Vapor-permeable waterproof coating as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a vapor-permeable waterproof coating as well as a preparation method and application thereof. The vapor-permeable waterproof coating comprises an emulsion and a modified functional material, the emulsion comprises a hollow porous microsphere emulsion and an acrylic emulsion; the mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion is 1: (2.5-3.5); the modified functional material is obtained by modifying a functional material with a tert-butyl alkyl chlorosilane modifier; the functional material comprises a molecular sieve. The hollow porous microsphere emulsion is introduced and can be communicated with pores of the modified functional material, so that the wet flow density of a coating film is improved; the waterproof performance of the coating is ensured by limiting the mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion; besides, hydrophilic groups (silicon hydroxyl and aluminum hydroxyl) in the pore channels of the functional material are modified, so that crystal water in the pore channels can be prevented from forming and blocking the channels, and finally, good waterproof and vapor-permeable functions are realized.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, and specifically relates to a breathable and waterproof coating, its preparation method, and its application. Background Technology

[0002] With rapid societal development, people have increasingly higher demands for the quality of their living environment. Traditional exterior wall waterproofing coatings achieve waterproofing by completely sealing the capillaries of the wall. While this method effectively prevents water penetration, it also restricts the release of water vapor from within the wall. This leads to condensation on the inside of the waterproofing coating, causing waterlogging and significantly reducing the adhesion between the coating and the substrate. Consequently, problems such as efflorescence, mold growth, blackening, frost damage, rust, cracking, and even peeling may occur. Therefore, exterior wall waterproofing coatings must not only be waterproof but also breathable.

[0003] A study has disclosed a breathable waterproof coating that uses acrylic monomers grafted with cage-like polysilsesquioxane (POSS) to form an emulsion containing a cage structure (three-dimensional dimensions between 1.3 nm) through an emulsification process. This emulsion possesses steric hindrance and moisture conduction channels, thus endowing the coating with breathability. Water vapor is transported through microchannel conduction to avoid increasing the coating's water absorption and volume expansion rate (moisture absorption and re-release mechanism) during water vapor conduction. However, during the modification of the acrylic emulsion with cage-like POSS, morphological transformations such as chain segment growth, extension, folding, and helicalization occur. These morphological transformations create steric hindrance above and below the cage-like framework structure, and may even block the framework structure, thus hindering water vapor transport. Therefore, the wet flow density of the prepared coating is not stable.

[0004] A study has disclosed a breathable polymer cement waterproof coating for exterior walls and its preparation method. This study imparts breathability to the coating film through three aspects: 1. A modified acrylic emulsion was prepared using organic-inorganic composite technology, grafting inorganic substances onto the side chains of organic substances to form a breathable emulsion; 2. An excess oxidant in the system undergoes a micro-reaction with cement to form a micro-foaming system, creating micron-sized pores during film formation; 3. Breathable materials (porous quartz sand, zeolite powder, calcium carbonate, etc.) were introduced into the powder system, further enhancing breathability. However, this study did not disclose the breathability mechanism of the modified acrylic emulsion. Furthermore, the introduced breathable materials were simply mixed as aggregates, without considering the pore size of the breathable materials (i.e., the size of the breathable channels), which may allow liquid water to pass through. It also did not consider whether the groups (hydrogen bonds) in the channels would hinder water vapor permeation, thus reducing the lifespan of the breathability function.

[0005] Therefore, it is of great significance to provide a coating that has both good waterproof and breathable properties, which can reduce the risk of exterior wall materials falling off. Summary of the Invention

[0006] The present invention aims to solve one or more technical problems existing in the prior art, and at least provide a beneficial solution. Specifically, the present invention provides a breathable and waterproof coating that has both good waterproof and breathable functions, which can reduce the risk of exterior wall materials falling off.

