JPH0768258B2 - Method for producing tris (trihaloneopentyl) phosphate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing tris (trihaloneopentyl) phosphate used for imparting flame retardancy to a combustible material. In particular, it relates to a method capable of safely and efficiently producing tris (trihaloneopentyl) phosphate, which is highly pure and hardly colored when melted.

(Prior Art) Resin materials used for electric products, automobile interior parts, textile products, etc. are flammable. As a method for making them flame-retardant, halogen compounds are used as flame retardants, and resin compositions are used. The method of adding to a thing is known. However, halogen compounds are generally unstable to ultraviolet light and visible light, which causes discoloration of the final product.

Of the halogen-containing compounds, the use of tris (trihaloneopentyl) phosphate is known to be relatively advantageous. This tris (trihaloneopentyl) phosphate is stable to ultraviolet rays and visible rays and has little discoloration of the product. Furthermore, since this compound increases the plasticity of the resin material, it also has the effect of improving processability and impact strength.

Thus, tris (trihaloneopentyl) phosphate useful as a flame retardant is generally obtained by reacting trihaloneopentyl alcohol with phosphorus oxyhalide such as phosphorus oxychloride or phosphorus oxybromide.

For example, Japanese Examined Patent Publication (Kokoku) No. 45-36894 discloses a method in which the above reaction is carried out using tetrachloroethylene as a solvent, and the hydrogen halide produced by this reaction is removed using pyridine as a scavenger. In this reaction,
The reaction mixture was poured into cooling water to precipitate and collect tris (trihaloneopentyl) phosphate crystals. In this method, pyridine used as a hydrogen halide scavenger is expensive, and further, it is necessary to wash with a large amount of water in order to remove the formed pyridine salt, and the production efficiency is low.

In JP-B-46-6865, aluminum chloride is used as a catalyst and chlorobenzene is used as a solvent. JPA
JP-A-62-187478 discloses a method in which a solvent substantially inactive to hydrogen halide, such as tetrachloroethylene, is used as a solvent, and a slurry-like reaction liquid generated as needed is washed with hydrochloric acid water. ing. However, when the reaction solution is cooled to precipitate crystals, a solvent of 3 to 5 times the volume of the product is required to maintain the fluidity of the reaction solution.
Therefore, since the volume of the reaction liquid becomes large, a large reaction container is required, and the productivity is significantly reduced. Furthermore, due to the low purity of the product, the resin product is colored when used as a flame retardant. In the method of JP-A-62-187478,
In order to remove impurities such as a catalyst and improve the purity of the product, the reaction solution in a slurry state is mixed with a large amount of hydrochloric acid water for 2 to 3 times.
Although it is washed twice, in such a method, the volume at the time of purification becomes large, and the productivity decreases for the same reason as above.

As described above, the conventional method for producing tris (trihaloneopentyl) phosphate has problems in safety, purity of the product, and productivity, and is not sufficient as an industrial method.

(Problems to be Solved by the Invention) The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide tris (trihaloneopentyl) phosphate of high purity safely and with high productivity. It is to provide a manufacturing method.

(Means and Actions for Solving the Problems) The method for producing tris (trihaloneopentyl) phosphate according to the present invention comprises a water-insoluble trihaloneopentyl alcohol represented by the following general formula (I) and phosphorus oxyhalide. Dissolved in a high boiling point solvent, and reacting in the presence of a catalyst, and water, or a neutral, alkaline or acidic aqueous solution in the reaction mixture after the reaction is 0.001 to 100% by weight with respect to the mixture. Of tris (trihaloneopentyl) phosphate represented by the following general formula (II), thereby achieving the above object: In the above formulas (I) and (II), X is independently bromine or chlorine.

As the trihaloneopentyl alcohol used in the method of the present invention, tribromoneopentyl alcohol, trichloroneopentyl alcohol, dibromo-chloroneopentyl alcohol, or bromo-dichloroneopentyl alcohol is used.

