Water-based two-component polyurethane refinishing paint resistant to impact of high-pressure water gun and preparation method thereof

Abstract

The invention discloses water-based two-component polyurethane refinishing paint resistant to impact of a high-pressure water gun and a preparation method of the water-based two-component polyurethane refinishing paint. The water-based two-component polyurethane refinishing paint is prepared from a component A and a component B, the component A is prepared by mixing the following raw materials in parts by weight: 60 to 70 parts of hydroxyl acrylic dispersion, 2 to 3 parts of dispersing agent, 0.1 to 0.3 part of defoaming agent, 0.5 to 1.0 part of wetting agent, 0.1 to 0.2 part of amine, 0.2 to 0.5 part of anti-settling agent, 2 to 25 parts of pigment filler, 0.2 to 0.4 part of flatting agent, 2 to 6 parts of cosolvent, 0.2 to 0.5 part of thickening agent, 0.2 to 0.5 part of ultraviolet absorber, 0.2 to 0.5 part of light stabilizer and 5 to 10 parts of water; the component B is prepared by mixing the following raw materials in parts by weight: 60-70 parts of an isocyanate curing agent and 30-40 parts of an ester solvent. The water-based two-component polyurethane refinishing paint disclosed by the invention can resist the impact of a high-pressure water gun, is good in weather resistance and quick to dry, and can be widely used for repairing a damaged paint film of engineering mechanical equipment.

Description

Technical Field

[0001] The invention relates to a water-based paint, in particular to a water-based two-component polyurethane repair paint resistant to high-pressure water gun impact and a preparation method thereof. Background Art

[0002] At present, water-based paint has been widely used in the field of engineering machinery. The water-based topcoat usually used in the field of engineering machinery is water-based two-component polyurethane paint. In the paint coating process of mechanical equipment, the parts are usually painted first, and then the equipment is assembled and debugged. During the equipment assembly and debugging process, part of the paint film is often damaged, and the damaged paint film needs to be repaired. Due to environmental protection needs, the use of traditional solvent-based paint for repair will cause VOCs to exceed the standard, so water-based two-component polyurethane paint is needed for repair. However, during the coating process of the repair process, the paint film is generally self-dried or baked at a low temperature of 50-60℃. Therefore, it is required to use a water-based two-component polyurethane paint with a faster drying speed for repair; in addition, some equipment (such as mixer trucks and aerial work machines) need to be washed with a high-pressure water gun of more than 20MPa after the paint film is repaired. Therefore, the water-based two-component polyurethane repair paint requires not only a fast drying speed, but more importantly, the paint film is required to withstand high-pressure water gun washing of more than 20MPa. Existing water-based two-component polyurethane repair paints are difficult to meet these two requirements at the same time.

[0003] CN 111944409 A discloses a water-based two-component polyurethane coating, comprising a main agent and a hardener, wherein the main agent is composed of the following components in parts by weight: 15-20 parts of deionized water, 1-2 parts of a dispersant, 15-21 parts of titanium dioxide, 4-6 parts of precipitated barium sulfate, 50-60 parts of a water-based acrylic dispersion, 4-6 parts of a cosolvent, 0.1-0.2 parts of a pH regulator, 0.3-0.5 parts of a substrate wetting agent, 0.1-0.2 parts of a defoamer, 0.1-0.2 parts of a leveling agent, 0.5-1.0 parts of a thickener, and 0.1-0.3 parts of a catalyst; and the hardener is composed of the following components in parts by weight: 70-80 parts of a water-based isocyanate and 20-30 parts of propylene glycol diacetate. Although the surface drying speed of the water-based two-component polyurethane coating is fast, the actual drying speed is as long as 18-23.5 hours; furthermore, the falling ball impact test is only 30cm / 1kg without abnormality, and no high-pressure water gun test data is recorded. Based on this, the technicians in this field can infer that the water-based two-component polyurethane coating is difficult to withstand high-pressure water gun washing above 20MPa. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a water-based two-component polyurethane repair paint and a preparation method thereof which can withstand high-pressure water gun washing of more than 20MPa and has a fast drying speed, especially a fast actual drying speed.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a water-based two-component polyurethane repair paint resistant to high-pressure water gun impact is composed of component A and component B; component A is prepared by mixing the following raw materials in parts by weight: 60-70 parts of hydroxy acrylic dispersion, 2-3 parts of dispersant, 0.1-0.3 parts of defoamer, 0.5-1.0 parts of wetting agent, 0.1-0.2 parts of amine, 0.2-0.5 parts of anti-settling agent, 2-25 parts of pigment and filler, 0.2-0.4 parts of leveling agent, 2-6 parts of cosolvent, 0.2-0.5 parts of thickener, 0.2-0.5 parts of ultraviolet light absorber, 0.2-0.5 parts of light stabilizer and 5-10 parts of water; component B is prepared by mixing the following raw materials in parts by weight: 60-70 parts of isocyanate curing agent and 30-40 parts of ester solvent.