[0007] The inventive concept of this invention is as follows: The coating of this invention comprises an emulsion and a modified functional material; the emulsion comprises a hollow porous microsphere emulsion and an acrylic emulsion; the mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion is 1:(2.5-3.5); the modified functional material is obtained by modifying the functional material with a tert-butylalkylchlorosilane modifier; the functional material includes a molecular sieve.

[0008] This invention introduces a hollow porous microsphere emulsion, which can connect the pores of modified functional materials and increase the wet flow density of the coating film. Furthermore, by limiting the mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion, the waterproof performance of the coating is guaranteed. In addition, by modifying the hydrophilic groups (silanol and aluminumol) in the pores of the functional materials, the formation of crystal water in the pores can be avoided to prevent blockage of the channels, ultimately achieving good waterproof and breathable functions.

[0009] Therefore, a first aspect of the present invention provides a breathable and waterproof coating.

[0010] Specifically, the breathable and waterproof coating includes emulsions and modified functional materials;

[0011] The emulsion includes hollow porous microsphere emulsion and acrylic emulsion; The mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion is 1:(2.5-3.5). The modified functional material is obtained by modifying the functional material with a tert-butylalkylchlorosilane modifier; The functional materials include molecular sieves.

[0012] Preferably, the acrylic emulsion includes at least one of styrene-acrylic emulsion, butadiene-acrylic emulsion, pure acrylic emulsion, silicone-acrylic emulsion, and vinyl acetate-acrylic emulsion.

[0013] Preferably, the hollow porous microsphere emulsion comprises hollow porous polystyrene microspheres.

[0014] Preferably, the pore size of the hollow porous microsphere emulsion is 2-4 nm.

[0015] Preferably, the particle size of the hollow porous microsphere emulsion is 90-110 nm; for example, 90 nm, 100 nm, 110 nm, etc.

[0016] Preferably, the porosity of the hollow porous microsphere emulsion is 40-60%; for example, 40%, 50%, 60%, etc.

[0017] Specifically, the inner layer (inner side of the shell) of the hollow porous microsphere emulsion is hydrophobic, while the outer layer (outer side of the shell) is hydrophilic.

[0018] Preferably, the emulsion comprises a hollow porous microsphere emulsion and a styrene-acrylic emulsion.

[0019] Preferably, the tert-butylalkylchlorosilane modifier includes at least one of tert-butyldimethylchlorosilane and tert-butyldiethylchlorosilane.

[0020] Preferably, the raw materials for preparing the modified functional material include functional materials, tert-butylalkylchlorosilane modifiers, catalysts, solvents, and alkalis.

[0021] Preferably, by weight, the raw materials for preparing the modified functional material include 26-34 parts of functional material, 10-15 parts of tert-butylalkylchlorosilane modifier, 1.2-2.3 parts of catalyst, 260-340 parts of solvent, and 20-30 parts of alkali.

[0022] Preferably, the pore size of the functional material is 2-4 nm.

[0023] Specifically, the pore size of the functional material of this invention is in the range of 2-4nm, which is 5-10 times that of water molecules (0.4nm). Liquid water has characteristics such as intermolecular forces, surface tension, viscosity, and molecular orientation. Under normal pressure, it will not enter the gaps or pores in this range, thus having good waterproof properties.

[0024] Preferably, the molecular sieve is a synthetic molecular sieve, such as mordenite.

[0025] Preferably, the catalyst comprises 4-dimethylaminopyridine.

[0026] Preferably, the alkali agent includes at least one of triethylamine, ethylenediamine, imidazole, and pyridine.

[0027] Specifically, the alkaline agent is a weak alkaline reagent.

[0028] Preferably, the solvent includes at least one of CH2Cl2, tetrahydrofuran (THF), and N,N-dimethylformamide (DMF).

[0029] Preferably, the coating comprises 48-60 parts by weight of emulsion and 25-35 parts by weight of modified functional material.

[0030] Preferably, the coating further includes pigments, fillers, additives, and water.

