A high-strength liquid tile adhesive and its preparation method

Abstract

The present invention discloses a preparation method of a high-strength liquid tile adhesive, comprising the following steps: S1, preparation of a composite filler; S2, preparation of a modified polyurethane; S3, preparation of a modified epoxy resin; S4, preparation of a liquid tile adhesive. This liquid tile adhesive, by using the modified composite filler, polyurethane, and modified epoxy resin as the main raw materials, has excellent interfacial bonding properties and mechanical properties. It can not only ensure the convenience of construction but also significantly improve the bonding strength between the tile and the substrate.

Description

Technical Field

[0001] The present invention belongs to the technical field of adhesives, and particularly relates to a high-strength liquid tile adhesive and a preparation method thereof. Background Art

[0002] Tiles are building materials widely used in the building materials field. Whether it is for floor or wall decoration, tiles are relatively common building materials. Tile adhesives are key materials in the process of tile bonding, especially for wall tiles, and their formulation technology has a significant impact on the service life of tiles.

[0003] Currently, common tile adhesives include dry-hard mortar plus cement oil, mortar mixed with building glue, cement-based dry powder tile adhesives, and tile back adhesives. Dry-hard mortar cement oil is a traditional tile adhesive. It has a large consumption per square meter. Workers mix the materials on-site, and the mixing ratio is adjusted according to the on-site situation, which is not suitable for automated construction that requires a determined mixing ratio. Moreover, since medium-coarse river sand is used in dry-hard mortar, the fluidity is poor, which is also very unfavorable for automated construction. In addition, the material properties of cement oil are unstable, and there will be problems of blocked pipes during machine construction due to poor transportation. Also, the bonding strength between dry-hard mortar cement oil and tiles is low, and late-stage hollowing is likely to occur. Mortar mixed with building glue is also commonly used in the paving of wall tiles in building construction. Similarly, workers mix the materials on-site, and the mixing ratio is adjusted according to the on-site situation, which is not suitable for automated construction that requires a determined mixing ratio. Moreover, if machine automated construction is adopted, during the process of machine transfer and material transportation in long pipelines, its bonding performance is difficult to guarantee. In addition, building glue has poor water resistance, and tile dropping is likely to occur in the high-humidity environment of the bathroom. One-component tile back adhesives are mainly prepared from polymer emulsion, and then combined with additives such as defoamers, dispersants, and mildew inhibitors. Although they are convenient to use and have low costs, they generally have disadvantages such as low bonding strength, poor water resistance, anti-aging ability, and durability.

[0004] In the prior art, Chinese Patent Application CN113845802A discloses a waterproof coating composition, a waterproof coating, and a preparation method and application thereof. The composition contains a polymer emulsion, a silicate solution, a filler, quartz sand, a thickener, a preservative, an antifoaming agent, water, and an inorganic color paste; the polymer emulsion is a styrene-acrylic emulsion with a glass transition temperature of 20-30°C and a solid content of 47-48 wt%; the silicate solution is selected from at least one of potassium silicate solution and sodium silicate solution. The waterproof coating prepared from the waterproof coating composition provided by this invention has a relatively high bonding strength and a relatively low film shrinkage rate. However, the bonding strength of this coating to tiles is very low and it cannot be used as a tile adhesive for pasting tiles. Chinese Patent Application CN116715811A discloses a two-component tile back adhesive emulsion, which includes the following components in parts by weight: 33-110 parts of styrene, 303-410 parts of n-butyl acrylate, 105-215 parts of isooctyl acrylate, 7-11 parts of β-carboxyethyl acrylate, 14-20 parts of hydroxyethyl methacrylate, 2.4-4 parts of acrylamide, 3.5-6 parts of ethyl acetoacetate methacrylate, 0.4-0.8 parts of antifoaming agent, 1.8-2.5 parts of fungicide, 0.6-2 parts of initiator, 4.5-13 parts of emulsifier, and 3-6 parts of curing agent. The back adhesive emulsion of this invention does not contain APEO, and has no formaldehyde, no ammonia, and no other pollution emissions. The product has very good stability, solves the problems of poor water resistance and low bonding strength of two-component tile back adhesive emulsions, and at the same time has advantages such as good powder compatibility and good toughness. The final product has excellent performance and is green and environmentally friendly. However, the bonding strength and water resistance of the tile back adhesive of this invention still need to be further improved. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a high-strength liquid tile adhesive and a preparation method thereof. This tile adhesive has the characteristics of high bonding strength and good water resistance. After using this high-strength liquid tile adhesive to lay tiles, the tiles are not prone to falling off, and the service life and use safety of the tiles are improved.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A preparation method of a high-strength liquid tile adhesive, comprising the following steps:

