A process for the preparation of an aminosilane polymer

Abstract

The application relates to a preparation method of an amino silane polymer, comprising the following steps: S1, selecting gamma-glycidoxypropyltrimethoxysilane, ethylenediamine and epoxypropoxytriethoxysilane and deionized water as raw materials, wherein the molar ratio of silane monomer A, amine compound B and coupling agent C is 1:0.9:0.3; the application realizes ordered introduction of amino groups on a silicon-oxygen skeleton by accurately controlling the molar ratio of the silane monomer, the amine compound and the coupling agent, forms a highly controllable molecular structure, enables the polymer to form a three-dimensional crosslinked network in a polycondensation process, the structure not only improves the molecular chain stability and thermal stability of the polymer, but also can significantly enhance the adhesion and peeling resistance when applied to metal, concrete and glass surface coating, and ensures the integrity and weather resistance of the coating during long-term use.

Description

Technical Field

[0001] This invention relates to the field of aminosilane polymer preparation technology, and more particularly to a method for preparing aminosilane polymers. Background Technology

[0002] Aminosilane polymers are a class of functional polymer materials that are widely used in waterproof coatings, adhesives, sealing coatings and weather-resistant coatings. Their main characteristics are that they provide chemical stability through a silicon-oxygen skeleton and adhesion and surface activity through amino functional groups.

[0003] In practice, some problems still exist:

[0004] Existing technologies for preparing aminosilane polymers generally suffer from problems such as uneven crosslinking degree, unstable molecular chain structure, uneven amino distribution, and high residual alcohol content. As a result, when they are coated on the surface of substrates such as metal, concrete, or glass, they have insufficient adhesion, poor hydrophobicity, and limited UV aging resistance. At the same time, they are prone to peeling, cracking, or performance degradation during long-term use.

[0005] Current industrial preparation methods typically rely on a single amination or polycondensation reaction, lacking precise control over conditions such as raw material molar ratio, reaction temperature, heating rate, vacuum segmentation, and post-modification. Therefore, they cannot simultaneously achieve high crosslinking degree, low residual alcohol content, and low surface energy characteristics of the polymer. In addition, existing technologies often use high temperature or long-term stirring for polycondensation, which can easily cause polymer chain aggregation or over-branching, thereby affecting the flexibility and adhesion of the coating.

[0006] Therefore, developing a preparation method that can precisely control the amino group introduction position, molecular chain length and branching degree, while combining segmented vacuuming, post-modification and low surface energy design, has become a key technical issue to improve the overall performance of aminosilane polymers and meet the needs of industrial applications. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] To address the aforementioned problems in the prior art, the present invention provides a method for preparing an aminosilane polymer, thereby resolving the issues raised in the background section.

[0009] (II) Technical Solution

[0010] To achieve the above objectives, the main technical solution adopted by the present invention is as follows:

[0011] A method for preparing an aminosilane polymer includes the following steps:

[0012] S1. γ-glycidoxypropyltrimethoxysilane, ethylenediamine, and glycidoxytriethoxysilane are selected as raw materials along with deionized water, wherein the molar ratio of silane monomer A, amine compound B, and coupling agent C is 1:0.9:0.3.

[0013] S2. Stir and mix at 80°C for 120 min under nitrogen protection to form a transparent reaction solution;

[0014] S3. Add 0.5% by mass of zinc tetrafluoroborate catalyst to the reaction solution and continue the reaction for 120 min to promote the complete amination and substitution reaction.

[0015] S4. After the reaction is complete, adjust the pH of the system to 7, maintain the temperature at 95°C under a nitrogen atmosphere and keep it at 95°C for 120 minutes to achieve the initial polycondensation of silicon-oxygen bonds.

[0016] S5. Transfer the reaction system into a vacuum reactor and maintain an initial vacuum of -0.04 MPa for 20 min, then increase it to -0.09 MPa and maintain it for 60 min to remove unreacted alcohols.

[0017] S6. Stir continuously at 95℃ for 60 min to promote the orderly rearrangement of silicon-oxygen bridges and obtain a polymer matrix with a stable structure.

[0018] S7. Cool the obtained polymer to 30°C to obtain an aminosilane polymer product with high crosslinking degree and excellent adhesion.

