High-temperature-resistant paint and preparation method thereof

Abstract

The invention relates to the technical field of preparation of high-temperature-resistant paint, and discloses high-temperature-resistant paint and a preparation method thereof.The high-temperature-resistant paint is prepared from, by weight, 35-55 parts of waterborne organic silicon resin, 10-20 parts of epoxy acrylic resin, 8-15 parts of nano-zinc oxide, 5-12 parts of flake graphite, 3-8 parts of composite curing agent, 1.5-2.5 parts of dispersing agent, 0.8-1.5 parts of defoaming agent and 0.6-1.2 parts of flatting agent. 6-12 parts of an alcohol ether solvent and a proper amount of deionized water; the preparation method comprises a pre-mixing stage, a grinding and dispersing stage, an auxiliary adding stage and a diluting stage. The paint is good in high temperature resistance, good in corrosion resistance, friendly to construction and good in mechanical property, the limitation of solvent type paint can be effectively solved, the corrosion resistance is improved through the nano-zinc oxide and flake graphite composite filler, the mechanical property and the construction efficiency are considered, and the paint is adaptive to multiple processes such as spraying and brush coating.

Description

Technical Field

[0001] The present invention relates to the technical field of high temperature resistant paint preparation, in particular to a high temperature resistant paint and a preparation method thereof. Background Art

[0002] High-temperature resistant paint is a special coating that can maintain stable physical and chemical properties in high-temperature environments (usually above 100°C, up to 1200°C or even higher), and has anti-corrosion, anti-oxidation, and heat-insulating functions.

[0003] With the iterative upgrade of industrial technology, the performance requirements for materials in the fields of automobile manufacturing, mechanical equipment, energy and chemical industry, and home appliance manufacturing are becoming increasingly stringent. In scenarios such as motorcycle engines, industrial ovens, thermal pipelines, and chemical reactors, metal components must not only withstand continuous high temperatures of 200-500°C, but also resist complex working conditions such as corrosion from oil, water vapor, and acidic and alkaline media.

[0004] While traditional solvent-based heat-resistant paints offer some protection, they often suffer from high VOC emissions (>300g / L), high toxicity during application, and insufficient flexibility (prone to cracking). Conventional water-based paints also face technical bottlenecks, including a low temperature limit (<200°C) and a short corrosion protection cycle (<200 hours in a salt spray test). Against this backdrop, new heat-resistant paints have emerged, combining environmentally friendly, low-VOC coatings with high-temperature stability and comprehensive protection. Through innovative resin systems, nanofiller compounding, and process optimization, these paints address the performance shortcomings of traditional materials in high-temperature corrosive environments, becoming a key technological breakthrough in the field of industrial protection.

[0005] In view of the above problems, it is urgent to carry out innovative design based on the existing solvent-based high-temperature resistant paint. Summary of the Invention

[0006] In order to solve the technical problems that existing metal parts not only need to withstand continuous high temperatures of 200-500°C, but also need to resist corrosion from oil, water vapor, acid and alkali media, the present invention provides a high-temperature resistant paint and a preparation method thereof.

[0007] The present invention adopts the following technical scheme: a high-temperature resistant paint is composed of the following raw materials in parts by weight: water-based silicone resin: 35-55 parts, epoxy acrylic resin: 10-20 parts, nano zinc oxide: 8-15 parts, flake graphite: 5-12 parts, composite curing agent: 3-8 parts, dispersant: 1.5-2.5 parts, defoaming agent: 0.8-1.5 parts, leveling agent: 0.6-1.2 parts, alcohol ether solvent: 6-12 parts, and deionized water: appropriate amount.

[0008] Preferably, it is composed of the following raw materials in parts by weight: water-based silicone resin: 45 parts, epoxy acrylic resin: 15 parts, nano zinc oxide: 15 parts, flake graphite: 6 parts, composite curing agent: 5 parts, dispersant: 2.5 parts, defoaming agent: 1.2 parts, leveling agent: 0.8 parts, alcohol ether solvent: 8 parts, and deionized water: appropriate amount.

