Conductive black-base coating capable of being subjected to laser etching as well as preparation method and application of conductive black-base coating

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a laser-engravable conductive black base coating and a preparation method and application thereof.The laser-engravable conductive black base coating is prepared from, by weight, 30-40 parts of hydroxy acrylic resin, 1-5 parts of polyester resin, 5-10 parts of CAB resin, 1-5 parts of dispersing agent, 0.5-1 part of anti-settling aid, 1-5 parts of conductive carbon black and 10-15 parts of filler. 20-40 parts of a solvent and 0-1 part of a leveling agent; the conductive carbon black is obtained by sequentially treating carbon black with an acid solution, an alkali solution and a metal salt solution and calcining. Compared with the prior art, the problems that in the prior art, after coating laser etching, blistering is likely to happen, a base material is likely to be damaged, the conductivity of the coating is poor, and electrostatic spraying is not likely to happen are solved. The primer provided by the invention has laser etching performance and conductivity, can meet electrostatic spraying, and can save the waste of paint during construction in the field of automobile bulky parts.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and in particular relates to a laser-engraving conductive black-bottom coating, a preparation method thereof, and an application thereof. Background Art

[0002] A coating is applied to the surface of an object to be protected or decorated and can form a continuous film firmly adhered to the object to be coated. The application of coatings is very extensive. They can be applied to the surface of objects by different construction processes to form a solid film with firm adhesion, certain strength, and continuity, covering all aspects of residents' lives.

[0003] With the continuous progress of society and the improvement of living standards and ecological balance requirements, people's appearance requirements for related electronic products such as home appliances and new energy vehicles are increasing day by day. The laser-engraving process is a kind of surface treatment process, similar to screen printing, pad printing, etc. It is used to print words or patterns on products. However, compared with them, laser engraving has the advantages of fast marking speed, beautiful image marking, high resolution, never wearing, wide range, safe and reliable, high precision, consistent effect, high speed, low cost, and strong anti-counterfeiting. Based on this, the combination of the laser-engraving process and coatings has also begun to be applied in fields such as home appliances and automobiles.

[0004] For example, CN117986907A discloses a high-covering PP conductive light-transmitting primer coating, a preparation method thereof, and an application thereof, including the following components in percentage by weight: 20-40% of acrylic acid-modified polyolefin resin, 10-20% of acrylic resin, 2-6% of adhesion promoter, 15-30% of titanium dioxide, 1-4% of conductive carbon black, 1-4% of wetting and dispersing agent, 0.2-0.8% of anti-settling agent, 0.2-0.6% of leveling agent, and 20-40% of solvent. Among them, the acrylic resin is one of 2-phenoxyethyl acrylate, ethoxyethoxy acrylate, and ethoxylated bisphenol A dimethacrylate; the adhesion promoter is a modified chlorinated polyolefin and a high-molecular compound without polysiloxane; the solvent is a mixture of toluene, xylene, propylene glycol methyl ether acetate, ethyl ethoxypropionate, and butyl acetate. However, at present, the coatings on the market are prone to problems such as foaming and easy damage to the substrate after laser engraving, and the performance test also fails to meet the requirements. At the same time, the conductivity of the coatings is poor (high resistance), and it is difficult to achieve simple and rapid spraying through electrostatic spraying and other forms. In this regard, it is necessary to develop a coating that can meet the requirements of laser engraving and has excellent conductivity. Summary of the Invention

[0005] The object of the present invention is to provide a laser-engravable conductive black bottom coating, its preparation method and application to solve at least one of the above problems, so as to solve the problems in the prior art that the coating is prone to blistering and substrate damage after laser engraving, and the coating has poor conductivity and is not easy to electrostatic spraying. The primer of the present invention has laser-engraving performance while taking into account its conductivity, can meet electrostatic spraying, and can save coating waste during construction in the field of large automotive parts.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] The present invention discloses a laser-engravable conductive black bottom coating in the first aspect, which comprises the following components in parts by weight: 30-40 parts of hydroxyl acrylic resin, 1-5 parts of polyester resin, 5-10 parts of CAB resin, 1-5 parts of dispersant, 0.5-1 part of anti-settling agent, 1-5 parts of conductive carbon black, 10-15 parts of filler, 20-40 parts of solvent, 0-1 part of leveling agent;

[0008] The conductive carbon black is obtained by treating carbon black with acid solution, alkali solution and metal salt solution in sequence and then calcining.

