Coating materials, their production and use

Abstract

The application discloses a coating and a preparation method and application thereof, and belongs to the technical field of coating materials.The coating comprises a base material, a phenolphthalein type polyether ketone and an inorganic filler.The coating has excellent high-temperature resistance, insulation, fireproof and flame-retardant properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of paint, in particular to a paint, a preparation method and application thereof. BACKGROUND

[0002] High temperature resistant paint generally refers to paint that does not fall off and can still maintain certain physical and mechanical properties at a temperature above 200 DEG C, so that the protected substrate can still function normally at a higher temperature. High temperature resistant paint is generally divided into inorganic high temperature resistant paint and organic high temperature resistant paint. However, the adhesion of the existing inorganic high temperature resistant paint is weak, resulting in poor film forming property of the paint, and the insulating property is not good; and the organic high temperature resistant paint has poor high temperature resistance, is expensive, and has poor storage performance. Therefore, how to provide a paint with good insulating property, high temperature resistance and strong adhesion and good film forming property has become the key. SUMMARY

[0003] The purpose of the present application is to provide a paint, a preparation method and application thereof, and to solve the problems of poor stability and poor high temperature resistance of the existing paint.

[0004] To achieve the purpose of the present application, the present application provides the following technical solutions:

[0005] In a first aspect, the present application provides a paint, which comprises a base material, a phenolphthalein type polyether ketone and an inorganic filler.

[0006] In an embodiment, the phenolphthalein type polyether ketone comprises a hydroxylated phenolphthalein type polyether ketone, and the hydroxylated phenolphthalein type polyether ketone reacts with the base material to form a crosslinked structure.

[0007] In an embodiment, the base material comprises one or more of epoxy resin, polyester resin, polyurea-formaldehyde resin, polyurethane, polyimide and phenolic resin.

[0008] In an embodiment, the mass ratio of the phenolphthalein type polyether ketone, the base material and the inorganic filler is 1:(1-4):(7-20).

[0009] In an embodiment, the weight average molecular weight of the hydroxylated phenolphthalein type polyether ketone is 30000-100000.

[0010] In an embodiment, the inorganic filler comprises glass powder, and in the paint, the mass fraction of the glass powder is 10%-20%.

[0011] In an embodiment, the softening point of the glass powder is 320 DEG C-430 DEG C.

[0012] In an embodiment, the average particle size of the glass powder is 5-30 mu m.

[0013] In an embodiment, the inorganic filler comprises boron nitride, and the mass percentage of the boron nitride in the coating is 20% to 40%.

[0014] In an embodiment, the average particle size of the boron nitride is 10 μm to 30 μm.

[0015] In an embodiment, the inorganic filler comprises a flame-retardant filler, and the mass percentage of the flame-retardant filler in the coating is 1% to 15%.

[0016] In an embodiment, the flame-retardant filler comprises one or more of aluminum hydroxide, magnesium hydroxide, ceramic powder, and sericite.

[0017] In an embodiment, the inorganic filler comprises an oxide filler, and the mass percentage of the oxide filler in the coating is 10% to 30%.

[0018] In an embodiment, the oxide filler comprises one or more of aluminum oxide, boron oxide, zirconium oxide, zinc oxide, and silicon powder.

[0019] In an embodiment, the coating further comprises a curing agent, and the mass percentage of the curing agent in the coating is 1% to 8%.

[0020] In an embodiment, the coating further comprises a coupling agent, and the mass percentage of the coupling agent in the coating is 1% to 8%.

[0021] In a second aspect, the application provides a method for preparing a coating, comprising: dissolving a phenolphthalein-type polyether ketone in a solvent to obtain a polymer solution; and mixing a base material, an inorganic filler, and the polymer solution to obtain the coating after uniform mixing.

[0022] In a third aspect, the application provides a sheet metal, comprising: a metal base material and a coating layer coated on the metal base material, wherein the coating layer is obtained by solidifying the coating of the first aspect.

[0023] The coating provided by the application includes a base material, a phenolphthalein type polyether ketone and an inorganic filler, and can form a protective film layer after brushing. The coating has the following advantages: 1) the film forming effect of the high molecular organic matter (phenolphthalein type polyether ketone) is good, the material itself is not easy to be brittle, and it is not easy to appear cracks before and after solidification and film formation, and has good water resistance, so the stability is high; 2) the phenolphthalein type polyether ketone itself has high high-temperature resistance, and the addition of the phenolphthalein type polyether ketone in the coating can obviously improve the temperature resistance of the coating; 3) after the coating is formed into a film, the inorganic filler can be combined in the base material and the phenolphthalein type polyether ketone, and after the phenolphthalein type polyether ketone fails beyond the first temperature range, the inorganic filler further provides high-temperature resistance (at the second temperature range), thereby improving the high-temperature resistance of the coating. The combination of organic and inorganic materials can make the coating provided by the application have a high-temperature resistance of 600℃.