[0009] Preferably, it is composed of the following raw materials in parts by weight: water-based silicone resin: 55 parts, epoxy acrylic resin: 10 parts, nano zinc oxide: 8 parts, flake graphite: 12 parts, composite curing agent: 6 parts, dispersant: 2.0 parts, defoaming agent: 1.0 part, leveling agent: 1.0 part, alcohol ether solvent: 10 parts, and deionized water: appropriate amount.

[0010] Preferably, it is composed of the following raw materials in parts by weight: water-based silicone resin: 40 parts, epoxy acrylic resin: 20 parts, nano zinc oxide: 12 parts, flake graphite: 9 parts, composite curing agent: 4 parts, dispersant: 1.8 parts, defoaming agent: 0.9 parts, leveling agent: 1.1 parts, alcohol ether solvent: 9 parts, and deionized water: appropriate amount.

[0011] Preferably, the particle size of the nano zinc oxide is ≤100 nm, and the diameter-to-thickness ratio of the flake graphite is ≥50:1.

[0012] Preferably, the composite curing agent includes amino resin and isocyanate, and the alcohol ether solvent includes propylene glycol methyl ether and diethylene glycol butyl ether.

[0013] Preferably, a method for preparing a high temperature resistant paint comprises the following steps: S1. First, add water-based silicone resin and epoxy acrylic resin into a mixing tank and stir to form a uniform resin base; S2. Add nano zinc oxide, flake graphite, and dispersant in sequence, stirring continuously to ensure that the filler is fully wetted and dispersed; S3, then transferring the premix to a sand mill, adding alcohol ether solvent, and grinding to a fineness of ≤20 μm; S4, return to the mixing tank, add defoamer, leveling agent, and composite curing agent, stir to eliminate bubbles and promote cross-linking reaction; S5. Finally, deionized water is gradually added to adjust the pH value and viscosity.

[0014] Preferably, in step S1, the stirring is performed at a speed of 600-800 RPM for 15-20 minutes.

[0015] Preferably, the grinding in step S3 is performed at a speed of 1200-1500 RPM.

[0016] Preferably, in step S4, the stirring is performed at a speed of 400-600 RPM for 10-15 minutes.

[0017] Preferably, in step S5, the pH value is adjusted to 7.8-8.5, and the viscosity is controlled to a coating-4 cup flow time of 55-70 seconds.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention has good high temperature resistance, good corrosion resistance, friendly construction, and good mechanical properties. It can effectively solve the problem of breaking through the temperature resistance limitations of ordinary water-based paints and overcome the high VOC pollution problem of solvent-based paints. Through the composite filler of nano zinc oxide and flaky graphite, the corrosion resistance is improved, which is better than the traditional single filler system. Taking into account both mechanical properties and construction efficiency, it is suitable for various processes such as spraying and brushing, and solves the problems of easy cracking, corrosion, and complex construction of coatings in high temperature scenes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the preparation process of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0021] Example 1: Please refer to Figure 1 The high-temperature resistant paint of this embodiment is composed of the following raw materials in parts by weight: water-based silicone resin: 45 parts, epoxy acrylic resin: 15 parts, nano zinc oxide: 15 parts, flake graphite: 6 parts, composite curing agent: 5 parts, dispersant: 2.5 parts, defoaming agent: 1.2 parts, leveling agent: 0.8 parts, alcohol ether solvent: 8 parts, and deionized water: appropriate amount (60%).

[0022] The nano zinc oxide particle size is ≤100nm, the diameter-to-thickness ratio of the flake graphite is ≥50:1; the composite curing agent includes amino resin and isocyanate, and the alcohol ether solvent includes propylene glycol methyl ether and diethylene glycol butyl ether; Secondly, epoxy acrylic resin is used to enhance adhesion and chemical resistance, improve the flexibility of the paint film, nano zinc oxide is used as anti-corrosion filler with a particle size of ≤100nm, and improves high-temperature oxidation resistance, flake graphite is used as thermal conductivity and high-temperature resistant filler, reflecting heat to reduce the temperature of the substrate, composite curing agent is used to promote cross-linking and curing, dispersant is used to: improve the uniformity of filler dispersion, defoaming agent is used to: eliminate construction bubbles, leveling agent is used to improve the flatness of the paint film, and alcohol ether solvent is used to adjust viscosity.

