Two-component silicone caulk and method of making

Abstract

The application discloses a kind of two-component organic silicon joint beautifying materials and preparation method thereof, belong to the technical field of joint beautifying material.The two-component organic silicon joint beautifying material includes the volume ratio of 1:1 of A component and B component, wherein, A component includes: organic silicon modified epoxy resin, active epoxy diluent, silane coupling agent, hydrophobic fumed silica and inorganic filler;B component includes: amino silane curing agent, catalyst, hydrophobic fumed silica and inorganic filler;Wherein, organic silicon modified epoxy resin is epoxy polymer grafted with organic silicon and / or epoxy-silicone block copolymer;Amino silane curing agent contains polysiloxane main chain and active amino and hydrolysable siloxy connected on main chain.The application can overcome many defects such as existing joint beautifying material outdoor yellowing, insufficient weather resistance, poor wet area bonding, insufficient toughness and the like.

Description

Technical Field

[0001] This invention relates to the technical field of tile grout materials, and in particular to a two-component silicone tile grout material and its preparation method. Background Technology

[0002] Grout sealant is a paste or liquid material used for filling and decorating gaps in paving materials such as tiles and stone. It makes the gaps smooth, beautiful, waterproof, mildew-proof, and easy to clean, avoiding the problems of traditional white cement grout turning black, getting moldy, and falling off.

[0003] Currently, the mainstream grout materials mainly include epoxy grout and silicone (siloxane) sealant, also known as organosilicon grout. Epoxy grout consists of two components: epoxy resin and a curing agent. It has high hardness, high bonding strength, and rich decorative properties. However, the aromatic rings and carbon-carbon bonds in its molecular structure are sensitive to ultraviolet light. After long-term outdoor use, it is prone to photo-oxidative degradation, leading to severe yellowing, chalking, and loss of gloss. At the same time, its cured network is relatively rigid, but its resistance to high and low temperature cycles and water vapor erosion is limited. In environments with large temperature differences or long-term humidity, it is prone to cracking and peeling due to the accumulation of internal stress. More importantly, when applied in wet areas such as kitchens, bathrooms, and swimming pools, residual moisture on the substrate surface or in the gaps can seriously interfere with and inhibit the epoxy-amine curing reaction, resulting in incomplete curing and interface failure. This causes the wet bonding strength to decrease by more than 50% compared to the dry state, which has long plagued construction quality and project acceptance. While traditional silicone sealants have excellent weather resistance, flexibility, and hydrophobicity, they have low strength, are prone to dust accumulation on their surface leading to poor stain resistance, and their adhesion to porous inorganic substrates such as tiles and cement mainly relies on physical adsorption, resulting in weak bonding force. They are easily "lifted" by moisture, causing blistering and detachment, and cannot meet the stringent requirements of grout for mechanical properties and durable adhesion.

[0004] To address the aforementioned issues, some existing improvement solutions attempt to combine the advantages of epoxy grout and silicone sealant. However, actual production has revealed numerous insurmountable problems in their integration: for instance, fusing the two by adding silane coupling agents or through physical blending of silicone resins often results in system instability and phase separation due to poor compatibility between components, failing to form a uniform, synergistically reinforced composite material structure, and leading to limited and uncontrollable improvement in material performance.

[0005] Therefore, there is still an urgent need in this field for a new type of grout material that can successfully and efficiently combine the advantages of both ceramic sealant and silicone sealant, and overcome the core defects of existing grout materials such as easy yellowing outdoors, insufficient weather resistance, and poor adhesion in wet areas. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to propose a new type of grout material and its preparation method that combines the advantages of epoxy grout and silicone sealant, and can overcome many defects of existing grout materials such as easy yellowing outdoors, insufficient weather resistance, poor adhesion in wet areas, and insufficient toughness.

