Composite mortar, method for producing a composite mortar and backing plate

Abstract

The application provides a composite mortar, a preparation method of the composite mortar and a backing plate, and relates to the field of building materials. The composite mortar comprises 250-500 parts by weight of a polymer emulsion, 400-700 parts by weight of quartz powder, 382-387 parts by weight of heavy calcium powder, 10-15 parts by weight of gypsum powder, 1-2 parts by weight of a water reducing agent, 0.5-2 parts by weight of polyvinyl alcohol and 1-2 parts by weight of bentonite. The specific contents of the quartz powder, the heavy calcium powder, the gypsum powder, the polymer emulsion, the polyvinyl alcohol, the water reducing agent and the bentonite in the composite mortar of the application are matched with each other, so that the composite mortar can realize rapid hardening, high bonding strength, high bending strength, smooth construction and multiple protection functions, the production cost can be controlled at a low level, the composite mortar does not contain toxic and harmful components and meets the environmental protection requirements.

Description

Technical Field

[0001] This application relates to the field of building materials, and more particularly to a composite mortar, a method for preparing the composite mortar, and a backing board. Background Technology

[0002] Currently, in the construction industry, polystyrene boards and mortar composite backing panels are commonly used on interior walls and the exterior of pipes to provide insulation, soundproofing, moisture resistance, waterproofing, crack resistance, and aesthetics. Without a mortar layer, the backing panel will have lower strength and lack moisture resistance. However, the mortar used with polystyrene boards generally has the following drawbacks:

[0003] 1. Low construction efficiency: The setting time of existing mortar is too long, and some mortars even require additional drying or sun-drying processes, which seriously slows down the construction progress.

[0004] 2. Poor adhesion and mechanical properties: The mortar layer formed by mortar has low adhesion strength to the polystyrene board, the mortar layer is not flexible enough, it is prone to brittle fracture, and the appearance is rough.

[0005] 3. High overall cost and poor environmental performance: The production cost of existing mortars is relatively high, and some mortars contain components that are harmful to the environment and the health of construction workers.

[0006] Therefore, there is an urgent need to develop an environmentally friendly composite mortar that can harden quickly, has high bonding strength, is easy to construct, and is inexpensive, in order to improve the overall performance and engineering efficiency of the backing board. Summary of the Invention

[0007] The purpose of this application is to provide a composite mortar, a method for preparing the composite mortar, and a backing plate to solve the above-mentioned problems.

[0008] To achieve the above objectives, this application adopts the following technical solution:

[0009] A composite mortar comprises 250-500 parts by weight of polymer emulsion, 400-700 parts by weight of quartz powder, 382-387 parts by weight of heavy calcium carbonate powder, 10-15 parts by weight of gypsum powder, 1-2 parts by weight of water-reducing agent, 0.5-2 parts by weight of polyvinyl alcohol, and 1-2 parts by weight of bentonite.

[0010] According to embodiments of this application, the polymer emulsion includes a styrene-acrylic emulsion.

[0011] According to embodiments of this application, the solid content of the polymer emulsion is 46-50%.

[0012] According to an embodiment of this application, the water-reducing agent is a polycarboxylate water-reducing agent.

[0013] According to an embodiment of this application, the particle size of the quartz powder is 150-200 mesh.

[0014] According to an embodiment of this application, the particle size of the heavy calcium carbonate powder is 200-500 mesh.

[0015] According to embodiments of this application, the composite mortar satisfies at least one of the following conditions:

[0016] (1) The 28-day bond strength of the composite mortar is ≥0.7 MPa;

[0017] (2) The 28-day flexural strength of the composite mortar is ≥4.5 MPa;

[0018] (3) The initial setting time of the composite mortar is 15-20 min;

[0019] (4) The impermeability pressure of the composite mortar is ≥1.0 MPa.

[0020] This application also provides a method for preparing the composite mortar as described above, comprising:

[0021] Quartz powder, heavy calcium carbonate powder, gypsum powder, water-reducing agent, polyvinyl alcohol and bentonite are mixed to obtain powder;

[0022] The polymer emulsion is mixed with the powder to obtain the composite mortar.

