JPH06157737A - Production of carbonate-type flame retardant - Google Patents

Abstract

PURPOSE:To economically obtain a halocarbonate-type flame retardant in high yield by the use of phosgene saved to a minimum. CONSTITUTION:This flame retardant is produced by reaction between an aqueous alkaline solution of a halogen-substituted dihydric phenol and phosgene in the presence of an organic solvent and a catalyst. In this case, the amounts of the substances to be used are, respectively, as follows (based on the dihydric phenol): (1) the alkaline compound: 1.3-2.4 molar times; (2) the phosgene: 1.1-1.8 molar times; and (3) the amine catalyst: 0.01-0.1 molar times. The reaction is conducted as follows: phosgenation is made at pH9-12 at 10-30 deg.C followed by completing the reaction at pH>=12 at 30-38 deg.C in the presence of a monohydric phenol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a carbonate type flame retardant, and more particularly to a carbonate type flame retardant from a halogen-substituted dihydric phenol and phosgene in a high yield with a minimized use amount of phosgene. Manufacturing method.

[0002]

2. Description of the Related Art Conventionally, carbonate type flame retardants, particularly halogenated polycarbonate oligomers, have been known as flame retardants for thermoplastic resins. The halogenated polycarbonate oligomer is usually a halogen-substituted dihydric phenol such as 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane (hereinafter referred to as tetrabromobisphenol A) and phosgene in the presence of an aqueous alkaline solution and an organic solvent. It is manufactured by reacting below. However, the reaction between a halogen-substituted dihydric phenol such as tetrabromobisphenol A and phosgene is a reaction between phosgene and 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), which is a raw material for general polycarbonate resins. Compared with the above, the reactivity is low due to the steric hindrance of the hydroxyl group due to the ortho-position substitution of two bromines, and in order to obtain an oligomer with a low average degree of polymerization, it is necessary to use an excess of phosgene and an alkali compound rather than obtaining a polymer Therefore, there is a drawback that the decomposition reaction by the alkali compound occurs at a high rate.

JP-A-3-2216 discloses that dihydric phenol, phosgene, an alkali compound, water, an organic solvent and a trialkylamine are mixed in a volume ratio of an organic solvent phase relative to water of 0.
5 to 1.0: 1, alkali compound to dihydric phenol molar ratio of 2.0 to 2.4: 1, phosgene to dihydric phenol molar ratio of 1.08 to 1.50: 1 and trialkylamine. A method of producing a bischloroformate of a carbonate oligomer by using a low proportion of phosgene by interfacial reaction at 0.01 to 0.35 mol% with respect to a dihydric phenol at 15 to 50 ° C. has been proposed. There is. However, when this method is applied to tetrabromobisphenol A, the reaction is difficult to proceed sufficiently, the rate of decomposition reaction of phosgene is large, and it is not possible to produce a halogenated polycarbonate oligomer in good yield.

Further, in Japanese Patent Publication No. 55-14093, when a phosgene is reacted with a halogen-substituted dihydric phenol dissolved in an alkaline aqueous solution in the presence of an organic solvent and an amine catalyst, phosgene is added to the halogen-substituted dihydric phenol. There has been proposed a method for producing a halogenated polycarbonate oligomer in which the molar ratio is 0.5 to 1.1 and the pH of the alkaline aqueous solution is 10 to 11. However, the halogenated polycarbonate oligomer obtained by this method has a mixture of hydroxyl groups and chloroformate groups, which are reactive molecular chain ends, and when used as a flame retardant for thermoplastic resins, it has poor heat resistance, poor physical properties, and surface defects. However, problems such as mold corrosion occur.

Further, JP-B-52-36799 discloses that when the halogen-substituted dihydric phenol and phosgene are subjected to an interfacial reaction, the pH is set to 7 to 9 and the catalyst is 2 to 20 mol% based on the halogen-substituted dihydric phenol. A method for producing a polycarbonate has been proposed, in which a polycondensation reaction is carried out by increasing the pH to above 13 after the phosgenation reaction in the presence of. However, in this method, the catalyst effect is not exerted probably because the pH during the phosgenation reaction is too low, the formation reaction of the chloroformate is difficult to proceed sufficiently, and the halogenated polycarbonate oligomer cannot be produced in a high yield. .

