Preparation method of amino / alkylsilane oligomer

Abstract

The invention relates to a preparation method of an amino / alkylsilane oligomer, and belongs to the technical field of organic chemical synthesis. The preparation method comprises the following steps: carrying out catalytic hydrolysis on propyltrimethoxysilane through an immobilized catalyst, and then copolymerizing the hydrolyzed propyltrimethoxysilane and hydrolyzed 3-aminopropyltrimethoxysilane to obtain the product. The product not only has an amino functional group with high reaction activity, but also has a propyl functional group with waterproof performance and flexible performance, and chloride ions are not introduced in the reaction process, so that the product has the characteristics of excellent storage stability, strong adhesive force and low chlorine.

Description

Technical Field

[0001] The invention relates to a method for preparing an amino / alkylsilane oligomer, belonging to the technical field of organic chemical synthesis. Background Art

[0002] Silane oligomers are oligomers with high functionality obtained by hydrolysis and condensation of one or two or more silane coupling agents. They have the characteristics of high cross-linking, high boiling point, and low volatility. Due to their excellent high and low temperature resistance, weather resistance, dielectric properties, low surface tension, physiological inertness, and easy processing, they are widely used in electronics, electrical appliances, transportation, aerospace, construction, textiles, papermaking, leather, food, medicine, health and other fields.

[0003] The synthesis methods for silane oligomers are generally categorized into acid-catalyzed, base-catalyzed, quaternary ammonium salt-catalyzed, organotin-catalyzed, and organotitanium-catalyzed methods. As the application areas of silane oligomer products continue to expand, these commonly used synthesis methods are no longer suitable for the synthesis of all silane oligomer products. This is primarily due to the presence of residual catalysts in these methods, which can affect product quality. Patent application number 201911370061.6 discloses a method for preparing organosilane oligomers. Under anhydrous conditions, an organosilane is dissolved in an organic solvent, boric acid or sodium fluoride is added as a catalyst, and the mixture is then heated to 50-60°C, slowly added dropwise to a mixture of water and alcohol. After the addition is complete, the mixture is heated to 70-80°C and maintained for two hours. The alcohol is then removed by vacuum to produce a colorless, transparent organosilane oligomer with a uniform degree of polymerization. The catalyst used is boric acid or sodium fluoride, which can catalyze the hydrolysis of silane very well. However, the catalyst is easily soluble and cannot be separated from the system. Its residue will affect the application range of the product.

[0004] In addition, the oligomers synthesized from two or more silane coupling agents also have the problem of hydrolysis imbalance. The main reason is that the activities of the single-molecule coupling agents are different, and the hydrolysis rates are different. When the two silane coupling agents are mixed and hydrolyzed together, the one with a faster hydrolysis rate will hydrolyze first, and the one with a slower hydrolysis rate will hydrolyze later. Therefore, the synthesized silane oligomer product will have one silane monomer deeply hydrolyzed, while the other silane monomer will hydrolyze shallowly, resulting in a hydrolysis imbalance problem. The patent application with application number 202011205260.4 discloses an amino copolymer silane coupling agent, its preparation method and application. Aminoethylaminopropylmethyldimethoxysilane and phenyltrimethoxysilane are mixed and hydrolyzed together. Aminoethylaminopropylmethyldimethoxysilane will be hydrolyzed deeply, and phenyltrimethoxysilane will be hydrolyzed shallowly. If the amount of phenyltrimethoxysilane fed is large and the amount of aminoethylaminopropylmethyldimethoxysilane fed is small, it will cause deep hydrolysis of aminoethylaminopropylmethyldimethoxysilane. The synthesized oligomer product will have stratification problems due to large density differences, which seriously affects the quality of the silane oligomer product.

[0005] Therefore, in the preparation of amino / alkyl silane oligomer, it is necessary to develop a preparation method of amino / alkyl silane oligomer to solve the above problems. SUMMARY

[0006] The purpose of the present application is to provide a preparation method of amino / alkyl silane oligomer which can reduce catalyst residue, ensure hydrolysis balance and guarantee the preparation of amino / alkyl silane oligomer.

