Fluorocarbon powder coating
By mixing polyvinylidene fluoride with a modified hydrogenated rosin alcohol with a modified curing agent, and adding nano-hard particles, fluorocarbon powder coatings are prepared, which solves the curing problems and insufficient adhesion of existing fluorocarbon coatings, and achieves coatings with high adhesion and friction properties.
Patent Information
- Application Number
- CN202510151016.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-06
- Publication Date
- 2025-05-30
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing fluorocarbon coatings have problems such as high curing temperature, long curing time, poor adhesion and expensive prices, which limit their application.
By mixing polyvinylidene fluoride with a modified hydrogenated rosin alcohol with a modified curing agent, combined with nano-hard particles, a fluorocarbon powder coating was prepared to improve its adhesion and frictional properties.
The strong adhesion and friction properties of the coating are achieved, the curing temperature and time are reduced, and the mechanical properties are enhanced through the use of nano-hard particles.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of powder coatings, and specifically to a fluorocarbon powder coating. Background Art
[0002] Powder coatings originated in the early 1960s. They are a new type of coating that is applied in the form of powder particles to form a coating film. They have the characteristics of being solvent-free, pollution-free, recyclable, environmentally friendly, energy-saving, and high mechanical strength of the coating film, meeting the principles of "economy, efficiency, ecology, and energy" put forward internationally. The varieties of powder coatings are continuously developed, the coating technologies are continuously innovated, and the application fields are continuously expanded. From thick coatings to thin coatings that can be as thin as 10μm; from mainly having anti-corrosion functions to having high decoration and high functionality, powder coatings have become one of the most promising coating varieties, and are gradually replacing traditional solvent-based coatings and are widely used in various fields such as household appliances, metal components, building materials, the automotive industry, telecommunications equipment, transportation equipment, and the pipeline industry.
[0003] In recent years, fluoropolymers have been often applied to coatings to improve the hydrophobic and oleophobic properties and acid and alkali resistance of the coating film due to their outstanding properties, and have received more and more extensive attention; fluorine has special physical and chemical properties. For example, the fluorine atom radius and the polarizability of the fluorocarbon bond are relatively small. Therefore, the internal structure of the fluoropolymer molecule is relatively dense, showing special surface properties such as low surface tension and hydrophobic and oleophobic properties. At the same time, the bond energy of the fluorocarbon bond is as high as 487.6 kJ / mol, and the fluorine atoms tightly wrap the polymer carbon-carbon main chain in a spiral manner and fill the gaps, maximizing the protection of the integrity and density of the polymer molecular structure, preventing liquid and gas molecules from entering the coating. Therefore, fluorocarbon coatings not only have good corrosion resistance, but also have excellent weather resistance, pollution resistance and other properties, and are usually used for the anti-corrosion of steel structure buildings, bridges, ships, rail vehicles, pipelines, chemical facilities and color-coated steel plates. Although fluorocarbon coatings have many excellent properties, defects such as high curing temperature, long curing time, poor adhesion and high price limit their application. Summary of the Invention
[0004] The purpose of the present invention is to provide a fluorocarbon powder coating and its preparation method to solve the problems existing in the prior art.
[0005] To solve the above technical problems, the present invention provides the following technical solution: a fluorocarbon powder coating, which is prepared by mixing modified hydrogenated rosin alcohol and a modified curing agent with polyvinylidene fluoride.
[0006] Further, the modified hydrogenated rosin alcohol is prepared from 3H-1,2-benzodithiol-3-one modified hydrogenated rosin alcohol.
[0007] Further, the modified curing agent is prepared by modifying isophthalic dimethyl diisocyanate with dihydroxyphenylalanine.
[0008] Further, a preparation method of a fluorocarbon powder coating includes the following preparation steps: (1) Mix 3H-1,2-benzodisulfenol-3-one and hydrogenated rosin alcohol, and under a nitrogen atmosphere, dropwise add a 17 wt% sodium ethoxide aqueous solution, stir at 50-120 rpm for 30-60 min, and let stand for 4-8 h to obtain modified hydrogenated rosin alcohol; (2) Mix dihydroxyphenylalanine, isophthalic dimethyl diisocyanate, and dibutyltin dilaurate in a mass ratio of 2:10-20:0.05, stir at 40-80 rpm for 8-20 min under a nitrogen atmosphere, adjust the pH of the solution to 8.3-8.8 with a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution, and let stand for 10-30 min to obtain a modified curing agent; (3) Mix the modified hydrogenated rosin alcohol, the modified curing agent, polyvinylidene fluoride, and benzoin, stir at 80-140 rpm for 2-10 min, add nano hard particles, stir at 1500-2500 rpm for 2-6 min, then at 120-150 °C, knead, extrude and cool to room temperature, and grind through a 160-220 mesh sieve to obtain the fluorocarbon powder coating.