[0023] Example 2: Please refer to Figure 1A high-temperature resistant paint of this embodiment is composed of the following raw materials in parts by weight: water-based silicone resin: 55 parts, epoxy acrylic resin: 10 parts, nano zinc oxide: 8 parts, flake graphite: 12 parts, composite curing agent: 6 parts, dispersant: 2.0 parts, defoaming agent: 1.0 part, leveling agent: 1.0 part, alcohol ether solvent: 10 parts, deionized water: appropriate amount (58%).

[0024] Example 3: Please refer to Figure 1 The high-temperature resistant paint of this embodiment is composed of the following raw materials in parts by weight: water-based silicone resin: 40 parts, epoxy acrylic resin: 20 parts, nano zinc oxide: 12 parts, flake graphite: 9 parts, composite curing agent: 4 parts, dispersant: 1.8 parts, defoaming agent: 0.9 parts, leveling agent: 1.1 parts, alcohol ether solvent: 9 parts, and deionized water: appropriate amount (62%).

[0025] Example 4: Please refer to Figure 1 A method for preparing a high-temperature resistant paint according to this embodiment includes the following steps: (1) Premixing stage a. Add water-based silicone resin and epoxy acrylic resin to a mixing tank and stir at 600-800 RPM for 15-20 minutes to form a uniform resin base; b. Add nano zinc oxide, flake graphite and dispersant in sequence and continue stirring for 25-35 minutes to ensure that the filler is fully wetted and dispersed.

[0026] (2) Grinding and dispersion stage The premix is ​​transferred to a sand mill, alcohol ether solvent is added, and the mixture is ground at a speed of 1200-1500 RPM to a fineness of ≤20 μm (detected by a scraper fineness meter).

[0027] (3) Addition and dilution of additives a. Return to the mixing tank, add defoamer, leveling agent, composite curing agent, and stir at 400-600RPM for 10-15 minutes to eliminate bubbles and promote cross-linking reaction; b. Gradually add deionized water, adjust the pH value to 7.8-8.5 (with ammonia or acetic acid), and control the viscosity to a flow time of 55-70 seconds for a 4-cup coating.

[0028] Performance test: The high temperature paint prepared by the preparation method of the present invention was tested by using the raw materials of Examples 1 to 3 parts by weight. The results are shown in Table 1. Table 1: Performance test comparison ; In Example 1, the proportion of nano zinc oxide (15 parts) is increased to enhance chemical corrosion resistance; the medium-sized silicone resin (45 parts) ensures high-temperature resistance, and a larger amount of epoxy acrylic resin (15 parts) is added to improve adhesion, resulting in a performance that is more corrosion-resistant. In Example 2, the maximum silicone resin (55 parts) increases the upper limit of high temperature resistance; the flake graphite is increased to 12 parts to form dense heat conduction channels; the amino resin ratio in the composite curing agent is increased (2:1) to enhance the stability of the cross-linked structure, and the performance tends to be high thermal conductivity. In Example 3, the ratio of silicone resin to epoxy acrylic resin is 2:1, which takes into account both high temperature resistance and flexibility; the ratio of nano zinc oxide to flake graphite is moderate, which balances corrosion resistance and thermal conductivity; the ratio of alcohol ether solvent is optimized (2:1) to ensure construction viscosity (55-70 seconds for 4 cups of coating), and the performance is relatively balanced.

[0029] In summary, the overall performance advantages after testing are: Good high temperature resistance: can withstand high temperature of 300℃ for a long time, and the paint film will not change color or crack after baking at 220℃ for 2 hours, which is better than traditional water-based paint; Good anti-corrosion performance: Nano zinc oxide and flake graphite form a composite protective layer, which can withstand neutral salt spray for 500 hours without rust; Construction-friendly: VOC content <50g / L, supports spraying and brushing, surface drying time ≤1 hour, actual drying time ≤24 hours; Good mechanical properties: paint film hardness reaches HB (pencil hardness), flexibility ≤1mm, impact resistance ≥50cm (GB / T1732).

