A method for preparing a silane-terminated polyether

Abstract

The present application relates to the technical field of modified polyether, and provides a preparation method of silane-terminated polyether.The present application carries out allylation reaction by mixing polyether, alkali metal alcoholate, inorganic catalyst, first catalyst aid and 3-halogenated propylene, to obtain allyl polyether crude product; the allyl polyether crude product is subjected to desalting washing to obtain allyl polyether; the allyl polyether, platinum-based catalyst, second catalyst aid and silane are mixed to carry out silanization reaction, to obtain the silane-terminated polyether.The present application uses polyether as a basic raw material, improves the traditional allyl-silicon hydrogen addition method, realizes the preparation of silane-terminated polyether resin, the silane functionality of the silane-terminated polyether prepared by the present application is greater than 1.75, the viscosity is 4.5-30 Pa·s, has wide applicability, and can meet the application requirements in different fields such as building materials and automobile industry.

Description

Technical Field

[0001] This invention relates to the field of modified polyether technology, and more particularly to a method for preparing silane-terminated polyether. Background Technology

[0002] Silane-modified polyether adhesive (MS adhesive) is a high-performance adhesive whose base polymer is an organosilane-terminated polyether. These adhesives, thanks to the siloxane groups at their end groups, can hydrolyze and cross-link upon contact with water, forming a stable Si-O-Si structure. Therefore, they possess excellent substrate adhesion, weather resistance, paintability, and environmental performance, and are widely used in prefabricated buildings, automobiles, ships, tunnel transportation, containers, and many other fields.

[0003] The structural characteristic of MS adhesive is that both ends of the long polyether chain are capped with siloxane groups. Due to the chemical stability of the polyether backbone itself, MS adhesive possesses excellent cold resistance, heat resistance, and weather resistance, ensuring long-term use without aging. The core of MS adhesive lies in the synthesis of silane-capped polyether resin. Currently, the mainstream technical routes include polyurethane prepolymerization and allyl-hydrosilylation. The allyl-hydrosilylation method first modifies the terminal hydroxyl groups of the polyether polyol by allylation to generate allyl polyether, then uses a silanization reaction to allow the silane containing Si-H bonds to add to the allyl polyether, ultimately achieving silane capping of the polyether. This method has relatively mild reaction conditions and produces a resin with a narrow molecular weight distribution, making it one of the most promising technical routes in current industrial production.

[0004] However, in the allyl-hydrosilylation method, the resulting allyl polyether typically has a low degree of unsaturation, which leads to a low silane functionality in the silane-terminated polyether after the subsequent silanization reaction. Low silane functionality directly weakens the resin's crosslinking ability, preventing the formation of a dense and stable Si-O-Si crosslinking network, and consequently causing a significant decrease in the adhesive's core properties such as adhesive strength. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing silane-terminated polyethers. The present invention improves the traditional allyl-hydrosilylation method, thereby increasing the unsaturation of allyl polyethers and the silane functionality of silane-terminated polyethers.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A method for preparing a silane-terminated polyether includes the following steps: Polyether, alkali metal alkoxide, inorganic catalyst, first catalyst promoter, and 3-halopropylene are mixed and subjected to an allylation reaction to obtain crude allyl polyether product; the molar amount of the alkali metal alkoxide is 7.5 to 12 times the molar amount of the polyether; the molar amount of the 3-halopropylene is 2.5 to 4.8 times the molar amount of the polyether; the inorganic catalyst is a halide salt; the first catalyst promoter is arylboronic acid. The crude allyl polyether product was desalted and washed to obtain allyl polyether. The allyl polyether, platinum-based catalyst, second catalyst promoter, and silane are mixed and subjected to a silanization reaction to obtain the silane-terminated polyether; the mass of the platinum-based catalyst is more than 0.0002 times the mass of the silane, based on the platinum element content; the second catalyst promoter is an ether compound; and the molar amount of the silane is more than twice the molar amount of the polyether.

[0007] Preferably, the number-average molecular weight of the polyether is 8000~31000.

[0008] Preferably, the alkali metal alkoxide includes one or both of sodium methoxide and sodium ethoxide; the alkali metal alkoxide is used in the form of an alcohol solution; The halogen salt includes one or more of sodium bromide, potassium bromide, lithium bromide, sodium iodide, and potassium iodide, and the molar amount of the inorganic catalyst is 0.02 to 0.25 times the molar amount of the polyether raw material; The arylboronic acid includes one or both of 3,5-bis(trifluoromethyl)phenylboronic acid and 2-formylphenylboronic acid, and the molar amount of the first catalyst promoter is 0.005 to 0.05 times the molar amount of the polyether. The 3-halopropene includes one or both of 3-chloropropene and 3-bromopropene.

[0009] Preferably, the allylation reaction is carried out at a temperature of 70-150°C for a time of 30-150 min.

[0010] Preferably, after the allylation reaction is completed, the reaction further includes: mixing the obtained reaction solution with an azeotropic aid and then performing vacuum distillation; the azeotropic aid is one or more of hexane, cyclohexane, and pentane; the molar amount of the azeotropic aid is 0.05 to 0.5 times the molar amount of 3-halopropylene.

