JPH02147627A - Preparation of carbonate type flame-retardant - Google Patents

Abstract

PURPOSE:To obtain the title flame-retardant with a low MW and suitable for flame-retarding of a thermoplastic resin with a low molding temp. by reacting a halogenated dihydric phenol and a non-halogenated dihydric phenol with phosgene under a specified condition. CONSTITUTION:When the title flame-retardant is prepd. by reacting a mixture of 1mol of a halogenated dihydric phenol (e.g. tetrabromobisphenol A) with 0.1-0.5mol of a non-halogenated dihydric phenol with phosgene in the presence of a solvent (e.g. methylene chloride), the amt. of phosgene used is 2.2 to 3.0-fold mol based on the total amt. of the dihydric phenol, and phosgene is reacted at a pH of 11-12 and a temp. of 20-27 deg.C in the reaction system. Then, 0.5 to 1.5-fold mol of a monohydric phenol (e.g. t-butylphenol) base on the total amt. of the dihydric phenol and a catalyst (e.g. triethylamine) are added thereto and the reaction is completed at a pH of 12.5 or higher and a temp. of 30-36 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for producing carbonate flame retardants. More specifically, it is suitable for flame retardant thermoplastic resins that require relatively low molding temperatures.

The present invention relates to a method for producing a low molecular weight halogenated carbonate type flame retardant with good yield.

[Prior art and problems] Halogenated polycarbonate oligomers have been known as oligomer flame retardants for thermoplastic resins (
Special Publication No. 47-44537, Special Publication No. 56-2595
Publication No. 3).

However, such halogenated polycarbonate oligomers are homopolymers of tetrahalogenated bisphenol A, and have a high melting point of 220 to 290°C, and when kneaded into ABS resin, etc., which has a low molding temperature, they cause poor dispersion, resulting in molded pieces. Problems such as deterioration of physical properties and surface defects occur, making it unsuitable for use.

In order to solve these problems, a copolymerized carbonate oligomer consisting of a halogen-substituted dihydric phenol and a non-halogen-substituted dihydric phenol and having an average degree of polymerization of 2 to 50 was proposed (Japanese Patent Publication No. 50987/1987). However, in order to use this copolymerized carbonate oligomer in ABS resin, which has a low molding temperature, it is necessary to increase the proportion of non-halogen-substituted dihydric phenol in order to lower the melting point, which increases the durability of the copolymerized carbonate oligomer. This has the disadvantage that the physical properties of the resin are greatly deteriorated, resulting in a need to increase the amount used.

Instead of increasing the proportion of halogen-unsubstituted dihydric phenol,
When we attempted to produce a carbonate-type flame retardant with a low average degree of polymerization, we found that when co-electrifying compounds with significantly different reactivities, such as halogen-substituted dihydric phenol and non-halogen-substituted dihydric phenol, we found that conventional synthetic In this case, the polymerization of halogen-unsubstituted dihydric phenol easily proceeded, and it was not possible to obtain a carbonate-type flame retardant with a low average degree of polymerization in a good yield.

JP-A No. 63-139914 discloses a method for producing bischlorobaume-1 from dihydric phenol, which comprises water, an organic solvent such as methylene chloride, dihydric phenol, and an alkali metal hydroxide such as sodium hydroxide. A method has been proposed in which when blowing phosgene into a heterogeneous mixture, an alkali metal hydroxide is introduced at a rate that maintains the Pl+ in the range of 8 to 11.

However, when this method was applied to the copolymerization of halogen-substituted dihydric phenol and non-halogen-substituted dihydric phenol, which have significantly different reactivities, it was found that the yield of bischloroformate with a low average degree of polymerization was extremely low.

[Objective of the Invention] The object of the present invention is to provide a halogen-substituted resin that does not cause poor physical properties or surface defects even when used in thermoplastic resins whose molding temperature is relatively low.
1 mole of phenol and 0 mol of non-halogen-substituted dihydric phenol
, a specific viscosity of 0.015 to 0.02 consisting of 1 to 0.5 mol.
An object of the present invention is to provide a method for producing a low molecular weight carbonate flame retardant of No. 2 in high yield.

The present inventor has discovered that in order to obtain a carbonate-type flame retardant with a low average degree of polymerization in a high yield from compounds with greatly different reactivities such as halogen-substituted dihydric phenol and halogen-free 'f1-substituted dihydric phenol, the average degree of polymerization is Toshiba et al. discovered that the phosgenation reaction step, which produces bischloroformate of dihydric phenol with a low level of oxidation, is the most important, and that the subsequent polymerization reaction is important, and based on this knowledge, further studies were carried out. As a result, we have arrived at the present invention.

