Water-based polymer coating as well as preparation method and application thereof

Abstract

The invention discloses a water-based polymer coating as well as a preparation method and application thereof, and relates to the technical field of coatings. The water-based polymer coating comprises an acrylic emulsion, titanium dioxide, water-washed diatomite and calcined diatomite. Wherein the mass ratio of the titanium dioxide to the washed diatomite to the calcined diatomite is 1: (0.05-0.6): (0.04-0.4). The washed diatomite and the calcined diatomite in the water-based polymer coating provided by the invention can provide steric hindrance, fully disperse the titanium dioxide, improve the utilization rate of the titanium dioxide, and cooperate with other components to improve the covering power of the coating. The water-based polymer coating has good processing performance and construction performance, does not have hard blocks, is in a uniform state after being stirred, and is good in paint film appearance, high in covering power and suitable for the field of buildings needing high-covering-power coatings.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a water-based polymer coating, a preparation method thereof, and an application thereof. Background Art

[0002] Hiding power is an important indicator to measure the ability of coating to cover the substrate. Coatings with high hiding power can effectively cover the substrate, avoid the bottom showing phenomenon, ensure the uniformity and aesthetics of the coating, and improve construction efficiency and quality.

[0003] Currently, most high-hiding coatings on the market use titanium dioxide as a high-hiding pigment, often at high dosages. However, with increasingly severe ecological and environmental issues and growing awareness of environmental protection, the highly polluting and energy-intensive titanium dioxide industry faces significant challenges. Therefore, achieving sustainable development in high-hiding coatings requires improving the efficiency of titanium dioxide and reducing its usage while maintaining high hiding power. Summary of the Invention

[0004] The present invention aims to address at least one of the aforementioned technical problems existing in the prior art. To this end, the present invention provides a water-based polymer coating that incorporates washed diatomaceous earth and calcined diatomaceous earth into the coating to provide steric hindrance, prevent titanium dioxide flocculation, increase titanium dioxide utilization, and synergize with other components to enhance the coating's hiding power.

[0005] The second aspect of the present invention is to provide a method for preparing a water-based polymer coating.

[0006] The third aspect of the present invention is to provide an application of a water-based polymer coating.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A first aspect of the present invention provides a water-based polymer coating comprising acrylic emulsion, titanium dioxide, washed diatomaceous earth and calcined diatomaceous earth; wherein the mass ratio of the titanium dioxide, washed diatomaceous earth and calcined diatomaceous earth is 1:(0.05-0.6):(0.04-0.4).

[0009] The present invention incorporates water-based diatomaceous earth and calcined diatomaceous earth into a water-based polymer coating. The washed diatomaceous earth mineral source contains few impurities and has a uniform pore size. Since it is not subjected to high-temperature calcination, it retains its original structure to the greatest extent possible, providing steric hindrance to prevent titanium dioxide flocculation, allowing for full dispersion and improving titanium dioxide utilization. Calcined diatomaceous earth, on the other hand, has higher strength and whiteness, and can synergize with the washed diatomaceous earth to introduce a large amount of air, creating a refractive index difference, thereby improving the coating's dry and wet film hiding power. Therefore, the water-based polymer coating of the present invention improves the coating's hiding power while reducing the amount of titanium dioxide used.

[0010] In some embodiments, the mass content of titanium dioxide in the water-based polymer coating is 10 to 40%.

[0011] In some specific embodiments, the mass content of titanium dioxide in the water-based polymer coating is 10-20%.

[0012] In some embodiments, the water-based polymer coating comprises the following components in parts by mass:

[0013] 10-25 parts of acrylic emulsion, 15-25 parts of titanium dioxide, 2-8 parts of washed diatomaceous earth, 1-5 parts of calcined diatomaceous earth, 10-30 parts of filler, 1.5-15 parts of additive, and 20-50 parts of water.

[0014] In some specific embodiments, the water-based polymer coating comprises the following components in parts by mass:

[0015] 10-20 parts of acrylic emulsion, 15-20 parts of titanium dioxide, 2-8 parts of washed diatomaceous earth, 1-5 parts of calcined diatomaceous earth, 10-25 parts of filler, 2-11 parts of additive, and 30-50 parts of water.

[0016] In some embodiments, the average particle size of the titanium dioxide is 0.2 to 0.4 μm.

[0017] In some embodiments, the average pore size of the water-washed diatomaceous earth is 0.3 to 0.4 μm. Specifically, the water-washed diatomaceous earth is in the shape of a round sieve.

[0018] By limiting the pore size of the water-washed diatomite and the particle size of titanium dioxide, the pores of the water-washed diatomite can be embedded with titanium dioxide, further dispersing the titanium dioxide and providing better steric hindrance. At the same time, the air in the internal pores of the water-based diatomite can form a refractive index difference with the titanium dioxide particles, improving the hiding power of the coating.

