A solid powder leveling agent and its preparation method

Abstract

The present invention belongs to the field of leveling agents, and particularly relates to a solid powder leveling agent and a preparation method thereof. The method includes: 1) Using aluminum silicate and / or alumina as an inorganic carrier, dispersing it in water, adding an organic acid, and stirring and adjusting to form a uniformly dispersed white turbid liquid; 2) Adding methyl acrylate, alkylamine, amino-modified polysiloxane, and an alkaline regulator to the white turbid liquid, stirring until it becomes a light yellow or light green or light yellowish-green turbid liquid, then filtering, washing, and drying to obtain the solid powder leveling agent. By surface-treating a special inorganic carrier, the present invention constitutes a leveling agent with good leveling effect, which can avoid the two major performance defects of shrinkage holes and orange peel in existing leveling agents, and has strong universality and can be applied to most existing organic coatings.

Description

Technical Field

[0001] The present invention belongs to the field of leveling agents, and particularly relates to a solid powder leveling agent and a preparation method thereof. Background Art

[0002] A leveling agent is a commonly used coating additive that can promote the formation of a flat, smooth, and uniform coating film during the drying and film-forming process of the coating. It is a kind of substance that can effectively reduce the surface tension of the coating liquid and improve its leveling property and uniformity.

[0003] At present, most leveling agents are divided into solvent-based and solid types. One type of solvent-based leveling agent acts by adjusting the viscosity and leveling time of the paint film, while the second type acts by adjusting the surface properties of the paint film. The second type of solvent leveling agent makes the paint film obtain good leveling by affecting surface properties such as the interfacial tension of the paint film, which is also a common type of leveling agent. However, solvent-based leveling agents are prone to surface shrinkage pores during actual use, especially when the surface conditions of the coating surface are poor and the cleanliness is low, and are greatly affected by the temperature. When the temperature is too low, the shrinkage pore phenomenon is likely to be aggravated. In addition, the storage ability of solvent leveling agents is also not as good as that of solid-type leveling agents.

[0004] In response to this, more and more solid powder leveling agents have been developed. Most common solid powder leveling agents use metal salts or similar metal compounds and inorganic silicon as particle carriers, and after surface modification, they have limited compatibility with the coating, thereby migrating to the surface of the paint film to achieve the effect of promoting leveling. However, for the current solid leveling agents, although they can effectively resist shrinkage pores, the actual leveling effect is not as good as that of liquid leveling agents, and orange peel is likely to occur, and the actual use effect is also relatively limited. Summary of the Invention

[0005] In order to solve the problems that most existing solid-state leveling agents have poor leveling effects, are prone to orange peel, etc. due to powder agglomeration effects and limited migration effects, the present invention provides a solid powder leveling agent and a preparation method thereof.

[0006] The purpose of the present invention is as follows:

[0007] First, it can ensure that the solid powder leveling agent has excellent leveling effects;

[0008] Second, it can effectively avoid the generation of orange peel;

[0009] Third, it can optimize the mechanical properties of the coating to a certain extent.

[0010] To achieve the above object, the present invention adopts the following technical solutions.

[0011] A preparation method of a solid powder leveling agent

[0012] The method includes:

[0013] 1) Using aluminum silicate and / or alumina as the inorganic carrier, dispersing it in water, adding organic acid, and stirring to adjust it to form a uniformly dispersed white turbid liquid;

[0014] 2) Adding methyl acrylate, alkylamine, amino-modified polysiloxane, and basic regulator to the white turbid liquid, stirring until it becomes a light yellow or light green or light yellowish-green turbid liquid, then filtering, washing, and drying to obtain the solid powder leveling agent.

[0015] Preferably,

[0016] The mesh numbers of the aluminum silicate and alumina in step 1) are both ≥1500 meshes;

[0017] The mass ratio of the amounts of the aluminum silicate and alumina used is 1:(8 - 11).

