Magnetic powder coating as well as preparation method and application thereof

Abstract

The invention belongs to the field of coatings, and particularly relates to a magnetic powder coating and a preparation method and application thereof, the magnetic powder coating comprises the following components by mass: 30-80 parts of soft magnetic powder, 16-69 parts of an adhesive, 0-20 parts of a filler, and 1-10 parts of an auxiliary agent; the adhesive comprises an organic adhesive and an inorganic adhesive; the mass ratio of the organic adhesive to the inorganic adhesive is 1: (4-20). The magnetic powder coating disclosed by the invention has excellent magnetic performance, has relatively good storage stability at high and low temperatures, and does not have the problems of deterioration and the like after three times of high and low temperature circulation; a paint film obtained through construction of the magnetic powder coating is smooth in surface, free of cracks, free of blistering, cracking, obvious powder falling and the like after being soaked in water for 48 h and excellent in water resistance and bonding performance.

Description

Technical Field

[0001] This invention belongs to the field of coatings, specifically relating to a magnetic powder coating, its preparation method, and its application. Background Technology

[0002] Magnetic adsorption materials are already widely used in daily life, such as magnetic dolls, magnetic refrigerator magnets, and magnetic sheets. These are attached to the surface of iron products, allowing for easy access without the need for adhesives or nails. However, iron products are not common, mainly consisting of iron plates, galvanized sheets, ferromagnetic films, and iron-based paint. It's difficult to find a piece of iron on a wall surface in a typical household, and it requires a certain size; existing refrigerators are often too small to accommodate large-scale functional displays or painted scenes. Ferromagnetic films are adhered to wall / decorative panel surfaces with adhesive backing, but their black surface alters the original appearance of the wall and is not popular with consumers. The emergence of iron-based paint has enabled commercial projects to achieve functional walls, allowing for painting on the wall surface before applying white or colored conventional interior wall paint.

[0003] CN104231708A discloses a soft magnetic coating containing flake-shaped soft magnetic powder, preferably 65%-85% flake-shaped soft magnetic powder, 9%-25% binder, 5-15% diluent, and 1-5.5% additives. The flake-shaped soft magnetic powder has a diameter along its long axis of 10nm-300μm, preferably 10μm-200μm, and an aspect ratio of 1-300, preferably 5-100. When used in conjunction with a permanent magnet material possessing a multi-pole static magnetic field, the soft magnetic coating exhibits ideal attraction between the permanent magnet material and the coating. The diluent is water, alcohol, ester, etc. The coating in CN104231708A is processed, produced, stored, and transported in a liquid state, which is difficult to manufacture and requires special pressure-resistant packaging, posing a risk of leakage and increasing transportation and storage costs. In addition, due to the density and cold resistance of the emulsion, there are many problems that need to be solved and overcome: For example: 1. The powder has a high density, while the organic polymer and water have low densities, resulting in a large density difference. This can cause sedimentation and clumping during storage and transportation, making it difficult to redisperse; 2. The emulsion is prone to freezing and demulsification at low temperatures, posing a freeze-thaw stability problem; 3. The viscosity is relatively low, making it suitable for roller and brush coating, but not for trowel application. Multiple coats are required to achieve a certain thickness, and the total thickness after application should not exceed 0.5 mm, otherwise problems such as paint film cracking and sagging may occur. These problems all lead to unstable paint quality, short shelf life, and difficulty in application. Summary of the Invention

[0004] In order to overcome at least one of the technical problems existing in the prior art, one of the objectives of the present invention is to provide a magnetic powder coating.

[0005] The second objective of this invention is to provide a method for preparing magnetic powder coating.

[0006] The third objective of this invention is to provide a method for applying magnetic powder coatings.

[0007] The fourth objective of this invention is to provide a sheet material.

[0008] The fifth objective of this invention is to provide the application of the above-mentioned magnetic powder coating or the above-mentioned construction method in the field of building construction or material surface finishing.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a magnetic powder coating comprising the following components in parts by weight: 30-80 parts of soft magnetic powder, 16-69 parts of binder, 0-20 parts of filler, and 1-10 parts of additives; The adhesive includes organic adhesive and inorganic adhesive; the mass ratio of the organic adhesive to the inorganic adhesive is 1:(4~20).

