Anti-crack high-flexibility ceramic tile adhesive and preparation method thereof

Abstract

The invention relates to the technical field of ceramic tile adhesives, and discloses an anti-crack high-flexibility ceramic tile adhesive and a preparation method thereof.The anti-crack high-flexibility ceramic tile adhesive is formed by mixing an adhesive A and an adhesive B according to the weight ratio of 1: 1, and water is not added in the mixing process; the adhesive A is prepared from the following components in percentage by weight: 45 to 60 percent of Portland cement, 25 to 40 percent of quartz sand, 10 to 18 percent of polymer emulsion, 0.5 to 2 percent of water reducing agent and 0.2 to 1 percent of cellulose ether; and the glue B comprises the following components in percentage by weight: 35-55% of epoxy resin, 15-25% of a curing agent, 8-20% of a flexibilizer, 0.5-2% of a defoaming agent and 2-6% of a coupling agent. Through the synergistic effect of an inorganic cement matrix of the adhesive A and an organic epoxy toughening network of the adhesive B, a gradient curing structure is formed, an interpenetrating network is formed by combining a polymer emulsion flexible film layer, alicyclic epoxy resin in the adhesive B and a toughening agent, the crack resistance is improved by 3 times compared with that of a traditional adhesive, and the cracking problem is thoroughly solved.

Description

Technical Field

[0001] The invention relates to the technical field of tile adhesives, in particular to a crack-resistant and highly flexible tile adhesive and a preparation method thereof. Background Art

[0002] In the field of building decoration materials technology, tile adhesive is a key material for bonding tiles to substrates. Its performance directly determines the safety and durability of building finishes. As the construction industry develops towards higher-rise and more complex structures, tile laying scenarios are becoming increasingly diverse, placing higher demands on tile adhesive's crack resistance, flexibility, and environmental adaptability.

[0003] The current mainstream tile adhesive technology uses Portland cement as the base material (50-70%), compounded with 40-80 mesh quartz sand (30-50%), and mixed with 5-10% common polymer emulsion (such as acrylic emulsion) and 0.2-0.5% cellulose ether. Its mechanism of action is as follows: cement hydration forms a rigid skeleton providing initial adhesion, the polymer emulsion forms a film to fill pores and enhance toughness, and the sand aggregate regulates strength and shrinkage.

[0004] However, this system has defects: the elastic modulus of the cement-based rigid matrix is ​​as high as 15GPa, the polymer film layer can only form a discontinuous distribution in the microscopic pores, and the overall adhesive layer presents a "rigid-dominated" characteristic. When the substrate undergoes temperature deformation, settlement and other displacements, stress concentration can easily cause the adhesive layer to crack. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a crack-resistant and highly flexible tile adhesive and a preparation method thereof, which solves the problem of poor crack resistance caused by insufficient flexibility of traditional tile adhesives.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a crack-resistant and highly flexible tile adhesive, which is prepared by mixing glue A and glue B in a weight ratio of 1:1, and no water is added during the mixing process; the glue A contains the following components in weight percentage: 45-60% of silicate cement, 25-40% of quartz sand, 10-18% of polymer emulsion, 0.5-2% of water reducer, and 0.2-1% of cellulose ether; the glue B contains the following components in weight percentage: 35-55% of epoxy resin, 15-25% of curing agent, 8-20% of toughening agent, 0.5-2% of defoaming agent, and 2-6% of coupling agent.

[0007] By adopting the above technical solution, the present invention adopts a two-component waterless printing and dyeing system in which glue A and glue B are mixed in a ratio of 1:1 to construct a gradient solidification structure. The silicate cement in glue A provides strength, and the high-dosage polymer emulsion forms a flexible film layer. In combination with a water reducer and cellulose ether, the elastic modulus of the glue layer is reduced to 6-8GPa and the flexibility is increased by 2 times. The alicyclic epoxy resin and the modified amine curing agent in glue B form a cross-linked network, which is toughened by polysulfide rubber or nano-silica. The fracture toughness reaches 2.8MPa·m1 / 2, the lateral deformation is ≥4.0mm, the bonding strength is 0.9MPa when the substrate is displaced by 3mm, and the crack resistance is increased by 3 times. The silane coupling agent enhances the interfacial bonding, and the wet base surface strength is ≥1.5MPa, which solves the problem of deterioration of the crack resistance of traditional tile adhesives.

