Mildew-proof and moisture-proof modified polymer mortar and preparation method thereof

Abstract

The invention provides mildew-proof and moisture-proof modified polymer mortar and a preparation method thereof, and the mildew-proof and moisture-proof modified polymer mortar comprises the following components in parts by weight: 100-150 parts of Portland cement, 18-30 parts of a modified polymer emulsion, 2-6 parts of an antibacterial and mildew-proof additive, 1-2 parts of a water reducing agent, 0.1-0.5 part of a defoaming agent, 0.2-0.5 part of a thickening agent and 40-80 parts of water, the modified polymer emulsion improves the microstructure of the mortar, so that the mortar is more compact, and pores and capillary channels are reduced, so that the permeation of water is reduced, and the water resistance and moisture resistance are improved; by adding the antibacterial and mildew-proof additive, the growth and reproduction of mildew can be directly inhibited, so that a mildew-proof effect is achieved; the mildew-proof and damp-proof modified polymer mortar is smeared on the surface of the backing plate, so that the backing plate has remarkable effects in the aspects of damp-proof, mildew-proof and water-resistant performance.

Description

Technical Field

[0001] The invention relates to the field of mortar, and in particular to a mildew-proof and moisture-proof modified polymer mortar and a preparation method thereof. Background Art

[0002] In the field of construction, backing board is an important building material and is widely used in various building structures. Backing board is usually used in building exterior walls, roofs, basements and other parts to play the role of heat preservation, heat insulation, moisture resistance, sound insulation and so on. It can be used in combination with finishing materials, waterproof materials and the like to improve the overall performance of the building. The core material of the backing board is an extruded board with a closed-cell structure, which has a low water absorption rate, but it is still difficult to avoid water vapor penetration during long-term use. If the backing board is in a humid environment for a long time, moisture will penetrate into the backing board, resulting in a decrease in the performance of the backing board. In addition, a humid environment will also provide conditions for the growth of mold, thereby affecting the beauty and service life of the building, and endangering the health of indoor residents.

[0003] Polymer mortar is a composite material composed of cement, polymer emulsion and other materials. It has high strength, adhesion and durability, and also has good waterproof, moisture-proof and crack-resistant properties. The polymer emulsion in the polymer mortar can form a good bond with cement and other materials, thereby improving the adhesion of the mortar. This strong adhesion can make the polymer mortar tightly bonded to the backing board to prevent moisture penetration. By applying polymer mortar on the surface of the backing board, a waterproof and moisture-proof protective layer can be formed to prevent moisture penetration, thereby inhibiting the growth of mold and improving the moisture-proof and mold-proof ability of the backing board. Polymer mortar has high strength and adhesion, which can enhance the strength and stability of the backing board. This enhancement can improve the bearing capacity of the backing board, thereby extending the service life of the backing board.

[0004] At present, some research has been conducted at home and abroad on the application of polymer mortar in moisture and mildew resistance of backing board. Researchers have improved the moisture and mildew resistance of polymer mortar by adding different modified substances, such as nanomaterials and antibacterial agents, to polymer mortar. In addition, researchers have also improved the performance and service life of polymer mortar by optimizing the formula and construction process of polymer mortar. However, the cost of polymer mortar is relatively high, which limits its application in some construction projects. Moreover, the construction process of polymer mortar is relatively complicated and requires professional construction personnel to operate, which also increases the construction cost. Although polymer mortar has good durability, it will still be affected by external environmental factors such as ultraviolet rays and temperature changes during long-term use. These factors will cause the performance of polymer mortar to decline, thereby affecting the moisture and mildew resistance of backing board. Polymer mortar contains a certain amount of organic matter, such as various organic regulators, which may release harmful gases during use, causing harm to the environment and human health.

[0005] In view of the problems existing in the prior art, how to provide a mildew-proof and moisture-proof polymer mortar to solve the problem that the moisture-proof and mildew-proof capabilities of the backing board become weak and the water resistance becomes poor during long-term use is a problem to be solved urgently by the present invention. Summary of the invention

[0006] Purpose of the invention: The purpose of the present invention is to provide a mildew-proof and moisture-proof polymer mortar to solve the problem that the moisture-proof and mildew-proof abilities of the backing board become weak and the water resistance becomes poor during long-term use.

