A waterborne two-component polyurethane coating, its preparation method and application

Abstract

The application discloses a kind of water-based two-component polyurethane coating and its preparation method and application, belong to coating technical field;The water-based two-component polyurethane coating provided by the application can realize excellent water resistance, humidity resistance, neutral salt fog resistance, aging resistance and excellent adhesion by selecting siloxane modifier of certain structure, cooperating with water-based hydroxyl acrylic dispersion of specific hydroxyl mass content, under the action of organic silicon modified ionic aliphatic isocyanate curing agent, while other components cooperate with each other, and combining certain preparation method.The preparation method of the water-based two-component polyurethane coating provided by the application is simple to operate, which is beneficial to actual production.

Description

TECHNICAL FIELD

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

[0002] Chemical storage tanks are generally located in suburban mountains and forests, and have a large temperature difference between day and night. Condensed water often condenses on the outer wall of the storage tank device in spring and autumn. Since the chemical storage tank generally stores corrosive substances, without corrosion protection measures, the strength of the tank body will rapidly decrease, the service life will be shortened, and the environment will be harmed. Since the current water-based anticorrosive paint needs to have anticorrosive efficacy, it itself has many hydrophilic groups, and the condensed water will cause a high humidity problem on the surface of the paint film. Under this condition, since the paint film itself has poor moisture resistance, the paint film is prone to blistering, bulging and other drawbacks, thereby affecting the safety of the tank body. However, the prior art has less research on how to improve the moisture resistance of the paint film. SUMMARY

[0003] The present application aims to overcome the deficiencies of the prior art and provide a water-based two-component polyurethane coating having excellent water resistance, moisture resistance, neutral salt spray resistance, aging resistance and excellent adhesion, as well as a preparation method and application thereof.

[0004] To achieve the above-mentioned purpose, in the first aspect of the present application, the present application provides a water-based two-component polyurethane coating, which comprises component A and component B, and the mass ratio of the component A and the component B is component A: component B = (5.5-8.5): 1.

[0005] The component A comprises the following components by mass: water-based hydroxyl acrylic acid dispersion 45-65 parts, wet dispersant 0.5-1 part, defoaming agent 0.1-2 parts, pH adjuster 0.5-2 parts, cosolvent 5-8 parts, titanium white 20-30 parts, leveling agent 0.1-2 parts, thickening agent 1-4 parts, siloxane modifier 0.1-3 parts, and deionized water 9-18 parts.

[0006] The component B is an organic silicon modified ionic aliphatic isocyanate curing agent.

[0007] In the water-based hydroxyl acrylic acid dispersion, the mass content of the hydroxyl group is 3.3-4.2%.

[0008] The end group of the siloxane modifier contains any one of an amino group and a methacryloyloxy group.

[0009] The water-based two-component polyurethane coating provided by the present application can realize excellent water resistance, humidity resistance, neutral salt spray resistance, aging resistance and excellent adhesion by selecting a siloxane modifier with a certain structure, cooperating with a water-based hydroxyl acrylic dispersion with a specific hydroxyl mass content, and under the action of a silicone-modified ionic aliphatic isocyanate curing agent and other components.

[0010] Specifically, the water-based hydroxyl acrylic dispersion with a hydroxyl mass content of 3.3-4.2% can effectively improve the crosslinking density of the polyurethane system, and can cooperate with the silicone-modified ionic aliphatic isocyanate curing agent to increase the hydrophobicity of the curing agent by using the hydrophobicity of the silicone segment in the curing agent, thereby improving the water resistance and humidity resistance of the cured paint film.

[0011] In an embodiment, the water-based hydroxyl acrylic dispersion is Antkote 2042N of Wanhua Chemical.

[0012] In an embodiment, the silicone-modified ionic aliphatic isocyanate curing agent is OS-9030 of Guanzhinew Materials. The present application researches and finds that when OS-9030 is specifically selected, it can better react with the water-based hydroxyl acrylic dispersion to form crosslinking points, improve the compactness of the paint film, and thereby improve the water resistance and humidity resistance of the paint film.