[0024] In addition, the coating provided by the application can also have the following effects: 1) high insulation, because the coating is obtained by mixing inorganic and organic materials, the high molecular organic matter has insulation characteristics, and the inorganic materials used are mostly oxides and inorganic salts, which are poor conductors, so it can be applied to the surface of a metal substrate to play an insulating role; 2) fireproof and flame retardant, because the phenolphthalein type polyether ketone and the inorganic filler both have flame retardant properties, the coating can be applied to the surface of a metal substrate to play a fireproof and flame retardant role; 3) strong adhesion, the high molecular organic matter can be used as an excellent adhesive, so the base material and the phenolphthalein type polyether ketone in the coating can provide high adhesion properties, and the shear strength of the coating prepared by the coating to aluminum plate or stainless steel material can reach more than 7MPa; 4) shock resistance and weather resistance, the cross-linked structure of the formed coating, the high molecular chain is connected by covalent bond, the connection strength is high, and it is not easy to break even at low temperature, so the coating prepared by the coating does not crack under the condition of 600℃ to air quenching. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Figure 1 is a molecular structure diagram of a phenolphthalein type polyether ketone;

[0027] Figure 2 is a molecular structure diagram of a hydroxylated phenolphthalein type polyether ketone;

[0028] Figure 3 is a preparation flowchart of a coating of one embodiment. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

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

[0031] Some embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0032] The following are explanations of the terms appearing in the text:

[0033] Weight average molecular weight (Mw): refers to the molecular weight of all molecules multiplied by the sum of the weight fraction of each, which is an important parameter for describing the distribution of high molecular weight. The test methods of weight average molecular weight include gel permeation chromatography, light scattering method, viscosity method and mass spectrometry.

[0034] Softening point: refers to the temperature at which a substance begins to soften, which is used to describe a specific point at which an amorphous polymer changes from a hard and solid state to a plastic state at a certain temperature.

[0035] Average particle size: the particle size D50 of inorganic fillers, also referred to as the diameter of the cumulative 50% point; measured by laser particle size analysis method, the size distribution of particles is determined by analyzing the mode of scattered light through laser beam irradiation of particles.

[0036] The present application provides a coating material, which can be used in high temperature environment, and the high temperature resistance can reach 600℃. The coating material comprises a base material, a phenolphthalein type polyether ketone and an inorganic filler.

[0037] Specifically, the base material is a high molecular organic matter, which can be specifically epoxy resin, polyester resin, polyurea-formaldehyde resin, polyurethane, polyimide, phenolic resin, etc. The phenolphthalein type polyether ketone is a special polymer material (please refer to Figure 1Phenolphthalein polyether ketone has a molecular structure as shown in the figure, and combines the properties of phenolphthalein and polyether ketone. The high polymer material is connected by phenylene rings through ether bonds and carbonyl groups. The material has the advantages of high strength, high modulus, impact resistance, good thermal stability, good electrical insulation, corrosion resistance, and good dimensional stability.

[0038] Optionally, the inorganic filler can include one or more of metal oxides (aluminum oxide, zirconium oxide, etc.), non-metal oxides (silicon dioxide, boron oxide, etc.), nitrides (boron nitride, silicon nitride, etc.), silicates, phosphates, ethyl silicate, etc. It needs to be explained that the high-temperature resistance of the inorganic filler can reach 400-1000℃, or even higher; and the hardness is generally higher than that of the high-molecular organic material, and the inorganic filler can further provide temperature resistance after the high-molecular organic material fails at high temperature.

[0039] The coating provided by the present application is an organic-inorganic hybrid composite high-temperature-resistant material, which is mainly composed of high-molecular organic material and added with inorganic filler. The film-forming material will be changed from organic material to inorganic material at high temperature, thereby realizing the protection of the metal substrate in a wide temperature range. The general film-forming mechanism is as follows: when the high-molecular organic material is decomposed and carbonized under heat, loses sufficient adhesive property, and the inorganic filler of the film-forming material melts and replaces the high-molecular organic material to continue to adhere to the filler. The melting point of the film-forming material is adapted to the thermal decomposition temperature of the high-molecular organic material.

[0040] Further, the decomposition temperature of the phenolphthalein polyether ketone is a first temperature range, the decomposition temperature of the inorganic filler is a second temperature range, and the maximum value of the first temperature range is less than the maximum value of the second temperature range. The decomposition temperature of the phenolphthalein polyether ketone is a first temperature range, which can be 400-600℃, i.e. the phenolphthalein polyether ketone starts to decompose in this temperature range. The decomposition temperature of the inorganic filler is a second temperature range, which can be 400-1000℃. Therefore, the coating provided by the present application can ensure thermal stability in the range of 400-1000℃.

[0041] The coating provided by the present application includes a base material, phenolphthalein polyether ketone, and inorganic filler, and can form a protective film layer after being brushed. The coating has the following advantages: 1) the film-forming effect of the high-molecular organic material (phenolphthalein polyether ketone) is good, the material itself is not easy to break, and is not easy to crack before and after solidification and film formation, and has good water resistance, so the stability is high; 2) the phenolphthalein polyether ketone itself has high high-temperature resistance, and the addition of the phenolphthalein polyether ketone in the coating can significantly improve the temperature resistance of the coating; 3) after the coating is formed into a film, the inorganic filler can be combined in the cross-linked structure, and further provide high-temperature resistance after the cross-linked structure fails at high temperature, thereby improving the high-temperature resistance of the coating. The combination of organic and inorganic materials can make the coating provided by the present application resistant to high temperature of 600℃.

[0042] In addition, the coating provided by the present application can also have the following effects: 1) high insulation, because the coating is obtained by mixing inorganic materials and organic materials, the high molecular organic matter itself has insulating properties, and the inorganic materials used are mostly oxides and inorganic salts, which are poor conductors, so it can be applied to the surface of the metal substrate to play an insulating role; 2) fire retardancy, because the phenolphthalein type polyether ketone and the inorganic filler both have flame retardant properties, the coating can be applied to the surface of the metal substrate to play a fire retardant role; 3) strong adhesion, the high molecular organic matter can be used as an excellent binder, so the collective material and the phenolphthalein type polyether ketone in the coating can provide higher bonding properties, and the shear strength of the coating prepared by the coating with the aluminum plate or stainless steel can reach more than 7MPa; 4) seismic resistance and weather resistance, the film-forming coating has a cross-linked structure, and the polymer chains are connected by covalent bonds, and the connection strength is high, and it is not easy to break even at low temperatures, so the coating prepared by the coating does not crack under conditions of 600°C to air rapid cooling.

