Ceramic tile back adhesive and preparation method thereof

Abstract

The invention discloses a ceramic tile back adhesive and a preparation method thereof. The ceramic tile back adhesive is prepared from the following components in parts by mass: 40 to 50 parts of cement, 40 to 50 parts of fine aggregate, 3 to 8 parts of flexible polymer emulsion, 0.3 to 0.7 part of plasticizer, 0.2 to 0.5 part of dispersing agent, 0.1 to 0.3 part of defoaming agent, 0.1 to 0.3 part of preservative and 0.2 to 0.5 part of anti-ultraviolet agent. By optimizing the components, the adhesive property, the flexibility and the construction adaptability are improved. The preparation method disclosed by the invention adopts a step-by-step mixing process, and ensures full mixing and uniform dispersion of solid and liquid components by gradually adding different components and controlling the stirring speed and time.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and particularly relates to a tile back adhesive and a preparation method thereof. Background Art

[0002] With the rapid development of the building decoration industry, tiles have become an important material widely used in indoor and outdoor decoration, and the reliability, efficiency, and environmental friendliness of their paving processes have also been increasingly emphasized. Traditional tile pasting methods mostly rely on cement mortar, but this method has problems such as unstable bonding performance, complex construction, and insufficient flexibility, making it difficult to meet the higher requirements of modern buildings for bonding materials in terms of strength, flexibility, and durability. In addition, the cracking and hollowing phenomena caused by temperature changes or long-term use directly affect the overall quality of building decoration.

[0003] In recent years, tile back adhesives, as a new type of bonding material, have gradually replaced traditional cement mortar. By introducing polymer modified materials and various additives, they can significantly improve the bonding strength and construction efficiency. However, existing tile back adhesives still have some technical bottlenecks. For example, their flexibility is insufficient and it is difficult to adapt to the deformation of the construction substrate; their ultraviolet resistance and anti-aging performance are limited, resulting in a short service life in outdoor environments; some formulations contain plasticizers or other chemical components that are unfriendly to humans and the environment, and cannot meet the development trend of modern green building materials. In addition, the optimization of existing technologies in terms of formulation design and preparation processes is insufficient, and problems such as uneven dispersion of the bonding layer and poor workability are likely to occur, affecting the actual application effect. Summary of the Invention

[0004] The purpose of the present invention is to provide a tile back adhesive and a preparation method thereof to at least solve the above technical problems.

[0005] To achieve the above purpose, the technical scheme adopted by the present invention is as follows:

[0006] On the one hand, a tile back adhesive is provided, which includes the following components in parts by mass: 40 - 50 parts of cement, 40 - 50 parts of fine aggregate, 3 - 8 parts of flexible polymer emulsion, 0.3 - 0.7 parts of plasticizer, 0.2 - 0.5 parts of dispersant, 0.1 - 0.3 parts of defoamer, 0.1 - 0.3 parts of preservative, and 0.2 - 0.5 parts of anti-ultraviolet agent.

[0007] Further, the cement is Portland cement with a fineness of 20 - 30 μm and an alkali content < 0.6%.

[0008] Cement, as the core cementitious material of tile back glue (adhesive), its selection needs to be based on the durability and strength characteristics required for construction. The present invention preferably uses low-alkalinity portland cement. By adjusting its particle fineness (average fineness 20 - 30μm, alkali content <0.6%), the best bonding effect and construction performance can be achieved. In addition, the alkali content (Na2O equivalent) of portland cement needs to be controlled below 0.6% to effectively avoid the performance degradation caused by alkali-aggregate reaction and ensure the stability of long-term bonding performance.

[0009] Furthermore, the fine aggregate is natural quartz sand, with a particle size range of 50 - 100 mesh, water content <0.1%, and iron content <0.05%.

[0010] Fine aggregate mainly plays a role of filling and strengthening in tile back glue. To ensure the stability of the bonding layer, the present invention selects natural quartz sand with a particle size range of 50 - 100 mesh. The natural quartz sand is dried, and the water content is controlled below 0.1%, which can improve the construction performance. The iron content of the fine aggregate is less than 0.05% to avoid adverse reactions with cement. The reasonable grading of 50 - 100 mesh can optimize the density of the bonding layer, improve the shear strength and anti-aging performance, and meet the high-performance requirements of complex construction scenarios.