[0030] It can be seen from the above embodiments and comparative examples that the present invention has good high temperature resistance, good corrosion resistance, friendly construction, and good mechanical properties. It can effectively solve the problem of breaking through the temperature resistance limitations of ordinary water-based paints and overcome the high VOC pollution problem of solvent-based paints; through the composite filler of nano zinc oxide and flaky graphite, the corrosion resistance is improved, which is better than the traditional single filler system; taking into account both mechanical properties and construction efficiency, it is suitable for various processes such as spraying and brushing, and solves the problems of easy cracking, corrosion, and complex construction of coatings in high temperature scenes.

[0031] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A high temperature resistant paint, characterized in that, The invention is composed of the following raw materials in parts by weight: 35-55 parts of water-based organic silicone resin, 10-20 parts of epoxy acrylic resin, 8-15 parts of nano zinc oxide, 5-12 parts of flake graphite, 3-8 parts of composite curing agent, 1.5-2.5 parts of dispersant, 0.8-1.5 parts of defoaming agent, 0.6-1.2 parts of leveling agent, 6-12 parts of alcohol ether solvent and appropriate amount of deionized water.

2. A high temperature resistant paint according to claim 1, characterized in that: The invention is composed of the following raw materials in parts by weight: 45 parts of water-based silicone resin, 15 parts of epoxy acrylic resin, 15 parts of nano zinc oxide, 6 parts of flake graphite, 5 parts of composite curing agent, 2.5 parts of dispersant, 1.2 parts of defoaming agent, 0.8 parts of leveling agent, 8 parts of alcohol ether solvent and appropriate amount of deionized water.

3. A high temperature resistant paint according to claim 1, characterized in that: The invention is composed of the following raw materials in parts by weight: 55 parts of water-based silicone resin, 10 parts of epoxy acrylic resin, 8 parts of nano zinc oxide, 12 parts of flake graphite, 6 parts of composite curing agent, 2.0 parts of dispersant, 1.0 parts of defoaming agent, 1.0 parts of leveling agent, 10 parts of alcohol ether solvent and appropriate amount of deionized water.

4. A high temperature resistant paint according to claim 1, characterized in that: The invention is composed of the following raw materials in parts by weight: 40 parts of water-based silicone resin, 20 parts of epoxy acrylic resin, 12 parts of nano zinc oxide, 9 parts of flake graphite, 4 parts of composite curing agent, 1.8 parts of dispersant, 0.9 parts of defoaming agent, 1.1 parts of leveling agent, 9 parts of alcohol ether solvent and appropriate amount of deionized water.

5. The high temperature resistant paint according to claim 1, characterized in that: The particle size of the nano zinc oxide is ≤100 nm, the diameter-to-thickness ratio of the flake graphite is ≥50:1, the composite curing agent comprises amino resin and isocyanate, and the alcohol ether solvent comprises propylene glycol methyl ether and diethylene glycol butyl ether.

6. A method for preparing a high temperature resistant paint, characterized in that: A high temperature resistant paint according to any one of claims 1 to 5, comprising the following steps: S1. First, add water-based silicone resin and epoxy acrylic resin into a mixing tank and stir to form a uniform resin base; S2. Add nano zinc oxide, flake graphite, and dispersant in sequence, stirring continuously to ensure that the filler is fully wetted and dispersed; S3, then transferring the premix to a sand mill, adding alcohol ether solvent, and grinding to a fineness of ≤20 μm; S4, return to the mixing tank, add defoamer, leveling agent, and composite curing agent, stir to eliminate bubbles and promote cross-linking reaction; S5. Finally, deionized water is gradually added to adjust the pH value and viscosity.

7. The method for preparing a high temperature resistant paint according to claim 6, characterized in that: In the step S1, the stirring is performed at a speed of 600-800 RPM for 15-20 minutes.

8. The method for preparing a high temperature resistant paint according to claim 6, characterized in that: In the step S3, the grinding is performed at a rotation speed of 1200-1500 RPM.

9. The method for preparing a high temperature resistant paint according to claim 6, characterized in that: In the step S4, the stirring is performed at a speed of 400-600 RPM for 10-15 minutes.

10. The method for preparing a high temperature resistant paint according to claim 6, characterized in that: In the step S5, the pH value is adjusted to 7.8-8.5, and the viscosity is controlled so that the coating-4 cup outflow time is 55-70 seconds.

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