[0023] This application also provides a backing plate, including a substrate and a mortar layer formed of composite mortar;

[0024] The composite mortar is the composite mortar described above or the composite mortar prepared by the preparation method described above.

[0025] According to an embodiment of this application, the substrate includes a polystyrene board;

[0026] And / or, the backing plate further includes a fiberglass mesh embedded in the mortar layer or located between the substrate and the mortar layer.

[0027] Compared with the prior art, the beneficial effects of this application include:

[0028] The gypsum powder in this composite mortar can shorten the setting time, significantly reducing the initial setting time of the mortar and achieving rapid hardening, thus avoiding drying processes. The addition of polymer emulsion helps improve the adhesion and flexibility of the mortar. The addition of polyvinyl alcohol can enhance the adhesive properties of the material, which is beneficial for improving the water retention and smoothness of the mortar. The synergy between polymer emulsion and polyvinyl alcohol ensures that the mortar has sufficient bond strength and crack resistance (high flexural strength). Quartz powder has high skeletal strength; heavy calcium carbonate powder acts as a micro-filler and improves workability, which is beneficial for improving the strength of the mortar. The synergy between quartz powder and heavy calcium carbonate powder can improve the density, intrinsic strength, and waterproof and seepage-resistant capabilities of the mortar. The water-reducing agent can effectively disperse the powder, reduce water consumption, and thus improve the final strength and density of the mortar. Bentonite has excellent water retention and anti-bleeding effects, ensuring the stability of the mortar during construction and avoiding problems such as construction difficulties, decreased adhesion, and surface cracking caused by water migration. The composite mortar of this application contains specific amounts of quartz powder, heavy calcium carbonate powder, gypsum powder, polymer emulsion, polyvinyl alcohol, water-reducing agent, and bentonite, which work together to achieve rapid hardening, high bonding strength, flexibility and crack resistance (high flexural strength), smooth construction, and multiple protective functions, while keeping production costs at a low level. It does not contain toxic or harmful components, meets environmental protection requirements, and effectively improves the overall performance and engineering efficiency of the backing board. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0030] Figure 1 This is a photograph of the backing plate of Example 1;

[0031] Figure 2 This is a schematic diagram of the 28-day bond strength test of the composite mortar in Example 1. Detailed Implementation

[0032] As used in this article:

[0033] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0034] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0035] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0036] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0037] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0038] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0039] This application provides a composite mortar comprising 250-500 parts by weight of polymer emulsion, 400-700 parts by weight of quartz powder, 382-387 parts by weight of heavy calcium carbonate powder, 10-15 parts by weight of gypsum powder, 1-2 parts by weight of water-reducing agent, 0.5-2 parts by weight of polyvinyl alcohol, and 1-2 parts by weight of bentonite.

[0040] The specific amounts of polymer emulsion, quartz powder, heavy calcium carbonate powder, gypsum powder, water-reducing agent, polyvinyl alcohol, and bentonite in this application work together to achieve a balanced improvement in the mechanical properties, adhesive properties, and impermeability of the composite slurry.

[0041] When the amount of polymer emulsion added to the composite slurry is 250-500 parts by weight, it can maintain high flexural strength while ensuring high bonding strength and high flexibility. If the amount of polymer emulsion added is too small, there will be problems with low bonding strength and poor flexibility. If the amount of polymer emulsion added is too large, there will be problems with low flexural strength and increased production costs.

[0042] When the amount of quartz powder added to the composite slurry is 400-700 parts by weight, it is beneficial to achieve a balance between high compressive strength, smooth application, and high adhesion performance. If too little quartz powder is added, the compressive strength will be reduced, and there will be problems with smooth application. If too much quartz powder is added, the adhesion strength will be reduced.

[0043] When the amount of polyvinyl alcohol added to the composite slurry is 0.5-2 parts by weight, it is beneficial to achieve a balance between high adhesive performance and high flexural strength. If the amount of polyvinyl alcohol added is too small, the adhesive strength will be reduced. If the amount of polyvinyl alcohol added is too large, the flexural strength will be reduced.