[0011] Furthermore, the flexible polymer emulsion is styrene-acrylate copolymer emulsion, with a solid content of 50 - 55% and a particle size range of 100 - 300nm.

[0012] The flexible polymer emulsion is the core component to improve the flexibility and crack resistance of the adhesive. The present invention selects styrene-acrylate copolymer emulsion, with a solid content of 50% - 55% and a particle size range of 100 - 300nm. After the bonding layer is cured, this emulsion forms a continuous phase structure with a high elastic modulus, which can absorb the stress caused by temperature changes and improve the crack resistance. In addition, the emulsion formula is optimized by combining emulsifiers and initiators to ensure uniform product particle size and long-term storage stability.

[0013] Furthermore, the styrene-acrylate copolymer emulsion includes the following components in parts by mass: 45 - 55 parts of styrene monomer, 45 - 55 parts of acrylate monomer, 2 - 4 parts of emulsifier, 0.5 - 1.0 part of initiator, 0.5 - 1.0 part of buffer, 100 - 150 parts of deionized water. The acrylate monomer is preferably butyl acrylate or methyl methacrylate, the emulsifier is preferably alkylphenol polyoxyethylene ether or fatty alcohol polyoxyethylene ether, the initiator is preferably ammonium persulfate or hydrogen peroxide, and the buffer is preferably sodium bicarbonate or sodium dihydrogen phosphate.

[0014] Furthermore, the preparation method of the styrene-acrylate copolymer emulsion is as follows:

[0015] (1) Emulsification stage: Dissolve the emulsifier in deionized water, stir evenly to obtain an emulsion, and heat it up to 50 - 60 °C.

[0016] (2) Polymerization stage: Drop styrene monomer and acrylate monomer into the emulsion, and at the same time add an initiator to carry out a polymerization reaction. The polymerization reaction temperature is 70 - 80 °C.

[0017] (3) Stabilization and cooling stage: After the polymerization reaction is completed, add a buffer to adjust the pH value to 6 - 7 and stir evenly, then cool to room temperature and filter to obtain a styrene - acrylate copolymer emulsion.

[0018] After adding the buffer, stir evenly to enhance the storage stability of the emulsion. Cooling and filtering ensure uniform particle size and no gel phenomenon.

[0019] Furthermore, the plasticizer is a citrate plasticizer.

[0020] The plasticizer maintains the fluidity of the adhesive while enhancing the high - temperature resistance performance and can maintain stability in an environment above 50 °C. The present invention uses a citrate plasticizer to replace the traditional phthalate plasticizer, which not only improves the high - temperature resistance performance but also reduces the potential harm to the human body and the environment.

[0021] Furthermore, the dispersant is an anionic dispersant containing a carboxyl functional group, and the molecular weight is 3000 - 5000 daltons.

[0022] The dispersant is used to improve the dispersion uniformity of each component, thereby enhancing the overall bonding performance. The present invention selects an anionic dispersant containing a carboxyl functional group, which can form a stable adsorption layer on the surface of cement particles, prevent particle aggregation, and improve the stability of the mixture during construction.

[0023] Furthermore, the defoamer is a polyether - modified silicone defoamer with a surface tension < 22 mN / m; the preservative is sodium dichloroisocyanurate; the ultraviolet absorber is a bisphenol A - type ultraviolet absorber with an absorption peak range of 280 - 400 nm.

[0024] The defoamer is used to reduce the bubbles generated due to air entrainment during the mixing process, thereby enhancing the strength and density of the bonding layer. The present invention uses a polyether - modified silicone defoamer, which continuously releases bubbles before and after construction to avoid the phenomenon of surface hollowing during construction.

[0025] The addition of the preservative aims to improve the storage stability of the adhesive and prevent the erosion of molds and bacteria. The present invention uses sodium dichloroisocyanurate, which has strong oxidizing properties and has a strong bactericidal effect on various pathogenic microorganisms such as viruses, bacterial spores, and fungi.

