The method for polishing the surface of automotive paint

Abstract

According to the features of the present invention for achieving the above-mentioned purpose, the present invention comprises a first step of polishing defects on the surface of an automobile using a wool pad coated with a first polishing agent, a second step of hydrophilically coating the surface of the automobile using a polyester-based urethane foam pad coated with a second polishing agent after polishing, and a third step of polishing the surface of the automobile using a microfiber pad coated with a curing agent after hydrophilic coating, wherein the polishing of the first step is characterized by attaching the wool pad coated with the first polishing agent to a position eccentrically offset from the centerline of the drive shaft of a polisher by 10 to 30 mm and rotating it at a speed of 3,500 to 4,500 rpm for 10 to 20 minutes.

Description

Technology Field

[0001] The present invention relates to a method for polishing an automobile paint surface, and more specifically, to an automobile surface restoration technology that effectively corrects defects occurring on the automobile surface, improves gloss, and minimizes paint film loss to maintain stable automobile surface quality for a long period. Background Technology

[0003] Conventional polishing methods for restoring automotive surfaces primarily involve grinding the surface using compound, followed by additional coating and polishing. While this method effectively removes scratches and contaminants, it suffers from the problem of excessive paint film thickness loss during the physical grinding process. This paint film loss weakens the durability of the vehicle's surface, and since repainting eventually becomes necessary after repeated operations, maintaining the vehicle's appearance over the long term is difficult.

[0004] In particular, water-based paints recently used in the automotive industry feature thin film thicknesses and high hardness. When restoration is performed using conventional methods, there is a problem where physical damage to the paint surface becomes more pronounced due to excessive frictional heat and abrasion. In conventional polishing methods, microscopic damage occurring during the abrasion stage and a reduction in film thickness lead to a decline in the durability and surface quality of the paint, while weakening performance in preventing UV discoloration and contaminant adhesion.

[0005] Furthermore, the dust generated during these physical polishing processes and the use of chemical removers degrade the working environment and cause environmental pollution, revealing limitations in terms of work efficiency and economic feasibility. Consequently, there is a need for more efficient and environmentally friendly alternative technologies for automotive surface restoration. Prior art literature

[0007] Republic of Korea Registered Patent No. 10-2567731 The problem to be solved

[0008] To solve the aforementioned problems, the objective of the present invention is to provide a polishing method that minimizes paint film loss for automobile surface restoration and maintains long-term durability and appearance quality. means of solving the problem

[0010] According to the features of the present invention for achieving the above-mentioned purpose, the present invention comprises a first step of polishing defects on the surface of an automobile using a wool pad coated with a first polishing agent, a second step of hydrophilically coating the surface of the automobile using a polyester-based urethane foam pad coated with a second polishing agent after polishing, and a third step of polishing the surface of the automobile using a microfiber pad coated with a curing agent after hydrophilic coating, wherein the polishing of the first step is characterized by attaching the wool pad coated with the first polishing agent to a position eccentrically offset from the centerline of the drive shaft of a polisher by 10 to 30 mm and rotating it at a speed of 3,500 to 4,500 rpm for 10 to 20 minutes.

[0011] In addition, the hydrophilic coating of the second step is characterized by attaching a polyester-based urethane foam pad coated with the second polishing agent to a position 10 to 30 mm eccentric from the centerline of the drive shaft of the polisher and rotating it at a speed of 3,000 to 3,500 rpm for 5 to 15 minutes.

[0012] In addition, the polishing treatment of the third step is characterized by attaching a microfiber pad coated with the curing agent to a position 5 to 15 mm eccentric from the centerline of the drive shaft of the polisher and rotating it at a speed of 2,500 to 3,000 rpm for 5 to 10 minutes.

[0013] In addition, the first polishing agent has a particle size of 3 to 5 μm and, based on 55 parts by weight of water, comprises 5 to 15 parts by weight of glycerin, 1 part by weight of triethanolamine, 0.01 parts by weight of sodium hydroxide, 10 to 13 parts by weight of alpha-aluminum oxide, 1 to 5 parts by weight of pajama oil, 1 to 5 parts by weight of paraffin oil, 10 to 20 parts by weight of hydrogenated light refined oil, 5 parts by weight of graphene oxide, 5 parts by weight of silicon carbide, and 5 parts by weight of trimethylsiloxane.

[0014] The above second polishing agent has a particle size of 1 to 2 μm and, based on 60 parts by weight of water, comprises 1 to 10 parts by weight of glycerin, 0.1 parts by weight of morpholine, 0.3 parts by weight of triethanolamine, 0.1 parts by weight of 1,2-benzoisothiazolin-3-one, 1 part by weight of castor oil, 5 to 15 parts by weight of aluminum oxide, 15 to 25 parts by weight of hydrodesulfurized light petroleum, 1 to 10 parts by weight of paraffin oil, 1 to 5 parts by weight of dimethylsiloxane, 5 parts by weight of graphite, and 1 part by weight of silica.

[0015] The above curing agent is characterized by comprising, for every 25 parts by weight of naphtha, 1 to 10 parts by weight of toluene, 1 to 5 parts by weight of isoalkane (C8-10), 1 to 5 parts by weight of isoalkane (C9-11), 5 to 15 parts by weight of vinyltrimethoxysilane, 25 to 35 parts by weight of hydrogenated light refined oil, 10 to 20 parts by weight of trimethoxysilane, 5 parts by weight of graphite, and 1 part by weight of silica.

[0016] In addition, the wool pad and polyester-based urethane foam pad are characterized by having a diameter of 3 to 5 inches, and the microfiber pad is characterized by having a diameter of 2.5 to 3.5 inches. Effects of the invention

[0018] The method for polishing an automobile paint surface according to the present invention can effectively remove scratches and contaminants while minimizing paint film loss on the automobile surface. In addition, by maintaining the thickness of the paint film, the durability of the automobile surface is enhanced, and the appearance quality can be stably maintained over the long term even with repeated polishing operations.

[0019] In addition, it forms a hydrophilic coating film on the vehicle surface to simultaneously improve antifouling properties and durability, and resolves the paint damage issues that occur with conventional compound polishing methods. Brief explanation of the drawing