[0011] Preferably, the desalination washing includes a first washing and a second washing; The detergent used in the first washing is an acidic aqueous solution; the acid in the acidic aqueous solution includes one or more of ascorbic acid, citric acid and tartaric acid; the concentration of the acid in the acidic aqueous solution is 0.1~2wt%; the mass of the acidic aqueous solution is 0.3~0.8 times the mass of the crude allyl polyether product; the temperature of the first washing is 50~100℃; The detergent used in the second washing is water and a neutral salt solution; the salt in the neutral salt solution includes one or more of sodium sulfate, ammonium chloride and ammonium sulfate; the concentration of the neutral salt solution is 5~25wt%; the mass of the neutral salt solution is 0.1~0.5 times the mass of the crude allyl polyether product; the mass of the water is 0.2~1 times the mass of the crude allyl polyether product; the temperature of the second washing is 50~100℃.

[0012] Preferably, before the silanization reaction, the process further includes mixing the allyl polyether and an azeotropic aid and then performing vacuum distillation; the azeotropic aid is one or more of hexane, cyclohexane, and pentane; and the molar amount of the azeotropic aid is 0.4 to 1.2 times the molar amount of the polyether.

[0013] Preferably, the platinum-based catalyst includes one or more of Karstedt catalyst, Speier catalyst and Ashby catalyst; the mass of the platinum-based catalyst is 0.0002 to 0.0005 times the mass of silane, based on the platinum element content. The ether compounds include one or more of diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, and 18-crown 6; the amount of the second catalyst promoter is 15 to 250 times the mass of platinum in the platinum-based catalyst.

[0014] Preferably, the silane includes one or more of dimethylmethoxysilane, methyldimethoxysilane, and trimethoxysilane; the molar amount of the silane is 2 to 5 times the molar amount of the polyether.

[0015] Preferably, the silanization reaction is carried out at a temperature of 70-90°C for 2-5 hours.

[0016] This invention provides a method for preparing silane-terminated polyether, comprising the following steps: mixing polyether, alkali metal alkoxide, inorganic catalyst, first catalyst promoter, and 3-halopropylene for an allylation reaction to obtain crude allyl polyether product; wherein the molar amount of the alkali metal alkoxide is 7.5 to 12 times the molar amount of the polyether; the molar amount of the 3-halopropylene is 2.5 to 4.8 times the molar amount of the polyether; the inorganic catalyst is a halogen salt; the first catalyst promoter is arylboronic acid; the crude allyl polyether product is desalted and washed to obtain allyl polyether; mixing the allyl polyether, platinum-based catalyst, second catalyst promoter, and silane for a silanization reaction to obtain the silane-terminated polyether; wherein, based on the platinum element content, the mass of the platinum-based catalyst is more than 0.0002 times the mass of the silane; the second catalyst promoter is an ether compound; and the molar amount of the silane is more than 2 times the molar amount of the polyether. This invention employs a halogen salt as a catalyst and arylboronic acid as a catalyst promoter in the allylation reaction, which can improve the reaction activity and the degree of unsaturation of the product. By controlling the amount of alkali metal alkoxide and 3-halopropylene, this invention can improve the degree of unsaturation of the product and reduce its total chlorine content. After the allylation reaction is completed, the crude allyl polyether product is desalted and washed to remove chlorine-containing impurities and further reduce the total chlorine content. In the silylation reaction, this invention adds a platinum-based catalyst and uses ether compounds as promoters, which can improve the reaction activity and increase the silane functionality of the product. In summary, this invention uses polyether as a base material and improves the traditional allyl-hydrosilylation method to prepare silane-terminated polyether resin. In the scheme described in this invention, the allyl polyether obtained by the allylation reaction has an unsaturation degree >1.8, and the silane-terminated polyether obtained by the silanization reaction has a silane functionality >1.75. Furthermore, the silane-terminated polyether structure is free of isocyanate, has a viscosity of 4.5~30 Pa·s, and a total chlorine content ≤230ppm. It has wide applicability and meets the application needs of different fields, from building materials to the automotive industry. Detailed Implementation

[0017] This invention provides a method for preparing silane-terminated polyethers, comprising the following steps: Polyether, alkali metal alkoxide, inorganic catalyst, first catalyst promoter, and 3-halopropylene are mixed and subjected to an allylation reaction to obtain crude allyl polyether product; the molar amount of the alkali metal alkoxide is 7.5 to 12 times the molar amount of the polyether; the molar amount of the 3-halopropylene is 2.5 to 4.8 times the molar amount of the polyether; the inorganic catalyst is a halide salt; the first catalyst promoter is arylboronic acid. The crude allyl polyether product was desalted and washed to obtain allyl polyether. The allyl polyether, platinum-based catalyst, second catalyst promoter, and silane are mixed and subjected to a silanization reaction to obtain the silane-terminated polyether; the mass of the platinum-based catalyst is more than 0.0002 times the mass of the silane, based on the platinum element content; the second catalyst promoter is an ether compound; and the molar amount of the silane is more than twice the molar amount of the polyether.

