A process for the preparation of fluorinated pentachlorophosphate

Abstract

The present application relates to the chemical industry field, specifically to a preparation method of fluorinated pentachlorophosphate; the method provides fluorinated pentachlorophosphate prepared by using phosphorus pentachloride, MF and catalyst as raw materials; the raw material mixed solution utilizes the concentration difference, passes through the metal sintered filter plate provided with the catalyst, can accelerate the reaction, the catalyst usage amount is minimum, and the loss amount is minimum; due to the design of the metal sintered plate, the reaction kettle bottom discharge after the reaction is completed is the high-purity product; the present application provides a preparation of the catalyst sintered filter, the organic antimony complex, the lanthanum complex and the zirconium silicate beads are connected through intermolecular force, the active component is uniformly distributed on the zirconium silicate beads, the connection is firm, the loss is not easy, separation is easy, the service life of the catalyst can be improved, the catalyst is inlaid in the sintered filter, the catalyst loss is very small, the reaction material passes through the filter plate containing the catalyst and continuously refluxes, and the reaction efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering, and in particular to a method for preparing fluoropentachlorophosphate. Background Technology

[0002] Fluoropentachlorophosphate has a stable structure and can be used as a pharmaceutical intermediate or to prepare polyfluorophosphates. This substance can be prepared by fluorination of hexachlorophosphate.

[0003] CN104478742A: This invention provides a fluorinated compound having the following structural formula, which serves as a fluorinated pharmaceutical intermediate and has wide applications, wherein R is selected from C1-C6 alkyl groups. The invention also provides a method for preparing the above-mentioned fluorinated compound, which has at least the following advantages: mild reaction conditions, inexpensive and readily available raw materials, high yield per step, simple purification method, and high product purity.

[0004] CN101591211B discloses a method for preparing fluorinated compounds via microwave halogen exchange fluorination. The method comprises the following steps: drying a fluorinating agent in a microwave oven; adding reactants, a fluorinating agent, a solvent, and a catalyst to a reactor; sealing the reactor, introducing nitrogen gas, pressurizing, and heating with microwaves while stirring to ensure complete reaction; after the reaction, cooling to room temperature, and filtering the material to obtain a crude fluorinated compound product. This invention uses a microwave generator for internal radiative heating of the reactor instead of the traditional external heating method, which improves efficiency; the sealed method prevents air oxidation and reduces high-temperature coking of the product; increasing the nitrogen pressure during the reaction accelerates the reaction rate; by-products are recovered through filtration, and the liquid phase transfer catalyst and solvent are recycled after distillation. By adding reactants and a fluorinating agent, the catalyst can be reused. Compared with the previous method of recovering solid phase transfer catalysts via aqueous crystallization, this method generates no wastewater and reduces costs.

[0005] CN112851464B: This application provides a novel method for preparing fluorinated compounds from allyl alcohol compounds. The method is characterized by using an aromatic allyl alcohol compound as a raw material, and reacting it with a fluorinating agent using naphthol phosphate and a copper salt as catalysts. The allyl alcohol compound has the structural formula [not specified in the original text]. The fluorinated compound has the structural formula [not specified in the original text]. R is H, a C1-C6 alkyl group, a C1-C6 alkoxy group, a halogen, a cyano group, a nitro group, or a trifluoromethyl group, and R can be monosubstituted or polysubstituted. When R is polysubstituted, the substituents can be the same or different. Compared to other ligands in the prior art, naphthol phosphate in the catalyst has a simpler structure and is easier to obtain; it can be purchased directly or synthesized. Copper salt is also relatively inexpensive and more environmentally friendly. This application combines two simple, readily available, economical, and environmentally friendly substances, unexpectedly finding that they have high application value in the catalytic reaction of allyl alcohol compounds to prepare fluorinated products.

[0006] The above patents and existing technologies use the fluorination of hexachlorophosphate to prepare fluoropentachlorophosphate, which requires the preparation of hexachlorophosphate first, and then the preparation of fluoropentachlorophosphate using fluorine gas or hydrogen fluoride in a catalytic environment. This process has a long reaction chain and the fluorination process is highly dangerous.