[0026] The addition of the anti-ultraviolet agent is mainly used to improve the weather resistance of the adhesive. The present invention uses a bisphenol A type ultraviolet absorber, which can significantly improve the anti-aging performance of the bonding layer by efficiently absorbing ultraviolet light and is suitable for outdoor environments with long-term exposure.

[0027] On the other hand, a method for preparing a tile back adhesive is provided, including the following steps:

[0028] S1. Mix fine aggregate and cement evenly by low-speed stirring, and gradually add a dispersant during the stirring process; preferably, the rotation speed of the low-speed stirring is 50-100 r / min, and the stirring time is 5-10 min;

[0029] S2. Continue stirring, slowly add a flexible polymer emulsion, and then add a plasticizer, an antifoaming agent and a preservative in batches, and stir for 2-3 min after each addition;

[0030] S3. Finally, add the anti-ultraviolet agent and stir at high speed to obtain the tile back adhesive; preferably, the rotation speed of the high-speed stirring is 300-500 r / min, and the stirring time is 8-15 min.

[0031] The tile back adhesive obtained by the above preparation method can be further detected and adjusted.

[0032] Detection: Take samples of the tile back adhesive and detect its bonding strength, flexibility and workability parameters to ensure compliance with the design requirements.

[0033] Adjustment: Appropriately increase the flexible polymer emulsion or plasticizer to improve flexibility, or increase the proportion of fine aggregate to enhance the bonding strength.

[0034] Through the addition performance detection, key indicators such as bonding strength, flexibility and workability are evaluated in real time and the formulation is adjusted to ensure the reliability and consistency of the finished product quality.

[0035] Finally, the tested and adjusted tile back adhesive is packaged and stored.

[0036] Remove impurities from the tile back adhesive through a filtering device to ensure the fineness and uniformity of the finished product; then package it in a sealed container and store it in a cool and dry place, avoiding direct sunlight and high-temperature environments.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention optimizes each component to improve the bonding performance, flexible performance and construction adaptability. The highest bonding strength reaches 1.4 MPa, which is about 20-40% higher than that of the prior art; the flexibility is significantly improved, and the elongation rate reaches 30%, meeting the dynamic stress requirements of complex construction scenarios.

[0039] 2. The preparation method of the present invention adopts a step-by-step mixing process. By gradually adding different components and controlling the stirring rate and time, the full mixing and uniform dispersion of solid and liquid components are ensured. Finally, the ultraviolet absorber is distributed through a high-speed stirring stage to further improve the colloidal uniformity and performance stability. Detailed implementation manners

[0040] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further details the present invention in conjunction with embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0041] In the embodiments of the present invention, the cement is Portland cement with a fineness of 20 - 30 μm and an alkali content of < 0.6%.

[0042] In the embodiments of the present invention, the fine aggregate is natural quartz sand with a particle size range of 50 - 100 mesh, a moisture content of < 0.1%, and an iron content of < 0.05%.

[0043] In the embodiments of the present invention, the flexible polymer emulsion is a styrene-acrylate copolymer emulsion with a solid content of 50 - 55% and a particle size range of 100 - 300 nm.

[0044] In the embodiments of the present invention, the styrene-acrylate copolymer emulsion comprises the following components in parts by mass: 45 - 55 parts of styrene monomer, 45 - 55 parts of acrylate monomer, 2 - 4 parts of emulsifier, 0.5 - 1.0 part of initiator, 0.5 - 1.0 part of buffer, and 100 - 150 parts of deionized water. The acrylate monomer is preferably butyl acrylate or methyl methacrylate, the emulsifier is preferably alkylphenol polyoxyethylene ether or fatty alcohol polyoxyethylene ether, the initiator is preferably ammonium persulfate or hydrogen peroxide, and the buffer is preferably sodium bicarbonate or sodium dihydrogen phosphate.