[0018] This invention involves mixing polyether, alkali metal alkoxide, inorganic catalyst, first catalyst promoter, and 3-halopropylene for an allylation reaction to obtain crude allyl polyether. In this invention, the polyether preferably has a number-average molecular weight of 8000-31000, a weight-average molecular weight of 10000-50000, a molecular weight distribution of 1.2-1.5, and a hydroxyl value of 0.3-1.5. The polyether is preferably obtained by ring-opening polymerization of cycloalkanes using dipropylene glycol (DPG) as an initiator. The cycloalkanes can be propylene oxide (PO) and / or butane oxide (BO). This invention does not specify a particular method for preparing the polyether; any method well-known to those skilled in the art can be used.

[0019] In this invention, the alkali metal alkoxide preferably includes one or both of sodium methoxide and sodium ethoxide; the molar amount of the alkali metal alkoxide is 7.5 to 12 times the molar amount of the polyether, specifically 7.5, 9 or 12 times; the alkali metal alkoxide is preferably used in the form of an alcohol solution, specifically an alkali metal alkoxide methanol solution.

[0020] In this invention, the inorganic catalyst is a halogen salt, which preferably includes one or more of sodium bromide, potassium bromide, lithium bromide, sodium iodide, and potassium iodide, more preferably sodium bromide; the molar amount of the inorganic catalyst is preferably 0.02 to 0.25 times the molar amount of the polyether, specifically 0.02, 0.05, or 0.25 times.

[0021] In this invention, the first catalyst promoter is arylboronic acid; the arylboronic acid preferably includes one or both of 3,5-bis(trifluoromethyl)phenylboronic acid and 2-formylphenylboronic acid, more preferably 3,5-bis(trifluoromethyl)phenylboronic acid; the molar amount of the first catalyst promoter is preferably 0.005 to 0.05 times the molar amount of polyether, specifically 0.005, 0.025 or 0.05 times.

[0022] In this invention, the 3-halopropylene preferably includes one or both of 3-chloropropylene and 3-bromopropylene, more preferably 3-chloropropylene; the molar amount of the 3-halopropylene is 2.5 to 4.8 times the molar amount of the polyether, specifically 2.5, 3.6 or 4.8 times.

[0023] In this invention, the temperature of the allylation reaction is preferably 70~150℃, specifically 70℃, 120℃ or 150℃, and the reaction time is preferably 30~150min, specifically 30, 60 or 150min; the time of the allylation reaction is started from the time when the 3-halopropylene is completely added.

[0024] In a specific embodiment of the present invention, it is preferable to first add polyether to the reaction vessel, then add an alcohol solution of alkali metal alkoxide, then add an inorganic catalyst and a first catalyst promoter, stir evenly and then perform vacuum distillation to remove the alcohol solvent in the material, then use nitrogen to replace the atmosphere in the reaction vessel, then heat the material in the reaction vessel to the temperature of the allylation reaction, and then add 3-halopropylene dropwise to carry out the reaction.

[0025] After the allylation reaction is completed, the present invention preferably further includes: mixing the obtained reaction solution with an azeotropic aid and then subjecting it to vacuum distillation; the azeotropic aid is preferably one or more of hexane, cyclohexane, and pentane, more preferably hexane; the molar amount of the azeotropic aid is preferably 0.05 to 0.5 times the molar amount of 3-halopropylene, more preferably 0.2 times. The present invention distills off alcohols introduced by alkali metal alkoxides and alcohols generated by the reaction of alkali metal alkoxides with polyethers through vacuum distillation.

[0026] After obtaining the crude allyl polyether product, the present invention performs desalting washing on the crude allyl polyether product to obtain allyl polyether. In this invention, the desalination washing preferably includes a first washing and a second washing; the detergent used in the first washing is preferably an acidic aqueous solution; the acid in the acidic aqueous solution preferably includes one or more of ascorbic acid, citric acid and tartaric acid, more preferably ascorbic acid; the concentration of the acid in the acidic aqueous solution is preferably 0.1~2wt%, specifically 0.05wt%; the mass of the acidic aqueous solution is preferably 0.3~0.8 times the mass of the crude allyl polyether product, more preferably 0.5 times; the temperature of the first washing is preferably 50~100℃, more preferably 85℃; in a specific embodiment of this invention, the crude allyl polyether product is preferably transferred into a washing tank, stirring and heating are turned on to maintain the material temperature at 50~100℃, an acidic aqueous solution is added to the washing tank, and the mixture is continuously stirred at a rate of 500 rpm for 50 min, then the stirring is reduced to 70 rpm for 15 min, and after the two phases slowly separate into layers, the stirring is turned off and the mixture is allowed to stand for 30 min, the lower aqueous phase is separated, and the upper organic phase is subjected to the second washing.

