JP2964671B2 - Method for separating and recovering bis (3,5-dibromo-4-dibromopropoxyphenyl) propane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

In the present invention, bis [3,5-dibromo-4- (2,3-dibromopropoxy) phenyl] propane (hereinafter abbreviated as TBA-BP) was obtained by its production process. The present invention relates to a method of separating and recovering a powder from a solution.

[0002] TBA-BP is useful as a flame retardant such as polyolefin resin.
It is extremely useful as a flame retardant such as polystyrene and the like in JP-A-60-240750 and JP-A-61-25225.
No. 6, Publication No. 6, etc.

[0003]

2. Description of the Related Art Generally, bis (4-allyloxy-3,5-dibromophenyl) propane (hereinafter abbreviated as TBA-BA) is used as a raw material for TBA-BP.
It is produced by dissolving A-BA in a halogenated hydrocarbon solvent and then reacting with bromine. Therefore, the generated TBA-B
P is obtained as a solution of a halogenated hydrocarbon solvent which is a good solvent. As a method of separating and recovering TBA-BP as a powder from the TBA-BP solution, a method of evaporating and removing the halogenated hydrocarbon solvent from the TBA-BP solution, followed by crystallization through a purification step such as recrystallization, or , TBA-
A method is known in which a BP solution is reprecipitated in a solvent having low TBA-BP solubility, that is, a poor solvent (Japanese Patent Application Laid-Open No. 49-49).
-125348, JP-A-55-111429, and JP-B-57-289).

However, in the recrystallization method, since the recrystallization is performed after the reaction solvent is once distilled off, the operation is very complicated. On the other hand, in the reprecipitation method, a large amount of seed crystals are added. Alternatively, TBA-BP has a disadvantage that it becomes a resinous material unless a special device having a strong shearing force is used. In addition, both methods have a problem that TBA-BP is dissolved in the filtrate after reprecipitation, so that the recovery is not quantitative and the obtained crystals are of low quality (low melting point, coloring, etc.). As a separation and recovery method on a scale,
I was not always satisfied.

The inventors of the present invention have intensively studied a method of separating and recovering TBA-BP as a powder by a simple reprecipitation method in order to solve the above-mentioned problems.
Under stirring, a poor solvent having a boiling point higher than that of a good solvent is dropped into the BP solution, and after the dropping is completed, the good solvent is distilled off immediately by distillation, so that the TBA-BP powder can be separated and recovered in a short time. In addition, the obtained TBA-BP was found to be of high quality, and a patent application was previously filed (Japanese Patent Application No. 2-4).
No. 15384).

However, this method is not economically advantageous because a large amount of organic solvent is used as a poor solvent, and the operation of separating and recovering the good solvent and the poor solvent remaining in the filtrate after reprecipitation is difficult. Because of the necessity and the problem of exposure to an organic solvent, which is a problem in the working environment, it has not been satisfactory enough as an industrial method.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of separating and recovering TBA-BP as a powder, which has been conventionally complicated and economically problematic in the production process.
It is to provide an industrial method that is economically advantageous and simplifies conventional processes.

[0008] It is another object of the present invention to develop an industrial process in which the exposure to an organic solvent which poses a problem in the working environment is reduced, the flammable organic solvent is prevented from being ignited, and the safety is improved.

[0009]

In view of the above situation, the present inventors dropped a TBA-BP solution into heated water, and simultaneously separated the TBA-BP as a powder in which TBA-BP was dispersed in water while removing the solvent. After extensive studies on the method of recovery, the TBA-BP has extremely high hydrophobicity, so the viscous TBA-BP in the middle of desolvation aggregates during desolvation and adheres to the inner wall of the desolvation tank and the stirring blades. It becomes a nodule, T
BA-BP was not obtained as a powder, and it was found that the operation was difficult to perform.

In order to solve this problem, TBA-BP
Vigorously searching for a dispersant in water, many cation, anion and nonionic surfactants did not show a dispersing effect when added in a small amount. Then, it became clear that the foaming during the stripping of the solvent was so severe that the operation could not be continued satisfactorily.

There are adverse effects such as the adverse effect of the dispersant remaining in the TBA-BP, contamination of factory wastewater by the dispersant, and the effect of the dispersant cost on the product cost. A dispersant capable of picking up BP as a powder is desired.

