Preparation method of bisphenol A bis (diphenyl phosphate)

Abstract

The invention discloses a preparation method of bisphenol A bis (diphenyl phosphate), which comprises the following steps: S1, reacting phosphorus oxychloride with bisphenol A, and removing excessive raw materials after the reaction to obtain a reaction solution containing bisphenol A tetrachloro diphosphate; in the reaction, the mass ratio of the bisphenol A dichloro diphosphate intermediate to the bisphenol A tetrachloro diphosphate is controlled to be less than 0.1; and S2, adding phenol into the reaction liquid containing bisphenol A tetrachloro diphosphate, carrying out an end capping reaction, and removing excessive raw materials to obtain bisphenol A bis (diphenyl phosphate). By controlling the process conditions of the reaction in the first step, the reaction in the first step can be more sufficient and thorough, the final BDP monomer selectivity is improved, the impurity content of triphenyl phosphate is obviously reduced, and meanwhile, the product has better flowability and flame retardant property.

Description

Technical Field

[0001] The invention relates to a method for preparing a halogen-free phosphorus flame retardant monomer, in particular to a method for preparing bisphenol A bis(diphenyl phosphate). Background Art

[0002] Bisphenol A bis(diphenyl phosphate), hereinafter referred to as BDP, is an important type of organophosphorus flame retardant, which has the advantages of good compatibility with polymer substrates, resistance to migration, resistance to volatility, resistance to radiation, low toxicity, and long-lasting flame retardant effect. It is not only widely used in thermoplastic engineering plastics such as PC / ABS blends, polyethylene and foamed polyurethane, but also in terms of the type of terminal application, electronic appliances are also the most critical sub-application of BDP flame retardants, including home appliances, consumer electronics, and electronic product accessories. In addition, BDP flame retardants are also used in automotive parts (including new energy vehicles), charging piles, 5G base stations and other fields.

[0003] There are currently three main methods for the synthesis of BDP:

[0004] (1) Phosphorus oxychloride reacts with bisphenol A to obtain bisphenol A tetrachlorobisphosphate, which is then capped with phenol to obtain the target product.

[0005] (2) Phosphorus oxychloride reacts with phenol to obtain diphenylphosphoryl chloride, which is then reacted with bisphenol A to obtain the target product.

[0006] (3) Sodium phenolate is used as the raw material instead of phenol, that is, bisphenol A tetrachlorobisphosphate is capped with sodium phenolate to obtain the product.

[0007] Among them, in method (2), while phosphorus oxychloride reacts with phenol to obtain diphenyl phosphoryl chloride, monophenyl phosphoryl chloride and triphenyl phosphate are also generated, and it is difficult to obtain qualified products; in method (3), the sodium phenolate raw material used is difficult to obtain, and the market product is reduced. If phenol is used to prepare sodium phenolate, additional alkali is required, and sodium phenolate generates sodium chloride after the end-capping reaction of bisphenol A tetrachlorobisphosphate, and "chlorine" cannot be recycled, and the atom economy is poor. Therefore, considering factors such as the availability of raw materials, atom economy, reaction difficulty, and overall process cost, the current industrialized solutions all adopt method (1), and the synthesis equation of the two-step reaction is as follows:

[0008]

[0009] There are two main problems with the above method (1). The first is that the product produced is usually a mixture of BDP monomer, BDP dimer, BDP trimer and BDP tetramer. If the oligomer content is too high, it will not only affect the viscosity and fluidity of the product, but more importantly, it will significantly reduce the effective phosphorus content, thereby affecting the flame retardant properties. Therefore, improving the selectivity of BDP monomer is the key to the reaction. The second point is that studies have found that the products prepared by the prior art contain a certain amount of triphenyl phosphate, which affects the product color and quality, performance, etc. It is speculated that the impurity is generated by the phosphorus oxychloride carried by the first step reaction product and phenol in the second step reaction. How to reduce the content of this impurity is also a technical problem that needs to be solved urgently.

[0010] Patent CN106496264B uses a staged reaction method to control the reaction selectivity. Specifically, the reaction temperature is controlled by the method of feeding and discharging materials in a four-stage reactor, so that the reaction reaches different conversion rates in different reactors. The temperature of the first-stage reactor is controlled at 95-100°C, and the temperature of the second-stage reactor is controlled at 105-110°C. The temperatures of the first two reactors are low to control the selectivity of the raw materials. The third and fourth-stage reactors are controlled at 110-120°C to control the raw material conversion rate. The BDP monomer content in the obtained product is 83%, that is, the selectivity is 83%, the converted phosphorus content is 8.5%, the TPP content is 0.73%, and the chromaticity is 40Hazen. There is still a lot of room for improvement in the indicators of each product, and the production process is long, and the industrial applicability is limited.

[0011] Patent CN109912646B synthesizes a new type of solid superacid catalyst and uses it in esterification reaction. The BDP selectivity of the product reaches 90.45%. However, the industrial preparation of the catalyst is complicated and the production cost is extremely high, so it has no prospect of industrial application.

[0012] Patent CN103214513A also prepared a HZSM-5 molecular sieve catalyst and used it in the esterification reaction. The reaction temperature was first raised to 80°C, and bisphenol A was added to the reactor in 5-7 batches. The temperature was raised to 105°C and the reaction was continued for 2 hours. This method also has the problem of high production cost of synthesizing special catalysts, and the obtained BDP product has a chromaticity value of 80 Hazen, which is a light yellow viscous liquid, which is somewhat different from the commercially available colorless and transparent products. Summary of the invention

[0013] In order to solve the above technical problems, the present invention provides a method for preparing bisphenol A bis(diphenyl phosphate).

