Method for preparing chlorophosphazene intermediate mixture solution, and method for preparing phenoxyphosphazene mixture flame retardant

Abstract

The present invention provides a method for preparing a chlorophosphazene intermediate mixture solution and a method for preparing a phenoxyphosphazene mixture flame retardant, belonging to the field of organic synthesis. The present invention reduces the cyclization reaction time and the proportion of by-products by controlling the dropwise addition speed, the cyclization reaction temperature during the dropwise addition, and the cyclization reaction temperature after the dropwise addition. An acid-binding agent can react with the acid generated during the synthesis process, accelerating the reaction rate, further reducing the cyclization reaction time and reducing the proportion of by-products. In addition, the present invention mixes phosphorus pentachloride with other preparation raw materials and then dropwise adds a chlorobenzene solution of phosphorus pentachloride to the resulting mixture. The phosphorus pentachloride is added in two steps, which is beneficial to promoting the catalytic efficiency of the metal chloride, further reducing the cyclization reaction time and reducing the proportion of by-products.

Description

Technical Field

[0001] The present invention relates to the field of organic synthesis, and in particular to a method for preparing a chlorophosphazene intermediate mixture solution and a method for preparing a phenoxyphosphazene mixture flame retardant. Background Art

[0002] Phosphazene flame retardants are a class of compounds with P and N elements arranged alternately as the basic skeleton. The special P / N hybrid structure and rich phosphorus and nitrogen flame retardant elements give them good thermal stability and flame retardancy.

[0003] Phenoxyphosphazene is the most basic phosphazene compound, obtained by attaching a phenoxy group to the phosphorus atom. The introduction of the phenoxy group makes it a product combining inorganic and organic elements. It has excellent flame retardancy, water resistance, thermal stability, and mechanical stability. It is widely used in products such as flexible copper foil substrate (FCCL), copper clad laminate (CCL), electronic and electrical insulation adhesives, tinned flat copper wire (FFC), and high-temperature resistant powder coatings (epoxy and polyester).

[0004] The existing method for preparing phenoxyphosphazene primarily involves synthesizing a chlorophosphazene intermediate, which is then reacted with sodium phenolate via a nucleophilic substitution reaction. The chlorophosphazene intermediate is primarily synthesized using phosphorus pentachloride and ammonium chloride in the presence of a catalyst. This reaction takes a long time, and the byproduct, pentamers and higher, of chlorophosphazenes, accounts for a significant proportion (over 15%). The target products, hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene, linear phosphazenes, and dodecachlorocyclohexaphosphazene, account for a relatively small proportion. Summary of the Invention

[0005] The present invention aims to provide a method for preparing a chlorophosphazene intermediate mixture solution and a method for preparing a phenoxyphosphazene mixture flame retardant. The chlorophosphazene intermediate mixture solution prepared by the present invention contains few by-products.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a chlorophosphazene intermediate mixture solution, comprising the following steps:

[0008] After mixing phosphorus pentachloride, chlorobenzene, ammonium chloride, a metal chloride salt and an acid binding agent, a chlorobenzene solution of phosphorus pentachloride is added dropwise to the resulting mixture to carry out a cyclization reaction, thereby obtaining a chlorophosphazene intermediate mixture solution;

[0009] The dropping speed is 0.05 to 0.15 L / h, the cyclization reaction includes the cyclization reaction during the dropping process and after the dropping is completed, and the temperature of the cyclization reaction during the dropping process is 120 to 126° C.;

[0010] The cyclization reaction temperature after the dropwise addition is 130-132°C and the time is 3-4 hours;

[0011] The chlorophosphazene intermediate mixture includes: hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene and chlorocyclophosphazenes with pentamers or higher;

[0012] The mass proportion of chlorocyclic phosphazenes with pentamers or higher in the chlorophosphazene intermediate mixture is no more than 15%.

[0013] Preferably, the metal chloride salt includes two or more of zinc chloride, magnesium chloride, ferrous chloride, ferric chloride, cupric chloride and nickel chloride.

[0014] Preferably, the metal chloride salt is 15-20% of the total mass of phosphorus pentachloride and the phosphorus pentachloride in the chlorobenzene solution of phosphorus pentachloride.

[0015] Preferably, the acid binding agent comprises an amine compound.

[0016] Preferably, the amine compound includes one or more of triethylamine, diisopropylethylamine and pyridine.

[0017] Preferably, the acid binding agent is 8-10% of the total mass of phosphorus pentachloride and the phosphorus pentachloride in the chlorobenzene solution of phosphorus pentachloride.

[0018] The present invention also provides a method for preparing a phenoxyphosphazene mixture flame retardant, comprising the following steps:

[0019] A chlorobenzene solution containing potassium phenoxide and sodium phenoxide, a liquid organic amine catalyst and a chlorophosphazene intermediate mixture solution prepared by the preparation method described in the above scheme are mixed to carry out a nucleophilic substitution reaction to obtain a phenoxyphosphazene mixture flame retardant.