[0009] Further, the hydrogenated rosin alcohol in step (1) is composed of dehydroabietyl alcohol, methyl abietate, and dihydroabietyl alcohol in a mass ratio of 1:0.7:2.
[0010] Further, the dropping rate in step (1) is 0.1-0.8 mL / s.
[0011] Further, the mass ratio of 3H-1,2-benzodisulfenol-3-one, hydrogenated rosin alcohol, and the 17 wt% sodium ethoxide aqueous solution in step (1) is 1-5:9:0.5.
[0012] Further, the nano hard particles in step (3) are composed of nano zirconium carbide, nano chromium carbide, and nano boron carbide in a mass ratio of 1-3:0.5:0.1.
[0013] Further, the molecular weight of the polyvinylidene fluoride in step (3) is 3×10 5 .
[0014] Further, the mass ratio of the modified hydrogenated rosin alcohol, the modified curing agent, polyvinylidene fluoride, benzoin, and nano hard particles in step (3) is 5:25:50-100:0.5:1-2.
[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: In the present invention, the ketone group in 3H-1,2-benzodisulfonylphenol-3-one reacts with the hydroxyl group in hydrogenated rosin alcohol under the catalysis of a base to undergo a condensation reaction, thereby introducing the benzene ring in 3H-1,2-benzodisulfonylphenol-3-one and the three-membered aliphatic cyclic structure of hydrogenated rosin alcohol into the matrix. Then, dihydroxyphenylalanine is grafted onto the side chain of polyvinylidene fluoride through the isocyanate group in m-xylene diisocyanate. The presence of a large number of benzene rings hinders the overall sliding of molecular chains after the matrix is coated and cured. Moreover, the catechol in dihydroxyphenylalanine reacts with oxygen in the air to be transformed into an o-benzoquinone group, and then undergoes intramolecular cyclization through an addition reaction. After double oxidation and rearrangement, isomers with different degrees of polymerization are generated. They can branch with other reactants through multiple reaction sites of their own, and through catechol and o-benzoquinone with different degrees of oxidation, disproportional reaction occurs to generate semiquinone free radicals, which are further coupled to form covalent bonds, forming strong hydrogen bond coupling with the polyvinylidene fluoride matrix. At the same time, due to the interaction of various non-covalent forces, a strong adhesion relationship is generated between the matrix and the substrate, realizing the strong adhesion and friction performance of the coating. Then, a nano-hard phase is introduced into the polyvinylidene fluoride, and the melted matrix can wrap around it to form an effective mechanical locking effect, which can effectively protect the polymer molecular chain from slipping and falling under shear force while destroying the continuity of the polymer matrix molecular chain. And when the matrix is rubbed, the nanoparticles will be embedded in the counter surface under mechanical action, forming a riveting behavior on the cured film, and enhancing the adhesion of the matrix to the substrate through physical adsorption. Detailed implementation manners
[0016] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0017] In order to more clearly illustrate the method provided by the present invention, the following examples are used for detailed description. The test methods for each index of the fluorocarbon powder coating prepared in the following examples are as follows: The fluorocarbon powder coating is electrostatically sprayed on an iron plate and baked at 150 °C for 10 min to form a cured film.
[0018] Adhesion: Take the same examples and comparative examples, and use ASTM D3363 as the reference standard, and use the pull-off adhesion test to detect the adhesion of the specimens; Abrasion resistance: Take the same examples and comparative examples and refer to GB / T15036.2, and use a film abrasion tester to rub 500 circles and then detect its mass loss rate.
[0019] Mechanical properties: For the same examples and comparative examples, refer to GB / T 1732 to test the impact strength; and use a universal testing machine to test the tensile strength of the specimens at a tensile rate of 10 mm / min.
[0020] Example 1 (1) Mix dehydroabietyl alcohol, methyl abietate, and dihydroabietyl alcohol in a mass ratio of 1:07:2 to obtain hydrogenated abietyl alcohol; mix 3H-1,2-benzodisulfonyl-3-one and hydrogenated abietyl alcohol, and under a nitrogen atmosphere, dropwise add a 17 wt% sodium ethoxide aqueous solution at a rate of 0.1 mL / s, stir at 50 rpm for 30 min, and let stand for 4 h to obtain modified hydrogenated abietyl alcohol; the mass ratio of 3H-1,2-benzodisulfonyl-3-one, hydrogenated abietyl alcohol, and 17 wt% sodium ethoxide aqueous solution is 1:9:0.5; (2) Mix dihydroxyphenylalanine, m-xylylene diisocyanate, and dibutyltin dilaurate in a mass ratio of 2:10:0.05, stir at 40 rpm for 8 min under a nitrogen atmosphere, adjust the pH of the solution to 8.3 with a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution, and let stand for 10 min to obtain a modified curing agent; (3) Mix nanozirconium carbide, nanochromium carbide, and nanoboron carbide in a mass ratio of 1:0.5:0.1 to obtain nano hard particles; mix the modified hydrogenated abietyl alcohol, the modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 and benzoin, stir at 80 rpm for 2 min, add the nano hard particles, stir at 1500 rpm for 2 min, then at 120 °C, knead, extrude and cool to room temperature, and grind through a 160-mesh sieve to obtain a fluorocarbon powder coating; the mass ratio of the modified hydrogenated abietyl alcohol, the modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 and benzoin, and the nano hard particles is 5:25:50:0.5:1.