[0014] From the above reaction mechanism of the production method, it can be seen that the key technical difficulty of this route lies in the first step reaction. The present invention can make the first step reaction more complete by controlling the process conditions of the first step reaction, which not only improves the final BDP monomer selectivity, but also significantly reduces the impurity content of triphenyl phosphate, and the product has better fluidity and flame retardant properties.

[0015] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0016] A method for preparing bisphenol A bis(diphenyl phosphate) comprises the following steps:

[0017] S1, reacting phosphorus oxychloride and bisphenol A, removing excess raw materials after the reaction, and obtaining a reaction solution containing bisphenol A tetrachlorobisphosphate;

[0018] In this step of the reaction, the mass ratio of the bisphenol A dichlorobisphosphate intermediate to the bisphenol A tetrachlorobisphosphate is controlled to be less than 0.1, preferably less than 0.08;

[0019] S2, adding phenol to the reaction solution containing bisphenol A tetrachlorobisphosphate to carry out end-capping reaction, and removing excess raw materials to obtain bisphenol A bis(diphenyl phosphate).

[0020] The molecular structure of the main substance involved in step S1 of the present invention is as follows:

[0021]

[0022] The present invention has been found through continuous research that bisphenol A dichlorobisphosphate is used as the main intermediate in step S1, and its content control during the reaction process has an important influence on the selectivity of BDP monomer and the selectivity of triphenyl phosphate impurity in the product. In particular, by controlling the mass ratio of bisphenol A dichlorobisphosphate intermediate to bisphenol A tetrachlorobisphosphate to be less than 0.1, the selectivity of BDP monomer can be improved, and the content of triphenyl phosphate impurity can be advantageously reduced. The obtained product has not only low color number and good fluidity, but also high phosphorus content and good flame retardant properties.

[0023] As some preferred embodiments of the present invention, in step S1, bisphenol A is mixed with phosphorus oxychloride in a dropwise manner for reaction, and preferably the dropwise addition time of the two portions of A is 1-10 hours, more preferably 3-7 hours;

[0024] Preferably, the molar ratio of bisphenol A to phosphorus oxychloride is 1:(2-7), preferably 1:(3-6).

[0025] As some preferred embodiments of the present invention, in step S1, the mass ratio of bisphenol A dichlorobisphosphate intermediate to bisphenol A tetrachlorobisphosphate is controlled by adjusting the feeding rate of bisphenol A.

[0026] Since the reaction in step S1 is an exothermic reaction, the concentration of the reactants is high and the reaction speed is fast in the early stage, resulting in a large amount of bisphenol A dichlorobisphosphate intermediate being generated and not having enough time to be completely converted into bisphenol A tetrachlorobisphosphate. By slowly dropping bisphenol A in the early stage of the reaction and continuously accelerating the dropping speed of bisphenol A in the subsequent reaction process, the mass ratio of bisphenol A dichlorobisphosphate intermediate to bisphenol A tetrachlorobisphosphate can be easily controlled within a specific range. Therefore, controlling the above mass ratio by adjusting the feeding rate of bisphenol A is only a simple and feasible solution provided by the present invention, but should not be used as any limitation to the present invention.

[0027] In a specific scheme for adjusting the feeding rate of bisphenol A, preferably when the amount of bisphenol A added is within 50 wt% of the total amount, the dropping rate of bisphenol A is adjusted to be less than 330 mol / h*m 3 When the amount of bisphenol A added is ≥ 50 wt% of the total amount, the drop rate of bisphenol A is adjusted to 330-500 mol / h*m 3 .

[0028] More preferably, the feed rate of bisphenol A is adjusted, for example, by the following method:

[0029] The addition rate of bisphenol A = the total amount of bisphenol A added to the reaction system (mol) / [addition time (h) * reactor volume (m 3 )]

[0030] For example: 1.5L reactor, adding material for 1h, the total amount of bisphenol A added to the reaction system is 30g, then the addition rate of bisphenol A is 30g / (1h*0.015m 3 *228.29)=87.6mol / (h*m 3 ). Where 228.29 is the molecular weight of bisphenol A, in g / mol.

[0031] In addition to the above-mentioned method of controlling the mass ratio of bisphenol A dichlorobisphosphate intermediate to bisphenol A tetrachlorobisphosphate by adjusting the feeding rate of bisphenol A, the mass ratio can also be adjusted by controlling the HCl gas production rate and / or the temperature change in the reactor, etc., which are not listed here one by one.

[0032] As some preferred embodiments of the present invention, the reaction in step S1 is carried out in the presence of an esterification catalyst;

[0033] Preferably, the esterification catalyst is a hydrochloride of a Group 3-4 metal, preferably one or more of aluminum chloride, magnesium chloride, ferric chloride, zinc chloride and titanium tetrachloride;

[0034] Preferably, the amount of the esterification catalyst used is 0.1-5% by mass of bisphenol A, preferably 0.5-2.5%.

[0035] As some preferred embodiments of the present invention, the reaction conditions in step S1 are: the reaction temperature is 70-140°C, preferably 80-120°C; and / or the reaction pressure is 0.05-0.5MPaA, preferably 0.08-0.2MpaA; and / or the reaction stirring speed is 100-800rpm, preferably 200-400rpm.

[0036] As some preferred embodiments of the present invention, in step S1, after the addition of bisphenol A is completed, the reaction is continued by heat preservation for 1-10 hours, preferably 2-6 hours.

[0037] As some preferred embodiments of the present invention, in step S2, the amount of phenol used is 4-10 times, preferably 6-8 times, that of bisphenol A in terms of molar amount;

[0038] Preferably, in step S2, phenol is added dropwise to the reaction solution containing bisphenol A tetrachlorobisphosphate, and the phenol addition time is preferably 0.5-5 h, preferably 1.0-3 h.

