CN115521650A - High weather-resistant stain-resistant water-based exterior wall coating and preparation method thereof - Google Patents

Abstract

The invention provides a high weather-resistant stain-resistant water-based exterior wall coating and a preparation method thereof, wherein the coating comprises the following components in parts by weight: 35-60 parts of water-based emulsion, 15-30 parts of titanium dioxide, 5-10 parts of vinyl acetate, 5-15 parts of heavy calcium carbonate, 4-10 parts of kaolin, 1-5 parts of pH regulator, 1-5 parts of film-forming assistant and 10-20 parts of deionized water; the water-based emulsion is formed by mixing a silicon pure acrylate copolymer emulsion and a pure acrylic emulsion, wherein the weight part ratio of the silicon pure acrylate copolymer emulsion to the pure acrylic emulsion is 2-8: 1, wherein the silicon pure acrylate copolymerization emulsion has an interpenetrating network type core-shell structure taking vinyl siloxane as a shell and an acrylic monomer as a core, and the content of organic silicon in the silicon pure acrylate copolymerization emulsion is not less than 8%. The invention can improve the weather resistance and the stain resistance of the building outer wall coating and reduce the cost at the same time.

Description

High weather-resistant stain-resistant water-based exterior wall coating and preparation method thereof

Technical Field

The invention relates to the field of building exterior wall coatings, in particular to a high-weather-resistance stain-resistant water-based exterior wall coating and a preparation method thereof.

Background

The outer wall of the building is exposed in the natural environment for a long time and is subjected to the invasion of wind, rain and sunshine, so that the aging phenomenon is easy to occur. In order to protect the external wall, it is generally necessary to coat paint on the surface of the external wall and form a coating with the paint, and the coating not only can play a role in decoration, but also can replace the wall body to be exposed in the natural environment and withstand the natural phenomena of wind, sun, salt spray corrosion, rain, cold and heat changes and the like. Under the long-term repeated action of the external natural environment, the coating is easy to age and pollute, part of the appearance is changed, and the coating cracks and even peels off, so that the coating loses the original decorative protection function.

The existing exterior wall coating usually adopts silicone-acrylate emulsion, but the content of organic silicon in the existing silicone-acrylate emulsion is relatively small (generally not more than 6%), and under the combined action of oxygen and water, ultraviolet rays in natural light accelerate aging of a coating mainly composed of the silicone-acrylate emulsion. When the content of the organic silicon in the silicone-acrylate emulsion is too high, the hydrophobicity of the coating is increased, and the basic adhesion is slightly poor. In addition, the silicone-acrylic emulsion has relatively high cost, and particularly the silicone-acrylic emulsion with high organosilicon content.

Disclosure of Invention

The invention aims to solve the technical problem that the performance and the cost of the existing coating are difficult to be considered at the same time, and provides a novel high-weather-resistance stain-resistant water-based exterior wall coating and a preparation method thereof.

The technical scheme for solving the technical problems is to provide a high weather-resistant stain-resistant water-based exterior wall coating which comprises the following components in parts by weight: 35-60 parts of water-based emulsion, 15-30 parts of titanium dioxide, 5-10 parts of vinyl acetate, 5-15 parts of heavy calcium carbonate, 4-10 parts of kaolin, 1-5 parts of pH regulator, 0.1-3 parts of thickener, 0.1-3 parts of mildew inhibitor, 1-5 parts of film-forming assistant, 0.1-1 part of defoamer, 0.1-1 part of flatting agent, 0.1-1 part of dispersant, 0.1-1 part of defoamer, 0.1-1 part of rheological assistant and 10-20 parts of deionized water;

the water-based emulsion is formed by mixing a silicon pure acrylate copolymer emulsion and a pure acrylic emulsion, wherein the weight part ratio of the silicon pure acrylate copolymer emulsion to the pure acrylic emulsion is 2-8: 1, wherein the silicon pure acrylate copolymerization emulsion has an interpenetrating network type core-shell structure taking vinyl siloxane as a shell and an acrylic monomer as a core, and the content of organic silicon in the silicon pure acrylate copolymerization emulsion is not less than 8%.