[0020] Preferably, the preparation method of the chlorobenzene solution containing potassium phenoxide and sodium phenoxide comprises the following steps:

[0021] Chlorobenzene, sodium hydroxide, potassium hydroxide and molten phenol are mixed to carry out a substitution reaction to obtain the chlorobenzene solution containing potassium phenoxide and sodium phenoxide.

[0022] Preferably, the liquid organic amine catalyst includes one or more of tetrabutylammonium bromide, di-n-butylamine and tetraethylammonium bromide.

[0023] Preferably, the mass ratio of the liquid organic amine catalyst to the molten phenol is 0.01 to 0.02:1.

[0024] The invention provides a preparation method of a chlorophosphazene intermediate mixture solution. The method comprises the following steps: mixing phosphorus pentachloride, chlorobenzene, ammonium chloride, a metal chloride and an acid binding agent, and then dropwise adding a chlorobenzene solution of phosphorus pentachloride into the obtained mixture for a cyclization reaction to obtain a chlorophosphazene intermediate mixture solution; the dropping speed is 0.05-0.15 L / h; the cyclization reaction includes cyclization reactions during the dropping process and after the dropping process is completed; the temperature of the cyclization reaction during the dropping process is 120-126° C.; the temperature of the cyclization reaction after the dropping process is 130-132° C., and the reaction time is 3-4 hours; the chlorophosphazene intermediate mixture comprises hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene and chlorocyclophosphazenes with pentamers or higher; and the mass proportion of chlorocyclophosphazenes with pentamers or higher in the chlorophosphazene intermediate mixture is no more than 15%. The present invention reduces the cyclization reaction time and reduces the proportion of by-products by controlling the dropwise addition speed, the cyclization reaction temperature during the dropwise addition, and the cyclization reaction temperature after the dropwise addition. The acid-binding agent can react with the acid generated in the synthesis process, accelerate the reaction rate, further reduce the cyclization reaction time, and reduce the proportion of by-products. In addition, the present invention mixes phosphorus pentachloride with other preparation raw materials and then dropwise adds a chlorobenzene solution of phosphorus pentachloride to the obtained mixture. The phosphorus pentachloride is added in two steps, which is beneficial to promoting the catalytic efficiency of the metal chloride, further reducing the cyclization reaction time, and reducing the proportion of by-products.

[0025] The prior art method JP2015108854 takes a long time to synthesize phenoxyphosphazene, taking 15 hours. Furthermore, the process involves multiple alkali washes during post-processing, which generates a large amount of wastewater and increases production costs. The present invention, however, accelerates the synthesis of phenoxyphosphazene by introducing a liquid organic amine catalyst, eliminating the multiple alkali washes required in the conventional process, reducing production costs and alleviating environmental concerns.

[0026] According to the present invention, the obtained chlorophosphazene intermediate mixture solution is directly reacted with sodium phenolate, thereby reducing the separation process of the chlorophosphazene intermediate mixture solution, simplifying the process flow, and avoiding waste of resources. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a chlorophosphazene intermediate mixture solution, comprising the following steps:

[0028] After mixing phosphorus pentachloride, chlorobenzene, ammonium chloride, a metal chloride salt and an acid binding agent, a chlorobenzene solution of phosphorus pentachloride is added dropwise to the resulting mixture to carry out a cyclization reaction, thereby obtaining a chlorophosphazene intermediate mixture solution;

[0029] The dropping speed is 0.05 to 0.15 L / h, the cyclization reaction includes the cyclization reaction during the dropping process and after the dropping is completed, and the temperature of the cyclization reaction during the dropping process is 120 to 126° C.;

[0030] The cyclization reaction temperature after the dropwise addition is 130-132°C and the time is 3-4 hours;

[0031] The chlorophosphazene intermediate mixture includes: hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene and chlorocyclophosphazenes with pentamers or higher;

[0032] The mass proportion of chlorocyclic phosphazenes with pentamers or higher in the chlorophosphazene intermediate mixture is no more than 15%.

[0033] In the present invention, the acid binding agent preferably includes a liquid acid binding agent.

[0034] In the present invention, the mixing preferably comprises dissolving phosphorus pentachloride in a portion of chlorobenzene, mixing the resulting solution with the remaining chlorobenzene, ammonium chloride, and a metal chloride salt, and then adding an acid-binding agent dropwise to the resulting mixture. Phosphorus pentachloride is highly hygroscopic, and dissolving it in a portion of chlorobenzene first can ensure its purity and prevent a violent reaction.

[0035] In the present invention, the mass ratio of the partial chlorobenzene to the remaining chlorobenzene is preferably 2 to 3:1.

[0036] In the present invention, the dissolution temperature is preferably 85-90° C., the dissolution is preferably carried out under stirring, and the dissolution is preferably carried out under nitrogen protection.