[0007] The technical scheme of the present application is: A preparation method of amino / alkyl silane oligomer, characterized in that it comprises the following steps: 1) Put propyl trimethoxysilane, solvent methanol and solid catalyst into the reaction kettle, and put deionized water and solvent methanol into the metering tank; 2) Start stirring the reaction kettle and slowly heat it, and after the kettle temperature reaches the process temperature, the mixture in the metering tank is uniformly added to the reaction kettle at a speed of 60-80 kg / h to carry out the hydrolysis reaction of propyl trimethoxysilane; after the feeding is completed, the temperature is maintained for aging reaction for 2 h to ensure complete reaction of deionized water; after aging, the propyl trimethoxysilane hydrolysis material is transferred to the transfer tank after being cooled to room temperature; 3) Put 3-aminopropyl trimethoxysilane product into the reaction kettle, start stirring the reaction kettle and slowly heat it, and after the kettle temperature reaches the process temperature, the propyl trimethoxysilane hydrolysis material obtained in step 3) is uniformly added to the reaction kettle; 4) Put deionized water and solvent methanol into the metering tank, and uniformly add the mixture to the reaction kettle at a speed of 60-80 kg / h to carry out the hydrolysis reaction; after the feeding is completed, the temperature is maintained for aging reaction for 2 h to ensure complete reaction of deionized water; in this reaction, 3-aminopropyl trimethoxysilane is copolymerized with the propyl trimethoxysilane hydrolysis material while being hydrolyzed, and the hydrolysis reaction speed is controlled by the feeding speed of deionized water; 5) After hydrolysis, the reaction kettle is slowly heated, and the solvent methanol in the reaction kettle is distilled out in the order of normal pressure and reduced pressure; after the distillation of solvent methanol is completed, the reaction kettle material is first cooled to room temperature, and then the solid catalyst is removed by filtration to obtain the amino / alkyl silane oligomer product.

[0008] The solid catalyst in step 1) is acid clay, and the addition amount of the solid catalyst is 0.15% of the feeding amount of propyl trimethoxysilane.

[0009] The molar ratio of propyl trimethoxysilane to deionized water in step 1) is 1:0.65-0.85. During the silane hydrolysis process, silicon hydroxyl groups are first formed, two molecules of silicon hydroxyl groups condense to produce one molecule of water, and then continue to hydrolyze to form silicon hydroxyl groups. Therefore, 1 mol of water is added, and the actual amount of water participating in the chemical reaction is 2 mol, so the hydrolysis reaction is actually water excess.

[0010] The mass ratio of propyl trimethoxysilane to solvent methanol in the step 1) is 1:0.2.

[0011] The mass ratio of deionized water to solvent methanol in the step 1) is 1:2. In the hydrolysis reaction process, the main role of the solvent methanol is dilution, the mass ratio of propyl trimethoxysilane to methanol is the ratio of methanol diluting propyl trimethoxysilane in the reaction kettle, and the mass ratio of deionized water to solvent methanol is the ratio of methanol diluting water in the metering tank, which is the most economical ratio in industry.

[0012] The molar ratio of propyl trimethoxysilane to 3-aminopropyl trimethoxysilane in the step 3) is 1:0.2-2.

[0013] The mass ratio of deionized water to solvent methanol in the step 4) is 1:2.

[0014] The molar ratio of 3-aminopropyl trimethoxysilane to deionized water in the metering tank in the step 4) is 1:0.65-0.85. In the silane hydrolysis process, silicon hydroxyl is first formed, two molecules of silicon hydroxyl condense to produce one molecule of water as a byproduct, and then continue to hydrolyze to form silicon hydroxyl. Therefore, 1 mol of water is actually involved in the chemical reaction of 2 mol of water, so the hydrolysis reaction is actually water excess. The polymer is a mixture, and there is also a single molecule of silane component, which does not need to be removed and is an effective component of the polymer.