[0010] The powder coating in this invention is solid, and simple packaging (e.g., inner bag is a bone bag or sealed bag, outer bag is waterproof kraft paper or waterproof woven bag) is sufficient for storage and transportation. There is no need for pressure-resistant packaging such as iron cans, iron drums, and plastic drums. Production, storage and transportation costs are significantly reduced, and continuous automated production and automatic packaging can be achieved.

[0011] In some embodiments of the present invention, the mass ratio of the organic adhesive to the inorganic adhesive is any value or a range formed by any two of the following: 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20.

[0012] In some embodiments of the present invention, the mass fraction of the soft magnetic powder is selected from any value or a range formed by any two of the following: 30 parts, 32 parts, 34 parts, 35 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 45 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 55 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 65 parts, 66 parts, 68 parts, 70 parts, 72 parts, 74 parts, 76 parts, 78 parts, and 80 parts. If the soft magnetic powder content is low, its performance is low, requiring a very thick coating to achieve good adsorption. A very thick coating is prone to cracking, and the drying time is too long, thus seriously affecting the construction quality of the coating. If the soft magnetic powder content is too high, it easily affects the physical and construction properties of the coating, resulting in problems such as powdering after drying, poor adhesion to the wall, and low strength.

[0013] In some embodiments of the present invention, the soft magnetic powder is selected from at least one of iron, cobalt, nickel, ferric oxide, cobalt oxide, nickel oxide, and iron(II,III) oxide.

[0014] In some embodiments of the present invention, the average particle size of the soft magnetic powder is 0.01~297μm; in some embodiments of the present invention, the average particle size of the soft magnetic powder is any value or a range formed by any two of the following: 0.01μm, 1μm, 10μm, 30μm, 50μm, 70μm, 100μm, 110μm, 130μm, 150μm, 170μm, 200μm, 210μm, 230μm, 250μm, 270μm, 297μm; in some embodiments of the present invention, the average particle size of the soft magnetic powder is 1~297μm; in some embodiments of the present invention, the average particle size of the soft magnetic powder is 5~250μm. The ferromagnetic powder used for putty can have a larger average particle size than that used for iron powder paint. It has a higher viscosity, does not have a sedimentation problem, and its coarser average particle size solves the agglomeration problem.

[0015] In some embodiments of the present invention, the mass fraction of the adhesive is selected from any value of 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, or 69 parts, or a range formed by any two of these values.

[0016] In some embodiments of the present invention, the organic adhesive is selected from at least one of ethylene-vinyl acetate copolymer, vinyl acetate-ethylene tert-carbonate copolymer, and acrylic acid copolymer.

[0017] In some embodiments of the present invention, the organic adhesive is selected from at least one of Wacker 5044, Wacker 5048, and Wacker 5549.

[0018] In some embodiments of the present invention, the inorganic binder is selected from at least one of silicate cement and fly ash.

[0019] In some embodiments of the present invention, the silicate cement is at least one of grades 32.5 and 42.5.

[0020] In some embodiments of the present invention, the fly ash is secondary fly ash.

[0021] In some embodiments of the present invention, the mass fraction of the filler is selected from any value of 0 parts, 1 part, 5 parts, 10 parts, 15 parts, 20 parts, or a range formed by any two of these values.

[0022] In some embodiments of the present invention, the filler is selected from at least one of fine sand, calcium carbonate, gypsum, and talc. Introducing fillers into coatings can reduce the cost of the coatings.

[0023] In some embodiments of the present invention, the average particle size of the filler is 1~300μm; in some embodiments of the present invention, the average particle size of the filler is 5~250μm; in some embodiments of the present invention, the average particle size of the filler is 10~250μm.

[0024] In some embodiments of the present invention, the mass fraction of the adjuvant is selected from any value of 1 part, 2 parts, 4 parts, 5 parts, 6 parts, 8 parts, 10 parts, or a range formed by any two of these values.

[0025] In some embodiments of the present invention, the additive is selected from at least one of water-reducing agents, water-retaining agents, early-strength agents, defoamers, water-repellent agents, and mildew inhibitors.