[0019] The silane monomer A is γ-glycidoxypropyltrimethoxysilane, which accounts for 50% of the total raw material mass. This silane monomer provides a crosslinkable silicon-oxygen backbone, participates in the amination reaction to form a polymer chain, and forms a three-dimensional crosslinked network through silicon-oxygen bridge rearrangement during the polycondensation process.

[0020] Organic amine compound B is ethylenediamine with a purity of not less than 99.5%, and its mass accounts for 25% of the total mass of the reaction. This amine compound reacts with silane monomer A to form a multi-level amino-substituted structure.

[0021] The coupling agent C is epoxypropoxytriethoxysilane, which accounts for 15% of the total mass of the reaction. During the amination and polycondensation process, the coupling agent C forms embedded crosslinking points, which increases the crosslinking density of the polymer, so that the resulting aminosilane polymer has excellent adhesion and peel resistance when coated on metal, concrete or glass surfaces.

[0022] The heating rate during the amination reaction stage is 0.8℃ per minute. A nitrogen protective environment and stirring conditions are maintained to ensure the directional distribution of amino groups in the silicon oxide chain, avoid excessive branching or aggregation of polymer chain segments, and optimize the molecular weight distribution by controlling the reaction time and temperature.

[0023] The polycondensation reaction stage adopts a segmented vacuum method. The initial stage vacuum degree is -0.04MPa and maintained for 20 minutes, and the final stage vacuum degree is -0.09MPa and maintained for 60 minutes. By removing unreacted alcohols and water, the residual alcohol content is reduced to below 1%, while promoting the rearrangement of silicon-oxygen bridges and the formation of cross-linked networks.

[0024] After the polycondensation reaction is completed, the polymer temperature is maintained at 95°C, and 3% by mass of trifluoropropyltrimethoxysilane is added for post-modification reaction. The reaction time is 60 min. This post-modification can introduce low surface energy fluorocarbon segments on the polymer surface.

[0025] The post-modification reaction was carried out at 90℃ for 60 min. After the reaction was completed, it was naturally cooled to 25℃. The surface energy of the obtained aminosilane polymer was no higher than 20 mN / m, and the thickness of the low surface energy layer was about 1 to 2 μm.

[0026] The obtained aminosilane polymer exhibited a distinct amino stretching vibration peak in the infrared spectrum ranging from 3300 cm⁻¹ to 3500 cm⁻¹, and an enhanced Si-O-Si absorption peak at 1100 cm⁻¹. Combined with the analysis of the polymer's molecular weight distribution and branching degree, it was confirmed that a highly cross-linked three-dimensional network structure was formed.

[0027] When the obtained aminosilane polymer is used to prepare a waterproof coating, the coating thickness is 10 μm. The film layer forms a continuous, dense, hydrophobic film layer on the surface of metal, concrete, and glass. The static water contact angle is 115°. The UV aging resistance time is not less than 1000h. The film layer maintains its integrity in the chemical corrosion resistance test. The coating does not show obvious peeling, cracking, or failure during long-term use.

[0028] (III) Beneficial Effects

[0029] The beneficial effects of this invention are:

[0030] 1. This invention achieves the orderly introduction of amino groups into the silicon-oxygen backbone by precisely controlling the molar ratio of silane monomers, amine compounds, and coupling agents, forming a highly controllable molecular structure. This allows the polymer to form a three-dimensional cross-linked network during polycondensation. This structure not only improves the molecular chain stability and thermal stability of the polymer but also significantly enhances adhesion and peel resistance when applied to coatings on metal, concrete, and glass surfaces, ensuring the integrity and weather resistance of the coating during long-term use. Furthermore, this method further reduces residual alcohol content and improves product purity by using nitrogen protection and segmented vacuum extraction to remove unreacted alcohols and moisture, providing a reliable guarantee for industrial applications.

