Preparation method of breathable exterior wall material

Abstract

The application discloses a preparation method of breathable outer wall material, and is specifically implemented according to the following steps: step 1, precast concrete; step 2, preparation of a moisturizing precursor; step 3, solid-liquid reaction to obtain a porous breathing function layer; step 4, self-condensation to obtain the breathable outer wall material; the moisturizing precursor obtained in step 2 is in a plastic period and is coated on the precast concrete layer obtained in step 1 which is in a latent period, and then the porous breathing function layer obtained in step 3 which is in a dough period is coated on the moisturizing precursor layer to obtain a mixture, and the mixture is self-condensed and formed in a mixed solution of methyl methacrylate and a retarder to obtain the breathable outer wall material. The preparation method does not need to introduce green plants, and can realize the functions of absorbing carbon dioxide and slowly releasing oxygen.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a method for preparing breathable exterior wall materials. Background Technology

[0002] With the advancement of urbanization, while changing people's material living conditions, it has also brought serious resource crises to cities, such as reduced urban green space, the urban heat island effect, and increased carbon dioxide emissions. Reduced green space means fewer plants capable of photosynthesis, while urban congestion and heavy vehicle emissions increase carbon dioxide emissions. Singapore, known as a garden city, has significantly improved its atmospheric environment and reduced the urban heat island effect by using vertical greening to allow plants to grow among concrete buildings. However, due to the adaptability of plants, the selection of greening plants is relatively limited, and subsequent maintenance is difficult, requiring significant investment of human and financial resources. Therefore, the development of breathable building materials that can consume carbon dioxide and release oxygen is particularly important.

[0003] Chinese patent "An Integrated Environmentally Friendly Building Exterior Wall System Based on Green Algae Bioactive Material" (Application No.: 201911253085.3, Publication No.: CN 110886398 A, Publication Date: 2020.03.17) discloses an integrated environmentally friendly building exterior wall system based on green algae bioactive material. This system utilizes the photosynthesis of green algae to absorb carbon dioxide and release oxygen by installing a layer of green algae bioactive material on the building exterior wall surface. However, this structure requires an expandable water storage layer that is tightly bonded to the green algae bioactive material layer to provide the necessary moisture for the green algae to survive. For buildings in arid climates, this system has a relatively short lifespan.

[0004] Chinese patent "A Green and Environmentally Friendly Exterior Wall Structure" (Application No.: 201720581247.6, Authorization No.: CN207314577 U, Publication Date: 2018.05.04) discloses a green and environmentally friendly exterior wall structure, which consists of roof tiles, a breathable membrane, a concrete layer, an insulation layer, a fine-grained concrete layer, and an air self-cleaning negative ion layer. The air self-cleaning negative ion layer contains nano-sized titanium dioxide, which can produce free hydroxyl radicals and active oxygen with oxidizing capabilities, decomposing organic compounds and thus achieving self-cleaning and air purification functions. However, nano-titanium dioxide requires light to produce an oxidation-reduction reaction, and the air self-cleaning negative ion layer in this patent is located far from the exterior wall, on the innermost side, which is not conducive to the application of light conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a breathable exterior wall material that does not require the introduction of greenery and can absorb carbon dioxide and slowly release oxygen under conditions without the need for light.

[0006] The technical solution adopted in this invention is a method for preparing breathable exterior wall materials, which is implemented according to the following steps:

[0007] Step 1, Precast concrete;

[0008] Step 2, prepare the moisturizing precursor;

[0009] Step 3: Solid-liquid reaction yields a porous, breathable layer;

[0010] Step 4: Self-condensing to obtain breathable exterior wall material;

[0011] The moisturizing precursor obtained in step 2, which is in the plastic stage, is coated onto the precast concrete layer obtained in step 1, which is in the latent stage. Then, the porous breathable functional layer obtained in step 3, which is in the dough stage, is coated onto the moisturizing precursor layer to obtain a mixture. The mixture is then self-cured in a mixed solution of methyl methacrylate and a retarder to obtain a breathable exterior wall material.

[0012] The invention is further characterized in that,

[0013] The specific process of step 1 is as follows:

[0014] Step 1.1: Weigh the following raw materials by mass percentage: river sand 24%-26%, ceramsite 24%-26%, retarder water-reducing agent 0.2%-0.3%, air-entraining agent 0.1%-0.5%, polymethyl methacrylate 23.55%-28.97%, benzoyl peroxide 0.15%-0.23%, and ordinary silicate cement slurry 18%-28%. The total mass of the above components is 100%.