[0008] Preferably, the polymer emulsion in the A glue is vinyl acetate-ethylene copolymer emulsion or styrene acrylic emulsion, and the glass transition temperature is -10°C to 5°C.

[0009] Preferably, the epoxy resin in the B glue is an alicyclic epoxy resin with an epoxy value of 0.5-0.6 eq / 100g, and the curing agent is a modified amine curing agent with an active hydrogen equivalent of 200-300 g / eq.

[0010] Preferably, the toughening agent in the B glue is polysulfide rubber or nano-silicon dioxide modified epoxy resin, with a particle size of 20-100 nm and an amount of 10-15% of the weight of the epoxy resin.

[0011] Preferably, the pot life of the mixture of glue A and glue B is 1.5-2 hours, and the initial fluidity of the mixed slurry is 200-250 mm, and the fluidity loss rate within 60 minutes is ≤10%.

[0012] Preferably, the properties of the tile adhesive after curing meet the following requirements: 28-day tensile bonding strength ≥ 2.0 MPa, lateral deformation capacity ≥ 4.0 mm, and wet base bonding strength ≥ 1.5 MPa.

[0013] Preferably, a method for preparing a crack-resistant and highly flexible tile adhesive comprises the following steps:

[0014] S1. Prepare glue A: Mix silicate cement and quartz sand in a dry environment for 2-4 minutes, add polymer emulsion and stir at 600-800 rpm for 15-20 minutes, then add water reducer and cellulose ether and continue stirring for 5-10 minutes;

[0015] S2. Prepare glue B: Heat the epoxy resin to 40-50°C, add toughening agent, defoaming agent and coupling agent in sequence, stir for 20-30 minutes under vacuum degree of -0.06 to -0.08 MPa, and finally add curing agent and mix well;

[0016] S3. Construction mixing: First, pour the heating pack into the container, pour 2.5 liters of water into the container, then place glue A and glue B in the container and heat them with the heating pack. Pour glue A and glue B into the container in a 1:1 ratio, and use an electric stirrer to stir at 800-1000 rpm for 3-5 minutes until the slurry is free of bubbles, lumps and is uniform.

[0017] Preferably, the slurry after stirring in S3 needs to be constructed within 1.5 hours, and the applicable period is shortened to 1 hour when the construction environment temperature is higher than 30°C, and the applicability is optimized in winter: the heating pack heats by conduction, so that the temperature of glue A and glue B rises to 35-45°C, and the viscosity is reduced to 60-70% of the normal temperature state, restoring good fluidity.

[0018] Preferably, the moisture content of the glue A is ≤0.5%, the volatile matter content of the glue B is ≤1%, and the gas content of the slurry after mixing is ≤3%.

[0019] Preferably, during construction, the scraping thickness of the back of the tile is ≥0.8 mm, and the uniformity deviation of the adhesive layer thickness after scraping is ≤0.2 mm, and the adhesive loss rate is ≤5%.

[0020] The present invention provides a crack-resistant and highly flexible tile adhesive and a preparation method thereof. It has the following beneficial effects:

[0021] 1. The inorganic cement matrix of glue A of the present invention and the organic epoxy toughening network of glue B work synergistically to form a gradient solidification structure. 42.5R grade silicate cement provides a 24h compressive strength ≥18MPa. Combined with the flexible film layer of polymer emulsion, the elastic modulus of the adhesive layer is reduced from 15GPa to 6-8GPa, and the flexibility is increased by 2 times. The alicyclic epoxy resin and the toughening agent in glue B form an interpenetrating network with a fracture toughness of 2.8MPa·m1 / 2 and a lateral deformation of ≥4.0mm. When the substrate is displaced by 3mm, it still maintains a bonding strength of 0.9MPa, and the crack resistance is increased by 3 times compared with traditional adhesives, which completely solves the cracking problem.

[0022] 2. The 0.3% latent retarder of the present invention extends the pot life to 1.2h at a high temperature of 35°C, the fluidity loss rate is ≤10%, the strength retention rate after 25 freeze-thaw cycles is ≥95%, the slurry thixotropic index is ≥3.5, the air content is ≤2.5%, there is no sagging when constructing on vertical surfaces, and the thickness deviation of the adhesive layer is ≤0.2mm, which is suitable for complex scenes.

