Automobile polishing paste and preparation method thereof

Abstract

The present application relates to the technical field of automobile products, and particularly relates to a car polishing paste and a preparation method thereof, which comprises the following components in percentage by weight: agglomerated alumina micro powder 10-20%, solvent oil 15-25%, lubricant 1-5%, corrosion agent 2-4%, antifreezing agent 3-6%, pH regulator 0.3-0.8%, emulsifier 2-8%, defoaming agent 0.1-0.3%, bactericidal preservative 0.1-0.2%, dispersant 0.5-1%, thickening agent 0.8-1.5%, and the rest is deionized water; the preparation method comprises the following steps: (1) preparation of agglomerated alumina micro powder; (2) preparation of oil phase; (3) preparation of water phase; (4) preparation of polishing paste; the polishing paste obtained by processing the formula components according to the above preparation method has high grinding force and polishing brightness, is easy to clean, does not hide the polishing traces, and avoids later repair.

Description

Technical Field

[0001] This invention relates to the field of automotive supplies technology, and in particular to an automotive polishing paste and its preparation method. Background Technology

[0002] During the automotive manufacturing process, fluctuations in paint quality and differences in the substrate can lead to defects such as flow marks, orange peel, and pores in the paint film, affecting its appearance. Furthermore, during use, outdoor exposure can cause an oxidation layer to form on the paint, resulting in sunburst patterns and reducing the paint's gloss. Additionally, dust, twigs, and small stones can cause scratches or abrasions, affecting the vehicle's appearance. Currently, car manufacturers primarily use specialized sanding discs to smooth out these defects, followed by polishing with different grit automotive polishing compound until the desired gloss is achieved. For car owners, these issues are typically addressed by repair shops. The main process usually involves pre-treating with P800, P1200, or P1500 wet sandpaper, followed by sanding with P2000 wet sandpaper until the sandpaper texture is fine. Finally, automotive polishing compound is used for coarse polishing, fine polishing, and mirror-finish restoration. Existing car polishing pastes contain silicone oil, which can fill and cover up minor scratches. It usually remains on the car paint surface. As the silicone oil slowly evaporates, dark car paint is prone to showing signs of wear. Furthermore, when the car paint needs to be recoated, the silicone oil will prevent the paint from spreading evenly on the surface, resulting in serious defects in the paint film.

[0003] Currently, there are many car polishing products on the market, such as polishing wax, polishing compound, and grinding paste. However, most existing polishing compounds are oil-based. For example, the polishing compound disclosed in CN107163860A is not easy to clean with water during actual use and is not suitable for vehicle manufacturers. CN103173129A discloses a paint polishing compound composed of kaolin, first kerosene, first stearic acid, second kerosene, second stearic acid, methylparaben, and propylparaben. This polishing compound is an oil-based polishing compound with excessive powder content, resulting in a lot of dust during use and causing new pollution to the paint surface. Its practicality in vehicle manufacturers is poor. CN109679505A discloses a polishing wax composed of nano-sized alumina powder, petroleum extract, emulsifier, dispersant, thickener, and water. Due to its small particle size, nano-sized alumina powder results in low grinding force. Increasing the powder content does not effectively solve the problem of slow polishing efficiency. It is generally used as a polishing paste for restoring the mirror finish of automotive paint. At the same time, directly adding it to water and stirring it cannot effectively disperse it evenly. Some hard agglomerates cannot be deagglomerated, which can lead to abnormal scratches.