[0015] Step 1.2: Add the river sand, ceramsite, retarder, air-entraining agent, polymethyl methacrylate and benzoyl peroxide weighed in Step 1.1 to ordinary silicate cement slurry and stir for 10-15 minutes to obtain precast concrete.

[0016] The water-cement ratio of ordinary silicate cement paste is 0.44.

[0017] The retarding water-reducing agent is any one of calcium lignosulfonate and sodium lignosulfonate, and the air-entraining agent is any one of sodium rosinate, sodium dodecylbenzenesulfonate, and sodium dodecyl sulfate.

[0018] The specific process of step 2 is as follows:

[0019] Step 2.1 Weigh the following raw materials by mass percentage: diatomaceous earth 30%-32%, kaolin 11%-14%, acrylic adhesive 2%-4%, polymethyl methacrylate 14.89%-16.87%, benzoyl peroxide 0.11%-0.13%, with the balance being water. The total mass of the above components is 100%.

[0020] Step 2.2: Add the diatomaceous earth, kaolin, acrylic resin, polymethyl methacrylate and benzoyl peroxide weighed in step 2.1 to water in sequence to obtain a mixture. After mixing and stirring evenly for 1-2 hours, a moisturizing precursor with coatability in the plastic stage is obtained.

[0021] The specific process of step 3 is as follows:

[0022] Step 3.1: Weigh the following raw materials by mass percentage: calcium oxide 16%-18%, calcium peroxide 11%-13%, zeolite 6%-10%, polymethyl methacrylate 37.72%-41.7%, benzoyl peroxide 0.28%-0.3%, double-acting baking powder 8%-10%, and methyl methacrylate 15%-17%. The total mass of the above components is 100%.

[0023] Step 3.2: Add the calcium oxide, calcium peroxide, zeolite, polymethyl methacrylate, benzoyl peroxide and double-acting baking powder weighed in step 3.1 to methyl methacrylate, mix and stir for 10 min-16 min to obtain an adhesive mixture, treat it in a constant temperature water bath at 30℃-37℃ for 2 min-8 min, and immediately take it out to obtain a workable breathing functional layer in the dough stage.

[0024] The particle size of zeolite is 0.5mm-1mm.

[0025] In step 4, the volume ratio of the precast concrete layer, the moisture-retaining precursor layer, and the breathable functional layer is 2:1:2; the self-setting time is 20-30 minutes.

[0026] In step 4, the mass percentage of methyl methacrylate is 99.9%-99.99%, the mass percentage of the retarder is 0.01%-0.1%, and the sum of the mass percentages of the two is 100%.

[0027] In step 4, the retarder is any one of hydroquinone, p-tert-butylcatechol, etc.

[0028] The beneficial effects of this invention are:

[0029] (1) The method for preparing the breathable exterior wall material of the present invention enables the exterior wall material to absorb carbon dioxide and slowly release oxygen through the composite of a breathable functional layer, a moisturizing layer, and a concrete layer; by controlling the pore structure and zeolite particle size of the breathable functional layer, channels for absorbing carbon dioxide and releasing oxygen are established, and a path is provided for the diffusion of water molecules provided by the moisturizing layer. The setting of the moisturizing layer provides the breathable functional layer with long-lasting water molecules to promote the absorption of carbon dioxide and release of oxygen by calcium oxide and calcium peroxide in a humid environment;

[0030] (2) The method for preparing the breathable exterior wall material of the present invention provides good mechanical properties for the exterior wall material by setting the concrete layer, and can isolate the moisture of the moisture-retaining layer from entering the interior wall. At the same time, by controlling the reaction time of each layer, good mechanical properties can be obtained after self-curing.

[0031] (3) The method for preparing the breathable exterior wall material of the present invention does not require sintering or the introduction of green plants. It is easy to operate and has broad prospects in reducing the urban heat island effect and green and environmentally friendly building materials. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a breathable exterior wall material prepared according to the present invention.

