A special plastic track surface layer for cross-country pulley track and field and its preparation method

Abstract

The present invention discloses a plastic track surface layer specifically designed for off-road track and field use. The surface layer comprises a base layer, an intermediate layer, and a surface layer. The base layer is a highly elastic modified polyurethane layer, the intermediate layer is a carbon fiber-reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite anti-slip layer. A preparation method is also disclosed. The resulting plastic track surface layer boasts over three times improved wear resistance, a long service life, a dry-wet friction coefficient difference of less than 0.07, good rebound in low-temperature environments, and resistance to discoloration, suggesting broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic runways, and in particular to a special plastic runway surface layer for cross-country pulley track and field and a preparation method thereof. Background Art

[0002] Roller-skating, a summer training method derived from cross-country skiing, allows athletes to maintain competitive form and improve their performance during the off-season. The sport shares over 90% technical similarity with cross-country skiing, making it not only an important summer training tool for cross-country skiers but also a growing competitive and fitness sport, particularly in southern China. The national government is also promoting and popularizing the sport. However, existing plastic track surfaces are not wear-resistant and easily break during cross-country roller-skating training and competitions, resulting in significant wear and tear on the surface, seriously impacting the service life of the track.

[0003] The following technical defects exist in the traditional plastic track surface layer for pulley sports applications: (1) Conventional polyurethane materials are prone to groove deformation under high-frequency friction of the pulley. (2) The existing anti-slip particles have insufficient bonding strength with the substrate interface, and are prone to falling off after long-term use. (3) The brittleness of the subsurface increases in low-temperature environments, and the impact resistance is significantly reduced. (4) The surface drainage structure is not designed properly, which affects the grip performance of pulley sports.

[0004] CN 114933885 B discloses a breathable, environmentally friendly, high-performance plastic track base layer, comprising the following ingredients: (a) at least one single-component moisture-curing silicone-containing polyurethane adhesive; (b) at least one EPDM rubber particle; (c) at least one polyether siloxane wetting agent; and (d) at least one thermoplastic polyurethane foamed with supercritical carbon dioxide, wherein the surface tension of a 0.5% mass concentration of component (c) in aqueous solution is ≤25 mN / m. The breathable, environmentally friendly, high-performance plastic track base layer prepared by the present invention partially replaces EPDM particles with E-TPU particles for hybrid track base layers. The high elasticity of the E-TPU particles enables hybrid tracks to have good impact absorption and low vertical deformation. The addition of the polyether siloxane wetting agent solves the problem of E-TPU's difficulty dispersing in the system. When used on sports surfaces, the material exhibits excellent elasticity, absorbs impact forces, moderately absorbs foot impact forces, and exhibits good permanent deformation resistance. However, it remains unsuitable for use on cross-country roller track tracks. Summary of the Invention

[0005] The purpose of the present invention is to provide a special plastic track surface layer for cross-country pulley track and field, comprising a bottom layer, an intermediate layer, and a surface layer. The bottom layer is a high-elasticity modified polyurethane layer, the intermediate layer is a carbon fiber reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite anti-slip layer.

[0006] Furthermore, the bottom layer comprises the following components in parts by mass: 100-120 parts of polyether polyurethane prepolymer, 10-15 parts of activated rubber particles, 2-3 parts of triethyl citrate, and 1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0007] Furthermore, the middle layer includes the following components in parts by mass: 100-110 parts of epoxy resin, 8-10 parts of nano-Al2O3, 30-35 parts of epoxy curing agent, 1-2 parts of coupling agent, and 20-30 parts of modified carbon fiber. Introducing the carbon fiber reinforced epoxy resin layer into the middle layer of the runway can significantly improve the overall compressive strength.

[0008] Furthermore, the surface layer comprises the following components in parts by mass: 100-120 parts of hydroxyl-terminated polybutadiene polyurethane prepolymer, 25-30 parts of isocyanate curing agent, 3-5 parts of ceramic microbeads with a particle size of 50-150 μm, 2 parts of polytetrafluoroethylene fine powder with a particle size of 5-10 μm, 2-3 parts of gas-phase SiO2, and 1 part of benzotriazole. The synergistic effect of the nano-ceramic microbeads and polytetrafluoroethylene significantly improves the wear resistance index of the surface layer. The addition of benzotriazole ultraviolet absorber can delay aging and discoloration of the surface layer and extend the service life.