[0037] In the present invention, the mixing temperature is preferably 90-100° C., the mixing is preferably performed under stirring, and the dissolving is preferably performed under nitrogen protection.

[0038] In the present invention, when the acid binding agent is added dropwise to the obtained mixture, the dropping rate is preferably 9.5 to 15 mL / min, the temperature is preferably 120 to 126° C., and the holding time after the dropping is preferably 0.5 to 1 h.

[0039] In the present invention, the mass ratio of chlorobenzene to phosphorus pentachloride is preferably 3 to 4:1.

[0040] In the present invention, the mass ratio of phosphorus pentachloride to chlorobenzene in the chlorobenzene solution of phosphorus pentachloride is preferably 1:1 to 2, more preferably 1:1.6 to 1.8.

[0041] In the present invention, the mass ratio of the phosphorus pentachloride to the phosphorus pentachloride in the chlorobenzene solution is preferably 7:3.

[0042] In the present invention, the ratio of the amount of ammonium chloride to the total amount of phosphorus pentachloride and the phosphorus pentachloride in the chlorobenzene solution of phosphorus pentachloride is preferably 1.14 to 1.2:1.

[0043] In the present invention, the metal chloride salt is 15-20% of the total mass of phosphorus pentachloride and the phosphorus pentachloride in the chlorobenzene solution of phosphorus pentachloride; the metal chloride salt preferably includes two or more of zinc chloride, magnesium chloride, ferrous chloride, ferric chloride, cupric chloride and nickel chloride.

[0044] In the present invention, the acid binding agent is preferably 80-90% of the total mass of phosphorus pentachloride and the phosphorus pentachloride chlorobenzene solution; the acid binding agent preferably includes an amine compound; the amine compound preferably includes one or more of triethylamine, diisopropylethylamine and pyridine.

[0045] In the present invention, the dropping speed is 0.05 to 0.15 L / h, preferably 0.06 to 0.12 L / h, more preferably 0.08 to 0.1 L / h; the cyclization reaction includes the cyclization reaction during the dropping process and after the dropping process is completed, and the temperature of the cyclization reaction during the dropping process is preferably 120 to 126° C., more preferably 124 to 125° C.;

[0046] The temperature of the cyclization reaction after the dropwise addition is 130-132° C., and the time is 3-4 hours.

[0047] After the cyclization reaction, the present invention preferably cools and filters the product obtained by the cyclization reaction to obtain a first filtrate; washes the first filtrate with water and separates the phases to obtain a first organic phase; washes the first organic phase with alkali and separates the phases to obtain a second organic phase; mixes the second organic phase with a decolorizing agent, decolorizes the phases, and then filters the phases to obtain a second filtrate; and desolventizes the second filtrate to obtain the chlorophosphazene intermediate mixture solution.

[0048] In the present invention, the product obtained by the cyclization reaction is cooled and filtered to obtain a first filtrate.

[0049] In the present invention, the temperature of the product obtained by the cyclization reaction after cooling is preferably 30 to 40°C.

[0050] After obtaining the first filtrate, the present invention washes the first filtrate with water and separates the phases to obtain a first organic phase.

[0051] In the present invention, the amount of water used for washing is preferably 1 to 1.5 times the total mass of phosphorus pentachloride and the phosphorus pentachloride in the chlorobenzene solution of phosphorus pentachloride, the temperature is preferably 60 to 70° C., and the time is preferably 0.5 to 1 h.

[0052] In the present invention, the phase separation method preferably includes static separation.

[0053] After obtaining the first organic phase, the present invention performs alkali washing on the first organic phase and performs phase separation to obtain the second organic phase.

[0054] In the present invention, the alkali solution used for alkali washing preferably includes a sodium carbonate solution. The amount of the sodium carbonate solution is preferably 1 to 1.5 times the total mass of phosphorus pentachloride and the phosphorus pentachloride chlorobenzene solution. The concentration of the sodium carbonate solution is preferably 1 to 5%, more preferably 2 to 4%. The temperature of the alkali washing is preferably 60 to 70°C, and the time is preferably 0.5 to 1 hour.

[0055] After obtaining the second organic phase, the present invention mixes the second organic phase with a decolorizing agent to decolorize the phase and then filters the phase to obtain a second filtrate.

[0056] In the present invention, the decolorizing agent preferably includes one or two of activated clay, diatomaceous earth and activated carbon; the amount of the decolorizing agent used is 1 to 5 wt %, more preferably 2 to 4 wt % of the second organic phase.

[0057] In the present invention, the dehydration temperature is preferably 70-80° C., and the dehydration time is preferably 1-2 hours.

[0058] After obtaining the second filtrate, the present invention desolventizes the second filtrate.

[0059] In the present invention, the desolventizing temperature is preferably 80-90°C, and the pressure is preferably 5-10 kPa. The desolventizing time is not particularly limited in the present invention; a method familiar to those skilled in the art can be used to remove half of the chlorobenzene in the second filtrate. Removing chlorobenzene can improve the utilization rate of the reactor.