[0039] As some preferred embodiments of the present invention, in step S2, the reaction temperature is 80-130°C, preferably 100-120°C; and / or the reaction pressure is 10kPaA-101kPaA, preferably 30kPaA-80kPaA; and / or the reaction stirring speed is 100-800rpm, preferably 200-400rpm.

[0040] As some preferred embodiments of the present invention, in step S2, after the addition of phenol is completed, the reaction is continued by heat preservation for 4-15 hours, preferably 6-10 hours.

[0041] As some preferred schemes of the present invention, the conditions for removing excess raw materials after the reaction in step S1 are: distilling to remove excess trichlorophosphine oxide at a temperature of 100-250°C, preferably 135°C-165°C, and a pressure of 10kPaA-100kPaA, preferably 20kPaA-80kPaA; preferably distilling under the condition of introducing a reaction inert gas, more preferably a nitrogen flow rate of 0.1-10L / min, preferably 1-5L / min.

[0042] As some preferred embodiments of the present invention, the conditions for removing excess raw materials after the reaction in step S2 are: distilling and removing excess phenol at a temperature of 100-250°C, preferably 135°C-165°C, and a pressure of 0.01MPaA-0.1MPaA, preferably 0.05MPaA-0.08MpaA to obtain a crude product.

[0043] As some preferred schemes of the present invention, after the reaction in step S2, excess raw materials are removed to obtain a crude product; the crude product is added to a solvent and dissolved, and then the solvent is removed after acid washing, alkali washing and water washing to obtain the product.

[0044] The solvent is an aromatic hydrocarbon and / or an alkane, preferably a mixture of the two, more preferably a mixture of an aromatic hydrocarbon and an alkane in a mass ratio of 1:(0.1-5) preferably 1:(0.5-2); wherein the aromatic hydrocarbon solvent may be selected from one or more of toluene, o-xylene, m-xylene, p-xylene, chlorobenzene, and mesitylene, preferably toluene; the alkane solvent may be selected from one or more of methylcyclohexane, cyclopentane, n-heptane, and n-hexane, preferably methylcyclohexane. The amount of the solvent used may be, for example, 0.5-2 times the mass of the crude product, preferably 0.75-1.25 times.

[0045] The acid used for pickling is one or more of hydrochloric acid, sulfuric acid, and nitric acid, preferably hydrochloric acid; the mass concentration of the acid is 1-30%, preferably 4-10%; the amount of the acid is 0.1-10, preferably 0.5-5 times the mass of the crude product; the temperature of the pickling is 40-100°C, preferably 60-80°C.

[0046] After pickling, the mixture is allowed to stand and the phases are separated. The aqueous phase is treated as wastewater and the oil phase is washed with alkaline solution.

[0047] The alkali used in the alkali washing is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, preferably sodium hydroxide; the mass percentage concentration of the alkali is 1-30%, preferably 4-10%; the amount of the alkali is 0.1-10 times the mass of the crude product, preferably 0.5-5 times; the temperature of the alkali washing is 40-100°C, preferably 60-80°C.

[0048] After the alkaline washing is completed, the phases are allowed to stand and separated, the aqueous phase is treated as wastewater, and the oil phase is washed with water again.

[0049] The amount of water used is 0.1-10 times the mass of the crude product, preferably 0.5-5 times; the temperature of the water washing is 40-100°C, preferably 60-80°C.

[0050] After washing, the mixture is allowed to stand for phase separation, the aqueous phase is treated as wastewater, and the oil phase is desolventized to obtain the final product.

[0051] The desolvation temperature is 80°C-200°C, preferably 135-165°C, and the pressure is 0.05KPaA-5KPaA, preferably 0.1KPaA-1.0KPaA.

[0052] The present invention also provides bisphenol A bis(diphenyl phosphate) prepared by the method described above, characterized in that, based on the total molar amount as 100%, it comprises the following components in the following proportions:

[0053] BDP monomer 90-92%,

[0054] BDP dimer 7-13%,

[0055] BDP trimer 0.6-2.0%,

[0056] BDP tetramer 0.1-0.3%.

[0057] The general structural formula of the above components can be expressed as follows:

[0058]

[0059] Here, n is a positive integer not less than 1, such as 1, 2, 3, 4, etc.

[0060] When n=1, it indicates BDP monomer;

[0061] When n = 2, it indicates a BDP dimer;

[0062] When n = 3, it indicates a BDP trimer;

[0063] When n=4, it represents a BDP tetramer.

[0064] In the bisphenol A bis(diphenyl phosphate) product obtained by the present invention, the phosphorus content is greater than 8.9% (better than commercially available products), so that the product has the advantages of high flame retardancy and low addition amount; the triphenyl phosphate content in the product is less than 500ppm, so that the product chromaticity is less than 20 and is environmentally friendly, which is significantly higher than the products on the market; the BDP tetramer content in the product is less than 0.5%, so that the product has a viscosity of 1000cP at 40°C, and the product fluidity is better than the products on the market, so that the product can be quickly blended with polymer plastics as a liquid flame retardant, and has extremely strong market competitiveness. DETAILED DESCRIPTION

[0065] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0066] Common chemical reagents used in the present invention, such as bisphenol A, trichlorophosphine, metal inorganic salts (such as magnesium chloride, aluminum chloride, ferric chloride, zinc chloride, etc.), toluene, methylcyclohexane, sodium hydroxide, etc., were purchased from Shanghai Titan Technology Co., Ltd.