Structure of the Invention] The present invention produces a carbonate-type flame retardant by reacting a mixture of 1 mole of halogen-substituted dihydric phenol and 0.1 to 0.5 mole of halogen-unsubstituted dihydric phenol with phosgene in the presence of a solvent. In doing so, the amount of phosgene used is 2.2 to 3.0 times the mole of the total amount of the dihydric phenol, and the phosgenation reaction is carried out at a pH of 11 to 12 in the reaction system and a temperature of 20 to 27°C. 0.5 based on the total amount of hydric phenols
pH 1 in the presence of ~1.5 times the mole of monohydric phenol and a catalyst
This is a method for producing a carbonate-type flame retardant, characterized in that the reaction is completed at a temperature of 2.5 or more and a temperature of 30 to 36°C.

Examples of the halogen-substituted dihydric phenol used in the present invention include 2,2-bis(3,5-dibromo4-hydroxyphenyl)propane and 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-human 0xyphenyl) sulfide, bis(3,5-dichloro-4-hydroxyphenyl) sulfide, bis(3,5-dibromo-4-hydroxyphenyl) oxide, bis(3, 5-dichloro-4-hydroxyphenyl)oxide, bis(3,5-
dibromo-4-hydroxyphenyl) sulfoxide, bis(3,5-dichloro=4-droxyphenyl) sulfoxide, bis(3,5-dibromo-4-hydroxyphenyl) sulfone, bisque 3,5-dichloro-4. -hydroxyphenyl) sulfone, bis(3,5-dibromo-4-hydroxyphenyl) getone, bis(3,5-dichloro-4-hydroxyphenyl) getone, and the like.

Examples of the halogen-unsubstituted dihydric phenol include compounds in which the halogen of the halogen-substituted dihydric phenol is replaced with hydrogen.

These dihydric phenols are used after being dissolved in an aqueous solution of an alkali metal hydroxide. As the alkali metal hydroxide, sodium hydroxide, potassium hydroxide, etc. are preferably used, and the concentration of (N is preferably 3 to 13% by weight).

The organic solvent used in the present invention is an organic compound that is substantially insoluble in water, inert to the reaction, and capable of dissolving the polycarbonate oligomer produced by the reaction. Specific examples 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 can be used alone or in a mixed form. Among these, methylene chloride is most preferred.

Examples of catalysts include tertiary amines such as triethylamine, tri-11-propylamine, diethyl-〇-propylamine, triloproplyamine, and 4-dimethylaminopyridine, trimethyldodecylammonium chloride, dimethylbenzylphenylammonium chloride, diethylbenzylphenylammonium chloride, Quaternary ammonium salts such as trimethyldodecylbenzylammonium hydroxide and the like are used.

In addition, in this invention, monohydric phenol is used as a terminal stopper. Examples of the monovalent phenol include phenol, cresol, thi-butylphenol, nonylphenol, octylphenol, and 2,4.6-tribromophenol.

In general, the specific viscosity of a carbonate type compound is approximately determined by the amount of monohydric phenol used, but it is greatly influenced by other reaction conditions, especially Pl+ and temperature conditions during the phosgenation reaction. employs the specific reaction conditions described above, in which
The amount of monohydric phenol used above is used as a raw material2
The target specific viscosity is 0 by appropriately selecting from the range of 0.5 to 1.5 times the mole based on the total amount of hydric phenol.
．． 0.015 to 0.022 carbonate type flame retardant is obtained.

The reaction mode of the present invention will be explained in detail. The pH during the phosgenation reaction is 11.0-12. By specifying O within the range, it suppresses the polymerization reaction and the decomposition of phosgene and chlorobomate caused by excess alkali metal hydroxide, promoting the production of bischloroformate with a low average degree of polymerization. do. That is, before blowing in phosgene, add sodium hydroxide to 1.8 to 1 mole of total dihydric phenol.
Use 2.1 mol, dissolve dihydric phenol in a 3-13% by weight aqueous solution, and add an organic solvent such as methylene chloride to the above aqueous solution so that the volume ratio of solvent:aqueous solution is 1:0.5-1.6. While blowing 2.2 to 3.0 moles of phosgene per 1 mole of total dihydric phenol into the mixture at 20 to 27°C, add an aqueous solution of an alkali metal hydroxide (4 in the case of sodium hydroxide). .1 to 4.8 mol) is added dropwise to maintain Pl+ in the system at 11.0 to -12.0. At this time, no matter whether the amount of alkali metal hydroxide dropped with the phosgene blowing is large or small, that is, Pl+11.0 to 12.
When the value is outside the range of 0, unreacted substances increase and the reaction yield decreases. In addition, if the temperature during the phosgenation reaction is lower than 20°C, the phosgenation reaction rate will be slow, unreacted substances will increase, and the yield will decrease; if it is too high than 27°C, the polymerization reaction will proceed and the average degree of polymerization will decrease. Because it goes up, you won't be able to get what you want.