[0007] The technical solution of the present invention is as follows: A two-component silicone grout sealant comprises component A and component B in a 1:1 volume ratio. Component A comprises: 65-75 wt% silicone-modified epoxy resin, 0-5 wt% active epoxy diluent, 0.5-2 wt% silane coupling agent, 1-3 wt% hydrophobic fumed silica, and the balance being a first inorganic filler. Component B comprises: 85-95 wt% aminosilane curing agent, 0.1-0.5 wt% catalyst, 1-3 wt% hydrophobic fumed silica, and the balance being a second inorganic filler. The silicone-modified epoxy resin is a silicone-grafted epoxy polymer and / or an epoxy-silicone block copolymer. The aminosilane curing agent contains a polysiloxane backbone and active amino groups and hydrolyzable siloxy groups attached to the backbone. The catalyst is selected from organotin and / or titanate catalysts.

[0008] In the above technical solution of the present invention, the components of component A are physically blended and will not react with each other; the components of component B are also physically blended when not in contact with moisture and will not react with each other; after component A and component B come into contact, the organosilicon-modified epoxy resin in component A and the active amino group in the aminosilane curing agent of component B will undergo an epoxy-amine ring-opening addition reaction; the hydrolyzable siloxy groups in the aminosilane curing agent of component B and the residual alkoxy groups or silanol groups in the organosilicon-modified epoxy resin of component A will undergo hydrolysis and condensation crosslinking reactions under the action of moisture, which significantly improves the mechanical properties and weather resistance of the material under moisture.

[0009] The above technical solution of the present invention, after mixing components A and B, simultaneously triggers two independent chemical reactions to form an organic-inorganic hybrid network of amine-epoxy ring-opening addition and siloxane moisture hydrolysis condensation, which overcomes all the shortcomings of ordinary existing epoxy grout and other similar products from the root.

[0010] In the above technical solutions of the present invention, hydrophobic fumed silica can be used to provide thixotropy and anti-settling properties. Simultaneously, it exhibits significant synergistic effects with organosilicon-modified epoxy resin and aminosilane curing agents. For example, in the organosilicon-curing agent system formed by components A and B, the hydrophobic organic groups on the surface of the hydrophobic fumed silica can interact strongly with the organosilicon segments of the resin, achieving uniform dispersion and wetting of the material at the microscopic level, and constructing a more uniform and stable microphase structure. The surface of the hydrophobic fumed silica usually retains trace amounts of silanol groups, which can serve as weak acid centers for catalytic reactions. Combined with its porous structure's strong adsorption and fixation capabilities for water vapor, these residual silanol groups jointly promote the condensation reaction of components A and B under humid conditions. Furthermore, it can grow in situ into the condensation network formed by components A and B in the form of chemical bonds, forming a highly cross-linked organic-inorganic hybrid network, eliminating interfacial weakening between the filler and the resin matrix, and improving the overall mechanical properties and weather resistance of the material.

[0011] According to some preferred embodiments of the present invention, component A further includes 2-8 wt% pigment and / or color paste.

[0012] It is understandable that those skilled in the art may add other functional additives or ingredients, such as defoamers, leveling agents, thickeners, viscosity reducers, etc., to components A and B according to actual needs.

[0013] According to some preferred embodiments of the present invention, the silicone-modified epoxy resin has an epoxy equivalent of 180-250 g / eq, a viscosity of less than 5000 mPa·s at 25°C, and a silicon-oxygen bond content of not less than 10%.

[0014] According to some preferred embodiments of the present invention, the aminosilane curing agent has a silicon-oxygen bond content of 36-40 wt%, a methoxy group content of 11-18 wt%, and an active hydrogen equivalent of 240-260 g / eq.

[0015] According to some preferred embodiments of the present invention, the first inorganic filler is selected from one or more of quartz sand, glass microspheres, precipitated barium sulfate, and silica powder.

[0016] According to some preferred embodiments of the present invention, the second inorganic filler is selected from one or more of quartz sand, glass microspheres, precipitated barium sulfate, and silica powder.

[0017] According to some preferred embodiments of the present invention, the silane coupling agent is selected from epoxy silane coupling agents such as KH-560 to further enhance adhesion to inorganic substrates.

[0018] According to some specific embodiments of the present invention, the hydrophobic fumed silica can be selected from fumed silica such as HDK® H18 and AEROSIL® R 202.