[0009] Furthermore, the polyether polyurethane prepolymer is UC-902 produced by Shandong Zero New Materials Co., Ltd.

[0010] Furthermore, the epoxy curing agent is Huntsman D230, and the coupling agent is KH-560.

[0011] Furthermore, the hydroxy-terminated polybutadiene polyurethane prepolymer is Covestro 1150, isocyanate curing agent is Covestro N 3900.

[0012] Furthermore, the thicknesses of the bottom layer, middle layer and surface layer are 3-5 mm, 3-5 mm and 3-5 mm respectively.

[0013] At the same time, the present invention also provides a method for preparing the above-mentioned cross-country track and field special plastic track surface layer, comprising the following steps:

[0014] S1. Preparation of the bottom layer

[0015] S11. Raw material pretreatment

[0016] Activation of rubber particles: Use waste tire rubber powder with a particle size of 2-3 mm, soak it in 5% silane coupling agent ethanol solution, with a solid-liquid ratio of 1:5 and ultrasonic treatment at a frequency of 40kHz for 30 minutes, and then dry it to a moisture content of <0.3%.

[0017] S12. Mixing and degassing

[0018] The polyether polyurethane prepolymer is heated to 55-65° C., and rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are added, followed by stirring evenly, and then vacuum degassing to obtain a mixture;

[0019] S13. Molding and pre-curing

[0020] The mixture obtained in step S12 was coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then scraped at a constant speed. It was then cured in an 80°C hot air oven for 30 minutes and then naturally dried for 24 hours.

[0021] S2. Intermediate layer preparation

[0022] S21. Carbon fiber surface treatment

[0023] Polydopamine coating deposition: Prepare 2mg / mL dopamine hydrochloride, immerse the carbon fiber bundle in the solution, stir magnetically, react at 25-30°C for 24h, then filter, wash, and dry to obtain modified carbon fiber. The modified carbon fiber has improved surface wettability because the polydopamine coating is rich in polar groups such as amino and hydroxyl groups, which can significantly improve the hydrophobic properties of the carbon fiber and increase its surface energy, thereby improving its wettability with the resin matrix. In addition, the modified carbon fiber can covalently bond with the epoxy groups in the resin to form a strong interface bond.

[0024] S22. Mixing process:

[0025] After epoxy resin, nano-Al2O3, epoxy curing agent and coupling agent are evenly mixed, a three-roll mill is used for dispersion treatment, and the process is repeated three times until the particle size is ≤10μm. The modified carbon fiber is then mixed with the modified carbon fiber. The optimal treatment method is to use an automatic fiber placement machine to mix the modified carbon fiber in a 0° / 90° orthogonal arrangement to obtain a mixture.

[0026] S23.Hot pressing

[0027] The mixture obtained in step S22 is placed in a mold, closed at a pressure of 0.5 MPa, pre-pressed for 5 minutes, then cured at 80°C for 20 minutes, then heated to 120°C for 40 minutes, cooled to 60°C while maintaining pressure, and demolded to obtain an intermediate layer;

[0028] S3. Surface layer preparation

[0029] S31. Composite slurry preparation

[0030] The terminal hydroxyl polybutadiene polyurethane prepolymer and the isocyanate curing agent are evenly mixed, and then ceramic microbeads, polytetrafluoroethylene fine powder, gas-phase SiO2, and benzotriazole are added. A high-speed disperser is used for shear dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are plasma treated in an Ar gas environment at a power of 300W for 15 minutes.

[0031] S32. Spray deposition

[0032] The slurry obtained in step S31 is sprayed by a spraying robot at a spraying distance of 200 mm and a gun speed of 0.5 m / s in three spraying steps;

[0033] S33. Surface structuring

[0034] Using fiber laser, wavelength 1064nm, power density 8J / cm 2 , etching a diamond grid with a depth of 0.3mm, a grid side length of 1.2mm, and a width of 250μm between diamond grids on the surface after spraying in step S32. The unique laser micro-engraving texture design makes the friction coefficient retention rate in the wet state ≥85%;

[0035] S4. Interlayer interface enhancement treatment

[0036] Bottom layer / middle layer interface: spray epoxy primer on the surface of pre-cured bottom layer to form a chemically bonded transition layer to enhance the bonding strength between bottom layer and middle layer;

[0037] Intermediate / surface layer interface: After the base / intermediate layers are bonded, the intermediate layer undergoes plasma surface activation using Ar gas at 300W for 90 seconds, raising its surface energy to over 72mN / m before bonding to the surface layer. This refined interlayer process design increases interlayer bond strength by over 40% (to 3.5MPa).

