High-weather-resistance two-component silicone sealant for hollow glass and preparation method of high-weather-resistance two-component silicone sealant

Abstract

The invention relates to the technical field of sealants, in particular to a high-weather-resistance two-component silicone sealant for hollow glass and a preparation method thereof.The high-weather-resistance two-component silicone sealant comprises a component A and a component B, and the weight ratio of the component A to the component B is 10: 1; the component A is prepared from the following raw materials: modified polysiloxane base rubber, composite modified filler, a plasticizer, a coupling agent and an antioxidant; the component B is prepared from the following raw materials in parts by weight: a cross-linking agent, a catalyst and an accelerant; the modified polysiloxane base adhesive is used as a core matrix of the sealant, and through copolymerization modification of alpha, omega-dihydroxy polydimethylsiloxane and phenyltrimethoxysilane, a rigid phenyl structure is introduced into a molecular chain. Due to the structural characteristic, the steric hindrance effect of a molecular chain is enhanced, the damage of ultraviolet light to the molecular chain is reduced, and the molecular chain is prevented from being easily broken, so that the ultraviolet aging resistance of the basic rubber is improved; and the regularity of the molecular chain is also optimized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealant, in particular to a high-weatherability two-component silicone sealant for hollow glass and a preparation method thereof. BACKGROUND

[0002] Hollow glass, as a key material for building energy saving, sound insulation and noise reduction, is increasingly widely used in modern construction engineering. The performance of sealant, as the core sealing supporting material of hollow glass, directly determines the service life and safety of hollow glass. Two-component silicone sealant, with good adhesion, high and low temperature resistance and elastic recovery, has become the mainstream choice for sealing hollow glass. However, in practical application, the sealant exposed to outdoor environment for a long time still faces severe weather resistance challenges.

[0003] The natural factors such as high and low temperature alternation, ultraviolet radiation and humidity change in outdoor environment continuously erode the sealant. The base glue of traditional two-component silicone sealant is mostly polysiloxane, which has insufficient molecular chain stability and is prone to oxidative degradation under long-term ultraviolet radiation, leading to molecular chain rupture and thus causing problems such as hardness reduction, tensile strength attenuation and surface cracking of the sealant. At the same time, the compatibility of conventional fillers with the base glue is poor, and the interfacial bonding force is weak. In the process of high and low temperature cycle, micro cracks are easily generated between the fillers and the matrix, and water and harmful substances easily penetrate into them, accelerating the aging failure of the sealant.

[0004] At present, the industry often adds antioxidants, ultraviolet absorbers and other additives to the sealant to improve weather resistance. However, this method can only delay aging on the surface and cannot fundamentally solve the core problems such as unstable molecular structure of the base glue and poor interfacial bonding between the fillers and the matrix. With the increasing requirements of the building industry on the service life and reliability of hollow glass, the weather resistance of traditional two-component silicone sealant has been difficult to meet the actual application requirements, and problems such as sealing failure, fogging and water ingress of hollow glass often occur, which not only affects the appearance of the building, but also requires a lot of manpower and material resources for maintenance and replacement, increasing the use cost.

[0005] Therefore, it is of great practical significance to develop a two-component silicone sealant with improved weather resistance from raw material modification, formula optimization to process adaptation, to solve the pain points of traditional products such as easy aging and rapid performance degradation in outdoor environment, and to promote the high-quality development of the hollow glass industry and reduce the building operation and maintenance cost. SUMMARY

[0006] The present application relates to the technical field of sealant, in particular to a high-weatherability two-component silicone sealant for hollow glass and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A high-weatherability two-component silicone sealant for hollow glass, comprising an A component and a B component, the weight ratio of the A component to the B component being 10:1; The A component is composed of the following raw materials in parts by weight: modified polysiloxane base glue 50-70 parts, composite modified filler 15-25 parts, plasticizer 5-10 parts, coupling agent 2-5 parts, antioxidant 0.5-1.5 parts; The B component is composed of the following raw materials in parts by weight: crosslinking agent 8-15 parts, catalyst 0.5-2 parts, accelerator 0.3-1 part; The modified polysiloxane base glue is a copolymerization modified product of α, ω-dihydroxy polydimethylsiloxane and phenyltrimethoxysilane. The composite modified filler is modified fumed silica.

[0008] As a further technical solution, the preparation method of the modified polysiloxane base glue is: α, ω-dihydroxy polydimethylsiloxane and phenyltrimethoxysilane are mixed in a weight ratio of 8-10:1, 0.3-0.5% of tetrabutyl titanate catalyst based on the total weight of the mixed system is added, the temperature is raised to 120-130°C under nitrogen protection, and the temperature is kept for 3-4h with stirring, then the temperature is lowered to below 60°C, and low-boiling substances are removed under reduced pressure to obtain the modified polysiloxane base glue.

