Water-based ceramic tile back adhesive and preparation method thereof

Abstract

The invention belongs to the technical field of coatings. The invention relates to a water-based ceramic tile back adhesive and a preparation method thereof. The water-based ceramic tile back adhesive is prepared from the following raw materials in parts by weight: 60 to 70 parts of modified acrylic resin, 3.0 to 5.0 parts of modified nano silicon oxide, 2.0 to 5.0 parts of a silane coupling agent, 1.0 to 2.0 parts of an anti-alkali agent, 0.1 to 0.3 part of an antioxidant, 0.1 to 0.2 part of a de-foaming agent and the balance of de-ionized water. The raw materials are mixed and stirred to prepare the ceramic tile back adhesive, so that the problems of insufficient interface bonding force and poor bonding durability of the ceramic tile back adhesive in the prior art can be effectively solved, and the ceramic tile back adhesive has a relatively great application prospect.

Description

Technical Field

[0001] This invention relates to a water-based ceramic tile adhesive and its preparation method. This invention belongs to the field of adhesive technology. Background Technology

[0002] As a core supporting material in the building decoration field, the interfacial bonding performance and durability of tile adhesive directly determine the quality of tile installation. Existing technologies generally suffer from two major pain points: insufficient interfacial bonding leading to hollowing and detachment, and poor bonding durability resulting in a shortened service life. Traditional cement-based adhesives have poor wetting properties on dense substrates such as ceramic tiles, with bonding strength often below 1.5 MPa, making hollowing easily occur shortly after application. They also exhibit weak water resistance and alkali resistance; after 72 hours of immersion in water, the bond strength retention rate is often below 60%, and after soaking in a 5% NaOH solution, the strength decreases by more than 40%, resulting in a generally short tile lifespan. Furthermore, existing products are only suitable for ordinary ceramic tiles, with poor compatibility with special substrates such as marble and mosaic, limiting their application in high-end scenarios.

[0003] To address these issues, the industry typically employs three optimization methods: first, adding inorganic fillers such as nano-SiO2 to enhance mechanical properties; second, changing the type of silane coupling agent to improve interfacial compatibility; and third, designing multi-component systems to compound functional additives, achieving complementary performance through on-site mixing. These methods can improve bond strength and slightly improve short-term weather resistance in laboratory environments.

[0004] However, existing optimization methods have significant drawbacks: nanofillers are prone to agglomeration, leading to uneven dispersion and a reduction in strength improvement effect of more than 30% in practical applications; single coupling agents cannot be simultaneously adapted to organic resins, inorganic substrates, and nanofillers, resulting in insufficient interfacial synergy; multi-component systems require precise on-site mixing, and mixing errors can easily lead to incomplete curing, increasing storage and labor costs, with a raw material waste rate of 10%-15%. In summary, existing technologies have failed to fundamentally solve the core contradiction between interfacial bonding strength and durability, and a new adhesive solution that balances strong adhesion, high durability, wide compatibility, and convenient construction is urgently needed. Summary of the Invention

[0005] The purpose of this invention is to address the problems of insufficient interfacial bonding strength and poor adhesion durability in existing tile backing adhesives, and to provide a water-based tile backing adhesive and its preparation method. This invention uses a self-made modified acrylic resin combined with modified nano-silica, and adds alkali-resistant agents, antioxidants, and other additives through formulation design. This solution effectively solves the aforementioned problems while also possessing advantages such as being formaldehyde-free, odorless, environmentally friendly, and easy to use. The technical solution adopted by this invention to solve its technical problems is as follows: This invention provides a water-based tile backing adhesive, comprising the following raw materials in parts by weight: 60-70 parts of modified acrylic resin; 3.0-5.0 parts of modified nano-silica; 2.0-5.0 parts of silane coupling agent; Alkali-resistant agent 1.0-2.0 parts; Antioxidant 0.1-0.3 parts; 0.1-0.2 parts of defoamer; Deionized water balance.

[0006] Furthermore, The modified acrylic resin includes the following preparation steps: S11, Monomer Mixture: Weigh 100 parts of monomer by weight, stir for 10-15 minutes until homogeneous, and obtain mixed monomer; S12, Pre-emulsification: Add 80-100 parts of deionized water and 2-4 parts of emulsifier OP-10 to the reaction vessel, stir to dissolve, and then slowly add the mixed monomers of S11. Emulsify at 300-500 r / min for 20-30 min to obtain a pre-emulsion. S13, triggers aggregation: Heat the pre-emulsion to 75-80℃, add 0.3-0.5 parts of ammonium persulfate initiator, keep warm and stir for 3-4 hours, and adjust the pH of the system to 6.0-7.0 by adding 5wt% sodium bicarbonate solution dropwise during the process. S14, Post-processing: Heat to 85-90℃ and hold for 1 hour, then cool to below 40℃. Adjust the pH to 7.0-8.0 with 10wt% ammonia water, and filter through a 200-mesh filter to obtain a modified acrylic resin emulsion with a solid content of 45%-50%.