[0033] In the diagram, 1. Breathable layer, 2. Moisturizing precursor layer, 3. Concrete layer. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] The method for preparing the breathable exterior wall material of the present invention is specifically implemented according to the following steps:

[0036] Step 1, Precast concrete;

[0037] The specific process is as follows:

[0038] Step 1.1: Weigh the following raw materials by mass percentage: river sand 24%-26%, ceramsite 24%-26%, retarder water-reducing agent 0.2%-0.3%, air-entraining agent 0.1%-0.5%, polymethyl methacrylate 23.55%-28.97%, benzoyl peroxide 0.15%-0.23%, and ordinary silicate cement slurry 18%-28%. The total mass of the above components is 100%.

[0039] The water-cement ratio of ordinary silicate cement paste is 0.44;

[0040] The retarding water-reducing agent is either calcium lignosulfonate or sodium lignosulfonate;

[0041] The air-entraining agent is any one of sodium rosinate, sodium dodecylbenzene sulfonate, and sodium dodecyl sulfate;

[0042] Step 1.2: Add the river sand, ceramsite, retarder, air-entraining agent, polymethyl methacrylate and benzoyl peroxide weighed in Step 1.1 to ordinary silicate cement slurry and stir for 10-15 minutes to obtain precast concrete.

[0043] Step 2, prepare the moisturizing precursor;

[0044] The specific process is as follows:

[0045] Step 2.1 Weigh the following raw materials by mass percentage: diatomaceous earth 30%-32%, kaolin 11%-14%, acrylic adhesive 2%-4%, polymethyl methacrylate 14.89%-16.87%, benzoyl peroxide 0.11%-0.13%, with the balance being water. The total mass of the above components is 100%.

[0046] Step 2.2: Add the diatomaceous earth, kaolin, acrylic glue, polymethyl methacrylate and benzoyl peroxide weighed in step 2.1 to water in sequence to obtain a mixture. After mixing and stirring evenly for 1-2 hours, a moisturizing precursor with coatability in the plastic period is obtained.

[0047] Step 3: Solid-liquid reaction yields a porous, breathable layer;

[0048] The specific process is as follows:

[0049] Step 3.1: Weigh the following raw materials by mass percentage: calcium oxide 16%-18%, calcium peroxide 11%-13%, zeolite 6%-10%, polymethyl methacrylate 37.72%-41.7%, benzoyl peroxide 0.28%-0.3%, double-acting baking powder 8%-10%, and methyl methacrylate 15%-17%. The total mass of the above components is 100%.

[0050] The particle size of the zeolite is 0.5mm-1mm;

[0051] Step 3.2: Add the calcium oxide, calcium peroxide, zeolite, polymethyl methacrylate, benzoyl peroxide and double-acting baking powder weighed in step 3.1 to methyl methacrylate, mix and stir for 10 min-16 min to obtain an adhesive mixture, treat it in a constant temperature water bath at 30℃-37℃ for 2 min-8 min, and immediately take it out to obtain a workable breathing functional layer in the dough stage;

[0052] Step 4: Self-condensing to obtain breathable exterior wall material;

[0053] The moisturizing precursor obtained in step 2, which is in the plastic stage, is coated onto the precast concrete layer obtained in step 1, which is in the latent stage. Then, the porous breathable functional layer obtained in step 3, which is in the dough stage, is coated onto the moisturizing precursor layer to obtain a mixture. The volume ratio of the precast concrete layer, the moisturizing precursor layer and the breathable functional layer is 2:1:2. The mixture is self-cured in a mixed solution of methyl methacrylate and a retarder for 20-30 minutes to form a breathable exterior wall material.

[0054] The methyl methacrylate comprises 99.9%-99.99% by mass, the retarder comprises 0.01%-0.1% by mass, and the sum of the two by mass percentages is 100%.

[0055] The retarder is any one of hydroquinone, p-tert-butylcatechol, etc.

[0056] This invention selects zeolite with a particle size of 0.5mm-1mm, double-acting baking powder with a mass ratio of 8%-10%, and constant temperature water bath treatment at 30℃-37℃ to construct channels for absorbing carbon dioxide and releasing oxygen in the breathable layer. The zeolite particle size and double-acting baking powder content are selected to control the partial exposure of zeolite in the channels. By controlling the reaction time of the precast concrete to 10min-15min, a plastic precast concrete layer in the latent stage is obtained; by controlling the reaction time of the moisture-retaining precursor to 1h-2h, a coatable moisture-retaining layer in the plastic stage is obtained; and by controlling the reaction time of the breathable layer to 10min-16min, a workable breathable layer in the dough stage is obtained. By controlling the coating sequence and volume ratio of the precast concrete layer, moisture-retaining layer, and breathable layer to 2:1:2, it is ensured that the moisture-retaining layer can both provide long-lasting water molecules to the breathable layer and prevent moisture from entering the interior wall. By controlling the self-curing time to 20-30 minutes and using excess polymethyl methacrylate in the breathable layer, a breathable exterior wall material with good mechanical properties is obtained. This invention provides a breathable exterior wall material that requires no sintering, is easy to operate, simple to design, and eliminates the need for additional greenery, enabling it to absorb carbon dioxide from humid air and slowly release oxygen. This invention has broad prospects in the field of reducing the urban heat island effect and developing green and environmentally friendly building materials.

