Wear-resistant powder coating as well as preparation method and application thereof

Abstract

The invention relates to the technical field of powder coatings, and particularly discloses a wear-resistant powder coating as well as a preparation method and application thereof. The wear-resistant powder coating provided by the invention is prepared from the following components in parts by weight: 60 to 80 parts of epoxy resin, 8 to 12 parts of curing agent, 0.3 to 0.5 part of cellulose acetate butyrate and 0.2 to 2.0 parts of polytetrafluoroethylene modified polyethylene wax, the epoxy resin is bisphenol A epoxy resin and o-cresol formaldehyde epoxy resin in a weight ratio of 1: (0.5-1.5); further, the weight ratio of the bisphenol A epoxy resin to the o-cresol formaldehyde epoxy resin is 1: (0.8-1.3); the invention also provides a preparation method of the wear-resistant powder coating and a spraying method of the wear-resistant powder coating. The wear-resistant powder coating provided by the invention not only has very good skid resistance and wear resistance, but also can present a leather-imitated super-large texture effect, and has a very good use prospect.

Description

Technical Field

[0001] The present application relates to the technical field of powder coatings, and in particular to a wear-resistant powder coating and a preparation method and application thereof. Background Art

[0002] In recent years, powder coating technology has been increasingly used in modern industries such as automobile manufacturing and special machinery and equipment. With the continuous development of composite materials, the market demand for high-performance powder coatings is also growing, which requires powder coatings to not only meet the basic protective function of composite materials, but also have excellent decorative and functional properties, thereby improving the overall quality of the product and user experience.

[0003] At present, the performance of powder coatings applied to composite materials is mainly improved by adding various fillers and additives. For example, there are reports that the bonding between powder coatings and substrates is enhanced by adding silane coupling agents; there are also technologies that use nano-silicon dioxide to improve the hardness and scratch resistance of coatings; there are also literature reports that use micron-sized ceramic particles to improve the wear resistance of coatings. Although these methods can improve the performance of powder coatings to a certain extent, the effect of such powder coatings in terms of anti-slip and wear resistance is still unsatisfactory; in addition, existing powder coatings cannot achieve large texture effects of imitation leather, which limits their use in high-end application scenarios.

[0004] Therefore, there is an urgent need to provide a powder coating that has super anti-slip and wear-resistant properties and can also have a leather-like super-textured effect to meet a wider range of application needs. Summary of the invention

[0005] In order to improve the anti-slip and wear resistance of powder coatings and achieve a large leather-like texture effect, the present application provides a wear-resistant powder coating and a preparation method and application thereof.

[0006] In the first aspect, the present application provides a wear-resistant powder coating, which adopts the following technical solution: A wear-resistant powder coating comprises the following components in parts by weight: 60-80 parts of epoxy resin, 8-12 parts of curing agent, 0.3-0.5 parts of cellulose acetate butyrate and 0.2-2.0 parts of polytetrafluoroethylene modified polyethylene wax; The epoxy resin is bisphenol A epoxy resin and o-cresol formaldehyde epoxy resin in a weight ratio of 1: (0.5-1.5).

[0007] The present application uses epoxy resin, curing agent and cellulose acetate butyrate to prepare a wear-resistant powder coating, which can not only achieve the ultra-large texture effect of imitation leather, but also significantly improve the anti-skid and wear resistance of the coating. Specifically, the specific type and proportion of epoxy resin can give the coating excellent anti-skid, wear resistance and mechanical strength; the curing agent can give the coating good strength and adhesion; the addition of cellulose acetate butyrate helps to form a delicate and rich texture, thereby simulating the ultra-large texture appearance effect of imitation leather. In addition, cellulose acetate butyrate can also improve the flexibility and impact resistance of the coating, so that the coating can still maintain excellent physical properties under complex working conditions; the addition of polytetrafluoroethylene modified polyethylene wax further enhances the wear resistance of the coating, making it not easy to wear under long-term friction, and can also maintain good grip in slippery environments. In summary, the wear-resistant powder coating provided by the present application is superior to existing products in terms of anti-slip, wear resistance, hardness, and aesthetics. It can maintain the integrity and aesthetics of the coating under high pressure and complex working conditions, and can especially exhibit superior performance on the anti-slip interface of automobiles and special equipment. It is suitable for high-performance composite materials and meets the needs of high-end applications.

[0008] Optionally, the weight ratio of the bisphenol A epoxy resin to the o-cresol-formaldehyde epoxy resin is 1:(0.8-1.3).