[0009] Preferably, it comprises the following components in parts by weight: 40 parts of hydroxyl acrylic resin, 2.5 parts of polyester resin, 5 parts of CAB resin, 4 parts of dispersant, 0.5 part of anti-settling agent, 4 parts of conductive carbon black, 11 parts of filler, 37.8 parts of solvent, 0.2 part of leveling agent.

[0010] Preferably, the hydroxyl acrylic resin is an acrylic resin with a low hydroxyl content, the polyester resin is a polyester polyol with a high hydroxyl content, and the CAB resin is a 20% solid content cellulose acetate butyrate resin solution.

[0011] Preferably, the dispersant is a high molecular weight non-ionic dispersant, and the anti-settling agent is fumed silica.

[0012] Preferably, the conductive carbon black is prepared by the following method:

[0013] ① Mix carbon black with sulfuric acid solution and stir evenly, stand at high temperature, then filter and wash to neutral, and dry to obtain intermediate A;

[0014] ② Mix intermediate A with sodium hydroxide solution and stir evenly, stand at room temperature, then filter and wash to neutral, and dry to obtain intermediate B;

[0015] ③ Mix intermediate B with metal sulfate solution and stir evenly, stand at room temperature, then filter and wash to neutral, and dry to obtain intermediate C;

[0016] ④ Calcinate intermediate C to obtain the conductive carbon black.

[0017] Preferably, the conductive carbon black is prepared by the following method:

[0018] ① Mix carbon black with 5 mol / L sulfuric acid solution in a ratio of 1 g:1 mL and stir evenly. Let it stand for 24 h at 50 - 60 °C, then filter and rinse with deionized water until neutral, and dry to obtain intermediate A;

[0019] ② Mix intermediate A with 10 mol / L sodium hydroxide solution in a ratio of 1 g:1 mL and stir evenly. Let it stand for 24 h at room temperature, then filter and rinse with deionized water until neutral, and dry to obtain intermediate B;

[0020] ③ Mix intermediate B with 1 mol / L copper sulfate solution and 0.5 mol / L aluminum sulfate solution in a ratio of 2 g:1 mL:1 mL and stir evenly. Let it stand for 24 h at room temperature, then filter and rinse with deionized water until neutral, and dry to obtain intermediate C;

[0021] ④ Calcinate intermediate C at 1000 °C for 1 - 2 h to obtain the conductive carbon black.

[0022] Preferably, the filler is barium sulfate and calcium carbonate.

[0023] Preferably, the solvent is one or more of isobutyl acetate, propylene glycol methyl ether acetate, and diacetone alcohol.

[0024] The second aspect of the present invention discloses a preparation method of a laser - engraving conductive black - bottom coating as described above, including the following steps:

[0025] S1: Add hydroxyl acrylic resin, polyester resin, and dispersant to part of the solvent in sequence, and mix evenly under stirring;

[0026] S2: Continuously add conductive carbon black, anti - settling agent, and filler under stirring, stir evenly, and grind through a sand mill until the fineness is not higher than 15 μm;

[0027] S3: Then add CAB resin solution, leveling agent, and the remaining solvent in sequence and stir evenly to obtain the laser - engraving conductive black - bottom coating.

[0028] The third aspect of the present invention discloses an application of a laser - engraving conductive black - bottom coating as described above in the fields of automobiles and household appliances.

[0029] The present invention selects self - made highly conductive and light - shielding conductive carbon black and high - hardness and low - hydroxyl acrylic resin. Compared with the prior art, it has the following beneficial effects:

[0030] (1) The primer of the present invention is applicable to a variety of plastic materials;

[0031] (2) It is conductive and has very low resistance, making it suitable for electrostatic spraying construction;

[0032] (3) The paint film can be laser engraved. The laser engraved area does not emit fog and has high transparency, which can meet customers' diverse appearance requirements;

[0033] (4) Good adhesion to the substrate, excellent resistance to water, high pressure water washing, high temperature and high humidity, etc.

