Bismuth oxychloride-based anti-static coating for door handle and preparation method of bismuth oxychloride-based anti-static coating

Abstract

The invention relates to a bismuth oxychloride-based anti-static coating for a door handle and a preparation method of the bismuth oxychloride-based anti-static coating. Bismuth oxychloride (BiOCl) is used as a novel functional material, has a unique layered crystal structure, excellent chemical stability and good semiconductor performance, is wide in raw material source and low in cost, and is widely applied to the fields of photocatalysis, pigments and the like.

Description

Technical Field

[0001] This invention relates to an antistatic coating for door handles based on bismuth oxychloride and its preparation method. Background Technology

[0002] In daily life and industrial production, door handles, as frequently touched components, are prone to accumulating static electricity due to human friction or environmental factors. This accumulation can lead to electric shock and discomfort, and in special locations such as electronics factories and laboratories, it can also trigger electrostatic discharge, damaging precision electronic equipment and even posing safety hazards such as fires and explosions in flammable and explosive environments. Therefore, developing door handle coatings with excellent antistatic properties is of significant practical importance. Currently, most antistatic coatings for door handles on the market use conductive polymers (such as polyaniline and polythiophene) or conductive metal fillers (such as silver powder and copper powder) as their core functional components. However, these coatings have significant limitations: the antistatic performance of conductive polymer coatings is easily affected by environmental humidity, with performance significantly decreasing in dry environments, and they have poor wear resistance, leading to coating peeling and failure after long-term use; while conductive metal filler coatings offer stable conductivity, the cost of metal fillers is high, they are prone to oxidation leading to color changes, and the poor settling properties of metal particles can cause uneven dispersion during preparation, affecting the appearance and performance uniformity of the coating. However, there are currently no reports on the application of bismuth oxychloride in the antistatic coating of door handles, and its application potential in the field of antistatics needs to be further developed. Summary of the Invention

[0003] To address the problems of unstable antistatic performance, poor wear resistance, high cost, and easy oxidation of existing antistatic coatings for door handles, this invention provides an antistatic coating for door handles based on bismuth oxychloride and its preparation method. This coating uses bismuth oxychloride as the core antistatic component, combined with the synergistic effect of modifiers and binders, to achieve excellent and stable antistatic performance. It also has good wear resistance, corrosion resistance, and decorative properties. Moreover, the preparation process is simple and low-cost, making it suitable for large-scale industrial production. Technical solution

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is an antistatic coating for door handles based on bismuth oxychloride, wherein the coating is prepared from the following raw materials in the indicated mass percentages: 15-30% bismuth oxychloride, 3-8% modifier, 25-40% binder, 20-45% solvent, and 1-5% additives; wherein the modifier is silane coupling agent KH-550 or KH-570; and the binder is one or a mixture of epoxy resin E-44, polyurethane, or acrylic resin.

[0005] Furthermore, the bismuth oxychloride is in the form of nano-sized particles with a particle size of 50-200 nm. Its surface is treated with hydroxylation, and the hydroxyl content is 0.8-1.5 mmol / g. The hydroxylation treatment can improve the compatibility of bismuth oxychloride with binders and modifiers, and enhance the internal bonding force of the coating.

[0006] Furthermore, the solvent is one or a mixture of ethanol, ethyl acetate, and xylene, wherein the mass percentage of ethanol is not less than 30% of the total mass of the solvent. The addition of ethanol can improve the dispersibility of each raw material and reduce the film-forming temperature of the coating.

[0007] Furthermore, the additives include a dispersant, a leveling agent, and an anti-aging agent in a mass ratio of 3:2:1; the dispersant is a polycarboxylate dispersant, the leveling agent is an organosilicon leveling agent, and the anti-aging agent is a hindered phenolic anti-aging agent.

[0008] This invention also provides a method for preparing the above-mentioned bismuth oxychloride-based antistatic coating for door handles, comprising the following steps: 1. Hydroxylation modification of bismuth oxychloride: Add nano-bismuth oxychloride particles to deionized water and ultrasonically disperse for 30-60 min to obtain a bismuth oxychloride suspension with a mass concentration of 10-20%; heat the suspension to 60-80℃, add sodium hydroxide at 5-10% mass of bismuth oxychloride, and stir for 2-3 h; after the reaction is completed, centrifuge, wash with deionized water until neutral, and dry at 80-100℃ for 4-6 h to obtain hydroxylated bismuth oxychloride.