[0015] The temperature in the step 2) and the reaction process in the step 4) and the propyl trimethoxysilane hydrolysis material feeding process in the step 3) is 40-50℃, and the pressure is 0-30kPa.

[0016] The reaction equation of the present application is as follows:

[0017] The free chlorine in the obtained amino / alkyl silane oligomer product is 1.0ppm or less, the silicon content is 40-45%, the appearance is colorless transparent liquid, there is no yellowing problem after 1 year of closed storage or 24h oven test at 80℃, and the molar yield is 99.0% or more.

[0018] The present application has the following beneficial effects: The amino / alkyl silane oligomer product of the present application has both high reactive amino functional groups and propyl functional groups with water resistance and flexibility, thus has excellent storage stability and strong adhesion characteristics, and can be used as an adhesion promoter in the paint, adhesive and sealant industries to improve the adhesion between inorganic surfaces, plastic surfaces and inorganic fillers and resins with amino reactivity, including room temperature vulcanized (RTV) silicone rubber, two-component polyurethane, silicone modified polyurethane, silane modified (MS) resin and two-component epoxy resin, and has good transparency and compatibility in two-component RTV pouring sealant.

[0019] Since no chlorine-containing compound is used in the synthesis process, the product obtained by the present application also has the characteristics of low chlorine, and the free chlorine can be controlled below 1.0 ppm. The low chlorine polymer has low corrosion, and at the same time, the low chlorine polymer has good electrical insulation performance. DETAILED DESCRIPTION Example 1

[0020] The preparation method of the amino / alkyl silane oligomer includes the following steps: 1) Put 820 kg of propyl trimethoxysilane, 164 kg of solvent methanol and 1.23 kg of acidic white clay into the reaction kettle; put 63 kg of ionized water and 126 kg of solvent methanol into the metering tank; 2) Start stirring, slowly heat the reaction kettle, and when the kettle temperature reaches 40℃, evenly pour the mixture in the metering tank into the reaction kettle to carry out the hydrolysis reaction of propyl trimethoxysilane. During the hydrolysis reaction, the kettle temperature is controlled at 40-50℃, and the pressure is 0-30 kPa; 3) After the metering tank mixture is completely fed, carry out aging reaction at a temperature of 40-50℃ for 2 hours. The water content is 0.04% after sampling detection, indicating that the hydrolysis is complete. Then, the propyl trimethoxysilane hydrolysis material is transferred to the transfer tank after being cooled to room temperature; 4) Put 1432 kg of 3-aminopropyl trimethoxysilane product into the reaction kettle, start stirring, and slowly heat the reaction kettle. When the kettle temperature reaches 40℃, evenly pour the propyl trimethoxysilane hydrolysis material in 3) into the reaction kettle. During the feeding of the propyl trimethoxysilane hydrolysis material, the kettle temperature is controlled at 40-50℃, and the pressure is 0-30 kPa; 5) Put 100.8 kg of ionized water and 201.6 kg of solvent methanol into the metering tank, and then evenly pour the mixture into the reaction kettle to carry out the hydrolysis reaction of 3-aminopropyl trimethoxysilane. During the hydrolysis reaction, the kettle temperature is controlled at 40-50℃, and the pressure is 0-30 kPa; 6), after the second feeding of the metering tank is completed, aging reaction is carried out at 40-50℃ for 2h, and the moisture content is detected to be 0.05%, indicating that the hydrolysis is complete; 7), after the hydrolysis is complete, the reaction kettle is gradually heated, the solvent methanol in the reaction kettle is distilled out in the order of normal pressure and reduced pressure, after the solvent methanol is distilled, the reaction kettle material is first cooled to room temperature, and then the supported catalyst is removed to obtain the amino / alkyl silane oligomer product in an amount of 1788kg, which is detected to have a free chlorine content of 0.8ppm, a silicon content of 43.33%, and an appearance of colorless transparent liquid, and no yellowing occurs in the 80℃, 24h oven experiment. Example 2