[0009] As a further technical solution, the preparation method of the composite modified filler is: the fumed silica is dried in a 110°C oven for 2h, then after cooling, it is added to anhydrous ethanol and ultrasonically dispersed for 30min to obtain a dispersion liquid with a mass concentration of 10-15%; 3-5% of KH550 based on the weight of the fumed silica is added to the dispersion liquid, the temperature is raised to 60-70°C for stirring for 1.5h for aminolysis reaction, then 1-2% of UV-327 based on the weight of the fumed silica is added, the temperature is continuously raised to 75-80°C for stirring for 1h for grafting reaction, after filtration, the precipitate is dried in a 100°C oven for 3h, and then ground through a 200-mesh sieve to obtain the composite modified filler.

[0010] As a further technical solution, the viscosity of the α, ω-dihydroxy polydimethylsiloxane is 5000-10000 mPa·s (25°C).

[0011] As a further technical solution, the plasticizer is hydroxy-terminated polydimethylsiloxane, and the viscosity of the hydroxy-terminated polydimethylsiloxane is 100-500 mPa·s.

[0012] As a further technical solution, the coupling agent is γ-glycidyl ether propyltrimethoxysilane.

[0013] As a further technical solution, the cross-linking agent is methyltriacetoxysilane, the catalyst is dibutyltin dilaurate, and the accelerator is divinyltetramethyldisilazane.

[0014] As a further technical solution, the antioxidant is hindered phenolic antioxidant 1010.

[0015] The preparation method of the high-weatherability two-component silicone sealant for hollow glass comprises A component preparation and B component preparation, and specifically as follows: (1) A component preparation: according to the weight parts, modified polysiloxane base glue and plasticizer are added into a reaction kettle, heated to 90-100 DEG C under nitrogen protection, vacuum stirring for 1.5-2 h, the vacuum degree of the vacuum stirring is less than or equal to-0.09 MPa, cooling to 60-70 DEG C, adding composite modified filler, coupling agent and antioxidant, continuing vacuum stirring for 2-3 h, discharging and sealing storage; (2) B component preparation: according to the weight parts, cross-linking agent and accelerator are added into a mixing kettle, stirring for 30 min at room temperature, then adding catalyst, continuing stirring for 1 h, discharging and sealing storage.

[0016] As a further technical solution, when used, the A component and the B component are mixed uniformly according to a weight ratio of 10:1, construction is carried out at 15-30 DEG C and 50-60% RH, and curing is carried out for 2-4 hours.

[0017] Compared with the prior art, the present application has the following beneficial effects: 1. The modified polysiloxane base glue in the present application is used as the core matrix of the sealant, and by copolymerization modification of alpha, omega-dihydroxy polydimethylsiloxane and phenyltrimethoxysilane, rigid phenyl structures are introduced into the molecular chain. This structural characteristic not only enhances the steric hindrance effect of the molecular chain, reduces the damage of ultraviolet light to the molecular chain, avoids easy breakage of the molecular chain, thereby improving the ultraviolet aging resistance of the base glue itself; and optimizes the regularity of the molecular chain, so that the base glue is not prone to excessive shrinkage or expansion in high-low temperature alternating environment, thereby ensuring the structural stability of the sealant matrix, and further solving the problems of insufficient weather resistance and easy aging degradation of the traditional polysiloxane base glue.

[0018] 2. The composite modified filler is modified in stages using KH550 and UV-327. The amine groups of KH550 undergo an aminolysis reaction with the hydroxyl groups on the surface of fumed silica, which greatly enhances the activity of the filler surface and significantly improves its compatibility with the polysiloxane base adhesive. This effectively reduces the micro-gaps between the filler and the matrix, preventing moisture and harmful substances from penetrating into the material through the interface gaps. Meanwhile, UV-327, as an ultraviolet absorber, is grafted onto the filler surface and can efficiently absorb ultraviolet light in the outdoor environment, reducing the radiation damage of ultraviolet light to the molecular chains of the base adhesive. The synergistic effect of the two makes the composite modified filler not only a reinforcing phase of the sealant, but also plays a dual role in resisting ultraviolet rays and preventing penetration, solving the defects of traditional unmodified fillers, such as poor bonding with the matrix and inability to resist environmental erosion.

[0019] 3. The plasticizer selected is a hydroxyl-terminated polydimethylsiloxane with a specific viscosity. Its molecular structure has good compatibility with the base adhesive and can be uniformly dispersed in the matrix. It effectively adjusts the hardness and flexibility of the sealant, avoiding internal stress caused by excessive hardness during temperature changes or loss of supporting strength due to excessive softness. This ensures that the sealant maintains good elastic recovery ability during long-term use, solving the problem of poor compatibility and easy migration of traditional plasticizers, which leads to fluctuations in sealant performance.