[0057] Example 1

[0058] The method for preparing the breathable exterior wall material of the present invention is specifically implemented according to the following steps:

[0059] Step 1, Precast concrete;

[0060] The specific process is as follows:

[0061] Step 1.1 Weigh the following raw materials by mass percentage: 24% river sand, 24% ceramsite, 0.2% calcium lignosulfonate, 0.1% sodium rosinate, 23.55% polymethyl methacrylate, 0.15% benzoyl peroxide, and 28% ordinary silicate cement slurry;

[0062] The water-cement ratio of ordinary silicate cement paste is 0.44;

[0063] Step 1.2: Add the river sand, ceramsite, calcium lignosulfonate, sodium rosinate, polymethyl methacrylate and benzoyl peroxide weighed in Step 1.1 to ordinary silicate cement slurry and stir for 10-15 minutes to obtain precast concrete.

[0064] Step 2, prepare the moisturizing precursor;

[0065] The specific process is as follows:

[0066] Step 2.1 Weigh the following raw materials by mass percentage: diatomaceous earth 30%, kaolin 14%, acrylic glue 2%, polymethyl methacrylate 14.89%, benzoyl peroxide 0.11%, and water 39%.

[0067] Step 2.2: Add the diatomaceous earth, kaolin, acrylic glue, polymethyl methacrylate and benzoyl peroxide weighed in step 2.1 to water in sequence to obtain a mixture. After mixing and stirring evenly for 1 hour, a moisturizing precursor with coatability in the plastic period is obtained.

[0068] Step 3: Solid-liquid reaction yields a porous, breathable layer;

[0069] The specific process is as follows:

[0070] Step 3.1 Weigh the following raw materials by mass percentage: 16% calcium oxide, 11% calcium peroxide, 6% zeolite, 41.7% polymethyl methacrylate, 0.3% benzoyl peroxide, 8% double-acting baking powder, and 17% methyl methacrylate;

[0071] The particle size of the zeolite is 0.5 mm.

[0072] Step 3.2: Add the calcium oxide, calcium peroxide, zeolite, polymethyl methacrylate, benzoyl peroxide and double-acting baking powder weighed in step 3.1 to methyl methacrylate, mix and stir for 13 minutes to obtain an adhesive mixture, treat it in a constant temperature water bath at 37°C for 5 minutes, and then take it out immediately to obtain a workable breathing functional layer in the dough stage.

[0073] Step 4: Self-condensing to obtain breathable exterior wall material;

[0074] The moisturizing precursor obtained in step 2, which is in the plastic stage, is coated onto the precast concrete layer obtained in step 1, which is in the latent stage. Then, the porous breathable functional layer obtained in step 3, which is in the dough stage, is coated onto the moisturizing precursor layer to obtain a mixture. The volume ratio of the precast concrete layer, the moisturizing precursor layer and the breathable functional layer is 2:1:2. The mixture is self-cured in a mixed solution of methyl methacrylate and a retarder for 25 minutes to obtain a breathable exterior wall material.

[0075] Of which, methyl methacrylate accounts for 99.99% by mass, and p-tert-butylcatechol accounts for 0.01% by mass.

[0076] Example 2

[0077] The method for preparing the breathable exterior wall material of the present invention is specifically implemented according to the following steps:

[0078] Step 1, Precast concrete;

[0079] The specific process is as follows:

[0080] Step 1.1 Weigh the following raw materials by mass percentage: 25% river sand, 24% ceramsite, 0.25% calcium lignosulfonate, 0.3% sodium dodecyl sulfate, 25.26% polymethyl methacrylate, 0.19% benzoyl peroxide, and 28% ordinary silicate cement slurry;

[0081] The water-cement ratio of ordinary silicate cement paste is 0.44;

[0082] Step 1.2: Add the river sand, ceramsite, retarder, air-entraining agent, polymethyl methacrylate and benzoyl peroxide weighed in Step 1.1 to ordinary silicate cement slurry and stir for 15 minutes to obtain precast concrete.

