Nylon 6 composite material and preparation method thereof

Abstract

The invention generally relates to a high polymer material modification technology, in particular to a nylon 6 composite material and a preparation method thereof, and the nylon 6 composite material comprises the following raw materials by mass: 60-75 parts of nylon 6; 8 to 15 parts of lamellar potassium titanate whisker; 5-12 parts of glass fiber and / or carbon fiber; 1-3 parts of molybdenum disulfide; 2 to 4 parts of nano montmorillonite; 4-5 parts of a coupling agent; 3 to 5 parts of a crosslinking compatilizer; 1-2 parts of a tackifier; and 0.5 to 1.5 parts of an antioxidant. The high-friction and high-viscosity nylon 6 composite material is successfully prepared through collaborative design of the lamellar potassium titanate whiskers and the fiber filler in combination with precise regulation and control of the tackifier.

Description

Technical Field

[0001] This invention generally relates to polymer material modification technology, and specifically to a nylon 6 composite material and its preparation method. Background Technology

[0002] Nylon 6 is widely used in bearing manufacturing due to its good overall performance. However, traditional nylon 6 has a low coefficient of friction, which makes it prone to slippage in scenarios requiring stable friction transmission. At the same time, its melt viscosity is low, which can lead to uneven dispersion when multi-component fillers are added, resulting in fluctuations in material properties.

[0003] Existing technologies often use a single friction filler to improve friction performance, but the effect is limited; while simply increasing viscosity can easily sacrifice processability.

[0004] Therefore, the key to the development of high-performance nylon bearing materials lies in how to improve the material's friction coefficient and system viscosity while also taking into account mechanical properties and processing stability. Summary of the Invention

[0005] This invention aims to solve the above-mentioned problems and provides a nylon 6 composite material. It uses lamellar potassium titanate whiskers as the core friction filler, combined with glass fiber / carbon fiber reinforcement, and adds a tackifier to adjust the viscosity, so as to achieve synergistic optimization of the material's friction performance, viscosity and mechanical properties. In its preparation process, through the design of pre-dispersion process and blending temperature control, the high viscosity and high friction of the material are further achieved.

[0006] The technical solution of the present invention is that, on one hand, the present invention provides a nylon 6 composite material, the raw material composition of which includes: nylon 6, lamellar potassium titanate whiskers, glass fiber and / or carbon fiber, molybdenum disulfide, nano-montmorillonite, coupling agent, crosslinking compatibilizer, tackifier and antioxidant.

[0007] Furthermore, the content of the raw materials is expressed in parts by mass: Nylon 6: 60-75 parts; Lamellar potassium titanate whiskers: 8-15 parts; Glass fiber and / or carbon fiber: 5-12 parts; Molybdenum disulfide: 1-3 parts; Nano-montmorillonite: 2-4 parts; Coupling agent: 4-5 parts; Crosslinking compatibilizer: 3-5 parts; Tackifier: 1-2 parts; Antioxidant: 0.5-1.5 parts.

[0008] Furthermore, the relative viscosity of the nylon 6 is 2.2-3.8, and the nylon 6 is a mixture of low-viscosity nylon 6 with a relative viscosity of 2.4, medium-viscosity nylon 6 with a relative viscosity of 2.8, and high-viscosity nylon 6 with a relative viscosity of 3.4; the mass ratio of the low-viscosity nylon 6, medium-viscosity nylon 6, and high-viscosity nylon 6 is 20-30:15-20:15-20; the aspect ratio of the lamellar potassium titanate whiskers is 15-25:1, and the lamellar diameter is 5-10 μm; the glass fiber is alkali-free chopped glass fiber with a length of 3-5 mm; the carbon fiber is PAN-based chopped carbon fiber with a length of 2-4 mm; and the coupling agent is KH560.

[0009] Furthermore, the crosslinking compatibilizer is maleic anhydride-grafted polypropylene or maleic anhydride-grafted ethylene-octene copolymer; the tackifier is hydrogenated petroleum resin or terpene resin; and the antioxidant is obtained by compounding antioxidant 1076 and antioxidant 168 at a mass ratio of 2:1.