[0009] In some embodiments, the weight ratio of the bisphenol A epoxy resin to the o-cresol epoxy resin can be 1:(0.5-0.8), 1:(0.5-1), 1:(0.5-1.3), 1:(0.5-1.5), 1:(0.8-1), 1:(0.8-1.3), 1:(0.8-1.5), 1:(1-1.3), 1:(1-1.5) or 1:(1.3-1.5).

[0010] In a specific embodiment, the weight ratio of the bisphenol A epoxy resin to the o-cresol-formaldehyde epoxy resin may also be 1:0.5, 1:0.8, 1:1, 1:1.3 or 1:1.5.

[0011] Optionally, the weight portion of the polytetrafluoroethylene modified polyethylene wax is 0.45-0.65 parts.

[0012] In some embodiments, the weight portion of the polytetrafluoroethylene modified polyethylene wax can be 0.2-0.5 parts, 0.2-0.8 parts, 0.2-1.5 parts, 0.2-2.0 parts, 0.5-0.8 parts, 0.5-1.5 parts, 0.2-2.0 parts, 0.8-1.5 parts, 0.8-2.0 parts or 1.5-2.0 parts.

[0013] In a specific embodiment, the weight portion of the polytetrafluoroethylene modified polyethylene wax can also be 0.2 parts, 0.5 parts, 0.8 parts, 1.5 parts or 2.0 parts.

[0014] Optionally, the curing agent is selected from one or more of a modified ammonia curing agent and a dicyandiamide curing agent.

[0015] Optionally, the curing agent is a modified ammonia curing agent and a dicyandiamide curing agent.

[0016] Optionally, the weight ratio of the modified ammonia curing agent to the dicyandiamide curing agent is (2.5-3.5):1.

[0017] In some embodiments, the weight ratio of the modified ammonia curing agent to the dicyandiamide curing agent can be (1-2): 1, (1-2.5): 1, (1-3): 1, (1-3.5): 1, (1-4): 1, (2-2.5): 1, (2-3): 1, (2-3.5): 1, (2-4): 1, (2.5-3): 1, (2.5-3.5): 1, (2.5-4): 1, (3-3.5): 1, (3-4): 1 or (3.5-4): 1.

[0018] In a specific embodiment, the weight ratio of the modified ammonia curing agent to the dicyandiamide curing agent can also be 1:1, 2:1, 2.5:1, 3:1, 3.5:1 or 4:1.

[0019] Optionally, the wear-resistant powder coating further comprises 20-25 parts of barium sulfate and 0.7-1 part of carbon black.

[0020] Optionally, the particle size of the wear-resistant powder coating is 45±2 μm.

[0021] In a second aspect, the present application provides a method for preparing a wear-resistant powder coating, comprising the following steps: mixing the components evenly, and obtaining the wear-resistant powder coating through melt extrusion, tableting, coarse crushing, grinding and sieving.

[0022] In a third aspect, the present application provides a method for spraying a wear-resistant powder coating, comprising the following steps: spraying the wear-resistant powder coating at a rate of 0.08-0.12 kg / m 2 The coating amount is sprayed onto the surface of the substrate, and an electric field is used for breakdown during the spraying process, and then the coating is cured at 200-220°C for 15-20 minutes; the spraying adopts an electrostatic spraying process, and the spraying temperature is 90-100°C.

[0023] In summary, this application has the following beneficial effects: 1. The present application utilizes epoxy resin, curing agent and cellulose acetate butyrate to prepare a wear-resistant powder coating with excellent anti-slip and wear resistance. The wear-resistant powder coating also has a large texture effect of imitation leather. The use of the above-mentioned wear-resistant powder coating on the surface of high-performance composite materials has good decorative and functional properties and can significantly improve the overall quality of the product.

[0024] 2. The present application further controls the weight ratio of bisphenol A epoxy resin and o-cresol epoxy resin within the range of 1:(0.8-1.3), controls the addition amount of polytetrafluoroethylene modified polyethylene wax within the range of 0.2-0.8 parts, and uses a modified ammonia curing agent and a dicyandiamide curing agent with a weight ratio of (2.5-3.5):1 as a curing agent. The obtained wear-resistant powder coating has better anti-slip and wear resistance, and the anti-slip value PTV of the formed coating film is ≥60, the impact torque resistance is ≥55kg·cm, and the wear amount is ≤15.0mg. DETAILED DESCRIPTION