[0023] 3. The silane coupling agent KH550 of the present invention forms Si-O-Si bonds with the hydroxyl groups of ceramic tiles, with a wet-surface bonding strength of ≥1.5MPa. The low-viscosity epoxy resin penetrates the ceramic tile holes to a depth of 0.5mm, with a 28-day tensile strength of 2.8-3.5MPa. There is no delamination after 1000h of wet heat aging, and the strength retention after 50 thermal cycles is ≥92%, with a hollowing rate of ≤0.5%, ensuring long-term stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flow chart of a method for preparing a crack-resistant and highly flexible tile adhesive. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Please see the attached Figure 1 An embodiment of the present invention provides a crack-resistant and highly flexible tile adhesive, which is prepared by mixing adhesive A and adhesive B in a weight ratio of 1:1, without adding water during the mixing process; adhesive A contains the following components in weight percentages: 45-60% silicate cement, 25-40% quartz sand, 10-18% polymer emulsion, 0.5-2% water reducer, and 0.2-1% cellulose ether; adhesive B contains the following components in weight percentages: 35-55% epoxy resin, 15-25% curing agent, 8-20% toughening agent, 0.5-2% defoaming agent, and 2-6% coupling agent.

[0027] Specifically, the components of glue A are:

[0028] Portland cement (45-60%): acts as an inorganic bonding matrix, providing early strength and chemical bonding with the substrate. 42.5R grade cement is preferred to ensure hydration activity.

[0029] Quartz sand (25-40%): Use 40-80 mesh graded sand as aggregate and control the bulk density at 1.6-1.8g / cm3 to enhance mechanical strength and prevent system shrinkage;

[0030] Polymer emulsion (10-18%): Ethylene-vinyl acetate copolymer emulsion (EVA) is used. Its film-forming property forms a continuous flexible network in the cement pores, reducing the elastic modulus of the bonding layer by 30-50%;

[0031] Polycarboxylate water reducer (0.5-2%): disperses cement particles through steric hindrance, reduces the water-binder ratio to 0.18-0.22, and improves the density of the paste;

[0032] Hydroxypropyl methylcellulose ether (0.2-1%): has the dual functions of water retention and thickening, extending the open time to more than 40 minutes and preventing quick drying and cracking.

[0033] B glue components:

[0034] Cycloaliphatic epoxy resin (35-55%): Select low viscosity (≤2000mPa·s) models to penetrate into the pores of tiles to form micro-anchors. The epoxy groups react with cement hydration products to form an organic-inorganic hybrid structure.

[0035] Modified amine curing agent (15-25%): A Mannich base curing agent with a rigid benzene ring structure that reacts with epoxy resin to form a cross-linked network with a glass transition temperature (Tg) of 80-100°C.

[0036] Polysulfide rubber toughening agent (8-20%): By grafting the thiol end group with the epoxy group, an elastic phase is introduced into the curing system, and the impact strength is increased by 2-3 times;

[0037] Silicone defoamer (0.5-2%): inhibits the generation of bubbles during stirring, ensures the density of the adhesive layer, and makes the gas content ≤2.5%;

[0038] Silane coupling agent (2-6%): γ-aminopropyltriethoxysilane (KH550) hydrolyzes and condenses during mixing to form Si-O-Si covalent bonds with the hydroxyl groups on the surface of the tiles.

[0039] The polymer emulsion in glue A is vinyl acetate-ethylene copolymer emulsion or styrene acrylic emulsion, and the glass transition temperature is -10℃ to 5℃.

[0040] Specifically, the polymer emulsion in glue A is selected from vinyl acetate-ethylene copolymer emulsion (VAE emulsion) or styrene-acrylate emulsion (styrene-acrylate copolymer emulsion). By controlling its glass transition temperature (Tg) between -10°C and 5°C, it can achieve improved flexibility in low temperature environments and enhanced crack resistance in high temperature and high humidity conditions. Specific mechanism of action:

[0041] Low-temperature adaptability is optimized. The molecular segments of VAE emulsion (Tg = -5°C) or styrene-acrylic emulsion (Tg = 3°C) still maintain mobility at low temperatures, giving the colloid deformation adaptability in the range of -5°C to 40°C.

[0042] The cement matrix is ​​toughened and crack-resistant. After the emulsion forms a film, it forms an interpenetrating network structure with a thickness of 50-200nm with the cement hydration products, reducing the colloidal elastic modulus from 15GPa of the pure cement system to 6-8GPa, and increasing the flexibility by more than 2 times. When the substrate is displaced by ±1.5mm, the emulsion film disperses the stress through microcrack bridging, and the critical fracture energy of the adhesive layer can reach 350-400J / m 2 (Pure cement system is only 80-100J / m 2 ), effectively inhibiting shrinkage and cracking of tiles after paving.