[0021] The preparation method of the amino / alkyl silane oligomer comprises the following steps: 1), in the reaction kettle, 1312kg of propyltrimethoxysilane, 262kg of solvent methanol, and 1.97kg of acid clay are added; in the metering tank, 115.2kg of deionized water and 230kg of solvent methanol are added; 2), the stirring is started, the reaction kettle is slowly heated, after the kettle temperature reaches 40℃, the mixture in the metering tank is uniformly fed into the reaction kettle to carry out propyltrimethoxysilane hydrolysis reaction, and the kettle temperature is controlled to be 40-50℃ and the pressure is 0-30kPa during the hydrolysis reaction; 3), after the feeding of the metering tank is completed, aging reaction is carried out at 40-50℃ for 2h, and the moisture content is detected to be 0.05%, indicating that the hydrolysis is complete, then the propyltrimethoxysilane hydrolysis material is cooled to room temperature and transferred to a transfer tank; 4), in the reaction kettle, 1432kg of 3-aminopropyltrimethoxysilane product is added, the stirring is started, the reaction kettle is slowly heated, after the kettle temperature reaches 40℃, the propyltrimethoxysilane hydrolysis material in step 3) is uniformly fed into the reaction kettle, and the kettle temperature is controlled to be 40-50℃ and the pressure is 0-30kPa during the feeding of the propyltrimethoxysilane hydrolysis material; 5), in the metering tank, 115.2kg of deionized water and 230kg of solvent methanol are added, and then the mixture is uniformly fed into the reaction kettle to carry out 3-aminopropyltrimethoxysilane hydrolysis reaction, and the kettle temperature is controlled to be 40-50℃ and the pressure is 0-30kPa during the hydrolysis reaction; 6), after the second feeding of the metering tank is completed, aging reaction is carried out at 40-50℃ for 2h, and the moisture content is detected to be 0.05%, indicating that the hydrolysis is complete; 7) After the hydrolysis is complete, the temperature of the reactor is gradually increased, and the solvent methanol in the reactor is evaporated out at normal pressure and then at reduced pressure. After the distillation of the solvent methanol is completed, the contents of the reactor are first cooled to room temperature, and the solid-supported catalyst is removed by filtration. The amount of amino / alkylsilane oligomer product obtained is 2166 kg. The product is tested to have a free chlorine content of 0.7 ppm and a silicon content of 44.47%. The product is a colorless, transparent liquid, and there is no yellowing in an 80°C, 24-hour oven test.

[0022] Comparative Example 1 The preparation method of the amino / alkylsilane oligomer comprises the following steps: 1) Add 820kg of propyltrimethoxysilane, 164kg of methanol solvent, and 0.5kg of concentrated hydrochloric acid into the reactor; add 63kg of deionized water and 126kg of methanol solvent into the measuring tank; 2) Start stirring and slowly heat the reactor. When the reactor temperature reaches 40°C, evenly add the mixed material in the metering tank into the reactor to carry out the hydrolysis reaction of propyltrimethoxysilane. During the hydrolysis reaction, the reactor temperature is controlled at 40~50°C and the pressure is 0~30kPa; 3) After the mixing of the metering tank is completed, the aging reaction is carried out at a temperature of 40-50 ° C for 2 hours. The moisture content is 0.03% after sampling and testing, indicating that the hydrolysis is complete. Then the propyltrimethoxysilane hydrolyzed material is cooled to room temperature and transferred to the transfer tank; 4) Add 1432 kg of 3-aminopropyltrimethoxysilane product into the reactor, start stirring, and slowly heat the reactor. After the reactor temperature reaches 40°C, evenly add the propyltrimethoxysilane hydrolyzate in step 3) into the reactor. During the feeding process of the propyltrimethoxysilane hydrolyzate, the reactor temperature is controlled at 40-50°C and the pressure is 0-30 kPa. 5) Add 100.8 kg of deionized water and 201.6 kg of solvent methanol into the metering tank, and then evenly add the mixed liquid into the reactor to carry out the hydrolysis reaction of 3-aminopropyltrimethoxysilane. During the hydrolysis reaction, the temperature of the reactor is controlled at 40-50 ° C and the pressure is 0-30 kPa; 6) After the second feeding of the mixing material into the metering tank is completed, the aging reaction is carried out at a temperature of 40-50 ° C for 2 hours. The moisture content of the sample is 0.04%, indicating that the hydrolysis is complete; 7) After the hydrolysis is complete, the temperature of the reactor is gradually increased, and the solvent methanol in the reactor is evaporated out at normal pressure and then at reduced pressure. After the distillation of the solvent methanol is completed, the materials in the reactor are first cooled to room temperature and then filtered to obtain 1789 kg of amino / alkyl silane oligomer products. The free chlorine content of the product is 90 ppm, the silicon content is 43.23%, the appearance is a colorless transparent liquid, and there is no yellowing in the 80°C, 24h oven test.