[0060] In the present invention, the chlorophosphazene intermediate mixture includes: hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene and chlorocyclophosphazenes with pentamers or higher;

[0061] The mass proportion of chlorocyclic phosphazenes with pentamers or higher in the chlorophosphazene intermediate mixture is no more than 15%.

[0062] The present invention also provides a method for preparing a phenoxyphosphazene mixture flame retardant, comprising the following steps:

[0063] A chlorobenzene solution containing potassium phenoxide and sodium phenoxide, a liquid organic amine catalyst and a chlorophosphazene intermediate mixture solution prepared by the preparation method described in the above scheme are mixed to carry out a nucleophilic substitution reaction to obtain a phenoxyphosphazene mixture flame retardant.

[0064] In the present invention, the preparation method of the chlorobenzene solution containing potassium phenoxide and sodium phenoxide preferably comprises the following steps:

[0065] Chlorobenzene, sodium hydroxide, potassium hydroxide and molten phenol are mixed to carry out a substitution reaction to obtain the chlorobenzene solution containing potassium phenoxide and sodium phenoxide.

[0066] In the present invention, the mixing is preferably carried out under nitrogen protection; the mixing temperature is preferably 60-70° C., and the holding time is preferably 2-3 h.

[0067] In the present invention, the mass ratio of the phenol to the chlorobenzene is preferably 4 to 5:1, and the ratio of the amount of the phenol to the amount of the chlorophosphazene intermediate in the chlorophosphazene intermediate mixture solution is preferably 2 to 2.05:1;

[0068] The total mass of the sodium hydroxide and potassium hydroxide is preferably 0.4 to 0.5 times the mass of phenol; and the mass ratio of the sodium hydroxide to potassium hydroxide is preferably 25 to 27:1.

[0069] In the present invention, the temperature of the substitution reaction is preferably 120-125°C.

[0070] The water generated by the substitution reaction is taken out of the system through azeotropy with chlorobenzene, and chlorobenzene returns to the system. When the water to be removed is close to the theoretical value (the water generated after the complete reaction of phenol is the theoretical value), 1 / 4 of the chlorobenzene is removed.

[0071] In the present invention, when a chlorobenzene solution containing potassium phenoxide and sodium phenoxide, a liquid organic amine catalyst, and a chlorophosphazene intermediate mixture solution prepared by the preparation method described in the above scheme are mixed to carry out a nucleophilic substitution reaction, the liquid organic amine catalyst is preferably first added dropwise to the chlorobenzene solution containing potassium phenoxide and sodium phenoxide, and the chlorophosphazene intermediate mixture solution is then secondly added dropwise to the obtained mixture to carry out the nucleophilic substitution reaction.

[0072] In the present invention, the temperature of the first dropwise addition is preferably 125-130°C, the time is preferably 0.5-1h, the speed of the first dropwise addition is preferably 40-50mL / h, more preferably 42-45mL / h; the temperature of the second dropwise addition is preferably 125-130°C, the speed of the second dropwise addition is preferably 0.5-1L / h, more preferably 0.6-0.8L / h.

[0073] After the second addition, the mixture is preferably heated to a temperature of 130-132° C., and the temperature is preferably kept at this temperature for 10-12 hours. The nucleophilic substitution reaction has already occurred during the second addition, and heating after the second addition can increase the speed of the nucleophilic substitution reaction.

[0074] In the present invention, the mass ratio of the liquid organic amine catalyst to phenol is preferably 0.01 to 0.02:1; the liquid organic amine catalyst preferably includes one or more of tetrabutylammonium bromide, di-n-butylamine and tetraethylammonium bromide.

[0075] After the reaction, the present invention preferably washes the reaction product with water and separates the phases to obtain a third organic phase; washes the third organic phase with alkali and separates the phases to obtain a fourth organic phase; mixes the fourth organic phase with a decolorizer and an acid scavenger to decolorize and remove acid, and then filters to obtain a third filtrate; and desolventizes the third filtrate to obtain the above.

[0076] The present invention washes the product obtained by the reaction with water, and separates the phases to obtain a third organic phase.

[0077] In the present invention, the amount of water used for washing is preferably 30-40 wt% of the total mass of the mixture solution of chlorobenzene, sodium hydroxide, potassium hydroxide, molten phenol and chlorophosphazene intermediate, the temperature is preferably 70-80° C., and the time is preferably 1-2 h.

[0078] In the present invention, the phase separation method preferably includes static separation.

[0079] After obtaining the first organic phase, the present invention performs alkali washing on the third organic phase and performs phase separation to obtain a fourth organic phase.

