A wear-resistant, low-warpage, flame-retardant nylon composite material and its preparation method

Abstract

The present invention relates to the technical field of wear-resistant, low-warpage flame-retardant nylon composites, and particularly relates to a wear-resistant, low-warpage flame-retardant nylon composite material and a preparation method thereof. The wear-resistant, low-warpage flame-retardant nylon composite material uses nylon resin, syndiotactic polystyrene, antioxidant, lubricant, compatibilizer, flame retardant, wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch. It has a low warpage degree, high flatness, better dimensional stability, excellent wear resistance and chemical resistance, and better flame-retardant and antistatic effects. It is particularly suitable for coin counting machines, can withstand 200,000 times of coin counting, and ensures the normal operation of the coin counting machine.

Description

Technical Field

[0001] The present invention relates to the technical field of wear-resistant, low-warpage and flame-retardant nylon composites, and particularly relates to a wear-resistant, low-warpage and flame-retardant nylon composite material and a preparation method thereof. Background Art

[0002] Nylon engineering plastics are widely used in industries such as electronics and electrical appliances, automobiles, construction, office equipment, machinery, aerospace, etc. due to their high-performance advantages in mechanical properties, durability, corrosion resistance, heat resistance, etc. Replacing steel with plastics and replacing wood with plastics has become an international trend.

[0003] A coin counting machine, namely a coin sorting machine, can accurately distinguish various coins and can also display the total amount of the coins placed and the number of coins of various denominations. In the existing coin counting machines, during the use process, due to the high-speed collision and friction between the coins and the counting machine, and there are usually residues such as sweat stains and oil stains on the coins, it is easy to cause wear on the surface of the counting machine in contact with the coins and the problem of coin jamming during the operation process. Static electricity / sparks are easily generated during the collision between the coins and the counting machine and between the coins. However, the existing nylon composites have insufficient wear resistance, poor antistatic and flame-retardant effects, and have a high warpage degree, resulting in product deformation, which affects the normal coin counting operation of the counting machine. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies existing in the prior art, one of the purposes of the present invention is to provide a wear-resistant, low-warpage and flame-retardant nylon composite material, which has a low warpage degree, a high flatness, excellent wear resistance and chemical resistance, and better flame-retardant and antistatic effects. It is particularly suitable for coin counting machines and can withstand 200,000 times of coin counting to ensure the normal coin counting operation of the counting machine.

[0005] The second purpose of the present invention is to provide a preparation method of a wear-resistant, low-warpage and flame-retardant nylon composite material. The preparation method is simple in operation, convenient to control, high in production efficiency, low in production cost, and can be used for large-scale production.

[0006] One of the purposes of the present invention is achieved through the following technical solutions: A wear-resistant, low-warpage and flame-retardant nylon composite material, comprising the following raw materials in parts by weight:

[0007]

[0008] This wear-resistant, low-warping, flame-retardant nylon composite material has low warping, high flatness, excellent wear resistance and chemical resistance, and better flame retardant and antistatic effects. It is particularly suitable for coin counting machines and can withstand 200,000 coin countings to ensure the normal counting operation of the coin counting machine. Among them, special nylon resin and syndiotactic polystyrene are used as the main materials, which interact with each other to obtain higher rigidity, chemical resistance, dimensional stability, lower water absorption and low warping; the added lubricant can fully lubricate and disperse the wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch, and the lubricant, wear-resistant masterbatch and wear-resistant filler powder work synergistically in the special nylon resin to significantly improve the surface hardness and wear resistance of the nylon composite material; the added carbon nanotube masterbatch is evenly dispersed in the nylon composite material, which can not only reduce the resistivity of the nylon composite material to achieve antistatic effect, but also help to enhance the toughness, hardness and wear resistance of nylon, improve its ability to resist external forces, thereby enhancing the overall mechanical strength of the material; the added special flame retardant has high hydrophobicity, hydrolysis resistance and excellent flame retardancy, effectively maintaining its stable fire retardancy and avoiding the migration of flame retardants to the surface during use to affect the overall flame retardancy.

[0009] Preferably, the nylon resin is a PA66 / 6I copolymer, and its relative viscosity is 2.0-2.4; in the PA66 / 6I copolymer, the mass ratio of PA66:PA6I is 6-7:3-4; and the number average molecular weight of the syndiotactic polystyrene is 200,000-1,000,000.