[0019] According to some preferred embodiments of the present invention, the active epoxy diluent is selected from butyl glycidyl ether and / or benzyl glycidyl ether.

[0020] According to some preferred embodiments of the present invention, the catalyst is selected from dibutyltin dilaurate.

[0021] According to some preferred embodiments of the present invention, both the first inorganic filler and the second inorganic filler are selected from quartz sand.

[0022] More preferably, the particle size of the quartz sand is 500-700 mesh.

[0023] According to some preferred embodiments of the present invention, obtaining the aminosilane curing agent includes: (1) Add an end-capping agent to an amino-containing alkoxysilane to obtain a premix, and dissolve the premix in an alcohol solvent to obtain a mixture; wherein the end-capping agent is an amino-free alkoxysilane; (2) Under an inert atmosphere, the pH of the mixture is adjusted to 5.0-5.5, and then water is added to carry out a hydrolysis reaction to obtain a hydrolyzed mixture; wherein the amount of water added is 0.5-1.0 times the amount of total alkoxy groups of the premix, and the hydrolysis temperature is 30-60℃. (3) Add a condensation catalyst to the hydrolysis mixture and carry out a condensation oligomerization reaction at 50-80°C. Monitor the amine value of the reaction system. When the amine value drops to the target range, terminate the reaction and remove the volatile components to obtain the aminosilane curing agent.

[0024] The aminosilane curing agent obtained through the above preferred embodiments has the following special properties: the amino groups in its molecule are capped by amino-free alkoxysilanes, resulting in low reactivity when mixed with epoxy resin at room temperature, preventing instantaneous curing and providing a longer pot life; the alkoxy groups in its molecule, such as methoxy groups and silanols produced by condensation, all possess hygroscopic curing capabilities, enabling cross-linking and film formation on damp substrates or in the presence of moisture in the air; after polycondensation, its molecular weight is larger than that of amino-containing alkoxysilanes, and its viscosity increases, but remains smaller than that of linear polymers, making it easy to disperse in components A and B; it simultaneously retains highly active amino and siloxane groups, exhibiting high activity; its main chain is a flexible polysiloxane, while its side chains / end groups are rigid amino groups, thus possessing both high strength and high toughness.

[0025] According to some preferred embodiments of the present invention, the amino-containing alkoxysilane is selected from N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0026] The N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane provided in this preferred embodiment has an asymmetric structure, which allows the resulting aminosilane curing agent to possess both the toughness of siloxanes and similar or better strength as conventional amine curing agents after curing.

[0027] According to some preferred embodiments of the present invention, the capping agent is selected from methyltrimethoxysilane (MTMS).

[0028] The MTMS provided in this preferred embodiment has only one hydrolyzable group, which can simultaneously protect the amino group and introduce a methyl group at the end of the main chain. This not only increases the hydrophobicity and water resistance of the molecular chain, but also effectively controls the viscosity of the final oligomer.

[0029] According to some preferred embodiments of the present invention, the condensation catalyst is selected from dibutyltin dilaurate.

[0030] This invention further provides a method for preparing the above-mentioned two-component silicone sealant, which includes the following steps: (1) The organosilicon modified epoxy resin, active epoxy diluent and silane coupling agent are mixed evenly, and then hydrophobic fumed silica in component A is added for high-speed dispersion, and then the pre-dried first inorganic filler is added and mixed evenly, and then vacuum degassing is performed to obtain component A. (2) The aminosilane curing agent and the siloxane condensation catalyst in component B are mixed evenly, and then the hydrophobic fumed silica in component B is added for high-speed dispersion. Then the pre-dried second inorganic filler is added and mixed evenly. Then the vacuum degassing treatment is performed to obtain component B. (3) The components A and B are packaged in a volume ratio of 1:1 to obtain the two-component silicone sealant.

[0031] According to some preferred embodiments of the present invention, step (1) further includes: after the high-speed dispersion, adding the additive material and the pre-dried first inorganic filler and mixing them evenly; wherein the additive material is pigment and / or color paste.

