A high-strength frost-resistant tile back adhesive and its preparation method

Abstract

The present invention discloses a high-strength frost-resistant tile back adhesive and a preparation method thereof. The high-strength frost-resistant tile back adhesive comprises: an organosilicon-modified styrene-acrylic polymer emulsion, an antifoaming agent, a preservative, an active silica-based filler, an adhesion promoter, an antifreezing agent and a nonionic surfactant. The high-strength frost-resistant tile back adhesive provided by the present invention has the characteristics of high bonding strength, good water resistance, strong weather resistance, good stability and construction feel. While achieving high-strength bonding, the back adhesive can resist low temperature, and even during transportation and storage under severe cold conditions such as in autumn and winter in the north, the back adhesive will not demulsify and denature.

Description

Technical Field

[0001] The invention belongs to the technical field of tile adhesive, and more specifically, relates to a high-strength antifreeze tile adhesive and a preparation method thereof. Background Art

[0002] In recent years, with the development of finishing materials, ceramic tiles with high water absorption rate can no longer meet people's needs for decoration. Instead, they are replaced by paving materials such as vitrified tiles, glazed tiles, microcrystalline stones, natural stones, etc. with beautiful visual effects, beautiful texture and a wide variety of categories. The characteristics of paving materials are also transitioning to large size and low water absorption rate. Faced with increasingly dense paving materials with extremely low water absorption rate and a wide variety of categories, such as vitrified tiles, it has become difficult to bond traditional cement mortar to the back of tiles, and it is easily affected by external stress. Adhesive bonding failure, tile hollowing and other phenomena often occur, and brick falling occurs frequently. Tile back glue is a flexible auxiliary tile paving material that can effectively improve the bonding effect of low water absorption tiles and adhesive materials. It is suitable for indoor wall tile paving. Tile paving companion can not only enhance the bonding effect of the adhesive layer and the tile, but also has a good absorption capacity for the stress caused by the base layer, tile adhesive layer and the tile due to slight deformation, thereby effectively avoiding the problem of hollowing and falling of tile paving.

[0003] Existing tile adhesive products are divided into two types: single-component emulsion type and two-component type. Among them, single-component adhesive is more popular because it is ready to use and easy to construct. However, due to its composition, compared with two-component adhesives, single-component adhesives generally have low strength and high water absorption. It is very easy to absorb water and swell under high humidity conditions, and the strength of the adhesive is greatly affected by the environment. In addition, the polymer emulsions used in the construction coating industry generally have the defects of demulsification and denaturation at low temperatures (below -5°C), and the transportation and storage stability of the products in the autumn and winter seasons in the northern region are challenged. The traditional solution is to install insulation devices during transportation and storage when the temperature is low, but this results in high additional costs. Summary of the invention

[0004] The purpose of the present invention is to provide a high-strength frost-resistant tile adhesive and a preparation method thereof, aiming to solve the defects of low strength and poor water resistance of single-component adhesive and easy demulsification and denaturation during transportation and storage in a low-temperature environment.

[0005] In order to achieve the above-mentioned purpose, one aspect of the present invention provides a high-strength antifreeze tile adhesive, which comprises: a silicone-modified styrene acrylic polymer emulsion, a defoaming agent, a preservative, an active silica filler, an adhesion promoter, an antifreeze agent and a nonionic surfactant.

[0006] According to the present invention, preferably, by mass parts, the high-strength frost-resistant tile back adhesive comprises: 88-92 parts of the organosilicon-modified styrene-acrylic polymer emulsion, 0.2-0.3 parts of the defoaming agent, 0.2-0.4 parts of the preservative, 2-5 parts of the active silica filler, 1-3 parts of the adhesion promoter, 1-2 parts of the antifreezing agent, and 1-2 parts of the nonionic surfactant.

