Water-based paint and preparation method thereof

Abstract

The invention discloses a water-based coating which comprises a basic coating, a regulator A and a regulator B, the regulator A is used for regulating the surface tension of the coating system, and the regulator B is used for regulating the rheological property of the coating system; the basic coating is prepared from the following components in parts by weight: 50 to 70 parts of refractory powder, 2 to 8 parts of binder, 20 to 40 parts of water and 0.1 to 5 parts of clay mineral. According to the water-based paint disclosed by the invention, the adaptive barrier of different sand molds and different coating processes is broken through, that is, the adaptive problem of different sand molds and different coating processes is solved through modular formula design, and multiple purposes are achieved through one paint. Customization of a coating product is achieved by adding a regulator A and a regulator B into a basic coating, two technical adaptation layers are included, the first layer adapts to different sand molds through an aggregate grading scheme and an adjustment scheme of the regulator A, and the second layer adapts to different coating modes through an adjustment scheme of the regulator B.

Description

Technical Field

[0001] The present invention relates to the technical field of casting auxiliary materials, in particular to a water-based coating and a preparation method thereof. Background Art

[0002] The surface properties of various sand molds vary greatly, and the use of any existing coating cannot take into account the wettability requirements of each sand mold. For example, the surface of cold-box molding sand molds is hydrophobic, while the surface of inorganic binder and water glass sand molds is hydrophilic. Excessive penetration will affect the strength of the sand mold, and phosphate inorganic binder sand molds are more sensitive to water; 3D printing sand molds have low density and high porosity, while cold-box sand molds have high density, high sand mold compactness, and low porosity. The physical structural differences such as the porosity of 3D printing sand molds and the density of cold-box sand molds result in very significant permeability differences when using the same coating, resulting in uncontrollable coating penetration behavior. In addition, traditional coatings are unable to adapt to various application process requirements such as brushing, spraying, and dipping.

[0003] Existing technologies require the development of specialized coatings for each sand mold, resulting in high production costs and complex storage. For example, cold-box sand molds typically utilize coatings with good permeability and wettability to ensure proper wetting of the oily sand substrate, preventing poor wetting and forming a permeable layer on the highly compacted substrate. 3D printing sand molds typically utilize low-permeability coatings with moderate wettability to ensure effective coating thickness and prevent excessive penetration of coating aggregate particles into the sand mold voids. Sand molds using inorganic binders or water glass typically utilize coatings with high suspension properties and low wettability to prevent excessive moisture penetration and weakening of the sand mold's strength. Summary of the Invention

[0004] Based on this, in order to solve the technical problem that existing coatings cannot adapt to different sand molds and different coating processes, the present invention provides a modular water-based coating that can adapt to different sand molds and coating processes and a preparation method thereof.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A water-based coating comprises: a base coating, an adjuster A and an adjuster B; the adjuster A is used to adjust the surface tension of the coating system to adapt to different sand molds; the ratio of the added amount of the adjuster A to the base coating is 0.01 to 5:100; the adjuster A is a surfactant; the adjuster B is used to adjust the rheological properties of the coating system to adapt to different application methods; the ratio of the added amount of the adjuster B to the base coating is 0.01 to 3:100; the adjuster B is a dispersing adjuster; the base coating comprises, by weight, 50 to 70 parts of refractory powder, 2 to 8 parts of binder, 20 to 40 parts of water and 0.1 to 5% of clay mineral.

[0007] Furthermore, the water-based coating is applied to the surface of the foundry sand mold. When the foundry sand mold is a hydrophobic sand mold, for example, a furan sand mold, a coated sand mold, a hot core box sand mold, a shell mold, a cold core box sand mold, etc., the adjusting agent A is a non-ionic surfactant, and the surface tension of the coating system is adjusted to ≤35mN / m. Preferably, the ratio of the amount of the non-ionic surfactant to the base coating is 0.02 to 1.2:100. When the foundry sand mold is a hydrophilic sand mold, for example, a water glass sand mold, a phosphate inorganic binder sand mold, an alkali phenolic sand mold, etc., the adjusting agent A is an anionic surfactant, and the surface tension of the coating system is adjusted to 35 to 45mN / m. Preferably, the ratio of the amount of the anionic surfactant to the base coating is 0.01 to 0.5:100.