[0031] Preferably, by weight, the coating comprises 48-60 parts emulsion, 25-35 parts modified functional material, 4-6 parts pigments and fillers, 0.95-1.05 parts additives, and 7-15 parts water.

[0032] Preferably, the pigment or filler comprises titanium dioxide; more preferably, the titanium dioxide comprises rutile titanium dioxide.

[0033] Preferably, the additives include at least one of the following: defoamer, bactericide, dispersant, plasticizer, thickener, wetting agent, waterproofing agent, and water-repellent agent.

[0034] Preferably, the additives include defoamers, bactericides, dispersants, and thickeners.

[0035] Preferably, the defoamer includes an organosilicone defoamer.

[0036] Preferably, the bactericide includes Kathon-type bactericides.

[0037] Preferably, the dispersant comprises a high molecular weight ammonium salt dispersant.

[0038] Preferably, the thickener includes an alkali-swellable thickener.

[0039] Preferably, the thickener is a diluted thickener, that is, it is first diluted with water.

[0040] A second aspect of the present invention provides a method for preparing the breathable and waterproof coating described in the first aspect of the present invention.

[0041] Specifically, the preparation method of the breathable and waterproof coating includes the following steps: The breathable and waterproof coating is prepared by mixing the various raw material components.

[0042] Preferably, the preparation method of the modified functional material includes the following steps: Functional materials and solvents are mixed to obtain a suspension; The alkali, catalyst, tert-butylalkylchlorosilane modifier and the suspension are mixed and then rotary evaporated to obtain the product.

[0043] Preferably, the rotary evaporation process further includes centrifugation and drying.

[0044] A third aspect of the present invention provides the application of the breathable and waterproof coating described in the first aspect of the present invention in the exterior walls of buildings.

[0045] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows: (1) This invention designs and synthesizes modified functional materials for the first time and applies them to breathable and waterproof coatings for the first time. By modifying the hydrophilic groups (silanol and aluminumol) in the pores of the functional material, the modified functional material shields the formation of hydrogen bonds in the pores during the breathable process, which can avoid the formation of crystal water in the pores, thereby avoiding the blockage of the channels by crystal water and improving the breathability.

[0046] (2) The functional material of this invention has a pore size of 2-4 nm. Under normal pressure, water molecules will not enter the gaps or pores within this range, thus exhibiting good waterproof properties. This invention introduces a hollow porous microsphere emulsion, which occupies part of the emulsion position and connects the pores of the modified functional material, thereby increasing the wet flow density of the coating film, i.e., improving the vapor permeability. Furthermore, by limiting the mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion, the waterproof performance of the coating is guaranteed.

[0047] (3) Modified functional materials are combined with hollow porous microsphere emulsion, styrene-acrylic emulsion and additives as fillers to obtain waterproof coatings with both waterproof and breathable functions, and have a long breathable life. Attached Figure Description

[0048] Figure 1 The chemical equation for the modified functional material in Example 1 of this invention is as follows; Figure 2 A schematic diagram illustrating the principle of forming a blocking channel for water of crystallization; Figure 3 This is a demonstration diagram of the vapor permeability and waterproof test of the present invention. Detailed Implementation

[0049] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0050] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0051] The information on the relevant raw material components in this embodiment of the invention is as follows: Hollow porous microsphere emulsion: Zhongke Keyou, porous polystyrene microspheres, particle size 500nm, pore size 2-4nm, porosity 50%; Molecular sieve: Zhuoran Environmental Protection Technology MCM-41; Defoamer: Organosilicon defoamer (polyether siloxane), Anhui Guangcheng New Material Technology Co., Ltd. GAXSN® G-564; Fungicide: Isothiazolinone fungicide, Rohm and Haas ROCIMA TM 562; Dispersant: High molecular weight polycarboxylate ammonium salt dispersant, Anhui Guangcheng New Material Technology Co., Ltd. GAXSN® G-5047; Thickener: Alkali-swellable thickener, Rohm and Haas ASE60; Titanium dioxide, rutile titanium dioxide, Longbai Group Co., Ltd. R996.