Furthermore, if the amount of phosgene used is less than 2.2 times the mole based on 1 mole of total dihydric phenol, the reaction will not proceed sufficiently, the amount of unreacted substances will increase, the reaction yield will decrease, and the amount will be 3.0 times the mole. If the amount increases, it becomes difficult for the reaction to proceed in this case as well.

After the above phosgenation reaction is completed, the reaction is further carried out in the presence of a catalyst and a monohydric phenol. At this time, add an alkali metal hydroxide to adjust the pH in the system to 12.5 or higher.
React at ~36°C. If the pH is less than 12.5, the effect of the catalyst will not be fully exhibited, and if the reaction temperature is less than 30°C, the reaction will be difficult to proceed, and in both cases the yield will decrease.If the reaction temperature is higher than 36°C, a decomposition reaction will occur. It becomes like this.

In addition, when adding the catalyst, the entire amount may be added at once, but approximately 1/3 of the amount to be used is added immediately after the phosgenation reaction is completed, and the catalyst is added for several minutes (usually 3 to 6 minutes). It is preferable to complete the reaction by stirring for a while and then adding the remaining amount.At the end of phosgenation, add a small amount of catalyst and stir for several minutes to allow the phosgenation reaction to proceed more fully.
Residual free phosgene can be eliminated. Furthermore, 1
It is preferable to add a small amount of phenol during the second addition of the catalyst, and the reaction between the dihydric phenol chloroforme-1~ obtained by the above reaction and monohydric phenol is also carried out at 30°C.
If the temperature is lower than 36°C, the reaction rate will be slow, and if the temperature is higher than 36°C, a decomposition reaction will occur, so from this point of view, the reaction temperature should be set to 30 to 36°C. After removing impurities by washing with water or the like, the organic solvent is evaporated to obtain a powder.

[Effects of the Invention] According to the method of the present invention, a predetermined low molecular weight carbonate flame retardant can be obtained at a high yield of 99% or more from halogen-substituted dihydric phenol and halogen-unsubstituted dihydric phenol, which have significantly different reactivities. Can be done.

Even when this flame retardant is kneaded into a thermoplastic resin such as ABS whose molding temperature is relatively low, problems such as deterioration of physical properties and surface defects will not occur.

[Example] The method of the present invention will be explained below by giving Examples and Comparative Examples, but the present invention is not limited to these. The physical properties of the molded plates were evaluated using the methods described below.

(1) Reaction yield The amount of phenol components (including monohydric phenol) in the aqueous layer after the completion of the reaction is determined by measuring the ultraviolet absorption spectrum,
It was calculated using the following formula.

Reaction yield (%) = ((Prepared phenol component) (Reacted phenol component)) / (Prepared phenol component) xloo The amount of charged phenol component referred to here includes monohydric phenol.

In the examples, 2,2-bis(3,5-dibromo4-
Hydroxyphenyl)propane (abbreviated as TBA) 2
．． 2-bis(4-hydroxyphenyl)propane (BP
A) and 2゜4.6-)ribromophenol (abbreviated as 'I' B P) were used as the end capping agent. Unreacted TBA, BPA and TBP present
The concentration of each component appears as a result of the overlapping UV absorption of each component, so find the extinction coefficient at the maximum absorption wavelength of each component,
It was calculated using the following simultaneous equations.

A 294.0nn=22.02bCx+11.4
6bCy+ 7.56bCzA 309.9ni=
6.22bCx+18.85bCy+13.06b
CzA 315.6n1! = 1.34bCX 1,0001
6.52bCV+13.88tlCZ absorbance was measured using an ultraviolet absorption spectrometer (model U-3200 manufactured by Hitachi).

(2) Specific viscosity (η5ly) 0.700 g of dried sample was added to 100 ml of methylene chloride.
It was measured at 20°C using an Ostwald viscometer.

