High-conductivity high-adhesion automobile bumper primer and preparation method thereof

Abstract

The invention discloses a high-conductivity high-adhesion automobile bumper primer and a preparation method thereof, and belongs to the technical field of automobile bumper primers. The high-conductivity and high-adhesion automobile bumper primer is prepared from the following raw material components: polar modified chlorinated polypropylene, waterborne acrylic resin, a dispersing agent, a flatting agent, a defoaming agent, titanium dioxide, superfine precipitated barium sulfate, fumed silica, conductive filler and deionized water. The polar modified chlorinated polypropylene is obtained by carrying out free radical polymerization on a polar unsaturated monomer and chlorinated polypropylene; the polar unsaturated monomer is prepared from acrylic acid, methyl methacrylate, hydroxyethyl acrylate and 3-allyl-2-hydroxybenzaldehyde; the water-based acrylic resin is obtained by carrying out copolymerization on hydroxyethyl methylacrylate, hydroxyethyl acrylate, methacrylamide and 2, 5-divinyl benzene-1, 4-diamine; the conductive filler adopts carbon nanotubes, graphene and conductive carbon black; the high-conductivity and high-adhesion automobile bumper primer prepared by the preparation method disclosed by the invention is excellent in mechanical property and relatively good in conductivity.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of automobile bumper primers, in particular to a high-conductivity high-adhesion automobile bumper primer and a preparation method thereof. BACKGROUND

[0002] With the rapid development of the automobile industry and the increasing requirements of consumers on the appearance, safety and environmental performance of vehicles, the coating quality of automobile exterior parts, especially bumpers, is increasingly concerned. Automobile bumpers are usually made of low-surface-energy thermoplastic plastics such as polypropylene (PP), polypropylene / elastomer blend (TPO) or polycarbonate / ABS alloy (PC / ABS). Such materials have the advantages of light weight, good toughness and low cost, but their surface polarity is low and they lack active functional groups, which makes it difficult for conventional coatings to form firm adhesion on their surface, and problems such as coating peeling and blistering are prone to occur.

[0003] In addition, in the modern automobile manufacturing process, in order to meet the requirements of electrostatic spraying process, the primer needs to have certain conductivity to ensure effective charge conduction during electrocoating or electrostatic spraying, so as to achieve uniform and efficient coating effect. However, the traditional primer for plastic bumpers is mostly made of acrylic resin, chlorinated polyolefin (CPO) and the like as the main film-forming material, which improves the wettability of the substrate to a certain extent, but its intrinsic insulating property limits the conductivity and it is difficult to meet the requirements of automatic coating line on conductivity.

[0004] Therefore, it is urgent to develop a special primer for automobile bumpers with high conductivity and high adhesion. SUMMARY

[0005] The purpose of the present application is to provide a high-conductivity high-adhesion automobile bumper primer and a preparation method thereof to solve the technical problems mentioned in the background.

[0006] The technical solution to achieve the purpose of the present application is: In a first aspect, the present application provides a high-conductivity high-adhesion automobile bumper primer, by mass fraction, the raw material components include: 30-50 mass fractions of polar modified chlorinated polypropylene, 10-20 mass fractions of water-based acrylic resin, 0.5-1 mass fractions of dispersant, 0.3-2 mass fractions of leveling agent, 0.1-1 mass fractions of defoaming agent, 10-30 mass fractions of titanium white, 5-15 mass fractions of ultra-fine precipitated barium sulfate, 0.3-1 mass fractions of fumed silica, 0.5-1.5 mass fractions of conductive filler, 10-20 mass fractions of deionized water.

[0007] Further, the polar modified chlorinated polypropylene is obtained by free radical polymerization of polar unsaturated monomers and chlorinated polypropylene.

[0008] Further, the polar unsaturated monomer comprises acrylic acid, methyl methacrylate, hydroxyethyl acrylate, 3-allyl-2-hydroxybenzaldehyde.