[0080] In the present invention, the alkali solution used for alkali washing preferably includes sodium hydroxide solution, and the amount of the sodium hydroxide solution is preferably 30-40wt% of the total mass of the mixture solution of chlorobenzene, sodium hydroxide, potassium hydroxide, molten phenol and chlorophosphazene intermediate. The concentration of the sodium hydroxide solution is preferably 5-10%, more preferably 6-8%; the temperature of the alkali washing is preferably 70-80°C, and the time is preferably 0.5-1h.

[0081] After obtaining the fourth organic phase, the present invention mixes the fourth organic phase with a decolorant and an acid scavenger to perform decolorization and deacidification, and then filters the mixture to obtain a third filtrate.

[0082] In the present invention, the decolorizing agent preferably includes one or two of activated clay, diatomaceous earth and activated carbon; the amount of the decolorizing agent used is 2 to 5 wt % of the fourth organic phase.

[0083] In the present invention, the acid scavenger is preferably hydrotalcite; the amount of the acid scavenger is 1 to 2 wt % of the fourth organic phase.

[0084] In the present invention, the temperature for decolorization and deacidification is preferably 70-80° C., and the time is preferably 2-3 hours.

[0085] After obtaining the third filtrate, the present invention desolventizes the third filtrate.

[0086] In the present invention, the desolventizing preferably includes a first desolventizing and a second desolventizing; the temperature of the first desolventizing is preferably 70 to 90° C., and the pressure is preferably 5 to 10 kPa. The first desolventizing can recover most of the chlorobenzene.

[0087] The temperature of the second desolventization is preferably 120-150° C., more preferably 130-140° C., and the pressure is preferably 0.5 kPa. The second desolventization can remove residual chlorobenzene.

[0088] In the present invention, the phenoxyphosphazene mixture flame retardant preferably comprises, by mass fraction, 80-86% of hexaphenoxy cyclotriphosphazene, 2-3% of octaphenoxy cyclotetraphosphazene, 6-7% of decaphenoxy cyclopentaphosphazene, and 5-11% of phenoxyphosphazene with pentamers or higher.

[0089] The following describes in detail the preparation method of the chlorophosphazene intermediate mixture solution and the preparation method of the phenoxyphosphazene mixture flame retardant provided by the present invention in conjunction with the examples, but they should not be construed as limiting the scope of protection of the present invention.

[0090] Example 1

[0091] (1) Chlorophosphazene intermediate mixture solution

[0092] Under nitrogen protection, dissolve 1 kg of phosphorus pentachloride in 2 kg of chlorobenzene at 90°C and keep warm for later use.

[0093] Add 1 kg of chlorobenzene to a reactor, followed by 295.4 g of ammonium chloride, 155 g of zinc chloride, and ferric chloride (the mass ratio of zinc chloride to ferric chloride is 1.07:1.00). Nitrogen is introduced, and the temperature is raised to 95°C with stirring. 2.1 kg of phosphorus pentachloride chlorobenzene solution is then added dropwise, followed by 815 g of pyridine. Add the remaining phosphorus pentachloride chlorobenzene solution dropwise at 126°C over 8 hours, raise the temperature to 132°C, and hold for 4 hours. After the reaction is complete, cool the mixture to 40°C and filter. Wash the filtrate with 1000 mL of pure water for 1 hour at 60°C, then allow the mixture to stand and separate the aqueous layer. Wash the organic phase with 1000 mL of 5% sodium carbonate solution for 0.5 hour, then perform an alkaline wash at 60°C, and allow the aqueous layer to stand. The organic phase was decolorized by adding 32.7 g of activated clay at 80° C. for 2 h, followed by suction filtration. The filtrate was decolorized at 80° C. under a reduced pressure of 10 kPa to remove half of the chlorobenzene, yielding a chlorophosphazene intermediate mixture solution (hexachlorocyclotriphosphazene: 75%, octachlorocyclotetraphosphazene: 2%, decachlorocyclopentaphosphazene: 7%, and chlorophosphazenes with pentamers or higher: 16%) (yield 80%).

[0094] (2) Phenoxyphosphazene mixture flame retardant

[0095] First, add 3.15 kg of chlorobenzene to the reactor, stir and introduce nitrogen, add 326 g of sodium hydroxide and 12.5 g of potassium hydroxide, quickly add 787.5 g of molten phenol to the reactor, slowly heat to 60 ° C, keep warm for 2 hours, and gradually heat to 124 ° C. The water generated by the reaction is taken out of the system through azeotropy with chlorobenzene, and chlorobenzene returns to the system. When the water to be removed is close to the theoretical value, 1 / 4 of the chlorobenzene is removed.