[0023] Comparative Example 2 The preparation method of the amino / alkylsilane oligomer comprises the following steps: 1) Add 820kg of propyltrimethoxysilane, 164kg of methanol solvent, and 0.5kg of concentrated hydrochloric acid into the reactor; add 63kg of deionized water and 126kg of methanol solvent into the measuring tank; 2) Start stirring and slowly heat the reactor. When the reactor temperature reaches 40°C, evenly add the mixed material in the metering tank into the reactor to carry out the hydrolysis reaction of propyltrimethoxysilane. During the hydrolysis reaction, the reactor temperature is controlled at 40~50°C and the pressure is 0~30kPa; 3) After the mixing of the metering tank is completed, the aging reaction is carried out at a temperature of 40-50 ° C for 2 hours. The moisture content is 0.03% after sampling and testing, indicating that the hydrolysis is complete. Then the propyltrimethoxysilane hydrolyzed material is cooled to room temperature and transferred to the transfer tank; 4) Add 1432 kg of 3-aminopropyltrimethoxysilane product into the reactor, start stirring, and slowly heat the reactor. After the reactor temperature reaches 40°C, evenly add the propyltrimethoxysilane hydrolyzate in step 3) into the reactor. During the feeding process of the propyltrimethoxysilane hydrolyzate, the reactor temperature is controlled at 40-50°C and the pressure is 0-30 kPa. 5) Add 100.8 kg of deionized water and 201.6 kg of solvent methanol into the metering tank, and then evenly add the mixed liquid into the reactor to carry out the hydrolysis reaction of 3-aminopropyltrimethoxysilane. During the hydrolysis reaction, the temperature of the reactor is controlled at 40-50 ° C and the pressure is 0-30 kPa; 6) After the second feeding of the mixing material into the metering tank is completed, the aging reaction is carried out at a temperature of 40-50 ° C for 2 hours. The moisture content of the sample is 0.04%, indicating that the hydrolysis is complete; 7) After the hydrolysis is complete, 0.816 kg of sodium methoxide is used for neutralization and chlorine removal. After completion, the reactor is gradually heated up slowly, and the solvent methanol in the reactor is evaporated out first at normal pressure and then at reduced pressure. After the distillation of the solvent methanol is completed, the reactor material is first cooled to room temperature and then filtered to obtain 1787 kg of amino / alkyl silane oligomer product. After testing, the product has 0.8 ppm of free chlorine, 43.38% of silicon content, and an appearance of a colorless transparent liquid. Due to the need to ensure that the free chlorine is reduced to within the process requirements, a slight excess of sodium methoxide is required, so that after the reaction is completed, a trace amount of sodium methoxide remains in the product. The residual sodium methoxide causes the product to denature during the 80°C, 24h oven experiment, and the color becomes a brown-red transparent liquid and the product performance is significantly reduced.