[0009] Further, the water-based acrylic resin is obtained by copolymerization of hydroxyethyl methacrylate, hydroxyethyl acrylate, methacrylamide, and 2,5-divinylbenzene-1,4-diamine.

[0010] Further, the conductive filler is obtained by compounding carbon nanotubes, graphene, and conductive carbon black.

[0011] In a second aspect, the present application provides a preparation method of the high-conductivity high-adhesion automobile bumper primer according to the first aspect, and the preparation steps comprise: (1) weighing the raw materials; (2) mixing the polar modified chlorinated polypropylene and 400-800 parts by mass of anhydrous ethanol, stirring at 35-45°C for 15-25 min to obtain a mixed solution A; mixing the water-based acrylic resin and 200-400 parts by mass of anhydrous ethanol, stirring at 35-45°C for 15-25 min to obtain a mixed solution B; mixing the mixed solution A and the mixed solution B, and then condensing and refluxing at 70-80°C under nitrogen protection for 11-13 h, and then performing filtration, washing, and drying to obtain a first mixed material; (3) stirring the first mixed material and deionized water for 1-3 h, then adding a dispersant, a leveling agent, and a defoaming agent, stirring for 20-40 min, then adding titanium white, ultra-fine precipitated barium sulfate, fumed silica, and a conductive filler, stirring and mixing for 20-30 min, and then grinding to a fineness of 200 mesh or less to obtain the high-conductivity high-adhesion automobile bumper primer.

[0012] Further, the preparation steps of the polar modified chlorinated polypropylene are as follows: stirring and mixing 60-70 parts by mass of chlorinated polypropylene and 30-35 parts by mass of butyl acetate for 15-30 min, then heating to 105-115°C, adding 95-100 parts by mass of polar unsaturated monomer, stirring for 20-40 min, then adding a solution of 0.2-0.4 parts by mass of initiator dicumyl peroxide in 25-35 parts by mass of butyl acetate dropwise within 30 min, stirring for 50-70 min, then continuously adding a solution of 0.1-0.2 parts by mass of initiator dicumyl peroxide in 10-20 parts by mass of butyl acetate, and stirring for 110-120 min to obtain the polar modified chlorinated polypropylene.

[0013] Further, the mass ratio of the polar unsaturated monomer, which comprises acrylic acid, methyl methacrylate, hydroxyethyl acrylate, and 3-allyl-2-hydroxybenzaldehyde, is (30-34):(14-18):(14-18):(18-22).

[0014] Further, the preparation steps of the water-based acrylic resin are as follows: under nitrogen protection, 50-55 parts by mass of deionized water, 2.5-2.75 parts by mass of emulsifier sodium dodecyl benzene sulfonate are stirred and dispersed for 10-20 min, then 11-12 parts by mass of hydroxyethyl methacrylate, 10-15 parts by mass of hydroxyethyl acrylate, 1-1.5 parts by mass of methacrylamide, 10-15 parts by mass of 2,5-divinylbenzene-1,4-diamine, and 0.4-0.5 parts by mass of 3-mercaptopropionamide are pre-emulsified for 5-25 min, then the temperature is raised to 75-85 DEG C, 0.4-0.6 parts by mass of initiator dicumyl peroxide is added within 30 min, the temperature is raised to 85-90 DEG C after 10-20 min of incubation, and the stirring is continued for 3-10 h to obtain the water-based acrylic resin.

[0015] Further, the conductive filler is obtained by compounding carbon nanotubes, graphene and conductive carbon black at a mass ratio of (0.05-1):(0.05-1):(0.5-5).

[0016] By adopting the technical scheme, the present application has the following beneficial effects: The high-conductivity high-adhesion automobile bumper primer provided by the present application comprises the following raw material components: polar modified chlorinated polypropylene, water-based acrylic resin, dispersant, leveling agent, defoaming agent, titanium white, ultra-fine precipitated barium sulfate, fumed silica, conductive filler and deionized water. The polar modified chlorinated polypropylene is introduced to improve the adhesion between the high-conductivity high-adhesion automobile bumper primer and the bumper. The conductive filler is introduced to improve the conductivity of the high-conductivity high-adhesion automobile bumper primer. The water-based acrylic resin is used as the main film-forming component to provide good mechanical strength. The titanium white, ultra-fine precipitated barium sulfate and fumed silica are used to provide hiding, filling and thixotropic anti-settling effects, respectively. The dispersant, leveling agent and defoaming agent are used to ensure that the high-conductivity high-adhesion automobile bumper primer has excellent storage stability, construction performance and film appearance.

