JPH11228549A - Method for producing tris (dibromopropyl) isocyanurate - Google Patents

Abstract

(57) [Problem] To provide an industrial production method of tris (dibromopropyl) isocyanurate. SOLUTION (1) A good solvent, a poor solvent and a raw material triallyl isocyanurate are charged into a reaction vessel, and bromine is dropped therein to synthesize tris (dibromopropyl) isocyanurate. Subsequently, the good solvent was distilled off by distillation,
Tris (dibromopropyl) isocyanurate is produced in good yield. (2) A good solvent, a poor solvent and triallyl isocyanurate as a raw material are charged into a reaction vessel, and bromine is dropped therein to synthesize tris (dibromopropyl) isocyanurate. Subsequently, the poor solvent corresponding to the distillation amount is added, and the good solvent is distilled off by distillation to produce tris (dibromopropyl) isocyanurate in good yield. (3) A good solvent, a poor solvent, and triallyl isocyanurate as a raw material are charged into a reaction vessel, and bromine is dropped therein to synthesize tris (dibromopropyl) isocyanurate. Subsequently, the good solvent was distilled off by distillation while adding the poor solvent for the distillation, and tris (dibromopropyl) was obtained in good yield.
Produce isocyanurate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing tris (dibromopropyl) isocyanurate (hereinafter abbreviated as TAIC-6B) which is a good flame retardant for synthetic resins.

[0002]

2. Description of the Related Art Conventionally, as a method for producing TAIC-6B, a reaction solution obtained by reacting triallyl isocyanurate (hereinafter abbreviated as TAIC) with bromine in a good solvent is added to a poor solvent to form a crystal. Method, TAI
A method is known in which C is reacted with bromine in a mixed solvent of a good solvent and a poor solvent to form crystals. For example, in JP-A-56-53668, TAIC and bromine are reacted in an aliphatic halogenated hydrocarbon, and after completion of the dropping of bromine, a saturated hydrocarbon having 5 or more carbon atoms is added to crystallize the reaction product. After filtration, the product is obtained. Further, the same publication discloses a method of performing a reaction between TAIC and bromine in a mixed solvent of an aliphatic halogenated hydrocarbon and a saturated hydrocarbon having 5 or more carbon atoms, and filtering the obtained reaction solution to obtain crystals. It is shown.

[0003]

However, the method described in JP-A-56-53668 has not been satisfactory as an industrial production method. That is, when crystallization is performed by adding a saturated hydrocarbon having 5 or more carbon atoms to a reaction solution obtained by reacting TAIC and bromine in a good solvent, there is a problem that scaling or the like occurs at the initial stage of crystallization. Was. In a method in which TAIC and bromine are reacted in a mixed solvent of an aliphatic halogenated hydrocarbon and a saturated hydrocarbon having 5 or more carbon atoms, and the resulting reaction solution is filtered to obtain crystals, TAIC-6B is used. However, there was a problem that the yield was low, and it was not sufficient as an industrial production method.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on a process for producing TAIC-6B which can simplify the operability and has a good yield. It was found that TAIC-6B was obtained in a high yield by adding a poor solvent to the reaction solution obtained by bromination of TAIC and heating it, and distilling off the good solvent to crystallize the reaction product. The present invention has been completed.

That is, according to the present invention, (1) a poor solvent is added to a reaction solution obtained by reacting TAIC and bromine in a mixed solvent of a good solvent and a poor solvent, and the reaction solution is heated to distill the good solvent. A method for producing TAIC-6B, characterized in that the reaction product is crystallized at a high recovery rate by removing, and (2) TAIC and bromine can be reacted in a mixed solvent of a good solvent and a poor solvent. TAIC characterized by heating the obtained reaction solution while adding a poor solvent to the reaction solution and distilling off the good solvent to crystallize the reaction product at a high recovery rate.
-6B.

Hereinafter, the present invention will be described in detail.

[0007] The good solvent used in the method of the present invention is not particularly limited as long as it can dissolve TAIC and is inactive or has extremely low reactivity to bromine. Specifically, a halogenated hydrocarbon solvent is used. Specifically, for example, 1,1,1-
Trichloroethane, dichloromethane, chloroform,
1,1,2-trichloroethane, ethylene dichloride,
Examples include methylene bromide and bromoform. The amount of the organic solvent used is not particularly limited, but is preferably 2 to 50 times the weight of TAIC used in the reaction due to the viscosity of the reaction solution, economy, and the like.