As a further improvement of the present invention, the aqueous exterior wall coating comprises the following components in parts by weight: 35-50 parts of water-based emulsion, 20-30 parts of titanium dioxide, 5-10 parts of vinyl acetate, 10-15 parts of heavy calcium carbonate, 5-10 parts of kaolin, 2-5 parts of pH regulator, 0.1-1 part of thickener, 0.1-1 part of mildew inhibitor, 2-5 parts of film-forming assistant, 0.1-1 part of defoamer, 0.1-1 part of flatting agent, 0.1-1 part of dispersant, 0.1-1 part of defoamer, 0.1-1 part of rheological assistant and 10-15 parts of deionized water, wherein the weight part ratio of the silicon pure acrylate copolymer emulsion to the pure acrylic emulsion in the water-based emulsion is 3-8: 1.

as a further improvement of the invention, the defoaming agent is one or more of an organic silicon defoaming agent, a mineral oil defoaming agent or an amide defoaming agent; the defoaming agent is polyether siloxane copolymer; the flatting agent is one or more of fatty acid, sulfonate or polyoxyethylene fatty alcohol ether; the rheological additive is an acrylic acid association type alkali swelling thickener; the film-forming assistant is one or more of dipropylene glycol methyl ether, alcohol ester dodeca or dipropylene glycol butyl ether; the mildew inhibitor is one or more of benzimidazole methyl carbamate and nano silver; the thickening agent is hydroxyethyl cellulose.

As a further improvement of the invention, the dispersant is an acrylate polymer dispersant.

As a further improvement of the invention, the titanium dioxide is rutile titanium dioxide; the pH regulator is 2-amino-2-methyl-1-propanol.

The invention also provides a preparation method of the high weather-resistant stain-resistant water-based exterior wall coating, which comprises the following steps:

(a) Stirring and dispersing deionized water, a dispersing agent and a defoaming agent to form a first dispersion liquid;

(b) Slowly adding a thickening agent, a pH regulator and a dispersing agent in preset weight parts into the first dispersion liquid, and then adding titanium dioxide and kaolin for dispersing to obtain a second dispersion liquid;

(c) Mixing the silicon pure acrylate copolymer emulsion and the pure acrylic emulsion to form a water-based emulsion;

(d) Sequentially adding the water-based emulsion, the film-forming assistant and the mildew preventive into the second dispersion liquid and stirring to form a third dispersion liquid;

(e) And sequentially adding a thickening agent and deionized water into the third dispersion liquid for viscosity regulation, standing and filtering to obtain the water-based exterior wall coating.

The invention has the following beneficial effects: the silicon pure acrylate copolymer emulsion with the interpenetrating network type core-shell structure taking vinyl siloxane as a shell and an acrylic monomer as a core is mixed with the pure acrylic emulsion in proportion to form the water-based emulsion, so that the weather resistance and the stain resistance of the building outer wall coating can be improved, and the cost is reduced.

Drawings

FIG. 1 is a schematic flow chart of a method for preparing a weather-resistant and stain-resistant water-based exterior wall coating provided by the embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the invention provides a high weather-resistant stain-resistant water-based exterior wall coating which can be applied to exterior walls of hotels, residential buildings, schools, office buildings and the like and can protect the exterior walls. The aqueous exterior wall coating of this example comprises the following components in parts by weight: 35-60 parts of water-based emulsion, 15-30 parts of titanium dioxide, 5-10 parts of vinyl acetate, 5-15 parts of heavy calcium carbonate, 4-10 parts of kaolin, 1-5 parts of pH regulator, 0.1-3 parts of thickener, 0.1-3 parts of mildew inhibitor, 1-5 parts of film-forming assistant, 0.1-1 part of defoamer, 0.1-1 part of flatting agent, 0.1-1 part of dispersant, 0.1-1 part of defoaming agent, 0.1-1 part of rheological assistant and 10-20 parts of deionized water.

In the water-based exterior wall coating, the water-based emulsion is formed by mixing the pure silicon acrylate copolymer emulsion and the pure acrylic emulsion, and the weight part ratio of the pure silicon acrylate copolymer emulsion to the pure acrylic emulsion is 2-8: 1, namely in the water-based exterior wall coating, the weight portion of the silicon pure acrylate copolymerization emulsion is 30-40, the weight portion of the pure acrylic emulsion is 5-15, and the content of organic silicon in the silicon pure acrylate copolymerization emulsion is not less than 8 percent, and the silicon pure acrylate copolymerization emulsion has an interpenetrating network type core-shell structure taking vinyl siloxane as a shell and taking acrylic monomers as a core.