[0010] The second aspect of this law provides a method for preparing the aforementioned nylon 6 composite material, comprising the following steps: S1. Mix the coupling agent with anhydrous ethanol, then add lamellar potassium titanate whiskers, molybdenum disulfide and nano montmorillonite, heat and stir until the mixture becomes emulsion, add part of the crosslinking compatibilizer and all of the thickener, continue stirring to obtain the pre-dispersed functional filler pre-material. S2. Dry nylon 6, glass fiber and / or carbon fiber, and control the moisture content to ≤0.1% to obtain dried nylon 6, dried glass fiber and / or carbon fiber; S3. Mix and stir the dried nylon 6, pre-dispersed functional filler pre-material, antioxidant and remaining crosslinking compatibilizer to obtain pretreated material; S4. Add the pretreated material, dried glass fiber and / or carbon fiber to a twin-screw extruder for melt blending to obtain a blended melt; 6. S5. The blended melt is extruded, water-cooled, and pelletized to obtain the nylon 6 composite material.

[0011] Furthermore, in step S1 above: The coupling agent and anhydrous ethanol are mixed at a mass ratio of 1:3, stirred and then left to stand for 2-3 hours. The cross-linking compatibilizer constitutes 20-30% of the total mass of the cross-linking compatibilizer; The coupling agent, anhydrous ethanol, lamellar potassium titanate whiskers, molybdenum disulfide, nano-montmorillonite, crosslinking compatibilizer, and thickener were mixed in a high-speed mixer. The heating and stirring temperature after adding nano-montmorillonite was 80℃, and the stirring temperature after adding thickener was 90-110℃. The stirring speed was 150-200 R / min, and the stirring time was 20-25 min.

[0012] Furthermore, in S2 above: The nylon was dried in a vacuum environment at 110-130℃ for 5-7 hours. The glass fiber and / or carbon fiber are dried by forced air drying at 80-100℃ for 3-4 hours.

[0013] Furthermore, in S3 above, the dried nylon 6, pre-dispersed functional filler pre-material, antioxidant and remaining crosslinking compatibilizer are mixed and stirred in a high-speed mixer at a temperature of 60°C, a stirring speed of 150-200 R / min and a stirring time of 3 min; in S4 above, during melt blending, the temperature of each zone of the extruder is controlled at 160-265°C and the screw speed is controlled at 250-350 r / min.

[0014] Furthermore, in step S4, the screw length-to-diameter ratio of the twin-screw extruder is 40-44:1, and the temperature distribution of each zone of the twin-screw extruder is as follows: feeding zone 160-240℃, compression zone 240-250℃, homogenization zone 250-260℃, and die head 255-260℃.

[0015] The third aspect of the present invention also provides the application of the above-mentioned nylon 6 composite material for the preparation of nylon bearings. The specific application method is as follows: the nylon 6 composite material is injection molded to prepare nylon bearings; wherein the injection temperature is 240-260°C, the mold temperature is 70-90°C, the injection pressure is 90-110MPa, and the holding pressure is 60-80MPa.

[0016] The advantage of this invention over the prior art lies in: 1. The nylon 6 in the composite material of this invention is selected from high viscosity grades (relative viscosity 3.0-3.8), medium viscosity grades (relative viscosity 2.6-2.8), and low viscosity grades (relative viscosity 2.2-2.4) to provide the basic viscosity of the system and ensure the interfacial bonding with the filler.

[0017] 2. The aspect ratio of the sheet potassium titanate whiskers of the present invention is 15-25:1. The sheet structure can increase the surface contact area and significantly improve the friction coefficient. The addition amount is 8-15 parts, which balances the friction performance and processability.

[0018] 3. The composite material of the present invention contains glass fiber and / or carbon fiber: alkali-free glass fiber has low cost and good reinforcing effect; PAN-based carbon fiber has higher strength and can be selected according to needs, improving the rigidity and wear resistance of the material.

[0019] 4. The small amount of molybdenum disulfide added to the composite material of the present invention can optimize frictional stability and avoid excessive wear caused by excessively high friction coefficient.

