A waterborne one-component coating, its preparation method and use

Abstract

The present application belongs to the technical field of paint, and particularly relates to a water-based single-component paint, a preparation method and application thereof. The water-based single-component paint comprises a hydrophilic pure acrylic emulsion, a silicone acrylic emulsion, first titanium white, a pre-prepared slurry, cellulose, an additive and water. The pre-prepared slurry comprises second titanium white, superfine calcium carbonate and water. The particle size of the superfine calcium carbonate is less than 2.0 microns. The hydrophilic pure acrylic emulsion is matched with a certain amount of the silicone acrylic emulsion, which can effectively balance the water resistance and water permeability of the coating film while improving the stain resistance of the coating film, so that the coating has good stain resistance, water resistance and low water permeability. The synergistic effect of the superfine calcium carbonate and the second titanium white can enhance the steric hindrance effect of the superfine calcium carbonate, improve the dispersibility of the second titanium white, and make the coating film have high surface flatness and compactness, and improve the gloss, stain resistance and contrast ratio of the coating film. The first titanium white is matched with the pre-prepared slurry containing the second titanium white, which can better improve the contrast ratio, stain resistance and gloss.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coatings, and particularly relates to a water-based single-component coating, a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of urban viaduct construction, the surface of the bridge usually needs to be water-based anticorrosive coated. However, the solvent-based coatings on the market at present have high cost and contain a large amount of volatile organic compounds, which are harmful to the construction personnel and the environment.

[0003] In the field of viaduct coatings, there are generally water-based products and oil-based products. The oil-based coatings are mainly based on oil-based thermoplastic acrylic, chlorinated rubber, acrylic polyurethane or fluorine ethylene-vinyl ether (FEVE fluorocarbon coating). The water-based single-component outdoor coating is generally a single-component water-based high-gloss coating, and the stain resistance can only reach 15-20%. Generally speaking, the single-component high-solid product has low gloss; the high-gloss product has poor stain resistance, so it is difficult to simultaneously have high gloss, high solid content and high stain resistance.

[0004] Therefore, it is of great significance to provide a coating with high gloss, high solid content and good stain resistance. SUMMARY

[0005] The present application aims to solve one or more problems existing in the prior art, and at least provide a beneficial alternative. Specifically, the present application provides a water-based single-component coating with good gloss, solid content and stain resistance.

[0006] The present application is based on the following concept: the coating of the present application comprises a hydrophilic pure acrylic emulsion, a silicone-acrylate emulsion, a first titanium white powder, a pre-prepared slurry, cellulose, an additive and water; the pre-prepared slurry comprises a second titanium white powder, ultra-fine calcium carbonate and water; the particle size of the ultra-fine calcium carbonate is <2.0 μm. The hydrophilic pure acrylic emulsion is combined with a certain amount of silicone-acrylate emulsion, which can effectively improve the stain resistance of the coating surface. The super-hydrophilic surface design of the coating film is effective for both hydrophilic pollutants and oleophilic pollutants, and the addition of a certain amount of silicone-acrylate emulsion can make the coating film have a certain internal hydrophobic and external hydrophilic effect, which can effectively balance the water resistance and hydrophilicity of the coating film and improve the stain resistance. At the same time, the combination of ultra-fine calcium carbonate and the second titanium white powder can improve the steric hindrance effect of the ultra-fine calcium carbonate, improve the dispersibility of the second titanium white powder, and improve the contrast ratio of the coating film, and the surface smoothness and compactness of the coating film are higher, which improves the gloss and stain resistance of the coating film. In addition, the combination of the first titanium white powder and the pre-prepared slurry containing the second titanium white powder can improve the contrast ratio, stain resistance and gloss. In summary, the combined action of the components makes the coating have high solid content, high gloss, high stain resistance, high weather resistance, high contrast ratio and low water permeability.

[0007] Therefore, the first aspect of the present application provides an aqueous single-component coating.