[0020] 4. The addition of the coupling agent γ-glycidyl etheroxypropyltrimethoxysilane further strengthens the interfacial bonding between the filler and the base adhesive. Its functional groups at both ends react with the surface-active groups of the filler and the molecular chains of the base adhesive, forming a stable chemical bond. This makes the filler and matrix an organic whole, improving the mechanical strength and structural density of the sealant, preventing the filler from detaching from the matrix under environmental stress, and thus enhancing the overall weather resistance of the sealant. Antioxidant 1010 effectively inhibits the oxidation reaction of the base adhesive molecular chains, captures free radicals generated during oxidation, prevents the chain reaction of oxidation, and slows down the aging and degradation rate of the base adhesive. It forms a synergistic anti-aging effect with UV-327 in the composite modified filler, protecting the sealant from the two key aging pathways of oxidation and ultraviolet radiation, further extending the service life of the sealant.

[0021] 5. In component B, the crosslinking agent methyltriacetoxysilane undergoes a crosslinking reaction with the base adhesive molecular chains to form a three-dimensional network structure, making the sealant structure more compact and improving its resistance to penetration and deformation. The catalyst dibutyltin dilaurate accelerates the crosslinking reaction, ensuring a thorough and uniform reaction. The accelerator divinyltetramethyldisilazane further optimizes the crosslinking reaction efficiency, resulting in a more regular crosslinking network structure. The synergistic effect of these three components ensures that the sealant can be quickly cured after application, and the cured product has a stable structure and excellent mechanical properties, solving the problems of incomplete reaction and irregular crosslinking network in traditional crosslinking systems that lead to poor sealant performance.

[0022] 6. The components of this invention do not function independently, but rather form a multi-dimensional synergistic effect. The modified polysiloxane base adhesive provides a stable matrix framework, while the composite modified filler, through interface modification, tightly binds to the matrix, enhancing mechanical properties while synergistically resisting UV and moisture erosion. Coupling agents and plasticizers further optimize interface bonding and matrix flexibility, while antioxidants and UV-327 in the filler form a dual anti-aging barrier. The crosslinking agent, catalyst, and accelerator in component B regulate the crosslinking reaction, constructing a dense and regular three-dimensional network structure. Coupled with a scientific preparation process, nitrogen protection and vacuum stirring are used during the preparation of component A, effectively preventing oxidation of the raw materials during high-temperature processing and removing bubbles and impurities from the system, ensuring the purity and uniformity of component A. The room-temperature stirring process of component B ensures the uniform dispersion of the crosslinking agent, catalyst, and accelerator, avoiding local reaction imbalances. The compatibility of each component and process enables the sealant to form a system with uniform structure, strong interfacial bonding and perfect anti-aging mechanism at the micro level. At the macro level, it exhibits excellent resistance to high and low temperature cycle aging and UV aging, while maintaining good adhesion and elastic recovery ability. Attached Figure Description

[0023] Figure 1 The bar chart shows the tensile strength retention rates of the examples and comparative examples. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides a high weather-resistant two-component silicone sealant for insulating glass and its preparation method. The sealant includes component A and component B, with a weight ratio of component A to component B of 10:1.

[0026] Specific raw materials include: A component raw materials: Modified polysiloxane base glue: It is a copolymerization modified product of α, ω-dihydroxy polydimethylsiloxane and phenyl trimethoxysilane. The viscosity of the α, ω-dihydroxy polydimethylsiloxane is 5000-10000 mPa・s (25℃), and a commercially available product known to those skilled in the art can be used.

[0027] Composite modified filler: It is a modified fumed silica prepared by a specific modification process.

[0028] Plasticizer: It is a hydroxy-terminated polydimethylsiloxane with a viscosity of 100-500 mPa・s, and a conventional commercially available product is used.

[0029] Coupling agent: It is γ-glycidyl ether propyl trimethoxysilane, and a commercially available qualified product is selected.

[0030] Antioxidant: It is a hindered phenolic antioxidant 1010, which is commercially available.

[0031] B component raw materials: Crosslinking agent: It is methyltriacetoxysilane, and a commercially available product commonly used in the art is used.

[0032] Catalyst: It is dibutyltin dilaurate, and a conventional commercially available catalyst can be used.

[0033] Promoter: It is divinyltetramethyldisilazane, and a commercially available qualified product is selected.

[0034] The present application does not have special restrictions on the sources of other raw materials except for the modified polysiloxane base glue and the composite modified filler, and commercially available products known to those skilled in the art can be used.

