Preparation method of new energy strong acid and alkali resistant powder coating

Abstract

The invention discloses a preparation method of a new energy strong acid and alkali resistant powder coating, comprising the following steps: S1, weighing the following preparation raw materials by mass percentage: epoxy resin, curing agent, polyester resin, catalyst, accelerator, silicon micropowder, leveling agent, brightener, benzoin, and pigment; by adopting high-viscosity epoxy resin and polyester resin, they can penetrate and mix with each other, and can form a uniform coating during application, effectively improving the corrosion resistance of the coating, and preventing acid and alkali substances from penetrating into the interior of the coating, wherein the polyester resin and the epoxy resin both have a large molecular weight, and their molecular structures contain polar groups, which can react with acid and alkali substances to form stable chemical bonds, thereby improving the corrosion resistance of the coating. In the application of new energy batteries, the electrolyte filter grid can have an excellent effect of strong acid and alkali resistance, and can be widely used in the coating of facilities that need to be resistant to strong acids and alkalis.

Description

Technical Field

[0001] The present invention relates to the technical field of powder coatings, and in particular to a method for preparing a new energy strong acid and alkali resistant powder coating. Background Art

[0002] Powder coating is a solvent-free, volatile-free solid coating with advantages such as environmental friendliness, high efficiency, and low cost. It is widely used in industries such as home appliances, automobiles, construction, and the petroleum and petrochemical industry. New energy vehicles (NEVs) are vehicles powered by unconventional fuels. They are gaining increasing national attention due to their environmental and energy-saving benefits. Electric vehicles account for a significant portion of these new energy vehicles, and their most important component is the battery pack. New energy batteries require a large amount of electrolyte and have strict requirements. Filtration is an essential process step, but conventional filters are generally not very acid- or alkali-resistant and are easily corroded, posing safety risks and compromising the effectiveness of precision filtration.

[0003] In the prior art, powder coatings are typically composed of resins, pigments, fillers, curing agents, and additives, and are prepared through melt extrusion, crushing, and grinding. Resin is the base material and the most important film-forming substance in powder coatings. Epoxy resin is typically used, and reacts with the curing agent. After curing, the epoxy resin forms a three-dimensional cross-linked network structure, which gives it high chemical stability and corrosion resistance. However, in strong acid and alkaline environments, since epoxy resin is a high-molecular polymer with reactive groups such as ether bonds and hydroxyl groups in its molecular structure, these groups may react with acidic and alkaline substances under these conditions, potentially affecting its resistance to corrosion.

[0004] Therefore, it is necessary to improve the powder coatings in the prior art to solve the above problems. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a method for preparing a new energy strong acid and alkali resistant powder coating.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a new energy strong acid and alkali resistant powder coating, comprising the following steps:

[0007] S1. Weigh the following raw materials by mass percentage: epoxy resin 45%-55%, curing agent 5%-12%, polyester resin 20%-32%, catalyst 1%-4%, accelerator 0.5%-1.5%, silica powder 5%-12%, leveling agent 0.8%-1.5%, brightener 0.5%-1.2%, benzoin 0.3%-0.6%, pigment 4%-8%;

[0008] S2, fluorinating the polyester resin weighed in S1, adding the epoxy resin and curing agent into the mixer Misecara to obtain a mixture A;

[0009] S3, adding the fluorinated polyester resin in S1 and S2, mixture A, catalyst, accelerator, silica powder, leveling agent, brightener, benzoin and pigment into a mixer Misecara cylinder to obtain mixture B;

[0010] S4, sequentially subjecting the mixture B to melt extrusion, tableting, crushing, pulverization and low-temperature dispersion;

[0011] S5. The product in S4 is screened and graded in a screening machine to obtain a new energy strong acid and strong alkali resistant powder coating.

[0012] In a preferred embodiment of the present invention, in S2, the method for preparing the fluorinated polyester resin comprises the following steps:

[0013] S1. Evenly mix the polyester resin and the fluorinating agent in a mass ratio of 1:1-3, and stir at a temperature of 60-90° C. for 30-60 minutes and react for 1-3 hours;

[0014] S2. The product in S1 is adjusted to a pH of 6-8 with an alkaline solution, washed with water, and dried at a temperature of 50-80° C. for 1-3 hours to obtain a fluorinated polyester resin.

[0015] In a preferred embodiment of the present invention, the fluorinating agent is one of hydrogen fluoride, sodium fluoride or tetrafluoroethylene; and the alkaline solution is one of sodium hydroxide or potassium hydroxide.