[0045] In the embodiments of the present invention, the preparation method of the styrene-acrylate copolymer emulsion is as follows:

[0046] (1) Dissolve the emulsifier in deionized water, stir evenly to obtain an emulsion, and heat it to 50 - 60 °C;

[0047] (2) Dropwise add the styrene monomer and acrylate monomer into the emulsion, and at the same time add the initiator for polymerization reaction. The polymerization reaction temperature is 70 - 80 °C;

[0048] (3) After the polymerization reaction is completed, add the buffer to adjust the pH value to 6 - 7, stir evenly, then cool to room temperature and filter to obtain the styrene-acrylate copolymer emulsion.

[0049] In the embodiments of the present invention, the plasticizer is a citrate plasticizer.

[0050] In the embodiments of the present invention, the defoamer is a polyether-modified silicone defoamer with a surface tension < 22 mN / m; the preservative is sodium dichloroisocyanurate; the ultraviolet absorber is a bisphenol A type ultraviolet absorber with an absorption peak range of 280 - 400 nm.

[0051] Example 1

[0052] As a preferred embodiment of the present invention, the specific composition of the tile back adhesive in this embodiment is shown in Table 1 below.

[0053] Table 1

[0054]

[0055]

[0056] Prepare the tile back adhesive of this embodiment according to the mass parts of each component in Table 1:

[0057] S1. Mix 45 parts of fine aggregate and 45 parts of cement evenly by low-speed stirring at a speed of 100 r / min for 5 min, and gradually add 0.3 part of dispersant during the stirring process;

[0058] S2. Continue stirring, slowly add 6 parts of flexible polymer emulsion and stir for 5 min, then add 0.5 part of plasticizer, 0.2 part of defoamer and 0.2 part of preservative in batches, and stir for 3 min after each addition;

[0059] S3. Finally, add 0.4 part of ultraviolet absorber and stir at high speed at a speed of 300 r / min for 8 min to obtain the tile back adhesive.

[0060] Detect the bonding strength, flexibility and construction performance parameters of the tile back adhesive of this embodiment. The detection results are as follows:

[0061] Bonding strength: 1.2 MPa;

[0062] Flexibility: elongation rate 25%;

[0063] Water resistance: the bonding strength remains above 95% after immersion in water;

[0064] Ultraviolet resistance: no cracking after 200 hours of ultraviolet light irradiation.

[0065] Example 2

[0066] As a preferred embodiment of the present invention, the specific composition of the tile back adhesive in this embodiment is shown in Table 2 below.

[0067] Table 2

[0068]

[0069]

[0070] Prepare the tile back adhesive of this example according to the parts by mass of each component in Table 2:

[0071] S1. Mix 50 parts of fine aggregate and 40 parts of cement evenly by low-speed stirring at a rotation speed of 80 r / min for 6 min, and gradually add 0.4 part of dispersant during the stirring process;

[0072] S2. Continue stirring, slowly add 8 parts of flexible polymer emulsion and stir for 6 min, then add 0.6 part of plasticizer, 0.3 part of defoamer and 0.1 part of preservative in batches, and stir for 3 min after each addition;

[0073] S3. Finally, add 0.2 part of ultraviolet light absorber and stir at a high speed of 400 r / min for 8 min to obtain the tile back adhesive.

[0074] Detect the bonding strength, flexibility and construction parameters of the tile back adhesive of this example, and the test results are as follows:

[0075] Bonding strength: 1.4 MPa;

[0076] Flexibility: elongation rate 30%;

[0077] Water resistance: the bonding strength remains above 98% after immersion in water;

[0078] Ultraviolet resistance: no cracking after 200 hours of ultraviolet light irradiation.

[0079] Example 3

[0080] As a relatively preferred example of the present invention, the specific composition of the tile back adhesive in this example is shown in Table 3 below.