[0008] Furthermore, the nonionic surfactant includes at least one of a fluorocarbon surfactant, a polyether-modified polysiloxane, a polyoxyethylene ether surfactant, an alkyl alcohol amide and an alkyl glycoside; the anionic surfactant includes at least one of a sodium alkylbenzene sulfonate, an alkyl ether sulfate, a sulfosuccinate salt and an alkyl carboxylate.

[0009] Preferably, after the surface tension of the coating system is adjusted using the adjuster A, the contact angle between the coating system and its corresponding sand mold can be between 20° and 50°.

[0010] Furthermore, the water-based coating is applied to the surface of the foundry sand mold. When the application method is flow coating or dipping, the dispersing agent includes lignin sulfonate, and the viscosity of the coating system is adjusted to 15-25 seconds per 4 cup of coating; the ratio of the amount of the dispersing agent to the base coating is preferably 0.05-1:100. When the application method is spraying, the dispersing agent includes at least one of sodium polyacrylate, polyacrylamide, and styrene-maleic anhydride copolymer, and the viscosity of the coating system is adjusted to 25-40 seconds per 4 cup of coating; the ratio of the amount of the dispersing agent to the base coating is preferably 0.01-0.8:100. When the application method is brushing, the dispersing agent includes polyphosphate, and the viscosity of the coating system is adjusted to 40-60 seconds per 4 cup of coating; the ratio of the amount of the dispersing agent to the base coating is preferably 0.01-2:100.

[0011] Furthermore, the refractory powder comprises a combination of two or more refractory aggregates of different particle sizes, and the particle size range can be 100 mesh to 325 mesh to match the pore structure of the sand mold; that is, the refractory powder comprises a refractory aggregate of a first particle size and a refractory aggregate of a second particle size. The first particle size is preferably 100 mesh to 200 mesh, and the second particle size is preferably 200 mesh to 325 mesh.

[0012] The present invention designs a grading scheme for refractory aggregates for commonly used sand molds. For 3D printing furan sand molds, 325-mesh and 200-mesh refractory aggregates are optimally selected, and the ratio of the two can be 3:7 to 7:3. For cold-box core-shooting sand molds, hot-box sand molds, coated sand molds, or shell molds, 325-mesh and 200-mesh refractory aggregates are optimally selected, and the ratio of the two can be 6:4 to 9.9:0.1. For water glass sand molds, phosphate inorganic binder sand molds, or alkali phenolic sand molds, 150-mesh and 270-mesh refractory aggregates are optimally selected, and the ratio of the two can be 2:8 to 6:4.

[0013] Furthermore, the refractory aggregate includes at least one of quartz powder, corundum powder, high-alumina bauxite powder, mullite powder, cordierite powder, flake graphite, earthy graphite, quartz powder, forsterite, magnesia powder, pyrophyllite, magnesium-aluminum spinel, chromite powder, talc powder, dolomite, spodumene, feldspar powder, and mica powder.

[0014] Among them, for ordinary steel castings, the refractory aggregate is preferably at least one of zircon powder, corundum powder, magnesia-aluminum spinel, chromite powder, and quartz powder; for high manganese steel, the refractory aggregate is preferably at least one of magnesia powder and forsterite; for iron castings, the refractory aggregate is preferably at least one of mullite powder, high-alumina bauxite, zircon powder, flake graphite, earthy graphite, pyrophyllite, and chromite powder; for aluminum castings, the refractory aggregate is preferably at least one of talc powder, feldspar powder, and dolomite.

[0015] Furthermore, the binder comprises at least one of a water-soluble organic high molecular weight polymer, an organic high molecular weight polymer emulsion, an organic high molecular weight polymer aqueous dispersion, and an inorganic sol, wherein the solid content of the organic high molecular weight polymer emulsion or the organic high molecular weight polymer aqueous dispersion is preferably ≥40%.

[0016] Preferably, the binder is at least one of polyvinyl alcohol, acrylic polymer aqueous dispersion, polyvinyl acetate emulsion, and silica sol.

[0017] Furthermore, the coating system of the present invention uses water as a carrier liquid, and its hardness is preferably less than 350 mg / L. Of course, if the hardness of the water is ≥350 mg / L, it can be softened or the amount of clay mineral added can be increased by 5 to 20 parts.