[0006] Preferably, the hydroxylated acrylic dispersion is prepared by mixing a high-hydroxylated dispersion and a medium-low-hydroxylated dispersion in a weight ratio of 2:1-2.

[0007] Preferably, the dispersant is two of Digo's 760w, 755w, BYK190, Puwei's D-6390, D-1920, Shenzhu 1790A, and SN-1776.

[0008] Preferably, the defoaming agent is two of Digo's 810, 902w, Mingling 351, BYK's BYK022, BYK028

[0009] Preferably, the wetting agent is two or more of Digo's 4100, Xiaofan 104BC, BYK-346, Shenzhu's SN-4741, and Puwei W-118.

[0010] Preferably, the amine is one of industrial grade dimethylethanolamine and AMP-95.

[0011] Preferably, the anti-settling agent is one of Evonik A-200, R-972, and A-300.

[0012] Preferably, the anti-settling agent pigment filler is one or more of Dongjia 2377 titanium dioxide, Mitsubishi MA-100, tri-epoxy iron oxide red and iron oxide yellow, and Ruishi's high-gloss barium.

[0013] Preferably, the leveling agent is one of BYK-331, BYK-333, Shenzhu SN-4333, and Puwei FL-333.

[0014] Preferably, the thickener is one of Dow's RM2020, 8w and Boshes' 0620.

[0015] Preferably, the ultraviolet light absorber is one of 5400WB of QiTi and 400DW of BASF.

[0016] Preferably, the light stabilizer is one of QITAI's 101WB and BASF's 123DW.

[0017] Preferably, the ester solvent is one of industrial grade propylene glycol diacetate, propylene glycol methyl ether acetate, and dibasic acid ester.

[0018] Preferably, the co-solvent is two or more of dipropylene glycol methyl ether, No. 150 solvent oil, No. 100 solvent oil, dipropylene glycol butyl ether, ethylene glycol butyl ether, and diethylene glycol butyl ether.

[0019] Preferably, the isocyanate curing agent in the component B is a mixture of a hydrophilic isocyanate curing agent and a hydrophobic isocyanate curing agent in a weight ratio of 2:1-3.

[0020] Preferably, the hydrophilic isocyanate curing agent is one of Covestro's 2655 and Wanhua's 269.

[0021] Preferably, the hydrophobic isocyanate curing agent is one of Covestro's 3600, Wanhua's 280, and HT-600.

[0022] The preparation method of the components A and B of the water-based two-component polyurethane repair paint resistant to high-pressure water gun impact of the present invention is as follows.

[0023] The preparation method of the component A is as follows:

[0024] (1) Put the dispersant, defoamer, wetting agent, amine and part of the water into a batching tank, add part of the hydroxy acrylic acid dispersion, anti-settling agent, pigment and filler while stirring, and then grind and disperse until the average fineness of the solid phase is ≤10μm to obtain a color paste; the grinding speed is 2000-3000r / min;

[0025] (2) Add the remaining hydroxy acrylic dispersion, leveling agent, cosolvent, water, and thickener to the color paste while stirring, adjust the viscosity to 65-75 KU, and then grind and disperse for 15-25 minutes (preferably 20 minutes); the grinding speed is 500-1000 r / min.