[0021] FIG. 1 is a flowchart of a method for polishing an automobile paint surface according to the present invention. FIG. 2 is a photograph showing a first polishing agent and a second polishing agent used in the method for polishing an automobile paint surface according to the present invention. FIG. 3 is a photograph showing a curing agent used in the method for polishing an automobile paint surface according to the present invention. Figure 4 is a photograph showing a wool pad and a polyester-based urethane foam pad used in the method for polishing an automobile paint surface according to the present invention. FIG. 5 is a photograph showing a microfiber pad used in the method for polishing an automobile paint surface according to the present invention. FIG. 6 is a photograph showing a compound used in a conventional polishing method and a finish dark glaze for comparative testing with the automobile paint surface polishing method according to the present invention. FIG. 7 is a table summarizing the types and conditions of polishers used in the automobile paint surface polishing method according to the present invention. Figure 8 is a graph showing the results of measuring paint thickness after an experiment using a general compound, a first polishing agent, a second polishing agent, and a hardener. Figure 9 is a graph showing the results of photometric measurements after an experiment using a general compound, a first polishing agent, a second polishing agent, and a curing agent. Figure 10 is a graph showing the results of measuring the static friction coefficient after an experiment using a general compound, a first polishing agent, a second polishing agent, and a hardener on the surface of an automobile painted with a utility-based paint. Figure 11 is a graph showing the results of measuring the static friction coefficient after a first experiment using a general compound, a first polishing agent, a second polishing agent, and a curing agent on a water-soluble paint automotive coating surface. Figure 12 is a graph showing the results of measuring the static friction coefficient after a second experiment using a general compound, a first polish, a second polish, and a hardener on a water-soluble paint automotive coating surface. Figure 13 is a graph showing the results of measuring the static friction coefficient after a third experiment using a general compound, a first polish, a second polish, and a hardener on a water-soluble paint automotive coating surface. Figure 14 is a graph showing the contact angle measurement results after a third experiment using a general compound, a first polish, a second polish, and a hardener on an automobile paint surface. Specific details for implementing the invention

[0022] A preferred embodiment of the method for polishing an automobile paint surface according to the present invention will be described in detail below with reference to the attached drawings.

[0023] As illustrated in FIG. 1, the method for polishing a painted surface of an automobile may comprise a first step (S-1) of polishing defects on the surface of an automobile using a wool pad coated with a first polishing agent, a second step (S-2) of hydrophilic coating the surface of the automobile using a polyester-based urethane foam pad coated with a second polishing agent after polishing, and a third step (S-3) of polishing the surface of the automobile using a microfiber pad coated with a curing agent after hydrophilic coating.

[0024] Step 1 (S-1) polishes defects on the car surface using a wool pad coated with the first polishing agent.

[0025] Specifically, the wool pad coated with the first polishing agent is attached to a position 10 to 30 mm eccentric from the centerline of the drive shaft of the polisher and rotated at a speed of 3,500 to 4,500 rpm for 10 to 20 minutes to polish defects on the surface of the automobile.

[0027] The first polishing agent has a particle size of 3 to 5 μm and, based on 55 parts by weight of water, consists of 5 to 15 parts by weight of glycerin, 1 part by weight of triethanolamine, 0.01 parts by weight of sodium hydroxide, 10 to 13 parts by weight of alpha-aluminum oxide, 1 to 5 parts by weight of pajama oil, 1 to 5 parts by weight of paraffin oil, 10 to 20 parts by weight of hydrogenated light refined oil, 5 parts by weight of graphene oxide, 5 parts by weight of silicon carbide, and 5 parts by weight of trimethylsiloxane.

[0028] Here, if the particle size of the first polishing agent is used to be less than 3㎛, the abrasive particles are too fine and do not exert sufficient abrasive power, resulting in a problem where defects on the surface of the automobile are not effectively removed, and if used to be more than 5㎛, the abrasive particles are too large and have strong abrasive power, resulting in the surface of the automobile being excessively polished and the thickness of the coating film being unnecessarily reduced.

[0029] In addition, the first polishing agent contains water. The water is included in 55 parts by weight. If the amount of water is less than 55 parts by weight, the overall concentration of the composition increases, and if it is more than 55 parts by weight, the overall concentration of the composition decreases, making it difficult to work and causing defects.

[0030] In addition, glycerin is included. The glycerin is included in an amount of 5 to 15 parts by weight per 55 parts by weight of water. The glycerin combines with the water to fix moisture. If the glycerin is included in an amount less than 5 parts by weight, a problem arises where there is a lack of moisture during the process, and if it is included in an amount more than 15 parts by weight, a problem arises where moisture remains for a long time even after the process.

[0031] In addition, triethanolamine is included. The triethanolamine is included in an amount of 1 part by weight per 55 parts by weight of water. The triethanolamine serves to aid in the emulsification of the substance and to clean the surface; if the triethanolamine is not included, the emulsion separates and becomes watery, and basic cleaning is not performed. If the triethanolamine is included in an amount exceeding 1 part by weight, it is difficult to apply during use. Furthermore, because cleaning is not smooth, a problem arises where the substance adheres to the painted surface.

[0032] In addition, sodium hydroxide is included. The sodium hydroxide is included in an amount of 0.01 parts by weight per 55 parts by weight of water, and the sodium hydroxide serves to regulate the pH of the composition of the present invention and extend its shelf life.

[0033] In addition, alpha-aluminum oxide is included. The alpha-aluminum oxide is included in an amount of 10 to 13 parts by weight per 55 parts by weight of water. The alpha-aluminum oxide serves as an abrasive to finely polish the surface of the automobile.

[0034] In addition, pajama oil is included. The above pajama oil is included in an amount of 1 to 5 parts by weight per 55 parts by weight of water. During application, it maintains the lubrication and color of the clear coat surface to prevent the loss of gloss. If the above pajama oil is included in an amount of less than 2 parts by weight, no gloss is produced when applied to the automotive paint surface, and if it is included in an amount exceeding 4 parts by weight, the degree of gloss is no different from when 5 parts by weight are included.

[0035] In addition, paraffin oil is included. The paraffin oil is included in an amount of 1 to 5 parts by weight per 55 parts by weight of water. The paraffin oil adds gloss to the surface of the automobile after coating and helps maintain the stability of the coating layer. If the paraffin oil is less than 1 part by weight, the stability of the hydrophilic coating layer is reduced, and if it exceeds 5 parts by weight, the surface may become excessively slippery.

[0036] In addition, hydrogenated light refined oil is included. The hydrogenated light refined oil is included in an amount of 10 to 20 parts by weight per 55 parts by weight of water. If the hydrogenated light refined oil is included in an amount of less than 10 parts by weight, the frictional force and viscosity decrease, and if it is included in an amount of more than 20 parts by weight, the composition becomes excessively overloaded overall, causing problems that make operation difficult.

[0037] In addition, graphene oxide is included. The graphene oxide is included in an amount of 5 parts by weight per 55 parts by weight of water. If the graphene oxide is included in an amount relatively smaller than 5 parts by weight, sufficient gloss enhancement effect and protective performance will not be exhibited on the automobile surface, and if it is included in an amount relatively larger than 5 parts by weight, the composition of the first gloss agent will be unbalanced, which may have a negative effect on surface quality.

[0038] In addition, silicon carbide is included. The silicon carbide acts as an abrasive, similar to the alpha-aluminum oxide. It is preferable that the silicon carbide be included in an amount of 5 parts by weight per 55 parts by weight of water. If the silicon carbide is included in an amount relatively smaller than 5 parts by weight, the efficiency of polishing decreases, and if it is included in an amount relatively larger than 5 parts by weight, the amount of polishing increases, which is contrary to the purpose of the present invention.

[0039] In addition, trimethylsiloxane is included. The trimethylsiloxane serves to fix the gloss composition according to the present invention. It is preferable that the trimethylsiloxane be included in an amount of 5 parts by weight per 55 parts by weight of water. If the trimethylsiloxane is included in an amount less than 5 parts by weight, the gloss composition of the present invention peels off easily from the surface of the automobile, and if the trimethylsiloxane is included in an amount relatively greater than 5 parts by weight, a problem arises in which the surface of the automobile becomes contaminated.

