High-heat-resistant and high-paint-ratio ABS composition, preparation method and application thereof

Abstract

The application discloses a kind of high heat resistance high painting rate ABS composition and preparation method and application thereof.The ABS composition includes the following components: ABS resin 80-90 parts by weight, spraying accelerator 2-7 parts by weight, conductive filler 1-3 parts by weight, antioxidant 0.1-0.3 parts by weight, lubricant 0.3-0.8 parts by weight.The branched styrene-acrylonitrile copolymer grafted with GMA is introduced into the ABS composition system, which reacts with the mixture composed of carboxylated carbon nanotube and carboxylated conductive carbon black to achieve good dispersion of conductive filler, which can make the ABS composition have very low surface resistance, and the entanglement structure formed can greatly improve the heat resistance temperature of ABS material.The products produced by injection molding of this ABS composition can meet the demand of electrostatic spraying process, have high painting rate and excellent heat deformation resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of general plastic styrene materials, in particular to a high-heat-resistant and high-paint-ratio ABS composition, a preparation method and application thereof. BACKGROUND

[0002] With the continuous strengthening of the greenhouse effect and the deterioration of the natural environment, green environmental protection has further become the mainstream concept and trend of society. Plastic parts surface spraying can significantly improve the material's impact resistance, scratch resistance, solvent resistance, aging resistance and other properties, greatly prolonging the service life of the parts and achieving the purpose of carbon and emission reduction in the entire life cycle. Different spraying processes have obvious differences in paint adhesion rate. The traditional air spraying has a paint adhesion rate of only 30%-60%, while electrostatic spraying mainly relies on the electrostatic adsorption force of the paint to adsorb on the workpiece surface, and the paint adhesion rate can reach 70%-90%, which can increase the utilization rate of paint by 30%-40%, further achieving the purpose of saving and energy saving and emission reduction, so electrostatic spraying has received more and more attention and selection in the market.

[0003] Acrylonitrile-butadiene-styrene terpolymer resin (ABS) has the superior properties of the three components in the composition, excellent chemical stability, impact strength and good processing performance, and is an excellent paint spraying substrate. However, the surface resistance of ordinary ABS is generally more than 10 14 Ω, if directly electrostatic spraying, the paint adhesion rate is very low, which has no practical significance, and the conductive performance must be improved. In the prior art, ABS is mixed with copper, iron, manganese, titanium, nickel and other metal powders by oscillation, and then a conductive ABS composite material is obtained by hot pressing, but it cannot be injection molded, which limits the application field; there is also a method of obtaining ABS / graphene conductive plastic particles by blending graphite with ABS, extruding and granulating, and then foaming with water, blowing agent, separating agent and other materials in an autoclave, and then debubbling by post-blasting stripping method, which has a complex process route and high equipment investment; there is also a method of preparing a conductive reinforced ABS by using conductive carbon fibers, but the ABS contains a large amount of carbon fibers and has a poor appearance, and cannot be sprayed for post-treatment. Therefore, there is an urgent need for an ABS composition with excellent conductive performance suitable for electrostatic spraying process, taking into account the requirements of the working environment, and at the same time having high heat resistance. SUMMARY

[0004] Therefore, the purpose of the present application is to overcome the shortcomings of the prior art, and to provide a high-heat-resistant and high-paint-ratio ABS composition and a preparation method thereof. The ABS composition has extremely low surface resistance with a small amount of conductive filler, and at the same time has high heat resistance. The injection molded product can meet the requirements of electrostatic spraying process, has high paint adhesion rate and heat deformation resistance.

[0005] To achieve the above object, the application provides a high-heat-resistant and high-paint-ratio ABS composition, which comprises the following components in parts by weight: ABS resin 80-90 parts, spraying promoter 2-7 parts, conductive filler 1-3 parts, antioxidant 0.1-0.3 parts, and lubricant 0.3-0.8 parts.