[0010] By adopting the above technical scheme, the mass ratio of PA66:PA6I in the PA66 / 6I copolymer is controlled to be 6-7:3-4, and the excellent performance of PA66 and PA6I (PA6I model: Anaiji A1315) is combined to improve the tensile strength, bending strength and impact strength of the copolymer, especially at high temperatures, it can still maintain good mechanical properties, and is more conducive to obtaining higher rigidity, chemical corrosion resistance, heat resistance, dimensional stability, wear resistance, lower water absorption and low warpage. The number average molecular weight of syndiotactic polystyrene is between 200,000 and 1 million, with good heat resistance, good chemical resistance, and extremely low water absorption, which is conducive to reducing the water absorption of the composite material, maintaining stability, good dimensional stability, and excellent mechanical properties.

[0011] Preferably, the antioxidant is antioxidant 1098 and / or antioxidant S9228.

[0012] The above technical solution is helpful to avoid the degradation of nylon composite materials caused by oxidation during processing and use, thereby improving the heat resistance, durability and stability of nylon composite materials. More preferably, the antioxidant is a mixture of antioxidant 1098 and antioxidant S9228 in a weight ratio of 1:2-3.

[0013] Preferably, the lubricant is at least one of high-temperature resistant silicone masterbatch MB50-001, K6105M, and HMB-6301.

[0014] Adopting the above technical solution is beneficial to increasing the lubrication within the system, facilitating demolding, improving the surface finish and feel of the product, reducing the friction coefficient, improving the dispersion and compatibility of the wear-resistant masterbatch, wear-resistant filler powder, and carbon nanotube masterbatch, and also having good wear resistance and scratch resistance.

[0015] Preferably, the compatibilizer is POE-g-MAH, and its grafting rate is 1.0-1.3 MA%.

[0016] Adopting the above technical solution is beneficial to providing the compatibility between materials in the system and simultaneously achieving a toughening effect on the nylon composite material.

[0017] Preferably, the particle size of the flame retardant is 10-16 μm, and its chemical structural formula is as follows:

[0018]

[0019] Adopting the above technical solution, the phosphorus content of the flame retardant is higher, it has a higher bulk density and glass transition temperature, good dispersion compatibility, high hydrophobicity, hydrolysis resistance, and excellent flame retardancy, effectively maintaining its fireproof performance stability, and avoiding the migration of the flame retardant to the surface during use, which affects the overall flame retardancy.

[0020] Preferably, the preparation method of the wear-resistant masterbatch includes the following steps:

[0021] (R1), take 10-20 parts of ultra-high molecular weight polyethylene, 1-3 parts of graft monomer, 0.01-0.1 part of initiator, 0.1-0.2 part of regulator, and 100 parts of PA66 with a relative viscosity of 2.4 by weight, and set aside;

[0022] (R2), perform low-temperature plasma treatment on the ultra-high molecular weight polyethylene with nitrogen for 5-10 min to obtain polarized polyethylene;

[0023] (R3), mix the polarized polyethylene, graft monomer, initiator, and regulator evenly, feed them into a screw extruder under nitrogen protection, and extrude and pelletize at a temperature of 150-200 °C, and obtain graft-modified polarized polyethylene after cooling;

[0024] (R4) Dispersedly mix the graft-modified polarized polyethylene and PA66 evenly in a high-speed mixer, and extrude and pelletize them through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are respectively: 190 - 210 °C, 230 - 250 °C, 250 - 260 °C, 250 - 260 °C, 235 - 245 °C, 235 - 245 °C. The temperature of the die head is 230 - 240 °C, and the screw speed is 320 - 400 r / min to obtain the wear-resistant masterbatch.

[0025] Adopting the above technical solution, in the preparation process, the ultra-high molecular weight polyethylene is treated by low-temperature plasma to form new active groups on its surface, increasing its reaction activity. After grafting reaction with the graft monomer, a modified polyethylene with stronger polarity is generated, which has better dispersion compatibility and is more conducive to improving the tear resistance, wear resistance, chemical corrosion resistance, and aging resistance of the nylon composite material, and reducing the friction coefficient. Further, the operating power of the low-temperature plasma treatment is 8 kW - 15 kW, and the voltage is 380 V.