[0032] According to some preferred embodiments of the present invention, the preparation of the aminosilane curing agent includes: (1) Add 20-30% by mass of methyltrimethoxysilane to N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane to obtain a premix, and dissolve the premix in an alcohol solvent to obtain a mixture; (2) Under an inert atmosphere, the pH of the mixture is adjusted to 5.0-5.5, and then water is added to carry out a hydrolysis reaction to obtain a hydrolyzed mixture; wherein the amount of water added is 0.5-1.0 times the amount of total alkoxy groups of the premix, and the hydrolysis temperature is 30-60℃. (3) Add dibutyltin dilaurate to the hydrolyzed mixture and carry out a condensation oligomerization reaction at 50-80°C. Monitor the amine value of the reaction system. When the amine value drops to 240-260 g / eq, terminate the reaction and remove the volatile components to obtain the aminosilane curing agent.

[0033] The present invention has the following beneficial effects: This invention constructs a network structure with dual curing modes of amine-epoxy curing and moisture curing by using organosilicon-modified epoxy resin and an aminosilane curing agent containing a polysiloxane backbone and active amino and hydrolyzable siloxy bifunctional groups connected to the backbone. This results in an organosilicon grout material with excellent resistance to yellowing, wet-area bonding strength, flexibility, and overall weather resistance. This not only achieves a comprehensive improvement in the performance of organosilicon grout materials, but also pioneers a new grout material technology path that can utilize humid environments for efficient bonding, demonstrating significant technological advancement and industrial application value. Ordinary epoxy grout contains a large number of aromatic rings and low-bond-energy carbon-carbon bonds in its molecular skeleton, but lacks weather-resistant silicon-oxygen structures. Under ultraviolet light, it is extremely prone to photo-oxidative degradation. After QUV 500h ultraviolet aging test, its color difference ΔE is generally greater than 4.5. After long-term use outdoors or in sunrooms, it will show severe yellowing, surface chalking, and complete loss of gloss, and the decorative effect of light-colored grout will quickly fail. In contrast, the two-component organosilicon grout material obtained by this invention introduces a large number of high-bond-energy Si-O-Si structures into the molecular chain, which can effectively resist ultraviolet photo-oxidative degradation. Under the same QUV 500h ultraviolet aging test conditions, its color difference ΔE can be controlled within 1.5, and the degree of yellowing is very slight. Even when placed outdoors or in direct sunlight for a long time, it is not easy to discolor, chalk, or lose gloss. It can be used stably in both indoor and outdoor scenarios. Ordinary epoxy grout relies solely on a single epoxy-amine addition reaction for curing. Moisture directly blocks the chemical bonding between epoxy groups and amino groups, resulting in incomplete curing, interfacial delamination, and hollowing. According to GB / T 7124-2008 standard testing, the dry surface adhesion strength of ordinary epoxy grout is approximately 6.7-7.5 MPa, but the adhesion strength on a damp surface with a water film is only 2.2-4.1 MPa. After construction in high-humidity environments such as kitchens, bathrooms, swimming pools, and during the rainy season, it is extremely prone to peeling and detachment, leading to a high rate of project rework. In contrast, the two-component organosilicon grout material system obtained in this invention allows water vapor to participate in cross-linking reactions such as siloxane polycondensation. Moisture can actually promote the improvement of the cross-linking network. Under the same test conditions on a damp surface with a water film, its tensile adhesion strength can reach 9.7-10.5 MPa, with a strength retention rate of over 90%. It is less prone to hollowing and detachment during construction in kitchens, bathrooms, swimming pools, and high-humidity environments, significantly improving the construction error tolerance. Ordinary epoxy grout only forms a rigid pure carbon chain cross-linked network without flexible buffer segments, and its elongation at break is only 5%~10%. This means that the internal stress generated by underfloor heating temperature differences, high and low temperature cycles throughout the year, and micro-deformation of the building cannot be released, leading to frequent cracking and water seepage with long-term use. At the same time, its overall molecular polarity is relatively high, and the surface water contact angle is only 70°-75°, resulting in weak hydrophobic barrier ability. Water vapor continuously penetrates into the substrate interface, making it very easy for mold to grow and the gaps to turn black. In contrast, the two-component organosilicon grout material system obtained by this invention has a double cross-linked network, and combines the high strength of the epoxy system with the high flexibility of the siloxane chain segments. Its elongation at break can reach 29%-34%, which can effectively buffer the internal stress generated by underfloor heating and high and low temperature cycles, making it less prone to cracking with long-term use. At the same time, the material surface is rich in hydrophobic methylsiloxane groups, with a water contact angle of over 100°, which significantly improves the hydrophobic barrier ability to prevent water vapor penetration, greatly reducing the risk of mold and blackening. Its long-term water resistance and temperature cycle stability are far superior to ordinary epoxy grout. The two-component silicone grout material obtained by this invention is easy to apply and has excellent performance. It provides a one-stop solution to the durability challenges faced by the grout industry in outdoor high-weather and wet kitchen and bathroom scenarios, and has broad market application prospects. Detailed Implementation