[0013] In an embodiment, the siloxane modifier is any one of Silquest A-1170, Silquest A-1100 and Silquest A-174NT; and the average molecular weight of the siloxane modifier is 500-3000. The present application researches and finds that when the siloxane modifier is further selected as any one of Silquest A-1170, Silquest A-1100 and Silquest A-174NT, the amino group and the methacryloyloxy group contained in the end group can chemically react with the hydroxyl group and the carboxyl group, thereby connecting the siloxane modifier to the resin structure in the form of chemical crosslinking, and the siloxane modifier with the above-mentioned average molecular weight range has better chemical reactivity, and the crosslinking effect obtained is more optimal, so that the comprehensive performance of the paint film is more optimal.

[0014] Preferably, the mass ratio of the siloxane modifier to the deionized water is 1:(7-10).

[0015] The present application researches and finds that the mass ratio of the siloxane modifier to the deionized water will affect the comprehensive performance of the product, and when the mass ratio of the two is further selected as 1:(7-10), the comprehensive effect of the obtained product is more excellent.

[0016] As a preferred embodiment of the water-based two-component polyurethane coating of the present application, any one of (a)-(f) is:

[0017] (a) the wetting dispersant is an acrylate copolymer;

[0018] (b) the defoaming agent is at least one of a mineral oil modified copolymer, a silicone defoaming agent;

[0019] (c) the pH regulator is AMP-95;

[0020] (d) the co-solvent is at least one of dipropylene glycol butyl ether, dipropylene glycol methyl ether, diethylene glycol butyl ether;

[0021] (e) the leveling agent is a special structure silicone polymer;

[0022] (f) the thickening agent is an associative polyurethane thickening agent.

[0023] Preferably, the defoaming agent is a mixture of a mineral oil modified copolymer and a silicone defoaming agent, and the mass ratio of the two is mineral oil modified copolymer: silicone defoaming agent = (0.8-1.2):1.

[0024] Preferably, the co-solvent is a mixture of dipropylene glycol butyl ether and diethylene glycol butyl ether, and the mass ratio of the two is dipropylene glycol butyl ether: diethylene glycol butyl ether = (1-3.5):1.

[0025] In an embodiment, the leveling agent is DiGoo 4100.

[0026] In an embodiment, the thickening agent is Vesmody U902 polyurethane thickening agent; the present application finds that this thickening agent has excellent low shear thickening effect on the polyurethane coating of the present application, improves the rheological properties of the coating under low shear, and provides better sag resistance and anti-settling.

[0027] In a second aspect of the present application, the present application also provides a preparation method of the water-based two-component polyurethane coating, the preparation method comprising the following steps:

[0028] (1) adding a siloxane modifier and titanium dioxide into part of deionized water, stirring, adjusting the pH value to be acidic, then heating and reacting, cooling to room temperature after the reaction is completed, to obtain solution 1;

[0029] (2) adding a wetting dispersant, part of a defoaming agent, part of a co-solvent, a pH regulator and the remaining part of deionized water into solution 1 in sequence, dispersing uniformly, and grinding, to obtain slurry 1;

[0030] (3) adding water-based hydroxyl acrylic dispersion, the remaining part of defoaming agent, leveling agent, the remaining part of co-solvent into the slurry 1 in sequence, uniformly dispersing, adding thickening agent, adjusting viscosity, obtaining A component;

[0031] (4) uniformly dispersing the silicone-modified ionic aliphatic isocyanate curing agent, obtaining B component;

[0032] (5) uniformly mixing A component and B component, obtaining water-based two-component polyurethane coating.

[0033] The preparation method provided by the application mixes the siloxane modifier, titanium white powder and deionized water and heats and reacts under acidic conditions, which can accelerate the hydrolysis of the siloxane modifier, the alkoxyl group on the siloxane is hydrolyzed to form silanol, the silanol forms a chemical bond on the surface of the titanium white powder and is coated on the surface of the titanium white powder, the active group thereof faces outward and can react with the hydroxyl group, carboxyl group or isocyanate of the curing agent on the resin to form a chemical bond; and then the product is mixed with other components to realize the preparation of a product with excellent overall performance.

[0034] As a preferred embodiment of the preparation method, in step (1), the part of deionized water accounts for 70-80% of the mass of the deionized water.

[0035] As a preferred embodiment of the preparation method, in step (1), the adjustment of the pH value to acidity is to adjust the pH value to 3-4 by using acetic acid.

[0036] As a preferred embodiment of the preparation method, in step (1), the heating reaction temperature is 40-50℃, and the heating reaction time is 50-70min.

