JPH10237080A - Production of tribromoneopentyl chloroalkyl phosphate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and economically produce the subject compound capable of inhibiting hydrolysis of a specific phosphite, promoting an oxidation reaction by an aqueous hydrogen peroxide solution and useful as a flame retardant, etc., by oxidizing the specific phosphite with the aqueous hydrogen peroxide solution. SOLUTION: (A) A tribromoneopentyl chloroalkyl phosphite is oxidized by (C) an aqueous hydrogen peroxide solution in the presence of (B) an inorganic or organic base at 0-100 deg.C to provide the objective compound. The component B is preferably one kind selected from sodium hydroxide, potassium hydroxide, etc., and triethylamine, pyridine, etc., and the component A is preferably the reaction product obtained by reacting the reaction product represented by the formula [R is H or a lower (chloro)alkyl; (n) is 0.9-1.1] and obtained by reacting phosphorus trichloride with tribromoneopentyl alcohol in the molar ratio of (1.0-6.0):1.0, with an alkylene oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing chloroalkyl tribromoneopentyl phosphate. More specifically, the present invention relates to a method for obtaining a chloroalkyl tribromoneopentyl phosphate by oxidizing the chloroalkyl tribromoneopentyl phosphite with an aqueous hydrogen peroxide solution without hydrolysis.

[0002]

2. Description of the Related Art Chloroalkyl tribromoneopentyl phosphate has been attracting attention as a flame retardant for thermosetting resins or thermoplastic resins, and research and development have been progressing. The method for producing the chloroalkyl tribromoneopentyl phosphate is disclosed, for example, in U.S. Pat. No. 4,046,719 and JP-B-61-3797. In the methods described in these publications, for example, phosphorus oxychloride is reacted with tribromoneopentyl alcohol, and further, an alkylene oxide is reacted to obtain a desired ester. In these reactions, a reaction catalyst such as aluminum chloride, magnesium chloride, or titanium tetrachloride is used. However, metals such as aluminum, magnesium, and titanium in these reaction catalysts remain in the produced ester, and cause contamination and corrosion of a mold during molding of a resin to which the ester is added. Furthermore, the metal causes deterioration, discoloration, and deterioration of physical properties of the molded resin.

[0003]

The chloroalkyl tribromoneopentyl phosphate is obtained, for example, by reacting phosphorus trichloride with tribromoneopentyl alcohol,
Further, it can be produced by oxidizing chloroalkyl tribromoneopentyl phosphite obtained by reacting an alkylene oxide. In the method,
Since no metal chloride is used as a reaction catalyst, the problem of remaining metal is eliminated. The oxidation of this chloroalkyl tribromoneopentyl phosphite includes ozone, oxygen or air, chlorine, peroxide, aqueous hydrogen peroxide,
An oxidizing agent such as sulfur is used (for example, Quat. Rev., 1
6,208-238,1662). Among the oxidizing agents, an aqueous solution of hydrogen peroxide is industrially inexpensive and easy to handle, but chloroalkyl tribromoneopentyl phosphite can be obtained by simply using an aqueous solution of hydrogen peroxide. There was a problem of being decomposed.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention.

Thus, according to the present invention, chloroalkyl tribromoneopentyl phosphite is oxidized with an aqueous hydrogen peroxide solution at a temperature of 0 to 100 ° C. in the presence of an inorganic or organic base to give the corresponding trichloroneopentyl phosphite. Tribromoneopentyl phosphoric acid chloroalkyl ester (hereinafter, referred to as bromoneopentyl phosphoric acid chloroalkyl ester)
Abbreviated as phosphate ester).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Chloroalkyl tribromoneopentyl phosphite (hereinafter abbreviated as alkyl phosphite) used in the present invention can be obtained by a known method. For example, as the alkyl phosphite, a reaction product obtained by further reacting an alkylene oxide with a reaction product of phosphorus trichloride and tribromoneopentyl alcohol is preferable. Hereinafter, the above reaction will be described as an example. This reaction consists of the following two-stage reaction.

[0007]

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Wherein R is a hydrogen atom or a lower alkyl group or a lower chloroalkyl group, and n is 0.9 to 1.1.