[0017] The polar modified chlorinated polypropylene is obtained by free radical polymerization of polar unsaturated monomers and chlorinated polypropylene. The polar unsaturated monomers include acrylic acid, methyl methacrylate, hydroxyethyl acrylate and 3-allyl-2-hydroxybenzaldehyde. The copolymerization of chlorinated polypropylene and polar unsaturated monomers introduces polar functional groups such as carboxyl, ester, hydroxyl and aldehyde groups, which significantly improves the molecular polarity and hydrophilicity of the chlorinated polypropylene. The modified chlorinated polypropylene has improved compatibility with the water-based acrylic resin due to the enhanced polarity, which effectively avoids the phase separation or aggregation of traditional chlorinated polypropylene in the water-based system, ensures the uniformity and compactness of the film structure, helps to maintain the mechanical properties and adhesion of the coating, provides a stable matrix environment for the uniform dispersion of the conductive filler in the system, and further ensures the continuity of the conductive network and the stable performance of the overall conductivity.

[0018] The water-based acrylic resin of the present application is obtained by copolymerization of hydroxyethyl methacrylate, hydroxyethyl acrylate, methacrylamide and 2,5-divinylbenzene-1,4-diamine, both hydroxyethyl methacrylate and hydroxyethyl acrylate contain hydrophilic hydroxyl groups, which enhances the affinity of the resin main chain to water molecules, methacrylamide introduces amide groups, which have strong polarity and hydrogen bond formation ability, further improving the solubility stability of the resin in water; 2,5-divinylbenzene-1,4-diamine, as a multifunctional monomer containing divinyl and diamino groups, can not only participate in the construction of the main chain through the vinyl group after copolymerization, but also can partially protonate to form cations in aqueous environment through its primary amino group, giving the resin certain self-emulsifying ability and excellent water dispersibility, the prepared acrylic resin is stably dispersed in deionized water, avoiding the dependence of traditional solvent-based primer on a large amount of volatile organic solvents; water as a green, safe and low-cost dispersion medium instead of organic solvents not only significantly reduces the VOC emissions of coatings during production, construction and drying process.

[0019] The conductive filler of the present application is obtained by compounding carbon nanotubes, graphene and conductive carbon black, graphene forms a conductive substrate in the form of "surface contact", which can form a high-speed electron transmission plane; carbon nanotubes provide long-range conductive paths in the form of "line contact", penetrating between the layers of graphene interlayers, expanding the two-dimensional conduction space into a three-dimensional bridging structure, effectively connecting isolated particles and preventing graphene stacking; conductive carbon black fills the micro gaps between graphene layers and carbon nanotubes through "point contact", reducing local resistance and improving the compactness of the conductive network, the three form a "point-line-surface" three-dimensional conductive network, greatly shortening the electron transmission path and effectively improving the conductivity of the high-conductive high-adhesion automobile bumper primer.

