Modified wollastonite-calcium carbonate prefabricated slurry, coating composition suitable for wet area wall surface and preparation method of modified wollastonite-calcium carbonate prefabricated slurry

Abstract

The invention discloses modified wollastonite-calcium carbonate prefabricated slurry, a coating composition of a wet-area wall surface and a preparation method of the coating composition, and belongs to the technical field of water-based coatings. The modified wollastonite-calcium carbonate prefabricated slurry is prepared by modifying wollastonite with maleic acid and cyclohexane, and a unique grafting and embedding structure is formed between modified barium sulfate and modified wollastonite-calcium carbonate through an ingenious design of a formula, so that a paint film surface which is tighter and more compact and has higher aggregation density is obtained, and the paint film surface is more uniform. The water resistance, moisture resistance, stain resistance, stain resistance and paint film strength can be further greatly improved, and the water-based paint is applied to preparation of a coating composition suitable for a wet area wall surface, so that the technical difficulty that wall paint cannot be applied in a wet room environment for a long time is overcome.

Description

Technical Field

[0001] The present invention belongs to the technical field of waterborne coatings, and particularly relates to a modified wollastonite-calcium carbonate prefabricated slurry, a coating composition suitable for wet area walls, and a preparation method thereof. Background Art

[0002] With the development of modern society and the continuous improvement of people's living standards, the pursuit of quality of life by modern families has been continuously increasing, so that people's demands and choices for home decoration have become more diverse.

[0003] For modern family wall decoration, waterborne latex paint has always been a wall decoration product with very high public recognition. It is not only beautiful, but also can give the wall corresponding decoration and certain protection. However, these waterborne latex paint products are generally applied to relatively dry areas such as living rooms and bedrooms. Different from these dry decoration environments, relatively humid environments such as kitchens and bathrooms lack the presence of waterborne latex paint.

[0004] At the same time, in recent years, some kitchen and bathroom latex paint products that feature "waterproof" functions have emerged in China. However, it remains to be discussed whether this type of product can really cope with the relatively "high temperature and high humidity" environments such as kitchens and bathrooms.

[0005] Traditional wall coatings will have problems such as bubbling, powdering, and mildew when applied in "wet room" scenarios for a long time. Therefore, tiles are usually used in such scenarios, and wall coatings are not considered. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a modified wollastonite-calcium carbonate prefabricated slurry, a coating composition suitable for wet area walls, and a preparation method thereof. The present invention modifies wollastonite with maleic acid and cyclohexane to prepare a modified wollastonite-calcium carbonate prefabricated slurry. Through a clever formula design, a unique grafted filling structure is formed between the modified barium sulfate and the modified wollastonite-calcium carbonate, with a more compact, dense, and higher aggregation density film surface, which can further leapfrog the improvement in water resistance, moisture resistance, stain resistance, stain resistance, and film strength, and apply it to the preparation of a coating composition suitable for wet area walls, overcoming the technical difficulty that wall paint cannot be applied in wet room environments for a long time.

[0007] To solve the above problems, the present invention is achieved through the following technical solutions:

[0008] The first object of the present invention is:

[0009] To provide a modified wollastonite-calcium carbonate prefabricated slurry, which comprises the following components in parts by weight:

[0010] 30 - 45 parts of water, 0.6 - 1.5 parts of thickener, 0.1 - 0.25 parts of pH regulator, 0.3 - 0.9 parts of dispersant, 0.15 - 0.6 parts of defoamer, 25 - 40 parts of modified wollastonite, 15 - 30 parts of heavy calcium carbonate, 0.05 - 0.15 parts of bactericidal and preservative agent;

[0011] The modified wollastonite is prepared by heating, drying and grinding wollastonite with maleic acid and non - polar solvent cyclohexane.

[0012] The further optimization of the modified wollastonite - calcium carbonate pre - slurry of the present invention is as follows:

[0013] It includes the combination of one or several of the following features:

[0014] The thickener is hydrophobic modified hydroxyethyl cellulose and bentonite;

[0015] The pH regulator is butyldiethanolamine;

[0016] The dispersant is sodium polyacrylate salt;

[0017] The defoamer is a mineral oil / silicone composite defoamer;

[0018] The particle size of the heavy calcium carbonate is 10 - 14 μm;

[0019] The bactericidal and preservative agent is 2 - methyl - 4 - isothiazolin - 3 - one.