[0007] Existing technologies use antimony or antimony oxide as chlorination catalysts, but due to their low catalytic activity and tendency to agglomerate, the catalytic efficiency and selectivity are reduced, requiring further improvement of the catalysts. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method for preparing fluoropentachlorophosphate, which addresses the shortcomings of the prior art.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing fluoropentachlorophosphate, with the molecular formula MPCl5F, and the operation steps are as follows:

[0010] S1: Add a catalyst sintering filter to the bottom of the reactor;

[0011] S2: Add organic solvent to the reaction vessel, slowly add MF and mix well to obtain a mixture;

[0012] S3: Turn on the stirrer in the reactor and set the speed to 20-100 rpm. Add a reflux pump to the bottom of the reactor to draw out the solvent from the bottom and then continuously reflux it from the top of the reactor.

[0013] S4: Phosphorus pentachloride is slowly added to the reactor in proportion to carry out the reaction;

[0014] S5: After the reaction is complete, the solution is pumped from the bottom reflux pump to the cooling crystallization vessel to obtain fluoropentachlorophosphate.

[0015] Preferably, M is an alkali metal such as Li, Na, K, Rb, or Cs.

[0016] Preferably, the organic solvent is one or more selected from ethyl acetate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and ethylene carbonate.

[0017] Preferably, the catalyst sintering filter is prepared with a bottom of 316L stainless steel sintered filter plate with a filtration accuracy of 0.1-1 micrometer, a catalyst layer in the middle, and a top metal wire mesh of 100-500 mesh, made of materials such as 316L, Hastelloy, or Monel alloy.

[0018] Preferably, the molar ratio of MF to PCl5 is 0.8-5:1.

[0019] Preferably, the reaction temperature of S4 is -10℃ to 60℃, and the reaction time is 5 to 20 hours.

[0020] This invention also provides a fluorination catalyst supported on an organometallic antimony and its preparation method, the preparation mechanism of which is as follows:

[0021] Antimony trichloride reacts with 4,4'-divinyl-2,2'-bipyridine to obtain a 4,4'-divinyl-2,2'-bipyridine antimony complex; this complex then undergoes a mercapto-vinyl addition reaction with zirconium silicate beads treated with mercaptosilane; lanthanum acrylate then undergoes a mercapto-vinyl addition reaction with zirconium silicate beads treated with mercaptosilane; the above organoantimony complexes, with the lanthanum complex and zirconium silicate beads linked by intermolecular forces, exhibit uniform distribution of the active components on the zirconium silicate beads, strong bonding, and are not easily lost or separated; further reduction of some elemental antimony yields a fluorinated catalyst supported on organometallic antimony.

[0022] Specifically, the preparation method of the fluorination catalyst supported on organometallic antimony is as follows:

[0023] T1: Take 5-10 parts by mass of antimony trichloride, 100-130 parts by mass of tetrahydrofuran, and 7-15 parts by mass of 4,4'-divinyl-2,2'-bipyridine, add them to a hydrothermal reactor, and react at 50-62°C for 30-60 minutes to obtain the 4,4'-divinyl-2,2'-bipyridine antimony complex;

[0024] T2: Under a nitrogen atmosphere, add 100-200 parts of mercaptosilane-treated zirconium silicate beads, 0.01-0.1 parts of lanthanum acrylate, 2-4 parts of sodium tert-butoxide, and 500-1000 parts of tetrahydrofuran to the S1 reactor. Stir at 70-80℃ for 40-70 minutes, filter, and dry to obtain the catalyst precursor.

[0025] T3: The catalyst precursor is reduced in a hydrogen atmosphere at a temperature of 80-110°C for 50-100 minutes to obtain a fluorinated catalyst supported on an organometallic antimony.

[0026] Preferably, the method for preparing the mercaptosilane-treated zirconium silicate beads is as follows:

[0027] Take 150-240 parts by weight of zirconium silicate beads, 1000-1500 parts of water, and 4-7 parts of mercaptosilane, react at 30-45℃ for 40-150 minutes, filter, and dry to obtain mercaptosilane-treated zirconium silicate beads.