[0020] The high-conductivity high-adhesion automobile bumper primer of the present application is prepared by mixing and reacting the polar modified chlorinated polypropylene with the water-based acrylic resin first, and then mixing with the remaining components. The aldehyde group of the 3-allyl-2-hydroxybenzaldehyde structure introduced on the molecular chain of the polar modified chlorinated polypropylene can undergo condensation reaction with the aniline group in the molecular chain of the water-based acrylic resin to generate salicylaldehyde Schiff base structure in situ. Not only does it serve as a covalent grafting point to chemically bond the two polymer main chains with limited compatibility to form a three-dimensional branched topological structure film-forming substrate, but also significantly improves the compatibility and film-forming uniformity of the primer system, effectively improving the impact toughness of the high-conductivity high-adhesion automobile bumper primer. Furthermore, the salicylaldehyde Schiff base structure itself has excellent ultraviolet absorption capacity, can effectively capture free radicals generated in the photooxidation process and inhibit the photo-degradation chain reaction, thereby significantly enhancing the anti-ultraviolet aging performance of the coating. In addition, the three-dimensional branched topological structure film-forming substrate has cavities inside, which provide physical confinement space for the conductive fillers added subsequently. The conductive fillers enter the cavities to achieve preliminary spatial isolation and uniform distribution, effectively inhibiting their tendency to agglomerate in the water-based system. The salicylaldehyde Schiff base structure rich in the inner wall of the cavity contains an aromatic ring and a conjugated π electron system, which can undergo strong π-π interaction with the sp² hybridized carbon network on the surface of carbon-based conductive materials such as carbon nanotubes and graphene. This non-covalent interaction not only further anchors the conductive fillers to prevent their sedimentation or aggregation, but also promotes their high dispersion and orientation arrangement in the resin matrix, thereby more efficiently constructing a continuous and low-resistance three-dimensional conductive network, further improving the conductivity of the high-conductivity high-adhesion automobile bumper primer. DETAILED DESCRIPTION

[0021] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with specific embodiments.

[0022] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0023] The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0024] Chlorinated polypropylene, industrial grade, chlorine content 30% (w / w).

[0025] The dispersing agent is BYK-190.

[0026] The defoaming agent is Tego 830.

[0027] The leveling agent is BTK-381.

[0028] The carbon nanotubes are commercially available with an average tube diameter of 8 nm and a length of about 50 μm.

[0029] The acrylic resin is a commercially available acrylic resin Acust® 5020. Example 1

[0030] A preparation method of a high-conductivity high-adhesion automobile bumper primer, the preparation steps comprising: (1) 30 parts by mass of polar modified chlorinated polypropylene, 400 parts by mass of anhydrous ethanol are mixed, stirred at 35°C for 15 min to obtain a mixed solution A; 10 parts by mass of water-based acrylic resin, 200 parts by mass of anhydrous ethanol are mixed, stirred at 35°C for 15 min to obtain a mixed solution B; the mixed solution A and the mixed solution B are mixed, heated to 70°C under nitrogen protection, and condensed refluxed for 11 h, then filtered, washed, and dried to obtain a first mixed material; (2) The first mixed material and 10 parts by mass of deionized water are stirred for 1 h, then 0.5 parts by mass of a dispersing agent, 0.3 parts by mass of a leveling agent, and 0.1 parts by mass of a defoaming agent are added and stirred for 20 min, then 10 parts by mass of titanium dioxide, 5 parts by mass of ultra-fine precipitated barium sulfate, 0.3 parts by mass of fumed silica, and 0.5 parts by mass of conductive filler are added and stirred for 20 min, and then ground to a fineness of 200 mesh or less to obtain a high-conductivity high-adhesion automobile bumper primer.

[0031] The preparation steps of the polar modified chlorinated polypropylene are as follows: 60 parts by mass of chlorinated polypropylene and 30 parts by mass of butyl acetate are stirred and mixed for 15 min, then heated to 105°C, 95 parts by mass of polar unsaturated monomer is added and stirred for 20 min, a solution of 0.2 parts by mass of initiator dimethylbenzoyl peroxide in 25 parts by mass of butyl acetate is added dropwise within 30 min and stirred for 50 min, then a solution of 0.1 parts by mass of initiator dimethylbenzoyl peroxide in 10 parts by mass of butyl acetate is added dropwise and stirred for 110 min to obtain the polar modified chlorinated polypropylene; wherein the mass ratio of acrylic acid, methyl methacrylate, hydroxyethyl acrylate, and 3-allyl-2-hydroxybenzaldehyde in the polar unsaturated monomer is 30:14:18:22.