[0019] In some embodiments, the median particle size (D50) of the calcined diatomaceous earth is 10 to 20 μm.

[0020] In some embodiments, the filler includes calcined kaolin and / or calcium carbonate. Combining calcined kaolin and calcium carbonate helps reduce costs and improve hiding power.

[0021] In some embodiments, the filler comprises the following components in parts by mass: 10 to 20 parts of calcined kaolin and 1 to 10 parts of calcium carbonate.

[0022] In some specific embodiments, the filler comprises the following components by weight: 10 to 20 parts of calcined kaolin and 1 to 5 parts of calcium carbonate.

[0023] In some embodiments, the maximum size of the calcium carbonate is 600-1000 mesh.

[0024] In other specific embodiments, the maximum size of the calcium carbonate is 600-800 mesh.

[0025] In some embodiments, the auxiliary agent includes at least one of a dispersant, a defoaming agent, a pH regulator, a thickener, a film-forming aid, and a preservative.

[0026] In some embodiments, the auxiliary agent comprises the following components in parts by mass:

[0027] Dispersant 0.1-1 part, defoaming agent 0.1-1 part, pH adjuster 0.1-1 part, thickener 0.3-3 parts, film-forming aid 0.5-3 parts, preservative 0.5-5 parts.

[0028] In some specific embodiments, the auxiliary agent comprises the following components in parts by mass:

[0029] Dispersant 0.5-1 part, defoamer 0.3-0.6 part, pH adjuster 0.1-0.5 part, thickener 0.5-1 part, film-forming aid 0.5-1.5 parts, preservative 0.5-1.5 parts.

[0030] In some embodiments, the water-based polymer coating comprises the following components in parts by mass:

[0031] 10-25 parts of acrylic emulsion, 15-25 parts of titanium dioxide, 2-8 parts of washed diatomaceous earth, 1-5 parts of calcined diatomaceous earth, 10-20 parts of calcined kaolin, 1-10 parts of calcium carbonate, 0.1-1 part of dispersant, 0.1-1 part of defoaming agent, 0.1-1 part of pH regulator, 0.3-3 parts of thickener, 0.5-3 parts of film-forming aid, 0.5-5 parts of preservative, and 20-50 parts of water.

[0032] In some embodiments, the acrylic emulsion includes a vinyl acetate-acrylate copolymer emulsion.

[0033] In some embodiments, the dispersant comprises a polycarboxylate.

[0034] In some embodiments, the defoaming agent comprises a mineral oil defoaming agent.

[0035] In some embodiments, the pH adjuster comprises 2-amino-2-methyl-1-propanol.

[0036] In some embodiments, the thickener includes hydroxyethyl cellulose or a polyurethane thickener.

[0037] In some embodiments, the film-forming aid includes a dodecyl alcohol ester.

[0038] In some embodiments, the preservative includes at least one of 2-methyl-4-isothiazoline-3-one, 1,2-benzisothiazol-3-one, methylisothiazolinone, and 5-chloro-2-methyl-4-isothiazolin-3-one. Specifically, the preservative can be a combination of multiple ones, for example, including 2-methyl-4-isothiazolin-3-one, 1,2-benzisothiazol-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one, with a mass ratio of 2-methyl-4-isothiazolin-3-one:1,2-benzisothiazol-3-one:5-chloro-2-methyl-4-isothiazolin-3-one=1:(25-27):(2-4).

[0039] In some embodiments, the titanium dioxide is rutile titanium dioxide.

[0040] The second aspect of the present invention provides a method for preparing the water-based polymer coating according to the first aspect of the present invention, comprising the following steps:

[0041] The components are mixed to obtain the water-based polymer coating.

[0042] In some embodiments, the method for preparing the water-based polymer coating comprises the following steps:

[0043] Acrylic emulsion, titanium dioxide, washed diatomaceous earth, calcined diatomaceous earth, fillers, additives and water are mixed and dispersed; wherein, titanium dioxide and water-based diatomaceous earth are divided into two equal parts and added twice in the order of titanium dioxide, washed diatomaceous earth, titanium dioxide, and washed diatomaceous earth; the water-based polymer coating is obtained.

[0044] The third aspect of the present invention provides an application of the water-based polymer coating described in the first aspect of the present invention in the field of architecture.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention provides a water-based polymer coating. Washed diatomite and calcined diatomite are introduced into the coating to provide steric hindrance, preventing titanium dioxide flocculation and improving titanium dioxide utilization. Air is introduced through the pores to create a refractive index difference, thereby synergistically improving the hiding power of the coating with the other components, resulting in a water-based polymer coating with high hiding power. The water-based polymer coating has excellent processing and construction properties, is free of lumps, and exhibits a uniform state after stirring. The paint film has a good appearance and a hiding power of 0.98 or above, making it suitable for use in construction applications requiring high-hiding coatings. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below using specific examples. Unless otherwise specified, the raw materials, reagents, and apparatus used in the examples and comparative examples are available from conventional commercial sources or by conventional methods. Unless otherwise specified, all experimental or testing methods are conventional in the art.

