Acid and alkali corrosion resistant powder coating and preparation method thereof

Abstract

The invention discloses an acid-base corrosion resistant powder coating and a preparation method thereof, and relates to the field of powder coatings. Wherein, the acid-base corrosion resistant powder coating includes 440-450 parts by weight of bisphenol A epoxy resin, 160-170 parts by weight of hydroxy acrylic resin, 110-120 parts by weight of isocyanate-terminated polyurethane resin, 28-33 parts by weight of aminosilane coupling agent modified filler and 80-85 parts by weight of curing agent. The acid-base corrosion resistant powder coating has excellent adhesion fastness to metal substrates and excellent acid-base corrosion resistance. It can withstand a hydrochloric acid solution with a volume concentration of 5% and a sodium hydroxide solution with a mass concentration of 5% for more than 300 hours, respectively, and is conducive to lasting protection and decoration of the substrate.

Description

Technical Field

[0001] The present application relates to the field of powder coatings, and in particular to an acid and alkali corrosion resistant powder coating and a preparation method thereof. Background Art

[0002] Traditional protective coatings often have limitations in their resistance to acid and alkali corrosion. For example, under long-term exposure to acid and alkali, they are prone to blistering, flaking, and discoloration, gradually degrading the metal substrate's protection and leading to corrosion damage. This not only increases equipment repair and replacement costs, but can also cause environmental pollution and even safety hazards due to the leakage of metal corrosion products.

[0003] To address the acid and alkali corrosion resistance of metal substrates, researchers are continuously exploring and developing new protective coatings. Powder coatings, as an environmentally friendly and highly effective coating type, are gaining increasing attention. However, existing powder coatings still need to be further improved in terms of adhesion to metal substrates and acid and alkali corrosion resistance. Therefore, there is an urgent need to develop powder coatings with excellent adhesion to metal substrates and excellent acid and alkali corrosion resistance to meet the protection needs of metal products in harsh environments. Summary of the Invention

[0004] In order to improve the adhesion strength of existing powder coatings to metal substrates and the acid and alkali resistance of powder coatings, the present application provides an acid and alkali corrosion resistant powder coating and a preparation method thereof.

[0005] In the first aspect, the present application provides an acid and alkali corrosion resistant powder coating adopting the following technical solution:

[0006] The invention discloses an acid and alkali corrosion resistant powder coating, which comprises, based on raw materials, 440-450 parts by weight of bisphenol A epoxy resin, 160-170 parts by weight of hydroxy acrylic resin, 110-120 parts by weight of isocyanate terminated polyurethane resin, 28-33 parts by weight of aminosilane coupling agent modified filler and 80-85 parts by weight of curing agent.

[0007] In the present application, the acid and alkali corrosion resistant powder coating is prepared by combining a specific ratio of bisphenol A epoxy resin, hydroxyl acrylic resin, isocyanate terminated polyurethane resin, aminosilane coupling agent modified filler and curing agent. The acid and alkali corrosion resistant powder coating has excellent adhesion to the metal substrate and excellent acid and alkali corrosion resistance. It can withstand a hydrochloric acid solution with a volume concentration of 5% and a sodium hydroxide solution with a mass concentration of 5% for more than 300 hours, which is beneficial for long-term protection and decoration of the substrate.

[0008] In some specific embodiments, the raw materials for preparing the isocyanate-terminated polyurethane resin include polymeric diols, double-terminal hydroxyalkyl silicone oil, small molecule diol chain extender and diisocyanate, and the molar ratio of the polymeric diols, double-terminal hydroxyalkyl silicone oil, small molecule diol chain extender and diisocyanate is (0.5-0.6): (0.1-0.2): (0.05-0.06): 1.

[0009] In this application, the isocyanate-terminated polyurethane resin is prepared by reacting a polymerized diol, a double-ended hydroxyalkyl silicone oil, a small molecule diol chain extender and a diisocyanate in a specific molar ratio. This is beneficial to further improve the adhesion between the powder coating and the substrate and the acid and alkali resistance of the powder coating. At the same time, for a thick coating film of up to 150 μm formed by the powder coating, it can also maintain excellent surface quality and no pinhole problem occurs in the coating film.

[0010] In some specific embodiments, the polymeric diol includes non-fluorinated polyether diol and perfluoropolyether diol in a molar ratio of (3-4):1.