[0067] In the embodiment of the present invention, the content (for example, raw material bisphenol A, trichlorophosphine, product BDP, etc.) and purity of each component are tested and calculated by external standard method of high performance liquid chromatograph (Shimadzu LC-20AD), and the conversion rate is calculated based on the content of the product; the liquid chromatography conditions are as follows: chromatographic column: WAters XSelect HSS T3, 4.6μm×250mm; injection volume: 2-10μL, fine-tuned according to the sample conditions; column temperature: 40°C; flow rate: 1mL / min; detector: ultraviolet detector (UV), detection wavelength is 254-400nm; mobile phase: acetonitrile / 0.1% phosphoric acid aqueous solution; when measuring the sample, first establish a liquid phase external standard curve with a pure product, and calculate the mass fraction (content) of each test substance based on the linear relationship between concentration and liquid phase peak area.

[0068] It is particularly noted that in the embodiments of the present invention, the contents of bisphenol A dichlorobisphosphate and bisphenol A tetrachlorobisphosphate in the reaction system are monitored online by a near-infrared tester. The near-infrared spectroscopy equipment model is a FTPA-2000 series product, specifically ABB FTPA2000-260+insertion transflection probe+Horizon MB software. The entire set of test equipment and analysis software is from Shanghai ABB Engineering Co., Ltd. First, under laboratory conditions, three batches of tests were conducted to try to establish a preliminary near-infrared model and make predictions. The measurement parameters were set to a probe gap of 1 mm and a wavenumber range of 4500-10000 cm -1 , Scan times 64 times, resolution 16cm -1 After the model correction is completed, the probe is inserted into the reactor in the embodiment for online monitoring.

[0069] The molecular structure of triphenyl phosphate in the present invention is as follows, and the molecular weight is 326.07 g / mol.

[0070]

[0071] The molecular structure of bisphenol A in the present invention is as follows, and the molecular weight is 228.29 g / mol.

[0072]

[0073] The molecular structure of bisphenol A dichlorobisphosphate in the present invention is as follows, and the molecular weight is 345.16 g / mol.

[0074]

[0075] The molecular structure of bisphenol A tetrachlorobisphosphate in the present invention is as follows, and the molecular weight is 426.03 g / mol.

[0076]

[0077] The present invention defines the raw material conversion rate, selectivity and yield within the scope of industry knowledge as follows:

[0078] In terms of bisphenol A, the formula for calculating the raw material conversion rate is: (total molar amount of bisphenol A in the raw material - total molar amount of bisphenol A remaining in the reaction solution) / total molar amount of bisphenol A in the raw material * 100%.

[0079] Selectivity of bisphenol A tetrachlorobisphosphate = (total molar amount of bisphenol A tetrachlorobisphosphate obtained) / (total molar amount of bisphenol A in the raw material - total molar amount of bisphenol A remaining in the reaction solution)

[0080] The yield of bisphenol A tetrachlorobisphosphate = the conversion rate of bisphenol A * the selectivity of bisphenol A tetrachlorobisphosphate.

[0081] The selectivity and yield of other intermediates / single products are calculated in the same way. Among them, based on the final product of bisphenol A bis(diphenyl phosphate), the selectivity calculation formula is (total molar amount of BDP monomer + BDP dimer + BDP trimer + BDP tetramer) / (total molar amount of bisphenol A in the raw material-total molar amount of bisphenol A remaining in the reaction solution)*100%, and the yield = bisphenol A conversion rate*selectivity of the final product of bisphenol A bis(diphenyl phosphate).

[0082] [Example 1]

[0083] S1. Nitrogen replaces a 1.5L glass jacketed reactor before the reaction. Weigh 769.59g (about 5mol) of phosphorus oxychloride with a purity of 99% and add it to the glass jacketed reactor at one time. Weigh 3g of 99% catalyst magnesium chloride (1% of the mass of bisphenol A) and add it to the glass jacketed reactor at one time. Turn on the mechanical stirring and set the speed to 350rpm. Turn on the diaphragm pump to adjust the system pressure to 0.05MPaA. Turn on the oil bath heating equipment, so that the system temperature rises to 120°C, and then start to drip a total of 304.2g of bisphenol A with a purity of 99% into the reaction bottle. The bisphenol A dripping rate is adjusted in real time using the following formula to control the mass ratio of bisphenol A dichlorobisphosphate to bisphenol A tetrachlorobisphosphate (denoted as W1 / W2) within a certain range:

[0084] The addition rate of bisphenol A = the total amount of bisphenol A added to the reaction system (mol) / [addition time (h) * reactor volume (m 3 )]

[0085] During the addition process, the mass of bisphenol A added to the reaction system = the theoretical total added mass minus the remaining unadded mass, and the mass is weighed using a conventional measuring balance.

[0086] The bisphenol A drop acceleration rate and the real-time adjustment of W1 / W2 are shown in Table 1.

[0087] Table 1

[0088] Dropping time, h <![CDATA[Bisphenol A feeding rate, mol / h*m 3 > Content of bisphenol A dichlorobisphosphate, wt% W1 / W2 0.1 61.33 0.012 0.025 0.2 90.53 0.041 0.034 0.3 148.93 0.100 0.043 0.4 195.66 0.197 0.052 0.5 233.62 0.335 0.061 0.6 262.82 0.517 0.070 0.8 277.42 0.892 0.080 1.2 284.73 1.499 0.080 1.8 326.10 2.456 0.080 2.4 340.70 2.983 0.070 2.7 350.43 2.523 0.052 3.0 381.97 3.287 0.061

[0089] After the addition of bisphenol A was completed, the reaction process conditions were not changed, and the heat preservation reaction was continued for 6.0 hours. The reaction was terminated, and the content of bisphenol A tetrachlorobisphosphate was 54.63%, and the content of bisphenol A dichlorobisphosphate was 2.33%. The total mass of the reaction solution was weighed and the conversion rate of the raw material bisphenol A was calculated to be 100%, the selectivity of bisphenol A tetrachlorobisphosphate was 95.1%, and the selectivity of the total bisphenol A chlorobisphosphate (including dichlorobisphosphate and tetrachlorobisphosphate) was >99.9%.