[0037] The application researches and finds that when the pH value is adjusted to 3-4 and the heating reaction temperature is 40-50℃ and the heating reaction time is 50-70min, the product prepared can achieve good comprehensive effect. If the temperature during the reaction process is too high, on the one hand, energy is wasted, and on the other hand, there is a risk of gelation, which leads to the failure to effectively prepare the corresponding product.

[0038] As a preferred embodiment of the preparation method, the fineness of the slurry 1 is ≤25μm,

[0039] And / or, the viscosity of the A component is 70-80KU.

[0040] In an embodiment, the thickening agent is used to adjust the viscosity of the Stormer viscometer to 70-80KU.

[0041] In an embodiment, in step (1), the stirring speed is 200-300rpm.

[0042] In an embodiment, in the step (2), the material is added at a speed of 500-700 rpm, and then dispersed uniformly at a speed of 1000-1500 rpm, and the time for uniform dispersion is 10-15 min.

[0043] In an embodiment, in the step (3), the material is added at a speed of 400-600 rpm and dispersed uniformly, and the stirring time before viscosity adjustment is 5-10 min.

[0044] In an embodiment, the part of the defoaming agent accounts for 30-70% of the total amount of the defoaming agent.

[0045] In an embodiment, the part of the cosolvent accounts for 50-80% of the total amount of the cosolvent.

[0046] In a third aspect of the present application, the present application provides the use of the water-based two-component polyurethane coating in the preparation of a chemical storage tank.

[0047] The water-based two-component polyurethane coating provided by the present application has good water resistance, humidity resistance, neutral salt spray resistance and aging resistance, and has excellent adhesion, and therefore can be effectively applied in the preparation of a chemical storage tank.

[0048] Compared with the prior art, the present application has the following beneficial effects:

[0049] The water-based two-component polyurethane coating provided by the present application can realize excellent water resistance, humidity resistance, neutral salt spray resistance, aging resistance and excellent adhesion by selecting a siloxane modifier with a certain structure, cooperating with a water-based hydroxyl acrylic dispersion with a certain hydroxyl mass content, under the action of an organic silicon modified ionic aliphatic isocyanate curing agent, and in cooperation with other components, and by using a certain preparation method. Specifically, the adhesion of the obtained water-based two-component polyurethane coating is above 7.0 MPa, the water resistance time is above 932 h, the humidity resistance time is above 960 h, the neutral salt spray resistance time is above 1360 h, and the artificial climate aging resistance time is 1000 h without blistering. At the same time, the preparation method of the water-based two-component polyurethane coating provided by the present application is simple to operate and is conducive to actual production. DETAILED DESCRIPTION

[0050] For the purpose of better illustrating the object, technical scheme and advantages of the present application, the present application will be further described in combination with specific embodiments.

[0051] The reagents, methods and equipment used in the present application are all conventional reagents, methods and equipment in the art unless otherwise specified.

[0052] Water-based hydroxyl acrylic dispersion 1: the mass content of hydroxyl is 4.2%, Antkote 2042N, Wanhua Chemical;

[0053] Aqueous hydroxyl acrylic dispersion 2: mass content of hydroxyl group is 2.2%, Uacryl 2720, Kobo chemicals;

[0054] Wetting dispersant: 750w, Digo;

[0055] Defoamer: mixture of WEELMAN F3111 and Digo TG-904W in a mass ratio of 1:1;

[0056] pH adjuster: AMP-95, Dow Chemical;

[0057] Co-solvent: mixture of dipropylene glycol butyl ether and diethylene glycol butyl ether in a mass ratio of 1:1;

[0058] Titanium dioxide: CR-826, TNO;

[0059] Leveling agent: TG-4100, Digo;

[0060] Thickener: Vesmody U902, Wanhua Chemical;

[0061] Silicone modifier 1: end group contains amino group, A-1170, Silquest;

[0062] Silicone modifier 2: end group contains epoxy group, A-186, Silquest;

[0063] Isocyanate curing agent 1: silicone-modified ionic aliphatic isocyanate curing agent, OS-9030, Guanzhinew Materials;

[0064] Isocyanate curing agent 2: 268, Wanhua Chemical.