[0011] In some specific embodiments, the non-fluorinated polyether diol is at least one of polypropylene glycol, polyethylene glycol, and polytetramethylene glycol.

[0012] In some specific embodiments, the structural formula of the perfluoropolyether diol is as follows:

[0013]

[0014] The value range of m is 1-3, and the value range of n is 1-3.

[0015] In the present application, when non-fluorinated polyether diols, perfluoropolyether diols, double-ended alcohol hydroxyalkyl silicone oils, small molecule diol chain extenders and diisocyanates are used to prepare isocyanate-terminated polyurethane resins, the perfluoropolyether diol using the perfluoropolyether diol with the above-mentioned structure can further improve the acid and alkali resistance of the powder coating. At the same time, for the thick coating film formed by the powder coating with a thickness of up to 150 μm, it can also maintain excellent surface quality and no pinhole problem occurs in the coating film.

[0016] In some specific embodiments, the double-terminal alcohol hydroxyl alkyl silicone oil adopts double-terminal alcohol hydroxyl long-chain alkyl silicone oil IOTA-8865H.

[0017] In some specific embodiments, the method for preparing the isocyanate-terminated polyurethane resin comprises the following steps:

[0018] The polymerization diol is heated to 45-50°C according to the ratio, and then double-terminal alcohol hydroxyalkyl silicone oil and diisocyanate are added, and the temperature is raised to 85-115°C for polymerization reaction. Then, a small molecule diol chain extender is added for chain extension reaction to obtain isocyanate-terminated polyurethane resin.

[0019] In some specific embodiments, the epoxy equivalent of the bisphenol A epoxy resin is 600-650 g / eq.

[0020] In some specific embodiments, the curing agent is a composition of triglycidyl isocyanurate and β-hydroxyalkylamide, and the weight ratio of triglycidyl isocyanurate to β-hydroxyalkylamide is 1:(3-4).

[0021] In some specific embodiments, the aminosilane coupling agent modified filler is at least one of aminosilane coupling agent modified titanium dioxide, aminosilane coupling agent modified nano-silicon powder, and aminosilane coupling agent modified nano-silicon dioxide.

[0022] In a second aspect, the present application provides a method for preparing an acid and alkali corrosion resistant powder coating, comprising the following steps:

[0023] A method for preparing an acid and alkali corrosion resistant powder coating comprises the following steps:

[0024] Evenly mixing epoxy resin, hydroxy acrylic resin, isocyanate-terminated polyurethane resin, aminosilane coupling agent-modified filler and curing agent to obtain a premix;

[0025] The premix is ​​melted, extruded and crushed at 90-105° C. to obtain an acid and alkali corrosion resistant powder coating.

[0026] In the present application, the above method is used to prepare the acid and alkali corrosion resistant powder coating, which is conducive to the uniform mixing of the components and improves the product uniformity of the acid and alkali corrosion resistant powder coating.

[0027] In summary, this application has at least the following beneficial technical effects:

[0028] (1) In the present application, the acid and alkali corrosion resistant powder coating is prepared by combining a specific ratio of bisphenol A type epoxy resin, hydroxy acrylic resin, isocyanate terminated polyurethane resin, aminosilane coupling agent modified filler and curing agent. The acid and alkali corrosion resistant powder coating has excellent adhesion to the metal substrate and excellent acid and alkali corrosion resistance. It can withstand a hydrochloric acid solution with a volume concentration of 5% and a sodium hydroxide solution with a mass concentration of 5% for more than 300 hours, which is beneficial for long-term protection and decoration of the substrate.

[0029] (2) In the present application, when non-fluorinated polyether diol, perfluoropolyether diol, double-ended alcohol hydroxyalkyl silicone oil, small molecule diol chain extender and diisocyanate are used to prepare isocyanate-terminated polyurethane resin, the perfluoropolyether diol using the perfluoropolyether diol of the above structure can further improve the acid and alkali resistance of the powder coating. At the same time, for the thick coating film formed by the powder coating with a thickness of up to 150 μm, it can also maintain excellent surface quality and no pinhole problem occurs in the coating film. DETAILED DESCRIPTION

[0030] The present application is further described below in conjunction with specific experiments.