In the water-based exterior wall coating, the silicon pure acrylate copolymer emulsion is an interpenetrating network (IPN) type core-shell structure which is prepared by polymerizing the seed emulsion and takes vinyl siloxane as a shell and acrylic monomers as a core, and the content of organic silicon is not less than 8 percent of the total amount of the silicon pure acrylate copolymer emulsion. In the silicon pure acrylate copolymer emulsion, because the Si-O bond energy is high, the silicon pure acrylate copolymer emulsion is difficult to damage by ultraviolet rays, and simultaneously because the silicon pure acrylate copolymer emulsion has the characteristic of good hydrophobicity and air permeability, the damage of the ultraviolet rays to a coating formed by the water-based exterior wall coating under the combined action of oxygen and moisture is reduced, and the weather resistance and the ultraviolet resistance of the coating are improved. In addition, the surface energy of the silicone resin formed by the pure silicone acrylate copolymer emulsion is low, the coating is not easy to accumulate dust, and the pollution resistance is good. In order to overcome the problems of high hydrophobicity, slightly poor basic adhesive force and poor self-drying property caused by too high silicon content in the silicon pure acrylate copolymer emulsion, the pure acrylic emulsion is added into the water-based emulsion of the water-based exterior wall coating, and the self-drying property and the compatibility of the silicon pure acrylate copolymer emulsion are compensated by utilizing the characteristics that linear molecules lack intersection points and the formed three-dimensional network structure is less due to the plastic limitation of acrylic resin. Meanwhile, the silicon pure acrylate copolymer emulsion and the pure acrylic emulsion are mixed to form the water-based emulsion, so that the high price caused by the high content of the silicon pure acrylate copolymer emulsion can be reduced.

The high weather-resistant stain-resistant water-based exterior wall coating adopts two water-based emulsions, namely silicon pure acrylic acid copolymer emulsion and pure acrylic acid emulsion, which have excellent weather-resistant and stain-resistant properties, to be mixed, so that the cross-linking density of the coating is further improved, and an auxiliary agent with certain hydrophobicity is added, so that the stain resistance and weather resistance of a paint film are further improved, the adhesive force is further enhanced, the coating has excellent weather resistance, stain resistance, adhesive force, covering power, water resistance and brushing resistance, the weather resistance can reach more than 2000h, and the cost is moderate, so that the high weather-resistant stain-resistant water-based exterior wall coating is widely applied to buildings such as hotels, residential buildings, schools, office buildings and the like.

In one embodiment of the invention, in order to further improve the performance of the weather-resistant stain-resistant water-based exterior wall coating, the water-based exterior wall coating comprises the following components in parts by weight: 35-50 parts of water-based emulsion, 20-30 parts of titanium dioxide, 5-10 parts of vinyl acetate, 10-15 parts of heavy calcium carbonate, 5-10 parts of kaolin, 2-5 parts of pH regulator, 0.1-1 part of thickener, 0.1-1 part of mildew inhibitor, 2-5 parts of film-forming assistant, 0.1-1 part of defoamer, 0.1-1 part of flatting agent, 0.1-1 part of dispersant, 0.1-1 part of defoamer, 0.1-1 part of rheological assistant and 10-15 parts of deionized water, wherein the weight part ratio of the silicon pure acrylate copolymer emulsion to the pure acrylic emulsion in the water-based emulsion is 3-8: 1.

particularly, in the water-based exterior wall coating, the rheological additive is an acrylic acid association type alkali swelling thickener which can be used in a wide pH range, so that the water-based exterior wall coating has the characteristics of high sagging resistance, strong controllability, good fluidity, leveling property, glossiness, splashing resistance and the like.

The titanium dioxide can adopt rutile type titanium dioxide, the dispersing agent can adopt acrylate polymer type dispersing agent, and the titanium dioxide can be deflocculated through electrostatic stabilization, so that the luster of a paint film of a coating formed by the water-based exterior wall coating is improved, the viscosity is reduced, and meanwhile, the titanium dioxide has the functions of hydrophobicity and improving the stain resistance and weather resistance of the coating.