[0012] Then, when a further search was conducted for a dispersant, among the nonionic surfactants, particularly when polyoxyalkylene sorbitan fatty acid ester was used,
With a very small addition amount, TBA-BP can be dispersed in the aqueous phase, and TBA-BP can be obtained as a powder,
In addition, the inventors have found that there is little foaming at the time of removing the solvent and the operability is extremely good, and the present invention has been completed.

That is, the gist of the present invention is to provide a method of separating and recovering TBA-BP produced by the bromination reaction of TBA-BA as a powder, wherein the solution of TBA-BP obtained in the production process is poly- A method of separating and recovering TBA-BP, wherein the method is carried out by dropping the solution into heated water containing oxyallylylene sorbitan fatty acid ester and simultaneously recovering the TBA-BP as a powder dispersed in water while distilling off the solvent.

The details will be described below.

[0015]

The separation and recovery of TBA-BP according to the present invention is carried out by dropping a solution of TBA-BP obtained in the manufacturing process into heated water containing polyoxyalkylene sorbitan fatty acid ester, and simultaneously removing the solvent while distilling off the solvent. -Achieved by picking up BP as a powder dispersed in water.

The reaction for producing TBA-BP using bromine and TBA-BA as a raw material in the method of the present invention can be explained by using the following reaction formula.

[0017]

Embedded image The organic solvent of the TBA-BP solution obtained in the production process referred to in the method of the present invention refers to a good solvent that dissolves TBA-BP, and is a halogenated hydrocarbon that is inactive in the bromination reaction of TBA-BA. And a solvent which can be distilled at 100 ° C. or lower or azeotropically distilled with water. For example, carbon tetrachloride, chloroform, methylene chloride, dichloroethane, trichloroethane, tetrachloroethane and the like.

The concentration of the TBA-BP solution is not particularly limited, but is usually about 5 to 50% by weight.

The polyoxyalkylene sorbitan fatty acid ester used in the present invention is generally 1,5-sorbitan, 1,4-sorbitan, 3,6-sorbitan, 1,4-sorbitan, 1,4-sorbitan obtained by intramolecular dehydration of sorbitol. A compound in which a mixture of 3,6-sorbide or the like is converted into a partial ester derivative of a fatty acid, and then a polyoxyalkylene chain is further introduced into an unreacted hydroxyl group. That is, chemical formula 2, chemical formula 3, chemical formula 4

[0020]

Embedded image

[0021]

Embedded image

[0022]

Embedded image (Wherein the substituent R ¹ is a fatty acid residue, the substituents R ² , R ³ ,
R ⁴ is a fatty acid residue or (C _m H2 _{m + 1} O) _n H
(Where m represents an integer of 2 to 4 and n represents an integer of 1 to 50), and at least one of the substituents of each compound is a polyoxyalkylene group.
Or a mixture thereof. As the fatty acid portion of the present compound, a linear carboxylic acid having 10 to 18 carbon atoms is selected, and specific examples include lauric acid, palmitic acid, stearic acid, and oleic acid.

Further, the HLB (hydrophilic-lipophilic balance) value of the present compound is in the range of 8 to 18. For example,
Specifically, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate,
Polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxypropylene sorbitan monolaurate and the like. The amount of the surfactant used varies slightly depending on the operating conditions.
-It is usually 0.05 to 5 parts by weight, preferably 1.0 to 3.0 parts by weight, based on 100 parts by weight of the BP powder.

When the amount of the surfactant used is less than 0.05 parts by weight, the TBA-BP precipitated during the desolvation does not disperse well in hot water, but partially solidifies to form a uniform powder. Not obtained as

On the other hand, if the amount of the surfactant exceeds 5 parts by weight, it is not preferable because foaming at the time of desolvation is increased and operability is deteriorated and the above-mentioned adverse effects are caused.

This surfactant is usually used by previously mixing it in hot water, but from the viewpoint of operation, it may be mixed with a TBA-BP solution to which a part is dropped.

The amount of hot water in the desolvation tank is determined by T
The amount is determined by the slurry concentration of BA-BP, and an amount which can be handled as a slurry and is economically advantageous is selected. Usually, about 0.2 to 10 liters is selected for 100 g of TBA-BP.

The temperature of the hot water for desolvation is at least one of the boiling point of the TBA-BP solution and the azeotropic temperature with water,
Usually, it is about 40 to 100 ° C. During desolvation, it is desirable that sufficient stirring is performed in the desolvation tank so that TBA-BP is uniformly dispersed in water. TBA- into hot water
As the addition of the BP solution, a method of dripping onto a heated water surface or a method of ejecting the BP solution from a small-diameter nozzle into hot water is selected.