[0007] Furthermore, The monomer comprises the following raw materials in parts by weight: 35-40 parts butyl acrylate, 20-25 parts methyl methacrylate, 15-18 parts hydroxyethyl methacrylate, 5-8 parts acrylic acid, 3-5 parts glycidyl methacrylate, 5-10 parts isooctyl acrylate, 0.5-2.0 parts N-(2-acryloyloxyethyl)-N-benzyl-N,N-dimethylammonium chloride, 2-3 parts 4-allyl catechol, and 1-2 parts N-hydroxymethylacrylamide.

[0008] Furthermore, The modified nano-silica includes the following preparation steps: S21, take 100 parts by weight of nano-SiO2, add 500 parts by weight of anhydrous ethanol, and ultrasonically disperse for 30 min to obtain a uniform nano-SiO2 ethanol dispersion; add 5 parts by weight of silane coupling agent KH-570, stir at 500 r / min, heat to 60℃, and maintain the temperature for 1 h; set aside for later use. S22: Cool the nano-SiO2 dispersion of S21 to 50℃, add 0.3 parts of AIBN, stir to dissolve, and slowly add 20-25 parts of functional monomer; after the addition is complete, heat to 70℃, increase the stirring rate to 800r / min, and keep the reaction at this temperature for 2h; cool to room temperature, centrifuge, remove impurities, and dry to obtain modified nano-silica.

[0009] Furthermore, the particle size of the nano-SiO2 is 10-40 nm.

[0010] Furthermore, The functional monomers are hydroxyethyl methacrylate, glycidyl methacrylate, and isooctyl acrylate added in a mass ratio of 10:5:8.

[0011] Furthermore, the antialkali agent is a mixture of diethanolamine and sodium pyrophosphate in a ratio of (2-4):1.

[0012] Another object of the present invention is to provide a method for preparing a water-based tile backing adhesive, comprising the following steps: S31, Aqueous phase preparation: Heat deionized water to 80-85℃, add anti-alkali agent and antioxidant, stir for 10-15 minutes until dissolved, and form a homogeneous aqueous phase system; S32, Mixed Dispersion: Add modified acrylate resin to the aqueous system and stir at 800-1000 r / min for 10 min. Then add modified nano silica and defoamer and continue stirring for 20 min until the mixture is evenly dispersed. S33, emulsification crosslinking: Add the silane coupling agent in three equal portions and emulsify and disperse at 80-85℃ for 30-40 minutes. S34, aging filtration: Cool to 40-45℃, keep warm and stir for 2-3 hours, cool to room temperature and filter through a 100-mesh filter to obtain the tile backing adhesive.

[0013] Another objective of this invention is to provide an application of a water-based ceramic tile adhesive in the construction industry.

[0014] The beneficial effects of this invention are: (1) This invention provides a water-based ceramic tile adhesive, using a self-made modified acrylic resin as the main resin, which contains hydroxyl, carboxyl, epoxy, catechol, and quaternary ammonium salt structures; and the soft and hard monomers are carefully designed. First, hydroxyl groups can form hydrogen bonds with the substrate to enhance the bonding force; second, carboxyl and catechol structures can form coordination bonds with mortar to significantly enhance the bonding strength; third, epoxy groups can form cross-linking structures with hydroxyl or carboxyl groups, further enhancing the bonding strength and improving durability. In addition, the balanced design of soft and hard monomers endows the molecular chains with anti-embrittlement and anti-flow properties over a wide temperature range, avoids stress concentration, and improves its durability.

[0015] (2) This invention provides a water-based ceramic tile adhesive containing self-made modified nano-silica, specifically a spherical core-shell structure in which nano-silica (core layer) is embedded in an acrylate copolymer (shell layer) containing hydroxyl, epoxy, and long carbon chain structures. First, the acrylate copolymer with hydroxyl, epoxy, and long carbon chain structures is similar in structure to acrylic resin and has chain entanglement, giving it excellent dispersibility in acrylic resin systems; second, the spherical modified nano-silica structure has a high modulus, which can improve strength; at the same time, it acts as a crosslinking point to inhibit the generation of microcracks and prevent the propagation of cracks; third, the spherical structure can fill pores to physically block the penetration of corrosive media such as moisture and OH⁻, thereby improving durability.