[0034] In summary, compared with the technologies currently disclosed on the market, the conductive black matrix of the present invention has good wettability during construction, and its lower resistance can greatly improve the adsorption rate of color paint and varnish, and can reduce the waste of paint; it has excellent adhesion and can be applied to various plastic substrates such as ABS / ABS+PC / PC / PMMA / PN; at the same time, the conductive black matrix is ​​laser-engravable, which can meet the current customer needs for various patterns, fonts and other appearances of parts such as automobiles and home appliances; the conductive black matrix of the present invention has high covering power and can also be applied to various transparent substrates. The laser-engraved area does not fog and has high transparency, and at the same time meets the two-coating and three-coating processes. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to specific embodiments, but this is by no means a limitation of the present invention.

[0036] Hydroxyl acrylic resin: commercially available domestic KN1055F or WXU-880 from DIC (Di Ai Sheng) of Japan,

[0037] Polyester resin: commercially available SETAL 168SS-80,

[0038] CAB resin: commercially available Eastman CAB-381-0.5,

[0039] Dispersant: Commercially available BASF EFKA PX 4310,

[0040] Anti-settling agent: Evonik AEROSIL 380,

[0041] Conductive carbon black: The laboratory-made superconductive carbon black has super conductivity and is used in the field of coatings. It is easy to disperse and grind to obtain a paint film with high hiding power. At the same time, it has strong light absorption during the laser engraving process, which can improve the efficiency of laser engraving and will not leave paint on the material, causing problems such as edge jaggedness. The preparation method of the homemade superconductive carbon black includes:

[0042] ① Mix 100g of carbon black and 100mL of sulfuric acid solution (5mol / L) and stir evenly, let stand at 50-60°C for 24h, filter the mixture with filter paper, rinse with deionized water until neutral, and dry to obtain intermediate A;

[0043] ② Mix 90 g of the prepared intermediate A with 90 mL of sodium hydroxide solution (10 mol / L), stir evenly, let stand at room temperature for 24 h, filter the mixture using filter paper, and rinse with deionized water until neutral. After drying, intermediate B is obtained.

[0044] ③ Mix 80 g of the prepared intermediate B with 40 mL of copper sulfate solution (1 mol / L) and 40 mL of aluminum sulfate solution (0.5 mol / L), stir evenly, let stand at room temperature for 24 h, filter the mixture using filter paper, and rinse with deionized water until neutral. After drying, intermediate C is obtained.

[0045] ④ Place intermediate C in a muffle furnace at 1000 °C and calcine for 1 - 2 h to obtain the finished product of conductive carbon black.

[0046] Filler: Commercially available barium sulfate with 2000 mesh and calcium carbonate with 800 mesh.

[0047] Solvent: Selected from one or more of isobutyl acetate, propylene glycol methyl ether acetate, and diacetone alcohol.

[0048] Leveling agent: Commercially available BASF EFKA3777.

[0049] In the following examples and comparative examples, if there is no special description of raw materials or treatment techniques, it means that they are all conventional commercially available raw material products or conventional treatment techniques in the art.

[0050] A laser-engravable conductive black bottom coating comprises the following components in parts by weight: 30 - 40 parts of hydroxyl acrylic resin, 1 - 5 parts of polyester resin, 5 - 10 parts of CAB resin, 1 - 5 parts of dispersant, 0.5 - 1 part of anti-settling agent, 1 - 5 parts of conductive carbon black, 10 - 15 parts of filler, 20 - 40 parts of solvent, and 0 - 1 part of leveling agent. Table 1 summarizes the formulations of Examples 1 - 3.

[0051] Table 1 Coating formulations of Examples 1 - 3 (parts by mass)

[0052]

[0053] A preparation method of the above-mentioned laser-engravable conductive black bottom coating comprises the following steps:

[0054] S1: Add hydroxyl acrylic resin, polyester resin, and dispersant to part of the solvent in sequence, and mix evenly under stirring.

[0055] S2: Continuously add conductive carbon black, anti-settling agent, and filler under stirring, stir evenly, and grind through a sand mill until the fineness is not higher than 15 μm.

[0056] S3: Subsequently, add the CAB resin solution, leveling agent, and the remaining solvent in sequence and stir evenly to obtain the described laser-engravable conductive black base coating.

[0057] Application of a laser-engravable conductive black base coating as described above in decorative fields such as the automotive field and the home appliance field.