[0018] Preferably,

[0019] The organic acid in step 1) is formic acid solution, and the formic acid solution adjusts the pH value of the solution system to 4.0 - 5.0.

[0020] Preferably,

[0021] The alkylamine in step 2) is n-propylamine and / or n-butylamine and / or n-pentylamine;

[0022] The amino-modified polysiloxane in step 2) is bis(3-aminopropyl) terminated polydimethylsiloxane.

[0023] The above-mentioned bis(3-aminopropyl) terminated polydimethylsiloxane is also called polydimethylsiloxane, bis(3-aminopropyl) terminated.

[0024] Preferably,

[0025] The molar ratio of the amounts of methyl acrylate, alkylamine, and amino-modified polysiloxane used is 1:(0.2 - 0.4):(0.08 - 0.12);

[0026] The total amount of methyl acrylate, alkylamine, and amino-modified polysiloxane used is 60 - 90 g / L of the white turbid liquid.

[0027] Preferably,

[0028] The basic regulator in step 2) is calcium oxide;

[0029] The amount of calcium oxide used is 30 - 50 g / L of the white turbid liquid.

[0030] Preferably,

[0031] Step 2) The stirring lasts for at least 15 min, and after the stirring is completed, it is left standing for at least 15 min until the conversion is completed and then filtered.

[0032] A solid powder leveling agent.

[0033] The present invention is different from conventional solid leveling agents. It uses all-organic material particles and dissolves in the coating in a dissolved manner to release organic components and / or ionic components to control the leveling process. It is also different from the existing few inorganic particle carriers that control the surface tension through suspension and other methods to control the leveling process.

[0034] The present invention adopts a more unique method to realize the self-arrangement of the solid powder leveling agent, and at the same time controls the surface tension of the coating, thereby very effectively avoiding the generation of orange peel. At the same time, after the coating is cured, an intermediate protective layer can also be formed to realize the strength, wear resistance and other properties of the coating film.

[0035] And the above effects are firstly based on the ultrafine alumina powder. After research by researchers, alumina powder will form particles with a positively charged surface in some organic acid systems, and show a relatively orderly dispersion state. And when its fineness reaches a certain degree, its dispersion distribution trend will change. After the mesh number of the alumina powder ≥ 1200 mesh, actually under certain organic acid system conditions, it will preferentially show a planar / laminar dispersion trend. That is, like a small amount of alumina powder, after being stirred in a certain organic acid system until it forms a uniformly dispersed turbid liquid, after standing for a period of time, it will actually be found that the white suspended matter particles will evenly float to the upper layer of the solution system, and basically no agglomeration occurs. After tilting the solution, the layer of white suspended matter particles also always maintains a horizontal distribution trend and will not change. Similarly, the change in temperature will not affect its distribution form. Based on this phenomenon, researchers first believe that the reasonable use of its floating trend can very well show the surface regulation effect in the coating, and can avoid the cratering problem of liquid leveling agents and the orange peel problem of solid leveling agents at the same time, and has a very broad application prospect.

[0036] On this basis, the R & D personnel of the present invention use methyl acrylate, alkylamine and aminated modified polysiloxane to modify the surface of the inorganic carrier, so that after floating, it can adjust and control the surface tension of the coating. The above-mentioned methyl acrylate and alkylamine can undergo Michael addition reaction under alkaline conditions to synthesize a toothed branched molecular compound with alkylamine at the end. This toothed branched molecular compound then reacts with the amino group of bis(3-aminopropyl) terminated polydimethylsiloxane through amidation condensation reaction, introducing secondary amino groups and long-chain polysiloxanes that can greatly reduce the surface tension of the coating. Both the secondary amino groups and the carbonyl groups of the toothed branched molecules themselves can effectively link to the positively charged inorganic carrier ion surface, and the alkyl groups have good compatibility with conventional coatings, forming a polymer cladding layer that controls the surface tension of the coating on its surface.

