JP3106506B2 - Method for separating and recovering bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002] TBS-BP is useful as a flame retardant for polyolefin resins and the like, and is particularly useful as a flame retardant for polypropylene and the like.
No. 5103, Japanese Patent Publication No. 50-23693, and the like.

[0003]

2. Description of the Related Art Generally, when bis (4-allyloxy-3,5-dibromophenyl) sulfone (hereinafter abbreviated as TBS-BA) is used as a raw material,
It is produced by dissolving S-BA in a halogenated hydrocarbon solvent and then reacting with bromine. Therefore, the generated TBS-B
P is obtained as a solution of a halogenated hydrocarbon solvent which is a good solvent. As a method of separating and recovering TBS-BP as a crystallized substance or powder from the TBS-BP solution,
A method of removing a halogenated hydrocarbon solvent from a TBS-BP solution by evaporating the TBS-BP solution,
A method of reprecipitation in a solvent having low solubility of BP, that is, a poor solvent is known (Japanese Patent Publication No. 50-35103,
JP-B-50-23693, JP-B-63-39585).

[0004] However, the method of removing the solvent by evaporation is T
Since BS-BP is obtained as a glassy solid, there is a problem that the recovery operation becomes very complicated. In addition, the method of reprecipitating in a poor solvent is that TBS-BP is obtained as a powder, There was a drawback that the recovery rate was low because TBS-BP was dissolved in the filtrate after precipitation. In addition, the reprecipitation method has problems such as the necessity of separating and recovering a good solvent and a poor solvent in the filtrate after the reprecipitation and the treatment of TBS-BP in the filtrate. Was not yet fully satisfactory.

[0005]

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

[0006] 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.

[0007]

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

[0008] To solve this problem, TBS-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. It was also found that foaming during stripping of the solvent was so severe that the operation could not be continued satisfactorily.

[0009] Due to such adverse effects, for example, the adverse effect of the dispersant remaining in the TBS-BP, the contamination of the factory effluent by the dispersant, the effect of the dispersant cost on the product cost, and the like, the TBS-BP may be added in a very small amount. A dispersant capable of extracting BP as a powder is desired.

[0010] Therefore, when further subjected to the search of the dispersant, in a nonionic surfactant, in particular polyoxy A
In the case of using a rutilen sorbitan fatty acid ester,
With the addition of a very small amount of both, TBS-BP can be dispersed in the aqueous phase, and TBS-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 TBS-BP produced by the bromination reaction of TBS-BA as a powder, wherein the solution of TBS-BP obtained in the production process is polyoxyethylene. A method for separating and recovering TBS-BP, which comprises dropping TBS-BP as a powder dispersed in water while simultaneously dropping the solvent into heated water containing an alkylene sorbitan fatty acid ester.

The details will be described below.

[0013]

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

The reaction of producing TBS-BP from bronze using TBS-BA as a raw material in the method of the present invention can be explained using the following reaction formula.

[0015]

Embedded image The organic solvent of the TBS-BP solution obtained in the production process referred to in the method of the present invention refers to a good solvent that dissolves TBS-BP, and is a halogenated hydrocarbon that is inactive in the bromination reaction of TBS-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 TBS-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 generally means 1,5-sorbitan, 1,4-sorbitan, 3,6-sorbitan, 1,1-sorbitan obtained by intramolecular dehydration of sorbitol. A compound in which a mixture of 4,3,6-sorbide or the like is converted into a partial ester derivative of a fatty acid, and then a polyoxyalkylene chain is introduced into an unreacted hydroxyl group. That is, chemical formula 2, chemical formula 3, chemical formula 4

[0018]

Embedded image

[0019]

Embedded image

[0020]

Wherein the substituent R ¹ is a fatty acid residue, the substituent R ² ,
R ³ and R ⁴ represent a fatty acid residue or a polyoxyalkyl group represented by (C ₁ H _{2l + 1} O) _m H (here, l = 2 to 4, m = 1 to 50); At least one of the compounds is a compound represented by｝, which is a polyoxylalkylene group, or a mixture thereof.