[0083] Step 2, prepare the moisturizing precursor;

[0084] The specific process is as follows:

[0085] Step 2.1: Weigh the following raw materials by mass percentage: diatomaceous earth 31%, kaolin 13%, acrylic glue 3%, polymethyl methacrylate 16.87%, benzoyl peroxide 0.13%, and water 38%.

[0086] Step 2.2: Add the diatomaceous earth, kaolin, acrylic glue, polymethyl methacrylate and benzoyl peroxide weighed in step 2.1 to water in sequence to obtain a mixture. After mixing and stirring evenly for 1.5 hours, a moisturizing precursor with coatability in the plastic period is obtained.

[0087] Step 3: Solid-liquid reaction yields a porous, breathable layer;

[0088] The specific process is as follows:

[0089] Step 3.1 Weigh the following raw materials by mass percentage: 17% calcium oxide, 11% calcium peroxide, 8% zeolite, 37.72% polymethyl methacrylate, 0.28% benzoyl peroxide, 9% double-acting baking powder, and 17% methyl methacrylate;

[0090] The particle size of the zeolite is 0.8 mm.

[0091] Step 3.2: Add the calcium oxide, calcium peroxide, zeolite, polymethyl methacrylate, benzoyl peroxide and double-acting baking powder weighed in step 3.1 to methyl methacrylate, mix and stir for 10 minutes to obtain an adhesive mixture, treat it in a constant temperature water bath at 35°C for 8 minutes, and then take it out immediately to obtain a workable breathing functional layer in the dough stage.

[0092] Step 4: Self-condensing to obtain breathable exterior wall material;

[0093] The moisturizing precursor obtained in step 2, which is in the plastic stage, is coated onto the precast concrete layer obtained in step 1, which is in the latent stage. Then, the porous breathable functional layer obtained in step 3, which is in the dough stage, is coated onto the moisturizing precursor layer to obtain a mixture. The volume ratio of the precast concrete layer, the moisturizing precursor layer and the breathable functional layer is 2:1:2. The mixture is self-cured in a mixed solution of methyl methacrylate and a retarder for 20 minutes to form a breathable exterior wall material.

[0094] Of which, methyl methacrylate accounts for 99.9% by mass and hydroquinone accounts for 0.1% by mass.

[0095] Example 3

[0096] The method for preparing the breathable exterior wall material of the present invention is specifically implemented according to the following steps:

[0097] Step 1, Precast concrete;

[0098] The specific process is as follows:

[0099] Step 1.1 Weigh the following raw materials by mass percentage: river sand 26%, ceramsite 25%, calcium lignosulfonate 0.3%, sodium dodecylbenzenesulfonate 0.5%, polymethyl methacrylate 28.97%, benzoyl peroxide 0.23%, and ordinary silicate cement slurry 19%.

[0100] The water-cement ratio of ordinary silicate cement paste is 0.44;

[0101] Step 1.2: Add the river sand, ceramsite, retarder, air-entraining agent, polymethyl methacrylate and benzoyl peroxide weighed in Step 1.1 to ordinary silicate cement slurry and stir for 10 minutes to obtain precast concrete.

[0102] Step 2, prepare the moisturizing precursor;

[0103] The specific process is as follows:

[0104] Step 2.1 Weigh the following raw materials by mass percentage: diatomaceous earth 32%, kaolin 11%, acrylic glue 4%, polymethyl methacrylate 15.88%, benzoyl peroxide 0.12%, and water 37%.

[0105] Step 2.2: Add the diatomaceous earth, kaolin, acrylic glue, polymethyl methacrylate and benzoyl peroxide weighed in step 2.1 to water in sequence to obtain a mixture. After mixing and stirring evenly for 1 hour, a moisturizing precursor with coatability in the plastic period is obtained.

[0106] Step 3: Solid-liquid reaction yields a porous, breathable layer;

[0107] The specific process is as follows:

[0108] Step 3.1 Weigh the following raw materials by mass percentage: 18% calcium oxide, 11% calcium peroxide, 6% zeolite, 38.72% polymethyl methacrylate, 0.28%-0.4% benzoyl peroxide, 10% double-acting baking powder, and 16% methyl methacrylate;

[0109] The particle size of the zeolite is 1 mm.