[0052] The raw material components and dosages of the breathable and waterproof coatings of Examples 1-5 and Comparative Examples 1-3 of the present invention are shown in Table 1.

[0053] Table 1: Raw material components and dosages (parts by weight) of the breathable and waterproof coatings used in Examples 1-5 and Comparative Examples 1-3 raw material components Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Modified functional materials 25 30 35 30 30 0 30 30 Functional Material Molecular Sieves 0 0 0 0 0 30 0 0 Hollow porous microsphere emulsion 15 12 13 14 13 13 0 39 Styrene-acrylic emulsion 45 36 39 42 39 39 52 13 Deionized water 10 15 7 8 12 12 12 12 Titanium dioxide 4 6 5 5 5 5 5 5 Defoamer 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 dispersant 0.2 0.25 0.3 0.25 0.25 0.25 0.25 0.25 bactericide 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Thickener 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Example 1 The raw material components and dosage of the breathable and waterproof coating in Example 1 are shown in Table 1.

[0054] Example 1: The preparation method of the breathable and waterproof coating is as follows: Add 6wt% deionized water to the mixing tank, add dispersant and defoamer, turn on the stirrer at 800 r / min, and then add titanium dioxide to make a slurry; After the titanium dioxide is evenly dispersed, add the remaining deionized water, 30% of the mixed emulsion of styrene-acrylic emulsion and hollow porous microsphere emulsion, and add the modified functional material. Stir at 600 r / min. After the modified functional material is evenly dispersed, add the remaining mixed emulsion and bactericide, stir for 10 minutes, and gradually add the diluted thickener (before adding, dilute the thickener with water, the weight ratio of water to ASE60 is 1:1, and then add it dropwise). After the addition is complete, stir for 10 minutes to obtain a breathable and waterproof coating.

[0055] The specific preparation method of the modified functional materials is as follows: (1) Mix 30g of molecular sieve with CH2Cl2 at a weight ratio of 1:10 and place it in a beaker. Place the beaker in an ultrasonic instrument, put a stirrer on top, turn on the stirrer (150r / min), and ultrasonically disperse for 30min to obtain 330g of suspension. (2) Modification of functional materials: 20g of triethylamine, 1.5g of 4-dimethylaminopyridine (DMAP) and 10g of tert-butyldimethylchlorosilane were added to the above suspension to obtain a mixed liquid; then the mixed liquid was quickly transferred into a rotary evaporator, and vacuumed for 2h at a speed of 80r / min, 23℃ and atmospheric pressure. The valve was opened to maintain atmospheric pressure for 2min. After 5 cycles, the speed was maintained (without vacuum) for 13 hours and 50 minutes; finally, the mixed liquid was taken out from the rotary evaporator, poured into a test tube and centrifuged to dry, and the dried modified functional material was obtained.

[0056] The chemical equation for the modified functional material in Example 1 is as follows: Figure 1 As shown. During the modification process of functional materials, the modifier occupies the position of the hydroxyl group, causing the hydroxyl group to detach, i.e., removing the positively charged hydrogen atom. Hydrogen bonds no longer have binding sites, thus preventing their formation. Furthermore, the steric hindrance effect can shield the hydrogen atoms in water molecules from the negatively charged atoms (AlO4) within the pores. - O - The combination of these elements effectively shields the formation of hydrogen bonds within the molecular sieve pores, preventing the formation of water of crystallization that could block the channels and achieving excellent waterproof and vapor-permeable properties.

[0057] The principle of crystal water forming a blocked channel is shown in the diagram below. Figure 2 As shown, water molecules form hydrogen bonds within the molecular sieve cavity, gradually aggregating to form water of crystallization, thus blocking the channels.

[0058] Example 2 The raw material components and dosage of the breathable and waterproof coating in Example 2 are shown in Table 1.