Further, the dropping rate of the TBA-BP solution into the hot water is desirably equal to or lower than the distillation rate of the organic solvent in order to prevent the TBA-BP from solidifying.

The method of the present invention is usually carried out under normal pressure, but can also be carried out under reduced pressure.

When the TBA-BP solution was dropped into hot water containing the above-mentioned surfactant, and simultaneously the solvent was removed by the above-mentioned operation, TBA-BP precipitated out in a short time and was uniformly dispersed in water. It becomes a powder. Therefore, the precipitated TBA-BP
The powder can be easily separated from the slurry liquid by a conventional method. For example, it can be separated by centrifugation, suction filtration, spray drying, or the like.

According to these methods, TBA-BP can be quantitatively separated and recovered as a powder from the reaction solution obtained in the production process.

[0033]

As is clear from the above description, according to the method of the present invention, it is possible to separate and recover TBA-BP powder from water. Therefore, as compared with the conventional reprecipitation method using an organic solvent, it is economically advantageous, and it is not necessary to separate and recover the solvent in the filtrate, so that the production process can be greatly simplified.

Further, the working environment is less likely to be exposed to an organic solvent, so that it is preferable from the viewpoint of occupational health. In addition, since handling operations such as stirring, mixing, and filtration of the flammable organic solvent can be avoided, the safety of the work is improved. And TBA-BP, which is industrially advantageous, can be separated and recovered.

[0035]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 A 5 liter flask having a thermometer, a stirring blade and a condenser was charged with 3500 g (2646 ml) of methylene chloride and 1750 g (2.8 mol) of TBA-BA.
941 g (5.9 mol) of bromine was added at 24-28 ° C for 1.2 hours.
The mixture was added dropwise over a period of time, and after the addition, aging was performed at that temperature for 1 hour.

After the reaction, the residual bromine was reduced with an aqueous solution of sodium hydrogen sulfite, and further washed with water to obtain TBA-BP258.
4 g (2.74 mmol), methylene chloride 3384 g
(2,558 ml) containing 5996 g (4002 m
1) was obtained. The solution was analyzed by liquid chromatography, and as a result, the yield of TBA-BP was 9
7.8%, TBA-BA conversion was 100%.
Hereinafter, the obtained methylene chloride solution containing TBA-BP is referred to as a treatment liquid. From this treatment solution, TBS-BP18
5 g (196 mmol), 242 g of methylene chloride (18
429 g (287 ml) of a solution containing 3 ml) were used in the next separation and recovery.

In a 1000 ml four-necked flask having a thermometer, a stirring blade and a distillation apparatus, 800 ml of water and H
1.23 g of polyoxyethylene sorbitan monopalmitate having an LB value of 15.6 was dissolved and heated to 90 ° C.

The methylene chloride was continuously added to the heated water while stirring at a rate of 0.07 l / hr while the above-mentioned treatment solution in which 2.47 g of polyoxyethylene sorbitan monopalmitate was dissolved was added dropwise. Distilled off. The total amount of polyoxyethylene sorbitan monopalmitate used corresponds to 2.0 parts by weight based on 100 parts by weight of TBA-BP. During distillation, almost no foaming was observed and TBA-
BP immediately precipitated and became a powder, and was uniformly dispersed in water.

After the completion of the treatment solution dropping, the obtained TBA-B
The water slurry of P was filtered, washed with water, and dried to obtain 189.9 g of a white powder. The obtained powder was analyzed by liquid chromatography. As a result, the purity of TBS-BP was 97.3%.
The recovery of BS-BP was almost quantitative at 99.9%.

Example 2 A capacity of 1000 ml having a thermometer, a stirring blade and a distillation apparatus
800 ml of water and HLB value of 11.
0 polyoxyethylene sorbitan trioleate
85 g was dissolved and heated to 90 ° C. The amount of polyoxyethylene sorbitan trioleate used was TBA-
It corresponds to 1.0 part by weight based on 100 parts by weight of BP.

Next, 429 g (287 g) of a solution containing 185 g (196 mmol) of TBA-BP and 242 g (183 ml) of methylene chloride were obtained from the treatment solution prepared in Example 1.
ml) was taken out, and methylene chloride was continuously distilled off while dropping at a dropping rate of 0.08 l / hr into the above-mentioned stirring heated water. At the time of distillation, almost no foaming was observed, and TBA-BP immediately precipitated and turned into a powder, which was uniformly dispersed in water.