[0016] In a preferred embodiment of the present invention, in S1, the curing agent is one of triglycidyl isocyanurate, m-phenylenediamine or diaminodiphenylmethane; the catalyst is one of N,N-dimethylcyclohexylamine, triethanolamine or solid amine; the accelerator is a composite of dimethyl silicone oil and silica; the leveling agent is PV88 leveling agent; the brightener is one of polypropylene brightener or polyethylene brightener; the pigment is one of ultramarine, ultramarine violet or iron oxide.

[0017] In a preferred embodiment of the present invention, in S2 and S3, the mixing time is: 2-4 minutes for low-speed mixing and 5-8 minutes for high-speed mixing; the rotation speed of the low-speed mixing is 110 r / min and the rotation speed of the high-speed mixing is 320 r / min.

[0018] In a preferred embodiment of the present invention, in S4, the melt extrusion refers to: adding the mixture B to a twin-screw extruder for extrusion, wherein the feeding section temperature is 80-85°C, the extrusion head temperature is 95-100°C, and the residence time of the mixture B is 45-60s.

[0019] In a preferred embodiment of the present invention, in S4, the tableting process refers to tableting the melt-extruded mixture B by a tablet press.

[0020] In a preferred embodiment of the present invention, in S4, the pulverization process is to use an airflow vortex grinder for graded pulverization, wherein the main grinding frequency is 35-45 Hz and the auxiliary grinding frequency is 30-40 Hz.

[0021] In a preferred embodiment of the present invention, in S4, the low-temperature dispersion treatment refers to: introducing liquid nitrogen, dispersing at a temperature of -196°C and a rotation speed of 850-1100 r / min for 0.5-1.5 hours.

[0022] In a preferred embodiment of the present invention, in S5, the screening and grading process is to pass through a 180-200 mesh sieve.

[0023] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0024] (1) The present invention provides a method for preparing a new energy strong acid and strong alkali resistant powder coating, which adopts high-viscosity epoxy resin and polyester resin. The two have good compatibility and can penetrate and mix with each other. A uniform coating can be formed during application, which effectively improves the corrosion resistance of the coating and prevents acid and alkali substances from penetrating into the interior of the coating. There is a strong interaction force between the molecules, which can enhance the adhesion and wear resistance of the coating, and improve the durability and protective effect of the coating. The polyester resin and the epoxy resin both have a large molecular weight, and their molecular structures contain polar groups, which can react with acid and alkali substances to form stable chemical bonds, thereby improving the corrosion resistance of the coating. In the application of new energy batteries, the electrolyte filter grid can play an excellent role in strong acid and strong alkali resistance, and can be widely used in the coating of facilities that need to be resistant to strong acids and strong alkalis.

[0025] (2) In the present invention, the polyester resin is fluorinated, and the large number of ester groups and hydroxyl active groups contained in its molecular chain are utilized, so that a chemical reaction is easily generated when the polyester resin is fluorinated, and it is easier to introduce fluorine atoms to complete the fluorination. After the polyester resin is fluorinated, its surface can form a larger contact angle with water or solution, thereby enhancing its hydrophobicity. After being prepared in combination with epoxy resin and curing agent, the contact angle of the coating with water or solution becomes larger during application, thereby further improving the ability to resist strong acids and strong alkalis.

[0026] (3) In the present invention, since the epoxy groups in the epoxy resin are relatively stable, the hydroxyl groups therein are difficult to react with fluorine atoms, and therefore it is difficult to undergo a fluorination reaction. The polyester resin after the fluorination reaction has strong polarity and chemical activity, and the epoxy resin has even worse compatibility, making it difficult to form an effective chemical bond. By first fluorinating the polyester resin, and then cross-linking the epoxy resin and the curing agent, introducing the fluorinated polyester resin and an amine catalyst, etc., the interfacial properties between the epoxy resin and the fluorinated polyester resin can be improved, the wetting and adhesion at the interface can be promoted, and the ring-opening reaction of the epoxy groups in the epoxy resin and the alkylation reaction of the hydroxyl groups in the polyester resin can be promoted, which can make the chemical bond more stable and less prone to decomposition, thereby improving the bonding performance.