[0020] 5. Other components in the composite material of the present invention include nano-montmorillonite, which can enhance the barrier properties of the material and help increase the viscosity of the system; hydrogenated petroleum resin or terpene resin as a thickener can specifically increase the melt viscosity and promote the dispersion of fillers; and crosslinking compatibilizer can improve the compatibility between fillers and matrix and reduce interface defects.

[0021] This invention successfully prepared a high-friction, high-viscosity nylon 6 composite material by synergistic design of lamellar potassium titanate whiskers and fiber fillers, combined with precise control of the tackifier.

[0022] - High friction: The synergistic effect of the lamellar potassium titanate whiskers increases the coefficient of friction of the material by 50-70% compared with pure nylon 6, meeting the transmission requirements.

[0023] - High viscosity: The tackifier is combined with high, medium, and low viscosity nylon 6 to reduce the melt viscosity (260℃, 100s). - ¹) Increases by 30-40%, improving packing dispersibility.

[0024] - Strong mechanical properties: The reinforcement of glass fiber / carbon fiber increases the bending strength of the material by 40-60% and the impact strength.

[0025] 6. In the preparation method of the present invention, 1) preliminary dispersion is achieved by high temperature and high speed stirring, laying the foundation for subsequent melt blending; 2) raw material drying: strictly control the moisture content of nylon 6 and fiber filler to avoid generating bubbles during processing and affecting performance; 3) melt blending: by optimizing the temperature and speed of the twin-screw extruder, ensure that each component is uniformly dispersed, while maintaining suitable melt flowability.

[0026] The pre-dispersion process solves the problem of dispersing multi-component fillers. The preparation process is simple and controllable, and easy to industrialize. The resulting material has excellent friction and mechanical properties, and is especially suitable for transmission components such as nylon bearings that have strict requirements for friction stability and structural strength. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0028] Example 1 A method for preparing glass fiber reinforced nylon 6 composite material includes the following steps: 1. Raw material ratio (parts by weight): 30 parts of low viscosity nylon 6 (relative viscosity 2.4, the same relative viscosity as in subsequent examples), 20 parts of medium viscosity nylon 6 (relative viscosity 2.8, the same relative viscosity as in subsequent examples), 20 parts of high viscosity nylon 6 (relative viscosity 3.4, the same relative viscosity as in subsequent examples), 10 parts of lamellar potassium titanate whiskers (diameter-to-thickness ratio 20:1), 8 parts of alkali-free chopped glass fiber (length 4mm), 2 parts of molybdenum disulfide, 3 parts of organically modified nano-montmorillonite, 4 parts of crosslinking compatibilizer maleic anhydride grafted polypropylene, 1.5 parts of hydrogenated petroleum resin, and 1 part of antioxidant 1076 / antioxidant 168 (compounded in a mass ratio of 2:1).

[0029] 2. Preparation of the pre-material: The coupling agent and anhydrous ethanol were mixed at a mass ratio of 1:3 (the same as in this example in subsequent examples) and left to stand for 2-3 hours. Then, layered potassium titanate whiskers, molybdenum disulfide, and nano-montmorillonite were added and mixed. The mixture was heated to 80°C in a high-speed mixer and stirred until the substance became emulsion. 1.2 parts of maleic anhydride-grafted polypropylene and 1.5 parts of hydrogenated petroleum resin were added and stirred in a high-speed mixer at 100°C for 22 minutes to obtain the pre-material. The small molecule part of the substance was slowly extracted to obtain the pre-material.

[0030] 3. Raw material drying: Nylon 6 was vacuum dried at 120℃ for 6 hours, and glass fiber was dried by forced air at 90℃ for 3.5 hours.

[0031] 4. Secondary mixing: The dried nylon 6, the pre-material, the remaining crosslinking compatibilizer and antioxidant are stirred in a high-speed mixer at 60°C for 3 minutes to obtain the pre-treated material.

[0032] 5. Melt blending: Add the pretreated material and glass fiber to a twin-screw extruder (length-to-diameter ratio 44:1). The temperatures of each zone are as follows: starting from the feeding section, the temperatures of zones 1-11 are 160℃, 220℃, 235℃, 245℃, 260℃, 255℃, 250℃, 250℃, 260℃, 255℃, and 255℃ respectively. The screw speed is 380 r / min.