[0006]

DISCLOSURE OF THE INVENTION The present inventor aims to improve the drawbacks of the prior art and provide a method for economically producing a halogenated polycarbonate oligomer in a high yield with a minimum amount of phosgene used. As a result of intensive studies, not only halogenated polycarbonate oligomers but also monomeric halogenated carbonates to halogenated polycarbonates can be used in a high yield by minimizing the amount of phosgene used as long as the conditions specified below are satisfied. They have found that they can be manufactured economically and have reached the present invention.

[0007]

Means for Solving the Problems In the present invention, an alkaline aqueous solution of a halogen-substituted dihydric phenol is reacted with phosgene in the presence of an organic solvent and a catalyst to produce a carbonate type flame retardant. The amount of phosgene used is 1.3 to 2.4 times the molar amount of the dihydric phenol, the amount of phosgene used is 1.1 to 1.8 times the molar amount of the dihydric phenol, and 0 as a catalyst is used. .01-
PH 9 of the reaction system in the presence of 0.1 times mol of amine catalyst
-12, phosgenation reaction at a temperature of 10 to 30 ° C., then pH 12 or more in the presence of monohydric phenol, temperature of 30 to 38
A method for producing a carbonate type flame retardant characterized by completing the reaction at a temperature of ° C.

The halogen-substituted dihydric phenol used in the present invention is mainly tetrabromobisphenol A, but part or all of it may be replaced with another halogen-substituted dihydric phenol. Other halogen-substituted dihydric phenols include, for example, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 1,1-bis (3,5-dibromo-4-hydroxyphenyl) ethane, 1, 1-bis (3,5-dichloro-4-hydroxyphenyl) ethane, 1,1-bis (3,5-dibromo-)
4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dichloro-4-hydroxyphenyl) cyclohexane, bis (3,5-dibromo-4-hydroxyphenyl) sulfide, bis (3,5-dichloro-4) −
Hydroxyphenyl) sulfide, bis (3,5-dibromo-4-hydroxyphenyl) oxide, bis (3,3
5-dichloro-4-hydroxyphenyl) oxide, bis (3,5-dibromo-4-hydroxyphenyl) sulfoxide, bis (3,5-dichloro-4-hydroxyphenyl) sulfoxide, bis (3,5-dibromo-4) −
Hydroxyphenyl) sulfone, bis (3,5-dichloro-4-hydroxyphenyl) sulfone, bis (3,5
-Dibromo-4-hydroxyphenyl) ketone, bis (3,5-dichloro-4-hydroxyphenyl) ketone and the like.

The alkali compound is a compound of an alkali metal or an alkaline earth metal, preferably a hydroxide of an alkali metal or an alkaline earth metal such as sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide,
Of these, sodium hydroxide and potassium hydroxide are particularly preferable.

Examples of amine catalysts include trimethylamine, triethylamine, tripropylamine, tributylamine, trihexylamine, trioctylamine, tridecylamine, dimethyl-n-propylamine, diethyl-n-propylamine, N-dimethylcyclohexyl. Amine, pyridine, quinoline, N-dimethylaniline, N-dimethyl-4-aminopyridine, N-diethyl-
Tertiary amines such as 4-aminopyridine, trimethyldodecyl ammonium chloride, triethyl dodecyl ammonium chloride, dimethylbenzylphenylammonium chloride, diethylbenzylphenylammonium chloride, trimethyldodecylbenzylammonium hydroxide, triethyldodecylbenzylammonium hydroxide, trimethylbenzylammonium chloride ,
Examples thereof include quaternary ammonium compounds such as triethylbenzylammonium chloride, tetramethylammonium chloride and tetraethylammonium chloride. Further, a quaternary phosphonium salt such as triphenyl-n-butylphosphonium bromide or triphenylmethylphosphonium bromide may be used. These catalysts are most effectively added during the phosgenation reaction, but may be added during the subsequent polymerization reaction.

The organic solvent used in the present invention is an organic solvent which is substantially insoluble in water, inactive to the reaction and capable of dissolving the halogenated polycarbonate oligomer produced by the reaction. Examples of such organic solvents include chlorinated aliphatic hydrocarbons such as methylene chloride, 1,2-dichloroethane, tetrachloroethane and chloroform, chlorinated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and chlorotoluene, acetophenone, cyclohexanone and anisole. These may be used alone or in admixture of two or more. Of these, methylene chloride is preferred. The amount used is usually about 15 to 45 times the molar amount of the halogen-substituted dihydric phenol.