[0032] The preparation steps of the water-based acrylic resin are as follows: under nitrogen protection, 50 parts by mass of deionized water and 2.5 parts by mass of emulsifier sodium dodecylbenzenesulfonate are stirred and dispersed for 10 min, then 11 parts by mass of hydroxyethyl methacrylate, 10 parts by mass of hydroxyethyl acrylate, 1 part by mass of methacrylamide, 10 parts by mass of 2,5-divinylbenzene-1,4-diamine, and 0.4 parts by mass of 3-mercaptopropionamide are pre-emulsified for 5 min, then heated to 75°C, 0.4 parts by mass of initiator dimethylbenzoyl peroxide is added dropwise within 30 min, heated to 85°C after 10 min of reaction, and stirred for another 3 h to obtain the water-based acrylic resin.

[0033] The conductive filler is obtained by compounding carbon nanotubes, graphene and conductive carbon black at a mass ratio of 0.05:0.05:0.5. Example 2

[0034] A preparation method of a high-conductivity and high-adhesion automobile bumper primer, the preparation steps comprising: (1) 40 parts by mass of polar modified chlorinated polypropylene and 600 parts by mass of anhydrous ethanol are mixed and stirred at 40°C for 20 min to obtain a mixed solution A; 15 parts by mass of water-based acrylic resin and 300 parts by mass of anhydrous ethanol are mixed and stirred at 40°C for 20 min to obtain a mixed solution B; the mixed solution A and the mixed solution B are mixed, and then heated to 70-80°C under nitrogen protection for condensation reflux for 12 h, followed by filtration, washing and drying to obtain a first mixed material; (2) The first mixed material and 15 parts by mass of deionized water are stirred for 2 h, then 0.8 parts by mass of a dispersing agent, 1.2 parts by mass of a leveling agent and 0.6 parts by mass of a defoaming agent are added and stirred for 30 min, then 20 parts by mass of titanium white, 10 parts by mass of ultra-fine precipitated barium sulfate, 0.7 parts by mass of fumed silica and 1 part by mass of conductive filler are added and stirred for 25 min, and then ground to a fineness of 200 mesh or less to obtain a high-conductivity and high-adhesion automobile bumper primer.

[0035] The preparation steps of the polar modified chlorinated polypropylene are as follows: 65 parts by mass of chlorinated polypropylene and 32 parts by mass of butyl acetate are stirred and mixed for 30 min, then heated to 110°C, 98 parts by mass of polar unsaturated monomer is added and stirred for 30 min, then a solution of 0.3 parts by mass of initiator peroxide dimethylbenzoyl in 30 parts by mass of butyl acetate is added dropwise within 30 min and stirred for 60 min, then a solution of 0.15 parts by mass of initiator peroxide dimethylbenzoyl in 15 parts by mass of butyl acetate is added dropwise and stirred for 115 min to obtain the polar modified chlorinated polypropylene; wherein the mass ratio of acrylic acid, methyl methacrylate, hydroxyethyl acrylate and 3-allyl-2-hydroxybenzaldehyde in the polar unsaturated monomer is 32:16:16:20.

[0036] The preparation steps of the water-based acrylic resin are as follows: under nitrogen protection, 55 parts by mass of deionized water and 2.5-2.75 parts by mass of emulsifier sodium dodecylbenzenesulfonate are stirred and dispersed for 15 min, then 11.5 parts by mass of hydroxyethyl methacrylate, 13 parts by mass of hydroxyethyl acrylate, 1.2 parts by mass of methacrylamide, 13 parts by mass of 2,5-divinylbenzene-1,4-diamine and 0.45 parts by mass of 3-mercaptopropionamide are pre-emulsified for 15 min, then heated to 80°C, 0.5 parts by mass of initiator peroxide dimethylbenzoyl is added dropwise within 30 min, and after 15 min of heat preservation, the temperature is increased to 85°C, and stirring is continued for 10 h to obtain the water-based acrylic resin.