[0043] In one embodiment, please refer to Figure 2 The phenolphthalein type polyetherketone includes a hydroxylated phenolphthalein type polyetherketone, which reacts with the matrix material to form a cross-linked structure. Figure 1 and Figure 2 The difference between phenolphthalein polyether ketone and hydroxylated phenolphthalein polyether ketone can be seen in the figure. By converting the carbonyl position of phenolphthalein polyether ketone into a hydroxyl group, hydroxylated phenolphthalein polyether ketone with higher heat resistance is obtained.

[0044] During the synthesis process, hydroxylated phenolphthalein-based polyetherketone (PEK) is modified by introducing hydroxyl functional groups, thus modifying its original chemical properties. Hydroxylated phenolphthalein-based polyetherketone (PEK) exhibits excellent thermal stability, mechanical strength, and specific chemical reactivity, making it suitable for use in various extreme environments such as high temperature, high pressure, or chemical corrosion.

[0045] Understandably, the temperature resistance of ordinary matrix materials is generally between 100°C and 400°C. However, polymers with cross-linked structures have significantly improved thermal stability, mechanical strength, and chemical resistance. Moreover, as the degree of cross-linking increases, the free mobility of the chain segments decreases, resulting in decreased plasticity and elongation, while strength, elasticity, and hardness increase. The hydroxyl groups on hydroxylated phenolphthalein-based polyetherketones have high reactivity and can act as a "linker" for the matrix material. Hydroxylated phenolphthalein-based polyetherketones react with the polymer segments on the matrix material and connect the molecular chains to form a large-scale three-dimensional network structure, which can significantly improve the high-temperature resistance of the coating.

[0046] The phenolphthalein type polyether ketone is used as a "linking agent" to form a cross-linked structure with the matrix material. After the coating is formed, the phenolphthalein type polyether ketone and the matrix material can play a high-temperature resistant role before 450 DEG C to 500 DEG C. Meanwhile, the coating provided by the application can also have corrosion resistance. After the matrix material is cross-linked with the phenolphthalein type polyether ketone, the resistance to inorganic / organic solvents is further improved, and the inorganic filler does not react with the organic solvent, so that the coating can provide good corrosion resistance for the metal substrate.

[0047] In an embodiment, in the coating, the mass ratio of the phenolphthalein type polyether ketone, the matrix material and the inorganic filler is 1:(1-4):(7-20).

[0048] Alternatively, the mass ratio of the phenolphthalein type polyether ketone, the matrix material and the inorganic filler can be 1:1:(7-20), 1:2:(7-20), 1:3:(7-20), 1:4:(7-20), 1:(1-4):7, 1:(1-4):10, 1:(1-4):12, 1:(1-4):14, 1:(1-4):16, 1:(1-4):18, 1:(1-4):20.

[0049] In an embodiment, in the coating, the mass fraction of the phenolphthalein type polyether ketone can be 5%-15%. Alternatively, the mass fraction of the phenolphthalein type polyether ketone can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%. The mass fraction of the phenolphthalein type polyether ketone is within the above range, which can ensure that the phenolphthalein type polyether ketone improves the temperature resistance of the coating, or can fully play the role of the functional groups in the hydroxylated phenolphthalein type polyether ketone to form a cross-linked structure with the matrix material.

[0050] In an embodiment, the weight average molecular weight of the hydroxylated phenolphthalein type polyether ketone is 30000-100000. Alternatively, the weight average molecular weight of the hydroxylated phenolphthalein type polyether ketone can be 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000. The weight average molecular weight of the hydroxylated phenolphthalein type polyether ketone is within the above range, which can ensure that the hydroxylated phenolphthalein type polyether ketone has high structural strength and high temperature resistance; at the same time, it also has excellent solubility in a specific solvent, which is convenient for processing.

[0051] In one embodiment, the matrix material is an epoxy resin, and the weight percentage of the epoxy resin in the coating can be 10% to 20%. Optionally, the weight percentage of the epoxy resin can be 10%, 11%, 12%, 13%, 14%, 5%, 20%, 16%, 17%, 18%, 19%, or 20%. Meeting the weight percentage of the epoxy resin within the above range can ensure that the coating has enhanced film-forming properties, good dispersibility, and the ability to form a cross-linked structure.

[0052] Optionally, the type of epoxy resin may be E-44, E-51, E-42, or E-54.

[0053] As you can understand, due to the chemical activity of the epoxy group, it can be ring-opened with a variety of compounds containing active hydrogen, cured and cross-linked to form a network structure, making it a thermosetting resin. Epoxy resin has excellent physical and chemical properties, including heat resistance, chemical stability, electrical insulation, and mechanical strength. It maintains stability in extreme environments such as high temperature and high pressure, and the desired performance can be achieved by adjusting the formulation. Furthermore, cured epoxy resin products are characterized by high cleanliness, resistance to dust contamination, rich colors, waterproof and mildew-resistant, good toughness, and corrosion resistance. However, please note that epoxy resin has relatively poor high-temperature resistance and is prone to scratching, so attention should be paid to the applicable environmental conditions when using it.

