Fluorine-free metal-friction-resistant modified polyketone composite material and preparation method thereof

Abstract

The invention discloses a fluorine-free metal friction-resistant modified polyketone composite material and a preparation method thereof. The modified polyketone composite material comprises the following components in parts by weight: 80-95 parts of polyketone, 5-15 parts of modified ultra-high molecular weight polyethylene, 1-5 parts of a metal wear-resistant agent, 0.3-0.7 part of an antioxidant and 0.3-0.5 part of a lubricant, wherein the modified ultra-high molecular weight polyethylene is obtained by blending and modifying branched-chain-free linear polyethylene with the molecular weight of 1.5 million or above and maleic anhydride, and the metal wear-resistant agent is obtained by coating the surface of metal sulfide with a silane coupling agent. Polyketone, modified ultra-high molecular weight polyethylene and metal sulfide are subjected to blending modification, and the fluorine-free low-abrasion metal-friction-resistant material is obtained by combining good wear resistance of polyketone, low friction coefficient of ultra-high molecular weight polyethylene and high load capacity of metal sulfide.

Description

Technical Field

[0001] The invention relates to the technical field of polymer composite materials, and in particular to a fluorine-free, metal-friction-resistant modified polyketone composite material and a preparation method thereof. Background Art

[0002] Polyketone (POK) is a highly crystalline polymer. It is a new type of green polymer material synthesized from carbon monoxide and olefins (ethylene, propylene). The main chain of the molecule is a dense crystalline structure formed by high crystallization of carbon and hydrogen. It has low water absorption, good wear resistance, hydrolysis resistance, excellent chemical resistance, excellent fluidity and molding processability. In recent years, POK has been widely used in many industrial fields due to its unique properties, especially in application scenarios that require high strength, good chemical resistance and temperature resistance, such as automotive manufacturing, electronics and electrical, medical equipment and other industries. However, despite the many advantages of POK, its wear resistance is poor during friction with metal, which limits its application in certain specific fields.

[0003] In the prior art, polytetrafluoroethylene (PTFE) is often used to enhance the wear resistance of polyketone materials. Polytetrafluoroethylene is an engineering plastic with excellent self-lubricating properties, low friction coefficient, good thermal stability, and strong corrosion resistance, which makes PTFE widely used in mechanical parts, bearings, seals and other fields. Due to its unique properties, PTFE was once regarded as an ideal friction material. However, with the increase in environmental awareness and global restrictions on fluorinated compounds, such as the introduction of the fluorine ban, the application of PTFE has been affected to a certain extent. Many companies have begun to look for fluorine-free or low-fluorine alternative materials to meet increasingly stringent environmental regulations.

[0004] Therefore, there is an urgent need to explore and obtain a fluorine-free, metal-friction-resistant polyketone composite material.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a fluorine-free metal friction resistant modified polyketone composite material and a preparation method thereof, so as to improve the above technical problems.

[0007] The present invention is achieved in that:

[0008] In a first aspect, the present invention provides a fluorine-free metal friction-resistant modified polyketone composite material, which comprises the following components in parts by weight: 80 to 95 parts of polyketone, 5 to 15 parts of modified ultra-high molecular weight polyethylene, 1 to 5 parts of metal wear-resistant agent, 0.3 to 0.7 parts of antioxidant and 0.3 to 0.5 parts of lubricant;

[0009] The modified ultra-high molecular weight polyethylene is obtained by blending and modifying unbranched linear polyethylene with a molecular weight of more than 1.5 million and maleic anhydride, and the metal wear-resistant agent is obtained by coating a silane coupling agent on the surface of a metal sulfide.

[0010] In an optional embodiment, it includes the following components in parts by weight: 85-90 parts of polyketone, 8-12 parts of modified ultra-high molecular weight polyethylene, 1.5-2.5 parts of metal wear resistance agent, 0.5-0.7 parts of antioxidant and 0.3-0.5 parts of lubricant.

[0011] In an optional embodiment, the number average molecular weight of the polyketone is 10,000 to 100,000, preferably 80,000 to 100,000;

[0012] Preferably, the polyketone is a polymer synthesized from carbon monoxide and olefins.

[0013] In an optional embodiment, the antioxidant is selected from at least one of 2,2-oxalylamino-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and pentaerythritol tetrakis(3-laurylthiopropionate);

[0014] Preferably, the antioxidant comprises 2,2-oxalyl-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and pentaerythritol tetrakis(3-laurylthiopropionate); the mass ratio of the 2,2-oxalyl-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and pentaerythritol tetrakis(3-laurylthiopropionate) is (0.8-1.2):(0.8-1.2):2.