[0090] The obtained reaction liquid was distilled to remove phosphorus oxychloride. The distillation conditions were: heat source temperature 135°C, pressure 80KPaA, and 1L / min of nitrogen was introduced into the system to assist in removal. After sampling and analysis of phosphorus oxychloride <10ppm, the operation was terminated to obtain a reaction liquid containing bisphenol A tetrachlorobisphosphate.

[0091] S2. Weigh 496.6g of 99% phenol under nitrogen atmosphere, heat to 50°C, and seal with nitrogen for later use. Heat the reaction solution containing bisphenol A tetrachlorobisphosphate obtained above to 120°C, adjust the pressure to 80KPaA, set the stirring speed to 400rpm, and drop the prepared phenol into the reaction solution for 1h. After the dropwise addition is completed, continue to keep warm for 6h to obtain a capped reaction solution. Sampling analysis shows that the total selectivity of the final product of bisphenol A bis(diphenyl phosphate) is 100%, wherein the contents of each component are as follows: 90mol% of BDP monomer, 9mol% of BDP dimer, 0.7mol% of BDP trimer, and 0.3mol% of BDP tetramer.

[0092] [Example 2]

[0093] S1. Nitrogen replaces a 1.5L glass jacketed reactor before the reaction. Weigh 769.59g (about 5mol) of phosphorus oxychloride with a purity of 99% and add it to the glass jacketed reactor at one time. Weigh 3g of catalyst magnesium chloride with a purity of 99% (1% of the mass of bisphenol A) and add it to the glass jacketed reactor at one time. Turn on the mechanical stirring and set the speed to 600rpm. Turn on the diaphragm pump to adjust the system pressure to 0.1MPaA. Turn on the oil bath heating equipment, so that the system temperature rises to 100°C, and then start to drip a total of 304.2g of bisphenol A with a purity of 99% into the reaction bottle. The bisphenol A dripping rate is adjusted in real time using the following formula to control the mass ratio of bisphenol A dichlorobisphosphate to bisphenol A tetrachlorobisphosphate (denoted as W1 / W2) within a certain range:

[0094] The addition rate of bisphenol A = the total amount of bisphenol A added to the reaction system (mol) / [addition time (h) * reactor volume (m 3 )]

[0095] During the addition process, the mass of bisphenol A added to the reaction system = the theoretical total added mass minus the remaining unadded mass, and the mass is weighed using a conventional measuring balance.

[0096] The bisphenol A drop acceleration rate and the real-time adjustment of W1 / W2 are shown in Table 2.

[0097] Table 2

[0098] Dropping time, h <![CDATA[Bisphenol A feeding rate, mol / h*m 3 > Content of bisphenol A dichlorobisphosphate, wt% W1 / W2 0.5 158.28 0.207％ 0.034 1.0 195.07 0.562％ 0.043 1.5 228.95 1.255％ 0.061 2.0 321.81 2.399％ 0.080 2.5 394.24 2.547％ 0.061 3.0 478.57 1.409％ 0.025

[0099] After the addition of bisphenol A was completed, the reaction process conditions were not changed, and the heat preservation reaction was continued for 2.0 hours. The reaction was terminated, and the content of bisphenol A dichlorobisphosphate was 1.40%, and the content of bisphenol A tetrachlorobisphosphate was 55.78%. The total mass of the reaction solution was weighed and the conversion rate of the raw material bisphenol A was calculated to be greater than 99.9%, and the selectivity of the total bisphenol A chlorobisphosphate (including dichlorobisphosphate and tetrachlorobisphosphate) was greater than 99.9%.

[0100] The obtained reaction liquid was distilled to remove phosphorus oxychloride. The distillation conditions were: heat source temperature 135°C, pressure 50KPaA, and 3L / min of nitrogen was introduced into the system to assist in removal. After sampling and analysis of phosphorus oxychloride <10ppm, the operation was terminated to obtain a reaction liquid containing bisphenol A tetrachlorobisphosphate.

[0101] S2. Weigh 496.6g of 99% phenol under nitrogen atmosphere, heat to 50°C, and seal with nitrogen for later use. Heat the reaction solution containing bisphenol A tetrachlorobisphosphate obtained above to 130°C, adjust the pressure to 80KPaA, set the stirring speed to 600rpm, and drop the prepared phenol into the reaction solution for 1h. After the dropwise addition is completed, continue to keep warm for 7h to obtain a capped reaction solution. Sampling analysis shows that the total selectivity of the final product of bisphenol A bis(diphenyl phosphate) is 100%, wherein the content of each component is as follows: BDP monomer 91mol%, BDP dimer 8mol%, BDP trimer 0.8mol%, BDP tetramer 0.2mol%.

[0102] [Example 3]

[0103] S1. Nitrogen replaces a 1.5L glass jacketed reactor before the reaction. Weigh 404.4g (about 2.638mol) of phosphorus oxychloride with a purity of 99% and add it to the glass jacketed reactor at one time. Weigh 1.5g of catalyst titanium tetrachloride with a purity of 99% (0.5% of the mass of bisphenol A) and add it to the glass jacketed reactor at one time. Turn on the mechanical stirring and set the speed to 400rpm. Turn on the diaphragm pump to adjust the system pressure to 0.5MPaA. Turn on the oil bath heating equipment, so that the system temperature rises to 70°C, and then start to drip a total of 304.2g of bisphenol A with a purity of 99% into the reaction bottle. The bisphenol A dripping rate is adjusted in real time using the following formula to control the mass ratio of bisphenol A dichlorobisphosphate to bisphenol A tetrachlorobisphosphate (denoted as W1 / W2) within a certain range:

[0104] The addition rate of bisphenol A = the total amount of bisphenol A added to the reaction system (mol) / [addition time (h) * reactor volume (m 3 )]

[0105] During the addition process, the mass of bisphenol A added to the reaction system = the theoretical total added mass minus the remaining unadded mass, and the mass is weighed using a conventional measuring balance.