[0007] The technical solution of the present invention:

[0008] The present application provides a mildew-proof and moisture-proof modified polymer mortar, characterized in that the components of the mildew-proof and moisture-proof modified polymer mortar, measured by weight, include: 100-150 parts of silicate cement, 18-30 parts of modified polymer emulsion, 2-6 parts of antibacterial and mildew-proof additives, 1-2 parts of water reducer, 0.1-0.5 parts of defoaming agent, 0.2-0.5 parts of thickener, and 40-80 parts of water.

[0009] Furthermore, the raw materials for preparing the modified polymer emulsion include: EVA emulsion, styrene-butadiene latex, and 3-(trimethoxysilane)propyl acrylate toluene solution.

[0010] The preparation of the modified polymer emulsion comprises the following steps:

[0011] S1: weigh EVA emulsion, styrene-butadiene latex, and 3-(trimethoxysilane)propyl acrylate for later use;

[0012] S2: Add the EVA emulsion and 3-(trimethoxysilane)propyl acrylate toluene solution weighed in step S1 into a reaction bottle, stir at 20-30° C. for 1-2 hours at a stirring speed of 300-400 r / min to obtain a modified EVA emulsion;

[0013] S3: adding styrene-butadiene latex to the modified EVA emulsion obtained in step S2, raising the temperature to 50-60° C., and stirring for 1-2 hours to obtain the modified polymer emulsion.

[0014] Furthermore, the mass ratio of the EVA emulsion, styrene-butadiene latex, and 3-(trimethoxysilane)propyl acrylate toluene solution is 8-12:5-10:1.

[0015] Furthermore, the mass fraction of the 3-(trimethoxysilane)propyl acrylate toluene solution is 20-30%.

[0016] Furthermore, the weight average molecular weight of the EVA emulsion is 15 to 25 kDa; the weight average molecular weight of the styrene-butadiene latex is 8 to 15 kDa.

[0017] Furthermore, the antibacterial and mildew-proof additive is a mixture of one or more of calcium acetate, paint bactericidal preservative CL-141, and mortar bactericidal, preservative and mildew-proof agent LF-300-1.

[0018] Furthermore, the water reducing agent is a mixture of one or more of sodium gluconate and sodium lignosulfonate.

[0019] Furthermore, the defoaming agent is a mixture of one or more of Dow Corning AFE-1410 and BYK-024.

[0020] Furthermore, one or more of the thickeners hydroxypropyl methylcellulose, sodium alginate and xanthan gum are mixed.

[0021] The present application also provides a method for preparing a mildew-proof and moisture-proof modified polymer mortar, which is characterized by comprising the following steps:

[0022] Step 1: Place silicate cement in a mixing container, add antibacterial and anti-mildew additives, and stir at an appropriate speed to fully mix;

[0023] Step 2: Add the modified polymer emulsion, water reducing agent, defoaming agent and thickener into another container, stir evenly to prepare a mixed emulsion;

[0024] Step 3: Slowly pour the mixed emulsion prepared in step 2 into the container in step 1 and stir at a certain speed for a period of time;

[0025] Step 4: While stirring, slowly add water to the mixture in step 3 and stir for a while to obtain a uniform and fine mildew-proof and moisture-proof modified polymer mortar.

[0026] Furthermore, the stirring speed of step 1 is 300-400 rpm; the stirring speed of step 2 is 200-300 rpm; the stirring speed of step 3 is 200-300 rpm, and the stirring time is 0.5-1 hour; the stirring speed of step 4 is 200-300 rpm; and the stirring time is 1-2 hours.

[0027] EVA emulsion and styrene butadiene latex form a continuous polymer film in the mortar, and EVA emulsion and styrene butadiene latex are interwoven with cement hydration products to form a solid three-dimensional network structure. This structure can improve the integrity and water resistance of the mortar and reduce the erosion of water on the mortar. The polymer film has a certain flexibility and can deform to a certain extent without breaking under the action of water, thereby maintaining the integrity of the mortar. This film has a low permeability and can prevent the invasion of water and play a moisture-proof role. After the silane component in the toluene solution of 3-(trimethoxysilane) propyl acrylate reacts with the cement hydration product, it will form a hydrophobic structure inside the mortar, further reducing the mortar's ability to adsorb water and enhancing moisture-proof performance. After the silane component in the toluene of 3-(trimethoxysilane) propyl acrylate reacts with the cement hydration product, it will form siloxane bonds on the surface and inside of the mortar, enhancing the water resistance of the mortar. The active ingredients in the antibacterial and anti-mildew additive can inhibit the growth and reproduction of mold. These ingredients can destroy the cell wall and cell membrane of mold or interfere with the metabolic process of mold, thereby achieving the purpose of mold prevention. The additives are evenly distributed in the mortar and can continuously play an antibacterial and mold-proof role, effectively preventing mold growth even in a humid environment. The polymer film can prevent mold spores in the air from entering the mortar, reducing the chance of mold growth. The polymer emulsion can also increase the density of the mortar and reduce the supply of nutrients and oxygen required by mold, thereby inhibiting the growth of mold.