[0081] Table 3

[0082] Composition Parts by mass / part Cement 50 Fine aggregate 40 Flexible polymer emulsion 5 Plasticizer 0.4 Dispersant 0.5 Defoamer 0.1 Preservative 0.3 UV absorber 0.5

[0083] Prepare the tile back adhesive of this example according to the parts by mass of each component in Table 2:

[0084] S1. Mix 40 parts of fine aggregate and 50 parts of cement evenly by low-speed stirring at a rotation speed of 120 r / min for 6 min, and gradually add 0.5 part of dispersant during the stirring process;

[0085] S2. Continue stirring and slowly add 5 parts of the flexible polymer emulsion and stir for 4 minutes. Then, add 0.4 part of the plasticizer, 0.1 part of the defoamer, and 0.3 part of the preservative in batches, and stir for 3 minutes after each addition.

[0086] S3. Finally, add 0.5 part of the anti-ultraviolet agent and stir at a high speed of 500 r / min for 10 minutes to obtain the tile back adhesive.

[0087] The bonding strength, flexibility, and workability parameters of the tile back adhesive in this example were tested, and the test results are as follows:

[0088] Bonding strength: 1.1 MPa;

[0089] Flexibility: elongation rate of 20%;

[0090] Water resistance: the bonding strength remains above 92% after immersion in water;

[0091] Ultraviolet resistance: no cracking after 150 hours of ultraviolet light irradiation;

[0092] Aging resistance: the performance shows no obvious decline after simulating 5 years of aging.

[0093] Comparative Example 1

[0094] The tile back adhesive in this comparative example is the same as that in Example 1 except that it does not contain the flexible polymer emulsion.

[0095] The bonding strength, flexibility, and workability parameters of the tile back adhesive in this comparative example were tested, and the test results are as follows:

[0096] Bonding strength: 0.8 MPa;

[0097] Flexibility: elongation rate of 10%;

[0098] Water resistance: the bonding strength remains above 80% after immersion in water;

[0099] Poor workability, and the bonding layer is prone to cracking.

[0100] Comparative Example 2

[0101] The tile back adhesive in this comparative example is the same as that in Example 2 except that the anti-ultraviolet agent is reduced to 0.1 part.

[0102] The bonding strength, flexibility, and workability parameters of the tile back adhesive in this comparative example were tested, and the test results are as follows:

[0103] Bonding strength: 1.3 MPa;

[0104] Flexibility: elongation rate of 28%;

[0105] Water resistance: The bonding strength remains above 97% after immersion in water;

[0106] UV resistance: Cracking occurs after 100 hours of UV light irradiation.

[0107] Comparative Example 3

[0108] The tile back adhesive of this comparative example is the same as that of Example 2 except that the solid content of the flexible polymer emulsion is 40 - 55%.

[0109] The bonding strength, flexibility and workability parameters of the tile back adhesive of this comparative example were tested, and the test results are as follows:

[0110] Bonding strength: 1.0 MPa;

[0111] Flexibility: Elongation rate 20%;

[0112] Water resistance: The bonding strength remains 85% after immersion in water;

[0113] UV resistance: Slight cracking occurs after 150 hours of UV light irradiation.

[0114] Comparative Example 4

[0115] The tile back adhesive of this comparative example is the same as that of Example 2 except that the particle size range of the flexible polymer emulsion is 50 - 100 nm.

[0116] The bonding strength, flexibility and workability parameters of the tile back adhesive of this comparative example were tested, and the test results are as follows:

[0117] Bonding strength: 0.9 MPa

[0118] Flexibility: Elongation rate 18%

[0119] Water resistance: The bonding strength remains 80% after immersion in water;

[0120] UV resistance: Obvious cracking occurs after 120 hours of UV light irradiation.

[0121] Comparative Example 5

[0122] The tile back adhesive of this comparative example is the same as that of Example 2 except that the alkali content of the portland cement > 0.6%.

[0123] The bonding strength, flexibility and workability parameters of the tile back adhesive of this comparative example were tested, and the test results are as follows:

[0124] Bonding strength: 0.85 MPa;

[0125] Flexibility: Elongation rate 15%;

[0126] Water resistance: The bonding strength remains 70% after immersion in water;

[0127] UV resistance: Severe cracking occurs after 100 hours of UV irradiation.