[0008] Specifically, the aqueous single-component coating comprises a hydrophilic pure acrylic emulsion, a silicone-acrylate emulsion, a first titanium white powder, a pre-prepared slurry, cellulose, an auxiliary agent, and water.

[0009] The pre-prepared slurry comprises a second titanium white powder, ultra-fine calcium carbonate, and water.

[0010] The particle size of the ultra-fine calcium carbonate is less than 2.0 μm.

[0011] Preferably, the solid content of the hydrophilic pure acrylic emulsion is 57-59%, and the minimum film-forming temperature is 8-32℃.

[0012] Preferably, the hydrophilic pure acrylic emulsion is Bafu RS2808A.

[0013] Preferably, the solid content of the silicone-acrylate emulsion is 48-50%, and the minimum film-forming temperature is 20-24℃.

[0014] Preferably, the silicone-acrylate emulsion is Bafu NPT907.

[0015] Preferably, the mass ratio of the first titanium white powder to the second titanium white powder is (0.27-1):1; further preferably, the mass ratio of the first titanium white powder to the second titanium white powder is (0.3-0.9):1.

[0016] The mass ratio of the first titanium white powder to the second titanium white powder in the present application is (0.27-1):1. According to the different particle sizes of the ultra-fine calcium carbonate and the titanium white powder, the suitable addition amount ratio of the second titanium white powder and the ultra-fine modified calcium carbonate can improve the steric hindrance effect of the ultra-fine calcium carbonate, improve the dispersibility of the second titanium white powder, and improve the contrast ratio of the coating film. Meanwhile, the surface flatness and compactness of the coating film are higher, the gloss and stain resistance of the coating film are improved, and the carbon emission can be reduced to a certain extent, thereby meeting the low-carbon environmental protection requirements.

[0017] Preferably, the first titanium white powder and the second titanium white powder are both rutile type.

[0018] Preferably, the first titanium white powder and the second titanium white powder both comprise at least one of titanium white powder R706 and titanium white powder R996.

[0019] Preferably, the particle size of the first titanium white powder and the second titanium white powder is both 0.27-0.45 μm; further preferably, the particle size of the first titanium white powder and the second titanium white powder is both 0.3-0.4 μm.

[0020] Preferably, the Mohs hardness of the first titanium white powder and the second titanium white powder are both greater than 5.5; further preferably, the Mohs hardness of the first titanium white powder and the second titanium white powder are both greater than 6; more preferably, the Mohs hardness of the first titanium white powder and the second titanium white powder are both 6.5.

[0021] Preferably, the oil absorption of the superfine calcium carbonate is 16-30g / 100g; further preferably, the oil absorption of the superfine calcium carbonate is 18-27g / 100g.

[0022] Preferably, the superfine calcium carbonate is Omya Calcigloss-IK high gloss functional calcium carbonate.

[0023] Preferably, the auxiliary agent includes at least one of anti-freeze-thaw auxiliary agent, film-forming auxiliary agent, wetting agent, dispersing agent, pH regulator, bactericide, anti-settling agent, mildew-proof agent, defoaming agent.

[0024] Preferably, the coating includes, in terms of mass fraction, 45-65 parts of hydrophilic pure acrylic emulsion, 2.7-11 parts of silicone-acrylic emulsion, 6.5-16.5 parts of first titanium white powder, 9-33 parts of pre-prepared slurry, 0.1-0.55 parts of cellulose, 0.27-1.6 parts of anti-freeze-thaw auxiliary agent, 0.45-5.5 parts of film-forming auxiliary agent, 0.1-0.33 parts of wetting agent, 0.1-0.65 parts of dispersing agent, 0-0.11 parts of pH regulator, 0-1.1 parts of bactericide, 0.1-0.33 parts of anti-settling agent, 0.45-2.2 parts of mildew-proof agent, 0.5-11 parts of defoaming agent, and more than 0 parts to less than or equal to 30 parts of water.

