A high weather-resistant MS resin sealant and its preparation method

Abstract

This invention belongs to the field of sealant materials and provides a high weather-resistant MS resin sealant and its preparation method. The invention designs the proportions of trimethoxysilane-terminated polyether prepolymer, added polypropylene glycol, composite filler, unmodified calcium carbonate, fumed silica, silane coupling agent, and tetrabutyl titanate. It also regulates the calcium carbonate filler with a surface organic layer containing epoxy silane, hindered amine light-stabilizing components, and ultraviolet-absorbing components, forming a sealant system in which the resin matrix, filler interface, and light-stabilizing components work together. This improves the balance between processing fluidity, weather resistance, mechanical strength, and light-stabilizing component migration control, solving the problem of existing systems struggling to simultaneously achieve plasticization and weather resistance, interface reinforcement, and light-stabilizing component migration. It is suitable for sealing joints in buildings, prefabricated components, and industrial applications.

Description

Technical Field

[0001] This invention relates to the field of polymer sealant materials, specifically to a high weather-resistant MS resin sealant and its preparation method. Background Technology

[0002] MS resin sealant, primarily composed of silane-terminated polyether, combines elastic sealing, moisture curing, low odor, and substrate compatibility, making it widely used for bonding and sealing building curtain walls, prefabricated components, door and window joints, industrial equipment, and transportation parts. In outdoor or semi-outdoor joints, the sealant not only needs to maintain suitable flowability and extrudability during application but also needs to withstand long-term exposure to UV light, thermal cycling, humid environments, and joint displacement after curing. Therefore, the system typically requires a resin with stable crosslinking capabilities, fillers with good dispersibility, interfaces with sufficient load-bearing capacity, and light-stabilizing components that continue to function throughout the service life. For high-weather-resistant MS resin sealants, low resistance during processing, post-curing strength retention, interfacial coordination between fillers and resin, and low migration of light-stabilizing components are crucial factors determining application efficiency, service life, and appearance stability.

[0003] Existing MS resin sealants typically improve processing fluidity by increasing plasticizers, reducing the structural effect of fillers, or introducing ordinary calcium carbonate. However, such approaches can easily reduce the restrictive effect of the filler interface on the resin network, affecting post-cured strength, weather resistance, and media stability. On the other hand, to improve weather resistance, UV absorbers, hindered amine light stabilizers, or active fillers are often added. However, free small-molecule light stabilizers may migrate within the polyether matrix, and excessive or insufficiently dispersed fillers can increase system viscosity and narrow the application window. For example, Chinese patent CN106634771A discloses a silane-modified polyether sealant and its preparation method. It uses a silane-modified polyether polymer, plasticizer, reactive diluent, filler, and initial tack promoter to form the sealant system, emphasizing improved initial tack and ease of application. However, this approach still struggles to simultaneously address the issues of low migration and fixation of light stabilizers, enhanced filler interface, and coordinated processing fluidity. Summary of the Invention

[0004] The purpose of this invention is to provide a high weather-resistant MS resin sealant and its preparation method, which solves the problems of difficulty in balancing processing fluidity and weather resistance, and difficulty in coordinating mechanical strength and light-stable component migration control in current MS resin sealants.

[0005] This invention introduces epoxy silane treatment, hindered amine light-stabilizing components, and ultraviolet absorbing components into a calcium carbonate surface regulation system by interfacial matching of trimethoxysilane-terminated polyether prepolymer and composite filler. This coordinates filler enhancement with system viscosity control, reduces the tendency of light-stabilizing components to migrate in a free state, and maintains construction adaptability through mixing sequence and moisture control. Thus, it balances processing fluidity, weather resistance, mechanical strength, and control of light-stabilizing component migration.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high weather-resistant MS resin sealant, based on 100 parts by weight of trimethoxysilane-terminated polyether prepolymer, comprises the following components: 100 parts by weight of trimethoxysilane-terminated polyether prepolymer; Add 20-60 parts by weight of polypropylene glycol; 80-180 parts by weight of composite filler; Unmodified calcium carbonate, 0-80 parts by weight; 1-6 parts by weight of fumed silica; 1-4 parts by weight of vinyltrimethoxysilane; 0.5-3 parts by weight of 3-aminopropyltrimethoxysilane; Tetrabutyl titanate 0.05-0.80 parts by weight; The trimethoxysilane-terminated polyether prepolymer is obtained by reacting prepolymerized polypropylene glycol, isophorone diisocyanate and 3-aminopropyltrimethoxysilane. The composite filler is prepared from calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone.

[0007] In this invention, the added polypropylene glycol refers to the polypropylene glycol added in the final formulation stage of the sealant but not used to prepare the trimethoxysilane-terminated polyether prepolymer; the prepolymer polypropylene glycol refers to the polypropylene glycol used to react with isophorone diisocyanate to prepare the trimethoxysilane-terminated polyether prepolymer.

[0008] Furthermore, the composite filler is prepared through the following steps: A1. Calcium carbonate is dried to obtain dried calcium carbonate; A2. The dried calcium carbonate is dispersed in a mixture of ethanol and deionized water, wherein the mass ratio of ethanol to deionized water is 100:5-100:30, and the pH of the dispersion system is adjusted to alkaline using ammonia. A3. Add 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone to the dispersion system obtained in step A2; A4. React the system obtained in step A3, maintaining alkaline conditions during the reaction; A5. After the reaction is complete, the composite filler is obtained by filtration, washing with ethanol, washing with deionized water, and drying.

[0009] Furthermore, the preparation conditions of the composite filler include: In step A1, calcium carbonate is dried at 90-120℃ and an absolute pressure of 0.005-0.040MPa for 1-4 hours; In step A2, ammonia is used to adjust the pH value to 8.5-10.5; In step A4, the reaction is carried out at 45-75℃ for 2-4 hours, and the composition of the reaction medium is maintained by reflux condensation, and the pH value is maintained at 8.5-10.5. In step A5, dry at 70-110℃ and absolute pressure of 0.005-0.040MPa for 4-12 hours.

[0010] Further, in step A3, the mass ratio of the calcium carbonate, the 3-glycidyloxypropyltrimethoxysilane, the bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and the 2-hydroxy-4-n-octyloxybenzophenone is 100:1.00-8.00:0.20-3.00:0.20-3.00; the surface organic layer content of the composite filler obtained after washing and drying is 0.50-5.00wt%, the D50 is 60-500nm, and the water content is 0.01-0.30wt%.

[0011] Furthermore, the trimethoxysilane-terminated polyether prepolymer is prepared through the following steps: B1. Dehydrate prepolymerized polypropylene glycol at 100-120℃ and 0.005-0.040MPa absolute pressure for 1-3 hours to obtain dehydrated polypropylene glycol; B2. Under inert gas protection, isophorone diisocyanate is added to the dehydrated polypropylene glycol to make the NCO:OH molar ratio 1.60-2.20, and the reaction is carried out at 70-90℃ for 2-5 hours to obtain isocyanate-terminated polyether prepolymer. B3. Add 3-aminopropyltrimethoxysilane to the isocyanate-terminated polyether prepolymer, such that the molar ratio between the residual NCO group in the isocyanate-terminated polyether prepolymer and the amino group in the 3-aminopropyltrimethoxysilane is 0.95-1.05, and react at 45-75°C for 1-3 hours to obtain the trimethoxysilane-terminated polyether prepolymer; B4. The NCO residue of the trimethoxysilane-terminated polyether prepolymer is not higher than 0.10 wt%, the water content is 0.01-0.10 wt%, and the viscosity at 25°C is 5000-100000 mPa·s. The viscosity at 25°C is measured by a rotational viscometer at 25°C after the reading has stabilized for 60 seconds.

[0012] Furthermore, the D90 of the composite filler is 150-1200nm, and the mass percentage of dispersible agglomerates in the composite filler does not exceed 10.00wt%.

[0013] Furthermore, when the amount of unmodified calcium carbonate fed is greater than 0, the mass ratio of the composite filler to the unmodified calcium carbonate is 1.00-6.00:1, while simultaneously satisfying the respective feeding ranges of the composite filler and the unmodified calcium carbonate.

[0014] As a concept of this invention, the present invention employs a design combining a trimethoxysilane-terminated polyether prepolymer with a composite filler containing a light-stabilized organic layer, primarily to achieve a balance between processing flowability and weather resistance. In existing technologies, to improve extrudability during application, additional polypropylene glycol is typically added or the structural effect of fillers is reduced, but this easily weakens the filler's ability to support the resin network and retain its properties after light aging. To improve weather resistance, the effect of inorganic fillers or light-stabilizing components is often enhanced, but filler agglomeration and the free migration of small-molecule light-stabilizing components can increase system viscosity and affect long-term stability. This invention regulates the calcium carbonate surface using 3-glycidoxypropyltrimethoxysilane, while simultaneously introducing bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone, and matching the proportions of the trimethoxysilane-terminated polyether prepolymer, added polypropylene glycol, and silane additives. This allows filler reinforcement, light stability, and processing flowability to mutually correct each other within the same system, resulting in a more balanced sealant solution.

[0015] This invention also discloses a method for preparing the high weather-resistant MS resin sealant as described above, comprising the following steps: S1. Provide the prepared composite filler; S2. Provide the prepared trimethoxysilane-terminated polyether prepolymer; S3. According to the components and feed amounts, the trimethoxysilane-terminated polyether prepolymer, added polypropylene glycol, the composite filler, unmodified calcium carbonate, and fumed silica are vacuum mixed at 40-90°C for 0.5-3 hours. S4. After cooling to 20-50℃, first add vinyltrimethoxysilane, then add 3-aminopropyltrimethoxysilane, and finally add tetrabutyl titanate. Continue vacuum mixing for 0.2-1.5h. S5. Degas and moisture-proof packaging to obtain the high weather-resistant MS resin sealant.

[0016] Furthermore, in steps S3 and S4, the absolute pressure of vacuum mixing is 0.005-0.040 MPa.

[0017] Furthermore, in step S3, when the amount of unmodified calcium carbonate fed is greater than 0, the mass ratio of the composite filler to the unmodified calcium carbonate is 1.00-6.00:1, and simultaneously meets the respective feeding ranges of the composite filler and the unmodified calcium carbonate.

[0018] Furthermore, in step S5, the moisture content of the high weather-resistant MS resin sealant before moisture-proof packaging is 0.01-0.10 wt%.

[0019] Furthermore, in the preparation of the composite filler, in step A1, 100 parts by mass of calcium carbonate are dried at 90-120℃ and an absolute pressure of 0.005-0.040MPa for 1-4 hours to obtain dried calcium carbonate for dispersion treatment in step A2.

[0020] Furthermore, in the preparation of the composite filler, in step A2, a mixture of ethanol and deionized water is used as the continuous phase to disperse the dried calcium carbonate, and the mass ratio of ethanol to deionized water is 100:5-100:30; the pH value of the dispersion system is adjusted to 8.5-10.5 using ammonia water to obtain the alkaline calcium carbonate dispersion system that enters step A3.

[0021] Furthermore, in the preparation of the composite filler, in step A3, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 2-hydroxy-4-n-octyloxybenzophenone are added to the alkaline calcium carbonate dispersion system obtained in step A2, so that the mass ratio of calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 2-hydroxy-4-n-octyloxybenzophenone is 100:1.00-8.00:0.20-3.00:0.20-3.00. After the addition, the system is subjected to step A4 reaction for 2-4 hours at 45-75℃ and pH 8.5-10.5, and the reaction medium composition is maintained by reflux condensation in the ethanol-containing reaction system. The resulting reaction slurry enters step A5.

[0022] Furthermore, in the preparation of the composite filler, the reaction slurry obtained in step A4 is filtered in step A5, and the resulting filter cake is washed with ethanol and then with deionized water in sequence. Then it is dried at 70-110℃ and absolute pressure of 0.005-0.040MPa for 4-12h to obtain a composite filler with a surface organic layer content of 0.50-5.00wt%, D50 of 60-500nm and water content of 0.01-0.30wt%.