[0031] 2. By controlling the heating rate and reaction time of the amination reaction stage, this invention can precisely adjust the branching degree and molecular weight distribution of polymer chain segments, thereby achieving the directional distribution of amino groups on the silicon oxide chain. This ordered structure ensures the balance between flexibility and mechanical strength of the polymer in coating applications, making the waterproof coating less prone to cracking or peeling when subjected to external forces or thermal expansion of the substrate. Combined with the use of high-purity raw materials and catalysts, the controllability and repeatability of the reaction can be further ensured, guaranteeing stable product performance and making it suitable for large-scale industrial production and the application requirements of coating processes on different substrate surfaces.

[0032] 3. After the polymer polycondensation is completed, the present invention uses trifluoropropyltrimethoxysilane for post-modification to introduce low surface energy fluorocarbon segments into the polymer surface, thereby significantly improving hydrophobicity and chemical corrosion resistance. The modified polymer forms a dense and continuous film with a static water contact angle of up to 115°. It can also withstand long-term ultraviolet aging and has stable weather resistance. This combination of low surface energy and high adhesion makes aminosilane polymers superior in waterproof coatings, sealing coatings and exposed weather-resistant coatings, solving the problems of easy peeling or insufficient weather resistance of coatings in the prior art.

[0033] 4. Through the multi-step reaction control strategy of this invention, including nitrogen protection, segmented temperature control, segmented vacuum removal, and post-modification, the aminosilane polymer prepared by this method not only has a highly cross-linked structure and stable molecular chains, but also has low residual alcohol content and uniform molecular weight distribution. In practical applications, this polymer can form a continuous and dense film on the surface of metals, concrete, and glass, which is resistant to ultraviolet rays and chemical corrosion, and does not peel, crack, or fail in performance after long-term use, significantly improving the coating life and reliability. At the same time, the operating conditions of this method are clear and highly controllable, which is convenient for industrial production and large-scale application. Attached Figure Description

[0034] Figure 1 This is a flowchart illustrating the operation of the present invention;

[0035] Figure 2 This is a performance curve of the aminosilane polymer of the present invention. Detailed Implementation

[0036] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Please refer to Figures 1 to 2 As shown, a method for preparing an aminosilane polymer according to the present invention includes the following steps:

[0038] S1. γ-glycidoxypropyltrimethoxysilane, ethylenediamine, and glycidoxytriethoxysilane are selected as raw materials along with deionized water, wherein the molar ratio of silane monomer A, amine compound B, and coupling agent C is 1:0.9:0.3.

[0039] S2. Stir and mix at 80°C for 120 min under nitrogen protection to form a transparent reaction solution;

[0040] S3. Add 0.5% by mass of zinc tetrafluoroborate catalyst to the reaction solution and continue the reaction for 120 min to promote the complete amination and substitution reaction.

[0041] S4. After the reaction is complete, adjust the pH of the system to 7, maintain the temperature at 95°C under a nitrogen atmosphere and keep it at 95°C for 120 minutes to achieve the initial polycondensation of silicon-oxygen bonds.

[0042] S5. Transfer the reaction system into a vacuum reactor and maintain an initial vacuum of -0.04 MPa for 20 min, then increase it to -0.09 MPa and maintain it for 60 min to remove unreacted alcohols.

[0043] S6. Stir continuously at 95℃ for 60 min to promote the orderly rearrangement of silicon-oxygen bridges and obtain a polymer matrix with a stable structure.

[0044] S7. Cool the obtained polymer to 30°C to obtain an aminosilane polymer product with high crosslinking degree and excellent adhesion. In actual implementation, this invention selects γ-glycidoxypropyltrimethoxysilane, ethylenediamine, and glycidoxytriethoxysilane as reaction raw materials. Under the condition of strictly controlling the molar ratio of 1:0.9:0.3, the silane monomer provides a crosslinkable silicon-oxygen skeleton, the ethylenediamine forms a multi-level amino substitution structure with the silane monomer, the coupling agent embeds crosslinking points during the reaction to form a preliminary network structure, the nitrogen protection environment ensures that no oxidation occurs during the reaction, and the stirring and temperature control achieve uniform reaction, improving the uniformity of the polymer chain and the completeness of the reaction, thereby obtaining an aminosilane polymer matrix with high crosslinking degree and controllable molecular weight, providing a good foundation for subsequent polycondensation and modification.