[0106] The bisphenol A drop acceleration rate and the real-time adjustment of W1 / W2 are shown in Table 3.

[0107] Table 3

[0108]

[0109]

[0110] After the addition of bisphenol A was completed, the reaction process conditions were not changed, and the reaction was continued at a temperature of 4.0 hours. The reaction was terminated and sampling was performed. The total mass of the reaction liquid was weighed and the conversion rate of the raw material bisphenol A was calculated to be 100%, the selectivity of bisphenol A tetrachlorobisphosphate was 98.0%, and the selectivity of the total bisphenol A chlorobisphosphate (including dichlorobisphosphate and tetrachlorobisphosphate) was >99.9%.

[0111] The obtained reaction liquid was distilled to remove phosphorus oxychloride. The distillation conditions were: heat source temperature 250°C, pressure 100KPaA, and 5L / min of nitrogen was introduced into the system to assist in removal. After sampling and analysis showed that phosphorus oxychloride was less than 10ppm, the operation was terminated to obtain a reaction liquid containing bisphenol A tetrachlorobisphosphate.

[0112] S2. Weigh 1241.3g of phenol with a purity of 99% (10:1 relative to the molar amount of bisphenol A) under nitrogen atmosphere, heat to 50°C, and seal with nitrogen for use. Heat the reaction solution obtained by removing trichlorophosphine oxide to 200°C, adjust the pressure to 10KPaA, set the stirring speed to 800rpm, and add the prepared phenol to the reaction solution dropwise for 1h. After the addition is completed, continue to keep warm for 4h to obtain a capped reaction solution. Sampling and analysis show that the total selectivity of the final product of bisphenol A bis(diphenyl phosphate) is 100%, wherein the content of each component is as follows: BDP monomer 91.2mol%, BDP dimer 7.5mol%, BDP trimer 1.1mol%, BDP tetramer 0.2mol%.

[0113] [Example 4]

[0114] S1. Nitrogen replaces a 1.5L glass jacketed reactor before the reaction. Weigh 1429.7g (about 9.233mol) of phosphorus oxychloride with a purity of 99% and add it to the glass jacketed reactor at one time. Weigh 4.5g of aluminum chloride (1.5% of the mass of bisphenol A) with a purity of 99% and add it to the glass jacketed reactor at one time. Turn on the mechanical stirring and set the speed to 800rpm. Turn on the diaphragm pump to adjust the system pressure to 0.4MPaA. Turn on the oil bath heating equipment, so that the system temperature rises to 140°C, and then start to drip a total of 304.2g of bisphenol A with a purity of 99% into the reaction bottle. The bisphenol A dripping rate is adjusted in real time using the following formula to control the mass ratio of bisphenol A dichlorobisphosphate to bisphenol A tetrachlorobisphosphate (denoted as W1 / W2) within a certain range:

[0115] The addition rate of bisphenol A = the total amount of bisphenol A added to the reaction system (mol) / [addition time (h) * reactor volume (m 3 )]

[0116] During the addition process, the mass of bisphenol A added to the reaction system = the theoretical total added mass minus the remaining unadded mass, and the mass is weighed using a conventional measuring balance.

[0117] The bisphenol A drop acceleration rate and the real-time adjustment of W1 / W2 are shown in Table 4.

[0118] Table 4

[0119] Dropping time, h <![CDATA[Bisphenol A feeding rate, mol / h*m 3 > Content of bisphenol A dichlorobisphosphate, wt% W1 / W2 1.0 64.54 0.069％ 0.025 2.0 68.33 0.094％ 0.017 4.0 79.14 0.301％ 0.025 5.0 160.91 0.913％ 0.052 6.0 197.12 0.849％ 0.034 7.0 239.29 0.561％ 0.017

[0120] After the addition of bisphenol A was completed, the reaction process conditions were not changed, and the reaction was continued to be kept warm for 3.0 hours. The reaction was terminated and sampling was taken for analysis. The total mass of the reaction liquid was weighed and the conversion rate of the raw material bisphenol A was calculated to be 100%, the selectivity of bisphenol A tetrachlorobisphosphate was 97.7%, and the selectivity of total bisphenol A chlorobisphosphate (including dichlorobisphosphate and tetrachlorobisphosphate) was >99.9%.

[0121] The obtained reaction liquid was distilled to remove phosphorus oxychloride. The distillation conditions were: heat source temperature 165°C, pressure 10KPaA, and 10L / min of nitrogen was introduced into the system to assist in removal. After sampling and analysis of phosphorus oxychloride <10ppm, the operation was terminated to obtain a reaction liquid containing bisphenol A tetrachlorobisphosphate.

[0122] S2. Weigh 993.05g of phenol with a purity of 99% (8:1 relative to the molar amount of bisphenol A) under nitrogen atmosphere, heat it to 50°C, and seal it with nitrogen for use. The reaction solution obtained by removing trichlorophosphine oxide is heated to 100°C, the pressure is adjusted to 101KPaA, the stirring speed is set to 100rpm, and the prepared phenol is added dropwise to the reaction solution for 10h. After the addition is completed, continue to keep warm for 10h to obtain a capped reaction solution. Sampling and analysis show that the total selectivity of the final product of bisphenol A bis(diphenyl phosphate) is 100%, wherein the content of each component is as follows: BDP monomer 92mol%, BDP dimer 7.0mol%, BDP trimer 0.9mol%, BDP tetramer 0.1mol%.