[0096] 16.1 g of di-n-butylamine was added dropwise at 130°C for 0.5 h. After the addition was complete, 1851 mL of the chlorophosphazene intermediate mixture solution was added dropwise over 2 h at 125°C. After the addition was complete, the temperature was raised to 132°C and maintained for 12 h. After the reaction was complete, the temperature was lowered to 80°C, and the mixture was washed with pure water for 1 h. The mixture was then allowed to stand to drain. The organic phase was washed with 1481.5 mL of 10% sodium hydroxide solution at 70°C for another 0.5 h. The mixture was then allowed to stand to drain. The organic phase was washed with 1385 mL of pure water at 70°C for 1 h. The mixture was then allowed to stand to drain. 86.4 g of activated carbon and 43.2 g of hydrotalcite were added to the organic phase and decolorized at 80°C for 3 h. The mixture was then filtered. The filtrate was concentrated at 90° C. under a reduced pressure of 10 kPa to recover the solvent to obtain a crude product. The crude product was cooled and solidified at 145° C. under a reduced pressure of 0.5 kPa to remove residual chlorobenzene to obtain a yellow phenoxyphosphazene mixture flame retardant (hexaphenoxycyclotriphosphazene: 80%, octaphenoxycyclotetraphosphazene: 2%, decaphenoxycyclopentaphosphazene: 7%, phenoxyphosphazene mixture flame retardant with pentamers or above: 11%) (yield 72%).

[0097] Example 2

[0098] (1) Chlorophosphazene intermediate mixture solution

[0099] Under nitrogen protection, dissolve 1 kg of phosphorus pentachloride in 2 kg of chlorobenzene at 90°C and keep warm for later use.

[0100] Add 1 kg of chlorobenzene to a reactor, followed by 295.4 g of ammonium chloride, 155 g of magnesium chloride, and ferric chloride (magnesium chloride:ferric chloride mass ratio of 1.07:1). Purge with nitrogen, stir, and heat to 95°C. Add 2.1 kg of phosphorus pentachloride chlorobenzene solution, then dropwise add 815 g of pyridine over 1 hour. Raise the temperature to 126°C and hold for 0.5 hour. Begin adding the remaining phosphorus pentachloride chlorobenzene solution dropwise at 126°C over 8 hours. Raise the temperature to 132°C and hold for 4 hours. After the reaction is complete, cool to 40°C and filter. Wash the filtrate with 1000 mL of pure water for 1 hour at 60°C, then allow to stand and separate the aqueous layer. Wash the organic phase with 1000 mL of 5% sodium carbonate solution for 0.5 hour, then perform an alkaline wash at 60°C and allow to stand and separate the aqueous layer. The organic phase was decolorized by adding 32.7 g of activated carbon at 80° C. for 2 h, followed by suction filtration. The filtrate was decolorized at 80° C. under a reduced pressure of 10 kPa to remove half of the chlorobenzene, yielding a chlorophosphazene intermediate mixture solution (hexachlorocyclotriphosphazene: 76%, octachlorocyclotetraphosphazene: 3%, decachlorocyclopentaphosphazene: 6%, and chlorophosphazenes with pentamers or higher: 15%) (yield 85%).

[0101] (2) Phenoxyphosphazene mixture flame retardant

[0102] First, add 3.15 kg of chlorobenzene to the reactor, stir and introduce nitrogen, add 326 g of sodium hydroxide and 12.5 g of potassium hydroxide, quickly add 787.5 g of molten phenol to the reactor, slowly heat to 60 ° C, keep warm for 2 hours, and gradually heat to 125 ° C. The water generated by the reaction is taken out of the system through azeotropy with chlorobenzene, and chlorobenzene returns to the system. When the water to be removed is close to the theoretical value, 1 / 4 of the chlorobenzene is removed.

[0103] 16.1g of tetrabutylammonium bromide was added dropwise at 130°C for 0.5h. After the addition was complete, 1851mL of the chlorophosphazene intermediate mixture solution was added dropwise over 2h at 125°C. After the addition was complete, the temperature was raised to 132°C and maintained for 12h. After the reaction was complete, the temperature was lowered to 80°C, and the mixture was washed with pure water for 1h. The mixture was then allowed to stand to drain. The organic phase was washed with 1481.5mL of 10% sodium hydroxide solution at 70°C for another 0.5h. The mixture was then allowed to stand to drain. The organic phase was washed with 1385mL of pure water at 70°C for 1h. The mixture was then allowed to stand to drain. 86.4g of activated clay and 43.2g of hydrotalcite were added to the organic phase and decolorized at 80°C for 3h. The mixture was then filtered. The filtrate was concentrated at 90°C under a reduced pressure of 10 kPa to recover the solvent to obtain a crude product. The crude product was cooled and solidified at 150°C under a reduced pressure of 0.5 kPa to remove residual chlorobenzene to obtain a yellow phenoxyphosphazene mixture flame retardant (hexaphenoxycyclotriphosphazene: 81%, octaphenoxycyclotetraphosphazene: 3%, decaphenoxycyclopentaphosphazene: 6%, phenoxyphosphazene mixture flame retardant with pentamers or above: 10%) (yield 72%).

[0104] Example 3

[0105] (1) Chlorophosphazene intermediate mixture solution

[0106] Under nitrogen protection, dissolve 1 kg of phosphorus pentachloride in 2 kg of chlorobenzene at 90°C and keep warm for later use.