As the phosphorus oxyhalide used in the method of the present invention, phosphorus oxychloride or phosphorus oxybromide is used.
These phosphorus oxyhalides are used in a ratio of 1 mol with respect to 3 mol of the above-mentioned trihaloneopentyl alcohol. When the phosphorus oxyhalide is excessive, the production rate of intermediate products such as trihaloneopentyl phosphorodichloridate and bis (trihaloneopentyl) phosphorochloridate increases during the reaction. If the phosphorus oxyhalide is too small, unreacted trihaloneopentyl alcohol remains, and the purity of the product is low in any case.

In the method of the present invention, chlorobenzene as a high-boiling solvent,
Dichlorobenzene, tetrachloroethylene, toluene,
Xylene, isopropylbenzene, dimethyl sulfoxide, diphenyl ether, etc. are used. Preferably dichlorobenzene is used, particularly preferably o-dichlorobenzene. The amount of the solvent used may be 1/10 or more of the volume of tris (trihaloneopentyl) phosphate that can be produced by the reaction, and is preferably based on the volume of tris (trihaloneopentyl) phosphate.
It is 1.0 to 2.0 times.

The catalyst used in the method of the present invention includes aluminum chloride, magnesium chloride, titanium tetrachloride, zinc chloride, tin chloride, magnesium sulfate, magnesium, aluminum and the like. You may use these compounds in mixture of 2 or more types. Aluminum chloride is particularly preferable. The amount used is 0.1% by weight or more, preferably 0.5 to 2.0% by weight, based on phosphorus oxyhalide.

In the method of the present invention, the reaction solution after the reaction is preferably brought into contact with water or a neutral, alkaline or acidic aqueous solution. As the neutral aqueous solution, an aqueous solution of a neutral salt such as sodium chloride, sodium sulfate, potassium chloride, potassium sulfate, ammonium chloride or ammonium sulfate is used. As the alkaline aqueous solution, an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia or the like is used. As the acidic aqueous solution, an aqueous solution of hydrochloric acid, sulfuric acid, acetic acid, oxalic acid or the like is used. In particular, sodium chloride, sodium carbonate,
An aqueous solution of hydrochloric acid is preferred. And these aqueous solutions are
The concentration is preferably 10% by weight or less. The amount of water or the above aqueous solution used is 0 with respect to the reaction mixture after completion of the reaction.
The amount is 001 to 100% by weight, preferably 1 to 20% by weight, and more preferably 5 to 15% by weight.

In the method of the present invention, tris (trihaloneopentyl) phosphate is produced as follows. First, the above-mentioned trihaloneopentyl alcohol, phosphorus oxyhalide and catalyst are dissolved in a high boiling point solvent. Alternatively,
It is also possible to dissolve trihaloneopentyl alcohol in a high boiling point solvent, and add to the mixture thereof a catalyst in which phosphorus oxyhalide is dissolved. The reaction is carried out by refluxing the obtained mixture at room temperature to a temperature not higher than the boiling point of the solvent. If the reaction temperature is low, the formed tris (trihaloneopentyl) phosphate will precipitate as crystals, so it is preferable to carry out the reaction at a temperature as high as possible. For example, when o-dichlorobenzene is used as the solvent, the boiling point of o-dichlorobenzene is 180 ° C, and therefore it is preferable to carry out the reaction at a temperature of 100 to 180 ° C. After completion of the reaction, the pressure inside the reaction system may be reduced in order to complete the reaction by removing the hydrogen halide dissolved in the reaction system.

The reaction mixture thus obtained is contacted with water or the above neutral, alkaline or acidic aqueous solution.
As the temperature at the time of contact, a temperature from room temperature to the boiling point of dichlorobenzene or less, at which crystals of the product do not precipitate, can be used. However, if the contact temperature is much higher than 100 ° C, an accident due to water vapor may occur.
Contact at 120 ° C. The contact time is not particularly limited, but 5
~ 30 minutes is preferred. The contacted mixed solution is cooled as it is to precipitate crystals and the solid components are separated by a method such as filtration, or after contacting, once placed, the aqueous layer is removed and then the crystals are precipitated to precipitate solid components. You may separate. The obtained crystals are used as they are after drying, or,
It is used after being washed with a solvent that does not dissolve tris (trihaloneopentyl) phosphate such as water, methanol and ethanol, and then dried.

