A PC / ABS material with high strength and low friction coefficient and its preparation method and application

Abstract

The present invention discloses a PC / ABS material with high strength and low friction coefficient, and a preparation method and application thereof. The PC / ABS material with high strength and low friction coefficient of the present invention comprises the following components: PC resin, ABS resin, PMMA resin, nano-silicon dioxide, nano-titanium dioxide, toughening agent, surface modifier, antioxidant and lubricating dispersant; the surface modifier is composed of oleamide and / or erucamide and graphite flakes in a mass ratio of 1:(1-5). The present invention mixes oleamide and / or erucamide with graphite flakes in a specific mass ratio to form a surface modifier, and combines it with nano-titanium dioxide and nano-silicon dioxide reinforcement materials at the same time, so that oleamide and / or erucamide and graphite flakes are enriched on the surface of the PC / ABS material, and work together with the nano reinforcement material to form a dense surface layer, thereby achieving a low friction coefficient while also having good mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer compound compositions, and more specifically to a PC / ABS material with high strength and low friction coefficient, and a preparation method and application thereof. Background Art

[0002] At present, the common low friction coefficient plastics are mainly polyoxymethylene (POM) and nylon (PA). Among them, POM has a high surface hardness and a dense surface, can withstand general chemicals and solvents, and has good electrical properties; it also has good mechanical properties and rigidity, close to metal materials. Although it has a large shrinkage rate, it is dimensionally stable and light in weight, making it an ideal material to replace copper, cast zinc, aluminum and other metal materials; it has excellent fatigue resistance and creep resistance, and immediately returns to its original state after the external force is removed, and has good wear resistance, self-lubrication and friction properties; but POM is easily decomposed by heating, has a large molding shrinkage rate, and is difficult to mold; at higher temperatures, thermal degradation is very rapid, and thermal oxidation degradation will also occur in the presence of oxygen. Although nylon materials have good toughness, high tensile and compressive strength, smooth and wear-resistant surface, and low friction coefficient; it is very easy to absorb water, and water absorption will affect the size and precision of the parts to a certain extent, and will also greatly reduce its mechanical strength.

[0003] In view of the defects and shortcomings of polyoxymethylene and nylon, PC / ABS alloy materials have been developed in the prior art, and modified to enhance their wear resistance. For example, the prior art discloses a low friction coefficient PC / ABS alloy material and a preparation method thereof, which uses low friction coefficient POM to mix with PC / ABS, and uses a specific compatibilizer to improve the dispersion uniformity of POM in the PC / ABS system, effectively reducing the friction coefficient of the PC / ABS alloy material (the friction coefficient reaches 0.36 to 0.48), but the friction coefficient is still relatively high and needs further improvement. In addition, the prior art mainly reduces the friction coefficient by increasing lubrication, but this technical means has limited effect on reducing the friction coefficient, and excessive addition of lubricant will have a greater impact on the comprehensive performance of the material, especially it is easy to cause low surface strength of the material and poor scratch resistance. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects and shortcomings of existing wear-resistant PC / ABS alloy materials that are difficult to have both low friction coefficient and high strength, and to provide a PC / ABS material with high strength and low friction coefficient, wherein oleamide and / or erucic acid amide are mixed with graphite flakes in a specific mass ratio to form a surface modifier, and a synergistic effect is formed with two nanoparticles of nano titanium dioxide and nano silicon dioxide to further enhance the surface strength of the material. The difference in fluidity between the surface modifier and the matrix is ​​utilized to promote oleamide and / or erucic acid amide and graphite flakes to be enriched on the surface of the material, and to work together with the nano-reinforcement material to form a dense surface layer, thereby achieving low friction coefficient while also having good mechanical properties.

[0005] Another object of the present invention is to provide a method for preparing a PC / ABS material with high strength and low friction coefficient.

[0006] Another object of the present invention is to provide the use of the above-mentioned high-strength and low-friction coefficient PC / ABS material in the preparation of silent plastic parts.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] The present invention protects a PC / ABS material with high strength and low friction coefficient, which comprises the following components by weight:

[0009]

[0010] The surface modifier is composed of oleamide and / or erucamide and graphite flakes in a mass ratio of 1:(1-5).

[0011] The present invention forms a surface modifier by mixing oleamide and / or erucamide with graphite flakes in a specific mass ratio. The graphite flakes can be better dispersed under the action of oleamide or erucamide, and are combined with nano-titanium dioxide and nano-silicon dioxide reinforcing materials at the same time. The difference in fluidity between the surface modifier and the matrix is ​​utilized to promote oleamide and / or erucamide and graphite flakes to be enriched on the material surface, and act together with the nano-reinforcement material to form a dense surface layer, thereby achieving a low friction coefficient and having good mechanical properties.

[0012] Preferably, the surface modifier is composed of oleamide and / or erucamide and graphite flakes in a mass ratio of 1:(3-5).

[0013] Preferably, the average particle size of the nano-silicon dioxide and / or titanium dioxide is ≤100 nm. Specifically, the average particle size of the nano-silicon dioxide is 7 to 12 nm, and the average particle size of the titanium dioxide is 21 to 30 nm.