In the present invention, in the phosgenation reaction,
The amount of the alkali compound used is 1.3 to 2.4 times, and preferably 1.5 to 2.4 times the mol of the halogen-substituted dihydric phenol.
The molar ratio is 2.0 times and the pH of the reaction system is set to 9 to 12 to suppress decomposition of phosgene and the formed chloroformate by an excessive alkali compound and accelerate the formation of chloroformate. When the amount of the alkaline compound used is less than the above range and / or when the pH is less than 9, it is difficult for the chloroformate-forming reaction to proceed, the amount of unreacted substances increases, and the reaction yield decreases. When the amount of the alkali compound used is larger than the above range and / or the pH is higher than 12, it is difficult to control the degree of polymerization, and unreacted substances are increased to decrease the reaction yield.

The amount of phosgene used in the phosgenation reaction is 1.1 to 1.8 with respect to the halogen-substituted dihydric phenol.
It is necessary to adjust the reaction temperature to 10 to 30 ° C. by doubling the mole. When the amount of phosgene used is less than the above range, the formation reaction of the chloroformate is difficult to proceed, the unreacted substance is increased, and the reaction yield is lowered. Since a compound is required, decomposition of phosgene and the formed chloroformate increases, and further, a chloroformate group remains in the obtained product to deteriorate the heat resistance. When the reaction temperature is lower than 10 ° C, the reaction rate of phosgenation is slow, unreacted substances increase, and the reaction yield decreases, and when it is higher than 30 ° C, the decomposition of phosgene and the formed chloroformate increases.

Further, in the phosgenation reaction, 0.01 to 0.1 times mol of amine catalyst is present with respect to the halogen-substituted dihydric phenol. If the amount of the amine catalyst used is less than the above range, the formation reaction of the chloroformate is difficult to proceed, and the reaction yield tends to decrease with many unreacted substances. If the amount is more than the above range, it is difficult to control the degree of polymerization. In addition, the reaction yield also decreases.

After completion of the phosgenation reaction, an alkaline compound is added in the presence of a monohydric phenol to adjust the pH of the reaction system to 12 or higher, and the polymerization reaction is further carried out at 30 to 38 ° C. Examples of the monohydric phenol include phenol, cresol, sec-butylphenol, tert-butylphenol, tert-octylphenol, nonylphenol, cumylphenol, 2,4,6-tribromophenol, pentabromophenol and chromanes. These may be used alone or in combination of two or more. If the pH is less than 12, the effect of the catalyst is not sufficiently exerted, and if the reaction temperature is lower than 30 ° C., the reaction is difficult to proceed and the yield is lowered in any case. When the reaction temperature is higher than 38 ° C, a decomposition reaction occurs. The amount of monohydric phenol used depends on the degree of polymerization of the desired product, and may be adjusted by a conventional method. A powdery or granular product is obtained by removing impurities from the organic solvent solution obtained by the reaction by acid washing, water washing and the like and then removing the organic solvent.

The carbonate type flame retardant thus obtained is a monomeric halogenated carbonate or halogenated polycarbonate oligomer having a specific viscosity of 0.01 to 0.7 depending on the amount of the monohydric phenol used as the terminal stopper.
According to the present invention, a monomeric or oligomeric carbonate flame retardant having a specific viscosity of about 0.01 to 0.1, which is a halogenated polycarbonate and which has been particularly difficult to manufacture in the past, can be easily obtained. Further, although a polymer type is used as a flame retardant, it can also be used as a flame retardant resin.

[0017]

EXAMPLES The present invention will be further described below with reference to examples. In addition,
Parts and% in the examples are parts by weight and% by weight, and the reaction yield, phosgene decomposition rate, specific viscosity, terminal chlorine content, measurement of melting point and impact strength, flame retardancy, and evaluation of appearance are according to the following methods. .

(A) Reaction yield: The amount of phenol component (amount of unreacted phenol component) in the aqueous phase after completion of the reaction was determined by measuring the ultraviolet absorption spectrum and calculated by the following formula. The amount of charged phenol component and the amount of unreacted phenol component include monohydric phenol component.