[0026] Preferably, the number-average molecular weight of the ultra-high molecular weight polyethylene is 2 million - 3 million; the graft monomer is maleic anhydride; the initiator is diisopropylbenzene peroxide and / or di-tert-butyl peroxide; the regulator is zinc dimethyldithiocarbamate.

[0027] Adopting the above technical solution, the number-average molecular weight of the ultra-high molecular weight polyethylene is controlled within 2 million - 3 million to enhance the wear resistance of the ultra-high molecular weight polyethylene. Its molecular chains are long and highly entangled, enabling the material to resist wear during the friction process and maintain stable performance for a long time. Coupled with maleic anhydride as the graft monomer, its polar groups can improve the surface wettability of the material, reduce the friction coefficient, thereby improving the lubrication performance, and can form stronger intermolecular forces with nylon resin and syndiotactic polystyrene, thereby improving the interfacial bonding force between it and the substrate, dispersing more evenly, and avoiding the phenomenon of shedding or delamination during use. It helps to control the rate and degree of the graft reaction and avoid the decline of material performance caused by over-grafting. The regulator uses zinc dimethyldithiocarbamate, which helps to control the rate and degree of the graft reaction, avoid the decline of material performance caused by over-grafting, and at the same time, improve the processing fluidity of the wear-resistant masterbatch.

[0028] Preferably, the wear-resistant filler powder is nano-aluminum trioxide and / or nano-silicon carbide; the carbon nanotube masterbatch is made by melt granulation with PA66 having a relative viscosity of 2.4 as the carrier and carbon nanotubes. The content of the carbon nanotubes is 14 - 18 wt%, the diameter of the carbon nanotubes is 8 - 12 nm, and the tube length of the carbon nanotubes is 30 - 50 μm.

[0029] With the above technical solution, the nano-silicon carbide powder has good compatibility and dispersibility in the nylon resin, binds tightly to the matrix, improves the surface hardness of the nylon composite material, increases the elastic modulus, significantly improves the tensile strength and wear resistance of the nylon composite material, plays a lubricating and filling role, and can reduce the friction and wear between materials; more preferably, the wear-resistant filler powder is a mixture of nano-aluminum oxide and nano-silicon carbide in a weight ratio of 1:5-8. The nano-aluminum oxide is obtained by soaking nano-aluminum oxide in KH-560 coupling agent for 10-20 h and then filtering out the coupling agent. The KH-560 coupling agent is adsorbed on the surface of the nano-aluminum oxide, reducing the interaction between particles, avoiding the agglomeration of nano-aluminum oxide, and contributing to the uniform dispersion of nano-aluminum oxide in the nylon composite material. The added carbon nanotube masterbatch is uniformly dispersed in the nylon composite material, which can not only reduce the resistivity of the nylon composite material to achieve an antistatic effect, but also be beneficial to enhancing the toughness, hardness and wear resistance of the nylon, improving its ability to resist external forces, and thus enhancing the overall mechanical strength of the material.

[0030] The second object of the present invention is achieved by the following technical solution: The preparation method of the above-mentioned wear-resistant low-warpage flame-retardant nylon composite material includes the following steps:

[0031] (S1), Weigh nylon resin, syndiotactic polystyrene, antioxidant, lubricant, compatibilizer, flame retardant, wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch by weight parts for later use;

[0032] (S2), Premix the nylon resin with 0.1 part of diffusion oil in a high-speed mixer for 2 min, then mix with other raw materials for 2 min and discharge. Extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder from the feeding section are: 200 °C, 260-280 °C, 260-280 °C, 260-280 °C, 260-280 °C, 260-280 °C, 260-280 °C, 260-280 °C, 260-280 °C, 260-280 °C, and the head temperature is 270-290 °C, and the screw speed is 500 r / min to obtain the wear-resistant low-warpage flame-retardant nylon composite material.