[0027] (4) In the present invention, the adhesion of the powder coating can be enhanced by mixing the accelerator, and the dielectric constant of the silicon micropowder is large, which can play an electrical insulation effect. At the same time, the mixing of the leveling agent can reduce the surface tension of the coating film, making the coating film uniformly leveled. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0029] Figure 1 This is a flow chart of a method for preparing a new energy strong acid and strong alkali resistant powder coating according to a preferred embodiment of the present invention; DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0032] In the description of this application, it should be understood that the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0033] It should be noted that the raw materials, equipment, reagents, etc. used in the present invention can be purchased from the market or obtained through existing preparation methods.

[0034] like Figure 1 As shown, a method for preparing a new energy strong acid and alkali resistant powder coating comprises the following steps:

[0035] S1. Weigh the following raw materials by mass percentage: epoxy resin 45%-55%, curing agent 5%-12%, polyester resin 20%-32%, catalyst 1%-4%, accelerator 0.5%-1.5%, silica powder 5%-12%, leveling agent 0.8%-1.5%, brightener 0.5%-1.2%, benzoin 0.3%-0.6%, pigment 4%-8%;

[0036] S2, fluorinating the polyester resin weighed in S1, adding the epoxy resin and curing agent into the mixer Misecara to obtain a mixture A;

[0037] S3, adding the fluorinated polyester resin in S1 and S2, mixture A, catalyst, accelerator, silica powder, leveling agent, brightener, benzoin and pigment into a mixer Misecara cylinder to obtain mixture B;

[0038] S4, sequentially subjecting the mixture B to melt extrusion, tableting, crushing, pulverization and low-temperature dispersion;

[0039] S5. The product in S4 is screened and graded in a screening machine to obtain a new energy strong acid and strong alkali resistant powder coating.

[0040] In S1 of the present invention, the curing agent is one of triglycidyl isocyanurate, m-phenylenediamine or diaminodiphenylmethane; the catalyst is one of N,N-dimethylcyclohexylamine, triethanolamine or solid amine; the accelerator is a composite of dimethyl silicone oil and silicon dioxide; the leveling agent is PV88 leveling agent; the brightener is one of polypropylene brightener or polyethylene brightener; and the pigment is one of ultramarine, ultramarine violet or iron oxide.

[0041] In S2 and S3 of the present invention, the mixing time is: 2-4 minutes for low-speed mixing and 5-8 minutes for high-speed mixing; the rotation speed of low-speed mixing is 110 r / min and the rotation speed of high-speed mixing is 320 r / min.

[0042] In S4 of the present invention, melt extrusion refers to: adding mixture B to a twin-screw extruder for extrusion, wherein the feeding section temperature is 80-85°C, the extrusion head temperature is 95-100°C, and the residence time of mixture B is 45-60s; tableting refers to: tableting the melt-extruded mixture B through a tablet press; pulverization refers to graded pulverization using an air flow vortex pulverizer, wherein the main grinding frequency is 35-45Hz and the secondary grinding frequency is 30-40Hz; low-temperature dispersion refers to: introducing liquid nitrogen and dispersing at a temperature of -196°C and a speed of 850-1100r / min for 0.5-1.5h.

[0043] In S5 of the present invention, the screening and classification process is to pass through a 180-200 mesh sieve.

[0044] It should be noted that by using high-viscosity epoxy resin and polyester resin, the two have good compatibility, can penetrate and mix with each other, and can form a uniform coating during application, effectively improving the corrosion resistance of the coating and preventing acid and alkali substances from penetrating into the interior of the coating. There is a strong interaction force between the molecules, which can enhance the adhesion and wear resistance of the coating, and improve the durability and protective effect of the coating. Among them, polyester resin and epoxy resin both have a large molecular weight, and their molecular structure contains polar groups, which can react with acid and alkali substances to form stable chemical bonds, thereby improving the corrosion resistance of the coating.

[0045] The preparation method of the fluorinated polyester resin comprises the following steps:

[0046] S1. Evenly mix the polyester resin and the fluorinating agent in a mass ratio of 1:1-3, and stir at a temperature of 60-90° C. for 30-60 minutes and react for 1-3 hours;

[0047] S2. The product in S1 is adjusted to a pH of 6-8 with an alkaline solution, washed with water, and dried at a temperature of 50-80° C. for 1-3 hours to obtain a fluorinated polyester resin.

[0048] It should be noted that the fluorinating agent is one of hydrogen fluoride, sodium fluoride or tetrafluoroethylene; and the alkaline solution is one of sodium hydroxide or potassium hydroxide.

