JPS6311352B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing S-triazine compounds, and particularly to a method for producing S-triazine compounds by reacting dianuric chloride, phenols, and diphenols. The present inventors have discovered that certain halogen-containing S-
We discovered that triazine compounds have excellent properties as flame retardants for synthetic resins, etc., and filed a patent application for this (Japanese Patent Application No. 157300, 1972:
(See Publication No. 90193). This compound is an oligomer-type compound having two or more S-triazine rings obtained by reacting cyanuric chloride with phenols and diphenols.
Alternatively, by using halides as diphenols, compounds effective as flame retardants for synthetic resins and the like can be obtained. However, at the beginning of the development of the above-mentioned S-triazine compounds, organic solvents such as tetrahydrofuran (THF) were used as reaction solvents.
It was difficult to recover the solvent. That is, when an alkali is added during the reaction, water is added to the solvent, and when the solvent is recovered, the water and the solvent azeotropically boil, making it impossible to separate the two by distillation. In addition, when separating and purifying the product, the same organic solvent as in the water-containing reaction system is sometimes used, and recovery of this solvent also poses a problem. On the other hand, solvents such as THF are flammable, and their handling causes various inconveniences, and the production equipment requires explosion-proof equipment, making it unavoidable to increase the size and complexity. Therefore, it is preferable to use a nonflammable solvent, but nonflammable organic solvents such as halogenated hydrocarbons generally have the disadvantage that they are not compatible with water and have low solubility of raw materials. A further problem is that cyanuric chloride, one of the raw materials, easily reacts with water, and to prevent this, the reaction system must be cooled. By reaction between cyanuric chloride and water
The presence of OH groups impairs the thermal stability of the product S-triazine compounds, leading to coloration and performance deterioration of products such as synthetic resins added as flame retardants. Furthermore, with conventional methods, it has been difficult to produce compounds having 20 or more S-triazine rings in one molecule.
In other words, even if you try to produce a high molecular weight compound,
The system gels and is extremely difficult to separate from the solvent. In order to solve these problems, the present inventor conducted various research studies and found that a heterogeneous mixed solvent of water and an organic solvent (hereinafter referred to as a heterogeneous solvent) and a special catalyst were used. We have discovered that these problems can be solved all at once. That is, first, regarding the recovery of the solvent, it is possible to distill the mixed solvent to recover an azeotrope of water and organic solvent, or it is possible to recover the organic solvent containing water by steam distillation. The organic solvent containing can be reused as is. Furthermore, regarding recovery, the azeotrope of water and organic solvent is recovered by distilling the heterogeneous solvent or steam distilling it, and further separating the aqueous layer and the organic solvent layer, and removing the organic solvent layer as necessary. Water can be completely removed using a solid dehydrating agent. Further, since a nonflammable organic solvent can be used as the organic solvent and the reaction can be carried out in a heterogeneous solvent system with water, explosion-proof equipment is not required. Furthermore, if a heterogeneous solvent is used, cyanuric chloride is dissolved in the organic solvent and rarely comes into contact with water, so there is no need to cool the reaction system, and the reaction can be carried out at room temperature. Furthermore, high molecular weight compounds can also be produced according to the present invention. The feature of the present invention is the use of a heterogeneous solvent and a special catalyst as described above, namely:
The present invention provides cyanuric chloride and cyanuric chloride 1
Moles of phenols (3-2a) represented by () below and a mol of diphenols (0.5<a<1.2) shown below (where 0.5<a<1.2) are treated with 3 equivalents or more of alkali to form the following (()) per mole: ), wherein the solvent used is a heterogeneous solvent of water and an organic solvent, and a phase transfer catalyst is used as the catalyst. This is the manufacturing method. First, when the solvent is a homogeneous or heterogeneous solvent of water and an organic solvent, a phase transfer catalyst works in the same way as a normal catalyst, but it is difficult to obtain a nonflammable organic solvent that is compatible with water, and cyanuric chloride The present invention uses a heterogeneous solvent because reactions between the solvent and water are likely to occur, and the system may need to be cooled. When a heterogeneous solvent is used, an organic solvent that is not compatible with water can be used, so a nonflammable organic solvent such as a halogenated hydrocarbon can be used. As specific organic solvents,
Aliphatic and aromatic halogenated hydrocarbons include methylene chloride, chloroform, carbon tetrachloride, trichloroethane, trichloroethylene, perchlorethylene, chlorobenzene, dichlorobenzene, and other halogenated hydrocarbons. Particularly preferred are nonflammable halogenated hydrocarbons. Furthermore, these various organic solvents can be used in combination of two or more. Also,
Only the organic solvent can be used initially and mixed with an aqueous alkaline solution to form a mixed solvent. Also,
Recovery of the solvent is not particularly limited, but even if water is present in a gaseous state during recovery of the organic solvent, it is easy to separate after cooling and liquefying it, so it may be used as an azeotrope with water by steam distillation or ordinary distillation. can be collected. A phase transfer catalyst is used as the catalyst. This catalyst can cause a compound dissolved in water to react with a compound dissolved in an organic solvent in a heterogeneous solvent system of water and an organic solvent. Although the reaction mechanism is not necessarily clear, for example, in the present invention, phenols or diphenols react with the catalyst in the aqueous phase in the presence of an alkali to become an organic solvent-soluble compound, which is transferred to the organic solvent phase. is believed to react with cyanuric chloride in the organic solvent phase and the catalyst is regenerated and transferred to the aqueous phase. That is, the catalyst reacts with a water-soluble compound in the aqueous phase to become an organic solvent-soluble compound and transfers to the organic solvent phase, and reacts with the compound dissolved in the organic solvent in the organic solvent phase to form the desired product. At the same time, the catalyst is regenerated and, since it is water-soluble, it passes into the aqueous phase. Such a catalyst is called a phase transfer catalyst, and quaternary ammonium salts, quaternary phosphonium salts, and other compounds are known. In the present invention, by using this catalyst,
The reaction can proceed in a heterogeneous solvent system, but at this time, cyanuric chloride exists in the organic solvent and rarely comes into contact with water, so water and cyanuric chloride rarely react. Therefore, it is not necessary to keep the reaction system at a low temperature to prevent the reaction between water and cyanuric chloride, and the reaction can be carried out at room temperature or under heating. Specific compounds as catalysts include, for example, quaternary ammonium salts such as triethylbenzylammonium chloride, methyltricaptylammonium chloride, tetrabutylammonium bromide, todecyltrimethylammonium chloride, tetrapropylammonium chloride, n-hexadecyl For example, quaternary phosphonium salts include n-hexadecyltributylphosphonium bromide. The raw material, cyanuric chloride, is