[0009] 2. Preparation of pre-dispersion: Add solvent to a stirred tank, and add dispersant and leveling agent in sequence at a speed of 300-500 r / min, and stir for 10-15 min; then add hydroxylated bismuth oxychloride, heat to 40-50℃, stir at high speed for 20-30 min, and then disperse by ultrasonication for 20-40 min to obtain a uniform bismuth oxychloride pre-dispersion.

[0010] 3. Preparation of coating slurry: Add the binder to the above pre-dispersion liquid and stir at 600-800 r / min for 30-45 min; then add the modifier and anti-aging agent, continue stirring for 15-20 min, and finally filter through a 300-500 mesh filter to remove impurities and agglomerated particles to obtain the coating slurry.

[0011] 4. Coating application and curing: Immerse the pretreated door handle substrate in the coating slurry and apply it using the dip coating method. Control the coating speed at 5-10 cm / min. After removing it, let it stand at room temperature for 10-20 minutes to remove excess slurry from the surface. Then place it in an oven and cure it at 120-160℃ for 20-40 minutes. Allow it to cool naturally to room temperature to obtain a door handle coating with antistatic properties.

[0012] Furthermore, the pretreatment process of the door handle substrate in step 4 is as follows: sanding with sandpaper, ultrasonic cleaning with ethanol, rinsing with deionized water, and finally drying at 60-80℃ for 10-15 minutes to remove oil and impurities from the surface of the substrate and improve the adhesion between the coating and the substrate.

[0013] Furthermore, the coating thickness is 50-150μm, which ensures excellent antistatic performance while avoiding cracking and peeling caused by excessive coating thickness.

[0014] The beneficial effects of the antistatic coating for door handles based on bismuth oxychloride and its preparation method of the present invention are that the coating uses bismuth oxychloride as the core antistatic component, combined with the synergistic effect of modifiers and binders, to achieve excellent and stable antistatic performance, while also possessing good wear resistance, corrosion resistance and decorative properties. Moreover, the preparation process is simple and low in cost, making it suitable for large-scale industrial production. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation Example 1

[0016] An antistatic coating for door handles based on bismuth oxychloride is prepared from the following raw materials in the indicated weight percentages: bismuth oxychloride 20%, silane coupling agent KH-550 5%, epoxy resin E-44 30%, ethanol 25%, ethyl acetate 15%, polycarboxylate dispersant 2%, organosilicon leveling agent 1.3%, and hindered phenolic anti-aging agent 0.7%; wherein the bismuth oxychloride is in the form of nano-sized particles with a particle size of 50-100 nm and a surface hydroxyl content of 1.0 mmol / g.

[0017] Its preparation method includes the following steps: Hydroxylation modification of bismuth oxychloride: 20g of nano-bismuth oxychloride particles were added to 100mL of deionized water and ultrasonically dispersed for 45min to obtain a bismuth oxychloride suspension; the suspension was heated to 70℃, 1.5g of sodium hydroxide was added, and the mixture was stirred for 2.5h; after the reaction was completed, the mixture was centrifuged, washed with deionized water until neutral, and dried at 90℃ for 5h to obtain hydroxylated bismuth oxychloride.

[0018] Preparation of pre-dispersion: 25g of ethanol and 15g of ethyl acetate were added to a stirred tank. 2g of polycarboxylate dispersant and 1.3g of organosilicon leveling agent were added sequentially at a speed of 400r / min and stirred for 12min. Then, hydroxylated bismuth oxychloride was added, the temperature was raised to 45℃, and the mixture was stirred at high speed for 25min. After ultrasonic dispersion for 30min, bismuth oxychloride pre-dispersion was obtained.

[0019] Preparation of coating slurry: Add 30g of epoxy resin E-44 to the pre-dispersion liquid and stir for 40min at 700r / min; then add 5g of silane coupling agent KH-550 and 0.7g of hindered phenol anti-aging agent, continue stirring for 18min, and finally filter through a 400-mesh filter to obtain the coating slurry.

[0020] Coating application and curing: The stainless steel door handle substrate was successively sanded with 2000-grit sandpaper, ultrasonically cleaned with ethanol for 10 min, rinsed with deionized water, and dried at 70℃ for 12 min; the pretreated substrate was immersed in the coating slurry at a speed of 8 cm / min, removed and left to stand at room temperature for 15 min; then placed in an oven and cured at 140℃ for 30 min, and naturally cooled to room temperature to obtain an antistatic coating with a thickness of 100 μm. Example 2

[0021] An antistatic coating for door handles based on bismuth oxychloride is prepared from the following raw materials in the indicated mass percentages: bismuth oxychloride 25%, silane coupling agent KH-570 6%, polyurethane 35%, ethanol 30%, xylene 10%, polycarboxylate dispersant 2.5%, organosilicon leveling agent 1.7%, and hindered phenolic anti-aging agent 0.8%; wherein the bismuth oxychloride is in the form of nano-sized particles with a particle size of 100-150 nm and a surface hydroxyl content of 1.2 mmol / g.

