JP2001354642A - Method for producing bis(3,5-dibromo-4- dibromopropoxyphenyl) sulfone granule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for industrially advantageously producing a granule of bis(3,5-dibromo-4-dibromopropoxyphenyl)sulfone excellent in handleability. SOLUTION: In this method for producing bis(3,5-dibromo-4- dibromopropoxyphenyl)sulfone as a granule produced by a bromination reaction of a bis(4-allyloxy-3,5-dibromophenyl)sulfone, the method is characterized in that a solution of bis(3,5-dibromo-4-dibromopropoxyphenyl)sulfone obtained by the production process is dripped into a heated poor solvent and simultaneously cold water is added to bis(3,5-dibromo-4-dibromopropoxyphenyl)sulfone dispersed into the poor solvent while distilling away the solvent to give the granule of bis(3,5-dibromo-4-dibromopropoxyphenyl)sulfone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone (hereinafter abbreviated as TBS-BP) using a solution obtained from the production process as a raw material, The present invention relates to a method for producing granules. TBS-BP is extremely useful as a flame retardant for polyolefin resins and the like, particularly polypropylene and the like (Japanese Patent Publication No. 50-23693, Japanese Patent Publication No. Sho 5).
No. 0-35103).

[0002]

2. Description of the Related Art Generally, as a method for producing TBS-BP, bis (4-allyloxy-
3,5-dibromophenyl) sulfone (hereinafter referred to as TBS-
BA) and a solution of TBS-BP obtained by reacting bromine with a specific solvent are added to a poor solvent, and T
A method of precipitating BS-BP is generally performed.
However, the TBS-BP powder thus obtained has fine particles and is inferior in handleability, and tends to agglomerate under high-temperature and weighted conditions, and tends to cause phenomena such as blocking during long-term storage.

On the other hand, as a method for obtaining granules of TBS-BP, it is known that TBS-BP powder is mixed with a poor solvent at 50 ° C. or higher and granulated (JP-A-11-158).
No. 104). However, in this method, once the powder is taken out and granulated, the operation is complicated,
It was not yet satisfactory as an industrial method.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for obtaining granules of TBS-BP which is complicated in production and industrially problematic in such a manner to obtain granules of TBS-BP having excellent handleability. It is therefore an object of the present invention to provide an industrial method that is economical and simplifies conventional processes.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors dropped a solution of TBS-BP in a poor solvent and dispersed TBS-BP in the poor solvent while simultaneously removing the solvent. After careful study on how to make it work,
Until now, granules could not be produced without the presence of a large amount of seed crystals. However, since TBS-BP is extremely hydrophobic, TBS-B can be produced without the presence of seed crystals.
After dispersing P in a poor solvent, by adding cold water and rapidly cooling, TBS-BP can be obtained as granules,
Moreover, they found that the operability was extremely good, and completed the present invention. That is, according to the present invention, the screw (4-
In a method of obtaining bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone produced by the bromination reaction of allyloxy-3,5-dibromophenyl) sulfone as granules, the bis (3,5-dibromopropoxyphenyl) sulfone obtained in the production step is obtained. A solution of 5-dibromo-4-dibromopropoxyphenyl) sulfone was dropped into a heated poor solvent, and the bis (3,5-dibromo-4-dibromo) dispersed in the poor solvent was simultaneously distilled off. The above method is provided, wherein granules of bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone are obtained by adding cold water to (propoxyphenyl) sulfone.

[0006]

DETAILED DESCRIPTION OF THE INVENTION Granular TBS-B according to the invention
The production of P is achieved by dropping a good solvent solution of TBS-BP obtained in the production process into a heated poor solvent, distilling off the good solvent at the same time, adding cold water and quenching. The good solvent for TBS-BP as used herein means a solvent that dissolves TBS-BP and is inactive in the bromination reaction of TBS-BA. Examples of such a solvent include halogenated hydrocarbons such as carbon tetrachloride, chloroform, methylene chloride, dichloroethane, trichloroethane, and tetrachloroethane. The boiling point of this good solvent is usually 30 to 150 ° C, preferably 30 to 90 ° C.
The amount of the solvent for obtaining the solution of TBS-BP is not particularly limited, but usually 1 to 5 parts by weight, per 1 part by weight of TBS-BP,
Preferably it is 2.5 to 3.5 parts by weight. TBS-BP
Is a solvent having a solubility at 20 ° C. of less than 2%. Specifically, water, methanol, ethanol, n-
Propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, ter
t-butanol and the like, and a mixture of these solvents may be used. The boiling point of this poor solvent is usually 50 to 170
° C, preferably 50 to 100 ° C. The poor solvent must have a boiling point higher than that of the good solvent, and usually need to be higher by about 0 to 100 ° C, preferably by about 20 to 60 ° C. The amount of the solvent to be added to the TBS-BP solution is usually 1 to 1 part by weight of the TBS-BP.
To 5 parts by weight, preferably 2.0 to 3.5 parts by weight.