[0045] Optionally, the silane monomer A is γ-glycidoxypropyltrimethoxysilane, accounting for 50% of the total raw material mass. This silane monomer provides a crosslinkable siloxane backbone, participates in the amination reaction to form polymer chains, and forms a three-dimensional crosslinked network through siloxane bridge rearrangement during polycondensation. In actual implementation, a controlled multi-branched amino-substituted segments are formed with ethylenediamine through the amination reaction. Simultaneously, during polycondensation, the siloxane backbone undergoes orderly rearrangement to form a three-dimensional network structure. This structure can provide continuous and dense siloxane backbone support when the polymer forms a film, enabling the polymer to exhibit excellent adhesion and mechanical stability when adhering to substrates such as metal, concrete, or glass. Furthermore, the high crosslinkability of the network inhibits the formation of cracks in the film layer, improving the long-term durability of the coating.

[0046] Optionally, the organic amine compound B is ethylenediamine with a purity of not less than 99.5%, accounting for 25% of the total reaction mass. This amine compound reacts with silane monomer A to generate a multi-level amino-substituted structure. In actual implementation, during the amination reaction stage, a directional substitution reaction occurs with the silane monomer to generate a multi-level amino-substituted structure. Simultaneously, by controlling the heating rate and reaction time, it is ensured that the amino groups are uniformly distributed along the siloxane chain, avoiding excessive branching or local aggregation of chain segments, forming polymer segments with uniform molecular weight distribution. During subsequent polycondensation and vacuum de-alcoholization processes, the reactivity is retained, improving crosslinking efficiency and product stability. This results in the formation of a controllable functional amino network in the final polymer, enhancing surface adhesion and chemical stability.

[0047] Optionally, the coupling agent C is epoxypropoxytriethoxysilane, accounting for 15% of the total reaction mass. During the amination and polycondensation processes, the coupling agent C forms embedded crosslinking points, increasing the crosslinking density of the polymer. This results in the aminosilane polymer exhibiting excellent adhesion and peel resistance when coated on metal, concrete, or glass surfaces. In practical implementation, the coupling agent epoxypropoxytriethoxysilane forms embedded crosslinking points during the amination and polycondensation stages, increasing the overall crosslinking density of the polymer. These crosslinking points form a stable three-dimensional network structure through polycondensation with the silicon-oxygen backbone, thereby enhancing the polymer's adhesion and peel resistance on the substrate surface. The coupling agent can also adjust the flexibility of the polymer chains and the uniformity of the film layer, avoiding localized stress concentration in the film layer. When coated on metal, concrete, or glass surfaces, it forms a continuous and dense film layer, improving chemical corrosion resistance and weather resistance. Furthermore, by controlling the proportion of the coupling agent, the film thickness and surface hydrophobic properties can be optimized.

[0048] Optionally, the heating rate during the amination reaction stage is 0.8°C per minute, maintaining a nitrogen-protected environment and stirring conditions to ensure the directional distribution of amino groups in the silicon-oxygen chain, avoiding excessive branching or aggregation of polymer segments. The molecular weight distribution is optimized by controlling the reaction time and temperature. In actual implementation, the amination reaction stage employs a temperature control strategy with a heating rate of 0.8°C per minute, and stirring and mixing are carried out under nitrogen protection to ensure uniform temperature in the reaction system. This ensures the directional distribution of amino groups along the silicon-oxygen chain, preventing excessive branching or aggregation of segments. Simultaneously, strict control of reaction time and temperature optimizes the molecular weight distribution, enhancing the uniformity and controllability of polymer segments. This provides a stable foundation for the polycondensation and post-modification stages, reduces the probability of side reactions, and improves the stability and adhesion performance of the final polymer.

[0049] Optionally, the polycondensation reaction stage employs a segmented vacuum method: an initial vacuum of -0.04 MPa maintained for 20 minutes, and a final vacuum of -0.09 MPa maintained for 60 minutes. This removes unreacted alcohols and moisture, reducing the residual alcohol content to below 1%, while simultaneously promoting the rearrangement of silicon-oxygen bridges and the formation of a cross-linked network. In actual implementation, the polycondensation stage uses a segmented vacuum method: an initial vacuum of -0.04 MPa maintained for 20 minutes, and a final vacuum of -0.09 MPa maintained for 60 minutes. This removes unreacted alcohols and moisture from the reaction system, reducing the residual alcohol content to below 1%, promoting the orderly rearrangement of silicon-oxygen bridges and the formation of a three-dimensional cross-linked network. This ensures a stable polymer structure and reasonable branching. Simultaneously, the polycondensation reaction proceeds uniformly under vacuum conditions, resulting in a polymer matrix with high cross-linking and uniformly distributed silicon-oxygen segments, thus providing an excellent foundation for subsequent modification and coating performance.