[0025] Further preferably, the coating includes, in terms of mass fraction, 50-60 parts of hydrophilic pure acrylic emulsion, 3-10 parts of silicone-acrylic emulsion, 7-15 parts of first titanium white powder, 10-30 parts of pre-prepared slurry, 0.2-0.5 parts of cellulose, 0.3-1.5 parts of anti-freeze-thaw auxiliary agent, 0.5-5 parts of film-forming auxiliary agent, 0.1-0.3 parts of wetting agent, 0.1-0.6 parts of dispersing agent, 0-0.1 parts of pH regulator, 0-1 parts of bactericide, 0.1-0.3 parts of anti-settling agent, 0.5-2 parts of mildew-proof agent, 3-10 parts of defoaming agent, and more than 0 parts to less than or equal to 28 parts of water.

[0026] Preferably, the cellulose includes hydroxyethyl cellulose.

[0027] Preferably, the hydroxyethyl cellulose includes at least one of HBR250 cellulose and HHBR250 cellulose.

[0028] Preferably, the anti-freeze-thaw auxiliary agent includes at least one of propylene glycol (PG) and ethylene glycol.

[0029] Preferably, the film forming aid comprises at least one of 2-methyl-propionic acid, 2,2,4-trimethyl-1,3-pentanediol monoester, polyol monobutyl ether.

[0030] Preferably, the film forming aid comprises carbon dodecanol ester; further preferably, the film forming aid comprises carbon dodecanol ester of Eastman.

[0031] Preferably, the wetting agent is a non-ionic surfactant.

[0032] Preferably, the wetting agent comprises at least one of Kao Genapol PF20, Emulsogen LCN070.

[0033] Preferably, the dispersing agent comprises at least one of polypropionate, polystyrene salt, maleate salt.

[0034] Preferably, the dispersing agent comprises AD 504 of Sanyo Fine Chemicals Nantong Co., Ltd.

[0035] Preferably, the pH adjuster comprises 2-amino-2-methyl-1-propanol.

[0036] Preferably, the pH adjuster is AMP95.

[0037] Preferably, the bactericide comprises at least one of formaldehyde releasing agents, isothiazolones, benzimidazoles.

[0038] Preferably, the bactericide comprises BIOBAN 623A of Dow, BW20 of Thor Speciality Chemicals (Shanghai) Co., Ltd., and Preservative of Thor Speciality Chemicals (Shanghai) Co., Ltd. LPC5.

[0039] Preferably, the anti-settling agent comprises at least one of sepiolite, bentonite, high viscosity attapulgite, organically modified hectorite clay.

[0040] Preferably, the anti-settling agent comprises Bentone DY CE of Decheng (Shanghai) Chemical Co., Ltd.

[0041] Preferably, the mildewcide comprises at least one of dibromonitrilopropionamide (DBNPA), isothiazolinones, benzimidazoles, substituted arenes, dithiocarbamate salts.

[0042] Preferably, the mildewcide comprises AA146 of Lanxess (Changzhou) Co., Ltd.

[0043] Preferably, the antifoam agent comprises mineral oil / silicone composite antifoam agent.

[0044] Preferably, the defoaming agent comprises Bafu Foamaster NXZ.

[0045] Preferably, the pre-prepared slurry further comprises at least one of a dispersing agent and a defoaming agent.

[0046] Specifically, the pre-prepared slurry comprises the same optional dispersing agent and defoaming agent as the coating.

[0047] Preferably, the pre-prepared slurry further comprises a dispersing agent and a defoaming agent, and comprises, by mass fraction, 9-22 parts of ultra-fine calcium carbonate, 45-70 parts of the second titanium white, 0.45-3.3 parts of the dispersing agent, 0.45-3.3 parts of the defoaming agent, and 4.5-16.5 parts of water.

[0048] Further preferably, the pre-prepared slurry further comprises a dispersing agent and a defoaming agent, and comprises, by mass fraction, 10-20 parts of ultra-fine calcium carbonate, 50-65 parts of the second titanium white, 0.5-3 parts of the dispersing agent, 0.5-3 parts of the defoaming agent, and 5-15 parts of water.

[0049] The second aspect of the present application provides a method for preparing the water-based single-component coating of the first aspect of the present application.

