect of precipitation and obtain a high-purity bromine compound. .

Next, an embodiment of the continuous method will be described. The continuous method basically precipitates the bromine compound in the container while continuously supplying the crude solution into the container,
This is a method of taking out the slurry from the container continuously or intermittently. According to the present invention, the following method is proposed as a preferred embodiment for continuously performing the method of the present invention.

That is, according to the present invention, from a crude solution containing a bromine compound represented by the above general formula (1),
A method for continuously purifying a bromine compound by precipitating the bromine compound as solid particles, comprising: (i) placing the crude solution in a vessel containing a slurry containing the bromine compound particles together with a poor solvent for the bromine compound; To continuously precipitate the bromine compound in the slurry with stirring. (Ii) At this time, the slurry in the vessel has a concentration of bromine compound particles of 1%.
(Iii) the solvent in the slurry in the container is a mixed solvent composed of a good solvent and a poor solvent for the bromine compound, and the mixed solvent has a solubility of the bromine compound. Is maintained at a composition of 0.1 to 5 g / 100 g of solvent, and (iv) continuously removing the slurry from the vessel and separating solid particles of a bromine compound from the slurry. Provided is a method for continuous purification of bromine compounds.

The above-described continuous method may be further modified or added as described below in a concrete implementation. (A) A good solvent can also be supplied to the container in a complementary manner. (B) A part of the slurry taken out of the container can be circulated again into the container. (C) The slurry taken out of the container may be separated into a wet cake of bromine compound and mother liquor by solid-liquid separation, and a part of the mother liquor may be supplied into the container. This circulating supply of the mother liquor is a preferred embodiment because it serves to improve the recovery of the target bromine compound. The above-described embodiments (a) to (c) may be carried out independently, or may be carried out in any combination.

The slurry containing bromine compound particles obtained by the above-mentioned batch method and continuous method is separated into a wet cake and a mother liquor by centrifugation or filtration, and the wet cake is dried and optionally ground. By,
The desired high purity bromine compound particles can be obtained.

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

According to the purification method of the present invention, a high-purity bromine compound can be industrially advantageously obtained, and is useful as a flame retardant for resins, particularly for ABS resins, polystyrene resins and polyolefin resins. It is an excellent high-quality fuel.

It has been found that according to the preferred conditions of the process of the present invention, very high quality bromine compounds of excellent quality can be obtained. That is, since the bromine compound is obtained by a bromination reaction, it contains not a small amount of bromine ions.
The bromine ion concentration is at least about 10 ppm for bromine compounds on the market, and 20 ppm for most of them.
That is all. If the bromine ion concentration is high, when it is added to a resin as a flame retardant, it causes decomposition, deterioration and coloring of the resin, and also causes corrosion of the molding machine. However, according to the preferred conditions of the present invention, it has become possible to provide a high quality bromine compound having a bromine ion concentration of 5 ppm or less, preferably 4 ppm or less.

Further, it has been found that the bromine compound particles obtained by the purification method of the present invention have different shape characteristics from the conventional ones. This shape characteristic is that when the particles are compressed, the compression ratio is extremely small. When the shape characteristics of the particles are expressed by the following formula of compressibility (%), the bromine compound particles of the present invention have a compressibility of 0.1 to 20%, more preferably 1 to 15%.

[0058]

(Equation 1) Here, A indicates the loose apparent density of the particles (g / cm ³ ), and P indicates the solid apparent density of the particles (g / cm ³ ).

The bromine compound obtained in the present invention is not only high in purity, but also has a low degree of compression of 0.1 to 20%. It has the advantage of being difficult to handle.

The bromine compound obtained by the purification method of the present invention generally has a purity of 94% by weight or more, preferably 95% by weight.
% By weight, particularly preferably 96% by weight or more, having extremely high purity and extremely low content of undesirable impurities.

Further, the bromine compound particles obtained by the present invention have an inclination angle of 5 measured by the method described later.
It has a feature that it is ~ 70 °, preferably 5-45 °. The small angle of inclination means that the particles are hardly blocked, and has an advantage that the handling of the particles is easy.

[0062]

The present invention will be described below in detail with reference to examples. The following methods were used to measure the purity, the average particle size, the solubility, the proportion of crystals in the slurry, and the specific gravity.

(1) Analysis of Purity Purity was measured by high performance liquid chromatography.
It carried out by the method of detecting the absorption of 80 nm. (HPLC:
Shimadzu Corporation SCL-6B)

(2) Average Particle Size Samples were prepared for 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. In addition, the average particle size that cannot be measured by sieving is 0.1.
For those having a particle size of not more than mm, the average particle size was determined from a cumulative particle size distribution graph based on the obtained weight using a Coulter LS230 type particle size distribution analyzer.

(3) Solubility At a predetermined temperature, an excess of the sample powder is dissolved in a predetermined solvent, and after the solution is completely saturated at that temperature, a certain amount of this solution is accurately measured, and then the solvent is removed from the solution. After complete removal,
The remaining weight was measured to calculate the solubility of the sample in the solvent.