[0028] Preferably, the zirconium silicate beads have a CAS number of 1314-23-4 and a particle size of 5-10 mm.

[0029] Technical effects:

[0030] The present invention provides a method for preparing fluoropentachlorophosphate, which has the following significant advantages compared with the prior art:

[0031] 1. The raw material mixture solution of the present invention utilizes the concentration difference and passes through a metal sintered filter plate containing a catalyst to accelerate the reaction. The amount of catalyst used is minimized and the loss is minimized. Due to the design of the metal sintered plate, the material discharged from the bottom of the reaction vessel after the reaction is completed is a high-purity product.

[0032] 2. This invention provides a novel synthetic route for fluorinated pentachlorophosphate, which is simpler, consumes less energy, is safer, and uses readily available raw materials compared to traditional preparation methods.

[0033] 3. This invention provides a method for preparing a catalyst sintered filter. The organic antimony complex, lanthanum complex and zirconium silicate beads are connected by intermolecular forces. The active components are evenly distributed on the zirconium silicate beads, the connection is firm, not easy to lose, and easy to separate, which can improve the service life of the catalyst. The catalyst is embedded in the sintered filter, the catalyst loss is very small, and the reactants are continuously refluxed through the filter plate containing the catalyst, which greatly improves the reaction efficiency. Attached image description:

[0034] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0035] To better understand the above technical solutions, the embodiments of the present invention further illustrate the present invention in detail by listing the preparation of fluoropentachlorophosphate.

[0036] The following specific embodiments are detailed descriptions of the technical solutions of this application. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solutions of this application, and not limitations thereof. Unless otherwise specified, the embodiments and compounds and technical features in the embodiments can be combined with each other. It should be understood that the term "and / or" as used herein includes any and all combinations of one or more of the listed associated items.

[0037] The present application will be described in more detail below through embodiments. These embodiments are merely descriptions of the best implementation of the present application and do not limit the scope of the present application in any way.

[0038] Example 1

[0039] A method for preparing a fluoropentachlorophosphate with the molecular formula MPCl5F, comprising the following steps:

[0040] S1: Add a catalyst sintering filter to the bottom of the reactor;

[0041] S2: Add ethyl acetate to the reaction vessel, then slowly add 200g of LiF and mix thoroughly to obtain a mixture;

[0042] S3: Turn on the stirrer in the reactor and set the speed to 20 rpm. Add a reflux pump to the bottom of the reactor to draw out the solvent from the bottom and then continuously reflux it from the top of the reactor.

[0043] S4: Slowly add 1600g of phosphorus pentachloride to the reactor to carry out the reaction;

[0044] S5: After the reaction is complete, the mixture is pumped from the bottom to the cooling crystallization vessel to obtain 1766g of lithium fluoropentachlorophosphate.

[0045] The catalyst sintering filter is prepared by using a 316L stainless steel sintered filter plate at the bottom with a filtration accuracy of 0.1 micrometers, a catalyst layer in the middle, and a 100-mesh metal wire mesh at the top made of 316L stainless steel.

[0046] The catalyst is a fluorinated catalyst supported on an organometallic antimony, and its preparation method is as follows:

[0047] T1: Take 5g of antimony trichloride, 100g of tetrahydrofuran, and 7g of 4,4'-divinyl-2,2'-bipyridine, add them to a hydrothermal reactor, and react at 50°C for 30 minutes to obtain the 4,4'-divinyl-2,2'-bipyridine antimony complex;

[0048] T2: Under a nitrogen atmosphere, add 100g of mercaptosilane-treated zirconium silicate beads, 0.01g of lanthanum acrylate, 2g of sodium tert-butoxide, and 500g of tetrahydrofuran to the S1 reactor. Stir at 70°C for 40 minutes, filter, and dry to obtain the catalyst precursor.

[0049] T3: The catalyst precursor is reduced in a hydrogen atmosphere at a temperature of 80°C for 50 minutes to obtain a fluorinated catalyst supported on an organometallic antimony.

[0050] The method for preparing the mercaptosilane-treated zirconium silicate beads is as follows:

[0051] Take 150g of zirconium silicate beads, 1000g of water, and 4g of mercaptosilane, react them at 30℃ for 40 minutes, filter, and dry to obtain mercaptosilane-treated zirconium silicate beads.