[0037] The conductive filler is obtained by compounding carbon nanotubes, graphene and conductive carbon black at a mass ratio of 0.5:0.5:3. Example 3

[0038] A preparation method of a high-conductivity and high-adhesion automobile bumper primer, the preparation steps comprising: (1) 50 parts by mass of polar modified chlorinated polypropylene and 800 parts by mass of anhydrous ethanol are mixed and stirred at 45℃ for 25 min to obtain a mixed solution A; 20 parts by mass of water-based acrylic resin and 400 parts by mass of anhydrous ethanol are mixed and stirred at 45℃ for 25 min to obtain a mixed solution B; the mixed solution A and the mixed solution B are mixed, and then heated to 80℃ under nitrogen protection and condensed reflux for 13 h, followed by filtration, washing and drying to obtain a first mixed material; (2) The first mixed material and 20 parts by mass of deionized water are stirred for 3 h, then 1 part by mass of a dispersing agent, 2 parts by mass of a leveling agent and 1 part by mass of a defoaming agent are added and stirred for 40 min, then 30 parts by mass of titanium white, 15 parts by mass of ultra-fine precipitated barium sulfate, 1 part by mass of fumed silica and 1.5 parts by mass of conductive filler are added and stirred for 30 min, and then ground to a fineness of 200 mesh or less to obtain a high-conductivity and high-adhesion automobile bumper primer.

[0039] The preparation steps of the polar modified chlorinated polypropylene are as follows: 70 parts by mass of chlorinated polypropylene and 35 parts by mass of butyl acetate are stirred and mixed for 30 min, then heated to 115℃, 100 parts by mass of polar unsaturated monomer is added and stirred for 40 min, then a solution of 0.4 parts by mass of initiator dimethylbenzoyl peroxide in 35 parts by mass of butyl acetate is added dropwise within 30 min and stirred for 70 min, then a solution of 0.2 parts by mass of initiator dimethylbenzoyl peroxide in 20 parts by mass of butyl acetate is added dropwise and stirred for 120 min to obtain the polar modified chlorinated polypropylene; wherein the mass ratio of acrylic acid, methyl methacrylate, hydroxyethyl acrylate and 3-allyl-2-hydroxybenzaldehyde in the polar unsaturated monomer is 34:18:18:18.

[0040] The preparation steps of the water-based acrylic resin are as follows: under nitrogen protection, 55 parts by mass of deionized water and 2.75 parts by mass of emulsifier sodium dodecylbenzenesulfonate are stirred and dispersed for 20 min, then 12 parts by mass of hydroxyethyl methacrylate, 15 parts by mass of hydroxyethyl acrylate, 1.5 parts by mass of methacrylamide, 115 parts by mass of 2,5-divinylbenzene-1,4-diamine and 0.5 parts by mass of 3-mercaptopropionamide are pre-emulsified for 25 min, then heated to 85℃, 0.6 parts by mass of initiator dimethylbenzoyl peroxide is added dropwise within 30 min, and after 20 min of heat preservation, the temperature is increased to 90℃, and stirring is continued for 10 h to obtain the water-based acrylic resin.

[0041] The conductive filler is compounded by carbon nanotubes, graphene and conductive carbon black at a mass ratio of 1:1:5. Comparative Example 1

[0042] Comparative Example 1 and Example 2 differ only in that the high-conductivity high-adhesion automobile bumper primer uses chlorinated polypropylene, and the remaining steps and components are the same as Example 2. Comparative Example 2

[0043] Comparative Example 2 and Example 2 differ only in that the high-conductivity high-adhesion automobile bumper primer uses a commercially available acrylic resin, and the remaining steps and components are the same as Example 2. Comparative Example 3

[0044] Comparative Example 3 and Example 2 differ only in that the conductive filler uses only carbon nanotubes, and the remaining steps and components are the same as Example 2. Comparative Example 4

[0045] Comparative Example 4 and Example 2 differ only in that the conductive filler uses only graphene, and the remaining steps and components are the same as Example 2. Comparative Example 5