It is a compound represented by the formula: The chlorine can react with the phenolic OH group, and the liberated hydrogen chloride is neutralized with an alkali. Phenols () are

It is a compound represented by the formula: R ¹ is an alkyl group or a halogenated alkyl group having 4 or less carbon atoms,
X is halogen, h and k are each 0 to
It is an integer of 5 and h+k≦5. Preferably, monohalogenated phenol or trihalogenated phenol is used, and the halogen is bromine or chlorine. Furthermore, phenols that do not contain halogen can also be used. Others: cresol,
Xylenol, halogenated alkyl-substituted phenols, their nuclear halides, etc. can be used. In addition, not only one type of the above phenols but also two types of phenols are used.
More than one type can be used in combination. Diphenols ()

It is a compound represented by the formula: R ² is an alkyl group or a halogenated alkyl group having 4 or less carbon atoms, Z is a halogen, and s, t, p, and q are each integers of 0 to 4, and s+t≦4 and p+q≦4. Y is an alkylene group having 5 or less carbon atoms or a halogenated alkylene group, -SO ₂ -, -SO-, -S-, -O-, -
CO- or none (i.e. aromatic nucleus directly bonded)
It is. Preferably,

[Formula] Y: Alkylene group having 1 to 3 carbon atoms or halogenated alkylene group -SO ₂ -, -
O-Z: Br or Cl p, q: an integer from 0 to 2. Particularly preferred are bisphenol A, bisphenol S, 4,4 ¹ -dihydroxydiphenylmethane, and their tetrabromides or tetrachlorides. others

[Formula] and diphenols such as the tetrahalide in which Y is a halogenated alkylene group,

[Formula] and various diphenols such as diphenols having an alkyl group in the aromatic nucleus such as the tetrahalide thereof can be used. Moreover, the above-mentioned diphenols can of course be used alone or in combination of two or more types. The higher the halogen content of the S-triazine compound used as a flame retardant, the better. Therefore, it is preferable that at least one of the phenols and diphenols contains a halogen (X or Z), and in particular, the number of halogens k + p + q is 3 or more. It is preferable that there be. The compound obtained by reacting the above three raw materials is a compound obtained by condensing a trifunctional compound, a bifunctional compound, and a monofunctional compound, so it has a complex structure, and especially as the proportion of diphenols increases. It has a high molecular weight. The reaction ratio is 1 mole of cyanuric chloride to phenols (3-
2a) mol, diphenols a mol (0.5<a<
1.2), and as a increases, the molecular weight becomes higher. Moreover, according to the present invention, the S-triazine compound () can be prepared by selecting the organic solvent used.
It can be produced relatively easily even when it contains a high molecular weight substance, and the obtained product can be easily dispersed in a synthetic resin etc. when used as a flame retardant. In other words, by using a solvent in the reaction that does not easily dissolve the high molecular weight S-triazine compound (), or by replacing the non-solvent after the reaction, the S-triazine compound () will not dissolve in organic solvents and water. It is obtained in the form of a suspension of fine solids. Since it is in a suspension state, it is easy to handle without solidifying or becoming viscous in the equipment during work. The S-triazine compound () obtained in this manner is extremely easy to crush and easily becomes a fine powder and is well dispersed in a synthetic resin. Therefore, according to the production method of the present invention, S-triazine compounds represented by the general formula () having extremely large molecular weights can be substantially produced. Also,
When a<0.5, a mixture of an S-triazine compound in which three phenol () residues are bonded to the S-triazine ring and a compound having two or more S-triazine rings is produced, but this mixture is effective as a flame retardant. However, the bleed resistance and weather resistance are poor. In addition, when a>1.2, a high molecular weight compound can be obtained, but as a flame retardant, it has poor dispersibility in synthetic resins and moldability, and the formed molded product has poor impact resistance.
Bleed resistance becomes low. The S-triazine compound (2), which is the main product of the present invention, is often a mixture containing complex compounds, especially those with high molecular weights, which include not only linear compounds but also branched compounds. There are also compounds that are difficult to express in a general formula, but they are thought to have a structure roughly as shown below.

[Formula] R: OH, R ³ , R ⁴ or R ⁵ However, at least one is not OH. ^R3 :

[Formula] R ¹ , X, h, and k are the same as for phenols (). ^R4 :

[Formula] R ² , Z, Y, s, t, p, and q are the same as for diphenols (). ^R5 :