[0007] In the present invention, the adhesion between the back adhesive and the substrate or tile is improved by the combination of the organosilicon-modified styrene-acrylic polymer emulsion, the adhesion promoter and the active silica filler, realizing the high-strength feature of the back adhesive described in the invention. In addition, the active silica filler introduced into the back adhesive has a large specific surface area, and the "extrusion effect" enhances the good construction feel and strong anti-sagging property of the back adhesive. The organosilicon-modified styrene-acrylic polymer emulsion used in the back adhesive has a low T g , thus making the back adhesive itself have good flexibility, enabling it to resist the stresses generated by the shrinkage of the paving material and the vibration of the building when applied to tile paving, preventing hollowing and enhancing the reliability of the paving system. By combining the nonionic surfactant and the antifreezing agent to construct a stable mechanism for the latex particles of the back adhesive at low temperatures, the back adhesive of the present invention has good frost resistance. The back adhesive of the present invention can be transported and stored at as low as -30°C without the back adhesive breaking emulsion and denaturing, and its mechanical properties will not be affected.

[0008] According to the present invention, preferably, the organosilicon-modified styrene-acrylic polymer emulsion is obtained by the following preparation method:

[0009] (1) In the presence of a first organic solvent and a first initiator, polymerize a styrene monomer, an acrylic acid monomer and a first chain transfer agent;

[0010] (2) In the presence of a second organic solvent and a second initiator, polymerize the polymer obtained in step (1), an organosilicon monomer, an acrylate monomer and a second chain transfer agent;

[0011] (3) Mix the polymer obtained in step (2), an emulsifier and water to obtain the organosilicon-modified styrene-acrylic polymer emulsion.

[0012] In the present invention, in step (3), the polymer obtained in step (2) is emulsified in water by an emulsifier to obtain the organosilicon-modified styrene-acrylic emulsion used in the back adhesive of the present invention.

[0013] According to the present invention, preferably, the acrylate monomer is at least one of butyl acrylate, isooctyl acrylate and methyl methacrylate;

[0014] The organosilicon monomer is at least one of 3-(methacryloyloxy)propyltrimethoxysilane (KH570), 3-methacryloyloxypropylmethyldimethoxysilane (KH572), vinyltrimethoxysilane (KH171), and vinyltriisopropoxysilane;

[0015] Both the first chain transfer agent and the second chain transfer agent are tribenzyl trithiocarbonate;

[0016] The first initiator and the second initiator are each independently 2,2'-azobis(2-methylbutyronitrile) (ABN-E) and / or azobisisobutyronitrile (AIBN); preferably 2,2'-azobis(2-methylbutyronitrile) (ABN-E);

[0017] The emulsifier is an anionic emulsifier, preferably sodium dodecylbenzenesulfonate;

[0018] Both the first organic solvent and the second organic solvent are ethyl acetate;

[0019] By mass, the dosage of styrene is 20-35 parts, the dosage of acrylate is 40-55 parts, the dosage of acrylic acid is 10-20 parts, the dosage of organosilicon monomer is 0.5-2 parts, the dosage of the first chain transfer agent is 1-2 parts, the dosage of the first initiator is 1-2 parts, the dosage of the second chain transfer agent is 1-2 parts, the dosage of the second initiator is 1-2 parts, the dosage of the emulsifier is 1-2 parts, and the dosage of water is 100-120 parts;

[0020] In step (1), the temperature of the polymerization reaction is 70-90 °C and the time is 6-8 h;

[0021] In step (2), the temperature of the polymerization reaction is 70-90 °C and the time is 6-15 h.

[0022] In the present invention, the organosilicon-modified styrene-acrylic polymer emulsion microscopically exhibits the topological structure characteristics of a soft shell and a hard core, and its synthesis is obtained by the reversible addition-fragmentation chain transfer (RAFT) radical polymerization method of monomers.

[0023] The organosilicon-modified styrene-acrylic polymer emulsion designed and synthesized in the present invention has a glass transition temperature below -10 °C, and microscopically has a topological structure of a soft shell (acrylate and organosilicon segments) and a hard core (styrene and acrylic segments). Because the soft shell segment contains organosilicon modification, while ensuring its flexibility (pressure sensitivity), the hydrophobic effect of organosilicon enhances the water resistance of the emulsion itself and can also provide more chemical bonds when the back glue acts on the substrate, not only enhancing the bonding effect with the substrate, but also improving the wetting effect on the substrate.