[0052] The zirconium silicate beads have a CAS number of 1314-23-4 and a particle size of 5 mm.

[0053] The molar ratio of MF to PCl5 is 0.8:1.

[0054] The reaction temperature of S4 is -10℃, and the reaction time is 5h.

[0055] Example 2

[0056] A method for preparing a fluoropentachlorophosphate with the molecular formula MPCl5F, comprising the following steps:

[0057] S1: Add a catalyst sintering filter to the bottom of the reactor;

[0058] S2: Add dimethyl carbonate to the reaction vessel, slowly add 180g NaF and mix well to obtain a mixture;

[0059] S3: Turn on the stirrer in the reactor and set the speed to 50 rpm. Add a reflux pump to the bottom of the reactor to draw out the solvent from the bottom and then continuously reflux it from the top of the reactor.

[0060] S4: Slowly add 900g of phosphorus pentachloride to the reactor to carry out the reaction;

[0061] S5: After the reaction is complete, the solution is pumped from the bottom reflux pump to the cooling crystallization vessel to obtain 1052g of sodium fluoropentachlorophosphate.

[0062] The catalyst sintering filter described herein has a bottom of 316L stainless steel sintered filter plate with a filtration accuracy of 0.5 micrometers, a catalyst layer in the middle, and a top metal wire mesh of 200 mesh made of Hastelloy alloy.

[0063] The catalyst is a fluorinated catalyst supported on an organometallic antimony, and its preparation method is as follows:

[0064] T1: Take 6g of antimony trichloride, 110g of tetrahydrofuran, and 9g of 4,4'-divinyl-2,2'-bipyridine, add them to a hydrothermal reactor, and react at 55℃ for 40 minutes to obtain the 4,4'-divinyl-2,2'-bipyridine antimony complex;

[0065] T2: Under a nitrogen atmosphere, add 140g of mercaptosilane-treated zirconium silicate beads, 0.05g of lanthanum acrylate, 3g of sodium tert-butoxide, and 600g of tetrahydrofuran to the S1 reactor. Stir at 75°C for 50 minutes, filter, and dry to obtain the catalyst precursor.

[0066] T3: The catalyst precursor is reduced in a hydrogen atmosphere at a temperature of 90°C for 60 minutes to obtain a fluorinated catalyst supported on an organometallic antimony.

[0067] The method for preparing the mercaptosilane-treated zirconium silicate beads is as follows:

[0068] Take 180g of zirconium silicate beads, 1100g of water, and 5g of mercaptosilane, react them at 35℃ for 80 minutes, filter, and dry to obtain mercaptosilane-treated zirconium silicate beads.

[0069] The zirconium silicate beads have a CAS number of 1314-23-4 and a particle size of 6 mm.

[0070] The molar ratio of MF to PCl5 is 2:1.

[0071] The reaction temperature of S4 is 10℃ and the reaction time is 10h.

[0072] Example 3

[0073] A method for preparing a fluoropentachlorophosphate with the molecular formula MPCl5F, comprising the following steps:

[0074] S1: Add a catalyst sintering filter to the bottom of the reactor;

[0075] S2: Add ethyl methyl carbonate to the reactor, slowly add 150g KF and mix well to obtain a mixture;

[0076] S3: Turn on the stirrer in the reactor and set the speed to 80 rpm. Add a reflux pump to the bottom of the reactor to draw out the solvent from the bottom and then continuously reflux it from the top of the reactor.

[0077] S4: Slowly add 530g of phosphorus pentachloride to the reactor to carry out the reaction;

[0078] S5: After the reaction is complete, the solution is pumped from the bottom reflux pump to the cooling crystallization vessel to obtain 655g of potassium fluoropentachlorophosphate.

[0079] The catalyst sintering filter is prepared by using a 316L stainless steel sintered filter plate at the bottom with a filtration accuracy of 0.8 micrometers, a catalyst layer in the middle, and a 400-mesh metal wire mesh at the top made of Hastelloy alloy.