(4) Proportion of Crystals in Slurry A certain amount of the slurry was filtered to remove 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.

(5) Specific gravity The specific gravity was measured at 20 ° C. using a glass specific gravity bottle.

(6) Degree of Compression A TBA-BE powder sample was prepared with a diameter of 50 mm and a volume of 100 c.
gently added from above to a stainless cylindrical vessel m ^3,
The TBA-BE powder was ground at the upper edge of the cylindrical container, and the weight X (g) of the TBA-BE powder in the container was measured.
Loose apparent density A (g / cm ³ ) ｛= X (g) / 10
0 (cm ³ )}, then add the same diameter frame (diameter 50 mm, height 40 mm) of the accessory to the container,
After adding BA-BE powder and granules, and using a powder tester manufactured by Hosokawa Micron Co., Ltd., tapping was performed 180 times at a fall height of 18 mm at a pace of 1 time / second, and the frame was removed.
The TBA-BE powder is abraded at the upper edge of the cylindrical container, the weight Y (g) of the TBA-BE powder in the cylindrical container is measured, and the apparent bulk density P (g / cm ³ ) ｛= Y (g) / 1
00 (cm ³ )}, and the degree of compression was calculated by the following equation (1).

[0069]

(Equation 2)

(7) Long-term storage stability test 10 g of a TBA-BE powder sample was placed in a cylindrical cell having an inner diameter of 20 mmφ, and kept in a hot-air circulating drier kept at 40 ° C.
It was stored for 3 months while applying a load of 0.4 kgf to the granular material layer from the upper surface of the cell. After 3 months, observe the degree of blocking of the granular material taken out of the cell. If the granularity does not change much compared to the state before the test, ◎. The one returning to the state of was represented by ○, and the one in which the granular material layer was solidified and did not collapse even when touched by hand was represented by ×.

(8) Concentration of bromine ion 1 g of a sample was dissolved in 10 mL of methylene chloride, 10 mL of water was added to this solution, and the mixture was thoroughly mixed. The concentration of bromine ion extracted in water was measured by ion chromatography (DIONEX). SERIES 2000i / S manufactured by
P), and the bromine ion concentration in the sample was calculated.

Reference Example A 2,93% pure 2,2-bis [{3,5-dibromo-4-]
(2,3-Dibromopropyloxy) {phenyl] propane was recrystallized using ethyl acetate. As a result, crystals of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane having a purity of 94% and an average particle diameter of 0.2 mm were obtained (hereinafter, referred to as "hereinafter"). Seed crystal A). Further, recrystallization was performed in the same manner twice, and 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane having a purity of 99% and an average particle diameter of 0.2 mm was used. Was obtained (hereinafter, referred to as
Seed crystal B).

Reference Example B A commercially available TBA-AE (manufactured by Teijin Chemicals Limited, FG-320) was placed in a flask equipped with a thermometer, stirrer, and reflux condenser.
0) 100 g (0.160 mol) and methylene chloride 1
50 g was added and dissolved at 20 ° C. Bromine 5
4 g (0.338 mol) was added dropwise over 1 hour, and stirring was continued at the same temperature for 1 hour to complete the bromine addition reaction.

Next, excess bromine in this solution was reduced with 30 ml of a 25% by weight aqueous sodium hydrogen sulfite solution, and the generated hydrogen bromide was neutralized with 11 ml of a 24% by weight aqueous sodium hydroxide solution. After washing with water, a 50% by weight solution of TBA-BE in methylene chloride was obtained. Also, add a methylene chloride solution to this solution,
A 33% strength by weight methylene chloride solution was prepared. When a part of this solution was taken out and concentrated, the purity of the solid was 90%.
%Met.

Reference Example C 2,2-bis {(3,5-dibromo-4-allyloxy)
Phenyl @ propane (raw material No. (1)) 1000g
(1.60 mol) in 1703 g (20.0 g) of methylene chloride.
mol). The specific gravity of this solution was 1.46, and the result of measurement by the Karl Fischer method was 160 ppm.
Water.

The solution was placed in a glass reaction vessel equipped with a stirring blade, a condenser and a thermometer through an inlet for 5.
At a rate of 3 × 10 ⁻³ L / min, bromine was introduced from the inlet 2 to 0.5.
It was added continuously at a rate of 8 × 10 ⁻³ L / min (bromine / compound (1) molar ratio 2.45). The solution mixed in the reaction vessel generated heat due to the reaction heat of bromination, and the vaporized vapor was refluxed to the reaction vessel by a sufficiently cooled condenser. About 20 minutes after the start of the addition of the solution of raw material No. (1) and bromine, the reaction solution began to be drawn out from the outlet, and then was continuously drawn out (residence time of 20.
4 minutes). In addition, a part of the reaction solution in the reaction vessel (120 ml) was circulated into the reaction vessel at a rate of 0.03 L / min using the pump 6 from the time when the reaction solution began to be discharged.