[0027] In this invention, the detergent used for the second washing is preferably water and a neutral salt solution; the salt in the neutral salt solution preferably includes one or more of sodium sulfate, ammonium chloride, and ammonium sulfate, more preferably sodium sulfate; the concentration of the neutral salt solution is preferably 5-25 wt%, more preferably 10 wt%; the mass of the neutral salt solution is preferably 0.1-0.5 times the mass of the crude allyl polyether product, more preferably 0.2 times; the mass of the water is preferably 0.2-1 times the mass of the crude allyl polyether product, more preferably 0.4 times; the temperature of the second washing is preferably 50-100℃, more preferably 85℃; the number of the second washing is preferably 2-5 times, specifically 3 times; in a specific embodiment of this invention, water is preferably added to the washing vessel first, and the mixture is continuously stirred at 500 rpm for 25 min at 50-100℃, then the stirring is reduced to 70 rpm for 5 min, a neutral salt solution is added to the washing vessel, and stirring is continued for 15 min. After the two phases slowly separate into layers, the stirring is turned off and the mixture is allowed to stand. The lower aqueous phase is separated, and the upper organic phase is repeated for the second washing. After the desalination washing is completed, the present invention preferably performs vacuum dehydration on the washed material. The vacuum dehydration temperature is preferably 90~100℃ and the time is preferably 30~60min, specifically 50min.

[0028] After obtaining the allyl polyether, the present invention mixes the allyl polyether, a platinum-based catalyst, a second catalyst promoter, and silane to carry out a silanization reaction to obtain the silane-terminated polyether. In the present invention, before the silanization reaction, it is preferable to further mix the allyl polyether and an azeotropic aid and perform vacuum distillation; the azeotropic aid is preferably one or more of hexane, cyclohexane, and pentane, more preferably hexane; the molar amount of the azeotropic aid is preferably 0.4 to 1.2 times the molar amount of the polyether, more preferably 0.8 times.

[0029] In this invention, the platinum-based catalyst preferably includes one or more of the following: Karstedt catalyst, Speier catalyst, and Ashby catalyst, more preferably the Karstedt catalyst (platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane); the mass of the platinum-based catalyst is more than 0.0002 times the mass of the silane, more preferably 0.0002 to 0.0005 times, and specifically 0.0003 times, based on the platinum element content.

[0030] In this invention, the second catalyst promoter preferably includes one or more of diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, and 18-crown 6; the amount of the second catalyst promoter is preferably 15 to 250 times the mass of platinum in the platinum-based catalyst, specifically 15, 48, 50, or 250 times.

[0031] In this invention, the silane preferably includes one or more of dimethylmethoxysilane, methyldimethoxysilane, and trimethoxysilane, more preferably methyldimethoxysilane; the molar amount of the silane is more than twice the molar amount of the polyether, preferably 2 to 5 times, specifically 2, 3, or 5 times.

[0032] In this invention, the temperature of the silanization reaction is preferably 70-90°C, more preferably 85°C, and the reaction time is preferably 2-5 hours, more preferably 3 hours. After the silanization reaction is completed, this invention preferably evaporates the residual silane in the system.

[0033] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] Preparation Example 1 Step 1: After leak testing of the polymerization reactor, continue purging with nitrogen for 30 minutes to remove residual moisture and air. Measure the water content of the raw materials propylene oxide (PO) and dipropylene glycol (DPG); the water content of the raw materials must be below 600 ppm. Add 356 g (6.13 mol, 58.1 Da) of propylene oxide (PO), 107 g (0.8 mol, 134.2 Da) of dipropylene glycol (DPG), and 4.04 kg (56 mol, 72.1 Da) of tetrahydrofuran to the polymerization reactor. Start stirring and continue adding 5.4 g of DMC catalyst (purchased from Huai'an Bad Polyurethane Technology Co., Ltd.). After the materials are mixed evenly, close the reactor and turn on the heater to raise the temperature of the materials to 85°C, and continue the reaction at this temperature for 30 minutes.

[0035] Step 2: After observing a significant decrease in pressure inside the reactor, heat the material inside the reactor to 105℃ and maintain this temperature. Then, add 9.14 kg (157.3 mol, 58.1 Da) of propylene oxide (PO) dropwise into the reactor at a uniform rate over 120 min. During the reaction, maintain the temperature of the material inside the reactor at 100–110℃. After the propylene oxide (PO) is completely added, continue to maintain the temperature for another 30 min.

[0036] Step 3: Cool the material in the reactor to 85°C, add 20.17 kg (347.3 mol, 58.1 Da) propylene oxide (PO) and 1.23 kg (9.2 mol, 134.2 Da) dipropylene glycol (DPG) to the reactor, start stirring, and continue stirring for 10 min to mix the material evenly. Then continue to keep the temperature and react for 60 min until the pressure in the reactor drops below 5 atm.

[0037] Step 4: Heat the material in the polymerization reactor to 130℃. Add 88.99 kg (1.53 kmol, 58.1 Da) of propylene oxide (PO) to the reactor at a uniform rate over 8 hours. During the reaction, the viscosity of the system gradually increases, and the stirring speed is gradually increased from 400 rpm to 700 rpm. Maintain the temperature of the material in the reactor at 130-140℃. After the PO is added, continue the reaction at this temperature for 30 minutes until the pressure inside the reactor drops below 5 atm. Vacuum the reactor and maintain the temperature while stirring for 60 minutes to remove THF solvent and low molecular weight impurities from byproducts.

