Water-based anti-decoloration coating and preparation method thereof

Abstract

The invention discloses a water-based anti-decoloration coating and a preparation method thereof, the water-based anti-decoloration coating comprises a main agent and a curing agent, and the main agent comprises the following components in percentage by weight: # imgabs0 #;

Description

Technical Field

[0001] The 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 has a large transportation volume and is usually suitable for long-distance transportation of large quantities of goods. Whether it is freight transported by ship or by train, containers are usually used.

[0003] The inside of the container is the space for transporting goods. Through the coating process, the paint film on the inside of the container is required to have not only good hardness, but also strong mechanical wear resistance, and the ability to withstand the collision and friction of forklifts when loading and unloading goods, and have certain corrosion resistance and chemical medium resistance. These are the basic properties that container coatings must have. If food and medicine are to be transported in the container, the inside paint is required to be non-toxic and tasteless. Especially in the United States, only by passing the regulations of the Food and Drug Administration and obtaining relevant certificates of approval can containers be used to transport food and medicine. Some containers also require "white stripping" tests.

[0004] Container coatings are more concerned about corrosion resistance and water resistance. When choosing pigments and fillers, they generally choose conventional talcum powder, calcium carbonate, barite powder, feldspar powder and other natural mineral powders with certain anti-rust properties, while ignoring other functionalities. For solvent-based coatings, since the surface tension of the paint is usually smaller than the surface tension of the pigment, the pigment is easy to soak and generally does not have a discoloration problem. For water-based coatings, since the surface tension of water is generally greater than that of organic pigments, although the wetting and dispersion stability of the pigment can be promoted by adding dispersants or surfactants, the discoloration / fading phenomenon of water-based coatings has become a major problem that plagues the development of the industry.

[0005] At present, there are two solutions to solve the technical problems of paint discoloration and fading in 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 will not only greatly increase the cost of the coating, but also has the problem that the anti-discoloration effect is not obvious. Summary of the invention

[0009] To solve the problem of discoloration / fading of the waterborne interior paint for containers, in the waterborne formulation system of the present invention, by introducing a certain amount of inorganic substances and / or organic substances with a flaky structure (such as mica powder, glass powder, etc.), a compact structure with layers stacked on top of each other is formed in the coating, firmly locking the pigments inside the paint and preventing them from floating to the surface of the coating during the drying process.

[0010] Compared with the prior art, in addition to having anti-corrosion performance and water resistance, the paint of the present invention also has a certain degree of shielding property and coating denseness, making the internal structure of the paint more compact, the pigments not easily falling off, and the anti-discoloration effect being remarkable.

[0011] One advantage of the present invention is to provide a waterborne anti-discoloration paint and a preparation method thereof, wherein the waterborne anti-discoloration paint can effectively fill the pigments inside the paint, thereby effectively preventing the paint from discoloring.

[0012] Another advantage of the present invention is to provide a waterborne anti-discoloration paint and a preparation method thereof, wherein the waterborne anti-discoloration paint only needs to simply adjust the formulation of the traditional paint, so that the waterborne anti-discoloration paint can be applicable to the improvement of the traditional paint.

[0013] Another advantage of the present invention is to provide a waterborne anti-discoloration paint and a preparation method thereof, wherein the waterborne anti-discoloration paint has a low production cost and a simple production process.

[0014] To achieve at least one of the above advantages, the present invention provides a waterborne anti-discoloration paint, wherein the waterborne anti-discoloration paint comprises:

[0015] A main agent and a curing agent, wherein the main agent comprises the following components in weight percentage:

[0016]

[0017] According to an embodiment of the present invention, the flaky color fixative comprises inorganic substances and organic substances with a flaky structure.

[0018] According to an embodiment of the present invention, the flaky color fixative comprises mica powder and / or glass powder with a flaky structure.

[0019] To achieve at least one of the above advantages, the present invention provides a preparation method of a waterborne anti-discoloration paint, wherein the preparation method of the waterborne anti-discoloration paint comprises the following steps:

[0020] S1001, adding raw materials such as resin emulsion, deionized water, and additives into a batching tank according to a proportion, using a disperser to stir at a rotation speed of 500 revolutions per minute for 8 - 20 minutes to make them fully mixed and dispersed;

[0021] S1002, while stirring, gradually add the pigment and the flaky curing agent into the above-mentioned mixed solution, and use a disperser to mix them evenly at a rotation speed of 3000 revolutions per minute, stir for 5 to 20 minutes, and mix evenly.

