JP2000080055A - Treating bromine compound solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To treat a bromine compound solution in a simple process in a short time by mixing a solution containing a specific bromine compound, etc., with an aqueous solution containing a reducer and reducing the bromine. SOLUTION: A bromine compound solution is treated by introducing a solution containing a bromine compound of the formula Ar1 and Ar2 are each a 5-16C aromatic hydrocarbon or the like; Y is a 1-6C saturated hydrocarbon or the like; R1 and R2 are each a 2-11C hydrocarbon; (p) and (q) are each 0-10) and bromine with an aqueous solution containing a reducer (preferably sodium hydrogensulfite or the like) into a flow mixer, mixing and putting a mixed solution introduced from the flow mixer into a stirring tank. Preferably, 2-100 mol of the reducer is used based on 1 mol of bromine. Preferably, the solvent of solution containing the bromine compound and bromine is a halogenated hydrocarbon compound, etc. Preferably, a flowing rate of the mixed solution in the flow mixer is 5-500 cm/sec and a residence time is 0.001-300 sec.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for treating a bromine compound solution for removing bromine from the bromine compound solution,
More specifically, there are few process operations, short process times,
Further, the present invention relates to a method for treating a bromine compound solution, which facilitates process control.

[0002]

2. Description of the Related Art Generally, in the field of organic chemistry, a bromination reaction to an aliphatic unsaturated group is a reaction frequently employed in synthesizing a bromine compound. In order to improve the bromine addition reaction rate, the reaction is usually performed using an excess of bromine relative to the unsaturated group. Therefore, after the reaction is completed, bromine remains in the solution, and if this residual bromine is not treated as it is, there arises a problem that metal corrosion or a low-purity brown colored bromine compound is obtained. Therefore, usually, a method of treating the residual bromine remaining in the bromine compound solution with a reducing agent and neutralizing the hydrobromic acid by temporarily adding hydrobromic acid and then adding an alkaline neutralizing agent. Has been adopted. This treatment is generally performed in a batch system in a usual stirring tank. However, bromination reactions are often carried out in solvents that are immiscible with water, and contact of oxidative excess bromine with an aqueous solution containing a reducing agent takes considerable time and many times due to its heterogeneity. Washing process is required twice.

For example, Japanese Patent Application Laid-Open No. 55-111429 discloses a method of adding bromine to a diallyl ether derivative of tetrabromobisphenol A. Among these, bromination in an aromatic halogenated hydrocarbon solvent is disclosed. In the examples, in the contact with the reducing agent during the treatment after the reaction, the reaction solution was stirred under the addition of the reducing agent, the reduction treatment was performed, and several further water washes were performed. A neutralization treatment is performed later.

In Japanese Patent Application Laid-Open No. 3-271267, in the bromination of {(3,5-dibromo-4-allyloxy) phenyl} sulfone, the compound is dissolved in methylene chloride and bromine is added by adding bromine. After the treatment, it is brought into contact with an aqueous solution of a reducing agent, but it is considered that this reduction treatment is not carried out by a special method but is carried out by ordinary stirring.

[0005] These methods are low-efficiency methods on a so-called industrial scale, and require long-time stirring and a large stirring tank. In many cases, and often becomes more complicated. Therefore, there is a demand for a method of efficiently treating a bromine-containing bromine compound solution in a short time with a simple apparatus.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the present inventors have conducted intensive studies for the purpose of providing a method capable of removing bromine in a bromine compound solution by a simple operation in a short time. The present inventors have found that the above object can be achieved by mixing the bromine compound solution and a solution containing a reducing agent with a flow mixer, and then pouring the mixed solution into a stirring tank, thereby achieving the present invention.

[0007]

That is, according to the present invention, a bromine compound represented by the following formula (1) and a solution containing bromine are mixed with an aqueous solution containing a reducing agent to reduce and treat bromine. In the method, the bromine compound and the solution containing bromine and the aqueous solution containing the reducing agent are introduced into a flow mixer and mixed, and then the mixed solution derived from the flow mixer is charged into a stirring tank. A method for treating a compound solution is provided.