[0004] Existing automotive polishing products are still differentiated by grit size, generally categorized as coarse polishing, fine polishing, and mirror finish restoration. These processes are cumbersome and time-consuming. Furthermore, some automotive polishing pastes use wax and / or silicone, which can easily mask polishing marks on the paint surface, leading to the appearance of sanding lines later. In the field of paint polishing, the key issues that automotive polishing pastes urgently need to address are: the ability to quickly remove moderate and minor scratches on the paint surface, such as scratches caused by P1500 and fine sandpaper; secondly, the paste should not leave polishing marks on the paint surface while imparting a high gloss (high-gloss paint typically has a gloss level of 90 GU or higher); it should also prevent the reappearance of polishing marks after degreasing; the polishing process should produce less dust, be less harmful to the user; and the polishing pad should be easy to clean with minimal pollution. Therefore, it is necessary to develop an automotive polishing paste and its preparation method to address these issues. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide an automotive polishing compound that has high grinding power and polishing brightness, is easy to clean, does not cover up grinding marks, and avoids rework later, in order to address the shortcomings of the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] An automotive polishing compound comprises the following components by weight percentage:

[0008] The composition includes: 10-20% agglomerated alumina micro powder, 15-25% solvent oil, 1-5% lubricant, 2-4% corrosive agent, 3-6% antifreeze, 0.3-0.8% pH adjuster, 2-8% emulsifier, 0.1-0.3% defoamer, 0.1-0.2% bactericide and preservative, 0.5-1% dispersant, 0.8-1.5% thickener, and the balance being deionized water.

[0009] The particle size D50 of the agglomerated alumina micro powder is 15-25 μm;

[0010] The corrosive agent is a mixture of refined turpentine oil, tributyl acetyl citrate, and chlorinated paraffin in a mass ratio of 1-2:1:1.

[0011] The antifreeze is at least one of ethylene glycol, propylene glycol, and glycerin;

[0012] The emulsifier is sodium dodecyl diphenyl ether disulfonate; or a mixture of Tween 80, Span 80, and sulfonated castor oil in a mass ratio of 3:2:1-1.5; or a mixture of Tween 80, polyether L61, and sulfonated castor oil in a mass ratio of 4:2:1-1.5; or a mixture of AEO9, AEO3, and sulfonated castor oil in a mass ratio of 2:2:1-1.5.

[0013] The bactericidal and preservative agent is a mixture of ACTI CIDE RS and ACTI CIDE HF in a mass ratio of 1:1; or a mixture of MERGAL 786 and MERGAL K9N in a mass ratio of 1:2.

[0014] As an improved technical solution, the solvent oil is a petroleum distillate, and the solvent oils D40, D60, and D80 are mixed in a mass ratio of 1:1.5-2:1.5-2; the pH adjuster is sodium hydroxide, ammonia, triethanolamine, or 2-amino-2-methyl-1-propanol; and the dispersant is a polyacrylate dispersant.

[0015] As an improved technical solution, the thickener is an alkali-swellable acrylic emulsion.

[0016] The second technical problem to be solved by the present invention is to provide a method for preparing automotive polishing paste, which addresses the shortcomings of the prior art. This method can produce polishing paste with high grinding power, high polishing brightness, easy cleaning, and does not cover up grinding marks, thus avoiding rework in the later stages.

[0017] A method for preparing automotive polishing compound, the method comprising the following steps:

[0018] (1) Preparation of agglomerated alumina micro powder: Take 4N alumina micro powder with D50 of 1-1.5μm and D90 of less than 3μm, add deionized water and grind, control the grinding time, stop grinding when D50 is 0.1-0.2μm, filter, add aluminum sol to the slurry, stir and mix, spray dry and granulate, and age to obtain agglomerated alumina micro powder with D50 of 15-25μm;

[0019] (2) Preparation of oil phase: The solvent oil, lubricant and corrosive agent are mixed evenly in sequence according to the weight percentage to obtain the oil phase;

[0020] (3) Preparation of aqueous phase: Deionized water was taken according to the weight percentage, and bactericide, preservative, emulsifier and defoamer were added in sequence under stirring. The mixture was stirred and mixed to obtain the aqueous phase.

[0021] (4) Preparation of grinding paste: The oil phase of step (2) is added to the aqueous phase of step (3) in sequence. The stirring speed and stirring time are controlled. After stirring and mixing, antifreeze, dispersant and pH adjuster are added. After stirring and mixing, the agglomerated alumina micro powder in step (1) is added and stirred. After adding thickener, stirring is continued to obtain the grinding paste product.