[0020] The further optimization of the modified wollastonite - calcium carbonate pre - slurry of the present invention is as follows:

[0021] It includes the following components in parts by weight:

[0022] 40.5 parts of water, 1 part of thickener, 0.2 part of pH regulator, 0.7 part of dispersant, 0.4 part of defoamer, 36 parts of modified wollastonite, 21 parts of heavy calcium carbonate, 0.2 part of bactericidal and preservative agent.

[0023] The second object of the present invention is:

[0024] To provide a preparation method of the modified wollastonite - calcium carbonate pre - slurry described above, which includes the following preparation steps:

[0025] Add part of the water into the reaction vessel according to the proportion, stir at a speed of 400 r / min, add the thickener, pH regulator, dispersant, part of the defoamer, modified wollastonite, heavy calcium carbonate, adjust the speed to 800 r / min and stir for 15 min, then add the bactericidal and preservative agent, the remaining part of the defoamer and the remaining part of the water, and continue to stir for 15 min to obtain the modified wollastonite - calcium carbonate pre - slurry;

[0026] The preparation method of the modified wollastonite described above includes the following components in parts by weight:

[0027] 8 - 9.5 parts of wollastonite, 0.5 - 2 parts of maleic acid, 5 parts of cyclohexane;

[0028] It includes the following preparation steps:

[0029] S1. Dry the wollastonite at 110 °C for 6 - 8 hours in proportion to remove excess moisture;

[0030] S2. Add the dried wollastonite, maleic acid and cyclohexane organic solvent into the reaction vessel, and place the reaction vessel on the heating plate stirrer in the fume hood for the modification reaction; the modification reaction is carried out at 80 °C until all the solvents evaporate;

[0031] S3. Dry the modified wollastonite obtained after the above modification reaction again in an 80 °C oven for 24 h;

[0032] S4. Use mortar to grind the dried reaction product obtained in step S3 into powder form to obtain the modified wollastonite.

[0033] The weighing of maleic acid and wollastonite is carried out using a Sartorius B 120S scale (accuracy ±0.1 mg).

[0034] The third object of the present invention is:

[0035] To provide a coating composition suitable for wet area walls, which includes the following components in parts by weight:

[0036] 5 - 20 parts of water, 0.1 - 5.0 parts of thickener, 0.1 - 1.0 parts of pH regulator, 0.1 - 1.0 parts of dispersant, 0.1 - 1.0 parts of wetting agent, 0.1 - 1 part of defoamer, 15 - 30 parts of titanium dioxide, 2 - 6 parts of modified barium sulfate, 3 - 10 parts of the above-mentioned modified wollastonite - heavy calcium carbonate slurry, 40 - 60 parts of emulsion, 2 - 4 parts of film-forming aid, 0.1 - 4 parts of bactericidal and preservative;

[0037] The modified barium sulfate is sodium palmitate / stearate composite modified barium sulfate;

[0038] The emulsion is a self-crosslinking pure acrylic emulsion, preferably Dow Corning 22.

[0039] The further optimization of the coating composition suitable for wet area walls of the present invention is:

[0040] It includes the combination of one or several of the following technical features:

[0041] The thickener described above is one or a combination of several of hydroxyethyl cellulose, hydrophobically modified hydroxyethyl cellulose, alkali-swellable thickener, acrylic-based alkali-soluble emulsion associative thickener, and organically modified montmorillonite clay thickener;

[0042] The pH regulator described above is butyldiethanolamine;

[0043] The dispersant described above is sodium polyacrylate;

[0044] The defoamer described above is one or a combination of several of mineral oil defoamers and metal soap defoamers;

[0045] The modified barium sulfate is modified by wet reaction;

[0046] The titanium dioxide described above is rutile titanium dioxide;

[0047] The bactericidal and preservative described above is one or a combination of several of 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 1,2-benzisothiazolin-3-one;

[0048] The film-forming aid described above is an ester mixture.