[0065] Examples 1-6 and Comparative Examples 1-6

[0066] The examples and comparative examples of the present application provide a water-based two-component polyurethane paint, the components (mass parts) of which are shown in Tables 1-2;

[0067] Table 1

[0068]

[0069]

[0070] Table 2

[0071]

[0072] The preparation method of the water-based two-component polyurethane coating provided in Example 1 comprises the following steps:

[0073] (1) The siloxane modifier and titanium white powder are added to 70% of the proportion of deionized water, stirred at a speed of 250 rpm, and acetic acid is added dropwise to adjust the pH value to 3.5, then heated to 45°C for 1h, after the reaction is completed, cooled to room temperature, to obtain solution 1;

[0074] (2) Under the speed of 500 rpm, the wetting dispersant, the defoaming agent WEELMAN F3111, the cosolvent dipropylene glycol butyl ether, the pH regulator and the remaining deionized water are sequentially added to solution 1, after the addition is completed, high-speed dispersion is carried out at a speed of 1500 rpm for 15 min, and after the dispersion is completed, the slurry is ground to a fineness of ≤25 μm, to obtain slurry 1;

[0075] (3) Under the speed of 400 rpm, the water-based hydroxyl acrylic dispersion, the remaining defoaming agent, the leveling agent, the remaining cosolvent are sequentially added to slurry 1, stirred for 10 min, after the dispersion is uniform, the thickening agent is added and stirred for 8 min, then the viscosity is adjusted to 75KU by the thickening agent at 25°C Stomer viscosity meter, to obtain component A;

[0076] (4) The silicone-modified ionic aliphatic isocyanate curing agent is uniformly dispersed, to obtain component B;

[0077] (5) The component A and the component B are uniformly mixed, to obtain the water-based two-component polyurethane coating.

[0078] The preparation methods of Examples 2-6 and Comparative Examples 1-6 remain the same as Example 1.

[0079] Comparative Example 7

[0080] The water-based two-component polyurethane coating provided in the comparative example of the application is only different from Example 1 in that the step (1) in the preparation method is different, and the step (1) in the comparative example is: the siloxane modifier and titanium white powder are added to 70% of the proportion of deionized water, stirred at a speed of 250 rpm, and acetic acid is added dropwise to adjust the pH value to 2, then heated to 45°C for 1h, after the reaction is completed, cooled to room temperature, to obtain solution 1.

[0081] Comparative Example 8

[0082] The water-based two-component polyurethane coating provided in the comparative example of the application is only different from Example 1 in that the step (1) in the preparation method is different, and the step (1) in the comparative example is: the siloxane modifier and titanium white powder are added to 70% of the proportion of deionized water, stirred at a speed of 250 rpm, and acetic acid is added dropwise to adjust the pH value to 6, then heated to 45°C for 1h, after the reaction is completed, cooled to room temperature, to obtain solution 1.

[0083] Comparative Example 9

[0084] The present application comparative example provides a water-based two-component polyurethane coating, which is only different from example 1 in the difference of step (1) in the preparation method, the step (1) of the present comparative example is: adding siloxane modifier, titanium white into 70% proportion of deionized water, stirring at a speed of 250 rpm, and adding acetic acid to adjust the pH value to 3.5, then reacting at 25℃ for 1h, after the reaction is completed, cooling to room temperature, obtaining solution 1.

[0085] Comparative Example 10

[0086] The present application comparative example provides a water-based two-component polyurethane coating, which is only different from example 1 in the difference of the preparation method, the preparation process of the present comparative example includes the following steps:

[0087] (1) under the speed of 500 rpm, add wet dispersant, defoaming agent WEELMAN F3111 in it, pH regulator, cosolvent, titanium white, 50% proportion of water-based hydroxyl acrylic dispersion into 60% proportion of deionized water, high speed dispersion for 15 min under the speed of 1200 rpm, after the dispersion is completed, grinding to the fineness of slurry≤25μm, obtaining slurry 1;

[0088] (3) under the speed of 400 rpm, add the remaining part of water-based hydroxyl acrylic dispersion, the remaining part of defoaming agent, leveling agent, pH regulator, siloxane modifier, the remaining part of deionized water into slurry 1 in turn, stirring for 10 min, after the dispersion is uniform, adding thickening agent and stirring for 8 min, then adjusting the viscosity with thickening agent to 75KU of stoke viscosity meter at 25℃, obtaining A component;

[0089] (4) uniformly dispersing the organic silicon modified ionic aliphatic isocyanate curing agent, obtaining B component;

[0090] (5) uniformly mixing A component and B component, obtaining water-based two-component polyurethane coating.

