JP2000053658A - Production of tris(dibromopropyl) isocyanurate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for tris(dibromopropyl) isocyanurate in an industrial scale. SOLUTION: In the production process for tris(dibromopropyl) isocyanurate via bromination reaction and crystallization, a good solvent and triallyl isocyanurate are charged in the reactor, bromine is dripped down to the mixture to form tris(dibromopropyl) isocyanurate. Then, a bad solvent is combined with seed crystals and the reaction mixture containing the isocyanurate product is dripped into the seed crystal dispersion, as the good solvent is distilled off, finally water is added to crystallize the objective tris(dibromopropyl) isocyanurate in high yield.

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, TAIC-6B has been prepared by reacting triallyl isocyanurate (hereinafter abbreviated as TAIC) with bromine in a good solvent, adding a poor solvent to a reaction solution, and crystallizing the reaction solution. There is known a method of reacting bromine with bromine in a mixed solvent of a good solvent and a poor solvent to form crystals. For example, JP-A-56-53668 discloses that
Disclosed is a method of reacting TAIC with bromine in an aliphatic halogenated hydrocarbon, and after dropping bromine, adding a saturated hydrocarbon having 5 or more carbon atoms to crystallize the reaction product, followed by filtration to obtain a product. Have been. The publication also 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 liquid to obtain crystals. ing.

[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 method for producing TAIC-6B which is simple and has a good yield, and as a result, reacted TAIC and bromine in a good solvent,
The good solvent is distilled off while adding the reaction solution to the heated poor solvent containing seed crystals, and it is found that TAIC-6B can be obtained in high yield by crystallizing the reaction product, thereby completing the present invention. Reached.

That is, according to the present invention, (1) a reaction solution obtained by reacting triallyl isocyanurate and bromine in a good solvent is added to a heated poor solvent containing seed crystals, and the good solvent is distilled off. A method for producing tris (dibromopropyl) isocyanurate, which comprises precipitating (dibromopropyl) isocyanurate, and (2) a reaction solution obtained by reacting triallyl isocyanurate with bromine in a good solvent, Tris (dibromopropyl) isocyanurate characterized in that tris (dibromopropyl) isocyanurate is precipitated by adding a good solvent while adding to a heated poor solvent containing crystals, and then adding water. It is a manufacturing method of.

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-
Examples include trichloroethane, dichloromethane, chloroform, carbon tetrachloride, 1,1,2-trichloroethane, ethylene dichloride, methylene bromide, bromoform and the like. The amount of the organic solvent to be used is not particularly limited.
It is desirable to use 1 to 50 times by weight of IC.

[0008] The amount of bromine used as a brominating agent in the method of the present invention is 3 to 5 with respect to TAIC used in the reaction.
A double molar ratio is used, and preferably a molar ratio of 3 to 3.5.

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.

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 in combination.

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 10 ° C. or more. 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.

The amount of the poor solvent used is not particularly limited, but is ultimately 1 to 1 with respect to TAIC-6B.
An amount that is 10 times the amount is preferable.

After the completion of the reaction, the excess solvent is removed as it is or after reduction, and the good solvent is distilled off by heating while dropping the reaction solution into a poor solvent containing seed crystals. The drop time of the good solvent is
If the time is usually 30 minutes or more, there is no problem, preferably,
Considering the dispersion state of the crystals, the range is preferably about 1 to 3 hours.

The amount of the seed crystal used in the present invention is not less than 5% by weight based on TAIC-6B, but adding too much is not economical, and preferably 5 to 20%. % By weight.

The distillation of the good solvent is usually carried out under normal pressure, but can also be carried out under reduced pressure. After the distillation of the good solvent, water may be further added to increase the amount of precipitated crystals. 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.

[0019]

According to the present invention, high purity TAIC-6B can be obtained in a high yield without any scale problem during crystallization.

[0020]

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 1 L of 4 L equipped with a stirrer, thermometer and Dimroth condenser
TAIC 60g, dichloromethane 1 in one-necked round bottom flask
After 75 g was charged and the temperature was adjusted to 30 ° C. on a water bath, 119 g of bromine was added dropwise over 3 hours, followed by aging at the same temperature for 1 hour.

After the reaction is completed, 60 g of water is 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 and washing with water, TAIC-6B
Was obtained.

Seed TAI in a 1 L 4-neck round bottom flask
17.5 g of C-6B and 340 g of methanol were charged and heated under normal pressure stirring, and when the internal temperature exceeded 55 ° C., TAI was added.
An organic phase containing C-6B was dropped with a dropping funnel, and methylene chloride was distilled off.

After completion of the dropwise addition, distillation was continued for about 30 minutes while heating the internal temperature to 60 ° C. After distilling off, the internal temperature should be 3
Cooled to 0 ° C. TAIC-6B was white crystals and was uniformly dispersed in methanol.

Thereafter, the TAIC-6B slurry solution was filtered by suction, washed with water, and dried to obtain 180 g of the desired TAIC-6B white powder.

Example 2 Using the same reaction apparatus 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 185 g of TAIC-6B white powder was obtained by performing the same operation as in Example 1.

Example 3 Using the same reactor as in Example 1, 178 g of TAIC-6B white powder was obtained in the same manner as in Example 1, except that the good solvent as the raw material was changed to chloroform and the poor solvent was changed to isopropanol. Obtained.

Example 4 The same operation as in Example 1 was carried out, except that the poor solvent was changed to heptane, and the same operation as in Example 1 was carried out to obtain TAIC-6B.
178 g of a white powder was obtained.

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 solution of hydrazine was added to reduce excess bromine.
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 The same reactor as in Example 1 was used, and TAIC60 was used in the reactor.
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 hydrazine aqueous solution was added to reduce excess bromine. Here, filtration was performed to obtain 140 g of TAIC-6B white powder.

Claims (5)

[Claims] A reaction solution obtained by reacting triallyl isocyanurate and bromine in a good solvent is added to a heated poor solvent containing seed crystals, and the good solvent is distilled off to obtain tris (dibromopropyl) isocyanurate. A process for producing tris (dibromopropyl) isocyanurate. 2. A reaction solution obtained by reacting triallyl isocyanurate and bromine in a good solvent is added to a heated poor solvent containing seed crystals, and the good solvent is distilled off. A method for producing tris (dibromopropyl) isocyanurate, characterized by depositing (dibromopropyl) isocyanurate. 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 solvents selected from the group consisting of alcohols, aliphatic hydrocarbons and water are used as the poor solvent. The production method described in Crab. 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.