[0008]

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(In the formula, Ar ¹ and Ar ² may be the same or different and represent an aromatic hydrocarbon group having 5 to 16 carbon atoms or a saturated alicyclic hydrocarbon group having 5 to 12 carbon atoms. The hydrogen group may be substituted by at least one halogen atom, and Y is a saturated hydrocarbon group having 1 to 6 carbon atoms, a sulfone group, a sulfide group, a ketone group, an alkylene oxide group having 2 to 6 carbon atoms or a single atom. Represents a bond, R
¹ and R ² may be the same or different, and have 2 carbon atoms.
Represents 11 to 11 hydrocarbon groups, and p and q are each 0 to
It is an integer of 10, and (p + q) represents an integer of 1 or more. )

The bromine compound used in the method of the present invention is
It is represented by the above equation (1). In the above equation (1),
Ar ¹ and Ar ² may be the same or different and have an aromatic hydrocarbon group having 5 to 16 carbon atoms, preferably 6 to 12 carbon atoms or 5 to 12 carbon atoms, preferably 6 to 1 carbon atoms.
0 is a saturated alicyclic hydrocarbon group. It is industrially advantageous that Ar ¹ and Ar ² are the same and are aromatic hydrocarbon groups. Specific examples of Ar ¹ and Ar ² include 1,4-phenylene group, 1,4-methylphenylene group, 1,4-dimethylphenylene group, 2,6-naphthylene group, and 2,7-
A naphthylene group is mentioned, and a 1,4-phenylene group is preferable.

In these Ar ¹ and Ar ² , the carbon atom forming the hydrocarbon may be substituted with a halogen atom. Particularly, when used as a flame retardant, a halogen atom, especially a bromine atom is used. Is preferably substituted. The number of halogen atoms substituted with each of Ar ¹ and Ar ² is ¹ to 6 with respect to Ar ¹ (or Ar ² ),
Preferably 2 to 4 are advantageous.

In the above formula (1), Y is a group or a bond connecting Ar ¹ and Ar ² and has 1 to 6 carbon atoms;
Preferably a saturated hydrocarbon group having 1 to 3 carbon atoms; sulfone group (-SO ₂ -); sulfide groups (-S-); ketone group (-CO-); 2 to 6 carbon atoms, preferably 2 to carbon atoms 4
Or an alkylene oxide group of the formula: or a single bond.
Desirable Y is a methylene group, an isopropylidene group, a cyclohexylidene group, a sulfone group, a sulfide group, a ketone group or a single bond.

In the above formula (1), R ¹ and R ² may be the same or different and represent a hydrocarbon group having 2 to 11 carbon atoms, preferably 2 to 5 carbon atoms. Specific examples of the hydrocarbon group include an ethyl group, a propyl group, an isopropyl group, a butyl group and an isobutyl group, and preferably an ethyl group and a propyl group.

In the above formula (1), p and q are each an integer of 0 to 10, (p + q) is an integer of 1 or more, preferably p and q are each an integer of 2 to 10.

As the bromine compound represented by the 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, [3,3 ', 5,5'
-Tetrabromo-4,4 '-(2,3-dibromopropyloxy)] biphenyl, [3,3', 5,5'-tetrabromo-4,4 '-(1,2-dibromoethyloxy)] biphenyl, Bis [3,5-dibromo-4-
(2,3-dibromopropyloxy) phenyl] sulfone and bis [3,5-dibromo-4- (2,3-dibromo-2-methylpropyloxy) phenyl] sulfone, among which 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,
[3,3 ', 5,5'-tetrabromo-4,4'-
(2,3-dibromopropyloxy)] biphenyl and [3,3 ', 5,5'-tetrabromo-4,4'-
(1,2-Dibromoethyloxy)] biphenyl is preferred, and 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 and bis [3,5-dibromo-4- (2,3-dibromo-2-methylpropyloxy) phenyl] methane are more preferred, especially 2,2-
Bis [3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl] propane is preferably used.

In the present invention, the bromine compound solution to be treated is a solution containing a bromine compound represented by the above formula (1) and bromine. As this solution, the solution after the reaction when synthesizing the bromine compound represented by the above formula (1) is preferably used.

Such a solution is specifically bromine (Br ₂ )
Is a solution containing a bromine compound produced by the addition reaction of This addition reaction is a reaction for brominating an unsaturated bromine compound represented by the following general formula (3), and the treatment method of the present invention is advantageously applied to a solution obtained by this reaction.