[0038] The products of the polymerization reaction were sampled and tested using gel permeation chromatography (GPC) according to the test methods provided in GB / T 27843-2011. The molecular weight data were obtained as follows: number-average molecular weight Mn = 12281, weight-average molecular weight Mw = 16211, and molecular weight distribution D = 1.32. The samples were also tested according to the test methods provided in GB / T 12008.3-2009, and the hydroxyl value OHV of the product was found to be 0.903 mg KOH / g.

[0039] Preparation Examples 2-7 Other conditions are the same as in Preparation Example 1, only the type or amount of monomer in each step is changed to prepare polyether raw materials of different specifications. Specific conditions are shown in Table 1: Table 1. Raw material usage in Preparation Examples 1-7

[0040] Samples of each batch of polyether were taken and their molecular weight data and hydroxyl values ​​were tested according to the same procedure as in Preparation Example 1. The test results are shown in Table 2. Table 2. Molecular weight and hydroxyl value of the polyethers obtained in Preparation Examples 1-7

[0041] Example 1 1. Allylation 12.28 kg (1 mol) of the polyether product from Preparation Example 1 was weighed and added to the reactor. 486 g (9 mol, 9 eq, 54 Da) of sodium methoxide was prepared into a 30 wt% methanol solution. Stirring was started and the sodium methoxide solution was uniformly added to the reactor within 10 min. 5.2 g (0.05 mol, 0.05 eq, 102.9 Da) of sodium bromide and 6.4 g (0.025 mol, 0.025 eq, 257.9 Da) of 3,5-bis(trifluoromethyl)phenylboronic acid were added to the reactor. Stirring was started to mix the materials evenly. Heating was started and maintained at 70 °C and reduced pressure for 30 min to distill off the methanol in the materials.

[0042] The atmosphere inside the reactor was purged with nitrogen and the pressure maintained at 0.5 MPa. The material inside the reactor was heated to 120°C, and the stirring rate was increased. 275 g (3.6 mol, 3.6 eq, 76.5 Da) of 3-chloropropene was added dropwise uniformly to the reactor over 30 min. After the addition was complete, the reaction was maintained at 120°C for another 60 min. After the reaction was completed, the reactor was cooled to below 50°C, and 17.2 g (0.2 mol, 0.2 eq, 86.2 Da) of hexane was added. The mixture was stirred for 10 min until homogeneous. The pressure was reduced and the reactor was heated. Hexane and residual 3-chloropropene were distilled off below 135°C.

[0043] The product of the allylation reaction was sampled and the degree of unsaturation of the sample was tested according to the test method provided in GB / T 12008.6-2010. The degree of unsaturation of the product was U = 1.89.

[0044] 2. Desalination washing The material in the reactor was transferred into the washing vessel. Stirring and heating were started to maintain the material temperature at 85°C. 6 kg of 0.5% ascorbic acid aqueous solution was added to the washing vessel. The mixture was stirred at 500 rpm for 50 min and then the stirring was reduced to 70 rpm for 15 min. After the two phases slowly separated, the stirring was turned off and the mixture was allowed to stand for 30 min to separate the lower aqueous phase.

[0045] The polyether product in the washing vessel was washed three times with water and sodium sulfate solution according to the following steps: Add 4.8 kg of water to the washing vessel, stir continuously at 500 rpm for 25 min at 85°C, then reduce the stirring speed to 70 rpm for 5 min. Add 2.4 kg of a 10% sodium sulfate aqueous solution to the washing vessel and continue stirring at low speed for 15 min. After the two phases slowly separate, turn off the stirring and let stand for 30 min to separate the lower aqueous phase. After washing, turn on the reactor to stir, heat, and reduce the pressure, allowing the material to be vacuum dehydrated at 90-100°C for 50 min.

[0046] 3. Silanization reaction The desalted material was transferred to a reactor, and 69.0 g (8 mol, 0.8 eq, 86.2 Da) of hexane was added. The temperature was raised to 85°C, and the reactor was depressurized to distill off the hexane and remove residual moisture from the material. 3.2 g of a platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane isopropanol solution (Karstedt catalyst, 3% platinum content), 4.8 g (50 times the mass of Pt in the platinum-based catalyst) of diethylene glycol dimethyl ether, and 318.6 g (3 mol, 3 eq, 106.2 Da) of methyldimethoxysilane (DMS) were added to the reactor. The temperature was raised to 85°C, and the reaction was maintained at this temperature for 180 min. After the reaction, the residual DMS in the system was removed by vacuum distillation at 85°C for 10 min.

[0047] The obtained product was sampled, and the chlorine content was tested by titration according to the test method provided in GB / T 7139-2023. The total chlorine content of the product was 182 ppm. The water content of the product was tested by Karl Fischer method according to the method provided in GB / T 6283-2008, and X = 75.6 ppm. The viscosity of the product was tested using an Ubbelohde viscometer according to the test method in GB / T 1632.1-2024, and τ = 4450 cP.