The pH regulator can adopt 2-amino-2-methyl-1-propanol, has the functions of dispersing, thickening, regulating pH value and the like, also has the antimicrobial (bactericidal) characteristic, can reduce the total amount of VOC (volatile organic compounds), is beneficial to improving the environmental protection performance of the coating, and can prevent titanium dioxide from re-agglomerating as a strong co-dispersant in the coating.

The defoaming agent is one or more of an organic silicon defoaming agent, a mineral oil defoaming agent or an amide defoaming agent; the defoaming agent is polyether siloxane copolymer; the flatting agent is one or more of fatty acid, sulfonate or polyoxyethylene fatty alcohol ether; the film-forming assistant is one or more of dipropylene glycol methyl ether, alcohol ester dodeca or dipropylene glycol butyl ether; the mildew inhibitor is one or more of benzimidazole methyl carbamate and nano silver; the thickener is hydroxyethyl cellulose.

As shown in fig. 1, the embodiment of the present invention further provides a preparation method of the above-mentioned high weather-resistant and stain-resistant water-based exterior wall coating, and the water-based exterior wall coating can be prepared by the following steps:

step S11: stirring and dispersing deionized water, a dispersing agent and a defoaming agent to form a first dispersion liquid;

step S12: slowly adding a thickening agent, a pH regulator and a dispersing agent in preset weight parts into the first dispersion liquid, and then adding titanium dioxide and kaolin for dispersing to obtain a second dispersion liquid;

step S13: mixing the silicon pure acrylate copolymer emulsion and the pure acrylic emulsion to form a water-based emulsion;

step S14: sequentially adding the aqueous emulsion, the film-forming assistant and the mildew preventive into the second dispersion liquid and stirring to form a third dispersion liquid;

step S15: and sequentially adding a thickening agent and deionized water into the third dispersion liquid for viscosity regulation, standing and filtering to obtain the water-based exterior wall coating.

Because deionized water is adopted as a solvent, the emission of Volatile Organic Compounds (VOC) in the water-based exterior wall coating system is extremely low, basically no pungent smell exists, and the water-based exterior wall coating system is nonflammable, safe, stable, good in environmental protection performance and good in stain resistance. Moreover, the preparation method is simple and feasible, the required equipment is simple, the operation can be carried out under the normal temperature and normal pressure environment, the safety and the high efficiency are realized, and the industrial production requirements are met.

The following describes the preparation steps of the weather-resistant stain-resistant water-based exterior wall coating with reference to specific examples.

Example 1

(1) Taking a stirrer, weighing 120g of deionized water, 6g of dispersing agent, 2g of defoaming agent, 220g of titanium dioxide and 1g of pH regulator according to 1kg of sample for later use;

(2) Stirring and dispersing the deionized water, the dispersing agent and the defoaming agent to form a first dispersion liquid, slowly adding 1.5g of cellulose (namely thickening agent), a pH regulator and a dispersing agent into the first dispersion liquid, then adding 50g of titanium dioxide, 50g of kaolin, 50g of talcum powder and 100g of heavy calcium carbonate into the first dispersion liquid, dispersing, stirring for 20-30 minutes at normal temperature at 500-700 r/min to obtain a second dispersion liquid in the form of white slurry for later use;

(3) Weighing 350g of silicon pure acrylate copolymer emulsion, 50g of pure propylene emulsion, 20g of film forming additive, 3g of defoaming agent, 3g of flatting agent, rheological additive, deionized water and the like for later use;

(4) And sequentially adding 1g of the emulsion, the film-forming assistant and the mildew preventive into the second dispersion liquid, stirring for 10-20 minutes, dispersing at the normal temperature of 700-1000 rpm, sequentially adding 2g of the thickening agent and deionized water, adjusting viscosity, standing and filtering to obtain the water-based exterior wall coating.

Wherein the silicon pure acrylate copolymer emulsion is commercially available Enze chemical 2573; the pure acrylic emulsion is a commercially available Dow chemical AC261P waterborne acrylic polymer emulsion; the titanium dioxide is general rutile titanium dioxide prepared by a chlorination method, and is prepared by using commercially available DuPont R-706; the defoaming agent is a commercial Pick BYK-034 mineral oil defoaming agent; the cellulose is Dow QP15000H; the film-forming additive is alcohol ester twelve; the rheological aid is commercially available sublevel DR7700, and the mildew inhibitor is Dow 623A.