[0043] Interface bonding and humidity adaptability, the benzene ring of styrene acrylic emulsion and tile glaze enhance adsorption through π-π conjugation, the acetyloxy group (-OCOCH3) of VAE emulsion and Ca in cement 2+ A coordination bond is formed, and the two work together to make the tile-adhesive layer bond strength reach 1.8-2.3MPa. At the same time, the styrene acrylic emulsion with Tg = 3°C dynamically adsorbs water molecules through the carboxylic acid group (-COOH) in an environment with humidity > 85%, inhibiting hollowing caused by swelling and shrinkage, and the loss rate of wet bond strength is ≤8%.

[0044] The epoxy resin in glue B is an alicyclic epoxy resin with an epoxy value of 0.5-0.6eq / 100g, and the curing agent is a modified amine curing agent with an active hydrogen equivalent of 200-300g / eq; the toughening agent in glue B is polysulfide rubber or nano-silica modified epoxy resin with a particle size of 20-100nm, and the dosage is 10-15% of the weight of the epoxy resin.

[0045] Specifically, glue B constructs a high-permeability, high-toughness organic bonding system through the cooperation of alicyclic epoxy resin, modified amine curing agent and nano-toughening agent.

[0046] A cycloaliphatic epoxy resin with an epoxy value of 0.5-0.6 eq / 100g is selected. Its low viscosity (≤1500mPa·s) allows it to penetrate into the ceramic tile pores to a depth of 0.2-0.5mm within 5 minutes after mixing, forming a mechanical anchoring interface. Paired with a modified amine curing agent with an active hydrogen equivalent of 200-300g / eq, the molar ratio of epoxy groups to active hydrogen is precisely controlled to achieve gradient curing: the initial curing rate at 25°C is ≤0.05% / min, accelerating to 0.3% / min after 1 hour. Even in high-temperature environments (40°C), the pot life remains for more than 30 minutes, making it suitable for large-area paving needs.

[0047] The pot life after mixing glue A and glue B is 1.5-2 hours, and the initial fluidity of the mixed slurry is 200-250mm, and the fluidity loss rate within 60 minutes is ≤10%; the performance of the tile adhesive after curing meets the following requirements: 28-day tensile bonding strength ≥2.0MPa, lateral deformation capacity ≥4.0mm, and wet base bonding strength ≥1.5MPa.

[0048] Specifically, glue A and glue B are mixed in a ratio of 1:1 to form a highly adaptable slurry with an initial fluidity of 200-250mm and a fluidity loss rate of ≤10% within 60 minutes, ensuring construction uniformity; the application period is precisely controlled at 1.5-2 hours, and is extended to 1 hour at a high temperature of 35°C by adding 0.3% latent retarder to adapt to complex working conditions. After curing, the tensile bonding strength of the adhesive layer is ≥2.8MPa 28 days later, and the lateral deformation capacity reaches 4.0-5.2mm, far exceeding the C2TE grade standard (≥2.5mm), and can withstand a 3mm displacement of the substrate without cracking; the wet base surface bonding strength is ≥1.5MPa, which is 50% higher than that of traditional adhesives. Its core mechanism lies in the synergistic effect of the polymer emulsion of glue A and the epoxy toughening network of glue B, which achieves a balance between rigid support and flexible crack resistance, and completely solves the hidden dangers of hollowing and falling off.

[0049] A method for preparing a crack-resistant and highly flexible tile adhesive comprises the following steps:

[0050] S1. Prepare glue A: Mix silicate cement and quartz sand in a dry environment for 2-4 minutes, add polymer emulsion and stir at 600-800 rpm for 15-20 minutes, then add water reducer and cellulose ether and continue stirring for 5-10 minutes;

[0051] S2. Prepare glue B: Heat the epoxy resin to 40-50°C, add toughening agent, defoaming agent and coupling agent in sequence, stir for 20-30 minutes under vacuum degree of -0.06 to -0.08 MPa, and finally add curing agent and mix well;

[0052] S3. Construction mixing: First, pour the heating pack into the container, pour 2.5 liters of water into the container, then place glue A and glue B in the container and heat them with the heating pack. Pour glue A and glue B into the container in a 1:1 ratio, use an electric stirrer at 800-1000 rpm to stir for 3-5 minutes until the slurry is free of bubbles, lumps and uniform.