[0008] S1. Preparation of composite filler: Add montmorillonite to deionized water, then add cetyltrimethylammonium bromide, stir, and after stirring is completed, add ethanol, tetrabutyl titanate, and ammonia water for hydrothermal reaction. After the reaction is completed, filter, wash, and dry to obtain a solid product; Subsequently, add the solid product to an ethanol aqueous solution, then add vinyltrimethoxysilane, stir and react, and after the reaction is completed, filter, wash, and dry to obtain the composite filler;

[0009] S2. Preparation of modified polyurethane: Mix polytetrahydrofuran diol, the composite filler in step S1, diethylenetriamine, sodium dodecyl sulfate, and ethyl acetate, stir at 50 - 60 °C for 0.5 - 1 h, then add isophorone diisocyanate, pentaerythritol stearate, polyether-modified polydimethylsiloxane, and stannous octoate, and carry out a heating reaction. After the reaction is completed, the modified polyurethane is obtained.

[0010] S3. Preparation of modified epoxy resin: Add epoxy resin to a mixed solvent of ethyl acetate and xylene, then add γ-aminopropyltriethoxysilane, 4-amino-3-fluoroallyl benzoate, and triphenylphosphine, and carry out a constant-temperature reaction. After the reaction is completed, the modified epoxy resin is obtained.

[0011] S4. Preparation of liquid tile adhesive: Add the modified epoxy resin in step S3 to the modified polyurethane in step S2, then add polyvinyl alcohol and azobisisobutyronitrile, and stir. After stirring is completed, remove ethyl acetate under reduced pressure to obtain the liquid tile adhesive.

[0012] Preferably, in step S1, the mass ratio of montmorillonite, deionized water, cetyltrimethylammonium bromide, ethanol, tetrabutyl titanate, and ammonia water is 50 - 60:700 - 800:3 - 5:200 - 300:60 - 70:80 - 90, and the mass fraction of ammonia water is 10 - 15%; the temperature of the hydrothermal reaction is 110 - 120 °C, and the time is 7 - 9 h.

[0013] Preferably, in step S1, the mass fraction of ethanol in the ethanol aqueous solution is 70 - 80%, and the mass ratio of the solid product to vinyltrimethoxysilane is 70 - 80:6 - 10; the temperature of the stirring reaction is 60 - 70 °C, and the time is 2 - 3 h.

[0014] In the present invention, montmorillonite is organically modified with cetyltrimethylammonium bromide to increase the layer spacing, and then titanium dioxide is generated on montmorillonite by hydrothermal method. On the one hand, the roughness of the montmorillonite lamellae is increased, the mechanical interlocking between montmorillonite and the polyurethane matrix is enhanced, and the strength of the tile adhesive is improved; on the other hand, the hydroxyl groups on the surface of titanium dioxide can react with the subsequent silane coupling agent, providing more chemical bonding sites, which is beneficial to the subsequent reaction.

[0015] Preferably, in step S2, the mass ratio of polytetrahydrofuran diol, composite filler, diethylenetriamine, sodium dodecyl sulfate, ethyl acetate, isophorone diisocyanate, pentaerythritol stearate, polyether-modified dimethylsiloxane, and stannous octoate is 70 - 80:15 - 20:10 - 15:3 - 5:40 - 50:50 - 60:2 - 3:1 - 2:0.5 - 0.8.