[0048] The raw materials used in the examples and comparative examples are shown in Table 1.

[0049] Table 1 Formula raw materials of water-based polymer coatings of Examples and Comparative Examples

[0050]

[0051] The following is a detailed description with reference to different embodiments and comparative examples.

[0052] Example 1

[0053] A water-based polymer coating, the formula of which is shown in Table 2, and the preparation method is as follows:

[0054] Add water into the dispersion tank and control the speed at 300 rpm; add dispersant, defoaming agent, hydroxyethyl cellulose, polyurethane thickener, and pH adjuster in sequence, then adjust the speed to 700 rpm, and add raw materials in the order of calcined kaolin-titanium dioxide-washed diatomaceous earth-titanium dioxide-washed diatomaceous earth-calcined diatomaceous earth-calcined diatomaceous earth and calcium carbonate. The feeding speed is based on the standard of no powder accumulation; after the feeding is completed, adjust the speed to 1200 rpm and disperse for 15 minutes; then adjust the speed to 400 rpm, add film-forming aid and preservative in sequence, stir evenly, and finally add water to adjust the viscosity to 105-115 KU to obtain a water-based polymer coating.

[0055] Table 2 Waterborne polymer coating formula of Example 1

[0056]

[0057]

[0058] Example 2

[0059] A water-based polymer coating, the formula of which is shown in Table 3, and the preparation method is the same as that of Example 1.

[0060] Table 3 Waterborne polymer coating formula of Example 2

[0061] raw material parts by mass Vinyl acetate-acrylate copolymer emulsion 17.00 dispersants 0.60 defoaming agent 0.50 pH adjusters 0.20 Hydroxyethyl cellulose 0.30 Polyurethane thickener 0.40 Calcined kaolin 15.00 calcium carbonate 3.00 Titanium dioxide 18.00 Washed diatomaceous earth 4.00 Calcined diatomaceous earth 5.00 Coal-forming aids 1.00 preservative 1.00 water 40.00

[0062] Example 3

[0063] A water-based polymer coating, the formula of which is shown in Table 4, and the preparation method is the same as that of Example 1.

[0064] Table 4 Waterborne polymer coating formula of Example 3

[0065]

[0066]

[0067] Example 4

[0068] A water-based polymer coating, the formula of which is shown in Table 5, and the preparation method is the same as in Example 1.

[0069] Table 5 Waterborne polymer coating formula of Example 4

[0070] raw material parts by mass Vinyl acetate-acrylate copolymer emulsion 17.00 dispersants 0.80 defoaming agent 0.50 pH adjusters 0.20 Hydroxyethyl cellulose 0.20 Polyurethane thickener 0.30 Calcined kaolin 15.00 calcium carbonate 1.00 Titanium dioxide 20.00 Washed diatomaceous earth 6.00 Calcined diatomaceous earth 3.00 Coal-forming aids 1.00 preservative 1.00 water 40.00

[0071] Comparative Example 1

[0072] A water-based polymer coating, the formula of which is shown in Table 6, and the preparation method is the same as in Example 1.

[0073] Table 6 Water-based polymer coating formula of comparative example 1

[0074]

[0075]

[0076] Comparative Example 2

[0077] A water-based polymer coating, the formula of which is shown in Table 7, and the preparation method is the same as in Example 1.

[0078] Table 7 Waterborne polymer coating formula of comparative example 2

[0079] raw material parts by mass Acrylic emulsion 17.00 dispersants 0.80 defoaming agent 0.50 pH adjusters 0.20 Hydroxyethyl cellulose 0.20 Polyurethane thickener 0.30 Calcined kaolin 15.00 calcium carbonate 3.00 Titanium dioxide 18.00 Washed diatomaceous earth 9.00 Coal-forming aids 1.00 preservative 1.00 water 40.00

[0080] Comparative Example 3

[0081] A water-based polymer coating, the formula of which is shown in Table 8, and the preparation method is the same as in Example 1.

[0082] Table 8 Water-based polymer coating formula of comparative example 3

[0083] raw material parts by mass Acrylic emulsion 17.00 dispersants 0.80 defoaming agent 0.50 pH adjusters 0.20 Hydroxyethyl cellulose 0.20 Polyurethane thickener 0.30 Calcined kaolin 15.00 calcium carbonate 12.00 Titanium dioxide 18.00 Coal-forming aids 1.00 preservative 1.00 water 40.00

[0084] Comparative Example 4

[0085] A water-based polymer coating, the formula of which is shown in Table 9, and the preparation method is the same as in Example 1.