[Formula] R ⁶ :OH, R ³ , R ⁴ or R ⁵ R ² , Z, Y, s,
t, p, q are the same as diphenols (). Therefore, at least one of R in the above general formula is R ⁵
and at least one of R ⁶ is R ⁵ ,
This S-triazine compound () has an infinite molecular weight. However, like general polycondensation polymers, the molecular weight does not become infinite. In addition, OH in S-triazine compounds ()
The number of hydroxyl groups per molecule is preferably 0.5 or less, that is, the number of molecules having one or more hydroxyl groups is preferably less than half of the S-triazine compound (). In particular, it is preferable that the number of OH groups directly bonded to the S-triazine ring be as small as possible. The alkali in the present invention is not particularly limited. For example, sodium hydroxide,
Various alkalis such as alkali metal hydroxides such as potassium hydroxide, basic salts thereof, alkaline earth metal hydroxides, tertiary amines, and pyridine can be used.
In particular, their aqueous solutions are convenient to handle;
This aqueous solution can also be used as water being a component of the solvent. Although various methods can be used for the operation, a few preferred methods include first dissolving the raw material phenols (2), diphenols (2), and cyanuric chloride in a solvent. It is preferable that the solvent at this time be only an organic solvent in order to suppress the reaction between cyanuric chloride and water. When using a heterogeneous water-organic solvent, it is preferable to dissolve at a low temperature. Also preferred is a method in which cyanuric chloride is separately dissolved in an organic solvent and this is added later. The point at which the catalyst and alkali are added is not particularly limited, but the catalyst may be added from the beginning. The addition of an alkali, especially an aqueous solution thereof, is important in the mixed solvent format and in order to initiate the reaction. The reaction hardly progresses until an alkali is added, so when all other raw materials are dissolved using only an organic solvent and an aqueous alkali solution is added to start the reaction, a heterogeneous mixed solvent system of water and organic solvent is formed. be done. Therefore, in the present invention, a heterogeneous mixed solvent system means a system after the alkali is added.
Of course, water may be present in the solvent before the alkali is added, but it is preferable to prevent this water from reacting with the cyanuric chloride as described above.
Although the reaction temperature at the time the reaction starts is not particularly limited, the reaction is faster if the reaction is carried out at room temperature or under heating. After the reaction is completed, the organic solvent is removed by distillation or the like, and the product precipitates, which is filtered off and washed and purified. In addition, the product can be separated by various methods such as adding a precipitation solvent. As another method, diphenols (2) and cyanuric chloride can be first reacted in the presence of an alkali, and then the phenols (2) can be added and the reaction can be carried out again in the presence of an alkali. In this method, it is easy to control the reaction conditions to obtain the desired S-triazine compound with a certain structure, and it is possible to obtain a compound with a relatively narrow molecular weight distribution. Alternatively, the reaction can be carried out by dissolving cyanuric chloride and a catalyst in an organic solvent, and adding thereto simultaneously or sequentially diphenols () and phenols () that have been previously dissolved in water by reacting with an alkali. You can also do it. In this case as well, the method and time of addition of the catalyst and the diphenols () and phenols () which have been previously dissolved in water by reacting with an alkali are not particularly limited, but it is preferable to add the catalyst from the beginning. The reaction is initiated by the addition of either diphenols () or phenols (), which have been previously dissolved in water by reacting with an alkali, and once initiated, a heterogeneous mixed solvent system of water and organic solvent is formed. Ru. Therefore, the term "heterogeneous mixed solvent system" in the present invention also refers to the time after the addition of either diphenols () or phenols () which have been dissolved in water by reacting with an alkali in advance. Other operations in the present invention include phenols ()
By changing the combination of the ratio and method of substantially dissolving and diphenols () in an organic solvent and using them in the reaction, and the ratio and method of reacting them with an alkali in advance and using them as a substantially aqueous solution in the reaction, it is also possible to dissolve the solvent. Various operations become possible by addition, but are not limited to these. Furthermore, in the present invention, it is also possible to add and use various commonly used additives, ie, surfactants such as PH regulators, reducing agents, stabilizers, and antifoaming agents. The S-triazine compound obtained by the present invention is useful as a flame retardant for synthetic resins, synthetic fibers, paper, wood, natural fibers, and the like. This flame retardant has higher thermal stability than various conventional flame retardants, and is particularly excellent as a flame retardant for synthetic resins. EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. Example 1 Triethylbenzylammonium chloride