[0031] Preparation Example

[0032] [Preparation Example 1]

[0033] The invention discloses an isocyanate-terminated polyurethane resin. The raw materials for preparing the resin include polytetramethylene ether glycol (Hyosung, South Korea) with a molecular weight of 1000, double-end hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol, diphenylmethane diisocyanate, dibutyltin dilaurate and acetone. The molar ratio of polytetramethylene ether glycol, double-end hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol and diphenylmethane diisocyanate is 0.5:0.2:0.06:1. The amount of dibutyltin dilaurate is 0.01% of the weight of the diphenylmethane diisocyanate used, and the amount of acetone is 20% of the weight of the diphenylmethane diisocyanate used.

[0034] In this preparation example, the preparation method of the isocyanate-terminated polyurethane resin comprises the following steps:

[0035] According to the ratio, polytetramethylene ether glycol was heated to 45°C, and then double-terminated hydroxyl long-chain alkyl silicone oil IOTA-8865H, diphenylmethane diisocyanate and dibutyltin dilaurate were added. The temperature was raised to 85°C for prepolymerization, and the reaction time was 3.5 hours. Subsequently, acetone was added and stirred evenly, and propylene glycol was added for chain extension reaction, and the reaction time was 1 hour. Finally, the acetone was removed and granulated to obtain an isocyanate-terminated polyurethane resin.

[0036] [Preparation Example 2]

[0037] The invention discloses an isocyanate-terminated polyurethane resin. The raw materials for preparing the resin include polytetramethylene ether glycol (Hyosung, South Korea) with a molecular weight of 1000, double-end hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol, isophorone diisocyanate, dibutyltin dilaurate and acetone. The molar ratio of polytetramethylene ether glycol, double-end hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol and isophorone diisocyanate is 0.6:0.1:0.05:1. The amount of dibutyltin dilaurate is 0.01% of the weight of the isophorone diisocyanate used, and the amount of acetone is 20% of the weight of the isophorone diisocyanate used.

[0038] In this preparation example, the preparation method of the isocyanate-terminated polyurethane resin comprises the following steps:

[0039] According to the ratio, polytetramethylene ether glycol was heated to 50°C, and then double-terminal alcohol hydroxy long-chain alkyl silicone oil IOTA-8865H, isophorone diisocyanate and dibutyltin dilaurate were added. The temperature was raised to 115°C for prepolymerization reaction. The reaction time was 3 hours. Then, acetone was added and stirred evenly. Propylene glycol was added for chain extension reaction. The reaction time was 1 hour. Finally, the acetone was removed and granulated to obtain an isocyanate-terminated polyurethane resin.

[0040] [Preparation Example 3]

[0041] An isocyanate-terminated polyurethane resin, which differs from [Preparation Example 1] in that the double-terminal hydroxyl long-chain alkyl silicone oil IOTA-8865H is replaced by an equimolar amount of polytetramethylene ether glycol with a molecular weight of 1000 (Hyosung, Korea).

[0042] [Preparation Example 4]

[0043] An isocyanate-terminated polyurethane resin, which differs from [Preparation Example 1] in that: in this Preparation Example, the raw materials for preparing the isocyanate-terminated polyurethane resin include polytetramethylene glycol (Hyosung, South Korea) with a molecular weight of 1000, perfluoropolyether diol, double-terminal hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol, diphenylmethane diisocyanate, dibutyltin dilaurate, and acetone, and the molar ratio of polytetramethylene glycol, perfluoropolyether diol, double-terminal hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol, and diphenylmethane diisocyanate is 0.375:0.125:0.2:0.06:1; wherein the perfluoropolyether diol and the polytetramethylene glycol are added simultaneously, and the structural formula of the perfluoropolyether diol used in this Preparation Example is as follows:

[0044]

[0045] The value range of m is 1, and the value range of n is 1.

[0046] Preparation Example 5

[0047] An isocyanate-terminated polyurethane resin, which differs from [Preparation Example 1] in that: in this Preparation Example, the raw materials for preparing the isocyanate-terminated polyurethane resin include polytetramethylene glycol (Hyosung, South Korea) with a molecular weight of 1000, perfluoropolyether diol, double-terminal hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol, diphenylmethane diisocyanate, dibutyltin dilaurate, and acetone, and the molar ratio of polytetramethylene glycol, perfluoropolyether diol, double-terminal hydroxyl long-chain alkyl silicone oil IOTA-8865H, propylene glycol, and diphenylmethane diisocyanate is 0.4:0.1:0.2:0.06:1; wherein the perfluoropolyether diol and the polytetramethylene glycol are added simultaneously, and the structural formula of the perfluoropolyether diol used in this Preparation Example is as follows:

[0048]

[0049] The value range of m is 3, and the value range of n is 3.