[0059] The preparation method of the breathable and waterproof coating in Example 2 is the same as that in Example 1, and the preparation method of the modified functional material is the same as that in Example 1.

[0060] Example 3 The raw material components and dosage of the breathable and waterproof coating in Example 3 are shown in Table 1.

[0061] The preparation method of the breathable and waterproof coating in Example 3 is the same as that in Example 1, and the preparation method of the modified functional material is the same as that in Example 1.

[0062] Example 4 The raw material components and dosage of the breathable and waterproof coating in Example 4 are shown in Table 1.

[0063] The preparation method of the breathable and waterproof coating in Example 4 is the same as that in Example 1, and the preparation method of the modified functional material is the same as that in Example 1.

[0064] Example 5 The raw material components and dosage of the breathable and waterproof coating in Example 5 are shown in Table 1.

[0065] The preparation method of the breathable and waterproof coating in Example 5 is the same as that in Example 1, and the preparation method of the modified functional material is the same as that in Example 1.

[0066] Comparative Example 1 The only difference between Comparative Example 1 and Example 5 is that Comparative Example 1 uses a functional material molecular sieve to replace the modified functional material in Example 5 in an equal amount; otherwise, they are the same as in Example 5.

[0067] Comparative Example 2 The only difference between Comparative Example 2 and Example 5 is that Comparative Example 2 uses an equal amount of styrene-acrylic emulsion to replace the hollow porous microsphere emulsion, i.e. it does not contain hollow porous microsphere emulsion. Otherwise, it is the same as Example 5.

[0068] Comparative Example 3 The only difference between Comparative Example 3 and Example 5 is that in Comparative Example 3, the mass ratio of hollow porous microsphere emulsion to styrene-acrylic emulsion is 3:1, while the rest is the same as in Example 5.

[0069] Performance testing 1. Coating wet flow density (water vapor transmission rate) test The wet flow density (water vapor transmission rate) of the coatings in Examples 1-5 and Comparative Examples 1-3 was tested using the following methods: (1) Coating preparation: The coating was prepared according to section 6.4 of standard JG / T 375-2012. The coating sample was allowed to stand for 24 hours under standard test conditions, stirred evenly, and the coating was poured onto a polytetrafluoroethylene film without introducing air bubbles. A second coating was applied using a 1.5 mm mold, and the dry film thickness reached (1.0±0.5) mm. The prepared specimen was cured under standard test conditions for 96 hours, demolded, and then placed in a (40±2)℃ drying oven for 48 hours. After removal, it was placed under standard test conditions for more than 4 hours. The appearance of the coating was checked, and the surface of the specimen should be smooth and flat without obvious air bubbles. (2) Wet flow density (water vapor permeability) test: The wet method test is performed according to the standard GB / T 17146-2015 Test Method for Water Vapor Permeability of Building Materials and Their Products. As shown in Appendix E.3, if the specimen is a self-supporting specimen, the shape of the test cup should be as shown in Figure A.1 of Appendix A. Since the actual thickness of the waterproof coating on the exterior wall is 1-1.5 mm, it belongs to the self-supporting film type. Therefore, the D-type cup in Figure A.1 of Appendix A is selected as the test cup.

[0070] The testing steps are as follows: a. Prepare a saturated ammonium dihydrogen phosphate solution; b. Pour the prepared saturated ammonium dihydrogen phosphate solution into a D-type mold (D-type cup); c. Place the cut coating film (thickness 1±0.1mm) into the mold and seal it with paraffin wax; d. Place the mold in a standard curing room (temperature: 23±0.5℃, humidity: 55±3%) and weigh it on a balance with an error of 1mg; e. Perform 5 independent experiments on each group of coatings, remove the highest and lowest values, and calculate the average of the last 3 data. Repeat the test 3 times.

[0071] The wet flow density (water vapor transmission rate) test results of the coatings in Examples 1-5 and Comparative Examples 1-3 are shown in Table 2.