[0018] Furthermore, the clay mineral includes at least one of attapulgite, sepiolite, and synthetic hectorite.

[0019] Preferably, the clay mineral is prepared as a dispersion using deionized water, has a Brookfield viscosity of ≥4000 rpm, and contains no bubbles or foam visible to the naked eye.

[0020] Furthermore, the base coating may further include 0.01 to 3 parts of a defoamer and 0.01 to 1 part of a preservative. The defoamer may be a mineral oil defoamer, a silicone defoamer, tributyl phosphate, etc., and the preservative may be a benzoate preservative, a phenol preservative, an organic amine preservative, an isothiazolinone preservative, etc.

[0021] In a second aspect, the present application further provides a preparation method, which is applied to any of the water-based coatings described above, and the water-based coating is prepared using a coating intelligent unit. Specifically, the preparation method may include the following steps:

[0022] S1. Inputting production parameters into the coating intelligent unit, wherein the production parameters include casting material, sand mold type, and coating method;

[0023] S2. Add water, binder and clay mineral to the coating preparation kettle of the coating intelligent unit and disperse for 20 to 40 minutes; add refractory powder to the coating preparation kettle and disperse for 10 to 40 minutes to prepare the base coating;

[0024] S3, adding the adjusting agent A to the base coating and dispersing for 1 to 10 minutes;

[0025] S4. Add the adjusting agent B to the base coating and disperse for 1 to 10 minutes.

[0026] Compared with the prior art, the method of the present invention has the following beneficial effects:

[0027] The water-based coating disclosed in this invention overcomes the barriers to adaptability to different sand molds and coating processes. This is achieved through a modular formulation design, solving the adaptation issues for different sand molds and coating processes, thus achieving "one coating for multiple uses." Customization is achieved by adding Regulators A and B to the base coating. This approach involves two technical adaptation layers: the first, adapting to different sand molds through aggregate grading and Regulator A adjustments; the second, adapting to different coating methods through Regulator B adjustments.

[0028] The water-based coating disclosed in this invention significantly improves sand mold compatibility, completely resolving the industry challenge of "one coating for each sand mold." Adjusting agent B is matched according to the application method, achieving dynamic rheological control and adapting to the entire application process. The product line significantly reduces the number of coating types, from multiple coatings to one base coating and two additives. This improves production efficiency, reduces storage costs, and increases coating switching efficiency. This helps upgrade the industry, provides standardized coating solutions for smart casting, and supports flexible production. DETAILED DESCRIPTION

[0029] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant examples. Preferred embodiments of the present invention are provided in the examples. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] One of the objectives of the present invention is to disclose a water-based coating, comprising: a base coating, an adjuster A, and an adjuster B. The adjuster A is used to adjust the surface tension of the coating system, and the ratio of the adjuster A to the base coating is 0.01 to 5:100. The adjuster A is a surfactant. The adjuster B is used to adjust the rheological properties of the coating system, and the ratio of the adjuster B to the base coating is 0.01 to 3:100. The adjuster B is a dispersing adjuster. The base coating comprises, by weight, 50 to 70 parts of refractory powder, 2 to 8 parts of binder, 20 to 40 parts of water, and 0.1 to 5% of clay mineral.

[0032] Preferably, the base coating comprises, by weight, 50 to 70 parts of refractory powder, 2 to 8 parts of binder, 25 to 40 parts of water and 0.1 to 5% of clay mineral.

[0033] A second object of the present invention is to disclose a method for preparing the above-mentioned water-based coating, which may include the following steps:

[0034] S1. Enter the casting material in the coating intelligent unit to obtain and select the refractory aggregate type scheme; enter the sand mold type to obtain the refractory aggregate grading scheme and the mixing scheme of the adjusting agent A; enter the application method to obtain and select the mixing scheme of the adjusting agent B.