After the completion of the treatment solution dropping, the obtained TBS-B
The P water slurry was treated in the same manner as in Example 1 to obtain a white powder 1
89.2 g were obtained. The obtained powder was analyzed by liquid chromatography, and as a result, TBS-B
The purity of P was 97.7%, and the recovery of TBS-BP from the treatment solution was almost quantitative at 99.9%.

Example 3 1.5 liters of water and 5.55 g of polyoxyethylene sorbitan monolaurate having an HLB value of 16.7 were placed in a 2.0-liter four-necked flask having a thermometer, a stirring blade and a distillation apparatus. Was dissolved and heated to 90 ° C. In addition, the amount of the polyoxyethylene sorbitan trioleate used was determined by TBA.
-3.0 parts by weight per 100 parts by weight of BP.

Next, 429 g (287 g) of a solution containing 185 g (196 mmol) of TBA-BP and 242 g (183 ml) of methylene chloride were obtained from the treatment solution prepared in Example 1.
ml) and put into agitated heated water as above.
Methylene chloride was continuously distilled off while dropping at a dropping rate of 07 l / hr. At the time of distillation, almost no foaming was observed, and TBA-BP immediately precipitated and turned into a powder, which was uniformly dispersed in water.

After the completion of the dropping of the treatment liquid, the obtained TBA-B
The P water slurry was treated in the same manner as in Example 1 to obtain a white powder 1
89.7 g were obtained. The obtained powder was analyzed by liquid chromatography, and as a result, TBS-B
The purity of P was 97.4%, and the recovery of TBS-BP from the treatment solution was almost quantitative at 99.9%.

Example 4 A capacity of 1000 ml having a thermometer, a stirring blade and a distillation apparatus
13. In a four-necked flask, 800 ml of water and an HLB value of 14.
2.78 g of polyoxyethylene sorbitan monostearate of No. 9 were dissolved and heated to 95 ° C. The amount of polyoxyethylene sorbitan monostearate used is T
It corresponds to 1.5 parts by weight based on 100 parts by weight of BA-BP.

Next, 429 g (287 g) of a solution containing 185 g (196 mmol) of TBA-BP and 242 g (183 ml) of methylene chloride were obtained from the treatment solution prepared in Example 1.
ml) and put into agitated heated water as above.
Methylene chloride was continuously distilled off while dropping at a dropping rate of 05 liter / hr. At the time of distillation, almost no foaming was observed, and TBA-BP immediately precipitated and turned into a powder, which was uniformly dispersed in water.

After completion of the dropping of the treatment liquid, the obtained TBA-B
The P water slurry was treated in the same manner as in Example 1 to obtain a white powder 1
89.4 g were obtained. The obtained powder was analyzed by liquid chromatography, and as a result, TBS-B
The purity of P was 97.6%, and the recovery of TBS-BP from the treatment solution was almost quantitative at 99.9%.

Example 5 5000 ml capacity with thermometer, stirring blade and distillation apparatus
400 ml of water and HLB value of 15.
1.23 g of polyoxyethylene sorbitan monopalmitate of No. 6 was dissolved and heated to 90 ° C.

From the treatment solution prepared in Example 1, TBA
-BP 185 g (196 mmol), methylene chloride 24
429 g (287 ml) of a solution containing 2 g (183 ml)
, And solvent replacement with chloroform, and then 2.47 g of polyoxyethylene sorbitan monopalmitate
Was dissolved to make 290 ml of a chloroform solution.
The total amount of polyoxyethylene sorbitan monopalmitate used corresponds to 2.0 parts by weight based on 100 parts by weight of TBA-BP.

Next, chloroform was continuously distilled off while dropping this solution into the above-mentioned stirring heated water at a dropping rate of 0.06 l / hr. At the time of distillation, almost no foaming was observed, and TBA-BP immediately precipitated and turned into a powder, which was uniformly dispersed in water.

After the completion of the treatment solution dropping, the obtained TBA-B
The P water slurry was treated in the same manner as in Example 1 to obtain a white powder 1
89.4 g were obtained. The obtained powder was analyzed by liquid chromatography, and as a result, TBS-B
The purity of P was 97.6%, and the recovery of TBS-BP from the treatment solution was almost quantitative at 99.9%.