(31 Melting temperature (Ill, D,) Place the sample on a cover glass, set it on a hot plate of a trace melting point n] constant device (willow wood), heat at 3°C/min, and use a magnifying glass to measure the r! The melting temperature was defined as the temperature from when slightly thin droplets were observed in Sample 74 until the sample finished melting and became transparent droplets.

(4) Fluid ABS resin (bundled ■ TOYOLAC type 100) 100
5b2o in weight part, (Japan Concentrate (111ATOX-3)
6 parts by weight and 23 parts by weight of the carbonate flame retardants obtained in Examples and Comparative Examples were mixed and pelletized using a 30 nmφ extruder. The obtained pellet was heated at 80℃ for 3
After time drying, fluidity was evaluated. Liquidity evaluation (MfR)
was conducted according to JIS K-7210 flow test method for thermoplastics (test temperature 230°C, trial yI!
RM Giant E5kin.

(5) After drying the pellets used for evaluating the physical properties and fluidity of the molded plate at 80°C for 3 hours, the pellets were molded using an injection molding machine at a cylinder temperature of 230°C.
64 cities x 12.7 strokes x 3.18mm and 6411+n
Each test piece was formed into an impact test piece of X6.351+111 between Xt2.7 and a notch of 0.250111R. After treating this test piece at a temperature of 23° C. and a humidity of 50% for 24 hours, the impact strength (IIQD) was measured using an Izod impact test a (manufactured by Toyo R@). Higher impact strength does not indicate better impact resistance.

After drying the pellets used for the evaluation of f61 flame retardancy and fluidity at 80°C for 3 hours, they were molded using an injection molding machine at a cylinder temperature of 230°C. 7 days x 3.18 days and 152 ms+ x 1
Each was molded into a test piece between 2.7aun
Combustion tests were carried out according to T 94.

Example 1 2! equipped with a phosgene blowing tube, thermometer and stirrer! Add TBA106.6 ir (0,19
6 mol) and 398 ml of 4,37% NaOH aqueous solution (NaO
684 ml of methylene chloride and 62.4 t of phosgene (0.6 mol) were added under stirring.
3 mol) and 59.0 ml of 48.5% NaOH aqueous solution
It took 67 minutes to maintain the temperature between 0 and 27°C''C-P 1.0 and 12.0 to carry out the phosgenation reaction.The actual temperature and pH in the reaction system are as shown in Table 1. Met.

After completion of phosgenation, 0.6% triethylamine was added as a catalyst.
2 ml (0,0045 mol) was added and stirred for 5 minutes, and then 7.6% NaOH water in which 78.1 g (0,236 mol) of TBP was dissolved was added. 1.24011 (0,0089 mol) of triethylamine was added together with 410 ml of gfi, and the mixture was reacted with stirring for 3 hours while maintaining the temperature at 30 to 36°C. The actual reaction temperature was as shown in Table 1. After the reaction was completed, it was left to stand and separated into an aqueous layer and a methylene chloride layer, and the reaction yield determined from the dissolved monomer concentration in the aqueous layer was 99.9%. there were.

At the end of this reaction, the methylene chloride layer was washed with acid and water until the inorganic salts and amines were removed, and then the methylene chloride layer was removed. The obtained carbonate-type flame-retardant material ηsohao, 01
7, n, o, LL172~180℃Te1>f,
:.

Using the obtained carbonate type flame retardant, a test piece was molded under the above conditions and a physical property test was conducted. The results are shown in Table 1.

Example 2 In Example 1, the amount used for BP was 4.56rfo,
020 mol) and dissolve BPA and 18^4,37
A carbonate-type flame retardant was obtained by carrying out the reaction in the same manner as in Example 1, except that the amount of the 48.5% Na0fl aqueous solution used during phosgene injection was changed to 54.6 ml. Yield is 99.
8%, ηsp is 0.015, 11.11. is 166~
The temperature was 172°C. The physical properties of this material mixed into ABS were as shown in Table 1.

Example 3 In Example 1, the amount of BPA used was changed to 18°01gf0.
079 mol) and dissolve BPA and TB^4,37
A carbonate-type flame retardant was obtained by carrying out the reaction in the same manner as in Example 1, except that the amount of the %NaOH aqueous solution used was 464 ml, and the amount of the 48.5% Na0tt aqueous solution added dropwise at the same time as phosgene was changed to 63.5011. , yield is 99.7%
, ηso is 0.021.

1, p, was 175-183'C. The physical properties of this product mixed into 83S were as shown in Table 1.