[0049] It should be noted that by fluorinating the polyester resin and utilizing the large number of active ester and hydroxyl groups on its molecular chain, chemical reactions are easily generated during the fluorination of the polyester resin, making it easier to introduce fluorine atoms to complete the fluorination. After the polyester resin is fluorinated, a larger contact angle can be formed between its surface and water or solution, thereby enhancing its hydrophobicity. After being prepared in combination with epoxy resin and curing agent, the contact angle of the coating with water or solution becomes larger during application, thereby further improving its resistance to strong acids and strong alkalis.

[0050] The following is a detailed description of the overall implementation of the present invention with reference to specific examples.

[0051] The raw materials and raw material ratios used in Examples 1-6 are different, as shown in Table 1. The raw materials are measured in percentage by mass.

[0052] Table 1:

[0053]

[0054]

[0055] The preparation method of the fluorinated polyester resin used in Examples 1 and 3 is:

[0056] S1. Mix polyester resin and hydrogen fluoride in a mass ratio of 1:2.5, stir at 80°C for 45 minutes, and react for 2 hours;

[0057] S2. The product in S1 was adjusted to pH 7 with potassium hydroxide, washed with water, and dried at 70° C. for 3 h to obtain a fluorinated polyester resin.

[0058] The preparation method of the fluorinated polyester resin used in Examples 4 and 5 is basically the same as the preparation method of the fluorinated polyester resin in Examples 1 and 3, except that the mass ratio of the polyester resin to hydrogen fluoride is 1:3.

[0059] The preparation method of the fluorinated polyester resin used in Example 6 is basically the same as the preparation method of the fluorinated polyester resin in Examples 1 and 3, except that the fluorinating agent is sodium fluoride.

[0060] Example 1

[0061] A method for preparing a new energy strong acid and alkali resistant powder coating comprises the following steps:

[0062] S1. Add epoxy resin and triglycidyl isocyanurate into a mixer, mix at a low speed of 110 r / min for 3 min, and mix at a high speed of 320 r / min for 5 min to obtain a mixture A;

[0063] S2. Add fluorinated polyester resin, mixture A, N,N-dimethylcyclohexylamine, a composite of dimethyl silicone oil and silicon dioxide, silicon powder, PV88 leveling agent, polypropylene brightener, benzoin and iron oxide into a mixer, mix at a low speed of 110 r / min for 4 min, and at a high speed of 320 r / min for 8 min to obtain mixture B;

[0064] S3, mixture B is added into a twin-screw extruder and extruded, wherein, the feeding section temperature is 80 ℃, the extrusion head temperature is 100 ℃, and the mixture B residence time is 60s. After melt extrusion, tableting is performed by a tablet press, and the mixture is crushed after cooling. After crushing, an air flow vortex mill is used for graded crushing, wherein, the main grinding frequency is 40 Hz, and the secondary grinding frequency is 30 Hz. After crushing, liquid nitrogen is introduced and dispersed for 1 h at a temperature of -196 ℃ with a rotating speed of 950 r / min.

[0065] S4. The product in S3 is sieved and graded in a screening machine and passed through a 200-mesh sieve to obtain a new energy strong acid and alkali resistant powder coating.

[0066] Example 2

[0067] This embodiment is basically the same as embodiment 1, except that: in step S2, the fluorinated polyester resin is a polyester resin without N,N-dimethylcyclohexylamine;

[0068] Example 3

[0069] This embodiment is substantially the same as embodiment 1, except that step S1 is omitted; step S2 comprises adding epoxy resin, triglycidyl isocyanurate, fluorinated polyester resin, mixture A, N,N-dimethylcyclohexylamine, a composite of dimethyl silicone oil and silicon dioxide, silicon powder, PV88 leveling agent, polypropylene brightener, benzoin, and iron oxide into a mixer, mixing at a low speed of 110 r / min for 4 min, and then mixing at a high speed of 320 r / min for 8 min to obtain mixture B;

[0070] Example 4

[0071] This embodiment is basically the same as Example 1, except that: in step S1, low-speed mixing is performed for 4 minutes and high-speed mixing is performed for 6 minutes; in step S2, low-speed mixing is performed for 3 minutes and high-speed mixing is performed for 7 minutes; in step S3, the feeding section temperature is 85°C, the extrusion head temperature is 95°C, the residence time of mixture B is 50 seconds, and the mixture is dispersed at a speed of 1100 r / min for 0.5 hours at a temperature of -196°C; and in step S4, the mixture is sieved and graded to pass through a 180-mesh sieve.