First, in the first step reaction between phosphorus trichloride and tribromoneopentyl alcohol, phosphorus trichloride and tribromoneopentyl alcohol are used in an amount of 1.0-6.
The reaction is carried out at a molar ratio of 0: 1.0, preferably 1.5 to 3.0: 1.0. Tribromoneopentyl alcohol 1
When the amount of phosphorus trichloride is 1.0 mol or less with respect to the mol, the phosphoric acid ester of the final target substance contains crystalline tris (tribromoneopentyl) phosphate or bis (tribromoneopentyl) chloroalkyl. A large amount of by-products is contained. These by-products are undesirable because they cause a rise in viscosity and lower the fluidity of the phosphate ester. In addition, a crystalline floating substance is formed in the phosphate ester, which deteriorates workability during molding of a thermoplastic resin or foaming of urethane foam, which is not preferable. On the other hand, when the amount of phosphorus trichloride is 6.0 mol or more, the production efficiency of the phosphoric acid ester is remarkably reduced, which is not economical.

[0010] The reaction temperature is 0 to 70 ° C, preferably 40 to 70 ° C.
60 ° C. A temperature of 0 ° C or lower is not preferable because the reaction between phosphorus trichloride and tribromoneopentyl alcohol is insufficient, and a temperature of 70 ° C or higher is not preferable because decomposition of the intermediate 1 occurs. The reaction time varies depending on the reaction temperature, the reaction scale and the like, but is usually 4 to 6 hours.
After completion of the reaction, the produced hydrochloric acid and unreacted phosphorus trichloride are distilled off under reduced pressure at a temperature of 80 ° C. or lower to obtain Intermediate 1. In addition,
In the first-stage reaction, a reaction catalyst may be used within a range that does not affect the subsequent reaction. Examples of the reaction catalyst include triethylamine.

Next, the intermediate 1 produced in the first-stage reaction is reacted with an alkylene oxide to produce an alkyl phosphite (intermediate 2). Examples of the alkylene oxide used in the reaction include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin and the like, and among them, ethylene oxide and propylene oxide are preferable.

The amount of the alkylene oxide to be used is preferably 5 to 10% by weight in excess of the theoretical amount. The theoretical amount of the alkylene oxide is calculated by the following equation.

[0013]

(Equation 1)

Wherein A is the weight (g) of Intermediate 1, B is the chlorine content (%) of Intermediate 1, C is the molecular weight of alkylene oxide, and 35.5 is the atomic weight of chlorine.

[0015] The reaction temperature is 40-80 ° C, preferably 50-80 ° C.
７０70 ° C. At a temperature of 40 ° C. or less, the progress of the reaction becomes extremely slow and impractical. At a temperature of 80 ° C. or more, the intermediate 1 is decomposed, which is not preferable. The reaction time varies depending on the reaction temperature, the reaction scale, and the like.
~ 4 hours. After completion of the reaction, excess alkylene oxide is distilled off under reduced pressure at a temperature of 80 ° C. or lower to obtain Intermediate 2. The reaction between the intermediate 1 and the alkylene oxide may be a known continuous reaction.

In the production method of the present invention, an alkyl phosphite represented by the following formula is preferably used.

[0017]

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Wherein R is a hydrogen atom or a lower alkyl group or a lower chloroalkyl group, and n is 0.9 to 1.1. The first and second reactions and the substituent R in the above formula
As the “lower alkyl group”, an alkyl group having 1 to 4 carbon atoms is preferable. Specifically, a linear alkyl group such as methyl, ethyl, n-propyl and n-butyl, and a branched alkyl group such as iso-propyl, iso-butyl, sec-butyl and tert-butyl are No. The “lower chloroalkyl group” for the substituent R includes the above “lower alkyl group”
And a hydrogen atom in which a chlorine atom is substituted.
Among them, a hydrogen atom and a methyl group are preferred.

According to the present invention, the alkyl phosphite (intermediate 2) obtained as described above is oxidized with an aqueous hydrogen peroxide solution at a temperature of 0 to 100 ° C. in the presence of an inorganic or organic base. To give the corresponding chloroalkyl tribromoneopentyl phosphate. This reaction is represented by the following formula.

[0020]

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Wherein R is a hydrogen atom, a lower alkyl group or a lower chloroalkyl group, and n is 0.9 to 1.1.

Examples of the inorganic base that can be used in the present invention include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide; carbonates of alkali metals represented by sodium carbonate; An alkali metal bicarbonate represented by sodium; ammonia; and the like, which can be used in the form of an aqueous solution. Among them, an aqueous sodium hydroxide solution is preferable, and the concentration is not particularly limited, but is 10 to 40% (preferably 20 to 3%).
0%).