[0038] In the above preparation method, a gradient curing process is adopted to achieve optimized distribution of interlayer stress.

[0039] Furthermore, the silane coupling agent in step S11 is KH-550.

[0040] Beneficial effects of the present invention:

[0041] 1. The wear resistance of the surface layer of the cross-country pulley track and field special plastic track prepared by the present invention is improved by more than 3 times, and the service life is long.

[0042] 2. The difference between dry and wet friction coefficients is controlled within 0.07.

[0043] 3. Good rebound rate in low temperature environment, not easy to change color, and has broad application prospects. DETAILED DESCRIPTION

[0044] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0045] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0046] Example 1

[0047] A special plastic track surface layer for off-road pulley track and field includes a bottom layer, an intermediate layer, and a surface layer. The bottom layer is a high-elasticity modified polyurethane layer, the intermediate layer is a carbon fiber reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite anti-slip layer.

[0048] The bottom layer comprises the following components in parts by mass: 100 kg of polyether polyurethane prepolymer, 10 kg of activated rubber particles, 2 kg of triethyl citrate, and 1 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0049] The middle layer includes the following components by mass: 100kg epoxy resin, 8kg nano-Al2O3, Covestro 1150 30kg, KH-560 1kg, modified carbon fiber 20kg.

[0050] The surface layer comprises the following components in parts by mass: 100 kg of hydroxyl-terminated polybutadiene polyurethane prepolymer, N 3900 25kg, ceramic micro beads with particle size of 50-150μm 3kg, polytetrafluoroethylene fine powder with particle size of 5-10μm 2kg, gas-phase SiO2 2kg, and benzotriazole 1kg.

[0051] The method for preparing the surface layer of the cross-country track and field special plastic track comprises the following steps:

[0052] S1. Preparation of the bottom layer

[0053] S11. Raw material pretreatment

[0054] Activation of rubber particles: Use waste tire rubber powder with a particle size of 2 to 3 mm, soak it in 5% silane coupling agent KH-550 ethanol solution, with a solid-liquid ratio of 1:5 and ultrasonic treatment at a frequency of 40 kHz for 30 minutes, and then dry it to a moisture content of <0.3%.

[0055] S12. Mixing and degassing

[0056] The polyether polyurethane prepolymer is heated to 55-65° C., and rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are added, followed by stirring evenly, and then vacuum degassing to obtain a mixture;

[0057] S13. Molding and pre-curing

[0058] The mixture obtained in step S12 was coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then scraped at a constant speed. It was then cured in an 80°C hot air drying oven for 30 minutes and then naturally dried for 24 hours.

[0059] S2. Intermediate layer preparation

[0060] S21. Carbon fiber surface treatment

[0061] Polydopamine coating deposition: Prepare 2 mg / mL dopamine hydrochloride, immerse the carbon fiber bundle in the solution, stir magnetically, and react at 25-30°C for 24 hours, then filter, wash, and dry to obtain the modified carbon fiber;

[0062] S22. Mixing process:

[0063] After epoxy resin, nano-Al2O3, epoxy curing agent and coupling agent are evenly mixed, a three-roll mill is used for dispersion treatment, and the process is repeated three times until the particle size is ≤10μm, and then the modified carbon fiber is mixed;

[0064] S23.Hot pressing

[0065] The mixture obtained in step S22 is placed in a mold, closed at a pressure of 0.5 MPa, pre-pressed for 5 minutes, then cured at 80°C for 20 minutes, then heated to 120°C for 40 minutes, cooled to 60°C while maintaining pressure, and demolded to obtain an intermediate layer;

[0066] S3. Surface layer preparation

[0067] S31. Composite slurry preparation

[0068] The terminal hydroxyl polybutadiene polyurethane prepolymer and the isocyanate curing agent are evenly mixed, and then ceramic microbeads, polytetrafluoroethylene fine powder, gas-phase SiO2, and benzotriazole are added. A high-speed disperser is used for shear dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are plasma treated in an Ar gas environment at a power of 300W for 15 minutes.