[0041] The above wool pad is manufactured by compressing natural wool into high or low density yarns and fixing them perpendicularly to a circular pad.

[0042] The above wool pad has a diameter of 3 to 5 inches. If the diameter of the wool pad is less than 3 inches, the gap between the center line of the drive shaft of the wool pad and the center axis of rotation of the polisher narrows, causing the first polishing agent to be concentrated in a narrow area. This results in problems such as a reduction in paint thickness due to excessive polishing or deformation of the hydrophilic coating layer generated by excessive frictional heat. If the diameter exceeds 5 inches, the size of the wool pad becomes excessively large, making effective pressure distribution difficult, and uneven rotation causes a haze phenomenon to occur on the surface of the automobile.

[0043] The above-mentioned haze phenomenon refers to a blurry or hazy effect that occurs when light passes through an optically transparent surface or material, caused by scattering due to surface roughness or microstructure. This phenomenon mainly appears in transparent or translucent materials such as painted surfaces, plastics, and glass, and can be exacerbated by surface defects or a lack of coating uniformity. The haze phenomenon visually degrades quality and causes a decrease in object clarity or contrast along with reduced light transmittance.

[0045] In addition, if the wool pad coated with the first polish is attached at an eccentric position less than 10 mm from the center line of the drive shaft of the polisher, the gap between the center axis of rotation of the polisher and the center line of the drive shaft narrows, causing the first polish to be concentrated in a narrow area and resulting in excessive damage to the paint film. If it is attached at an eccentric position exceeding 30 mm, the eccentricity between the drive shaft of the polisher and the pad is excessive, causing severe vibration during rotation and uneven rotation, which results in a haze phenomenon on the surface of the automobile.

[0047] In addition, if the rotational speed of the polisher is less than 3,500 rpm, the rotational speed is insufficient, which reduces the frictional force between the wool pad and the car surface, resulting in a problem where defect removal and polishing work are not performed well. If the operation is performed at a speed exceeding 4,500 rpm, the rotational speed increases excessively, causing excessive frictional heat between the car surface and the wool pad, which results in excessive damage to the paint film and causes paint deformation or damage to the car surface due to overheating.

[0049] In addition, if the polishing in the first step is performed for less than 10 minutes, there is a problem that the polishing time is insufficient and the defect removal and polishing work are not sufficiently carried out. If the work is performed for more than 20 minutes, the frictional heat between the vehicle surface and the wool pad increases due to excessive polishing, causing damage to the paint film, and consequently, there is a problem that the thickness of the paint film on the vehicle surface is unnecessarily reduced.

[0051] Step 2 (S-2) involves applying a second polishing agent to the surface of the automobile using a polyester-based urethane foam pad after the above polishing, and then hydrophilically coating the surface of the automobile.

[0052] Specifically, a polyester-based urethane foam pad coated with the second polishing agent is attached at a position 10 to 30 mm eccentric from the centerline of the drive shaft of the polisher and rotated at a speed of 3,000 to 3,500 rpm for 5 to 15 minutes to hydrophilically coat the surface of the automobile.

[0054] The above second polishing agent has a particle size of 1 to 2 μm and, based on 60 parts by weight of water, consists of 1 to 10 parts by weight of glycerin, 0.1 parts by weight of morpholine, 0.3 parts by weight of triethanolamine, 0.1 parts by weight of 1,2-benzoisothiazolin-3-one, 1 part by weight of pajama oil, 5 to 15 parts by weight of aluminum oxide, 15 to 25 parts by weight of hydrodesulfurized light petroleum, 1 to 10 parts by weight of paraffin oil, 1 to 5 parts by weight of dimethylsiloxane, 5 parts by weight of graphite, and 1 part by weight of silica.

[0055] The second polish contains 60 parts by weight of water. The water acts as a basic solvent for the second polish composition to help all components be mixed uniformly. If the amount of water is less than 60 parts by weight, the viscosity of the composition increases, which leads to a problem of reduced workability; if it exceeds 60 parts by weight, the composition is excessively diluted, which leads to a problem of the second polish becoming thin.

[0056] In addition, glycerin is included. The glycerin is included in an amount of 1 to 10 parts by weight per 60 parts by weight of water. Glycerin acts to fix moisture, preventing the composition from drying out during operation and helping to maintain stability even after the coating process. If less than 1 part by weight of glycerin is included, the composition may dry out during operation, forming an uneven hydrophilic coating layer; if more than 10 parts by weight is included, the hydrophilic coating effect may be reduced due to excessive residue after operation.

[0057] In addition, morpholine is included. The morpholine is included in an amount of 0.1 parts by weight per 60 parts by weight of water. Morpholine maintains the pH of the composition stably and enhances the uniform coating effect on the coated surface. If morpholine is not included, the stability of the composition is reduced, and the formation of the coating layer may be incomplete. On the other hand, if used in an amount exceeding 0.1 parts by weight, there is a possibility that the surface may corrode slightly after coating.

[0058] In addition, triethanolamine is included. The triethanolamine is included in an amount of 0.3 parts by weight per 60 parts by weight of water. The triethanolamine serves to aid in the emulsification of the substance and to clean the surface; if the triethanolamine is not included, the emulsion separates and becomes watery, and basic cleaning is not performed. If the triethanolamine is included in an amount exceeding 0.3 parts by weight, it is difficult to apply during use. Furthermore, because cleaning is not smooth, a problem arises where the substance adheres to the painted surface.

[0059] In addition, 1,2-benzoisothiazoline-3-one is included. The 1,2-benzoisothiazoline-3-one is included in an amount of 0.1 parts by weight per 60 parts by weight of water. This component provides antibacterial and preservative functions to the composition, helping to maintain the quality of the composition even during long-term storage. If the amount is less than 0.1 parts by weight, the preservation stability of the composition is reduced, and if it exceeds 0.1 parts by weight, there is a possibility that the uniformity of the surface coating may decrease.

[0060] In addition, pajama oil is included. The above pajama oil is included in an amount of 1 part by weight per 60 parts by weight of water. During application, it lubricates the surface of the clear coat and maintains color to prevent the loss of gloss. If the above pajama oil is not included, gloss will not be produced when applied to the painted surface of a car, and if it is included in an amount exceeding 1 part by weight, a problem may occur where the coating surface becomes excessively slippery.

[0061] In addition, aluminum oxide is included. The aluminum oxide is included in an amount of 5 to 15 parts by weight per 60 parts by weight of water. The aluminum oxide acts as a fine abrasive to smooth the surface of the automobile and helps form a hydrophilic coating layer. If used in an amount less than 5 parts by weight, the abrasive effect is insufficient, and if used in an amount exceeding 15 parts by weight, damage to the surface of the automobile may occur.

[0062] In addition, hydrodesulfurized light petroleum is included. The hydrodesulfurized light petroleum is included in an amount of 15 to 25 parts by weight per 60 parts by weight of water. This component controls the viscosity of the composition to provide stable application and workability. If the amount is less than 15 parts by weight, the viscosity is insufficient, resulting in poor workability; if it exceeds 25 parts by weight, the viscosity of the composition becomes excessively high, making uniform application difficult.