[0035] Preparation of modified polysiloxane base glue: α, ω-dihydroxy polydimethylsiloxane and phenyl trimethoxysilane are mixed in a weight ratio of 8-10:1, 0.3-0.5% of tetrabutyl titanate catalyst based on the total weight of the mixed system is added, and the temperature is raised to 120-130℃ under nitrogen protection. Stir for 3-4h, cool to below 60℃, and remove low boiling point substances under reduced pressure to obtain modified polysiloxane base glue.

[0036] Preparation of composite modified filler: The fumed silica is dried in a 110℃ oven for 2h, and after cooling, is added into anhydrous ethanol and ultrasonically dispersed for 30min to obtain a dispersion liquid with a mass concentration of 10-15%; 3-5% of KH550 by weight of the fumed silica is added into the dispersion liquid, and the temperature is raised to 60-70℃ for stirring to perform an amination reaction for 1.5h; then 1-2% of UV-327 by weight of the fumed silica is added, and the temperature is continuously raised to 75-80℃ for stirring to perform a grafting reaction for 1h; after filtration, the precipitate is dried in a 100℃ oven for 3h, and is ground through a 200-mesh sieve to obtain a composite modified filler.

[0037] The sealant preparation method comprises the following steps: Preparation of A component: According to the weight parts, the modified polysiloxane base glue and the plasticizer are added into a reaction kettle, and the temperature is raised to 90-100℃ under nitrogen protection; vacuum stirring is performed for 1.5-2h, and the vacuum degree of the vacuum stirring is ≤-0.09MPa; the temperature is lowered to 60-70℃, and the composite modified filler, the coupling agent and the antioxidant are added; vacuum stirring is continuously performed for 2-3h, and the material is discharged and stored in a sealed manner.

[0038] Preparation of B component: According to the weight parts, the crosslinking agent and the accelerator are added into a mixing kettle, and stirring is performed at room temperature for 30min; then the catalyst is added, and stirring is continuously performed for 1h; the material is discharged and stored in a sealed manner.

[0039] Use method: When used, the A component and the B component are mixed uniformly at a weight ratio of 10:1, and are constructed and cured for 2-4h under the conditions of 15-30℃ and 50-60% RH.

[0040] The high-weatherability two-component silicone sealant for hollow glass provided by the application has excellent weather resistance, can adapt to the use requirements under different environmental conditions, prolongs the service life of the hollow glass, and has a simple and easy-to-implement preparation process and is suitable for industrialized production.

[0041] In order to further illustrate the application, the following examples and comparative examples are used for detailed description.

[0042] Example 1: Preparation of modified polysiloxane base glue: α,ω-dihydroxypolydimethylsiloxane (viscosity 5000mPa・s (25℃)) and phenyltrimethoxysilane are mixed at a weight ratio of 8:1, and 0.3% of tetrabutyl titanate catalyst by weight of the total mixed system is added; the temperature is raised to 120℃ under nitrogen protection, and stirring is performed for 3h; the temperature is lowered to below 60℃, and low-boiling substances are removed under reduced pressure to obtain the modified polysiloxane base glue.

[0043] Composite modified filler preparation: The fumed silica was dried in a 110°C oven for 2h, and after cooling, it was added to anhydrous ethanol and ultrasonically dispersed for 30min to obtain a dispersion with a mass concentration of 10%; 3% of KH550 by weight of the fumed silica was added to the dispersion, and the temperature was raised to 60°C for amineolysis reaction for 1.5h; then 1% of UV-327 by weight of the fumed silica was added, and the temperature was raised to 75°C for grafting reaction for 1h; after filtration, the precipitate was dried in a 100°C oven for 3h, ground through a 200-mesh sieve, and the composite modified filler was obtained.

[0044] A component preparation: 50 parts of modified polysiloxane base glue and 5 parts of plasticizer were taken by weight and added to a reaction kettle, which was heated to 90°C under nitrogen protection, and stirred under vacuum for 1.5h with a vacuum degree of-0.09MPa; the temperature was lowered to 60°C, 15 parts of composite modified filler, 2 parts of coupling agent, and 0.5 parts of antioxidant were added, and vacuum stirring was continued for 2h, and the product was sealed and stored.

[0045] B component preparation: 8 parts of crosslinking agent and 0.3 parts of accelerator were taken by weight and added to a mixing kettle, which was stirred at room temperature for 30min, then 0.5 parts of catalyst was added, and stirring was continued for 1h, and the product was sealed and stored.

[0046] Sealant molding: A and B components were mixed uniformly at a weight ratio of 10:1, and cured at 15°C and 50%RH for 2h to obtain a two-component silicone sealant.