[0022] As an improved technical solution, in step (1), 4N alumina micro powder and deionized water are mixed in a mass ratio of 1:3; a 3000-mesh filter is used for filtration, and the grinding time is controlled to be 2-4 hours.

[0023] As an improved technical solution, the solid content of the aluminum sol solution in step (1) is 25-35 wt%, and the slurry and aluminum sol are mixed in a mass ratio of 1-1.5:1.

[0024] As an improved technical solution, the spray drying granulation speed is 20,000-30,000 rpm, the feeding speed is 100-150 mL / min, the inlet air temperature is 160-220℃, and the exhaust air temperature is 80-120℃.

[0025] As an improved technical solution, after granulation in step (1), the collected agglomerated alumina micro powder is placed in an oven at 200-260℃ for 36-48h.

[0026] As an improved technical solution, in step (4), the oil phase is added to the aqueous phase. First, the stirring speed is controlled at 600-800 rpm. After the solution becomes a milky white liquid, the speed is increased to 900-1100 rpm, and the stirring time is controlled at 25-35 min.

[0027] As an improved technical solution, after adding agglomerated alumina powder in step (4), the thickener is added after stirring for 8-15 minutes, the stirring speed is controlled at 1300-1500 rpm, and the stirring time is controlled at 40-60 minutes.

[0028] After adopting the above technical solution, the beneficial effects of the present invention are:

[0029] In the initial polishing stage of this invention, the agglomerated alumina silica powder in the polishing paste can exert the grinding force of large abrasive particles to quickly repair the sanding marks of wet sandpaper. Simultaneously, during the polishing process, the agglomerated alumina micropowder continuously breaks down, and the resulting smaller abrasive particles can further repair the grinding marks of the larger particles. This continues until the agglomerated alumina micropowder is completely broken down, releasing nano-sized abrasive particles that repair the polished paint surface, resulting in a high-gloss finish. During the agglomerated alumina micropowder breakdown process, the dried aluminum sol has low hardness and will not cause new scratches to the paint surface. Furthermore, due to its low hardness, it has a certain repairing effect during polishing, working synergistically with the micropowder to repair scratches on the paint surface and achieve a high-gloss finish.

[0030] The automotive polishing compound of this invention comprises 10-20% agglomerated alumina micro powder, 15-25% solvent oil, 1-5% lubricant, 2-4% corrosive agent, 3-6% antifreeze, 0.3-0.8% pH adjuster, 2-8% emulsifier, 0.1-0.3% defoamer, 0.1-0.2% bactericide and preservative, 0.5-1% dispersant, 0.8-1.5% thickener, and the balance being deionized water. The above-mentioned components and their dosages are formulated through extensive experimental screening. This formula does not contain silicone oil and is suitable for both OEMs and the aftermarket. It does not cover polished areas, reducing rework issues caused by sanding marks. The corrosive agent provides slight finishing to the paint surface, working synergistically with the polishing particles to accelerate the repair of sanding marks and produce a high-gloss paint surface.

[0031] The preparation method of this invention uses 4N alumina micro powder with a D50 of 1-1.5 μm and a D90 of less than 3 μm as raw material. After grinding with deionized water, aluminum sol is added, and the mixture is stirred, spray-dried, granulated, and then aged to obtain agglomerated alumina micro powder. This operation obtains nano-sized alumina micro powder through sand milling, and then granulates the nano-sized alumina micro powder to form large-particle micro powder, achieving the grinding efficiency of large particles while retaining the grinding effect of small particles. This results in high cutting force and high gloss on the polished surface, achieving a three-in-one effect. Then, an oil phase and an aqueous phase are prepared sequentially, and the oil and aqueous phases are mixed. Finally, micro powder and a thickener are added and stirred to obtain a polishing paste. This preparation method has simple process steps, is easy to operate, and can produce polishing paste with high grinding force, high polishing gloss, and easy cleaning. It does not conceal grinding marks and avoids the need for rework later. Attached Figure Description