[0016] Preferably, the temperature of the heating reaction in step S2 is 70 - 80 °C, and the time is 1 - 2 h.

[0017] In the present invention, a composite filler is added during the preparation of polyurethane, which is embedded in the polyurethane, improving the dispersibility of the composite filler. At the same time, diethylenetriamine added as a chain extender can adjust the molecular weight of the polyurethane, and polyether-modified polydimethylsiloxane added as a wetting agent can improve the wettability of the liquid tile adhesive, enabling it to spread rapidly on the tile; sodium dodecyl sulfate added as an emulsifier can improve the stability of the tile adhesive.

[0018] Preferably, in the mixed solution in step S3, the mass ratio of ethyl acetate to xylene is 80 - 90:10 - 20, and the mass ratio of epoxy resin, γ-aminopropyltriethoxysilane, 4-amino-3-fluorobenzene allyl benzoate, and triphenylphosphine is 100 - 120:10 - 15:5 - 10:1 - 2.

[0019] Preferably, the temperature of the constant-temperature reaction in step S3 is 50 - 60 °C, and the time is 60 - 90 min.

[0020] In the present invention, by modifying epoxy resin, aminotriethoxysilane and 4-amino-3-fluorobenzene allyl benzoate are introduced into the epoxy resin by covalent bonding, which not only improves the bonding force between the epoxy resin and the tile, but also the introduced fluorine-containing group can improve the water resistance and weather resistance of the tile adhesive.

[0021] Preferably, in step S4, the mass ratio of the modified epoxy resin, modified polyurethane, polyvinyl alcohol, and azobisisobutyronitrile is 20 - 30:70 - 80:3 - 4:0.3 - 0.5.

[0022] Preferably, the temperature of the stirring in step S4 is 40 - 50 °C, the rotation speed is 100 - 150 r / min, and the time is 40 - 60 min.

[0023] In the present invention, the modified epoxy resin and the modified polyurethane are connected through a chemical reaction, further improving the bonding performance of the tile adhesive. The added polyvinyl alcohol can be used as a thickener and a film-forming agent to improve the comprehensive performance of the tile adhesive.

[0024] The present invention also protects a high-strength liquid tile adhesive prepared by the method as described above.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The high-strength liquid tile adhesive provided by the present invention uses modified composite filler, polyurethane, and modified epoxy resin as the main raw materials. The prepared liquid tile adhesive has excellent interfacial bonding performance and mechanical properties, which can not only ensure the convenience of construction but also significantly improve the bonding strength between the tile and the substrate.

[0027] (2) The high-strength liquid tile adhesive provided by the present invention in-situ generates titanium dioxide on montmorillonite by the hydrothermal method. The prepared liquid tile adhesive has excellent interfacial bonding performance and mechanical properties, which can significantly improve the bonding strength between the tile and the substrate while ensuring the convenience of construction. Subsequently, vinyltrimethoxysilane is used to modify the montmorillonite, improving the compatibility between the montmorillonite and the polyurethane, and introducing double bonds on the montmorillonite, which is beneficial to the subsequent reaction. During the preparation of polyurethane, composite filler is added and embedded in the polyurethane, improving the bonding strength between the composite filler and the polyurethane, and endowing the tile adhesive with good comprehensive performance.

[0028] (3) The high-strength liquid tile adhesive provided by the present invention chemically introduces aminotriethoxysilane and 4-amino-3-fluorallyl benzoate into the epoxy resin by covalent bonding. The siloxane bond in aminotriethoxysilane can bond with the inorganic materials in the tile, improving the bonding force between the epoxy resin and the tile. At the same time, the fluorine-containing group in 4-amino-3-fluorallyl benzoate can improve the water resistance and weather resistance of the tile adhesive. Finally, the modified epoxy resin and the modified polyurethane are reacted, and the double bonds in the composite filler and the double bonds in 4-amino-3-fluorallyl benzoate undergo grafting reaction, forming a crosslinked interpenetrating structure between the epoxy resin and the polyurethane, further improving the water resistance and adhesive performance of the tile adhesive. The added polyvinyl alcohol can be used as a thickener and film-forming agent to improve the comprehensive performance of the tile adhesive. When in use, an appropriate amount of ethylenediamine can be added as a curing agent for the epoxy resin, thereby improving the adhesion of the tile adhesive. Detailed implementation mode

[0029] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. 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.