[0053] Specifically, A glue preparation

[0054] Raw material pretreatment: Portland cement should be grade 42.5R, with a specific surface area of ​​≥350m 2 / kg, dried at 80℃ to a moisture content of ≤0.3% before use; quartz sand adopts 40-70 mesh grading, and after washing and drying, the SiO2 content is ≥99% and the mud content is ≤0.02%;

[0055] Dry mixing process:

[0056] Place cement and quartz sand into a double-shaft zero-gravity mixer and dry mix at 250 rpm for 3 minutes at 25-30°C and humidity <40% to ensure that the aggregates evenly coat the cement particles and the coefficient of variation (CV) of mixing uniformity is ≤2%.

[0057] Wet mix modification: VAE emulsion (solid content 52%) was injected, and the mixture was switched to a planetary mixer and stirred at 700 rpm for 18 minutes. During this period, the slurry temperature was monitored to be ≤45°C to prevent emulsion demulsification. Polycarboxylate superplasticizer (water reduction rate 25%) and hydroxypropyl methylcellulose ether (viscosity 40,000 mPa·s) were added in sequence. The mixture was reduced to 400 rpm and stirred for 8 minutes to obtain a thixotropic slurry (initial fluidity 210±5 mm, fluidity loss ≤8% after 20 minutes of standing).

[0058] Preparation of B glue

[0059] Resin preheating: alicyclic epoxy resin (EPON826, epoxy value 0.55eq / 100g) was placed in a jacketed reactor, heated to 48±2°C, and the viscosity was reduced to 1200mPa·s at a constant temperature;

[0060] Nano-dispersion process: Add nano-silica (Aerosil200, specific surface area 200m 2 / g) and polysulfide rubber (JLY-124) were dispersed at 1200 rpm for 25 minutes under a vacuum degree of -0.07 MPa, and vacuum degassing was used to simultaneously deagglomerate the nanoparticles (D50 particle size ≤ 80 nm). γ-Aminopropyltriethoxysilane (KH550) was injected, and the vacuum condition was maintained and stirring was continued for 10 minutes to complete the in-situ grafting of the coupling agent.

[0061] Accurate incorporation of curing agent: Finally, add the modified amine curing agent (Ancamine 2049, active hydrogen equivalent 250 g / eq) and stir at a low speed of 500 rpm for 5 minutes. The gel time of the colloid is tested (58 ± 2 minutes at 25°C) to obtain a B glue with a viscosity of 2500 ± 200 mPa·s.

[0062] Construction Mix

[0063] First, pour the heating pack into the container, then pour 2.5 liters of water into the container, then put glue A and glue B in the container to heat, wait for 15-20 minutes, then glue A and glue B can be used normally

[0064] Proportional control: A:B=1:1 (weight ratio) synchronous output;

[0065] High shear mixing: Using a three-blade spiral stirrer, stir vigorously at 900 rpm for 4 minutes. The slurry goes through three stages:

[0066] Stage 1 (0-1 minute): Initial infiltration, epoxy resin wraps around cement particles to form a "core-shell" structure;

[0067] Stage 2 (1-3 minutes): Shear densification, gas content decreased from 4.5% to 2.1%;

[0068] Stage 3 (3-4 minutes): The rheology is stable and the slurry reaches a thixotropic index (TI) ≥ 3.5, meeting the anti-sagging requirements for vertical surface construction.

[0069] During the construction mixing step, the heating pack's function is to reduce the viscosity of glue A and glue B in low-temperature environments by raising the ambient temperature (to 40-50°C), optimizing winter applicability. When the ambient temperature is below 5°C, the polymer emulsion (such as VAE emulsion) in glue A and the epoxy resin in glue B will significantly increase in viscosity (the viscosity increases by 2-3 times) due to low-temperature conditions, making stirring difficult and mixing uneven. The heating pack heats the mixture through conduction, raising the temperature of glue A and glue B to 35-45°C, reducing the viscosity to 60-70% of the normal temperature state, restoring good fluidity.

[0070] Maintaining material properties: During the heating process, the temperature is controlled at 40-50°C to avoid exceeding the upper limit of the glass transition temperature of the polymer emulsion (-10°C to 5°C) and the thermal decomposition temperature of the epoxy resin (>60°C), ensuring that the flexible film-forming ability of glue A and the activity of the epoxy group of glue B are not affected.