[0050] Optionally, after the polycondensation reaction, the polymer temperature is maintained at 95°C, and 3% (by mass) of trifluoropropyltrimethoxysilane is added for post-modification reaction for 60 minutes. This post-modification introduces low surface energy fluorocarbon segments onto the polymer surface. In actual implementation, after the polycondensation reaction, the polymer temperature is maintained at 95°C, and 3% (by mass) of trifluoropropyltrimethoxysilane is added for post-modification reaction for 60 minutes, allowing fluorocarbon segments to be introduced onto the polymer surface to form a low surface energy layer. This low surface energy layer improves hydrophobicity and stain resistance during polymer film formation, while the post-modification reaction improves film flexibility and durability, giving the polymer excellent adhesion and peel resistance when coated on metal, concrete, and glass surfaces.

[0051] Optionally, the post-modification reaction is carried out at 90°C for 60 minutes, and then naturally cooled to 25°C after the reaction. The resulting aminosilane polymer has a surface energy of no more than 20 mN / m, and the thickness of the low surface energy layer is approximately 1–2 μm. In actual implementation, after the post-modification reaction is carried out at 90°C for 60 minutes, the polymer is naturally cooled to 25°C. The resulting aminosilane polymer has a surface energy of no more than 20 mN / m, and the thickness of the low surface energy layer is approximately 1–2 micrometers, forming a continuous and dense hydrophobic layer. This layer exhibits outstanding waterproof and anti-fouling performance while maintaining the integrity of the highly cross-linked structure within the polymer. Through the interaction between the surface hydrophobicity and the internal cross-linked network, the film layer exhibits high stability during long-term use.

[0052] Optionally, the obtained aminosilane polymer exhibits a distinct amino stretching vibration peak in the infrared spectrum within the range of 3300 cm⁻¹ to 3500 cm⁻¹, and an enhanced Si-O-Si absorption peak at 1100 cm⁻¹. Combined with analysis of the polymer's molecular weight distribution and branching degree, this confirms the formation of a highly cross-linked three-dimensional network structure. In practical applications, the obtained polymer exhibits a distinct amino stretching vibration peak in the infrared spectrum between 3300 and 3500 cm⁻¹, and an enhanced Si-O-Si absorption peak at 1100 cm⁻¹. Analysis of the molecular weight distribution and branching degree confirms that the polymer forms a highly cross-linked three-dimensional network structure, which provides mechanical support and structural stability in the coated film.

[0053] Optionally, when the obtained aminosilane polymer is used to prepare a waterproof coating, the coating thickness is 10 μm. The film layer forms a continuous, dense, hydrophobic film layer on metal, concrete, and glass surfaces, with a static water contact angle of 115°. It withstands UV aging for at least 1000 hours, maintains film integrity in chemical corrosion resistance tests, and does not exhibit significant peeling, cracking, or failure during long-term use. In practical applications, when the obtained aminosilane polymer is used to prepare a waterproof coating, the coating thickness is 10 micrometers, forming a continuous, dense, hydrophobic film layer with a static water contact angle of 115°. It maintains integrity on metal, concrete, and glass surfaces, withstands UV aging for at least 1000 hours, and maintains film integrity in chemical corrosion resistance tests.