[0080] The catalyst is a fluorinated catalyst supported on an organometallic antimony, and its preparation method is as follows:

[0081] T1: Take 8g of antimony trichloride, 120g of tetrahydrofuran, and 13g of 4,4'-divinyl-2,2'-bipyridine, add them to a hydrothermal reactor, and react at 60℃ for 50 minutes to obtain the 4,4'-divinyl-2,2'-bipyridine antimony complex;

[0082] T2: Under a nitrogen atmosphere, add 180g of mercaptosilane-treated zirconium silicate beads, 0.08g of lanthanum acrylate, 3g of sodium tert-butoxide, and 900g of tetrahydrofuran to the S1 reactor. Stir at 75°C for 60 minutes, filter, and dry to obtain the catalyst precursor.

[0083] T3: The catalyst precursor is reduced in a hydrogen atmosphere at a temperature of 100°C for 90 minutes to obtain a fluorinated catalyst supported on an organometallic antimony.

[0084] The method for preparing the mercaptosilane-treated zirconium silicate beads is as follows:

[0085] Take 220g of zirconium silicate beads, 1400g of water, and 6g of mercaptosilane, react them at 40℃ for 120 minutes, filter, and dry to obtain mercaptosilane-treated zirconium silicate beads.

[0086] The zirconium silicate beads have a CAS number of 1314-23-4 and a particle size of 8 mm.

[0087] The molar ratio of MF to PCl5 is 4:1.

[0088] The reaction temperature of S4 is 40℃ and the reaction time is 15h.

[0089] Example 4

[0090] A method for preparing a fluoropentachlorophosphate with the molecular formula MPCl5F, comprising the following steps:

[0091] S1: Add a catalyst sintering filter to the bottom of the reactor;

[0092] S2: Add ethylene carbonate to the reactor, slowly add 130g CsF and mix well to obtain a mixture;

[0093] S3: Turn on the stirrer in the reactor and set the speed to 100 rpm. Add a reflux pump to the bottom of the reactor to draw out the solvent from the bottom and then continuously reflux it from the top of the reactor.

[0094] S4: Slowly add 185g of phosphorus pentachloride to the reactor to carry out the reaction;

[0095] S5: After the reaction is complete, the mixture is pumped from the bottom reflux pump to the cooling crystallization vessel to obtain 315g of cesium fluoropentachlorophosphate.

[0096] The catalyst sintering filter described herein has a bottom of 316L stainless steel sintered filter plate with a filtration accuracy of 1 micrometer, a catalyst layer in the middle, and a top metal wire mesh of 500 mesh made of Monel alloy.

[0097] The catalyst is a fluorinated catalyst supported on an organometallic antimony, and its preparation method is as follows:

[0098] T1: Take 10g of antimony trichloride, 130g of tetrahydrofuran, and 15g of 4,4'-divinyl-2,2'-bipyridine, add them to a hydrothermal reactor, and react at 62℃ for 60 minutes to obtain the 4,4'-divinyl-2,2'-bipyridine antimony complex;

[0099] T2: Under a nitrogen atmosphere, add 200g of mercaptosilane-treated zirconium silicate beads, 0.1g of lanthanum acrylate, 4g of sodium tert-butoxide, and 1000g of tetrahydrofuran to the S1 reactor. Stir at 80°C for 70 minutes, filter, and dry to obtain the catalyst precursor.

[0100] T3: The catalyst precursor is reduced in a hydrogen atmosphere at a temperature of 110°C for 100 minutes to obtain a fluorinated catalyst supported on an organometallic antimony.

[0101] The method for preparing the mercaptosilane-treated zirconium silicate beads is as follows:

[0102] Take 240g of zirconium silicate beads, 1500g of water, and 7g of mercaptosilane, react them at 45℃ for 150 minutes, filter, and dry to obtain mercaptosilane-treated zirconium silicate beads.

[0103] The zirconium silicate beads mentioned above have a CAS number of 1314-23-4 and a particle size of 10 mm.

[0104] The molar ratio of MF to PCl5 is 5:1.

[0105] The reaction temperature of S4 is 60℃ and the reaction time is 20h.

[0106] Comparative Example 1

[0107] Zirconium silicate beads without the addition of mercaptosilane treatment are otherwise the same as in Example 1.