According to the method of the present invention, since a high-boiling solvent is used as the solvent, the reaction temperature can be increased, and even if the amount of the solvent is small, the product does not precipitate and a safe reaction is performed. Is possible. Further, in the method of the present invention, the fluidity of the reaction liquid is remarkably improved by bringing the reaction liquid after the reaction into contact with water or a neutral, alkaline or acidic aqueous solution. Therefore, when the crystals are precipitated by cooling after contact, the crystals do not take in impurities such as a catalyst, and high-purity crystals can be obtained. For example, the resulting tris (trihaloneopentyl) phosphate is 95%
With the above yield, the purity is 99.5% or higher. Further, the amount of solvent used can be reduced to 1/2 to 1/5 as compared with the conventional method. And in the method of the present invention, as described above,
Since the amount of solvent used is greatly reduced, productivity is improved. For example, the volumetric efficiency represented by the following formula is 2-3 times that of the conventional method.

Here, the volume of the reaction vessel was calculated assuming that 1 was 1000 g.

In the method of the present invention, the volumetric efficiency is 70% or more,
29.4% when using the method disclosed in JP-A-62-187478
Met.

Thus, according to the method of the present invention, highly pure tris (trihaloneopentyl) phosphate can be safely produced with high productivity. And such high-purity tris (trihaloneopentyl) phosphate,
Addition to a resin material can impart excellent heat resistance to a flammable material such as a resin material. Further, since tris (trihaloneopentyl) phosphate has a high purity, it is preferably used as a flame retardant without causing coloring during melting and not impairing the color of the resin material.

(Examples) Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1 A four-necked flask having a stirrer, a thermometer, a dropping funnel,
A condenser connected with a water scrubber was attached, and 762 g of tribromoneopentyl alcohol, 1075 g of o-dichlorobenzene and 1.2 g of aluminum chloride were added to the flask, and the mixture was heated and mixed. When the temperature of the reaction solution reached 100 ° C, 120 g of phosphorus oxychloride was added to about 30
Added over minutes. The hydrochloric acid gas generated at this time was led to a water scrubber. After the addition of phosphorus oxychloride was completed, the temperature of the reaction solution was gradually raised to 160 ° C. to complete the reaction. Then, the reaction solution was cooled to 85 ° C., 50 g of water was added, and the mixture was stirred and contacted at 85 ° C. for about 15 minutes, and then cooled to room temperature to precipitate crystals. The precipitated crystals are separated by filtration and washed with 300 g of methanol and then 100
It was dried under reduced pressure at ℃. The obtained crystals were white needle-like crystals, the yield was 773 g, and the yield was 97%. When analyzed by liquid chromatography, the crystals obtained had a purity of 9
It was 9.8% tris (tribromoneopentyl) phosphate. The melting point was 181-182 ° C. The yield, yield, purity, melting point, color upon melting, and volume efficiency of the obtained crystals are shown in the table below. The results of the products obtained in Examples 2 to 5 and Comparative Examples 1 to 2 described later are also shown in the table below.

Example 2 Tris (tribromoneo) was used in the same manner as in Example 1 except that tetrachloroethylene was used instead of o-dichlorobenzene, and 1% sodium chloride aqueous solution was added to the reaction solution after the reaction instead of water. White crystals of pentyl) phosphate were obtained.

Example 3 After the completion of the reaction, white crystals of tris (tribromoneopentyl) phosphate were obtained in the same manner as in Example 1 except that 1% aqueous sodium carbonate solution was added instead of water to the reaction solution.

Example 4 Substituting chlorobenzene for o-dichlorobenzene,
After completion of the reaction, white crystals of tris (tribromoneopentyl) phosphate were obtained in the same manner as in Example 1 except that 1% hydrochloric acid was added to the reaction solution instead of water.

Example 5 743 g of trichloroneopentyl alcohol was replaced with 762 g of tribromoneopentyl alcohol, and 12 g of phosphorus oxychloride was added.
White crystals of tris (trichloroneopentyl) phosphate were obtained in the same manner as in Example 1 except that 371 g of phosphorus oxybromide was used instead of 0 g, and 2 g of magnesium chloride was used instead of 1.2 g of aluminum chloride as a catalyst. It was The melting point of the obtained crystal was 157 to 158 ° C.