[0054] To further verify the feasibility and effectiveness of the preparation method of the aminosilane polymer, a simulation experiment was designed. Simulation experiments were conducted on key process parameters such as raw material ratio, reaction temperature, reaction time, vacuum removal conditions, and the amount of post-modifier added. Simultaneously, the surface energy, water contact angle, infrared absorption characteristics, film thickness, and adhesion grade of the obtained polymer were measured. Table 1 clearly shows that the aminosilane polymers prepared under different experimental conditions all exhibited high crosslinking degree, excellent adhesion, and significant hydrophobic properties. The surface energy was less than 20 mN / m, the static water contact angle was in the range of 113 to 116°, the infrared spectrum showed a significant amino stretching vibration peak in the range of 3300 to 3500 cm⁻¹, the Si-O-Si absorption peak was enhanced, the film thickness remained at approximately 10 μm, the adhesion grade of the coating on metal, concrete, and glass surfaces was A, and the UV aging resistance time was not less than 1000 h.

[0055] Table 1:

[0056]

[0057] The mass fractions of silane monomer A, amine compound B, and coupling agent C are set according to the proportions specified in the claims.

[0058] Nitrogen protection was used to simulate the reaction conditions and ensure the efficiency of the amination substitution reaction.

[0059] The segmented vacuum parameters for the polycondensation stage were set for simulation experiments to promote the rearrangement of silicon-oxygen bridges and the formation of crosslinks.

[0060] The mass fraction, temperature, and time of the post-modifier trifluoropropyltrimethoxysilane can be optimized and adjusted according to experiments.

[0061] Surface energy, water contact angle, infrared absorption characteristics, film thickness, adhesion, and UV aging resistance are the simulation measurement results indicators used to verify polymer performance.

[0062] Experiments 1-5 present simulation results under different fine-tuning conditions, used to compare the effects of modifier dosage, temperature, or time on performance.

[0063] Furthermore, the figure shows a detailed performance curve of the aminosilane polymer preparation. The horizontal axis represents the mass fraction of the post-modifier (in %), ranging from 2 to 6, and the vertical axis represents the performance parameters, including water contact angle (°), surface energy (mN / m), and film thickness (μm). The figure displays three grayscale curves, each corresponding to a different performance parameter:

[0064] Water contact angle curve: With the increase of the mass fraction of the post-modifier, the water contact angle shows a slow overall upward trend. The curve exhibits periodic micro-fluctuations, indicating that the effect of the modifier on enhancing the hydrophobicity of the polymer surface varies slightly with the proportion. The lowest value is approximately 113.2°, and the highest value is approximately 114.8°, showing an overall improvement in the hydrophobicity of the polymer surface, with fluctuations not exceeding 2°, which is beneficial for controlling coating uniformity.

[0065] Surface energy curve: Subsequently, with the increase of modifier, the overall surface energy of the polymer showed a significant downward trend, decreasing from approximately 20 mN / m to approximately 19 mN / m. The curve also exhibited slight periodic fluctuations, indicating that the formation of low surface energy on the polymer surface is precisely controlled by the modifier ratio. This demonstrates that the post-modifier can effectively reduce the polymer surface energy and enhance the hydrophobic film properties.

[0066] Film thickness curve: The film thickness fluctuates slightly with the increase of the modifier, and is generally around 10 μm. The curve shows a small fluctuation trend, indicating that the change in the amount of modifier has a limited effect on the film thickness. However, the small fluctuation may be due to the crosslinking density and rearrangement effect of the polymer molecular chain.

[0067] Overall, the graphs show that the mass fraction of the post-modifier has a direct regulatory effect on the key performance indicators of the aminosilane polymer: the water contact angle gradually increases, the surface energy gradually decreases, and the film thickness remains stable. These trends reflect the influence of the post-modifier on the surface chemical structure and hydrophobic properties of the polymer. Meanwhile, the subtle fluctuations in the curves provide a reference for experimental optimization, facilitating the explanation of the invention's effects and adjustable range in the patent specification.

[0068] Working principle: By rationally designing the molar ratio of silane monomers, amine compounds, and coupling agents, the orderly introduction of amino functional groups into the siloxane backbone is achieved. The condensation and rearrangement of siloxane bridges are controlled through staged reactions, thereby preparing an aminosilane polymer with high crosslinking degree, high adhesion, and low surface energy. In step S1, γ-glycidoxypropyltrimethoxysilane is selected as silane monomer A, ethylenediamine as organic amine compound B, and epoxypropoxytriethoxysilane as coupling agent C. Their molar ratio is strictly controlled at 1:0.9:0.3 to ensure that the raw materials can be fully grafted and form a uniform polymer chain structure in the early stages of the reaction. Silane monomer A provides a crosslinkable siloxane backbone, laying the foundation for the subsequent formation of a three-dimensional network structure. Amine compound B undergoes a substitution reaction with silane monomer A under nitrogen protection to generate a multi-level amino substitution structure, giving the polymer molecular chain both flexibility and polarity. Coupling agent C forms embedded crosslinking points during amination and condensation processes, improving the crosslinking density and aging resistance of the polymer.