[0033] The beneficial effects of the present invention are as follows: The wear-resistant, low-warpage, flame-retardant nylon composite material of the present invention has a low warpage degree, high flatness, excellent wear resistance and chemical resistance, and better flame-retardant and antistatic effects. It is particularly suitable for coin counting machines, can withstand 200,000 times of coin counting, and ensures the normal operation of the counting machine. Among them, special nylon resin and syndiotactic polystyrene are used as the main materials, and interact with each other to obtain higher rigidity, chemical resistance, dimensional stability, as well as lower water absorption and low warpage; the added lubricant can fully lubricate and disperse the wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch, and the lubricant, wear-resistant masterbatch and wear-resistant filler powder act synergistically in the special nylon resin, significantly improving the surface hardness and wear resistance of the nylon composite material; the added carbon nanotube masterbatch is evenly dispersed in the nylon composite material, which can not only reduce the resistivity of the nylon composite material to achieve an antistatic effect, but also help to enhance the toughness, hardness and wear resistance of the nylon, improve its ability to resist external forces, and thus enhance the overall mechanical strength of the material; the added special flame retardant has high hydrophobicity, hydrolysis resistance and excellent flame retardancy, effectively maintaining its fire resistance stability and avoiding the migration of the flame retardant to the surface during use, which affects the overall flame retardancy.

[0034] The preparation method of the present invention is simple in operation, convenient to control, high in production efficiency and low in production cost, and can be used for large-scale production. Specific embodiments

[0035] For the convenience of understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments. The content mentioned in the embodiments does not limit the present invention.

[0036] Example 1

[0037] A wear-resistant, low-warpage, flame-retardant nylon composite material, comprising the following raw materials in parts by weight:

[0038]

[0039] The nylon resin is a PA66 / 6I copolymer with a relative viscosity of 2.0; in the PA66 / 6I copolymer, the mass ratio of PA66 to PA6I is 7:3; the number average molecular weight of the syndiotactic polystyrene is 500,000.

[0040] The antioxidant is composed of antioxidant 1098 and antioxidant S9228 mixed in a weight ratio of 1:2.8.

[0041] The lubricant is a high-temperature silicone masterbatch MB50-001.

[0042] The compatibilizer is POE-g-MAH with a grafting rate of 1.2MA%.

[0043] The particle size of the flame retardant is 13 μm, and its chemical structural formula is as follows:

[0044]

[0045] The preparation method of the wear-resistant masterbatch comprises the following steps:

[0046] (R1) Take 15 parts by weight of ultra-high molecular weight polyethylene, 2 parts of graft monomer, 0.05 part of initiator, 0.15 part of regulator and 100 parts of PA66 with a relative viscosity of 2.4, and set aside;

[0047] (R2) Carry out low-temperature plasma treatment on the ultra-high molecular weight polyethylene with nitrogen for 6 min to obtain polarized polyethylene;

[0048] (R3) Mix the polarized polyethylene, graft monomer, initiator and regulator evenly, feed them into a screw extruder under nitrogen protection and extrude and pelletize at a temperature of 180 °C, and obtain graft-modified polarized polyethylene after cooling;

[0049] (R4) Disperse the graft-modified polarized polyethylene and PA66 evenly in a high-speed mixer, extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder from the feeding section are: 200 °C, 240 °C, 255 °C, 255 °C, 240 °C, 240 °C, the head temperature is 235 °C, and the screw speed is 380 r / min to obtain the wear-resistant masterbatch.

[0050] The number-average molecular weight of the ultra-high molecular weight polyethylene is 2.5 million; the graft monomer is maleic anhydride; the initiator is dicumyl peroxide; the regulator is zinc dimethyldithiocarbamate. The power of the low-temperature plasma treatment is 10 kW and the voltage is 380 V.

[0051] The wear-resistant filler powder is composed of nano-aluminum trioxide and nano-silicon carbide mixed in a weight ratio of 1:7. The nano-aluminum trioxide is obtained by soaking nano-aluminum trioxide in KH-560 coupling agent for 12 h and then filtering out the coupling agent; the carbon nanotube masterbatch is made by using PA66 with a relative viscosity of 2.4 as a carrier and melt-pelletizing with carbon nanotubes. The content of carbon nanotubes is 15 wt%, the diameter of the carbon nanotubes is 10 nm, and the tube length of the carbon nanotubes is 40 μm.