[0054] In one embodiment, the inorganic filler comprises glass powder. Specifically, glass powder is an inorganic, amorphous, hard, ultrafine particle powder with a white appearance. Its production raw materials primarily include high-temperature, high-purity silicon oxide and aluminum oxide. Through an ultra-clean production process, it forms a disordered, transparent glass powder. This material possesses stable chemical properties, exhibiting acid and alkali resistance, chemical inertness, and a low coefficient of expansion, making it a highly weather-resistant powder material.

[0055] The purpose of using glass powder in this application is: 1) to use glass powder to increase the upper limit of high temperature resistance of the coating. It can be understood that glass powder, as an inorganic material, has excellent high temperature resistance itself and can continue to provide heat resistance after the organic material fails; 2) hydroxylated phenolphthalein polyether ketone and glass powder are combined as the main film-forming materials. Before 450-500°C, the hydroxylated phenolphthalein polyether ketone mainly plays a high temperature resistance role, and after exceeding 500°C, the glass powder mainly plays a high temperature resistance role. The prepared coating can withstand up to 600°C; 3) glass powder can serve as a "binder" for other inorganic fillers. At high temperatures, the glass powder can melt and bond other inorganic fillers together, thereby ensuring that the coating will not crack or be damaged.

[0056] In one embodiment, the mass percentage of the glass powder in the coating is 10% to 20%. Optionally, the mass percentage of the glass powder can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.

[0057] In one embodiment, the softening point of the glass powder is 320°C to 430°C. Optionally, the softening point of the glass powder can be 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, or 430°C.

[0058] In one embodiment, the average particle size of the glass powder is 5 μm to 30 μm. Optionally, the average particle size of the glass powder can be 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, or 30 μm.

[0059] In one embodiment, the inorganic filler includes boron nitride, and the mass percentage of the boron nitride in the coating is 20% to 40%. Optionally, the mass percentage of the boron nitride can be 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 37%, or 40%.

[0060] In one embodiment, the average particle size of the boron nitride is 10 μm to 30 μm. The average particle size of the boron nitride can be 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, or 30 μm.

[0061] In one embodiment, the inorganic filler includes a flame-retardant filler, and the mass percentage of the flame-retardant filler in the coating is 1% to 15%. Optionally, the mass percentage of the flame-retardant filler can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%. The flame-retardant filler is mainly used for flame retardation, so as to avoid burning of the coating after forming a coating.

[0062] In one embodiment, the flame-retardant filler includes one or more of aluminum hydroxide, magnesium hydroxide, ceramic powder, and sericite.

[0063] In one embodiment, the flame-retardant filler includes aluminum hydroxide, and the mass percentage of the aluminum hydroxide in the coating is 1% to 8%. Optionally, the mass percentage of the aluminum hydroxide can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%.

[0064] In one embodiment, the average particle size of the aluminum hydroxide is 5 μm to 15 μm. Alternatively, the average particle size of the aluminum hydroxide can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm.

[0065] In one embodiment, the flame-retardant filler includes magnesium hydroxide, and the mass percentage of the magnesium hydroxide in the coating is 1% to 8%. Alternatively, the mass percentage of the magnesium hydroxide can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%.

[0066] In one embodiment, the average particle size of the magnesium hydroxide is 5 μm to 15 μm. Alternatively, the average particle size of the magnesium hydroxide can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm.

[0067] In one embodiment, the flame-retardant filler includes porcelain powder. In particular, the porcelain powder has good compatibility and porcelain performance, so that the addition of the porcelain powder in the coating can improve the fire resistance of the coating.

[0068] In one embodiment, the mass percentage of the porcelain powder in the coating is 0% to 8%. Alternatively, the mass percentage of the porcelain powder can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%.

[0069] In one embodiment, the flame-retardant filler includes sericite. In particular, the sericite is a silicate mineral with a layered structure. The sericite has high strength, good elasticity, flexibility, wear resistance, and abrasion resistance. Moreover, the sericite has stable chemical properties, and is resistant to acid and alkali, and thus is resistant to corrosion. The sericite has a stable crystal lattice, high volume and surface resistivity, low dielectric loss, high insulation strength, and is resistant to electric arc and corona. In addition, the sericite is a monoclinic crystal with a large diameter-thickness ratio, and has strong shielding and scattering effects on visible light. In particular, the sericite has excellent heat resistance, and does not change properties at high temperatures of 550°C, has a small thermal expansion coefficient, and has a high melting point of above 1260°C. Therefore, the addition of the sericite in the coating can improve the comprehensive performance of the coating.

[0070] In one embodiment, the mass percentage of the sericite in the coating is 0% to 8%. Alternatively, the mass percentage of the sericite can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%.

[0071] In one embodiment, the average particle size of the sericite is 10 μm to 20 μm. Alternatively, the average particle size of the sericite can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm.

[0072] In one embodiment, the flame-retardant filler includes hollow glass microspheres, and the mass percentage of the hollow glass microspheres in the coating is 0% to 8%. Alternatively, the mass percentage of the hollow glass microspheres can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%.

[0073] In one embodiment, the average particle size of the hollow glass microspheres is 35 μm to 60 μm. The average particle size of the hollow glass microspheres can be 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm.

[0074] In one embodiment, the inorganic filler includes an oxide filler, and the mass percentage of the oxide filler in the coating is 10% to 30%. Alternatively, the mass percentage of the oxide filler can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%. The addition of the oxide filler to the coating can improve the temperature resistance of the coating, and the oxide filler can also maintain structural stability at a temperature higher than the decomposition temperature of the phenolphthalein type polyether ketone. In addition, the oxide filler can improve the wear resistance and corrosion resistance of the coating (coating layer).