[0072] Example 5

[0073] This embodiment is basically the same as Example 1, except that: in step S2, low-speed mixing is performed for 3 minutes and high-speed mixing is performed for 7 minutes; in step S3, the feeding section temperature is 85°C, the extruder head temperature is 95°C, the residence time of mixture B is 45 seconds, and the mixture is dispersed at a speed of 850 r / min for 1.5 hours at a temperature of -196°C; and in step S4, the mixture is sieved and graded to pass through a 180-mesh sieve.

[0074] Example 6

[0075] This embodiment is substantially the same as embodiment 1, except that in step S2, no N,N-dimethylcyclohexylamine is present.

[0076] Comparative Example 1: The new energy strong acid and alkali resistant powder coating is basically the same as that in Example 1, the difference is that in step S1, the curing agent is diaminodiphenylmethane; in step S2, the catalyst is triethanolamine.

[0077] Comparative Example 2: The new energy strong acid and alkali resistant powder coating is basically the same as that in Example 1, except that in step S2, the catalyst is triethanolamine.

[0078] Comparative Example 3: The new energy strong acid and alkali resistant powder coating is basically the same as that in Example 1, the difference is that: in step S1, the curing agent is diaminodiphenylmethane; in step S2, the brightener is polyethylene brightener, and the pigment is ultramarine.

[0079] Comparative Example 4: The new energy strong acid and alkali resistant powder coating is basically the same as that in Example 1, the difference is that: in step S1, the curing agent is m-phenylenediamine; in step S2, the catalyst is solid amine, and the brightener is polyethylene brightener.

[0080] Performance testing: The powder coatings prepared in Examples 1-6 and Comparative Examples 1-4 were sprayed onto a 100 mm × 100 mm aluminum sheet and cured in an oven at 200°C for 1.5 h. After curing, the thickness of the coating on the aluminum sheet was 90 μm. The coatings formed by the powder coatings of Examples 1-6 and Comparative Examples 1-4 were tested for impact resistance, wear resistance, contact angle, and electrolyte resistance.

[0081] Impact resistance test: refer to GB / T 1732-1993 "Determination of impact resistance of paint films" for testing, and conduct three parallel tests and take the average value.

[0082] Abrasion resistance test: Test according to GB / T 23988-2009, "Determination of Abrasion Resistance of Coatings - Falling Sand Method," with three parallel tests performed and the average value taken. A higher value indicates more falling sand required to achieve unit wear of the coating, indicating better abrasion resistance.

[0083] Contact angle test: The test was conducted in accordance with GB / T 30693-2014 Measurement of contact angle of plastic film with water. The test equipment was a water drop projection contact angle meter. The contact angle was measured within 60 seconds after the water droplet was transferred. The contact angle was measured three times on the same sample and the average value was taken.

[0084] Electrolyte resistance test: The samples of Examples 1-6 and Comparative Examples 1-4 were placed in a constant temperature water bath at 98°C containing electrolyte. After 5 minutes, they were taken out and placed in a freezer at -30°C for 5 minutes. The above method was repeated for 1000 cycles and the changes in the coating on the sample surface were observed.

[0085] The test results of impact resistance, wear resistance, contact angle and electrolyte resistance of the samples of Examples 1-6 and Comparative Examples 1-4 are shown in Table 2.

[0086] Table 2:

[0087]

[0088]

[0089] The coating samples formed by the powder coatings of Examples 1-6 and Comparative Examples 1-4 were immersed in 15 wt% sodium hydroxide for 24 hours. The alkali resistance changes of the coating films on the surface of the samples were tested after 12 hours, 16 hours, 20 hours and 24 hours, respectively. The results are shown in Table 3.

[0090] Table 3

[0091]

[0092]

[0093] It can be seen from the performance test and alkali resistance test results in Table 2 and Table 3 that the coating obtained by the new energy strong acid and alkali resistant powder coating prepared by the present invention has an impact resistance of 70.3 kg / cm at room temperature and an impact resistance of 68.1 kg / cm at low temperature of -20°C. It also has a wear resistance of 3.77 L / μm and a water contact angle of 148°. In the application of new energy batteries, it can have excellent resistance to strong acids and strong alkalis for the filter grid of the electrolyte, and can be widely used in the coating of facilities that require resistance to strong acids and strong alkalis.

[0094] From the comparison between Example 2 and Example 6, it can be seen that the impact resistance, wear resistance and hydrophobicity of the coating can be increased by fluorinating the polyester resin and introducing an amine catalyst.