[0052] The preparation method of the wear-resistant low-warpage flame-retardant nylon composite material comprises the following steps:

[0053] (S1) Take nylon resin, syndiotactic polystyrene, antioxidant, lubricant, compatibilizer, flame retardant, wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch by weight, and set aside;

[0054] (S2) Premix nylon resin with 0.1 part of diffusion oil in a high-speed mixer for 2 min, then blend with other raw materials for another 2 min and discharge. Extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200 °C, 260 °C, 270 °C, 280 °C, 270 °C, 260 °C, 260 °C, 260 °C, 260 °C, 260 °C, and the head temperature is 270 °C, and the screw speed is 500 r / min to obtain a wear-resistant, low-warpage, flame-retardant nylon composite material.

[0055] Example 2

[0056] A wear-resistant, low-warpage, flame-retardant nylon composite material, comprising the following raw materials in parts by weight:

[0057]

[0058] The nylon resin is a PA66 / 6I copolymer with a relative viscosity of 2.0; in the PA66 / 6I copolymer, the mass ratio of PA66 to PA6I is 7:3; the number-average molecular weight of the syndiotactic polystyrene is 500,000.

[0059] The antioxidant is a mixture of antioxidant 1098 and antioxidant S9228 in a weight ratio of 1:2.

[0060] The lubricant is a high-temperature resistant silicone masterbatch MB50-001.

[0061] The compatibilizer is POE-g-MAH with a grafting rate of 1.2 MA%.

[0062] The particle size of the flame retardant is 16 μm, and its chemical structural formula is as follows:

[0063]

[0064] The preparation method of the wear-resistant masterbatch comprises the following steps:

[0065] (R1) Weigh 10 parts of ultra-high molecular weight polyethylene, 1 part of grafting monomer, 0.01 part of initiator, 0.1 part of regulator and 100 parts of PA66 with a relative viscosity of 2.4, and set aside;

[0066] (R2) Carry out low-temperature plasma treatment on the ultra-high molecular weight polyethylene with nitrogen for 5 min to obtain polarized polyethylene;

[0067] (R3) Mix the polarized polyethylene, grafting monomer, initiator and regulator evenly, feed them into a screw extruder under nitrogen protection and extrude and pelletize at a temperature of 180 °C, and obtain graft-modified polarized polyethylene after cooling;

[0068] (R4) Disperse the graft-modified polarized polyethylene and PA66 evenly in a high-speed mixer, and then extrude and pelletize them through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 190 °C, 230 °C, 250 °C, 250 °C, 235 °C, 235 °C, the head temperature is 230 °C, and the screw speed is 380 r / min to obtain the wear-resistant masterbatch.

[0069] The number-average molecular weight of the ultra-high molecular weight polyethylene is 2 million; the graft monomer is maleic anhydride; the initiator is dicumyl peroxide; the regulator is zinc dimethyldithiocarbamate. The power of the low-temperature plasma treatment is 10 kW and the voltage is 380 V.

[0070] The wear-resistant filler powder is composed of nano-aluminum trioxide and nano-silicon carbide mixed in a weight ratio of 1:5. The nano-aluminum trioxide is obtained by soaking nano-aluminum trioxide in KH-560 coupling agent for 12 h and then filtering out the coupling agent; the carbon nanotube masterbatch is made by using PA66 with a relative viscosity of 2.4 as the carrier and melting and pelletizing with carbon nanotubes. The content of carbon nanotubes is 14 wt%, the diameter of the carbon nanotubes is 12 nm, and the tube length of the carbon nanotubes is 50 μm.

[0071] The preparation method of the wear-resistant low-warpage flame-retardant nylon composite material includes the following steps:

[0072] (S1) Weigh nylon resin, syndiotactic polystyrene, antioxidant, lubricant, compatibilizer, flame retardant, wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch by weight and set aside;

[0073] (S2) Premix the nylon resin with 0.1 part of diffusion oil in a high-speed mixer for 2 min, then mix it with other raw materials for 2 min and discharge. Extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200 °C, 260 °C, 270 °C, 280 °C, 270 °C, 260 °C, 260 °C, 260 °C, 260 °C, 260 °C, the head temperature is 270 °C, and the screw speed is 500 r / min to obtain the wear-resistant low-warpage flame-retardant nylon composite material.