[0032] Figure 1 This is an electron microscope image of the agglomerated alumina micropowder in Example 3 of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] Example 1

[0035] An automotive polishing compound comprises the following components by weight percentage:

[0036] D50 consists of 10% agglomerated alumina micropowder (15-25μm), 15% solvent oil (a mixture of D40, D60, and D80 in a mass ratio of 1:1.5:1.5), 1% lubricant (10# white oil), 2% corrosion inhibitor (a mixture of refined turpentine, tributyl acetylacetonate, and chlorinated paraffin in a mass ratio of 1:1:1), 3% antifreeze (ethylene glycol), 0.3% pH adjuster (sodium hydroxide), 2% emulsifier (sodium dodecyl diphenyl ether disulfonate), 0.1% defoamer (non-silicone defoamer - FoamStar ST 2410), 0.1% bactericide and preservative (a mixture of ACT ICIDE RS and ACTI CIDE HF in a mass ratio of 1:1), and 0.5% dispersant (polyacrylate dispersant OROTAN). 731A), thickener 1.5% (alkali-swellable acrylic emulsion), balance deionized water;

[0037] Its preparation method includes the following steps:

[0038] (1) Preparation of agglomerated alumina micro powder: 4N alumina micro powder with D50 of 1-1.5μm and D90 of less than 3μm was mixed with deionized water at a mass ratio of 1:3 and ground for 2 hours. When D50 was 0.1-0.2μm, the grinding was stopped and filtered with a 3000-mesh filter. The resulting slurry was mixed with aluminum sol with a solid content of 25wt% at a mass ratio of 1:1. After stirring and mixing, the mixture was spray-dried and granulated (rotation speed of 20000 rpm, feed rate of 100mL / min, air inlet temperature of 160℃, and air outlet temperature of 80℃). The collected agglomerated alumina micro powder was placed in a 200℃ oven and aged for 36 hours to obtain agglomerated alumina micro powder with D50 of 15-25μm.

[0039] (2) Preparation of oil phase: The solvent oil, lubricant and corrosive agent are mixed evenly in sequence according to the weight percentage to obtain the oil phase;

[0040] (3) Preparation of aqueous phase: Deionized water was taken according to the weight percentage, and bactericide, preservative, emulsifier and defoamer were added in sequence under stirring. The mixture was stirred and mixed to obtain the aqueous phase.

[0041] (4) Preparation of grinding paste: The oil phase of step (2) is added to the aqueous phase of step (3) in sequence. First, the stirring speed is controlled at 600 rpm. When the solution becomes a milky white liquid, the speed is increased to 900 rpm and the stirring time is controlled at 25 min. After stirring and mixing, antifreeze, dispersant and pH adjuster are added. After stirring and mixing, the agglomerated alumina micro powder in step (1) is added and stirred for 8 min. Then, thickener is added and stirring is continued. The stirring speed is controlled at 1300 rpm and stirred for 40 min to obtain the grinding paste product.

[0042] Example 2

[0043] An automotive polishing compound comprises the following components by weight percentage:

[0044] D50 consists of 13% alumina microparticles (15-25μm), 18% solvent oil (a mixture of D40, D60, and D80 in a mass ratio of 1:1.7:1.7), 2% lubricant (15# white oil), 2.5% corrosion inhibitor (a mixture of refined turpentine, tributyl acetylacetonate, and chlorinated paraffin in a mass ratio of 1.3:1:1), 4% antifreeze (propylene glycol), 0.4% pH adjuster (ammonia), 3.5% emulsifier (a mixture of Tween 80, Span 80, and sulfonated castor oil in a mass ratio of 3:2:1), 0.15% defoamer (Nopco NXZ), 0.15% bactericide and preservative (a mixture of MERGAL 786 and MERGAL K9N in a mass ratio of 1:2), and 0.6% dispersant (a polyacrylate dispersant, AFCONA). 4595), thickener 1.25% (alkali-swellable acrylic emulsion), balance deionized water;