Examples of the organic base that can be used in the present invention include aliphatic amines such as dimethylamine, diethylamine, trimethylamine, triethylamine and tributylamine; aromatic amines represented by dimethylaniline; and pyridine and picoline. An aromatic heterocyclic ring is mentioned, and among them, triethylamine and pyridine are preferable. The inorganic and organic bases may be used as a mixture.

The amount of the inorganic and organic base that can be used in the present invention is preferably an amount that can make the reaction mixture alkaline during the oxidation reaction with the aqueous hydrogen peroxide solution. Specifically, the amount of the reaction mixture is preferably adjusted to pH 8 to 12. Surprisingly, under such conditions, hydrolysis of the alkyl phosphite is suppressed, decomposition of hydrogen peroxide is promoted, and the oxidation reaction can be completed. The base may be added before the start of the oxidation reaction, or may be added simultaneously with the aqueous hydrogen peroxide solution.

As the aqueous hydrogen peroxide solution used in the oxidation reaction of the present invention, commercially available ones can be used. The concentration is not particularly limited, but 3-50% (preferably 20%
~ 35%). When the concentration is lower than 3%, the volumetric efficiency of the reaction is poor, which is not preferable. When the concentration is higher than 50%,
It is not preferable because it is difficult to obtain industrially.

The oxidation reaction of the present invention can be carried out without a solvent or in the presence of a solvent. Examples of the solvent include water or an organic solvent inert to the reaction. Specifically, ethane dichloride, benzene, toluene, chlorobenzene and the like can be mentioned, and among them, toluene and chlorobenzene are preferable.

The reaction temperature is 0-100 ° C, preferably 30-60 ° C, more preferably 50-60 ° C.
A temperature of 0 ° C. or lower is not preferred because the progress of the reaction becomes very slow and is not practical. On the other hand, at a temperature of 100 ° C. or higher, the alkyl phosphite is hydrolyzed, which is not preferable. The reaction time varies depending on the concentration of the aqueous hydrogen peroxide solution, but is usually 3 to 5 hours. After the completion of the oxidation reaction, the reaction mixture can be commercialized through purification steps such as washing with water, neutralization, and dehydration. This step may be a batch method or a continuous method.

According to the present invention, a phosphoric acid ester can be obtained by oxidizing an alkyl phosphite with an aqueous hydrogen peroxide solution without hydrolysis. Further, by using an alkyl phosphite obtained by further reacting an alkylene oxide with a reaction product of phosphorus trichloride and tribromoneopentyl alcohol, metals derived from a reaction catalyst such as aluminum chloride and titanium chloride remain. Phosphoric acid ester can be obtained. In addition, the organic polymer using the phosphoric ester obtained by the production method of the present invention as a flame retardant does not show a decrease in physical properties inherent in the polymer.

The phosphoric ester obtained by the production method of the present invention can be applied to various organic polymers as a flame retardant, and among them, vinyl chloride resin, polystyrene resin, ABS
It can be preferably used for organic polymers such as resins and polyurethane foams.

[0030]

EXAMPLES Examples of the present invention will be described below, but these examples do not limit the scope of the present invention.

Example 1 (First-stage reaction) In a 1-liter four-necked flask equipped with a stirrer, a thermometer, and a water scrubber for recovering hydrochloric acid, 275 g (2 mol) of phosphorus trichloride, triethylamine 0.6
g (5.9 mmol) and 50-60 ° C under stirring.
324.7 g of tribromoneopentyl alcohol (1
Mol) was added over about 3 hours. 55-65 ° C
After 2 hours, the generated hydrochloric acid and unreacted phosphorus trichloride were removed over 2 hours at a vacuum of 20 Torr. Then
Nitrogen was blown at a flow rate of 5 m ³ / hour at a degree of vacuum of 20 Torr for 2 hours to obtain 425 g of an intermediate 1a. This intermediate 1
The chlorine content of a was 16.7%.

(Second Stage Reaction) Following the first stage reaction,
The obtained intermediate 1a was cooled to 50 ° C., and 92.4 g (2.1 mol) of ethylene oxide was maintained while maintaining the temperature.
For about 1 hour. Thereafter, the temperature was raised to 60 ° C. and maintained for 1 hour to obtain intermediates 2a and 514 g.

(Third Stage Reaction) Following the second stage reaction,
The obtained intermediate 2a was cooled to 50 ° C., and 15 g of triethylamine was added thereto. This is 50-55 ° C, p
35% hydrogen peroxide solution while adjusting to H9-12.
6 g (1.2 mol) are added over a period of 40 minutes and an additional 55
Hold at で 60 ° C. for 1 hour. The reaction mixture is washed with water,
The oil layer was separated from the aqueous layer. Next, the degree of vacuum is 10
The low-boiling components were removed by Torr to obtain 503 g of the target phosphate ester A.

