Waterborne polyurethane paint for preventing water and dirt on surface of reflective mirror and preparation method of waterborne polyurethane paint

Abstract

The invention relates to a waterproof and antifouling waterborne polyurethane paint for the surface of a reflective mirror and a preparation method thereof, and the waterborne polyurethane paint is prepared from the following raw material components in parts by weight: 50-60 parts of waterborne polymer polyurethane emulsion, 4-10 parts of waterborne amino resin, 2-7 parts of waterborne blocked isocyanate, 0.1-0.3 part of a waterborne catalyst, 1-4 parts of a dispersing agent and 0.2-0.5 part of a defoaming agent. The coating is prepared from the following components in parts by weight: 0.5-1 part of a flatting agent, 0.2-0.5 part of a wetting flatting agent, 0.1-2 parts of a thickening agent, 2-6 parts of a coalescing agent and 20-38 parts of deionized water. Compared with the prior art, the water-based polyurethane paint has the advantages that the water-based polyurethane emulsion is used as main resin, and the water-based amino resin and the water-based blocked isocyanate are used as cross-linking agents, so that the prepared water-based polyurethane paint has good adhesive force, good flexibility, good recoatability and good water resistance and salt fog resistance after forming a film.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a water-based polyurethane paint for waterproofing and anti-fouling of reflector surfaces and a preparation method thereof. Background Art

[0002] Anti-fouling coating is a technology applied to the surface of lenses. Its main function is to reduce or prevent the lenses from being contaminated. The emergence of this technology is closely related to anti-reflection film. After wearing for a period of time, anti-reflection film lenses are prone to absorb dirt in the air due to their microporous structure, making them difficult to clean. In order to solve this problem, people coat the anti-fouling film layer with oil and water resistance on the anti-reflection film layer.

[0003] The principle of the anti-fouling film is to use an evaporation process to coat fluoride on the anti-reflection film, thereby covering the pore structure of the anti-reflection film, reducing the contact area between water, oil and other objects and the mirror surface, making it difficult for stains to adhere to the surface of the lens, thereby achieving an anti-fouling effect. At the same time, this coating technology can also enhance the radiation resistance of the lens.

[0004] In recent years, as consumers' requirements for the clarity, aesthetics, comfort and durability of eyeglass lenses continue to increase, the surface coating technology of lenses has developed rapidly. As a technology with high commercial added value, anti-fouling coating has received extensive attention and investment from manufacturers and sellers, further promoting the development of this technology. For example, the Lotus film and Diamond Cube film (silver film, gold film) of Zeiss in Germany are typical representatives of anti-fouling coating technology. They not only have the functions of anti-fouling and anti-radiation, but also have multiple functions such as clearer, more wear-resistant and more waterproof.

[0005] At present, the coating used for reflector materials is mainly epoxy coating, among which epoxy-amino paint is the most widely used. For example, the Chinese invention patent with application number CN202110350444.8 discloses a weather-resistant, high-hardness water-based epoxy-amino paint and its preparation method, and its coating components and weight fractions are: 55-60 parts of water-based epoxy emulsion, 40-45 parts of amino resin, 0.5-2 parts of enhancer, 0.3-0.8 parts of surfactant, 0.1-0.5 parts of defoamer, 15-20 parts of deionized water, and the enhancer is PS / ADGDE / DMPD. This patent is an epoxy-amino paint. Through experiments, it was found that the epoxy-amino paint has adhesion on glass, but it also has the following problems: (1) poor waterproof and anti-fouling performance; (2) poor recoatability; (3) poor water and salt spray resistance on glass; (4) poor adhesion on glass material after multiple recoatings. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a water-based polyurethane paint for the surface of a reflector that is waterproof and anti-fouling and a preparation method thereof.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] One of the technical solutions of the present invention is to provide a water-based polyurethane paint for waterproof and anti-fouling of the surface of a reflector, comprising the following raw material components in parts by weight:

[0009] 50-60 parts of water-based polymer polyurethane emulsion, 4-10 parts of water-based amino resin, 2-7 parts of water-based blocked isocyanate, 0.1-0.3 parts of water-based catalyst, 1-4 parts of dispersant, 0.2-0.5 parts of defoaming agent, 0.2-0.5 parts of wetting and leveling agent, 0.1-2 parts of thickener, 2-6 parts of film-forming aid, and 20-38 parts of deionized water.

