Waterborne fade-resistant coating and preparation method

Abstract

The present application discloses a waterborne fade-resistant coating and a preparation method therefor. The waterborne fade-resistant coating comprises: a main agent and a curing agent, wherein the main agent comprises the following components in percentage by weight: 35-50% of a resin emulsion, 0.1-1.0% of a dispersing agent, 8-20% of a pigment, 20-45% of a flaky color-fixing agent, and 9-10% of deionized water.

Description

Water-based anti-discoloration coating and preparation method Technical Field

[0001] The present invention relates to a coating, in particular to a water-based anti-discoloration coating and a preparation method thereof. Background Art

[0002] Freight is a traditional mode of transportation. Although it takes a long time to transport goods, it can transport large quantities of goods and is usually suitable for long-distance transportation. Whether it is transported by ship or by train, containers are usually used.

[0003] The inside of a container is where cargo is carried. Through the coating process, the paint film on the inside of the container must not only have good hardness and strong resistance to mechanical wear and tear, able to withstand the collisions and friction of forklifts loading and unloading cargo, but also have certain corrosion resistance and chemical resistance, which are the basic properties required of container coatings. If the container is to carry food and medicine, the inside paint must be non-toxic and odorless. In the United States, in particular, containers can only be used to transport food and medicine after passing regulations and obtaining relevant approvals from the U.S. Food and Drug Administration. Some containers also require "whitening" testing.

[0004] Container coatings prioritize corrosion resistance and water resistance. When selecting pigments and fillers, conventional natural mineral powders with some rust-resistant properties, such as talc, calcium carbonate, barite, and feldspar, are often chosen, while other functional properties are neglected. For solvent-based coatings, the surface tension of the paint is generally lower than that of the pigment, allowing for easy wetting of the pigment and generally preventing discoloration. However, for water-based coatings, the surface tension of water is generally higher than that of organic pigments. While dispersants or surfactants can be added to enhance pigment wetting and dispersion stability, discoloration remains a major challenge plaguing the industry.

[0005] Currently, there are two solutions to solve the technical problems of paint discoloration and fading inside containers:

[0006] Reduce the pigment-to-base ratio (PVC) of the coating and increase the resin content of the coating to ensure that the resin has a good encapsulation of the pigment and filler particles;

[0007] Wax-containing additives are added to improve the slipperiness of the coating surface and reduce the surface tension of the coating, thereby reducing the probability of pigment particles falling off during friction.

[0008] However, the above solution not only greatly increases the cost of the coating, but also has the problem that the anti-discoloration effect is not obvious.

[0009] Summary of the Invention

[0010] To address the discoloration / fading problem of water-based interior container topcoats, the present invention introduces a certain amount of flaky inorganic and / or organic substances (such as mica powder, glass powder, etc.) into the water-based formulation system, so that the coating forms a compact layered structure, firmly locking the pigment inside the coating to prevent it from floating to the coating surface during the drying process.

[0011] Compared with the prior art, the coating of the present invention not only has anti-corrosion performance and water resistance, but also has certain shielding properties and coating density, making the internal structure of the coating more compact, the pigment is not easy to fall off, and the anti-discoloration effect is significant.

[0012] An advantage of the present invention is to provide a water-based anti-fading coating and a preparation method thereof, wherein the water-based anti-fading coating can effectively fill the pigment inside the coating, thereby effectively preventing the coating from fading.

[0013] Another advantage of the present invention is to provide a water-based anti-fading coating and a preparation method thereof, wherein the water-based anti-fading coating only needs to simply adjust the formula of traditional coatings, so that the water-based anti-fading coating can be applied to the improvement of traditional coatings.

[0014] Another advantage of the present invention is to provide a water-based anti-fading coating and a preparation method thereof, wherein the water-based anti-fading coating has low production cost and simple production process.

[0015] To achieve at least one of the above advantages, the present invention provides a water-based anti-fading coating, wherein the water-based anti-fading coating comprises:

[0016] A main agent and a curing agent, wherein the main agent includes the following components in % by weight:

[0017] According to an embodiment of the present invention, the flaky color fixing agent includes flaky inorganic matter and organic matter.

[0018] According to one embodiment of the present invention, the flaky color fixing agent includes mica powder and / or glass powder in a flaky structure.

[0019] To achieve at least one of the above advantages, the present invention provides a method for preparing a water-based anti-discoloration coating, wherein the method for preparing the water-based anti-discoloration coating comprises the following steps:

[0020] S1001, adding resin emulsion, deionized water, additives and other raw materials into a mixing tank in proportion, using a disperser to stir at 500 rpm for 8 to 20 minutes to fully mix and disperse;

[0021] S1002, while stirring, gradually add the pigment and the flake curing agent into the above mixed solution, and use a disperser to mix them evenly at a speed of 3000 rpm for 5 to 20 minutes to mix them evenly.