[0050] Specifically, the method for preparing the water-based single-component coating comprises the following steps:

[0051] Mixing the raw material components to obtain the coating.

[0052] Preferably, the method for preparing the pre-prepared slurry comprises the following steps:

[0053] Mixing the raw material components to obtain the pre-prepared slurry.

[0054] Preferably, under the action of stirring, the ultra-fine calcium carbonate, the titanium white, the dispersing agent, and the defoaming agent are added to water, and then high-speed stirring is performed to obtain the pre-prepared slurry.

[0055] Preferably, the stirring speed is 400-600 r / min; further preferably, the stirring speed is 450-550 r / min; more preferably, the stirring speed is 500 r / min.

[0056] Preferably, the high-speed stirring speed is 1300-1700 r / min, and the high-speed stirring time is 13-18 min; further preferably, the high-speed stirring speed is 1400-1600 r / min, and the high-speed stirring time is 14-16 min; more preferably, the high-speed stirring speed is 1500 r / min, and the high-speed stirring time is 15 min.

[0057] The third aspect of the present application provides an application of the water-based single-component coating according to the first aspect of the present application in the field of bridges.

[0058] Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects:

[0059] (1) The present application uses hydrophilic pure acrylic emulsion in combination with a certain amount of silicone-acrylic emulsion, so that the surface of the coating film has the characteristics of being hydrophilic inside and hydrophobic outside. This kind of coating film with the characteristics of being hydrophilic inside and hydrophobic outside can effectively improve the stain resistance of the coating film surface, and at the same time can well balance the water resistance of the coating film, that is, the stain resistance and water resistance of the coating film can be effectively considered. A certain amount of small molecule silicone-acrylic emulsion can be uniformly dispersed in the pure acrylic emulsion system by using hydrogen bond force during cross-linking and curing, so that a large amount of hydrophilic pure acrylic emulsion is cross-linked and cured to improve the hydrophilicity of the coating film surface, so that the coating film has good stain resistance. A small amount of small molecule silicone-acrylic emulsion forms a silicon-oxygen bond inside the coating film, which provides a certain water resistance of the coating film, so that the coating film has a low water permeability and water resistance.

[0060] (2) The present application uses ultra-fine calcium carbonate in combination with a certain amount of second titanium white powder to prepare a premixed slurry, so that the ultra-fine calcium carbonate effectively disperses a part of the titanium white powder by using the steric hindrance effect. The two work together to make the coating film surface have higher flatness and compactness, improve the gloss, stain resistance and contrast ratio of the coating film. In addition, the use of the first titanium white powder in combination with the premixed slurry containing the second titanium white powder can better improve the contrast ratio, stain resistance and gloss. The components work together to make the stain resistance of the coating layer reach 3-4% and the gloss reach about 65-70% when the solid content of the coating is greater than 60%, and the coating layer has high weather resistance, high contrast ratio and low water permeability. At the same time, a certain amount of ultra-fine calcium carbonate replaces a certain amount of titanium white powder, which can reduce the amount of titanium white powder and reduce carbon emissions to a certain extent, meeting the requirements of low carbon and environmental protection. DETAILED DESCRIPTION

[0061] In order to make those skilled in the art more clearly understand the technical scheme of the present application, the following examples are given for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0062] The raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0063] Example 1

[0064] A water-based single-component coating, by mass fraction, comprises

[0065]

[0066] The pre-prepared slurry comprises, by mass fraction, water 16.4 parts, superfine calcium carbonate 15 parts, titanium white R706 65 parts, dispersing agent 0.6 parts, and defoaming agent 3 parts.

[0067] A preparation method of a water-based single-component paint comprises the following steps:

[0068] The raw material components are mixed to prepare the water-based single-component paint.

[0069] The preparation method of the pre-prepared slurry comprises the following steps:

[0070] Water is added to a container and stirred at a speed of 500 r / min, and then superfine calcium carbonate, titanium white, dispersing agent, and defoaming agent are added. The stirring speed is adjusted to 1500 r / min for high-speed stirring for 15 min to prepare the pre-prepared slurry.