[0072] Table 2: Test results of wet flow density (water vapor transmission rate) of coatings in Examples 1-5 and Comparative Examples 1-3

[0073] 2. Coating impermeability test To evaluate the impermeability (i.e., waterproofing) of the coatings in Examples 1-5 and Comparative Examples 1-3, the domestic standard for waterproof and breathable membranes (GB / T 328.10-2007) was referenced. The test specified a pressure of 1000 mm water column for 2 hours with no leakage. The test method was conducted according to Method A, without the use of an indicator, as follows: (1) Coating preparation: Prepared according to the coating preparation method in the test method of wet flow density (water vapor transmission rate) of coating; (2) Impermeability test (hydrostatic pressure test for impermeability): a. Place the specimen on an acrylic plate of the same size. The acrylic plate should have a certain thickness to ensure that it does not deform during the test; b. Place an acrylic tube with an inner diameter of 100 mm and a height of not less than 1000 mm in the center of the specimen and seal it around the outside of the specimen with sealant. Cure at room temperature for 24 hours; c. Place a medium-speed qualitative filter paper between the specimen and the acrylic plate. Place the entire set of equipment on a dry container with no cover and a size similar to that of the acrylic plate. A fixing device should be used to prevent the acrylic tube from tipping over; d. Add Class III water that meets the national standard GB / T6682-2008 "Specifications and Test Methods for Water Used in Analytical Laboratories" into the acrylic tube above. It should not leak from the seal. Control the water level to (1000±5) mm. After 2 hours, observe whether there are water marks in the container below and on the filter paper under the specimen.

[0074] The test results of the impermeability of the coatings in Examples 1-5 and Comparative Examples 1-3 are shown in Table 3.

[0075] Table 3: Test results of the impermeability of the coatings in Examples 1-5 and Comparative Examples 1-3 Group Impermeable (1000mm water column, 2h) Example 1 qualified Example 2 qualified Example 3 qualified Example 4 qualified Example 5 qualified Comparative Example 1 qualified Comparative Example 2 qualified Comparative Example 3 Unqualified As can be seen from Tables 2 and 3, the coating of the present invention has both good water vapor permeability and water impermeability, that is, it has both good waterproof and breathable functions, which can reduce the risk of exterior wall materials falling off.

[0076] Comparative Example 1: The molecular sieve was not modified. Although it had a good wet flow density in the first wet flow density cycle test, the wet flow density dropped rapidly in the second and third cycles. This is because water vapor gradually forms hydrogen bonds with hydrophilic groups (hydroxyl groups) in the functional material channels during the vapor permeability test, further forming water of crystallization, blocking the channels, and reducing the wet flow density of the coating.

[0077] In Comparative Example 2, hollow porous microsphere emulsion was missing, while styrene-acrylic emulsion would increase the coating of aggregate (modified functional material), resulting in a reduction of vapor permeability channels and thus a decrease in wet flow density.

[0078] In Comparative Example 3, the coating film exhibited excellent wet flow density, but failed the impermeability test in the hydrostatic pressure test. This is because the coating contains only a small amount of styrene-acrylic emulsion, i.e., gelling material, and the porosity between the modified functional materials is relatively high, resulting in poor waterproofing performance of the coating film.

[0079] In other words, it is difficult to obtain a coating film with both excellent breathability and waterproofing properties in the coatings of Comparative Examples 1-3.

[0080] 3. Vapor permeability and waterproof demonstration test An electric air permeability and waterproof tester was used to conduct a vapor permeability and waterproof demonstration test on the coating film prepared by the coating in Example 1. The coating film was prepared according to the coating film preparation method in the coating wet flow density (water vapor transmission rate) test method.