[0026] The preparation method of the B component is: mix the ester solvent and the isocyanate curing agent, grind and disperse for 15 to 25 minutes (preferably 20 minutes), and the grinding and dispersing speed is 500 to 1000 r / min.

[0027] The preparation method of the water-based two-component polyurethane repair paint capable of resisting high-pressure water gun impact is as follows: firstly, component A and component B are prepared separately, then component A, component B and water are mixed in a weight ratio of 3-4:1:0.3-0.8, and stirred evenly to obtain the product.

[0028] The water-based two-component polyurethane repair paint capable of resisting the impact of a high-pressure water gun is prepared by mixing the OH group of the hydroxyl resin in the A component and the NCO group in the isocyanate in the B component according to a designed ratio, and then rapidly undergoing a chemical reaction to form a coating film with high cross-linking density and high strength, wherein the high hydroxyl value resin ensures the compactness and later hardness of the coating film after curing, and the medium and low hydroxyl value resins ensure the drying speed and early hardness of the coating film after curing, thereby obtaining a coating film with a fast actual drying speed and the ability to resist the impact of a high-pressure water gun; and at the same time, the coating film contains a pigment with excellent weather resistance and a combination of an ultraviolet light absorber and a light stabilizer, thereby ensuring the excellent weather resistance of the coating film.

[0029] The water-based two-component polyurethane repair paint of the present invention can withstand the impact of high-pressure water guns and can withstand high-pressure water gun washing above 20MPa; and has a fast drying speed, especially a fast actual drying speed (actual drying time 5-10h), good weather resistance, and can be widely used in repairing damaged paint films of engineering machinery and equipment. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the embodiments.

[0031] The dispersants used in the embodiments of the present invention given below are DEGO 755W, 760, the defoamers are DEGO-810, 902w, the wetting agents are DEGO 4100W, 104BC, BYK 346, the anti-settling agent is Evonik A200, the leveling agent is BYK-331, the thickener is Dow's RM2020, and the amine is industrial-grade dimethylethanolamine. The high-hydroxyl resin is Tongde 0519, and the medium-low hydroxyl resin is Tongde 56w. Other pigments, fillers and cosolvents are all industrial-grade commercial products.

[0032] The raw materials used in the embodiments of the present invention are all obtained through conventional commercial channels.

[0033] Example 1

[0034] The present embodiment provides a water-based two-component polyurethane repair paint that can withstand the impact of a high-pressure water gun, which is composed of a component A and a component B. Calculated as 1 gram per part, the component A is prepared by mixing the following raw materials in parts by weight: 66 parts of hydroxylated acrylic dispersion (of which 0519 is 44 parts and 56w is 22 parts), 2.4 parts of dispersant (755W is 1.6 parts and 760w is 0.8 parts), 0.3 parts of defoamer (810 is 0.1 parts and 902w is 0.2 parts), 0.8 parts of wetting agent (4100W is 0.3 parts and 104BC is 0.8 parts), and 0.6 parts of hydroxylated acrylic dispersion. 0.5 parts), 0.2 parts of amine, 0.3 parts of anti-settling agent, 18 parts of pigment (0.15 parts of carbon black, 16 parts of titanium dioxide, 0.75 parts of iron oxide red, 1.1 parts of iron oxide yellow, 0.2 parts of leveling agent, 4 parts of ether solvent (2 parts of dipropylene glycol butyl ether, 2 parts of tetramethylbenzene), 0.3 parts of thickener, 0.3 parts of ultraviolet light absorber, 0.3 parts of light stabilizer, 6.9 parts of deionized water; the B component includes the following raw materials in parts by weight: 20 parts of hydrophobic isocyanate curing agent, 40 parts of hydrophilic isocyanate curing agent, and 40 parts of ester solvent.