[0019]

[Equation 1]

In the examples, tetrabromobisphenol A was used as the halogen-substituted dihydric phenol, and p-tert-butylphenol or 2,4,6-tribromophenol was used as the terminal terminator. The case where these are used will be described. . The concentration of each of unreacted tetrabromobisphenol A, p-tert-butylphenol, and 2,4,6-tribromophenol present in the aqueous phase after the completion of the reaction appears because the ultraviolet absorption of each component overlaps. , The absorption coefficient of each component at the maximum absorption wavelength was calculated, and was calculated by the following simultaneous equations. In addition, the absorbance is an ultraviolet absorption spectrometer [U-3200 manufactured by Hitachi, Ltd.].
Mold]. With tetrabromobisphenol A
To measure the concentration of p-tert-butylphenol

[0021]

[Equation 2]

[A is the absorbance at each wavelength, b is the cell optical path length (cm), Cx is the concentration of p-tert-butylphenol (g / liter), Cy is the concentration of tetrabromobisphenol A.
(g / liter)], the concentration of tetrabromobisphenol A and 2,4,6-tribromophenol can be measured by

[0023]

[Equation 3]

[A is the absorbance at each wavelength, b is the cell optical path length (cm), Cy is the concentration of tetrabromobisphenol A (g
/ L), and Cz depends on the concentration of 2,4,6-tribromophenol (g / L)].

(B) Decomposition rate of phosgene: The amount of sodium carbonate in the aqueous phase after completion of the reaction was determined by neutralization titration and calculated by the following formula. In addition, the decomposition rate of phosgene includes the decomposition of chloroformate.

[0026]

[Equation 4]

(C) Specific viscosity: 0.700 g of the dried sample was dissolved in 100 ml of methylene chloride and measured at 20 ° C. with an Ostwald viscometer.

(D) Amount of terminal chlorine: The dried sample was dissolved in methylene chloride, triethylamine was added, and the mixture was stirred, and the one without addition of triethylamine was used as a blank value and measured by the Horhard method. (e) Melting point: Place the sample on a cover glass, set it on the hot plate of a trace melting point measuring device [manufactured by Yanagimoto Co., Ltd.], and heat it at 3 ° C / min while observing it with a magnifying glass to form fine droplets. The temperature from when it was observed to when it became a transparent droplet was measured. (f) Impact strength: 100 parts by weight of polybutylene terephthalate resin [TRB-H manufactured by Teijin Ltd.] and 7 parts by weight of antimony trioxide [ATOX-S manufactured by Nippon Seiko Co., Ltd.] and in each Example and Comparative Example. 14 parts by weight of the obtained carbonate type flame retardant was mixed, pelletized by an extruder of 30 mmφ, and the obtained pellet was dried and then 64 mm × 12.7 mm × by an injection molding machine [3 ounces manufactured by Meiki Co., Ltd.]. 3.18 mm (1 /
8 ") and 64 mm x 12.7 mm x 6.35 mm (1 /
4 ") test pieces were molded into these test pieces by 0.25 mm
After notching R, the sample was treated at a temperature of 23 ° C. and a humidity of 50% for 24 hours, and then measured with an Izod impact tester [Toyo Seiki (manufactured by)].

(G) Flame retardance (UL-94): After drying the pellets obtained in (f), 152 mm × 12.7 mm × 3.18 mm by an injection molding machine [3 ounces manufactured by Meiki Co., Ltd.] (1 /
8 ") and 152 mm x 12.7 mm x 6.35 mm (1 /
4 ") test pieces were molded, and these test pieces were used and measured according to Subject 94 of Underwriters Laboratory. (H) Appearance: The surface of the test piece was visually inspected to have unevenness and no gloss. Poor, with unevenness and less gloss, was evaluated as Δ, and with no unevenness and having good gloss, was evaluated as ○.