[0075] In one embodiment, the oxide filler includes aluminum oxide, and the mass percentage of the aluminum oxide in the coating is 0% to 20%. Alternatively, the mass percentage of the aluminum oxide can be 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%.

[0076] In one embodiment, the average particle size of the aluminum oxide is 5 μm to 25 μm. The average particle size of the aluminum oxide can be 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 25 μm.

[0077] In one embodiment, the oxide filler includes boron oxide, and the mass percentage of the boron oxide in the coating is 0% to 5%. Alternatively, the mass percentage of the boron oxide can be 0%, 1%, 2%, 3%, 4%, 5%.

[0078] In one embodiment, the average particle size of the boron oxide is 10 μm to 25 μm. The average particle size of the boron oxide can be 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 25 μm.

[0079] In one embodiment, the inorganic filler includes zirconium oxide, and the mass percentage of the zirconium oxide in the coating is 0% to 5%. Alternatively, the mass percentage of the zirconium oxide can be 0%, 1%, 2%, 3%, 4%, or 5%.

[0080] In one embodiment, the average particle size of the zirconium oxide is 10 μm to 20 μm. Alternatively, the average particle size of the zirconium oxide can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm.

[0081] In one embodiment, the inorganic filler includes zirconium oxide, and the mass percentage of the zirconium oxide in the coating is 0% to 5%. Alternatively, the mass percentage of the zirconium oxide can be 0%, 1%, 2%, 3%, 4%, or 5%.

[0082] In one embodiment, the average particle size of the zirconium oxide is 10 μm to 20 μm. Alternatively, the average particle size of the zirconium oxide can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm.

[0083] In one embodiment, the inorganic filler includes zinc oxide, and the mass percentage of the zinc oxide in the coating is 0% to 5%. Alternatively, the mass percentage of the zinc oxide can be 0%, 1%, 2%, 3%, 4%, or 5%.

[0084] In one embodiment, the average particle size of the zinc oxide is 10 μm to 20 μm. Alternatively, the average particle size of the zinc oxide can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm.

[0085] In one embodiment, the inorganic filler includes silicon powder. Specifically, the silicon powder is a micro powder processed by multiple processes such as crushing, ball milling (or vibration, air flow milling), flotation, acid washing purification, high-purity water treatment, etc. of natural quartz (SiO2) or fused quartz (amorphous SiO2 after high-temperature melting and cooling of natural quartz). The addition of the silicon powder to the coating can improve the hardness, wear resistance, heat resistance, dimensional stability, and other properties of the material. The silicon powder also has high dielectric properties, low thermal expansion coefficient, small thermal conductivity, corrosion resistance, and other advantages.

[0086] In one embodiment, the mass percentage of the silicon powder in the coating is 10% to 20%. Alternatively, the mass percentage of the silicon powder can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.

[0087] In an embodiment, the average particle size of the silicon powder is 10-20 μm. The average particle size of the silicon powder can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm.

[0088] The mass ratio of the inorganic filler satisfying the above-mentioned range can ensure that the mixing ratio of the organic material and the inorganic material is within a suitable range, thereby ensuring that the coating has stable temperature resistance within 600°C, and avoiding the problems of poor compatibility of the material and cracking and damage of the coating at high temperatures.

[0089] The particle size of the inorganic filler satisfying the above-mentioned range can ensure that the inorganic filler particles are not prone to agglomeration, and the preparation process is simple and low in cost, and can also ensure that the formed coating has good uniformity and high surface flatness.

[0090] In an embodiment, the coating further comprises a curing agent. Specifically, the curing agent can comprise one or more of diethylamine triamine, triethylene tetramine, tetraethylene pentamine, divinylpropylamine, mentane diamine, isophorone diamine, N-aminoethyl piperazine, bis(4-amino-3-methylcyclohexyl) methane, and bis(4-aminocyclohexyl) methane.

[0091] In an embodiment, the mass ratio of the curing agent in the coating is 1-8%. Alternatively, the mass ratio of the curing agent can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%.

[0092] In an embodiment, the coating further comprises a coupling agent. Specifically, the coupling agent can comprise γ-aminopropyl triethoxysilane (KH-550), octadecyl trimethoxysilane (KH560), γ-methacryloyloxypropyl trimethoxysilane (agent KH-570), and γ-mercaptopropyl triethoxysilane (KH580).

[0093] In an embodiment, the mass ratio of the coupling agent in the coating is 1-8%. Alternatively, the mass ratio of the coupling agent can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%.

[0094] In an embodiment, the application further provides a preparation method of the coating, which can refer to Figure 3 , and comprises the following steps:

[0095] In step S10, the phenolphthalein type polyether ketone is dissolved in a solvent to obtain a polymer solution.

[0096] In step S20, the base material, the inorganic filler, and the polymer solution are mixed to obtain the coating after uniform mixing.

[0097] Specifically, the coating preparation method involves first dissolving hydroxylated phenolphthalein polyetherketone in a solvent to prepare a phenolphthalein polyetherketone solution. Then, epoxy resin, silica powder, glass powder, boron nitride, hollow glass microspheres, sericite, aluminum hydroxide, boron oxide, aluminum oxide, zirconium oxide, a coupling agent, and the like are added to the hydroxylated phenolphthalein polyetherketone. The mixture is then uniformly stirred for one hour and then ground in a grinder for approximately three hours to obtain the coating.