[0016] (3) This invention provides a water-based ceramic tile backing adhesive, in which modified acrylic resin and modified nano-silica form an integrated structure by "point-line combination", which synergistically improves the bonding performance, durability, and aging resistance, and has broad application potential. Detailed Implementation

[0017] The present invention will be described in detail below with reference to embodiments. However, it should be understood that the following embodiments are merely illustrative examples of implementation of the present invention and are not intended to limit the scope of the present invention.

[0018] The purpose of this invention is to address the shortcomings of existing tile adhesives, such as insufficient interfacial bonding strength and poor bonding durability. The approach is as follows: Since the main resin in the adhesive plays a decisive role in the final performance and needs to possess high polarity, this invention uses a self-made waterborne acrylic resin, introducing polar groups such as hydroxyl and carboxyl groups, which can form hydrogen bonds or coordination bonds with tiles and cement, thereby improving bonding strength. Furthermore, the addition of catechol structures further enhances bonding strength, and quaternary ammonium salt structures provide anti-mildew properties. Considering the water resistance issue of waterborne resins, crosslinking monomers are added to increase the crosslinking density and improve water resistance. On the other hand, the adhesive is subjected to different stress and heat conditions during curing and long-term use, affecting its durability. It also needs to be doped with high-modulus, low-thermal-expansion-coefficient materials, but physical blending presents interfacial bonding problems, which degrade bonding strength. Therefore, a self-made reactive filler is also required, based on nano-silica, modified with an acryloyloxysilane coupling agent, and then polymerized in situ with functional monomers to synergistically improve bonding strength and durability. Finally, through formulation design, alkali-resistant agents, antioxidants, and other additives are added to synergistically enhance interfacial adhesion and bonding durability. Examples of the present invention are as follows: This invention provides a water-based ceramic tile adhesive, comprising the following raw materials in parts by weight: 60-70 parts of modified acrylic resin; 3.0-5.0 parts of modified nano-silica; 2.0-5.0 parts of silane coupling agent; Alkali-resistant agent 1.0-2.0 parts; Antioxidant 0.1-0.3 parts; 0.1-0.2 parts of defoamer; Deionized water balance.

[0019] The modified acrylic resin described in the following embodiments of the present invention includes the following preparation steps: S11, Monomer Mixture: Weigh 100 parts of monomer by weight, stir for 15 minutes until homogeneous, and obtain mixed monomer; S12, Pre-emulsification: Add 90 parts of deionized water and 3 parts of emulsifier OP-10 to the reaction vessel, stir to dissolve, and slowly add the mixed monomers of S11. Emulsify at 400 r / min for 15 min to obtain a pre-emulsion. S13, triggers aggregation: The pre-emulsion was heated to 78°C, and 0.4 parts of ammonium persulfate initiator were added. The mixture was kept at this temperature and stirred for 3.5 hours. During this time, the pH of the system was adjusted to 6.0 by adding 5 wt% sodium bicarbonate solution dropwise. S14, Post-processing: The mixture was heated to 88℃ and held for 1 hour, then cooled to below 40℃. The pH was adjusted to 8.0 with 10wt% ammonia water, and the mixture was filtered through a 200-mesh filter to obtain a modified acrylic resin emulsion with a solid content of 48%.

[0020] The monomer comprises the following raw materials in parts by weight: 38.5 parts butyl acrylate, 22 parts methyl methacrylate, 16 parts hydroxyethyl methacrylate, 6 parts acrylic acid, 4 parts glycidyl methacrylate, 8 parts isooctyl acrylate, 1.5 parts N-(2-acryloyloxyethyl)-N-benzyl-N,N-dimethylammonium chloride, 2.5 parts 4-allyl catechol, and 1.5 parts N-hydroxymethylacrylamide.

[0021] The modified nano-silica includes the following preparation steps: S21, take 100 parts of nano-SiO2 by mass, add 500 parts of anhydrous ethanol, and ultrasonically disperse for 30 min to obtain a uniform nano-SiO2 ethanol dispersion; add 5 parts of silane coupling agent KH-570, stir at 500 r / min, heat to 60℃, and keep the reaction at this temperature for 1 h; set aside for use. The nano-SiO2 has a particle size of 10-40 nm and an average particle size of 20 nm. It is product number JL-SiO2-N20 and was purchased from Ningbo Jinlei Nanomaterials Technology Co., Ltd.