[0050] Preparation Example 6

[0051] An isocyanate-terminated polyurethane resin, which differs from [Preparation Example 5] in that the perfluoropolyether diol is different. In this preparation example, the structural formula of the perfluoropolyether diol is as follows:

[0052] HOCH2CF2CF2(OCF2CF2CF2) a OCF2CF2O(CF2CF2CF2O) b CF2CF2CH2OH; in this preparation example, the value range of m is 3, and the value range of n is 3.

[0053] Preparation Example 7

[0054] An isocyanate-terminated polyurethane resin differs from [Preparation Example 5] in that: in the perfluoropolyether diol, the values ​​of m and n are different; in this Preparation Example, the value range of m is 8, and the value range of n is 8.

[0055] Example

[0056] [Example 1]

[0057] An acid and alkali corrosion resistant powder coating comprising the following raw materials:

[0058] Bisphenol A epoxy resin: 440 kg; in this embodiment, the epoxy equivalent weight of the bisphenol A epoxy resin is 600-650 g / eq; Hydroxylated acrylic resin: 170 kg; in this embodiment, the hydroxylated acrylic resin is BASF Joncryl@587 hydroxylated acrylic resin;

[0059] Isocyanate-terminated polyurethane resin: 110 kg; in this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 1];

[0060] Aminosilane coupling agent modified filler: 28 kg; in this embodiment, the aminosilane coupling agent modified filler adopts silane coupling agent KH550 modified titanium dioxide;

[0061] Curing agent: 80 kg; in this embodiment, the curing agent includes triglycidyl isocyanurate and β-hydroxyalkylamide, and the weight ratio of triglycidyl isocyanurate and β-hydroxyalkylamide is 1:3.

[0062] The preparation method of the acid and alkali corrosion resistant powder coating in this embodiment comprises the following steps:

[0063] Bisphenol A epoxy resin, hydroxy acrylic resin, isocyanate terminated polyurethane resin, aminosilane coupling agent modified filler and curing agent are uniformly mixed to obtain a premix;

[0064] The premix is ​​put into a twin-screw extruder for melt extrusion and crushing to obtain an acid and alkali corrosion resistant powder coating; wherein the temperature of the extruder zone I is 90-95°C, the temperature of the extruder zone II is 90-100°C, the temperature of the extruder zone III is 100-105°C, and the temperature of the extruder zone IV is 100-105°C.

[0065] [Example 2]

[0066] An acid and alkali corrosion resistant powder coating comprising the following raw materials:

[0067] Bisphenol A epoxy resin: 450 kg; in this embodiment, the epoxy equivalent weight of the bisphenol A epoxy resin is 600-650 g / eq; Hydroxylated acrylic resin: 160 kg; in this embodiment, the hydroxylated acrylic resin is BASF Joncryl@587 hydroxylated acrylic resin;

[0068] Isocyanate-terminated polyurethane resin: 120 kg; in this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 2];

[0069] Aminosilane coupling agent modified filler: 33 kg; in this embodiment, the aminosilane coupling agent modified filler adopts silane coupling agent KH550 modified titanium dioxide;

[0070] Curing agent: 85 kg; in this embodiment, the curing agent includes triglycidyl isocyanurate and β-hydroxyalkylamide, and the weight ratio of triglycidyl isocyanurate and β-hydroxyalkylamide is 1:4.

[0071] The preparation method of the acid and alkali corrosion resistant powder coating in this embodiment comprises the following steps:

[0072] Bisphenol A epoxy resin, hydroxy acrylic resin, isocyanate terminated polyurethane resin, aminosilane coupling agent modified filler and curing agent are uniformly mixed to obtain a premix;

[0073] The premix is ​​put into a twin-screw extruder for melt extrusion and crushing to obtain an acid and alkali corrosion resistant powder coating; wherein the temperature of the extruder zone I is 90-95°C, the temperature of the extruder zone II is 90-100°C, the temperature of the extruder zone III is 100-105°C, and the temperature of the extruder zone IV is 100-105°C.

[0074] [Example 3]

[0075] An acid and alkali corrosion resistant powder coating, which differs from [Example 1] in that:

[0076] In this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 3].

