Special plastic track surface layer for cross-country pulley track and preparation method of special plastic track surface layer

Abstract

The invention discloses a special plastic track surface layer for cross-country pulley track and field, which is characterized by comprising a bottom layer, a middle layer and a surface layer, the bottom layer is a high-elasticity modified polyurethane layer, the middle layer is a carbon fiber reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite antiskid layer. Meanwhile, the invention further discloses a preparation method of the plastic track surface layer, the wear resistance of the prepared special plastic track surface layer for cross-country pulley track and field is improved by more than 3 times, the service life is long, the dry and wet friction coefficient difference is controlled within 0.07, the rebound rate in a low-temperature environment is good, discoloration is not prone to occurring, and wide application prospects are achieved.

Description

Technical Field

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

[0002] Cross-country roller skating is a summer training method that originated from cross-country skiing. It allows athletes to maintain their competitive state and improve their competition ability by using roller skating in the off-snow season. The technical similarity between this sport and cross-country skiing is very high, reaching more than 90%. Therefore, it is not only an important means of summer training for cross-country skiers, but also gradually developed into an independent competition and fitness sport, especially in the south, where more and more people like this sport. The country is also gradually promoting and popularizing it. The existing plastic track surface is not wear-resistant and easy to break in cross-country roller track training and competition, resulting in serious loss of the plastic track surface, which seriously affects the service life of the venue.

[0003] The traditional plastic track surface has the following technical defects in the application of pulley sports: (1) Conventional polyurethane materials are prone to groove deformation under high-frequency friction of pulleys. (2) The existing anti-skid particles have insufficient bonding strength with the matrix interface and are prone to fall off after long-term use. (3) The brittleness of the lower layer increases in low-temperature environments, and the impact resistance decreases significantly. (4) The surface drainage structure is not designed reasonably, which affects the grip performance of pulley sports.

[0004] CN 114933885 B discloses a breathable, environmentally friendly, high-performance plastic track bottom layer, which is composed of the following raw materials: (a) at least one single-component moisture-cured silicone-containing polyurethane adhesive; (b) at least one EPDM rubber particle; (c) at least one polyether siloxane wetting agent; (d) at least one thermoplastic polyurethane foamed by supercritical carbon dioxide, wherein the surface tension of the aqueous solution of component (c) with a mass concentration of 0.5% is ≤25mN / m. The breathable, environmentally friendly, high-performance plastic track bottom layer prepared by the present invention is used for the hybrid track bottom layer by replacing EPDM particles with part of E-TPU particles. The high elasticity of the E-TPU particles can make the hybrid track have good impact absorption performance and low vertical deformation performance. At the same time, the addition of a polyether siloxane wetting agent solves the problem of the difficulty of dispersing E-TPU in the system. When used in sports venues, the material has good elasticity, absorbs impact force, and moderately absorbs foot impact force, and the sports venue has good permanent deformation performance. However, it still cannot be used 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 off-road roller track and field, comprising a bottom layer, an intermediate layer and a surface layer, wherein the bottom layer is a high-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.

[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 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 by mass: 100-120 parts of terminal hydroxyl 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 nano-ceramic microbeads and polytetrafluoroethylene significantly improves the wear resistance index of the surface layer. Adding 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 Lingde 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, the middle layer and the 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 to 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., rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are added, and then stirred evenly, and then vacuum degassing is performed to obtain a mixture;

[0019] S13. Molding and pre-curing

[0020] The mixture obtained in step S12 is coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then coated at a uniform speed, and then cured with hot air at 80°C 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℃ 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 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 mixture is circulated for 3 times until the particle size is ≤10μm, and then mixed with modified carbon fiber. The best treatment method is to use an automatic fiber laying machine to mix the modified carbon fiber in an orthogonal arrangement of 0° / 90° to obtain a mixture;

[0026] S23.Hot pressing

[0027] The mixed material 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, and a high-speed disperser is used for shearing and dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are treated with plasma in an Ar gas environment at a power of 300 W 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 times;

[0033] S33. Surface structure treatment

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

[0035] S4. Interlayer interface enhancement treatment

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

[0037] Intermediate layer / surface layer interface: After the bottom layer / intermediate layer is combined, the surface of the intermediate layer is activated by plasma, using Ar gas, 300W power, and 90s processing time, and the surface energy is increased to more than 72mN / m, and then combined with the surface layer. Through the above-mentioned refined interlayer process design, the interlayer bonding strength can be increased by more than 40% (up to 3.5MPa).