Comparative Example 1 185 g of TBA-BP was obtained from the processing solution prepared in Example 1.
(196 mmol), 242 g of methylene chloride (183 m
429 g (287 ml) of the solution containing 1) were taken out and added dropwise to 549 ml of stirring isopropanol at a rate of 0.20 l / hr. After dropping, TB
A-BP was a slurry solution containing a large amount of resinous material. The obtained crystals were filtered by suction, washed with water and dried to obtain 177.6 g of yellow crystals containing a large amount of resinous substances.
The obtained crystals were analyzed by liquid chromatography, and as a result, the purity of TBA-BP was 97.9.
%, And the recovery of TBA-BP from the treatment solution was 94.0%.

Comparative Example 2 185 g of TBA-BP from the processing solution prepared in Example 1
(196 mmol), 242 g of methylene chloride (183 m
429 g (287 ml) of the solution containing 1) was taken out and added dropwise to 915 ml of stirring methanol at a rate of 0.10 l / hr. After the completion of dropping, TBA-B
P was a slurry solution containing a large amount of resinous material.
The obtained crystals were subjected to suction filtration, washed with water, and dried to obtain 174.6 g of yellow crystals containing a large amount of resinous substances. The obtained powder was analyzed by liquid chromatography. As a result, the purity of TBS-BP was 98.3%, and the recovery rate of TBS-BP from the processing solution was 92.8%.

Comparative Example 3 Capacity of 1000 ml having a thermometer, a stirring blade and a distillation apparatus
800 ml of water and HLB value of 11.
0 polyoxyethylene sorbitan trioleate
04 g was dissolved and heated to 90 ° C. The amount of polyoxyethylene sorbitan trioleate used was TBA-
It corresponds to 0.02 parts by weight for 100 parts by weight of BP.

Next, 429 g (287 g) of a solution containing 185 g (196 mmol) of TBA-BP and 242 g (183 ml) of methylene chloride were obtained from the treatment solution prepared in Example 1.
ml) and put into agitated heated water as above.
Methylene chloride was continuously distilled off while dropping at a dropping rate of 05 liter / hr. TB that precipitates during distillation
A-BP was poorly dispersed in water, and most of the A-BP adhered to the stirring blades and vessel walls in a resin state, and thus could not be obtained as powder.

Comparative Example 4 Capacity of 1000 ml having a thermometer, a stirring blade and a distillation apparatus
800 ml of water and HLB value 15.
Polyoxyethylene sorbitan monopalmitate 6
3.0 g was dissolved and heated to 90 ° C. The amount of polyoxyethylene sorbitan monopalmitate used was TB
It corresponds to 7.5 parts by weight for 100 parts by weight of A-BP.

Next, 429 g (287 g) of a solution containing 185 g (196 mmol) of TBA-BP and 242 g (183 ml) of methylene chloride were obtained from the treatment solution prepared in Example 1.
ml) and put into agitated heated water as above.
Methylene chloride was continuously distilled off while dropping at a dropping rate of 05 liters / hr, but the foaming was so severe that the operation could not be performed.

Further, the precipitated TBA-BP was poorly dispersed in water, and most of the deposited TBA-BP adhered to the vessel wall in a resin state, and thus could not be obtained as a powder.

Comparative Example 5 A capacity of 1000 ml having a thermometer, a stirring blade and a distillation apparatus
800 ml of water and HLB value 15.
3.7 polyoxyethylene nonyl phenyl ether
0 g was dissolved and heated to 90 ° C. The amount of polyoxyethylene nonylphenyl ether used was TBA-BP.
It corresponds to 2.0 parts by weight for 100 parts by weight.

Next, 429 g (287 g) of a solution containing 185 g (196 mmol) of TBA-BP and 242 g (183 ml) of methylene chloride were obtained from the treatment solution prepared in Example 1.
ml) and put into agitated heated water as above.
Methylene chloride was continuously distilled off while dropping at a rate of 08 liter / hr. TB that precipitates during distillation
A-BP was poorly dispersed in water, and most of the A-BP adhered to the stirring blades and vessel walls in a resin state, and thus could not be obtained as powder.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C07C 41/34 C07C 43/225 C07C 41/22 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] A powder of bis [3,5-dibromo-4- (2,3-dibromopropoxy) phenyl] propane produced by a bromination reaction of bis (4-allyloxy-3,5-dibromophenyl) propane. The solution of bis [3,5-dibromo-4- (2,3-dibromopropoxy) phenyl] propane obtained in the production process is heated with the polyoxyalkylene sorbitan fatty acid ester Bis [3,5-dibromo-4- (2,3-dibromopropoxy) phenyl] propane is recovered as a powder dispersed in water while dropping into water and simultaneously distilling off the solvent. , 5-Dibromo-4- (2,3-dibromopropoxy) phenyl] propane.