[0046] Comparative Example 5 and Example 2 differ only in that the conductive filler uses only conductive carbon black, and the remaining steps and components are the same as Example 2. Comparative Example 6

[0047] Comparative Example 6 and Example 2 differ only in that the high-conductivity high-adhesion automobile bumper primer is prepared by directly mixing the components uniformly, and the remaining steps and components are the same as Example 2. Effect Example

[0048] Conductivity: Place two small pieces of iron (1 cm x 1 cm) on the PP plate with a 15 μm thick coating of the high-conductivity high-adhesion automobile bumper primer prepared in Examples 1-3 and Comparative Examples 1-6 on the surface, with a spacing of 1-2 cm between the two pieces of iron. Turn on the power of the multimeter, connect the probes to the resistance measurement interface, place the probes on the two pieces of iron, and read the resistance reading.

[0049] Table 1 below shows the performance test results of the 15 μm thick coating of the high-conductivity high-adhesion automobile bumper primer prepared in Examples 1-3 and Comparative Examples 1-6 on the clean PP plate surface using the electrostatic spraying process, and baking at 80°C for 30 min: Table 1

[0050] From Table 1, it can be seen that the coating formed by the high-conductivity and high-adhesion automobile bumper primer of Examples 1-3 has higher adhesion, better impact resistance, better conductivity and better UV aging resistance than the coating formed by the high-conductivity and high-adhesion automobile bumper primer of Examples 1-3 and Comparative Examples 1-6.

[0051] The difference between Comparative Example 1 and Example 2 is that the high-conductivity and high-adhesion automobile bumper primer uses chlorinated polypropylene, and the coating formed by the high-conductivity and high-adhesion automobile bumper primer has lower adhesion, weaker impact resistance, conductivity and UV aging resistance.

[0052] The difference between Comparative Example 2 and Example 2 is that the high-conductivity and high-adhesion automobile bumper primer uses commercially available acrylic resin, and the coating formed by the high-conductivity and high-adhesion automobile bumper primer has weaker impact resistance, conductivity and UV aging resistance.

[0053] The difference between Comparative Example 3 and Example 2 is that the conductive filler only uses carbon nanotubes, and the coating formed by the high-conductivity and high-adhesion automobile bumper primer has weaker conductivity.

[0054] The difference between Comparative Example 4 and Example 2 is that the conductive filler only uses graphene, and the coating formed by the high-conductivity and high-adhesion automobile bumper primer has weaker impact resistance and conductivity.

[0055] The difference between Comparative Example 5 and Example 2 is that the conductive filler only uses conductive carbon black, and the coating formed by the high-conductivity and high-adhesion automobile bumper primer has weaker impact resistance and conductivity.

[0056] The difference between Comparative Example 6 and Example 2 is that the high-conductivity and high-adhesion automobile bumper primer is prepared by directly mixing the components uniformly, and the coating formed by the high-conductivity and high-adhesion automobile bumper primer has lower adhesion, weaker impact resistance, conductivity and UV aging resistance.

[0057] The above specific examples further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A high conductive high adhesion automotive bumper primer, characterized by, The raw material components include, by mass fraction: 30-50 mass parts of polar modified chlorinated polypropylene, 10-20 mass parts of water-based acrylic resin, 0.5-1 mass part of dispersant, 0.3-2 mass parts of leveling agent, 0.1-1 mass part of defoaming agent, 10-30 mass parts of titanium white powder, 5-15 mass parts of ultra-fine precipitated barium sulfate, 0.3-1 mass part of fumed silica, 0.5-1.5 mass parts of conductive filler, and 10-20 mass parts of deionized water.

2. The high conductive high adhesion automotive bumper primer of claim 1, wherein, The polar modified chlorinated polypropylene is obtained by free radical polymerization of polar unsaturated monomers and chlorinated polypropylene.

3. The high conductive high adhesion automotive bumper primer of claim 2, wherein, The polar unsaturated monomers include acrylic acid, methyl methacrylate, hydroxyethyl acrylate, and 3-allyl-2-hydroxybenzaldehyde.