The reaction solution derived from the reaction vessel is
After reducing excess bromine with an aqueous sodium disulfite solution (about 15% by weight), the generated hydrogen bromide was neutralized with an aqueous sodium hydroxide solution. Then, 1000 g of ion-exchanged water was added to this solution.
, And the mixture was stirred. The methylene chloride layer was separated, and the purity of the solid 2,2-bis {3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl} propane recovered from the methylene chloride solution was increased. Was 94.2%. The concentration of the bromine compound in the methylene chloride layer was 50.2%.

Example 1 2.5 kg of methylene chloride, 2.5 kg of methanol and the seed crystal B obtained in Reference Example A were placed in the flask shown in FIG.
2.5 kg was added and mixed (the specific gravity of this solid-liquid mixture was 1.15, and the volume was 6.5 L).

While stirring the inside of the flask, 2,2-bis [@ 3,5-dibromo-4 having a purity of 90% at a temperature of 25 ° C.
-(2,3-dibromopropyloxy) {phenyl] propane in a methylene chloride solution having a concentration of 50% by weight, methanol and a weight ratio of methylene chloride to methanol of 50:
The solid-liquid mixture having a ratio of 50% and having a seed crystal B ratio of 33% by weight obtained in Reference Example A was subjected to 0.05 L / min, 0.05 L / min, and 0.03 L / min by a metering pump, respectively. For 8 hours continuously. Ten minutes after the start of the addition, the slurry in the flask was circulated at a rate of 3.5 L / min.
It was withdrawn at a rate of L / min from the withdrawal port 8 (residence time was 60 minutes). The slurry withdrawn between 7 and 8 hours after the start of the addition was filtered, and 80 ° C., 3 hours, 5 mmHg
Then, crystals of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane were obtained. The obtained crystals had a purity of 96%, an average particle diameter of 0.4 mm, and a recovery of 96%.

The weight ratio of methylene chloride to methanol in the slurry was 50:50 and 2,2-bis [｛3,5-dibromo-4- (2,3-dibromopropyloxy) at 25 ° C. [Phenyl] propane (hereinafter T
BA-BE) may have a solubility of 0.7% by weight｝, and the ratio of TBA-BE crystals in the slurry may be 33%.
% By weight.

Example 2 2.5 kg of methylene chloride, 2.5 kg of methanol and the seed crystal B obtained in Reference Example A were placed in the flask shown in FIG.
2.5 kg was added and mixed (the specific gravity of this solid-liquid mixture was 1.15, and the volume was 6.5 L).

While stirring the inside of the flask, 2,2-bis [@ 3,5-dibromo-4 having a purity of 90% at a temperature of 25 ° C.
A 50% strength by weight methylene chloride solution and methanol of-(2,3-dibromopropyloxy) {phenyl] propane were each added to a 0.05 L /
Min, at a rate of 0.05 L / min for 8 hours continuously.
Ten minutes after the start of the addition, while the slurry in the flask was circulated at a rate of 3.5 L / min by the pump 6,
The slurry was withdrawn at a rate of 0.1 L / min from the withdrawal port 8 (residence time was 75 minutes). 7 ~ after starting the addition
The slurry withdrawn during 8 hours was filtered,
Drying under reduced pressure at 5 mmHg for 2,2-
Crystals of bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane were obtained. The obtained crystals had a purity of 96%, an average particle diameter of 0.2 mm, and a recovery of 95%.

The weight ratio of methylene chloride to methanol in the slurry was 50:50 (T at 25 ° C.).
BA-BE has a solubility of 0.7% by weight) and T in the slurry.
The proportion of BA-BE crystals was 33% by weight.

Example 3 50% by weight of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane having a purity of 90% was added to the flask shown in FIG. The solid-liquid mixture having a concentration of methylene chloride solution, methanol and a weight ratio of methylene chloride to methanol of 50:50 and a seed crystal B ratio of 33% by weight obtained in Reference Example A was metered into a metering pump. 0.05 L / min and 0.0 respectively
5 L / min, 0.03 L / min for 8 hours continuously
It was added at a temperature of 5 ° C. while stirring the inside of the flask.

Twenty minutes after the start of the addition, the slurry in the flask was withdrawn at a rate of 0.13 L / min from the discharge port 8 while circulating the slurry in the flask at a rate of 3.5 L / min by the pump 6 ( Residence time is 20 minutes). The slurry withdrawn between 7 and 8 hours after the start of the addition was filtered and dried under reduced pressure at 5 mmHg at 80 ° C. for 3 hours to give 2,2-bis [@ 3,5-dibromo-4- ( A few
[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 96%. The weight ratio of methylene chloride to methanol in the slurry was 50:50 (the solubility of TBA-BE at 25 ° C. was 0.7% by weight), and the ratio of TBA-BE crystals in the slurry was 33% by weight. Met.

Example 4 The procedure of Example 1 was repeated, except that the crystallization temperature was changed from 25 ° C. to 40 ° C., and the seed crystal B was changed to the seed crystal A. -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 0.2 mm, and a recovery of 94%.