[0091] Effect Example

[0092] The present application effect example verifies the performance of water-based two-component polyurethane coating prepared by example 1-6 and comparative example 1-10, which specifically includes the following aspects:

[0093] 1. Pencil hardness (scratch): tested according to GB / T 6739-2006;

[0094] 2. Adhesion: tested according to GB / T 5210-2006;

[0095] 3. Water resistance: tested according to GB / T 1733-1993;

[0096] 4. Humidity resistance: tested according to GB / T 13893-2008;

[0097] 5. Neutral salt spray resistance: tested according to GB / T 1771-2007;

[0098] 6. Artificial climate aging resistance: tested according to GB / T 1865-2009;

[0099] The results obtained by the test are shown in Table 3;

[0100] Table 3

[0101]

[0102]

[0103] As can be seen from Table 3, the product prepared by using the technical scheme of the present application has excellent comprehensive effect, the obtained product has moderate hardness, excellent water resistance, humidity resistance, neutral salt spray resistance and artificial climate aging resistance, and also has high adhesion; specifically, the obtained product has a pencil hardness of 2H, an adhesion of more than 7.0 MPa, a water resistance of more than 932 h, a humidity resistance of more than 960 h, a neutral salt spray resistance of more than 1360 h, and no blistering for 1000 h of artificial climate aging;

[0104] As can be seen from Example 1 and Examples 3-5, the mass ratio of the siloxane modifier and deionized water in the A component will affect the performance of the product, when the mass ratio of the siloxane modifier and deionized water in the A component is further selected to be (7-10): 1, the comprehensive performance of the obtained product is more excellent, specifically, the adhesion of the obtained product is more than 7.8 MPa, the water resistance is more than 1008 h, the humidity resistance is more than 1056 h, the neutral salt spray resistance is more than 1500 h, and no blistering for 1000 h of artificial climate aging; as can be seen from Example 1 and Comparative Example 1, when no siloxane coupling agent is added, the comprehensive performance of the obtained product is significantly reduced, compared with Example 1, the adhesion is reduced by 35.8%, the water resistance is reduced by 55.6%, the humidity resistance is reduced by 62.5%, and the neutral salt spray resistance is reduced by 46.7%;

[0105] As can be seen from Example 1, Example 6 and Comparative Examples 2-3, the mass ratio of A component and B component in the water-based two-component polyurethane coating also affects the performance of the product. When the mass ratio of the components in Comparative Example 2-3 is not within the scope of the present application, the comprehensive performance of the obtained product is significantly reduced. Specifically, when the mass ratio of A component and B component in Comparative Example 2 is too small, compared with Example 1, the water resistance of the obtained product is reduced by 48.1%, the humidity resistance is reduced by 53.0%, and the neutral salt spray resistance is reduced by 40.0%; when the mass ratio of A component and B component in Comparative Example 3 is too large, compared with Example 1, the adhesion of the obtained product is significantly reduced, and the water resistance, humidity resistance, neutral salt spray resistance and artificial climate aging resistance are all significantly reduced, among which the adhesion is reduced by 48.1%, the water resistance is reduced by 66.7%, the humidity resistance is reduced by 75.8%, and the neutral salt spray resistance is reduced by 68.0%;

[0106] As can be seen from Example 1 and Comparative Example 4, the mass content of hydroxyl groups in the water-based hydroxyl acrylic dispersion affects the comprehensive performance of the product. When the mass content of hydroxyl groups in the water-based hydroxyl acrylic dispersion in Comparative Example 4 is too low, the water resistance and humidity resistance of the obtained product show a significant downward trend, compared with Example 1, the water resistance is reduced by 22.2%, and the humidity resistance is reduced by 31.3%;

[0107] As can be seen from Example 1 and Comparative Example 5, the type of active end group in the siloxane coupling agent affects the performance of the product. When the active end group in the siloxane in Comparative Example 5 is not within the scope given in the present application, compared with Example 1, the water resistance of the obtained product is reduced by 51.9%, the humidity resistance is reduced by 58.3%, and the neutral salt spray resistance is reduced by 42.7%;