[0074] Example 3

[0075] A wear-resistant low-warpage flame-retardant nylon composite material, comprising the following raw materials in parts by weight:

[0076]

[0077] The nylon resin is a PA66 / 6I copolymer with a relative viscosity of 2.0; in the PA66 / 6I copolymer, the mass ratio of PA66 to PA6I is 7:3; the number-average molecular weight of the syndiotactic polystyrene is 500,000.

[0078] The antioxidant is a mixture of antioxidant 1098 and antioxidant S9228 in a weight ratio of 1:3.

[0079] The lubricant is a high-temperature resistant silicone masterbatch MB50-001.

[0080] The compatibilizer is POE-g-MAH, and its grafting rate is 1.2MA%.

[0081] The particle size of the flame retardant is 10 μm, and its chemical structural formula is as follows:

[0082]

[0083] The preparation method of the wear-resistant masterbatch includes the following steps:

[0084] (R1), Take 20 parts of ultra-high molecular weight polyethylene, 3 parts of graft monomer, 0.1 part of initiator, 0.2 part of regulator, and 100 parts of PA66 with a relative viscosity of 2.4 by weight, and set aside;

[0085] (R2), Carry out low-temperature plasma treatment on the ultra-high molecular weight polyethylene with nitrogen for 10 min to obtain polarized polyethylene;

[0086] (R3), Mix the polarized polyethylene, graft monomer, initiator, and regulator evenly, feed them into a screw extruder under nitrogen protection, and extrude and pelletize at a temperature of 180 °C. After cooling, graft-modified polarized polyethylene is obtained;

[0087] (R4), Disperse the graft-modified polarized polyethylene and PA66 evenly in a high-speed mixer, and extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder from the feeding section are: 210 °C, 250 °C, 260 °C, 260 °C, 245 °C, 245 °C, the head temperature is 240 °C, and the screw speed is 380 r / min to obtain the wear-resistant masterbatch.

[0088] The number-average molecular weight of the ultra-high molecular weight polyethylene is 3 million; the graft monomer is maleic anhydride; the initiator is dicumyl peroxide; the regulator is zinc dimethyldithiocarbamate. The power of the low-temperature plasma treatment is 10 kW and the voltage is 380 V.

[0089] The wear-resistant filler powder is composed of nano-aluminum trioxide and nano-silicon carbide mixed in a weight ratio of 1:8. The nano-aluminum trioxide is obtained by soaking nano-aluminum trioxide in KH-560 coupling agent for 12 hours and then filtering out the coupling agent. The carbon nanotube masterbatch is prepared by melt granulation with PA66 having a relative viscosity of 2.4 as the carrier and carbon nanotubes. The content of carbon nanotubes is 18 wt%, the diameter of the carbon nanotubes is 8 nm, and the length of the carbon nanotubes is 30 μm.

[0090] The preparation method of the wear-resistant low-warpage flame-retardant nylon composite material comprises the following steps:

[0091] (S1), take nylon resin, syndiotactic polystyrene, antioxidant, lubricant, compatibilizer, flame retardant, wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch by weight parts for standby;

[0092] (S2), premix the nylon resin with 0.1 part of diffusion oil in a high-speed mixer for 2 minutes, then mix with other raw materials for 2 minutes and discharge, and extrude and granulate through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200 °C, 260 °C, 270 °C, 280 °C, 270 °C, 260 °C, 260 °C, 260 °C, 260 °C, 260 °C, and the head temperature is 270 °C, and the screw speed is 500 r / min to obtain the wear-resistant low-warpage flame-retardant nylon composite material.

[0093] Example 4

[0094] A wear-resistant low-warpage flame-retardant nylon composite material, comprising the following raw materials by weight parts:

[0095]

[0096]

[0097] The nylon resin is a PA66 / 6I copolymer with a relative viscosity of 2.0; in the PA66 / 6I copolymer, the mass ratio of PA66 to PA6I is 7:3; the number-average molecular weight of the syndiotactic polystyrene is 500,000.

[0098] The antioxidant is composed of antioxidant 1098 and antioxidant S9228 mixed in a weight ratio of 1:2.3.

[0099] The lubricant is a high-temperature resistant silicone masterbatch MB50-001.

[0100] The compatibilizer is POE-g-MAH with a grafting rate of 1.2 MA%.