The weight ratio of methylene chloride to methanol in the slurry was 50:50 (T at 40 ° C.).
BA-BE has a solubility of 1.6% by weight) and T in the slurry.
The proportion of BA-BE crystals was 33% by weight.

Example 5 2 kg of methylene chloride, 3 kg of methanol and the seed crystal B2.5 k obtained in Reference Example A were placed in the flask shown in FIG.
g and mixed (the specific gravity of the solid-liquid mixture was 1.10).
And the capacity is 6.8 L. ).

While stirring the inside of the flask, 2,2-bis [｛3,5-dibromo-4 having a purity of 90% at a temperature of 25 ° C.
A 50% strength by weight solution of-(2,3-dibromopropyloxy) {phenyl] propane in methylene chloride and methanol were each fed to a metering pump at 0.02 L /
Min, at a rate of 0.03 L / min for 8 hours continuously.
Ten minutes after the start of the addition, while the slurry in the flask was circulated at a rate of 3.5 L / min by the pump 6,
The slurry was withdrawn at a rate of 0.05 L / min from the withdrawal port 8 (residence time was 146 minutes). The slurry withdrawn between 7 and 8 hours after the start of the addition was filtered and 80
By drying under reduced pressure at 5 mmHg for 3 hours.
Crystals of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane were obtained. The obtained crystals have a purity of 95% and an average particle size of 0.3.
mm, and the recovery was 96%.

The weight ratio of methylene chloride to methanol in the slurry was 40:60 (T at 25 ° C.).
BA-BE has a solubility of 0.2% by weight) and T in the slurry.
The proportion of BA-BE crystals was 28-33% by weight.

Example 6 1.5 kg of methylene chloride, 3.5 kg of methanol and the seed crystal B obtained in Reference Example A were placed in the flask shown in FIG.
2.5 kg was added and mixed (the specific gravity of the solid-liquid mixture was 1.04, and the volume was 7.2 L).

While stirring the inside of the flask, 2,2-bis [@ 3,5-dibromo-4 having a purity of 90% at a temperature of 40 ° C.
A 50% strength by weight solution of methylene chloride and methanol of-(2,3-dibromopropyloxy) {phenyl] propane was added by a metering pump to 0.015 L /
Min, at a rate of 0.035 L / min for 8 hours continuously. Ten minutes after the start of the addition, the slurry was withdrawn from the outlet 8 at a rate of 0.05 L / min while circulating the slurry in the flask at a rate of 3.5 L / min by the pump 6 (residence time was 154 minutes). The slurry withdrawn between 7 and 8 hours after the start of the addition was filtered,
By drying at 0 ° C. for 3 hours under reduced pressure at 5 mmHg,
Crystals of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane were obtained. The obtained crystals have a purity of 95% and an average particle size of 0.4.
mm, and the recovery was 97%.

The weight ratio of methylene chloride to methanol in the slurry was 30:70 (T at 40 ° C.).
BA-BE has a solubility of 0.1% by weight) and T in the slurry.
The proportion of BA-BE crystals was 22-33% by weight.

Example 7 3 kg of methylene chloride, 2 kg of methanol and 2.5 k of the seed crystal B obtained in Reference Example A were placed in the flask shown in FIG.
g and mixed (the specific gravity of this solid-liquid mixture was 1.20).
And the capacity is 6.3 L. ).

While stirring the inside of the flask, a 2,2-bis [@ 3,5-dibromo-4 having a purity of 90% was obtained at a temperature of 35 ° C.
A 50% strength by weight methylene chloride solution and methanol of-(2,3-dibromopropyloxy) {phenyl] propane were continuously fed for 8 hours at a rate of 0.06 L / min and 0.04 L / min by means of a metering pump. Was added. Ten minutes after the start of the addition, the slurry was withdrawn from the outlet 8 at a rate of 0.1 L / min while the slurry in the flask was circulated at a rate of 3.5 L / min by the pump 6 (residence time was 73 minutes). The slurry withdrawn between 7 and 8 hours after the start of the addition was filtered and 80
By drying under reduced pressure at 5 mmHg for 3 hours.
Crystals of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane were obtained. The obtained crystals have a purity of 97% and an average particle size of 0.2.
mm, and the recovery was 84%.

The weight ratio of methylene chloride to methanol in the slurry was 60:40 (T at 35 ° C.).
BA-BE has a solubility of 4.0% by weight) and T in the slurry.
The proportion of BA-BE crystals was 33% by weight.

Example 8 The procedure of Example 1 was repeated, except that 1,2-dichloroethane was used instead of methylene chloride, and 2,2-bis [@ 3,5-dibromo-4- (2,3-
Crystals of dibromopropyloxy) {phenyl] propane were obtained. The obtained crystals had a purity of 94%, an average particle diameter of 0.3 mm, and a recovery of 95%.

The weight ratio of 1,2-dichloroethane to methanol in the slurry was 50:50 (at 25 ° C.
The solubility of TBA-BE in the slurry was 0.5% by weight), and the ratio of TBA-BE crystals in the slurry was 33% by weight.