[0025] The present application provides a wear-resistant powder coating, comprising the following components in parts by weight: 60-80 parts of epoxy resin, 8-12 parts of curing agent, 0.3-0.5 parts of cellulose acetate butyrate, 0.2-2.0 parts of polytetrafluoroethylene modified polyethylene wax, 20-25 parts of barium sulfate and 0.7-1 parts of carbon black. Among them, the epoxy resin is a bisphenol A epoxy resin and an o-cresol epoxy resin in a weight ratio of 1: (0.5-1.5), and the curing agent is selected from one or more of a modified ammonia curing agent and a dicyandiamide curing agent. Further, the weight ratio of the bisphenol A epoxy resin and the o-cresol epoxy resin is 1: (0.8-1.3), and the weight of the polytetrafluoroethylene modified polyethylene wax is 0.2-0.8 parts; the curing agent is a modified ammonia curing agent and a dicyandiamide curing agent. Further, the weight ratio of the modified ammonia curing agent and the dicyandiamide curing agent is (2.5-3.5):1.

[0026] The preparation method of the wear-resistant powder coating comprises the following steps: mixing the components uniformly to obtain the wear-resistant powder coating.

[0027] The present application also provides a method for spraying a wear-resistant powder coating, comprising the following steps: using an electrostatic spraying process to spray the wear-resistant powder coating at a rate of 0.08-0.12 kg / m 2 The spray amount is sprayed onto the surface of the substrate at a spraying temperature of 90-100°C. During the spraying process, an electric field is used for breakdown, and then the coating is cured at 200-220°C for 15-20 minutes.

[0028] The sources and brands of the raw materials used in the examples of this application are shown in Table 1 below. The remaining raw materials, reagents, solvents, etc. used in this application can also be obtained commercially; Table 1 Sources and grades of raw materials used in the examples The present application is further described in detail below in conjunction with embodiments and performance testing experiments.

[0029] Examples 1-5 Embodiments 1-5 respectively provide a kind of wear-resistant powder coating.

[0030] The difference between the above embodiments lies in: the type and ratio of epoxy resin, as shown in Table 2 below.

[0031] The preparation method of the wear-resistant powder coating provided in Examples 1-5 comprises the following steps: 66 g of epoxy resin, 8.8 g of curing agent (modified ammonia curing agent and dicyandiamide curing agent in a weight ratio of 3:1), 0.3 g of cellulose acetate butyrate, 0.5 g of polytetrafluoroethylene modified polyethylene wax, 23.6 g of barium sulfate and 0.8 g of carbon black are weighed respectively, and the above components are mixed evenly; then the mixture is poured into an extruder, melt-extruded at 120°C, and fed into a tablet press for tableting, a coarse grinder for crushing, a fine grinder for grinding, and a sieve to obtain a wear-resistant powder coating with a particle size of 45±2 μm.

[0032] Table 2 Components and ratios of epoxy resins in Examples 1-5 Example Weight ratio of bisphenol A epoxy resin and o-cresol epoxy resin 1 1：0.5 2 1：0.8 3 1：1 4 1：1.3 5 1：1.5 Embodiment 6-9 Examples 6-9 each provide a wear-resistant powder coating.

[0033] The difference between the above embodiment and embodiment 3 is that the amount of polytetrafluoroethylene modified polyethylene wax added is as shown in Table 3 below.

[0034] Table 3 Addition amount of polytetrafluoroethylene modified polyethylene wax in Example 3, Examples 6-9 Example Addition amount of polytetrafluoroethylene modified polyethylene wax (g) 3 0.5 6 0.2 7 0.8 8 1.5 9 2.0 Examples 10-14 Examples 10-14 each provide a wear-resistant powder coating.

[0035] The difference between the above embodiment and embodiment 3 is: the type and ratio of the curing agent, as shown in Table 4 below.

[0036] Table 4 Types and ratios of curing agents in Example 3, Examples 10-14 Comparative Example 1 Comparative Example 1 provides a wear-resistant powder coating.

[0037] The difference between the comparative example and Example 3 is that the epoxy resin only uses bisphenol A epoxy resin.

[0038] Comparative Example 2 Comparative Example 2 provides a wear-resistant powder coating.

[0039] The difference between the comparative example and Example 3 is that the epoxy resin only uses o-cresol-formaldehyde epoxy resin.

[0040] Comparative Example 3 Comparative Example 3 provides a wear-resistant powder coating.

[0041] The difference between the comparative example and Example 3 is that the added amount of polytetrafluoroethylene modified polyethylene wax is 0.