[0018]

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(In the formula, Ar ¹ , Ar ² and Y have the same meanings as defined in the above formula (1). Q ¹ and Q ² are the same or different and each have at least one unsaturated group.
, Preferably one or two carbon atoms having 2 to 11,
It preferably represents a hydrocarbon group having 2 to 5 carbon atoms. )

In the above formula (3), the definitions of Ar ¹ , Ar ² and Y have the same meanings as in the general formula (1), and the preferred definitions also mean the same. Q ¹ and Q ²
Specific examples of the hydrocarbon group include a vinyl group, an allyl group and an isobutenyl group, and an allyl group is preferable.

As the unsaturated bromine compound represented by the formula (3), 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 among others, 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 preferred, and 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 and bis} (3,5
-Dibromo-4-isobutenyloxy) phenyl {methane is more preferred, and 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane is particularly preferred.

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 uniformly conducting the reaction, but also preferably functions as a solvent for effectively removing the heat of reaction out of the reaction system. have. Therefore, the solvent has a normal pressure boiling point of 0 to 100 ° C, preferably 20 to 90 ° C.
In particular, when the heat of reaction is substantially removed by the heat of vaporization of the solvent, those having a normal pressure boiling point of 20 to 80 ° C, particularly 20 to 60 ° C, are desirable.

Examples of the solvent include halogenated hydrocarbon compounds such as methylene chloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethane, bromoethane, butyl chloride, chloropropane, chlorobenzene, dichlorobenzene and acetone chloride, diethyl ether, Examples thereof include ether hydrocarbon compounds such as ethyl isopropyl ether, tetrahydrofuran, and dioxane; aromatic hydrocarbon compounds such as benzene, toluene, and xylene; cyclohexanone; and ethyl acetate. Also, bromine can be used as a solvent.

Among these solvents, halogenated hydrocarbon compounds and aromatic hydrocarbon compounds are preferable, and methylene chloride, chloroform, 1,2-dichloroethane, 1,1-
Dichloroethane, chlorobenzene, dichlorobenzene,
Toluene is more preferred, and methylene chloride and chlorobenzene are particularly preferred. These solvents are used alone or in combination of two or more.

The amount of bromine used in the bromination reaction may be a sufficient molar ratio to the unsaturated bromine compound in order to obtain a desired bromine compound. The bromine is preferably used in an amount corresponding to the number of 1 to 5 bromine molecules, more preferably in an amount corresponding to the number of 1 to 3 bromine molecules.

In the bromination reaction, bromine is used by itself or as a bromine solution. 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 reaction, as specific means,
By mixing a solution of an unsaturated bromine compound in a solvent inert to the reaction with bromine or a bromine solution, the unsaturated bromine compound is reacted with bromine. 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 refers to the theoretical calorific value generated by the desired bromination reaction of 8
0% or more, preferably 85% or more.

In a static mixer having 4 to 20 elements, the flow rate of a solution of a compound having an aliphatic unsaturated bond and bromine or a mixed solution of bromine solution is 15 cm.
/ Second or more, and mixed with the residence time within the static mixer within 180 seconds.
Thereafter, a method of charging the mixture into a stirring tank having a capacity of 30 times or more the capacity of the static mixer can also be used. By using a static mixer as the mixer, mixing is performed efficiently, and a high-purity bromine compound can be obtained in a short time with high yield.

Performing the bromination reaction in a short time by employing the above bromination method is combined with a method in which the removal of residual bromine by the reduction and neutralization reactions described below is performed in a short time by a simple operation. Therefore, the process from the bromination reaction to obtaining the bromine compound powder can be shortened, which is preferable.

As described above, the reaction temperature in the bromination reaction is preferably a temperature at which a 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 from 0 to 60 ° C, preferably in the range from 5 to 55 ° C, particularly preferably 10 to 55 ° C.
A range of ５０50 ° C. is advantageous.

In the treatment method of the present invention, the reaction mixture obtained by the above-mentioned bromination reaction is advantageously applied. Unreacted bromine remains in such a reaction mixture, and the residual bromine adversely affects the purification step and the recovery step. Therefore, it is necessary to perform chemical treatment to convert the compound into another compound. .

In the present invention, a bromine compound represented by the above formula (1) and a solution containing bromine and an aqueous solution containing a reducing agent are introduced into a flow mixer, mixed, and then the mixed solution derived from the flow mixer is mixed. A method for treating a bromine compound solution charged into a stirring tank is used.