[0024] In the present invention, the organosilicon monomers containing unsaturated bonds, 3-(methacryloyloxy)propyltrimethoxysilane (KH570), 3-methacryloyloxypropylmethyldimethoxysilane (KH572), vinyltrimethoxysilane (KH171) and vinyltriisopropoxysilane are preferably purchased from Hangzhou Jessica Chemical Co., Ltd.

[0025] According to the present invention, preferably, the active silica-based filler is at least one of fly ash, fumed silica, metakaolin and diatomite.

[0026] In the present invention, the active silica-based filler is preferably fumed silica, and its typical characteristics are: large specific surface area and high activity of fumed silica. Using it as a filler can not only effectively improve the construction feel and anti-sagging property of the back glue, but also it can react with the hydration product Ca(OH)2 (hydration product of cement mineral phases C2S and C3S) in the bonding mortar at the bonding interface through its own Brownian motion, generating a pozzolanic effect and forming C-S-H gel, and finally effectively improving the bonding effect of the back glue by improving the compactness of the back glue-substrate transition region.

[0027] According to the present invention, preferably, the adhesion promoter is an organosilane compound, preferably at least one of KH560, MP200 and A187.

[0028] In the present invention, KH560 is Jessica Chemical-KH560, MP200 is Momentive MP200 and A187 is Momentive A187.

[0029] In the present invention, the adhesion promoter has strong anti-hydrolysis ability and good compatibility with the back glue polymer emulsion. After the back glue forms a film, it can provide more chemical bonds to enhance the bonding force with the inorganic substrate. The organosilicon-modified styrene-acrylic emulsion is supplemented with an adhesion promoter to jointly achieve the characteristics of high strength and good water resistance of the back glue in a physical riveting (pressure sensitivity of the emulsion) and chemical bond manner.

[0030] According to the present invention, preferably, the antifreeze is at least one of propylene glycol, ethylene glycol and PEG300; preferably PEG300.

[0031] In the present invention, the antifreeze is preferably PEG300, which has a high boiling point compared with the antifreezes ethylene glycol and propylene glycol and will not introduce additional VOCs to the back glue product.

[0032] According to the present invention, preferably, the non-ionic surfactant is a fatty acid polyoxyethylene ether polymer, and the weight average molecular weight of the fatty acid polyoxyethylene ether polymer is above 500.

[0033] In the present invention, the introduction of a non-ionic surfactant and an antifreeze is used to construct the stabilization mechanism of latex particles in the back glue. On the premise of achieving the high-strength function of the back glue, its low-temperature resistance is more excellent, and it can be realized that the back glue emulsion does not undergo demulsification and denaturation at a low temperature of -30°C. This technology also overcomes the problem that the back glue is prone to freezing and denaturation during transportation and storage in autumn and winter in northern regions.

[0034] According to the present invention, preferably, the defoaming agent is an organosilicon defoaming agent and / or a mineral oil defoaming agent;

[0035] The preservative is preferably Marken 315 and / or Marken 410.

[0036] On the other hand, the present invention provides a method for preparing the above-mentioned high-strength antifreeze ceramic tile back glue, and the preparation method includes:

[0037] (1) Mix the organosilicon-modified styrene-acrylic polymer emulsion, the preservative, the adhesion promoter, the antifreeze and the non-ionic surfactant;

[0038] (2) Mix the mixture obtained in step (1) with the active silica-based filler;

[0039] (3) Mix the mixture obtained in step (2) with the defoaming agent to obtain the high-strength antifreeze ceramic tile back glue;

[0040] Preferably, in step (1), the mixing speed is 500 - 600 r / min, and the time is 10 - 20 min; in step (2), the mixing speed is 700 - 800 r / min, and the time is 15 - 30 min; in step (3), the mixing speed is 700 - 800 r / min, and the time is 10 - 20 min.

[0041] The technical solution of the present invention has the following beneficial effects: The high-strength antifreeze ceramic tile back glue provided by the present invention has the characteristics of high bonding strength, good water resistance, strong weather resistance, good stability and construction feel. While achieving high-strength bonding, the back glue can resist low temperatures, and even during transportation and storage under severe cold conditions such as in autumn and winter in the north, the back glue will not undergo demulsification and denaturation.