[0033] 6. Granulation: After extrusion, water cooling, air drying, and pelletizing are performed to obtain nylon 6 composite material.

[0034] Example 2 A method for preparing carbon fiber reinforced nylon 6 composite material includes the following steps: 1. Raw material ratio (parts by weight): 28 parts of low viscosity nylon 6, 20 parts of medium viscosity nylon 6, 20 parts of high viscosity nylon 6, 12 parts of lamellar potassium titanate whiskers (diameter-to-thickness ratio 22:1), 7 parts of PAN-based short-cut carbon fiber (length 3mm), 1.5 parts of molybdenum disulfide, 2.5 parts of organically modified nano-montmorillonite, 3.5 parts of crosslinking compatibilizer maleic anhydride grafted ethylene-octene copolymer, 1.2 parts of terpene resin, and 0.8 parts of antioxidant 1076 / 168 (2:1).

[0035] 2. Preparation of pre-materials: Mix the coupling agent with anhydrous ethanol at a ratio of 1:3 and let stand for 2-3 hours. Then add layered potassium titanate whiskers, molybdenum disulfide and nano-montmorillonite and mix. Heat to 80°C in a high-speed mixer and stir until the mixture becomes emulsion. Add 2 parts of crosslinking compatibilizer and 1.2 parts of terpene resin and stir at 105°C for 24 minutes. Slowly extract the small molecule part of the mixture.

[0036] 3. Raw material drying: Nylon 6 was vacuum dried at 125℃ for 5.5 hours, and carbon fiber was dried by forced air drying at 95℃ for 3 hours.

[0037] 4. Secondary mixing: The dried nylon 6, the pre-material, the remaining crosslinking compatibilizer and antioxidant are stirred in a high-speed mixer at 60°C for 3 minutes to obtain the pre-treated material.

[0038] 5. Melt blending: Add the pretreated material and carbon fiber to a twin-screw extruder (length-to-diameter ratio 44:1). The temperatures of each zone are as follows: starting from the feeding section, the temperatures of zones 1-11 are 160℃, 220℃, 235℃, 245℃, 260℃, 255℃, 250℃, 250℃, 260℃, 255℃, and 255℃ respectively. The screw speed is 380 r / min.

[0039] 5. Granulation: After extrusion, water cooling, air drying, and pelletizing are performed to obtain nylon 6 composite material.

[0040] Example 3 A method for preparing a nylon 6 composite material with a high coefficient of friction includes the following steps: 1. Raw material ratio (parts by weight): 28 parts of low viscosity nylon 6, 17 parts of medium viscosity nylon 6, 20 parts of high viscosity nylon 6, 15 parts of lamellar potassium titanate whiskers (diameter-to-thickness ratio 25:1), 6 parts of glass fiber, 3 parts of molybdenum disulfide, 4 parts of nano montmorillonite, 5 parts of crosslinking compatibilizer maleic anhydride grafted polypropylene, 2 parts of hydrogenated petroleum resin, and 1.2 parts of antioxidant.

[0041] 2. Preparation of pre-material: Mix the coupling agent and anhydrous ethanol at a ratio of 1:3 and let stand for 2-3 hours. Then add lamellar potassium titanate whiskers, molybdenum disulfide and nano-montmorillonite and mix. Heat to 80°C in a high-speed mixer and stir until the mixture becomes emulsion. Add 2 parts of crosslinking compatibilizer and 2 parts of hydrogenated petroleum resin and stir at 95°C for 25 minutes. Slowly extract the small molecule part of the mixture to obtain the pre-material.

[0042] 3. Raw material drying: Nylon 6 was vacuum dried at 125℃ for 5.5h, and glass fiber was dried by forced air at 90℃ for 3.5h.

[0043] 4. Secondary mixing: The dried nylon 6, pre-materials, remaining crosslinking compatibilizer, and antioxidant are stirred in a high-speed mixer at 60°C for 3 minutes to obtain the pre-treated material.