[0123] [Example 5]

[0124] S1. Nitrogen replaces a 1.5L glass jacketed reactor before the reaction. Weigh 1021.2g (about 6.595mol) of phosphorus oxychloride with a purity of 99% and add it to the glass jacketed reactor at one time. Weigh 7.5g of 99% catalyst ferric chloride (2.5% of the mass of bisphenol A) with a purity of 99% and add it to the glass jacketed reactor at one time. Turn on the mechanical stirring and set the speed to 100rpm. Turn on the diaphragm pump to adjust the system pressure to 0.08MPaA. Turn on the oil bath heating equipment, so that the system temperature rises to 80°C, and then start to drip a total of 304.2g of bisphenol A with a purity of 99% into the reaction bottle. The bisphenol A dripping rate is adjusted in real time using the following formula to control the mass ratio of bisphenol A dichlorobisphosphate to bisphenol A tetrachlorobisphosphate (denoted as W1 / W2) within a certain range:

[0125] The addition rate of bisphenol A = the total amount of bisphenol A added to the reaction system (mol) / [addition time (h) * reactor volume (m 3 )]

[0126] During the addition process, the mass of bisphenol A added to the reaction system = the theoretical total added mass minus the remaining unadded mass, and the mass is weighed using a conventional measuring balance.

[0127] The bisphenol A drop acceleration rate and the real-time adjustment of W1 / W2 are shown in Table 4.

[0128] Table 5

[0129] Dropping time, h <![CDATA[Bisphenol A feeding rate, mol / h*m 3 > Content of bisphenol A dichlorobisphosphate, wt% W1 / W2 1.0 598.65 0.060％ 0.017 2.0 616.18 0.355％ 0.034 4.0 731.53 0.775％ 0.043 5.0 905.28 1.387％ 0.052 6.0 1131.60 1.595％ 0.043 7.0 1516.78 1.121％ 0.025

[0130] After the addition of bisphenol A was completed, the reaction process conditions were not changed, and the reaction was continued to be kept warm for 10.0 hours. The reaction was terminated and sampling was taken for analysis. The total mass of the reaction liquid was weighed and the conversion rate of the raw material bisphenol A was calculated to be 100%, the selectivity of bisphenol A tetrachlorobisphosphate was 97.2%, and the selectivity of total bisphenol A chlorobisphosphate (including dichlorobisphosphate and tetrachlorobisphosphate) was >99.9%.

[0131] The obtained reaction liquid was distilled to remove phosphorus oxychloride. The distillation conditions were: heat source temperature 100°C, pressure 20KPaA, and 0.1L / min of nitrogen was introduced into the system to assist in removal. After sampling and analysis showed that phosphorus oxychloride was less than 10ppm, the operation was terminated to obtain a reaction liquid containing bisphenol A tetrachlorobisphosphate.

[0132] S2. Weigh 744.79g of phenol with a purity of 99% (6:1 relative to the molar amount of bisphenol A) under nitrogen atmosphere, heat to 50°C, and seal with nitrogen for use. Heat the reaction solution obtained by removing trichlorophosphine oxide to 140°C, adjust the pressure to 30KPaA, set the stirring speed to 200rpm, and add the prepared phenol to the reaction solution dropwise for 5h. After the addition is completed, continue to keep warm for 15h to obtain a capped reaction solution. Sampling and analysis show that the total selectivity of the final product of bisphenol A bis(diphenyl phosphate) is 100%, wherein the content of each component is as follows: BDP monomer 90.5mol%, BDP dimer 8.6mol%, BDP trimer 0.6mol%, BDP tetramer 0.3mol%.

[0133] [Comparative Example 1]

[0134] Bisphenol A bis(diphenyl phosphate) was prepared in a method substantially the same as that in Example 1, except that step S1 was adjusted according to the control conditions in Table 4 below:

[0135] Table 4

[0136] Dropping time, h <![CDATA[Bisphenol A feeding rate, mol / h*m 3 > Content of bisphenol A dichlorobisphosphate, wt% W1 / W2 0.1 296.15 0.983％ 0.810 0.2 296.15 1.560％ 0.540 0.3 296.15 1.739％ 0.347 0.4 296.15 1.533％ 0.203 0.5 296.15 2.850％ 0.347 0.6 296.15 4.521％ 0.540 0.8 296.15 8.891％ 1.215 1.2 296.15 4.302％ 0.203 1.8 296.15 4.616％ 0.143 2.4 296.15 9.806％ 0.270 2.7 296.15 12.952％ 0.347 3.0 296.15 23.479％ 0.810

[0137] After the end-capping reaction, sampling and analysis showed that the total selectivity of the final product of bisphenol A bis(diphenyl phosphate) was 100%, wherein the contents of each component were as follows: BDP monomer 84 mol%, BDP dimer 8 mol%, BDP trimer 6 mol%, and BDP tetramer 2 mol%.

[0138] [Comparative Example 2]

[0139] Analysis of the commercially available product Aidico Fine Chemical Co., Ltd. (bisphenol A bis(diphenyl phosphate)) shows that its product composition includes: BDP monomer 83.51 mol%, BDP dimer 11.61 mol%, BDP trimer 1.44 mol%, and BDP tetramer 0.5 mol%.

[0140] The end-capping reaction solution obtained in step S2 of Examples 1-3 and Comparative Example 1 was uniformly separated and purified by the following method to obtain purified bisphenol A bis(diphenyl phosphate), and the various parameter indicators of the product bisphenol A bis(diphenyl phosphate) in Examples 1-3 and Comparative Example 1-2 were analyzed, as shown in Table 5.

[0141] End-capping reaction solution purification method:

[0142] The reaction solution was added into a flask, and the heat source temperature was set to 135°C and the pressure to 0.08 MPaA to remove phenol from the system. The phenol content was monitored in real time and was qualified when it was less than 10 ppm.