[0107] Add 1 kg of chlorobenzene to a reactor, followed by 295.4 g of ammonium chloride, 155 g of zinc chloride, and 155 g of magnesium chloride (1.07:1 weight ratio of zinc chloride to magnesium chloride). Nitrogen was introduced, and the mixture was stirred and heated to 95°C. 2.1 kg of phosphorus pentachloride chlorobenzene solution was then added dropwise, followed by 815 g of pyridine. The addition was continued over 1 hour, and the temperature was raised to 126°C and held for 0.5 hour. The remaining phosphorus pentachloride chlorobenzene solution was then added dropwise at 126°C, and the temperature was raised to 132°C and held for 4 hours. After the reaction was complete, the temperature was lowered to 40°C and filtered. The filtrate was washed with 1000 mL of pure water at 60°C for 1 hour, and the aqueous layer was separated. The organic phase was washed with 1000 mL of 1% sodium carbonate solution for 0.5 hour, followed by an alkaline wash at 60°C, and the aqueous layer was separated. The organic phase was decolorized by adding 32.7 g of activated clay at 80° C. for 2 h, followed by suction filtration. The filtrate was decolorized at 80° C. under a reduced pressure of 10 kPa to remove half of the chlorobenzene, yielding a 90% yield of a chlorophosphazene intermediate mixture solution (80% hexachlorocyclotriphosphazene, 3% octachlorocyclotetraphosphazene, 6% decachlorocyclopentaphosphazene, and 11% pentamers or higher).

[0108] (2) Phenoxyphosphazene mixture flame retardant

[0109] First, add 3.34 kg of chlorobenzene to the reactor, stir and introduce nitrogen, add 345.2 g of sodium hydroxide and 13.3 g of potassium hydroxide, quickly add 833.8 g of molten phenol to the reactor, slowly heat to 60 ° C, keep warm for 3 hours, and gradually heat to 125 ° C. The water generated by the reaction is taken out of the system through azeotropy with chlorobenzene, and chlorobenzene returns to the system. When the water to be removed is close to the theoretical value, 1 / 4 of the chlorobenzene is removed.

[0110] Add 16.1g of tetraethylammonium bromide dropwise at 130°C for 0.5h. After the addition is complete, begin adding 1851mL of the chlorophosphazene intermediate mixture dropwise over 2h at 125°C. Raise the temperature to 132°C and maintain for 12h. After the reaction is complete, cool to 80°C, wash with pure water for 1h, and allow to stand to drain. The organic phase is washed with 1481.5mL of 5% sodium hydroxide solution at 70°C for another 0.5h, then allowed to stand to drain. The organic phase is washed with 1385mL of pure water at 70°C for 1h, then allowed to stand to drain. Decolorize the organic phase with 86.4g of activated carbon and 43.2g of hydrotalcite at 80°C for 3h, then filter. The filtrate was concentrated at 90°C under a reduced pressure of 10 kPa to recover the solvent to obtain a crude product. The crude product was cooled and solidified at 150°C under a reduced pressure of 0.5 kPa to remove residual chlorobenzene to obtain a yellow phenoxyphosphazene mixture flame retardant (hexaphenoxycyclotriphosphazene: 85%, octaphenoxycyclotetraphosphazene: 3%, decaphenoxycyclopentaphosphazene: 6%, phenoxyphosphazene mixture flame retardant with pentamers or above: 6%) (yield 78%).

[0111] Example 4

[0112] (1) Chlorophosphazene intermediate mixture solution

[0113] Under nitrogen protection, dissolve 1 kg of phosphorus pentachloride in 2 kg of chlorobenzene at 90°C and keep warm for later use.

[0114] Add 1 kg of chlorobenzene to a reactor, followed by 295.4 g of ammonium chloride, 155 g of zinc chloride, and 155 g of magnesium chloride (1.2:1 weight ratio of zinc chloride to magnesium chloride). Nitrogen was introduced, and the mixture was stirred and heated to 95°C. 2.1 kg of phosphorus pentachloride chlorobenzene solution was then added dropwise, followed by 815 g of pyridine. The addition was continued over 1 hour, and the temperature was raised to 124°C and held for 0.51 hour. The remaining phosphorus pentachloride chlorobenzene solution was added dropwise at 126°C, and the temperature was completed over 10 hours. The temperature was then raised to 132°C and held for 4 hours. After the reaction was complete, the temperature was cooled to 30°C and filtered. The filtrate was washed with 1000 mL of pure water for 0.5 hour at 60°C, and the aqueous layer was separated. The organic phase was washed with 1000 mL of 1% sodium carbonate solution for 0.5 hour, followed by an alkaline wash at 60°C, and the aqueous layer was separated. The organic phase was decolorized by adding 32.7 g of activated carbon at 80° C. for 2 h, followed by suction filtration. The filtrate was decolorized at 80° C. under a reduced pressure of 10 kPa to remove half of the chlorobenzene, yielding a 90% yield of a chlorophosphazene intermediate mixture solution (81% hexachlorocyclotriphosphazene, 3% octachlorocyclotetraphosphazene, 6% decachlorocyclopentaphosphazene, and 10% pentamers or higher).