[0069] S32. Spray deposition

[0070] The slurry obtained in step S31 is sprayed by a spraying robot at a spraying distance of 200 mm and a gun speed of 0.5 m / s in three spraying steps;

[0071] S33. Surface structuring

[0072] Using fiber laser, wavelength 1064nm, power density 8J / cm 2 , etching a diamond grid with a depth of 0.3 mm on the surface sprayed in step S32, with a grid side length of 1.2 mm and a width of 250 μm between the diamond grids;

[0073] S4. Interlayer interface enhancement treatment

[0074] Bottom layer / middle layer interface: spray epoxy primer on the surface of pre-cured bottom layer to form a chemically bonded transition layer to enhance the bonding strength between bottom layer and middle layer;

[0075] Intermediate layer / surface layer interface: After the bottom layer / intermediate layer are bonded, the surface of the intermediate layer is activated by plasma using Ar gas, a power of 300W, and a treatment time of 90s. The surface energy is increased to above 72mN / m, and then the intermediate layer is bonded to the surface layer.

[0076] The thicknesses of the bottom layer, middle layer and surface layer are 4 mm, 5 mm and 4 mm respectively.

[0077] Example 2

[0078] A special plastic track surface layer for off-road pulley track and field includes a bottom layer, an intermediate layer, and a surface layer. The bottom layer is a high-elasticity modified polyurethane layer, the intermediate layer is a carbon fiber reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite anti-slip layer.

[0079] The bottom layer includes the following components in parts by mass: 120 kg of polyether polyurethane prepolymer, 15 kg of activated rubber particles, 3 kg of triethyl citrate, and 1 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The polyether polyurethane prepolymer is UC-902 produced by Shandong Zero New Materials Co., Ltd.

[0080] The middle layer includes the following components by mass: epoxy resin 110kg, nano Al2O3 10kg, Covestro 1150 35kg, KH-560 2kg, modified carbon fiber 30kg.

[0081] The surface layer comprises the following components in parts by mass: 1150 120kg, Covestro N 3900 30kg, ceramic micro beads with particle size of 50-150μm 5kg, polytetrafluoroethylene fine powder with particle size of 5-10μm 2kg, gas-phase SiO2 3kg, and benzotriazole 1kg.

[0082] The method for preparing the surface layer of the cross-country track and field special plastic track comprises the following steps:

[0083] S1. Preparation of the bottom layer

[0084] S11. Raw material pretreatment

[0085] Activation of rubber particles: Use waste tire rubber powder with a particle size of 2 to 3 mm, soak it in 5% silane coupling agent KH-550 ethanol solution, with a solid-liquid ratio of 1:5 and ultrasonic treatment at a frequency of 40 kHz for 30 minutes, and then dry it to a moisture content of <0.3%.

[0086] S12. Mixing and degassing

[0087] The polyether polyurethane prepolymer is heated to 55-65° C., and rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are added, followed by stirring evenly, and then vacuum degassing to obtain a mixture;

[0088] S13. Molding and pre-curing

[0089] The mixture obtained in step S12 was coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then scraped at a constant speed. It was then cured in an 80°C hot air drying oven for 30 minutes and then naturally dried for 24 hours.

[0090] S2. Intermediate layer preparation

[0091] S21. Carbon fiber surface treatment

[0092] Polydopamine coating deposition: Prepare 2 mg / mL dopamine hydrochloride, immerse the carbon fiber bundle in the solution, stir magnetically, and react at 25-30°C for 24 hours, then filter, wash, and dry to obtain the modified carbon fiber;

[0093] S22. Mixing process:

[0094] After epoxy resin, nano-Al2O3, epoxy curing agent and coupling agent are uniformly mixed, a three-roll mill is used for dispersion treatment, and the process is repeated three times until the particle size is ≤10μm. The modified carbon fiber is then mixed with the modified carbon fiber using an automatic fiber placement machine in a 0° / 90° orthogonal arrangement to obtain a mixture;

[0095] S23.Hot pressing

[0096] The mixture obtained in step S22 is placed in a mold, closed at a pressure of 0.5 MPa, pre-pressed for 5 minutes, then cured at 80°C for 20 minutes, then heated to 120°C for 40 minutes, cooled to 60°C while maintaining pressure, and demolded to obtain an intermediate layer;

[0097] S3. Surface layer preparation

[0098] S31. Composite slurry preparation

[0099] The terminal hydroxyl polybutadiene polyurethane prepolymer and the isocyanate curing agent are evenly mixed, and then ceramic microbeads, polytetrafluoroethylene fine powder, gas-phase SiO2, and benzotriazole are added. A high-speed disperser is used for shear dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are plasma treated in an Ar gas environment at a power of 300W for 15 minutes.