The solvent in the bromine compound and the solution containing bromine is a solvent which is substantially immiscible with water, and is preferably a solvent having a solubility of water of 5% by weight or less in the solvent. Chloroform,
1,2-dichloroethane, 1,1-dichloroethane, bromoethane, butyl chloride, chloropropane, chlorobenzene, dichlorobenzene, halogenated hydrocarbon compounds such as acetone chloride, diethyl ether, ether hydrocarbon compounds such as ethyl isopropyl ether, benzene, Toluene, aromatic hydrocarbon compounds such as xylene, carbon disulfide, pentane and the like, among which halogenated hydrocarbon compounds and aromatic hydrocarbon compounds are preferable, and methylene chloride, chloroform, 1,2-dichloroethane, 1-Dichloroethane, chlorobenzene, dichlorobenzene, benzene, toluene and xylene are more preferred, especially methylene chloride and chlorobenzene.

The reducing agent 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, tin, stannous oxide and hydrazine, etc., and sodium hydrogen sulfite, sodium dithionite, sodium sulfite, oxalic acid and sodium nitrite It is preferably used. These reducing agents are used as aqueous solutions. These reducing agents are used alone or in combination of two or more.

The amount of the reducing agent used in the present invention is
The amount is preferably 2 mol or more, more preferably 2 to 100 mol, still more preferably 2 to 50 mol, and particularly preferably 2 to 20 mol, based on 1 mol of bromine in the solution containing a bromine compound and bromine. If the amount is less than 2 mol, the reduction reaction becomes insufficient, and bromine tends to remain.

In the reduction reaction for bromine, it is necessary to efficiently mix a solution containing bromine and an aqueous solution containing a reducing agent. Therefore, when a normal stirring device is used, the stirring efficiency is not sufficient, and it is necessary to repeat the reaction several times in order to complete the reduction reaction. Therefore, by using a flow mixer as a mixer, mixing can be performed efficiently, and bromine can be processed in a short time with a simple device.

The method for introducing the solution containing a bromine compound and bromine or the aqueous solution containing a reducing agent into the flow mixer is not particularly limited, and it may be introduced using a dropping funnel. For ease of use, supplying a constant volume within a fixed time by a pump is also preferably used.

This flow mixer may be any device that can effectively and uniformly mix a liquid mixture flow in a short time, and is a device for dispersing droplets by a method utilizing kinetic energy due to the flow of a liquid. The disperser can be installed in the flow path during liquid transport. Specific examples of the flow mixer include a nozzle, an orifice plate, an injector, and a static mixer, and a static mixer is particularly preferable. As the static mixer, a mixer having 4 to 20 elements, preferably 5 to 18 elements is advantageously used. A static mixer having such a number of elements is preferable because mixing is sufficient.

A static mixer is a chemical engineering device commonly known as a mixer or heat exchanger. The static mixer is a mixer that has been developed and marketed by Kenix Corporation of the United States, and is a tube-type mixer without a drive unit. An object having a twisted structure is built in, and the torsion directions are arranged so that the cross sections of the right and left cross each other at right angles.

As a condition for using a static mixer, the degree of substantial mixing can be determined by the number of elements in the tube. Usually, when the number of elements is divided as a power of two and mixing is performed, It is conceivable that the mixing efficiency may be affected by factors such as the flow rate of the liquid component into the tube, the viscosity, and the Reynolds number. In the treatment method of the present invention, the flow rate of the mixed solution of the solution containing the bromine compound and bromine and the aqueous solution containing the reducing agent at the inlet of the static mixer is preferably 5 to 500.
cm / sec, more preferably 10 to 500 cm / sec. When such a flow rate is satisfied, the mixing efficiency becomes sufficient and the reduction reaction proceeds sufficiently. Here, the flow rate is defined as A (mL / sec), the addition rate of the bromine compound and the solution containing bromine to be introduced into the static mixer, and B (mL / sec), the addition rate of the aqueous solution containing the reducing agent. When the sectional area is C (cm ² ), (A + B) / C (c
m / sec).

The residence time of the mixed solution of the bromine compound and the solution containing bromine introduced into the static mixer and the aqueous solution containing the reducing agent in the static mixer is as follows:
0.001 to 300 seconds are preferable, and 0.005 to 180 seconds
Seconds are more preferred, 0.01 to 120 seconds are still more preferred, 0.05 to 60 seconds are even more preferred, and 0.1 to
10 seconds is particularly preferred. When the residence time is within such a range, the subsequent separation of the organic solvent phase and the aqueous phase is easy and preferable.
Here, the residence time is determined by controlling the addition rate of the bromine compound and the solution containing bromine to be introduced into the static mixer by A.
(ML / sec) and the rate of addition of the aqueous solution containing the reducing agent is B (m
L / sec) and the internal volume of the static mixer is X
(Cm ³ ), it is calculated by the formula of X / (A + B) (seconds).