[0035] The preparation method of the water-based two-component polyurethane repair paint is to prepare component A and component B respectively, and then mix component A: component B: water in a weight ratio of 3: 1: 0.45 and stir evenly to obtain the product.

[0036] The preparation method of the component A is as follows:

[0037] (1) putting a dispersant, a defoamer, a wetting agent, an amine, and part of the water into a batching tank, adding part of the hydroxy acrylic acid dispersion, an anti-settling agent, a pigment, and a filler while stirring, and then grinding and dispersing at a speed of 2500 r / min until the solid phase fineness is 10 μm to obtain a color paste;

[0038] (2) Add the remaining hydroxy acrylic dispersion, leveling agent, cosolvent, water, and thickener to the color paste while stirring, adjust the viscosity to 70KU, and then grind and disperse at a speed of 1000 r / min for 20 minutes.

[0039] The preparation method of the B component is: mix the ester solvent and the isocyanate curing agent, and disperse them at a grinding and dispersion speed of 1000 r / min for 20 minutes.

[0040] Example 2

[0041] This embodiment provides a water-based two-component polyurethane repair paint that can withstand the impact of a high-pressure water gun, which is composed of component A and component B. Calculated as 1 gram per component, component A includes the following raw materials in parts by weight: 5 parts of deionized water, 2.4 parts of dispersant (1.6 parts for 755W and 0.8 parts for 760w), 0.3 parts of defoamer (0.1 parts for 810 and 0.2 parts for 902w), 0.7 parts of wetting agent (0.3 parts for 4100W and 0.4 parts for 104BC), 0.2 parts of amine, 0.3 parts of anti-settling agent, 68 parts of hydroxylated acrylic dispersion (34 parts for 0519 and 0.6 parts for 56 w is 34 parts), 18 parts of pigment (0.15 parts of carbon black, 16 parts of titanium dioxide, 0.75 parts of red iron oxide, 1.1 parts of yellow iron oxide), 0.2 parts of leveling agent, 4 parts of ether solvent (2 parts of dipropylene glycol butyl ether, 2 parts of tetramethylbenzene), 0.3 parts of thickener, 0.3 parts of ultraviolet light absorber, and 0.3 parts of light stabilizer; the B component includes the following raw materials in parts by weight: 20 parts of hydrophobic isocyanate curing agent, 40 parts of hydrophilic isocyanate curing agent, and 40 parts of ester solvent.

[0042] The preparation method of the water-based two-component polyurethane repair paint is to first prepare component A and component B separately, and then mix component A: component B: water in a weight ratio of 3.5:1:0.45 and stir evenly.

[0043] The preparation method of the component A is as follows:

[0044] (1) putting water, dispersant, defoamer, wetting agent and amine into a batching tank, adding part of hydroxy acrylic acid dispersion, anti-settling agent, pigment and filler while stirring, and then grinding and dispersing at a speed of 2800 r / min until the solid phase fineness is 10 μm to obtain a color paste;

[0045] (2) Add the remaining hydroxy acrylic dispersion, leveling agent, cosolvent, water, and thickener to the color paste while stirring, adjust the viscosity to 70 KU, and then disperse at a speed of 800 r / min for 20 minutes.

[0046] The preparation method of the B component is: dispersing the ester solvent and the isocyanate curing agent at a dispersing speed of 800 r / min for 20 minutes.