[0110] Step 3.2: Add the calcium oxide, calcium peroxide, zeolite, polymethyl methacrylate, benzoyl peroxide and double-acting baking powder weighed in step 3.1 to methyl methacrylate, mix and stir for 14 minutes to obtain an adhesive mixture, treat it in a constant temperature water bath at 37°C for 2 minutes, and then take it out immediately to obtain a workable breathing functional layer in the dough stage.

[0111] Step 4: Self-condensing to obtain breathable exterior wall material;

[0112] The moisturizing precursor obtained in step 2, which is in the plastic stage, is coated onto the precast concrete layer obtained in step 1, which is in the latent stage. Then, the porous breathable functional layer obtained in step 3, which is in the dough stage, is coated onto the moisturizing precursor layer to obtain a mixture. The volume ratio of the precast concrete layer, the moisturizing precursor layer and the breathable functional layer is 2:1:2. The mixture is self-cured in a mixed solution of methyl methacrylate and a retarder for 30 minutes to obtain a breathable exterior wall material.

[0113] Of which, methyl methacrylate accounts for 99.99% by mass and hydroquinone accounts for 0.01% by mass.

[0114] Example 4

[0115] The method for preparing the breathable exterior wall material of the present invention is specifically implemented according to the following steps:

[0116] Step 1, Precast concrete;

[0117] The specific process is as follows:

[0118] Step 1.1 Weigh the following raw materials by mass percentage: river sand 26%, ceramsite 26%, sodium lignosulfonate 0.3%, sodium dodecyl sulfate 0.5%, polymethyl methacrylate 28.97%, benzoyl peroxide 0.23%, and ordinary silicate cement slurry 18%.

[0119] The water-cement ratio of ordinary silicate cement paste is 0.44;

[0120] Step 1.2: Add the river sand, ceramsite, retarder, air-entraining agent, polymethyl methacrylate and benzoyl peroxide weighed in Step 1.1 to ordinary silicate cement slurry and stir for 10 minutes to obtain precast concrete.

[0121] Step 2, prepare the moisturizing precursor;

[0122] The specific process is as follows:

[0123] Step 2.1 Weigh the following raw materials by mass percentage: diatomaceous earth 30%, kaolin 14%, acrylic glue 4%, polymethyl methacrylate 14.89%, benzoyl peroxide 0.11%, and water 42%.

[0124] Step 2.2: Add the diatomaceous earth, kaolin, acrylic glue, polymethyl methacrylate and benzoyl peroxide weighed in step 2.1 to water in sequence to obtain a mixture. After mixing and stirring evenly for 2 hours, a moisturizing precursor with coatability in the plastic period is obtained.

[0125] Step 3: Solid-liquid reaction yields a porous, breathable layer;

[0126] The specific process is as follows:

[0127] Step 3.1 Weigh the following raw materials by mass percentage: 16% calcium oxide, 13% calcium peroxide, 8% zeolite, 39.7% polymethyl methacrylate, 0.3% benzoyl peroxide, 8% double-acting baking powder, and 15% methyl methacrylate;

[0128] The particle size of the zeolite is 0.5 mm.

[0129] Step 3.2: Add the calcium oxide, calcium peroxide, zeolite, polymethyl methacrylate, benzoyl peroxide and double-acting baking powder weighed in step 3.1 to methyl methacrylate, mix and stir for 15 minutes to obtain an adhesive mixture, treat it in a constant temperature water bath at 37°C for 3 minutes, and then take it out immediately to obtain a workable breathing functional layer in the dough stage.

[0130] Step 4: Self-condensing to obtain breathable exterior wall material;

[0131] The moisturizing precursor obtained in step 2, which is in the plastic stage, is coated onto the precast concrete layer obtained in step 1, which is in the latent stage. Then, the porous breathable functional layer obtained in step 3, which is in the dough stage, is coated onto the moisturizing precursor layer to obtain a mixture. The volume ratio of the precast concrete layer, the moisturizing precursor layer and the breathable functional layer is 2:1:2. The mixture is self-cured in a mixed solution of methyl methacrylate and a retarder for 25 minutes to obtain a breathable exterior wall material.

[0132] Of which, methyl methacrylate accounts for 99.9% by mass, and p-tert-butylcatechol accounts for 0.1% by mass.