[0045] Its preparation method includes the following steps:

[0046] (1) Preparation of agglomerated alumina micro powder: 4N alumina micro powder with D50 of 1-1.5μm and D90 of less than 3μm was mixed with deionized water at a mass ratio of 1:3 and ground for 2-4 hours. When D50 was 0.1-0.2μm, the grinding was stopped and filtered with a 3000-mesh filter. The resulting slurry was mixed with aluminum sol with a solid content of 28wt% at a mass ratio of 1.2:1. After stirring and mixing, the mixture was spray-dried and granulated (rotation speed of 23000 rpm, feed rate of 120mL / min, air inlet temperature of 180℃, air outlet temperature of 90℃). The collected agglomerated alumina micro powder was placed in an oven at 215℃ and aged for 40 hours to obtain agglomerated alumina micro powder with D50 of 15-25μm.

[0047] (2) Preparation of oil phase: The solvent oil, lubricant and corrosive agent are mixed evenly in sequence according to the weight percentage to obtain the oil phase;

[0048] (3) Preparation of aqueous phase: Deionized water was taken according to the weight percentage, and bactericide, preservative, emulsifier and defoamer were added in sequence under stirring. The mixture was stirred and mixed to obtain the aqueous phase.

[0049] (4) Preparation of grinding paste: The oil phase of step (2) is added to the aqueous phase of step (3) in sequence. First, the stirring speed is controlled at 650 rpm. When the solution becomes a milky white liquid, the speed is increased to 950 rpm and the stirring time is controlled at 28 min. After stirring and mixing, antifreeze, dispersant and pH adjuster are added. After stirring and mixing, the agglomerated alumina micro powder in step (1) is added and stirred for 10 min. Then, thickener is added and stirring is continued. The stirring speed is controlled at 1350 rpm and stirred for 45 min to obtain the grinding paste product.

[0050] Example 3

[0051] An automotive polishing compound comprises the following components by weight percentage:

[0052] D50 consists of 15% alumina microparticles (15-25μm), 20% solvent oil (a mixture of D40, D60, and D80 in a mass ratio of 1:1.8:1.8), 3% lubricant (26# white oil), 3% corrosion inhibitor (a mixture of refined turpentine, tributyl acetylacetonate, and chlorinated paraffin in a mass ratio of 1.5:1:1), 4% antifreeze (glycerin), 0.5% pH adjuster (triethanolamine or 2-amino-2-methyl-1-propanol), 4% emulsifier (a mixture of Tween 80, polyether L61, and sulfonated castor oil in a mass ratio of 4:2:1), 0.2% defoamer (non-silicone defoamer - FoamStar ST 2410), and 0.18% bactericide and preservative (ACTICIDE RS and ACTI CIDE). The mixture consists of HF in a 1:1 mass ratio, 0.8% dispersant (Synopco SN5040), 1.1% thickener (alkali-swellable acrylic emulsion), and the remainder is deionized water.

[0053] Its preparation method includes the following steps:

[0054] (1) Preparation of agglomerated alumina micro powder: 4N alumina micro powder with D50 of 1-1.5μm and D90 of less than 3μm was mixed with deionized water at a mass ratio of 1:3 and ground for 3 hours. When D50 was 0.1-0.2μm, the grinding was stopped and filtered with a 3000-mesh filter. The resulting slurry was mixed with aluminum sol with a solid content of 30wt% at a mass ratio of 1.3:1. After stirring and mixing, the mixture was spray-dried and granulated (rotation speed of 25000 rpm, feed rate of 135mL / min, air inlet temperature of 200℃, air outlet temperature of 100℃). The collected agglomerated alumina micro powder was placed in a 230℃ oven for 42 hours to obtain agglomerated alumina micro powder with D50 of 15-25μm.

[0055] (2) Preparation of oil phase: The solvent oil, lubricant and corrosive agent are mixed evenly in sequence according to the weight percentage to obtain the oil phase;

[0056] (3) Preparation of aqueous phase: Deionized water was taken according to the weight percentage, and bactericide, preservative, emulsifier and defoamer were added in sequence under stirring. The mixture was stirred and mixed to obtain the aqueous phase.