[0063] In addition, paraffin oil is included. The paraffin oil is included in an amount of 1 to 10 parts by weight per 60 parts by weight of water. The paraffin oil adds gloss to the surface of the automobile after coating and helps maintain the stability of the coating layer. If the paraffin oil is less than 1 part by weight, the stability of the hydrophilic coating layer is reduced, and if it exceeds 10 parts by weight, the surface may become excessively slippery.

[0064] In addition, dimethylsiloxane is included. The dimethylsiloxane is included in an amount of 1 to 5 parts by weight per 60 parts by weight of water. Dimethylsiloxane enhances the durability of the coating surface and provides an antifouling effect after application. If the amount is less than 1 part by weight, the hydrophilic coating effect is insufficient, and if it exceeds 5 parts by weight, the hydrophilic coating layer becomes too thick, which may reduce the gloss effect.

[0065] In addition, graphite is included. The graphite is included in an amount of 5 parts by weight per 60 parts by weight of water. The graphite forms a fine protective film on the surface of the automobile to enhance durability and increase the antifouling effect of the hydrophilic coating layer. If the amount is less than 5 parts by weight, the formation of the protective film is insufficient, and if it exceeds 5 parts by weight, the uniformity of the hydrophilic coating layer may be reduced.

[0066] In addition, silica is included. The silica is included in an amount of 1 part by weight per 60 parts by weight of water. The silica imparts hydrophilicity to the coating layer, preventing the adhesion of contaminants and facilitating surface maintenance. If less than 1 part by weight is included, the hydrophilic effect is reduced, and if more than 1 part by weight is included, the uniformity of the hydrophilic coating layer may decrease.

[0068] Here, if the particle size of the second polishing agent is used to be less than 1㎛, there is a problem in that the particles are too fine to exert sufficient polishing power and generate sufficient frictional heat, so the silica particles cannot be coated on the surface of the automobile, and if used to be more than 2㎛, the particles are too large and have strong polishing power, so the surface of the automobile is excessively polished and the silica is not coated uniformly, which reduces the hydrophilic coating effect.

[0070] The above polyester-based urethane foam pad was made of a polyester-based urethane material with an inner pore diameter of 50 to 90 PPI (Pores per inch).

[0071] Here, if the polyester-based urethane foam pad is manufactured with an inner diameter of less than 50 PPI, the pores of the polyester-based urethane foam pad are excessively wide, so the coating agent is not sufficiently absorbed, resulting in an incomplete formation of the hydrophilic coating layer; if it is manufactured with a diameter exceeding 90 PPI, the pores are excessively dense, causing the second gloss agent to be excessively absorbed into the interior of the polyester-based urethane foam pad, and the hydrophilic coating is discharged unevenly onto the surface of the vehicle. This results in the hydrophilic coating layer being formed too thickly or causing a glossy phenomenon, and causes a haze phenomenon on the surface of the vehicle.

[0072] The above polyester-based urethane foam pad has a diameter of 3 to 5 inches. If the diameter of the above polyester-based urethane foam pad is less than 3 inches, the gap between the center line of the drive shaft of the above polyester-based urethane foam pad and the center axis of rotation of the above polisher narrows, causing the second polishing agent to be concentrated in a narrow area, resulting in excessive polishing that reduces the paint thickness or causes the hydrophilic coating layer generated by excessive frictional heat to deform. If the diameter exceeds 5 inches, the size of the above polyester-based urethane foam pad becomes excessively large, making effective pressure distribution difficult, and there is a problem that a haze phenomenon occurs on the surface of the above automobile due to uneven rotation.

[0074] In addition, if the polyester-based urethane foam pad coated with the second polishing agent is attached at an eccentric position of less than 10 mm from the center line of the drive shaft of the polisher, the gap between the center axis of rotation of the polisher and the center line of the drive shaft narrows, causing the second polishing agent to be concentrated in a narrow area, resulting in the formation of an excessive hydrophilic coating layer and deformation of the hydrophilic coating layer created due to excessive frictional heat. If it is attached at an eccentric position of more than 30 mm, the eccentricity between the drive shaft of the polisher and the pad is excessive, causing severe vibration during rotation and a haze phenomenon to occur on the surface of the vehicle due to uneven rotation.

[0076] In addition, if the rotational speed of the polisher is less than 3,000 rpm, there is a problem that a hydrophilic coating layer is not sufficiently formed on the surface of the automobile due to insufficient rotational speed, and if the operation is exceeded 3,500 rpm, there is a problem that excessive frictional heat is generated between the polyester-based urethane foam pad and the surface of the automobile due to the excessive rotational speed, and deformation of the generated hydrophilic coating layer occurs.

[0078] In addition, if the hydrophilic coating of the second step is performed for less than 5 minutes, the silica particles in the second polish are not uniformly applied to the surface of the automobile due to insufficient working time, and the frictional heat required to form the coating layer is not sufficiently generated, resulting in a thin hydrophilic coating layer and reduced hydrophilic coating effect. If the work is performed for more than 15 minutes, excessive frictional heat is generated due to the excessive working time, which deforms the hydrophilic coating layer formed on the surface of the automobile and reduces the effectiveness of the hydrophilic coating layer. Furthermore, excessive working time causes physical damage to the surface of the automobile, leading to a haze phenomenon.

[0080] Step 3 (S-3) is to polish the surface of the automobile using a microfiber pad coated with a curing agent after the hydrophilic coating.

[0082] Specifically, the polishing treatment of the third step is performed by attaching a microfiber pad coated with the curing agent to a position 5 to 15 mm eccentric from the centerline of the drive shaft of the polisher and rotating it at a speed of 2,500 to 3,000 rpm for 5 to 10 minutes to polish the surface of the automobile.

[0084] The above curing agent consists of, for every 25 parts by weight of naphtha, 1 to 10 parts by weight of toluene, 1 to 5 parts by weight of isoalkane (C8-10), 1 to 5 parts by weight of isoalkane (C9-11), 5 to 15 parts by weight of vinyltrimethoxysilane, 25 to 35 parts by weight of hydrogenated light refined oil, 10 to 20 parts by weight of trimethoxysilane, 5 parts by weight of graphite, and 1 part by weight of silica.

[0085] The above curing agent contains 25 parts by weight of naphtha. Naphtha acts as the base solvent for the curing agent, uniformly mixes other components, and contributes to the stable formation of a superhydrophobic coating layer upon application. If the amount of naphtha is less than 25 parts by weight, the viscosity of the composition increases, which reduces workability; if it exceeds 25 parts by weight, the superhydrophobic coating layer becomes excessively thin, which may reduce the curing effect.

[0086] In addition, toluene is included. The toluene is included in an amount of 1 to 10 parts by weight per 25 parts by weight of naphtha. Toluene controls the viscosity of the composition and helps form a uniform superhydrophobic coating layer by rapidly volatilizing during operation. If toluene is included in an amount less than 1 part by weight, the curing speed decreases, reducing work efficiency, and if it exceeds 10 parts by weight, the volatilization speed is excessively fast, which may result in an uneven superhydrophobic coating layer.