4. The high conductive high adhesion automotive bumper primer of claim 1, wherein, The water-based acrylic resin is obtained by copolymerization of hydroxyethyl methacrylate, hydroxyethyl acrylate, methyl methacrylamide, and 2,5-divinylbenzene-1,4-diamine.

5. The high conductive high adhesion automotive bumper primer of claim 1, wherein, The conductive filler is obtained by compounding carbon nanotubes, graphene, and conductive carbon black.

6. A method of preparing a high conductive high adhesion automotive bumper primer according to any one of claims 1 to 5, characterized in that, The preparation steps include: (1) weighing the raw materials; (2) mixing the polar modified chlorinated polypropylene and 400-800 mass parts of anhydrous ethanol, stirring at 35-45°C for 15-25 min to obtain a mixed solution A; mixing the water-based acrylic resin and 200-400 mass parts of anhydrous ethanol, stirring at 35-45°C for 15-25 min to obtain a mixed solution B; mixing the mixed solution A and the mixed solution B, warming to 70-80°C under nitrogen protection, condensing and refluxing for 11-13 h, then filtering, washing, and drying to obtain a first mixed material; (3) stirring the first mixed material and deionized water for 1-3 h, then adding the dispersant, leveling agent, and defoaming agent, stirring for 20-40 min, then adding the titanium white powder, ultra-fine precipitated barium sulfate, fumed silica, and conductive filler, stirring and mixing for 20-30 min, and grinding to a fineness of 200 mesh or less to obtain a high-conductivity high-adhesion automobile bumper primer.

7. The method for preparing a high-conductivity, high-adhesion automotive bumper primer according to claim 6, characterized in that, The preparation steps of the polar modified chlorinated polypropylene are as follows: mixing 60-70 mass parts of chlorinated polypropylene and 30-35 mass parts of butyl acetate, stirring for 15-30 min, warming to 105-115°C, adding 95-100 mass parts of polar unsaturated monomers, stirring for 20-40 min, adding a solution of 0.2-0.4 mass parts of initiator dicumyl peroxide in 25-35 mass parts of butyl acetate dropwise within 30 min, stirring for 50-70 min, then adding a solution of 0.1-0.2 mass parts of initiator dicumyl peroxide in 10-20 mass parts of butyl acetate dropwise, and stirring for 110-120 min to obtain the polar modified chlorinated polypropylene.

8. The method for preparing a high-conductivity, high-adhesion automotive bumper primer according to claim 7, characterized in that, The mass ratio of acrylic acid, methyl methacrylate, hydroxyethyl acrylate, and 3-allyl-2-hydroxybenzaldehyde in the polar unsaturated monomers is (30-34):(14-18):(14-18):(18-22).

9. The method for preparing a high-conductivity, high-adhesion automotive bumper primer according to claim 6, characterized in that, The preparation steps of the water-based acrylic resin are as follows: under nitrogen protection, 50-55 parts by mass of deionized water, 2.5-2.75 parts by mass of emulsifier sodium dodecyl benzene sulfonate are stirred and dispersed for 10-20 min, then 11-12 parts by mass of hydroxyethyl methacrylate, 10-15 parts by mass of hydroxyethyl acrylate, 1-1.5 parts by mass of methacrylamide, 10-15 parts by mass of 2,5-divinylbenzene-1,4-diamine, 0.4-0.5 parts by mass of 3-mercaptopropylamide are pre-emulsified for 5-25 min, then the temperature is raised to 75-85 DEG C, 0.4-0.6 parts by mass of initiator dicumyl peroxide is added within 30 min, after 10-20 min of incubation, the temperature is raised to 85-90 DEG C, and the stirring is continued for 3-10 h to obtain the water-based acrylic resin.

10. The method for preparing a high-conductivity, high-adhesion automotive bumper primer according to claim 6, characterized in that, The conductive filler is obtained by compounding carbon nanotubes, graphene and conductive carbon black at a mass ratio of (0.05-1):(0.05-1):(0.5-5).

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