[0071] Example 2

[0072] A water-based single-component paint comprises, by mass fraction,

[0073]

[0074] The pre-prepared slurry comprises, by mass fraction, water 16.4 parts, superfine calcium carbonate 10 parts, titanium white R706 70 parts, dispersing agent 0.6 parts, and defoaming agent 3 parts.

[0075] A preparation method of a water-based single-component paint comprises the following steps:

[0076] The raw material components are mixed to prepare the water-based single-component paint.

[0077] The preparation method of the pre-prepared slurry comprises the following steps:

[0078] Water is added to a container and stirred at a speed of 500 r / min, and then superfine calcium carbonate, titanium white, dispersing agent, and defoaming agent are added. The stirring speed is adjusted to 1500 r / min for high-speed stirring for 15 min to prepare the pre-prepared slurry.

[0079] Example 3

[0080] A water-based single-component paint comprises, by mass fraction,

[0081]

[0082] The pre-prepared slurry comprises, by mass fraction, water 16.4 parts, superfine calcium carbonate 15 parts, titanium white R996 65 parts, dispersing agent 0.6 parts, and defoaming agent 3 parts.

[0083] A preparation method of a water-based single-component paint comprises the following steps:

[0084] The raw material components are mixed to prepare an aqueous single-component coating.

[0085] The preparation method of the pre-slurry comprises the following steps:

[0086] The water is added to the container and stirred at a speed of 500 r / min, and then the superfine calcium carbonate, titanium dioxide, dispersant and defoaming agent are added. The stirring speed is adjusted to 1500 r / min for high-speed stirring for 15 min to prepare the pre-slurry.

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 3 is that no pre-slurry is added in Comparative Example 1, and in order to keep the total amount of titanium dioxide added consistent with that in Example 3, the superfine modified calcium carbonate is replaced by conventional calcium carbonate. The amount of titanium dioxide R996 is 24.6 parts, the amount of calcium carbonate CC700 is 3.6 parts, and the amount of water is 8.7 parts. The other conditions are the same as in Example 3.

[0089] Comparative Example 2

[0090] The difference between Comparative Example 2 and Example 3 is that the same amount of hydrophilic pure acrylic emulsion RS2808A is used to replace the silicone-acrylate emulsion NPT907 in Comparative Example 2. The other conditions are the same as in Example 3.

[0091] Comparative Example 3

[0092] The difference between Comparative Example 3 and Example 3 is that in Comparative Example 3, the titanium dioxide is all used to prepare the slurry, and no first titanium dioxide is added separately in the coating. The amount of pre-slurry is 36 parts, the amount of superfine calcium carbonate in the pre-slurry is 10 parts, the amount of titanium dioxide is 68.3 parts, and the amount of water is 1.9 parts. The other conditions are the same as in Example 3.

[0093] Performance Test

[0094] The coatings prepared in Examples 1-3 and Comparative Examples 1-3 are tested for performance. The specific test items and test methods are shown in Table 1.

[0095] Table 1: Test items and test methods

[0096]

[0097]

[0098] The performance test results of the coatings of Examples 1-3 and Comparative Examples 1-3 are shown in Table 2.

[0099] Table 2: Performance test results of the coatings of Examples 1-3 and Comparative Examples 1-3

[0100]

[0101] As can be seen from Table 2, the prepared coating has high solid content, good stain resistance, gloss, contrast ratio, and good resistance to scrubbing, artificial aging, algae resistance, mold resistance, and low water permeability.

[0102] As can be seen from Comparative Example 1 and Example 3, even if the amount of titanium dioxide and pure acrylic emulsion, silicone acrylic emulsion added in Comparative Example 1 is the same as that in Example 3, but only ordinary calcium carbonate is used in Comparative Example 1, and no ultra-fine calcium carbonate is used, and the ordinary calcium carbonate is added to the formula according to the conventional mixing method, so that the contrast ratio, stain resistance, water resistance and gloss of Comparative Example 1 are all lower than those of Example 3, which shows that the pre-prepared slurry prepared by using part of titanium dioxide and ultra-fine calcium carbonate, and then mixing with the remaining titanium dioxide, plays an important role in improving the contrast ratio, stain resistance and gloss of the coating.