[0058] Example 1

[0059] A laser-engravable conductive black base coating, comprising the following steps:

[0060] (1) Prepare materials according to the weight fraction content of each component;

[0061] (2) Add 40 parts by mass of KN1055F, 2.5 parts by mass of SETAL 168SS-80, 3 parts by mass of EFKA4310, and 16 parts by mass of isobutyl acetate in sequence under stirring and mix evenly to prepare Component A;

[0062] (3) Add 3 parts by mass of self-made conductive carbon black, 0.5 parts by mass of AEROSIL 380 anti-settling silica, 8 parts by mass of BaSO4, and 3 parts by mass of CaCO3 to Component A in sequence under stirring at 800 - 1000 rpm, stir for 45 min until evenly mixed, and then grind to a fineness of less than 15 microns on a sand mill to prepare Component B;

[0063] (4) Under stirring, add 5 parts by mass of CAB 381-0.5 (NV: 20%), 0.2 parts by mass of EFKA3777, 12.8 parts by mass of propylene glycol methyl ether acetate, and 10 parts by mass of diacetone alcohol to Component B in sequence to obtain the laser-engravable conductive black base coating.

[0064] Performance tests of the laser-engravable conductive black base coating for resistance to chemicals, laser engraving, etc.:

[0065] Mix the laser-engravable conductive black base, curing agent (Desmodur N75 / butyl acetate = 50 / 50 (m / m, the same below)), and diluent (ethyl acetate / propylene glycol methyl ether / ethylene glycol monobutyl ether = 25 / 50 / 25 (m / m, the same below)) evenly according to a mass ratio of 100:10:60, spray it on a transparent PMMA material, let it stand at room temperature for 5 - 10 min for leveling, and then bake it in an 80°C oven for 30 min. Engrave a 60 cm * 30 cm transparent square frame on the sample sprayed with the primer under a laser engraving machine, and then coat it with a transparent varnish. Let it stand at room temperature for 7 days, and the performance test results are shown in Table 2 below:

[0066] Table 2 Performance test results of Example 1

[0067]

[0068] Example 2

[0069] A kind of laser-engraving conductive black bottom coating, comprising the following steps:

[0070] (1) Prepare materials according to the weight content of each component;

[0071] (2) Add 40 parts by mass of KN1055F, 2.5 parts by mass of SETAL 168SS-80, 4 parts by mass of EFKA4310, and 16 parts by mass of isobutyl acetate in sequence under stirring and mix evenly to prepare Component A;

[0072] (3) Add 4 parts by mass of self-made conductive carbon black, 0.5 part by mass of AEROSIL 380 anti-settling silica, 8 parts by mass of BaSO4, and 3 parts by mass of CaCO3 to Component A in sequence under stirring at 800 - 1000 rpm, stir for 45 min until evenly mixed, and then grind the fineness to below 15 microns on a sand mill to prepare Component B;

[0073] (4) Under stirring, add 5 parts by mass of CAB 381-0.5 (NV: 20%), 0.2 part by mass of EFKA3777, 11.8 parts by mass of propylene glycol methyl ether acetate, and 10 parts by mass of diacetone alcohol to Component B in sequence to obtain the laser-engraving conductive black bottom coating.

[0074] Performance tests on properties such as laser-engraving conductivity and chemical resistance of the black bottom:

[0075] Mix the laser-engraving conductive black bottom, curing agent (Desmodur N75 / butyl acetate = 50 / 50), and thinner (ethyl acetate / propylene glycol methyl ether / ethylene glycol monobutyl ether = 25 / 50 / 25) evenly according to a mass ratio of 100:10:60, spray on a transparent PMMA material, let it stand at room temperature for 5 - 10 min for leveling, and bake in an 80°C oven for 30 min. Engrave a 60 cm * 30 cm transparent square on the sample sprayed with the primer under a laser engraver, and then coat with a transparent varnish. Place it at room temperature for 7 days, and the performance test results are shown in Table 3 below:

[0076] Table 3 Performance test results of Example 2

[0077]

[0078]

[0079] Example 3

[0080] A kind of laser-engraving conductive black bottom coating, comprising the following steps:

[0081] (1) Prepare materials according to the weight content of each component;

[0082] (2) Add 40 parts by mass of WXU-880, 2.5 parts by mass of SETAL 168SS-80, 4 parts by mass of EFKA4310, and 15 parts by mass of isobutyl acetate in sequence under stirring and mix them evenly to prepare Component A;