[0101] The particle size of the flame retardant is 13 μm, and its chemical structural formula is as follows:

[0102]

[0103] The preparation method of the wear-resistant masterbatch comprises the following steps:

[0104] (R1) Take 16 parts by weight of ultra-high molecular weight polyethylene, 1.6 parts of graft monomer, 0.06 part of initiator, 0.16 part of regulator and 100 parts of PA66 with a relative viscosity of 2.4, and set aside;

[0105] (R2) Carry out low-temperature plasma treatment on the ultra-high molecular weight polyethylene with nitrogen for 6 min to obtain polarized polyethylene;

[0106] (R3) Mix the polarized polyethylene, graft monomer, initiator and regulator evenly, feed them into a screw extruder under nitrogen protection and extrude and pelletize at a temperature of 180 °C, and obtain graft-modified polarized polyethylene after cooling;

[0107] (R4) Disperse the graft-modified polarized polyethylene and PA66 evenly in a high-speed mixer, extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder from the feeding section are: 200 °C, 240 °C, 255 °C, 255 °C, 240 °C, 240 °C, the head temperature is 235 °C, and the screw speed is 380 r / min to prepare the wear-resistant masterbatch.

[0108] The number-average molecular weight of the ultra-high molecular weight polyethylene is 2.8 million; the graft monomer is maleic anhydride; the initiator is dicumyl peroxide; the regulator is zinc dimethyldithiocarbamate. The power of the low-temperature plasma treatment is 10 kW and the voltage is 380 V.

[0109] The wear-resistant filler powder is a mixture of nano-aluminum trioxide and nano-silicon carbide in a weight ratio of 1:7. The nano-aluminum trioxide is obtained by soaking nano-aluminum trioxide in KH-560 coupling agent for 12 h and then filtering out the coupling agent; the carbon nanotube masterbatch is made by using PA66 with a relative viscosity of 2.4 as a carrier and melt-pelletizing with carbon nanotubes. The content of carbon nanotubes is 16 wt%, the diameter of the carbon nanotubes is 10 nm, and the tube length of the carbon nanotubes is 38 μm.

[0110] The preparation method of the wear-resistant low-warpage flame-retardant nylon composite material comprises the following steps:

[0111] (S1) Take nylon resin, syndiotactic polystyrene, antioxidant, lubricant, compatibilizer, flame retardant, wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch by weight, and set aside;

[0112] (S2) Premix the nylon resin with 0.1 parts of diffusion oil in a high-speed mixer for 2 minutes, then blend with other raw materials for 2 minutes and discharge the mixture, and extrude and granulate it through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200°C, 260°C, 270°C, 280°C, 270°C, 260°C, 260°C, 260°C, 260°C, 260°C, and 260°C, respectively. The head temperature is 270°C and the screw speed is 500r / min to obtain a wear-resistant, low-warpage, flame-retardant nylon composite material.

[0113] Comparative Example 1

[0114] The difference between this comparative example and Example 1 is:

[0115] The nylon resin is a mixture of PA66 (relative viscosity of 2.4) and PA6I (model: Anaiji A1315) in a weight ratio of 7:3.

[0116] Comparative Example 2

[0117] The difference between this comparative example and Example 1 is:

[0118] The flame retardant is aluminum diethylphosphinate FR-13.

[0119] Comparative Example 3

[0120] The difference between this comparative example and Example 1 is:

[0121] The preparation method of the wear-resistant masterbatch comprises the following steps:

[0122] (R1), take 17 parts by weight of ultra-high molecular weight polyethylene with a number average molecular weight of 2.5 million and 100 parts of PA66 with a relative viscosity of 2.4, and set aside;

[0123] (R2) Disperse the ultra-high molecular weight polyethylene and PA66 evenly in a high-speed mixer, and extrude and granulate them through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200°C, 240°C, 255°C, 255°C, 240°C, 240°C, the head temperature is 235°C, and the screw speed is 380r / min to obtain wear-resistant masterbatch.

[0124] Performance Testing

[0125] The nylon composite materials of Examples 1-4 and Comparative Examples 1-3 were tested for impact strength, tensile strength, flexural strength, dimensional shrinkage, flame retardant index, surface resistivity, wear loss and wear resistance coefficient. The test results are shown in Table 1 below:

[0126]

[0127]

[0128] As can be seen from Table 1 above, the wear-resistant, low-warpage, flame-retardant nylon composite material of the present invention has a lower shrinkage rate, which is beneficial to reducing the warpage degree, improving the flatness and dimensional stability, has more excellent wear resistance, and has good flame-retardant and antistatic effects.