[0022] S22: Cool the nano-SiO2 dispersion of S21 to 50℃, add 0.3 parts of AIBN, stir to dissolve, and slowly add 20-25 parts of functional monomer. After the addition is complete, heat to 70℃, increase the stirring rate to 800 r / min, and keep the reaction at this temperature for 2 h. Cool to room temperature, centrifuge, wash the precipitate 3 times with anhydrous ethanol, place it in a vacuum drying oven, and vacuum dry at 60℃ for 4 h to obtain modified nano-silica.

[0023] The functional monomers are hydroxyethyl methacrylate, glycidyl methacrylate, and isooctyl acrylate added in a mass ratio of 10:5:8.

[0024] The alkali-resistant agent is a mixture of diethanolamine and sodium pyrophosphate in a ratio of (2-4):1.

[0025] The silane coupling agent is an aminosilane coupling agent; specifically, it is silane coupling agent KH550.

[0026] The antioxidant is a hindered phenolic antioxidant; specifically, antioxidant 1010.

[0027] The defoamer is BYK-024.

[0028] The preparation method of the water-based ceramic tile adhesive described in the following embodiments of the present invention includes the following steps: S31, Aqueous phase preparation: Deionized water was heated to 80°C, and anti-alkali agent and antioxidant were added. The mixture was stirred for 15 minutes until dissolved to form a homogeneous aqueous phase system. S32, Mixed Dispersion: Add modified acrylate resin to the aqueous system and stir at 900 r / min for 10 min. Then add modified nano-silica and defoamer and continue stirring for 20 min until the mixture is evenly dispersed. S33, emulsification crosslinking: The silane coupling agent was added in three equal portions and emulsified and dispersed at 80°C for 40 minutes. S34, aging filtration: The temperature was lowered to 40°C, and the mixture was stirred for 3 hours. After cooling to room temperature, it was filtered through a 100-mesh filter to obtain the tile backing adhesive.

[0029] In the water-based ceramic tile adhesive of this invention, the core functions of modified acrylic resin and modified nano-silica are combined to form a highly efficient system of "molecular design-structural complementarity." Each component not only exerts its unique properties but also achieves a significant improvement in "bonding strength and durability" through a synergistic effect. Its mechanism of action is as follows: In this invention, the modified acrylic resin, through precise monomer ratios and polymerization processes, forms a three-dimensional system containing "polar functional groups + a balanced soft and hard segment structure + a cross-linked network," the effects of which are manifested in the following aspects: (1) The “molecular anchoring” effect of interfacial bonding: The multi-polar groups on the resin molecular chain form a strong bond with the substrate through chemical / physical action: the hydroxyl groups form hydrogen bonds with the silanol groups on the surface of the ceramic tile and the hydroxyl groups of the cement substrate, providing bonding performance; the carboxyl groups can react with Ca in the cement. 2 ⁺ Coordination reactions occur, transforming physical adsorption into chemical bonding, significantly improving the basic adhesion strength; epoxy groups undergo ring-opening reactions with amino or hydroxyl groups on the substrate surface, forming covalent cross-links, further enhancing the interfacial "anchoring" effect; catechols can react with Ca... 2 ⁺ It undergoes a bidentate coordination reaction, which further significantly enhances the bond strength; and it still maintains high bond strength in humid environments; the quaternary ammonium salt structure has excellent broad-spectrum antibacterial properties, which can effectively improve anti-mildew performance; and it can form electrostatic adsorption with cement, which enhances the interfacial bond strength.

[0030] (2) The "mechanical balance" function of the adhesive layer: By optimizing the ratio of "hard segment - soft segment" monomers (methyl methacrylate is the hard segment, butyl acrylate and isooctyl acrylate are the soft segments), the strength and flexibility of the adhesive layer are balanced, providing anti-embrittlement and anti-flow properties in a wide temperature range, avoiding stress concentration, and improving its durability.

[0031] (3) The “crosslinking enhancement” effect of the system: Through the synergy of crosslinking monomer (N-hydroxymethylacrylamide) and epoxy group, a three-dimensional network structure is formed: the hydroxymethyl group of N-hydroxymethylacrylamide undergoes a condensation reaction with the hydroxyl group of the resin molecular chain to form a crosslinking bond; the epoxy group undergoes a ring-opening reaction with the hydroxyl group to further densify the crosslinking network, effectively blocking the penetration of water and alkaline substances and improving alkali and water resistance.