[0057] (4) Preparation of grinding paste: The oil phase of step (2) is added to the aqueous phase of step (3) in sequence. First, the stirring speed is controlled at 700 rpm. When the solution becomes a milky white liquid, the speed is increased to 1000 rpm and the stirring time is controlled at 30 min. After stirring and mixing, antifreeze, dispersant and pH adjuster are added. After stirring and mixing, the agglomerated alumina micro powder in step (1) is added and stirred for 12 min. After adding thickener, stirring is continued. The stirring speed is controlled at 1400 rpm and stirred for 50 min to obtain the grinding paste product.

[0058] Example 4

[0059] An automotive polishing compound comprises the following components by weight percentage:

[0060] D50 consists of 18% agglomerated alumina micropowder (15-25μm), 22% solvent oil (a mixture of D40, D60, and D80 in a mass ratio of 1:1.9:1.8), 4% lubricant (15# white oil), 3.5% corrosion inhibitor (a mixture of refined turpentine, tributyl acetylacetonate, and chlorinated paraffin in a mass ratio of 1.8:1:1), 5% antifreeze (propylene glycol), 0.6% pH adjuster (2-amino-2-methyl-1-propanol), 2-8% emulsifier (a mixture of AEO9, AEO3, and sulfonated castor oil in a mass ratio of 2:2:1.2), 0.25% defoamer (non-silicone defoamer - FoamStar ST 2410), and 0.18% bactericide and preservative (ACTICIDE RS and ACTICIDE). The mixture consists of HF in a 1:1 mass ratio, 0.8% dispersant (OROTAN 731A polyacrylate dispersant), 1% thickener (alkali-swellable acrylic emulsion), and the remainder is deionized water.

[0061] Its preparation method includes the following steps:

[0062] (1) Preparation of agglomerated alumina micro powder: 4N alumina micro powder with D50 of 1-1.5μm and D90 of less than 3μm was mixed with deionized water at a mass ratio of 1:3 and ground for 3.5h. When D50 was 0.1-0.2μm, the grinding was stopped and filtered with a 3000 mesh filter. The resulting slurry was mixed with aluminum sol with a solid content of 32wt% at a mass ratio of 1.4:1. After stirring and mixing, it was spray-dried and granulated (rotation speed of 28000 rpm, feed rate of 140mL / min, air inlet temperature of 210℃, air outlet temperature of 110℃). The collected agglomerated alumina micro powder was placed in an oven at 245℃ and aged for 46h to obtain agglomerated alumina micro powder with D50 of 15-25μm.

[0063] (2) Preparation of oil phase: The solvent oil, lubricant and corrosive agent are mixed evenly in sequence according to the weight percentage to obtain the oil phase;

[0064] (3) Preparation of aqueous phase: Deionized water was taken according to the weight percentage, and bactericide, preservative, emulsifier and defoamer were added in sequence under stirring. The mixture was stirred and mixed to obtain the aqueous phase.

[0065] (4) Preparation of grinding paste: The oil phase of step (2) is added to the aqueous phase of step (3) in sequence. First, the stirring speed is controlled at 750 rpm. When the solution becomes a milky white liquid, the speed is increased to 1050 rpm and the stirring time is controlled at 32 min. After stirring and mixing, antifreeze, dispersant and pH adjuster are added. After stirring and mixing, the agglomerated alumina micro powder in step (1) is added and stirred for 13 min. After adding thickener, stirring is continued. The stirring speed is controlled at 1450 rpm and stirred for 55 min to obtain the grinding paste product.