[0087] In addition, isoalkanes (C8-10) are included. The isoalkanes (C8-10) are included in an amount of 1 to 5 parts by weight per 25 parts by weight of naphtha. The isoalkanes (C8-10) act as a lubricant and increase the smoothness of the surface and improve the antifouling effect when forming a superhydrophobic coating layer. If the isoalkanes (C8-10) are included in an amount of less than 1 part by weight, the smoothness of the superhydrophobic coating layer may be insufficient, which may degrade the coating quality; if the amount exceeds 5 parts by weight, the viscosity of the superhydrophobic coating layer may become excessively low, making it difficult to form a uniform layer.

[0088] In addition, isoalkanes (C9-11) are included. The isoalkanes (C9-11) are included in an amount of 1 to 5 parts by weight per 25 parts by weight of naphtha. The isoalkanes (C9-11) are used together with C8-10 to provide a stable protective effect on the superhydrophobic coating layer and improve the durability of the superhydrophobic coating layer after curing. If the isoalkanes (C9-11) are less than 1 part by weight, the durability of the superhydrophobic coating layer decreases, and if they exceed 5 parts by weight, the uniformity of the superhydrophobic coating layer may decrease.

[0089] In addition, vinyltrimethoxysilane is included. The vinyltrimethoxysilane is included in an amount of 5 to 15 parts by weight per 25 parts by weight of naphtha. Vinyltrimethoxysilane forms Si-O-Si bonds to strengthen the chemical bond between the automobile surface and the superhydrophobic coating layer. If included in an amount less than 5 parts by weight, the chemical bonding strength is insufficient, which reduces the water repellency and durability of the superhydrophobic coating layer; if included in an amount exceeding 15 parts by weight, the superhydrophobic coating layer becomes excessively hard, which may cause cracking.

[0090] In addition, hydrogenated light refined oil is included. The hydrogenated light refined oil is included in an amount of 25 to 35 parts by weight per 25 parts by weight of naphtha. This component controls the viscosity and workability of the curing agent and helps maintain the flexibility of the superhydrophobic coating layer after curing. If the amount is less than 25 parts by weight, the workability of the curing agent decreases, and if the amount exceeds 35 parts by weight, the superhydrophobic coating layer becomes excessively flexible, which may result in reduced durability.

[0091] In addition, trimethoxysilane is included. The trimethoxysilane is included in an amount of 10 to 20 parts by weight per 25 parts by weight of naphtha. Trimethoxysilane balances superhydrophobicity and hydrophilicity and enhances the physical stability of the superhydrophobic coating layer. If the amount is less than 10 parts by weight, the superhydrophobic effect becomes insufficient, and if the amount exceeds 20 parts by weight, the superhydrophobic coating layer may be formed too thickly, which may reduce the gloss effect.

[0092] In addition, graphite is included. The graphite is included in an amount of 5 parts by weight per 25 parts by weight of naphtha. Graphite forms a fine protective film on the superhydrophobic coating layer to enhance durability against external impacts. If included in an amount less than 5 parts by weight, the formation of a protective film on the superhydrophobic coating layer is insufficient, and if included in an amount exceeding 5 parts by weight, there is a possibility that the uniformity of the superhydrophobic coating layer may be reduced.

[0093] In addition, silica is included. The silica is included in an amount of 1 part by weight per 25 parts by weight of naphtha. The silica imparts water repellency to the superhydrophobic coating layer and prevents contaminants from adhering to the surface of the vehicle after the superhydrophobic coating layer is formed. If the amount is less than 1 part by weight, the water repellency effect is negligible, and if the amount exceeds 1 part by weight, the uniformity of the superhydrophobic coating layer may decrease.

[0095] The microfiber pad described above is manufactured by processing natural wool into ultra-fine fibers and shaping them into a pad, and is formed by attaching the natural wool ultra-fine fiber pad to a polyester-based urethane foam pad. The natural wool ultra-fine fibers have a much thinner diameter than ordinary fibers, providing excellent surface adhesion and the ability to precisely process even minute defects. In addition, the natural wool ultra-fine fibers have high absorbency and provide uniform friction, which helps form a uniform super-hydrophobic coating layer when a curing agent is applied, effectively removes contaminants from the surface of the vehicle, and improves the precision of the polishing process.

[0096] In addition, polyester-based urethane foam plays a crucial role in preventing overheating of the work surface and maintaining the stability of the superhydrophobic coating layer by rapidly dissipating frictional heat generated during work based on its excellent thermal conductivity. As a result, polyester-based urethane foam increases work efficiency and minimizes deformation or damage to the superhydrophobic coating layer caused by frictional heat that may occur during work. The combination of the natural wool microfiber and the polyester-based urethane foam pad simultaneously guarantees work precision and stability, and provides an optimal superhydrophobic coating effect.

[0097] The microfiber pad has a diameter of 2.5 to 3.5 inches. If the diameter of the microfiber pad is less than 2.5 inches, the gap between the center line of the drive shaft of the microfiber pad and the center axis of rotation of the polisher narrows, causing the curing agent to be concentrated in a narrow area, and the superhydrophobic coating layer generated by excessive heat is deformed. If the diameter exceeds 3.5 inches, the size of the microfiber pad becomes excessively large, making effective pressure distribution difficult, and there is a problem where a haze phenomenon occurs on the surface of the automobile due to uneven rotation.

[0099] Here, if the microfiber pad coated with the curing agent is attached at an eccentric position of less than 5 mm from the center line of the drive shaft of the polisher, the gap between the center axis of rotation of the polisher and the center line of the drive shaft narrows, causing the microfiber pad to move in a manner closer to simple rotation than orbital rotation on the surface of the vehicle, resulting in the curing agent being concentrated in a narrow area, forming an excessive superhydrophobic coating layer, and causing deformation of the superhydrophobic coating layer generated due to excessive frictional heat. If it is attached at an eccentric position of more than 15 mm, the excessive eccentricity causes severe vibration during the rotation of the polisher, and the uneven rotation causes a haze phenomenon on the surface of the vehicle.

[0101] In addition, if the rotational speed of the polisher is less than 2,500 rpm, there is a problem in that the frictional force between the microfiber pad and the car surface is insufficient due to the low rotational speed, so a superhydrophobic coating layer is not formed, and if the operation is exceeded 3,000 rpm, the frictional heat between the microfiber pad and the car surface increases due to the excessive rotational speed, and the generated superhydrophobic coating layer undergoes deformation due to overheating.

[0103] In addition, if the precision polishing of the third step is performed for less than 5 minutes, the working time is insufficient, so the curing agent cannot be applied uniformly to the surface of the automobile. As a result, the formation of the superhydrophobic coating layer is incomplete, and the water-repellent effect is reduced. If the work is performed for more than 10 minutes, the working time is excessive, causing excessive frictional heat to be generated between the microfiber pad and the surface of the automobile, which causes the superhydrophobic coating layer to deform and crack.

[0105] Hereinafter, the method for polishing an automobile paint surface according to the present invention will be explained in detail based on experimental results.

[0106] The first polishing agent, the second polishing agent, and the curing agent used in the experiment were used under the following conditions.