[0108] Comparative Example 2

[0109] Without the addition of 4,4'-divinyl-2,2'-bipyridine, everything else is the same as in Example 1.

[0110] Comparative Example 3

[0111] Lanthanum acrylate was not added; otherwise, it was the same as in Example 1.

[0112] Table 1. Detection results of the examples

[0113] Purity of fluoropentachlorophosphate / % Yield / % Example 1 99.95 98.60 Example 2 99.97 99.12 Example 3 99.98 99.46 Example 4 99.99 99.58 Comparative Example 1 85.65 83.71 Comparative Example 2 90.23 88.15 Comparative Example 3 92.19 90.53

[0114] The technical solutions described in the embodiments of this application have advantages such as simple preparation process, low energy consumption, low cost, and are easy to implement industrially.

[0115] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0116] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a fluoropentachlorophosphate, with the molecular formula MPCl5F, comprising the following steps: S1: Add a catalyst sintering filter to the bottom of the reactor; S2: Add organic solvent to the reaction vessel, slowly add MF and mix well to obtain a mixture; S3: Turn on the stirrer in the reactor and set the speed to 20-100 rpm. Add a reflux pump to the bottom of the reactor to draw out the solvent from the bottom and then continuously reflux it from the top of the reactor. S4: Phosphorus pentachloride is slowly added to the reactor in proportion to carry out the reaction; S5: After the reaction is complete, the solution is pumped from the bottom reflux pump to the cooling crystallization vessel to obtain fluoropentachlorophosphate; The catalyst is a fluorinated catalyst supported on an organometallic antimony, and its preparation method is as follows: T1: Take 5-10 parts by mass of antimony trichloride, 100-130 parts by mass of tetrahydrofuran, and 7-15 parts by mass of 4,4''-divinyl-2,2''-bipyridine, add them to a hydrothermal reactor, and react at 50-62°C for 30-60 minutes to obtain the 4,4''-divinyl-2,2''-bipyridine antimony complex; T2: Under a nitrogen atmosphere, add 100-200 parts of mercaptosilane-treated zirconium silicate beads, 0.01-0.1 parts of lanthanum acrylate, 2-4 parts of sodium tert-butoxide, and 500-1000 parts of tetrahydrofuran to the T1 reactor. Stir at 70-80℃ for 40-70 minutes, filter, and dry to obtain the catalyst precursor. T3: The catalyst precursor is reduced in a hydrogen atmosphere at a temperature of 80-110°C for 50-100 minutes to obtain a fluorinated catalyst supported on an organometallic antimony. The method for treating zirconium silicate beads with mercaptosilane is as follows: Take 150-240 parts by weight of zirconium silicate beads, 1000-1500 parts of water, and 4-7 parts of mercaptosilane, react at 30-45℃ for 40-150 minutes, filter, and dry to obtain mercaptosilane-treated zirconium silicate beads.

2. The method for preparing fluoropentachlorophosphate according to claim 1, characterized in that: M is an alkali metal, such as Li, Na, K, Rb, or Cs.

3. The method for preparing fluoropentachlorophosphate according to claim 1, characterized in that: The organic solvent is one or more of ethyl acetate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and ethylene carbonate.

4. The method for preparing fluoropentachlorophosphate according to claim 1, characterized in that: The catalyst sintering filter is prepared by using a 316L stainless steel sintered metal filter plate at the bottom with a filtration accuracy of 0.1-1 micrometer, a catalyst layer in the middle, and a 100-500 mesh metal wire mesh at the top, made of 316L, Hastelloy, or Monel alloy.

5. The method for preparing fluoropentachlorophosphate according to claim 1, characterized in that... The zirconium silicate beads mentioned above have a CAS number of 10101-52-7 and a particle size of 5-10 mm.

6. The method for preparing fluoropentachlorophosphate according to claim 1, characterized in that: The molar ratio of MF to PCl5 is 0.8-5:

1.

7. The method for preparing fluoropentachlorophosphate according to claim 1, characterized in that: The reaction temperature of S4 is -10℃ to 60℃, and the reaction time is 5 to 20 hours.

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