In order to carry out the present invention preferably, bis (4-allyloxy-3,5-dibromophenyl) sulfone (TBS-BA) is first brominated in the above-mentioned good solvent.
This bromination step can be performed according to a conventionally known method. In this case, the use ratio of the good solvent is not particularly limited, but is 1 to 5 parts by weight, preferably 2.5 to 3.5 parts by weight, per 1 part by weight of TBS-BP produced by this reaction. It is. The reaction temperature is 10 to 50 ° C,
Preferably it is 20-30 degreeC.

Next, in the present invention, the good solvent solution of TBS-BP obtained as described above is dropped into a heated poor solvent, and the good solvent is distilled off. In this case, the temperature of the poor solvent is a temperature higher than the boiling point of the good solvent, and preferably about 20 to 60 ° C. higher than the boiling point of the good solvent.
It is preferable that the poor solvent to which the TBS-BP good solvent solution is dropped is stirred by a stirrer. TBS-B in poor solvent
The rate of dropping of the P good solvent solution is equal to or less than the rate of distilling the good solvent, usually 0.2 to 1.0 times the rate of distilling the good solvent, preferably 0.1 to avoid solidification of TBS-BP. It is better to keep it at 5 to 0.8 times.

After the dropping of the TBS-BP good solvent solution to the poor solvent is completed, stirring is continued for a certain time in order to further remove the good solvent. In this case, the amount of the good solvent distilled off is at least 60%, preferably about 70 to 95% of the total good solvent amount. When the good solvent is distilled off as described above, a suspension in which TBS-BP is dispersed in the form of fine particles in the poor solvent is obtained. In the present invention, cold water is added to this suspension. The amount of cold water is not particularly limited, but is usually 0.1 to 5 parts by weight, preferably 0.5 to 1 part by weight of TBS-BP.
~ 2 parts by weight. The temperature of the cold water is 20 ° C. or lower, preferably 10 ° C. or lower, more preferably 5 ° C. or lower. In the present invention, use of ice water is particularly preferable. TBS-BP is granulated simultaneously with the addition of cold water, and the granules are separated from the slurry liquid by a conventional solid-liquid separation method such as centrifugation and suction filtration.

As described above, TBS-BP granules can be quantitatively obtained from the reaction solution obtained in the TBS-BP manufacturing process. The average particle size of the granules is 300 to
It is 500 μm, especially 400-500 μm. The particle size of the granules can be adjusted by the temperature of cold water, the amount of cold water added, and the like.

[0011]

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
After charging 182 g of TBS-BA (purity 98.4%) and 544 g of methylene chloride, and confirming dissolution, 91 g of bromine was added to 20 to 90 g of bromine.
The solution was added dropwise at 30 ° C. over 2 hours, and ripened at that temperature for 30 minutes after completion of the addition. After the reaction, the residual bromine is reduced with an aqueous solution of sodium hydrogen sulfite, and further washed with an aqueous solution of sodium hydroxide, and a methylene chloride solution 790 containing TBS-BP is added.
g was obtained. In a flask equipped with a thermometer, a stirrer, and a distillation apparatus, 440 g of methanol was charged and heated to 55 ° C. While adjusting the methanol liquid to 50 to 55 ° C,
The above methylene chloride solution was added dropwise over about 2 hours, and simultaneously, methylene chloride was continuously distilled off. About 55 methylene chloride
After distilling out 0 g, while cooling, 160 g of 5 ° C. cold water was added at once, and the mixture was cooled to 25 ° C. or less. After cooling, the obtained TBS-BP slurry was filtered and dried to obtain 260 g of white granules. The obtained granules were analyzed by liquid chromatography, and as a result, TBS-BP
Was 97.5% and the average particle size of the granules was 401 μm.