[0100] S32. Spray deposition

[0101] The slurry obtained in step S31 is sprayed by a spraying robot at a spraying distance of 200 mm and a gun speed of 0.5 m / s in three spraying steps;

[0102] S33. Surface structuring

[0103] Using fiber laser, wavelength 1064nm, power density 8J / cm 2 , etching a diamond grid with a depth of 0.3 mm on the surface sprayed in step S32, with a grid side length of 1.2 mm and a width between the diamond grids of 250 μm;

[0104] S4. Interlayer interface enhancement treatment

[0105] Bottom layer / middle layer interface: spray epoxy primer on the surface of pre-cured bottom layer to form a chemically bonded transition layer to enhance the bonding strength between bottom layer and middle layer;

[0106] Intermediate layer / surface layer interface: After the bottom layer / intermediate layer are bonded, the surface of the intermediate layer is activated by plasma using Ar gas, a power of 300W, and a treatment time of 90s. The surface energy is increased to above 72mN / m, and then the intermediate layer is bonded to the surface layer.

[0107] The thicknesses of the bottom layer, middle layer and surface layer are 4 mm, 5 mm and 4 mm respectively.

[0108] Example 3

[0109] A special plastic track surface layer for off-road pulley track and field includes a bottom layer, an intermediate layer, and a surface layer. The bottom layer is a high-elasticity modified polyurethane layer, the intermediate layer is a carbon fiber reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite anti-slip layer.

[0110] The bottom layer includes the following components in parts by mass: 110 kg of polyether polyurethane prepolymer, 12 kg of activated rubber particles, 3 kg of triethyl citrate, and 1 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The polyether polyurethane prepolymer is UC-902 produced by Shandong Zero New Materials Co., Ltd.

[0111] The middle layer includes the following components by mass: epoxy resin 110kg, nano Al2O3 9kg, Covestro 1150 32kg, KH-560 2kg, modified carbon fiber 30kg.

[0112] The surface layer comprises the following components in parts by mass: 1150 120kg, Covestro N 3900 28kg, ceramic micro beads with particle size of 50-150μm 5kg, polytetrafluoroethylene fine powder with particle size of 5-10μm 2kg, gas-phase SiO2 3kg, and benzotriazole 1kg.

[0113] The method for preparing the surface layer of the cross-country track and field special plastic track comprises the following steps:

[0114] S1. Preparation of the bottom layer

[0115] S11. Raw material pretreatment

[0116] Activation of rubber particles: Use waste tire rubber powder with a particle size of 2 to 3 mm, soak it in 5% silane coupling agent KH-550 ethanol solution, with a solid-liquid ratio of 1:5 and ultrasonic treatment at a frequency of 40 kHz for 30 minutes, and then dry it to a moisture content of <0.3%.

[0117] S12. Mixing and degassing

[0118] The polyether polyurethane prepolymer is heated to 55-65° C., and rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are added, followed by stirring evenly, and then vacuum degassing to obtain a mixture;

[0119] S13. Molding and pre-curing

[0120] The mixture obtained in step S12 was coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then scraped at a constant speed. It was then cured in an 80°C hot air oven for 30 minutes and then naturally dried for 24 hours.

[0121] S2. Intermediate layer preparation

[0122] S21. Carbon fiber surface treatment

[0123] Polydopamine coating deposition: Prepare 2 mg / mL dopamine hydrochloride, immerse the carbon fiber bundle in the solution, stir magnetically, and react at 25-30°C for 24 hours, then filter, wash, and dry to obtain the modified carbon fiber;

[0124] S22. Mixing process:

[0125] After epoxy resin, nano-Al2O3, epoxy curing agent and coupling agent are evenly mixed, a three-roll mill is used for dispersion treatment, and the process is repeated three times until the particle size is ≤10μm, and then the modified carbon fiber is mixed;

[0126] S23.Hot pressing

[0127] The mixture obtained in step S22 is placed in a mold, closed at a pressure of 0.5 MPa, pre-pressed for 5 minutes, then cured at 80°C for 20 minutes, then heated to 120°C for 40 minutes, cooled to 60°C while maintaining pressure, and demolded to obtain an intermediate layer;

[0128] S3. Surface layer preparation

[0129] S31. Composite slurry preparation

[0130] The terminal hydroxyl polybutadiene polyurethane prepolymer and the isocyanate curing agent are evenly mixed, and then ceramic microbeads, polytetrafluoroethylene fine powder, gas-phase SiO2, and benzotriazole are added. A high-speed disperser is used for shear dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are plasma treated in an Ar gas environment at a power of 300W for 15 minutes.