[0023] Furthermore, when determining the parameters of the composite packing obtained in step A5, the washed and dried composite packing was used as the sample to be tested; the mass change in the range of 200-600℃ was recorded by thermogravimetric analysis under a nitrogen atmosphere, and the surface organic layer content was calculated based on the initial mass of the sample to be tested; the D50 and D90 of the composite packing were determined by laser particle size analysis, with ethanol as the dispersion medium and the dispersion conditions, particle size distribution curve, D50 and D90 recorded during the test; the water content of the composite packing was determined by Karl Fischer method.

[0024] Furthermore, the mass percentage of the dispersible agglomerates is tested using composite filler dry powder as the test object. The composite filler dry powder is added to ethanol dispersion medium and processed according to the same dispersion procedure as before D50 and D90 determination. After dispersion, the particle components with a particle size greater than 1200nm are collected and the percentage of the dry mass of the particle component to the dry mass of the test sample is calculated. The obtained value is used as the mass percentage of the dispersible agglomerates.

[0025] Further, in preparing the trimethoxysilane-terminated polyether prepolymer, in step B1, 100 parts by mass of prepolymerizable polypropylene glycol are dehydrated at 100-120°C and 0.005-0.040 MPa absolute pressure for 1-3 hours to obtain dehydrated polypropylene glycol; in step B2, isophorone diisocyanate is added to the dehydrated polypropylene glycol under industrial-grade nitrogen protection to make the NCO:OH molar ratio 1.60-2.20, and the reaction is carried out at 70-90°C for 2-5 hours to obtain the isocyanate-terminated polyether prepolymer; In step B3, 3-aminopropyltrimethoxysilane is added to the isocyanate-terminated polyether prepolymer, such that the molar ratio between the residual NCO groups in the isocyanate-terminated polyether prepolymer and the amino groups in the 3-aminopropyltrimethoxysilane is 0.95-1.05. The reaction is carried out at 45-75°C for 1-3 hours to obtain a trimethoxysilane-terminated polyether prepolymer with an NCO residue of no more than 0.10 wt%, a water content of 0.01-0.10 wt%, and a viscosity of 5000-100000 mPa·s at 25°C.

[0026] Furthermore, when determining the parameters of the trimethoxysilane-terminated polyether prepolymer, the prepolymer sample after the reaction in step B3 was used as the test sample. The NCO residue was determined by the di-n-butylamine back titration method, the water content was determined by the Karl Fischer method, and the viscosity was measured by a rotational viscometer at 25°C. The viscometer model, rotor model, rotation speed, test temperature, and reading stabilization time were recorded. The viscosity value was recorded after the reading stabilized for 60 seconds. The obtained NCO residue, water content, and viscosity were used as quality control data for the prepolymer to enter the sealant preparation step.

[0027] Furthermore, in preparing the high weather-resistant MS resin sealant, in step S3, the trimethoxysilane-terminated polyether prepolymer, added polypropylene glycol, composite filler, unmodified calcium carbonate, and fumed silica are vacuum mixed at 40-90℃ and an absolute pressure of 0.005-0.040 MPa for 0.5-3 h, and the resulting mixture proceeds to step S4; in step S4, the mixture obtained in step S3 is cooled to 20-50℃, vinyltrimethoxysilane is added first, followed by 3-aminopropyltrimethoxysilane, and finally tetrabutyl titanate is added, and vacuum mixing continues at an absolute pressure of 0.005-0.040 MPa for 0.2-1.5 h to obtain the sealant to be degassed.

[0028] Furthermore, the vacuum mixing in steps S3 and S4 is carried out by planetary stirring, kneading or biaxial stirring, and the material is controlled to be in a moisture-proof environment during the mixing process; in step S5, the sealant to be degassed obtained in step S4 is degassed, and the moisture content of the sealant is determined by Karl Fischer method before moisture-proof packaging, so that the moisture content of the sealant before moisture-proof packaging is 0.01-0.10wt%, and then moisture-proof packaging is carried out.

[0029] Furthermore, when characterizing the surface organic layer of the composite filler, calcium carbonate raw material, calcium carbonate treated with 3-glycidoxypropyltrimethoxysilane, and the composite filler obtained in step A5 were used as test samples. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were performed respectively. Fourier transform infrared spectroscopy recorded the characteristic peak regions of epoxy, carbonate, and organic groups, while X-ray photoelectron spectroscopy recorded the Si2p, N1s, O1s, and C1s signals. The obtained spectral data were used as quality control data for the assignment of the surface organic layer of the composite filler and batch consistency.

[0030] Furthermore, when testing the retention of organic components in the composite packing, samples were taken from the unwashed and dried sample after step A3, the washed and dried sample after step A5, and the control sample obtained by physically mixing calcium carbonate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone in the same mass ratio and then washing and drying. The surface organic layer content of each sample was recorded using the same method for determining the surface organic layer content, and the change in surface organic layer content before and after washing was used as the quality control standard for the retention of organic components in the composite packing.

[0031] As another aspect of this invention, the present invention employs segmented vacuum mixing and post-addition of silane additives and tetrabutyl titanate, primarily to achieve, maintain, or amplify the aforementioned synergistic effects. Existing processes, if silane additives and catalytic components are added at an early stage, can easily cause localized viscosity increases or moisture-induced reactions in the system before the filler is uniformly dispersed, thus impairing processing fluidity. Simply delaying all reactive components may result in insufficient filler interface control and decreased curing uniformity. This invention first provides a pre-prepared composite filler and a trimethoxysilane-terminated polyether prepolymer. Then, the resin, added polypropylene glycol, composite filler, unmodified calcium carbonate, and fumed silica are mixed under vacuum conditions. Subsequently, the mixture is cooled, and vinyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and tetrabutyl titanate are added sequentially. This allows for sequential advancement of filler dispersion, interface control, and curing activation, reducing interference from moisture and localized catalysis on the application window, thereby maintaining a stable expression of the synergistic relationship.

[0032] The composite filler primarily serves to reinforce, stabilize, and improve weather resistance, while the added polypropylene glycol (PPG) mainly contributes to processing flowability and system regulation. While a high proportion of the composite filler alone can improve interfacial load-bearing capacity and retention of light-stabilized components, it can also compromise extrudability due to increased particle contact, system densification, and elevated rheological properties. Conversely, a high proportion of PPG alone, while reducing mixing resistance and improving application conditions, may weaken the network load-bearing capacity after curing and increase the migration tendency of small molecules. This invention uses calcium carbonate treated with 3-glycidyloxypropyltrimethoxysilane, along with bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone, to form a composite filler. Simultaneously, the proportions of added PPG, silane additives, and tetrabutyl titanate are limited to ensure that filler dispersion, light-stabilized component retention, and resin compatibility adjustment are mutually corrected, ultimately achieving a balance between processing flowability and weather resistance, mechanical strength, and light-stabilized component migration control.

[0033] Beneficial technical effects 1. This invention maintains the continuous resin phase in a mixable and workable state by matching the proportions of trimethoxysilane-terminated polyether prepolymer, added polypropylene glycol, and composite filler. At the same time, the composite filler provides interfacial support, reducing the risk of a loose cured system due to simple molding, and helps to achieve a balance between workability and post-curing strength.

[0034] 2. The composite filler of the present invention is prepared from calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone, which allows the surface regulation of the inorganic filler to cooperate with the light-stabilizing components, reducing the migration tendency caused by the free distribution of the light-stabilizing components, and thus improving the weather resistance stability.

[0035] 3. By limiting the composite filler's D50, D90, surface organic layer content, water content, and the mass ratio of dispersible agglomerates, this invention enables the filler to have a more stable dispersion state in the resin system, reduces the negative impact of coarse agglomerates on rheology and interface uniformity, and is beneficial to forming a sealant with both processing adaptability and durability.

[0036] 4. The preparation method of the present invention first vacuum mixes the resin, adds polypropylene glycol, composite filler, unmodified calcium carbonate and fumed silica, and then cools down before sequentially adding vinyltrimethoxysilane, 3-aminopropyltrimethoxysilane and tetrabutyl titanate. This can reduce the interference of moisture and catalytic activity on early mixing and make the filler dispersion, additive introduction and curing activation process more coordinated. Attached Figure Description

[0037] Figure 1 The figure shows the effect of the amount of filler added to the MS resin sealant composite on the tensile bond strength.

[0038] Figure 2 The graph shows the effect of the amount of MS resin sealant composite filler added on the retention rate of weather resistance tensile strength.

[0039] Figure 3 The graph shows the effect of the amount of polypropylene glycol added to MS resin sealant on tensile bond strength.

[0040] Figure 4 The graph shows the effect of the amount of polypropylene glycol added to MS resin sealant on the retention rate of weather resistance tensile strength.

[0041] Figure 5 The image shows a superimposed FTIR absorption spectrum of Example 1, Comparative Example 11, and Comparative Example 8.

[0042] Figure 6 Scatter plots of relative peak area ratios in XPS for Example 1, Comparative Example 11, and Comparative Example 8.

[0043] Figure 7 The TGA mass-temperature curves are for Example 1, Comparative Example 9, and Comparative Example 10.

[0044] Figure 8 The chart shows the mass loss of the organic layer at 200–600°C for Examples 1, 9, and 10.

[0045] Figure 9 The graph shows the retention rates of organic components after washing for Examples 1, 9, and 10.

[0046] Figure 10 The viscosity-shear rate curves are for Example 1, Comparative Example 2, and Comparative Example 4.

[0047] Figure 11 The graphs show the energy storage modulus G′-shear rate curves for Examples 1, 2, and 4.

[0048] Figure 12 The graphs show the loss modulus G″-shear rate curves for Example 1, Comparative Example 2, and Comparative Example 4.

[0049] Figure 13 The scatter plot shows the extrusion rate-sag correlation of Example 1, Comparative Example 2, and Comparative Example 4.

[0050] Figure 14 The particle size differential volume distribution curves are for Example 1, Comparative Example 8, and Comparative Example 11.

[0051] Figure 15 The cumulative particle size distribution curves for Example 1, Comparative Example 8, and Comparative Example 11 are shown.

[0052] Figure 16The scatter plots show the D50 and D90 scatter mean values ​​for Example 1, Comparative Example 8, and Comparative Example 11.

[0053] Figure 17 This is a statistical chart showing the mass percentage of dispersible aggregates in Example 1, Comparative Example 8, and Comparative Example 11.

[0054] Figure 18 This is a scatter plot of the average moisture content of the sealant in Example 1 and Comparative Example 6.

[0055] Figure 19 This is a scatter plot of the average values ​​of the surface drying time for Example 1 and Comparative Example 6.

[0056] Figure 20 The graphs show the curing depth of Example 1 and Comparative Example 6 as a function of time.

[0057] Figure 21 Macroscopic optical photographs of Example 1 and Comparative Example 11; Figure 21 a is a macroscopic optical photograph of the sealant sample from Example 1; Figure 21 b is a macroscopic optical photograph of the sealant sample in Comparative Example 11.

[0058] Figure 22 This is a comparison of the SEM morphology of the cured adhesive cross-sections of Example 1 and Comparative Example 11; Figure 22 a and Figure 22 b are low-magnification SEM images of the cross-sections of the cured adhesive in Example 1 and Comparative Example 11, respectively. Figure 22 c and Figure 22 d are medium-magnification SEM images of the cross-sections of the cured adhesive in Example 1 and Comparative Example 11, respectively. Figure 22 e and Figure 22 f are high-magnification SEM images of the cured adhesive cross-sections of Example 1 and Comparative Example 11, respectively.