[0015] In an optional embodiment, the lubricant includes polyethylene wax and calcium stearate, and the mass ratio of the polyethylene wax to calcium stearate is 1:(1.5-2.5).

[0016] In an optional embodiment, the metal sulfide is selected from at least one of molybdenum disulfide, tungsten disulfide, tin sulfide and bismuth sulfide.

[0017] In an optional embodiment, the metal sulfide is a multiphase sulfide based on molybdenum, tungsten and manganese, and the D50 of the metal sulfide is 5 to 7 μm.

[0018] In a second aspect, the present invention provides a method for preparing a fluorine-free, metal-friction-resistant modified polyketone composite material as described in any one of the aforementioned embodiments, comprising: mixing the polyketone, the modified ultra-high molecular weight polyethylene, the metal wear-resistant agent, the antioxidant and the lubricant according to a ratio, and then extruding.

[0019] In an optional embodiment, extrusion, cooling and granulation are performed by a twin-screw extruder.

[0020] In an optional embodiment, the temperatures of 11 zones of the twin-screw extruder are set to 95-105°C, 215-225°C, 215-225°C, 215-225°C, 205-215°C, 205-215°C, 205-215°C, 195-205°C, 195-205°C, 195-205°C and 215-225°C, respectively, and the main engine speed is 200-300rpm.

[0021] The present invention has the following beneficial effects: by blending and modifying modified ultra-high molecular weight polyethylene, metal wear-resistant agent and polyketone, the good wear resistance of polyketone, the low friction coefficient of modified ultra-high molecular weight polyethylene and the high load capacity of metal wear-resistant agent are combined, and the metal friction resistance of polyketone material is comprehensively improved. Among them, ultra-high molecular weight polyethylene and maleic anhydride are blended and grafted and modified, so that its compatibility with polyketone is greatly improved and the dispersion is more uniform. The metal wear-resistant agent is a metal sulfide with a special surface treatment, so that the surface of the metal sulfide is coated with a layer of silane coupling agent, and the silane coupling agent has a strong bonding force with the matrix resin, so that the metal sulfide is firmly fixed in the matrix, not easy to fall off due to friction, and has better dispersibility in the matrix resin. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0023] The following is a detailed description of a fluorine-free metal friction-resistant modified polyketone composite material and a preparation method thereof provided by the present invention.

[0024] Some embodiments of the present invention provide a fluorine-free, metal-friction-resistant modified polyketone composite material, which includes the following components in parts by weight: 80 to 95 parts of polyketone, 5 to 15 parts of modified ultra-high molecular weight polyethylene, 1 to 5 parts of metal wear-resistant agent, 0.3 to 0.7 parts of antioxidant and 0.3 to 0.5 parts of lubricant; wherein the modified ultra-high molecular weight polyethylene is obtained by blending and modifying an unbranched linear polyethylene with a molecular weight of more than 1.5 million and maleic anhydride, and the metal wear-resistant agent is obtained by coating a metal sulfide surface with a silane coupling agent.

[0025] The inventor found that the fluorine ban required a specific replacement of polytetrafluoroethylene used to enhance the wear resistance of polyketone and metal. After a lot of research and practice, the inventor creatively selected a combination of ultra-high molecular weight polyethylene and metal wear-resistant agent to jointly enhance the wear resistance of polyketone and metal. Ultra-high molecular weight polyethylene (UHMWPE) has good chemical resistance, low friction coefficient, quietness, self-lubrication, and does not contain formaldehyde, while the metal wear-resistant agent has a layer lattice structure, the atomic layers are easy to move with each other, good metal adhesion, can form a stable lubricating film on the contact surface, high load capacity, low friction coefficient, and low wear.

[0026] However, in the process of blending and modifying polyketone by combining ultra-high molecular weight polyethylene and metal wear-resistant agent, the inventor found that the compatibility of ultra-high molecular weight polyethylene and polyketone is poor, and the dispersion is not uniform enough. Therefore, after research, ultra-high molecular weight polyethylene is blended and grafted by maleic anhydride, so that its compatibility with polyketone is greatly improved, and the dispersion is more uniform. At the same time, the metal wear-resistant agent is granular, which is directly blended with the matrix resin (mainly polyketone), and the bonding force between it and the matrix resin is weak, and it is easy to fall off during friction. Therefore, based on this defect, after research and practice, the inventor conducts special surface treatment on the metal sulfide, that is, the surface of the metal sulfide is coated with a layer of silane coupling agent, and the silane coupling agent has a strong bonding force with the matrix resin, so that the metal sulfide is firmly fixed in the matrix, not easy to fall off by friction, and the dispersibility is further improved.