Comparative Example 1 A four-necked flask having a stirrer, a thermometer, a dropping funnel,
A condenser connected with a water scrubber was attached, and 762 g of tribromoneopentyl alcohol, 1075 g of chlorobenzene and 1.2 g of aluminum chloride were added to this flask, and the mixture was heated and mixed. Reaction temperature is 10
Upon reaching 0 ° C., 120 g of phosphorus oxychloride was added over about 30 minutes. At this time, the generated hydrochloric acid gas was led to a water scrubber. After the addition of phosphorus oxychloride is complete,
The temperature of the reaction solution was gradually raised to 130 ° C. to complete the reaction. Then, the reaction solution was cooled to 85 ° C., 2500 g of chlorobenzene was added as an additional solvent, and then cooled to room temperature to precipitate crystals. The precipitated crystals were separated by filtration, washed with 300 g of methanol, and then dried under reduced pressure at 100 ° C. The obtained crystals were white needle-like crystals, and the yield of tris (tribroneopentyl) phosphate was 92%,
The crystal purity was 96%. And the melting point was 179 to 180 ° C.

Comparative Example Trichloroneopentyl alcohol 762g in place of trichloroneopentyl alcohol 743g, magnesium chloride in place of aluminum chloride 2g as a catalyst, the reaction temperature was 125 ℃, as a reaction solvent and additional solvent o
Crystals of tris (trichloroneopentyl) phosphate were obtained in the same manner as in Comparative Example 1 except that dichlorobenzene was used.

(Effect of the invention) As described above, according to the present invention, the degree of completion of the reaction between trihaloneopentyl alcohol and phosphorus oxyhalide is good, and tris (trihaloneopentyl) phosphate can be obtained in high yield. Is. In addition, since it is not necessary to add an excess solvent to the reaction solution after the reaction is completed, the volume efficiency is high and the productivity can be remarkably improved. Since the method of the present invention uses a high boiling point solvent as a solvent,
It is possible to set the reaction temperature high, and it is possible to perform the work safely without causing the product crystals to precipitate during the reaction to cause the bumping phenomenon. Furthermore, the tris (trihaloneopentyl) phosphate obtained by the method of the present invention has a high purity and shows little coloring during melting, and is suitably used as a flame retardant for resin materials.

Claims (4)

[Claims] 1. A step of dissolving a trihaloneopentyl alcohol represented by the following general formula (I) and phosphorus oxyhalide in a water-insoluble high boiling point solvent and reacting them in the presence of a catalyst, and the end of the reaction. Water or a neutral, alkaline or acidic aqueous solution is added to the subsequent reaction mixture in an amount of 0.001 to 100% by weight relative to the mixture, and the following general formula (I
A method for producing tris (trihaloneopentyl) phosphate, which comprises the step of obtaining tris (trihaloneopentyl) phosphate represented by I): In the above formulas (I) and (II), X is independently bromine or chlorine. 2. The trihalone pentyl alcohol is
Tris (trihaloneopentyl) according to claim 1, which is at least one selected from the group consisting of tribromoneopentyl alcohol, trichloroneopentyl alcohol, dibromo-chloroneopentyl alcohol, and bromo-dichloroneopentyl alcohol. ) Method for producing phosphate. 3. The tris (trihaloneopentyl) phosphate is tris (tribromoneopentyl) phosphate, tris (trichloroneopentyl) phosphate, tris (dibromochloroneopentyl) phosphate, and tris (bromodichloroneopentyl) phosphate. The tris (trihaloneopentyl) according to claim 1, which is at least one selected from the group consisting of:
Method for producing phosphate. 4. The tris (trihaloneopentyl) according to claim 1, wherein the water-insoluble high boiling point solvent is selected from the group consisting of chlorobenzene, dichlorobenzene, tetrachloroethylene, toluene, xylene, isopropylbenzene, and diphenyl ether. ) Method for producing phosphate.