[0044] For example, the amount of polymer emulsion added to the composite slurry is 250 parts by weight, 300 parts by weight, 400 parts by weight, 500 parts by weight, or any value between 250 and 500 parts by weight; the amount of quartz powder added to the composite slurry is 400 parts by weight, 500 parts by weight, 600 parts by weight, 700 parts by weight, or any value between 400 and 700 parts by weight; the amount of heavy calcium carbonate powder added to the composite slurry is 382 parts by weight, 383 parts by weight, 384 parts by weight, 385 parts by weight, 386 parts by weight, 387 parts by weight, or any value between 382 and 387 parts by weight. The amounts of gypsum powder added to the composite slurry are 10, 11, 12, 13, 14, 15 parts by weight, or any value between 10 and 15 parts by weight; the amounts of water-reducing agent added to the composite slurry are 1, 2, or any value between 1 and 2 parts by weight; the amounts of polyvinyl alcohol added to the composite slurry are 0.5, 1, 1.5, 2, or any value between 0.5 and 2 parts by weight; the amounts of bentonite added to the composite slurry are 1, 2, or any value between 1 and 2 parts by weight.

[0045] The composite mortar of this application exhibits rapid hardening speed, high bonding strength, and good adaptability to various substrates, thus improving construction efficiency. Furthermore, the raw materials of this composite mortar are inexpensive, environmentally friendly, non-toxic, and harmless, meeting green building standards. In addition, this composite mortar possesses excellent waterproofing performance (high resistance to seepage pressure) and excellent crack resistance (high flexural strength), contributing to improved overall project quality. In summary, the components of this composite mortar work synergistically to effectively solve the problems of traditional mortars, such as limited functionality, low construction efficiency, and insufficient environmental friendliness.

[0046] In some embodiments, the addition of gypsum powder can enhance the initial strength of the mortar, allowing it to meet strength requirements without drying and exhibiting rapid hardening. Simultaneously, gypsum powder helps to further enhance the sound insulation and thermal insulation properties of the slabs in later stages. Without gypsum powder, the mortar's setting time would be excessively long, hindering subsequent construction and reducing its later sound insulation and thermal insulation performance.

[0047] According to embodiments of this application, the polymer emulsion includes a styrene-acrylic emulsion. The addition of a styrene-acrylic emulsion helps reduce overall costs, improves the surface appearance of the finished product, and enhances the product's bonding strength, flexibility, and crack resistance.

[0048] In some embodiments, the styrene-acrylic emulsion is a rigid styrene-acrylic emulsion.

[0049] According to embodiments of this application, the polymer emulsion has a solid content of 46-50%. For example, the solid content of the polymer emulsion is any value between 46%, 47%, 48%, 49%, 50%, or 46-50%.

[0050] According to embodiments of this application, the water-reducing agent is a polycarboxylate superplasticizer. The addition of a polycarboxylate superplasticizer helps improve the strength of the mortar. Without the addition of a water-reducing agent, the flexural strength of the mortar is difficult to achieve the desired level.

[0051] According to an embodiment of this application, the particle size of the quartz powder is 150-200 mesh. When the particle size of the quartz powder is within this range, it can improve the smoothness of the application and the surface gloss, which is beneficial for improving the appearance of the mortar layer formed by the mortar, and also helps to further enhance the strength of the mortar. Simultaneously, the addition of quartz powder helps to improve the density of the composite mortar, thereby improving its waterproofness. If the particle size of the quartz powder is not within the above-mentioned range, it will result in insufficient surface gloss and density, reducing flexural strength.

[0052] For example, the particle size of quartz powder is 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh, 200 mesh, or any value between 150 and 200 mesh.

[0053] According to an embodiment of this application, the particle size of the heavy calcium carbonate powder is 200-500 mesh. When the particle size of the heavy calcium carbonate powder is within the above range, it helps to improve the fineness and surface gloss of the mortar, thereby optimizing the appearance of the final mortar layer and further improving the strength of the mortar. If the particle size of the heavy calcium carbonate powder is not within the above range, it will result in insufficient surface gloss and density, reducing flexural strength.