[0027] It should be noted that the maleic anhydride used to modify the ultra-high molecular weight polyethylene is maleic anhydride with a sour taste and has the appearance of colorless needle-shaped or flaky crystals.

[0028] The preparation of the metal wear-resistant agent can be exemplified as follows: put the metal sulfide and 2% mass fraction of KH792 into a high-speed mixer, mix for 3 minutes, and then put into an oven for drying at 60°C to obtain the pretreated metal sulfide; KH792 is a liquid N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane coupling agent.

[0029] In some embodiments, in order to obtain better wear resistance, the formula of the modified polyketone composite material is further optimized, that is, the modified polyketone composite material includes the following components in parts by weight: 85-90 parts of polyketone, 8-12 parts of modified ultra-high molecular weight polyethylene, 1.5-2.5 parts of metal wear-resistant agent, 0.5-0.7 parts of antioxidant and 0.3-0.5 parts of lubricant.

[0030] In some embodiments, the number average molecular weight of the polyketone is 10000 to 100000, such as 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000 or 100000, etc., preferably 80000 to 100000. The appropriate number average molecular weight can ensure that the polyketone has better molecular chain intertwining performance, better crystallinity and toughness, so that it exhibits better wear resistance.

[0031] Exemplarily, polyketone is a polymer synthesized from carbon monoxide and olefins (ethylene, propylene), and is provided by the Hyosung Group of South Korea, model number M630A.

[0032] In some embodiments, the antioxidant is selected from at least one of 2,2-oxalylamino-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and pentaerythritol tetrakis(3-laurylthiopropionate). The selection of the above antioxidants is beneficial to prevent oxidative degradation of the material during use, and is beneficial to the thermal stability of the composite material during high-temperature processing. In addition, the use of antioxidants is also beneficial to enhancing the weather resistance of the polyketone-modified composite material and improving its processing performance.

[0033] Furthermore, in some preferred embodiments, the use of a combination of multiple antioxidants can enhance the effect of the antioxidant. For example, the antioxidant includes 2,2-oxalyl-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and pentaerythritol tetrakis(3-laurylthiopropionate); the mass ratio of the 2,2-oxalyl-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and pentaerythritol tetrakis(3-laurylthiopropionate) is (0.8-1.2):(0.8-1.2):2, for example 1:1:2.

[0034] In some embodiments, the lubricant includes polyethylene wax and calcium stearate, and the mass ratio of polyethylene wax to calcium stearate is 1: (1.5-2.5). By reasonably selecting the lubricant in the above specific ratio, the friction between the molecular chains of the composite material during processing can be effectively improved, making the material easier to flow during processing. In addition, the lubricant is also helpful to prevent excessive adhesion of the polyketone modified composite material to the mold during processing and molding.

[0035] For reference, the metal sulfide is at least one selected from molybdenum disulfide, tungsten disulfide, tin sulfide and bismuth sulfide.

[0036] Specifically, in order to achieve better metal adhesion and to more easily form a stable lubricating film, the metal sulfide is a multiphase sulfide based on molybdenum, tungsten and manganese, and the D50 of the metal sulfide is 5 to 7 μm.

[0037] Furthermore, some embodiments of the present invention also provide a method for preparing a fluorine-free metal friction-resistant modified polyketone composite material as described in any of the aforementioned embodiments, which comprises: mixing polyketone, modified ultra-high molecular weight polyethylene, metal wear-resistant agent, antioxidant and lubricant according to a ratio and then extruding.

[0038] Specifically, the modified polyketone composite material is obtained by extruding, cooling and granulating through a twin-screw extruder.

[0039] In order to ensure the best extrusion preparation effect, it is necessary to control the temperature of each zone of the twin-screw extruder. By way of example, the temperatures of 11 zones of the twin-screw extruder are set to 95-105°C, 215-225°C, 215-225°C, 205-215°C, 205-215°C, 205-215°C, 195-205°C, 195-205°C, 195-205°C and 215-225°C, respectively, and the main engine speed is 200-300rpm.

[0040] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0041] The polyketone in the following examples is provided by Hyosung Group of South Korea, model number is M630A, and the ultra-high molecular weight polyethylene is Lubmer L4000 produced by Mitsui Chemicals.

[0042] Example 1

[0043] This embodiment provides a fluorine-free metal friction-resistant modified polyketone composite material, which is prepared from the following components in parts by weight: 82 parts of polyketone, 15 parts of modified ultra-high molecular weight polyethylene, 2 parts of metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant.