[0032] In this invention, modified nano-SiO2 is polymerized in a single step to construct a multifunctional shell of "hydroxyl-epoxy-long-chain alkyl" on its surface, the function of which is as follows: (1) Nanoscale “rigidity enhancement” effect: The high specific surface area and high modulus of nano SiO2 (particle size 10-40nm) can be uniformly dispersed in the resin matrix to bear external stress; nanoparticles can “pin” the microcracks in the adhesive layer and prevent the cracks from expanding further.

[0033] (2) Interface "affinity and bridging" effect: The long-chain alkyl groups in the shell are similar to the soft segment structure of the resin, which reduces the interfacial tension through the principle of "like dissolves like" and avoids the aggregation of nanoparticles; the hydroxyl groups in the shell react with the epoxy groups in the resin to form covalent bonds, making the nanoparticles and resin an "integrated structure"; the hydroxyl and epoxy groups in the shell can react with Si-OH (hydrogen bonds) in ceramic tiles and Ca in cement. 2 The ⁺ (coordination bond) bonding is equivalent to building a "molecular bridge" between the resin and the substrate, thereby improving the interfacial bonding force.

[0034] (3) Aging resistance "barrier" effect: Dense shell blocks penetration: The continuous and non-porous polymer shell on the surface can physically block water, OH⁻ and other corrosive media from contacting the nano SiO2 core, avoid its hydrolysis, and improve water resistance and alkali resistance; At the same time, nano SiO2 as an inorganic filler has excellent thermal stability and can be used as a crosslinking point to improve the thermal decomposition temperature of the overall structure; It has excellent heat aging resistance.

[0035] The synergistic effect of modified resin and functionalized nano-SiO2 in this invention: The two components form a synergistic system through "chemical complementarity, structural synergy, and performance superposition," addressing the pain points of traditional adhesives such as "weak adhesion and poor durability." Specifically, this manifests as follows: (1) Synergistic “cross-reaction” of chemical groups: The hydroxyl groups of the resin and the hydroxyl groups of the nanoparticle shell interact through hydrogen bonds, further enhancing the cohesive force of the system and preventing the nanoparticles from desorbing from the resin under stress; at the same time, the epoxy groups of the resin and the hydroxyl groups of the functionalized nano-SiO2 shell undergo ring-opening reaction, and the carboxyl groups of the resin and the epoxy groups of the nanoparticle shell undergo esterification reaction, forming a “resin-nanoparticle” covalent cross-linking network, so that the resin and nanoparticles form an integrated structure. Through physical-chemical dual modification, the overall performance is improved.

[0036] (2) Synergistic performance enhancement: The flexible segments of the resin can absorb external impact stress, while the rigid skeleton of nano-SiO2 can resist static load. The combination of the two prevents excessive creep of the resin molecular chains in the adhesive layer and alleviates stress concentration caused by nanoparticle aggregation, thus maintaining stable mechanical properties over a wide temperature range (with excellent freeze-thaw stability). The high degree of cross-linking of the resin and the functionalized nano-SiO2 nanosphere structure can effectively fill the micropores between polymer chains, improve the density of the adhesive layer, and improve water and alkali resistance; at the same time, the high cross-linking density of the organic chains has a high thermal decomposition temperature, and the combination with inorganic fillers can effectively improve the thermal decomposition temperature of the overall structure; it has excellent heat aging resistance.

[0037] In the water-based ceramic tile adhesive of the present invention, through formulation design, composite anti-alkali agents and antioxidants are also introduced to further synergistically improve the durability of the adhesive.

[0038] Another objective of this invention is to provide an application of a water-based tile adhesive in the construction industry; specifically, it can be used in home and commercial decoration scenarios such as kitchens and bathrooms, shopping mall corridors, and hotel lobbies, and is especially suitable for humid or alkaline environments (such as bathrooms and basements).

[0039] The present invention also provides a method for applying the adhesive in the following embodiments, including the following steps: 1) Substrate pretreatment: Treat the ceramic tile and wall / floor substrates to ensure the surface is flat, dry, and free of oil and dust. Cracks should be filled with repair mortar. 2) Applying adhesive: Stir the adhesive directly from the container, then apply it to the back of the tile and the surface of the substrate using a bristle brush or small roller. Let it stand for 30-40 minutes until the surface becomes transparent; leave a 5mm area around the four edges of the tile. 3) Tile installation: Mix 325# or 425# cement with fine yellow sand at a mass ratio of 2:1, add water and stir to form a mortar with a consistency of 50-60mm. Apply the mortar to the back of the tile (thickness 3-5mm). After adhering to the substrate, gently tap it with a rubber mallet to level it. The position can be adjusted within 10 minutes. 4) Curing treatment: After pasting, let stand for 24 hours, and fill the gaps after curing. The construction environment temperature is ≥5℃ and the humidity is ≤75%.