[0048] Examples 2-7 Other conditions were the same as in Example 1, except that the amount of raw materials used in each step was changed. Different specifications of polyether were used as raw materials in Examples 2-7 to prepare MS resins of different specifications. The specific amounts of raw materials are shown in Table 3.

[0049] Table 3 Raw material input amounts for Examples 1-7

[0050] Examples 8-9: Sodium methoxide dosage MS resin was prepared using the polyether from Example 1 as a raw material, in the same manner as in Example 1. Based on Example 1, the amount of sodium methoxide added during the polyether allylation reaction was changed from 486 g (9 mol, 9 eq, 54 Da) in Example 1 to 405.0 g (7.5 mol, 7.5 eq, 54 Da) in Example 8 and 648.0 g (12 mol, 12 eq, 54 Da) in Example 9. The remaining processing steps and reaction conditions remained consistent with those in Example 1.

[0051] Examples 10-11: Allyl chloride dosage MS resin was prepared using the polyether from Example 1 as a raw material, in the same manner as in Example 1. Based on Example 1, the amount of allyl chloride added during the polyether allylation reaction was changed from 275.4 g (3.6 mol, 3.6 eq, 76.5 Da) in Example 1 to 191.3 g (2.5 mol, 2.5 eq, 76.5 Da) in Example 10 and 367.2 g (4.8 mol, 4.8 eq, 76.5 Da) in Example 11. The remaining processing steps and reaction conditions remained consistent with Example 1.

[0052] Examples 12-13: Sodium bromide dosage MS resin was prepared using the polyether from Example 2 as a raw material, following the same procedure as in Example 2. However, the amount of sodium bromide added during the polyether allylation reaction was changed from 7.7 g (0.075 mol, 0.05 eq, 102.9 Da) in Example 2 to 3.1 g (0.03 mol, 0.02 eq, 102.9 Da) in Example 12 and 38.6 g (0.375 mol, 0.25 eq, 102.9 Da) in Example 13. The remaining processing steps and reaction conditions remained consistent with those in Example 2.

[0053] Examples 14-15: Dosage of 3,5-bis(trifluoromethyl)phenylboronic acid MS resin was prepared using the polyether from Example 2 as a raw material, following the same procedure as in Example 2. The amount of 3,5-bis(trifluoromethyl)phenylboronic acid added during the polyether allylation reaction was changed from 9.7 g (0.0375 mol, 0.025 eq, 257.9 Da) in Example 2 to 1.9 g (0.0075 mol, 0.005 eq, 257.9 Da) in Example 14 and 19.3 g (0.075 mol, 0.05 eq, 257.9 Da) in Example 15. The remaining processing steps and reaction conditions remained consistent with Example 2.

[0054] Examples 16-17: Temperature and time of allylation reaction MS resin was prepared using the polyether from Example 2 as the raw material, in the same manner as in Example 2. Based on Example 2, the reaction temperature and time during the polyether allylation reaction were changed from 120°C and 60 min in Example 2 to 150°C and 30 min in Example 16, and 70°C and 150 min in Example 17. The remaining processing steps and reaction conditions remained consistent with Example 2.

[0055] Examples 18-19: Dosage of Platinum-based Catalyst MS resin was prepared using the polyether from Example 3 as the raw material, in the same manner as in Example 3. However, the amount of 3% Karstedt catalyst solution added during the polyether allylation reaction was changed from 2.5 g in Example 3 to 1.67 g in Example 18 and 4.17 g in Example 19. The remaining processing steps and reaction conditions remained consistent with those in Example 3.

[0056] Examples 20-21: Dosage of Second Catalyst Auxiliary MS resin was prepared using the polyether from Example 3 as a raw material, in the same manner as in Example 3. However, the amount of diethylene glycol dimethyl ether added during the polyether allylation reaction was changed from 3.8 g in Example 3 (50 times the mass of Pt in the platinum-based catalyst) to 1.14 g in Example 20 (15 times the mass of Pt in the platinum-based catalyst) and 18.7 g in Example 21 (250 times the mass of Pt in the platinum-based catalyst). The remaining processing steps and reaction conditions remained consistent with those in Example 3.

[0057] Examples 22-23: Silane dosage MS resin was prepared using the polyether from Example 3 as a raw material, in the same manner as in Example 3. However, the amount of methyl dimethoxysilane (DMS) added during the polyether allylation reaction was changed from 254.9 g (2.4 mol, 3 eq, 106.2 Da) in Example 3 to 169.9 g (1.6 mol, 2 eq, 106.2 Da) in Example 22 and 424.8 g (4 mol, 5 eq, 106.2 Da) in Example 23. The remaining processing steps and reaction conditions remained consistent with those in Example 3.

[0058] Comparative Examples 1-2: Sodium methoxide dosage MS resin was prepared using the polyether from Example 1 as a raw material, in the same manner as in Example 1. Based on Example 1, the amount of sodium methoxide added during the polyether allylation reaction was changed from 486 g (9 mol, 9 eq, 54 Da) in Example 1 to 378.0 g (7 mol, 7 eq, 54 Da) in Comparative Example 1 and 675.0 g (12.5 mol, 12.5 eq, 54 Da) in Comparative Example 2. The remaining processing steps and reaction conditions remained consistent with Example 1.