[0006] Further, the spraying promoter is a branched styrene-acrylonitrile copolymer grafted glycidyl methacrylate, and the branching degree is 65-78 (nuclear magnetic resonance method).

[0007] Preferably, the high-heat-resistant and high-paint-ratio ABS composition comprises the following components in parts by weight: ABS resin 86 parts, spraying promoter 4 parts, conductive filler 2.5 parts, antioxidant 0.2 parts, and lubricant 0.5 parts.

[0008] Further, the glycidyl methacrylate grafting rate (acid-base titration method) of the spraying promoter is 0.3-1.5 wt%, preferably 0.9-1.1 wt%.

[0009] Further, the preparation method of the branched styrene-acrylonitrile copolymer grafted with glycidyl methacrylate is as follows: the branched styrene-acrylonitrile copolymer, glycidyl methacrylate and dicumyl peroxide are uniformly mixed, and then are fed into a twin-screw extruder for melt extrusion, so as to obtain the branched styrene-acrylonitrile copolymer grafted with glycidyl methacrylate; the length-diameter ratio of the twin-screw extruder is 48:1-52:1, the extrusion temperature is set to 170-200°C, and the screw rotation speed is set to 200-300 rpm.

[0010] Further, the mass ratio of the carboxylated multi-walled carbon nanotube to the carboxylated conductive carbon black is 1:(2-4), preferably 1:3.

[0011] Further, the carboxyl content of the carboxylated multi-walled carbon nanotube is 1.5-3.5 wt%, preferably 2.4 wt%, and the average resistivity is 0.06-0.10 Ω·cm.

[0012] Further, the carboxyl content of the carboxylated conductive carbon black is 1.2-2.6 wt%, preferably 1.8 wt%, and the average resistivity is 0.16-0.21 Ω·cm.

[0013] Further, the preparation method of the carboxylated multi-walled carbon nanotube is as follows: multi-walled carbon nanotubes and concentrated nitric acid are added into a reaction flask for reflux reaction, and then are cooled to room temperature; after dilution with water, filtration is performed, and the filter cake is continuously washed with water until the pH of the filtrate is 6.5-7; finally, the filter cake is subjected to freeze-drying treatment and drying in a vacuum oven, so as to obtain the carboxylated multi-walled carbon nanotube.

[0014] Further, the preparation method of the carboxylated conductive carbon black is as follows: conductive carbon black and concentrated nitric acid are added into a reaction flask, a reflux reaction is carried out, then cooled to room temperature, diluted with water, filtered, and continuously washed with water until the pH of the filtrate is 6.5-7, finally the filter cake is freeze-dried, and then dried in a vacuum oven to obtain the carboxylated conductive carbon black.

[0015] Further, the antioxidant is any one or more of hindered phenolic antioxidants and / or phosphite antioxidants, such as 2,6-di-tert-butyl-4-methylphenol, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, bis(2,4-di-tert-butyl) pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, and pentaerythritol bisphosphite di(octadecyl) ester.

[0016] Further, the lubricant is any one or more of silane polymers, butyl stearate, stearic acid, fatty acid salts, fatty acid amides, ethylene bis-stearamide, and polyethylene wax.

[0017] Further, the melt flow rate of the ABS resin (test method: refer to ISO 1133-1-2011, 220℃ / 10kg) is 16-38g / 10min.

[0018] The application also provides a preparation method of the high-heat-resistant high-paint-uptake ABS composition, which comprises the following steps: weighing each raw material according to the weight parts, uniformly mixing, melting, dispersing, blending, extruding, drawing, cooling, drying, and cutting the obtained premix to obtain the high-heat-resistant high-paint-uptake ABS composition; the extrusion processing equipment used is a double-screw extruder, the screw rotation speed is 500-600r / min, and the processing temperature is 170-220℃; double vacuum is used, and the vacuum degree is-0.075 to-0.08MPa.