[0010] In some specific embodiments, the solid content of the aqueous polymer polyurethane emulsion is 30-45%.

[0011] Preferably, the aqueous polyurethane emulsion is 1526 polyurethane emulsion with a solid content of 30-40% and a pH of 6-8. It has the characteristics of good flexibility, good adhesion, good water and salt spray resistance, good interlayer adhesion, high gloss and high brightness.

[0012] In some specific embodiments, the water-based amino resin is a trimethyl etherified amino resin.

[0013] Preferably, the water-based amino resin is 5717 amino resin, which has the characteristics of low curing temperature (60-80° C.), good adhesion, good flexibility, etc.

[0014] In some specific embodiments, the water-based blocked isocyanate is a water-based special blocked HDI curing agent.

[0015] Preferably, the water-based blocked isocyanate is HL-W2100D, which has the characteristics of low curing temperature (60-80° C.), good adhesion, good flexibility, good water resistance, etc.

[0016] In some specific embodiments, the aqueous catalyst is an aqueous acid drier.

[0017] Preferably, the water-based catalyst is X49-110, which has the characteristics of increasing reaction speed, reducing reaction temperature, and having little effect on the flexibility of the paint film.

[0018] In some specific embodiments, the dispersant is 5040; the defoamer is BYK-024; the wetting and leveling agent is BYK-333; and the thickener is RM-8W.

[0019] In some specific embodiments, the film-forming aid is composed of ethylene glycol monobutyl ether and dipropylene glycol butyl ether in a mass ratio of 1:0.3-1.5.

[0020] The second technical solution of the present invention is to provide a method for preparing a waterborne polyurethane paint as described in one of the above technical solutions, comprising the following steps:

[0021] First, pour some deionized water into a container, then add dispersant and defoamer in turn, stir evenly, then add water-based polymer polyurethane emulsion and stir, then add water-based amino resin, water-based blocked isocyanate, catalyst, wetting and leveling agent, film-forming aid and thickener, and add the remaining deionized water, stir and mix, and then you are done to get water-based polyurethane paint.

[0022] A third technical solution of the present invention is to provide an application of the waterborne polyurethane paint as described in one of the above technical solutions, wherein the waterborne polyurethane paint is used to be coated on the surface of the reflector glass composite material and forms a paint film after curing.

[0023] In some embodiments, the curing temperature is 60-80°C.

[0024] Compared with the prior art, the present invention uses water-based polyurethane emulsion as the main resin, and uses water-based amino resin and water-based blocked isocyanate as cross-linking agents. The prepared water-based polyurethane paint has the following advantages after film formation:

[0025] (1) Good adhesion, flexibility, recoatability, water and salt spray resistance on the surface of reflector glass composite materials;

[0026] (2) Water-based polyurethane paint dries quickly and can be cured at 60-80°C; it has good adhesion to other topcoats.

[0027] In addition, the present invention uses a water-based catalyst, which can reduce the reaction temperature without affecting the properties of the paint film. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0029] In the following examples and comparative examples, unless otherwise specified, raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0030] Embodiment 1:

[0031] The components and weight contents of the waterborne polyurethane paint in this embodiment are as follows:

[0032] 1526 polyurethane emulsion 55%;

[0033] Amino resin 5717 6%;

[0034] Water-based blocked isocyanate HL-W2100D 2%;

[0035] Catalyst X49-110 0.2%;

[0036] Dispersant 5040 2%;

[0037] Defoamer BYK-024 0.2%;

[0038] Wetting and leveling agent BYK-333 0.2%;

[0039]

[0040] This embodiment also provides a method for preparing a water-based polyurethane paint, which specifically comprises the following steps:

[0041] (1) Weigh some deionized water and put it into the tank;

[0042] (2) Weigh the dispersant and defoamer and put them into the tank, stirring at low speed for 20 minutes;

[0043] (3) Add the above slurry into a 1526 polyurethane emulsion tank and stir at medium speed for 30 minutes;

[0044] (4) Add water-based amino resin, water-based blocked isocyanate and catalyst into a tank and stir at medium speed for 20 minutes;

[0045] (5) Add the wetting and leveling agent, ethylene glycol monobutyl ether, dipropylene glycol butyl ether, the remaining deionized water, and the thickener into a tank and stir at a medium speed for 30 minutes to obtain a water-based polyurethane paint.