[0107] The first polishing agent above preferably has a particle size of 3 to 4 μm and is composed of 10 parts by weight of glycerin, 1 part by weight of triethanolamine, 0.01 parts by weight of sodium hydroxide, 11.5 parts by weight of alpha-aluminum oxide, 1 to 5 parts by weight of pajama oil, 1 to 5 parts by weight of paraffin oil, 15 parts by weight of hydrogenated light refined oil, 5 parts by weight of graphene oxide, 5 parts by weight of silicon carbide, and 5 parts by weight of trimethylsiloxane, based on 55 parts by weight of water.

[0108] The above second polishing agent preferably has a particle size of 1 to 2 μm and is composed of 5 parts by weight of glycerin, 0.1 parts by weight of morpholine, 0.3 parts by weight of triethanolamine, 0.1 parts by weight of 1,2-benzoisothiazolin-3-one, 1 part by weight of pajama oil, 10 parts by weight of aluminum oxide, 20 parts by weight of hydrodesulfurized light petroleum, 5 parts by weight of paraffin oil, 2.5 parts by weight of dimethylsiloxane, 5 parts by weight of graphite, and 1 part by weight of silica, based on 60 parts by weight of water.

[0109] The above curing agent was preferably used with respect to 25 parts by weight of naphtha, consisting of 5 parts by weight of toluene, 3 parts by weight of isoalkane (C8-10), 3 parts by weight of isoalkane (C9-11), 10 parts by weight of vinyltrimethoxysilane, 30 parts by weight of hydrogenated light refined oil, 15 parts by weight of trimethoxysilane, 5 parts by weight of graphite, and 1 part by weight of silica.

[0111] Experiment 1. Comparison Experiment of Paint Thickness and Gloss on Automobile Surfaces

[0112] In this experiment, complex surface damage was observed on the clear coat of a bonnet of a vehicle from Company H (2021 model year) to which water-soluble paint had been applied. Therefore, the surface was corrected and restored using a general compound and the polishing method of the present invention, and the results regarding the film thickness and gloss intensity appearing on the vehicle surface were measured. For the experiment, the bonnet of the vehicle was divided using masking tape.

[0114] [Comparative Example 1]

[0115] Before the experiment, the paint thickness and gloss of the automobile surface are measured using a film thickness gauge and a gloss meter. First, in the first step, the automobile surface is polished by attaching a 5-inch diameter wool pad coated with a compound having an average particle size of 5 to 7㎛ (without using a primary primer compound with strong abrasive particles) to a position 25mm eccentrically offset from the centerline of the polisher's drive axis and rotating it at a speed of 4,000 rpm for 15 minutes. In the second step, the automobile surface is hydrophilically coated by attaching a 5-inch diameter polyester-based urethane foam pad coated with Finish dark glaze having a particle size of 3 to 5㎛ to a position 25mm eccentrically offset from the centerline of the polisher's drive axis and rotating it at a speed of 3,250 rpm for 10 minutes. After the hydrophilic coating, the automobile surface is dried and degreased for 30 minutes to measure the paint thickness and gloss.

[0117] [Example 1]

[0118] Before conducting the experiment, the paint thickness and gloss level of the automobile surface are measured using a film thickness gauge and a gloss level gauge. First, in the first step, to remove defect elements on the automobile surface, a 5-inch diameter wool pad coated with the first polishing agent having a particle size of 3 to 4 μm is attached to a position 25 mm eccentrically offset from the centerline of the drive shaft of the polisher, and the defects on the automobile surface are polished by rotating it at a speed of 4,000 rpm for 15 minutes. In the second step, a 5-inch diameter polyester-based urethane foam pad coated with the second polishing agent having a particle size of 1 to 2 μm is attached to a position 25 mm eccentrically offset from the centerline of the drive shaft of the polisher, and the automobile surface is hydrophilically coated by rotating it at a speed of 3,250 rpm for 10 minutes. The third step involves attaching a 3-inch diameter microfiber pad coated with the above-mentioned hardener to a position 10mm eccentric from the centerline of the drive shaft of the polisher and polishing the car surface by rotating it at a speed of 2,750 rpm for 7 minutes and 30 seconds. After drying the polished car surface for 30 minutes, it is degreased. Then, the paint thickness and gloss of the degreased car surface are measured.

[0120] Coating thickness (㎛) before experiment Coating thickness (㎛) after experiment Difference in coating thickness (㎛) Light intensity (Lux) before the experiment Light intensity (Lux) after experiment Luminous difference (Lux) Comparative Example 1 95 92 -3 40 49 +9 Example 1 97 99 +2 39 60 +21

[0121] As shown in Table 1 and Figures 8 and 9, it can be seen that the coating thickness of Comparative Example 1 decreased by an average of 3 μm after the experiment, while the coating thickness of Example 1 increased by an average of 2 μm. This indicates that Example 1 forms an additional hydrophilic coating layer on the surface of the automobile while preventing coating film loss.

[0122] In addition, as a result of measuring luminous intensity (Lux), Comparative Example 1 showed an increase of only 9 Lux after the process, whereas Example 1 showed an increase of 21 Lux, confirming that it has a gloss improvement effect of more than twice that of the conventional method.

[0124] Experiment 2. Vehicle Surface of Experiment comparing static friction coefficients

[0125] After applying a polishing method to correct and restore defects in the paint surface of a typical automobile, a separate body coating agent or wax is applied to provide slipperiness to the paint surface to prevent contaminants from adhering and to reduce friction on the paint surface, thereby reducing the occurrence of scratches. Additionally, HS-Clear Coat, a topcoat for water-based paints, also has a functional aspect in that slipperiness is added as an additive to reduce the static friction coefficient of the surface and provide slickness. However, as time passes, the durability of the slickness weakens due to exposure to ultraviolet rays, and after a certain period, it becomes easier for contaminants to adhere or fine scratches to occur. The hydrophilic coating layer formed on the automobile surface after applying the first polishing agent or the second polishing agent provides slickness and exhibits antifouling properties; an experiment was conducted using a static friction coefficient measuring instrument capable of measuring the static friction coefficient value of the automobile surface. The measuring instrument has a slider (contactor) embedded within the product structure. This slider is made of chrome-plated brass (Hard-cr plated brass) and contacts the measurement surface (sample) to measure the static coefficient of friction (μs). The static coefficient of friction is the force that opposes sliding against each other in parallel directions; as the static coefficient of friction decreases, the slipperiness of the clear coat increases.

[0126] For the experiment, the experiment was conducted on two car surfaces repainted with oil-soluble paint and water-soluble paint, respectively, and the static friction coefficient was measured.

[0128] [Comparative Example 2]

[0129] Before starting the experiment, the static friction coefficient of the oil-based paint vehicle surface is measured. First, in the first step, the oil-based paint vehicle surface is polished by attaching a 5-inch diameter wool pad coated with a compound having an average particle size of 5 to 7㎛ (without using a primary primer compound with strong abrasive particles) to a position 25mm eccentrically offset from the centerline of the polisher's drive axis and rotating it at a speed of 4,000 rpm for 15 minutes. In the second step, the oil-based paint vehicle surface is hydrophilically coated by attaching a 5-inch diameter polyester-based urethane foam pad coated with Finish dark glaze having a particle size of 3 to 5㎛ to a position 25mm eccentrically offset from the centerline of the polisher's drive axis and rotating it at a speed of 3,250 rpm for 10 minutes. After hydrophilic coating, the oil-based paint vehicle surface is dried for 30 minutes. The static friction coefficient of the oil-based paint vehicle surface is measured after drying.