[0071] Improved construction efficiency: After heating, the operability time (pot life) of glue A and glue B is maintained at 1.5-2 hours, and the initial fluidity of the mixed slurry reaches 200-250mm, meeting the needs of rapid construction in low temperature environments in winter and avoiding the problem of decreased bonding strength or construction hollowing due to excessive material thickness.

[0072] The slurry after stirring in S3 needs to be constructed within 1.5 hours, and the pot life is shortened to 1 hour when the construction environment temperature is higher than 30°C. The applicability is optimized in winter: the heating pack heats through conduction to raise the temperature of glue A and glue B to 35-45°C, and the viscosity is reduced to 60-70% of the normal temperature state, restoring good fluidity; the moisture content of glue A is ≤0.5%, the volatile content of glue B is ≤1%, and the air content of the mixed slurry is ≤3%; during construction, the scraping thickness of the back of the tile is ≥0.8mm, and the thickness uniformity deviation of the glue layer after scraping is ≤0.2mm, and the adhesive loss rate is ≤5%.

[0073] Specifically, the hydration reaction of cement in glue A and the cross-linking reaction of epoxy resin in glue B form a gradient curing, and the slurry remains workable within 1.5 hours.

[0074] The moisture content of A glue is ≤0.5%: by pre-treating the silicate cement (42.5R grade) by drying it at 80℃ and washing and drying the quartz sand to a SiO2 purity of ≥99%, the low moisture content of the dry mix system is ensured to avoid the polymer emulsion (VAE or styrene-acrylic emulsion) from demulsifying due to excessive water during the stirring process, and to maintain the continuity of the emulsion film (film thickness 50-200nm).

[0075] Volatile content of B glue ≤ 1%: After the epoxy resin is heated to 40-50°C and stirred in a vacuum environment of -0.06 to -0.08 MPa, it can effectively remove trace solvents in the toughening agent (polysulfide rubber) and coupling agent (KH550), while inhibiting the oxidation and volatilization of the alicyclic epoxy resin at high temperature, ensuring the stoichiometric accuracy of the cross-linked network (effective utilization rate of epoxy groups ≥ 95%).

[0076] The low moisture content and volatile matter enable the mixed slurry to form a dense organic-inorganic hybrid structure. The 28-day tensile bonding strength reaches 2.2-2.5MPa, and the wet base surface bonding strength is ≥1.6MPa, which significantly improves the interface bonding reliability.

[0077] The scraping thickness of the back of the tile is ≥0.8mm: the thickness of the glue layer is controlled by a toothed scraper to ensure that the glue fully fills the micropores on the back of the tile, forming a dual effect of mechanical anchoring and chemical bonding.

[0078] Thickness uniformity deviation ≤ 0.2mm: Use a scraper guide device with a scale and cooperate with construction personnel training to control the standard deviation of the adhesive layer thickness within ±0.15mm to avoid drying shrinkage and cracking caused by local excessive thickness and insufficient adhesion caused by excessive thinness.

[0079] Adhesive loss rate ≤ 5%: By optimizing the mixing process and scraper angle, the adhesive residue on the wall of the mixing barrel and the splashing of the scraping are reduced, which reduces the loss rate by 10-15% compared with the traditional process and improves material utilization.

[0080] Example 1

[0081] Formula composition

[0082] Glue A: Portland cement 50%, quartz sand 30% (40-70 mesh gradation), vinyl acetate-ethylene copolymer emulsion (VAE, solid content 52%) 15%, polycarboxylate superplasticizer (water reduction rate 25%) 1%, hydroxypropyl methylcellulose ether (viscosity 40,000 mPa·s) 0.5%;

[0083] Glue B: 45% alicyclic epoxy resin (EPON826, epoxy value 0.55eq / 100g), 20% modified amine curing agent (Ancamine2049, active hydrogen equivalent 250g / eq), 15% polysulfide rubber (JLY-124), 1% silicone defoamer, 4% γ-aminopropyltriethoxysilane (KH550);

[0084] Preparation method

[0085] S1 (preparation of gel A):

[0086] Place Portland cement (42.5R grade, moisture content ≤ 0.3%) and quartz sand (SiO2 ≥ 99%) into a twin-shaft mixer and dry mix at 250 rpm for 3 minutes at 25°C and humidity < 40%;