[0046] In the above steps (1) to (5), the low-speed stirring is 200-300 rpm, the medium-speed stirring is 300-500 rpm, and the high-speed stirring is 500-700 rpm.

[0047] The prepared waterborne polyurethane paint was coated on the surface of the reflector and cured at 60° C. to obtain a paint film.

[0048] The test results of the paint film performance of this embodiment are shown in Table 1 below.

[0049] Table 1 Paint film performance test results

[0050] Test items Technical indicators Test results Hundred Grid Attachment ≤1 level Level 0 Impact resistance 1Kg / 50cm OK Flexibility ≤2mm OK Water resistant 40℃*7 days OK Salt spray resistant 120 hours OK Interlayer Adhesion ≤1 level Level 0

[0051] Comparative Example 1:

[0052] The components and weight contents of the waterborne polyurethane paint in this comparative example 1 are as follows:

[0053]

[0054]

[0055] The rest was deionized water.

[0056] This embodiment also provides a method for preparing a water-based polyurethane paint, which specifically comprises the following steps:

[0057] (1) Pour some deionized water into the tank;

[0058] (2) Add dispersant and defoamer and stir at low speed for 20 minutes;

[0059] (3) Add the above slurry into a 1526 polyurethane emulsion tank and stir at medium speed for 30 minutes;

[0060] (4) adding water-based amino resin, water-based blocked isocyanate, and catalyst, and stirring at medium speed for 20 minutes;

[0061] (5) Add a wetting and leveling agent, ethylene glycol monobutyl ether, dipropylene glycol butyl ether, the remaining deionized water, and a thickener, and stir at a medium speed for 30 minutes to obtain a water-based polyurethane paint.

[0062] In the above steps (1) to (5), the low-speed stirring is 200-300 rpm, the medium-speed stirring is 300-500 rpm, and the high-speed stirring is 500-700 rpm.

[0063] The prepared waterborne polyurethane paint was coated on the surface of the reflector and cured at 60° C. to obtain a paint film.

[0064] The test results of the paint film performance of this comparative example 1 are shown in Table 2 below.

[0065] Table 2 Paint film performance test results

[0066] Test items Technical indicators Test results Hundred Grid Attachment ≤1 level Level 0 Impact resistance 1Kg / 50cm OK Flexibility ≤2mm OK Water resistant 40℃*7 days OK Salt spray resistant 120 hours OK Interlayer Adhesion ≤1 level Level 2

[0067] It can be seen from the table that compared with Example 1, the interlayer adhesion of the paint film prepared in Comparative Example 1 is poor.

[0068] Comparative Example 2:

[0069] The components and weight contents of the waterborne polyurethane paint in this comparative example 2 are as follows:

[0070]

[0071] The rest was deionized water.

[0072] This embodiment also provides a method for preparing a water-based polyurethane paint, which specifically comprises the following steps:

[0073] (1) Pour some deionized water into the tank;

[0074] (2) Add dispersant and defoamer and stir at low speed for 20 minutes;

[0075] (3) Add the above slurry into a 1526 polyurethane emulsion tank and stir at medium speed for 30 minutes;

[0076] (4) adding water-based amino resin, water-based blocked isocyanate, and catalyst, and stirring at medium speed for 20 minutes;

[0077] (5) Add a wetting and leveling agent, ethylene glycol monobutyl ether, dipropylene glycol butyl ether, the remaining deionized water, and a thickener, and stir at a medium speed for 30 minutes to obtain a water-based polyurethane paint.

[0078] In the above steps (1) to (5), the low-speed stirring is 200-300 rpm, the medium-speed stirring is 300-500 rpm, and the high-speed stirring is 500-700 rpm.