[0034] The technical solutions of the present invention will be further described below with reference to embodiments thereof. The embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0035] The silicone-modified epoxy resin used in the following examples is commercially available EPSI-3201 resin, with a viscosity of less than 5000 mPa·s at 25°C, an epoxy equivalent of 185-205 g / eq, and a silicon-oxygen bond content of 10%-20%. The reactive epoxy diluent used in the following examples is butyl glycidyl ether (BGE), the silane coupling agent used is KH-560, the hydrophobic fumed silica used is HDK H18 fumed silica, the color paste used is Kedi color paste (W1008 white color paste), the inorganic filler used in component A is 600-mesh quartz sand, the inorganic filler used in component B is 600-mesh quartz sand, and the catalyst used is dibutyltin dilaurate (DBTL).

[0036] The aminosilane curing agent used is prepared through the following process: (1) Add 20-30% by mass of methyltrimethoxysilane (MTMS) to N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (kh-792) as an end-capping regulator to obtain a premix, and dissolve the premix in isopropanol until the solid content reaches 60-70% to obtain a mixture; (2) Under nitrogen protection, the pH of the mixture is adjusted to 5.0-5.5 by glacial acetic acid, and then deionized water is added dropwise (the molar amount of deionized water added is 0.7-0.9 times the molar amount of total alkoxy groups in the premix). The dropping temperature is controlled to be ≤50℃. After the dropping is completed, the mixture is kept at 50-55℃ for 1-2 hours to complete the hydrolysis and obtain the hydrolyzed mixture. (3) Add dibutyltin dilaurate (DBTL) to the hydrolysis mixture at a mass of 0.05-0.1% of the total mass of the premix to obtain a condensation mixture. Heat the condensation mixture to 55-60℃ to condense oligomers for 2-3 hours. Monitor the amine value of the condensation mixture during the reaction. When the amine value drops to 220-240 mg KOH / g (corresponding to an active hydrogen equivalent of 240-260 g / eq), immediately cool down and remove the solvent and by-product methanol under reduced pressure to obtain aminosilane oligomers, i.e., the aminosilane curing agent.

[0037] This aminosilane curing agent has a =Si-O-Si= skeleton, while retaining hydrolyzable alkoxy groups and active amino groups. Its silicon-oxygen bond (Si-O-Si) content is 36-40wt%, its methoxy (-OCH3) content is 11-18wt%, and its active hydrogen equivalent is 240-260g / eq.