[0128] From the bonding strength, flexibility and workability parameters of the tile back adhesives in each example and comparative example, it can be seen that:

[0129] Bonding strength:

[0130] The bonding strength of Example 2 (1.4 MPa) performs the best, while the bonding strengths of Comparative Examples 3, 4, and 5 decrease by about 28.6%, 35.7%, and 39.3% respectively. The main reason is that the changes in the solid content, particle size of the flexible polymer emulsion and the cement alkali content all affect the uniformity and strength formation of the bonding layer.

[0131] Flexibility:

[0132] The flexibility of Example 2 (30% elongation) is better than that of other comparative examples. Comparative Example 3 (20% elongation), Comparative Example 4 (18% elongation) and Comparative Example 5 (15% elongation) all show a decrease in flexibility. Especially when the cement alkali content is relatively high (Comparative Example 5), the flexible effect will be further weakened.

[0133] Water resistance:

[0134] Example 2 has the best water resistance, and the retention rate of the bonding strength after immersion in water is 95%. Comparative Example 3 (85%), Comparative Example 4 (80%), and Comparative Example 5 (70%) decrease in turn, indicating that the increase in the cement alkali content has the most significant impact on the water resistance.

[0135] UV resistance:

[0136] There is no cracking in Example 2 after 200 hours of UV irradiation. Comparative Example 3 (slight cracking after 150 hours), Comparative Example 4 (obvious cracking after 120 hours), and Comparative Example 5 (severe cracking after 100 hours) show that with the change of the formula, the UV resistance deteriorates significantly.

[0137] Specifically, the solid content of the flexible polymer emulsion in Comparative Example 3 is relatively low, resulting in insufficient film-forming performance of the emulsion, affecting the integrity and flexible effect of the bonding layer. The bonding strength and flexibility decrease by about 28.6% and 33.3% respectively compared with Example 2. The UV resistance is also significantly affected, and microcracks appear on the surface after 150 hours of UV irradiation.

[0138] Specifically, in Comparative Example 4, the decrease in the particle size range of the flexible polymer emulsion results in a decrease in the distribution uniformity of the emulsion on the substrate surface, forming a thinner and uneven adhesive layer structure, with the adhesive strength reduced by about 35.7% and the flexibility reduced by about 40%. In addition, too small particle size of the emulsion easily leads to deterioration of the photoaging performance and poor ultraviolet resistance performance.

[0139] Specifically, in Comparative Example 5, the high alkali content in the cement leads to a decrease in the chemical stability of the system. The excessive alkali components are likely to generate inferior ettringite-like by-products during the hydration reaction, reducing the strength and stability of the adhesive layer. The adhesive strength decreases by about 39.3% and the flexibility decreases by about 50%. At the same time, due to the increase in the alkali content, the water resistance performance deteriorates significantly, and the water resistance after immersion drops from 98% in Example 2 to 70%. After 100 hours of ultraviolet light irradiation, serious cracks appear in the adhesive layer.

[0140] In summary, the adhesive performance of the tile back glue of the present invention is significantly improved: the highest adhesive strength reaches 1.4 MPa, which is about 20 - 40% higher than that of the prior art; the flexibility is significantly improved, and the elongation rate reaches 30%, meeting the dynamic stress requirements of complex construction scenarios.

[0141] The weather resistance of the tile back glue of the present invention is greatly enhanced: after adding an anti-ultraviolet agent, the adhesive layer does not crack after 200 hours of ultraviolet irradiation, and the anti-aging performance is significantly better than that of traditional tile back glue, ensuring the reliability of long-term use indoors and outdoors.

[0142] In addition, the tile back glue of the present invention has prominent green environmental protection advantages: by using environment-friendly plasticizers and functional additives, the potential pollution to the environment is reduced, meeting the development trend of modern green building materials; the construction performance and product stability are optimized synchronously: by improving the uniformity and fluidity of the adhesive layer during construction, problems such as hollowing and cracking are avoided, and at the same time, the performance consistency in mass production is ensured.

[0143] In summary, the present invention breaks through the limitations of the prior art in terms of adhesive strength, flexibility, weather resistance and environmental protection performance, providing a relatively reliable solution for the research and application of high-performance tile back glue to a certain extent.