[0026] In some embodiments of the present invention, the additive includes 0.01 to 1.5 parts by weight of a water-reducing agent; in some embodiments of the present invention, the water-reducing agent is any value or a range formed by any two of the following: 0.01 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, and 1.5 parts by weight.

[0027] In some embodiments of the present invention, the water-reducing agent includes at least one of the following: lignin sulfonic acid (such as sodium lignin sulfonate and calcium sodium lignin sulfonate), naphthalene sulfonate water-reducing agent (such as sodium naphthalene sulfonate water-reducing agent), melamine water-reducing agent (such as sulfonated melamine-formaldehyde resin), aminosulfonate water-reducing agent, fatty acid water-reducing agent (such as aliphatic hydroxysulfonate sodium polymer), aliphatic water-reducing agent (such as carbonyl pyraldehyde synthesized by polymer sulfonation), and polycarboxylic acid water-reducing agent.

[0028] In some embodiments of the present invention, the additive includes 0.1 to 3.0 parts by weight of a water-retaining agent; in some embodiments of the present invention, the parts by weight of the water-retaining agent are selected from any value or a range formed by any two of 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.8 parts, and 3.0 parts.

[0029] In some embodiments of the present invention, the water-retaining agent comprises cellulose ether. In some embodiments of the present invention, the water-retaining agent comprises hydroxypropyl methylcellulose ether.

[0030] In some embodiments of the present invention, the cellulose ether includes at least one of methylcellulose ether and hydroxypropyl methylcellulose ether.

[0031] In some embodiments of the present invention, the additive includes 0 to 2 parts by weight of an early strength agent; in some embodiments of the present invention, the mass parts of the early strength agent are any value or a range formed by any two of 0 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.8 parts, and 2.0 parts.

[0032] In some embodiments of the present invention, the early strength agent includes at least one of calcium chloride, sodium chloride, mirabilite, gypsum, water glass, sodium aluminate, sodium carbonate, calcium carbonate, and calcium formate.

[0033] In some embodiments of the present invention, the additive includes 0.01 to 1 part by weight of defoamer; in some embodiments of the present invention, the part by weight of defoamer is any value or a range formed by any two of 0.01 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, and 1.0 parts.

[0034] In some embodiments of the present invention, the defoamer includes at least one of three major categories of defoamers: polyether, silicone, and non-silicone. Polyether defoamers can significantly reduce the surface tension of foaming liquids and have excellent foam-suppressing ability, although their defoaming ability is slightly weaker than that of silicone defoamers. The advantages of silicone defoamers include: very small dosage, strong defoaming ability, low volatility, antioxidant properties, non-toxicity, odorless and without side effects, and low solubility in water and most oils. Non-silicone defoamers are mainly composed of organic compounds such as fatty amides, phosphate esters, alcohols, and ethers. They are inexpensive but have poor stability and some toxicity, resulting in poor safety. The defoamer described is a powder defoamer, which can eliminate bubbles generated during the mixing and stirring of coatings with water during application, thereby improving the wetting process of the coating. It can also prevent the formation of bubbles during application, thus improving the strength of the paint film formed after drying.

[0035] In some embodiments of the present invention, the polyether defoamer includes at least one of a block copolymer of polyethylene glycol and polypropylene glycol, a homopolymer of ethylene oxide, a homopolymer of propylene oxide, and a copolymer of ethylene oxide and propylene oxide.

[0036] In some embodiments of the present invention, the silicone defoamer includes at least one of polysiloxane, polyether-modified silicone, alkyl-modified silicone, and fluorine-modified silicone; in some embodiments of the present invention, the silicone defoamer includes at least one of polydimethylsiloxane and polysiloxane-polyether copolymer.

[0037] In some embodiments of the present invention, the additive comprises 0 to 5 parts of a water-repellent agent; in some embodiments of the present invention, the mass parts of the water-repellent agent are any value or a range formed by any two of the following: 0 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.8 parts, 3.0 parts, 3.2 parts, 3.4 parts, 3.5 parts, 3.6 parts, 3.8 parts, 4.0 parts, 4.2 parts, 4.4 parts, 4.5 parts, 4.6 parts, 4.8 parts, and 5.0 parts.