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

[0039] Furthermore, in step S11, the silane coupling agent 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. It has good rebound rate in low temperature environment, is 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 described embodiments 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 creative work 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 used to limit the present invention.

[0046] Example 1

[0047] A special plastic track surface layer for off-road roller track and field includes a bottom layer, an intermediate layer and a surface layer. The bottom layer is a high-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-skid layer.

[0048] The bottom layer comprises the following components 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 weight: 100 kg epoxy resin, 8 kg nano Al2O3, Covestro 1150 30kg, KH-560 1kg, modified carbon fiber 20kg.

[0050] The surface layer comprises the following components by weight: 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 special plastic track for off-road roller track and field 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 an ultrasonic treatment frequency of 40kHz 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., rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are added, and then stirred evenly, and then vacuum degassing is performed to obtain a mixture;

[0057] S13. Molding and pre-curing

[0058] The mixture obtained in step S12 is coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then coated at a uniform speed, and then cured with hot air at 80°C 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, 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 uniformly mixed, a three-roll mill is used for dispersion treatment, and the mixture is cycled for 3 times until the particle size is ≤10μm, and then mixed with modified carbon fiber;

[0064] S23.Hot pressing

[0065] The mixed material 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, and a high-speed disperser is used for shearing and dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are treated with plasma in an Ar gas environment at a power of 300 W 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 times;

[0071] S33. Surface structure treatment

[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 the pre-cured bottom layer to form a chemically bonded transition layer to enhance the bonding strength of the bottom layer / middle layer;

[0075] Intermediate layer / surface layer interface: After the bottom layer / intermediate layer are combined, the intermediate layer surface is activated by plasma, using Ar gas, 300W power, and 90s processing time. The surface energy is increased to above 72mN / m, and then combined with 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 roller track and field includes a bottom layer, an intermediate layer and a surface layer. The bottom layer is a high-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-skid layer.

[0079] The bottom layer includes the following components 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: 110 kg epoxy resin, 10 kg nano Al2O3, Covestro 1150 35kg, KH-560 2kg, modified carbon fiber 30kg.

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

[0082] The method for preparing the surface layer of the special plastic track for off-road roller track and field 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 an ultrasonic treatment frequency of 40kHz 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., rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are added, and then stirred evenly, and then vacuum degassing is performed to obtain a mixture;

[0088] S13. Molding and pre-curing

[0089] The mixture obtained in step S12 is coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then coated at a uniform speed, and then cured with hot air at 80°C 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, 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 mixture is circulated for 3 times until the particle size is ≤10μm, and then the mixture is mixed with modified carbon fiber. The modified carbon fiber is mixed by an automatic fiber laying machine in a 0° / 90° orthogonal arrangement to obtain a mixture;

[0095] S23.Hot pressing

[0096] The mixed material 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, and a high-speed disperser is used for shearing and dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are treated with plasma in an Ar gas environment at a power of 300 W 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 times;

[0102] S33. Surface structure treatment

[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 of 250 μm between the diamond grids;

[0104] S4. Interlayer interface enhancement treatment

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

[0106] Intermediate layer / surface layer interface: After the bottom layer / intermediate layer are combined, the intermediate layer surface is activated by plasma, using Ar gas, 300W power, and 90s processing time. The surface energy is increased to above 72mN / m, and then combined with 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 roller track and field includes a bottom layer, an intermediate layer and a surface layer. The bottom layer is a high-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-skid layer.

[0110] The bottom layer includes the following components 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 Lingdu New Materials Co., Ltd.