[0038] Example 1 Two-component silicone grout sealant is prepared through the following process: (1) Add 70 parts by weight of organosilicon modified epoxy resin, 2 parts by weight of reactive epoxy diluent, and 1 part by weight of silane coupling agent into a planetary mixer and mix at a speed of 300-500 rpm for 5-10 min until uniform; then slowly add 2 parts by weight of hydrophobic fumed silica, increase the speed to 1000-1500 rpm, and disperse at high speed for 15-20 min until the fumed silica is completely wetted and dispersed, and the system is uniformly thickened; then add 5 parts by weight of color paste and 20 parts by weight of pre-dried inorganic filler, and keep stirring until the color is uniform and there are no visible particles or agglomerates; then remove bubbles under a vacuum of -0.095 MPa or higher for 20-30 min to obtain component A; (2) Add 90 parts by weight of aminosilane curing agent and 0.2 parts by weight of catalyst DBTL into a stirring device and stir at a low speed of 300 rpm until uniform. While stirring, slowly add 2 parts by weight of hydrophobic fumed silica and disperse at a high speed of 1200 rpm for 10-15 min. Then add 7.8 parts by weight of pre-dried inorganic filler and stir at 800 rpm until uniform. Then degas under a vacuum of -0.095 MPa or higher for 20-30 min and discharge to obtain component B. (3) Fill the prepared components A and B into a double tube with a preset capacity ratio of 1:1 to ensure that the two components have equal volumes, and obtain a two-component silicone sealant.

[0039] The application method of this two-component silicone grout material is as follows: install the static mixing nozzle with two tubes, extrude equal volumes of components A and B with a glue gun, and after the materials are fully mixed in the nozzle by the spiral mixer, directly fill the tile gaps, smooth them, and wait for them to cure.

[0040] Example 2 The two-component silicone grout material was prepared using the same process as in Example 1, except that the amount of silicone-modified epoxy resin in step (1) was adjusted to 65 parts by mass, the amount of active epoxy diluent was adjusted to 3 parts by mass, and the amount of pre-dried inorganic filler was adjusted to 24 parts by mass.

[0041] Example 3 The two-component silicone grout material was prepared using the same process as in Example 1, except that the amount of catalyst DBTL in step (2) was adjusted to 0.5 parts by mass and the amount of pre-dried inorganic filler was adjusted to 7.5 parts by mass.

[0042] Comparative Example 1 The two-component silicone grout material was prepared using the same process as in Example 1, except that the silicone-modified epoxy resin in step (1) was replaced with an equal mass of ordinary bisphenol A epoxy resin E-51; the aminosilane curing agent in step (2) was replaced with 50 mass of conventional alicyclic amine curing agent 1,3-cyclohexanedimethylamine (1,3-BAC); at the same time, the catalyst DBTL was not added and the amount of pre-dried inorganic filler in component B was adjusted to 48 mass.

[0043] Comparative Example 2 The two-component silicone grout material was prepared using the same process as in Example 1, except that the aminosilane curing agent in step (2) was replaced with a mixture of 5 parts by weight of ordinary aminosilane resin KH-792 and 45 parts by weight of conventional alicyclic amine curing agent 1,3-cyclohexanedimethylamine (1,3-BAC), and the amount of pre-dried inorganic filler in component B was adjusted to 47.8 parts by weight.

[0044] Comparative Example 3 The two-component silicone grout material was prepared using the same process as in Example 1, except that the aminosilane curing agent in step (2) was replaced with 50 parts by weight of the conventional alicyclic amine curing agent 1,3-cyclohexanedimethylamine (1,3-BAC). At the same time, the catalyst DBTL was not added and the amount of pre-dried inorganic filler in component B was adjusted to 48 parts by weight.

[0045] The formulation comparison of the two-component silicone grout sealant materials in the above embodiments and comparative examples is shown in Table 1 below: Table 1. Formula Comparison The performance of the two-component silicone grout materials obtained in the examples and comparative examples was tested, and the results are shown in Table 2 below: Table 2 Performance test results of silicone grout sealant Among them, the wet substrate test conditions simulated construction in a wet area, with the substrate surface covered by a visible water film.

[0046] As can be seen from Table 2: Regarding yellowing resistance, the ΔE values ​​of the examples were all ≤1.5, which was far superior to Comparative Examples 1 and 2. In particular, even though Example 2 reduced the content of silicone resin, it still maintained excellent yellowing resistance, indicating that the high bond energy Si-O-Si skeleton in the dual network provides strong UV resistance. Example 3 had more catalyst and more complete curing, and the yellowing resistance was further improved to 1.1. Although Comparative Example 3 showed some improvement in yellowing (1.9), it was still not as effective as the products of the examples due to the lack of a complete silicone network.