[0103] As can be seen from Comparative Example 2 and Example 3, Comparative Example 2 uses an equal amount of pure acrylic emulsion RS2808A to replace silicone acrylic emulsion NPT907, i.e. no silicone acrylic emulsion is contained, so that the stain resistance, artificial aging performance and water permeability of Comparative Example 2 are significantly reduced, which shows that the combination of pure acrylic emulsion and silicone acrylic emulsion can improve the stain resistance of the coating film, and also improve the artificial aging performance of the coating, improve the water resistance of the coating film and reduce the water permeability of the coating film.

[0104] As can be seen from Comparative Example 3 and Example 3, Comparative Example 3 does not separately add titanium dioxide, but only adds titanium dioxide in the pre-prepared slurry, so that the contrast ratio, stain resistance and gloss of Comparative Example 3 are all lower than those of Example 3, which shows that the combination of the first titanium dioxide and the pre-prepared slurry containing the second titanium dioxide can improve the contrast ratio, stain resistance and gloss.

[0105] In summary, the combination of the hydrophilic pure acrylic emulsion and a certain amount of silicone acrylic emulsion can effectively improve the stain resistance of the coating surface, and also can well balance the water resistance of the coating film. The combination of the ultra-fine calcium carbonate and a certain amount of the second titanium dioxide to prepare the pre-prepared slurry can make the ultra-fine calcium carbonate effectively disperse part of the titanium dioxide by using the steric hindrance effect, and the two components can synergistically improve the flatness and compactness of the coating film, and improve the gloss, stain resistance and contrast ratio of the coating film. In addition, the first titanium dioxide needs to be combined with the pre-prepared slurry containing the second titanium dioxide to better improve the contrast ratio, stain resistance and gloss. The combination of the components can make the stain resistance of the coating reach 3-4% on the basis of the solid content of more than 60%, the gloss reach about 65-70%, the contrast ratio reach 95-97%, and the water permeability be less than or equal to 0.5 mL, so that the comprehensive performance of the coating is greatly improved.

[0106] The above examples are only used to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A coating, characterized in that, The coating comprises, by mass fraction, 45-65 parts of a hydrophilic pure acrylic emulsion, 2.7-11 parts of a silicone acrylic emulsion, 6.5-16.5 parts of first titanium white, 9-33 parts of a pre-prepared slurry, 0.1-0.55 parts of cellulose, 0.27-1.6 parts of an anti-freeze-thaw aid, 0.45-5.5 parts of a film-forming aid, 0.1-0.33 parts of a wetting agent, 0.1-0.65 parts of a dispersing agent, 0-0.11 parts of a pH regulator, 0-1.1 parts of a bactericide, 0.1-0.33 parts of an anti-settling agent, 0.45-2.2 parts of a mildew-proof agent, 0.5-11 parts of a defoaming agent, and more than 0 parts to 30 parts of water; The pre-prepared slurry comprises, by mass fraction, 9-22 parts of ultra-fine calcium carbonate, 45-70 parts of second titanium white, 0.45-3.3 parts of a dispersing agent, 0.45-3.3 parts of a defoaming agent, and 4.5-16.5 parts of water. The particle size of the ultra-fine calcium carbonate is less than 2.0 μm.

2. The coating of claim 1, wherein, The oil absorption of the ultra-fine calcium carbonate is 16-30 g / 100 g.

3. Process for the production of the coating according to any one of claims 1-2, characterized in that, The method comprises the following steps: Mixing the raw material components to prepare the coating.

4. The production method according to claim 3, characterized by, The method for preparing the pre-prepared slurry comprises the following steps: Mixing the raw material components of the pre-prepared slurry to prepare the pre-prepared slurry.

5. The coating of any one of claims 1-2 for use in the field of bridges.

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