[0047] Example 2: Modified polysiloxane base glue preparation: α,ω-dihydroxypolydimethylsiloxane (viscosity 8000mPa・s (25°C)) and phenyltrimethoxysilane were mixed at a weight ratio of 9:1, and 0.4% of tetrabutyl titanate catalyst based on the total weight of the mixed system was added, and the temperature was raised to 125°C under nitrogen protection, and stirred for 3.5h, and the temperature was lowered to below 60°C, and low-boiling substances were removed under reduced pressure to obtain the modified polysiloxane base glue.

[0048] Composite modified filler preparation: The fumed silica was dried in a 110°C oven for 2h, and after cooling, it was added to anhydrous ethanol and ultrasonically dispersed for 30min to obtain a dispersion with a mass concentration of 10%; 3% of KH550 by weight of the fumed silica was added to the dispersion, and the temperature was raised to 60°C for amineolysis reaction for 1.5h; then 1% of UV-327 by weight of the fumed silica was added, and the temperature was raised to 75°C for grafting reaction for 1h; after filtration, the precipitate was dried in a 100°C oven for 3h, ground through a 200-mesh sieve, and the composite modified filler was obtained.

[0049] A component preparation: take modified polysiloxane base glue 60 parts, plasticizer 8 parts by weight, add to the reaction kettle, heat to 95℃ under nitrogen protection, vacuum stirring for 1.8h, the vacuum degree is controlled at-0.095MPa; cooling to 65℃, adding composite modified filler 20 parts, coupling agent 3 parts, antioxidant 1 part, continue to vacuum stirring for 2.5h, discharge and seal.

[0050] B component preparation: take crosslinking agent 12 parts, accelerator 0.7 parts by weight, add to the mixing kettle, room temperature stirring for 30min, then add catalyst 1.2 parts, continue to stir for 1h, discharge and seal.

[0051] Sealant forming: A component and B component are mixed uniformly according to weight ratio 10:1, construction curing for 3 hours under the condition of 22℃, 55%RH, two-component silicone sealant is obtained.

[0052] Example 3: modified polysiloxane base glue preparation: α,ω-dihydroxy polydimethylsiloxane (viscosity 10000mPa・s (25℃)) and phenyl trimethoxysilane are mixed according to weight ratio 10:1, 0.5% of tetrabutyl titanate catalyst is added to the total weight of the mixed system, heated to 130℃ under nitrogen protection, heat stirring for 4h, cooling to below 60℃, removing low boiling point substances under reduced pressure, modified polysiloxane base glue is obtained.

[0053] Composite modified filler preparation: fumed silica is dried in 110℃ oven for 2h, after cooling, add anhydrous ethanol and ultrasonic dispersion for 30min, mass concentration 15% dispersion liquid is obtained; add 5% of KH550 to the weight of fumed silica in the dispersion liquid, heat to 70℃ and stir for 1.5h to carry out aminolysis reaction, then add 2% of UV-327 to the weight of fumed silica, continue to heat to 80℃ and stir for 1h to carry out grafting reaction, after filtration, the precipitate is placed in 100℃ oven for drying for 3h, grinding through 200 mesh sieve, composite modified filler is obtained.

[0054] A component preparation: take modified polysiloxane base glue 70 parts, plasticizer 10 parts by weight, add to the reaction kettle, heat to 100℃ under nitrogen protection, vacuum stirring for 2h, the vacuum degree is controlled at-0.1MPa; cooling to 70℃, adding composite modified filler 25 parts, coupling agent 5 parts, antioxidant 1.5 parts, continue to vacuum stirring for 3h, discharge and seal.

[0055] B component preparation: take crosslinking agent 15 parts, accelerator 1 part by weight, add to the mixing kettle, room temperature stirring for 30min, then add catalyst 2 parts, continue to stir for 1h, discharge and seal.

[0056] Sealant molding: Mix component A and component B at a weight ratio of 10:1 until homogeneous, apply and cure for 4 hours at 30℃ and 60%RH to obtain a two-component silicone sealant.

[0057] Comparative Example 1: Preparation of polysiloxane base adhesive: α,ω-dihydroxy polydimethylsiloxane (viscosity 8000 mPa・s (25℃)) was used directly as the base adhesive without copolymerization modification with phenyltrimethoxysilane.

[0058] Filler preparation: Unmodified fumed silica was used directly as the filler.

[0059] Comparative Example 2: Preparation of modified polysiloxane base adhesive: Same as in Example 2, i.e., α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane were mixed at a weight ratio of 9:1, and the modified polysiloxane base adhesive was obtained by catalytic reaction and removal of low-boiling substances.

[0060] Filler preparation: Unmodified fumed silica was used directly as the filler.