[0030] In the present invention, the montmorillonite is sodium-based montmorillonite with a mesh number of 800; the molecular weight of the polytetrahydrofuran diol is 3000; the polyether-modified polydimethylsiloxane is purchased from Guangzhou Situlong Chemical Co., Ltd., with the model of Walker VOK-1440; the epoxy resin has the brand number of E-51; the polyvinyl alcohol has the brand number of PVA1799.

[0031] Example 1

[0032] A preparation method of a high-strength liquid tile adhesive, comprising the following steps:

[0033] S1. Preparation of composite filler: Add 55 g of montmorillonite to 750 g of deionized water, then add 4 g of cetyltrimethylammonium bromide, stir at 65 °C for 35 min. After stirring, add 250 g of ethanol, 65 g of tetrabutyl titanate, and 85 g of ammonia water with a mass fraction of 13%, carry out hydrothermal reaction at 115 °C for 8 h. After the reaction is completed, filter, wash, and dry to obtain a solid product; Subsequently, add 75 g of the solid product to 900 g of an ethanol aqueous solution (the mass fraction of ethanol is 75%), then add 8 g of vinyltrimethoxysilane, stir and react at 65 °C for 2.5 h. After the reaction is completed, filter, wash, and dry to obtain the composite filler;

[0034] S2. Preparation of modified polyurethane: Mix 75 g of polytetrahydrofuran diol, 18 g of the composite filler in step S1, 13 g of diethylenetriamine, 4 g of sodium dodecyl sulfate, and 45 g of ethyl acetate, stir at 55 °C for 50 min. Subsequently, add 55 g of isophorone diisocyanate, 2.5 g of pentaerythritol stearate, 1.5 g of polyether-modified polydimethylsiloxane, and 0.7 g of stannous octoate, react at 75 °C for 1.5 h. After the reaction is completed, the modified polyurethane is obtained;

[0035] S3. Preparation of modified epoxy resin: Add 110 g of epoxy resin to a mixed solvent of ethyl acetate and xylene (the mass ratio of ethyl acetate to xylene is 85:15), then add 13 g of γ-aminopropyltriethoxysilane, 8 g of 4-amino-3-fluoroallyl benzoate, and 1.5 g of triphenylphosphine, carry out a constant-temperature reaction at 55 °C for 80 min. After the reaction is completed, the modified epoxy resin is obtained;

[0036] S4. Preparation of liquid tile adhesive: Add 25 g of the modified epoxy resin in step S3 to 75 g of the modified polyurethane in step S2, then add 3.5 g of polyvinyl alcohol and 0.4 g of azobisisobutyronitrile, stir at 45 °C for 50 min. After stirring is completed, remove ethyl acetate under reduced pressure at 13 kPa to obtain the liquid tile adhesive.

[0037] Example 2

[0038] A preparation method of a high-strength liquid tile adhesive, comprising the following steps:

[0039] S1. Preparation of composite filler: Add 55 g of montmorillonite into 750 g of deionized water, then add 3 - 5 g of cetyltrimethylammonium bromide, stir at 65 °C for 35 min. After stirring, add 220 g of ethanol, 63 g of tetrabutyl titanate, and 88 g of ammonia water with a mass fraction of 12%, carry out hydrothermal reaction at 115 °C for 8 h. After the reaction, filter, wash, and dry to obtain a solid product; Subsequently, add 73 g of the solid product into 900 g of an ethanol aqueous solution (the mass fraction of ethanol is 75%), then add 7 g of vinyltrimethoxysilane, stir and react at 65 °C for 2.5 h. After the reaction, filter, wash, and dry to obtain the composite filler;