[0022] According to an embodiment of the present invention, the preparation method of the water-based anti-decoloring coating includes the following steps:

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

[0024] According to an embodiment of the present invention, the preparation method of the water-based anti-decoloring coating includes the following steps:

[0025] S1004, remove impurities and particles from the mixed coating through a filtering device, and then carry out packaging and sealing.

[0026] According to an embodiment of the present invention, the weight percentage ratio of the main agent to the curing agent is 10:1 to 2:1. Description of the Drawings

[0027] Figure 1 Shows a schematic diagram of the grooved plates of Comparative Example 1 and Example 1 after being dragged 4 times.

[0028] Figure 2 Shows a schematic diagram of the grooved plates of Comparative Example 1 and Example 1 after being dragged 20 times. Detailed Description of the Invention

[0029] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description of the present invention can be applied to other embodiments, variations, improvements, equivalent solutions, and other technical solutions that do not depart from the spirit and scope of the present invention.

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

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

[0032]

[0033] Preferably, the weight percentage ratio of the main agent to the curing agent is 10:1 to 2:1, and more preferably, the weight percentage ratio of the main agent to the curing agent is 8:1. The curing agent is implemented as an amine curing agent.

[0034] It is worth mentioning that after adding the sheet-like color fixative, such as sheet-like mica powder, to the main agent, the coating formed by the coating material can form a compact structure with layers stacked on top of each other, and the pigments are filled in each layer, so that the pigment molecules are subjected to greater molecular forces, and the pigments in the coating are not easily floated to the surface of the coating. During the subsequent transportation of goods, it can effectively prevent the decolorization of the coating material from causing pollution or affecting the aesthetics of the goods.

[0035] Preferably, the main agent comprises the following components in weight percentage: 0.2-0.8% of an auxiliary agent. Those skilled in the art can understand that the added auxiliary agent can contribute to the formation of the layered structure of the coating material.

[0036] There are many types of the water-based coating auxiliary agents. In the present invention, it mainly includes at least one of the following: wetting agent, leveling agent, dispersant, thickening agent, film-forming auxiliary agent, defoaming agent, pH regulator or corrosion inhibitor.

[0037] It is worth mentioning that the wetting agent can be used for the wetting and penetration of the coating material on the base surface. The leveling agent can improve the ability of the coating material to be evenly distributed on the base surface. The dispersant can disperse fine-grained substances in the medium and stably suspend them. The thickening agent can increase the consistency of the coating material to obtain a better brushing effect. The film-forming auxiliary agent can assist in the formation of the paint film. The defoaming agent can eliminate the bubbles in the coating material and inhibit the generation of bubbles. The pH regulator can adjust the pH value of the coating material. The corrosion inhibitor can inhibit metal corrosion.

[0038] The pigment is an inorganic pigment and / or an organic pigment. The inorganic pigment can be selected from at least one of various metal oxides (such as iron oxide red, iron oxide yellow, etc.), chromates, carbonates, sulfates, sulfides, aluminum powder, copper powder, carbon black, zinc white, and titanium white. The organic pigment includes 59% azo pigment, 24% phthalocyanine pigment, 8% triarylmethane pigment, 6% special pigment, and 3% polycyclic pigment. Organic pigments are brightly colored and have strong coloring power; they are non-toxic, but the light resistance, heat resistance, solvent resistance, and migration resistance of some varieties are often not as good as those of inorganic pigments.

[0039] Preferably, the sheet-like functional filler includes sheet-like structured inorganic substances and organic substances. More preferably, the sheet-like functional filler includes mica powder and / or glass powder with a sheet-like structure.

[0040] It is worth mentioning that due to the addition of the sheet-like color fixative, the water retention of the final water-based anti-decolorization coating will be improved, thereby extending the subsequent drying time of the water-based anti-decolorization coating to a certain extent.

[0041] Therefore, preferably, the ratio between the curing agent and the flaky color fixative is: (1:4) to (9:2). In this way, the water-based anti-discoloration coating is not easily discolored, and at the same time, the curing agent can fully crosslink with the main agent, so that less time is required during the subsequent drying process.

[0042] The resin emulsion can be implemented as at least one of an acrylic emulsion, a polyurethane emulsion, and an epoxy emulsion.