[0083] (3) Add 4 parts by mass of self-made conductive carbon black, 0.5 parts by mass of AEROSIL 380 anti-settling silica, 8 parts by mass of BaSO4, and 3 parts by mass of CaCO3 in sequence into Component A under stirring at 800 - 1000 rpm, stir for 45 min until evenly mixed, and then grind it on a sand mill until the fineness is below 15 microns to prepare Component B;

[0084] (4) Under stirring, add 5 parts by mass of CAB 381-0.5 (NV: 20%), 0.2 parts by mass of EFKA3777, 12.8 parts by mass of propylene glycol methyl ether acetate, and 10 parts by mass of diacetone alcohol into Component B in sequence to obtain the laser-engraving conductive black bottom coating.

[0085] Performance tests such as laser engraving resistance and chemical resistance of the laser-engraving conductive black bottom coating:

[0086] Mix the laser-engraving conductive black bottom coating, curing agent (Desmodur N75 / butyl acetate = 50 / 50), and thinner (ethyl acetate / propylene glycol methyl ether / ethylene glycol monobutyl ether = 25 / 50 / 25) evenly according to the mass ratio of 100:10:60, spray it on the transparent PMMA material, let it stand and level for 5 - 10 min at room temperature, and then bake it in an 80°C oven for 30 min. Engrave a 60 cm * 30 cm transparent square on the sample sprayed with the primer under a laser engraving machine, and then coat it with transparent varnish. Place it at room temperature for 7 days, and the performance test results are shown in Table 4 below:

[0087] Table 4 Performance test results of Example 3

[0088]

[0089]

[0090] Comparative Example 1

[0091] A laser-engraving conductive black bottom coating, comprising the following steps:

[0092] (1) Prepare materials according to the weight fraction content of each component;

[0093] (2) Add 40 parts by mass of WXU-880, 2.5 parts by mass of SETAL 168SS-80, 4 parts by mass of EFKA4310, and 15 parts by mass of isobutyl acetate in sequence under stirring and mix them evenly to prepare Component A;

[0094] (3) Add 4 parts by mass of commercially available conductive carbon black, 0.5 parts by mass of AEROSIL 380 anti-settling silica, 8 parts by mass of BaSO4, and 3 parts by mass of CaCO3 to Component A successively under stirring at 800 - 1000 rpm. Stir for 45 min until evenly mixed, and then grind to a fineness of less than 15 microns on a sand mill to prepare Component B;

[0095] (4) Under stirring, add 5 parts by mass of CAB 381 - 0.5 (NV: 20%), 0.2 parts by mass of EFKA3777, 12.8 parts by mass of propylene glycol methyl ether acetate, and 10 parts by mass of diacetone alcohol to Component B in sequence to obtain the laser-engraving conductive black base coating.

[0096] Performance tests such as laser-engraving conductivity and chemical resistance of the laser-engraving conductive black base:

[0097] Mix the laser-engraving conductive black base, curing agent (Desmodur N75 / butyl acetate = 50 / 50), and diluent (ethyl acetate / propylene glycol methyl ether / ethylene glycol monobutyl ether = 25 / 50 / 25) evenly according to a mass ratio of 100:10:60. Spray it on a transparent PMMA material, let it stand at room temperature for 5 - 10 min for leveling, and then bake it in an 80°C oven for 30 min. Engrave a 60 cm * 30 cm transparent square on the sample with the sprayed primer under a laser engraver, and then coat it with transparent varnish. Place it at room temperature for 7 days, and the performance test results are shown in Table 5 below:

[0098] Table 5 Performance test results of Comparative Example 1

[0099]

[0100] Analyze and compare the test results among Examples 1, 2, and 3. The primer prepared in Example 1 has poorer covering power and a higher resistance value of the paint film compared with the primers in Examples 2 and 3, indicating that a small change in the proportion of the added conductive carbon black can affect the resistance value and conductivity of the product coating; the resistance value and laser-engraving property of the primer prepared in Example 2 are better than those in Example 3, and it can be found that different resin raw materials will also affect the key properties.