[0040] To further understand the present invention, the following detailed description of a water-based ceramic tile adhesive provided by the present invention is provided in conjunction with specific embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0041] Example 1 A water-based tile adhesive comprises the following raw materials in parts by weight: 65 parts of modified acrylic resin; 4.0 parts of modified nano-silica; 3.5 parts of silane coupling agent; 1.5 parts of alkali-resistant agent; Antioxidant 0.2 parts; 0.15 parts of defoamer; Deionized water balance.

[0042] The modified nano-silica includes the following preparation steps: S21, take 100 parts of nano-SiO2 by mass, add 500 parts of anhydrous ethanol, and ultrasonically disperse for 30 min to obtain a uniform nano-SiO2 ethanol dispersion; add 5 parts of silane coupling agent KH-570, stir at 500 r / min, heat to 60℃, and keep the reaction at this temperature for 1 h; set aside for use. S22: Cool the nano-SiO2 dispersion of S21 to 50℃, add 0.3 parts of AIBN, stir to dissolve, and slowly add 23 parts of functional monomer; after the addition is complete, heat to 70℃, increase the stirring rate to 800r / min, and keep the reaction at this temperature for 2h; cool to room temperature, centrifuge, remove impurities, and dry to obtain modified nano-silica.

[0043] The alkali-resistant agent is a mixture of diethanolamine and sodium pyrophosphate in a 3:1 ratio.

[0044] Example 2 Everything else is the same as in Example 1, except that: A water-based tile adhesive comprises the following raw materials in parts by weight: 60 parts of modified acrylic resin; 3.0 parts of modified nano-silica; 5.0 parts of silane coupling agent; Alkali-resistant agent 2.0 parts; Antioxidant 0.3 parts; 0.1 parts of defoamer; Deionized water balance.

[0045] Example 3 Everything else is the same as in Example 1, except that: A water-based tile adhesive comprises the following raw materials in parts by weight: 70 parts of modified acrylic resin; 5.0 parts of modified nano-silica; 2.0 parts of silane coupling agent; Alkali-resistant agent 1.0 part; Antioxidant 0.1 parts; 0.2 parts of defoamer; Deionized water balance.

[0046] Example 4 The rest is the same as in Example 1, except that the amount of functional monomer added in the modified nano-silica preparation step is 20 parts.

[0047] Example 5 The rest is the same as in Example 1, except that the amount of functional monomer added in the modified nano-silica preparation step is 25 parts.

[0048] Example 6 The rest is the same as in Example 1, except that the antialkali agent is a mixture of diethanolamine and sodium pyrophosphate in a 2:1 ratio.

[0049] Example 7 The rest is the same as in Example 1, except that the antialkali agent is a mixture of diethanolamine and sodium pyrophosphate in a 4:1 ratio.

[0050] The following comparative examples are all compared with Example 1: Comparative Example 1 The rest is the same as in Example 1, except that the monomer in the modified acrylic resin preparation step does not contain hydroxyethyl methacrylate.

[0051] Comparative Example 2 The rest is the same as in Example 1, except that the monomer in the modified acrylic resin preparation step does not contain acrylic acid.

[0052] Implement Comparative Example 3 The rest is the same as in Example 1, except that the monomer in the modified acrylic resin preparation step does not contain glycidyl methacrylate.

[0053] Comparative Example 4 The rest is the same as in Example 1, except that the monomer in the modified acrylic resin preparation step does not contain 4-allyl catechol.

[0054] Comparative Example 5 The rest is the same as in Example 1, except that the monomer in the modified acrylic resin preparation step does not contain N-(2-acryloyloxyethyl)-N-benzyl-N,N-dimethylammonium chloride.

[0055] Comparative Example 6 The rest is the same as in Example 1, except that the monomer in the modified acrylic resin preparation step does not contain N-hydroxymethylacrylamide.

[0056] Comparative Example 7 The rest is the same as in Example 1, except that: the water-based ceramic tile adhesive formulation does not contain modified nano-silica.

[0057] Implemented Comparative Example 8 The rest is the same as in Example 1, except that in the modified nano-silica preparation step, the amount of functional monomer added is 15 parts.

[0058] Comparative Example 9 The rest is the same as in Example 1, except that the amount of functional monomer added in the modified nano-silica preparation step is 30 parts.

[0059] Implement Comparative Example 10 The rest is the same as in Example 1, except that in the modified nano-silica preparation step, the nano-silica particle size is 100nm (product number SM, purchased from Dongna Biotechnology Co., Ltd.).