[0030]

Example 1 130 g of tetrabromobisphenol A was placed in a flask equipped with a phosgene blow-in tube, a thermometer and a stirrer.
(0.239 mol), 161 ml of 7.0% aqueous sodium hydroxide solution (0.298 mol of sodium hydroxide), 361 ml of methylene chloride and 0.84 ml of triethylamine (0.
006 mol) was charged and dissolved, and the mixture was maintained at 20 to 25 ° C. with stirring, and 7.76 ml of 48.5% sodium hydroxide aqueous solution.
While adding (0.141 mol of sodium hydroxide), 29.8 g (0.301 mol) of phosgene was blown thereinto over 90 minutes to carry out a phosgenation reaction. After completion of phosgenation reaction p-
tert-Butylphenol 11.1 g (0.074 mol)
And 185 ml of an aqueous solution in which 3.19 g (0.080 mol) of sodium hydroxide were dissolved, 9.64 ml of 48.5% aqueous sodium hydroxide solution (0.175 mol of sodium hydroxide) was added, and the mixture was kept at 30 to 36 ° C. The reaction was carried out for 2 hours. After completion of the reaction, the mixture was allowed to stand and separated into an aqueous phase and a methylene chloride phase. The reaction yield and phosgene decomposition rate were determined from the amount of unreacted phenol component and the amount of sodium carbonate in the aqueous phase, and the results are shown in Table 2.

The separated methylene chloride phase was washed with acid and water until the inorganic salts and amines were removed, and then methylene chloride was removed to obtain a halogenated polycarbonate oligomer. Charged molar ratio of each component, reaction conditions, reaction yield,
The phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point are shown in Tables 1 and 2. The obtained oligomer is mixed with polybutylene terephthalate resin and antimony trioxide as described above, pelletized by an extruder at 240 ° C., the obtained pellets are dried at 120 ° C. for 5 hours, and then by an injection molding machine at a cylinder temperature. Impact strength, flame retardancy, and appearance were evaluated by preparing impact strength measurement test pieces and flame retardancy measurement test pieces at 240 ° C., and the results are shown in Table 2.

[0032]

Example 2 The amount of 48.5% sodium hydroxide aqueous solution added at the time of blowing phosgene was 8.04 ml (0.146 mol of sodium hydroxide), and the amount of phosgene used was 31.
To 6 g (0.319 mol), p-tert-butylphenol aqueous solution added after the phosgenation reaction was added was p-tert-butylphenol 16.8 g (0.112 mol) and sodium hydroxide 4.83 g (0.121 mol). A halogenated polycarbonate oligomer was obtained in the same manner as in Example 1 except that the dissolved aqueous solution was 280 ml and the amount of the 48.5% sodium hydroxide aqueous solution added together was 8.42 ml (sodium hydroxide 0.153 mol). It was Tables 1 and 2 show the charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point. Further, an impact strength measurement test piece and a flame retardancy measurement test piece were prepared in the same manner as in Example 1 to evaluate the impact strength, flame retardancy and appearance, and the results are shown in Table 2.

[0033]

Example 3 The amount of 48.5% aqueous sodium hydroxide solution added at the time of blowing phosgene was 5.24 ml (0.095 mol of sodium hydroxide), and the amount of phosgene used was 27.
8 g (0.281 mol) and p-tert-butylphenol aqueous solution added after the completion of the phosgenation reaction was added with p-tert-butylphenol 4.84 g (0.032 mol) and sodium hydroxide 1.39 g (0.035 mol). A halogenated polycarbonate oligomer was prepared in the same manner as in Example 1 except that the amount of the dissolved aqueous solution was 80.6 ml, and the amount of the 48.5% sodium hydroxide aqueous solution added thereto was 13.9 ml (sodium hydroxide 0.253 mol). Got Tables 1 and 2 show the charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point. Further, an impact strength measurement test piece and a flame retardance measurement test piece were prepared in the same manner as in Example 1 except that the cylinder temperature was set to 250 ° C., and impact strength, flame retardancy and appearance were evaluated, and the results are shown in a table. Shown in 2.

[0034]

Example 4 The amount of 48.5% aqueous sodium hydroxide solution added at the time of blowing phosgene was 9.46 ml (0.172 mol of sodium hydroxide), and the amount of phosgene used was 33.
5 g (0.338 mol), and instead of the p-tert-butylphenol aqueous solution added after the completion of the phosgenation reaction, 2,
3,6-tribromophenol 36.4 g (0.110
Mol) and sodium hydroxide 15.2 g (0.38 mol)
197 ml of an aqueous solution in which was dissolved and added together with it 4
A halogenated polycarbonate oligomer was obtained in the same manner as in Example 1 except that the 8.5% sodium hydroxide aqueous solution was not added. Table 1 shows the charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point.
And shown in Table 2. Further, an impact strength measurement test piece and a flame retardancy measurement test piece were prepared in the same manner as in Example 1 to evaluate the impact strength, flame retardancy and appearance, and the results are shown in Table 2.

