Coating composition for metal substrate and preparation method thereof

Abstract

The invention relates to the field of coatings, in particular to a coating composition for a metal substrate and a preparation method of the coating composition. The invention discloses a coating composition for a metal substrate, which comprises the following components in parts by weight: 60-80 parts of a high-boiling-point aromatic hydrocarbon solvent; 3-10 parts of an ester solvent; 5 to 15 parts of polyether-ether-ketone resin; 0.1 to 0.5 part of a leveling agent; and 3-10 parts of color paste, wherein the high-boiling-point aromatic hydrocarbon solvent is a clear liquid composed of aromatic hydrocarbon. According to the present invention, the types and the proportions of the high boiling point aromatic hydrocarbon solvent, the ester solvent, the polyether-ether-ketone resin and the leveling agent are precisely controlled, such that the construction performance, the film forming quality and the final coating performance of the coating material can be significantly optimized, and the coating material is particularly suitable for the metal coating (such as kitchen ware) having strict requirements on the high temperature resistance and the surface flatness.

Description

Technical Field

[0001] This invention relates to the field of coatings, and more specifically to a coating composition for metal substrates and a method for preparing the same. Background Technology

[0002] Traditional metal substrate coatings include PTFE-based coatings, silicone resin coatings, epoxy resin coatings, and ceramic coatings. PTFE-based coatings offer excellent non-stick properties and a low coefficient of friction, but suffer from low mechanical strength. Silicone resin coatings are flexible but have poor adhesion and are prone to peeling. Epoxy resin coatings have high adhesion and are resistant to chemical corrosion, but have poor high-temperature resistance. Ceramic coatings are heat-resistant and have high hardness, but are brittle.

[0003] There is an urgent need for a coating that possesses high-temperature resistance, strong adhesion to metal substrates, and good film smoothness. Summary of the Invention

[0004] This invention discloses a coating composition for metal substrates, comprising, by weight:

[0005] 60-80 parts of high-boiling-point aromatic solvent;

[0006] 3-10 parts of ester solvent;

[0007] 5-15 parts of polyetheretherketone resin;

[0008] Leveling agent 0.1-0.5 parts;

[0009] Color paste: 3-10 parts;

[0010] Talc powder: 3-10 parts.

[0011] Preferably, the coating composition for metal substrates comprises, by weight, the following components:

[0012] 70 parts of high-boiling-point aromatic solvent;

[0013] 7.8 parts of ester solvents;

[0014] 10 parts of polyetheretherketone resin;

[0015] 0.3 parts leveling agent;

[0016] Color paste: 5 parts;

[0017] Talc powder: 5 parts.

[0018] The high-boiling-point aromatic solvent is a clear liquid composed of aromatic hydrocarbon compounds. In one embodiment, the high-boiling-point aromatic solvent has a boiling range (yield greater than 98%) of 160-240°C. Preferably, the high-boiling-point aromatic solvent includes aromatic solvents with a boiling range (yield greater than 98%) of 168-192°C and a boiling range (yield greater than 98%) of 190-240°C, wherein the weight ratio of the aromatic solvent with a boiling range (yield greater than 98%) of 168-192°C to the aromatic solvent with a boiling range (yield greater than 98%) of 190-240°C is 1-2:1-2. More preferably, the weight ratio of the aromatic solvent with a distillation range (distillation yield greater than 98%) of 168-192℃ [model GAlssol S-150A (Hualun)] and the aromatic solvent with a distillation range (distillation yield greater than 98%) of 190-240℃ [model GAlssol S-180A (Hualun)] is 1:1.

[0019] By selecting a certain proportion of high-boiling-point aromatic solvents for mixing, it is particularly suitable for polyether ether ketone resin, allowing it to fully level before high-temperature curing, and can effectively reduce the surface tension of the coating system and improve the wettability of metal substrates (such as stainless steel and aluminum alloys).