[0049] A further optimization of the coating composition applicable to wet area walls of the present invention is as follows:

[0050] It includes the following components in parts by weight:

[0051] 8 - 9 parts of water, 3 - 4 parts of thickener, 0.1 - 1.0 part of pH regulator, 0.1 - 1.0 part of dispersant, 0.1 - 1.0 part of wetting agent, 0.1 - 1 part of defoamer, 18 - 24 parts of titanium dioxide, 3 - 5 parts of modified barium sulfate, 5 - 8 parts of the modified wollastonite-ground calcium carbonate slurry described above, 50 - 55 parts of emulsion, 2 - 4 parts of film-forming aid, 0.1 - 4.0 parts of bactericidal and preservative.

[0052] The fourth object of the present invention is:

[0053] To provide a preparation method of the coating composition applicable to wet area walls described above, which includes the following preparation steps:

[0054] Weigh part of the water in proportion and add it to the dispersion tank, control the speed at 200-300r / min; add pH regulator, dispersant, wetting agent, part of defoamer, titanium dioxide, modified barium sulfate, modified wollastonite-heavy calcium carbonate slurry, adjust the speed to 1500 rpm, disperse for 15 minutes, then control the speed at 700-800r / min, then add emulsion, the remaining part of defoamer, film-forming aid, thickener, bactericidal preservative and the remaining part of water, maintain the speed at 1000-1200r / min and disperse for 30 minutes to prepare the coating composition suitable for wet area walls.

[0055] Traditional wollastonite modification is usually achieved through reaction with carboxylic acid, more specifically, through the interaction between calcium ions on the surface of wollastonite and organic acid carboxyl groups. The solvents for modifying wollastonite with carboxylic acid are usually ethanol and acetone. Although this traditional process of modifying wollastonite has a significant improvement in tensile strength, its water resistance is poor.

[0056] The modified wollastonite in the modified wollastonite-calcium carbonate prefabricated slurry of the present invention is modified by using maleic acid and cyclohexane. After being applied to the coating, it has excellent tensile strength and water resistance.

[0057] The coating composition suitable for wet area walls of the present invention is prepared by mixing self-crosslinking pure acrylic emulsion and various functional fillers, adding sodium palmitate / sodium stearate composite modified barium sulfate, the modified barium sulfate has a small particle size, and a modified wollastonite-calcium carbonate mechanical filling structure is manufactured. The modified barium sulfate and modified wollastonite-calcium carbonate cooperate with each other to form a unique grafting and embedding structure in the formula, which has a more compact, dense and denser paint film surface, and realizes the application experience in a long-term water immersion environment.

[0058] The coating composition suitable for wet area walls of the present invention forms a unique grafting and filling structure through a cleverly designed formula, which can further improve water resistance, moisture resistance, stain resistance, stain resistance and paint film strength. The wall paint that can be used for a long time in a wet room environment is developed, which can be used by consumers in daily life, breaking through the limitation that only tiles can be used in a wet room environment, and providing consumers with more choices.

[0059] The present invention breaks the traditional concept and seeks breakthroughs. The coating composition prepared for wet area walls is equivalent to a colorful "kitchen and bathroom special paint". The present invention solves the application problems of traditional wall coatings in such scenes, and it has excellent tensile strength, antibacterial and mildew-proof, waterproof, scrub-resistant, temperature-resistant, stain-resistant and stain-resistant properties. At the same time, it passes the wet room environment cycle simulation experiment. This is a "zero" breakthrough in the wet room field in China. Specific implementation method

[0060] To make the application, technical solution and advantages of the present invention clearer and more understandable, the content of the present invention will be described in detail in combination with specific embodiments. It should be understood that the embodiments are only used to illustrate the present invention, rather than limiting the protection scope of the present invention. Any simple improvement to the preparation method of the present invention under the premise of the inventive concept belongs to the protection scope of the present invention.