[0087] Inject VAE emulsion, switch to planetary mixer, and stir at high shear speed of 700 rpm for 18 minutes (slurry temperature ≤ 45°C);

[0088] Add water reducer and cellulose ether, reduce the speed to 400 rpm and stir for 8 minutes to obtain thixotropic glue A with a fluidity of 210 mm;

[0089] S2 (B glue preparation):

[0090] Heat the epoxy resin to 48°C until the viscosity reaches 1200 mPa·s;

[0091] Under a vacuum degree of -0.07 MPa, polysulfide rubber, defoaming agent, and coupling agent were added in sequence and dispersed at 1200 rpm for 25 minutes (D50 particle size ≤ 80 nm);

[0092] Add curing agent, stir at a low speed of 500 rpm for 5 minutes, and detect the gel time of 58 minutes to obtain glue B (viscosity 2500 mPa·s);

[0093] S3 (Construction Mix):

[0094] Inject the mixture into the container at a ratio of A:B = 1:1 and mix with a three-blade helical stirrer at 900 rpm for 4 minutes.

[0095] The slurry has an air content of ≤2.5%, a thixotropic index of ≥3.5, and a pot life of 1.5 hours;

[0096] Performance indicators

[0097] 28-day tensile bond strength: 2.8MPa;

[0098] Lateral deformation capacity: 5.2mm;

[0099] Wet base bonding strength: 1.8MPa;

[0100] Glue layer thickness uniformity deviation: ±0.15mm.

[0101] Implementation List 2

[0102] Formula composition

[0103] Glue A: Portland cement 55%, quartz sand 25% (40-80 mesh gradation), styrene acrylic emulsion (Tg = 3 ° C, solid content 50%) 16%, polycarboxylate water reducer 1.5%, hydroxypropyl methylcellulose ether 0.3%;

[0104] Glue B: alicyclic epoxy resin (TDE-85, epoxy value 0.6eq / 100g) 50%, modified amine curing agent (Ancamine1618, active hydrogen equivalent 280g / eq) 18%, nano-silica modified epoxy resin (Aerosil200, particle size 20-50nm) 12%, silicone defoamer 0.8%, silane coupling agent 3.2%;

[0105] Preparation method

[0106] S1 (preparation of gel A):

[0107] Portland cement (water content ≤ 0.5%) and quartz sand were dry mixed at 250 rpm for 3.5 minutes;

[0108] Add styrene acrylic emulsion and stir at 750 rpm for 17 minutes (temperature ≤ 42°C);

[0109] Add water reducing agent and cellulose ether, stir for 7 minutes, and obtain glue A with fluidity of 225 mm;

[0110] S2 (B glue preparation):

[0111] Preheat the epoxy resin to 45°C (viscosity 1500 mPa·s);

[0112] Nano-silica and defoamer were added under vacuum of -0.06 MPa and dispersed at 1000 rpm for 30 minutes;

[0113] Add curing agent and coupling agent, stir at low speed for 6 minutes, and gel time for 65 minutes;

[0114] S3 (Construction Mix):

[0115] The initial fluidity of the slurry after mixing is 235 mm, and the loss rate is 8% after 60 minutes;

[0116] The pot life is extended to 1.2 hours in a high temperature environment (35°C) (adding 0.3% retarder);

[0117] Performance indicators

[0118] 28-day tensile bond strength: 3.1MPa;

[0119] Lateral deformation capacity: 4.8mm;

[0120] Wet base bonding strength: 1.7MPa; Adhesive loss rate: 4.2%.

[0121]

[0122]

[0123] Among them, 28-day tensile bond strength: the ability of tile adhesive to resist tensile damage 28 days after curing (unit: MPa), reflects the degree of bonding between the adhesive layer and the tiles and substrate.

[0124] Wet base bond strength: the bond strength on a damp substrate (such as a wall that is not completely dry).

[0125] Crack and deformation resistance: After the tile adhesive is cured, it can withstand the maximum ability of transverse tension or compression deformation without cracking (unit: mm), reflecting the flexibility of the material.

[0126] Formula system, Example 1: Through cross-linking of elastic thiol chain segments with epoxy resin, an "elastic phase" is formed to disperse stress, and the impact strength is increased by 2-3 times. Example 2: Nanoparticles with a particle size of 20-50nm fill the pores of the adhesive layer, and through the "crack bridging" and "stress concentration and dispersion" mechanisms, the crack resistance is increased by 4 times.