[0020] The ester solvent is selected from at least one of ethyl acetate, ethyl propionate, ethyl butyrate, ethyl acetate, ethyl propionate, ethyl butyrate, propyl acetate, propyl propionate, propyl butyrate, butyl acetate, butyl propionate, and butyl butyrate. Preferably, the ester solvent is selected from ethyl acetate and butyl acetate, and the weight ratio of ethyl acetate to butyl acetate is 7:0.5-1. Preferably, the weight ratio of ethyl acetate to butyl acetate is 7:0.8.

[0021] By selecting aromatic solvents with a distillation range (distillation yield greater than 98%) of 168-192℃, aromatic solvents with a distillation range (distillation yield greater than 98%) of 190-240℃, and a combination of ethyl acetate and butyl acetate, the evaporation rate can be balanced, avoiding poor leveling caused by rapid drying or unevenness caused by slow drying.

[0022] The polyether ether ketone resin (PEEK) is a semi-crystalline linear aromatic polymer compound with an oxygen-p-phenylene-oxy-carbonyl-p-phenylene linkage in its main chain. It has properties such as high temperature resistance (melting point 343℃, continuous use temperature 260℃) and chemical corrosion resistance (only concentrated sulfuric acid can destroy it).

[0023] In this application, the polyetheretherketone resin is selected from Solvay KetaSpire KT-880SFP. KetaSpire KT-880SFP is provided in the form of a natural-colored ultrafine powder with an average particle size D50 of approximately 30 micrometers.

[0024] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:1-3. Preferably, the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:2.

[0025] The silicone leveling agent is a polyether-modified polysiloxane, such as BYK-333 or TEGO Glide 410. BYK-333 is preferred.

[0026] The preferred acrylate leveling agent is BYK-358.

[0027] This application combines polyether-modified polysiloxane leveling agent and acrylate leveling agent to achieve both immediate leveling and long-term stability of the coating film, making it particularly suitable for high-boiling-point aromatic solvents and PEEK resin systems.

[0028] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0029] Talc: The talc is flake-shaped talc with a particle size of 2-5μm and an oil absorption of 30-40ml / 100g. The flake-shaped talc is oriented to form a shielding layer of about 5μm in the coating film, which can improve the long-term protection of the coating without affecting the color stability of the coating.

[0030] The coating composition further includes 0.1-2 parts of anti-silver-dropping additive, 0.1-2 parts of defoamer, and 0.5-3 parts of matting agent.

[0031] The anti-silver-drop additive is used to improve the initial and long-term adhesion of coatings to metal substrates and the adhesion of coating inner layers. The anti-silver-drop additive is a low-acid modified polyester compound, product name 120 anti-silver-drop additive, product brand Aofan (Shanghai Aofan Chemical).

[0032] The defoamer can be any commonly used defoamer in the field, such as BYK-53 or BYK-141.

[0033] The matting agent is used to reduce the gloss of the coating and increase its fullness, giving the coating a smooth appearance. Examples of matting agents include HK440, HK450, and Grace. ED 80, Evonik TT 600.

[0034] The second aspect of this application provides a method for preparing the coating composition, wherein the components are mixed and stirred for 5-6 hours at a speed of 1500 rpm / min, and then ground 3-6 times to obtain the final product.

[0035] Beneficial effects

[0036] This application can significantly optimize the application performance, film quality, and final coating performance of coatings by precisely controlling the types and proportions of high-boiling-point aromatic solvents, ester solvents, polyether ether ketone resins, and leveling agents, making the coatings particularly suitable for metal coatings (such as kitchenware) that have stringent requirements for high-temperature resistance and surface smoothness. Implementation

[0037] Example 1

[0038] A coating composition for a metal substrate, comprising, by weight:

[0039] 70 parts of high-boiling-point aromatic solvent;

[0040] 7.8 parts of ester solvents;

[0041] 10 parts of polyetheretherketone resin;

[0042] 0.3 parts leveling agent;

[0043] Color paste: 5 parts;

[0044] Talc powder: 5 parts;

[0045] Silver-dissolving agent 0.5 parts;

[0046] 0.4 parts of defoamer;

[0047] 1 part matte powder.