[0131] S32. Spray deposition

[0132] The slurry obtained in step S31 is sprayed by a spraying robot at a spraying distance of 200 mm and a gun speed of 0.5 m / s in three spraying steps;

[0133] S33. Surface structuring

[0134] Using fiber laser, wavelength 1064nm, power density 8J / cm 2 , etching a diamond grid with a depth of 0.3 mm on the surface sprayed in step S32, with a grid side length of 1.2 mm and a width between the diamond grids of 250 μm;

[0135] S4. Interlayer interface enhancement treatment

[0136] Bottom layer / middle layer interface: spray epoxy primer on the surface of pre-cured bottom layer to form a chemically bonded transition layer to enhance the bonding strength between bottom layer and middle layer;

[0137] Intermediate layer / surface layer interface: After the bottom layer / intermediate layer are bonded, the surface of the intermediate layer is activated by plasma using Ar gas, a power of 300W, and a treatment time of 90s. The surface energy is increased to above 72mN / m, and then the intermediate layer is bonded to the surface layer.

[0138] The thicknesses of the bottom layer, middle layer and surface layer are 4 mm, 5 mm and 4 mm respectively.

[0139] Comparative Example 1

[0140] The carbon fiber modification step S21 in Example 3 is removed, and the rest is the same as Example 3 and will not be repeated here.

[0141] Comparative Example 2

[0142] Except for the polytetrafluoroethylene fine powder component in Example 3, the rest is the same as Example 3 and will not be described in detail.

[0143] Comparative Example 3

[0144] Remove step S33 in Example 2. The rest is the same as Example 2 and will not be repeated here.

[0145] Performance Testing

[0146] The performance test of the cross-country track and field special plastic track surface prepared in the above examples and comparative examples was carried out, and the test method was as follows:

[0147] 1. Abrasion resistance test (GB / T 1768-2006)

[0148] The mass loss was measured after 5000 revolutions using a CS-10 grinding wheel with a 1000 g load.

[0149] 2. Friction coefficient test (ASTM E303-93)

[0150] Use the British pendulum apparatus to test in both dry and wet conditions.

[0151] 3. Rebound rate

[0152] Refer to GB / T 2941-2006.

[0153] 4. Compressive strength

[0154] Reference GB / T 14833-2011

[0155] Table 1 Performance test results

[0156] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 DIN wear, mg 38 36 38 47 46 46 Dry friction coefficient 0.89 0.92 0.90 0.85 0.74 0.80 Wet friction coefficient 0.83 0.86 0.84 0.78 0.66 0.71 -20℃ rebound rate, % 90 92 90 85 82 88 Compressive strength, MPa 31 32 32 29 25 30

[0157] As can be seen from the data in the table above, the effects of Examples 1 to 3 are all good, with good performance in wear, dry and wet friction coefficients, rebound rate, and compressive strength, especially the wet friction coefficient is less reduced. The data of Comparative Example 1 shows that the modified carbon fiber technology after carbon fiber modification is more effective; the data of Comparative Example 2 shows that the lack of polytetrafluoroethylene fine powder eliminates the synergistic effect, significantly reduces the compressive strength, and significantly reduces the dry and wet friction coefficients; the data of Comparative Example 3 shows that step S33 can significantly improve the friction coefficient.

Claims

1. A special plastic track surface for cross-country track and field, characterized by: It includes a bottom layer, an intermediate layer, and a surface layer, wherein the bottom layer is a high-elasticity modified polyurethane layer, the intermediate layer is a carbon fiber reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite anti-slip layer; The bottom layer comprises the following components in parts by mass: 100-120 parts of polyether polyurethane prepolymer, 10-15 parts of activated rubber particles, 2-3 parts of triethyl citrate, and 1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; The intermediate layer comprises the following components in parts by mass: 100-110 parts of epoxy resin, 8-10 parts of nano-Al2O3, 30-35 parts of epoxy curing agent, 1-2 parts of coupling agent, and 20-30 parts of modified carbon fiber; The surface layer comprises the following components in parts by mass: 100-120 parts of hydroxyl-terminated polybutadiene polyurethane prepolymer, 25-30 parts of isocyanate curing agent, 3-5 parts of ceramic microbeads with a particle size of 50-150 μm, 2 parts of polytetrafluoroethylene fine powder with a particle size of 5-10 μm, 2-3 parts of gas-phase SiO2, and 1 part of benzotriazole.