[0028] Beneficial effects:

[0029] The mildew-proof and moisture-proof modified polymer mortar provided by the present invention is spread on the surface of the backing board, so that the backing board has the characteristics of moisture-proof, mildew-proof and good water resistance, and has good development prospects. DETAILED DESCRIPTION

[0030] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0031] EVA emulsion (15 kDa, 25 kDa) was purchased from Celanese Corporation; styrene butadiene latex (8 kDa, 15 kDa) was purchased from BASF AG.

[0032] Unless otherwise specified, the chemical reagents used in the present invention are all commercially available analytically pure.

[0033] Preparation of 3-(trimethoxysilane)propyl acrylate toluene solution:

[0034] Prepare 5kg of 3-(trimethoxysilane)propyl acrylate toluene solution with a mass fraction of 17.5%, 20%, 30% and 32.5%, prepare a container and a stirring device, weigh 0.875kg, 1kg, 1.5kg and 1.625kg of 3-(trimethoxysilane)propyl acrylate and put them into the container, add 4.125kg, 4kg, 3.5kg and 3.375kg of toluene solution respectively, start the stirring device and stir evenly to obtain 3-(trimethoxysilane)propyl acrylate toluene solution with a mass fraction of 17.5%, 20%, 30% and 32.5%.

[0035] Preparation of modified polymer emulsion A:

[0036] S1: weigh 4 kg EVA emulsion (15 kDa), 5 kg styrene-butadiene latex (15 kDa), and 0.5 kg 3-(trimethoxysilane)propyl acrylate (20%), and set aside;

[0037] S2: Add the EVA emulsion and 3-(trimethoxysilane)propyl acrylate toluene solution weighed in step S1 into a reaction bottle, stir at 25° C. for 1 hour at a stirring speed of 300 r / min to obtain a modified EVA emulsion;

[0038] S3: Add styrene-butadiene latex to the modified EVA emulsion obtained in step S2, raise the temperature to 50° C., and stir for 2 hours to obtain the modified polymer emulsion A.

[0039] Preparation of modified polymer emulsion B:

[0040] The difference between this preparation and modified polymer emulsion A is that 4 kg EVA emulsion (15 kDa), 5 kg styrene butadiene latex (15 kDa), and 0.5 kg 3-(trimethoxysilane) propyl acrylate (20%) in step S1 are replaced with 6 kg EVA emulsion (25 kDa), 5 kg styrene butadiene latex (8 kDa), and 0.5 kg 3-(trimethoxysilane) propyl acrylate (30%). Preparation of modified polymer emulsion C:

[0041] The difference between this preparation and modified polymer emulsion A is that 4 kg EVA emulsion (15 kDa), 5 kg styrene butadiene latex (15 kDa), and 0.5 kg 3-(trimethoxysilane) propyl acrylate (20%) in step S1 are replaced with 2 kg EVA emulsion (15 kDa), 8 kg styrene butadiene latex (15 kDa), and 0.5 kg 3-(trimethoxysilane) propyl acrylate (20%). Preparation of modified polymer emulsion D:

[0042] The difference between this preparation and the modified polymer emulsion A is that 0.5 kg of 3-(trimethoxysilyl)propyl acrylate (20%) in step S1 is replaced by 0.5 kg of 3-(trimethoxysilyl)propyl acrylate (17.5%).

[0043] Preparation of modified polymer emulsion E:

[0044] The difference between this preparation and the modified polymer emulsion A is that 0.5 kg of 3-(trimethoxysilyl)propyl acrylate (20%) in step S1 is replaced by 0.5 kg of 3-(trimethoxysilyl)propyl acrylate (32.5%).