[0059] Figure 23 Comparison of TEM microstructure and crystallographic information between Example 1 and Comparative Example 11; Figure 23 a and Figure 23 b are bright-field TEM images of the distribution of calcium carbonate particles in MS resin matrix in Example 1 and Comparative Example 11, respectively. Figure 23 c and Figure 23 d are HRTEM images of the calcium carbonate lattice fringes and particle surface interface layer of Example 1 and Comparative Example 11, respectively. Figure 23 e and Figure 23 f represents the SAED or elemental distribution diagrams of calcium carbonate crystallographic information and the spatial distribution of silane-related elements in Example 1 and Comparative Example 11, respectively. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0061] Example 1 Overall production scale and product form This embodiment prepares a one-component paste-like high weather-resistant MS resin sealant. Based on 1000g of trimethoxysilane-terminated polyether prepolymer used in the final sealant preparation stage, 100 parts by weight of the trimethoxysilane-terminated polyether prepolymer correspond to 1000g, 20 parts by weight of added polypropylene glycol correspond to 200g, 80 parts by weight of composite filler correspond to 800g, 80 parts by weight of unmodified calcium carbonate correspond to 800g, 1 part by weight of fumed silica corresponds to 10g, 1 part by weight of vinyltrimethoxysilane corresponds to 10g, 0.5 parts by weight of 3-aminopropyltrimethoxysilane corresponds to 5g, and 0.05 parts by weight of tetrabutyl titanate corresponds to 0.5g. All raw materials used in this embodiment are commercially available. The added polypropylene glycol is a hydroxyl-terminated polyether with a number-average molecular weight of approximately 2000 and a moisture content not exceeding 0.05 wt%. The unmodified calcium carbonate is a dry powder with a D50 of approximately 300 nm and a moisture content not exceeding 0.10 wt%. The fumed silica is a hydrophilic powder with a specific surface area of ​​150-250 m². 2 / g; the purity of vinyltrimethoxysilane, 3-aminopropyltrimethoxysilane and tetrabutyl titanate is not less than 98.0wt%.

[0062] Raw materials, components or material specifications The calcium carbonate used to prepare the composite filler is commercially available nano-calcium carbonate with a dry basis purity of not less than 98.0 wt%; 3-glycidyloxypropyltrimethoxysilane has a purity of not less than 98.0 wt%; bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate has a purity of not less than 98.0 wt%; 2-hydroxy-4-n-octyloxybenzophenone has a purity of not less than 98.0 wt%; ethanol is analytical grade; deionized water has a conductivity of not more than 10 μS / cm; and ammonia is commercially available analytical grade. The polypropylene glycol used for the prepolymerization of the trimethoxysilane-terminated polyether prepolymer is commercially available hydroxyl-terminated polyether with a hydroxyl value of approximately 56 mg KOH / g and a moisture content of not more than 0.05 wt%; isophorone diisocyanate has a purity of not less than 99.0 wt%; 3-aminopropyltrimethoxysilane has a purity of not less than 98.0 wt%; and industrial-grade nitrogen gas has a gas fraction of not less than 99.5%.

[0063] Step A1: Preparation of composite filler using dried calcium carbonate 1000g of calcium carbonate was placed in a vacuum desiccator and dried at 90℃ and 0.005MPa absolute pressure for 1 hour. During the drying process, the powder was slowly turned over every 30 minutes to ensure that the powder layer thickness did not exceed 20mm. After drying, the powder was cooled to 25℃ under nitrogen protection to obtain dried calcium carbonate. The criterion for completion of drying was that the mass of calcium carbonate measured by sampling did not change by more than 0.05wt% within 30 minutes.

[0064] Step A2: Preparation of alkaline calcium carbonate dispersion system 2000g of ethanol and 100g of deionized water were added to a reactor equipped with a reflux condenser, mechanical stirrer, and pH electrode. The mass ratio of ethanol to deionized water was 100:5. Mechanical stirring was started at 600 rpm, and 1000g of dried calcium carbonate obtained in step A1 was added in batches at 25°C over a period of 30 minutes. After the addition was complete, stirring continued for 20 minutes. The pH of the system was adjusted to 8.5 using ammonia water to obtain an alkaline calcium carbonate dispersion.

[0065] Steps A3 and A4: Surface treatment reaction of composite filler Under stirring at 600 rpm, 10.0 g of 3-glycidyloxypropyltrimethoxysilane, 2.0 g of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 2.0 g of 2-hydroxy-4-n-octyloxybenzophenone were added sequentially to the alkaline calcium carbonate dispersion system obtained in step A2, making the mass ratio of calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 2-hydroxy-4-n-octyloxybenzophenone 100:1.00:0.20:0.20. After the addition was completed, the temperature was raised to 45°C, and the reaction was carried out under reflux and condensation conditions for 2 hours. The pH value was measured every 30 minutes during the reaction, and the pH value was maintained at 8.5 with ammonia water. The reaction was considered complete when the pH value of the system did not change by more than 0.1 within 30 minutes and there were no visible coarse deposits in the slurry.

[0066] Step A5: Post-treatment of composite packing The reaction slurry obtained in step A4 was filtered, and the filter cake was washed three times with ethanol, each time using 1.5 times the mass of the filter cake. It was then washed three times with deionized water, each time using 1.5 times the mass of the filter cake. The washed filter cake was placed in a vacuum dryer and dried at 70°C and 0.005 MPa absolute pressure for 4 hours. After cooling to 25°C, it was pulverized and passed through an 80-mesh sieve to obtain the composite packing material of this embodiment.

[0067] Step B1: Dehydration of polypropylene glycol for prepolymerization 1000g of prepolymerized polypropylene glycol was added to a reactor equipped with a stirrer, temperature control, vacuum port, and nitrogen port. The mixture was dehydrated at 100℃ and 0.005MPa absolute pressure for 1 hour, with a stirring speed of 150rpm. After dehydration, industrial-grade nitrogen was introduced to restore the pressure to atmospheric level, and the material was cooled to 70℃ to obtain dehydrated polypropylene glycol.

[0068] Step B2: Preparation of isocyanate-terminated polyether prepolymer Under industrial-grade nitrogen protection, 177.8 g of isophorone diisocyanate was added to the dehydrated polypropylene glycol obtained in step B1 to achieve an NCO:OH molar ratio of 1.60. The addition time was 20 min, and the reaction temperature was maintained at 70 °C during the addition process. After addition, the reaction continued at 70 °C for 2 h with a stirring speed of 120 rpm, yielding an isocyanate-terminated polyether prepolymer. The completion criterion for the reaction was that the NCO content measured by the di-n-butylamine back titration method tended to stabilize, with the difference between two consecutive measurements not exceeding 0.02 wt%.

[0069] Steps B3 and B4: Preparation of trimethoxysilane-terminated polyether prepolymer 113.3 g of 3-aminopropyltrimethoxysilane was added to the isocyanate-terminated polyether prepolymer obtained in step B2, so that the molar ratio between the residual NCO groups in the isocyanate-terminated polyether prepolymer and the amino groups in the 3-aminopropyltrimethoxysilane was 0.95. The addition time was 30 min, the addition temperature was controlled at 45°C, and the reaction was carried out at 45°C for 1 h with a stirring speed of 100 rpm to obtain the trimethoxysilane-terminated polyether prepolymer. The reaction completion criterion was that the residual NCO content was not higher than 0.10 wt%. Sampling and measurement showed that the residual NCO content of the trimethoxysilane-terminated polyether prepolymer in this embodiment was 0.10 wt%, the water content was 0.01 wt%, and the viscosity at 25°C was 5000 mPa·s.

[0070] Steps S1 and S2: Providing composite fillers and prepolymers Take 800g of the composite filler obtained in step A5 as the composite filler provided in step S1. Take 1000g of the trimethoxysilane-terminated polyether prepolymer obtained in steps B3 and B4 as the trimethoxysilane-terminated polyether prepolymer provided in step S2. Before use, the composite filler should be stored in a sealed container in a dry nitrogen atmosphere at 25°C, and the prepolymer should be stored in a sealed container in a moisture-proof environment.

[0071] Step S3: Vacuum mixing of bulk components 1000g of trimethoxysilane-terminated polyether prepolymer and 200g of added polypropylene glycol were added to a planetary mixer and stirred at 30 rpm for 10 min at 25°C. Then, 800g of composite filler, 800g of unmodified calcium carbonate, and 10g of fumed silica were added, and the mixture was heated to 40°C and vacuum mixed at an absolute pressure of 0.005 MPa for 0.5 h. The planetary mixer revolved at 40 rpm and rotated at 600 rpm, with the wall scraper running continuously. The mixing was considered complete when no visible powder clumps were observed in three samples (top, middle, and bottom), and the difference in moisture content between the three samples did not exceed 0.01 wt%.

[0072] Step S4: Addition of silane promoter and catalytic components The mixture obtained in step S3 was cooled to 20°C and kept under vacuum at an absolute pressure of 0.005 MPa. First, 10 g of vinyltrimethoxysilane was added and mixed for 5 min; then 5 g of 3-aminopropyltrimethoxysilane was added and mixed for 5 min; finally, 0.5 g of tetrabutyl titanate was added, and vacuum mixing continued for 0.2 h. During the mixing process, the material was kept isolated from ambient moisture, and the equipment inlet was protected with dry nitrogen under slight positive pressure.

[0073] Step S5: Degassing and Moisture-proof Packaging The sealant obtained in step S4 was degassed for 15 minutes under an absolute pressure of 0.005 MPa at a degassed temperature of 20°C. After degassed, it was poured into an aluminum-plastic composite moisture-proof packaging tube under moisture-proof conditions and sealed to obtain the high weather-resistant MS resin sealant of this embodiment. The packaging completion criterion was that there were no visible large air bubbles in the packaging tube, the seal was continuous and intact, and the moisture content of the sealant before moisture-proof packaging was measured to be 0.01 wt%.

[0074] Quality testing methods and results In this embodiment, the composite filler sample after washing and drying was used as the test sample. Thermogravimetric analysis was used to record the mass change in the temperature range of 200-600℃ under a nitrogen atmosphere, and the surface organic layer content was calculated to be 0.50 wt%. Laser particle size analysis was used to determine D50 and D90. Using ethanol as the dispersion medium, ultrasonic dispersion power was 200W, and dispersion time was 5 min. The measured D50 was 60 nm and D90 was 150 nm. The Karl Fischer method was used to determine the water content of the composite filler to be 0.01 wt%. Particles with a diameter exceeding 1200 nm were collected according to the same dispersion procedure, and the mass percentage of agglomerates with a diameter exceeding 1200 nm after dispersion was measured to be 0.80 wt%. In this embodiment, the trimethoxysilane-terminated polyether prepolymer had an NCO residue of 0.10 wt% determined by di-n-butylamine back-tipping method, a water content of 0.01 wt% determined by Karl Fischer method, and a viscosity of 5000 mPa·s measured by rotational viscometer at 25℃ after the reading stabilized for 60 s. Before moisture-proof packaging, the moisture content of the sealant was measured to be 0.01 wt% using the Karl Fischer method, and the maximum deviation of three parallel measurements did not exceed 0.003 wt%.

[0075] Features and application scenarios of this embodiment This embodiment employs a relatively conservative low-ratio formulation, with polypropylene glycol, composite filler, fumed silica, silane additives, and tetrabutyl titanate all used in low quantities. Unmodified calcium carbonate is also incorporated as a filler, making it suitable for sealing applications in building doors and windows, prefabricated component joints, and general industrial joints where high levels of construction resistance, cost control, and basic joint filling are required. The process conditions in this embodiment are biased towards mild conditions, facilitating preparation at lower processing intensity and ensuring stability in batch operations.

[0076] Example 2 Overall production scale and product form This embodiment prepares a one-component paste-like high weather-resistant MS resin sealant. Based on 1000g of trimethoxysilane-terminated polyether prepolymer used in the final sealant preparation stage, 100 parts by weight of the trimethoxysilane-terminated polyether prepolymer correspond to 1000g, 60 parts by weight of added polypropylene glycol correspond to 600g, 180 parts by weight of composite filler correspond to 1800g, 0 parts by weight of unmodified calcium carbonate correspond to 0g, 6 parts by weight of fumed silica correspond to 60g, 4 parts by weight of vinyltrimethoxysilane correspond to 40g, 3 parts by weight of 3-aminopropyltrimethoxysilane correspond to 30g, and 0.80 parts by weight of tetrabutyl titanate correspond to 8.0g. All raw materials in this embodiment are commercially available. The added polypropylene glycol is a hydroxyl-terminated polyether with a number-average molecular weight of approximately 2000 and a moisture content not exceeding 0.05wt%; the fumed silica is a hydrophilic powder with a specific surface area of ​​150-250m². 2 / g; the purity of vinyltrimethoxysilane, 3-aminopropyltrimethoxysilane and tetrabutyl titanate is not less than 98.0wt%.