[0042] Other features and advantages of the present invention will be described in detail in the following specific implementation part. Specific implementation

[0043] Preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0044] The present invention will be further illustrated by the following examples:

[0045] The dosage of each component in the following examples is in parts by mass.

[0046] The preservatives used in the following examples are purchased from Macken Company, with the brand number 315; the defoamer is a mineral oil defoamer, purchased from BASF Company, with the brand number NXZ; the aerosil is purchased from Wacker Company, with a particle size of 20 nanometers; A187 is Momentive A187, and MP200 is Momentive MP200; the fatty acid polyoxyethylene ether polymer has a weight average molecular weight of more than 500, purchased from Shell Company, with the brand number AEO-9; polyethylene glycol PEG300 is purchased from Jiangsu Haishi Petrochemical Company, with the brand number PEG300;

[0047] The organosilicon-modified styrene-acrylic polymer emulsion used in the following examples is prepared by the following method (each dosage is in parts by mass):

[0048] (1) As shown in Equation (1), in a reaction kettle, using 100 parts of ethyl acetate as a solvent, while stirring, successively add 25 parts of styrene, 20 parts of acrylic acid, 2 parts of the chain transfer agent tribenzyl trithiocarbonate, and 1 part of 2,2'-azobis(2-methylbutyronitrile), and react at 80 °C for 8 h to obtain intermediate product I;

[0049] (2) As shown in Equation (2), in a reaction kettle, using 100 parts of ethyl acetate as a solvent, successively add all of the intermediate product I obtained in step (1), 1 part of the organosilicon monomer, 50 parts of the acrylate monomer, 2 parts of the chain transfer agent tribenzyl trithiocarbonate, and 1 part of 2,2'-azobis(2-methylbutyronitrile), and at 80 °C, control the stirring rate at 600 r / min, react for 12 h, remove the solvent, and mix the obtained product, 100 parts of deionized water, and 3 parts of sodium dodecylbenzenesulfonate to obtain the organosilicon-modified styrene-acrylic polymer emulsion. Among them, the organosilicon monomer is vinyltrimethoxysilane, and the acrylate monomer is butyl acrylate.

[0050]

[0051] For the following test items, the tensile bond strength, tensile bond strength after immersion in water, tensile bond strength after thermal aging, tensile bond strength after freeze-thaw cycles, and tensile bond strength after 20 rounds of freeze-thaw cycles of the back glue emulsion are all tested according to the method in JC / T 547-2017 "Ceramic Wall and Floor Tile Adhesives".

[0052] Example 1

[0053] A high-strength anti-freeze ceramic tile back glue is composed of 88.5 parts of organosilicon-modified styrene-acrylic polymer emulsion, 0.2 part of preservative, 0.3 part of defoamer NXZ, 5 parts of fumed silica, 3 parts of adhesion promoter A187, 1 part of non-ionic surfactant fatty acid polyoxyethylene ether polymer, and 2 parts of antifreeze polyethylene glycol PEG300.

[0054] The specific preparation method is as follows: (1) Add the organosilicon-modified styrene-acrylic polymer emulsion into a stirring kettle, start stirring at a speed of 500 r / min, and sequentially add the preservative, adhesion promoter, antifreeze, and non-ionic surfactant, and continue stirring for 15 min;

[0055] (2) Then add the active silica-based filler, and gradually increase the stirring rate to 800 r / min, and continue stirring for 20 min;

[0056] (3) Finally, add the defoamer, and stir at 800 r / min for 20 min, then discharge and package.

[0057] Test the performance of the high-strength anti-freeze ceramic tile back glue prepared in the above example, as shown in the following table; among them, freeze-thaw (the first item in the table) is measured according to the method of GB / T20623-2006 (the measured temperature is: -25 °C, 18 h and 25 °C 6 h).