[0048] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ [model: GAlssol S-150A (Hualun)] and an aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ [model: GAlssol S-180A (Hualun)]. The weight ratio of the aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ to the aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ is 1:1.

[0049] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of ethyl acetate to butyl acetate of 7:0.8.

[0050] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0051] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:2. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0052] The pigment is titanium dioxide pigment, model VERA.TM EXP1138.

[0053] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0054] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0055] The defoamer is BYK-53.

[0056] The matting agent is HK440.

[0057] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0058] Comparative Example 1

[0059] A coating composition for a metal substrate, comprising, by weight:

[0060] 70 parts of high-boiling-point aromatic solvent;

[0061] 7.8 parts of ester solvents;

[0062] 10 parts of polyetheretherketone resin;

[0063] 0.3 parts leveling agent;

[0064] Color paste: 5 parts;

[0065] Talc powder: 5 parts;

[0066] Silver-dissolving agent 0.5 parts;

[0067] 0.4 parts of defoamer;

[0068] 1 part matte powder.

[0069] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (yield greater than 98%) of 168-192℃ [model: GAlssol S-150A (Hualun)] and an aromatic solvent with a distillation range (yield greater than 98%) of 190-240℃ [model: GAlssol S-180A (Hualun)]. The weight ratio of the aromatic solvent with a distillation range (yield greater than 98%) of 168-192℃ to the aromatic solvent with a distillation range (yield greater than 98%) of 190-240℃ is 1:3.

[0070] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of ethyl acetate to butyl acetate of 7:0.8.

[0071] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0072] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:2. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0073] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0074] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0075] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0076] The defoamer is BYK-53.

[0077] The matting agent is HK440.

[0078] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0079] Comparative Example 2

[0080] A coating composition for a metal substrate, comprising, by weight:

[0081] 70 parts of high-boiling-point aromatic solvent;

[0082] 7.8 parts of ester solvents;

[0083] 10 parts of polyetheretherketone resin;

[0084] 0.3 parts leveling agent;

[0085] Color paste: 5 parts;

[0086] Talc powder: 5 parts;

[0087] Silver-dissolving agent 0.5 parts;

[0088] 0.4 parts of defoamer;

[0089] 1 part matte powder.

[0090] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (yield greater than 98%) of 168-192℃ [model: GAlssol S-150A (Hualun)] and an aromatic solvent with a distillation range (yield greater than 98%) of 190-240℃ [model: GAlssol S-180A (Hualun)]. The weight ratio of the aromatic solvent with a distillation range (yield greater than 98%) of 168-192℃ to the aromatic solvent with a distillation range (yield greater than 98%) of 190-240℃ is 3:1.

[0091] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of ethyl acetate to butyl acetate of 7:0.8.

[0092] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0093] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:2. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0094] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0095] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0096] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0097] The defoamer is BYK-53.

[0098] The matting agent is HK440.

[0099] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0100] Comparative Example 3

[0101] A coating composition for a metal substrate, comprising, by weight:

[0102] 70 parts of high-boiling-point aromatic solvent;

[0103] 7.8 parts of ester solvents;

[0104] 10 parts of polyetheretherketone resin;

[0105] 0.3 parts leveling agent;

[0106] Color paste: 5 parts;

[0107] Talc powder: 5 parts;

[0108] Silver-dissolving agent 0.5 parts;

[0109] 0.4 parts of defoamer;

[0110] 1 part matte powder.

[0111] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (distillation yield greater than 98%) of 178-210℃ [model: GAlssol S-150 (Hualun)].

[0112] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of ethyl acetate to butyl acetate of 7:0.8.

[0113] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0114] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:2. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0115] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0116] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0117] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0118] The defoamer is BYK-53.

[0119] The matting agent is HK440.

[0120] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0121] Comparative Example 4

[0122] A coating composition for a metal substrate, comprising, by weight:

[0123] 70 parts of high-boiling-point aromatic solvent;

[0124] 7.8 parts of ester solvents;

[0125] 10 parts of polyetheretherketone resin;

[0126] 0.3 parts leveling agent;

[0127] Color paste: 5 parts;

[0128] Talc powder: 5 parts;

[0129] Silver-dissolving agent 0.5 parts;

[0130] 0.4 parts of defoamer;

[0131] 1 part matte powder.