[0131] [Comparative Example 3]

[0132] Before starting the experiment, the static friction coefficient of the water-based paint vehicle surface is measured. First, in the first step, the water-based paint vehicle surface is polished by attaching a 5-inch diameter wool pad coated with a compound having an average particle size of 5 to 7㎛ (without using a primary primer compound with strong abrasive particles) to a position 25mm eccentrically offset from the centerline of the polisher's drive axis and rotating it at a speed of 4,000 rpm for 15 minutes. In the second step, the water-based paint vehicle surface is hydrophilically coated by attaching a 5-inch diameter polyester-based urethane foam pad coated with Finish dark glaze having a particle size of 3 to 5㎛ to a position 25mm eccentrically offset from the centerline of the polisher's drive axis and rotating it at a speed of 3,250 rpm for 10 minutes. After the hydrophilic coating, the water-based paint vehicle surface is dried for 30 minutes. Then, the static friction coefficient of the dried water-based paint vehicle surface is measured.

[0134] [Example 2]

[0135] Before starting the experiment, the static friction coefficient of the oil-soluble paint on the vehicle surface is measured. First, in the first step, to remove defect elements on the vehicle surface, a 5-inch diameter wool pad coated with the first polishing agent having a particle size of 3 to 4 μm is attached at a position 25 mm eccentric from the centerline of the drive shaft of the polisher and rotated at a speed of 4,000 rpm for 15 minutes to polish the defects on the vehicle surface. The defect elements on the oil-soluble paint on the vehicle surface are corrected and restored with a hydrophilic coating film. In the second step, a 5-inch diameter polyester-based urethane foam pad coated with the second polishing agent having a particle size of 1 to 2 μm is attached at a position 25 mm eccentric from the centerline of the drive shaft of the polisher and rotated at a speed of 3,250 rpm for 10 minutes to hydrophilically coat the oil-soluble paint on the vehicle surface. The third step involves attaching a 3-inch diameter microfiber pad coated with the above-mentioned curing agent to a position 10mm eccentric from the centerline of the drive shaft of the polisher and polishing the automobile surface by rotating it at a speed of 2,750 rpm for 7 minutes and 30 seconds. The polished automobile surface is dried for 30 minutes. Then, the static friction coefficient of the dried oil-soluble paint automobile surface is measured.

[0137] [Example 3]

[0138] Before starting the experiment, the static friction coefficient of the water-soluble paint on the vehicle surface is measured. First, in the first step, to remove defect elements on the vehicle surface, a 5-inch diameter wool pad coated with the first polishing agent having a particle size of 3 to 4 μm is attached at a position 25 mm eccentric from the centerline of the drive shaft of the polisher and rotated at a speed of 4,000 rpm for 15 minutes to polish the defects on the water-soluble paint on the vehicle surface. In the second step, a 5-inch diameter polyester-based urethane foam pad coated with the second polishing agent having a particle size of 1 to 2 μm is attached at a position 25 mm eccentric from the centerline of the drive shaft of the polisher and rotated at a speed of 3,250 rpm for 10 minutes to hydrophilically coat the water-soluble paint on the vehicle surface. The third step involves attaching a 3-inch diameter microfiber pad coated with the above-mentioned curing agent to a position 10mm eccentric from the centerline of the drive shaft of the polisher and rotating it at a speed of 2,750 rpm for 7 minutes and 30 seconds to polish the surface of the vehicle coated with the water-soluble paint. The polished surface of the vehicle coated with the water-soluble paint is dried for 30 minutes. Then, the static friction coefficient of the dried surface of the vehicle coated with the water-soluble paint is measured.

[0140] division 1st 2nd 3rd average Comparative Example 2 Static friction coefficient (μs) before experiment 0.459 0.465 0.463 0.462 Static friction coefficient (μs) after Comparative Example 2 experiment 0.328 0.333 0.341 0.334 Comparative Example 2nd difference static friction coefficient (μs) 0.131 0.132 0.122 0.128 Example 2 Static friction coefficient (μs) before experiment 0.454 0.455 0.452 0.454 Static friction coefficient (μs) after Example 2 experiment 0.147 0.148 0.146 0.147 Example 2 Secondary Static Friction Coefficient (μs) 0.307 0.307 0.306 0.307

[0141] As shown in Table 2 and Figure 10, Comparative Example 2 showed a difference of 0.128 μs, with the average static friction coefficient decreasing from 0.462 μs before operation to 0.334 μs after operation. On the other hand, Example 2 showed a difference of 0.307 μs, with the average static friction coefficient decreasing from 0.454 μs before operation to 0.147 μs after operation. This confirms that Example 2 reduces the static friction coefficient more effectively than Comparative Example 2, thereby significantly improving the antifouling effect of the oil-soluble paint on the automotive surface.

[0143] division 1st 2nd 3rd average Comparative Example 3 Static friction coefficient (μs) before experiment 0.392 0.449 0.414 0.418 Coefficient of static friction (μs) after Comparative Example 3 experiment 0.353 0.327 0.325 0.335 Comparative Example 3rd difference static friction coefficient (μs) 0.039 0.122 0.089 0.083 Example 3 Static friction coefficient (μs) before experiment 0.422 0.419 0.421 0.421 Static friction coefficient (μs) after Example 3 experiment 0.223 0.270 0.281 0.258 Example 3 Static friction coefficient (μs) 0.199 0.149 0.140 0.163

[0144] As shown in Table 3 and Figures 11 to 13, Comparative Example 3 showed a difference of 0.083 μs, with the average static friction coefficient decreasing from 0.418 μs before operation to 0.335 μs after operation. On the other hand, Example 3 showed a difference of approximately 0.163 μs, with the average static friction coefficient decreasing from 0.421 μs before operation to 0.258 μs after operation. This confirms that Example 3 reduces the static friction coefficient more effectively than Comparative Example 3, thereby significantly improving the antifouling effect of the water-soluble paint on the automotive surface.

[0146] Experiment 3. water-repellent contact angle Comparison test

[0147] In this experiment, a thin hydrophilic coating layer is formed on the vehicle surface after the application of the first and second polishes. To measure the hydrophobic contact angle—which ultimately exhibits hydrophobicity upon curing—a surface treatment was applied using a solvent-based curing agent and a microfiber pad to impart slickness to the silica hydrophilic coating layer and increase durability. Commercially available filler compounds, the first polish, and the second polish were applied to a 15 cm x 20 cm specimen through a predetermined three-step process. After drying in an oven at a constant temperature (approx. 45°C) and degreasing with IPA (isopropyl alcohol), the coating surface formed on the test specimen was tested using a contact angle measuring instrument. A contact angle measuring instrument is used to measure the angle at which a liquid droplet reaches thermodynamic equilibrium when in contact with a stationary solid surface. This is a technology capable of measuring the surface energy of a material and performing surface treatment or analysis, and is mostly measured using water droplets. The contact angle measurement method involves dropping a water droplet onto the surface of a test specimen and then gradually increasing the amount of liquid through a needle to measure the point where the tip of the droplet meets the solid surface. The scene of contact with the solid surface is captured using a high-resolution lens and an optical system, and the contact angle is calculated by analyzing the image through software. In the experimental method, a water droplet was formed on the tip of a syringe on each of two specimens that had been finished by applying a polishing process using a filled compound, a first polishing agent, and a second polishing agent. The contact angle was then determined by taking four optical images of the side of the droplet to measure accurate data values.