[0035] The refractory aggregate type options can be:

[0036] Refractory aggregates include at least one of quartz powder, corundum powder, high-alumina bauxite powder, mullite powder, cordierite powder, flake graphite, earthy graphite, quartz powder, forsterite, magnesia powder, pyrophyllite, magnesia-aluminum spinel, chromite powder, talc, dolomite, spodumene, feldspar powder, and mica powder. For ordinary steel castings, the refractory aggregate is preferably at least one of zircon powder, corundum powder, magnesia-aluminum spinel, chromite powder, and quartz powder; for high-manganese steel, the refractory aggregate is preferably at least one of magnesia powder and forsterite; for iron castings, the refractory aggregate is preferably at least one of mullite powder, high-alumina bauxite, zircon powder, flake graphite, earthy graphite, pyrophyllite, and chromite powder; and for aluminum castings, the refractory aggregate is preferably at least one of talc, feldspar powder, and dolomite.

[0037] The refractory aggregate grading scheme can be:

[0038] The refractory powder comprises a combination of two or more refractory aggregates of different particle sizes, ranging from 100 mesh to 325 mesh to match the pore structure of the sand mold; that is, the refractory powder comprises a first refractory aggregate and a second refractory aggregate. The first particle size is preferably 100 mesh to 200 mesh, and the second particle size is preferably 200 mesh to 325 mesh. The present invention designs a grading scheme for refractory aggregates for commonly used sand molds. For 3D printing furan sand molds, the optimal choice is 325 mesh and 200 mesh refractory aggregates, with the addition ratio of the two being 3:7 to 7:3. For cold box core shooting sand molds, hot box sand molds, coated sand molds, or shell molds, the optimal choice is 325 mesh and 200 mesh refractory aggregates, with the addition ratio of the two being 6:4 to 9.9:0.1. For water glass sand mold, phosphate inorganic binder sand mold or alkali phenolic sand mold, the best selection of 150 mesh and 270 mesh refractory aggregates, the addition ratio of the two can be 2:8 to 6:4.

[0039] The formulation of adjuster A can be:

[0040] The adjusting agent A is a surfactant used to adjust the surface tension of the coating system, and the ratio of the amount of adjusting agent A to the base coating is 0.01 to 5:100. When the casting sand mold is a hydrophobic sand mold, for example, a furan sand mold, a coated sand mold, a hot core box sand mold, a shell mold, a cold core box sand mold, etc., the adjusting agent A is a nonionic surfactant, and the surface tension of the coating system is adjusted to ≤35mN / m. The ratio of the amount of the nonionic surfactant to the base coating is preferably 0.02 to 1.2:100. When the casting sand mold is a hydrophilic sand mold, for example, a water glass sand mold, a phosphate inorganic binder sand mold, an alkali phenolic sand mold, etc., the adjusting agent A is an anionic surfactant, and the surface tension of the coating system is adjusted to 35 to 45mN / m. The ratio of the amount of the anionic surfactant to the base coating is preferably 0.01 to 0.5:100. The nonionic surfactant may include at least one of a fluorocarbon surfactant, a polyether-modified polysiloxane, a polyoxyethylene ether surfactant, an alkylolamide, and an alkyl glycoside; the anionic surfactant may include at least one of a sodium alkylbenzene sulfonate, an alkyl ether sulfate, a sulfosuccinate, and an alkyl carboxylate. After adjusting the surface tension of the coating system using the adjusting agent A, the contact angle between the coating system and the corresponding sand mold may be between 20° and 50°.

[0041] The formulation of adjuster B can be as follows: Adjuster B is a dispersing adjuster used to adjust the rheological properties of the coating system. The ratio of adjuster B to the base coating is 0.01 to 3:100. When the application method is flow coating or dipping, the dispersing adjuster can include lignin sulfonate to adjust the coating system's 4-cup viscosity to 15-25 seconds. The ratio of dispersing adjuster to the base coating is preferably 0.05 to 1:100. When the application method is spraying, the dispersing adjuster can include at least one of sodium polyacrylate, polyacrylamide, and styrene-maleic anhydride copolymer to adjust the coating system's 4-cup viscosity to 25-40 seconds. The ratio of dispersing adjuster to the base coating is preferably 0.01 to 0.8:100. When the application method is brushing, the dispersing adjuster can include polyphosphate to adjust the coating system's 4-cup viscosity to 40-60 seconds. The ratio of dispersing adjuster to the base coating is preferably 0.01 to 2:100.

[0042] S2. According to the selected aggregate type and grading scheme, retrieve the formula library and prepare the basic coating.