[0047] Example 3

[0048] This embodiment provides a water-based two-component polyurethane repair paint that can withstand the impact of a high-pressure water gun, which is composed of component A and component B. Calculated as 1 gram per component, component A includes the following raw materials in parts by weight: 8 parts of deionized water, 2.4 parts of dispersant (1.6 parts for 755W and 0.8 parts for 760w), 0.3 parts of defoamer (0.1 parts for 810 and 0.2 parts for 902w), 0.7 parts of wetting agent (0.3 parts for 4100W and 0.4 parts for 104BC), 0.2 parts of amine, 0.3 parts of anti-settling agent, 64 parts of hydroxylated acrylic dispersion (32 parts for 0519 and 0.6 parts for 56 w is 32 parts), 18 parts of pigment (0.15 parts of carbon black, 16 parts of titanium dioxide, 0.75 parts of red iron oxide, 1.1 parts of yellow iron oxide), 0.2 parts of leveling agent, 5 parts of ether solvent (2 parts of diethylene glycol butyl ether, 3 parts of trimethylolbenzene), 0.3 parts of thickener, 0.3 parts of ultraviolet light absorber, and 0.3 parts of light stabilizer; the B component includes the following raw materials in parts by weight: 30 parts of hydrophobic isocyanate curing agent, 30 parts of hydrophilic isocyanate curing agent, and 40 parts of ester solvent.

[0049] The preparation method of the water-based two-component polyurethane repair paint is to first prepare component A and component B separately, and then mix component A: component B: water in a weight ratio of 3.5:1:0.3 and stir evenly.

[0050] The preparation method of component A is as follows:

[0051] (1) putting water, dispersant, defoamer, wetting agent and amine into a batching tank, adding part of hydroxy acrylic acid dispersion, anti-settling agent, pigment and filler while stirring, and then grinding and dispersing at a speed of 2600 r / min until the fineness of the solid phase is 10 um μm, to obtain a color paste;

[0052] (2) Add the remaining hydroxy acrylic dispersion, leveling agent, cosolvent, water, and thickener to the color paste while stirring, adjust the viscosity to 68KU, and then disperse at a speed of 700 r / min for 20 minutes.

[0053] The preparation method of the B component is: dispersing the ester solvent and the isocyanate curing agent at a dispersing speed of 700 r / min for 20 minutes.

[0054] Example 4

[0055] This embodiment provides a water-based two-component polyurethane repair paint that can withstand the impact of a high-pressure water gun, which is divided into component A and component B. Calculated as 1g as one part, component A includes the following raw materials in parts by weight: 5.2 parts of deionized water, 2.2 parts of dispersant (1.4 parts of 755W and 0.8 parts of 760w), 0.3 parts of defoamer (0.1 parts of 810 and 0.2 parts of 902w), 0.7 parts of wetting agent (0.3 parts of 4100W and 0.4 parts of 104BC), 0.2 parts of amine, 0.3 parts of anti-settling agent, 62 parts of hydroxylated acrylic dispersion (0519 is 0.1 ...3 parts of amine, 0.2 parts of amine, 0.3 parts of anti-settling agent, 62 parts of hydroxylated acrylic dispersion (0519 is 0.1 parts of 104BC), 0.3 parts of amine, 0.3 parts of anti-settling agent, 62 parts of 35 parts, 56w is 27 parts), pigment 24 parts (titanium dioxide 22 parts, iron oxide red 0.5 parts, iron oxide yellow 1.5 parts), leveling agent 0.2 parts, ether solvent 4 parts (dipropylene glycol methyl ether 2 parts, trimethylbenzene 2 parts), thickener 0.3 parts, ultraviolet light absorber 0.3 parts, light stabilizer 0.3 parts; the B component includes the following raw materials in parts by weight: 30 parts of hydrophobic isocyanate curing agent, 30 parts of hydrophilic isocyanate curing agent, and 40 parts of ester solvent.

[0056] The preparation method of the water-based two-component polyurethane repair paint is to first prepare component A and component B separately, and then mix component A: component B: water in a weight ratio of 3.5:1:0.3 and stir evenly.

[0057] The preparation method of component A is as follows:

[0058] (1) putting a dispersant, a defoamer, a wetting agent, an amine and part of the water into a batching tank, adding part of the hydroxy acrylic acid dispersion, an anti-settling agent, a pigment and a filler while stirring, and then grinding and dispersing at a speed of 2700 r / min until the fineness of the solid phase is 10 μm to obtain a color paste;

[0059] (2) Add the remaining hydroxy acrylic dispersion, leveling agent, cosolvent, water, and thickener to the color paste while stirring, adjust the viscosity to 70 KU, and then disperse at a speed of 800 r / min for 20 minutes.