0.1g (0.00045mol), 10.88g (0.02mol) of tetrabromobisphenol A (hereinafter referred to as TBA),
Tribromophenol (hereinafter referred to as TBP) 16.54g
(0.05 mol), NaOH3.60g (0.09 mol) and water
Place 100 g into a 200 ml four-necked glass flask equipped with a reflux device, thermometer, and stirrer. After stirring at 25° C. to dissolve almost uniformly, a solution of 5.53 g (0.03 mol) of cyanuric chloride dissolved in 80 g of methylene chloride is added while stirring. Thereafter, the solution is maintained at a reflux temperature of 40° C. for 2 hours while stirring. Thereafter, the methylene chloride was distilled off, and the resulting mixture of solid and aqueous solution was taken out and pulverized in the usual manner, followed by 1.0 g (0.025 mol) of NAOH.
was added to dissolve unreacted substances in the aqueous solution, and then filtered, and the resulting precipitate was mixed with 100 g of water and 0.1N hydrochloric acid solution.
It was washed sequentially with 100 g and 500 g of water. After drying, 28.10 g of white powder was obtained as a product.
The bromine content of this product was 60.13%. Also,
The number average molecular weight of this product measured by vapor pressure method in tetrahydrofuran (TFH) solution is 5100.
It was hot. Next, as a result of neutralization titration using KOH ethanol solution and indicator phenolphthalein, 1
The average acidic group per molecule was found to be 0.12. Furthermore, in order to measure the thermal decomposition onset temperature of this material, a thermogravimetric analyzer (TG manufactured by Rigaku Denki Co., Ltd.) was used.
Measurements were carried out using a DSC (standard type) at a heating rate of 10°C/min under air flow, and the thermal decomposition onset temperature was 310°C. Example 2 Triethylbenzylammonium chloride
0.1g (0.00045 mol), cyanuric chloride 5.53g (0.03
mol) in 80 g of methylene chloride and place the solution in a 200 ml four-necked glass flask equipped with a reflux, thermometer, and stirrer. Add 10.88 g of TBA to 50 g of water in advance while stirring at 25℃.
(0.02 mol) with NaOH1.62g (0.0405 mol)
Add a solution of 0.05g of NaHSO ₃ and keep the solution at 25℃ for 1 hour while stirring.After that, add 50g of water to TBP16.54 with stirring.
g (0.05 mol) and NaOH2.02 g (0.0505 mol)
A solution containing the above is added and kept at 25°C for 1 hour while stirring, and then kept at a reflux temperature of 40°C for 3 hours. Thereafter, methylene chloride was distilled off, the resulting mixture of solid and aqueous solution was taken out, pulverized in the usual manner, 1.0 g (0.025 mol) of NaOH was added, unreacted substances were dissolved in the aqueous solution, and then filtered. The precipitate obtained was mixed with 100g of water and 0.1N hydrochloric acid.
It was washed with 100g of water, 500g of water, and 50g of methanol in this order. After drying, 27.96 g of white powder was obtained as a product. The bromine content of this product was 60.22%.
The number average molecular weight was 3010, the average acidic group per molecule was 0.37, and the thermal decomposition initiation temperature was 301°C. Example 3 Triethylbenzolammonium chloride
0.1g (0.00045mol), TBA16.32g (0.03mol),
TBP9.92g (0.03mol), cyanuric chloride 5.53g
Methylene chloride 150 dehydrated with (0.03 mol)
Pour into a 300 ml four-necked glass flask equipped with a reflux, thermometer, stirrer, and dropping funnel. Thereafter, 39.6 g (0.099 mol) of a 10 wt% NaOH aqueous solution was gradually added dropwise while stirring while keeping the temperature below 30°C. Thereafter, the temperature was increased at a rate of 20° C./hour, and once reflux started, the temperature was maintained for 3 hours. Then 1.0g (0.025mol) of NaOH and 100g of water
was added and methylene chloride was distilled off. The resulting mixture of solid and aqueous solution is taken out, pulverized in the usual way, filtered, and the resulting precipitate is poured into water.
100g of hydrochloric acid (0.1N), 100g of water, and 100g of methanol. After that, it was dried to obtain 28.13 g of white powder as a product. The bromine content of this stuff is 58.26
It was %. Example 4 TBP16.54g (0.05mol), Tetrabromobisphenol S11.32g (0.02mol), NaOH3.96g
(0.099 mol), 0.05 g of NaHSO ₃ , and 100 g of water were placed in a 300 ml four-necked glass flask equipped with a reflux device, thermometer, and stirrer, and after stirring to dissolve almost uniformly, chloride was added while stirring. Cyanuric 5.53g
(0.03 mol) and 0.40 g (0.0009 mol) of methyltricaptylammonium chloride dissolved in 100 g of O-dichlorobenzene are added while maintaining the temperature below 30°C. Thereafter, while stirring the solution, the temperature is increased at a rate of 20° C./hour and maintained at reflux temperature for 5 hours. Then NaOH1.0g (0.025mol)
was added, and O-dichlorobenzene was distilled off while blowing in steam. The resulting mixture of aqueous solution and solid is taken out, pulverized and filtered in the usual manner, and the resulting precipitate is mixed with 100 g of water and 0.1N hydrochloric acid.
100 g, water 500 g, and methanol 100 g. After drying, 28.29 g of white powder was obtained as a product. The bromine content of this product was 63.75%.
The number average molecular weight was 2930, the average number of acidic groups per molecule was 0.34, and the thermal decomposition initiation temperature was 308°C.