[0040] S2. Preparation of modified polyurethane: Mix 73 g of polytetrahydrofuran diol, 17 g of the composite filler in step S1, 12 g of diethylenetriamine, 4 g of sodium dodecyl sulfate, and 45 g of ethyl acetate, stir at 55 °C for 40 min. Subsequently, add 53 g of isophorone diisocyanate, 2.5 g of pentaerythritol stearate, 1.5 g of polyether-modified polydimethylsiloxane, and 0.6 g of stannous octoate, react at 75 °C for 1.5 h. After the reaction, obtain the modified polyurethane;

[0041] S3. Preparation of modified epoxy resin: Add 110 g of epoxy resin into a mixed solvent of ethyl acetate and xylene (the mass ratio of ethyl acetate to xylene is 85:15), then add 12 g of γ-aminopropyltriethoxysilane, 7 g of 4-amino-3-fluoroallyl benzoate, and 1.5 g of triphenylphosphine, carry out a constant-temperature reaction at 55 °C for 70 min. After the reaction, obtain the modified epoxy resin;

[0042] S4. Preparation of liquid tile adhesive: Add 25 g of the modified epoxy resin in step S3 into 75 g of the modified polyurethane in step S2, then add 3.5 g of polyvinyl alcohol and 0.4 g of azobisisobutyronitrile, stir at 45 °C for 50 min. After stirring, remove ethyl acetate under reduced pressure at 12 kPa to obtain the liquid tile adhesive.

[0043] Example 3

[0044] A preparation method of a high-strength liquid tile adhesive, comprising the following steps:

[0045] S1. Preparation of composite filler: Add 50 g of montmorillonite into 700 g of deionized water, then add 3 g of cetyltrimethylammonium bromide, stir at 60 °C for 40 min. After stirring, add 200 g of ethanol, 60 g of tetrabutyl titanate, and 80 g of ammonia water with a mass fraction of 15%, and carry out hydrothermal reaction at 110 °C for 9 h. After the reaction is completed, filter, wash, and dry to obtain a solid product; Subsequently, add 70 g of the solid product into 900 g of an ethanol aqueous solution (the mass fraction of ethanol is 70%), then add 6 g of vinyltrimethoxysilane, stir and react at 60 °C for 3 h. After the reaction is completed, filter, wash, and dry to obtain the composite filler;

[0046] S2. Preparation of modified polyurethane: Mix 70 g of polytetrahydrofuran diol, 15 g of the composite filler in step S1, 10 g of diethylenetriamine, 3 g of sodium dodecyl sulfate, and 40 g of ethyl acetate, stir at 50 °C for 1 h, then add 50 g of isophorone diisocyanate, 2 g of pentaerythritol stearate, 1 g of polyether-modified polydimethylsiloxane, and 0.5 g of stannous octoate, and react at 70 °C for 2 h. After the reaction is completed, the modified polyurethane is obtained;

[0047] S3. Preparation of modified epoxy resin: Add 100 g of epoxy resin into a mixed solvent of ethyl acetate and xylene (the mass ratio of ethyl acetate to xylene is 90:10), then add 10 g of γ-aminopropyltriethoxysilane, 5 g of 4-amino-3-fluoroallyl benzoate, and 1 g of triphenylphosphine, and carry out a constant-temperature reaction at 50 °C for 90 min. After the reaction is completed, the modified epoxy resin is obtained;

[0048] S4. Preparation of liquid tile adhesive: Add 20 g of the modified epoxy resin in step S3 into 70 g of the modified polyurethane in step S2, then add 3 g of polyvinyl alcohol and 0.3 g of azobisisobutyronitrile, stir at 40 °C for 60 min. After stirring, remove ethyl acetate under reduced pressure at 10 kPa to obtain the liquid tile adhesive.