The fatty acid moiety of the compound has 1 carbon atom.
A linear carboxylic acid of 0 to 18 is selected, and specific examples thereof 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 TBS-BP precipitated during desolvation does not disperse well in hot water, but is partially solidified to form a uniform powder. Not obtained as

On the other hand, if the amount of the surfactant exceeds 5 parts by weight, the foaming at the time of desolvation becomes large and the operability is deteriorated, and the above-mentioned disadvantages are not preferred.

This surfactant is usually used by previously mixing it in hot water, but from the viewpoint of operation, it may be mixed in a TBS-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 BS-BP, and an amount which can be handled as a slurry and is economically advantageous is selected. Usually, about 0.2 to 10 l is selected for 100 g of TBS-BP.

The temperature of the hot water for removing the solvent is at least one of the boiling point of the TBS-BP solution and the azeotropic temperature with water, and is usually about 40 to 100 ° C. During desolvation, the inside of the desolvation tank is
It is desirable to perform sufficient stirring so that TBS-BP is uniformly dispersed in water. TBS-B in hot water
For the addition of the P solution, a method of dropping the solution on a heated water surface or a method of ejecting the solution from a small-diameter nozzle into hot water is selected.

Further, the rate of dropping the TBS-BP solution into the hot water is desirably equal to or lower than the rate of distilling the organic solvent in order to prevent the TBS-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 TBS-BP solution was dropped into hot water containing the above-mentioned surfactant, and simultaneously the solvent was removed by the above-mentioned operation, TBS-BP precipitated out in a short time and was uniformly dispersed in water. It becomes a powder. Therefore, the precipitated TBS-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, TBS-BP can be quantitatively separated and recovered as a powder from the reaction solution obtained in the production process.

[0032]

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 10-liter flask having a thermometer, a stirring blade and a condenser was charged with methylene chloride; 6.2.
1 and TBS-BA; 1938 g (3.0 mol) were charged, and bromine; 1104 g (6.9 mol) was added to 35 to 39.
The mixture was added dropwise at 1.5 ° C. over 1.5 hours, and after the addition, aging was performed at that temperature for 2 hours.

After the reaction, the remaining bromine is reduced with an aqueous sodium hydrogen sulfite solution, and further washed with water to obtain TBS-BP;
7.2 l of a solution containing 65 g, methylene chloride; 6 l were obtained. This solution was analyzed by liquid chromatography. As a result, the yield of TBS-BP was 98.9%,
The conversion of TBS-BA was 100%. Hereinafter, the obtained methylene chloride solution containing TBS-BP is referred to as a treatment liquid. From this treatment solution, 0.5 l containing 199 g of TBS-BP was used for 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 1.33 g of polyoxyethylene sorbitan monopalmitate having an HLB value of 15.6 are dissolved and heated to 90 ° C. did.

To the heated water, while stirring, the above-mentioned treatment solution in which 2.65 g of polyoxyethylene sorbitan monopalmitate was dissolved was dropped at a rate of 0.13 l / hr, and methylene chloride was continuously added. Distilled off. The total amount of polyoxyethylene sorbitan monopalmitate used corresponds to 2.0 parts by weight with respect to 100 parts by weight of TBS-BP. During the distillation, almost no foaming was observed and TBS-B
P immediately precipitated and became a powder, and was uniformly dispersed in water.

After the completion of the treatment solution dropping, the obtained TBS-B
The water slurry of P was filtered, washed with water, and dried to obtain 203.9 g of a white powder. As a result of analyzing the obtained powder by liquid chromatography,
The purity of TBS-BP is 97.5%, and TBS
The recovery of -BP was almost quantitative at 99.9%.

Example 2 Water: 8 in a 1000 ml four-necked flask having a thermometer, a stirring blade and a distillation apparatus.
Dissolve 2.00 g of polyoxyethylene sorbitan trioleate having an HLB value of 11.0 ml and 90 ° C.
Heated. The amount of polyoxyethylene sorbitan trioleate used corresponds to 1.0 part by weight based on 100 parts by weight of TBS-BP.

Next, 0.5 ml of a methylene chloride solution containing 199 g of TBS-BP was prepared from the processing solution prepared in Example 1.
1 into the stirring heated water described above.
While dropping at a dropping rate of 1 / hr, methylene chloride was continuously distilled off. During the distillation, almost no foaming was observed and TBS-
BP immediately precipitated and became a powder, and 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 2
03.5 g were obtained. The obtained powder was analyzed by liquid chromatography. As a result, the purity of TBS-BP was 97.7%, and the recovery rate of TBS-BP from the processing solution was almost quantitative, 99.9%. .