[0022] The preparation method is basically the same as that in Example 1, except that: in step 1, the reaction temperature is 75℃ and the reaction time is 3h; in step 3, the stirring speed is 800r / min and the stirring time is 45min; in step 4, the curing temperature is 150℃, the curing time is 35min, and the coating thickness is 120μm.

Claims

1. A bismuth oxychloride-based antistatic coating for door handles, characterized in that, It is prepared from the following raw materials in the indicated mass percentages: 15-30% bismuth oxychloride, 3-8% modifier, 25-40% binder, 20-45% solvent, and 1-5% additives; the modifier is silane coupling agent KH-550 or KH-570; the binder is one or more of epoxy resin E-44, polyurethane, or acrylic resin.

2. The antistatic coating for door handles based on bismuth oxychloride according to claim 1, characterized in that, The bismuth oxychloride is in the form of nanoparticles with a particle size of 50-200 nm, and the surface is treated with hydroxylation, with a hydroxyl content of 0.8-1.5 mmol / g.

3. The antistatic coating for door handles based on bismuth oxychloride according to claim 1, characterized in that, The solvent is one or a mixture of ethanol, ethyl acetate, and xylene, and the mass percentage of ethanol is not less than 30% of the total mass of the solvent.

4. The antistatic coating for door handles based on bismuth oxychloride according to claim 1, characterized in that, The additives include a dispersant, a leveling agent, and an anti-aging agent, with a mass ratio of 3:2:1; the dispersant is a polycarboxylate dispersant, the leveling agent is an organosilicon leveling agent, and the anti-aging agent is a hindered phenolic anti-aging agent.

5. The method for preparing the bismuth oxychloride-based antistatic coating for door handles according to any one of claims 1-3, characterized in that, Nano-sized bismuth oxychloride particles were added to deionized water and ultrasonically dispersed for 30-60 min to obtain a bismuth oxychloride suspension with a mass concentration of 10-20%. The suspension was heated to 60-80℃, and sodium hydroxide at a mass of 5-10% of bismuth oxychloride was added. The mixture was stirred and reacted for 2-3 h. After the reaction was completed, the mixture was centrifuged, washed until neutral, and dried to obtain hydroxylated bismuth oxychloride. The method for preparing the antistatic coating for door handles based on bismuth oxychloride according to claim 4 is characterized in that the solvent is added to a stirred tank, and the dispersant and leveling agent are added sequentially under stirring conditions, and the mixture is stirred for 10-15 min; then hydroxylated bismuth oxychloride is added, the temperature is raised to 40-50℃, the mixture is stirred at high speed for 20-30 min, and the mixture is ultrasonically dispersed for 20-40 min to obtain a bismuth oxychloride pre-dispersion. The method for preparing the antistatic coating for door handles based on bismuth oxychloride according to claim 5 is characterized in that the binder is added to the pre-dispersion liquid and stirred at 600-800 r / min for 30-45 min; then the modifier and anti-aging agent are added, and stirring is continued for 15-20 min, and the mixture is filtered to obtain the coating slurry. The method for preparing the antistatic coating of door handle based on bismuth oxychloride according to claim 6 is characterized in that the coating is applied and cured as follows: the pretreated door handle substrate is immersed in the coating slurry for dip coating, and after being taken out, it is left to stand at room temperature for 10-20 minutes, and then cured at 120-160℃ for 20-40 minutes, and cooled to obtain the antistatic coating.

6. The method for preparing the antistatic coating for door handles based on bismuth oxychloride according to claim 7, characterized in that... , characterized in that, The pretreatment process of the door handle substrate in step 6 is as follows: sanding with sandpaper, ultrasonic cleaning with ethanol, rinsing with deionized water, and drying at 60-80℃ for 10-15 minutes.

7. The method for preparing the antistatic coating for door handles based on bismuth oxychloride according to claim 8, characterized in that, Its features are, In step 7, the dipping speed is 5-10 cm / min and the coating thickness is 50-150 μm.

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