[0086] Table 9 Waterborne polymer coating formula of comparative example 4

[0087] raw material parts by mass Acrylic emulsion 17.00 dispersants 0.80 defoaming agent 0.50 pH adjusters 0.20 Hydroxyethyl cellulose 0.20 Polyurethane thickener 0.30 Calcined kaolin 15.00 calcium carbonate 1.00 Titanium dioxide 24.00 Calcined diatomaceous earth 5.00 Coal-forming aids 1.00 preservative 1.00 water 40.00

[0088] Result detection

[0089] The performance of the water-based polymer coatings obtained in the above examples and comparative examples was tested, and the testing was carried out with reference to the GB / T9755-2024 standard.

[0090] The test results are shown in Table 10 below.

[0091] Table 10 Performance test results of waterborne polymer coatings of Examples and Comparative Examples

[0092]

[0093] It should be noted that in Table 10, the contrast ratio (hiding power) difference is 0.02, which is a significant difference in this field. In the standard, the difference between first-class and superior products is 0.02. In actual application, when the contrast ratio differs by 0.01, the difference in hiding power reaches a level visible to the naked eye.

[0094] As can be seen from the test results in Table 10, the present invention uses washed diatomite, calcined diatomite and titanium dioxide in combination, synergizing the effects of the other components, while reducing the amount of titanium dioxide used, while improving the hiding power of the water-based polymer coating. Among them, compared with Comparative Example 1, Example 1 uses a higher amount of titanium dioxide in Comparative Example 1, but due to the lack of washed diatomite, the hiding power is reduced. Compared with Comparative Example 1, Comparative Example 2 and Example 3, although the same amount of titanium dioxide is used, Examples 2 and 3 have higher hiding power due to the introduction of washed diatomite and calcined diatomite in combination with titanium dioxide. Compared with Comparative Example 4, Example 4 reduces the amount of titanium dioxide by 16%, but due to the synergistic effect of washed diatomite, calcined diatomite and titanium dioxide, the resulting water-based polymer coating has higher hiding power, achieving the technical problem of replacing part of the titanium dioxide.

[0095] In summary, the water-based polymer coating provided by the present invention incorporates washed diatomite and calcined diatomite, which can provide steric hindrance, prevent titanium dioxide flocculation, and improve titanium dioxide utilization. Air is introduced through the pores to form a refractive index difference, thereby synergistically improving the hiding power of the coating with the other components, resulting in a water-based polymer coating with high hiding power. This water-based polymer coating has good processing and construction properties, is free of lumps, and exhibits a uniform state after stirring. The paint film has a good appearance and a hiding power of 0.98 or above, making it suitable for use in the construction field where high-hiding coatings are required.

[0096] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A water-based polymer coating, characterized in that: The invention comprises acrylic emulsion, titanium dioxide, washed diatomaceous earth and calcined diatomaceous earth; wherein the mass ratio of the titanium dioxide, washed diatomaceous earth and calcined diatomaceous earth is 1:(0.05-0.6):(0.04-0.4).

2. The water-based polymer coating according to claim 1, characterized in that: Calculated by mass, it includes the following components: 10-25 parts of acrylic emulsion, 15-25 parts of titanium dioxide, 2-8 parts of washed diatomaceous earth, 1-5 parts of calcined diatomaceous earth, 10-30 parts of filler, 1.5-15 parts of additive, and 20-50 parts of water.

3. The water-based polymer coating according to claim 1 or 2, characterized in that: The average particle size of the titanium dioxide is 0.2 to 0.4 μm.

4. The water-based polymer coating according to claim 1 or 2, characterized in that: The water-washed diatomaceous earth has a porous structure; the average pore size of the water-washed diatomaceous earth is 0.3 to 0.4 μm; And / or, the median particle size of the calcined diatomaceous earth is 10 to 20 μm.

5. The water-based polymer coating according to claim 2, characterized in that: The filler includes calcined kaolin and / or calcium carbonate.

6. The water-based polymer coating according to claim 5, characterized in that: The filler comprises the following components in parts by mass: 10 to 20 parts of calcined kaolin and 1 to 10 parts of calcium carbonate.

7. The water-based polymer coating according to claim 2, characterized in that: The auxiliary agent includes at least one of a dispersant, a defoaming agent, a pH regulator, a thickener, a film-forming auxiliary agent, and a preservative.

8. The water-based polymer coating according to claim 7, characterized in that: The auxiliary agent comprises the following components in parts by mass: Dispersant 0.1-1 part, defoaming agent 0.1-1 part, pH adjuster 0.1-1 part, thickener 0.3-3 parts, film-forming aid 0.5-3 parts, preservative 0.5-5 parts.

9. A method for preparing a water-based polymer coating according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components are mixed to obtain the water-based polymer coating.

10. Use of the water-based polymer coating according to any one of claims 1 to 8 in the field of architecture.

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