[0144] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, rather than limiting it, and certainly not limiting the patent scope of the present invention; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; that is to say, any meaningless changes or polishing made in the main design concept and spirit of the present invention, as long as the technical problems solved by it are still consistent with the present invention, should be included in the protection scope of the present invention; in addition, directly or indirectly applying the technical solutions of the present invention to other related technical fields shall also be included in the patent protection scope of the present invention by the same token.

Claims

1. A tile adhesive, characterized in that: The invention comprises the following components in parts by mass: 40-50 parts of cement, 40-50 parts of fine aggregate, 3-8 parts of flexible polymer emulsion, 0.3-0.7 parts of plasticizer, 0.2-0.5 parts of dispersant, 0.1-0.3 parts of defoaming agent, 0.1-0.3 parts of preservative and 0.2-0.5 parts of anti-ultraviolet agent.

2. A tile adhesive according to claim 1, characterized in that: The cement is silicate cement with a fineness of 20-30 μm and an alkali content of less than 0.6%.

3. The tile adhesive according to claim 1, characterized in that: The fine aggregate is natural quartz sand with a particle size range of 50-100 meshes, a moisture content of less than 0.1%, and an iron content of less than 0.05%.

4. The tile adhesive according to claim 1, characterized in that: The flexible polymer emulsion is a styrene-acrylate copolymer emulsion with a solid content of 50-55% and a particle size range of 100-300nm.

5. The tile adhesive according to claim 4, characterized in that: The styrene-acrylate copolymer emulsion comprises the following components in parts by mass: 45-55 parts of styrene monomer, 45-55 parts of acrylate monomer, 2-4 parts of emulsifier, 0.5-1.0 parts of initiator, 0.5-1.0 parts of buffer, and 100-150 parts of deionized water. The acrylate monomer is preferably butyl acrylate or methyl methacrylate, the emulsifier is preferably alkylphenol polyoxyethylene ether or fatty alcohol polyoxyethylene ether, the initiator is preferably ammonium persulfate or hydrogen peroxide, and the buffer is preferably sodium bicarbonate or sodium dihydrogen phosphate.

6. The tile adhesive according to claim 5, characterized in that: The preparation method of the styrene-acrylate copolymer emulsion is as follows: (1) dissolving an emulsifier in deionized water, stirring to obtain an emulsion and heating the emulsion to 50-60° C.; (2) adding styrene monomer and acrylate monomer dropwise into the emulsion, and simultaneously adding an initiator to carry out a polymerization reaction at a polymerization reaction temperature of 70 to 80° C.; (3) After the polymerization reaction is completed, a buffer is added to adjust the pH value to 6-7 and stirred evenly, then cooled to room temperature and filtered to obtain a styrene-acrylate copolymer emulsion.

7. The tile adhesive according to claim 1, characterized in that: The plasticizer is a citrate plasticizer.

8. The tile adhesive according to claim 1, characterized in that: The dispersant is an anionic dispersant containing a carboxyl functional group, and the molecular weight is 3000 to 5000 Daltons.

9. The tile adhesive according to claim 1, characterized in that: The defoaming agent is a polyether-modified siloxane defoaming agent with a surface tension of less than 22 mN / m; the preservative is sodium dichloroisocyanurate; and the anti-ultraviolet agent is a bisphenol A type ultraviolet absorber with an absorption peak range of 280 to 400 nm.

10. A method for preparing a tile adhesive according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Mix the fine aggregate and cement uniformly by stirring at a low speed, and gradually add the dispersant during the stirring process; preferably, the rotation speed of the low-speed stirring is 50 to 100 r / min, and the stirring time is 5 to 10 min; S2, continue stirring, slowly add the flexible polymer emulsion, and then add the plasticizer, defoamer and preservative in batches, stirring for 2 to 3 minutes after each addition; S3. Finally, add an anti-ultraviolet agent and stir at high speed to obtain tile adhesive; preferably, the rotation speed of the high-speed stirring is 300-500 r / min, and the stirring time is 8-15 min.

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