[0044] 5. Melt blending: Add the pretreated material and glass fiber to a twin-screw extruder (length-to-diameter ratio 44:1). The temperatures of each zone are as follows: starting from the feeding section, the temperatures of zones 1-11 are 160℃, 220℃, 235℃, 245℃, 260℃, 255℃, 250℃, 260℃, 260℃, 255℃, and 255℃ respectively. The screw speed is 360 r / min.

[0045] 6. Granulation: After extrusion, water cooling, air drying, and pelletizing are performed to obtain nylon 6 composite material.

[0046] Example 4 A method for preparing a high-viscosity nylon 6 composite material includes the following steps: 1. Raw material ratio (parts by weight): 28 parts of low viscosity nylon 6, 20 parts of medium viscosity nylon 6, 27 parts of high viscosity nylon 6, 8 parts of lamellar potassium titanate whiskers (diameter-to-thickness ratio 20:1), 10 parts of carbon fiber, 1 part of molybdenum disulfide, 2 parts of nano montmorillonite, 3 parts of crosslinking compatibilizer, 1.8 parts of terpene resin, and 0.5 parts of antioxidant.

[0047] 2. Preparation of pre-material: The coupling agent and anhydrous ethanol are mixed at a ratio of 1:3 and left to stand for 2-3 hours. Then, layered potassium titanate whiskers, molybdenum disulfide and nano-montmorillonite are added and mixed. The mixture is heated to 80°C in a high-speed mixer and stirred until the mixture becomes emulsion. 0.9 parts of crosslinking compatibilizer and all of the terpene resin are added and stirred at 110°C for 20 minutes. The small molecule part of the mixture is slowly extracted to obtain the pre-material.

[0048] 3. Raw material drying: Nylon 6 was vacuum dried at 125℃ for 5.5 hours, and carbon fiber was dried by forced air drying at 90℃ for 3 hours.

[0049] 4. Secondary mixing: The dried nylon 6, pre-materials, remaining crosslinking compatibilizer and antioxidant are stirred in a high-speed mixer at 60℃ for 3 minutes to obtain the pre-treated material.

[0050] 5. Melt blending: The pretreated material and carbon fiber are added to a twin-screw extruder at a screw speed of 350 r / min. The temperature of each zone of the extruder is the same as in Example 1, except that the temperature of the second zone is 240°C and the temperature of the third zone is 245°C.

[0051] 6. Granulation: After extrusion, water cooling, air drying, and pelletizing are performed to obtain nylon 6 composite material.

[0052] Example 5 A method for preparing a glass fiber-carbon fiber reinforced nylon 6 composite material includes the following steps: 1. Raw material ratio (parts by weight): 25 parts low viscosity nylon 6, 20 parts medium viscosity nylon 6, 15 parts high viscosity nylon 6, 11 parts lamellar potassium titanate whiskers (diameter-to-thickness ratio 25:1), 4 parts glass fiber, 4 parts carbon fiber, 2.5 parts molybdenum disulfide, 3.5 parts nano montmorillonite, 4.5 parts crosslinking compatibilizer, 1.6 parts hydrogenated petroleum resin, and 1.1 parts antioxidant.

[0053] 2. Preparation of pre-materials: Mix the coupling agent and anhydrous ethanol at a ratio of 1:3 and let stand for 2-3 hours. Then add lamellar potassium titanate whiskers, molybdenum disulfide and nano-montmorillonite and mix. Heat to 80°C in a high-speed mixer and stir until the mixture becomes emulsion. Add 2 parts of crosslinking compatibilizer and 1.6 parts of hydrogenated petroleum resin. Stir at 100°C for 23 minutes and slowly extract the small molecule part of the mixture.

[0054] 3. Raw material drying: Nylon 6 was vacuum dried at 125℃ for 5.5h, and carbon fiber and glass fiber were blown dry at 90℃ for 3h.

[0055] 4. Secondary mixing: The dried nylon 6, pre-materials, remaining crosslinking compatibilizer and antioxidant are stirred in a high-speed mixer at 60℃ for 3 minutes to obtain the pre-treated material.