[0049] Example 4

[0050] A preparation method of a high-strength liquid tile adhesive, comprising the following steps:

[0051] S1. Preparation of composite filler: Add 60 g of montmorillonite to 800 g of deionized water, then add 5 g of cetyltrimethylammonium bromide, stir at 70 °C for 30 min. After stirring, add 300 g of ethanol, 70 g of tetrabutyl titanate, and 90 g of 10% ammonia water, and carry out hydrothermal reaction at 120 °C for 7 h. After the reaction is completed, filter, wash, and dry to obtain a solid product; Subsequently, add 80 g of the solid product to 900 g of an ethanol aqueous solution (the mass fraction of ethanol is 80%), then add 10 g of vinyltrimethoxysilane, stir and react at 70 °C for 2 h. After the reaction is completed, filter, wash, and dry to obtain the composite filler;

[0052] S2. Preparation of modified polyurethane: Mix 80 g of polytetrahydrofuran diol, 20 g of the composite filler in step S1, 15 g of diethylenetriamine, 5 g of sodium dodecyl sulfate, and 50 g of ethyl acetate, stir at 60 °C for 0.5 h, then add 60 g of isophorone diisocyanate, 3 g of pentaerythritol stearate, 2 g of polyether-modified polydimethylsiloxane, and 0.8 g of stannous octoate, and react at 80 °C for 1 h. After the reaction is completed, the modified polyurethane is obtained;

[0053] S3. Preparation of modified epoxy resin: Add 120 g of epoxy resin to a mixed solvent of ethyl acetate and xylene (the mass ratio of ethyl acetate to xylene is 80:20), then add 15 g of γ-aminopropyltriethoxysilane, 10 g of 4-amino-3-fluoroallyl benzoate, and 2 g of triphenylphosphine, and carry out a constant-temperature reaction at 60 °C for 60 min. After the reaction is completed, the modified epoxy resin is obtained;

[0054] S4. Preparation of liquid tile adhesive: Add 30 g of the modified epoxy resin in step S3 to 80 g of the modified polyurethane in step S2, then add 4 g of polyvinyl alcohol and 0.5 g of azobisisobutyronitrile, stir at 50 °C for 40 min. After stirring, remove ethyl acetate under reduced pressure at 15 kPa to obtain the liquid tile adhesive.

[0055] Comparative Example 1

[0056] A preparation method of a high-strength liquid tile adhesive, comprising the following steps:

[0057] S1. Preparation of composite filler: Add 55 g of montmorillonite to 750 g of deionized water, then add 4 g of cetyltrimethylammonium bromide, stir at 65 °C for 35 min. After stirring, the modified montmorillonite is obtained;

[0058] S2. Preparation of modified polyurethane: Mix 75 g of polytetrahydrofuran diol, 18 g of the modified montmorillonite in step S1, 13 g of diethylenetriamine, 4 g of sodium dodecyl sulfate, and 45 g of ethyl acetate, stir at 55 °C for 50 min, then add 55 g of isophorone diisocyanate, 2.5 g of pentaerythritol stearate, 1.5 g of polyether-modified polydimethylsiloxane, and 0.7 g of stannous octoate, react at 75 °C for 1.5 h. After the reaction is completed, the modified polyurethane is obtained;

[0059] S3. Preparation of modified epoxy resin: Add 110 g of epoxy resin to a mixed solvent of ethyl acetate and xylene (mass ratio of ethyl acetate to xylene is 85:15), then add 13 g of γ-aminopropyltriethoxysilane, 8 g of 4-amino-3-fluoroallyl benzoate, and 1.5 g of triphenylphosphine, react at a constant temperature of 55 °C for 80 min. After the reaction is completed, the modified epoxy resin is obtained;

[0060] S4. Preparation of liquid tile adhesive: Add 25 g of the modified epoxy resin in step S3 to 75 g of the modified polyurethane in step S2, then add 3.5 g of polyvinyl alcohol and 0.4 g of azobisisobutyronitrile, stir at 45 °C for 50 min. After stirring is completed, remove ethyl acetate under reduced pressure at 13 kPa to obtain the liquid tile adhesive.

[0061] Compared with Example 1, in this comparative example, titanium dioxide and vinyltrimethoxysilane were not used for modification on montmorillonite.