[0043] Specifically, add 25 to 40 parts of water, 2 to 8 parts of binder and 0.1 to 5 parts of clay mineral into the paint preparation kettle of the paint intelligent unit. In addition, 0.01 to 3 parts of defoaming agent and 0.01 to 1 part of preservative can be added selectively, and disperse at 800 to 1200 rpm for 20 to 40 minutes. According to the selected aggregate type and grading scheme, add refractory powder into the paint preparation kettle, disperse at 800 to 1200 rpm for 10 to 40 minutes to obtain the basic paint.

[0044] S3. According to the selected mixing scheme of the adjusting agent A, add the adjusting agent A to the base coating and disperse for 1 to 10 minutes.

[0045] S4. According to the mixing scheme of the selected adjusting agent B, the adjusting agent B is added to the base coating and dispersed for 1 to 10 minutes to obtain the water-based coating of the present invention.

[0046] Example 1

[0047] The production parameters of this embodiment are as follows: the casting material is cast iron, the sand mold is a 3D printed furan resin sand mold, and the coating method is dip coating.

[0048] The preparation method of the water-based coating of this embodiment may include the following steps:

[0049] S100: Input production parameters into the coating intelligent unit and select the refractory aggregate type, refractory aggregate grading, and formulations for adjuster A and adjuster B. The refractory aggregate is mullite, with a particle size of 325 mesh and 200 mesh, in a 1:1 weight ratio. Adjuster A is a fluorocarbon surfactant, with an addition level of 0.1% of the base coating. Adjuster B is a lignin sulfonate, with an addition level of 0.5% of the base coating. The coating system specifications require a surface tension of ≤35 mN / m and a viscosity of 15-25 seconds after applying four cups of paint.

[0050] S200, base coating preparation

[0051] S210: Input the paint volume of 1000 kg into the paint intelligent unit and retrieve the basic paint formula: 60 parts refractory aggregate, 5 parts binder, 30 parts water, 3 parts clay mineral, 1.9 parts defoamer, and 0.1 parts preservative. The refractory aggregate is 30 parts 200-mesh mullite and 30 parts 325-mesh mullite. The binder is polyvinyl acetate emulsion, and the clay mineral is attapulgite.

[0052] S220. Add 300 kg of water, 19 kg of defoamer, 1 kg of preservative, 50 kg of polyvinyl acetate emulsion and 30 kg of attapulgite into the coating preparation kettle of the coating intelligent unit, and disperse at 1000 rpm for 30 minutes.

[0053] S230, coating preparation: 300 kg of 200-mesh mullite and 300 kg of 325-mesh mullite were added into the kettle, and dispersed at 1000 rpm for 30 minutes to obtain the basic coating of this embodiment.

[0054] S300, add 1kg of fluorocarbon surfactant to the base coating and disperse for 5 minutes. The surface tension of the coating system is detected to be 32.9mN / m.

[0055] S400: Add 5 kg of lignin sulfonate to the coating system and disperse for 5 minutes. Detect the viscosity of the coating system after 4 cups of coating and it is 18.3 seconds. Thus, the water-based coating product of this embodiment is obtained.

[0056] Example 2

[0057] The production parameters of this embodiment are that the casting material is cast iron, the sand mold is a coated sand mold, and the coating method is brush coating.

[0058] The preparation method of the water-based coating of this embodiment may include the following steps:

[0059] S100: Input production parameters into the coating intelligent unit and select the refractory aggregate type, refractory aggregate grading, and the formulations for adjuster A and adjuster B. The refractory aggregate is high-alumina bauxite, with a particle size of 325 mesh and 200 mesh, in a weight ratio of 8:2. Alkyl polyglycoside is selected as adjuster A, with an addition level of 0.1% of the base coating; polyphosphate is selected as adjuster B, with an addition level of 0.2% of the base coating. The coating system specifications require a surface tension of ≤35 mN / m and a viscosity of 40-60 seconds after applying 4 cups of paint.