[0054] For example, the particle size of heavy calcium carbonate powder can be 200 mesh, 300 mesh, 400 mesh, 500 mesh, or any value between 200 and 500 mesh.

[0055] In some embodiments, the addition of bentonite and polyvinyl alcohol improves workability, enhances the water retention and ductility of the composite mortar, facilitates smoother construction, and reduces the risk of cracking. Without bentonite, the mortar is prone to bleeding. Without polyvinyl alcohol, the amount of polymer emulsion added needs to be increased to maintain performance, and the mortar is also prone to bleeding.

[0056] In some embodiments, the 28-day bond strength of the composite mortar is ≥0.7 MPa. For example, the 28-day bond strength of the composite mortar is any value of 0.7 MPa, 0.8 MPa, 0.9 MPa, 1.0 MPa, or ≥0.7 MPa.

[0057] In some embodiments, the 28-day flexural strength of the composite mortar is ≥4.5 MPa. For example, the 28-day flexural strength of the composite mortar is any value of 4.5 MPa, 4.6 MPa, 4.7 MPa, 4.8 MPa, 4.9 MPa, 5 MPa, or ≥4.5 MPa.

[0058] In some embodiments, the initial setting time of the composite mortar is 15-20 minutes. When the initial setting time of the composite mortar is within the above range, it is beneficial to achieve rapid construction, shorten the interval between procedures, and thus improve construction efficiency and project progress.

[0059] For example, the initial setting time of composite mortar can be any value between 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, or 15-20 min.

[0060] In some embodiments, the composite mortar has a seepage resistance pressure ≥1.0 MPa. For example, the composite mortar has a seepage resistance pressure of 1.0 MPa, 1.1 MPa, 1.2 MPa, or any value ≥1.0 MPa.

[0061] This application also provides a method for preparing the composite mortar as described above, comprising:

[0062] Quartz powder, heavy calcium carbonate powder, gypsum powder, water-reducing agent, polyvinyl alcohol and bentonite are mixed to obtain powder;

[0063] The polymer emulsion is mixed with the powder to obtain the composite mortar.

[0064] This application also provides a backing plate, including a substrate and a mortar layer formed of composite mortar;

[0065] The composite mortar is the composite mortar described above or the composite mortar prepared by the preparation method described above.

[0066] The mortar layer formed by the composite mortar of this application has good adhesion to various substrate materials, which is beneficial to improving the structural stability of the backing board and also to improving the ease of construction. It is widely applicable to the interior wall and ceiling systems of modern buildings and can meet the dual requirements of green buildings for environmental protection and functionality.

[0067] According to an embodiment of this application, the substrate comprises a polystyrene board.

[0068] In some embodiments, the backing plate further includes a fiberglass mesh embedded in the mortar layer or located between the substrate and the mortar layer.

[0069] The backing board of this application can be widely used in building interiors to replace traditional gypsum board, and is especially suitable for damp environments such as kitchens and bathrooms, exhibiting excellent water resistance and deformation resistance.

[0070] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0071] The raw material information used in the examples and comparative examples is as follows:

[0072] The styrene-acrylic emulsion is a rigid styrene-acrylic emulsion with a solid content of 48%.

[0073] The particle size of the quartz powder is 150-200 mesh;

[0074] The particle size of the heavy calcium carbonate powder is 400 mesh;

[0075] The water-reducing agent is a polycarboxylate water-reducing agent, purchased from Jiangsu Zhaojia Building Materials Technology Co., Ltd., model number ZJ-PC8800.

[0076] Example 1

[0077] Example 1 provides a composite mortar comprising: 300 parts by weight of styrene-acrylic emulsion, 600 parts by weight of quartz powder, 387 parts by weight of heavy calcium carbonate powder, 10 parts by weight of gypsum powder, 1 part by weight of water-reducing agent, 1 part by weight of polyvinyl alcohol, and 1 part by weight of bentonite.

[0078] Example 1 also provides a method for preparing composite mortar, comprising: mixing quartz powder, heavy calcium carbonate powder, gypsum powder, water-reducing agent, polyvinyl alcohol and bentonite to obtain powder;

[0079] At 20°C, styrene-acrylic emulsion with a solid content of 48% and powder are mixed in a high-speed mixer at a speed of 1000 rpm for 90 seconds to obtain composite mortar.