Example 2

(1) Taking a stirrer, weighing 120g of deionized water, 6g of dispersing agent, 2g of defoaming agent, 220g of titanium dioxide and 1g of pH regulator according to 1kg of sample for later use;

(2) Stirring and dispersing the deionized water, the dispersing agent and the defoaming agent to obtain a first dispersing agent, slowly adding 1.5g of cellulose, a pH regulator and the dispersing agent into the first dispersing agent, then adding 50g of titanium dioxide, 50g of kaolin and 150g of heavy calcium carbonate into the first dispersing agent for dispersing, stirring the mixture for 20 to 30 minutes at normal temperature at 500 to 700 revolutions per minute to obtain a second dispersing agent in a white slurry state for later use;

(3) Weighing 300g of silicon pure acrylate copolymer emulsion, 100g of pure propylene emulsion, 20g of film forming additive, 3g of defoaming agent, 3g of flatting agent, rheological additive and deionized water for later use;

(4) And (3) sequentially adding 1g of the emulsion, the film-forming aid and the bactericide into the second dispersion liquid, stirring for 10-20 minutes, dispersing at the normal temperature of 700-1000 rpm, sequentially adding 2g of the thickening agent and deionized water, adjusting viscosity, standing and filtering to obtain the water-based exterior wall coating.

Wherein the silicon pure acrylate copolymer emulsion is commercially available Enze chemical 2573; the pure acrylic emulsion is a commercially available Dow chemical AC261P waterborne acrylic polymer emulsion; titanium dioxide is general rutile titanium dioxide prepared by a chlorination method, and is prepared by using commercially available DuPont R-706; the defoaming agent is a commercial Pick BYK-034 mineral oil defoaming agent; the cellulose is Dow QP15000H; the film-forming additive is alcohol ester twelve; the rheological aid is commercially available sublevel DR7700, and the bactericide is Dow 623A.

Example 3

(1) Taking a stirrer, weighing 120g of deionized water, 6g of dispersing agent, 2g of defoaming agent, 230g of titanium dioxide and 1g of pH regulator according to 1kg of sample for later use;

(2) Stirring and dispersing the deionized water, the dispersing agent and the defoaming agent to form a first dispersion solution, slowly adding 1.5g of cellulose, a pH regulator and the dispersing agent into the first dispersion solution, then adding 50g of titanium dioxide, 50g of kaolin and 150g of ground calcium carbonate into the first dispersion solution, dispersing the mixture, stirring the mixture for 20 to 30 minutes at normal temperature at 500 to 700 revolutions per minute to obtain a second dispersion solution in a white slurry state for later use;

(3) Weighing 350g of silicon pure acrylate copolymer emulsion, 50g of pure acrylic emulsion, 20g of film-forming assistant, 3g of defoaming agent, 3g of flatting agent, rheological assistant and water for later use;

(4) And (3) sequentially adding 1g of the emulsion, the film-forming aid and the bactericide into the first dispersion liquid, stirring for 10-20 minutes, dispersing at the normal temperature of 700-1000 rpm, and sequentially adding 2g of the thickening agent and deionized water for viscosity regulation, standing and filtering to obtain the water-based paint.

Wherein the silicon pure acrylate copolymer emulsion is commercially available argentite chemical 8091; the pure acrylic emulsion is commercially available Yinyang chemical industry 8360; titanium dioxide is general rutile titanium dioxide prepared by a chlorination method, and is prepared by using commercially available DuPont R-706; the defoaming agent is a commercial Pick BYK-034 mineral oil defoaming agent; the cellulose is Tao's QP15000H; the film-forming additive is alcohol ester twelve; the rheological aid is commercially available sublevel DR7700, and the bactericide is Dow 623A.

Comparative example 1

(1) Weighing 120g of deionized water, 6g of dispersing agent, 2g of defoaming agent, 230g of titanium dioxide and 1g of pH regulator for later use according to 1kg of sample by using a stirrer;

(2) Stirring and dispersing the deionized water, the dispersing agent and the defoaming agent to form a first dispersion solution, slowly adding 1.5g of cellulose, a pH regulator and the dispersing agent into the first dispersion solution, then adding 50g of titanium dioxide, 50g of kaolin and 150g of heavy calcium carbonate into the first dispersion solution, dispersing the mixture, stirring the mixture for 20 to 30 minutes at normal temperature at 500 to 700 revolutions per minute to obtain a second dispersion solution in a white slurry state for later use;

(3) Weighing 400g of water-silicon pure acrylate copolymer emulsion, 20g of film forming additive, 3g of defoaming agent, 3g of flatting agent, rheological additive and deionized water for later use;

(4) And sequentially adding 1g of the emulsion, the film-forming assistant and the bactericide into the second dispersion liquid, stirring for 10-20 minutes, dispersing, then sequentially adding 2g of the thickening agent and deionized water at normal temperature for viscosity regulation, standing and filtering to obtain the water-based exterior wall coating.