[0060] S200, base coating preparation

[0061] S210: Input the paint volume of 1000 kg into the paint intelligent unit and retrieve the basic paint formula: 60 parts refractory aggregate, 2 parts binder, 33 parts water, 3 parts clay mineral, 1.9 parts defoamer, and 0.1 part preservative. The refractory aggregate is 12 parts 200-mesh high-alumina bauxite and 48 parts 325-mesh high-alumina bauxite. The binder is polyvinyl alcohol, and the clay mineral is sepiolite.

[0062] S220. Add 330 kg of water, 19 kg of defoamer, 1 kg of preservative, 20 kg of polyvinyl alcohol and 30 kg of sepiolite into the coating preparation kettle of the coating intelligent unit, and disperse at 1000 rpm for 30 minutes.

[0063] S230, coating preparation: 120 kg of 200-mesh high-alumina bauxite and 480 kg of 325-mesh high-alumina bauxite were added into the kettle, and dispersed at 1000 rpm for 30 minutes to obtain the basic coating of this embodiment.

[0064] S300: Add 1 kg of alkyl polyglycoside to the base coating and disperse for 5 minutes. The surface tension of the coating system is detected to be 29.6 mN / m.

[0065] S400, 2 kg of polyphosphate is added to the coating system and dispersed for 5 minutes. The viscosity of the coating system after 4 cups of coating is detected to be 44.7 seconds, thereby obtaining the water-based coating product of this embodiment.

[0066] Example 3

[0067] The production parameters of this embodiment are as follows: the casting material is ordinary steel casting, the sand mold is alkaline phenolic resin sand mold, and the coating method is spraying.

[0068] The preparation method of the water-based coating of this embodiment may include the following steps:

[0069] S100: Input production parameters into the coating intelligent unit and select the refractory aggregate type, refractory aggregate grading, and the formulations for adjuster A and adjuster B. The refractory aggregate is zircon powder, with a particle size of 150 mesh and 270 mesh, in a weight ratio of 4:6. Alkyl carboxylate is selected as adjuster A, with an addition level of 0.2% of the base coating. Styrene-maleic anhydride copolymer is selected as adjuster B, with an addition level of 0.5% of the base coating. The coating system specifications require a surface tension of 35-45 mN / m and a viscosity of 25-40 seconds after applying four cups of paint.

[0070] S200, base coating preparation

[0071] S210: Input the paint volume of 1000 kg into the paint intelligent unit and retrieve the basic paint formula: 70 parts refractory aggregate, 5 parts binder, 20 parts water, 3 parts clay mineral, 1.9 parts defoamer, and 0.1 parts preservative. The refractory aggregate is 28 parts 150-mesh zircon powder and 42 parts 270-mesh zircon powder. The binder is an aqueous acrylic polymer dispersion, and the clay mineral is synthetic hectorite.

[0072] S220. Add 200 kg of water, 19 kg of defoamer, 1 kg of preservative, 50 kg of acrylic polymer aqueous dispersion and 30 kg of synthetic hectorite into the coating preparation kettle of the coating intelligent unit, and disperse at 1000 rpm for 30 minutes.

[0073] S230, coating preparation: Add 280 kg of 150-mesh zircon powder and 420 kg of 270-mesh zircon powder into a kettle, and disperse at 1000 rpm for 30 minutes to prepare the basic coating of this embodiment.

[0074] S300: Add 2kg of alkyl carboxylate to the base coating and disperse for 5 minutes. The surface tension of the coating system is detected to be 38.6mN / m.

[0075] S400: Add 5 kg of styrene-maleic anhydride copolymer to the coating system and disperse for 5 minutes. Detect the viscosity of the coating system after 4 cups of coating and it is 31.9 seconds, thereby obtaining the water-based coating product of this embodiment.

[0076] Example 4

[0077] The production parameters of this embodiment are as follows: the casting material is high manganese steel, the sand mold is water glass sand mold, and the coating method is flow coating.

[0078] The preparation method of the water-based coating of this embodiment may include the following steps:

[0079] S100: Input production parameters into the coating intelligent unit and select the refractory aggregate type, refractory aggregate grading, and the formulations for adjuster A and adjuster B. The refractory aggregate is corundum powder, with a particle size of 150 mesh and 270 mesh, in a weight ratio of 3:7. Adjuster A is sulfosuccinate, with an addition level of 0.1% of the base coating; adjuster B is lignin sulfonate, with an addition level of 0.2% of the base coating. The coating system specifications require a surface tension of 35-45 mN / m and a viscosity of 15-25 seconds after applying four cups of paint.