[0037] However, it should be noted that this process requires very strict control conditions, that is, it is necessary to avoid the overall alkalinity being relatively controllable to prevent excessive alkalinity from causing the dissolution of alumina powder. At the same time, a certain degree of thermal catalysis is also required. Therefore, the present invention uses a very unique alkaline regulator, namely calcium oxide. When calcium oxide is added to the white turbid liquid, it will release a large amount of heat. As a weak base, it cannot dissolve alumina and can play a role in catalyzing the formation of the polymer cladding layer. However, simply introducing calcium oxide will also cause the situation of calcium ion occupancy and the precipitation of organic polymers, resulting in poor coating effect of the actual polymer cladding layer. Therefore, the inorganic carrier of the present invention also needs to be combined with aluminosilicate components to achieve the regulation of calcium ions, so that aluminosilicate captures calcium ions to avoid the adverse effects of excessive free calcium ions on the overall polymer cladding process.

[0038] At the same time, aluminosilicate / aluminosilicate calcium particles can also basically maintain a relatively uniform layered dispersion form in the dispersion system mainly composed of alumina without changing their dispersion trend.

[0039] Through the above process, the present invention can construct a special solid powder leveling agent with alumina and aluminum silicate / calcium aluminosilicate as inorganic carriers and a long-chain polymer compound coating formed on the outer surface. While the polymer coating does not change the dispersion tendency of the inorganic carrier in the solvent system, it enables the leveling agent to reduce the surface tension of the coating and achieve rapid leveling of the coating. At the same time, due to the dispersion tendency of the inorganic carrier itself, it is also conducive to driving the leveling of the coating. Therefore, the solid powder leveling agent of the present invention has extremely high leveling efficiency. On the other hand, the solid powder leveling agent of the present invention is different from the existing solid leveling agents. In the early stage of leveling and film formation, a substantial part of the upper layer is actually occupied by the solid powder leveling agent of the present invention. Therefore, different from the conventional trend of the coating to cure and form a film from the outside to the inside, the solid powder leveling agent of the present invention will change the existing coating to cure and form a film from the inside to the outside. During the process of leveling and film formation, the internal part starts to cure first, and then the polymer coating will be affected and gradually drive the solid powder leveling agent of the present invention to "sink", while the uncured coating will flow out through the gaps, and finally complete curing, and it can avoid the precipitation of the solid powder leveling agent on the film surface after the coating forms a film, affecting the film formation effect.

[0040] The beneficial effects of the present invention are as follows:

[0041] Through surface treatment of special inorganic carriers, the present invention constitutes a leveling agent with good leveling effect, which can avoid the two major performance defects of shrinkage holes and orange peel of existing leveling agents, and has strong universality and can be applied to most existing organic coatings. Detailed implementation manners

[0042] The following further clearly and detailedly describes the present invention in combination with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are usually only a part of the embodiments of the present invention, rather than all the embodiments. Therefore, all other embodiments obtained by those of ordinary skill in the art without creative work based on the embodiments of the present invention shall fall within the protection scope of the present invention.

[0043] Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available or raw materials that can be obtained by those skilled in the art; unless otherwise specified, the methods used in the embodiments of the present invention are all methods mastered by those skilled in the art.

[0044] Example 1

[0045] A solid powder leveling agent is prepared by the following method:

[0046] 1) Using aluminosilicate with a mesh size of 1500 and alumina with a mesh size of 1500 as inorganic carriers, mix them evenly according to a mass ratio of 1:9, disperse them in deionized water according to a ratio of 1 g of their total mass to 5 mL, add a 10 wt% formic acid aqueous solution to adjust the pH value to 4.5, and then stir until a uniformly dispersed white turbid liquid is formed;

[0047] 2) Add methyl acrylate, n-propylamine, bis(3-aminopropyl) terminated polydimethylsiloxane, and calcium oxide to the white turbid liquid. The molar ratio of the amounts of methyl acrylate, n-propylamine, and bis(3-aminopropyl) terminated polydimethylsiloxane is 1:0.3:0.1, and the total amount of the three is 75 g / L of the white turbid liquid. The amount of calcium oxide is 35 g / L of the white turbid liquid. Stir for 20 min and then let it stand for 20 min. After it becomes a light yellowish-green turbid liquid, filter it, wash it three times with deionized water, and then dry it to obtain a solid powder leveling agent.