[0024] Comparative Example 3 The preparation method of the amino / alkylsilane oligomer comprises the following steps: 1), in the reaction kettle put propyl trimethoxysilane 1312g, 3-aminopropyl trimethoxysilane 286.4g, solvent methanol 320g, acid white clay 1.97g; in the metering tank put ionized water 138.2g, solvent methanol 276g; 2), open the stirring, slowly heat the reactor, after the kettle temperature reaches 40℃, the mixture in the metering tank is evenly put into the reactor to carry out the hydrolysis reaction of propyl trimethoxysilane and 3-aminopropyl trimethoxysilane, the reactor temperature is controlled at 40~50℃ during the hydrolysis reaction, and the pressure is 0~30kPa; 3), after the metering tank mixture feeding is completed, aging reaction is carried out at 40~50℃ for 2h, and the moisture content is 0.04% after sampling detection, indicating that the hydrolysis is complete; 4), after the hydrolysis is complete, the reactor is slowly heated, the solvent methanol in the reactor is evaporated in the order of normal pressure and reduced pressure, after the solvent methanol distillation is completed, the reactor material is first reduced to room temperature, and then the supported catalyst is removed to obtain 2152g of amino / alkyl silane oligomer product, the product is obviously layered, the lower component has large viscosity and basically no fluidity.

Claims

1. A method for preparing an amino / alkylsilane oligomer, characterized in that: The following steps are involved: 1) Add propyltrimethoxysilane, methanol solvent and solid catalyst into the reactor; add deionized water and methanol solvent into the metering tank; 2) Start stirring the reactor and slowly heat it up. When the reactor temperature reaches the process temperature, add the mixed material in the metering tank into the reactor at a rate of 60-80 kg / h to carry out the hydrolysis reaction of propyltrimethoxysilane. After the feeding is completed, maintain the temperature for aging reaction for 2 hours to ensure that the deionized water reaction is complete. After aging, cool the hydrolyzed propyltrimethoxysilane material to room temperature and transfer it to the transfer tank. 3) Add 3-aminopropyltrimethoxysilane product into the reactor, start stirring and slowly heat the reactor. After the reactor temperature reaches the process temperature, evenly add the propyltrimethoxysilane hydrolyzate obtained in step 3) into the reactor; 4) Add deionized water and solvent methanol into the metering tank, and evenly add the mixed solution into the reactor at a rate of 60-80 kg / h for hydrolysis reaction; after the feeding is completed, maintain the temperature for aging reaction for 2 hours to ensure that the deionized water reacts completely; 5) After hydrolysis, the reactor is gradually heated up and the solvent methanol in the reactor is distilled out by first normal pressure and then reduced pressure. After the distillation of the solvent methanol is completed, the contents of the reactor are first cooled to room temperature, and the immobilized catalyst is removed by filtration to obtain the amino / alkylsilane oligomer product.

2. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: In step 1), the solid-supported catalyst is acidic clay, and the amount of the solid-supported catalyst added is 0.15% of the amount of propyltrimethoxysilane added.

3. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: In step 1), the molar ratio of propyltrimethoxysilane to deionized water is 1:0.65-0.

85.

4. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: In the step 1), the mass ratio of propyltrimethoxysilane to the solvent methanol is 1:0.

2.

5. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: In step 1), the mass ratio of deionized water to solvent methanol is 1:

2.

6. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: In step 3), the molar ratio of propyltrimethoxysilane to 3-aminopropyltrimethoxysilane is 1:0.2-2.

7. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: In step 4), the mass ratio of deionized water to solvent methanol is 1:

2.

8. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: In step 4), the molar ratio of 3-aminopropyltrimethoxysilane to deionized water in the measuring tank is 1:0.65-0.

85.

9. The method for preparing an amino / alkylsilane oligomer according to claim 1, wherein: During the reaction in step 2) and step 4) and during the feeding of the propyltrimethoxysilane hydrolyzate in step 3), the temperature is 40-50° C. and the pressure is 0-30 kPa.

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