[0047] Regarding the adhesion strength on the dry substrate, Example 3 had more catalyst and denser crosslinking, resulting in the highest strength (11.2 MPa); Example 2 had less resin and more filler, resulting in a slight decrease in strength (9.7 MPa), but it was still higher than the comparative example; all systems containing organosilicon-modified epoxy showed high strength.

[0048] Regarding adhesion strength on damp substrates, the pure epoxy system in Comparative Example 1 showed a sharp drop in strength to 2.2 MPa on damp substrates, with a retention rate of only 33%, fully exposing the fatal flaw of traditional epoxy's susceptibility to water. The pure amine-cured system in Comparative Example 3, lacking moisture curing capability, also experienced a significant decline in wet strength to 2.8 MPa. While the physically mixed curing system in Comparative Example 2 showed improvement (4.1 MPa, retention rate 55%), it was still far lower than the products in the examples. This indicates that only through chemical integration of amino and alkoxy groups can a highly efficient synergistic effect be achieved; simple physical mixing cannot achieve similar results.

[0049] In terms of elongation at break and hydrophilicity, the elongation at break of Examples 1 and 3 (34% and 32%) was significantly higher than that of Comparative Examples 1 (8%) and 3 (11%), indicating that the dual network effectively alleviated the brittleness of the epoxy system, buffered the stress generated by the thermal expansion and contraction of the substrate, prevented cracking, and thus greatly improved long-term corrosion resistance and weather resistance. In Example 2, the elongation at break decreased slightly to 29% due to the increase in filler, but it still maintained good toughness. At the same time, the surface contact angle of all examples was >100°, which is highly hydrophobic and can effectively block water penetration, further enhancing the anti-corrosion effect. In contrast, the contact angle of Comparative Examples 1 and 3 was only about 70°, which is hydrophilic and easily absorbs water, leading to performance degradation.

[0050] In terms of hardness and rigidity, the hardness of the embodiments is moderate (Shore D 74~78), which combines strength and toughness; the hardness of Comparative Examples 1 and 3 is too high (84, 81), and they are brittle; the hardness of Comparative Example 2 is too low (71), and its strength is insufficient.

[0051] Based on the above comparison, it can be seen that the product of Example 1 has the best overall performance, the product of Example 2 maintains excellent performance while reducing costs, and is suitable for scenarios where cost-effectiveness is required, and Example 3 further enhances the moisture curing speed by increasing the amount of catalyst, and is suitable for rapid construction or high humidity environments.

[0052] It should be noted that the above descriptions are merely preferred embodiments of the present invention and should not limit the scope of protection of the technical solutions of the present invention. Any modifications made to the technical solutions described in the foregoing embodiments, or equivalent substitutions of technical features, by those skilled in the art within the spirit and principles of the present invention, should be included within the scope of protection of the present invention.

Claims

1. A two-component silicone grout sealant, characterized in that, It comprises component A and component B in a volume ratio of 1:

1. Component A includes: 65-75 wt% silicone-modified epoxy resin, 0-5 wt% active epoxy diluent, 0.5-2 wt% silane coupling agent, 1-3 wt% hydrophobic fumed silica, and the balance being a first inorganic filler. Component B includes: 85-95 wt% aminosilane curing agent, 0.1-0.5 wt% catalyst, 1-3 wt% hydrophobic fumed silica, and the balance being a second inorganic filler. The silicone-modified epoxy resin is a silicone-grafted epoxy polymer and / or an epoxy-silicone block copolymer. The aminosilane curing agent contains a polysiloxane backbone and active amino groups and hydrolyzable siloxy groups attached to the backbone. The catalyst is selected from organotin and / or titanate catalysts.

2. The two-component silicone sealant material according to claim 1, characterized in that, Component A also includes 2-8 wt% pigments and / or color pastes.