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

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

[0113] The method for preparing the surface layer of the special plastic track for off-road roller track and field 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 an ultrasonic treatment frequency of 40kHz 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., rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are added, and then stirred evenly, and then vacuum degassing is performed to obtain a mixture;

[0119] S13. Molding and pre-curing

[0120] The mixture obtained in step S12 is coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then coated at a uniform speed, and then cured with hot air at 80°C 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, 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 uniformly mixed, a three-roll mill is used for dispersion treatment, and the mixture is cycled for 3 times until the particle size is ≤10μm, and then mixed with modified carbon fiber;

[0126] S23.Hot pressing

[0127] The mixed material 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, and a high-speed disperser is used for shearing and dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are treated with plasma in an Ar gas environment at a power of 300 W 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 times;

[0133] S33. Surface structure treatment

[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 of 250 μm between the diamond grids;

[0135] S4. Interlayer interface enhancement treatment

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

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

[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, and the rest is the same as Example 2, which will not be repeated here.

[0145] Performance Testing

[0146] The performance of the cross-country track special plastic track surface prepared in the above examples and comparative examples was tested, 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 load of 1000 g.

[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℃ Resilience, % 90 92 90 85 82 88 Compressive strength, MPa 31 32 32 29 25 30

[0157] It can be seen from the data in the above table that the effects of Examples 1 to 3 are good, and the wear, dry and wet friction coefficients, rebound rate, and compressive strength are all very good, 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 has better effect; the data of Comparative Example 2 shows that the lack of polytetrafluoroethylene fine powder, the synergistic effect disappears, the compressive strength is significantly reduced, and the dry and wet friction coefficients are significantly reduced; the data of Comparative Example 3 shows that the S33 step can significantly improve the friction coefficient.

Claims

1. A special plastic track surface for off-road roller track, characterized by: It comprises a bottom layer, a middle layer and a surface layer, wherein the bottom layer is a high-elastic modified polyurethane layer, the middle layer is a carbon fiber reinforced epoxy resin layer, and the surface layer is a ceramic-polyurethane composite anti-skid layer.

2. The cross-country track and field special plastic track surface layer according to claim 1 is characterized in that: The bottom layer comprises the following components by weight: 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.

3. The special plastic track surface layer for off-road roller track and field according to claim 1 is characterized in that: The middle layer comprises the following components by weight: 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.

4. The cross-country track and field special plastic track surface layer according to claim 1 is characterized in that: The surface layer comprises the following components by mass: 100-120 parts of terminal hydroxyl polybutadiene polyurethane prepolymer, 25-30 parts of isocyanate curing agent, 3-5 parts of ceramic micro beads 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.

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

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

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

8. The special plastic track surface layer for off-road roller track and field 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.

9. The method for preparing the surface layer of the special plastic track for off-road roller track and field according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Preparation of the bottom layer S11. Raw material pretreatment 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 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%. S12. Mixing and degassing The polyether polyurethane prepolymer is heated to 55-65° C., rubber particles, triethyl citrate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are added, and then stirred evenly, and then vacuum degassing is performed to obtain a mixture; S13. Molding and pre-curing The mixture obtained in step S12 is coated with a CNC scraper with a blade gap set to 1.5 mm, preheated to 50°C, and then coated at a uniform speed, and then cured with hot air at 80°C 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, 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 uniformly mixed, a three-roll mill is used for dispersion treatment, and the mixture is cycled for 3 times until the particle size is ≤10μm, and then mixed with modified carbon fiber; S23.Hot pressing The mixed material 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 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, and a high-speed disperser is used for shearing and dispersion for 30 minutes to obtain a slurry. The ceramic microbeads are treated with plasma in an Ar gas environment at a power of 300 W 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 times; S33. Surface structure treatment 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; S4. Interlayer interface enhancement treatment Bottom layer / middle layer interface: spray epoxy primer on the surface of the pre-cured bottom layer to form a chemically bonded transition layer to enhance the bonding strength of the bottom layer / middle layer; Intermediate layer / surface layer interface: After the bottom layer / intermediate layer are combined, the intermediate layer surface is activated by plasma, using Ar gas, 300W power, and 90s processing time. The surface energy is increased to above 72mN / m, and then combined with the surface layer.

10. The method for preparing the surface layer of the special plastic track for off-road roller track and field according to claim 9, characterized in that: The silane coupling agent in step S11 is KH-550.