[0077] Raw materials, components or material specifications The calcium carbonate used to prepare the composite filler is commercially available nano-calcium carbonate with a dry basis purity of not less than 98.0 wt%; 3-glycidyloxypropyltrimethoxysilane has a purity of not less than 98.0 wt%; bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate has a purity of not less than 98.0 wt%; 2-hydroxy-4-n-octyloxybenzophenone has a purity of not less than 98.0 wt%; ethanol is analytical grade; deionized water has a conductivity of not more than 10 μS / cm; and ammonia is commercially available analytical grade. The polypropylene glycol used for the prepolymerization of the trimethoxysilane-terminated polyether prepolymer is commercially available hydroxyl-terminated polyether with a hydroxyl value of approximately 56 mg KOH / g and a moisture content of not more than 0.05 wt%; isophorone diisocyanate has a purity of not less than 99.0 wt%; 3-aminopropyltrimethoxysilane has a purity of not less than 98.0 wt%; and industrial-grade nitrogen gas has a gas fraction of not less than 99.5%.

[0078] Step A1: Preparation of composite filler using dried calcium carbonate 1000g of calcium carbonate was placed in a vacuum desiccator and dried at 105℃ and 0.020MPa absolute pressure for 2 hours. During the drying process, the powder was slowly turned over every 30 minutes to ensure that the powder layer thickness did not exceed 25mm. After drying, the powder was cooled to 25℃ under nitrogen protection to obtain dried calcium carbonate. The criterion for completion of drying was that the mass of calcium carbonate measured at a sample did not change by more than 0.05wt% within 30 minutes.

[0079] Step A2: Preparation of alkaline calcium carbonate dispersion system 2000g of ethanol and 600g of deionized water were added to a reactor equipped with a reflux condenser, mechanical stirrer, and pH electrode. The mass ratio of ethanol to deionized water was 100:30. Mechanical stirring was started at 800 rpm, and 1000g of dried calcium carbonate obtained in step A1 was added in batches at 25°C over a period of 45 minutes. After the addition was complete, stirring continued for 30 minutes. The pH of the system was adjusted to 10.5 using ammonia water to obtain an alkaline calcium carbonate dispersion.

[0080] Steps A3 and A4: Surface treatment reaction of composite filler Under stirring at 800 rpm, 80.0 g of 3-glycidyloxypropyltrimethoxysilane, 30.0 g of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 30.0 g of 2-hydroxy-4-n-octyloxybenzophenone were added sequentially to the alkaline calcium carbonate dispersion system obtained in step A2, so that the mass ratio of calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 2-hydroxy-4-n-octyloxybenzophenone was 100:8.00:3.00:3.00. After the addition was completed, the temperature was raised to 60°C, and the reaction was carried out under reflux and condensation conditions for 3 hours. The pH value was measured every 30 minutes during the reaction, and the pH value was maintained at 10.5 with ammonia water. The reaction was considered complete when the pH value of the system did not change by more than 0.1 within 30 minutes and the slurry remained in a stirable state.

[0081] Step A5: Post-treatment of composite packing The reaction slurry obtained in step A4 was filtered, and the filter cake was washed four times with ethanol, each time using 1.5 times the mass of the filter cake. It was then washed four times with deionized water, each time using 1.5 times the mass of the filter cake. The washed filter cake was placed in a vacuum dryer and dried at 80°C and 0.040 MPa absolute pressure for 4 hours. After cooling to 25°C, it was pulverized and passed through a 60-mesh sieve to obtain the composite packing material of this embodiment.

[0082] Step B1: Dehydration of polypropylene glycol for prepolymerization 1000g of prepolymerized polypropylene glycol was added to a reactor equipped with a stirrer, temperature control, vacuum port, and nitrogen port. The mixture was dehydrated at 110℃ and 0.020MPa absolute pressure for 2 hours, with a stirring speed of 150rpm. After dehydration, industrial-grade nitrogen was introduced to restore the pressure to atmospheric level, and the material was cooled to 80℃ to obtain dehydrated polypropylene glycol.

[0083] Step B2: Preparation of isocyanate-terminated polyether prepolymer Under industrial-grade nitrogen protection, 200.1 g of isophorone diisocyanate was added to the dehydrated polypropylene glycol obtained in step B1 to achieve an NCO:OH molar ratio of 1.80. The addition time was 25 min, and the reaction temperature was maintained at 80°C during the addition process. After addition, the reaction continued at 80°C for 3 h with a stirring speed of 120 rpm, yielding an isocyanate-terminated polyether prepolymer. The completion criterion for the reaction was that the NCO content measured by the di-n-butylamine back titration method tended to stabilize, with the difference between two consecutive measurements not exceeding 0.02 wt%.

[0084] Steps B3 and B4: Preparation of trimethoxysilane-terminated polyether prepolymer 143.4 g of 3-aminopropyltrimethoxysilane was added to the isocyanate-terminated polyether prepolymer obtained in step B2, so that the molar ratio between the residual NCO groups in the isocyanate-terminated polyether prepolymer and the amino groups in the 3-aminopropyltrimethoxysilane was 1.00. The addition time was 40 min, the addition temperature was controlled at 60 °C, and the reaction was carried out at 60 °C for 2 h with a stirring speed of 100 rpm to obtain a trimethoxysilane-terminated polyether prepolymer. The reaction completion criterion was that the residual NCO content was not higher than 0.10 wt%. Sampling and testing showed that the residual NCO content of the trimethoxysilane-terminated polyether prepolymer in this embodiment was 0.03 wt%, the water content was 0.10 wt%, and the viscosity at 25 °C was 100,000 mPa·s.

[0085] Steps S1 and S2: Providing composite fillers and prepolymers Take 1800g of the composite filler obtained in step A5 as the composite filler provided in step S1. Take 1000g of the trimethoxysilane-terminated polyether prepolymer obtained in steps B3 and B4 as the trimethoxysilane-terminated polyether prepolymer provided in step S2. Before use, the composite filler should be stored in a sealed container in a dry nitrogen atmosphere at 25°C, and the prepolymer should be stored in a sealed container in a moisture-proof environment.

[0086] Step S3: Vacuum mixing of bulk components 1000g of trimethoxysilane-terminated polyether prepolymer and 600g of added polypropylene glycol were added to a planetary mixer and stirred at 30 rpm for 10 min at 25°C. Then, 1800g of composite filler and 60g of fumed silica were added, the temperature was raised to 90°C, and vacuum mixed at an absolute pressure of 0.040 MPa for 3 h. The planetary mixer's revolution speed was 50 rpm, its rotation speed was 800 rpm, and the wall scraper was kept running continuously. The criterion for complete mixing was that no visible powder clumps were observed when taking samples from the top, middle, and bottom of the sample, and the difference in moisture content among the three samples did not exceed 0.01 wt%.

[0087] Step S4: Addition of silane promoter and catalytic components The mixture obtained in step S3 was cooled to 50°C and kept under vacuum at an absolute pressure of 0.040 MPa. First, 40 g of vinyltrimethoxysilane was added and mixed for 10 min; then 30 g of 3-aminopropyltrimethoxysilane was added and mixed for 10 min; finally, 8.0 g of tetrabutyl titanate was added, and vacuum mixing continued for 1.5 h. During the mixing process, the material was kept isolated from ambient moisture, and the equipment inlet was protected with dry nitrogen under slight positive pressure.

[0088] Step S5: Degassing and Moisture-proof Packaging The sealant to be degassed obtained in step S4 was degassed for 25 minutes under an absolute pressure of 0.040 MPa at a degassed temperature of 50°C. After degassed, it was poured into an aluminum-plastic composite moisture-proof packaging tube under moisture-proof conditions and sealed to obtain the high weather-resistant MS resin sealant of this embodiment. The packaging completion criterion was that there were no visible large air bubbles in the packaging tube, the seal was continuous and intact, and the moisture content of the sealant before moisture-proof packaging was measured to be 0.10 wt%.

[0089] Quality testing methods and results In this embodiment, the composite filler was tested using a washed and dried sample. Thermogravimetric analysis was used to record the mass change between 200-600℃ under a nitrogen atmosphere, and the surface organic layer content was calculated to be 5.00 wt%. Laser particle size analysis was used to determine D50 and D90. Ethanol was used as the dispersion medium, and ultrasonic dispersion was performed at a power of 200W for 5 minutes, yielding a D50 of 500 nm and a D90 of 1200 nm. The Karl Fischer method was used to determine the water content of the composite filler to be 0.30 wt%. Particles with a diameter exceeding 1200 nm were collected using the same dispersion procedure, and the mass percentage of agglomerates with a residual diameter exceeding 1200 nm after dispersion was determined to be 10.00 wt%. In this embodiment, the NCO residue of the trimethoxysilane-terminated polyether prepolymer was determined to be 0.03 wt% using the di-n-butylamine back titration method, and the water content was determined to be 0.10 wt% using the Karl Fischer method. The viscosity was measured to be 100,000 mPa·s using a rotational viscometer at 25°C after the reading stabilized for 60 seconds. Before moisture-proof packaging, the water content of the sealant was determined to be 0.10 wt% using the Karl Fischer method, and the maximum deviation of three parallel measurements did not exceed 0.005 wt%.

[0090] Features and application scenarios of this embodiment This embodiment employs an optimized scheme with a relatively high loading rate. Polypropylene glycol, composite filler, fumed silica, vinyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and tetrabutyl titanate are all used in relatively high amounts. Unmodified calcium carbonate is not added. This approach is suitable for outdoor building joints, industrial equipment joints, and prefabricated component sealing applications where high requirements are placed on the interfacial interaction of the composite filler, retention of light-stabilized components, and curing activation efficiency. The mixing temperature and mixing time in this embodiment are biased towards the higher range, which is suitable for demonstrating dispersion and degassing adaptability under high filler loading conditions.

[0091] Example 3 Overall production scale and product form This embodiment prepares a one-component paste-like high weather-resistant MS resin sealant. Based on 1000g of trimethoxysilane-terminated polyether prepolymer used in the final sealant formulation stage, 100 parts by weight of the trimethoxysilane-terminated polyether prepolymer corresponds to 1000g, 40 parts by weight of added polypropylene glycol corresponds to 400g, 120 parts by weight of composite filler corresponds to 1200g, 40 parts by weight of unmodified calcium carbonate corresponds to 400g, 3 parts by weight of fumed silica corresponds to 30g, 2.5 parts by weight of vinyltrimethoxysilane corresponds to 25g, 1.5 parts by weight of 3-aminopropyltrimethoxysilane corresponds to 15g, and 0.40 parts by weight of tetrabutyl titanate corresponds to 4.0g. All raw materials used in this embodiment are commercially available. The added polypropylene glycol is a hydroxyl-terminated polyether with a number-average molecular weight of approximately 2000 and a moisture content not exceeding 0.05 wt%. The unmodified calcium carbonate is a dry powder with a D50 of approximately 350 nm and a moisture content not exceeding 0.10 wt%. The fumed silica is a hydrophilic powder with a specific surface area of ​​150-250 m². 2 / g; the purity of vinyltrimethoxysilane, 3-aminopropyltrimethoxysilane and tetrabutyl titanate is not less than 98.0wt%.

[0092] Raw materials, components or material specifications The calcium carbonate used to prepare the composite filler is commercially available nano-calcium carbonate with a dry basis purity of not less than 98.0 wt%; 3-glycidyloxypropyltrimethoxysilane has a purity of not less than 98.0 wt%; bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate has a purity of not less than 98.0 wt%; 2-hydroxy-4-n-octyloxybenzophenone has a purity of not less than 98.0 wt%; ethanol is analytical grade; deionized water has a conductivity of not more than 10 μS / cm; and ammonia is commercially available analytical grade. The polypropylene glycol used for the prepolymerization of the trimethoxysilane-terminated polyether prepolymer is commercially available hydroxyl-terminated polyether with a hydroxyl value of approximately 56 mg KOH / g and a moisture content of not more than 0.05 wt%; isophorone diisocyanate has a purity of not less than 99.0 wt%; 3-aminopropyltrimethoxysilane has a purity of not less than 98.0 wt%; and industrial-grade nitrogen gas has a gas fraction of not less than 99.5%.