[0042] Application Example 1-14 Application Examples 1-14 respectively provide a method for spraying a wear-resistant powder coating.

[0043] The difference between the above application examples is that the wear-resistant powder coatings used in the spraying method of the wear-resistant powder coatings are derived from Examples 1-14 respectively.

[0044] The spraying method of the wear-resistant powder coating provided in Application Examples 1-14 comprises the following steps: (1) Pretreatment of composite substrate: The hood of an off-road vehicle was used as the composite substrate, and its surface was cleaned and degreased (wiped with isopropyl alcohol); then, a water-based conductive paint (using Example 1 in CN117683439A) was sprayed on the back of the composite substrate, and then leveling was performed, baked at 80° C. for 60 min, and preheated at 130° C. for 10 min to obtain a pretreated composite substrate.

[0045] (2) Electrostatic spraying: Use a spraying device to evenly spray the wear-resistant powder coating on the surface of the pretreated composite substrate. Set the spray gun voltage to 80 kV, the current to 30 μA, the spray temperature to 90-100 °C, and the spray volume to 0.1 kg / m 2 ; Multiple coats of paint are sprayed continuously at one time, and an electric field is used for breakdown during the spraying process, and then cured at 200°C for 15 minutes, thereby forming a dense and uniform coating on the surface of the composite substrate.

[0046] Comparative Application Examples 1-3 Comparative Application Examples 1-3 respectively provide a method for spraying a wear-resistant powder coating.

[0047] The difference between the above comparative application example and application example 3 is that the wear-resistant powder coatings used in the spraying method of the wear-resistant powder coatings are derived from comparative examples 1-3 respectively.

[0048] Performance testing The surface coating of the composite substrate after electrostatic spraying of corresponding Example 1-14 and Comparative Application Example 1-3 was subjected to various performance tests, including hardness, anti-slip property, impact resistance, wear resistance, and adhesion. The results are shown in Table 5 below.

[0049] (1) Hardness: Pencil hardness is tested according to standard GB / T6739-2006.

[0050] (2) Anti-slip property: Anti-slip value PTV is tested according to BS7976-2-2002+A1-2013 (2) Impact resistance: The impact resistance torque is tested according to the standard GB / T1732-1993.

[0051] (3) Wear resistance: S-33 sandpaper was selected as the friction material. New sandpaper was used for every 100 turns of the test. The test load was 1 kg, and the wear amount of the coating was measured after 1000 turns.

[0052] (4) Adhesion: Adhesion level is tested according to standard GB / T9286-1998 Table 5 Test results of surface properties of coating film formed after powder coating spraying According to the test results of Table 5, the wear-resistant powder coating provided by Examples 1-14 of the present application forms a coating film on the surface of the composite material with a smooth appearance and a large texture effect of imitation leather, and the hardness is 6H, the anti-slip value PTV is 53-64, the impact torque is 50-63kg·cm, the wear amount is 2.0-16.4mg, and the adhesion level is 0. Therefore, it is explained that the wear-resistant powder is prepared by epoxy resin, cellulose acetate butyrate and polytetrafluoroethylene modified polyethylene wax, and a mixture of bisphenol A epoxy resin and o-cresol epoxy resin is used as the epoxy resin. The obtained powder coating has good anti-slip properties and good wear resistance after spraying on the surface of the composite material, and has a large texture effect of imitation leather, which can meet the use requirements of high-end scenes.

[0053] The anti-skid value PTV of the coating film formed on the surface of the composite material by the wear-resistant powder coating provided in Comparative Examples 1-2 is only 37-40, the impact torque resistance is only 32-34 kg·cm, and the wear loss is as high as 20.2-22.5 mg, indicating that the wear-resistant powder coating prepared by using only bisphenol A epoxy resin or o-cresol epoxy resin as the epoxy resin has poor anti-skid and wear resistance and cannot meet the use requirements; The anti-slip value PTV of the coating film formed by the wear-resistant powder coating provided in Comparative Example 3 on the surface of the composite material is 66, but the wear amount is as high as 35.7 mg, indicating that although the anti-slip property of the wear-resistant powder coating obtained without adding polytetrafluoroethylene modified polyethylene wax is good, the wear resistance is extremely poor and still cannot meet the use requirements.