Example 2 Bis (4-hydroxyphenyl) sulfone is brominated,
Thereafter, crude TBS-BA obtained by allyl etherification was used as a reaction raw material. The purity of this crude TBS-BA by liquid chromatography was 87%. Into a flask equipped with a thermometer, stirrer, and reflux condenser, 182 g of the crude TBS-BA and 544 g of methylene chloride were charged, and after confirming dissolution, 91 g of bromine was added dropwise at 20 to 30 ° C. over 2 hours. Aged at that temperature for minutes. After the reaction, the remaining bromine is reduced with an aqueous sodium hydrogen sulfite solution, and further washed with an aqueous sodium hydroxide solution.
770 g of a methylene chloride solution containing BS-BP was obtained. In a flask equipped with a thermometer, a stirrer, and a distillation apparatus, 440 g of methanol was charged and heated to 55 ° C. While adjusting the methanol solution to 50 to 55 ° C., the above methylene chloride solution was dropped in about 2 hours, and simultaneously, methylene chloride was continuously distilled off. After distilling off about 550 g of methylene chloride, 160 g of cold water at 5 ° C. was added all at once while cooling, and
Cooled to below 5 ° C. After cooling, the obtained TBS-BP
Is filtered and dried to obtain 250 g of white granules.
I got The obtained granules were analyzed by liquid chromatography, and as a result, the purity of TBS-BP was 8
5.1%, the average particle size of the granules was 473 μm. According to the results of the above examples, TBS was used without using a seed crystal.
It was confirmed that -BP could be granulated efficiently.

Comparative Example 1 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
Crude TBS-BA182 obtained in the same manner as in Example 2.
g (purity 87%) and 544 g of methylene chloride.
After confirming the dissolution, 91 g of bromine was added dropwise at 20 to 30 ° C over 2 hours, and the mixture was aged at that temperature for 30 minutes after completion of the addition. After the reaction, the remaining bromine is reduced with an aqueous sodium hydrogen sulfite solution,
After washing with sodium hydroxide aqueous solution, TBS-B
790 g of a methylene chloride solution containing P was obtained. In a flask equipped with a thermometer, stirrer, and distillation device, add methanol 4
40 g and 7 g of seed crystals were charged and heated to 55 ° C. While adjusting the methanol solution to 50 to 55 ° C., the above methylene chloride solution was dropped in about 2 hours, and methylene chloride was continuously distilled off. After distilling off about 550 g of methylene chloride, the mixture was cooled to 25 ° C. or lower. After cooling, the obtained TBS
The BP slurry is filtered and dried to give white granules 2
40 g were obtained. The obtained granules were analyzed by liquid chromatography. As a result, the purity of TBS-BP was 85.5%, and the average particle size of the granules was 295 μm.

Comparative Example 2 In a flask equipped with a thermometer, a stirrer, and a reflux condenser,
Crude TBS-BA182 obtained in the same manner as in Example 2.
g (purity 87%) and 544 g of methylene chloride.
After confirming the dissolution, 91 g of bromine was added dropwise at 20 to 30 ° C over 2 hours, and the mixture was aged at that temperature for 30 minutes after completion of the addition. After the reaction, the remaining bromine is reduced with an aqueous sodium hydrogen sulfite solution,
After washing with sodium hydroxide aqueous solution, TBS-B
790 g of a methylene chloride solution containing P was obtained. In a flask equipped with a thermometer, stirrer, and distillation device, add methanol 4
40 g was charged and heated to 55 ° C. While adjusting the methanol solution to 50 to 55 ° C., the above methylene chloride solution was dropped in about 2 hours, and methylene chloride was continuously distilled off. After distilling off about 550 g of methylene chloride, the mixture was cooled to 25 ° C. or lower. After cooling, the obtained TBS-BP slurry was filtered and dried to obtain 235 g of a white powder.
The obtained powder was analyzed by liquid chromatography. As a result, the purity of TBS-BP was 85.3%,
The average particle size of the powder was 80 μm, and no granules were obtained.

[0016]

According to the method of the present invention, TBS-BP produced by the bromination reaction of TBS-BA can be granulated after once forming a powder without requiring a large amount of seed crystals. No, it can be granulated. Furthermore, the reaction product can be easily taken out regardless of the purity of TBS-BP obtained in the production process, and is suitable as an economical industrial production method.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuaki Noike 7-10-1 Ichinomiya, Samukawa-cho, Koza-gun, Kanagawa F term (reference) in Sanko Chemical Industry Co., Ltd. 4H006 AA02 AD11 AD15 AD17 BB12 BB14 BB31 BC51 TA02 TB13

Claims (1)

[Claims] 1. A method for obtaining bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone produced by a bromination reaction of bis (4-allyloxy-3,5-dibromophenyl) sulfone as a granule. A solution of bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone obtained in the production process is dropped into a heated poor solvent, and the bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone is dispersed in the poor solvent while simultaneously distilling off the solvent. The above method, wherein bis (3,5-dibromo-4-dibromopropoxyphenyl) sulfone granules are obtained by adding cold water to (3,5-dibromo-4-dibromopropoxyphenyl) sulfone.