[0129] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A wear-resistant, low-warpage, flame-retardant nylon composite material, characterized in that, It comprises raw materials in the following parts by weight: The nylon resin is a PA66 / 6I copolymer with a relative viscosity of 2.0 - 2.4; in the PA66 / 6I copolymer, the mass ratio of PA66 to PA6I is 6 - 7:3 - 4; the number-average molecular weight of the syndiotactic polystyrene is 200,000 - 1,000,000; The compatibilizer is POE-g-MAH with a grafting rate of 1.0 - 1.3MA%; The particle size of the flame retardant is 10 - 16μm, and its chemical structural formula is as follows: The preparation method of the wear-resistant masterbatch comprises the following steps: (R1) Take 10 - 20 parts by weight of ultra-high molecular weight polyethylene, 1 - 3 parts of grafting monomer, 0.01 - 0.1 part of initiator, 0.1 - 0.2 part of regulator and 100 parts of PA66 with a relative viscosity of 2.4, and set aside; (R2) Carry out low-temperature plasma treatment on the ultra-high molecular weight polyethylene with nitrogen for 5 - 10 min to obtain polarized polyethylene; (R3) Mix the polarized polyethylene, grafting monomer, initiator and regulator evenly, feed them into a screw extruder under nitrogen protection and extrude and pelletize at a temperature of 150 - 200°C, and obtain graft-modified polarized polyethylene after cooling; (R4) Disperse the graft-modified polarized polyethylene and PA66 evenly in a high-speed mixer, extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder from the feeding section are: 190 - 210°C, 230 - 250°C, 250 - 260°C, 250 - 260°C, 235 - 245°C, 235 - 245°C, the head temperature is 230 - 240°C, and the screw speed is 320 - 400 r / min to prepare the wear-resistant masterbatch; The wear-resistant filler powder is nano-aluminum trioxide and / or nano-silicon carbide; the carbon nanotube masterbatch is made by melt granulation with PA66 with a relative viscosity of 2.4 as the carrier and carbon nanotubes, the content of carbon nanotubes is 14 - 18 wt%, the diameter of the carbon nanotubes is 8 - 12 nm, and the tube length of the carbon nanotubes is 30 - 50μm.

2. The wear-resistant, low-warpage and flame-retardant nylon composite material according to claim 1, characterized in that: The antioxidant is antioxidant 1098 and / or antioxidant S9228.

3. A wear-resistant, low-warpage, flame-retardant nylon composite material according to claim 1, characterized in that: The lubricant is at least one of high-temperature resistant silicone masterbatch MB50-001, K6105M and HMB-6301.

4. The wear-resistant, low-warpage and flame-retardant nylon composite material according to claim 1, characterized in that: The number-average molecular weight of the ultra-high molecular weight polyethylene is 2,000,000 - 3,000,000; the grafting monomer is maleic anhydride; the initiator is diisopropylbenzene peroxide and / or di-tert-butyl peroxide; the regulator is zinc dimethyldithiocarbamate.

5. A method for preparing a wear-resistant, low-warpage, flame-retardant nylon composite material as described in any one of claims 1-4, characterized in that, It comprises the following steps: (S1) Take the nylon resin, syndiotactic polystyrene, antioxidant, lubricant, compatibilizer, flame retardant, wear-resistant masterbatch, wear-resistant filler powder and carbon nanotube masterbatch by weight, and set aside; (S2) Premix nylon resin with 0.1 part of diffusion oil in a high-speed mixer for 2 minutes, then blend with other raw materials for another 2 minutes and discharge. Extrude and pelletize through a twin-screw extruder. The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200 °C, 260 - 280 °C, 260 - 280 °C, 260 - 280 °C, 260 - 280 °C, 260 - 280 °C, 260 - 280 °C, 260 - 280 °C, 260 - 280 °C, 260 - 280 °C. The temperature of the die head is 270 - 290 °C, and the screw speed is 500 r / min to obtain a wear-resistant, low-warpage flame-retardant nylon composite material.

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