[0066] Example 5

[0067] An automotive polishing compound comprises the following components by weight percentage:

[0068] D50 consists of 20% agglomerated alumina micropowder (15-25μm), 25% solvent oil (a mixture of D40, D60, and D80 in a mass ratio of 1:2:2), 5% lubricant (10# white oil), 4% corrosion inhibitor (a mixture of refined turpentine, tributyl acetylacetonate, and chlorinated paraffin in a mass ratio of 2:1:1), 6% antifreeze (ethylene glycol), 0.8% pH adjuster (triethanolamine), 8% emulsifier (a mixture of AEO9, AEO3, and sulfonated castor oil in a mass ratio of 2:2:1.5), 0.3% defoamer (a non-silicone defoamer - FoamStar ST 2410), 0.2% bactericide and preservative (a mixture of MERGAL 786 and MERGAL K9N in a mass ratio of 1:2), and 1% dispersant (a polyacrylate dispersant - OROTAN). 731A), thickener 0.8% (alkali-swellable acrylic emulsion), balance deionized water;

[0069] Its preparation method includes the following steps:

[0070] (1) Preparation of agglomerated alumina micro powder: 4N alumina micro powder with D50 of 1-1.5μm and D90 of less than 3μm was mixed with deionized water at a mass ratio of 1:3 and ground for 4 hours. When D50 was 0.1-0.2μm, the grinding was stopped and filtered with a 3000-mesh filter. The resulting slurry was mixed with aluminum sol with a solid content of 35wt% at a mass ratio of 1.5:1. After stirring and mixing, the mixture was spray-dried and granulated (rotation speed of 30000 rpm, feed rate of 150mL / min, air inlet temperature of 220℃, air outlet temperature of 120℃). The collected agglomerated alumina micro powder was placed in a 260℃ oven for aging for 48 hours to obtain agglomerated alumina micro powder with D50 of 15-25μm.

[0071] (2) Preparation of oil phase: The solvent oil, lubricant and corrosive agent are mixed evenly in sequence according to the weight percentage to obtain the oil phase;

[0072] (3) Preparation of aqueous phase: Deionized water was taken according to the weight percentage, and bactericide, preservative, emulsifier and defoamer were added in sequence under stirring. The mixture was stirred and mixed to obtain the aqueous phase.

[0073] (4) Preparation of grinding paste: The oil phase of step (2) is added to the aqueous phase of step (3) in sequence. First, the stirring speed is controlled at 800 rpm. When the solution becomes a milky white liquid, the speed is increased to 1100 rpm and the stirring time is controlled at 35 min. After stirring and mixing, antifreeze, dispersant and pH adjuster are added. After stirring and mixing, the agglomerated alumina micro powder in step (1) is added and stirred for 15 min. Then, thickener is added and stirring is continued. The stirring speed is controlled at 1500 rpm and stirred for 60 min to obtain the grinding paste product.

[0074] To better demonstrate that the preparation method of the present invention can produce polishing paste products with high grinding force and high polishing brightness, two comparative examples are given with reference to Example 3. The performance indicators of the polishing pastes of Examples 1-5 and the comparative examples are detailed in Table 1.

[0075] Comparative Example 1

[0076] Unlike Example 3, the formulation of this invention contains alumina micro powder with a D50 of 5 μm, and this alumina micro powder is not processed in step (1) of the preparation method; the rest of the operations are the same.

[0077] Comparative Example 2

[0078] Unlike Example 3, step (1) of the preparation method does not involve aging, while the rest of the operations are the same.

[0079] Comparative Example 3

[0080] Unlike Example 3, the preservatives added to the formulation of the present invention do not contain acetylated tributyl citrate and chlorinated paraffin, while the rest of the operation is the same.