[0043] According to another aspect of the present invention, 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 includes the following steps:

[0044] S1001, adding raw materials such as a resin emulsion, deionized water, and an auxiliary agent into a batching tank, and using a disperser to stir at a rotation speed of 500 revolutions per minute for 8 to 20 minutes to fully mix and disperse them;

[0045] S1002, gradually adding a pigment and a flaky color fixative into the above-mentioned mixed solution under stirring, and using a disperser to uniformly mix at a rotation speed of 3000 revolutions per minute for 5 to 20 minutes to mix evenly;

[0046] S1003, adding an auxiliary agent to adjust the viscosity and pH value;

[0047] S1004, filtering the mixed coating through a filtering device to remove impurities and particles, and then performing packaging and sealing.

[0048] Example 1

[0049] The water-based anti-discoloration coating includes:

[0050] A main agent and a curing agent, and the main agent includes the following components in weight percentages:

[0051]

[0052]

[0053] Among them, the weight percentage ratio of the main agent to the curing agent is 8:1.

[0054] Example 2

[0055] The water-based anti-discoloration coating includes:

[0056] A main agent and a curing agent, and the main agent includes the following components in weight percentages:

[0057]

[0058] Among them, the weight percentage ratio of the main agent to the curing agent is 2:1.

[0059] Example 3

[0060] The water-based anti-discoloration coating includes:

[0061] A main agent and a curing agent, and the main agent includes the following components by weight percentage:

[0062]

[0063]

[0064] Among them, the weight percentage ratio of the main agent to the curing agent is 10:1.

[0065] Comparative Example 1

[0066] The water-based coating includes:

[0067] A main agent and a curing agent, and the main agent includes the following components by weight percentage:

[0068]

[0069] Among them, the weight percentage ratio of the main agent to the curing agent is 8:1.

[0070] Comparative Example 2

[0071] The water-based coating includes:

[0072] A main agent and a curing agent, and the main agent includes the following components by weight percentage:

[0073]

[0074] Among them, the weight percentage ratio of the main agent to the curing agent is 1:1.

[0075] Comparative Example 3

[0076] The water-based coating includes:

[0077] A main agent and a curing agent, and the main agent includes the following components by weight percentage:

[0078]

[0079] Among them, the weight percentage ratio of the main agent to the curing agent is 10:1.

[0080] The water-based topcoats prepared in the above examples were detected by relevant national standard methods, and the results are as follows:

[0081] Table 1 Performance Detection of Water-based Container Coatings

[0082]

[0083] Table 2 Performance Testing of the Waterborne Container Coating Matching System

[0084]

[0085]

[0086] The materials prepared in the examples and comparative examples were subjected to a decolorization performance test. The test method is as follows:

[0087] The materials prepared in Example 1 and Comparative Example 1 were coated on a groove plate (1 meter in length). A 40*20*5 mm powerful magnet was used, with a 4A white paper placed underneath. It was dragged on the coating surface at a speed of 0.2 m / s in a straight line for 4 laps and 20 laps (the test straight line length is 0.5 meters). After the test, the A4 white paper was turned over to check the color pollution condition on the back, as Figure 1 、 Figure 2 shown, where Figure 1 and Figure 2 On the left is a schematic diagram of the coating made in Comparative Example 1 sprayed on the groove plate and after dragging, while on the right is a schematic diagram of the coating made in Example 1 sprayed on the groove plate and after dragging. The results are shown in the following table:

[0088]

[0089] The materials prepared in the examples and comparative examples were tested. The test method is as follows,

[0090]

[0091] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the drawings are only examples and do not limit the present invention. The advantages of the present invention have been fully and effectively realized. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the said principles, the embodiments of the present invention can have any deformation or modification.

Claims

1. An aqueous anti-discoloration coating, characterized in that, The water-based anti-discoloration coating includes: A main agent and a curing agent, wherein the main agent includes the following components in weight percentages: Resin emulsion 35 - 50; Dispersant 0.1 - 1.0%; Pigment 8 - 20; Flaky color fixative 20 - 45; Deionized water 9 - 10.

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

3. The water-based anti-discoloration paint according to claim 1, wherein 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, wherein The weight percentage ratio of the main agent to the curing agent is 10:1 - 2:

1.

5. The preparation method of the water-based anti-discoloration coating according to claim 1, characterized in that, The ratio between the curing agent and the flaky color fixative is: (1:4) - (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 - 20 minutes to fully mix and disperse them; S1002, Under the stirring state, gradually add the pigment and the flaky curing agent into the above-mentioned mixture, and use a disperser to mix evenly at a speed of 3000 revolutions per minute for 5 - 20 minutes to mix evenly.

7. The preparation method of the water-based anti-discoloration coating according to claim 6, wherein, 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, wherein, 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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