[0143] Add a mixed solvent containing 350g of toluene and 350g of methylcyclohexane to 700g of the reaction solution from which phenol has been removed, stir evenly at 60°C to form a uniform mixture. Prepare 350g of a 3.0wt% hydrochloric acid aqueous solution and add it to the mixture for pickling at a temperature of 60°C. After the pickling is completed, stand the phases for separation, collect the oil phase and add 350g of a 4wt% sodium hydroxide aqueous solution thereto for alkali washing at a temperature of 60°C. After the alkali washing is completed, stand the phases for separation, collect the obtained oil phase and add 350g of deionized water thereto for water washing at a temperature of 60°C. After the water washing is completed, stand the phases for separation, and the obtained oil phase is desolvated at 135°C and 1.0KPaA to obtain the final product bisphenol A bis(diphenyl phosphate).

[0144] Table 5

[0145] Phosphorus content, wt% Triphenyl phosphate content, ppm Chroma, Hazen Viscosity at 40℃, cP Example 1 8.93 50 15 800 Example 2 8.94 30 12 700 Example 3 8.99 20 11 900 Example 4 9.01 30 12 800 Example 5 9.04 15 15 900 Comparative Example 1 8.3 2000 500 2300 Comparative Example 2 8.25 4500 1200 1200

[0146] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing bisphenol A bis(diphenyl phosphate), characterized in that: The process includes: S1, reacting phosphorus oxychloride and bisphenol A, removing excess raw materials after the reaction, and obtaining a reaction solution containing bisphenol A tetrachlorobisphosphate; In this step of the reaction, the mass ratio of the bisphenol A dichlorobisphosphate intermediate to the bisphenol A tetrachlorobisphosphate is controlled to be less than 0.1, preferably less than 0.08; S2, adding phenol to the reaction solution containing bisphenol A tetrachlorobisphosphate to carry out end-capping reaction, and removing excess raw materials to obtain bisphenol A bis(diphenyl phosphate).

2. The method for preparing bisphenol A bis(diphenyl phosphate) according to claim 1, characterized in that: In step S1, bisphenol A is mixed with phosphorus oxychloride in a dropwise manner for reaction, and preferably the dropwise addition time of the two portions of A is 1-10 hours, more preferably 3-7 hours; Preferably, the molar ratio of bisphenol A to phosphorus oxychloride is 1:(2-7), preferably 1:(3-6).

3. The method for preparing bisphenol A bis(diphenyl phosphate) according to claim 2, characterized in that: In step S1, the mass ratio of bisphenol A dichlorobisphosphate intermediate to bisphenol A tetrachlorobisphosphate is controlled by adjusting the feeding rate of bisphenol A.

4. The method for preparing bisphenol A bis(diphenyl phosphate) according to claim 1-3, characterized in that: The reaction in step S1 is carried out in the presence of an esterification catalyst; Preferably, the esterification catalyst is a hydrochloride of a Group 3-4 metal, preferably one or more of aluminum chloride, magnesium chloride, ferric chloride, zinc chloride and titanium tetrachloride; Preferably, the amount of the esterification catalyst used is 0.1-5% by mass of bisphenol A, preferably 0.5-2.5%.

5. The method for preparing bisphenol A bis(diphenyl phosphate) according to any one of claims 1 to 4, characterized in that: The reaction conditions in step S1 are: reaction temperature of 70-140° C., preferably 80-120° C.; and / or reaction pressure of 0.05-0.5 MPaA, preferably 0.08-0.2 MPaA; and / or reaction stirring speed of 100-800 rpm, preferably 200-400 rpm.

6. The method for preparing bisphenol A bis(diphenyl phosphate) according to any one of claims 1 to 5, characterized in that: In step S2, the amount of phenol used is 2-10 times, preferably 4-8 times, that of bisphenol A on a molar basis; Preferably, in step S2, phenol is added dropwise to the reaction solution containing bisphenol A tetrachlorobisphosphate, and the phenol addition time is preferably 0.5-5 h, preferably 1.0-3 h.

7. The method for preparing bisphenol A bis(diphenyl phosphate) according to any one of claims 1 to 6, characterized in that: In step S2, the reaction temperature is 80-130°C, preferably 100-120°C; and / or the reaction pressure is 10kPaA-101kPaA, preferably 30kPaA-80kPaA; and / or the reaction stirring speed is 100-800rpm, preferably 200-400rpm.

8. The method for preparing bisphenol A bis(diphenyl phosphate) according to any one of claims 1 to 7, characterized in that: The conditions for removing excess raw materials after the reaction in step S1 are: distilling to remove excess trichlorophosphine oxide at a temperature of 100-250° C., preferably 135° C.-165° C., and a pressure of 10 kPaA-100 kPaA, preferably 20 kPaA-80 kPaA; preferably, distilling is carried out under the condition of introducing a reaction inert gas.

9. The method for preparing bisphenol A bis(diphenyl phosphate) according to any one of claims 1 to 8, characterized in that: The conditions for removing excess raw materials after the reaction in step S2 are: removing excess phenol by distillation at a temperature of 100-250° C., preferably 135° C.-165° C., and a pressure of 0.05 MPaA-0.5 MPaA, preferably 0.08 MPaA-0.25 MPaA, to obtain a crude product; Preferably, after the reaction in step S2, excess raw materials are removed to obtain a crude product; the crude product is added to a solvent and dissolved, and then the solvent is removed after acid washing, alkali washing and water washing to obtain a product.

10. Bisphenol A bis(diphenyl phosphate) prepared by the method according to any one of claims 1 to 9, characterized in that: Taking the total molar amount as 100%, the following components are included: BDP monomer 90-92%, BDP dimer 7-13%, BDP trimer 0.6-2.0%, BDP tetramer 0.1-0.3%.

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