Claims (1)

[Scope of Claims] 1. Cyanuric chloride, and phenols (3-
2a) In a method for producing an S-triazine compound represented by the following () by treating a mole of diphenols represented by the following () with alkali of 3 equivalents or more (0.5 < a1.2): A method for producing an S-triazine compound, characterized in that the solvent used is a heterogeneous mixed solvent of water and an organic solvent, and a phase transfer catalyst is used as the catalyst. R ¹ : Alkyl group or halogenated alkyl group having 4 or less carbon atoms X : Halogen h, K : Each integer from 0 to 5, h+k≦5 R ² : Alkyl group or halogenated alkyl group having 4 or less carbon atoms Z : Halogen Y : Alkylene group or halogenated alkylene group having 5 or less carbon atoms, -SO ₂ -, -
SO-, -S-, -O-, -CO-, or none (i.e., aromatic nuclei are directly bonded) a, t, p, q: each an integer from 0 to 4, s+p≦
4, t+q≦4 However, the total number of halogens bonded to the aromatic nucleus of phenols () and diphenols () (i.e. k
+p+q) is 3 or more R: OH, ^R3 , ^R4 or ^R5 . However, at least one is not OH. R ¹ , X, h, k are the same as () R ² , Z, Y, s, t, p, q are the same as () R ⁶ :OH, R ³ , R ⁴ or R ⁵ R ² , Z, Y, s, t, p, q are the same as in () 2 A patent claim characterized in that the organic solvent is a halogenated hydrocarbon A method for producing an S-triazine compound in scope 1. 3. The method for producing an S-triazine compound according to claim 1, wherein the phase transfer catalyst is a quaternary ammonium salt or a quaternary phosphonium salt capable of phase transfer. 4 S- of claim 1, wherein the phenol () is [Formula] X: Br or Cl, K: an integer from 0 to 3.
Method for producing triazine compounds. 5 Diphenols () Z: Br or Cl Y: Alkylene group having 1 to 3 carbon atoms or halogenated alkylene group, -SO ₂ or -O
- S- of Claim 1, characterized in that p, q: each is an integer of 0 to 2.
Method for producing triazine compounds. 6. The S-triazine compound according to claim 1, characterized in that the S-triazine compound (2) has an S-triazine compound (2) having 2 to 10 S-triazine rings as a main component. Manufacturing method. 7 Acidity in S-triazine compounds ()
The method for producing an S-triazine compound according to claim 1, characterized in that the number of OH groups per molecule is 1/2 or less.