Example 9 2.5 kg of toluene, 2.5 kg of methanol and the seed crystal B2.5 obtained in Reference Example A were placed in a flask shown in FIG.
kg and mixed (the specific gravity of this solid-liquid mixture was 0.9.
2 and the capacity is 8.2 L. ).

While stirring the inside of the flask, 2,3-bis [@ 3,5-dibromo-4 having a purity of 90% at a temperature of 35 ° C.
A 50% strength by weight toluene solution of-(2,3-dibromopropyloxy) {phenyl] propane and methanol were continuously added at a rate of 0.08 L / min and 0.05 L / min by a metering pump for 8 hours. did. Ten minutes after the start of the addition, the slurry was withdrawn at a rate of 0.13 L / min from the withdrawal port 8 while circulating the slurry in the flask at a rate of 3.5 L / min with the pump 6 (residence time was 73 minutes). 7 ~ after starting the addition
The slurry withdrawn during 8 hours was filtered,
Drying under reduced pressure at 5 mmHg for 2,2-
Crystals of bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane were obtained. The obtained crystals had a purity of 94%, an average particle diameter of 0.3 mm, and a recovery of 94%. The weight ratio of toluene and methanol in the slurry was 50:50 (the solubility of TBA-BE at 35 ° C. was 1.4% by weight), and the ratio of TBA-BE crystals in the slurry was 33% by weight. there were.

Example 10 2.5 kg of ethyl acetate, 2.5 kg of diisopropyl ether and 2.5 kg of a seed crystal B obtained in Reference Example A were placed in a flask shown in FIG. The specific gravity is 0.82, and the capacity is 9.1 L.)

While stirring the flask, at a temperature of 40 ° C., 90% pure 2,2-bis [５−3,5-dibromo-4
A 50% by weight solution of-(2,3-dibromopropyloxy) {phenyl] propane in ethyl acetate and diisopropyl ether were continuously fed for 8 hours at a rate of 0.07 L / min and 0.05 L / min by the metering pump 6. Was added. Ten minutes after the start of the addition, the slurry was withdrawn from the outlet 8 at a rate of 0.12 L / min while the slurry in the flask was circulated at a rate of 3.5 L / min by the pump 6 (residence time was 86 minutes). The slurry withdrawn between 7 and 8 hours after the start of the addition was filtered and dried under reduced pressure at 5 mmHg at 80 ° C. for 3 hours to give 2,2-bis [@ 3,5-dibromo-4- ( A few
[Dibromopropyloxy) {phenyl] propane crystals were obtained. The obtained crystals had a purity of 94%, an average particle diameter of 0.3 mm, and a recovery of 95%.

The weight ratio of ethyl acetate to diisopropyl ether in the slurry was 50:50 (40 ° C.
The solubility of TBA-BE in the slurry was 1.0% by weight), and the ratio of TBA-BE crystals in the slurry was 33% by weight.

Example 11 67 g of methylene chloride and 67 g of methanol were stirred at 25 ° C. in a four-necked 1 L flask equipped with a thermometer, a stirrer and a dropping funnel at a temperature of 25 ° C.
, A solid-liquid mixture consisting of 30 g of seed crystal B obtained in Reference Example A and 2,2-bis [｛3,5-dibromo-
4- (2,3-dibromopropyloxy) @phenyl]
225 g of a 50% strength by weight methylene chloride solution of propane
And 113 g of methanol from the dropping funnel, 3 g each.
Added continuously over 0 minutes. After the addition was completed, the slurry was further stirred for 30 minutes. Thereafter, the slurry was filtered and dried under reduced pressure at 5 mmHg at 80 ° C. for 3 hours to give 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 0.5 mm, and a recovery of 95%.

The weight ratio of methylene chloride to methanol in the slurry was 50:50 (T at 25 ° C.).
BA-BE has a solubility of 0.7% by weight) and T in the slurry.
The proportion of BA-BE crystals was 28% by weight.

Example 12 Solid-liquid mixing comprising 67 g of methylene chloride, 67 g of methanol and 30 g of the seed crystal B obtained in Reference Example A in a four-necked 1 L flask equipped with a thermometer, a stirrer and a dropping funnel. I put my body.

While stirring the inside of the flask, 2,2-bis [@ 3,5-dibromo-4 having a purity of 90% at a temperature of 25 ° C.
225 g of a 50% strength by weight solution of-(2,3-dibromopropyloxy) {phenyl] propane in methylene chloride and 113 g of methanol were each added through a dropping funnel to 30 g.
Minutes were added continuously. After the addition was completed, the slurry was further stirred for 30 minutes. Thereafter, the slurry was filtered and dried under reduced pressure at 5 mmHg at 80 ° C. for 3 hours to give 2,2-bis [｛3,5-dibromo-4- (2,3
[Dibromopropyloxy) {phenyl] propane crystals were obtained. The obtained crystals had a purity of 95%, an average particle diameter of 0.4 mm, and a recovery of 95%.