[0098] Optionally, the solvent of the hydroxylated phenolphthalein type polyetherketone can be one or more of toluene, xylene, propylene glycol methyl ether acetate, DMAc, NMP, and DMF, and the solid content is 8% to 35%.

[0099] The technical solution of the present invention is described in detail below through specific embodiments.

[0100] Example 1

[0101] This embodiment provides a coating, including phenolphthalein polyether ketone, epoxy resin (E-44), triethylenetetramine, KH550, glass powder, boron nitride, flame retardant filler (aluminum hydroxide), oxide filler (silicon powder, boron oxide, aluminum oxide, zirconium oxide); the weight average molecular weight of the phenolphthalein polyether ketone is 50,000.

[0102] The production steps of the coating of this embodiment are:

[0103] 1) Weigh 2.0 g of phenolphthalein polyether ketone and dissolve it in 23 g of NMP solvent to obtain a phenolphthalein polyether ketone solution.

[0104] 2) Add 4 g of epoxy resin E-44, 0.6 g of triethylenetetramine, 3.5 g of glass powder with a softening point of 400°C, 5 g of boron nitride, 1 g of aluminum hydroxide, 3 g of silica powder, 0.5 g of boron oxide, 0.5 g of aluminum oxide, 0.5 g of zirconium oxide, and 0.8 g of KH550 to the phenolphthalein type polyetherketone solution and stir evenly for 1 hour.

[0105] 3) Grinding the mixture with a grinder for 3.5 hours to obtain a high-temperature resistant insulating coating.

[0106] Among them, the mass proportions of the matrix material, phenolphthalein polyether ketone and inorganic filler in the above production steps are: phenolphthalein polyether ketone (10%), epoxy resin (20%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), aluminum oxide (2.5%), boron oxide (2.5%), microsilica powder (15%), and zirconium oxide (2.5%).

[0107] Example 2

[0108] This embodiment provides a coating. The difference between the coating configuration and that of Example 1 is that the coating uses hydroxylated phenolphthalein type polyether ketone.

[0109] The mass proportions of the matrix material, phenolphthalein polyether ketone and inorganic filler are as follows: hydroxylated phenolphthalein polyether ketone (10%), epoxy resin (20%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), aluminum oxide (2.5%), boron oxide (2.5%), microsilica powder (15%) and zirconium oxide (2.5%).

[0110] Example 3

[0111] This embodiment provides a coating, and the coating configuration differs from that of embodiment 1 in that: the coating comprises phenolphthalein polyetherketone and hydroxylated phenolphthalein polyetherketone, each accounting for 50%, namely, phenolphthalein polyetherketone (5%) and phenolphthalein polyetherketone (5%).

[0112] The mass proportions of the matrix material, phenolphthalein polyether ketone and inorganic filler are as follows: phenolphthalein polyether ketone (5%), hydroxylated phenolphthalein polyether ketone (5%), epoxy resin (20%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), aluminum oxide (2.5%), boron oxide (2.5%), microsilica powder (15%) and zirconium oxide (2.5%).

[0113] Example 4

[0114] This embodiment provides a coating. The difference between the coating configuration and that of Example 1 is that the mass of the phenolphthalein type polyether ketone accounts for a larger proportion.

[0115] The mass proportions of the matrix material, phenolphthalein polyether ketone and inorganic filler are as follows: phenolphthalein polyether ketone (15%), epoxy resin (15%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), aluminum oxide (2.5%), boron oxide (2.5%), microsilica powder (15%) and zirconium oxide (2.5%).

[0116] Example 5

[0117] This embodiment provides a coating. The difference between the coating configuration and that of Example 1 is that the mass proportion of phenolphthalein type polyether ketone is relatively small.

[0118] The mass proportions of the matrix material, phenolphthalein polyether ketone and inorganic filler are as follows: phenolphthalein polyether ketone (5%), epoxy resin (25%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), aluminum oxide (2.5%), boron oxide (2.5%), microsilica powder (15%) and zirconium oxide (2.5%).

[0119] Example 6

[0120] This embodiment provides a coating, and the coating configuration differs from that of Example 1 in that the mass proportion of the base material is smaller.

[0121] The mass ratio of the three of the base material, the phenolphthalein type polyether ketone, and the inorganic filler is phenolphthalein type polyether ketone (10%), epoxy resin (20%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), magnesium hydroxide (5%), ceramic powder (2.5%), sericite (2.5%), aluminum oxide (0.5%), boron oxide (0.5%), micro silicon powder (11%), and zirconium oxide (0.5%).

[0122] Example 7

[0123] This example provides a coating, and the difference between the coating configuration and that of Example 1 is that the type of the flame-retardant filler is different, and the mass ratio of the oxide filler is smaller.

[0124] The mass ratio of the three of the base material, the phenolphthalein type polyether ketone, and the inorganic filler is phenolphthalein type polyether ketone (10%), epoxy resin (20%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), magnesium hydroxide (5%), ceramic powder (2.5%), sericite (2.5%), aluminum oxide (0.5%), boron oxide (0.5%), micro silicon powder (11%), and zirconium oxide (0.5%).

[0125] Example 8

[0126] This example provides a coating, and the difference between the coating configuration and that of Example 1 is that the type of the flame-retardant filler is different and the mass ratio is larger, and the mass ratio of the oxide filler is smaller.

[0127] The mass ratio of the three of the base material, the phenolphthalein type polyether ketone, and the inorganic filler is phenolphthalein type polyether ketone (10%), epoxy resin (20%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), magnesium hydroxide (5%), ceramic powder (2.5%), sericite (2.5%), aluminum oxide (0.5%), boron oxide (0.5%), micro silicon powder (11%), and zirconium oxide (0.5%).