[0093] Step A1: Preparation of composite filler using dried calcium carbonate 1000g of calcium carbonate was placed in a vacuum desiccator and dried at 120℃ and 0.040MPa absolute pressure for 4 hours. During the drying process, the powder was slowly turned over every 30 minutes to ensure that the powder layer thickness did not exceed 20mm. After drying, the powder was cooled to 25℃ under nitrogen protection to obtain dried calcium carbonate. The criterion for completion of drying was that the mass of calcium carbonate measured by sampling did not change by more than 0.05wt% within 30 minutes.

[0094] Step A2: Preparation of alkaline calcium carbonate dispersion system 2000g of ethanol and 300g of deionized water were added to a reactor equipped with a reflux condenser, mechanical stirrer, and pH electrode. The mass ratio of ethanol to deionized water was 100:15. Mechanical stirring was started at 700 rpm, and 1000g of dried calcium carbonate obtained in step A1 was added in batches at 25°C over a period of 40 minutes. After the addition was complete, stirring continued for 25 minutes. The pH of the system was adjusted to 9.5 using ammonia water to obtain an alkaline calcium carbonate dispersion.

[0095] Steps A3 and A4: Surface treatment reaction of composite filler Under stirring at 700 rpm, 40.0 g of 3-glycidyloxypropyltrimethoxysilane, 12.0 g of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 12.0 g of 2-hydroxy-4-n-octyloxybenzophenone were added sequentially to the alkaline calcium carbonate dispersion system obtained in step A2, making the mass ratio of calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 2-hydroxy-4-n-octyloxybenzophenone 100:4.00:1.20:1.20. After the addition was complete, the temperature was raised to 75°C, and the reaction was carried out under reflux and condensation conditions for 4 hours. The pH value was measured every 30 minutes during the reaction, and the pH value was maintained at 9.5 with ammonia water. The reaction was considered complete when the pH value of the system did not change by more than 0.1 within 30 minutes and the slurry remained in a uniform flow state.

[0096] Step A5: Post-treatment of composite packing The reaction slurry obtained in step A4 was filtered, and the filter cake was washed three times with ethanol, each time using 1.5 times the mass of the filter cake. It was then washed three times with deionized water, each time using 1.5 times the mass of the filter cake. The washed filter cake was placed in a vacuum dryer and dried for 8 hours at 90°C and 0.020 MPa absolute pressure. After cooling to 25°C, it was pulverized and passed through an 80-mesh sieve to obtain the composite packing material of this embodiment.

[0097] Step B1: Dehydration of polypropylene glycol for prepolymerization 1000g of prepolymerized polypropylene glycol was added to a reactor equipped with a stirrer, temperature control, vacuum port, and nitrogen port. The mixture was dehydrated for 3 hours at 120℃ and 0.040MPa absolute pressure, with a stirring speed of 150rpm. After dehydration, industrial-grade nitrogen was introduced to restore the pressure to atmospheric level, and the material was cooled to 90℃ to obtain dehydrated polypropylene glycol.

[0098] Step B2: Preparation of isocyanate-terminated polyether prepolymer Under industrial-grade nitrogen protection, 244.5 g of isophorone diisocyanate was added to the dehydrated polypropylene glycol obtained in step B1, making the NCO:OH molar ratio 2.20. The addition time was 30 min, and the reaction temperature was maintained at 90℃ during the addition process. After addition, the reaction continued at 90℃ for 5 h with a stirring speed of 120 rpm, yielding an isocyanate-terminated polyether prepolymer. The completion criterion for the reaction was that the NCO content measured by the di-n-butylamine back titration method tended to stabilize, and the difference between two consecutive measurements did not exceed 0.02 wt%.

[0099] Steps B3 and B4: Preparation of trimethoxysilane-terminated polyether prepolymer 204.9 g of 3-aminopropyltrimethoxysilane was added to the isocyanate-terminated polyether prepolymer obtained in step B2, so that the molar ratio between the residual NCO groups in the isocyanate-terminated polyether prepolymer and the amino groups in the 3-aminopropyltrimethoxysilane was 1.05. The addition time was 45 min, the addition temperature was controlled at 75 °C, and the reaction was carried out at 75 °C for 3 h with a stirring speed of 100 rpm to obtain the trimethoxysilane-terminated polyether prepolymer. The reaction completion criterion was that the residual NCO content was not higher than 0.10 wt%. Sampling and measurement showed that the residual NCO content of the trimethoxysilane-terminated polyether prepolymer in this embodiment was 0.08 wt%, the water content was 0.05 wt%, and the viscosity at 25 °C was 30000 mPa·s.

[0100] Steps S1 and S2: Providing composite fillers and prepolymers Take 1200g of the composite filler obtained in step A5 as the composite filler provided in step S1. Take 1000g of the trimethoxysilane-terminated polyether prepolymer obtained in steps B3 and B4 as the trimethoxysilane-terminated polyether prepolymer provided in step S2. Before use, the composite filler should be stored in a sealed container in a dry nitrogen atmosphere at 25°C, and the prepolymer should be stored in a sealed container in a moisture-proof container.

[0101] Step S3: Vacuum mixing of bulk components 1000g of trimethoxysilane-terminated polyether prepolymer and 400g of added polypropylene glycol were added to a kneader and stirred at 25 rpm for 10 min at 25°C. Then, 1200g of composite filler, 400g of unmodified calcium carbonate, and 30g of fumed silica were added, and the mixture was heated to 65°C and vacuum mixed at an absolute pressure of 0.020 MPa for 1.5 h. The kneading paddle speed was 45 rpm, and the temperature fluctuation of the equipment jacket was controlled within ±3°C. The mixing was considered complete when no visible powder lumps were observed in three samples (top, middle, and bottom), and the difference in moisture content among the three samples did not exceed 0.01 wt%.

[0102] Step S4: Addition of silane promoter and catalytic components The mixture obtained in step S3 was cooled to 35°C and kept under vacuum at an absolute pressure of 0.020 MPa. First, 25 g of vinyltrimethoxysilane was added and mixed for 8 min; then 15 g of 3-aminopropyltrimethoxysilane was added and mixed for 8 min; finally, 4.0 g of tetrabutyl titanate was added, and vacuum mixing continued for 0.8 h. During the mixing process, the material was kept isolated from ambient moisture, and the equipment inlet was protected with dry nitrogen under slight positive pressure.

[0103] Step S5: Degassing and Moisture-proof Packaging The sealant obtained in step S4 was degassed for 20 minutes under an absolute pressure of 0.020 MPa at a degassed temperature of 35°C. After degassed, it was poured into an aluminum-plastic composite moisture-proof packaging tube under moisture-proof conditions and sealed to obtain the high weather-resistant MS resin sealant of this embodiment. The packaging completion criterion was that there were no visible large air bubbles in the packaging tube, the seal was continuous and intact, and the moisture content of the sealant before moisture-proof packaging was measured to be 0.06 wt%.

[0104] Quality testing methods and results In this embodiment, the composite filler was tested using a washed and dried sample. Thermogravimetric analysis was used to record the mass change between 200-600℃ under a nitrogen atmosphere, and the surface organic layer content was calculated to be 2.50 wt%. Laser particle size analysis was used to determine D50 and D90. Ethanol was used as the dispersion medium, and ultrasonic dispersion was performed at 200W for 5 minutes, yielding a D50 of 250 nm and a D90 of 600 nm. The Karl Fischer method was used to determine the water content of the composite filler to be 0.15 wt%. Particles with a diameter exceeding 1200 nm were collected using the same dispersion procedure, and the mass percentage of agglomerates with a residual diameter exceeding 1200 nm after dispersion was determined to be 5.00 wt%. In this embodiment, the NCO residue of the trimethoxysilane-terminated polyether prepolymer was determined to be 0.08 wt% using the di-n-butylamine back titration method, and the water content was determined to be 0.05 wt% using the Karl Fischer method. The viscosity was measured to be 30000 mPa·s using a rotational viscometer at 25°C after the reading stabilized for 60 seconds. Before moisture-proof packaging, the water content of the sealant was determined to be 0.06 wt% using the Karl Fischer method, and the maximum deviation of three parallel measurements did not exceed 0.004 wt%.

[0105] Features and application scenarios of this embodiment This embodiment employs a scheme combining intermediate proportions with strong prepolymerization reaction conditions. Composite filler and unmodified calcium carbonate participate in the filling simultaneously, with a mass ratio of composite filler to unmodified calcium carbonate of 3.00:1. This approach is suitable for industrial joint sealing applications that balance dispersibility, application viscosity, and interfacial load-bearing requirements. This embodiment uses a kneading method for mixing the main components, making it suitable for the batch preparation of high-viscosity materials and for sealant production requiring stable filler distribution and a more balanced application window.

[0106] Example 4 Overall production scale and product form This embodiment prepares a one-component paste-like high weather-resistant MS resin sealant. Based on 1000g of trimethoxysilane-terminated polyether prepolymer used in the final sealant preparation stage, 100 parts by weight of the trimethoxysilane-terminated polyether prepolymer corresponds to 1000g, 50 parts by weight of added polypropylene glycol corresponds to 500g, 180 parts by weight of composite filler corresponds to 1800g, 30 parts by weight of unmodified calcium carbonate corresponds to 300g, 4 parts by weight of fumed silica corresponds to 40g, 3 parts by weight of vinyltrimethoxysilane corresponds to 30g, 2 parts by weight of 3-aminopropyltrimethoxysilane corresponds to 20g, and 0.60 parts by weight of tetrabutyl titanate corresponds to 6.0g. All raw materials used in this embodiment are commercially available. The added polypropylene glycol is a hydroxyl-terminated polyether with a number-average molecular weight of approximately 2000 and a moisture content not exceeding 0.05 wt%. The unmodified calcium carbonate is a dry powder with a D50 of approximately 400 nm and a moisture content not exceeding 0.10 wt%. The fumed silica is a hydrophilic powder with a specific surface area of ​​150-250 m². 2 / g; the purity of vinyltrimethoxysilane, 3-aminopropyltrimethoxysilane and tetrabutyl titanate is not less than 98.0wt%.

[0107] Raw materials, components or material specifications The calcium carbonate used to prepare the composite filler is commercially available nano-calcium carbonate with a dry basis purity of not less than 98.0 wt%; 3-glycidyloxypropyltrimethoxysilane has a purity of not less than 98.0 wt%; bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate has a purity of not less than 98.0 wt%; 2-hydroxy-4-n-octyloxybenzophenone has a purity of not less than 98.0 wt%; ethanol is analytical grade; deionized water has a conductivity of not more than 10 μS / cm; and ammonia is commercially available analytical grade. The polypropylene glycol used for the prepolymerization of the trimethoxysilane-terminated polyether prepolymer is commercially available hydroxyl-terminated polyether with a hydroxyl value of approximately 56 mg KOH / g and a moisture content of not more than 0.05 wt%; isophorone diisocyanate has a purity of not less than 99.0 wt%; 3-aminopropyltrimethoxysilane has a purity of not less than 98.0 wt%; and industrial-grade nitrogen gas has a gas fraction of not less than 99.5%.

[0108] Step A1: Preparation of composite filler using dried calcium carbonate 1000g of calcium carbonate was placed in a vacuum desiccator and dried at 110℃ and 0.030MPa absolute pressure for 3 hours. During the drying process, the powder was slowly turned over every 30 minutes to ensure that the powder layer thickness did not exceed 20mm. After drying, the powder was cooled to 25℃ under nitrogen protection to obtain dried calcium carbonate. The criterion for completion of drying was that the mass of calcium carbonate measured at a sample did not change by more than 0.05wt% within 30 minutes.

[0109] Step A2: Preparation of alkaline calcium carbonate dispersion system 2000g of ethanol and 500g of deionized water were added to a reactor equipped with a reflux condenser, mechanical stirrer, and pH electrode. The mass ratio of ethanol to deionized water was 100:25. Mechanical stirring was started at 750 rpm, and 1000g of dried calcium carbonate obtained in step A1 was added in batches at 25°C over a period of 40 minutes. After the addition was complete, stirring continued for 25 minutes. The pH of the system was adjusted to 10.0 using ammonia water to obtain an alkaline calcium carbonate dispersion.