[0061] Comparative Example 3: Preparation of polysiloxane base adhesive: α,ω-dihydroxy polydimethylsiloxane (viscosity 8000 mPa・s (25℃)) was used directly as the base adhesive without copolymerization modification.

[0062] Preparation of composite modified filler: Same as in Example 2, that is, composite modified filler was obtained by KH550 amine hydrolysis modification and UV-327 graft modification.

[0063] Tests and experiments; Experiment 1: High and low temperature cycling aging test; 1. Experimental objective: By simulating extreme temperature change environments, the high and low temperature cycling aging resistance of the two-component silicone sealant prepared in the examples and comparative examples was examined, its performance stability under drastic temperature change conditions was evaluated, and the effect of the technical solution of the present invention on improving the weather resistance of the sealant was verified.

[0064] 2. Test sample: For the two-component silicone sealants prepared in Examples 1-3 and Comparative Examples 1-3, five standard specimens were prepared for each group of samples, with a specimen size of 100mm×25mm×5mm, and they were cured completely under the conditions specified in each example.

[0065] 3. Test instruments: High and low temperature test chamber, electronic universal testing machine, Shore hardness tester.

[0066] 4. Test environment: The laboratory environment temperature is 23℃±2℃, and the relative humidity is 50%±5%RH.

[0067] 5. Test methods: (1) Initial performance test: Initial Shore hardness (A) and tensile strength of each group of samples were tested at a tensile speed of 50 mm / min, and the test results were recorded.

[0068] (2) High and low temperature cycle aging treatment: each group of samples was placed in a high and low temperature test chamber and the cycle program was set as follows: -40℃ for 4h → heating up to 25℃ (heating rate 5℃ / min) → heating up for 2h → heating up to 80℃ (heating rate 5℃ / min) → heating up for 4h → cooling down to 25℃ (cooling rate 5℃ / min) → heating up for 2h, completing one cycle, and a total of 50 cycles were performed.

[0069] (3) Performance testing after aging: After aging, the sample was taken out and placed in a laboratory environment for 24 hours. Then, the Shore hardness (A) and tensile strength were tested using the same method as the initial performance test. The hardness change rate and tensile strength retention rate were calculated. Hardness change rate = (hardness after aging - initial hardness) / initial hardness × 100% Tensile strength retention rate = tensile strength after aging / initial tensile strength × 100%; The test results are as follows: Table 1 Results of high and low temperature cycling aging test Group Initial Shore hardness (A) Shore hardness after aging (A) Hardness change rate (%) Initial tensile strength (MPa) Tensile strength after aging (MPa) Tensile strength retention rate (%) Example 1 45 47 +4.44 1.85 1.72 92.97 Example 2 48 49 +2.08 2.10 1.98 94.29 Example 3 50 51 +2.00 2.25 2.15 95.56 Comparative Example 1 42 38 -9.52 1.50 1.10 73.33 Comparative Example 2 44 40 -9.09 1.70 1.28 75.29 Comparative Example 3 43 39 -9.30 1.60 1.15 71.88 As shown in Table 1, the test results of Examples 1-3 indicate that after 50 cycles of high and low temperature aging, the Shore hardness change rate of the sealant was controlled between +2.00% and +4.44%, with a relatively small change range; the tensile strength retention rate was all above 92%, reaching a maximum of 95.56%, indicating that the sealant prepared by the technical solution of this invention has excellent performance stability under drastic temperature changes and outstanding resistance to high and low temperature aging. The performance of Comparative Examples 1-3 was significantly inferior to that of the Examples. Comparative Example 1 did not use modified polysiloxane base adhesive and composite modified filler, and its hardness change rate was -9.52%, and its tensile strength retention rate was only 73.33%, showing a significant performance decline. The reason is that the molecular structure of unmodified α,ω-dihydroxypolydimethylsiloxane has poor stability and is prone to molecular chain breakage under high and low temperature cycling. In addition, the compatibility between unmodified fumed silica and base adhesive is poor, and the interfacial bonding force is weak, which makes the internal structure of the material prone to defects when the temperature changes, thus affecting the overall performance. Comparative Example 2 used a modified polysiloxane base adhesive but did not use a composite modified filler, while Comparative Example 3 used a composite modified filler but did not use a modified polysiloxane base adhesive. Neither showed effective performance improvement. This indicates that the modified polysiloxane base adhesive and the composite modified filler have a synergistic effect in the technical solution of this invention. The modified polysiloxane base adhesive enhances the stability of the molecular chain through copolymerization modification, while the composite modified filler improves compatibility and interfacial bonding with the base adhesive through surface modification. Only through their combined action can the sealant's resistance to high and low temperature cycling aging be significantly improved. The absence of either key modifying raw material will lead to a substantial decrease in performance.