[0081] The operation process is as follows: 1) Remove the acrylic bucket at the top of the breathability and waterproofness tester by loosening the buckle; 2) Place a gasket at the top of the bottom part, place the coating to be tested on the gasket, and then place another gasket on the coating. The purpose of the gasket is to prevent air leakage at the contact point between the coating and the acrylic bucket. 3) Place the top acrylic bucket removed in step 1) on the gasket and tighten the buckles; 4) Connect the exhaust pipe of the air pump to the air inlet of the lower plexiglass barrel; turn on the air pump switch and demonstrate the breathability and waterproof test.

[0082] As shown in the diagram of the vapor permeability and waterproof test. Figure 3 As shown. By Figure 3 It can be seen that the coating film prepared by the coating in Example 1 of the present invention can achieve the effect of being permeable to vapor but impermeable to water.

[0083] In summary, this invention introduces a hollow porous microsphere emulsion, which can connect the pores of the modified functional material, thereby increasing the wet flow density of the coating film. Furthermore, by limiting the mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion, the waterproof performance of the coating is guaranteed. In addition, by modifying the hydrophilic groups (silanol and aluminumol) in the pores of the functional material, the formation of crystal water in the pores can be avoided from blocking the channels, ultimately achieving good and long-lasting waterproof and breathable functions.

[0084] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A coating, characterized in that, The coating includes emulsions and modified functional materials; The emulsion includes hollow porous microsphere emulsion and acrylic emulsion; The mass ratio of the hollow porous microsphere emulsion to the acrylic emulsion is 1:(2.5-3.5). The modified functional material is obtained by modifying a functional material with a tert-butylalkylchlorosilane modifier; The functional materials include molecular sieves.

2. The coating according to claim 1, characterized in that, The acrylic emulsion includes at least one of styrene-acrylic emulsion, butadiene-acrylic emulsion, pure acrylic emulsion, silicone-acrylic emulsion, and vinyl acetate-acrylic emulsion; And / or, the hollow porous microsphere emulsion comprises hollow porous polystyrene microspheres; And / or, the tert-butylalkylchlorosilane modifier includes at least one of tert-butyldimethylchlorosilane and tert-butyldiethylchlorosilane; And / or, the raw materials for preparing the modified functional material include functional materials, tert-butylalkylchlorosilane modifiers, catalysts, solvents, and alkalis.

3. The coating according to claim 2, characterized in that, The raw materials for preparing the modified functional material, by weight, include 26-34 parts of functional material, 10-15 parts of tert-butylalkylchlorosilane modifier, 1.2-2.3 parts of catalyst, 260-340 parts of solvent, and 20-30 parts of alkali agent; And / or; the pore size of the functional material is 2-4 nm.

4. The coating according to claim 2, characterized in that, The catalyst includes 4-dimethylaminopyridine; And / or; the alkaline agent includes at least one of triethylamine, ethylenediamine, imidazole, and pyridine; And / or, the solvent includes at least one of CH2Cl2, tetrahydrofuran, and N,N-dimethylformamide.

5. The coating according to any one of claims 1-4, characterized in that, By weight, the coating comprises 48-60 parts of emulsion and 25-35 parts of modified functional material; and / or, the coating further comprises pigments, fillers, additives and water.

6. The coating according to claim 5, characterized in that, By weight, the coating comprises 48-60 parts emulsion, 25-35 parts modified functional materials, 4-6 parts pigments and fillers, 0.95-1.05 parts additives, and 7-15 parts water.

7. The coating according to claim 6, characterized in that, The additives include at least one of the following: defoamer, bactericide, dispersant, plasticizer, thickener, wetting agent, waterproofing agent, and water-repellent agent.

8. The method for preparing the coating according to any one of claims 1-7, characterized in that, The preparation method includes the following steps: The coating is prepared by mixing the various raw material components.

9. The preparation method according to claim 8, characterized in that, The preparation method of the modified functional material includes the following steps: Functional materials and solvents are mixed to obtain a suspension; The alkali, catalyst, tert-butylalkylchlorosilane modifier and the suspension are mixed and then rotary evaporated to obtain the product.

10. The application of the coating according to any one of claims 1-7 on building exterior walls.

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