[0021] Example 2 (1) Mix dehydroabietyl alcohol, methyl abietate, and dihydroabietyl alcohol in a mass ratio of 1:07:2 to obtain hydrogenated abietyl alcohol; mix 3H-1,2-benzodisulfonyl-3-one and hydrogenated abietyl alcohol, and under a nitrogen atmosphere, dropwise add a 17 wt% sodium ethoxide aqueous solution at a rate of 0.5 mL / s, stir at 80 rpm for 50 min, and let stand for 4 - 8 h to obtain modified hydrogenated abietyl alcohol; the mass ratio of 3H-1,2-benzodisulfonyl-3-one, hydrogenated abietyl alcohol, and 17 wt% sodium ethoxide aqueous solution is 3:9:0.5; (2) Mix dihydroxyphenylalanine, m-xylylene diisocyanate, and dibutyltin dilaurate in a mass ratio of 2:15:0.05. Under a nitrogen atmosphere, stir at 60 rpm for 15 min, adjust the pH of the solution to 8.5 with a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution, and let it stand for 15 min to obtain a modified curing agent; (3) Mix nanometer zirconium carbide, nanometer chromium carbide, and nanometer boron carbide in a mass ratio of 2:0.5:0.1 to obtain nanometer hard particles; Mix modified hydrogenated rosin alcohol, modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 and benzoin, stir at 110 rpm for 5 min, add the nanometer hard particles, stir at 2000 rpm for 4 min, then at 130 °C, knead, extrude and cool to room temperature, and grind through a 190-mesh sieve to obtain a fluorocarbon powder coating; The mass ratio of the modified hydrogenated rosin alcohol, modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 and benzoin, and nanometer hard particles is 5:25:75:0.5:1.5.
[0022] Example 3 (1) Mix dehydroabietyl alcohol, methyl abietate, and dihydroabietyl alcohol in a mass ratio of 1:07:2 to obtain hydrogenated rosin alcohol; Mix 3H-1,2-benzodisulfenol-3-one and hydrogenated rosin alcohol, under a nitrogen atmosphere, dropwise add a 17 wt% sodium ethoxide aqueous solution at a rate of 0.8 mL / s, stir at 120 rpm for 60 min, and let it stand for 8 h to obtain a modified hydrogenated rosin alcohol; The mass ratio of the 3H-1,2-benzodisulfenol-3-one, hydrogenated rosin alcohol, and 17 wt% sodium ethoxide aqueous solution is 5:9:0.5; (2) Mix dihydroxyphenylalanine, m-xylylene diisocyanate, and dibutyltin dilaurate in a mass ratio of 2:20:0.05. Under a nitrogen atmosphere, stir at 80 rpm for 20 min, adjust the pH of the solution to 8.8 with a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution, and let it stand for 30 min to obtain a modified curing agent; (3) Mix nanometer zirconium carbide, nanometer chromium carbide, and nanometer boron carbide in a mass ratio of 3:0.5:0.1 to obtain nanometer hard particles; Mix modified hydrogenated rosin alcohol, modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 and benzoin, stir at 140 rpm for 10 min, add the nanometer hard particles, stir at 2500 rpm for 6 min, then at 150 °C, knead, extrude and cool to room temperature, and grind through a 220-mesh sieve to obtain a fluorocarbon powder coating; The mass ratio of the modified hydrogenated rosin alcohol, modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 and benzoin, and nanometer hard particles is 5:25:100:0.5:2.
[0023] Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that step (1) is absent; the remaining steps are the same as those in Example 2.