From the area ratio of GPC (gel permeation chromatography) analysis, it was found that the obtained phosphate ester A was composed of the following components. Tribromoneopentyl bis (chloroethyl) phosphate 95% Bis (tribromoneopentyl) chloroethylphosphate 4% Tris (chloroethyl) phosphate 1% The viscosity at 25 ° C. was 1,500 cps.

Example 2 (First-stage reaction) The starting materials and reaction conditions were the same as in Example 1, to obtain 425 g of an intermediate 1b. The chlorine content of this intermediate 1b was 16.7%. (Second-stage reaction) Following the first-stage reaction, the obtained intermediate 1b was cooled to 50 to 55 ° C, and while maintaining this temperature, 121.8 g (2.1 mol) of propylene oxide was added over 1 hour. Added. Thereafter, the temperature was raised to 60 ° C. and maintained for 1 hour to obtain 540 g of an intermediate 2b.

(Third Stage Reaction) Following the second stage reaction,
50 g of toluene was added to the obtained intermediate 2b,
In the same manner as in Example 1 except that 15 g of a 25% aqueous NaOH solution was added, 116.6 g (1.2 mol) of a 35% aqueous hydrogen peroxide solution was added at pH 9 to 12 to carry out an oxidation reaction. The same post-treatment as in Example 1 was performed to obtain 530 g of the target phosphoric ester B.

From the area ratio of GPC analysis, it was found that the obtained phosphate ester B was composed of the following components. Tribromoneopentyl bis (chloropropyl) phosphate 93% Bis (tribromoneopentyl) chloropropylphosphate 4% Tris (chloropropyl) phosphate 2% The viscosity at 25 ° C. was 2,500 cps.

COMPARATIVE EXAMPLE 515 g of an intermediate was obtained in the same manner as in Example 1 except that the starting materials and reaction conditions for the first and second stage reactions were the same. Next, in the third step reaction, the obtained intermediate 2a was cooled to 50 ° C.
An oxidation reaction was performed by adding 116.6 g (1.2 mol) of a 5% aqueous hydrogen peroxide solution. The pH during the reaction was 2-3. The obtained reaction mixture was not sufficiently hydrolyzed, and did not reach commercialization due to difficult post-treatment.

[0039]

The process for producing a chloroalkyl tribromoneopentyl phosphite according to the present invention comprises reacting a chloroalkyl tribromoneopentyl phosphite at a temperature of 0 to 100 ° C. in the presence of an inorganic or organic base. Oxidizes with aqueous hydrogen oxide. The base suppresses hydrolysis of chloroalkyl tribromoneopentyl phosphite and promotes an oxidation reaction with an aqueous hydrogen peroxide solution. Therefore, chloroalkyl tribromoneopentyl phosphite can be efficiently and economically oxidized to obtain chloroalkyl tribromoneopentyl phosphate.

Claims (6)

[Claims] 1. A method for preparing a chloroalkyl tribromoneopentyl phosphite from 0 to 100 in the presence of an inorganic or organic base.
A process for producing chloroalkyl tribromoneopentyl phosphate, which comprises oxidizing with an aqueous solution of hydrogen peroxide at a temperature of ° C. to obtain the corresponding chloroalkyl tribromoneopentyl phosphate. 2. The method according to claim 1, wherein the base is a compound selected from the group consisting of inorganic bases of sodium hydroxide, potassium hydroxide, sodium carbonate and ammonia and organic bases of triethylamine and pyridine. 3. The process according to claim 1, wherein the chloroalkyl tribromoneopentyl phosphite is a reaction product obtained by further reacting an alkylene oxide with a reaction product of phosphorus trichloride and tribromoneopentyl alcohol. Production method. 4. The method according to claim 3, wherein phosphorus trichloride and tribromoneopentyl alcohol are reacted in a molar ratio of 1.0 to 6.0: 1.0. 5. A chloroalkyl tribromoneopentyl phosphite having the formula (I): 3. The method according to claim 1, wherein R is a hydrogen atom or a lower alkyl group or a lower chloroalkyl group, and n is 0.9 to 1.1. 4. 6. The temperature for oxidizing with an aqueous hydrogen peroxide solution is 50.
The production method according to any one of claims 1 to 5, wherein the temperature is in a range of from 60C to 60C.