[0080] Example 1 also provides a backing board, which includes a substrate and a mortar layer formed by composite mortar, wherein the substrate is a polystyrene board. Specifically, the preparation method of the backing board includes: laying a fiberglass mesh on the surface of the substrate, then coating the fiberglass mesh with composite mortar to the designed thickness, and drying to form a mortar layer.

[0081] A physical image of the backing plate prepared in Example 1 is shown below. Figure 1 As shown.

[0082] Examples 2-5 and Comparative Examples 1-4

[0083] The composite mortars of Examples 2-5 and Comparative Examples 1-4 were prepared according to the method of Example 1. The formulations of the composite mortars of Examples 2-5 and Comparative Examples 1-4 are shown in Table 1.

[0084] Comparative Example 5

[0085] Commercially available mortar was used. The mortar in Comparative Example 5 was adhesive mortar (ordinary type), purchased from Zhongde Xinya Building Materials Co., Ltd.

[0086] Table 1 Formulations of Examples and Comparative Examples

[0087]

[0088] The performance of the composite mortars in Examples 1-5 and Comparative Examples 1-5 was tested using the following methods.

[0089] 28-day bond strength: JG / T 158-2013 Adhesives and plastering mortar (for EPS boards)

[0090] 28-day flexural strength: GB / T 17671-2021 Test method for strength of cement mortar.

[0091] Initial setting time: JGJ / T 70-2009 Standard for Test Methods of Basic Performance of Building Mortar.

[0092] Anti-seepage pressure: JGJ / T 70-2009 Standard for Basic Performance Test Methods of Building Mortar.

[0093] The test results of the composite mortars in Examples 1-5 and Comparative Examples 1-5 are shown in Table 1.

[0094] Table 2 Comparison of performance test results between the examples and comparative examples

[0095]

[0096] From Table 2 and Figure 2 It can be seen that the composite mortars of Examples 1-5 have high bonding strength, high flexural strength, reasonable setting time, and high impermeability pressure, and their comprehensive performance is significantly better than that of Comparative Examples 1-5.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0098] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A composite mortar for backing boards, characterized in that, The backing plate includes a substrate and a mortar layer formed by the composite mortar; The composite mortar is composed of the following components: 250-500 parts by weight of polymer emulsion, 400-700 parts by weight of quartz powder, 382-387 parts by weight of heavy calcium carbonate powder, 10-15 parts by weight of gypsum powder, 1-2 parts by weight of water-reducing agent, 0.5-2 parts by weight of polyvinyl alcohol, and 1-2 parts by weight of bentonite. The polymer emulsion is a styrene-acrylic emulsion, and the solid content of the polymer emulsion is 46-50%. The water-reducing agent is a polycarboxylate water-reducing agent; the particle size of the quartz powder is 150-200 mesh; the particle size of the heavy calcium carbonate powder is 200-500 mesh. The composite mortar meets the following conditions: the 28-day bond strength of the composite mortar is ≥0.7 MPa; the 28-day flexural strength of the composite mortar is ≥4.5 MPa; the initial setting time of the composite mortar is 15-20 min; and the impermeability pressure of the composite mortar is ≥1.0 MPa.

2. A method for preparing composite mortar for backing plates as described in claim 1, characterized in that, include: Quartz powder, heavy calcium carbonate powder, gypsum powder, water-reducing agent, polyvinyl alcohol and bentonite are mixed to obtain powder; The polymer emulsion is mixed with the powder to obtain the composite mortar for the backing plate.

3. A backing plate, characterized in that, Includes a substrate and a mortar layer formed of composite mortar; The composite mortar is the composite mortar for backing plate as described in claim 1 or the composite mortar for backing plate prepared by the preparation method described in claim 2.

4. The backing plate according to claim 3, characterized in that, The substrate includes a polystyrene board; And / or, the backing plate further includes a fiberglass mesh embedded in the mortar layer or located between the substrate and the mortar layer.

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