[0077] [Example 4]

[0078] An acid and alkali corrosion resistant powder coating, which differs from [Example 1] in that:

[0079] In this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 4].

[0080] [Example 5]

[0081] An acid and alkali corrosion resistant powder coating, which differs from [Example 1] in that:

[0082] In this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 5].

[0083] [Example 6]

[0084] An acid and alkali corrosion resistant powder coating, which differs from [Example 1] in that:

[0085] In this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 6].

[0086] [Example 7]

[0087] An acid and alkali corrosion resistant powder coating, which differs from [Example 1] in that:

[0088] In this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 7].

[0089] Comparative Example

[0090] [Comparative Example 1]

[0091] A powder coating, which differs from Example 1 in that the raw material ratios of the components are different. In this comparative example, the raw material ratios of the components are as follows:

[0092] Bisphenol A epoxy resin: 550 kg; in this embodiment, the epoxy equivalent weight of the bisphenol A epoxy resin is 600-650 g / eq; Hydroxylated acrylic resin: 120 kg; in this embodiment, the hydroxylated acrylic resin is BASF Joncryl@587 hydroxylated acrylic resin;

[0093] Isocyanate-terminated polyurethane resin: 50 kg; in this embodiment, the isocyanate-terminated polyurethane resin is the isocyanate-terminated polyurethane resin prepared in [Preparation Example 1];

[0094] Aminosilane coupling agent modified filler: 28 kg; in this embodiment, the aminosilane coupling agent modified filler adopts silane coupling agent KH550 modified titanium dioxide;

[0095] Curing agent: 80 kg; in this embodiment, the curing agent includes triglycidyl isocyanurate and β-hydroxyalkylamide, and the weight ratio of triglycidyl isocyanurate and β-hydroxyalkylamide is 1:3.

[0096] Performance testing

[0097] 1. Adhesion Grade: Use an electrostatic spray gun to spray the prepared powder onto a surface-treated tinplate substrate to a film thickness of 50 μm. Fully cure at 175°C for 15 minutes to obtain a coating. The coating's adhesion grade is tested according to GB / T 9286-2021, "Paint and Varnish Film Cross-Cut Test." Lower grades indicate better adhesion to the substrate.

[0098] 2. Acid Resistance: The prepared powder was sprayed onto a surface-treated tinplate substrate using an electrostatic spray gun to a film thickness of 50 μm. The film was fully cured at 175°C for 15 minutes to obtain a coating. The acid resistance of the coating was tested according to Method A (immersion method) of GB / T 9274-1988, "Paints and varnishes - Determination of resistance to liquid media." The test liquid was a 5% mass concentration hydrochloric acid solution. The coating was immersed for 300, 450, and 600 hours, and the changes in the coating surface were observed.

[0099] 3. Alkali Resistance: The prepared powder was sprayed onto a surface-treated tinplate substrate using an electrostatic spray gun to a film thickness of 50 μm. The film was fully cured at 175°C for 15 minutes to obtain a coating. The alkali resistance of the coating was tested according to Method A (immersion method) of GB / T 9274-1988, "Paints and varnishes - Determination of resistance to liquid media." The test liquid was a 5% mass concentration sodium hydroxide solution. The coating was immersed for 300, 450, and 600 hours, and the changes in the coating surface were observed.

[0100] 4. Graffiti pen test: The prepared powder was sprayed onto a surface-treated tinplate substrate using an electrostatic spray gun. The film thicknesses were 50 μm, 100 μm, and 150 μm, respectively. After being fully cured at 175°C for 15 min, the coating surface was observed for pinholes or shrinkage cavities.

[0101] Table 1

[0102] Sample Adhesion grade Example 1 0 Example 2 0 Example 3 1 Example 4 0 Example 5 0 Example 6 0 Example 7 0 Comparative Example 1 1

[0103] Table 2

[0104]

[0105] Table 3

[0106]

[0107] Combining the test results of Comparative Example 1 and Example 1 and Tables 1-3, it can be seen that when the ratio of bisphenol A epoxy resin, hydroxy acrylic resin and isocyanate-terminated polyurethane resin in Comparative Example 1 is not within the scope of this application, the adhesion fastness of the powder coating to the substrate, the acid and alkali corrosion resistance of the powder coating and the surface quality of the coating film formed by the powder coating are all significantly reduced, indicating that the ratio of bisphenol A epoxy resin, hydroxy acrylic resin and isocyanate-terminated polyurethane resin is one of the key technical features of this application.