[0048] The solid powder leveling agent prepared in this example is a powdery particle that can flow freely at room temperature.

[0049] Add the prepared solid powder leveling agent to a commercially available weakly acidic floor organic coating (blue) at a dosage of 3.0 wt% to prepare a sample for performance testing.

[0050] The tests mainly include a natural flow experiment, a tube wall adsorption tension test, a scratch test, as well as a conventional 60° glossiness characterization, orange peel observation, and crater observation, and compare with the same type of coating without the leveling agent (blank control sample).

[0051] Among them:

[0052] For the natural flow test, take 15 ml of the sample and drop it on the same point (drop point) of a clean and smooth glass substrate. When dropping the sample, try to be as close to the glass substrate as possible to avoid experimental errors caused by sample splashing. After 2 min, observe the minimum distance from the drop point within the area covered by the sample after it flows out naturally, and record (natural flow distance) in units of mm;

[0053] For the tube wall adsorption test, take 5 mL of the sample and drop it at the bottom of a small beaker. When choosing the beaker, ensure that the 5 mL of the sample can fill the bottom of the beaker. After it completely solidifies, characterize the height difference between the height of the coating film hanging on the wall and the horizontal height of the coating film at the bottom of the beaker, and record (hanging wall height) in units of mm;

[0054] For the scratch test, take an appropriate amount of the sample and cure it into a film within a limited area of the glass substrate as a sample. Control the thickness of the sample film to be 1 mm, and test it with a coating film scratch tester. The initial scratch pressure is 10 N ± 0.5 N, increase it in increments of 5 N, cut at different positions each time (the scratches do not intersect), and the maximum scratch pressure is 50 N ± 0.5 N until the glass substrate at the bottom of the film is exposed, and record (scratch pressure) in units of N.

[0055] The 60° glossiness characterization, orange peel observation, and crater observation are all carried out according to the conventional procedures.

[0056] The characterization results are shown in the following table.

[0057]

[0058] Judging from the above characterization results, the leveling agent prepared in this example can very effectively improve the fluidity of the coating. Its natural flow distance has been significantly improved, while the wall hanging height has decreased significantly. Moreover, in the natural flow test characterization, after the leveling agent prepared in this example is added and used, the sample liquid unfolds in a relatively regular circular shape, while the blank control shows a certain irregular shape. In addition, in the scratch pressure test, after the sample liquid prepared in this example forms a film, the blue coating film on the test surface is partially scratched, but actually in the scratch test of 25 N to 50 N, it is always impossible to cut through to the bottom, but a layer of turquoise intermediate layer leaks out. The R & D personnel believe that this is formed by the leveling agent of the present invention being uniformly dispersed and shrinking into the film during the curing process and then constituting with the dye components in the coating, and it has relatively high scratch resistance. It can be seen that the leveling agent of the present invention can also improve the mechanical properties of the coating film to a certain extent. In addition, the film-forming color of the coating and the 60° glossiness characterization are basically the same as those of the blank control, which also shows that it presents a shrinking trend during the curing and film-forming stage. And actually, before the sample liquid of this example is completely mixed and dropped and completely forms a film, the surface will show yellowish green for a period of time, gradually turn into turquoise, and then turn into the same blue as the coating itself. This is the manifestation of the leveling agent powder floating up and then sinking and shrinking. Moreover, judging from the orange peel and crater observation results, the present invention effectively solves the orange peel and crater defects existing in the existing leveling agents, and even solves the possible slight crater phenomenon of the coating itself.