[0070] Experiment 2: Ultraviolet Aging Test; 1. Experimental objective: By simulating ultraviolet light irradiation in a natural environment, the UV aging resistance of the two-component silicone sealant prepared in the examples and comparative examples was examined, and its appearance changes and mechanical property stability under long-term ultraviolet irradiation were evaluated, further verifying the optimization effect of the technical solution of the present invention on the weather resistance of the sealant.

[0071] 2. Test sample: Similar to Experiment 1, for the two-component silicone sealants prepared in Examples 1-3 and Comparative Examples 1-3, 5 standard specimens were prepared for each group of samples, with a specimen size of 100mm×25mm×5mm, and they were cured completely under the conditions specified in each example.

[0072] 3. Test instruments: UV aging test chamber, electronic universal testing machine, colorimeter.

[0073] 4. Test environment: The laboratory environment temperature is 23℃±2℃, and the relative humidity is 50%±5%RH.

[0074] 5. Test methods: (1) Initial performance test: Initial appearance observation (record color and gloss), color difference test (use a colorimeter to test L*, a*, b* values ​​and calculate total color difference ΔE) and tensile strength test (tensile speed is 50mm / min) were performed on each group of samples, and the test results were recorded.

[0075] (2) Ultraviolet aging treatment: Each group of samples was placed in an ultraviolet aging test chamber, and the test conditions were set as follows: ultraviolet light wavelength 340nm, irradiation intensity 0.68W / m 2 The blackboard temperature was 60℃±3℃, the relative humidity was 50%±5%, and the continuous irradiation mode was used, with a cumulative irradiation time of 1000h.

[0076] (3) Performance testing after aging: After aging, the sample was removed and placed in a laboratory environment for 24 hours. Then, appearance observation, color difference testing, and tensile strength testing were performed. The testing methods were the same as those for the initial performance testing. The color difference change ΔE and tensile strength retention rate were calculated. Tensile strength retention rate = tensile strength after aging / initial tensile strength × 100%; The test results are as follows: Table 2 Results of UV aging test Group initial total color difference ΔΕ0 total color difference after aging DE1 Delta E (ΔE1- ΔE0) of color difference Initial tensile strength (MPa) Tensile strength after aging (MPa) Tensile strength retention rate (%) Appearance after aging Example 1 0.8 1.5 0.7 1.85 1.70 91.89 Color changed little, gloss decreased slightly Example 2 0.7 1.3 0.6 2.10 1.95 92.86 Color changed little, gloss was good Example 3 0.7 1.2 0.5 2.25 2.12 94.22 Color did not change, gloss remained good Comparative Example 1 0.9 4.8 3.9 1.50 0.95 63.33 Color changed yellow obviously, surface had cracks Comparative Example 2 0.8 4.2 3.4 1.70 1.05 61.76 Color changed yellow, surface had slight cracks Comparative Example 3 0.8 4.5 3.7 1.60 1.00 62.50 Color changed yellow obviously, surface had obvious cracks As shown in Table 2, the UV aging test results of Examples 1-3 indicate that after 1000 hours of UV irradiation, the color difference change ΔE of the sealant was controlled between 0.5 and 0.7, with a small variation range. The color remained essentially unchanged, and the gloss was well maintained. The tensile strength retention rate was above 91%, reaching a maximum of 94.22%. This demonstrates that the sealant prepared by the present invention has excellent UV aging resistance, effectively resisting the degradation effect of UV light on materials and maintaining the stability of appearance and mechanical properties. The UV aging resistance of Comparative Examples 1-3 was significantly inferior to that of the Examples. Comparative Example 1, which did not use modified polysiloxane base adhesive and composite modified filler, had a color difference change ΔE of 3.9. After aging, the color turned significantly yellow, and surface cracks appeared. The tensile strength retention rate was only 63.33%. This is because ultraviolet light induces oxidative degradation of the unmodified polysiloxane molecular chains, leading to chain breakage. Simultaneously, the weak interfacial bonding between unmodified fumed silica and the base adhesive makes the interface prone to peeling during UV aging, resulting in surface cracking and a significant decrease in mechanical properties. Comparative Example 2 used a modified polysiloxane base adhesive but without composite modified filler, while Comparative Example 3 used composite modified filler but without modified polysiloxane base adhesive. Neither showed effective improvement in color difference changes or tensile strength retention. The phenyl structure in the modified polysiloxane base adhesive absorbs ultraviolet light, reducing its damaging effect on the molecular chains. UV-327 in the composite modified filler, acting as an ultraviolet absorber, further enhances the material's UV resistance. The synergistic effect of both significantly improves the sealant's UV aging resistance. The absence of either key modifying ingredient leads to poor UV resistance and increased susceptibility to aging and degradation.