[0059] Comparative Examples 3-4: Allyl Chloride Dosage MS resin was prepared using the polyether from Example 1 as a raw material, in the same manner as in Example 1. Based on Example 1, the amount of allyl chloride added during the polyether allylation reaction was changed from 275.4 g (3.6 mol, 3.6 eq, 76.5 Da) in Example 1 to 175.9 g (2.3 mol, 2.3 eq, 76.5 Da) in Comparative Example 3 and 382.5 g (5 mol, 5 eq, 76.5 Da) in Comparative Example 4. The remaining processing steps and reaction conditions remained consistent with Example 1.

[0060] Comparative Example 5 (without sodium bromide) MS resin was prepared using the polyether from Example 2 as a raw material, in the same manner as in Example 2. However, the amount of sodium bromide added during the polyether allylation reaction was changed from 7.7 g (0.075 mol, 0.05 eq, 102.9 Da) in Example 2 to 0 g in Comparative Example 5, i.e., no sodium bromide was added. The remaining processing steps and reaction conditions remained consistent with those in Example 2.

[0061] Comparative Example 6 (without 3,5-bis(trifluoromethyl)phenylboronic acid) MS resin was prepared using the polyether from Example 2 as a raw material, in the same manner as in Example 2. However, the amount of 3,5-bis(trifluoromethyl)phenylboronic acid added during the polyether allylation reaction was changed from 9.7 g (0.0375 mol, 0.025 eq, 257.9 Da) in Example 2 to 0 g in Comparative Example 6, i.e., no 3,5-bis(trifluoromethyl)phenylboronic acid was added. The remaining processing steps and reaction conditions remained consistent with those in Example 2.

[0062] Comparative Example 7: The desalination washing step was omitted. MS resin was prepared using the polyether from Example 2 as the raw material, following the same procedure as in Example 2. However, after the polyether allylation reaction was completed, a separate washing and desalting step was omitted, and the product from the allylation reaction was directly fed into reactor 3 for silanization. The remaining processing steps and reaction conditions remained consistent with those in Example 2.

[0063] Comparative Example 8: Insufficient Platinum-based Catalyst MS resin was prepared using the polyether from Example 3 as the raw material, in the same manner as in Example 3. However, the amount of platinum-based catalyst added during the polyether allylation reaction was changed from 2.5 g in Example 3 to 0.8 g in Comparative Example 8. The remaining processing steps and reaction conditions remained consistent with those in Example 3.

[0064] Comparative Example 9 (without diethylene glycol dimethyl ether) MS resin was prepared using the polyether from Example 3 as a raw material, in the same manner as in Example 3. However, the amount of allyl chloride added during the polyether allylation reaction was changed from 3.8 g in Example 3 to 0 g in Comparative Example 9, i.e., no diethylene glycol dimethyl ether was added. The remaining processing steps and reaction conditions remained consistent with those in Example 3.

[0065] Comparative Example 10: Insufficient silane dosage MS resin was prepared using the polyether from Example 3 as a raw material, in the same manner as in Example 3. However, the amount of methyl dimethoxysilane (DMS) added during the polyether allylation reaction was changed from 254.9 g (2.4 mol, 3 eq, 106.2 Da) in Example 3 to 152.9 g (1.44 mol, 1.8 eq, 106.2 Da) in Comparative Example 10. The remaining processing steps and reaction conditions remained consistent with those in Example 3.

[0066] The allyl-substituted intermediates and MS resins prepared in the above examples and comparative examples were sampled, and the unsaturation data of the allylated polyether products and the total chlorine, water content, viscosity and other data of the MS resin products were tested according to the same scheme as in Preparation Example 1.

[0067] Table 4 is a statistical summary of the test results for product intermediates in each comparative example. Table 4 Test Results

[0068] In Preparation Examples 1-7, polyether polyols of different types and molecular weights were prepared by adjusting the types and proportions of monomers in the polyether. In Examples 1-7, MS resins were prepared using the polyether polyol products of Preparation Examples 1-7 as raw materials, demonstrating that the method described in this invention can be applied to the preparation of MS resins of different specifications.

[0069] Examples 8-11 and Comparative Examples 1-4 investigated the effects of sodium methoxide and allyl chloride on the allylation reaction during the allylation stage. Both excessively high and low amounts of sodium methoxide resulted in a decrease in the unsaturation of the allylation product. When the amount of allyl chloride was too low, the unsaturation of the allylation product decreased. When the amount of allyl chloride was too high, the chlorine-containing polymer impurities generated by allyl chloride led to an excessively high total chlorine content in the product.

[0070] Examples 12-17 and Comparative Examples 5-7 investigated the effects of the dosage ranges of sodium bromide catalyst and catalytic promoter 3,5-bis(trifluoromethyl)phenylboronic acid, the reaction temperature and time range, and the effects of boric acid catalyst and washing / desalting steps on the allylation reaction products during the allylation reaction stage. Under conditions without sodium bromide catalyst or without 3,5-bis(trifluoromethyl)phenylboronic acid, the substitution reaction activity was significantly reduced, and the unsaturation of the reaction products was low. After omitting the washing / desalting step, the total chlorine content of the reaction products increased.