[0038] In some embodiments of the present invention, the water-repellent agent includes a polysiloxane powder water-repellent agent. The polysiloxane powder water-repellent agent is a ternary fine-particle organosilicon powder resin composed of a powder carrier, a colloidal coating material, and an organosilicon active ingredient, with a pH value of 10-12. Its core component is a highly dispersible organosilicon active polymer material formed by redispersing activated silica-supported siloxane organic resin. This material stabilizes the active ingredient through colloidal coating technology, releases it upon addition of water, and reacts with cement to form calcium silicate, forming a structure with water-repellent and impermeable properties. The polysiloxane powder water-repellent agent not only exhibits highly efficient water-repellent properties but also has the ability to rapidly and uniformly mix the putty-type coatings of the present invention.

[0039] In some embodiments of the present invention, the water-repellent agent is selected from at least one of Dow Corning SHP-50, Wacker SILRES powder A, Wacker SILRES powder D, AkzoNobel ELOTEX SEAL80, and AkzoNobel ELOTEX SEAL 81.

[0040] In some embodiments of the present invention, the additive includes 0.01 to 1 part of a mildew inhibitor; in some embodiments of the present invention, the parts by weight of the mildew inhibitor are any one of 0.01 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1.0 parts, or a range formed by any two of these.

[0041] In some embodiments of the present invention, the antifungal agent includes at least one of titanium dioxide, zinc oxide, silver ion compounds, and copper ion compounds.

[0042] In some embodiments of the present invention, the additives include the following components: 0.01 to 1.5 parts by weight of water-reducing agent; 0.1 to 3.0 parts by weight of water-retaining agent; 0 to 2 parts by weight of early-strength agent; 0.01 to 1 part by weight of defoamer; 0 to 5 parts by weight of water-repellent agent; and 0.01 to 1 part by weight of mildew inhibitor.

[0043] The second aspect of the present invention provides a method for preparing the magnetic powder coating described in the first aspect of the present invention, comprising the following steps: The mixture is prepared by mixing the raw materials.

[0044] In some embodiments of the present invention, the mixing is carried out using mixing equipment such as kneaders, high-speed mixers, blenders, and twin-screw extruders.

[0045] The powder coating in this invention can be sealed and stored in a bone bag or vacuum bag.

[0046] A third aspect of the present invention provides a method for applying magnetic powder coatings, comprising the following steps: The magnetic powder coating described in the first aspect of the present invention is mixed with water and then applied by troweling.

[0047] In some embodiments of the present invention, the mass ratio of magnetic powder coating to water is (2~4):1.

[0048] In some embodiments of the present invention, the consistency of the magnetic powder coating after mixing with water is controlled at 5~7cm.

[0049] During construction, the coating of this invention can be mixed with water. The coating has good dispersibility in water, and it can be mixed evenly with simple stirring. Water is added to the coating on-site while stirring to achieve a putty-like consistency. Applying the coating to the wall using a putty-like troweling method allows for free control of the thickness, shortens construction time, and prevents cracking. In contrast, conventional iron powder paint requires multiple applications, has limited thickness, and is prone to cracking. The troweling method achieves a smooth paint film surface that can be sanded. Due to its thickness of 1-2mm, it can also create the rough texture of artistic paint.

[0050] A fourth aspect of the present invention provides a sheet material including a magnetic layer, said magnetic layer being made using the magnetic powder coating described in the first aspect of the present invention.

[0051] In some embodiments of the present invention, the thickness of the magnetic layer is 0.1~2mm.

[0052] The fifth aspect of the present invention provides the application of the magnetic powder coating described in the first aspect of the present invention or the construction method described in the third aspect of the present invention in the field of construction or material surface decoration.

[0053] The beneficial effects of this invention are as follows: The magnetic powder coating of this invention has excellent magnetic properties and good storage stability at both high and low temperatures, without deterioration after three high and low temperature cycles; the paint film obtained by applying the magnetic powder coating of this invention has a smooth, crack-free surface, and exhibits no bubbling, cracking, or significant powdering after immersion in water for 48 hours, demonstrating excellent water resistance and adhesion. Furthermore, the coating of this invention also has excellent application performance, can be applied to wall surfaces by troweling, achieving a paint film thickness of up to 2mm without cracking, and dries quickly, allowing for manual or mechanical sanding of the paint film surface.