[0059] Example 2

[0060] A solid powder leveling agent is prepared by the following method:

[0061] 1) Using 1500-mesh aluminum silicate and 1500-mesh alumina as inorganic carriers, after mixing them evenly according to the mass ratio of 1:9, dispersing them in deionized water according to the ratio of 1 g of their total mass: 5 mL, and adding 10 wt% formic acid aqueous solution to adjust the pH value to 4.5, and then stirring until a uniformly dispersed white turbid liquid is formed;

[0062] 2) Add methyl acrylate, n-propylamine, bis(3-aminopropyl) terminated polydimethylsiloxane and calcium oxide to the white turbid liquid. The molar ratio of the amounts of methyl acrylate, n-propylamine, and bis(3-aminopropyl) terminated polydimethylsiloxane is 1:0.2:0.12, and the total amount of the three is 90 g / L of the white turbid liquid. The amount of calcium oxide is 35 g / L of the white turbid liquid. Stir for 20 min and then let it stand for 20 min. After it becomes a light yellowish-green turbid liquid, filter it and wash it three times with deionized water and then dry it to obtain the solid powder leveling agent.

[0063] The solid powder leveling agent prepared in this example is a powdery particle that can flow freely at room temperature.

[0064] Perform the same performance characterization on the sample of this example as in Example 1. The characterization results are shown in the following table.

[0065]

[0066] Judging from the above characterization results, the leveling agent prepared in this example significantly and effectively improves the leveling property of the organic coating, and at the same time has a certain strengthening effect on the mechanical properties of the coating film.

[0067] Example 3

[0068] A solid powder leveling agent is prepared by the following method:

[0069] 1) Use 1500-mesh aluminum silicate and 1500-mesh alumina as inorganic carriers. Mix them evenly according to the mass ratio of 1:9, and then disperse them in deionized water according to the ratio of 1 g of their total mass: 5 mL, and add 10 wt% formic acid aqueous solution to adjust the pH value to 4.5. Then stir until a uniformly dispersed white turbid liquid is formed;

[0070] 2) Add methyl acrylate, n-propylamine, bis(3-aminopropyl) terminated polydimethylsiloxane and calcium oxide to the white turbid liquid. The molar ratio of the amounts of methyl acrylate, n-propylamine, and bis(3-aminopropyl) terminated polydimethylsiloxane is 1:0.4:0.08, and the total amount of the three is 60 g / L of the white turbid liquid. The amount of calcium oxide is 35 g / L of the white turbid liquid. Stir for 20 min and then let it stand for 20 min. After it becomes a light yellowish-green turbid liquid, filter it and wash it three times with deionized water and then dry it to obtain the solid powder leveling agent.

[0071] The solid powder leveling agent prepared in this example is a powdery particle that can flow freely at room temperature.

[0072] Perform the same performance characterization on the sample of this example as in Example 1. The characterization results are shown in the following table.

[0073]

[0074] From the above characterization results, it can be seen that the leveling agent prepared in this example significantly and effectively improves the leveling property of the organic coating, and at the same time has a certain strengthening effect on the mechanical properties of the coating film.

[0075] Example 4

[0076] A solid powder leveling agent is prepared by the following method:

[0077] 1) Using 1500-mesh aluminum silicate and 1500-mesh alumina as inorganic carriers, after mixing them in a mass ratio of 1:8, dispersing them in deionized water at a ratio of 1 g of their total mass: 5 mL, and adding 10 wt% formic acid aqueous solution to adjust the pH value to 4.5, and then stirring until a uniformly dispersed white turbid liquid is formed;

[0078] 2) Adding methyl acrylate, n-propylamine, bis(3-aminopropyl) terminated polydimethylsiloxane and calcium oxide to the white turbid liquid, where the molar ratio of the amounts of methyl acrylate, n-propylamine, and bis(3-aminopropyl) terminated polydimethylsiloxane is 1:0.3:0.1, and the total amount of the three is 75 g / L of the white turbid liquid, and the amount of calcium oxide is 35 g / L of the white turbid liquid. After stirring for 20 min and standing for 20 min, until it becomes a light yellow-green turbid liquid, then filtering and washing three times with deionized water and drying to obtain the solid powder leveling agent.