[0080] S200, base coating preparation

[0081] S210: Input the paint volume of 1000 kg into the paint intelligent unit and retrieve the basic paint formula: 64 parts refractory aggregate, 2 parts binder, 27 parts water, 4 parts clay mineral, 2.7 parts defoamer, and 0.3 parts preservative. The refractory aggregate is 19.2 parts 150-mesh corundum powder and 44.8 parts 270-mesh corundum powder. The binder is polyvinyl alcohol, and the clay mineral is attapulgite.

[0082] S220. Add 270 kg of water, 27 kg of defoamer, 3 kg of preservative, 20 kg of polyvinyl alcohol and 40 kg of attapulgite into the coating preparation kettle of the coating intelligent unit, and disperse at 1000 rpm for 30 minutes.

[0083] S230, coating preparation: 192 kg of 150-mesh corundum powder and 448 kg of 270-mesh corundum powder were added to the kettle, and dispersed at 1000 rpm for 30 minutes to obtain the basic coating of this embodiment.

[0084] S300: Add 1 kg of sulfosuccinate salt to the base coating and disperse for 5 minutes. The surface tension of the coating system is detected to be 40.2 mN / m.

[0085] S400: Add 2 kg of lignin sulfonate to the coating system and disperse for 5 minutes. Detect the viscosity of the coating system after 4 cups of coating and it is 22.6 seconds. Thus, the water-based coating product of this embodiment is obtained.

[0086] Example 5

[0087] The production parameters of this embodiment are as follows: the casting material is cast aluminum, the sand mold is a 3D printed furan resin sand mold, and the coating method is dip coating.

[0088] The preparation method of the water-based coating of this embodiment may include the following steps:

[0089] S100: Input production parameters into the coating intelligent unit and select the refractory aggregate type, refractory aggregate grading, and formulations for adjuster A and adjuster B. The refractory aggregates are talc and feldspar, with a 325-mesh talc and 200-mesh feldspar particle size, in a weight ratio of 7:3. Adjuster A is a fluorocarbon surfactant and an alkyl alcohol amide. The fluorocarbon surfactant is added at 0.01% of the base coating, and the alkyl alcohol amide at 0.8%. Adjuster B is a lignin sulfonate, added at 0.05% of the base coating. The coating system specifications require a surface tension of ≤35 mN / m and a viscosity of 15-25 seconds after applying four cups of paint.

[0090] S200, base coating preparation

[0091] S210: Input the paint volume of 1000 kg into the paint intelligent unit and retrieve the basic paint formula: 50 parts refractory aggregate, 8 parts binder, 33 parts water, 5 parts clay mineral, 3 parts defoamer, and 1 part preservative. The refractory aggregate is 35 parts 325-mesh talc and 15 parts 200-mesh feldspar powder. The binder is silica sol, and the clay mineral is a 1:1 ratio of attapulgite and sepiolite.

[0092] S220. Add 330 kg of water, 30 kg of defoamer, 10 kg of preservative, 80 kg of silica sol, 25 kg of attapulgite and 25 kg of sepiolite into the coating preparation kettle of the coating intelligent unit, and disperse at 1000 rpm for 30 minutes.

[0093] S230, coating preparation: 350 kg of 325-mesh talc powder and 150 kg of 200-mesh feldspar powder were added to the kettle, and dispersed at 1000 rpm for 30 minutes to obtain the basic coating of this embodiment.

[0094] S300: Add 0.1kg of fluorocarbon surfactant and 8kg of alkyl alcohol amide to the base coating, disperse for 5 minutes, and detect the surface tension value of the coating system to be 30.3mN / m.

[0095] S400: Add 0.5 kg of lignin sulfonate to the coating system and disperse for 5 minutes. Detect the viscosity of the coating system after 4 cups of coating and it is 21.2 seconds, thereby obtaining the water-based coating product of this embodiment.