[0054] Furthermore, the magnetic powder coating in this invention is solid, which facilitates storage and transportation, reduces storage and transportation costs, and avoids problems such as leakage, freeze-thaw cycles, demulsification, and sedimentation that exist in the storage and transportation of liquid coatings. Attached Figure Description

[0055] Figure 1 This is a photograph of the paint film formed after the application of the putty-type magnetic powder coating in Example 1.

[0056] Figure 2 This is a photograph of the paint film formed after the application of the soft magnetic coating in Comparative Example 3.

[0057] Figure 3 This is a photograph of the paint film formed after the application of the putty-type magnetic powder coating in Example 2.

[0058] Figure 4 This is a photograph of the paint film formed after the application of the putty-type magnetic powder coating in Comparative Example 2. Detailed Implementation

[0059] The specific implementation of the present invention will be further described in detail below with reference to the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described in detail below are those that can be implemented or understood by those skilled in the art by referring to the prior art. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0060] The raw material information used in the following examples and comparative examples is as follows: The organic adhesive is an ethylene-vinyl acetate copolymer, model number: Wacker 5044, purchased from Wacker Germany; The inorganic binder is a silicate binder, model: silicate cement 42.5, commercially available; Water-reducing agent: Polycarboxylate-based high-efficiency water-reducing agent, model: TD-JSS2, purchased from Tuoda (Shandong) New Material Technology Industry Group Co., Ltd.; Water-retaining agent: Hydroxypropyl methylcellulose ether (HPMC), purchased from Shandong Ruitai Chemical Co., Ltd. Early strength agent: Calcium chloride, commercially available; Hydrophobic agent: Siloxane powder hydrophobic agent SHP50, Dow Chemical; Powder defoamer: Modified organosiloxane defoamer JY-861, purchased from Jiangsu Jianyu Additives Technology Co., Ltd.; Example 1 This example provides a putty-type magnetic powder coating, which is composed of the following components: 4 kg of iron powder, 990 g of binder (the mass ratio of organic binder to inorganic binder is 1:10), 100 g of gypsum, 10 g of water-reducing agent, 20 g of water-retaining agent, 20 g of early strength agent, and 10 g of powder defoamer.

[0061] The putty-type magnetic powder coating in this example is prepared using a method that includes the following steps: The required materials in the formula are weighed using an electronic scale, and then mixed using a mixer at a speed of 100 rpm for 10 minutes to obtain a mixture. The mixture is then sealed and stored in a bone bag or vacuum bag to obtain the putty-type magnetic powder coating in this example.

[0062] Add the prepared putty-type magnetic powder coating to a mixer, and slowly add water, which accounts for one-third of the total mass of the powder coating. Disperse for 20 minutes and let stand for 30 minutes. Then apply it to the wall or board surface using a troweling method. Apply approximately 0.8 kg of iron powder per square meter, with a dry film thickness of 0.5 mm.

[0063] The various properties of the putty-type magnetic powder coating prepared in this example were tested. The specific test basis and test results are shown in Table 1 below.

[0064] Table 1 Performance test results of putty-type magnetic powder coatings

[0065] Example 2 This example provides a putty-type magnetic powder coating that has good waterproof performance after curing. It is composed of the following components: 4 kg of iron powder, 990 g of adhesive (the mass ratio of organic adhesive to inorganic adhesive is 1:10), 10 g of water-reducing agent, 20 g of water-retaining agent, 20 g of early-strength agent, 50 g of water-repellent agent, and 10 g of powder defoamer.

[0066] The putty-type magnetic powder coating in this example is prepared using a method that includes the following steps: The required materials in the formula are weighed using an electronic scale, and then prepared according to the preparation method in Example 1.

[0067] The putty-type magnetic powder coating prepared in this example is applied to the surface of a wall or board using a troweling method. Approximately 0.8 kg of iron powder can be applied per square meter, resulting in a dry film thickness of 0.5 mm. The vertical tensile strength is then tested and found to be 9.8-10.2 g / cm². 2 .