[0108] Combining Example 1 and Example 3 and the test results in Tables 1-3, it can be seen that compared with the isocyanate-terminated polyurethane resin prepared by reacting polytetramethylene ether glycol, propylene glycol, and isophorone diisocyanate, the isocyanate-terminated polyurethane resin prepared by reacting polytetramethylene ether glycol, a double-terminated hydroxyl long-chain alkyl silicone oil, propylene glycol, and isophorone diisocyanate is beneficial for further improving the adhesion between the powder coating and the substrate and the acid and alkali resistance of the powder coating. At the same time, for the thicker coating film formed by the powder coating, it can also maintain excellent surface quality, and the coating film has no pinhole problem.

[0109] Combining the test results in Example 1, Examples 4-7, and Tables 1-3, it can be seen that when the isocyanate-terminated polyurethane resin is prepared by reacting polytetramethylene ether diol, perfluoropolyether diol, double-terminated alcohol hydroxyl long-chain alkyl silicone oil, propylene glycol, and isophorone diisocyanate, the preferred structure of the perfluoropolyether diol is:

[0110] Perfluoropolyether diols with m values ​​ranging from 1 to 3 and n values ​​ranging from 1 to 3 can further improve the acid and alkali resistance of powder coatings. At the same time, for thicker coating films formed by powder coatings, excellent surface quality can be maintained without pinhole problems in the coating films.

[0111] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An acid and alkali corrosion resistant powder coating, characterized by: Based on the raw materials, it includes 440-450 parts by weight of bisphenol A epoxy resin, 160-170 parts by weight of hydroxy acrylic resin, 110-120 parts by weight of isocyanate-terminated polyurethane resin, 28-33 parts by weight of aminosilane coupling agent modified filler and 80-85 parts by weight of curing agent; The raw materials for preparing the isocyanate-terminated polyurethane resin include polymeric diol, di-terminal hydroxyalkyl silicone oil, small molecule diol chain extender and diisocyanate, and the molar ratio of the polymeric diol, di-terminal hydroxyalkyl silicone oil, small molecule diol chain extender and diisocyanate is (0.5-0.6): (0.1-0.2): (0.05-0.06): 1; The polymeric diol includes a non-fluorinated polyether diol and a perfluoropolyether diol in a molar ratio of (3-4):1; The structural formula of the perfluoropolyether diol is as follows: ； The value range of m is 1-3, and the value range of n is 1-3.

2. The acid and alkali corrosion resistant powder coating according to claim 1, characterized in that: The non-fluorine-containing polyether diol is at least one of polypropylene glycol, polyethylene glycol, and polytetramethylene glycol.

3. The acid and alkali corrosion resistant powder coating according to claim 1, characterized in that: The double-terminal alcohol hydroxyl alkyl silicone oil adopts double-terminal alcohol hydroxyl long-chain alkyl silicone oil IOTA-8865H.

4. The acid and alkali corrosion resistant powder coating according to any one of claims 1 to 3, characterized in that: The preparation method of the isocyanate-terminated polyurethane resin comprises the following steps: heating the polymeric diol to 45-50° C. according to the ratio, then adding diisocyanate and double-ended hydroxyalkyl silicone oil, and heating to 85-115° C. to carry out polymerization reaction, and then adding a small molecule diol chain extender to carry out chain extension reaction to obtain the isocyanate-terminated polyurethane resin.

5. The acid and alkali corrosion resistant powder coating according to claim 1, characterized in that: The epoxy equivalent of the bisphenol A epoxy resin is 600-650 g / eq.

6. The acid and alkali corrosion resistant powder coating according to claim 1, characterized in that: The curing agent is a composition of triglycidyl isocyanurate and beta-hydroxyalkylamide, and the weight ratio of the triglycidyl isocyanurate to the beta-hydroxyalkylamide is 1:(3-4).

7. A method for preparing an acid and alkali corrosion resistant powder coating according to any one of claims 1 to 6, characterized in that: The following steps are involved: Bisphenol A epoxy resin, hydroxy acrylic resin, isocyanate terminated polyurethane resin, aminosilane coupling agent modified filler and curing agent are uniformly mixed to obtain a premix; the premix is ​​melt-extruded at 90-105° C. and crushed to obtain an acid and alkali corrosion resistant powder coating.

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