[0071] Examples 18-23 and Comparative Examples 8-10 investigated the range of amounts of raw material DMS, platinum-based catalyst, and platinum-based catalyst promoter during the silanization reaction stage, and their effects on the silanization reaction products. Under the condition of no catalyst promoter diethylene glycol dimethyl ether, the silanization reaction activity was significantly reduced, and the silane functionality of the reaction product was low. When the amount of catalyst or DMS was too low, the silane functionality of the silanization product was also reduced.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a silane-terminated polyether, characterized in that, Includes the following steps: A polyether, an alkali metal alkoxide, an inorganic catalyst, a first catalyst promoter, and 3-halopropylene are mixed and subjected to an allylation reaction to obtain a crude allyl polyether product. The molar amount of the alkali metal alkoxide is 7.5 to 12 times that of the polyether; the molar amount of the 3-halopropylene is 2.5 to 4.8 times that of the polyether; the inorganic catalyst is a halogen salt; the first catalyst promoter is arylboronic acid; the halogen salt includes one or more of sodium bromide, potassium bromide, lithium bromide, sodium iodide, and potassium iodide; the molar amount of the inorganic catalyst is 0.02 to 0.25 times that of the polyether raw material; the arylboronic acid includes one or two of 3,5-bis(trifluoromethyl)phenylboronic acid and 2-formylphenylboronic acid; the molar amount of the first catalyst promoter is 0.005 to 0.05 times that of the polyether. The crude allyl polyether product was desalted and washed to obtain allyl polyether. The allyl polyether, platinum-based catalyst, second catalyst promoter, and silane are mixed and subjected to a silanization reaction to obtain the silane-terminated polyether; the mass of the platinum-based catalyst is more than 0.0002 times the mass of the silane, based on the platinum element content; the second catalyst promoter is an ether compound; the molar amount of the silane is more than twice the molar amount of the polyether; the ether compound includes one or more of diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, and 18-crown 6; the amount of the second catalyst promoter is 15 to 250 times the mass of platinum element in the platinum-based catalyst.

2. The preparation method according to claim 1, characterized in that, The number-average molecular weight of the polyether is 8000~31000.

3. The preparation method according to claim 1, characterized in that, The alkali metal alkoxide includes one or both of sodium methoxide and sodium ethoxide; the alkali metal alkoxide is used in the form of an alcohol solution; The 3-halopropene includes one or both of 3-chloropropene and 3-bromopropene.

4. The preparation method according to claim 1, characterized in that, The allylation reaction is carried out at a temperature of 70-150°C for a time of 30-150 minutes.

5. The preparation method according to claim 1, characterized in that, The allylation reaction further includes: mixing the resulting reaction solution with an azeotropic aid and then performing vacuum distillation; the azeotropic aid is one or more of hexane, cyclohexane, and pentane; the molar amount of the azeotropic aid is 0.05 to 0.5 times the molar amount of 3-halopropylene.

6. The preparation method according to claim 1, characterized in that, The desalination washing includes a first washing and a second washing; The detergent used in the first washing is an acidic aqueous solution; the acid in the acidic aqueous solution includes one or more of ascorbic acid, citric acid and tartaric acid; the concentration of the acid in the acidic aqueous solution is 0.1~2wt%; the mass of the acidic aqueous solution is 0.3~0.8 times the mass of the crude allyl polyether product; the temperature of the first washing is 50~100℃; The detergent used in the second washing is water and a neutral salt solution; the salt in the neutral salt solution includes one or more of sodium sulfate, ammonium chloride and ammonium sulfate; the concentration of the neutral salt solution is 5~25wt%; the mass of the neutral salt solution is 0.1~0.5 times the mass of the crude allyl polyether product; the mass of the water is 0.2~1 times the mass of the crude allyl polyether product; the temperature of the second washing is 50~100℃.

7. The preparation method according to claim 1, characterized in that, Before the silanization reaction, the process further includes mixing the allyl polyether and an azeotropic aid and then performing vacuum distillation; the azeotropic aid is one or more of hexane, cyclohexane, and pentane; the molar amount of the azeotropic aid is 0.4 to 1.2 times the molar amount of the polyether.

8. The preparation method according to claim 1, characterized in that, The platinum-based catalyst includes one or more of Karstedt catalyst, Speier catalyst and Ashby catalyst; the mass of the platinum-based catalyst is 0.0002 to 0.0005 times the mass of silane, based on the platinum element content.

9. The preparation method according to claim 1, characterized in that, The silane includes one or more of dimethylmethoxysilane, methyldimethoxysilane, and trimethoxysilane; the molar amount of the silane is 2 to 5 times the molar amount of the polyether.

10. The preparation method according to claim 1, characterized in that, The silanization reaction is carried out at a temperature of 70-90°C for 2-5 hours.

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