[0061] Example 1 Preparation method of a coating composition suitable for wet area walls

[0062] A preparation method of a coating composition suitable for wet area walls, which comprises the following components in parts by weight:

[0063] Water 5 - 20 parts, thickener 0.1 - 5.0 parts, pH regulator 0.1 - 1.0 parts, dispersant 0.1 - 1.0 parts, wetting agent 0.1 - 1.0 parts, defoamer 0.1 - 1 part, titanium dioxide 15 - 30 parts, modified barium sulfate 2 - 6 parts, modified wollastonite - heavy calcium carbonate slurry 3 - 10 parts, emulsion 40 - 60 parts, film - forming aid 2 - 4 parts, bactericidal and preservative 0.1 - 4 parts;

[0064] The modified barium sulfate is sodium palmitate / stearate composite - modified barium sulfate;

[0065] The emulsion is a self - crosslinking pure acrylic emulsion, preferably Dow Corning TEGO Glide 22.

[0066] The preparation method of the coating composition suitable for wet area walls comprises the following preparation steps:

[0067] Weigh a part of water according to the proportion and add it to the dispersion tank, and control the rotation speed at 200 - 300 r / min; add the pH regulator, dispersant, wetting agent, part of the defoamer, titanium dioxide, modified barium sulfate, and modified wollastonite - heavy calcium carbonate slurry, then adjust the rotation speed to 1500 r / min, disperse for 15 minutes, and then control the rotation speed at 700 - 800 r / min. Then add the emulsion, the remaining part of the defoamer, film - forming aid, thickener, bactericidal and preservative, and the remaining part of the water, and maintain the rotation speed at 1000 - 1200 r / min to disperse for 30 minutes to prepare the coating composition suitable for wet area walls.

[0068] Among them, the modified wollastonite - heavy calcium carbonate slurry comprises the following components in parts by weight:

[0069] Water 40.5 parts, thickener 1 part, pH regulator 0.2 part, dispersant 0.7 part, defoamer 0.4 part, modified wollastonite 36 parts, heavy calcium carbonate 21 parts, bactericidal and preservative 0.2 part.

[0070] Among them, the preparation method of the modified wollastonite - calcium carbonate pre - slurry

[0071] It includes the following preparation steps:

[0072] Add a part of water into the reaction vessel according to a proportion, stir at a speed of 400 r / min, add a thickener, a pH regulator, a dispersant, a part of an antifoaming agent, modified wollastonite, and heavy calcium carbonate, adjust the speed to 800 r / min and stir for 15 min, then add a bactericidal preservative, the remaining part of the antifoaming agent and the remaining part of water, and continue to stir for 15 min to obtain a modified wollastonite-calcium carbonate prefabricated slurry;

[0073] The preparation method of the modified wollastonite therein includes the following components in parts by weight:

[0074] 8.5 parts of wollastonite, 1.5 parts of maleic acid, 5 parts of cyclohexane;

[0075] It includes the following preparation steps:

[0076] S1. Dry the wollastonite at 110 °C for 6 - 8 hours according to a proportion to remove excess moisture;

[0077] S2. Add the dried wollastonite, maleic acid and cyclohexane organic solvent into the reaction vessel, and place the reaction vessel on a heating plate stirrer in a fume hood for a modification reaction; the modification reaction is carried out at 80 °C until all the solvents evaporate;

[0078] S3. Dry the modified wollastonite obtained after the above modification reaction in an oven at 80 °C for 24 h again;

[0079] S4. Grind the dried reaction product obtained in step S3 into a powder form using mortar to obtain the modified wollastonite.

[0080] The weighing of maleic acid and wollastonite is carried out using a Sartorius B 120S scale (accuracy ±0.1 mg).

[0081] Table 1 Specific raw material ratios (parts by weight) of each example and comparative example

[0082]

[0083] Table 2 Comparison of appearance and workability of each example and comparative example

[0084]

[0085] Touch the film: The handfeel score of the film: 5 points means the film is smooth, delicate and has no particle feeling; 4 points means the film is smooth and has no particle feeling; 3 points means the film is flat but not delicate; 2 points means the film has a slight rough feeling; 1 point means the film has an obvious rough feeling.

[0086] Fullness: 5 points is the best, 1 point is the worst.

[0087] From the comparison of Examples 1 to 3 and Comparative Examples 1 to 4, it can be seen that when adding fillers alone, the film appearance and fineness degree of Comparative Examples 1 to 4 are inferior to those of Examples 1 to 3; moreover, the workability and fullness of Comparative Examples 1 to 4 are relatively average.