[0022] According to one embodiment of the present invention, the preparation method of the water-based anti-discoloration coating comprises the following steps:

[0023] S1003, adjust the performance, add additives to adjust the viscosity and pH value to achieve the required performance indicators.

[0024] According to one embodiment of the present invention, the preparation method of the water-based anti-discoloration coating comprises the following steps:

[0025] S1004, the mixed paint is passed through a filtering device to remove impurities and particles, and then packaged and sealed.

[0026] According to one embodiment of the present invention, the weight % ratio of the main agent to the curing agent is 10:1 to 2:1. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 shows a schematic diagram of the groove plates of Comparative Example 1 and Example 1 after being dragged for 4 circles.

[0028] FIG2 shows a schematic diagram of the groove plates of Comparative Example 1 and Example 1 after being dragged 20 times. DETAILED DESCRIPTION

[0029] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0030] A water-based anti-discoloration coating according to a preferred embodiment of the present invention will be described in detail below, wherein the water-based anti-discoloration coating comprises:

[0031] A main agent and a curing agent, wherein the main agent includes the following components in % by weight:

[0032] Preferably, the weight % ratio of the main agent to the curing agent is 10:1 to 2:1, and more preferably, the weight % ratio of the main agent to the curing agent is 8:1. The curing agent is implemented as an amine curing agent.

[0033] It is worth mentioning that after adding the flaky color fixing agent, such as flaky mica powder, to the main agent, the coating formed by the paint can form a compact structure with layers stacked on top of each other, and the pigment is filled in each layer, so that the pigment molecules are subjected to greater molecular forces, and the pigment in the coating is not easy to float to the surface of the coating. In the subsequent transportation of goods, the paint can be effectively prevented from discoloring and causing contamination of the goods or affecting the appearance.

[0034] Preferably, the main agent includes the following components in weight %: 0.2-0.8 wt. % of auxiliary agent. It will be understood by those skilled in the art that the added auxiliary agent can help to form the layered structure of the coating.

[0035] There are many types of water-based coating additives, and the present invention mainly includes at least one of the following wetting agents, leveling agents, dispersants, thickeners, film-forming agents, defoaming agents, pH regulators or corrosion inhibitors.

[0036] It is worth mentioning that wetting agents can help the paint wet and penetrate the substrate. Leveling agents can improve the paint's ability to evenly distribute on the substrate. Dispersants can disperse fine particles in the medium and stabilize their suspension. Thickeners can increase the consistency of the paint to achieve better brushing effect. Film-forming agents can assist in paint film formation. Defoamers can eliminate bubbles in the paint and inhibit their formation. pH adjusters can adjust the pH value of the paint. Corrosion inhibitors can inhibit metal corrosion.

[0037] The pigments are inorganic and / or organic. Inorganic pigments can be selected from at least one of various metal oxides (red iron oxide, yellow iron oxide, etc.), chromates, carbonates, sulfates, sulfides, aluminum powder, copper powder, carbon black, zinc white, and titanium white. Organic pigments include azo pigments (59%), phthalocyanine pigments (24%), triarylmethane pigments (8%), special pigments (6%), and polycyclic pigments (3%). Organic pigments offer vibrant colors, strong tinting power, and are non-toxic, but some varieties often lack the light, heat, solvent, and migration resistance of inorganic pigments.

[0038] Preferably, the flaky functional filler comprises flaky inorganic and organic substances. More preferably, the flaky functional filler comprises flaky mica powder and / or glass powder.

[0039] It is worth mentioning that the addition of the flaky color fixing agent will improve the water retention of the final water-based anti-fading coating, thereby prolonging the subsequent drying time of the water-based anti-fading coating to a certain extent.

[0040] Therefore, preferably, the ratio of the curing agent to the flaky color fixing agent is (1:4) to (9:2). This not only makes the water-based anti-fading coating less prone to fading, but also allows the curing agent to fully cross-link with the main agent, thereby reducing the time required for the subsequent drying process.

[0041] The resin emulsion may be implemented as at least one of acrylic emulsion, polyurethane emulsion, and epoxy emulsion.

[0042] According to another aspect of the present invention, the present invention provides a method for preparing a water-based anti-decolorization coating, wherein the method for preparing the water-based anti-decolorization coating comprises the following steps:

[0043] S1001, adding resin emulsion, deionized water, additives and other raw materials into a mixing tank, using a disperser to stir at 500 rpm for 8 to 20 minutes to fully mix and disperse;

[0044] S1002, while stirring, gradually add the pigment and flake fixing agent to the above mixed solution, and use a disperser to mix evenly at 3000 rpm for 5 to 20 minutes to mix evenly;

[0045] S1003, adding additives to adjust viscosity and pH value;

[0046] S1004, the mixed paint is filtered through a filtering device to remove impurities and particles, and then packaged and sealed.