Wherein the silicon pure acrylate copolymer emulsion is commercially available argentite chemical 8091; the defoaming agent is a commercial Pick BYK-034 mineral oil defoaming agent; titanium dioxide is general rutile titanium dioxide prepared by a chlorination method, and is prepared by using commercially available DuPont R-706; the cellulose is Dow QP15000H; the film-forming additive is alcohol ester twelve; the rheological aid is commercially available sublevel DR7700, and the bactericide is Dow 623A.

Comparative example 2

(1) Weighing 120g of deionized water, 6g of dispersing agent, 2g of defoaming agent, 230g of titanium dioxide and 1g of pH regulator for later use according to 1kg of sample by using a stirrer;

(2) Stirring and dispersing the deionized water, the dispersing agent and the defoaming agent to form a first dispersion solution, slowly adding 1.5g of cellulose, a pH regulator and the dispersing agent into the first dispersion solution, then adding 50g of titanium dioxide, 50g of kaolin and 150g of ground calcium carbonate into the first dispersion solution, dispersing the mixture, stirring the mixture for 20 to 30 minutes at normal temperature at 500 to 700 revolutions per minute to obtain a second dispersion solution in a white slurry state for later use;

(3) Weighing 400g of pure acrylic emulsion, 20g of film forming additive, 3g of defoaming agent, 3g of flatting agent, rheological additive and water for later use;

(4) And sequentially adding 1g of the emulsion, the film-forming assistant and the bactericide into the first dispersion liquid, stirring for 10-20 minutes, dispersing at the normal temperature of 700-1000 rpm, sequentially adding 2g of the thickening agent and deionized water, adjusting viscosity, standing and filtering to obtain the water-based paint.

Wherein the pure acrylic emulsion is commercially available Yinyang chemical industry 8360; titanium dioxide is general rutile titanium dioxide prepared by a chlorination method, and is prepared by using commercially available DuPont R-706; the defoaming agent is a commercial Pick BYK-034 mineral oil defoaming agent; the cellulose is Tao's QP15000H; the film-forming additive is alcohol ester twelve; the rheological assistant is commercially available sublevel DR7700, and the bactericide is Dow 623A.

The silicon pure acrylate copolymer emulsion is compared with the commercially available examples 3, 4 and 5 of the Yinyang chemical 8091, wherein the contrast ratio is polyester film (or card paper), the wash-resistant PVC plastic sheet, the saltpetering-resistant alkaline asbestos-free fiber reinforced cement medium density board and the rest of the projects are asbestos-free cement flat boards meeting the JC/412.1-2006 NAF H V level requirement. The treatment of the cement board was carried out as specified in GB/T9271-2008 on day 10.2. The test standard refers to GB/T9755-2014 synthetic resin emulsion exterior wall coating. The test results are shown in table 1 below.

TABLE 1-test results for aqueous exterior wall coatings of examples 3-4

As is apparent from the detection data in Table 1, the water-based exterior wall coatings of the examples 3, the comparative examples 1 and the comparative examples 2 can form paint films with water resistance, alkali resistance, contrast ratio and adhesion which can reach the national standard qualified or above. In addition, in example 3, the solution of mixing the pure acrylic acid emulsion with the silicon pure acrylic acid ester copolymer emulsion is adopted, the paint film performance is better than that of the enterprise or national standard product, the water-based exterior wall coating of the comparative example 1 has better stain resistance and weather resistance than that of example 3, but has some defects in different aspects of washing resistance and adhesion, such as: in comparative example 1, the acrylic emulsion is not added, so that the adhesion of the paint film only reaches the level 2 standard, and the scrub resistance meets the relevant national standard but is slightly lower than the enterprise standard. The comparison example 2 adopts a pure acrylic emulsion scheme, the overall performance meets the standard, but the pollution resistance is only about 8 percent, the aging resistance is only 1200h, is slightly higher than the standard, and has no outstanding special performance.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (6)