In the treatment method of the present invention, a mixed solution of a bromine compound and a solution containing bromine and an aqueous solution containing a reducing agent mixed in the flow mixer is derived from the flow mixer, and the mixed solution is stirred. Put into the tank.

In the treatment method of the present invention, a part of the reduction reaction proceeds by mixing the solution containing the bromine compound and bromine and the aqueous solution containing the reducing agent in a flow mixer. In addition, in order to radiate the heat of reaction in the flow mixer, it is necessary to introduce the mixed solution into another stirring tank. Here, the stirring tank is
Any method may be used as long as the solution mixed in the flow mixer is continuously maintained in a mixed solution state, and the stirring method is not limited. For example, a method of stirring by rotating stirring blades (tank) The center axis and the stirring axis are aligned, the stirring axis is inclined, the stirring axis is provided on the side wall of the tank, etc.), the stirring is performed by rocking the tank, and the liquid in the tank is pumped. A circulation system or the like is used.

The capacity of the stirring tank is preferably 20 times or more the capacity of the flow mixer, and more preferably 30 times or more the capacity of the flow mixer. The upper limit of the size of the stirring tank is not particularly limited, but a stirring tank having a flow mixer capacity of 200,000 times or less is sufficient, and the use of a stirring tank exceeding 200,000 times is economically disadvantageous. It is. The stirring tank having such a large capacity has a function of completing the reduction reaction by stirring and mixing, and also has a function of radiating reaction heat generated when the reduction reaction occurs in the flow mixer in the stirring tank. Alternatively, a pipe from the stirring tank to the inlet of the flow mixer may be provided, and the solution in the stirring tank may be introduced again into the flow mixer.

The stirring time of the solution in the stirring tank is preferably 2 minutes or more, more preferably 2 to 90 minutes, further preferably 3 to 60 minutes, particularly preferably 5 to 45 minutes. The reduction reaction is completed by stirring and mixing for such a period of time.

After the completion of the reduction reaction, bromine becomes hydrogen bromide, most of which is dissolved in an aqueous solution containing a reducing agent, and becomes acidic water having a relatively low pH. In such a state, the target bromine compound may be recovered. However, since the reaction apparatus is usually made of metal, it often causes safety problems such as corrosion by acid and perforation. It is preferable to neutralize hydrogen bromide, and an alkaline neutralizing agent is preferably used.

Examples of such alkaline neutralizing agents include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides and alkaline earth metal carbonates. Sodium oxide, potassium hydroxide, sodium carbonate, potassium carbonate, calcium hydroxide, calcium carbonate and the like are preferred, and sodium hydroxide is particularly preferred. 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 this case, 2 mol or more, preferably 2 to 100 mol, more preferably 2 to 50 mol, and still more preferably 2 to 20 mol, per mol of bromine in the solution containing bromine compound and bromine. An alkaline neutralizing agent is mixed with the solution after the completion of the reduction reaction. At this time, the pH of the solution is preferably 7.5 or more.
Is more preferably 8 or more. When the amount of the neutralizing agent is within the above range, hydrogen bromide does not remain in the aqueous solution,
This aqueous solution can be discarded as it is, does not corrode metal, and is preferable in the working environment.

The time required for the neutralization reaction is preferably 2 minutes or more, more preferably 2 to 90 minutes, still more preferably 5 to 60 minutes, and particularly preferably 10 to 45 minutes.

The bromine compound is recovered from the solution treated by the method of the present invention by a method known per se, for example, by precipitation with a poor solvent. Further, the obtained bromine compound is extremely useful as a flame retardant for polyolefin resins such as polyethylene resins and polypropylene resins, ABS resins, polystyrene resins, and rubber-modified polystyrene (HIPS) resins.

[0052]

The present invention will be described below in detail with reference to examples. The bromine concentration in the solution was measured according to the following method.

(1) Measurement of bromine concentration After the KI solution was added to the sample solution and allowed to stand, I ₂
Was measured with a standard solution of Na ₂ S ₂ O ₃ to measure the concentration of bromine in the solution. The detection limit of the concentration of bromine by this measurement method was 0.03 g / L.