[0035]

Example 5 The amount of 48.5% sodium hydroxide aqueous solution added at the time of blowing phosgene was set to 14.6 ml (0.266 mol of sodium hydroxide), and the amount of phosgene used was 42.
4 g (0.428 mol), and p-tert-butylphenol aqueous solution added after the phosgenation reaction was added with p-tert-butylphenol 43.0 g (0.287 mol) and sodium hydroxide 12.4 g (0.310 mol). A monomeric halogenated carbonate was prepared in the same manner as in Example 1 except that 717 ml of the dissolved aqueous solution was added, and the amount of the 48.5% sodium hydroxide aqueous solution added thereto was 6.21 ml (0.113 mol of sodium hydroxide). Obtained. Tables 1 and 2 show the charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point. Further, an impact strength measurement test piece and a flame retardancy measurement test piece were prepared in the same manner as in Example 1 to evaluate the impact strength, flame retardancy and appearance, and the results are shown in Table 2.

[0036]

Example 6 The amount of 48.5% sodium hydroxide aqueous solution added at the time of blowing phosgene was 4.51 ml (sodium hydroxide 0.082 mol), and the amount of phosgene used was 26.
3 g (0.265 mol), and p-tert-butylphenol aqueous solution added after completion of the phosgenation reaction was added with p-tert-butylphenol 0.359 g (0.0024 mol) and sodium hydroxide 0.104 g (0.0026 mol). Dissolve aqueous solution to 6.0 ml and add with it 48.5%
A halogenated polycarbonate was obtained in the same manner as in Example 1 except that the amount of the aqueous sodium hydroxide solution used was 19.1 ml (sodium hydroxide 0.348 mol). The obtained halogenated polycarbonate was pre-crushed by an impact crusher and then finely crushed by a wet crusher to an average particle size of 4 μm. The finely ground halogenated polycarbonate was thoroughly dried. Table 1 and Table 2 show the charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point.
It was shown to. Further, an impact strength measurement test piece and a flame retardance measurement test piece were prepared in the same manner as in Example 1 except that the cylinder temperature was set to 250 ° C., and impact strength, flame retardancy and appearance were evaluated, and the results are shown in a table. Shown in 2.

[0037]

Comparative Example 1 108 g of tetrabromobisphenol A was placed in a flask equipped with a phosgene blow-in tube, a thermometer and a stirrer.
(0.199 mol), 420 ml of 4.6% aqueous sodium hydroxide solution (0.498 mol of sodium hydroxide) and 300 ml of methylene chloride were charged and dissolved, and stirred for 20 to 25
Hold at 4 ° C., 48.5% aqueous sodium hydroxide solution 30.
Phosgene 42.3 g (0.428 mol) was blown in over 90 minutes while adding 8 ml (sodium hydroxide 0.560 mol) to carry out a phosgenation reaction. After completion of the phosgenation reaction, 9.2 g (0.061 mol) of p-tert-butylphenol and 2.65 g (0.066 mol) of sodium hydroxide.
And 153 ml of an aqueous solution in which is dissolved in 48.5% sodium hydroxide aqueous solution 10.0 ml (sodium hydroxide 0.182).
Mol) and 0.78 ml of triethylamine (0.0056)
Mol) was added, and the mixture was kept at 30 to 36 ° C. and reacted for 2 hours. After completion of the reaction, a halogenated polycarbonate oligomer was obtained in the same manner as in Example 1. Charged molar ratio of each component,
The reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point are shown in Tables 1 and 2. Further, an impact strength measurement test piece and a flame retardancy measurement test piece were prepared in the same manner as in Example 1 to evaluate the impact strength, flame retardancy and appearance, and the results are shown in Table 2.