[0019] The application also provides application of the high-heat-resistant high-paint-uptake ABS composition in the field of electrostatic spraying decoration parts, such as automobile grilles, body decoration strips, rearview mirror housings, and the like.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] The high-heat-resistance high-painting-rate ABS composition of the present application can have a low surface resistance under the condition of a small amount of conductive filler, and meanwhile has high heat resistance, and the injection-molded product can meet the requirement of electrostatic spraying process, and has high spraying and painting rate and heat deformation resistance. The branched styrene-acrylonitrile copolymer grafted with GMA is introduced into the ABS composition system, and a new conductive filler is obtained by uniformly mixing carboxylated multi-walled carbon nanotubes and carboxylated conductive carbon black at a certain ratio, the active carboxyl groups carried by the conductive filler can react with the active epoxy groups of the branched styrene-acrylonitrile copolymer grafted with GMA to combine, the conductive filler is separated from each other by the unique dendritic branched structure to avoid agglomeration and difficult dispersion, and meanwhile the one-dimensional structure of the carboxylated multi-walled carbon nanotubes and the zero-dimensional structure of the carboxylated conductive carbon black are organically combined at a suitable formulation ratio, so that the conductive carbon black can be filled in the connecting gap of the multi-walled carbon nanotubes to strengthen the connection, which is further conducive to forming a rich conductive network in the ABS composition, accelerates the conduction and migration of electric charges, and makes the ABS composition have an extremely low surface resistance, which is very suitable for the requirement of electrostatic spraying process, and the produced product has a high painting rate. In addition, the combination formed by the mutual reaction, connection and filling of the branched styrene-acrylonitrile copolymer grafted with GMA, the carboxylated multi-walled carbon nanotubes and the carboxylated conductive carbon black can further strengthen the molecular entanglement brought by the branched structure, improve the rigidity at the micro level, and hinder the movement ability of ABS molecules under heat, so that the heat resistance temperature of the material can be greatly improved, and the heat deformation resistance can be improved.

[0022] The surface resistance of the high-heat-resistance high-painting-rate ABS composition of the present application is 10E8-10E6 Ω·m, the electrostatic spraying painting rate is 80-90 wt%, and the heat distortion temperature can reach 81-86℃. DETAILED DESCRIPTION

[0023] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0024] Example

[0025] The present application will be further described below in combination with specific examples and comparative examples. The following specific examples are preferred embodiments of the present application, but the embodiments of the present application are not limited to the types of raw materials used in the following specific examples.

[0026] The raw materials used in each component are as follows:

[0027] In the examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified.

[0028] ABS resin 1: Zhenjiang Qimei Chemical Co., Ltd., brand ABS PA-757K, melt flow rate (220℃ / 10kg) 21g / 10min;

[0029] ABS resin 2: Shanghai Gaoqiao Petrochemical Co., Ltd., brand ABS 8434, melt flow rate (220℃ / 10kg) 16g / 10min;

[0030] ABS resin 3: Hanjin Petrochemical Co., Ltd., brand ABS 750N SW, melt flow rate (220℃ / 10kg) 38g / 10min;

[0031] Branched styrene-acrylonitrile copolymer: Shanghai Jiaoyi Compatibility Agent Co., Ltd., brand EMI-230B, weight average molecular weight 250000-270000, branching degree (average number of branches contained in 1000 carbon atoms) 70.

[0032] Non-branched structure styrene-acrylonitrile copolymer: Taizhong Plastic (Ningbo) Co., Ltd., brand SAN2200AS, weight average molecular weight 400000-500000, melt flow rate at 220℃ / 10kg 30-35g / 10min, branching degree 0.