[0128] Example 9

[0129] This example provides a coating, and the difference between the coating configuration and that of Example 1 is that the mass ratio of boron nitride is smaller, and the mass ratio of glass powder is larger.

[0130] The mass ratio of the three of the base material, the phenolphthalein type polyether ketone, and the inorganic filler is phenolphthalein type polyether ketone (10%), epoxy resin (20%), boron nitride (20%), glass powder (22.5%), aluminum hydroxide (5%), aluminum oxide (2.5%), boron oxide (2.5%), micro silicon powder (15%), and zirconium oxide (2.5%).

[0131] Example 10

[0132] The embodiment provides a coating, and the difference between the coating configuration and the embodiment 1 is that the mass percentage of boron nitride is relatively high and the mass percentage of glass powder is relatively low.

[0133] The mass percentages of the base material, the phenolphthalein type polyether ketone and the inorganic filler are as follows: the phenolphthalein type polyether ketone (10%), the epoxy resin (20%), the boron nitride (40%), the glass powder (2.5%), the aluminum hydroxide (5%), the aluminum oxide (2.5%), the boron oxide (2.5%), the micro silicon powder (15%) and the zirconium oxide (2.5%).

[0134] Embodiment 11

[0135] The embodiment provides a coating, and the difference between the coating configuration and the embodiment 1 is that the mass percentage of boron nitride is relatively high and the mass percentage of glass powder is relatively low.

[0136] The mass percentages of the base material, the phenolphthalein type polyether ketone and the inorganic filler are as follows: the phenolphthalein type polyether ketone (10%), the epoxy resin (20%), the boron nitride (32.5%), the glass powder (10%), the aluminum hydroxide (5%), the aluminum oxide (2.5%), the boron oxide (2.5%), the micro silicon powder (15%) and the zirconium oxide (2.5%).

[0137] Embodiment 12

[0138] The embodiment provides a coating, and the difference between the coating configuration and the embodiment 1 is that the mass percentage of boron nitride is relatively high and the mass percentage of glass powder is relatively low.

[0139] The mass percentages of the base material, the phenolphthalein type polyether ketone and the inorganic filler are as follows: the phenolphthalein type polyether ketone (10%), the epoxy resin (20%), the boron nitride (22.5%), the glass powder (20%), the aluminum hydroxide (5%), the aluminum oxide (2.5%), the boron oxide (2.5%), the micro silicon powder (15%) and the zirconium oxide (2.5%).

[0140] Embodiment 13

[0141] The embodiment provides a coating, and the difference between the coating configuration and the embodiment 1 is that the weight average molecular weight of the phenolphthalein type polyether ketone is 100000.

[0142] Embodiment 14

[0143] The embodiment provides a coating, and the difference between the coating configuration and the embodiment 1 is that the weight average molecular weight of the phenolphthalein type polyether ketone is 30000.

[0144] Embodiment 15

[0145] The embodiment provides a coating, and the difference between the coating configuration and the embodiment 1 is that the epoxy resin is E-51 type.

[0146] Embodiment 16

[0147] This embodiment provides a coating, the coating configuration is different from that of Example 1 in that the curing agent is tetraethylene pentamine.

[0148] Example 17

[0149] This embodiment provides a coating, the coating configuration is different from that of Example 1 in that the curing agent is N-aminoethylpiperazine.

[0150] Example 18

[0151] This embodiment provides a coating, the coating configuration is different from that of Example 1 in that the glass powder softening point is 320℃.

[0152] Example 19

[0153] This embodiment provides a coating, the coating configuration is different from that of Example 1 in that the glass powder softening point is 430℃.

[0154] Example 20

[0155] This embodiment provides a coating, the coating configuration is different from that of Example 1 in that the coupling agent is KH580.

[0156] Comparative Example 1

[0157] This comparative example provides a coating, the coating configuration is 5.7g of epoxy resin E-44, 1.0g of triethylene tetramine, 3.3g of silica powder, 3.3g of glass powder with a softening point of 400℃, 3.8g of boron nitride, 1.0g of sericite, 1.1g of aluminum hydroxide, 0.4g of boron oxide, 0.6g of zirconium oxide, and 0.9g of KH580. No phenolphthalein type polyether ketone is added.

[0158] The mass ratio of the three of the matrix material and the inorganic filler is: epoxy resin (30%), boron nitride (25%), glass powder (17.5%), aluminum hydroxide (5%), aluminum oxide (2.5%), boron oxide (2.5%), silica powder (15%), and zirconium oxide (2.5%).

[0159] The coatings obtained from Examples 1-20 and Comparative Example 1 are coated on a stainless steel plate substrate, and cured at 80℃ for 1.5 hours and at 150℃ for 1 hour to obtain a high-temperature-resistant insulating coating layer (the coating layer thickness is 250μm). The stainless steel plate with the coating layer is subjected to coating layer thickness testing, shear strength testing, high-temperature-resistant insulation testing, thermal conductivity testing, and flame retardant performance testing, respectively.

[0160] Coating thickness testing: refer to the testing standard of GB / T13452.2-2008 "Determination of film thickness of pigments and varnishes".

[0161] Shear strength test: refer to GB / T7124-2008 "Determination of tensile shear strength of adhesives (rigid material to rigid material)" test standard. Select metal plate as test material: 100 mm ± 0.25 mm long, 25 mm ± 0.25 mm wide, the surface is treated according to the way the coating is used, and the sample with coating is bonded with high-strength adhesive, the bonding surface is 25 mm ± 0.25 mm, the adhesive thickness is recommended to be 0.2-0.3 mm, and interval wires or small glass balls can be used to control, if wires, the wires should be parallel to the direction of force to avoid errors in the experiment.