[0058] Table 1

[0059] Test Items Example 1 -25°C, 20 freeze-thaw cycles of the back adhesive emulsion The back adhesive does not break emulsion and denature Tensile bond strength / MPa 2.2 Tensile bond strength after immersion in water / MPa 1.8 Tensile bond strength after thermal aging / MPa 2.9 Tensile bond strength after freeze-thaw cycles / MPa 1.7 Tensile bond strength of the back adhesive emulsion after 20 freeze-thaw cycles / MPa 2.3

[0060] Example 2

[0061] A high-strength anti-freeze ceramic tile back glue is composed of 91.6 parts of organosilicon-modified styrene-acrylic polymer emulsion, 0.2 part of preservative, 0.2 part of defoamer NXZ, 2 parts of fumed silica, 2 parts of adhesion promoter A187, 2 parts of non-ionic surfactant fatty acid polyoxyethylene ether polymer, and 2 parts of antifreeze polyethylene glycol PEG300.

[0062] The specific preparation method is the same as that of Example 1.

[0063] Test the performance of the high-strength and freeze-resistant tile back adhesive prepared in the above embodiments, as shown in the following table; among them, freeze-thaw (the first item in the table) is measured according to the method of GB / T20623-2006 (the measurement temperature is: -30°C, 18h and 25°C 6h).

[0064] Table 2

[0065] Test Items Example 2 -30°C, 20 freeze-thaw cycles of the back adhesive emulsion The back adhesive does not break emulsion and denature Tensile bond strength / MPa 1.9 Tensile bond strength after immersion in water / MPa 1.6 Tensile bond strength after thermal aging / MPa 2.7 Tensile bond strength after freeze-thaw cycles / MPa 1.6 Tensile bond strength of the back adhesive emulsion after 20 freeze-thaw cycles / MPa 1.8

[0066] Example 3

[0067] A high-strength and freeze-resistant tile back adhesive is composed of 90 parts of organosilicon-modified styrene-acrylic polymer emulsion, 0.2 part of preservative, 0.3 part of defoamer NXZ, 4 parts of fumed silica, 3 parts of adhesion promoter MP200, 1 part of non-ionic surfactant fatty acid polyoxyethylene ether polymer, and 1.5 parts of antifreeze polyethylene glycol PEG300.

[0068] The specific preparation method is the same as that of Example 1.

[0069] Test the performance of the high-strength and freeze-resistant tile back adhesive prepared in the above embodiments, as shown in the following table; among them, freeze-thaw (the first item in the table) is measured according to the method of GB / T20623-2006 (the measurement temperature is: -25°C, 18h and 25°C 6h).

[0070] Table 3

[0071] Test Items Example 3 -25°C, 20 freeze-thaw cycles of the back adhesive emulsion The back adhesive does not break emulsion and denature Tensile bond strength / MPa 2.4 Tensile bond strength after immersion in water / MPa 1.7 Tensile bond strength after thermal aging / MPa 3.0 Tensile bond strength after freeze-thaw cycles / MPa 1.9 Tensile bond strength of the back adhesive emulsion after 20 freeze-thaw cycles / MPa 2.2

[0072] Examples 1-3 demonstrate the main physical properties and stability at low temperatures of the high-strength and freeze-resistant tile back adhesive provided by the present invention. At present, the strength of single-component back adhesives mainly composed of polymer emulsions on the market is generally below 1 MPa, and there is generally an obvious problem of strength attenuation after immersion in water, and the retention rate is less than 60%. In addition, the known back adhesives on the market generally have defects of demulsification and denaturation at low temperatures (below -5°C). Even if individual products can achieve non-demulsification and non-denaturation of the low-temperature back adhesive emulsion down to below -20°C, their strength (below 1 MPa) and water resistance (strength retention rate below 60% after immersion in water) are significantly inferior to the high-strength and freeze-resistant back adhesive provided by the present invention. The back adhesive of the present invention achieves high strength, and at the same time has excellent water resistance and good stability, and can ensure that the back adhesive does not undergo demulsification and denaturation even at a low temperature of -30°C.

[0073] The above has described the embodiments of the present invention. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments.