[0045] Preparation method A of mildew-proof and moisture-proof modified polymer mortar:

[0046] Step 1: Place silicate cement in a mixing container, add antibacterial and anti-mildew additives, and stir at a speed of 300 rpm to fully mix;

[0047] Step 2: Add the modified polymer emulsion, water reducing agent, defoaming agent and thickener into another container, and stir evenly at a speed of 250 rpm to prepare a mixed emulsion;

[0048] Step 3: slowly pour the mixed emulsion prepared in step 2 into the container of step 1 and stir at a speed of 200 rpm for 0.5 hours;

[0049] Step 4: While stirring, slowly add water to the mixture in step 3 at a stirring speed of 200 rpm. Stir for 1 hour to obtain a uniform and fine mildew-proof and moisture-proof modified polymer mortar.

[0050] Examples 1 to 6

[0051] The mildew-proof and moisture-proof modified polymer mortar was prepared according to the above-mentioned preparation method. Table 1 is the ingredient list of mildew-proof and moisture-proof modified polymer mortar of Examples 1 to 6 in parts by weight.

[0052] Table 1

[0053]

[0054]

[0055] Comparative Examples 1 to 3

[0056] The mildew-proof and moisture-proof modified polymer mortar was prepared according to the above-mentioned preparation method. Table 2 is the ingredient list of the mildew-proof and moisture-proof modified polymer mortar of Comparative Examples 1 to 3, calculated in parts by weight.

[0057] Table 2

[0058]

[0059]

[0060] Performance test: The mildew-proof and moisture-proof modified polymer mortar prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was applied to the surface of a 40×55 cm backing board at 2 g per square centimeter, and allowed to stand at 25°C for 48 hours to ensure that the sample surface was flat and had no obvious defects.

[0061] 1. Moisture-proof test: For moisture permeability test, prepare the test equipment, moisture permeable cup, desiccant, and sealing material. Install the backing plate on the moisture permeable cup to ensure good sealing. Place the moisture permeable cup in a constant temperature and humidity chamber, set the temperature to 45°C and the relative humidity to 75%. After 24 hours, measure the weight gain of the desiccant in the moisture permeable cup and calculate the moisture permeability.

[0062] 2. Anti-mildew performance test: Place the backing board sample in a test box with a humid environment of 30°C and a relative humidity of 90%, and spray 0.8×10 6 / mL of mold spore suspension was added to observe the moldiness of the sample, and the mold coverage was observed under a microscope with a magnification of 50 times.

[0063] 3. Water resistance test: prepare water pressure resistance test equipment, pressure pump, pressure gauge, and sealing fixture. Install the backing board sample in the sealing fixture. Use the pressure pump to apply gradually increasing water pressure to the sample. Observe the reading of the pressure gauge at the same time and record the water pressure value when the sample starts to leak, which is the water pressure resistance of the backing board.

[0064] Table 3: Test results

[0065]

[0066]

[0067] From the above data, it can be seen that the mildew-proof and moisture-proof modified polymer mortar prepared by the present invention makes the backing board have significant effects in terms of moisture-proof, mildew-proof and water-resistant properties. It can be seen from the comparison between Example 4 and Example 2 that when preparing the modified polymer emulsion, the mass ratio of EVA emulsion, styrene-butadiene latex, and 3-(trimethoxysilane) propyl acrylate toluene solution is unreasonable, which will lead to the poor moisture-proof, mildew-proof and water-resistant properties of the backing board using the mildew-proof and moisture-proof modified polymer mortar. It can be seen from the comparison between Examples 6 and 7 and Example 2 that when preparing the modified polymer emulsion, the mass fraction of 3-(trimethoxysilane) propyl acrylate toluene solution is unreasonable, which will lead to the application of mildew-proof and moisture-proof modified polymer mortar. The moisture-proof, mildew-proof and water-resistant performances of the backing board are deteriorated; from Comparative Example 1 and Example 2, not using the prepared modified polymer emulsion will result in the moisture-proof, mildew-proof and water-resistant performances of the backing board using the mildew-proof and moisture-proof modified polymer mortar being deteriorated; from Comparative Example 2 and Example 3, replacing the modified polymer emulsion with EVA emulsion will result in the moisture-proof, mildew-proof and water-resistant performances of the backing board using the mildew-proof and moisture-proof modified polymer mortar being deteriorated; from the comparison between Comparative Example 3 and Example 2, it can be seen that not using antibacterial and mildew-proof additives will result in the mold coverage rate of the backing board using the mildew-proof and moisture-proof modified polymer mortar being increased, the mildew-proof effect being deteriorated, and the expected effect being unable to be achieved.