Comparative Example 1 TBA103.9. (0,
191 mol) and BPA 14.61r (0,064 mol) in 1385.3 ml of 6.2% Naart aqueous solution (
Na0IIO, 638 mol) and methylene chloride 445 ml
Add 755.4 tons of phosge (
0.56 mol) and 48.5% NaOH in water i43.
7o1 was added dropwise over 67 minutes while maintaining the temperature at 20 to 27°C to cause a phosgenation reaction. The actual temperature and Pl+ in the reaction system were as shown in Table 1.

After completion of phosgenation, 1.5% of triethylamine was added as a catalyst.
Add a+1 (0,011 mol) and stir for 10 minutes, then TOP 42. Add 0.56 ml (0,004 mol) of triethylamine to the 7.6% Na leaf droplet aqueous solution 221 in which Or (0.t27 mol) was dissolved.
The reaction was carried out under stirring for 3 hours while maintaining the temperature at 0 to 36°C. The actual reaction temperature was as shown in Table 1. After the completion of the reaction,
A carbonate-type flame retardant was obtained by processing in the same manner as in Solid Line Example 1. The reaction yield was 96.4%, ηsp was 0.033, l
'i, p, were 202-214°C. This material was kneaded into ABS in the same manner as in Example 1, and the physical properties are shown in Table 1.

Comparative Example 4 A carbonate-type flame retardant was obtained in the same manner as in Example 1 except that the phosgenation reaction temperature was changed to 28 to 30°C.The zero reaction yield was poor at 85.5%, and ηsp was as high as 0.025. ABS of this thing
II) In the kneading test into I fat, the surface properties were somewhat poor as shown in Table 1.

Comparative Example 2 48.5% added simultaneously with phosgene in Example 1
The reaction was carried out in the same manner as in Example 1 except that 1 of the t4aOH aqueous solution was changed to 61.2+nl. The yield of the carbonate flame retardant obtained was as low as 65%, and a large amount of unreacted monomer remained.

Comparative Example 3 A carbonate-type flame retardant was obtained in the same manner as in Example 1 except that the temperature during phosgenation was kept as low as 10 to 18°C. The yield was as low as 76%, and a large amount of unreacted monomer remained.

Comparative Example 5 The reaction temperature after the phosgenation reaction in Example 1 was set to 23~
A carbonate type flame retardant was obtained in the same manner as in Example 1, except that the temperature was adjusted to 27°C.The reaction yield was rapid at 86%, and a large amount of unreacted monomer remained.

Comparative Example 6 Into the apparatus used in Example 1, 115.3 g of rBA (0.2
12 mol and 8PA9.8f (0,043 mol), 3
．． 779.1 ml of 5% NaOH aqueous solution (NaOH0
, 709 mol) and methylene chloride (442.2011 mol) and dissolved therein, and with stirring 61.4 mol of phosgene. (0,6
2 mol) and 48.7+nl of 48.5% NaOH aqueous solution were added dropwise over 65 minutes at 20 to 27°C while maintaining the pH in the range of 9.0 to 11.0. The actual temperature and Pll in the reaction system were as shown in Table 1. Because Pll is low, a small amount of phosgene leaks out of the system during the reaction.

After completion of phosgenation, triethylamine 0.6II+1(0
,0043 mol) and stirred for 5 minutes, then TBP
7.6% dissolved in 70.2 g (0,212 mol)
Add 1.2 ml (0,0087 mol) of triethylamine together with 369 ml of NaOH aqueous solution to make 30-36
The reaction was carried out under stirring for 3 hours so that the temperature reached ℃. The actual reaction temperature was as shown in Table 1. After the completion of the 0 reaction, a carbonate type flame retardant was obtained by processing in the same manner as in Example 1. The 0 reaction yield was extremely low at 62.5%, making it impractical. There wasn't.

Claims (1)

[Claims] 1 mol of halogen-substituted dihydric phenol and 2 non-halogen-substituted phenols
In producing a carbonate flame retardant by reacting a mixture of 0.1 to 0.5 mol of dihydric phenol with phosgene in the presence of a solvent, the amount of phosgene used is 2.2% of the total amount of the dihydric phenol.・~3.0 times the molar value, and the pH of the reaction system
11-12, phosgenation reaction at a temperature of 20-27°C,
Then, 0.5 to 1.5 based on the total amount of the dihydric phenol.
A method for producing a carbonate-type flame retardant, characterized in that the reaction is completed in the presence of twice the mole of monohydric phenol and a catalyst at a pH of 12.5 or higher and a temperature of 30 to 36°C.