[0044] Among them, the modified ultra-high molecular weight polyethylene is prepared by the following method: ultra-high molecular weight polyethylene and 1% mass fraction of maleic anhydride are melt-blended with a single screw, and the modified ultra-high molecular weight polyethylene is obtained by granulation after extrusion. Maleic anhydride is maleic anhydride with a sour taste, and its appearance is colorless needle-shaped or flaky crystals. The preparation of the metal wear-resistant agent is: metal sulfide and 2% mass fraction of KH792 are put into a high mixer, blended for 3 minutes, and then put into an oven at 60°C for drying to obtain pretreated metal sulfide; K792 is a liquid N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane coupling agent, and the metal sulfide is a multiphase sulfide based on molybdenum, tungsten and manganese, with a d50 of about 6μm, which is Teboko WS 44S. The antioxidant is composed of 2,2-oxalylamino-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)] propionate, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and pentaerythritol tetra(3-laurylthiopropionate) in a mass ratio of 1:1:2. The lubricant is a compound of polyethylene wax and calcium stearate in a mass ratio of 1:2.

[0045] The preparation process of the fluorine-free metal friction-resistant modified polyketone composite material is as follows: after mixing according to the above weight ratio, entering into a twin-screw extruder, and water-cooling granulation. The temperature of 11 zones of the twin-screw extruder is set to 100°C, 220°C, 220°C, 220°C, 210°C, 210°C, 210°C, 200°C, 200°C, 220°C in sequence, the main engine speed is 260rpm, and the vacuum degree is -0.08MPa.

[0046] Example 2

[0047] The only difference between this embodiment and embodiment 1 is that the components are: 87 parts of polyketone, 10 parts of modified ultra-high molecular weight polyethylene, 2 parts of metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The main engine speed of the twin-screw extruder is 240 rpm.

[0048] Example 3

[0049] The only difference between this embodiment and embodiment 2 is that the components are: 92 parts of polyketone, 5 parts of modified ultra-high molecular weight polyethylene, 2 parts of metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same.

[0050] Example 4

[0051] The only difference between this embodiment and embodiment 2 is that the components are: 88 parts of polyketone, 10 parts of modified ultra-high molecular weight polyethylene, 1 part of metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same as that of embodiment 2.

[0052] Example 5

[0053] The only difference between this embodiment and embodiment 2 is that the components are: 88 parts of polyketone, 10 parts of modified ultra-high molecular weight polyethylene, 4 parts of metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The main engine speed of the twin-screw extruder is 280 rpm.

[0054] Comparative Example 1

[0055] The only difference between this comparative example and Example 2 is that the components are: 89 parts of polyketone, 10 parts of polytetrafluoroethylene, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same as that of Example 2.

[0056] Comparative Example 2

[0057] The only difference between this comparative example and Example 2 is that the components are: 87 parts of polyketone, 10 parts of polytetrafluoroethylene, 2 parts of metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same as that of Example 2.

[0058] Comparative Example 3 The only difference between this comparative example and Example 2 is that the components are: 89 parts of polyketone, 10 parts of modified ultra-high molecular weight polyethylene, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same as that of Example 2.

[0059] Comparative Example 4 The only difference between this comparative example and Example 2 is that the components are: 97 parts of polyketone, 2 parts of metal anti-wear agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same as that of Example 2.

[0060] Comparative Example 5 The only difference between this comparative example and Example 2 is that the components are: 87 parts of polyketone, 10 parts of unmodified ultra-high molecular weight polyethylene, 2 parts of metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same as that of Example 2.

[0061] Comparative Example 6 The only difference between this comparative example and Example 2 is that the components are: 87 parts of polyketone, 10 parts of unmodified ultra-high molecular weight polyethylene, 2 parts of untreated metal wear-resistant agent, 0.6 parts of antioxidant and 0.4 parts of lubricant. The preparation process is the same as that of Example 2.

[0062] Comparative Example 7

[0063] The only difference between this comparative example and Example 2 is that the component is only 100 parts of polyketone, and the preparation process is the same as that of Example 2.

[0064] Comparative Example 8

[0065] The only difference between this comparative example and Example 2 is that the components are only: 100 parts of POM resin NW-02, and the preparation process is the same as that of Example 2.

[0066] The above embodiments and comparative examples were subjected to wear resistance test, and the specific test standard was: reference standard JIS K7218 method B, test speed 0.5 m / s, load 100 N, sliding distance 3 km; the test result data are shown in Table 1.

[0067] Table 1

[0068]

[0069] The calculation formula for the volume wear rate in Table 1 above is:

[0070] Where: K-volume wear rate; △m-mass difference of sample before and after wear; ρ-sample density; N-load; L-sliding friction distance.