[0038]

[Comparative Example 2] 93.0 g of tetrabromobisphenol A was placed in a flask equipped with a phosgene blow-in tube, a thermometer and a stirrer.
(0.171 mol), 318 ml of 4.3% sodium hydroxide aqueous solution (0.358 mol of sodium hydroxide) and 397 ml of methylene chloride were charged and dissolved, and the mixture was stirred for 20 to 25
Hold at 4 ° C., 48.5% aqueous sodium hydroxide solution 52.
Phosgene 49.5 g (0.5 mol) was blown in over 90 minutes while adding 0 ml (sodium hydroxide 0.946 mol) to carry out the phosgenation reaction. After completion of the phosgenation reaction, 0.36 ml (0.0025 mol) of triethylamine was added and stirred for 5 minutes, and then 26.0 g (0.079 mol) of 2,4,6-tribromophenol and 1 part of sodium hydroxide.
0.86 ml (0.006 mol) of triethylamine was added together with 141 ml of an aqueous solution in which 0.8 g (0.27 mol) was dissolved, and the mixture was kept at 30 to 36 ° C. and reacted for 2 hours. After completion of the reaction, a halogenated polycarbonate oligomer was obtained in the same manner as in Example 1. Charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine,
The melting points are shown in Tables 1 and 2. Further, an impact strength measurement test piece and a flame retardancy measurement test piece were prepared in the same manner as in Example 1 to evaluate the impact strength, flame retardancy and appearance, and the results are shown in Table 2.

[0039]

Comparative Example 3 A halogenated polycarbonate oligomer was obtained in the same manner as in Example 1 except that the temperature of the reaction performed after the completion of the phosgenation reaction was 23 to 27 ° C. Tables 1 and 2 show the charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point. Also,
Impact strength measurement test pieces and flame retardancy measurement test pieces were prepared in the same manner as in Example 1 to evaluate impact strength, flame retardancy and appearance,
The results are shown in Table 2.

[0040]

Comparative Example 4 A halogenated polycarbonate oligomer was obtained in the same manner as in Example 1 except that the 48.5% sodium hydroxide aqueous solution added after the completion of the phosgenation reaction in Example 1 was not added. Charged molar ratio of each component, reaction conditions,
The reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine, and melting point are shown in Tables 1 and 2. Further, an impact strength measurement test piece and a flame retardancy measurement test piece were prepared in the same manner as in Example 1 to evaluate the impact strength, flame retardancy and appearance, and the results are shown in Table 2.

[0041]

Comparative Example 5 A halogenated polycarbonate oligomer was obtained in the same manner as in Example 1 except that the temperature during the phosgenation reaction was 5 to 7 ° C. Charged molar ratio of each component, reaction conditions, reaction yield, phosgene decomposition rate, specific viscosity, amount of terminal chlorine,
The melting points are shown in Tables 1 and 2. Further, an impact strength measurement test piece and a flame retardancy measurement test piece were prepared in the same manner as in Example 1 to evaluate the impact strength, flame retardancy and appearance, and the results are shown in Table 2.

The symbols shown in the column of charged molar ratio in Table 1 indicate the following compounds, and ND indicates that they are not detected. (1) TEA: triethylamine (2) TBA: tetrabromobisphenol A (3) PG: phosgene (4) PTBP: p-tert-butylphenol (5) TBP: 2,4,6-tribromophenol

[0043]

[Table 1]

[0044]

[Table 2]

[0045]

According to the method of the present invention, the specific viscosity is 0.0
1-0.7 monomer type halogenated carbonates, halogenated polycarbonate oligomers, halogenated polycarbonate flame retardants can be produced in high yield with the minimum amount of phosgene used, and their industrial effect is exceptional. It is a thing.

Claims (1)

[Claims] 1. When a carbonate-type flame retardant is produced by reacting an alkaline aqueous solution of a halogen-substituted dihydric phenol with phosgene in the presence of an organic solvent and a catalyst, the amount of the alkali compound used is 1 with respect to the dihydric phenol. .3-2.
4 times mole, the amount of phosgene used is 1.1 to 1.8 times mole to the dihydric phenol, and 0.01 to 0.1 times mole of amines catalyst to the dihydric phenol is used as a catalyst. The phosgenation reaction is carried out at a pH of the reaction system of 9 to 12 at a temperature of 10 to 30 ° C, and then in the presence of a monohydric phenol.
A method for producing a carbonate-type flame retardant, characterized in that the reaction is completed at a temperature of 12 or more and a temperature of 30 to 38 ° C.