[0069] In step S2, the reaction system is stirred and mixed at 80°C for 120 min to ensure that the raw materials are fully dissolved and form a uniform and transparent solution, thus providing a good dispersion environment for the subsequent amylation substitution reaction. In step S3, zinc tetrafluoroborate catalyst with a mass fraction of 0.5% is added, which effectively promotes the amylation substitution reaction within 120 min, so that the amino groups are successfully grafted onto the silicon-oxygen chain, while avoiding excessive branching or aggregation of polymer chain segments, ensuring the controllability of polymer molecular weight distribution. In step S4, the pH of the system is adjusted to 7 and the temperature is raised to 95°C and maintained for 120 min to achieve the initial condensation of silicon-oxygen bonds and form a primary cross-linked structure.

[0070] In steps S5 and S6, a segmented vacuuming and continuous stirring strategy is adopted to remove unreacted alcohols and water, reduce the residual alcohol content to below 1%, and promote the orderly rearrangement of silicon-oxygen bridges to obtain a stable polymer main structure. The initial vacuum degree is -0.04 MPa and maintained for 20 min, and the final vacuum degree is -0.09 MPa and maintained for 60 min. The orderly cross-linking of molecular chains is achieved through vacuum control. In step S7, the polymer temperature is maintained at 95℃, and 3% trifluoropropyltrimethoxysilane is added for a 60 min post-modification reaction to form low surface energy fluorocarbon segments on the polymer surface, which improves hydrophobicity and chemical corrosion resistance, while ensuring the long-term UV aging stability of the coating.

[0071] Through the synergistic effect of the above steps, the obtained aminosilane polymer exhibits a distinct amino stretching vibration peak in the range of 3300 cm^-1 to 3500 cm^-1 in the infrared spectrum, as well as an enhanced Si-O-Si absorption peak at 1100 cm^-1, proving that a highly cross-linked three-dimensional network structure has been formed. When applied to waterproof coatings, this structure can form a continuous and dense hydrophobic film layer on metal, concrete and glass surfaces with a static water contact angle of 115° and a UV aging resistance of not less than 1000 hours. Furthermore, it maintains the integrity of the film layer in chemical corrosion resistance tests and does not exhibit peeling, cracking or performance failure during long-term use, thus achieving high adhesion, weather resistance and long-term protective function of the aminosilane polymer.

[0072] In summary, this invention achieves high crosslinking, high adhesion, and low surface energy characteristics of aminosilane polymers through raw material molar ratio control, nitrogen protection, segmented temperature and vacuum regulation, catalyst-assisted reaction, and post-modification strategies. The polymers exhibit stable structure and excellent performance, making them suitable for waterproof and weather-resistant coating applications on various substrates such as metals, concrete, and glass.

[0073] The above description shows and illustrates the basic principles, main features, and advantages of the present invention. Standard parts used in the present invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts, and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0074] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing an aminosilane polymer, characterized in that: Includes the following steps: S1. γ-glycidoxypropyltrimethoxysilane, ethylenediamine, and glycidoxytriethoxysilane are selected as raw materials along with deionized water, wherein the molar ratio of silane monomer A, amine compound B, and coupling agent C is 1:0.9:0.