[0149] [Comparative Example 4]

[0150] First, in the first step, a 5-inch diameter wool pad coated with a compound having an average particle size of 5 to 7㎛ is attached to a position 25mm eccentrically offset from the centerline of the drive axis of the polisher without using a primary primer compound with strong abrasive particles, and the surface of the test specimen is polished by rotating it at a speed of 4,000 rpm for 15 minutes. In the second step, a 5-inch diameter polyester-based urethane foam pad coated with a finish dark glaze having a particle size of 3 to 5㎛ is attached to a position 25mm eccentrically offset from the centerline of the drive axis of the polisher and rotated at a speed of 3,250 rpm for 10 minutes to hydrophilically coat the surface of the test specimen. After hydrophilic coating, the surface of the test specimen is dried for 30 minutes. Then, the hydrophobic contact angle of the dried automobile surface is measured.

[0152] [Example 4]

[0153] First, in the first step, to remove defect elements on the surface of the test specimen, a 5-inch diameter wool pad coated with the first polishing agent having a particle size of 3 to 4 μm is attached at a position 25 mm eccentric from the centerline of the drive axis of the polisher and rotated at a speed of 4,000 rpm for 15 minutes to polish the defects on the surface of the test specimen. In the second step, a 5-inch diameter polyester-based urethane foam pad coated with the second polishing agent having a particle size of 1 to 2 μm is attached at a position 25 mm eccentric from the centerline of the drive axis of the polisher and rotated at a speed of 3,250 rpm for 10 minutes to hydrophilically coat the surface of the test specimen. In the third step, a 3-inch diameter microfiber pad coated with the curing agent is attached at a position 10 mm eccentric from the centerline of the drive axis of the polisher and rotated at a speed of 2,750 rpm for 7 minutes and 30 seconds to polish the surface of the test specimen. The surface of the polished test specimen is dried for 30 minutes. Then, the water-repellent contact angle of the dried test specimen surface is measured.

[0155] division Primary contact angle (°) Secondary contact angle (°) Third contact angle (°) 4th contact angle (°) Average contact angle (°) Comparative Example 4 66.438 67.023 65.333 60.440 64.808 Example 4 87.359 90.669 88.692 90.000 89.180

[0156] As shown in Table 4 and Figure 14, the average contact angle of Comparative Example 4 was measured to be 64.808°, while the average contact angle of Example 4 was measured to be 89.180°. This indicates that Example 4 showed a contact angle approximately 24.372° higher than Comparative Example 4, confirming that it significantly improves the hydrophobicity and water-repellent effects of the automobile surface.

[0158] As such, those skilled in the art to which the present invention pertains will understand that the technical configuration of the present invention described above can be implemented in other specific forms without altering the technical concept or essential features of the present invention.

[0159] Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting, and the scope of the invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the invention. Explanation of the symbols

[0161] S-1: Step of polishing defects on the automobile surface using a wool pad coated with the first polishing agent. S-2: Step of hydrophilically coating the automobile surface using a polyester-based urethane foam pad coated with a second gloss agent. S-3: Step of polishing the car surface using a microfiber pad coated with a hardener.

Claims

Claim 1 A method for polishing a painted surface of an automobile, comprising: a first step of polishing defects on the surface of an automobile using a wool pad coated with a first polishing agent; a second step of hydrophilically coating the surface of the automobile using a polyester-based urethane foam pad coated with a second polishing agent after polishing; and a third step of polishing the surface of the automobile using a microfiber pad coated with a curing agent after hydrophilic coating; wherein the polishing in the first step is characterized by attaching the wool pad coated with the first polishing agent to a position eccentrically offset from the centerline of the drive shaft of a polisher and rotating it at a speed of 3,500 to 4,500 rpm for 10 to 20 minutes. Claim 2 A method for polishing an automobile paint surface according to claim 1, wherein the hydrophilic coating of the second step is performed by attaching a polyester-based urethane foam pad coated with the second polishing agent to a position 10 to 30 mm eccentric from the centerline of the drive shaft of a polisher and rotating it at a speed of 3,000 to 3,500 rpm for 5 to 15 minutes. Claim 3 A method for polishing an automobile paint surface according to claim 1, wherein the polishing treatment of the third step is performed by attaching a microfiber pad coated with the curing agent to a position 5 to 15 mm eccentric from the centerline of the drive shaft of the polisher and rotating it at a speed of 2,500 to 3,000 rpm for 5 to 10 minutes. Claim 4 In claim 1, the first polishing agent has a particle size of 3 to 5 μm and comprises, with respect to 55 parts by weight of water, 5 to 15 parts by weight of glycerin, 1 part by weight of triethanolamine, 0.01 parts by weight of sodium hydroxide, 10 to 13 parts by weight of alpha-aluminum oxide, 1 to 5 parts by weight of pajama oil, 1 to 5 parts by weight of paraffin oil, 10 to 20 parts by weight of hydrogenated light refined oil, 5 parts by weight of graphene oxide, 5 parts by weight of silicon carbide, and 5 parts by weight of trimethylsiloxane, and the second polishing agent has a particle size of 1 to 2 μm and comprises, with respect to 60 parts by weight of water, 1 to 10 parts by weight of glycerin, 0.1 parts by weight of morpholine, 0.3 parts by weight of triethanolamine, and 0.1 parts by weight of 1,2-benzoisothiazolin-3-one. A method for polishing an automobile paint surface, characterized in that the curing agent comprises 1 part by weight of castor oil, 5 to 15 parts by weight of aluminum oxide, 15 to 25 parts by weight of hydrodesulfurized light petroleum, 1 to 10 parts by weight of paraffin oil, 1 to 5 parts by weight of dimethylsiloxane, 5 parts by weight of graphite, and 1 part by weight of silica, wherein the curing agent comprises, based on 25 parts by weight of naphtha, 1 to 10 parts by weight of toluene, 1 to 5 parts by weight of isoalkane (C8-10), 1 to 5 parts by weight of isoalkane (C9-11), 5 to 15 parts by weight of vinyltrimethoxysilane, 25 to 35 parts by weight of hydrogenated light refined oil, 10 to 20 parts by weight of trimethoxysilane, 5 parts by weight of graphite, and 1 part by weight of silica. Claim 5 A method for polishing an automobile paint surface according to claim 1, characterized in that the wool pad and the polyester-based urethane foam pad have a diameter of 3 to 5 inches, and the microfiber pad has a diameter of 2.5 to 3.5 inches.

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