[0054] The test results of the coating formed by application examples 1-5 show that the anti-skid value PTV of the coating formed by the wear-resistant powder coating of Example 1 and Example 5 on the surface of the composite material is 55-57, the impact torque is 50-52kg·cm, and the wear amount is 13.6-16.4mg; while the anti-skid value PTV of the coating formed by the wear-resistant powder coating of Example 2-4 on the surface of the composite material is 60-63 (≥60), the impact torque is 55-58kg·cm (≥55kg·cm), and the wear amount is 5.4-13.2mg (≤15.0mg). Therefore, it is explained that the present application further controls the weight ratio of bisphenol A epoxy resin and o-cresol epoxy resin within the range of 1: (0.8-1.3), and the anti-skid and wear resistance of the obtained wear-resistant powder coating is better.

[0055] The test results of the coating formed by Application Examples 3 and Application Examples 6-9 show that, with the increase in the amount of polytetrafluoroethylene modified polyethylene wax added, the anti-skid value of the coating formed by the wear-resistant powder coating on the surface of the composite material gradually decreases, the impact torque does not change, and the wear amount also gradually decreases; further comparison shows that the anti-skid value PTV of the coating formed by the wear-resistant powder coating of Example 3 and Example 6-7 on the surface of the composite material is 60-64 (≥60). Therefore, considering comprehensively, the application further controls the addition amount of polytetrafluoroethylene modified polyethylene wax within the range of 0.2-0.8 parts, and the comprehensive performance of the anti-skid and wear resistance of the wear-resistant powder coating obtained is better.

[0056] The test results of the coating formed by Application Examples 3 and 10-14 show that the anti-skid value PTV of the coating formed by the wear-resistant powder coating of Examples 10-11 and 14 on the surface of the composite material is 57-59, and the wear amount is 12.8-16.0 mg; while the anti-skid value PTV of the coating formed by the wear-resistant powder coating of Examples 3 and 12-13 on the surface of the composite material is 61-64 (≥60), and the wear amount is 5.4-9.6 mg (≤10 mg). Therefore, it is explained that the present application further adopts a modified ammonia curing agent and a dicyandiamide curing agent with a weight ratio of (2.5-3.5): 1 as a curing agent, and the comprehensive performance of the anti-skid property and wear resistance of the wear-resistant powder coating obtained is better.

[0057] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A wear-resistant powder coating, characterized in that: The invention comprises the following components in parts by weight: 60-80 parts of epoxy resin, 8-12 parts of curing agent, 0.3-0.5 parts of cellulose acetate butyrate and 0.2-2.0 parts of polytetrafluoroethylene modified polyethylene wax; The epoxy resin is bisphenol A epoxy resin and o-cresol formaldehyde epoxy resin in a weight ratio of 1: (0.5-1.5).

2. The wear-resistant powder coating according to claim 1, characterized in that: The weight ratio of the bisphenol A epoxy resin to the o-cresol-formaldehyde epoxy resin is 1:(0.8-1.3).

3. The wear-resistant powder coating according to claim 1, characterized in that: The weight portion of the polytetrafluoroethylene modified polyethylene wax is 0.2-0.8 parts.

4. The wear-resistant powder coating according to claim 1, characterized in that: The curing agent is selected from one or more of a modified ammonia curing agent and a dicyandiamide curing agent.

5. The wear-resistant powder coating according to claim 4, characterized in that: The curing agent is a modified ammonia curing agent and a dicyandiamide curing agent.

6. The wear-resistant powder coating according to claim 5, characterized in that: The weight ratio of the modified ammonia curing agent to the dicyandiamide curing agent is (2.5-3.5):

1.

7. The wear-resistant powder coating according to claim 1, characterized in that: The wear-resistant powder coating further comprises 20-25 parts of barium sulfate and 0.7-1 part of carbon black.

8. The wear-resistant powder coating according to any one of claims 1 to 7, characterized in that: The particle size of the wear-resistant powder coating is 45±2 μm.

9. The method for preparing the wear-resistant powder coating according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing the components uniformly, performing melt extrusion, tabletting, coarse crushing, grinding and sieving to obtain the wear-resistant powder coating.

10. A method for spraying a wear-resistant powder coating, characterized in that: The invention comprises the following steps: applying the wear-resistant powder coating according to any one of claims 1 to 8 at a rate of 0.08-0.12 kg / m 2 The coating amount is sprayed onto the surface of the substrate, and an electric field is used for breakdown during the spraying process, and then the coating is cured at 200-220°C for 15-20 minutes; the spraying adopts an electrostatic spraying process, and the spraying temperature is 90-100°C.

Images