[0033] Spraying promoter:

[0034] GMA grafted branched styrene-acrylonitrile copolymer 1 (bSAN-g-GMA 1), self-made, GMA content 1.0wt%;

[0035] GMA grafted branched styrene-acrylonitrile copolymer 2 (bSAN-g-GMA 2), self-made, GMA content 0.3wt%;

[0036] GMA grafted branched styrene-acrylonitrile copolymer 3 (bSAN-g-GMA 3), self-made, GMA content 1.5wt%;

[0037] GMA grafted branched styrene-acrylonitrile copolymer 4 (bSAN-g-GMA 4), self-made, GMA content 0.1wt%;

[0038] GMA grafted branched styrene-acrylonitrile copolymer 5 (bSAN-g-GMA 5), self-made, GMA content 1.8 wt%;

[0039] GMA grafted non-branched styrene-acrylonitrile copolymer 1 (SAN-g-GMA 1), self-made, GMA content 1.6 wt%;

[0040] Multi-walled carbon nanotube: Shandong Dazhan Nanometer Material Co., Ltd., brand GC-21, average resistivity 0.08 Ω·cm;

[0041] Conductive carbon black: Denka Black, Japan Electric Chemical Industry Co., Ltd., average resistivity 0.19 Ω·cm;

[0042] Conductive filler self-made method: carboxylated multi-walled carbon nanotube and carboxylated conductive carbon black were mixed uniformly in a high-speed stirrer at a speed of 10000-12000 rpm for 5-8 min;

[0043] Conductive filler 1: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:3;

[0044] Conductive filler 2: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:2;

[0045] Conductive filler 3: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:4;

[0046] Conductive filler 4: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:0.8;

[0047] Conductive filler 5: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:4.9;

[0048] Conductive filler 6: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 1.5 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:3;

[0049] Conductive filler 7: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 3.5 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:3;

[0050] Conductive filler 8: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 1.2 wt%), mass ratio 1:3;

[0051] Conductive filler 9: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 2.6 wt%), mass ratio 1:3;

[0052] Conductive filler 10: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 1.0 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:3;

[0053] Conductive filler 11: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 4.2 wt%) and carboxylated conductive carbon black (carboxyl content 1.8 wt%), mass ratio 1:3;

[0054] Conductive filler 12: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 0.7 wt%), mass ratio 1:3;

[0055] Conductive filler 13: self-made, mixture of carboxylated multi-walled carbon nanotube (carboxyl content 2.4 wt%) and carboxylated conductive carbon black (carboxyl content 3.1 wt%), mass ratio 1:3;

[0056] Conductive filler 14: self-made, mixture of unactivated multi-walled carbon nanotube and unactivated conductive carbon black, mass ratio 1:3; activation, i.e. carboxylation, is a chemical method of bringing carboxyl groups to the multi-walled carbon nanotube, which can react with the GMA groups of the GMA grafted branched styrene-acrylonitrile copolymer to improve compatibility;

[0057] Antioxidant: hindered phenolic antioxidant, commercially available; phosphite antioxidant, commercially available; mass ratio of the two is 1:1, and the same substance is used in parallel experiments;

[0058] Lubricant: stearate, commercially available, and the same substance is used in parallel experiments;

[0059] The ABS composition components and weight parts of Examples 1-29 and Comparative Examples 1-5 are shown in Tables 1 and 2.

[0060] The ABS composition preparation method of examples 1-29 and comparative examples 1-5 includes the following steps: weighing ABS resin, spraying accelerator, conductive filler, antioxidant, lubricant in parts by weight, mixing in a high-speed mixer for 6 minutes, obtaining a premix, melting, dispersing, blending, extruding, drawing, cooling, drying, and cutting the particles to obtain a high-heat-resistant and high-paint-uptake ABS composition; the extrusion processing equipment used is a double-screw extruder, the screw rotation speed is 500-600 rpm, and the processing temperature is 170-220°C; double vacuum is used, and the vacuum degree is-0.075 to-0.08 MPa.