[0068] The present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A mildew-proof and moisture-proof modified polymer mortar, characterized in that: The components of the mildew-proof and moisture-proof modified polymer mortar include, by weight, 100 to 150 parts of silicate cement, 18 to 30 parts of modified polymer emulsion, 2 to 6 parts of antibacterial and mildew-proof additives, 1 to 2 parts of water reducer, 0.1 to 0.5 parts of defoamer, 0.2 to 0.5 parts of thickener, and 40 to 80 parts of water.

2. The mildew-proof and moisture-proof modified polymer mortar according to claim 1, characterized in that: The raw materials for preparing the modified polymer emulsion include: EVA emulsion, styrene-butadiene latex, and 3-(trimethoxysilane)propyl acrylate toluene solution.

3. The mildew-proof and moisture-proof modified polymer mortar according to claim 2, characterized in that: The preparation of the modified polymer emulsion comprises the following steps: S1: weigh EVA emulsion, styrene-butadiene latex, and 3-(trimethoxysilane)propyl acrylate for later use; S2: Add the EVA emulsion and 3-(trimethoxysilane)propyl acrylate toluene solution weighed in step S1 into a reaction bottle, stir at 20-30° C. for 1-2 hours at a stirring speed of 300-400 r / min to obtain a modified EVA emulsion; S3: adding styrene-butadiene latex to the modified EVA emulsion obtained in step S2, raising the temperature to 50-60° C., and stirring for 1-2 hours to obtain the modified polymer emulsion.

4. The mildew-proof and moisture-proof modified polymer mortar according to claim 3, characterized in that: The mass ratio of the EVA emulsion, styrene-butadiene latex and 3-(trimethoxysilane)propyl acrylate toluene solution is 8-12:5-10:

1.

5. The mildew-proof and moisture-proof modified polymer mortar according to claim 4, characterized in that: The mass fraction of the 3-(trimethoxysilane)propyl acrylate toluene solution is 20-30%.

6. The mildew-proof and moisture-proof modified polymer mortar according to claim 1, characterized in that: The weight average molecular weight of the EVA emulsion is 15 to 25 kDa; the weight average molecular weight of the styrene-butadiene latex is 8 to 15 kDa.

7. The mildew-proof and moisture-proof modified polymer mortar according to claim 1, characterized in that: The antibacterial and mildew-proof additive is a mixture of one or more of calcium acetate, paint bactericidal preservative CL-141, and mortar bactericidal, preservative and mildew-proof agent LF-300-1.

8. The mildew-proof and moisture-proof modified polymer mortar according to claim 1, characterized in that: The water reducer is a mixture of one or more of sodium gluconate and sodium lignosulfonate; the defoamer is a mixture of one or more of Dow Corning AFE-1410 and BYK-024; the thickener is a mixture of one or more of hydroxypropyl methylcellulose, sodium alginate and xanthan gum.

9. The method for preparing the mildew-proof and moisture-proof modified polymer mortar according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Place silicate cement in a mixing container, add antibacterial and anti-mildew additives, and stir at an appropriate speed to fully mix; Step 2: Add the modified polymer emulsion, water reducing agent, defoaming agent and thickener into another container, stir evenly to prepare a mixed emulsion; Step 3: Slowly pour the mixed emulsion prepared in step 2 into the container in step 1 and stir at a certain speed for a period of time; Step 4: While stirring, slowly add water to the mixture in step 3 and stir for a while to obtain a uniform and fine mildew-proof and moisture-proof modified polymer mortar.

10. The method for preparing the mildew-proof and moisture-proof modified polymer mortar according to claim 9, characterized in that: The stirring speed of step 1 is 300-400 rpm; the stirring speed of step 2 is 200-300 rpm; the stirring speed of step 3 is 200-300 rpm, and the stirring time is 0.5-1 hour; the stirring speed of step 4 is 200-300 rpm; and the stirring time is 1-2 hours.

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