[0071] From the data results in Table 1, it can be seen that the amount of modified ultra-high molecular weight polyethylene and metal wear-resistant agent added cannot be too much, which easily leads to agglomeration in the polyketone matrix, uneven dispersion, and peeling from the matrix during friction, resulting in increased wear. Compared with the composite material modified with polytetrafluoroethylene, pure polyketone resin and wear-resistant modified POM, the wear resistance of the prepared composite material against steel friction is greatly improved.

[0072] In summary, the blending and modification of polyketone (POK) with modified ultra-high molecular weight polyethylene and metal sulfide combines the good wear resistance of polyketone, the low friction coefficient of ultra-high molecular weight polyethylene, and the high load capacity of metal sulfide to obtain a fluorine-free, low-wear and metal friction-resistant material. Among them, the blending and grafting modification of ultra-high molecular weight polyethylene and maleic anhydride greatly improves its compatibility with polyketone and makes the dispersion more uniform. In addition, the metal sulfide used has undergone special surface treatment, so that the surface of the metal sulfide is coated with a layer of silane coupling agent. The silane coupling agent has a strong bonding force with the matrix resin, so that the metal sulfide is firmly fixed in the matrix, not easy to fall off due to friction, and has better dispersibility in the matrix resin.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fluorine-free metal friction-resistant modified polyketone composite material, characterized in that: The invention comprises the following components in parts by weight: 80-95 parts of polyketone, 5-15 parts of modified ultra-high molecular weight polyethylene, 1-5 parts of metal wear-resistant agent, 0.3-0.7 parts of antioxidant and 0.3-0.5 parts of lubricant; The modified ultra-high molecular weight polyethylene is obtained by blending and modifying unbranched linear polyethylene with a molecular weight of more than 1.5 million and maleic anhydride, and the metal wear-resistant agent is obtained by coating a silane coupling agent on the surface of a metal sulfide.

2. The fluorine-free metal friction-resistant modified polyketone composite material according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 85-90 parts of polyketone, 8-12 parts of modified ultra-high molecular weight polyethylene, 1.5-2.5 parts of metal wear-resistant agent, 0.5-0.7 parts of antioxidant and 0.3-0.5 parts of lubricant.

3. The fluorine-free metal friction-resistant modified polyketone composite material according to claim 1, characterized in that: The number average molecular weight of the polyketone is 10,000 to 100,000, preferably 80,000 to 100,000; Preferably, the polyketone is a polymer synthesized from carbon monoxide and olefins.

4. The fluorine-free metal friction-resistant modified polyketone composite material according to claim 1, characterized in that: The antioxidant is selected from at least one of 2,2-oxalylamino-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and pentaerythritol tetrakis(3-laurylthiopropionate); Preferably, the antioxidant comprises 2,2-oxalyl-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and pentaerythritol tetrakis(3-laurylthiopropionate); the mass ratio of the 2,2-oxalyl-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and pentaerythritol tetrakis(3-laurylthiopropionate) is (0.8-1.2):(0.8-1.2):

2.

5. The fluorine-free metal friction-resistant modified polyketone composite material according to claim 1, characterized in that: The lubricant comprises polyethylene wax and calcium stearate, and the mass ratio of the polyethylene wax to calcium stearate is 1:(1.5-2.5).

6. The fluorine-free metal friction-resistant modified polyketone composite material according to any one of claims 1 to 5, characterized in that: The metal sulfide is selected from at least one of molybdenum disulfide, tungsten disulfide, tin sulfide and bismuth sulfide.

7. The fluorine-free metal friction-resistant modified polyketone composite material according to claim 6, characterized in that: The metal sulfide is a multiphase sulfide based on molybdenum, tungsten and manganese, and the D50 of the metal sulfide is 5 to 7 μm.

8. The method for preparing the fluorine-free metal friction-resistant modified polyketone composite material according to any one of claims 1 to 7, characterized in that: It includes: The polyketone, the modified ultra-high molecular weight polyethylene, the metal wear-resistant agent, the antioxidant and the lubricant are mixed according to a proportion and then extruded.

9. The method for preparing the fluorine-free metal friction-resistant modified polyketone composite material according to claim 8, characterized in that: Extrusion, cooling and granulation are carried out by a twin-screw extruder.

10. The method for preparing the fluorine-free metal friction-resistant modified polyketone composite material according to claim 9, characterized in that: The temperatures of 11 zones of the twin-screw extruder are set to 95-105°C, 215-225°C, 215-225°C, 215-225°C, 205-215°C, 205-215°C, 205-215°C, 195-205°C, 195-205°C, 195-205°C and 215-225°C, respectively, and the main engine speed is 200-300rpm.

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