[0132] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ [model: GAlssol S-150A (Hualun)] and an aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ [model: GAlssol S-180A (Hualun)]. The weight ratio of the aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ to the aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ is 1:1.

[0133] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of 7:4 between ethyl acetate and butyl acetate.

[0134] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0135] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:2. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0136] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0137] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0138] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0139] The defoamer is BYK-53.

[0140] The matting agent is HK440.

[0141] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0142] Comparative Example 5

[0143] A coating composition for a metal substrate, comprising, by weight:

[0144] 70 parts of high-boiling-point aromatic solvent;

[0145] 7.8 parts of ester solvents;

[0146] 10 parts of polyetheretherketone resin;

[0147] 0.3 parts leveling agent;

[0148] Color paste: 5 parts;

[0149] Talc powder: 5 parts;

[0150] Silver-dissolving agent 0.5 parts;

[0151] 0.4 parts of defoamer;

[0152] 1 part matte powder.

[0153] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ [model: GAlssol S-150A (Hualun)] and an aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ [model: GAlssol S-180A (Hualun)]. The weight ratio of the aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ to the aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ is 1:1.

[0154] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of ethyl acetate to butyl acetate of 9:0.8.

[0155] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0156] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:2. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0157] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0158] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0159] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0160] The defoamer is BYK-53.

[0161] The matting agent is HK440.

[0162] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0163] Comparative Example 6

[0164] A coating composition for a metal substrate, comprising, by weight:

[0165] 70 parts of high-boiling-point aromatic solvent;

[0166] 7.8 parts of ester solvents;

[0167] 10 parts of polyetheretherketone resin;

[0168] 0.3 parts leveling agent;

[0169] Color paste: 5 parts;

[0170] Talc powder: 5 parts;

[0171] Silver-dissolving agent 0.5 parts;

[0172] 0.4 parts of defoamer;

[0173] 1 part matte powder.

[0174] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ [model: GAlssol S-150A (Hualun)] and an aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ [model: GAlssol S-180A (Hualun)]. The weight ratio of the aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ to the aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ is 1:1.

[0175] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of ethyl acetate to butyl acetate of 7:0.8.

[0176] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0177] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:0.4. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0178] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0179] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0180] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0181] The defoamer is BYK-53.

[0182] The matting agent is HK440.

[0183] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0184] Comparative Example 7

[0185] A coating composition for a metal substrate, comprising, by weight:

[0186] 70 parts of high-boiling-point aromatic solvent;

[0187] 7.8 parts of ester solvents;

[0188] 10 parts of polyetheretherketone resin;

[0189] 0.3 parts leveling agent;

[0190] Color paste: 5 parts;

[0191] Talc powder: 5 parts;

[0192] Silver-dissolving agent 0.5 parts;

[0193] 0.4 parts of defoamer;

[0194] 1 part matte powder.

[0195] The high-boiling-point aromatic solvent is an aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ [model: GAlssol S-150A (Hualun)] and an aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ [model: GAlssol S-180A (Hualun)]. The weight ratio of the aromatic solvent with a distillation range (distillate greater than 98%) of 168-192℃ to the aromatic solvent with a distillation range (distillate greater than 98%) of 190-240℃ is 1:1.

[0196] The ester solvent is selected from ethyl acetate and butyl acetate, with a weight ratio of ethyl acetate to butyl acetate of 7:0.8.

[0197] The polyetheretherketone resin was selected from Solvay KetaSpire KT-880SFP.

[0198] The leveling agent comprises a silicone leveling agent and an acrylate leveling agent, wherein the weight ratio of the silicone leveling agent to the acrylate leveling agent is 1:5. The silicone leveling agent is a polyether-modified polysiloxane, model BYK-333. The acrylate leveling agent is model BYK-358.