[0079] The solid powder leveling agent prepared in this example is a powdery particle that can flow freely at room temperature.

[0080] Perform the same performance characterization on the sample in this example as in Example 1, and the characterization results are shown in the following table.

[0081]

[0082] From the above characterization results, it can be seen that the leveling agent prepared in this example significantly and effectively improves the leveling property of the organic coating, and at the same time has a certain strengthening effect on the mechanical properties of the coating film.

[0083] Example 5

[0084] A solid powder leveling agent is prepared by the following method:

[0085] 1) Using 1500-mesh aluminum silicate and 1500-mesh alumina as inorganic carriers, after mixing them in a mass ratio of 1:11, dispersing them in deionized water at a ratio of 1 g of their total mass: 5 mL, and adding 10 wt% formic acid aqueous solution to adjust the pH value to 4.5, and then stirring until a uniformly dispersed white turbid liquid is formed;

[0086] 2) Methyl acrylate, n-propylamine, bis(3-aminopropyl) terminated polydimethylsiloxane, and calcium oxide were added to the white turbid liquid. The molar ratio of the amounts of methyl acrylate, n-propylamine, and bis(3-aminopropyl) terminated polydimethylsiloxane was 1:0.3:0.1, and the total amount of the three was 75 g / L of the white turbid liquid. The amount of calcium oxide was 35 g / L of the white turbid liquid. After stirring for 20 min, it was allowed to stand for 20 min. After it became a light yellow-green turbid liquid, it was filtered, washed three times with deionized water, and then dried to obtain the solid powder leveling agent.

[0087] The solid powder leveling agent prepared in this example is a powdery particle that can flow freely at room temperature.

[0088] The same performance characterization as in Example 1 was carried out on the sample of this example, and the characterization results are shown in the following table.

[0089]

[0090] Judging from the above characterization results, the leveling agent prepared in this example significantly and effectively improved the leveling property of the organic coating, and at the same time had a certain strengthening effect on the mechanical properties of the coating film.

[0091] Comparative Example 1

[0092] Based on the preparation process of Example 1, the solid powder leveling agent was prepared, and only the amount of calcium oxide was adjusted, as shown in the following table.

[0093]

[0094] The samples with the above various numbers were characterized in the same way as in Example 1, and the characterization results are shown in the following table.

[0095]

[0096] Judging from the above characterization results, in this example, the influence of the amount of calcium oxide on the actual use effect of the leveling agent was explored. It can be seen that when the amount of calcium oxide is too small (sample #7-1), the leveling effect of the leveling agent decreases to a certain extent. When the amount is increased to 55 g / L of the white turbid liquid (test #7-6), the orange peel phenomenon common to solid leveling agents appears after the leveling agent is used, indicating that the surface charge distribution of the particles may be damaged during the preparation process, resulting in agglomeration and other situations when it is dispersed in weakly acidic organic coatings, resulting in poor use effects. Therefore, judging from the current test results of the present invention, the amount of calcium oxide should be controlled within 30 - 50 g / L to show the best use effect.

[0097] Comparative Example 2

[0098] Based on the preparation process of Example 1, calcium oxide was replaced with sodium hydroxide in a 25 g / L white turbid solution (approximately added in an equimolar amount). After addition, stirring and standing were carried out under the condition of a constant temperature water bath at 55 °C to prepare a solid powder leveling agent. The samples prepared were characterized in the same way as in Example 1, and the characterization results are shown in the following table.