[0162] High temperature insulation test: the thickness of the metal plate (aluminum or stainless steel) is 2 mm, one side is sprayed with about 0.3 mm coating, the aluminum plate is quickly put into a high temperature muffle furnace (600°C), taken out after 30 min, and cooled to room temperature at room temperature. The insulation test of the coating at room temperature or after temperature resistance refers to GB / T1408.1-2016 "Insulating materials - Determination of electrical strength - Part 1: Test at power frequency". Apply 3000V (room temperature) or 1000V (after temperature resistance) AC to both ends of the electrode, and record the maximum current value passing through the sample in 60s, which is the leakage current.

[0163] Thermal conductivity test: refer to GB / T22588-2008 "Flash method for measuring thermal diffusivity or thermal conductivity".

[0164] Flame retardant performance test: vertical flame retardant: refer to UL94-2021. Sample size: 125 mm x 13 mm x 0.18 mm Sample pretreatment: samples are placed in a 23±2℃, 50±5%RH environment for 48h; test steps: flame height 20±1mm, bunsen burner is placed below the center of the sample, the distance between the bunsen burner tube and the bottom of the sample is 10±1mm, the bunsen burner is moved away at a speed of 300mm / sec for at least 150mm after 10±0.5s ignition time, and the afterflame time t1 is recorded at the same time. When the afterflame stops, ignite immediately, move the bunsen burner away at a speed of 300mm / sec for at least 150mm after 10±0.5s ignition time, and record the afterflame time t2 and afterburning time t3.

[0165] The test data of examples 1-20 and comparative example 1 are shown in table 1 and table 2:

[0166] Table 1

[0167]

[0168]

[0169] Table 2

[0170]

[0171] From the test results of the examples and comparative examples in Table 1 and Table 2, it can be found that the comparative examples without adding phenolphthalein type polyether ketone have reduced shear strength and poor high-temperature resistance; on the contrary, the coating has good high-temperature resistance by adding phenolphthalein type polyether ketone. Moreover, by further changing to add hydroxylated phenolphthalein type polyether ketone, the high-temperature resistance of the material can be further improved.

[0172] In the description of the embodiments of the present application, it should be noted that the terms “center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”, “inner”, “outer” and the like refer to the orientation or positional relationship based on the drawings described, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0173] The above only discloses one preferred embodiment of the present application, of course cannot limit the scope of the present application, and those skilled in the art can understand that the implementation of all or part of the above-mentioned processes, and the equivalent changes made according to the claims of the present application, still belong to the scope covered by the present application.

Claims

1. A coating, characterized in that: It includes a base material, a phenolphthalein polyether ketone and an inorganic filler; the phenolphthalein polyether ketone includes a hydroxylated phenolphthalein polyether ketone, and the hydroxylated phenolphthalein polyether ketone reacts with the base material to form a cross-linked structure; the base material includes one or more of epoxy resin, polyester resin, polyurea-formaldehyde resin, polyurethane, polyimide, and phenolic resin.

2. The coating according to claim 1, characterized in that In the coating, the mass ratio of the phenolphthalein polyether ketone, the base material and the inorganic filler is 1: (1-4): (7-20).

3. The coating according to claim 1, characterized in that The weight average molecular weight of the phenolphthalein type polyether ketone is 30,000-100,000.

4. The coating according to claim 1, characterized in that The inorganic filler includes glass powder. In the coating, the mass proportion of the glass powder is 10% to 20%, the softening point of the glass powder is 320° C. to 430° C., and the average particle size of the glass powder is 5 μm to 30 μm.

5. The coating according to claim 1, characterized in that The inorganic filler includes boron nitride. In the coating, the mass proportion of the boron nitride is 20% to 40%, and the average particle size of the boron nitride is 10 μm to 30 μm.

6. The coating according to claim 1, characterized in that The inorganic filler includes a flame retardant filler, and in the coating, the mass proportion of the flame retardant filler is 1% to 15%.

7. The coating according to claim 6, characterized in that The flame retardant filler includes one or more of aluminum hydroxide, magnesium hydroxide, ceramic powder, and sericite.

8. The coating according to claim 1, characterized in that The inorganic filler includes an oxide filler, and in the coating, the mass proportion of the oxide filler is 10% to 30%.

9. The coating according to claim 8, characterized in that The oxide filler includes one or more of aluminum oxide, boron oxide, zirconium oxide, zinc oxide, and silicon powder.

10. The coating according to claim 1, characterized in that The coating further includes a curing agent and a coupling agent. In the coating, the mass proportion of the curing agent is 1% to 8%, and the mass proportion of the coupling agent is 1% to 8%.

11. A method for preparing a coating, characterized in that: include: dissolving phenolphthalein type polyetherketone in a solvent to obtain a polymer solution; Mixing a base material, an inorganic filler and the polymer solution to obtain the coating; The phenolphthalein type polyether ketone includes hydroxylated phenolphthalein type polyether ketone, and the hydroxylated phenolphthalein type polyether ketone reacts with the matrix material to form a cross-linked structure; the matrix material includes one or more of epoxy resin, polyester resin, polyurea-formaldehyde resin, polyurethane, polyimide, and phenolic resin.

12. A sheet metal, characterized in that: include: A metal substrate and a coating applied on the metal substrate, wherein the coating is obtained by curing the coating according to any one of claims 1 to 10.

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