[0014] In a specific embodiment, the PC resin of the present invention adopts the GB / T 3682-2018 standard, and the melt index at 300° C. / 1.2 kg is 19 to 37 g / 10 min.

[0015] Optionally, the ABS resin adopts GB / T 3682-2018 standard, and the melt index at 220°C / 10kg is 15-25g / 10min.

[0016] In a specific embodiment, the toughening agent is a silicon-based toughening agent with a core-shell structure, wherein methyl methacrylate is used as a shell, silicone and acrylate are used as a core, and the content of silicone-acrylic acid is ≥30%.

[0017] In a specific embodiment, the lubricating dispersant is a PETS-based lubricating dispersant.

[0018] In a specific embodiment, the antioxidant is one or more of a hindered phenol antioxidant, a phosphite antioxidant, a thio antioxidant and a composite plastic antioxidant.

[0019] The present invention also protects a method for preparing the above-mentioned high-strength and low-friction coefficient PC / ABS material, comprising the following steps:

[0020] PC resin, ABS resin, PMMA resin, nano-silicon dioxide, nano-titanium dioxide, toughening agent, antioxidant and lubricating dispersant are mixed evenly and added to the twin-screw extruder from the main feeding port, and the surface modifier is added to the twin-screw extruder from the side feeding port. The mixture is melt-extruded and granulated to obtain PC / ABS material with high strength and low friction coefficient.

[0021] Specifically, the extrusion temperature of the twin-screw extruder is 240-250°C.

[0022] The use of the above-mentioned high-strength and low-friction coefficient PC / ABS material in the preparation of silent plastic parts is also within the scope of protection of the present invention. For example, the high-strength and low-friction coefficient PC / ABS material is used to prepare silent parts in household appliances.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The invention provides a PC / ABS material with high strength and low friction coefficient. Oleamide and / or erucamide are mixed with graphite flakes in a specific mass ratio to form a surface modifier, and the surface modifier is combined with nano titanium dioxide and nano silicon dioxide reinforcing materials. The difference in fluidity between the surface modifier and the matrix is ​​utilized to promote the enrichment of oleamide and / or erucamide and graphite flakes on the material surface, and the surface modifier and / or erucamide work together with the nano reinforcing materials to form a dense surface layer, thereby achieving the goal of obtaining a low friction coefficient while having good mechanical strength. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0026] 1. Raw materials and reagents

[0027] PC resin 1, melt index is 19.0g / 10min, brand PC-2458, manufacturer Shanghai Covestro;

[0028] PC resin 2, melt index is 37.0g / 10min, brand PC-2207, manufacturer Shanghai Covestro;

[0029] ABS resin is polyacrylonitrile-butadiene-styrene resin, brand 8391, manufacturer Shanghai Gaoqiao;

[0030] PMMA resin, brand CM-205, manufacturer Chimei Chemical;

[0031] Oleic acid amide, brand name Croda oleic acid amide ORX, manufacturer Croda Chemicals, UK;

[0032] Erucic acid amide, brand name erucic acid amide, manufacturer Sichuan Xipu Chemical;

[0033] Zinc stearate, brand 2818, manufacturer Huamingtai Chemical;

[0034] Graphite flake, brand flake graphite, manufacturer Qingdao Yubo;

[0035] Ordinary graphite powder, brand spherical graphite, manufacturer Qingdao Yubo;

[0036] Nano-silicon dioxide 1, average particle size 12nm, brand R974, manufacturer Evonik Degussa;

[0037] Nano-silicon dioxide 2, average particle size 7nm, brand A380, manufacturer Evonik Degussa;

[0038] Nano titanium dioxide 1, average particle size 21nm, brand AEROXIDE P25, manufacturer Evonik Degussa;

[0039] Nano titanium dioxide 2, average particle size 30nm, brand VK-T25Q, manufacturer Zhejiang Zhitai Nano;

[0040] Silicon dioxide, average particle size 6.5 μm, brand DL-805, manufacturer DeLan Chemical;

[0041] Titanium dioxide, average particle size 10 μm, brand BLR-886, manufacturer Longmang Chemical;

[0042] The toughening agent is a silicon core-shell toughening agent, brand S-2001, manufactured by Mitsubishi Rayon of Japan;

[0043] The lubricating dispersant is PETS, brand PETS-AP, manufactured by Guangzhou Yongzheng Chemical;

[0044] The antioxidant is prepared by compounding antioxidant 412S and antioxidant Y-002 in a mass ratio of 1:1, wherein antioxidant 412S and antioxidant Y-002 are both commercially available.

[0045] 2. The high-strength and low-friction PC / ABS materials of the embodiments and comparative examples of the present invention are prepared by the following preparation method:

[0046] PC resin, ABS resin, PMMA resin, nano-silicon dioxide, nano-titanium dioxide, toughening agent, surface modifier, antioxidant and lubricating dispersant are mixed evenly and added to the twin-screw extruder from the main feeding port, and the surface modifier is added to the twin-screw extruder from the side feeding port, and melt-extruded and granulated to obtain PC / ABS material with high strength and low friction coefficient.