[0127] Construction adaptability: The time that glue A and glue B remain in a construction state after mixing (such as the slurry does not harden and is easy to apply).

[0128] Through the above comparison, the embodiment is significantly superior to the existing technology in key indicators such as bonding strength, crack resistance, and construction convenience, and is particularly suitable for scenarios with high requirements for tile laying, such as high-rise buildings and humid environments.

[0129] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A crack-resistant and highly flexible tile adhesive, characterized in that: The invention is prepared by mixing glue A and glue B in a weight ratio of 1:1, and no water is added during the mixing process; the glue A contains the following components in weight percentage: 45-60% silicate cement, 25-40% quartz sand, 10-18% polymer emulsion, 0.5-2% water reducer, and 0.2-1% cellulose ether; the glue B contains the following components in weight percentage: 35-55% epoxy resin, 15-25% curing agent, 8-20% toughening agent, 0.5-2% defoaming agent, and 2-6% coupling agent.

2. The crack-resistant and highly flexible tile adhesive according to claim 1, characterized in that: The polymer emulsion in the A glue is vinyl acetate-ethylene copolymer emulsion or styrene acrylic emulsion, and the glass transition temperature is -10°C to 5°C.

3. The crack-resistant and highly flexible tile adhesive according to claim 1, characterized in that: The epoxy resin in the B glue is an alicyclic epoxy resin with an epoxy value of 0.5-0.6 eq / 100g, and the curing agent is a modified amine curing agent with an active hydrogen equivalent of 200-300 g / eq.

4. The crack-resistant and highly flexible tile adhesive according to claim 1, characterized in that: The toughening agent in the B glue is polysulfide rubber or nano-silicon dioxide modified epoxy resin, with a particle size of 20-100 nm and a dosage of 10-15% of the weight of the epoxy resin.

5. The crack-resistant and highly flexible tile adhesive according to claim 1, characterized in that: The pot life of the mixture of the A glue and the B glue is 1.5-2 hours, and the initial fluidity of the mixed slurry is 200-250 mm, and the fluidity loss rate within 60 minutes is ≤10%.

6. The crack-resistant and highly flexible tile adhesive according to claim 1, characterized in that: The performance of the tile adhesive after curing meets the following requirements: 28-day tensile bonding strength ≥2.0MPa, lateral deformation capacity ≥4.0mm, and wet base bonding strength ≥1.5MPa.

7. A method for preparing a crack-resistant and highly flexible tile adhesive, characterized in that: The crack-resistant and highly flexible tile adhesive according to any one of claims 1 to 5 comprises the following steps: S1. Prepare glue A: Mix silicate cement and quartz sand in a dry environment for 2-4 minutes, add polymer emulsion and stir at 600-800 rpm for 15-20 minutes, then add water reducer and cellulose ether and continue stirring for 5-10 minutes; S2. Prepare glue B: Heat the epoxy resin to 40-50°C, add toughening agent, defoaming agent and coupling agent in sequence, stir for 20-30 minutes under vacuum degree of -0.06 to -0.08 MPa, and finally add curing agent and mix well; S3. Construction mixing: First, pour the heating pack into the container, pour 2.5 liters of water into the container, then place glue A and glue B in the container and heat them with the heating pack. Pour glue A and glue B into the container in a 1:1 ratio, use an electric stirrer at 800-1000 rpm to stir for 3-5 minutes until the slurry is free of bubbles, lumps and uniform.

8. The method for preparing a crack-resistant and highly flexible tile adhesive according to claim 7, characterized in that: The slurry after stirring in S3 needs to be constructed within 1.5 hours, and the pot life is shortened to 1 hour when the construction environment temperature is higher than 30°C. The applicability is optimized in winter: the heating pack heats by conduction, so that the temperature of glue A and glue B rises to 35-45°C, and the viscosity is reduced to 60-70% of the normal temperature state, restoring good fluidity.

9. The method for preparing a crack-resistant and highly flexible tile adhesive according to claim 7, characterized in that: The water content of the glue A is ≤0.5%, the volatile matter content of the glue B is ≤1%, and the gas content of the slurry after mixing is ≤3%.

10. The method for preparing a crack-resistant and highly flexible tile adhesive according to claim 7, characterized in that: During construction, the scraping thickness of the back of the tile should be ≥0.8mm, and the uniformity deviation of the adhesive layer thickness after scraping should be ≤0.2mm, and the adhesive loss rate should be ≤5%.

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