[0024] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that step (1) is absent, and step (3) is changed to: Mix zirconium carbide nanoparticles, chromium carbide nanoparticles, and boron carbide nanoparticles in a mass ratio of 2:0.5:0.1 to obtain nano-hard particles; mix the modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 , polyvinylidene fluoride, and benzoin, stir at 110 rpm for 5 min, add the nano-hard particles, stir at 2000 rpm for 4 min, then at 130 °C, knead, extrude and cool to room temperature, grind through a 190-mesh sieve to obtain a fluorocarbon powder coating; the mass ratio of the modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 , polyvinylidene fluoride, benzoin, and nano-hard particles is 25:75:0.5:1.5; the remaining steps are the same as those in Example 2.
[0025] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that step (2) is absent, and the remaining steps are the same as those in Example 2.
[0026] Comparative Example 4 The difference between Comparative Example 4 and Example 2 is that step (3) is different, and step (3) is changed to: Mix the modified hydrogenated rosin alcohol, modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 , polyvinylidene fluoride, and benzoin, stir at 110 rpm for 5 min, add the nano-hard particles, stir at 2000 rpm for 4 min, then at 130 °C, knead, extrude and cool to room temperature, grind through a 190-mesh sieve to obtain a fluorocarbon powder coating; the mass ratio of the modified hydrogenated rosin alcohol, modified curing agent, polyvinylidene fluoride with a molecular weight of 3×10 5 , polyvinylidene fluoride, and benzoin is 5:25:75:0.5; the remaining steps are the same as those in Example 2.
[0027] Effect Example The following Table 1 gives the performance analysis results of the fluorocarbon powder coatings of Examples 1 to 3 and Comparative Examples 1 to 5 of the present invention.
[0028] Table 1 From the comparison of the experimental data of the examples and comparative examples in Table 1, it can be found that in the present invention, the ketone group in 3H-1,2-benzodisulfonylphenol-3-one reacts with the hydroxyl group in hydrogenated rosin alcohol under the catalysis of alkali to undergo a condensation reaction, thereby introducing the benzene ring in 3H-1,2-benzodisulfonylphenol-3-one and the ternary aliphatic cyclic structure of hydrogenated rosin alcohol into the matrix. Then, dihydroxyphenylalanine is grafted onto the side chain of polyvinylidene fluoride through the isocyanate group in isophthalic dimethyl diisocyanate. The presence of a large number of benzene rings hinders the overall sliding of molecular chains after the matrix is coated and cured. And through dihydroxyphenylalanine, a strong adhesion relationship is generated between the matrix and the substrate, realizing the strong adhesion and friction performance of the coating. Then, a nano hard phase is introduced into polyvinylidene fluoride, and the melted matrix can wrap around it to form an effective mechanical locking effect, which can effectively protect the polymer molecular chain from slipping and falling off under shear action while destroying the continuity of the polymer matrix molecular chain. And when the matrix is rubbed, the nanoparticles will be embedded in the counter surface under mechanical action, forming a riveting behavior on the cured film, and enhancing the adhesion of the matrix to the substrate through physical adsorption.
[0029] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed claim.
Claims
1. A fluorocarbon powder coating, characterized in that: The method comprises the following preparation steps: (1) Dehydroabietin alcohol, rosin methyl ester and dihydroabietin alcohol were mixed in a mass ratio of 1:07:2 to obtain hydrogenated abietin alcohol; 3H-1,2-benzodisulfonol-3-one and hydrogenated abietin alcohol were mixed, and a 17 wt% sodium ethoxide aqueous solution was added dropwise at a rate of 0.5 mL / s under a nitrogen atmosphere, stirred at 80 rpm for 50 min, and allowed to stand for 4-8 h to obtain modified hydrogenated abietin alcohol; the mass ratio of the 3H-1,2-benzodisulfonol-3-one, hydrogenated abietin alcohol and 17 wt% sodium ethoxide aqueous solution was 3:9:0.5; (2) Dihydroxyphenylalanine, m-xylene diisocyanate, and dibutyltin dilaurate were mixed in a mass ratio of 2:15:0.05, stirred at 60 rpm for 15 min under a nitrogen atmosphere, the pH of the solution was adjusted to 8.5 with tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution, and allowed to stand for 15 min to obtain a modified curing agent; (3) mixing nano zirconium carbide, nano chromium carbide and nano boron carbide in a mass ratio of 2:0.5:0.1 to obtain nano hard particles; Modified hydrogenated rosin alcohol, modified curing agent, molecular weight 3×10 5 The polyvinylidene fluoride and benzoin were mixed, stirred at 110 rpm for 5 min, nano hard particles were added, stirred at 2000 rpm for 4 min, then mixed at 130 ° C, extruded and cooled to room temperature, ground through a 190 mesh sieve to obtain a fluorocarbon powder coating; the modified hydrogenated rosin alcohol, modified curing agent, molecular weight of 3×10 5 The mass ratio of polyvinylidene fluoride, benzoin and nano hard particles is 5:25:75:0.5:1.5.