[0047] Among them, the melt extrusion conditions of the twin-screw extruder are: zone one temperature 140-160°C, zone two temperature 200-220°C, zone three temperature 220-240°C, zone four temperature 240-250°C, zone five temperature 240-250°C, zone six temperature 240-250°C, zone seven temperature 240-250°C, zone eight temperature 240-250°C, zone nine temperature 240-250°C, and the main engine speed 350-380r / min.

[0048] 3. Performance testing

[0049] (1) Mechanical properties test: The tensile strength was tested according to ISO 527-2019 standard at a tensile rate of 50 mm / min; the flexural strength was tested according to ISO 178-2019 standard at a tensile rate of 2 mm / min.

[0050] (2) Surface dynamic friction coefficient: tested in accordance with GB / T10006-2021, with the upper specimen being steel.

[0051] Examples 1 to 11

[0052] The weight proportions of the components of the high-strength and low-friction-coefficient PC / ABS materials in Examples 1 to 11 are shown in Table 1, wherein X represents the mass ratio of oleamide and / or erucamide to graphite flakes.

[0053] Table 1 PC / ABS materials with high strength and low friction coefficient in Examples 1 to 11

[0054]

[0055] Comparative Examples 1 to 10

[0056] The weight proportions of the components in the high-strength and low-friction-coefficient PC / ABS materials in Comparative Examples 1 to 10 are shown in Table 2.

[0057] Table 2 PC / ABS materials with high strength and low friction coefficient in Comparative Examples 1 to 10

[0058]

[0059]

[0060] The performance test results of the PC / ABS materials with high strength and low friction coefficient in each embodiment and comparative example according to the above-mentioned method are shown in Table 3.

[0061] Table 3 Test results of various embodiments and comparative examples

[0062]

[0063]

[0064] It can be seen from the data in Table 3 that the high-strength and low-friction coefficient PC / ABS material of the present invention not only has a low friction coefficient, but also has good mechanical properties, with a tensile strength of 56.5-59.7 MPa, a bending strength of 79.0-86.8 MPa, and a surface dynamic friction coefficient of 0.23-0.26.

[0065] From Comparative Example 1, it can be seen that it is difficult to effectively reduce the surface dynamic friction coefficient of PC / ABS material after the reaction of zinc stearate and graphite flakes; from Comparative Examples 2 and 5, it can be found that too much or too little addition of the surface modifier is not conducive to reducing the surface dynamic friction coefficient of PC / ABS material. From Comparative Examples 3 and 4, it can be seen that even if the addition amount of the surface modifier is appropriate, it is difficult to effectively improve the surface dynamic friction coefficient of PC / ABS material when the addition amount of graphite flakes is too much or too little.

[0066] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A PC / ABS material with high strength and low friction coefficient, characterized in that: By weight, it includes the following components: 60~75 parts of PC resin; ABS resin 20~35 parts; 4-8 parts of PMMA resin; 1~2 parts of nano silicon dioxide; 1~2 parts of nano titanium dioxide; 1~3 parts of toughening agent; Surface modifier 2~4 parts; Antioxidant 0~2 parts; Lubricating dispersant 0~1 part; The surface modifier is composed of oleamide and / or erucamide and graphite flakes in a mass ratio of 1:(1-5).

2. The PC / ABS material with high strength and low friction coefficient as claimed in claim 1, characterized in that: The surface modifier is composed of oleamide and / or erucamide and graphite flakes in a mass ratio of 1:(3-5).

3. The PC / ABS material with high strength and low friction coefficient as claimed in claim 1, characterized in that: The average particle size of the nano silicon dioxide and / or nano titanium dioxide is ≤100 nm.

4. The PC / ABS material with high strength and low friction coefficient as claimed in claim 1, characterized in that: The PC resin adopts the GB / T 3682-2018 standard, and has a melt index of 19-37 g / 10 min at 300° C. / 1.2 kg.

5. The PC / ABS material with high strength and low friction coefficient as claimed in any one of claims 1 to 4, characterized in that: The toughening agent is a core-shell structured organic silicon toughening agent.

6. The high-strength and low-friction PC / ABS material according to any one of claims 1 to 4, characterized in that: The lubricating dispersant is PETS lubricating dispersant.

7. The high-strength and low-friction PC / ABS material according to any one of claims 1 to 4, characterized in that: The antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants, thio antioxidants and composite plastic antioxidants.

8. A method for preparing the high-strength and low-friction-coefficient PC / ABS material according to any one of claims 1 to 7, characterized in that: The following steps are involved: PC resin, ABS resin, PMMA resin, nano-silicon dioxide, nano-titanium dioxide, toughening agent, antioxidant and lubricating dispersant are mixed evenly and added to the twin-screw extruder from the main feeding port, and the surface modifier is added to the twin-screw extruder from the side feeding port. The mixture is melt-extruded and granulated to obtain PC / ABS material with high strength and low friction coefficient.

9. The preparation method according to claim 8, characterized in that: The extrusion temperature of the twin-screw extruder is 240-250°C.

10. Use of the high-strength and low-friction-coefficient PC / ABS material according to any one of claims 1 to 7 in the preparation of silent plastic parts.

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