3. The two-component silicone sealant material according to claim 1, characterized in that, in, The organosilicon-modified epoxy resin has an epoxy equivalent of 180-250 g / eq, a viscosity of less than 5000 mPa·s at 25°C, and a silicon-oxygen bond content of not less than 10%; and / or, the aminosilane curing agent has a silicon-oxygen bond content of 36-40 wt%, a methoxy group content of 11-18 wt%, and an active hydrogen equivalent of 240-260 g / eq.

4. The two-component silicone sealant material according to claim 1, characterized in that, in, The first inorganic filler is selected from one or more of quartz sand, glass microspheres, precipitated barium sulfate, and silicon micropowder; and / or, the second inorganic filler is selected from one or more of quartz sand, glass microspheres, precipitated barium sulfate, and silicon micropowder; and / or, the silane coupling agent is selected from epoxy silane coupling agents.

5. The two-component silicone sealant material according to claim 1, characterized in that, in, The active epoxy diluent is selected from butyl glycidyl ether and / or benzyl glycidyl ether; and / or, the catalyst is selected from dibutyltin dilaurate; and / or, both the first inorganic filler and the second inorganic filler are selected from quartz sand.

6. The two-component silicone sealant material according to claim 1, characterized in that, Obtaining the aminosilane curing agent includes: (1) Add an end-capping agent to an amino-containing alkoxysilane to obtain a premix, and dissolve the premix in an alcohol solvent to obtain a mixture; wherein the end-capping agent is an amino-free alkoxysilane; (2) Under an inert atmosphere, the pH of the mixture is adjusted to 5.0-5.5, and then water is added to carry out a hydrolysis reaction to obtain a hydrolyzed mixture; wherein the amount of water added is 0.5-1.0 times the amount of total alkoxy groups of the premix, and the hydrolysis temperature is 30-60℃. (3) Add a condensation catalyst to the hydrolysis mixture and carry out a condensation oligomerization reaction at 50-80°C. Monitor the amine value of the reaction system. When the amine value drops to the target range, terminate the reaction and remove the volatile components to obtain the aminosilane curing agent.

7. The two-component silicone sealant material according to claim 6, characterized in that, in, The amino-containing alkoxysilane is selected from N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane; and / or, the end-capping agent is selected from methyltrimethoxysilane; and / or, the condensation catalyst is selected from dibutyltin dilaurate.

8. The method for preparing the two-component silicone grout sealant according to any one of claims 1-7, characterized in that, It includes the following steps: (1) The organosilicon modified epoxy resin, active epoxy diluent and silane coupling agent are mixed evenly, and then hydrophobic fumed silica in component A is added for high-speed dispersion, and then the pre-dried first inorganic filler is added and mixed evenly, and then vacuum degassing is performed to obtain component A. (2) The aminosilane curing agent and the catalyst in component B are mixed evenly, and then the hydrophobic fumed silica in component B is added for high-speed dispersion. Then the pre-dried second inorganic filler is added and mixed evenly. Then the vacuum degassing treatment is performed to obtain component B. (3) The components A and B are packaged in a volume ratio of 1:1 to obtain the two-component silicone sealant.

9. The preparation method according to claim 8, characterized in that, Step (1) further includes: after the high-speed dispersion, adding the additive material and the pre-dried first inorganic filler and mixing them evenly; wherein the additive material is pigment and / or color paste.

10. The preparation method according to claim 8, characterized in that, in, The preparation of the aminosilane curing agent includes: (1) Add 20-30% by mass of methyltrimethoxysilane to N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane to obtain a premix, dissolve the premix in an alcohol solvent until the solid content reaches 60-70% to obtain a mixture; (2) Under an inert atmosphere, the pH of the mixture is adjusted to 5.0-5.5, and then water is added to carry out a hydrolysis reaction to obtain a hydrolyzed mixture; wherein the amount of water added is 0.5-1.0 times the amount of total alkoxy groups of the premix, and the hydrolysis temperature is 30-60℃. (3) Add dibutyltin dilaurate to the hydrolyzed mixture and carry out a condensation oligomerization reaction at 50-80°C. Monitor the amine value of the reaction system. When the amine value drops to 240-260 g / eq, terminate the reaction and remove the volatile components to obtain the aminosilane curing agent.