[0096] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A water-based paint, characterized in that: include: Base coating, adjuster A and adjuster B; The adjusting agent A is used to adjust the surface tension of the coating system to adapt to different sand molds; the ratio of the adding amount of the adjusting agent A to the adding amount of the base coating is 0.01 to 5:100; the adjusting agent A is a surfactant; The adjusting agent B is used to adjust the rheological properties of the coating system to adapt to different application methods; the ratio of the adding amount of the adjusting agent B to the base coating is 0.01 to 3:100; the adjusting agent B is a dispersing adjusting agent; The basic coating comprises, by weight, 50 to 70 parts of refractory powder, 2 to 8 parts of binder, 20 to 40 parts of water and 0.1 to 5 parts of clay mineral.

2. The water-based paint according to claim 1, characterized in that The water-based coating is applied to the surface of the casting sand mold; When the foundry sand mold is a hydrophobic sand mold, the adjusting agent A is a nonionic surfactant, and the surface tension of the coating system is adjusted to ≤35mN / m; the hydrophobic sand mold is a furan sand mold, a coated sand mold, a hot box sand mold, a shell mold or a cold box sand mold; When the casting sand mold is a hydrophilic sand mold, the adjuster A is an anionic surfactant, and the surface tension of the coating system is adjusted to 35-45 mN / m; the hydrophilic sand mold is a water glass sand mold, a phosphate inorganic binder sand mold or an alkali phenolic sand mold.

3. The water-based paint according to claim 2, characterized in that After the surface tension of the coating system is adjusted by using the adjusting agent A, the contact angle between the coating and the sand mold is 20° to 50°.

4. The water-based paint according to claim 2, characterized in that The nonionic surfactant comprises at least one of a fluorocarbon surfactant, a polyether-modified polysiloxane, a polyoxyethylene ether surfactant, an alkylolamide and an alkyl glycoside; The anionic surfactant includes at least one of sodium alkylbenzene sulfonate, alkyl ether sulfate, sulfosuccinate, and alkyl carboxylate.

5. The water-based paint according to claim 1, characterized in that The water-based coating is applied to the surface of the casting sand mold; When the application method is flow coating or dipping, the dispersion regulator includes lignin sulfonate, and the coating system viscosity is adjusted to 15 to 25 seconds per 4 cup. When the application method is spraying, the dispersion adjusting agent includes at least one of sodium polyacrylate, polyacrylamide, and styrene-maleic anhydride copolymer, and the coating system viscosity is adjusted to 25-40s after 4 cup coating; When the application method is brush coating, the dispersion regulator includes polyphosphate, which adjusts the viscosity of the coating system to 40 to 60 seconds per 4 cups of coating.

6. The water-based paint according to claim 1, characterized in that The refractory powder comprises a refractory aggregate of a first particle size and a refractory aggregate of a second particle size; The first particle size is 100 mesh to 200 mesh, and the second particle size is 200 mesh to 325 mesh; The refractory aggregate includes at least one of quartz powder, corundum powder, high-alumina bauxite powder, mullite powder, cordierite powder, flake graphite, earthy graphite, quartz powder, forsterite, magnesia powder, pyrophyllite, magnesium aluminum spinel, chromite powder, talc powder, dolomite, spodumene, feldspar powder, and mica powder.

7. The water-based paint according to claim 1, characterized in that The binder includes at least one of a water-soluble organic high molecular polymer, an organic high molecular polymer emulsion, an organic high molecular polymer aqueous dispersion, and an inorganic sol.

8. The water-based paint according to claim 1, characterized in that The clay mineral includes at least one of attapulgite, sepiolite, and synthetic hectorite.

9. The water-based paint according to claim 1, characterized in that The basic coating further comprises 0.01 to 3 parts of a defoaming agent and 0.01 to 1 part of a preservative.

10. A preparation method, applied to the water-based coating according to any one of claims 1 to 9, characterized in that: The water-based paint is prepared using a paint intelligent unit; The preparation method comprises the following steps: S1. Inputting production parameters into the coating intelligent unit, wherein the production parameters include casting material, sand mold type, and coating method; S2. Add water, binder and clay mineral to the coating preparation kettle of the coating intelligent unit and disperse for 20 to 40 minutes; add refractory powder to the coating preparation kettle and disperse for 10 to 40 minutes to prepare the base coating; S3, adding the adjusting agent A to the base coating and dispersing for 1 to 10 minutes; S4. Add the adjusting agent B to the base coating and disperse for 1 to 10 minutes.