[0056] 5. Melt blending: The pretreated material, glass fiber, and carbon fiber are added to a twin-screw extruder. The screw speed is 320 r / min, and the temperature of each zone of the extruder is the same as in Example 1. The die head temperature is 260℃.

[0057] 6. Granulation: After extrusion, water cooling, air drying, and pelletizing are performed to obtain nylon 6 composite material.

[0058] Example 6 A method for preparing a low-cost nylon 6 composite material includes the following steps: 1. Raw material ratio (parts by weight): 25 parts low viscosity nylon 6, 17 parts medium viscosity nylon 6, 20 parts high viscosity nylon 6, 9 parts lamellar potassium titanate whiskers (diameter-to-thickness ratio 20:1), 12 parts glass fiber, 1.8 parts molybdenum disulfide, 2.2 parts nano montmorillonite, 3.2 parts crosslinking compatibilizer, 1 part terpene resin, and 0.7 parts antioxidant.

[0059] 2. Preparation of pre-material: Mix the coupling agent and anhydrous ethanol at a ratio of 1:3 and let stand for 2-3 hours. Then add lamellar potassium titanate whiskers, molybdenum disulfide and nano-montmorillonite and mix. Heat to 80°C in a high-speed mixer and stir until the mixture becomes emulsion. Add 2 parts of crosslinking compatibilizer and 1 part of hydrogenated petroleum resin. Stir at 100°C for 23 minutes and slowly extract the small molecule part of the mixture to obtain the pre-material.

[0060] 3. Raw material drying: Nylon 6 was vacuum dried at 125℃ for 5.5h, and glass fiber was dried by forced air at 95℃ for 3.5h.

[0061] 4. Secondary mixing: The dried nylon 6, the pre-material, the remaining crosslinking compatibilizer and antioxidant are stirred in a high-speed mixer at 60°C for 3 minutes to obtain the pretreated material.

[0062] 5. Melt blending: Add the pretreated material and glass fiber to a twin-screw extruder. The screw speed is 330 r / min. The temperature of each zone of the extruder is the same as in Example 1, except that the temperature of the third zone is 240℃ and the temperature of the third zone is 245℃.

[0063] 6. Granulation: After extrusion, water cooling, air drying, and pelletizing are performed to obtain nylon 6 composite material.

[0064] The product performance obtained from each example is shown in Table 1 below.

[0065] Table 1. Product performance obtained from each embodiment

[0066] By adjusting the material ratio, fiber reinforcement, viscosity control, and pre-treatment and dispersion processes, the agglomeration problem of nano-montmorillonite and the insufficient viscosity of potassium titanate whiskers were solved. Furthermore, molybdenum disulfide material was integrated with these materials to form a unified whole. The resulting material exhibits suitable friction coefficient, viscosity coefficient, cost, and performance for various applications. In Examples 1, 3, and 6, using whiskers with the same aspect ratio, potassium titanate whiskers were found to play a major role in friction resistance. Comparing Examples 2, 4, and 5 (in the same orientation), carbon fiber showed a significant advantage over glass fiber; however, the increase in glass fiber and whiskers could compensate for this deficiency. Simultaneously, the material's viscosity was moderate, addressing a fundamental problem with this type of material.

[0067] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A nylon 6 composite material, characterized in that, The raw material composition includes: nylon 6, lamellar potassium titanate whiskers, glass fiber and / or carbon fiber, molybdenum disulfide, nano-montmorillonite, coupling agent, crosslinking compatibilizer, tackifier and antioxidant.

2. The nylon 6 composite material according to claim 1, characterized in that, The content of the raw materials is expressed in parts by mass: Nylon 6: 60-75 parts; Lamellar potassium titanate whiskers: 8-15 parts; Glass fiber and / or carbon fiber: 5-12 parts; Molybdenum disulfide: 1-3 parts; Nano-montmorillonite: 2-4 parts; Coupling agent: 4-5 parts; Crosslinking compatibilizer: 3-5 parts; Tackifier: 1-2 parts; Antioxidant: 0.5-1.5 parts.