2. The cross-country track and field special plastic track surface layer according to claim 1 is characterized in that: The polyether polyurethane prepolymer is UC-902 produced by Shandong Lingdu New Materials Co., Ltd.

3. The cross-country track and field special plastic track surface layer according to claim 1, characterized in that: The epoxy curing agent is Huntsman D230, and the coupling agent is KH-560.

4. The cross-country track and field special plastic track surface layer according to claim 1, characterized in that: The hydroxyl-terminated polybutadiene polyurethane prepolymer is Covestro Desmophen® 1150, and the isocyanate curing agent is Covestro Desmodur® N 3900.

5. The cross-country track and field special plastic track surface layer according to claim 1 is characterized by: The thicknesses of the bottom layer, the middle layer and the surface layer are 3-5 mm, 3-5 mm and 3-5 mm respectively.

6. The method for preparing a special plastic track surface layer for off-road pulley track and field according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Preparation of the bottom layer S11. Raw material pretreatment Rubber particle activation: Use waste tire rubber powder with a particle size of 2-3mm, soak it in 5% silane coupling agent ethanol solution, with a solid-liquid ratio of 1:5, and ultrasonic treatment at a frequency of 40kHz for 30 minutes, and then dry it to a moisture content of less than 0.3%; S12. Mixing and degassing The polyether polyurethane prepolymer is heated to 55-65° C., and rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are added, followed by stirring evenly, and then vacuum degassing to obtain a mixture; S13. Molding and pre-curing The mixture obtained in step S12 was coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then scraped at a constant speed. It was then cured in an 80°C hot air drying oven for 30 minutes and then naturally dried for 24 hours. S2. Intermediate layer preparation S21. Carbon fiber surface treatment Polydopamine coating deposition: Prepare 2 mg / mL dopamine hydrochloride, immerse the carbon fiber bundle in the solution, stir magnetically, and react at 25-30°C for 24 hours. Then filter, wash, and dry to obtain the modified carbon fiber. S22. Mixing process: After epoxy resin, nano-Al2O3, epoxy curing agent and coupling agent are evenly mixed, a three-roll mill is used for dispersion treatment, and the process is repeated three times until the particle size is ≤10μm, and then the modified carbon fiber is mixed; S23.Hot pressing The mixture obtained in step S22 is placed in a mold, closed at a pressure of 0.5 MPa, pre-pressed for 5 minutes, then cured at 80°C for 20 minutes, then heated to 120°C for 40 minutes, cooled to 60°C while maintaining pressure, and demolded to obtain an intermediate layer; S3. Surface layer preparation S31. Composite slurry preparation The hydroxy-terminated polybutadiene polyurethane prepolymer and the isocyanate curing agent were mixed evenly, and then ceramic microbeads, polytetrafluoroethylene fine powder, gas-phase SiO2, and benzotriazole were added, and sheared and dispersed for 30 minutes using a high-speed disperser to obtain a slurry. The ceramic microbeads were plasma treated in an Ar gas environment at a power of 300W for 15 minutes; S32. Spray deposition The slurry obtained in step S31 is sprayed by a spraying robot at a spraying distance of 200 mm and a gun speed of 0.5 m / s in three spraying steps; S33. Surface structuring A fiber laser with a wavelength of 1064 nm and a power density of 8 J / cm² was used to etch a diamond grid with a depth of 0.3 mm, a grid side length of 1.2 mm, and a width of 250 μm between the diamond grids on the surface sprayed in step S32; S4. Interlayer interface enhancement treatment Bottom layer / middle layer interface: spray epoxy primer on the surface of pre-cured bottom layer to form a chemically bonded transition layer to enhance the bonding strength between bottom layer and middle layer; Intermediate layer / surface layer interface: After the bottom layer / intermediate layer are bonded, the surface of the intermediate layer is activated by plasma using Ar gas, a power of 300W, and a treatment time of 90s. The surface energy is increased to above 72mN / m, and then the intermediate layer is bonded to the surface layer.

7. The method for preparing the surface layer of the special plastic track for cross-country pulley track and field according to claim 6, characterized in that: The silane coupling agent in step S11 is KH-550.