[0088] From Examples 1 to 3, it can be seen that for different modified wollastonite-calcium carbonate slurries and different proportions of emulsions, there is no difference in workability and fullness, but the film appearance will deteriorate after the PVC is reduced. Compared with Comparative Example 5, after two kinds of fillers are removed, although the film appearance and workability are basically equivalent to those of Examples 1 to 3, the fullness becomes worse due to the reduction of the powder material.

[0089] Table 3 Comparison of wet chamber film properties of each example and comparative example

[0090]

[0091] From the comparison of Examples 1 to 3 and Comparative Examples 1 to 3, it can be seen that when adding various wollastonites alone, the overall film properties are inferior to those of Examples 1 to 3, and for several key properties such as water resistance, strength, scrub resistance, stain resistance and dirt pick-up resistance, through the addition of the modified wollastonite-calcium carbonate slurry, the performance has been significantly improved. The comparison among Examples 1 to 3 shows little difference and basically maintains the product performance characteristics required for the wet chamber.

[0092] When comparing Example 1 with Comparative Example 3, in the case where maleic acid-modified wollastonite is not premixed with calcium carbonate, the water resistance, contrast ratio, scrub resistance, tensile strength, stain resistance and dirt pick-up resistance are all inferior to the effect of premixing. When comparing Example 1 with Comparative Example 5, in the formulation without wollastonite and calcium carbonate, the performance such as contrast ratio, scrub resistance, water resistance, stain resistance and tensile strength is far inferior to that of Example 1 and cannot meet the characteristics of use in the wet chamber environment.

[0093] Through comprehensive comparison, after wollastonite is modified by maleic acid, the interaction between the calcium ions on the surface of wollastonite and the carboxyl groups of organic acids occurs. Without affecting its own characteristics, the tensile strength and hydrophobicity are significantly improved. After premixing with calcium carbonate, the maleic acid-modified wollastonite-calcium carbonate slurry is obtained. By combining with the emulsion to form a grafted filling structure, it has a film surface that is tighter, denser and has a greater aggregation density, realizing the application experience in a long-term immersion water environment.

[0094] In summary, the above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention; any equivalent changes, modifications and evolutions made by those skilled in the art within the scope of the technical solution of the present invention by using the disclosed technical content are regarded as equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments according to the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

[0095] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0096] The experimental methods without specific conditions mentioned in the present invention are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0097] For various optimization technical solutions in the present invention, unless otherwise stated, the various optimization technical solutions can be combined with each other.

[0098] Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0099] The experimental methods without specific conditions mentioned in the specification and embodiments are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0100] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the method of the present invention.

Claims

1. A modified wollastonite-calcium carbonate prefabricated slurry, characterized in that: It includes the following components by weight: 30-45 parts of water, 0.6-1.5 parts of thickener, 0.1-0.25 parts of pH regulator, 0.3-0.9 parts of dispersant, 0.15-0.6 parts of defoamer, 25-40 parts of modified wollastonite, 15-30 parts of heavy calcium carbonate, 0.05-0.15 parts of bactericidal preservative; The modified wollastonite is prepared by heating, drying and grinding wollastonite, maleic acid and non-polar solvent cyclohexane.

2. The modified wollastonite-calcium carbonate prefabricated slurry according to claim 1, characterized in that: It includes one or a combination of the following features: The thickeners are hydrophobically modified hydroxyethyl cellulose and bentonite; The pH regulator is butyl diethanolamine; The dispersant is polyacrylic acid sodium salt; The defoamer is a mineral oil / organic silicon composite defoamer; The particle size of the heavy calcium carbonate is 10 to 14 μm; The bactericidal preservative is 2-methyl-4-isothiazoline-3-one.

3. The modified wollastonite-calcium carbonate prefabricated slurry according to claim 1, characterized in that: It includes the following components by weight: 40.5 parts of water, 1 part of thickener, 0.2 parts of pH regulator, 0.7 parts of dispersant, 0.4 parts of defoamer, 36 parts of modified wollastonite, 21 parts of heavy calcium carbonate, and 0.2 parts of bactericidal preservative.