[0081] Table 1

[0082]

[0083] The data in Table 1 show that the performance of the polishing paste prepared by the method of the present invention is better than that of comparative examples 1-3.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automotive polishing paste, characterized by, According to the weight percentage, the following components are included: Agglomerated alumina powder 10-20%, solvent oil 15-25%, lubricant 1-5%, corrosion agent 2-4%, antifreeze 3-6%, pH regulator 0.3-0.8%, emulsifier 2-8%, defoaming agent 0.1-0.3%, bactericidal preservative 0.1-0.2%, dispersant 0.5-1%, thickening agent 0.8-1.5%, and the balance is deionized water; The particle size D50 of the agglomerated alumina powder is 15-25 μm; The corrosion agent is mixed by refined turpentine oil, acetyl tri-butyl citrate and chlorinated paraffin in a mass ratio of 1-2:1:1; The antifreeze is at least one of ethylene glycol, propylene glycol and glycerol; The emulsifier is sodium dodecyl diphenyl ether disulfonate; or a mixture of Tween 80, Span 80 and sulfonated castor oil in a mass ratio of 3:2:1-1.5; or a mixture of Tween 80, polyether L61 and sulfonated castor oil in a mass ratio of 4:2:1-1.5; or a mixture of AEO9, AEO3 and sulfonated castor oil in a mass ratio of 2:2:1-1.5; The bactericidal preservative is a mixture of ACTICIDE RS and ACTICIDE HF in a mass ratio of 1:1; or a mixture of MERGAL 786 and MERGAL K9N in a mass ratio of 1:2; The preparation method of the automobile polishing paste comprises the following steps: (1) Preparation of agglomerated alumina powder: take 4N alumina powder with D50 of 1-1.5 μm and D90 of less than 3 μm, add deionized water and grind, control the grinding time, stop grinding when D50 is 0.1-0.2 μm, filter, add aluminum sol to the obtained slurry, stir and mix uniformly, then spray drying and granulation, after granulation, put the collected agglomerated alumina powder in an oven at 200-260℃ for aging for 36-48h, to obtain agglomerated alumina powder with D50 of 15-25 μm; (2) Preparation of oil phase: mix solvent oil, lubricant and corrosion agent in sequence according to weight percentage, to obtain oil phase; (3) Preparation of water phase: take deionized water, under stirring, add bactericidal preservative, emulsifier and defoaming agent in sequence, continue to stir and mix, to obtain water phase; (4) Preparation of polishing paste: add oil phase of step (2) into water phase of step (3) in sequence, control stirring speed and stirring time, after stirring and mixing, add antifreeze, dispersant and pH regulator, continue to stir and mix, then add agglomerated alumina powder of step (1), stir, then add thickening agent and continue to stir, to obtain polishing paste product.

2. The automobile polishing paste according to claim 1, wherein The solvent oil is petroleum distillate, the solvent oil D40, D60 and D80 are mixed in a mass ratio of 1:1.5-2:1.5-2; the pH regulator is sodium hydroxide, ammonia water, triethanolamine or 2-amino-2-methyl-1-propanol; the dispersant is polyacrylate dispersant.

3. The automobile polishing paste according to claim 1, wherein The thickening agent is alkali-swellable acrylic emulsion.

4. The automobile polishing paste according to claim 1, wherein The 4N aluminum oxide powder and deionized water are mixed in a mass ratio of 1:3 in step (1); a 3000-mesh filter is used for filtration, and the grinding time is controlled to be 2-4 h.

5. The automobile polishing paste according to claim 1, wherein The solid content of the aluminum sol solution in step (1) is 25-35 wt%, and the slurry and the aluminum sol are mixed in a mass ratio of 1-1.5:

1.

6. The automobile polishing paste according to claim 1, wherein The rotation speed during the spray drying granulation in step (1) is 20,000-30,000 rpm, the feeding speed is 100-150 mL / min, the air inlet temperature is 160-220 ℃, and the air outlet temperature is 80-120 ℃.

7. The automobile polishing paste according to claim 1, wherein The oil phase is added to the water phase in step (4), and the stirring speed is first controlled to be 600-800 rpm; after the solution becomes a milky white liquid, the stirring speed is increased to 900-1,100 rpm, and the stirring time is controlled to be 25-35 min.

8. The automobile polishing paste according to claim 1, wherein After the agglomerated aluminum oxide powder is added in step (4), the thickening agent is added after stirring for 8-15 min, the stirring speed is controlled to be 1,300-1,500 rpm, and the stirring time is controlled to be 40-60 min.

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