Example 3 Water: 1.5 parts in a 2.0-liter four-necked flask having a thermometer, a stirring blade and a distillation apparatus.
l and a polyoxyethylene sorbitan monolaurate having an HLB value of 16.7; 5.97 g were dissolved and heated to 90 ° C. The amount of the oxyethylene sorbitan trioleate used was 3.0 per 100 parts by weight of TBS-BP.
It corresponds to parts by weight.

Next, 0.5 ml of a methylene chloride solution containing 199 g of TBS-BP was prepared from the treatment solution prepared in Example 1.
1 to the above stirred water.
While dropping at a dropping rate of 1 / hr, methylene chloride was continuously distilled off. During the distillation, almost no foaming was observed and TBS-
BP immediately precipitated and became a powder, and 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 2
04.5 g were obtained. The obtained powder was analyzed by liquid chromatography. As a result, the purity of TBS-BP was 97.4%, and the recovery rate of TBS-BP from the processing solution was almost quantitative, 99.9%. .

Example 4 A 1000 ml four-necked flask equipped with a thermometer, a stirring blade and a distillation apparatus was charged with water;
Dissolve 2.99 g of polyoxyethylene sorbitan monostearate having an HLB value of 14.9 ml and 95 ml
Heated to ° C. The amount of polyoxyethylene sorbitan monostearate used corresponds to 1.5 parts by weight with respect to 100 parts by weight of TBS-BP.

Next, 0.5 ml of a methylene chloride solution containing 199 g of TBS-BP was prepared from the processing solution prepared in Example 1.
1 into the above stirred water.
While dropping at a dropping rate of 1 / hr, methylene chloride was continuously distilled off. During the distillation, almost no foaming was observed and TBS-
BP immediately precipitated and became a powder, and was uniformly dispersed in water.

After completion of the dropping of the treatment liquid, the obtained TBS-B
The P water slurry was treated in the same manner as in Example 1 to obtain a white powder 2
03.7 g were obtained. The obtained powder was analyzed by liquid chromatography. As a result, the purity of TBS-BP was 97.6%, and the recovery rate of TBS-BP from the processing solution was almost quantitative, 99.9%. .

Example 5 A 5000 ml four-necked flask having a thermometer, a stirring blade and a distillation apparatus was charged with water;
Dissolve 1.33 g of polyoxyethylene sorbitan monopalmitate having an HLB value of 15.6 ml and 90 ml.
Heated to ° C.

From the processing solution prepared in Example 1, TBS
-BP; methylene chloride solution containing 199 g; 0.5 l was taken out, subjected to solvent replacement with chloroform, and further polyoxyethylene sorbitan monopalmitate; 2.65 g
Was dissolved to give 0.7 l of a chloroform solution. still,
The total amount of polyoxyethylene sorbitan monopalmitate used is 2. based on 100 parts by weight of TBS-BP.
It corresponds to 0 parts by weight.

Next, chloroform was continuously distilled off while dropping this solution into the above heated stirring water at a dropping rate of 0.10 l / hr. At the time of distillation, almost no foaming was observed, and TBS-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 TBS-B
The P water slurry was treated in the same manner as in Example 1 to obtain a white powder 2
03.7 g were obtained. The obtained powder was analyzed by liquid chromatography. As a result, the purity of TBS-BP was 97.6%, and the recovery rate of TBS-BP from the processing solution was almost quantitative, 99.9%. .

(Comparative Example 1) A methylene chloride solution containing 199 g of TBS-BP from the treatment solution prepared in Example 1;
Withdraw 0.5 l and stir isopropanol;
It was added dropwise at a rate of 0.15 l / hr into 0.9 l.
After completion of the dropping, the precipitated powder was filtered, washed with water, and dried to obtain 186.4 g of a white powder. As a result of analyzing the obtained powder by liquid chromatography,
The purity of TBS-BP is 98.2%, and TBS
-The recovery of BP was 92.0%.