3. The nylon 6 composite material according to claim 1, characterized in that: The relative viscosity of the nylon 6 is 2.2-3.8, and the nylon 6 is a mixture of low viscosity nylon 6 with a relative viscosity of 2.4, medium viscosity nylon 6 with a relative viscosity of 2.8, and high viscosity nylon 6 with a relative viscosity of 3.

4. The mass ratio of low-viscosity nylon 6, medium-viscosity nylon 6 and high-viscosity nylon 6 is 20-30:15-20:15-20; The aspect ratio of the lamellar potassium titanate whiskers is 15-25:1, and the lamellar diameter is 5-10 μm; The glass fiber is alkali-free chopped glass fiber with a length of 3-5 mm; The carbon fiber is PAN-based short-cut carbon fiber with a length of 2-4 mm; The coupling agent is KH560.

4. The nylon 6 composite material according to claim 1, characterized in that: The crosslinking compatibilizer is maleic anhydride-grafted polypropylene or maleic anhydride-grafted ethylene-octene copolymer. The tackifier is a hydrogenated petroleum resin or a terpene resin; The antioxidant is obtained by compounding antioxidant 1076 and antioxidant 168 in a mass ratio of 2:

1.

5. A method for preparing the nylon 6 composite material according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Mix the coupling agent with anhydrous ethanol, then add lamellar potassium titanate whiskers, molybdenum disulfide and nano montmorillonite, heat and stir until the mixture becomes emulsion, add part of the crosslinking compatibilizer and all of the thickener, continue stirring to obtain the pre-dispersed functional filler pre-material. S2. Dry nylon 6, glass fiber and / or carbon fiber, and control the moisture content to ≤0.1% to obtain dried nylon 6, dried glass fiber and / or carbon fiber; S3. Mix and stir the dried nylon 6, pre-dispersed functional filler pre-material, antioxidant and remaining crosslinking compatibilizer to obtain pretreated material; S4. Add the pretreated material, dried glass fiber and / or carbon fiber to a twin-screw extruder for melt blending to obtain a blended melt; S5. The blended melt is extruded, water-cooled, and pelletized to obtain the nylon 6 composite material.

6. The method for preparing nylon 6 composite material according to claim 5, characterized in that: In S1: The coupling agent and anhydrous ethanol are mixed at a mass ratio of 1:3, stirred and then left to stand for 2-3 hours. The cross-linking compatibilizer constitutes 20-30% of the total mass of the cross-linking compatibilizer; The coupling agent, anhydrous ethanol, lamellar potassium titanate whiskers, molybdenum disulfide, nano-montmorillonite, crosslinking compatibilizer, and thickener were mixed in a high-speed mixer. The heating and stirring temperature after adding nano-montmorillonite was 80℃, and the stirring temperature after adding thickener was 90-110℃. The stirring speed was 150-200 R / min, and the stirring time was 20-25 min.

7. The method for preparing nylon 6 composite material according to claim 5, characterized in that: In S2: The nylon was dried in a vacuum environment at 110-130℃ for 5-7 hours. The glass fiber and / or carbon fiber are dried by forced air drying at 80-100℃ for 3-4 hours.

8. The method for preparing nylon 6 composite material according to claim 5, characterized in that: In S3, the mixing and stirring of dried nylon 6, pre-dispersed functional filler pre-material, antioxidant and remaining crosslinking compatibilizer are carried out in a high-speed mixer at a temperature of 60°C, a stirring speed of 150-200 R / min and a stirring time of 3 min. In step S4, during melt blending, the temperature of each zone of the twin-screw extruder is controlled at 160-265℃, and the screw speed is controlled at 250-350 r / min.

9. The method for preparing nylon 6 composite material according to claim 8, characterized in that: In S4, the screw length-to-diameter ratio of the twin-screw extruder is 40-44:1, and the temperature distribution of each zone of the extruder is as follows: feeding section 160-240℃, compression section 240-250℃, homogenization section 250-260℃, and die head 255-260℃.

10. An application of the nylon 6 composite material according to any one of claims 1-4, characterized in that: The nylon 6 composite material is injection molded to prepare nylon bearings; wherein the injection temperature is 240-260℃, the mold temperature is 70-90℃, the injection pressure is 90-110MPa, and the holding pressure is 60-80MPa.

Images