[0077] In summary, this invention significantly improves the weather resistance of two-component silicone sealants by using modified polysiloxane base adhesives, composite modified fillers, and combining them with reasonable raw material ratios and preparation processes. This includes resistance to high and low temperature cycling and UV aging. It solves the problem of traditional silicone sealants being prone to aging and performance degradation in extreme environments, and is suitable for scenarios such as insulated glass where high weather resistance of sealants is required.

[0078] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0079] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high weatherable two-component silicone sealant for insulating glass, characterized in that, It comprises A component and B component, the weight ratio of A component to B component is 10:1; The A component is composed of the following raw materials in weight parts: modified polysiloxane base glue 50-70 parts, composite modified filler 15-25 parts, plasticizer 5-10 parts, coupling agent 2-5 parts, antioxidant 0.5-1.5 parts; The B component is composed of the following raw materials in weight parts: crosslinking agent 8-15 parts, catalyst 0.5-2 parts, accelerator 0.3-1 part; The modified polysiloxane base glue is a copolymerization modified product of α, ω-dihydroxy polydimethylsiloxane and phenyl trimethoxysilane. The composite modified filler is modified fumed silica.

2. The high weatherable two-component silicone sealant for insulating glass according to claim 1, wherein The preparation method of the modified polysiloxane base glue is as follows: α, ω-dihydroxy polydimethylsiloxane and phenyl trimethoxysilane are mixed in a weight ratio of 8-10:1, 0.3-0.5% of tetrabutyl titanate catalyst based on the total weight of the mixed system is added, the temperature is raised to 120-130℃ under nitrogen protection, and the temperature is kept for 3-4h with stirring, then the temperature is lowered to below 60℃, and low-boiling substances are removed under reduced pressure to obtain the modified polysiloxane base glue.

3. The high weatherable two-part silicone sealant for insulating glass according to claim 1, wherein The preparation method of the composite modified filler is as follows: fumed silica is dried in a 110℃ oven for 2h, then added into anhydrous ethanol after cooling and ultrasonic dispersion for 30min to obtain a dispersion liquid with a mass concentration of 10-15%; 3-5% of KH550 based on the weight of fumed silica is added into the dispersion liquid, the temperature is raised to 60-70℃ for amineolysis reaction for 1.5h, then 1-2% of UV-327 based on the weight of fumed silica is added, the temperature is continuously raised to 75-80℃ for grafting reaction for 1h, the precipitate is dried in a 100℃ oven for 3h after filtration, and then ground through a 200 mesh sieve to obtain the composite modified filler.

4. The high weatherable two-part silicone sealant for insulating glass according to claim 1, wherein The viscosity of the α, ω-dihydroxy polydimethylsiloxane is 5000-10000 mPa·s (25℃).

5. The high weatherable two-part silicone sealant for insulating glass according to claim 1, wherein The plasticizer is hydroxy-terminated polydimethylsiloxane, and the viscosity of the hydroxy-terminated polydimethylsiloxane is 100-500 mPa·s.

6. The high weatherable two-part silicone sealant for insulating glass according to claim 1, wherein The coupling agent is γ-glycidyl ether propyl trimethoxysilane.

7. The high weatherable two-part silicone sealant for insulating glass according to claim 1, wherein The crosslinking agent is methyltriacetoxysilane, the catalyst is dibutyltin dilaurate, and the accelerator is divinyltetramethyldisilazane.

8. The high weatherable two-part silicone sealant for insulating glass according to claim 1, wherein The antioxidant is hindered phenolic antioxidant 1010.

9. A process for the preparation of a high weatherable two-component silicone sealant for insulating glass according to any one of claims 1 to 8, characterized in that It comprises A component preparation and B component preparation, which are as follows: (1) A component preparation: the modified polysiloxane base glue and the plasticizer are added into a reaction kettle according to the weight parts, the temperature is raised to 90-100℃ under nitrogen protection, and vacuum stirring is carried out for 1.5-2h, the vacuum degree of the vacuum stirring is ≤-0.09MPa; the temperature is lowered to 60-70℃, the composite modified filler, the coupling agent, and the antioxidant are added, and vacuum stirring is continuously carried out for 2-3h, and then the product is discharged and sealed for storage; (2) B component preparation: the crosslinking agent and the accelerator are added into a mixing kettle according to the weight parts, stirring is carried out at room temperature for 30min, then the catalyst is added, and stirring is continuously carried out for 1h, and then the product is discharged and sealed for storage.

10. The method of claim 9, wherein, When used, the A component and the B component are mixed uniformly according to the weight ratio of 10:1, and construction and curing are carried out at 15-30℃ and 50-60% RH for 2-4h.

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