Comparative Example 2 A methylene chloride solution containing 199 g of TBS-BP from the processing solution prepared in Example 1;
Withdraw 0.5 l and stir methanol; 0.9
The solution was dropped at a rate of 0.10 l / hr. After completion of the dropping, the precipitated powder was filtered, washed with water, and dried to obtain 187.3 g of a white powder. The obtained powder was analyzed by liquid chromatography, and as a result, TBS
-BP purity: 98.3%, TBS-BP from processing solution
Was 92.5%.

(Comparative Example 3) A methylene chloride solution containing 199 g of TBS-BP from the treatment solution prepared in Example 1;
0.5 l was withdrawn and the methylene chloride was removed by evaporation under reduced pressure. The recovered TBS-BP was a glassy solid, and could not be obtained as a powder. In addition, the recovered amount was 204.9 g. The obtained solid was analyzed by liquid chromatography.
-BP purity is 97.2%, TBS-BP from processing solution
Was 99.9%.

(Comparative Example 4) In a four-necked flask having a capacity of 1000 ml having a thermometer, a stirring blade and a distillation apparatus, water: 8
0.04 g of polyoxyethylene sorbitan trioleate having an HLB value of 11.0 ml;
Heated. The amount of polyoxyethylene sorbitan trioleate used is equivalent to 0.02 parts by weight based on 100 parts by weight of TBS-BP.

Next, a methylene chloride solution containing 199 g of TBS-BP from the processing solution prepared in Example 1;
Take out 5 liters and add 0.01
Methylene chloride was continuously distilled off while dropping at a dropping rate of 5 l / hr. TBS-BP precipitated during distillation
Was poorly dispersed in water, and most of the resin adhered to the stirring blades and vessel walls in a resin state, and thus could not be obtained as powder.

Comparative Example 5 A 1000 ml four-necked flask having a thermometer, a stirring blade and a distillation apparatus was charged with water: 8
Dissolve 14.9 g of polyoxyethylene sorbitan monopalmitate having an HLB value of 15.6 ml and 90 ml.
Heated to ° C. The amount of polyoxyethylene sorbitan monopalmitate used corresponds to 7.5 parts by weight with respect to 100 parts by weight of TBS-BP.

Next, a methylene chloride solution containing 199 g of TBS-BP from the processing solution prepared in Example 1;
Take 5 liters and add 0.1 liter into the above-mentioned stirring heated water.
Methylene chloride was continuously distilled off while dropping at a dropping rate of 0 l / hr, but the foaming was so severe that the operation could not be performed.

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

(Comparative Example 6) Water: 8 in a four-neck flask having a capacity of 1000 ml having a thermometer, a stirring blade and a distillation apparatus.
3.98 g of 00 ml and polyoxyethylene nonylphenyl ether having an HLB value of 15.1 were dissolved and heated to 90 ° C. The amount of polyoxyethylene nonyl phenyl ether used corresponds to 2.0 parts by weight with respect to 100 parts by weight of TBS-BP.

Next, a methylene chloride solution containing 199 g of TBS-BP from the processing solution prepared in Example 1;
Take 5 liters and add 0.1 liter into the above-mentioned stirring heated water.
While dropping at a dropping rate of 2 l / hr, methylene chloride was continuously distilled off. TBS-BP precipitated during distillation
Was poorly dispersed in water, and most of the resin adhered to the stirring blades and vessel walls in a resin state, and thus could not be obtained as powder.

[0061]

As is apparent from the above description, according to the method of the present invention, it is possible to separate and recover TBS-BP powder from water. Therefore, as compared with the conventional reprecipitation method using an organic solvent and the like, the TBS-BP powder can be easily separated and recovered quantitatively, and the production control of the product is also facilitated.

In addition, the treatment of TBS-BP dissolved in the filtrate and the separation and recovery of the solvent, which are problems in the prior art, are not required, and the process can be greatly simplified.

Further, since the working environment reduces the chance of exposure to organic solvents, it is preferable from the viewpoint of occupational health. In addition, handling operations such as stirring, mixing, and filtration of the flammable organic solvent can be avoided, so that the safety of work can be reduced. And TBS-BP, which is industrially advantageous, can be separated and recovered.

Continuation of front page (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 317/00 C07C 315/00 CA (STN) REGISTRY (STN)

Claims (1)

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