[0047] Example 1

[0048] The water-based anti-discoloration coating comprises:

[0049] A main agent and a curing agent, wherein the main agent comprises the following components in % by weight:

[0050] The weight percent ratio of the main agent to the curing agent is 8:1.

[0051] Example 2

[0052] The water-based anti-discoloration coating comprises:

[0053] A main agent and a curing agent, wherein the main agent comprises the following components in % by weight:

[0054] The weight percent ratio of the main agent to the curing agent is 2:1.

[0055] Example 3

[0056] The water-based anti-discoloration coating comprises:

[0057] A main agent and a curing agent, wherein the main agent comprises the following components in % by weight:

[0058] Wherein, the weight % ratio of the main agent to the curing agent is 10:1.

[0059] Comparative Example 1

[0060] The water-based paint comprises:

[0061] A main agent and a curing agent, wherein the main agent comprises the following components in % by weight:

[0062] The weight percent ratio of the main agent to the curing agent is 8:1.

[0063] Comparative Example 2

[0064] The water-based paint comprises:

[0065] A main agent and a curing agent, wherein the main agent comprises the following components in % by weight:

[0066] Wherein, the weight % ratio of the main agent to the curing agent is 1:1.

[0067] Comparative Example 3

[0068] The water-based paint comprises:

[0069] A main agent and a curing agent, wherein the main agent comprises the following components in % by weight:

[0070] Wherein, the weight % ratio of the main agent to the curing agent is 10:1.

[0071] The water-based topcoats prepared in the above embodiments were tested using relevant national standard methods, and the results are as follows:

[0072] Table 1 Performance test of waterborne container coatings

[0073] Table 2 Performance test of waterborne container coating supporting system

[0074] The materials prepared in the examples and comparative examples were tested for decolorization performance. The test method was as follows:

[0075] The materials prepared in Example 1 and Comparative Example 1 were coated on a grooved plate (1 meter in length). A 40*20*5mm strong magnet was used, with 4A white paper placed underneath. The magnet was dragged across the coating surface at a speed of 0.2m / s, along the same straight line, for 4 or 20 rounds (the test straight line length was 0.5 meters). After the test, the A4 white paper was turned over to check the color contamination on the back, as shown in Figures 1 and 2. The left side of Figures 1 and 2 shows the coating prepared in Comparative Example 1 being sprayed on the grooved plate and dragged, while the right side shows the coating prepared in Example 1 being sprayed on the grooved plate and dragged. The results are shown in the following table:

[0076] The materials prepared in the examples and comparative examples were tested using the following test methods:

[0077] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended to be illustrative only and are not intended to limit the present invention. The advantages of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

Claims

1. An aqueous anti-discoloration coating, characterized in that, Among them, the water-based anti-discoloration coating includes: The main agent and the curing agent, wherein the main agent comprises the following components in weight percentages:

2. The water-based anti-discoloration coating according to claim 1, wherein The flaky color fixative includes an inorganic substance and an organic substance with a flaky structure.

3. The water-based anti-discoloration coating according to claim 1, characterized in that, The flaky color fixative includes mica powder and / or glass powder with a flaky structure.

4. The preparation method of the water-based anti-discoloration coating according to claim 1, characterized in that, The weight percentage ratio of the main agent to the curing agent is 10:1 to 2:

1.

5. The preparation method of the aqueous anti-discoloration coating according to claim 1, characterized in that, The ratio between the curing agent and the flaky color fixative is: (1:4) to (9:2).

6. A preparation method of an aqueous anti-discoloration coating, characterized in that, The preparation method of the water-based anti-discoloration coating includes the following steps: S1001, Add raw materials such as resin emulsion, deionized water, and additives into the batching tank according to the proportion, and use a disperser to stir at a speed of 500 revolutions per minute for 8 to 20 minutes to make them fully mixed and dispersed; S1002, Under the stirring state, gradually add the pigment and the flaky curing agent to the above-mentioned mixed solution, and use a disperser to mix evenly at a speed of 3000 revolutions per minute for 5 to 20 minutes to mix evenly.

7. The preparation method of the aqueous anti-discoloration coating according to claim 6, characterized in that, The preparation method of the water-based anti-discoloration coating includes the following steps: S1003, Adjust the performance, add additives to adjust the viscosity and pH value to meet the required performance indicators.

8. The preparation method of the water-based anti-discoloration coating according to claim 6, characterized in that, The preparation method of the water-based anti-discoloration coating includes the following steps: S1004, Remove impurities and particles from the mixed coating through a filtering device, and then carry out packaging and sealing.

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