The weight ratio of methylene chloride to methanol in the slurry was 50:50 (T at 25 ° C.).
BA-BE has a solubility of 0.7% by weight) and T in the slurry.
The proportion of crystals of BA-BE was 18-28% by weight.

Example 13 67 g of methanol and Reference Example A were obtained in a four-necked 1 L flask equipped with a thermometer, a stirrer and a dropping funnel at 25 ° C. while stirring the inside of the flask. Solid-liquid mixture of 30 g of seed crystal B, 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane having a purity of 90% at a concentration of 50% by weight 359 g of methylene solution and methanol 1
13 g were added continuously from the dropping funnel over 30 minutes each. After the addition was completed, the slurry was further stirred for 30 minutes. Thereafter, the slurry was filtered and dried under reduced pressure at 5 mmHg at 80 ° C. for 3 hours to give 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane. Was obtained. The obtained crystals had a purity of 94%, an average particle diameter of 0.5 mm, and a recovery of 95%.

Incidentally, the weight ratio of methylene chloride to methanol in the slurry was 50:50 (T
BA-BE has a solubility of 0.7% by weight) and T in the slurry.
The proportion of BA-BE crystals was 37% by weight.

Example 14 60 g of methylene chloride and 120 ml of methanol were placed in a four-necked 1 L flask equipped with a thermometer, a stirrer and a dropping funnel at 25 ° C. while stirring the inside of the flask.
g and 20 g of the seed crystal B obtained in Reference Example A, and 90% pure 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl ] Propane 50% strength by weight methylene chloride solution 1
20 g were added continuously from the dropping funnel over 30 minutes each. After the addition was completed, the slurry was further stirred for 30 minutes. Thereafter, the slurry was filtered and dried under reduced pressure at 5 mmHg at 80 ° C. for 3 hours to give 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane. Was obtained. The obtained crystals had a purity of 95%, an average particle diameter of 0.5 mm, and a recovery of 95%.

The weight ratio of methylene chloride to methanol in the slurry was 50:50 (T at 25 ° C.).
BA-BE has a solubility of 0.7% by weight) and T in the slurry.
The proportion of crystals of BA-BE was 25% by weight.

Comparative Example 1 In a flask equipped with a thermometer, a stirrer and a reflux tube,
240 g of methanol and seed crystal B obtained in Reference Example A
20 g were added and mixed. While stirring the inside of the flask,
At a temperature of 25 ° C., 90% pure 2,2-bis [｛3.5-
Dibromo-4- (2,3-dibromopropyloxy)
120 g of a 50% strength by weight methylene chloride solution of [phenyl] propane were added from the dropping funnel over 30 minutes. After the addition was completed, stirring was continued for another 30 minutes. Thereafter, the precipitated powder was filtered to obtain a powder of 2,2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane. This is at 80 ° C for 3 hours, 5
Drying under reduced pressure was performed at mmHg. However, in the drying under reduced pressure, powders adhered to each other, resulting in a large block and partial coloring. The bromine compound had a purity of 92% and a recovery of 96%.

The weight ratio of methylene chloride to methanol in the slurry after the addition of the methylene chloride solution was 20:80.
(The solubility of TBA-BE at 25 ° C. is 0.0
2% by weight), and the ratio of TBA-BE crystals in the slurry was 8 to 20% by weight.

[0115]

[Table 1]

[0116]

[Table 2]

Example 15 In a flask equipped with a thermometer, a stirrer and a reflux tube,
60 g of methylene chloride, 120 g of methanol and 20 g of the seed crystal B obtained in Reference Example A were added and mixed (the ratio of the seed crystal B in the solid-liquid mixture was 10% by weight). While stirring the solid-liquid mixture, at a temperature of 25 ° C, 90% pure 2,2
120 g of a 50% by weight methylene chloride solution of 2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane was added from the dropping funnel 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 24% by weight, and the weight ratio of methylene chloride to methanol in the slurry was 50:50).
50). Thereafter, the slurry was filtered to remove a crystal, which was dried at 80 ° C. for 3 hours under reduced pressure of 5 mmHg, and 2,2-bis [｛3,5-dibromo-4- (2,3-
Crystals of dibromopropyloxy) {phenyl] propane were obtained. The obtained crystals have a purity of 95% and an average particle size of 0.5.
5 mm and the recovery was 97%.

Example 16 In a flask equipped with a thermometer, a stirrer and a reflux tube,
60 g of methylene chloride, 120 g of methanol and 20 g of the seed crystal B obtained in Reference Example A were added and mixed (the ratio of the seed crystal B in the solid-liquid mixture was 10% by weight). While stirring the solid-liquid mixture, at a temperature of 25 ° C, 90% pure 2,2
120 g of a 25% by weight solution of 2-bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane in methylene chloride was added from the dropping funnel 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:
44). Thereafter, the slurry was filtered to remove a crystal, which was dried at 80 ° C. for 3 hours under reduced pressure of 5 mmHg, and 2,2-bis [｛3,5-dibromo-4- (2,3-
Crystals of dibromopropyloxy) {phenyl] propane were obtained. The obtained crystals have a purity of 95% and an average particle size of 0.5.
4 mm and the recovery was 96%.