[0062] Comparative Example 2

[0063] A preparation method of a high-strength liquid tile adhesive, comprising the following steps:

[0064] S1. Preparation of composite filler: Add 55 g of montmorillonite to 750 g of deionized water, then add 4 g of cetyltrimethylammonium bromide, stir at 65 °C for 35 min. After stirring is completed, add 250 g of ethanol, 65 g of tetrabutyl titanate, and 85 g of ammonia water with a mass fraction of 13%, carry out hydrothermal reaction at 115 °C for 8 h. After the reaction is completed, filter, wash, and dry to obtain a solid product; then add 75 g of the solid product to 900 g of an ethanol aqueous solution (mass fraction of ethanol is 75%), then add 8 g of vinyltrimethoxysilane, stir and react at 65 °C for 2.5 h. After the reaction is completed, filter, wash, and dry to obtain the composite filler;

[0065] S2. Preparation of modified polyurethane: Mix 75 g of polytetrahydrofuran diol, 18 g of the composite filler in step S1, 13 g of diethylenetriamine, 4 g of sodium dodecyl sulfate, and 45 g of ethyl acetate, stir at 55 °C for 50 min, then add 55 g of isophorone diisocyanate, 2.5 g of pentaerythritol stearate, 1.5 g of polyether-modified polydimethylsiloxane, and 0.7 g of stannous octoate, react at 75 °C for 1.5 h. After the reaction is completed, the modified polyurethane is obtained;

[0066] S3. Preparation of liquid tile adhesive: Add 25 g of epoxy resin to 75 g of the modified polyurethane in step S2, then add 3.5 g of polyvinyl alcohol and 0.4 g of azobisisobutyronitrile, stir at 45 °C for 50 min, and remove ethyl acetate under reduced pressure at 13 kPa after stirring to obtain the liquid tile adhesive.

[0067] Compared with Example 1, the epoxy resin was not modified in this comparative example.

[0068] Comparative Example 3

[0069] A preparation method of a high-strength liquid tile adhesive includes the following steps:

[0070] S1. Preparation of composite filler: Add 55 g of montmorillonite to 750 g of deionized water, then add 4 g of cetyltrimethylammonium bromide, stir at 65 °C for 35 min. After stirring is completed, the modified montmorillonite is obtained;

[0071] S2. Preparation of modified polyurethane: Mix 75 g of polytetrahydrofuran diol, 18 g of the modified montmorillonite in step S1, 13 g of diethylenetriamine, 4 g of sodium dodecyl sulfate, and 45 g of ethyl acetate, stir at 55 °C for 50 min, then add 55 g of isophorone diisocyanate, 2.5 g of pentaerythritol stearate, 1.5 g of polyether-modified polydimethylsiloxane, and 0.7 g of stannous octoate, react at 75 °C for 1.5 h. After the reaction is completed, the modified polyurethane is obtained;

[0072] S3. Preparation of liquid tile adhesive: Add 25 g of epoxy resin to 75 g of the modified polyurethane in step S2, then add 3.5 g of polyvinyl alcohol and 0.4 g of azobisisobutyronitrile, stir at 45 °C for 50 min, and remove ethyl acetate under reduced pressure at 13 kPa after stirring to obtain the liquid tile adhesive.

[0073] Compared with Example 1, in this comparative example, titanium dioxide and vinyltrimethoxysilane modification were not carried out on montmorillonite, and at the same time, the epoxy resin was not modified.

[0074] The high-strength liquid tile adhesives in Examples 1-4 and Comparative Examples 1-3 were tested for the performance of the tile adhesive according to the provisions of the national building materials industry standard JC / T 547-2017 "Ceramic Wall and Floor Tile Adhesives". When in use, add ethylenediamine accounting for 10% of the mass of the liquid tile adhesive, and mix evenly. The results are shown in Table 1.

[0075] Table 1 Test Results of Tile Adhesive Performance in Different Groups

[0076]

[0077] As can be seen from Table 1 above, the liquid tile adhesive prepared by the present invention has excellent bonding strength, and at the same time has good water resistance and weather resistance, and has good application prospects.