1. The high weather-resistant stain-resistant water-based exterior wall coating is characterized by comprising the following components in parts by weight: 35-60 parts of water-based emulsion, 15-30 parts of titanium dioxide, 5-10 parts of vinyl acetate, 5-15 parts of heavy calcium carbonate, 4-10 parts of kaolin, 1-5 parts of pH regulator, 0.1-3 parts of thickener, 0.1-3 parts of mildew inhibitor, 1-5 parts of film-forming assistant, 0.1-1 part of defoamer, 0.1-1 part of flatting agent, 0.1-1 part of dispersant, 0.1-1 part of defoaming agent, 0.1-1 part of rheological assistant and 10-20 parts of deionized water;

the water-based emulsion is formed by mixing a silicon pure acrylate copolymer emulsion and a pure acrylic emulsion, wherein the weight part ratio of the silicon pure acrylate copolymer emulsion to the pure acrylic emulsion is 2-8: 1, wherein the silicon pure acrylate copolymerization emulsion has an interpenetrating network type core-shell structure taking vinyl siloxane as a shell and an acrylic monomer as a core, and the content of organic silicon in the silicon pure acrylate copolymerization emulsion is not less than 8%.

2. The highly weather-resistant stain-resistant water-based exterior wall coating material as claimed in claim 1, wherein the water-based exterior wall coating material comprises the following components in parts by weight: 35-50 parts of water-based emulsion, 20-30 parts of titanium dioxide, 5-10 parts of vinyl acetate, 10-15 parts of heavy calcium carbonate, 5-10 parts of kaolin, 2-5 parts of pH regulator, 0.1-1 part of thickener, 0.1-1 part of mildew inhibitor, 2-5 parts of film-forming assistant, 0.1-1 part of defoamer, 0.1-1 part of flatting agent, 0.1-1 part of dispersant, 0.1-1 part of defoamer, 0.1-1 part of rheological assistant and 10-15 parts of deionized water, wherein the weight part ratio of the silicon pure acrylate copolymer emulsion to the pure acrylic emulsion in the water-based emulsion is 3-8: 1.

3. the highly weather-resistant stain-resistant water-based exterior wall coating material as claimed in claim 1 or 2, wherein the defoaming agent is one or more of a silicone defoaming agent, a mineral oil defoaming agent or an amide defoaming agent; the defoaming agent is polyether siloxane copolymer; the flatting agent is one or more of fatty acid, sulfonate or polyoxyethylene fatty alcohol ether; the rheological additive is an acrylic acid associated alkali swelling thickener; the film-forming assistant is one or more of dipropylene glycol methyl ether, alcohol ester dodeca or dipropylene glycol butyl ether; the mildew inhibitor is one or more of benzimidazole methyl carbamate and nano silver; the thickening agent is hydroxyethyl cellulose.

4. The highly weather-resistant stain-resistant water-based exterior wall coating material as claimed in claim 1 or 2, wherein the dispersant is an acrylate polymer type dispersant.

5. The weather-resistant stain-resistant water-based exterior wall coating material as claimed in claim 1 or 2, wherein the titanium dioxide is rutile type titanium dioxide; the pH regulator is 2-amino-2-methyl-1-propanol.

6. The preparation method of the weather-resistant stain-resistant water-based exterior wall coating material as claimed in any one of claims 1 to 5, which comprises the following steps:

(a) Stirring and dispersing deionized water, a dispersing agent and a defoaming agent to form a first dispersion liquid;

(b) Slowly adding a thickening agent, a pH regulator and a dispersing agent in preset weight parts into the first dispersion liquid, and then adding titanium dioxide and kaolin for dispersing to obtain a second dispersion liquid;

(c) Mixing the silicon pure acrylate copolymer emulsion and the pure acrylic emulsion to form a water-based emulsion;

(d) Sequentially adding the water-based emulsion, the film-forming assistant and the mildew preventive into the second dispersion liquid and stirring to form a third dispersion liquid;

(e) And sequentially adding a thickening agent and deionized water into the third dispersion liquid for viscosity regulation, standing and filtering to obtain the water-based exterior wall coating.

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