Example 17 The same procedure as in Example 15 was repeated, except that toluene was used instead of methylene chloride.
Crystals of bis [{3,5-dibromo-4- (2,3-dibromopropyloxy)} phenyl] propane were obtained. The obtained crystals had a purity of 95%, an average particle diameter of 0.6 mm, and a recovery of 98%. Examples 15 to 1
Table 3 below summarizes the conditions and results of No. 7.

[0120]

[Table 3]

Example 18 In a flask shown in FIG. 1, 500 g of methylene chloride, 500 g of methanol and 250 g of a 99% pure TBA-BE seed crystal were put and mixed.

While stirring the inside of the flask, the methylene chloride solution of 33% by weight of TBA-BE obtained in Reference Example B and methanol at a temperature of 25 ° C. were respectively 0.01 L / min. 8 at 012 L / min
Added continuously over time. 10 minutes after starting the addition,
While the slurry in the flask was circulated at a rate of 0.7 L / min by the pump 6, the slurry was withdrawn from the discharge port 8 at a rate of 0.022 L / min. The slurry withdrawn between 7 and 8 hours after the start of the addition was filtered and 80
C. by drying under reduced pressure at 5 mmHg for 3 hours.
Crystals of BA-BE (purity 94.0%) were obtained. The recovery was 94%. The obtained crystals have an average particle size of 0.5 mm.
And the degree of compression was 0.4%. Table 4 shows the results of measuring the long-term storage stability of the granules by the evaluation method described above.

The weight ratio of methylene chloride to methanol in the slurry was 50:50 (T at 25 ° C.).
BA-BE has a solubility of 0.7% by weight) and T in the slurry.
The proportion of crystals of BA-BE was 20% by weight.

Example 19 In a flask shown in FIG. 1, 500 g of methylene chloride, 500 g of methanol and 500 g of a seed crystal of TBA-BE having a purity of 99% were put and mixed.

While stirring the flask, at a temperature of 40 ° C., the 50% by weight solution of TBA-BE obtained in Reference Example B in methylene chloride and methanol were respectively fed at 0.01 L / min. It was added continuously at a rate of 01 L / min for 8 hours. Ten minutes after the start of the addition, the slurry in the flask was circulated by the pump 6 at a rate of 0.7 L / min, and the slurry was withdrawn from the discharge port 8 at a rate of 0.02 L / min. 7 after starting the addition
The slurry withdrawn between ８8 hours is filtered,
By drying under reduced pressure at 5 mmHg for 3 hours, TBA
-BE (94.3% purity) crystals were obtained. Recovery rate is 95
%Met. The obtained crystals were powders having an average particle size of 0.2 mm, and the degree of compression was 2.7%. Table 4 shows the results of measuring the long-term storage stability of the granules by the above-described evaluation method.

Incidentally, the weight ratio of methylene chloride to methanol in the slurry was 50:50 (T
BA-BE has a solubility of 0.7% by weight) and T in the slurry.
The proportion of BA-BE crystals was 33% by weight.

Example 20 The same procedure as in Example 11 was repeated, except that 225 g of the methylene chloride solution obtained in Reference Example C was used instead of 225 g of the 50% by weight methylene chloride solution. Was obtained. The purity of this solid powder is 96.8%
And the properties are shown in Table 4.

Example 21 The procedure of Example 1 was repeated, except that the methylene chloride solution obtained in Reference Example C was used in place of the 50% by weight methylene chloride solution. A powder (purity 95.7%) was obtained. Table 4 shows the properties of the powder. In Table 4 below, the properties of the bromine compound powder obtained in Comparative Example 1 are also shown.

[0129]

[Table 4]

[Brief description of the drawings]

FIG. 1 is an example of an apparatus for purifying a bromine compound according to the present invention.

[Explanation of symbols]

 1. Addition port 2. Addition port 3. Addition port 4. Condenser 5. Thermometer 6. Pump 7. Addition port for circulated slurry 8. Slurry extraction port 9. Stirrer blade 10. Slurry

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 317/22 C07C 317/22 (72) Inventor Akihiro Mukai 1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo (72) Inventor Yasuhisa Tabira 1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Teijin Chemical Co., Ltd. F term (reference) 4H006 AA02 AC30 AD15 AD17 BB11 BB12 BB14 BB15 BB16 BB17 BB31 BB49 BC15 BC51 BD10 BE53 GP03 GP05 GP06 GP20 GP21 GP22 TA02 TB13 TB42

Claims (21)