[0095] By comparing Example 1 and Example 6, it can be seen that when combining fluorinated polyester resin with raw materials such as epoxy resin, the introduction of amine catalysts can promote various organic reactions and polymerization reactions, form chemical bonds between the fluorinated polyester resin and the epoxy resin, and improve the bonding strength and overall performance.

[0096] By comparing Example 1 and Example 3, it can be seen that by first fluorinating the polyester resin and then introducing the fluorinated polyester resin and amine catalyst after the epoxy resin and the curing agent are cross-linked, the interfacial properties between the epoxy resin and the fluorinated polyester resin can be improved, the wetting and adhesion at the interface can be promoted, and the ring-opening reaction of the epoxy group in the epoxy resin and the alkylation reaction of the hydroxyl group in the polyester resin can be promoted, which can make the chemical bonding more stable and not easy to decompose, and improve the bonding performance, thereby further improving the coating's resistance to strong acids and alkalis and the overall performance effect.

[0097] The above description is based on the ideal embodiment of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the content of the specification and must be determined according to the scope of the claims.

Claims

1. A method for preparing a new energy strong acid and alkali resistant powder coating, characterized in that: The following steps are involved: S1. Weigh the following raw materials by mass percentage: epoxy resin 45%-55%, curing agent 5%-12%, polyester resin 20%-32%, catalyst 1%-4%, accelerator 0.5%-1.5%, silica powder 5%-12%, leveling agent 0.8%-1.5%, brightener 0.5%-1.2%, benzoin 0.3%-0.6%, pigment 4%-8%; S2, fluorinating the polyester resin weighed in S1, adding the epoxy resin and curing agent into the mixer Misecara to obtain a mixture A; S3, adding the fluorinated polyester resin in S1 and S2, mixture A, catalyst, accelerator, silica powder, leveling agent, brightener, benzoin and pigment into a mixer Misecara cylinder to obtain mixture B; S4, sequentially subjecting the mixture B to melt extrusion, tableting, crushing, pulverization and low-temperature dispersion; S5, screening and grading the product in S4 in a screening machine to obtain a new energy strong acid and alkali resistant powder coating; In S2, the preparation method of the fluorinated polyester resin comprises the following steps: S21, uniformly mixing the polyester resin and the fluorinating agent in a mass ratio of 1:1-3, stirring at a temperature of 60-90° C. for 30-60 minutes, and reacting for 1-3 hours; S22. The product in S21 is adjusted to a pH of 6-8 with an alkaline solution, washed with water, and dried at a temperature of 50-80° C. for 1-3 hours to obtain a fluorinated polyester resin.

2. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: The fluorinating agent is one of hydrogen fluoride, sodium fluoride or tetrafluoroethylene; and the alkaline solution is one of sodium hydroxide or potassium hydroxide.

3. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: In S1, the curing agent is one of triglycidyl isocyanurate, m-phenylenediamine or diaminodiphenylmethane; the catalyst is one of N,N-dimethylcyclohexylamine, triethanolamine or solid amine; the accelerator is a composite of dimethyl silicone oil and silicon dioxide; the leveling agent is PV88 leveling agent; the brightener is one of polypropylene brightener or polyethylene brightener; the pigment is one of ultramarine, ultramarine violet or iron oxide.

4. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: In S2 and S3, the mixing time is: 2-4 min for low-speed mixing and 5-8 min for high-speed mixing; the rotation speed of the low-speed mixing is 110 r / min, and the rotation speed of the high-speed mixing is 320 r / min.

5. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: In the S4, the melt extrusion means: adding the mixture B into a twin-screw extruder for extrusion, wherein the feeding section temperature is 80-85°C, the extrusion head temperature is 95-100°C, and the residence time of the mixture B is 45-60s.

6. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: In the step S4, the tableting process refers to tableting the melt-extruded mixture B using a tablet press.

7. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: In the S4, the pulverization process is to use an airflow vortex grinder for graded pulverization, wherein the main grinding frequency is 35-45 Hz and the auxiliary grinding frequency is 30-40 Hz.

8. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: In the S4, the low-temperature dispersion treatment refers to: introducing liquid nitrogen, dispersing at a temperature of -196°C and a rotation speed of 850-1100 r / min for 0.5-1.5 hours.

9. The method for preparing a new energy strong acid and alkali resistant powder coating according to claim 1, characterized in that: In the step S5, the screening and classification process is to pass through a 180-200 mesh sieve.

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