[0079] The prepared waterborne polyurethane paint was coated on the surface of the reflector and cured at 60° C. to obtain a paint film.

[0080] The test results of the paint film performance of this comparative example 2 are shown in Table 3 below.

[0081] Table 3 Paint film performance test results

[0082]

[0083] It can be seen from Table 3 that compared with Example 1, the paint film prepared in Comparative Example 2 is inferior in adhesion, impact, flexibility and water resistance.

[0084] Comparative Example 3:

[0085] The components and weight contents of acrylic modified epoxy paint in this comparative example 3 are as follows:

[0086] Acrylic modified epoxy emulsion YT-3230 60%;

[0087] Amino resin 5717 6%;

[0088] Water-based blocked isocyanate HL-W2100D 4%;

[0089] Catalyst X49-110 0.3%;

[0090] Dispersant 5040 4%;

[0091] Defoamer BYK-024 0.2%;

[0092] Wetting and leveling agent BYK-333 0.2%;

[0093] Thickener RM-8W 0.2%;

[0094] Ethylene glycol monobutyl ether 4%;

[0095] Dipropylene glycol butyl ether 0%;

[0096] The rest was deionized water.

[0097] This embodiment also provides a method for preparing acrylic acid modified epoxy paint, which specifically comprises the following steps:

[0098] (1) Pour deionized water into the tank;

[0099] (2) Add dispersant and defoamer and stir at low speed for 20 minutes;

[0100] (3) Add the above slurry into an acrylic modified epoxy emulsion YT-3230 emulsion tank and stir at medium speed for 30 minutes;

[0101] (4) adding water-based amino resin, water-based blocked isocyanate, and catalyst, and stirring at medium speed for 20 minutes;

[0102] (5) adding a wetting and leveling agent, ethylene glycol monobutyl ether, dipropylene glycol butyl ether, deionized water, and a thickener, and stirring at a medium speed for 30 minutes to obtain an acrylic modified epoxy paint;

[0103] In the above steps (1) to (5), the low-speed stirring is 200-300 rpm, the medium-speed stirring is 300-500 rpm, and the high-speed stirring is 500-700 rpm.

[0104] The prepared acrylic modified epoxy paint was coated on the surface of the reflector and cured at 60° C. to obtain a paint film.

[0105] The test results of the paint film performance of this comparative example 3 are shown in Table 4 below.

[0106] Table 4 Paint film performance test results Test items Technical indicators Test results

[0107]

[0108] It can be seen from Table 4 that, compared with Example 1, the paint film prepared in Comparative Example 3 has a film-forming aid that dries faster, a poor appearance, and many particles.

[0109] Comparative Example 4:

[0110] The acrylic modified epoxy paint components and weight contents of this comparative example 4 are as follows:

[0111]

[0112] The rest was deionized water.

[0113] (1) Pour some deionized water into the tank;

[0114] (2) Add dispersant and defoamer and stir at low speed for 20 minutes;

[0115] (3) Add the above slurry into an acrylic modified epoxy emulsion YT-323 emulsion tank and stir at medium speed for 30 minutes;

[0116] (4) adding water-based amino resin, water-based blocked isocyanate, and catalyst, and stirring at medium speed for 20 minutes;

[0117] (5) Add a wetting and leveling agent, ethylene glycol monobutyl ether, dipropylene glycol butyl ether, the remaining deionized water, and a thickener, and stir at a medium speed for 30 minutes to obtain an acrylic modified epoxy paint.

[0118] In the above steps (1) to (5), the low-speed stirring is 200-300 rpm, the medium-speed stirring is 300-500 rpm, and the high-speed stirring is 500-700 rpm.

[0119] The prepared acrylic modified epoxy paint was coated on the surface of the reflector and cured at 60° C. to obtain a paint film.

[0120] The test results of the paint film performance of this comparative example 4 are shown in Table 5 below.

[0121] Table 5 Paint film performance test results

[0122] Test items Technical indicators Test results Hundred Grid Attachment ≤1 level Level 0 Impact resistance 1Kg / 50cm OK Flexibility ≤2mm OK Water resistant 40℃*7 days OK Salt spray resistant 120 hours OK Interlayer Adhesion ≤1 level Level 0

[0123] It can be seen from Table 5 that compared with Example 1, the paint film prepared in Comparative Example 4 has a slower drying of the film-forming aid and severe sagging of the paint film.