[0060] The preparation method of the B component is: dispersing the ester solvent and the isocyanate curing agent at a dispersing speed of 700 r / min for 20 minutes.

[0061] The water-based two-component polyurethane repair paints of Examples 1-4 that can withstand the impact of a high-pressure water gun were tested for performance, and the results are shown in Table 1.

[0062] Table 1 Performance test results of water-based two-component polyurethane repair paints capable of withstanding high-pressure water gun impact in Examples 1-4

[0063]

Claims

1. A water-based two-component polyurethane repair paint resistant to high-pressure water gun impact, consisting of component A and component B; characterized in that: Component A is prepared by mixing the following raw materials in parts by weight: 60-70 parts of hydroxy acrylic dispersion, 2-3 parts of dispersant, 0.1-0.3 parts of defoamer, 0.5-1.0 parts of wetting agent, 0.1-0.2 parts of amine, 0.2-0.5 parts of anti-settling agent, 2-25 parts of pigment and filler, 0.2-0.4 parts of leveling agent, 2-6 parts of cosolvent, 0.2-0.5 parts of thickener, 0.2-0.5 parts of ultraviolet light absorber, 0.2-0.5 parts of light stabilizer, and 5-10 parts of water; Component B is prepared by mixing the following raw materials in parts by weight: 60-70 parts of isocyanate curing agent and 30-40 parts of ester solvent.

2. The water-based two-component polyurethane repair paint resistant to high-pressure water gun impact according to claim 1, characterized in that: The hydroxylated acrylic dispersion is prepared by mixing a high hydroxyl value resin and a low hydroxyl value resin in a weight ratio of 2:1-2.

3. A water-based two-component polyurethane repair paint resistant to high-pressure water gun impact according to claim 1 or 2, characterized in that: The isocyanate curing agent in the B component is prepared by mixing a hydrophilic isocyanate curing agent and a hydrophobic isocyanate curing agent in a weight ratio of 2:1-3.

4. A water-based two-component polyurethane repair paint resistant to high-pressure water gun impact according to any one of claims 1 to 3, characterized in that: The co-solvent is two or more of dipropylene glycol methyl ether, No. 150 solvent oil, No. 100 solvent oil, dipropylene glycol butyl ether, ethylene glycol butyl ether, and diethylene glycol butyl ether.

5. A water-based two-component polyurethane repair paint resistant to high-pressure water gun impact according to any one of claims 1 to 4, characterized in that: The preparation method of the component A is as follows: (1) Put the dispersant, defoamer, wetting agent, amine and part of the water into the batching tank, add part of the hydroxy acrylic acid dispersion, anti-settling agent and pigment filler while stirring, and then grind and disperse until the average fineness of the solid phase is ≤10μm to obtain the color paste; the grinding speed is 2000~3000r / min; (2) Add the remaining hydroxy acrylic dispersion, water, leveling agent, co-solvent and thickener to the color paste while stirring, adjust the viscosity to 65-75KU, and then grind and disperse for 15-25 minutes; the grinding speed is 500-1000r / min.

6. A water-based two-component polyurethane repair paint resistant to high-pressure water gun impact according to any one of claims 1 to 5, characterized in that: The preparation method of the B component is: mixing an ester solvent and an isocyanate curing agent, grinding and dispersing for 15 to 25 minutes, and the rotation speed of the grinding and dispersing is 500 to 1000 r / min.

7. A method for preparing a water-based two-component polyurethane repair paint resistant to high-pressure water gun impact according to any one of claims 1 to 6, characterized in that: First, prepare component A and component B separately, then mix component A, component B and water in a weight ratio of 3-4:1:0.3-0.8, stir evenly, and the mixture is ready.

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