4. A method for preparing the modified wollastonite-calcium carbonate prefabricated slurry according to claim 1, characterized in that: It comprises the following preparation steps: Add part of the water to the reaction container in proportion, stir at a speed of 400 r / min, add a thickener, a pH adjuster, a dispersant, a part of the defoamer, modified wollastonite, and heavy calcium carbonate, adjust the speed to 800 r / min and stir for 15 minutes, then add a bactericidal preservative, the remaining part of the defoamer and the remaining part of the water, continue stirring for 15 minutes to obtain a modified wollastonite-calcium carbonate prefabricated slurry; The preparation method of the modified wollastonite comprises the following components in parts by weight: Wollastonite 8-9.5 parts, maleic acid 0.5-2 parts, cyclohexane 5 parts; It comprises the following preparation steps: S1. Dry the wollastonite at 110°C for 6 to 8 hours to remove excess moisture; S2. Dry wollastonite, maleic acid and cyclohexane organic solvent were added to a reaction vessel, and the reaction vessel was placed on a hot plate stirrer in a fume hood for modification reaction; the modification reaction was carried out at 80 ° C until all the solvent evaporated; S3. The modified wollastonite obtained after the above modification reaction was dried again in an oven at 80°C for 24h; S4. Grind the dried reaction product obtained in step S3 into powder using a mortar to obtain the modified wollastonite.

5. A coating composition suitable for wet area walls, characterized in that: It includes the following components by weight: 5-20 parts of water, 0.1-5.0 parts of thickener, 0.1-1.0 parts of pH adjuster, 0.1-1.0 parts of dispersant, 0.1-1.0 parts of wetting agent, 0.1-1.0 parts of defoamer, 15-30 parts of titanium dioxide, 2-6 parts of modified barium sulfate, 3-10 parts of modified wollastonite-heavy calcium carbonate slurry according to claim 1, 40-60 parts of emulsion, 2-4 parts of film-forming aid, 0.1-4 parts of bactericidal preservative; The modified barium sulfate is a sodium palmitate / sodium stearate composite modified barium sulfate; The emulsion is a self-crosslinking pure acrylic emulsion.

6. The coating composition suitable for wet area walls according to claim 5, characterized in that: It includes one or a combination of the following technical features: The thickener is one or a combination of hydroxyethyl cellulose, hydrophobically modified hydroxyethyl cellulose, alkali swelling thickener, acrylic acid alkali soluble emulsion associative thickener and organically modified montmorillonite clay thickener; The pH regulator is butyl diethanolamine; The dispersant is polyacrylic acid sodium salt; The defoamer is one or a combination of mineral oil defoamers and metal soap defoamers; The modified barium sulfate is modified by wet reaction; The titanium dioxide is rutile titanium dioxide; The bactericidal preservative is one or a combination of 2-methyl-4-isothiazoline-3-one, 5-chloro-2-methyl-4-isothiazoline-3-one and 1,2-benzisothiazolin-3-one; The film-forming aid is an ester mixture.

7. The coating composition suitable for wet area walls according to claim 5, characterized in that: It includes the following components by weight: 8-9 parts of water, 3-4 parts of thickener, 0.1-1.0 parts of pH adjuster, 0.1-1.0 parts of dispersant, 0.1-1.0 parts of wetting agent, 0.1-1.0 parts of defoamer, 18-24 parts of titanium dioxide, 3-5 parts of modified barium sulfate, 5-8 parts of modified wollastonite-heavy calcium carbonate slurry according to claim 1, 50-55 parts of emulsion, 2-4 parts of film-forming aid, and 0.1-4.0 parts of bactericidal preservative.

8. A method for preparing a coating composition suitable for wet area walls according to claim 5, characterized in that: It comprises the following preparation steps: Weigh part of the water in proportion and add it to the dispersion tank, and control the speed at 200-300 r / min; add pH regulator, dispersant, wetting agent, part of defoamer, titanium dioxide, modified barium sulfate, and modified wollastonite-heavy calcium carbonate slurry, adjust the speed to 1500 r / min, and control the speed at 700-800 r / min after dispersing for 15 minutes, then add emulsion, the remaining part of defoamer, film-forming aid, thickener, bactericidal preservative and the remaining part of water, maintain the speed at 1000-1200 r / min and disperse for 30 minutes to prepare the coating composition suitable for wet area walls.

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