[0060] Comparative Example 11 The rest is the same as in Example 1, except that the amount of functional monomer added in the modified nano-silica preparation step is 0; that is, the product S21.

[0061] Comparative Example 12 The rest is the same as in Example 1, except that the anti-alkali agent is a mixture of diethanolamine and sodium pyrophosphate in a 1:1 ratio.

[0062] Comparative Example 13 The rest is the same as in Example 1, except that the antialkali agent is a mixture of diethanolamine and sodium pyrophosphate in a 5:1 ratio.

[0063] Comparative Example 14 The rest is the same as in Example 1, except that: the water-based tile adhesive formulation does not contain antioxidants.

[0064] The water-based ceramic tile adhesive prepared in the above embodiments and comparative examples of the present invention were applied and their relevant physical properties were measured. The results are shown in Table 1.

[0065] Table 1 Physical test performance of each embodiment Example Tensile bond strength / MPa Retention rate after soaking in water / alkaline water / % Freeze-thaw cycle retention rate / % Retention rate after heat aging / % Anti-mildew Example 1 2.87 93.2 / 90.5 98.6 104.7 Level 0 Example 2 2.71 91.5 / 89.4 98.1 104.2 Level 0 Example 3 2.63 93.8 / 91.0 98.8 104.6 Level 0 Example 4 2.76 90.7 / 88.6 97.9 104.2 Level 0 Example 5 2.69 91.4 / 88.9 98.0 104.4 Level 0 Example 6 2.78 93.0 / 87.7 98.4 104.5 Level 0 Example 7 2.72 93.0 / 85.2 98.2 104.3 Level 0 Comparative Example 1 2.34 85.6 / 80.3 91.7 95.7 Level 0 Comparative Example 2 1.83 87.1 / 81.8 90.3 94.6 Level 0 Implement Comparative Example 3 2.06 82.3 / 78.1 87.5 91.0 Level 1 Comparative Example 4 1.98 74.9 / 70.2 90.2 94.3 Level 0 Comparative Example 5 2.26 88.7 / 85.1 95.9 99.8 Level 3 Comparative Example 6 1.95 80.4 / 76.3 85.4 88.5 Level 1 Comparative Example 7 1.90 75.3 / 71.7 74.6 74.1 Level 2 Implemented Comparative Example 8 2.38 82.4 / 80.8 86.2 90.9 Level 1 Comparative Example 9 2.50 84.6 / 83.3 88.7 92.1 Level 0 Implement Comparative Example 10 2.47 83.1 / 82.0 88.1 91.4 Level 0 Comparative Example 11 2.12 80.5 / 78.4 76.0 85.7 Level 0 Comparative Example 12 2.79 91.9 / 68.9 98.3 104.4 Level 0 Comparative Example 13 2.70 91.2 / 71.6 98.0 104.3 Level 0 Comparative Example 14 2.84 93.2 / 90.5 97.8 79.9 Level 0 First, as can be seen from Examples 1-7 in Table 1, the water-based ceramic tile adhesive of the present invention has high bonding strength, durability (high performance retention rate), and mildew resistance.

[0066] Secondly, as can be observed from Example 1 and Comparative Examples 1-6, the self-made modified acrylic resin in the water-based ceramic tile adhesive of the present invention has unique characteristics in the selection of comonomers, which can improve bonding strength, water resistance, freeze-thaw stability, and mildew resistance; and different monomers have a synergistic effect in improving overall performance. As can be observed from Example 1 and Comparative Examples 7-11, the self-made modified acrylic resin has the characteristics of improved bonding strength, water resistance, and aging resistance; and nano-silica with a suitable particle size has a significant effect in improving performance. As can be observed from Example 1 and Comparative Examples 12-13, a reasonable ratio of compounded alkali-resistant agents can effectively improve alkali resistance. As can be observed from Example 1 and Comparative Example 14, antioxidants can synergistically improve heat aging resistance.

[0067] In summary, the water-based ceramic tile adhesive of the present invention has high bonding strength, durability, and mildew resistance, and has great application prospects.

[0068] The testing method is as follows: (1) Tensile bond strength, retention rate after immersion in water / alkali water, retention rate after freeze-thaw cycle, and retention rate after heat aging: The operation was carried out in accordance with JC / T 5472017; among them, the retention rate was calculated based on "tensile bond strength"; the alkali water was a 5wt% sodium hydroxide aqueous solution for immersion for 7 days.

[0069] (2) Anti-mildew property: Tested according to GB / T 1741-2020; the test strain is Aspergillus niger.