In the method of the present invention, the poor solvent may be T
AIC-6B is not particularly limited as long as it does not dissolve and is inert to bromine or has extremely low reactivity, but those having a boiling point equal to or higher than the boiling point of the good solvent used are preferred. preferable. For example, alcohols such as methanol, ethanol, n-propanol and isopropanol; aliphatic hydrocarbons such as pentane, hexane and cyclohexane; water; and the like may be used alone or as a mixture. In the method of the present invention, water is not preferred as a poor solvent used in the reaction between TAIC and bromine.

In the present invention, as a combination of a good solvent and a poor solvent, a poor solvent having a boiling point equal to or higher than the boiling point of the good solvent to be used is preferable. More preferably, it is higher than the boiling point of the solvent by at least 10 ° C. For example, methylene chloride (b.
p. 39.8 ° C.)-Methanol (bp 64.5)
° C), methylene chloride-isopropanol (bp 8).
2.4 ° C.), methylene chloride-diisopropyl ether (bp 68.5 ° C.), methylene chloride-heptane (bp 98.4 ° C.), chloroform (bp 6
1.2 ° C) -heptane, methylene chloride-methanol-
Suitable combinations include water, methylene chloride-isopropanol-water, methylene chloride-diisopropyl ether-water, methylene chloride-heptane-water, chloroform-heptane-water, and the like. Of these, a combination of methylene chloride-heptane-water with a good crystal dispersion state is particularly preferred.

In the bromination reaction step, the amount of the poor solvent used is
It is important that the total amount of the reaction product is not crystallized, and the weight ratio is usually 0.2 to 0.8 with respect to the good solvent.

After the completion of the bromination reaction, the amount of the poor solvent to be added depends on the amount of the good solvent when water is used in combination with one or more selected from the group consisting of alcohols and aliphatic hydrocarbons. 0.2 to 0.8 weight ratio and 0.1
When only water is added, the weight ratio is usually 0.5 to 1.5 with respect to the good solvent.

The amount of the poor solvent is not particularly limited, but is finally 2 to 10 based on TAIC-6B.
A doubled amount is preferred.

The amount of bromine used as a brominating agent in the method of the present invention is usually 3 to 5 times the molar ratio of TAIC used in the reaction, but is preferably 3 to 3 times.
The molar ratio is 5 times.

Although the method of the present invention does not require a catalyst,
A catalyst may be used. The Lewis acid catalyst to be used is not particularly limited, but those which are soluble in an organic solvent are preferred. For example, depending on the purpose, antimony halides such as antimony trichloride, antimony pentachloride and antimony tribromide, titanium halides such as titanium trichloride and titanium tetrachloride, and boron halides such as boron trichloride and boron tribromide. And boron halide complexes such as boron trifluoride diethyl ether complex. These may be used alone or in combination.

The temperature at which bromine is dropped depends on the catalyst and the desired bromination number, but is usually in the range of -30 to 50 ° C, preferably in the range of -5 to 40 ° C. The time of dropping bromine is adjusted depending on the type and amount of the catalyst, the concentration of TAIC, and the reaction temperature at the time of dropping.
It is dropped in about 12 hours. After the dropping, post-treatment may be performed immediately, or aging may be performed at a predetermined temperature for 1 to 12 hours.

After completion of the reaction, the surplus bromine may be transferred to the next step as it is, but if necessary, may be reduced by adding a reducing agent such as hydrazine or sodium hydrogen sulfite.

After completion of the reaction, excess bromine is directly or reduced, and then a poor solvent is dropped and then the good solvent is distilled off by heating, or the good solvent is distilled off while the poor solvent is dropped. The dripping time of the poor solvent is usually 30 minutes or more without any problem, preferably, about 1 to about the crystal dispersion state and the like.
A range of 3 hours is preferred.

The distillation of the good solvent is usually carried out under normal pressure, but can also be carried out under reduced pressure. A poor solvent may be added for the purpose of adjusting the slurry concentration during or after the distillation of the good solvent. After the distillation of the good solvent, to increase the amount of precipitated crystals,
Further, water may be added. The amount of water at this time is not particularly limited, but is preferably 0.2 to 2 weight ratio to the good solvent used for the reaction.