[0078] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a high-strength liquid tile adhesive, characterized in that, It includes the following steps: S1. Add montmorillonite into deionized water, then add cetyltrimethylammonium bromide and stir. After the stirring is completed, add ethanol, tetrabutyl titanate, and ammonia water, and carry out a hydrothermal reaction. After the reaction is completed, filter, wash, and dry to obtain a solid product. Subsequently, add the solid product into an ethanol aqueous solution, then add vinyltrimethoxysilane and carry out a stirring reaction. After the reaction is completed, filter, wash, and dry to obtain a composite filler; S2. Mix polytetrahydrofuran diol, the composite filler in step S1, diethylenetriamine, sodium dodecyl sulfate, and ethyl acetate, and stir at 50 - 60 °C for 0.5 - 1 h. Subsequently, add isophorone diisocyanate, pentaerythritol stearate, polyether-modified polydimethylsiloxane, and stannous octoate, and carry out a heating reaction. After the reaction is completed, obtain a modified polyurethane; S3. Add epoxy resin into a mixed solvent of ethyl acetate and xylene, then add γ-aminopropyltriethoxysilane, 4-amino-3-fluoropropenyl benzoate, and triphenylphosphine, and carry out a constant-temperature reaction. After the reaction is completed, obtain a modified epoxy resin; S4. Add the modified epoxy resin in step S3 into the modified polyurethane in step S2, then add polyvinyl alcohol and azodiisobutyronitrile, and stir. After the stirring is completed, remove ethyl acetate under reduced pressure to obtain the liquid tile adhesive.

2. The preparation method according to claim 1, wherein In step S1, the mass ratio of the montmorillonite, deionized water, cetyltrimethylammonium bromide, ethanol, tetrabutyl titanate, and ammonia water is 50 - 60:700 - 800:3 - 5:200 - 300:60 - 70:80 - 90, and the mass fraction of the ammonia water is 10 - 15%; the temperature of the hydrothermal reaction is 110 - 120 °C, and the time is 7 - 9 h.

3. The preparation method according to claim 1, characterized in that, In step S1, the mass fraction of ethanol in the ethanol aqueous solution is 70 - 80%, and the mass ratio of the solid product to vinyltrimethoxysilane is 70 - 80:6 - 10; the temperature of the stirring reaction is 60 - 70 °C, and the time is 2 - 3 h.

4. The preparation method according to claim 1, wherein, In step S2, the mass ratio of the polytetrahydrofuran diol, composite filler, diethylenetriamine, sodium dodecyl sulfate, ethyl acetate, isophorone diisocyanate, pentaerythritol stearate, polyether-modified dimethylsiloxane, and stannous octoate is 70 - 80:15 - 20:10 - 15:3 - 5:40 - 50:50 - 60:2 - 3:1 - 2:0.5 - 0.

8.

5. The preparation method according to claim 1, wherein In step S2, the temperature of the heating reaction is 70 - 80 °C, and the time is 1 - 2 h.

6. The preparation method according to claim 1, characterized in that, In step S3, the mass ratio of ethyl acetate to xylene in the mixed solvent is 80 - 90:10 - 20, and the mass ratio of the epoxy resin, γ-aminopropyltriethoxysilane, 4-amino-3-fluoropropenyl benzoate, and triphenylphosphine is 100 - 120:10 - 15:5 - 10:1 - 2.

7. According to the preparation method described in claim 1, characterized in that, In step S3, the temperature of the constant-temperature reaction is 50 - 60 °C, and the time is 60 - 90 min.

8. The preparation method according to claim 1, characterized in that, In step S4, the mass ratio of the modified epoxy resin, modified polyurethane, polyvinyl alcohol, and azodiisobutyronitrile is 20 - 30:70 - 80:3 - 4:0.3 - 0.

5.

9. The preparation method according to claim 1, characterized in that, The temperature of the stirring described in step S4 is 30 - 40 °C, the rotation speed is 100 - 150 r / min, and the time is 40 - 60 min.

10. A high-strength liquid tile adhesive prepared by the method according to any one of claims 1 - 9.

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