[0068] In this invention, the vertical tensile force is achieved by coating a 0.085mm thick PET film with a coating thickness of 0.30mm. After the coating has dried and cured for 3 hours, it is attached to a flat glass surface. A magnet with a magnetic moment of 1.5mm, a surface magnet of 100Gs, and an area of ​​100cm² is used. 2 The tensile tester on the circular magnetic adhesive test pan measured the vertical tensile force of the coating to be 1.80 g / cm. 2 .

[0069] The various properties of the putty-type magnetic powder coating prepared in this example were tested. The specific test basis and test results are shown in Table 2 below.

[0070] Table 2 Performance test results of putty-type magnetic powder coatings

[0071] Comparative Example 1 This example provides a putty-type magnetic powder coating, which is composed of the following components: 4 kg of iron powder, 990 g of binder (the mass ratio of organic binder to inorganic binder is 1:3), 100 g of gypsum, 10 g of water-reducing agent, 20 g of water-retaining agent, 20 g of early strength agent, and 10 g of powder defoamer.

[0072] In this example, the putty-type magnetic powder coating is prepared by weighing the required materials in the formula using an electronic scale and then referring to the preparation method in Example 1.

[0073] The putty-type magnetic powder coating used in this example is applied to the wall or panel surface using a plastering method. Approximately 0.75 kg of iron powder can be applied per square meter, resulting in a dry film thickness of 0.5 mm. The vertical tensile strength is then tested and found to be 9.0-9.4 g / cm². 2 .

[0074] Comparative Example 2 This example provides a putty-type magnetic powder coating, which is composed of the following components: 4 kg of iron powder, 990 g of binder (the mass ratio of organic binder to inorganic binder is 1:21), 10 g of water-reducing agent, 20 g of water-retaining agent, 20 g of early-strength agent, 50 g of water-repellent agent, and 10 g of powder defoamer.

[0075] In this example, the putty-type magnetic powder coating is prepared by weighing the required materials in the formula using an electronic scale and then referring to the preparation method in Example 1.

[0076] The putty-type magnetic powder coating used in this example is applied to the wall or panel surface using a plastering method. Approximately 0.8 kg of iron powder can be applied per square meter, resulting in a dry film thickness of 0.5 mm. The vertical tensile strength is then tested and found to be 10.0-10.4 g / cm². 2 However, the paint film obtained in this example has already cracked and does not meet the usage requirements.

[0077] Comparative Example 3 This example provides a soft magnetic coating, which is composed of the following components by mass percentage: 80.5 wt% soft magnetic powder (i.e., iron powder), 10 wt% binder (i.e., polyvinyl butyral), 8 wt% diluent (i.e., ethanol), 0.8 wt% polyurethane, 0.5 wt% silicone oil, and 0.2 wt% sodium dodecyl sulfate.

[0078] The soft magnetic coating in this example is prepared using a method that includes the following steps: The iron powder is ground into flake-shaped iron powder with a diameter of 50-80 μm and a diameter-to-thickness ratio of 20-35 along the long axis using a grinding mill. The flake-shaped iron powder is then mixed with binder, diluent and additives (i.e. polyurethane, silicone oil and sodium dodecyl sulfate) into a container and stirred for 50 minutes at 500 rpm using a disperser to obtain the soft magnetic coating in this example.

[0079] Because the soft magnetic coating in this example has a low viscosity, it needs to be applied to the wall surface by roller coating or brushing. After three coats, the final dry film thickness is approximately 0.22-0.24 mm. Then, using the same method, its vertical tensile strength was tested and found to be 4.6-5.0 g / cm². 2 .

[0080] The coatings in Examples 1-2 and Comparative Examples 1-3 were evaluated in terms of workability, waterproofing effect, bonding strength, whether the dry film cracked, and production cost. The specific evaluation results are shown in Table 3.