[0110] Steps A3 and A4: Surface treatment reaction of composite filler Under stirring at 750 rpm, 60.0 g of 3-glycidyloxypropyltrimethoxysilane, 25.0 g of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 25.0 g of 2-hydroxy-4-n-octyloxybenzophenone were added sequentially to the alkaline calcium carbonate dispersion system obtained in step A2, so that the mass ratio of calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 2-hydroxy-4-n-octyloxybenzophenone was 100:6.00:2.50:2.50. After the addition was completed, the temperature was raised to 65°C, and the reaction was carried out under reflux and condensation conditions for 3 hours. The pH value was measured every 30 minutes during the reaction, and the pH value was maintained at 10.0 with ammonia water. The reaction was considered complete when the pH value of the system did not change by more than 0.1 within 30 minutes and the slurry remained in a uniform flow state.

[0111] Step A5: Post-treatment of composite packing The reaction slurry obtained in step A4 was filtered, and the filter cake was washed four times with ethanol, each time using 1.5 times the mass of the filter cake. It was then washed four times with deionized water, each time using 1.5 times the mass of the filter cake. The washed filter cake was placed in a vacuum dryer and dried at 110°C and 0.040 MPa absolute pressure for 12 hours. After cooling to 25°C, it was pulverized and passed through an 80-mesh sieve to obtain the composite packing material of this embodiment.

[0112] Step B1: Dehydration of polypropylene glycol for prepolymerization 1000g of prepolymerized polypropylene glycol was added to a reactor equipped with a stirrer, temperature control, vacuum port, and nitrogen port. The mixture was dehydrated for 2.5 hours at 115℃ and 0.030MPa absolute pressure, with a stirring speed of 150rpm. After dehydration, industrial-grade nitrogen was introduced to restore the pressure to atmospheric level, and the material was cooled to 85℃ to obtain dehydrated polypropylene glycol.

[0113] Step B2: Preparation of isocyanate-terminated polyether prepolymer Under industrial-grade nitrogen protection, 233.4 g of isophorone diisocyanate was added to the dehydrated polypropylene glycol obtained in step B1, making the NCO:OH molar ratio 2.10. The addition time was 30 min, and the reaction temperature was maintained at 85℃ during the addition process. After addition, the reaction continued at 85℃ for 4 h with a stirring speed of 120 rpm, yielding an isocyanate-terminated polyether prepolymer. The completion criterion for the reaction was that the NCO content measured by the di-n-butylamine back titration method tended to stabilize, and the difference between two consecutive measurements did not exceed 0.02 wt%.

[0114] Steps B3 and B4: Preparation of trimethoxysilane-terminated polyether prepolymer 188.3 g of 3-aminopropyltrimethoxysilane was added to the isocyanate-terminated polyether prepolymer obtained in step B2, so that the molar ratio between the residual NCO groups in the isocyanate-terminated polyether prepolymer and the amino groups in the 3-aminopropyltrimethoxysilane was 1.05. The addition time was 45 min, the addition temperature was controlled at 70 °C, and the reaction was carried out at 70 °C for 2.5 h with a stirring speed of 100 rpm to obtain the trimethoxysilane-terminated polyether prepolymer. The reaction completion criterion was that the residual NCO content was not higher than 0.10 wt%. Sampling and measurement showed that the residual NCO content of the trimethoxysilane-terminated polyether prepolymer in this embodiment was 0.01 wt%, the water content was 0.08 wt%, and the viscosity at 25 °C was 80000 mPa·s.

[0115] Steps S1 and S2: Providing composite fillers and prepolymers Take 1800g of the composite filler obtained in step A5 as the composite filler provided in step S1. Take 1000g of the trimethoxysilane-terminated polyether prepolymer obtained in steps B3 and B4 as the trimethoxysilane-terminated polyether prepolymer provided in step S2. Before use, the composite filler should be stored in a sealed container in a dry nitrogen atmosphere at 25°C, and the prepolymer should be stored in a sealed container in a moisture-proof environment.

[0116] Step S3: Vacuum mixing of bulk components 1000g of trimethoxysilane-terminated polyether prepolymer and 500g of added polypropylene glycol were added to a twin-shaft mixer and stirred at 35 rpm for 10 min at 25°C. Then, 1800g of composite filler, 300g of unmodified calcium carbonate, and 40g of fumed silica were added, and the mixture was heated to 80°C and vacuum mixed at an absolute pressure of 0.030 MPa for 2.5 h. The twin-shaft mixer was set at 60 rpm, and the wall scraper was continuously operated. The mixing was considered complete when no visible powder lumps were observed in three samples (top, middle, and bottom), and the difference in moisture content between the three samples did not exceed 0.01 wt%.

[0117] Step S4: Addition of silane promoter and catalytic components The mixture obtained in step S3 was cooled to 45°C and kept under vacuum at an absolute pressure of 0.030 MPa. First, 30 g of vinyltrimethoxysilane was added and mixed for 10 min; then 20 g of 3-aminopropyltrimethoxysilane was added and mixed for 10 min; finally, 6.0 g of tetrabutyl titanate was added, and vacuum mixing continued for 1.0 h. During the mixing process, the material was kept isolated from ambient moisture, and the equipment inlet was protected with dry nitrogen under slight positive pressure.

[0118] Step S5: Degassing and Moisture-proof Packaging The sealant obtained in step S4 was degassed for 25 minutes under an absolute pressure of 0.030 MPa at a degassed temperature of 45°C. After degassed, it was poured into an aluminum-plastic composite moisture-proof packaging tube under moisture-proof conditions and sealed to obtain the high weather-resistant MS resin sealant of this embodiment. The packaging completion criterion was that there were no visible large air bubbles in the packaging tube, the seal was continuous and intact, and the moisture content of the sealant before moisture-proof packaging was measured to be 0.04 wt%.

[0119] Quality testing methods and results In this embodiment, the composite filler was tested using a washed and dried sample. Thermogravimetric analysis was used to record the mass change between 200-600℃ under a nitrogen atmosphere, and the surface organic layer content was calculated to be 4.00 wt%. Laser particle size analysis was used to determine D50 and D90. Ethanol was used as the dispersion medium, and ultrasonic dispersion was performed at a power of 200W for 5 minutes, yielding a D50 of 400 nm and a D90 of 900 nm. The Karl Fischer method was used to determine the water content of the composite filler to be 0.05 wt%. Particles with a diameter exceeding 1200 nm were collected using the same dispersion procedure, and the mass percentage of agglomerates with a residual diameter exceeding 1200 nm after dispersion was determined to be 2.00 wt%. In this embodiment, the NCO residue of the trimethoxysilane-terminated polyether prepolymer was determined to be 0.01 wt% using the di-n-butylamine back-tipping method, and the water content was determined to be 0.08 wt% using the Karl Fischer method. The viscosity was measured to be 80,000 mPa·s using a rotational viscometer at 25°C after the reading stabilized for 60 seconds. Before moisture-proof packaging, the water content of the sealant was determined to be 0.04 wt% using the Karl Fischer method, and the maximum deviation of three parallel measurements did not exceed 0.004 wt%.

[0120] Features and application scenarios of this embodiment This embodiment employs a high-load composite filler with a small amount of unmodified calcium carbonate. The mass ratio of composite filler to unmodified calcium carbonate is 6.00:1, suitable for building exterior cladding joints, metal-inorganic substrate joints, and industrial durable sealing applications where high requirements are placed on weather resistance, interfacial load-bearing capacity, and appearance stability. This embodiment utilizes a biaxial stirring method, combined with a high proportion of composite filler and a moderate amount of silane additive in the mid-to-high range, which facilitates feasibility across a wider process window.

[0121] Comparative Example 1: It is basically the same as Example 1, except that the amount of polypropylene glycol added in the final sealant preparation stage is adjusted from 200g to 100g, that is, based on 100 parts by mass of trimethoxysilane-terminated polyether prepolymer, the amount of polypropylene glycol added is 10 parts by mass, and other conditions remain unchanged.

[0122] Comparative Example 2: It is basically the same as Example 1, except that the amount of composite filler provided in step S1 and added in step S3 is adjusted from 800g to 600g, that is, based on 100 parts by mass of trimethoxysilane-terminated polyether prepolymer, the composite filler is 60 parts by mass, and other conditions remain unchanged.

[0123] Comparative Example 3: It is basically the same as Example 1, except that the amount of unmodified calcium carbonate added in step S3 is adjusted from 800g to 1200g, that is, based on 100 parts by mass of trimethoxysilane-terminated polyether prepolymer, the amount of unmodified calcium carbonate is 120 parts by mass, and other conditions remain unchanged.

[0124] Comparative Example 4: It is basically the same as Example 1, except that the amount of fumed silica added in step S3 is adjusted from 10g to 5g, that is, based on 100 parts by mass of trimethoxysilane-terminated polyether prepolymer, the amount of fumed silica is 0.5 parts by mass, and other conditions remain unchanged.

[0125] Comparative Example 5: It is basically the same as Example 1, except that the vacuum mixing temperature of the main components in step S3 is adjusted from 40°C to 25°C, the absolute pressure is still 0.005MPa, the vacuum mixing time is still 0.5h, and other conditions remain unchanged.

[0126] Comparative Example 6: It is basically the same as Example 1, except that the absolute pressure of vacuum mixing of the main components in step S3 is adjusted from 0.005MPa to 0.060MPa, the mixing temperature is still 40℃, the vacuum mixing time is still 0.5h, and other conditions remain unchanged.

[0127] Comparative Example 7: Basically the same as Example 1, except that the NCO:OH molar ratio in step B2 was adjusted from 1.60 to 1.40, and the corresponding amount of isophorone diisocyanate added was adjusted from 177.8g to 155.6g. The remaining reaction temperature, time, stirring speed and nitrogen protection conditions in step B2 remained unchanged, and other conditions remained unchanged.

[0128] Comparative Example 8: It is basically the same as Example 1, except that the reaction temperature of the composite filler surface treatment in step A4 is adjusted from 45°C to 35°C, the reaction time is still 2 hours, the pH value is still maintained at 8.5, the stirring speed is still 600 rpm, and other conditions remain unchanged.

[0129] Comparative Example 9: Essentially the same as Example 1, except that bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate was not added in step A3, 3-glycidyloxypropyltrimethoxysilane remained at 10.0 g, and 2-hydroxy-4-n-octyloxybenzophenone remained at 2.0 g, with other conditions unchanged. This comparative example was used to verify the synergistic effect of the bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2-hydroxy-4-n-octyloxybenzophenone, and the silane interface layer.

[0130] Comparative Example 10: Essentially the same as Example 1, except that 2-hydroxy-4-n-octyloxybenzophenone was not added in step A3, 3-glycidyloxypropyltrimethoxysilane remained at 10.0 g, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate remained at 2.0 g, with other conditions unchanged. This comparative example was used to verify the synergistic effect of 2-hydroxy-4-n-octyloxybenzophenone with the bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and the silane interface layer.

[0131] Comparative Example 11: Essentially the same as Example 1, except that 3-glycidoxypropyltrimethoxysilane was not added in step A3, while bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone remained at 2.0 g, and other conditions were unchanged. This comparative example was used to verify the synergistic effect between the interfacial layer constructed with 3-glycidoxypropyltrimethoxysilane and the retention of photostable components.

[0132] Characterization and performance testing: The experiments prioritized the use of conventional testing systems for building sealant materials. GB / T 13477 series covers items such as extrudability, flowability, tensile adhesion, and elastic recovery rate of building sealant materials; ISO 11600:2002 is used for the classification and requirements of building joint sealants, and the ISO page shows that this standard is still in the publication state after confirmation; ASTM C920-18(2024) covers the classification of cold-applied elastic joint sealants for building applications; ISO 4892-3:2024 is used for fluorescent ultraviolet lamp exposure methods.