[Claims] 1. A method for purifying a bromine compound by precipitating the bromine compound as solid particles from a crude solution containing a bromine compound represented by the following general formula (1),
(I) feeding the crude solution into a slurry containing the bromine compound particles to precipitate the bromine compound in the slurry with stirring; (ii) the slurry has a bromine compound particle concentration of 10%. Ii50% by weight, (ii
i) At that time, the solvent in the slurry is a mixed solvent comprising a good solvent and a poor solvent for the bromine compound, and the mixed solvent is maintained at a composition in which the solubility of the bromine compound is 0.1 to 5 g / 100 g of the solvent. And (iv) removing the slurry and separating solid particles of the bromine compound from the slurry. Embedded image (Wherein, Ar ¹ and Ar ² are the same or different aromatic hydrocarbon groups having 6 to 10 carbon atoms; Y is 1 to 3 carbon atoms)
R ¹ and R ² are the same or different and have ^{2 to} 5 carbon atoms; m and n are the same or different integers of 1 to 4; p and q are the same Alternatively, it represents a different integer of 2 or 4. ) 2. The bromine compound according to the above formula (1), wherein Ar ¹ and Ar ² are benzene; Y is a methylene group or isopropylidene group; R ¹ and R ² are an alkyl group having 2 or 3 carbon atoms; 2. The method for purifying a bromine compound according to claim 1, wherein m and n are 1 or 2; 3. The method for purifying a bromine compound according to claim 1, wherein the slurry has a concentration of bromine compound particles of 15 to 40% by weight. 4. The method for producing a bromine compound according to claim 1, wherein the mixed solvent is maintained at a composition such that the solubility of the bromine compound is 0.4 to 4 g / 100 g of the solvent. 5. The method for purifying a bromine compound according to claim 1, wherein the precipitation of the bromine compound is performed at a temperature of 5 to 50 ° C. 6. The good solvent has a bromine compound solubility of 1 g.
2. The method for purifying a bromine compound according to claim 1, wherein the amount of the solvent is 100 g or more. 7. The poor solvent has a bromine compound solubility of 0.1.
The method for purifying a bromine compound according to claim 1, wherein the amount is not more than 08 g / 100 g of a solvent. 8. The method for purifying a bromine compound according to claim 1, wherein the particles of the bromine compound in the slurry have an average particle size of 0.1 to 0.8 mm. 9. The good solvent includes methylene chloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethane,
The method for purifying a bromine compound according to claim 1, wherein the bromine compound is at least one selected from the group consisting of cyclohexanone, ethyl acetate, and toluene. 10. The poor solvent is at least one selected from the group consisting of water, methanol, ethanol, i-propanol and diisopropyl ether.
A method for purifying a bromine compound according to the above. 11. The crude solution is prepared by adding the bromine compound to
The method for purifying a bromine compound according to claim 1, which is a solution dissolved at a concentration of 80% by weight. 12. The crude solution containing a bromine compound represented by the general formula (1) is a solution derived from a method of reacting an unsaturated bromine compound represented by the following general formula (2) with bromine. The method for purifying a bromine compound according to claim 1. Embedded image (Wherein, the definitions of Ar ¹ , Ar ² , Y, m and n mean the same as those in the general formula (1). Q ¹ and Q ² are the same or different unsaturated groups by one or It represents a hydrocarbon group having 2 to 2 carbon atoms and having 2 to 5 carbon atoms.) 13. A method for continuously purifying a bromine compound by precipitating the bromine compound as solid particles from a crude solution containing the bromine compound represented by the general formula (1), wherein (i) (Ii) continuously feeding the crude solution into a vessel containing a slurry containing the bromine compound particles together with a poor solvent for the bromine compound to precipitate the bromine compound in the slurry while stirring (precipitation step); In this case, the slurry in the container has a concentration of bromine compound particles of 10 to 50% by weight.
(Iii) At this time, the solvent in the slurry in the container is a mixed solvent composed of a good solvent and a poor solvent for the bromine compound, and the mixed solvent has a solubility of the bromine compound of 0.1 to 0.1. (Iv) a method for continuously purifying a bromine compound, wherein the composition is maintained at 5 g / 100 g of a solvent, and (iv) the slurry is continuously taken out from the vessel and solid particles of the bromine compound are separated from the slurry. 14. The method for continuously purifying a bromine compound according to claim 13, wherein a part of the slurry continuously taken out of the vessel is circulated through the vessel in the precipitation step. 15. The method for continuously purifying a bromine compound according to claim 13, wherein a part of the filtrate obtained after separating the solid particles of the bromine compound from the slurry is circulated to a vessel in the precipitation step. 16. A purified bromine compound represented by the general formula (1) having a bromine ion concentration of 5 ppm or less. 17. The purified bromine compound according to claim 16, comprising at least 94% by weight of the bromine compound represented by the general formula (1). 18. The compression degree defined in the text is 0.1.
17. A purified bromine compound according to claim 16 which is ~ 20%. 19. The tilt angle defined in the description is 5-7.
The purified bromine compound according to claim 16, which is at 0 °. 20. The bromine compound represented by the general formula (1) is 2,2-bis [3,5-dibromo-4- (2,3-
17. The purified bromine compound according to claim 16, which is dibromopropyloxy) phenyl] propane. 21. Use of the purified bromine compound of claim 16 as a flame retardant for a resin.