TAIC-6B can be obtained as a product by filtering and drying the obtained slurry solution of TAIC-6B. The method of separation is not particularly limited, but examples include centrifugation, suction filtration, and the like.
Examples of the drying method include normal-pressure drying, reduced-pressure drying, and spray drying.

[0020]

According to the present invention, high purity TAIC-6B can be obtained in high yield.

[0021]

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

Example 1 A 1-liter four-necked round-bottomed round-bottomed flask equipped with a stirrer, a thermometer and a Dimroth condenser was charged with 60 g of TAIC, 394 g of dichloromethane, and 202 g of heptane.
After the temperature was lowered to 119 ° C., 119 g of bromine was added dropwise thereto over 4 hours, and aging was performed at the same temperature for 1 hour.

After completion of the reaction, 60 g of water was added to the reaction solution,
Next, 5 g of a 20% by weight aqueous hydrazine solution was added to reduce excess bromine.

After reducing excess bromine, 202 g of heptane was charged into a dropping funnel and added dropwise at 30 ° C. over 1 hour.

After the dropwise addition, the bath temperature was raised to 55 ° C. under normal pressure stirring, and methylene chloride was distilled off.

The distillation was continued for about 30 minutes while heating the internal temperature to 70 ° C. After distillation, the internal temperature was cooled to 30 ° C. TAIC-6B is converted into white crystals of heptane /
It was uniformly dispersed in water.

Thereafter, the slurry solution of TAIC-6B was subjected to suction filtration, washed with water, and dried to obtain 163 g of the target TAIC-6B white powder.

Example 2 Using the same reactor as in Example 1, except that the poor solvent as the raw material was changed to isopropanol, the same operation as in Example 1 was carried out to obtain 162 g of TAIC-6B white powder.

Example 3 Using the same reactor and raw materials as in Example 1, after distilling off methylene chloride, the internal temperature was cooled to 30 ° C., and 200 g of water was further added.
Was added dropwise over 30 minutes, and 168 g of TAIC-6B white powder was obtained in the same manner as in Example 1.

Example 4 Using the same reactor and raw materials as in Example 1, heptane 20
Methylene chloride was distilled off while 2 g was added dropwise, and after cooling the internal temperature to 30 ° C., the same operation as in Example 1 was carried out, except that 200 g of water was further added dropwise over 30 minutes, 168 g of TAIC-6B white powder. I got

Comparative Example 1 Using the same reactor as in Example 1, a TAIC 60
g, dichloromethane 394 g, and 30 ° C. on a water bath.
After that, 119 g of bromine was added dropwise thereto over 4 hours,
Further, aging was performed at the same temperature for 1 hour.

After completion of the reaction, 5 g of a 20% by weight aqueous hydrazine solution was added to reduce excess bromine, and then 202 g of heptane was added.
Was charged into a dropping funnel and dropped at a temperature of 30 ° C. over 1 hour, scaling occurred, and TAIC-6B became a viscous substance and could not be taken up.

Comparative Example 2 Using the same reactor as in Example 1, a TAIC 60
g, 394 g of dichloromethane and 202 g of heptane, and the mixture was heated to 30 ° C. in a water bath.
The mixture was added dropwise over a period of time, and further aged at the same temperature for 1 hour.

After completion of the reaction, 5 g of a 20% by weight aqueous hydrazine solution was added to reduce excess bromine. Here, filtration was performed to obtain 140 g of TAIC-6B white powder.

Claims (5)

[Claims] 1. A poor solvent is added to a reaction solution obtained by reacting triallylisocyanurate and bromine in a mixed solvent of a good solvent and a poor solvent, and the good solvent is distilled off by heating the reaction solution. A process for producing tris (dibromopropyl) isocyanurate, wherein the reaction product is crystallized at a high recovery rate. 2. A reaction solution obtained by reacting triallyl isocyanurate and bromine in a mixed solvent of a good solvent and a poor solvent is heated while adding a poor solvent to the reaction solution to distill off the good solvent. A process for producing tris (dibromopropyl) isocyanurate, wherein the reaction product is crystallized at a high recovery rate. 3. The method according to claim 1, wherein a halogenated hydrocarbon solvent is used as the good solvent. 4. The method according to claim 1, wherein one or more selected from the group consisting of alcohols, aliphatic hydrocarbons and water are used as the poor solvent. The manufacturing method as described. 5. The method according to claim 3, wherein the boiling point of the poor solvent is higher than the boiling point of the good solvent used.