[0133] Comparative Example 1

[0134] The difference between Comparative Example 1 and Example 1 is that the reaction time of the precast concrete in step 1 exceeds the latent period, the reaction time of the moisturizing precursor in step 2 exceeds the plasticity period, and the reaction time of the breathable functional layer in step 3 exceeds the dough period.

[0135] Comparative Example 2

[0136] The difference between Comparative Example 2 and Example 1 is that step 1 was not performed.

[0137] Comparative Example 3

[0138] The difference between Comparative Example 2 and Example 1 is that step 2 was not performed.

[0139] Comparative Example 4

[0140] The difference between Comparative Example 3 and Example 1 is that step 3 was not performed.

[0141] Comparative Example 5

[0142] The difference between Comparative Example 4 and Example 1 is that the mixture in step 3 does not contain calcium oxide, and the missing mass percentage of calcium oxide is made up with water, while the mass percentage of other raw materials remains unchanged.

[0143] Comparative Example 6

[0144] The difference between Comparative Example 5 and Example 1 is that the mixture in step 3 does not contain calcium peroxide, and the missing mass percentage of calcium peroxide is made up with water, while the mass percentage of other raw materials remains unchanged.

[0145] Comparative Example 7

[0146] The difference between Comparative Example 7 and Example 1 is that the mixture in step 3 does not contain double-acting baking powder and is not subjected to constant temperature water bath treatment. The missing mass percentage of double-acting baking powder is made up with water, while the mass percentage of other raw materials remains unchanged.

[0147] Comparative Example 8

[0148] The difference between Comparative Example 6 and Example 1 is that the self-condensing process in step 4 was not performed.

[0149] Table 1 compares the noise reduction coefficients of carbon dioxide absorption rate and oxygen release rate, as well as the compressive strength, of Example 1 and Comparative Examples 1-8. As shown in Table 1, the precast concrete layer, the moisture-retaining precursor layer, and the breathable functional layer in Example 1 are integrated into a single exterior wall material through self-curing at precisely controlled times, resulting in better mechanical properties. Furthermore, the moisture-retaining layer provides long-lasting water molecules to the calcium oxide and calcium peroxide in the breathable functional layer, allowing them to decompose slowly and release oxygen over a long period. Simultaneously, the breathable functional layer absorbs carbon dioxide and reacts to generate calcium carbonate, reinforcing the exterior wall material. Compared to Comparative Example 1, the reaction time of each layer exceeds the limit, preventing self-curing and reducing compressive strength. Additionally, the moisture-retaining layer cannot retain moisture in the breathable functional layer, reducing the oxygen release rate. Compared to Comparative Example 2, the exterior wall consists only of the moisture-retaining layer and the breathable functional layer, resulting in a significant decrease in compressive strength. Compared to Comparative Example 3, the exterior wall material consists only of a concrete base layer and the breathable functional layer, leading to a decrease in mechanical properties and a significant reduction in oxygen generation rate due to the absence of a moisture-retaining layer providing long-lasting water molecules. Compared to Comparative Example 4, the exterior wall material consists only of a concrete base and a moisture-retaining layer, resulting in decreased mechanical properties and a lack of breathability. The diatomaceous earth in the moisture-retaining layer can absorb a small amount of carbon dioxide. Compared to Comparative Example 5, the breathable layer of the exterior wall material does not contain calcium oxide, reducing the carbon dioxide absorption rate. Compared to Comparative Example 6, the breathable layer of the exterior wall material does not contain calcium peroxide, preventing it from reacting with water to generate oxygen. Compared to Comparative Example 7, the breathable layer lacks a porous structure, resulting in better mechanical properties, but the inability to release gas reduces both the carbon dioxide release rate and the oxygen generation rate. Compared to Comparative Example 8, the exterior wall material is not self-curing, leading to reduced mechanical properties. However, compared to Comparative Example 1, the layers are fully composited, allowing the moisture-retaining layer to provide water molecules and still release a small amount of oxygen.

[0150] Table 1

[0151]

[0152] Figure 1 This is a schematic diagram of the breathable exterior wall material prepared according to the present invention. Figure 1 As can be seen, the exterior wall material consists of a breathable functional layer 1, a moisture-retaining precursor layer 2, and a concrete layer 3. The breathable functional layer exhibits a porous structure, providing channels for carbon dioxide to enter and oxygen to escape, and also providing a path for water molecule diffusion provided by the moisture-retaining layer. The concrete layer not only provides good mechanical properties but also prevents moisture from the moisture-retaining layer from entering the interior wall. This exterior wall material is green and environmentally friendly, requires no sintering, is easy to operate, and can absorb carbon dioxide and slowly release oxygen.