[0070] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A water-based ceramic tile adhesive, characterized in that, Including the following ingredients by weight percentage: 60-70 parts of modified acrylic resin; 3.0-5.0 parts of modified nano-silica; 2.0-5.0 parts of silane coupling agent; Alkali-resistant agent 1.0-2.0 parts; Antioxidant 0.1-0.3 parts; 0.1-0.2 parts of defoamer; Deionized water balance.

2. The water-based ceramic tile adhesive according to claim 1, characterized in that, The modified acrylic resin includes the following preparation steps: S11, Monomer Mixture: Weigh 100 parts of monomer by weight, stir for 10-15 minutes until homogeneous, and obtain mixed monomer; S12, Pre-emulsification: Add 80-100 parts of deionized water and 2-4 parts of emulsifier OP-10 to the reaction vessel, stir to dissolve, and then slowly add the mixed monomers of S11. Emulsify at 300-500 r / min for 20-30 min to obtain a pre-emulsion. S13, triggers aggregation: Heat the pre-emulsion to 75-80℃, add 0.3-0.5 parts of ammonium persulfate initiator, keep warm and stir for 3-4 hours, and adjust the pH of the system to 6.0-7.0 by adding 5wt% sodium bicarbonate solution dropwise during the process. S14, Post-processing: Heat to 85-90℃ and hold for 1 hour, then cool to below 40℃. Adjust the pH to 7.0-8.0 with 10wt% ammonia water, and filter through a 200-mesh filter to obtain a modified acrylic resin emulsion with a solid content of 45%-50%.

3. The water-based ceramic tile adhesive according to claim 2, characterized in that, The monomer comprises the following raw materials in parts by weight: 35-40 parts butyl acrylate, 20-25 parts methyl methacrylate, 15-18 parts hydroxyethyl methacrylate, 5-8 parts acrylic acid, 3-5 parts glycidyl methacrylate, 5-10 parts isooctyl acrylate, 0.5-2.0 parts N-(2-acryloyloxyethyl)-N-benzyl-N,N-dimethylammonium chloride, 2-3 parts 4-allyl catechol, and 1-2 parts N-hydroxymethylacrylamide.

4. The water-based ceramic tile adhesive according to claim 1, characterized in that, The modified nano-silica includes the following preparation steps: S21, take 100 parts of nano-SiO2 by mass, add 500 parts of anhydrous ethanol, and ultrasonically disperse for 30 min to obtain a uniform nano-SiO2 ethanol dispersion; add 5 parts of silane coupling agent KH-570, stir at 500 r / min, heat to 60℃, and keep the reaction at this temperature for 1 h; set aside for use. S22: Cool the nano-SiO2 dispersion of S21 to 50℃, add 0.3 parts of AIBN, stir to dissolve, and slowly add 20-25 parts of functional monomer; after the addition is complete, heat to 70℃, increase the stirring rate to 800r / min, and keep the reaction at this temperature for 2h; cool to room temperature, centrifuge, remove impurities, and dry to obtain modified nano-silica.

5. The water-based ceramic tile adhesive according to claim 4, characterized in that, The particle size of the nano-SiO2 is 10-40 nm.

6. The water-based ceramic tile adhesive according to claim 4, characterized in that, The functional monomers are hydroxyethyl methacrylate, glycidyl methacrylate, and isooctyl acrylate added in a mass ratio of 10:5:

8.

7. The water-based ceramic tile adhesive according to claim 1, characterized in that, The alkali-resistant agent is a mixture of diethanolamine and sodium pyrophosphate in a ratio of (2-4):

1.

8. A method for preparing the water-based ceramic tile adhesive as described in claim 1, characterized in that, Includes the following steps: S31, Aqueous phase preparation: Heat deionized water to 80-85℃, add anti-alkali agent and antioxidant, stir for 10-15 minutes until dissolved, and form a homogeneous aqueous phase system; S32, Mixed Dispersion: Add modified acrylate resin to the aqueous system and stir at 800-1000 r / min for 10 min. Then add modified nano-silica and defoamer and continue stirring for 20 min until the mixture is evenly dispersed. S33, emulsification crosslinking: Add the silane coupling agent in three equal portions and emulsify and disperse at 80-85℃ for 30-40 minutes. S34, aging filtration: Cool to 40-45℃, keep warm and stir for 2-3 hours, cool to room temperature and filter through a 100-mesh filter to obtain the tile backing adhesive.

9. The application of the water-based ceramic tile adhesive as described in claim 1 in the construction industry.