Claims

1. A high-strength frost-resistant tile back adhesive, characterized in that, By mass parts, the high-strength frost-resistant tile back adhesive comprises: 88 - 92 parts of organosilicon-modified styrene-acrylic polymer emulsion, 0.2 - 0.3 parts of defoamer, 0.2 - 0.4 parts of preservative, 2 - 5 parts of active silica-based filler, 1 - 3 parts of adhesion promoter, 1 - 2 parts of antifreeze, and 1 - 2 parts of nonionic surfactant; Among them, the organosilicon-modified styrene-acrylic polymer emulsion is obtained by the following preparation method: (1) In the presence of a first organic solvent and a first initiator, polymerize styrene monomer, acrylic acid monomer and a first chain transfer agent; (2) In the presence of a second organic solvent and a second initiator, polymerize the polymer obtained in step (1), organosilicon monomer, acrylate monomer and a second chain transfer agent; (3) Mix the polymer obtained in step (2), emulsifier and water to obtain the organosilicon-modified styrene-acrylic polymer emulsion; The acrylate monomer is at least one of butyl acrylate, isooctyl acrylate and methyl methacrylate; the organosilicon monomer is at least one of 3-(methacryloyloxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, vinyltrimethoxysilane and vinyltriisopropoxysilane; both the first chain transfer agent and the second chain transfer agent are tribenzyl trithiocarbonate; the first initiator and the second initiator are each independently 2,2'-azobis(2-methylbutyronitrile) and / or azobisisobutyronitrile; the emulsifier is an anionic emulsifier; By mass parts, the dosage of styrene is 20 - 35 parts, the dosage of acrylate is 40 - 55 parts, the dosage of acrylic acid is 10 - 20 parts, the dosage of organosilicon monomer is 0.5 - 2 parts, the dosage of the first chain transfer agent is 1 - 2 parts, the dosage of the first initiator is 1 - 2 parts, the dosage of the second chain transfer agent is 1 - 2 parts, the dosage of the second initiator is 1 - 2 parts, the dosage of the emulsifier is 1 - 2 parts, and the dosage of water is 100 - 120 parts.

2. The high-strength frost-resistant tile back adhesive according to claim 1, wherein, The first initiator and the second initiator are each independently 2,2'-azobis(2-methylbutyronitrile); The emulsifier is sodium dodecylbenzenesulfonate; Both the first organic solvent and the second organic solvent are ethyl acetate; In step (1), the temperature of the polymerization reaction is 70 - 90°C and the time is 6 - 8h; In step (2), the temperature of the polymerization reaction is 70 - 90°C and the time is 6 - 15h.

3. The high-strength frost-resistant tile back adhesive according to claim 1, wherein, The active silica-based filler is at least one of fly ash, fumed silica, metakaolin and diatomite.

4. The high-strength frost-resistant tile back adhesive according to claim 1, wherein, The adhesion promoter is an organosilane compound.

5. The high-strength frost-resistant tile back adhesive according to claim 4, wherein, The adhesion promoter is at least one of KH560, MP200 and A187.

6. The high-strength frost-resistant tile back adhesive according to claim 1, wherein, The antifreeze is at least one of propylene glycol, ethylene glycol and PEG300.

7. The high-strength frost-resistant tile back adhesive according to claim 6, wherein, The antifreeze is PEG300.

8. The high-strength frost-resistant tile back adhesive according to claim 1, wherein, The nonionic surfactant is a fatty acid polyoxyethylene ether polymer, and the weight-average molecular weight of the fatty acid polyoxyethylene ether polymer is above 500.

9. The high-strength frost-resistant tile back adhesive according to claim 1, wherein, The defoamer is an organosilicon defoamer and / or a mineral oil defoamer.

10. The high-strength frost-resistant tile back adhesive according to claim 1, wherein, The preservative is Mycron 315 and / or Mycron 410.

11. A preparation method of the high-strength frost-resistant tile back adhesive according to any one of claims 1-10, characterized in that, The preparation method includes: (1) Mix the organosilicon-modified styrene-acrylic polymer emulsion, the preservative, the adhesion promoter, the antifreeze, and the nonionic surfactant; (2) Mix the mixture obtained in step (1) with the active silica-based filler; (3) Mix the mixture obtained in step (2) with the defoamer to obtain the high-strength antifreeze tile back adhesive.

12. The preparation method according to claim 11, wherein, In step (1), the mixing speed is 500 - 600 r / min and the time is 10 - 20 min; In step (2), the mixing speed is 700 - 800 r / min and the time is 15 - 30 min; In step (3), the mixing speed is 700 - 800 r / min and the time is 10 - 20 min.

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