Preparation Example 1 2,700 g of 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane was placed in a 10 L glass reaction vessel equipped with a stirrer, condenser, thermometer and dropping funnel. (4.33mo
l) and 4600 g of methylene chloride were added and dissolved. While stirring this solution and refluxing methylene chloride at a temperature of 39 to 41 ° C., 1394 g of bromine (8.72 mol
1) was dropped from the dropping funnel in 80 minutes. After completion of the dropwise addition, the reaction solution was continuously stirred at a temperature of 39 to 41 ° C. for 1 hour while refluxing methylene chloride, thereby completing the bromine addition reaction.
From the reaction solution, 10 mL is collected with a whole pipette,
3.68 g as a result of measuring the residual bromine in the bromine compound solution
/ L.

[Adjustment Example 2] 2,700 g of 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane was placed in a 10 L glass reaction vessel equipped with a stirrer, a condenser, a thermometer and a dropping funnel. (4.33mo
l) and 4600 g of chlorobenzene were added and dissolved.
While stirring the solution, at a temperature of 15 ° C.,
4 g (8.72 mol) was added dropwise from the dropping funnel over 10 hours. After completion of the dropwise addition, the reaction solution was continuously stirred at a temperature of 15 ° C. for 2 hours to complete the bromine addition reaction. From the reaction solution, 10 mL was collected by a whole pipette, and the residual bromine in the bromine compound solution was measured. As a result, it was 3.60 g / L.

[Adjustment Example 3] In Adjustment Example 1, 2,2-
Instead of 2700 g of bis {(3,5-dibromo-4-allyloxy) phenyl} propane, bis {(3,5-
Dibromo-4-allyloxy) phenyl @ methane258
A bromination reaction was carried out in the same manner as in Preparation Example 1 except that 0 g (4.33 mol) was used, and the result of measurement of residual bromine in the bromine compound solution was 3.05 g / L.

Example 1 A static mixer having an internal volume of 20 cm ³ and consisting of 12 elements (cross-sectional area 0.5
cm ² ), the methylene chloride solution prepared in Preparation Example 1 was added at a rate of 10.7 g / sec (7.2 mL / sec), and an aqueous solution of 15.6% by weight of sodium bisulfite was added at a rate of 0.4.
g / sec (0.38 mL / sec), that is, continuously introduced into the static mixer so that the flow rate of the mixed solution becomes 15.3 cm / sec, and after mixing (residence time in the static mixer is 2.6 seconds, 3.7 moles of sodium bisulfite per mole of bromine), and charged into a 30 L stirred tank with a bottomed valve at the bottom. The mixed solution was continuously stirred in this stirring tank, and after being kept in the stirring tank for about 10 minutes, a part was taken out from the bottom. When the bromine concentration in the methylene chloride solution phase was measured, no bromine was detected.

Next, 14 L of the reduced mixed solution taken out from the bottom of the stirring tank was added to 3000 g of a 2.5% by weight aqueous solution of sodium hydroxide with vigorous stirring (5 moles of sodium hydroxide per mole of bromine). .9 mol). This stirring was performed for 20 minutes. After completion of the stirring, the methylene chloride phase and the aqueous phase were separated. The aqueous phase was removed, and 2000 g of pure water was added to the methylene chloride phase, followed by stirring and washing for 20 minutes. The time required to complete the reduction and neutralization reactions was about 1 hour.

Example 2 The internal volume of Example 1 was 20 cm ^3.
Instead of the static mixer (cross-sectional area 0.5 cm ² ) having 12 elements, a static mixer (18 cross-sectional area of 0.3 cm ² ) having 18 elements having an internal volume of 30 cm ³ .
5 cm ² ), the concentration of the aqueous solution of sodium bisulfite was 5.2% by weight, and the addition rate was 0.8 g / sec (0.75 mL / sec). (The flow rate of the mixed solution was 15.9 cm / sec, the residence time in the static mixer was 3.8 seconds, and sodium hydrogen sulfite was added in an amount of 2.0 mol / mol bromine.
5 mol). When the bromine concentration of the methylene chloride solution phase after the reduction reaction was measured in the same manner as in Example 1, no bromine was detected.