[0133] Extrudability tests were conducted on a single-component paste-like high-weather-resistant MS resin sealant to evaluate its application flowability. Samples were equilibrated in a sealed environment at 23±2℃ and 50±5%RH for 24 hours, then loaded into a standard extrusion canister and extruded for 60 seconds under a specified nozzle and constant pressure. The extruded mass was weighed. The test was conducted according to GB / T 13477.4, and the nozzle specification, test pressure, and extrusion time were recorded. Each group consisted of n=3 samples, and samples with obvious air bubbles were discarded. Data were presented as mean and standard deviation.

[0134] Sagging tests were conducted on the cured high-weather-resistant MS resin sealant to evaluate its resistance to sag during facade construction. Uncured samples were filled into a specified mold, leveled, and placed vertically at 23±2℃ and 50±5%RH. The displacement distance after a specified time was recorded. Referring to GB / T 13477.6, the maximum displacement was taken, and the average value and standard deviation were calculated.

[0135] Tensile bond strength tests were conducted on high weather-resistant MS resin sealants cured between standard substrates to evaluate the filler-resin interface load-bearing capacity and joint mechanical strength. Samples were prepared into tensile bond specimens according to standard dimensions. After curing at 23±2℃ and 50±5%RH for a specified time, they were loaded at a constant tensile rate until failure. Testing was conducted according to GB / T 13477.8, and specimen dimensions, curing time, tensile rate, and failure mode were recorded. For each group, n=5, and the average and standard deviation of peak stress were calculated.

[0136] The elastic recovery rate of the cured high-weather-resistant MS resin sealant was tested to evaluate its deformation recovery ability after joint displacement. Samples were prepared into specimens according to standard dimensions and cured to the specified state at 23±2℃ and 50±5%RH. Afterward, the sealant was held at the specified elongation for the specified time, unloaded, and the dimensional changes after recovery were recorded. The test was conducted according to the elastic recovery rate test method in GB / T 13477 series, with n=3 per group. The mean and standard deviation were calculated.

[0137] The weather resistance of the cured high-weather-resistant MS resin sealant was evaluated by accelerated UV aging followed by tensile retention testing. Cured specimens were placed in a fluorescent UV aging chamber, and UVA-340 irradiation and condensation cycles were set according to the fluorescent UV lamp exposure methods in ISO 4892-3 and GB / T 16422.3. Irradiance, irradiation temperature, condensation temperature, and cycle procedure were recorded. After a cumulative exposure of 1000 hours, the tensile bond strength was determined according to the tensile bond strength test method, with n=5 per group. The ratio of the strength after aging to the strength before aging was calculated.

[0138] The migration rate of light-stable components in the cured high-weather-resistant MS resin sealant was tested to evaluate its low migration properties. Cured samples were weighed and their mass and dimensions recorded. The cured samples were placed in an ethanol / water mixture for extraction, and the ratio of ethanol to water and the volume of the extract were recorded. The samples were extracted at 50°C in a sealed environment for 24 hours. The migration amounts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone were quantified using either HPLC or UV-Vis. The migrations were calculated using an external standard curve. The testing methods were kept consistent within the same group of comparisons, with n=3 for each group.

[0139] The migration rate of light-stable components in the cured high-weather-resistant MS resin sealant was tested to evaluate its low migration properties. Cured samples of specified mass and size were placed in an ethanol / water mixture and extracted at 50°C for 24 h in a sealed environment. The migration amounts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone were quantified using HPLC or UV-Vis, and calculated using an external standard curve. Each group had n=3 samples.

[0140] Figure 1 This diagram illustrates the effect of the amount of composite filler added to the MS resin sealant on the tensile bond strength. Figure 2 This diagram illustrates the effect of the amount of composite filler added to the MS resin sealant in this scheme on the retention rate of weather resistance tensile strength. Figure 1 and Figure 2 This study evaluated the effect of composite filler dosage on the initial mechanical properties and weather resistance retention of sealants. The basic formulation for the single-factor experiment consisted of 1000 g of trimethoxysilane-terminated polyether prepolymer, 200 g of added polypropylene glycol, 800 g of unmodified calcium carbonate, 10 g of fumed silica, 10 g of vinyltrimethoxysilane, 5 g of 3-aminopropyltrimethoxysilane, and 0.5 g of tetrabutyl titanate. The mixing conditions for step S3 were 40°C, 0.005 MPa absolute pressure, and vacuum mixing for 0.5 h; the mixing conditions for step S4 were 20°C and vacuum mixing for 0.2 h. The variable was the amount of composite filler added. Figure 1 and Figure 2 It is evident that with the increase of composite filler dosage, both tensile bond strength and weather-resistant tensile strength retention rate exhibit a trend of first increasing and then decreasing, reaching an optimal level around 140 parts by mass. This result indicates that an appropriate amount of composite filler can form an effective reinforcing structure in the MS resin system, improving interfacial load-bearing capacity. However, when the dosage is too high, the interaction between fillers is enhanced, easily leading to local agglomeration or excessively high system viscosity, which weakens the continuous resin phase and interfacial bonding effect. Therefore, controlling the composite filler dosage within a moderate range can simultaneously ensure both initial bond strength and weather-resistant strength retention, proving the rationality of the composite filler dosage design.

[0141] Figure 3 This diagram illustrates the effect of the amount of added polypropylene glycol in the MS resin sealant on the tensile bond strength. Figure 4 This figure shows the effect of the amount of added polypropylene glycol in the MS resin sealant on the retention rate of weather resistance tensile strength. Figure 3 and Figure 4This study aimed to further evaluate the regulatory effect of added polypropylene glycol (PPG) on filler dispersion, system flexibility, and post-weather mechanical properties. The basic formulation for the single-factor experiment consisted of 1000 g of trimethoxysilane-terminated polyether prepolymer, 800 g of composite filler, 800 g of unmodified calcium carbonate, 10 g of fumed silica, 10 g of vinyltrimethoxysilane, 5 g of 3-aminopropyltrimethoxysilane, and 0.5 g of tetrabutyl titanate. The composite filler preparation conditions, prepolymer preparation conditions, and S3 and S4 mixing conditions from Example 1 were used, with the variable being the amount of added PPG. Figure 3 and Figure 4 It is evident that when the amount of added polypropylene glycol (PPG) increases to approximately 40 parts by mass, both tensile bond strength and weather-resistant tensile strength retention reach optimal levels; further increases lead to a decline in these properties. This result indicates that an appropriate amount of added PPG is beneficial for reducing rigid contact between fillers, improving the wetting and dispersion of the composite filler in the resin system, and enhancing the stress buffering capacity of the cured adhesive. However, excessive PPG increases the proportion of low-molecular-weight or flexible components, reducing the effective load-bearing capacity of the crosslinked network. Therefore, controlling the amount of added PPG at a moderate level can achieve synergistic optimization of dispersion stability, interfacial bonding, and mechanical properties.

[0142] Figure 5 This is a superimposed diagram of the FTIR absorption spectra of Example 1, Comparative Example 11, and Comparative Example 8. Figure 6 Scatter plots of relative peak area ratios in XPS for Example 1, Comparative Example 11, and Comparative Example 8. Figure 5 and Figure 6 This method is used to verify the construction effect of the organic layer on the surface of the composite filler from the perspective of chemical structure and surface elemental composition. The FTIR test wavenumber range is 4000–500 cm⁻¹. -1 XPS uses Si2p / O1s, N1s / O1s, and C1s / O1s as core evaluation parameters, with variables including whether a silane interface layer is applied and the surface treatment temperature change. Figure 5 As can be seen, Example 1 exhibits a more complete characteristic signal in the C–H, Si–O–C / Si–O–Si, and organic stable component related absorption regions; Figure 6 It is evident that the relative signals of Si, N, and C in Example 1 are more balanced, and the test repeatability is better. The above results corroborate each other, indicating that the silane interface layer and organic modified components in Example 1 can be more stably introduced into the surface of calcium carbonate filler, thereby forming a more complete and uniformly distributed composite organic layer, providing a chemical basis for subsequently improving filler dispersibility and interfacial bonding strength.

[0143] Figure 7 The TGA mass-temperature curves for Example 1, Comparative Example 9, and Comparative Example 10 are shown below. Figure 8This is a statistical graph showing the mass loss of the organic layer at 200–600°C for Examples 1, 9, and 10. Figure 9 The graph shows the retention rates of organic components after washing for Examples 1, 9, and 10. Figures 7 to 9 This was used to further evaluate the loading and fixation stability of organic components on the surface of the composite filler. The TGA test temperature range was 30–650℃, with 200–600℃ being the key observation range for the thermogravimetric loss of the organic layer. Figure 8 Using the percentage of mass loss in this temperature range as the core parameter, Figure 9 The retention rate of organic components after washing is used as the core parameter. Figure 7 and Figure 8 It is evident that Example 1 exhibits a more pronounced organic layer thermogravimetric characteristic in the medium-high temperature region, and its mass loss level at 200–600°C is higher than that of the comparative example, indicating that its surface organic components are more fully loaded; Figure 9 As can be seen, the high retention rate of organic components after washing in Example 1 indicates that the constructed composite surface layer is not simply physically adsorbed, but has good interfacial fixation ability. These results demonstrate that the silane interfacial layer can improve the binding stability of organic stable components on the filler surface, reduce the risk of component migration during use, and thus help maintain the performance stability of the sealant after weathering.

[0144] Figure 10 The viscosity-shear rate curves for Example 1, Comparative Example 2, and Comparative Example 4 are shown below. Figure 11 The graphs show the storage modulus G′-shear rate curves for Examples 1, 2, and 4. Figure 12 The graphs show the loss modulus G″-shear rate for Example 1, Comparative Example 2, and Comparative Example 4. Figure 13 The scatter plot shows the extrusion rate-sag correlation of Example 1, Comparative Example 2, and Comparative Example 4. Figures 10 to 13 This method is used to evaluate the effects of composite fillers and thixotropic structures on the rheological and application properties of sealants. Rheological testing uses uncured sealant as the test sample, and records the test temperature, measurement geometry, gap, and pre-shear conditions. The shear rate range is 0.01–100 s⁻¹. -1 The variables are the ratio of composite filler to unmodified calcium carbonate and the amount of fumed silica. Figure 10 As can be seen, Example 1 exhibits a clear shear-thinning characteristic, meaning it has higher viscosity at low shear levels to maintain morphological stability, and lower viscosity at high shear levels to facilitate extrusion. Figure 11 and Figure 12 It is evident that the energy storage modulus G′ in Example 1 remains at a moderately high level, and the loss modulus G″ has a good matching relationship with G′, indicating that a stable but not excessively stiffened packing network has been formed within the system. Further combining... Figure 13It can be seen that Example 1 maintains a high extrusion rate while exhibiting low sag, indicating that it can simultaneously meet the requirements of construction fluidity and facade anti-sagging. These results demonstrate that the combined structure formed by the composite filler and fumed silica can effectively adjust the thixotropy and deformation recovery ability of the sealant, resulting in a more balanced construction adaptability.

[0145] Figure 14 The following are particle size difference volume distribution curves for Example 1, Comparative Example 8, and Comparative Example 11. Figure 15 The graphs show the cumulative particle size distribution of Example 1, Comparative Example 8, and Comparative Example 11. Figure 16 This is a scatter plot showing the D50 and D90 averaging values ​​for Example 1, Comparative Example 8, and Comparative Example 11. Figure 17 This is a statistical chart showing the mass percentage of dispersible aggregates in Example 1, Comparative Example 8, and Comparative Example 11. Figures 14 to 17 This study aims to verify the effect of composite surface treatment on the dispersion of fillers from the perspective of particle size distribution. The particle size measurement range is 20–5000 nm, and the core parameters include D50, D90, and the mass percentage of dispersible agglomerates. Variables include surface treatment temperature and whether a silane interface layer is applied. Figure 14 As can be seen, Example 1 exhibits a more concentrated particle size distribution and less large-particle tailing; Figure 15 and Figure 16 It is evident that the cumulative distribution curve of Example 1 reaches the high percentile more quickly, with D50 and D90 generally lower than those of the comparative example; Figure 17 As can be seen, Example 1 exhibits the lowest proportion of dispersible agglomerates. These results indicate that composite surface treatment can reduce secondary agglomeration among calcium carbonate particles and improve their dispersion uniformity in the resin system. Optimization of particle size distribution not only helps improve macroscopic mechanical properties but also reduces local defects and stress concentration, thereby providing structural support for maintaining performance after weathering.