[0115] (2) Phenoxyphosphazene mixture flame retardant

[0116] First, add 3.34 kg of chlorobenzene to the reactor, stir and introduce nitrogen, add 345.2 g of sodium hydroxide and 13.3 g of potassium hydroxide, quickly add 833.8 g of molten phenol to the reactor, slowly heat to 65 ° C, keep warm for 3 hours, and gradually heat to 125 ° C. The water generated by the reaction is taken out of the system through azeotropy with chlorobenzene, and chlorobenzene returns to the system. When the water to be removed is close to the theoretical value, 1 / 4 of the chlorobenzene is removed.

[0117] 16.1g of tetrabutylammonium bromide was added dropwise at 130°C for 0.5h. After the addition was complete, 1851mL of the chlorophosphazene intermediate mixture solution was added dropwise over 2h at 125°C. After the addition was complete, the temperature was raised to 132°C and maintained for 12h. After the reaction was complete, the temperature was lowered to 80°C, and the mixture was washed with pure water for 1h. The mixture was then allowed to stand to drain. The organic phase was washed with 1481.5mL of 5% sodium hydroxide solution at 70°C for another 0.5h. The mixture was then allowed to stand to drain. The organic phase was washed with 1385mL of pure water at 70°C for 1h. The mixture was then allowed to stand to drain. 86.4g of activated clay and 43.2g of hydrotalcite were added to the organic phase and decolorized at 80°C for 3h. The mixture was then filtered. The filtrate was concentrated at 90°C under a reduced pressure of 10 kPa to recover the solvent to obtain a crude product. The crude product was cooled and solidified at 150°C under a reduced pressure of 0.5 kPa to remove residual chlorobenzene to obtain a yellow phenoxyphosphazene mixture flame retardant (hexaphenoxycyclotriphosphazene: 86%, octaphenoxycyclotetraphosphazene: 3%, decaphenoxycyclopentaphosphazene: 6%, phenoxyphosphazene mixture flame retardant with pentamers or above: 5%) (yield 79%).

[0118] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a phenoxyphosphazene mixture flame retardant, characterized in that: The following steps are involved: A chlorobenzene solution containing potassium phenoxide and sodium phenoxide, a liquid organic amine catalyst and a chlorophosphazene intermediate mixture solution are mixed to carry out a nucleophilic substitution reaction to obtain a phenoxyphosphazene mixture flame retardant; The liquid organic amine catalyst is di-n-butylamine; The method for preparing the chlorophosphazene intermediate mixture solution comprises the following steps: After mixing phosphorus pentachloride, chlorobenzene, ammonium chloride, a metal chloride salt and an acid binding agent, the chlorobenzene solution of phosphorus pentachloride is added dropwise to the resulting mixture for a cyclization reaction to obtain a chlorophosphazene intermediate mixture solution; the metal chloride salt is zinc chloride and ferric chloride; The dropping speed is 0.05 to 0.15 L / h, the cyclization reaction includes the cyclization reaction during the dropping process and after the dropping is completed, and the temperature of the cyclization reaction during the dropping process is 120 to 126° C.; The cyclization reaction temperature after the dropwise addition is 130-132°C and the time is 3-4 hours; The chlorophosphazene intermediate mixture includes: hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene and chlorocyclophosphazenes with pentamers or higher; The mass proportion of chlorocyclic phosphazenes with pentamers or higher in the chlorophosphazene intermediate mixture is no more than 15%.

2. The preparation method according to claim 1, characterized in that The metal chloride salt accounts for 15-20% of the total mass of phosphorus pentachloride and the phosphorus pentachloride in the chlorobenzene solution of phosphorus pentachloride.

3. The preparation method according to claim 1, characterized in that The acid binding agent includes an amine compound.

4. The preparation method according to claim 1, characterized in that The amine compound includes one or more of triethylamine, diisopropylethylamine and pyridine.

5. The preparation method according to claim 1 or 3, characterized in that The acid binding agent is 8-10% of the total mass of phosphorus pentachloride and the phosphorus pentachloride in the chlorobenzene solution of phosphorus pentachloride.

6. The preparation method according to claim 1, characterized in that The preparation method of the chlorobenzene solution containing potassium phenoxide and sodium phenoxide comprises the following steps: Chlorobenzene, sodium hydroxide, potassium hydroxide and molten phenol are mixed to carry out a substitution reaction to obtain the chlorobenzene solution containing potassium phenoxide and sodium phenoxide.

7. The preparation method according to claim 1 or 6, characterized in that The mass ratio of the liquid organic amine catalyst to the molten phenol is 0.01-0.02:1.