[0108] As can be seen from Example 1 and Comparative Example 6, the type of isocyanate curing agent also affects the performance of the product. When an isocyanate curing agent other than that in the present application is selected, the water resistance and humidity resistance of the obtained product show a certain downward trend;

[0109] As can be seen from Example 1 and Comparative Examples 7-10, the preparation method of the water-based two-component polyurethane coating provided in the present application also significantly affects the performance of the product. When the pH value adjusted during preparation in Comparative Examples 7-8 is not within the scope of the present application, the water resistance, humidity resistance and neutral salt spray resistance of the obtained product all show a significant downward trend; when the reaction temperature during preparation in Comparative Example 9 is not within the scope of the present application, the water resistance, humidity resistance and neutral salt spray resistance of the obtained product are all significantly reduced; when the mixing order during preparation in Comparative Example 10 is not provided in the present application, the water resistance, humidity resistance and neutral salt spray resistance of the obtained product are all significantly reduced.

[0110] It should be pointed out finally that the above embodiments are used to illustrate the technical solutions of the present application but not to limit the protection scope of the present application, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art 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 water-based two-component polyurethane coating, characterized in that, The waterborne two-component polyurethane coating comprises component A and component B, wherein the mass ratio of component A to component B is (5.5 8.5 ):

1. Component A comprises the following components in parts by weight: 45-65 parts of aqueous hydroxy acrylic dispersion, 0.5-1 part of wetting and dispersing agent, 0.1-2 parts of defoamer, 0.5-2 parts of pH adjuster, 5-8 parts of cosolvent, 20-30 parts of titanium dioxide, 0.1-2 parts of leveling agent, 1-4 parts of thickener, 0.1-3 parts of siloxane modifier, and 9-18 parts of deionized water; Component B is an organosilicon-modified ionic aliphatic isocyanate curing agent; In the aqueous hydroxyl acrylic acid dispersion, the mass content of hydroxyl groups is 3.3-4.2%; The end group of the siloxane modifier contains either an amino group or a methacryloxy group.

2. The waterborne two-component polyurethane coating according to claim 1, characterized in that, The mass ratio of the siloxane modifier to deionized water is siloxane modifier:deionized water = 1:(7-10).

3. The waterborne two-component polyurethane coating according to claim 1, characterized in that, Any one of (a)-(f): (a) The wetting and dispersing agent is an acrylate copolymer; (b) The defoamer is at least one of mineral oil modified copolymer and organosilicon defoamer; (c) The pH adjuster is AMP-95; (d) The co-solvent is at least one of dipropylene glycol butyl ether, dipropylene glycol methyl ether, and diethylene glycol butyl ether; (e) The leveling agent is Tigo 4100; (f) The thickener is an associative polyurethane thickener.

4. The method for preparing the waterborne two-component polyurethane coating according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: (1) Add siloxane modifier and titanium dioxide to part of deionized water, stir and adjust the pH value to acidic, then heat the reaction. After the reaction is completed, cool to room temperature to obtain solution 1. (2) Add wetting and dispersing agent, part of defoamer, part of cosolvent, pH adjuster and the remaining deionized water to solution 1 in sequence, disperse evenly and grind to obtain slurry 1; (3) Add water-based hydroxy acrylic dispersion, the remaining defoamer, the leveling agent, and the remaining cosolvent to slurry 1 in sequence. After dispersing evenly, add thickener to adjust the viscosity and obtain component A. (4) Disperse the organosilicon-modified ionic aliphatic isocyanate curing agent evenly to obtain component B; (5) Mix component A and component B evenly to obtain a water-based two-component polyurethane coating; In step (1), adjusting the pH value to acidic is done by adjusting the pH value to 3-4 with acetic acid; the temperature of the heating reaction is 40-50℃.

5. The preparation method according to claim 4, characterized in that, In step (1), the deionized water accounts for 70-80% of the deionized water mass.

6. The preparation method according to claim 4, characterized in that, In step (1), the heating reaction time is 50-70 min.

7. The preparation method according to claim 4, characterized in that, The fineness of the slurry 1 is ≤25μm. And / or, the viscosity of component A is 70-80 KU.

8. The application of the waterborne two-component polyurethane coating as described in any one of claims 1-3 in the preparation of chemical storage tanks.

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