Example 3 The internal volume of Example 1 was 20 cm ^3.
Instead of the static mixer (cross-sectional area 0.5 cm ² ) having 12 elements, a static mixer (18 cross-sectional area of 0.3 cm ² ) having 18 elements having an internal volume of 30 cm ³ .
5 cm ² ) and the addition rate of methylene chloride solution is 2
6.9 g / sec (18.2 mL / sec) and the addition rate of the aqueous solution of sodium bisulfite was 1.04 g / sec (0.9
The same operation as in Example 1 was performed except that the flow rate was 5 mL / sec (the flow rate of the mixed solution was 38.3 cm / sec, the residence time in the static mixer was 1.5 seconds,
3.7 moles of sodium bisulfite per mole of bromine). When the bromine concentration of the methylene chloride solution phase after the reduction reaction was measured in the same manner as in Example 1, no bromine was detected.

Example 4 In Example 1, the addition rate of the aqueous solution of sodium bisulfite was changed to 0.8 g / sec (0.
The same operation as in Example 1 was performed, except that the flow rate of the mixed solution was 16.0 cm / sec, the residence time in the static mixer was 2.6 seconds, and the amount of bromine 1 was changed. 7.4 moles of sodium bisulfite per mole
Mole). When the bromine concentration of the methylene chloride solution phase after the reduction reaction was measured in the same manner as in Example 1, no bromine was detected.

[Fifth Embodiment] In the first embodiment, the first adjustment example is used.
Exactly the same operation as in Example 1 was carried out except that the methylene chloride solution prepared in Step 2 was replaced with the chlorobenzene solution prepared in Preparation Example 2, and the addition rate was changed to 10.9 g / sec (9.9 mL / sec) ( The flow rate of the mixed solution was 20.7 cm / sec, the residence time in the static mixer was 1.9 sec, and sodium hydrogen sulfite was 3.0 mol per mol of bromine.
Mole). When the bromine concentration in the chlorobenzene solution phase after the reduction reaction was measured in the same manner as in Example 1, no bromine was detected.

[Sixth Embodiment] In the first embodiment, the first adjustment example will be described.
The same operation as in Example 1 was performed except that the methylene chloride solution prepared in Example 3 was replaced with the methylene chloride solution prepared in Preparation Example 3 (the flow rate of the mixed solution was 15.2 cm / sec,
The residence time in the static mixer is 2.7 seconds, 3.7 moles of sodium bisulfite per mole of bromine). When the bromine concentration of the methylene chloride solution phase after the reduction reaction was measured in the same manner as in Example 1, no bromine was detected.

[Example 7] In Example 1, the addition rate of the methylene chloride solution was 5.4 g / sec (3.6 mL / sec), and the addition rate of the aqueous solution of sodium bisulfite was 0.2.
g / sec (0.19 mL / sec) except for the same operation as in Example 1 (flow rate of the mixed solution was 7.6 cm / sec).
Seconds and the residence time in the static mixer is 5.
3 seconds, 3.7 moles of sodium bisulfite per mole of bromine). When the bromine concentration of the methylene chloride solution phase after the reduction reaction was measured in the same manner as in Example 1, no bromine was detected.

Example 8 In Example 1, a 15.6% by weight aqueous solution of sodium dithionite was used in place of the aqueous solution of sodium bisulfite, and the addition rate was 0.4 g / sec (0. The same operation as in Example 1 was performed except that the flow rate of the mixed solution was 15 mL / sec.
2 cm / sec, the residence time in the static mixer is 2.6 seconds, 2.5 mol of sodium dithionite per mol of bromine). When the bromine concentration of the methylene chloride solution phase after the reduction reaction was measured in the same manner as in Example 1, no bromine was detected.

[Comparative Example 1] 3300 g of the bromine compound solution obtained in Adjustment Example 1 was placed in a 10 L stirring tank, and 1
125 g of a 5.6% by weight aqueous sodium bisulfite solution
(3.7 mol of sodium bisulfite per mol of bromine) was added, and the mixture was stirred at 20 ° C. for 30 minutes at a speed of 50 rpm. After completion of the stirring, the methylene chloride phase and the aqueous phase were separated. As a result of measuring the residual bromine concentration of the methylene chloride solution phase, it was 3.0 g / L.

Further, the solution was again stirred for 30 minutes three times, but the amount of residual bromine was reduced by about 10%, but even after 2 hours, bromine was not completely reduced and remained. Then, 125 g of a 15.6% by weight aqueous sodium bisulfite solution was added to this solution, and the mixture was stirred for 4 hours. Further, 125 g of a 15.6% by weight aqueous solution of sodium bisulfite was added to this solution, and the mixture was stirred overnight. Was performed. As a result, when the bromine concentration of the methylene chloride solution phase was measured, no bromine was detected. After that, alkali treatment and cleaning with pure water were performed in the same manner as in Example 1. However, such a method is a method in which the number of process operations is increased and the process time is increased as compared with the examples.