[0081] Table 3 Performance evaluation results of the coatings in Examples 1-2 and Comparative Examples 1-3

[0082] As shown in Table 3, the putty-type magnetic powder coatings in Examples 1-2 of this invention, by introducing inorganic and organic binders, can achieve advantages such as superior workability, better waterproofing, superior bonding strength, crack-free paint film surface, and lower cost. A physical image of the paint film formed after application of the powder coating in Example 1 is shown below. Figure 1As shown, its surface is smooth and crack-free, and can be polished to achieve a smooth finish. However, Comparative Example 1 increased the proportion of organic adhesive in the binder, resulting in poorer waterproofing performance and increased cost. Comparative Example 2 increased the proportion of inorganic adhesive in the binder, significantly deteriorating both the waterproofing performance and bonding strength of the coating, and producing numerous cracks on the dry film surface. Comparative Example 3 used a liquid coating, which exhibited poor bonding strength and workability, requiring multiple applications and resulting in a thin dry film. Further increasing the film thickness would lead to numerous cracks on the surface. Furthermore, the coating in Comparative Example 3 was more expensive, and the surface roughness of the roller-coated film was greater, specifically as shown in... Figure 2 As shown, the paint film surface is uneven. A photograph of the paint film formed after the powder coating application in Example 2 is shown below. Figure 3 As shown, the actual product image after the paint application in Comparative Example 2 is as follows. Figure 4 As shown, by Figure 3 and Figure 4 It can be seen that, for the same thickness of paint film, the paint film surface of Example 2 is smooth and without cracks, while the paint film surface of Comparative Example 2 has a large number of cracks and cannot be used.

[0083] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A magnetically attractable powder coating, characterized in that: The components include the following quality parts: soft magnetic powder 30~80 parts, binder 16~69 parts, filler 0~20 parts, and additive 1~10 parts. The binder includes organic binder and inorganic binder; the mass ratio of the organic binder to the inorganic binder is 1: (4~20).

2. The magnetic powder coating according to claim 1, characterized in that: The organic binder is selected from at least one of ethylene-vinyl acetate copolymer, vinyl acetate-tert-vinyl acetate copolymer, and acrylic acid copolymer; and / or, the inorganic binder is selected from at least one of Portland cement and fly ash; and / or, the material of the soft magnetic powder is selected from at least one of iron, cobalt, nickel, diiron trioxide, cobalt oxide, nickel oxide, and triiron tetroxide; and / or, the filler is selected from at least one of fine sand, calcium carbonate, gypsum, and talcum powder.

3. The magnetic powder coating according to claim 1, characterized in that: The additive is selected from at least one of water reducing agent, water retaining agent, early strength agent, defoaming agent, water repellent agent, and mildew-proof agent.

4. The magnetic powder coating according to claim 3, characterized in that: The additive includes 0.01~1.5 mass parts of water reducing agent; and / or, the additive includes 0.1~3.0 mass parts of water retaining agent; and / or, the additive includes 0~2 mass parts of early strength agent; and / or, the additive includes 0.01~1 mass parts of defoaming agent; and / or, the additive includes 0~5 parts of water repellent agent; and / or, the additive includes 0.01~1 part of mildew-proof agent.

5. The magnetic powder coating according to claim 3 or 4, characterized in that: The water reducing agent includes at least one of lignin sulfonate, naphthalene sulfonate water reducing agent, melamine water reducing agent, aminosulfonate water reducing agent, fatty acid water reducing agent, HSB aliphatic water reducing agent, and polycarboxylic acid water reducing agent; and / or, the water retaining agent includes cellulose ether; and / or, the early strength agent includes at least one of calcium chloride, sodium chloride, mirabilite, gypsum, water glass, sodium aluminate, sodium carbonate, calcium carbonate, and calcium formate; and / or, the defoaming agent includes at least one of polyether type defoaming agent and silicone type defoaming agent; and / or, the water repellent agent includes polysiloxane powder water repellent agent; and / or, the mildew-proof agent includes at least one of titanium dioxide, zinc oxide, silver ion compound, and copper ion compound.

6. The method of producing the magnetic powder paint according to any one of claims 1 to 5, characterized by: The method includes the following steps: After mixing the raw materials, the magnetic powder coating is prepared.

7. A method of applying a magnetic powder coating, characterized by: The method includes the following steps: The magnetic powder coating of any one of claims 1~5 is mixed with water, and then the construction is performed in a batch manner.

8. A panel, characterized by: The magnetic layer is made of the magnetic powder coating of any one of claims 1~5.

9. The panel of claim 8, wherein: The thickness of the magnetic layer is 0.1~2 mm.

10. Application of the magnetic powder coating of any one of claims 1~5 or the construction method of claim 7 in the field of building or the field of material surface decoration.

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