[0199] The pigment is titanium dioxide pigment, model VERA. TM EXP1138.

[0200] The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

[0201] The anti-silver-dropping additive is a low-acid modified polyester compound, with the product name "120 Anti-silver-dropping Additive" and the product brand "Aofan" (Shanghai Aofan Chemical).

[0202] The defoamer is BYK-53.

[0203] The matting agent is HK440.

[0204] The coating composition is prepared by mixing and stirring the components for 5 hours at a speed of 1500 rpm / min, and then grinding it 5 times to obtain the final product.

[0205] Performance testing and data

[0206] 1. The above coating composition is sprayed onto a stainless steel substrate and cured under the following conditions: 80℃ for 20 minutes, 250℃ for 30 minutes, and natural cooling. The coating thickness is 20-25 micrometers.

[0207] (1) Appearance of wet film: Visually inspect the wet film immediately after spraying.

[0208] (2) Dry film appearance: After curing, visually inspect the appearance of the paint film and use a magnifying glass (10x).

[0209] (3) Adhesion: Refer to GB / T 9286-2021.

[0210] (4) Acid resistance test: Immerse the coated substrate in a 5% acetic acid aqueous solution and test at room temperature, and observe the time when the paint film shows abnormalities.

[0211] Test Results

[0212]

[0213] 2. VOC testing

[0214] Test method: GB / T 34682-2017

[0215] The volatile organic compound content of Test Example 1 was 15.9 g / L; which meets the standard.

[0216] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coating composition for a metal substrate, characterized in that, By weight, the components include: 60-80 parts of high-boiling-point aromatic solvent; 3-10 parts of ester solvent; 5-15 parts of polyetheretherketone resin; Leveling agent 0.1-0.5 parts; Color paste: 3-10 parts, wherein the high-boiling-point aromatic solvent is a liquid composed of aromatic hydrocarbon compounds.

2. The coating composition for a metal substrate as described in claim 1, characterized in that, By weight, the components include: 70 parts of high-boiling-point aromatic solvent; 7.8 parts of ester solvents; 10 parts of polyetheretherketone resin; 0.3 parts leveling agent; Color paste: 5 parts; Talc powder: 5 parts.

3. The coating composition for a metal substrate as described in claim 2, characterized in that, The boiling range (distillation yield greater than 98%) of the high-boiling-point aromatic solvent is 160-240℃.

4. The coating composition for a metal substrate as described in claim 2 or 3, characterized in that, The high-boiling-point aromatic solvents include aromatic solvents with a distillation range (distillation yield greater than 98%) of 168-192℃ and a distillation range (distillation yield greater than 98%) of 190-240℃.

5. The coating composition for a metal substrate as described in claim 4, characterized in that, The weight ratio of aromatic solvents with a distillation range (distillation yield greater than 98%) of 168-192℃ to aromatic solvents with a distillation range (distillation yield greater than 98%) of 190-240℃ is 1-2:1-2.

6. The coating composition for a metal substrate as described in claim 1, characterized in that, The ester solvent is selected from at least one of ethyl acetate, ethyl propionate, ethyl butyrate, ethyl acetate, ethyl propionate, ethyl butyrate, propyl acetate, propyl propionate, propyl butyrate, butyl acetate, butyl propionate, and butyl butyrate.

7. The coating composition for a metal substrate as described in claim 1, characterized in that, The talc powder is in the form of flakes, with a particle size of 2-5μm and an oil absorption capacity of 30-40ml / 100g.

8. The coating composition for a metal substrate as described in claim 1, characterized in that, The coating composition further includes 0.1-2 parts of anti-silver-dropping additive, 0.1-2 parts of defoamer, and 0.5-3 parts of matting agent.

9. The coating composition for a metal substrate as described in claim 8, characterized in that, The anti-silver-dropping additive is a low-acid modified polyester compound.

10. A method for preparing a coating composition for a metal substrate as described in any one of claims 1-9, characterized in that, Mix and stir each component for 5-6 hours at a speed of 1500 rpm / min, and then grind it 3-6 times to obtain the final product.

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