[0099]

[0100] From the above characterization results, it can be seen that using sodium hydroxide as an alkaline regulator to stimulate the formation of the polymer coating has a very poor actual effect, significantly weakening the actual use effect of the leveling agent of the present invention. After film formation, the film surface shows a partial yellow-green color bleeding situation, indicating that some leveling agent particles are not effectively coated with the polymer coating, and thus do not "sink" during the film formation process. At the same time, this also leads to a decrease in gloss. Although no observable orange peel is present, shrinkage holes are observed, which may instead be caused by some leveling agents actually being polymer agglomerate particles with serious sinking.

[0101] Comparative Example 3

[0102] Based on the preparation process of Example 1, during the preparation process, methyl acrylate and n-propylamine were not used respectively (#D3-1 sample number) and bis(3-aminopropyl) terminated polydimethylsiloxane was not used (#D3-2 sample number) to prepare a solid powder leveling agent. The samples prepared were characterized in the same way as in Example 1, and the characterization results are shown in the following table.

[0103]

[0104] From the above characterization results, for the leveling agent of the present invention, the synergistic coating effect of methyl acrylate, n-propylamine, and bis(3-aminopropyl) terminated polydimethylsiloxane is the key to enabling the inorganic carrier to have leveling performance. When the three cannot form an effective cooperation, the actual leveling agent almost loses the effect of promoting leveling, and it also causes serious discoloration of the coating film surface, the appearance of orange peel, and a relatively obvious decrease in gloss.

[0105] Comparative Example 4

[0106] Based on the preparation process of Example 1, during the preparation process, only aluminosilicate was not used to prepare a solid powder leveling agent. The samples prepared were characterized in the same way as in Example 1, and the characterization results are shown in the following table.

[0107]

[0108] From the above characterization results, the leveling agent prepared with alumina powder as the inorganic carrier has a good effect on promoting leveling. However, it has the common defects of solid leveling agents, that is, it causes orange peel in the paint film. The researchers believe that this is due to the uneven particle size caused by agglomeration during the preparation process. However, in terms of other properties, it still has excellent usage effects.

Claims

1. A preparation method of a solid powder leveling agent, characterized in that, the method comprises: 1) Using aluminum silicate and alumina as inorganic carriers, dispersing them in water, adding an organic acid, and stirring and adjusting to form a uniformly dispersed white turbid liquid; 2) Adding methyl acrylate, alkylamine, amino-modified polysiloxane and an alkaline regulator to the white turbid liquid, stirring until it becomes a light yellow or light green or light yellowish-green turbid liquid, then filtering, washing and drying to obtain the solid powder leveling agent; In step 1), the mesh numbers of both the aluminum silicate and the alumina are ≥1500 meshes; The mass ratio of the amounts of the aluminum silicate and the alumina used is 1:(8 - 11); In step 2), the alkaline regulator is calcium oxide; The amount of the calcium oxide used is 30 - 50 g / L of the white turbid liquid.

2. The preparation method of a solid powder leveling agent according to claim 1, characterized in that, in step 1), the organic acid is a formic acid solution, and the formic acid solution adjusts the pH value of the solution system to 4.0 - 5.

0.

3. The preparation method of a solid powder leveling agent according to claim 1, characterized in that, in step 2), the alkylamine is n-propylamine and / or n-butylamine and / or n-pentylamine; in step 2), the amino-modified polysiloxane is bis(3-aminopropyl) terminated polydimethylsiloxane.

4. The preparation method of a solid powder leveling agent according to claim 3, characterized in that, the molar ratio of the amounts of the methyl acrylate, the alkylamine and the amino-modified polysiloxane used is 1:(0.2 - 0.4):(0.08 - 0.12); the total amount of the methyl acrylate, the alkylamine and the amino-modified polysiloxane used is 60 - 90 g / L of the white turbid liquid.

5. The preparation method of a solid powder leveling agent according to claim 1, characterized in that, in step 2), the stirring lasts for at least 15 min, and after the stirring is completed, it is left standing for at least 15 min until the conversion is completed and then filtered.

6. A solid powder leveling agent prepared by any one of the methods according to claims 1 to 5.

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