[0146] Figure 18 This is a scatter plot showing the mean moisture content of the sealant in Example 1 and Comparative Example 6. Figure 19 This is a scatter plot showing the mean values ​​of the surface drying time for Example 1 and Comparative Example 6. Figure 20 The graphs show the curing depth of Example 1 and Comparative Example 6 as a function of time. Figures 18 to 20 Used to evaluate moisture control during the preparation process and its impact on curing behavior. Figure 18 The core parameter is the moisture content (wt%) before moisture-proof packaging. Figure 19 The core parameter is the surface drying time (min). Figure 20 The core parameter was the curing depth (in mm) at 1 day, 3 days, 7 days, and 14 days, with the vacuum mixing pressure and moisture control conditions as variables. Figure 18 It is evident that the water content of Example 1 is significantly lower than that of Comparative Example 6, indicating that it can effectively reduce the introduction of water during the preparation and packaging stages; Figure 19 It is evident that the surface drying time of Example 1 is more moderate and has less dispersion, indicating that its curing start-up process is more stable; further... Figure 20 It is evident that the curing depth of Example 1 increased more fully over time, indicating better continuity in its internal curing process. These results demonstrate that by controlling the vacuum mixing pressure, moisture-proof conditions, and the order of addition of silane additives and tetrabutyl titanate, the impact of moisture fluctuations on the storage and curing process of the single-component MS resin sealant can be reduced, resulting in a more controllable surface drying time and a more complete deep curing effect.

[0147] Figure 21 These are macroscopic optical photographs of Example 1 and Comparative Example 11, wherein... Figure 21 a is a macroscopic optical photograph of Example 1. Figure 21 b is a macroscopic optical photograph of Comparative Example 11. Figure 21 This study compared the appearance continuity, surface uniformity, and visible agglomeration of two MS resin sealant samples. Example 1 used a composite filler containing 3-glycidoxypropyltrimethoxysilane, with a D50 of 60 nm, a D90 of 150 nm, and a mass percentage of dispersible agglomerates exceeding 1200 nm. Therefore, it exhibited a relatively continuous, uniform appearance with no obvious powder clumps. In contrast, Comparative Example 11 did not contain 3-glycidoxypropyltrimethoxysilane, resulting in insufficient interfacial modification and a tendency for localized particle enrichment or decreased surface uniformity. This comparison demonstrates that the silane interfacial layer can improve the dispersion of the filler in the MS resin matrix and enhance the macroscopic structural integrity of the sealant.

[0148] Figure 22 These are SEM morphology comparison images of Example 1 and Comparative Example 11, in which... Figure 22 a and Figure 22 b are low-magnification SEM images of Example 1 and Comparative Example 11, respectively. Figure 22 c and Figure 22 d are medium-magnification SEM images of Example 1 and Comparative Example 11, respectively. Figure 22 e and Figure 22 Images f are high-magnification SEM images of Example 1 and Comparative Example 11, respectively. This set of images is used to compare the overall morphology of the cured adhesive cross-section, the large-scale distribution of fillers, particle agglomeration, pore defects, and the particle-matrix interface bonding state at the micron scale. In Example 1, the composite filler was surface-treated at 45°C and pH 8.5 for 2 h, and then vacuum-mixed at 40°C and 0.005 MPa for 0.5 h, which promoted a more thorough interfacial contact between the filler and the MS resin matrix; in Comparative Example 11, due to the lack of a silane interfacial layer, filler agglomeration and localized debonding were more likely to occur. Figure 22As can be seen, the cross-sectional structure of Example 1 is more continuous, the filler distribution is more uniform, and there are fewer interface voids and pore defects, indicating that this solution can suppress filler agglomeration and improve the internal density of the cured adhesive at the micron scale.

[0149] Figure 23 The images show a comparison of the TEM microstructure and crystallographic information of Example 1 and Comparative Example 11, in which... Figure 23 a and Figure 23 b are bright-field TEM images of Example 1 and Comparative Example 11, respectively. Figure 23 c and Figure 23 d are HRTEM images of Example 1 and Comparative Example 11, respectively. Figure 23 e and Figure 23 f represents the SAED or elemental distribution diagrams for Example 1 and Comparative Example 11, respectively. This set of diagrams is used to compare the distribution of calcium carbonate particles in the MS resin matrix, particle aggregation state, lattice fringes, surface amorphous organic / silane interface layer, and spatial distribution of silane-related elements at the nanoscale. The composite filler in Example 1 has an organic layer content of 0.50 wt%, which helps to form a stable interface layer on the surface of calcium carbonate particles and reduces direct particle contact aggregation; Comparative Example 11 did not introduce 3-glycidyloxypropyltrimethoxysilane, resulting in relatively insufficient interface layer continuity and dispersion stability. Figure 23 As can be seen, in Example 1, the filler particles are more uniformly distributed, the particle surface interface layer is clearer, and the distribution of relevant elements is more continuous. This indicates that the proposed scheme achieves synergistic control of filler dispersion, interface coupling, and structural stability through the construction of a nanoscale interface layer. Overall, Figures 1 to 23 The progressive verification from aspects such as formulation dosage, chemical structure, thermal stability, rheological workability, particle size distribution, curing behavior, and multi-scale morphology fully demonstrates that this solution can effectively improve the overall performance of MS resin sealant.

[0150] Table 1 Performance of Examples and Comparative Examples ; As can be seen from the performance of the examples and comparative examples in Table 1, Example 1 achieves a relatively balanced performance combination in terms of extrusion ratio, tensile bond strength, elastic recovery rate, weather resistance tensile strength retention rate, and light-stable component migration rate. Examples 2 and 4, due to their higher composite filler ratio and surface organic layer content, further improve mechanical strength, weather resistance retention, and low migration, but the extrusion ratio decreases relatively, which is consistent with the rheological characteristics of high filler and high viscosity systems. After changing the plasticizer, filler, fumed silica, mixing pressure, prepolymer ratio, or surface treatment conditions in Comparative Examples 1 to 8, at least two core indicators deviate. After dissecting the light-stable component and silane interface construction method in Comparative Examples 9 to 11, the weather resistance retention rate and migration rate change more significantly, indicating that the composite filler surface treatment system is a key technical unit for achieving a balance between mechanical load-bearing capacity, weather resistance retention, and low migration.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any equivalent structural transformations made under the concept of the present invention and using the contents of the specification and drawings of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high weather-resistant MS resin sealant, characterized in that, Based on 100 parts by weight of the trimethoxysilane-terminated polyether prepolymer, the following components are included: 100 parts by weight of trimethoxysilane-terminated polyether prepolymer; Add 20-60 parts by weight of polypropylene glycol; 80-180 parts by weight of composite filler; Unmodified calcium carbonate, 0-80 parts by weight; 1-6 parts by weight of fumed silica; 1-4 parts by weight of vinyltrimethoxysilane; 0.5-3 parts by weight of 3-aminopropyltrimethoxysilane; Tetrabutyl titanate 0.05-0.80 parts by weight; The trimethoxysilane-terminated polyether prepolymer is obtained by reacting prepolymerized polypropylene glycol, isophorone diisocyanate and 3-aminopropyltrimethoxysilane. The composite filler is prepared from calcium carbonate, 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone.

2. The high weather-resistant MS resin sealant according to claim 1, characterized in that, The composite filler is prepared by the following steps: A1. Calcium carbonate is dried to obtain dried calcium carbonate; A2. The dried calcium carbonate is dispersed in a mixture of ethanol and deionized water, wherein the mass ratio of ethanol to deionized water is 100:5-100:30, and the pH of the dispersion system is adjusted to alkaline using ammonia. A3. Add 3-glycidyloxypropyltrimethoxysilane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-hydroxy-4-n-octyloxybenzophenone to the dispersion system obtained in step A2; A4. React the system obtained in step A3 at 45-75℃ for 2-4 hours, using reflux condensation to maintain the composition of the reaction medium and maintain the pH value at 8.5-10.5; A5. After the reaction is complete, the composite filler is obtained by filtration, washing with ethanol, washing with deionized water, and drying.

3. The high weather-resistant MS resin sealant according to claim 2, characterized in that, The preparation conditions for the composite filler include: In step A1, calcium carbonate is dried at 90-120℃ and an absolute pressure of 0.005-0.040MPa for 1-4 hours; In step A2, ammonia is used to adjust the pH value to 8.5-10.5; In step A4, the reaction is carried out at 45-75°C while maintaining a pH of 8.5-10.5; In step A5, dry at 70-110℃ and absolute pressure of 0.005-0.040MPa for 4-12 hours.

4. The high weather-resistant MS resin sealant according to claim 2, characterized in that, In step A3, the mass ratio of the calcium carbonate, the 3-glycidyloxypropyltrimethoxysilane, the bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and the 2-hydroxy-4-n-octyloxybenzophenone is 100:1.00-8.00:0.20-3.00:0.20-3.00; the surface organic layer content of the composite filler obtained after washing and drying is 0.50-5.00wt%, the D50 is 60-500nm, and the water content is 0.01-0.30wt%.

5. The high weather-resistant MS resin sealant according to claim 1, characterized in that, The trimethoxysilane-terminated polyether prepolymer was prepared by the following steps: B1. Dehydrate prepolymerized polypropylene glycol at 100-120℃ and 0.005-0.040MPa absolute pressure for 1-3 hours to obtain dehydrated polypropylene glycol; B2. Under inert gas protection, isophorone diisocyanate is added to the dehydrated polypropylene glycol to make the NCO:OH molar ratio 1.60-2.20, and the reaction is carried out at 70-90℃ for 2-5 hours to obtain isocyanate-terminated polyether prepolymer. B3. Add 3-aminopropyltrimethoxysilane to the isocyanate-terminated polyether prepolymer, such that the molar ratio between the residual NCO group in the isocyanate-terminated polyether prepolymer and the amino group in the 3-aminopropyltrimethoxysilane is 0.95-1.05, and react at 45-75°C for 1-3 hours to obtain the trimethoxysilane-terminated polyether prepolymer; B4. The NCO residue of the trimethoxysilane-terminated polyether prepolymer is not higher than 0.10 wt%, the water content is 0.01-0.10 wt%, and the viscosity at 25°C is 5000-100000 mPa·s. The viscosity at 25°C is measured by a rotational viscometer at 25°C after the reading has stabilized for 60 seconds.

6. The high weather-resistant MS resin sealant according to claim 1, characterized in that, The composite filler has a D90 of 150-1200 nm, and after the composite filler is treated with the same dispersion procedure as the D50 and D90 determination, the mass percentage of residual agglomerates with a particle size exceeding 1200 nm does not exceed 10.00 wt%.

7. The high weather-resistant MS resin sealant according to claim 1, characterized in that, When the amount of unmodified calcium carbonate fed is greater than 0, the mass ratio of the composite filler to the unmodified calcium carbonate is 1.00-6.00:

1.

8. A method for preparing a high weather-resistant MS resin sealant as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Provide the prepared composite filler; S2. Provide the prepared trimethoxysilane-terminated polyether prepolymer; S3. According to the components and feed amounts, the trimethoxysilane-terminated polyether prepolymer, added polypropylene glycol, the composite filler, unmodified calcium carbonate, and fumed silica are vacuum mixed at 40-90°C for 0.5-3 hours. S4. After cooling to 20-50℃, first add vinyltrimethoxysilane, then add 3-aminopropyltrimethoxysilane, and finally add tetrabutyl titanate. Continue vacuum mixing for 0.2-1.5h. S5. Degas and moisture-proof packaging to obtain the high weather-resistant MS resin sealant.

9. The method according to claim 8, characterized in that, In steps S3 and S4, the absolute pressure of vacuum mixing is 0.005-0.040 MPa.

10. The method according to claim 8, characterized in that, In step S3, when the amount of unmodified calcium carbonate fed is greater than 0, the mass ratio of the composite filler to the unmodified calcium carbonate is 1.00-6.00:1.

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