Claims

1. Process for the production of a breathable outer wall material, characterized in that, The method is implemented according to the following steps: Step 1, preparing precast concrete; The specific process of step 1 is as follows: Step 1.1, taking the following raw materials by mass percentage: river sand 24%-26%, ceramsite 24%-26%, retarder 0.2%-0.3%, air entraining agent 0.1%-0.5%, polymethyl methacrylate 23.55%-28.97%, benzoyl peroxide 0.15%-0.23%, and ordinary Portland cement paste 18%-28%, wherein the total mass of the above components is 100%; Step 1.2, adding the river sand, ceramsite, retarder, air entraining agent, polymethyl methacrylate and benzoyl peroxide taken in step 1.1 into the ordinary Portland cement paste, and stirring for 10-15 minutes to obtain precast concrete; Step 2, preparing a moisturizing precursor; The specific process of step 2 is as follows: Step 2.1, taking the following raw materials by mass percentage: diatomite 30%-32%, kaolin 11%-14%, acrylic glue 2%-4%, polymethyl methacrylate 14.89%-16.87%, benzoyl peroxide 0.11%-0.13%, and the balance being water, wherein the total mass of the above components is 100%; Step 2.2, adding the diatomite, kaolin, acrylic glue, polymethyl methacrylate and benzoyl peroxide taken in step 2.1 into water in sequence to obtain a mixture, and uniformly mixing and stirring for 1-2 hours to obtain a moisturizing precursor in a plastic state which is capable of being coated; Step 3, solid-liquid reaction to obtain a porous respiration functional layer; The specific process of step 3 is as follows: Step 3.1, taking the following raw materials by mass percentage: calcium oxide 16%-18%, calcium peroxide 11%-13%, zeolite 6%-10%, polymethyl methacrylate 37.72%-41.7%, benzoyl peroxide 0.28%-0.3%, double-acting baking powder 8%-10%, and methyl methacrylate 15%-17%, wherein the total mass of the above components is 100%; Step 3.2, adding the calcium oxide, calcium peroxide, zeolite, polymethyl methacrylate, benzoyl peroxide and double-acting baking powder taken in step 3.1 into methyl methacrylate, and mixing and stirring for 10-16 minutes to obtain a mixture having adhesion, and then taking out the mixture after being treated in a constant-temperature water bath at 30-37°C for 2-8 minutes to obtain a respiration functional layer in a dough state which is capable of being operated; Step 4, self-condensation to obtain breathable external wall material; The moisturizing precursor in the plastic state obtained in step 2 is coated on the precast concrete layer in the incubation period obtained in step 1, and then the porous respiration functional layer in the dough state obtained in step 3 is coated on the moisturizing precursor layer to obtain a mixture, and the mixture is self-condensed and formed in a mixed solution of methyl methacrylate and a retarder to obtain breathable external wall material.

2. The method of claim 1, wherein the breathable exterior wall material is prepared by, The water-cement ratio of the ordinary Portland cement paste is 0.

44.

3. The method of claim 1, wherein the breathable exterior wall material is prepared by, The retarder is any one of calcium lignosulfonate and sodium lignosulfonate, and the air entraining agent is any one of sodium abietate, sodium dodecyl benzene sulfonate and sodium dodecyl sulfate.

4. The method of claim 1, wherein the breathable exterior wall material is prepared by, The particle size of the zeolite is 0.5mm-1mm.

5. The method of claim 1, wherein the breathable exterior wall material is prepared by, In step 4, the volume ratio of the precast concrete layer, the moisture-retaining precursor layer and the respiratory function layer is 2:1:2; and the self-solidification time is 20min-30min.

6. The method of claim 1, wherein the breathable exterior wall material is prepared by, In step 4, the mass percentage of methyl methacrylate is 99.9%-99.99%, the mass percentage of the retarder is 0.01%-0.1%, and the sum of the mass percentages of the two is 100%.

7. The method of claim 1, wherein the breathable exterior wall material is prepared by, In step 4, the retarder is any one of hydroquinone and p-tert-butyl hydroquinone.

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