[0068]

According to the present invention, bromine in a bromine compound solution can be removed by a method with a small number of process operations and a short process time, and the high-purity bromine compound obtained is a flame retardant for resin. And its industrial effect is exceptional.

Claims (11)

[Claims] 1. A solution containing a bromine compound and bromine represented by the following formula (1) and an aqueous solution containing a reducing agent are mixed:
In the method of reducing and treating bromine, a solution containing the bromine compound and bromine and an aqueous solution containing the reducing agent are introduced into a flow mixer and mixed, and then the mixed solution derived from the flow mixer is put into a stirring tank. A method for treating a bromine compound solution, comprising: Embedded image (In the formula, Ar ¹ and Ar ² may be the same or different, and have an aromatic hydrocarbon group having 5 to 16 carbon atoms or 5 carbon atoms.
To 12 saturated alicyclic hydrocarbon groups, which may be substituted with at least one halogen atom, and Y represents a saturated hydrocarbon group having 1 to 6 carbon atoms, a sulfone group, or a sulfide group. , A ketone group, an alkylene oxide group having 2 to 6 carbon atoms or a single bond, R ¹ and R ² may be the same or different, and represent a hydrocarbon group having 2 to 11 carbon atoms; It is an integer of 0 to 10, and (p + q) represents an integer of 1 or more. ) 2. The method for treating a bromine compound solution according to claim 1, wherein the reducing agent is used in an amount of 2 to 100 mol per mol of bromine. 3. The method for treating a bromine compound solution according to claim 1, wherein the solvent of the bromine compound and the solution containing bromine is a halogenated hydrocarbon compound or an aromatic hydrocarbon compound. 4. The group consisting of sodium bisulfite, sodium dithionite, sodium sulfite, oxalic acid, hydrogen sulfide, sodium nitrite, potassium nitrite, hydroxylamine sulfate, tin, stannous oxide and hydrazine. The method for treating a bromine compound solution according to claim 1, which is at least one compound selected from the group consisting of: 5. The method for treating a bromine compound solution according to claim 1, wherein the flow rate of the mixed solution in the flow mixer is 5 to 500 cm / sec. 6. The method for treating a bromine compound solution according to claim 1, wherein the residence time of the mixed solution in the flow mixer is 0.001 to 300 seconds. 7. The method for treating a bromine compound solution according to claim 1, wherein the flow mixer is a static mixer. 8. The flow mixer, wherein the number of elements is 4 to 2
The method for treating a bromine compound solution according to claim 1, wherein the method is a static mixer having 0. 9. The bromine compound represented by the formula (1)
The method for treating a bromine compound solution according to claim 1, which is a compound represented by the following formula (2). Embedded image (Wherein Y, R ¹ and R ² have the same meanings as defined in the above formula (1). Ar ¹ and Ar ² may be the same or different and have an aromatic hydrocarbon group having 5 to 16 carbon atoms. Or represents a saturated alicyclic hydrocarbon group having 5 to 12 carbon atoms,
m and n represent an integer of 2 to 4, and p and q represent 2 to 1
Represents an integer of 0. ) 10. The bromine compound represented by the formula (1) is 2,2-bis [3,5-dibromo-4- (2,3-
Dibromopropyloxy) phenyl] propane, 2,2
-Bis [3,5-dibromo-4- (2,3-dibromo-
2-methylpropyloxy) phenyl] propane, bis [3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl] methane, bis [3,5-dibromo-
4- (2,3-dibromo-2-methylpropyloxy)
Phenyl] methane, [3,3 ', 5,5'-tetrabromo-4,4'-(2,3-dibromopropyloxy)]
Biphenyl, [3,3 ', 5,5'-tetrabromo-
4,4 '-(1,2-dibromoethyloxy)] biphenyl, bis [3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl] sulfone and bis [3,5-dibromo-4- The method for treating a bromine compound solution according to claim 1, which is a compound selected from (2,3-dibromo-2-methylpropyloxy) phenyl] sulfone. 11. A mixed solution charged into a stirring tank and a mixed solution containing a bromine compound and bromine in an amount of 2 moles per mole of bromine.
2. The method for treating a bromine compound solution according to claim 1, wherein the neutralization treatment is carried out by further mixing with an alkali neutralizing agent in an amount of at least mol.