[0061] Table 1: Example formulation composition (parts by weight)

[0062]

[0063]

[0064]

[0065] Table 2: Comparative example formulation composition (parts by weight)

[0066] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 ABS resin 86 86 86 86 86 bSAN-g-MAH 1 4 4 4 4 SAN-g-GMA 1 4 Conductive filler 1 0.5 4 2.5 Conductive filler 14 2.5 Antioxidant 0.2 0.2 0.2 0.2 0.2 Lubricant 0.5 0.5 0.5 0.5 0.5

[0067] II. Performance testing

[0068] The ABS compositions of examples 1-29 and comparative examples 1-5 are dried in a blast oven at 80°C for 4 hours, and then injection-molded into standard ISO bars and 100*100*3mm sample plates using an injection molding machine. The injection-molded bars and sample plates are placed in an environment with a relative humidity of 50±5% and a temperature of 23±2°C for 24 hours before performance testing.

[0069] Test method:

[0070] (1) Surface resistance: tested according to the ISO 3915-1981 standard;

[0071] (2) Paint uptake: paint uptake = (sample plate weight after electrostatic spraying - sample plate weight before electrostatic spraying) / total loss of paint weight * 100%;

[0072] (3) Heat distortion temperature: according to the ISO 75-1-2013 standard, with a temperature rise rate of 120°C / h and a load of 1.80 MPa;

[0073] The performance test results of the ABS compositions of examples 1-29 and comparative examples 1-5 are shown in Tables 3 and 4.

[0074] Table 3: Example performance test results

[0075]

[0076] Table 4 Comparative Example Performance Test Results

[0077] Test item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Surface resistance (Ω) E12 E11 E11 E14 E12 Paintability (%) 38 43 47 24 36 Heat distortion temperature (°C) 71 74 74 73 73

[0078] The above test data results show that the high-heat-resistant high-painting-rate ABS composition of the present application has excellent comprehensive performance in surface resistance, painting rate, heat distortion temperature, etc., and is very suitable for use in the field of electrostatic spray decoration parts.

[0079] The above description is merely preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An ABS composition, characterized in that, Based on parts by weight, it comprises the following components: 80-90 parts of ABS resin; 2-7 parts of spraying accelerator; 1-3 parts of conductive filler; Antioxidant 0.1-0.3 parts; Lubricant 0.3-0.8 parts; The conductive filler is a mixture of carboxylated multi-walled carbon nanotubes and carboxylated conductive carbon black; The spraying accelerator is a branched styrene-acrylonitrile copolymer grafted with glycidyl methacrylate; The glycidyl methacrylate grafting rate of the spraying accelerator is 0.3-1.5 wt%.

2. The ABS composition according to claim 1, characterized in that, The mass ratio of the carboxylated multi-walled carbon nanotubes to the carboxylated conductive carbon black is 1:(2-4).

3. The ABS composition according to claim 2, characterized in that, The carboxylated multi-walled carbon nanotubes have a carboxyl content of 1.5-3.5 wt% and an average resistivity of 0.06-0.10 Ω·cm.

4. The ABS composition according to claim 2, characterized in that, The carboxylated conductive carbon black has a carboxyl content of 1.2-2.6 wt% and an average resistivity of 0.16-0.21 Ω·cm.

5. The ABS composition according to claim 1, characterized in that, The antioxidant is any one or more of 2,6-di-tert-butyl-4-methylphenol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis(2,4-di-tert-butyl)pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, and pentaerythritol diphosphite di(octadecyl) ester.

6. The ABS composition according to claim 1, characterized in that, The lubricant is any one or more of the following: silane polymer, butyl stearate, stearic acid, fatty acid salt, fatty acid amide, ethylene bis-stearamide, and polyethylene wax.

7. The ABS composition according to claim 1, characterized in that, The melt flow rate of the ABS resin is 16-38 g / 10 min at 220°C and 10 kg.

8. A method for preparing the ABS composition according to any one of claims 1-7, characterized in that, The process includes the following steps: weighing each raw material according to the weight proportions, mixing them evenly, and then melting, dispersing, blending, extruding, stretching, cooling, drying, and pelletizing the resulting premix to obtain the ABS composition.

9. The use of the ABS composition according to any one of claims 1-7 in the field of electrostatic spraying decorative parts.

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