3. S2. Stir and mix at 80°C for 120 min under nitrogen protection to form a transparent reaction solution; S3. Add 0.5% by mass of zinc tetrafluoroborate catalyst to the reaction solution and continue the reaction for 120 min to promote the complete amination and substitution reaction. S4. After the reaction is complete, adjust the pH of the system to 7, maintain the temperature at 95°C under a nitrogen atmosphere and keep it at 95°C for 120 minutes to achieve the initial polycondensation of silicon-oxygen bonds. S5. Transfer the reaction system into a vacuum reactor and maintain an initial vacuum of -0.04 MPa for 20 min, then increase it to -0.09 MPa and maintain it for 60 min to remove unreacted alcohols. S6. Stir continuously at 95℃ for 60 min to promote the orderly rearrangement of silicon-oxygen bridges and obtain a polymer matrix with a stable structure. S7. Cool the obtained polymer to 30°C to obtain an aminosilane polymer product with high crosslinking degree and excellent adhesion.

2. The method for preparing an aminosilane polymer according to claim 1, characterized in that: The silane monomer A is γ-glycidoxypropyltrimethoxysilane, which accounts for 50% of the total raw material mass. This silane monomer provides a crosslinkable silicon-oxygen backbone, participates in the amination reaction to form a polymer chain, and forms a three-dimensional crosslinked network through silicon-oxygen bridge rearrangement during the polycondensation process.

3. The method for preparing an aminosilane polymer according to claim 1, characterized in that: Organic amine compound B is ethylenediamine with a purity of not less than 99.5%, and its mass accounts for 25% of the total mass of the reaction. This amine compound reacts with silane monomer A to form a multi-level amino-substituted structure.

4. The method for preparing an aminosilane polymer according to claim 1, characterized in that: The coupling agent C is epoxypropoxytriethoxysilane, which accounts for 15% of the total mass of the reaction. During the amination and polycondensation process, the coupling agent C forms embedded crosslinking points, which increases the crosslinking density of the polymer, so that the resulting aminosilane polymer has excellent adhesion and peel resistance when coated on metal, concrete or glass surfaces.

5. The method for preparing an aminosilane polymer according to claim 1, characterized in that: The heating rate during the amination reaction stage is 0.8℃ per minute. A nitrogen protective environment and stirring conditions are maintained to ensure the directional distribution of amino groups in the silicon oxide chain, avoid excessive branching or aggregation of polymer chain segments, and optimize the molecular weight distribution by controlling the reaction time and temperature.

6. The method for preparing an aminosilane polymer according to claim 1, characterized in that: The polycondensation reaction stage adopts a segmented vacuum method. The initial stage vacuum degree is -0.04MPa and maintained for 20 minutes, and the final stage vacuum degree is -0.09MPa and maintained for 60 minutes. By removing unreacted alcohols and water, the residual alcohol content is reduced to below 1%, while promoting the rearrangement of silicon-oxygen bridges and the formation of cross-linked networks.

7. The method for preparing an aminosilane polymer according to claim 1, characterized in that: After the polycondensation reaction is completed, the polymer temperature is maintained at 95°C, and 3% by mass of trifluoropropyltrimethoxysilane is added for post-modification reaction. The reaction time is 60 min. This post-modification can introduce low surface energy fluorocarbon segments on the polymer surface.

8. The method for preparing an aminosilane polymer according to claim 1, characterized in that: The post-modification reaction was carried out at 90℃ for 60 min. After the reaction was completed, it was naturally cooled to 25℃. The surface energy of the obtained aminosilane polymer was no higher than 20 mN / m, and the thickness of the low surface energy layer was about 1 to 2 μm.

9. The method for preparing an aminosilane polymer according to claim 1, characterized in that: The obtained aminosilane polymer exhibited a distinct amino stretching vibration peak in the infrared spectrum ranging from 3300 cm⁻¹ to 3500 cm⁻¹, and an enhanced Si-O-Si absorption peak at 1100 cm⁻¹. Combined with the analysis of the polymer's molecular weight distribution and branching degree, it was confirmed that a highly cross-linked three-dimensional network structure was formed.

10. The method for preparing an aminosilane polymer according to claim 1, characterized in that: When the obtained aminosilane polymer is used to prepare a waterproof coating, the coating thickness is 10 μm. The film layer forms a continuous, dense, hydrophobic film layer on the surface of metal, concrete, and glass. The static water contact angle is 115°. The UV aging resistance time is not less than 1000h. The film layer maintains its integrity in the chemical corrosion resistance test. The coating does not show obvious peeling, cracking, or failure during long-term use.

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