[0124] Embodiment 2:

[0125] Compared with Example 1, most of them are the same, the only difference is that the formula of the water-based polyurethane paint in this example is adjusted to:

[0126] 55 parts of water-based polymer epoxy emulsion, 8 parts of water-based amino resin, 2 parts of water-based blocked isocyanate, 0.2 parts of water-based catalyst, 2 parts of dispersant, 0.2 parts of defoamer, 0.2 parts of wetting and leveling agent, 0.2 parts of thickener, 2 parts of film-forming aid, and 32.2 parts of deionized water.

[0127] Embodiment 3:

[0128] Compared with Example 1, most of them are the same, the only difference is that the formula of the water-based polyurethane paint in this example is adjusted to:

[0129] 60 parts of water-based polymer epoxy emulsion, 6 parts of water-based amino resin, 4 parts of water-based blocked isocyanate, 0.3 parts of water-based catalyst, 4 parts of dispersant, 0.2 parts of defoamer, 0.2 parts of wetting and leveling agent, 0.2 parts of thickener, 4 parts of film-forming aid, and 21.1 parts of deionized water.

[0130] Embodiment 4:

[0131] Compared with Example 1, most of them are the same, the only difference is that the formula of the water-based polyurethane paint in this example is adjusted to:

[0132] 50 parts of water-based polymer epoxy emulsion, 7 parts of water-based amino resin, 3 parts of water-based blocked isocyanate, 0.2 parts of water-based catalyst, 2 parts of dispersant, 0.3 parts of defoamer, 0.3 parts of wetting and leveling agent, 0.3 parts of thickener, 6 parts of film-forming aid, and 30.9 parts of deionized water.

[0133] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A water-based polyurethane paint for waterproof and anti-fouling of reflector surface, characterized in that: The raw material components include the following parts by weight: 50-60 parts of water-based polymer polyurethane emulsion, 4-10 parts of water-based amino resin, 2-7 parts of water-based blocked isocyanate, 0.1-0.3 parts of water-based catalyst, 1-4 parts of dispersant, 0.2-0.5 parts of defoaming agent, 0.2-0.5 parts of wetting and leveling agent, 0.1-2 parts of thickener, 2-6 parts of film-forming aid, and 20-38 parts of deionized water.

2. The waterborne polyurethane paint according to claim 1, characterized in that: The solid content of the aqueous high molecular weight polyurethane emulsion is 30-45%.

3. The waterborne polyurethane paint according to claim 1, characterized in that: The water-based amino resin is a trimethyl etherified amino resin.

4. The waterborne polyurethane paint according to claim 1, characterized in that: The water-based blocked isocyanate is a water-based special blocked HDI curing agent.

5. The waterborne polyurethane paint according to claim 1, characterized in that: The aqueous catalyst is an aqueous acid drier.

6. The waterborne polyurethane paint according to claim 1, characterized in that: The dispersant is 5040; the defoamer is BYK-024; the wetting and leveling agent is BYK-333; and the thickener is RM-8W.

7. The waterborne polyurethane paint according to claim 1, characterized in that: The film-forming aid is composed of ethylene glycol monobutyl ether and dipropylene glycol butyl ether in a mass ratio of 1:0.3-1.

5.

8. A method for preparing a waterborne polyurethane paint as claimed in any one of claims 1 to 7, characterized in that: The steps include: First, pour some deionized water into a container, then add dispersant and defoamer in turn, stir evenly, then add water-based polymer polyurethane emulsion and stir, then add water-based amino resin, water-based blocked isocyanate, catalyst, wetting and leveling agent, film-forming aid and thickener, and add the remaining deionized water, stir and mix, and then you are done to get water-based polyurethane paint.

9. Use of the waterborne polyurethane paint according to any one of claims 1 to 7, characterized in that: The water-based polyurethane paint is used to be coated on the surface of the reflector glass composite material and forms a paint film after being cured.

10. The use according to claim 9, characterized in that: The curing temperature is 60-80°C.

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