[0101] Comparative Example 1 uses domestically produced commercially available conductive carbon black. The resistance value of the coating prepared is seriously higher compared with the examples, which will cause the edge of the product to be not easy to adsorb the color paint during construction, resulting in the defect of less paint and exposed base color at the edge of the product; at the same time, there are problems such as light leakage in the primer and black residues on the surface of the product after laser engraving.

[0102] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A laser-engravable conductive black primer, characterized in that: The invention comprises the following components in parts by weight: 30-40 parts of hydroxy acrylic resin, 1-5 parts of polyester resin, 5-10 parts of CAB resin, 1-5 parts of dispersant, 0.5-1 parts of anti-settling aid, 1-5 parts of conductive carbon black, 10-15 parts of filler, 20-40 parts of solvent and 0-1 parts of leveling agent; The conductive carbon black is obtained by treating carbon black with an acid solution, an alkali solution and a metal salt solution in sequence and then calcining the carbon black.

2. The laser-engravable conductive black primer according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 40 parts of hydroxy acrylic resin, 2.5 parts of polyester resin, 5 parts of CAB resin, 4 parts of dispersant, 0.5 parts of anti-settling aid, 4 parts of conductive carbon black, 11 parts of filler, 37.8 parts of solvent and 0.2 parts of leveling agent.

3. The laser-engravable conductive black primer according to claim 1, characterized in that: The hydroxy acrylic resin is an acrylic resin with a low hydroxy content, the polyester resin is a polyester polyol with a high hydroxy content, and the CAB resin is a cellulose acetate butyrate resin solution with a solid content of 20%.

4. The laser-engravable conductive black primer according to claim 1, characterized in that: The dispersant is a high molecular weight nonionic dispersant, the anti-settling aid is fumed silica, and the leveling agent is a fluorine-modified acrylic resin solution.

5. The laser-engravable conductive black primer according to claim 1, characterized in that: The conductive carbon black is prepared by the following method: ① Mix carbon black and sulfuric acid solution and stir evenly, let stand at high temperature, then filter and rinse to neutrality, and dry to obtain intermediate A; ② Mix intermediate A and sodium hydroxide solution and stir evenly, let stand at room temperature, then filter and rinse until neutral, and dry to obtain intermediate B; ③ Mix intermediate B and metal sulfate solution and stir evenly, let stand at room temperature, then filter and rinse until neutral, and dry to obtain intermediate C; ④ Calcine the intermediate C to obtain the conductive carbon black.

6. The laser-engravable conductive black primer according to claim 5, characterized in that: The conductive carbon black is prepared by the following method: ① Mix carbon black and 5 mol / L sulfuric acid solution at a ratio of 1 g: 1 mL and stir evenly, let stand at 50-60 ° C for 24 hours, then filter and rinse with deionized water until neutral, and dry to obtain intermediate A; ② Mix intermediate A and 10 mol / L sodium hydroxide solution at a ratio of 1 g: 1 mL and stir evenly, let stand at room temperature for 24 hours, then filter and rinse with deionized water until neutral, and dry to obtain intermediate B; ③ Mix intermediate B with 1 mol / L copper sulfate solution and 0.5 mol / L aluminum sulfate solution in a ratio of 2g:1mL:1mL and stir evenly, let stand at room temperature for 24 hours, then filter and rinse with deionized water until neutral, and dry to obtain intermediate C; ④ Calcine the intermediate C at 1000°C for 1-2h to obtain the conductive carbon black.

7. The laser-engravable conductive black primer according to claim 1, characterized in that: The fillers are barium sulfate and calcium carbonate.

8. The laser-engravable conductive black primer according to claim 1, characterized in that: The solvent is one or more of isobutyl acetate, propylene glycol methyl ether acetate and diacetone alcohol.

9. A method for preparing a laser-engravable conductive black primer coating as claimed in any one of claims 1 to 8, characterized in that: The steps include: S1: adding hydroxy acrylic resin, polyester resin and dispersant to part of the solvent in sequence, and mixing them evenly under stirring; S2: Continue to add conductive carbon black, anti-settling agent and filler while stirring, stir evenly and grind with a sand mill to a fineness of no more than 15μm; S3: Then, the CAB resin solution, the leveling agent and the remaining solvent are added in sequence and stirred evenly to obtain the laser-engravable conductive black primer coating.

10. Use of the laser-engravable conductive black primer coating as claimed in any one of claims 1 to 8 in the automotive and household appliance fields.

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