High modulus tear resistant polyurethane material for track pads and method of making same

Abstract

This invention belongs to the field of track materials and discloses a high-modulus tear-resistant polyurethane material for track plates. The preparation components and their mass fractions are as follows: 60-80 parts of polytetrahydrofuran ether diol / polycaprolactone polyol; 20-40 parts of diphenylmethyl alkyl diisocyanate; 2-5 parts of catalyst; 1-5 parts of defoamer; 1-5 parts of wear-resistant reinforcing agent; 1-5 parts of toughening agent; 8-25 parts of crosslinking agent; and 3-8 parts of antistatic agent. This invention utilizes a composite material composed of diphenylmethane diisocyanate, tetrahydrofuran polyol, and polycaprolactone to improve the resilience, internal heat generation, and tear resistance of polyurethane, and adds wear-resistant agents to enhance wear resistance. Compared with traditional synthetic rubber track materials, the tear resistance and wear are significantly improved, effectively reducing chipping and spalling of the tracked vehicle's ground contact composite material, increasing the service life of vehicle tracks, and reducing maintenance costs.

Description

Technical Field

[0001] This invention belongs to the field of track materials, and particularly relates to a high-modulus tear-resistant polyurethane material for track plates and its preparation method. Background Technology

[0002] Tank and armored vehicle tracks are fitted with rubber pads or vulcanized rubber on the ground contact surface. Their function is to alleviate high-frequency, low-amplitude loads, improve vehicle ride comfort, enhance crew comfort, and extend the service life of tracks, running gear components, electronic components, and other system components. In recent years, with the development of equipment technology, rubber-coated tracks have become particularly crucial for equipment vibration reduction, noise reduction, silent driving, and infrared reflection technology.

[0003] Domestic universities and research institutions have conducted research on special rubbers used in tank vehicle tracks, and the resulting achievements have been applied to armored vehicles. These applications are primarily in high-temperature and high-dust-affected areas. However, in practical applications, the track's ground rubber blocks still exhibit insufficient tear resistance, easily leading to problems such as chipping and breakage in the early stages, affecting track lifespan and increasing maintenance costs. This invention addresses these common problems by developing a high-performance polyurethane composite material for track pad ground contact, thereby extending the service life of armored vehicle tracks. Summary of the Invention

[0004] The technical problem to be solved by this invention is: how to reduce the chipping and falling off of rubber blocks on tracked vehicles, improve the service life of vehicle tracks, and reduce maintenance costs.

[0005] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows: A high-modulus tear-resistant polyurethane material for track plates, wherein the components and their mass fractions in the preparation of the polyurethane material are as follows: 60-80 parts of polytetrahydrofuran ether diol / polycaprolactone polyol; 20-40 parts of diphenylmethyl alkyl diisocyanate; 2-5 parts catalyst; 1-5 parts of defoamer; 1-5 parts of wear-resistant reinforcing agent; Toughening agent 1-5 parts; 8-25 parts of crosslinking agent; 3 to 8 parts of antistatic agent.

[0006] The present invention also provides a track plate using the above-mentioned high modulus tear-resistant polyurethane material. The track plate is composed of a metal frame, anti-circumferential rotation components, and lateral and longitudinal fixing components. The anti-circumferential rotation components, lateral and longitudinal fixing components are fixed on the metal frame and vulcanized together with the rubber block made of high modulus tear-resistant polyurethane material to increase the bonding reliability.

[0007] Furthermore, the processing procedure for the track plates is as follows: S1: Track plate processing: Ultrasonic cleaning of the track plates using a volatile solvent as the cleaning agent. After the surface is dried, adhesive is sprayed on. The first coat needs to reach a thickness of 10-20 micrometers. After drying, a second coat is sprayed and dried. The overall dry film thickness reaches 30-60 micrometers. Then, the track plates are placed in a pre-set oven at a temperature of 125±25℃ for later use. S2: Raw material preparation: Add polytetrahydrofuran ether diol, polycaprolactone polyol, and diphenylmethyl alkyl diisocyanate to the casting machine, setting the temperature to 80±20℃; add the crosslinking agent to the auxiliary material tank B of the casting machine, setting the temperature to 140±20℃; add the antistatic agent to the auxiliary material tank C of the casting machine, at room temperature; add the catalyst to the special material tank of the casting machine, at room temperature; degas all raw materials for 1~3 hours. S3: Casting ratio measurement: After S2 is prepared, the ratio measurement is carried out first to confirm that the casting ratio is correct before starting the polyurethane casting process. S4: Casting process: Once the vulcanizing machine reaches the set temperature, turn on the casting machine to cast the polyurethane. Use the casting pipe to cast the polyurethane into the mold cavity. Once the required amount has been cast, turn off the casting machine and observe the changes in the polyurethane state. Turn on the vulcanizing machine at the appropriate time to automatically close the mold. S5: Flat vulcanizing machine preparation: Turn on the flat vulcanizing machine, set the temperature to the range of 70~150℃, and adjust the pressure to 5~15MPa. Place the track plate processed in S1 into the mold for vulcanization. S6: Post-treatment of release agent: Vulcanize in a vulcanizing machine for 1 to 4 hours. Set the vulcanization time and perform self-release treatment. Then place it in another oven for secondary vulcanization. S7: After demolding and cooling, manual inspection is carried out, and edge defects are repaired. After repair, the product is placed in a constant temperature and humidity warehouse for the third vulcanization process at room temperature.

[0008] Furthermore, in step S6, the secondary vulcanization process is carried out at a temperature of 60℃~130℃ for 20~36 hours.

[0009] Furthermore, the third vulcanization process in step S7 takes 1 to 3 months.

[0010] Furthermore, the metal frame is a spring steel base plate, which is formed by stamping with a mold.

[0011] Furthermore, the anti-circumferential rotation components, as well as the lateral and longitudinal fixing components, are bolts or studs.

[0012] The present invention has the following advantages: The tracked vehicle ground contact composite material provided by this invention employs wear-resistant fillers. It utilizes diphenylmethane diisocyanate, tetrahydrofuran polyurethane, and polycaprolactone to form a composite material, improving the resilience, internal heat generation, and tear resistance of polyurethane. The addition of wear-resistant agents further enhances its wear resistance. Compared to traditional synthetic rubber tracked vehicles, its tear resistance and abrasion resistance are significantly improved, effectively reducing chipping and spalling of the tracked vehicle ground contact composite material, extending the service life of vehicle tracks, and lowering maintenance costs. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the track plate structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram showing the test conditions of the ground-holding rubber at different mileage stages. Detailed Implementation

[0014] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0015] like Figure 1 As shown, this invention provides a high-modulus tear-resistant track plate ground contact material and its preparation method. The components and their mass fractions in the preparation of the polyurethane material are as follows: 60-80 parts of polytetrahydrofuran ether diol / polycaprolactone polyol; 20-40 parts of diphenylmethyl alkyl diisocyanate; 2-5 parts of catalyst; 1-5 parts of defoamer; 1-5 parts of wear-resistant reinforcing agent; 1-5 parts of toughening agent; 8-25 parts of crosslinking agent; and 3-8 parts of antistatic agent.

[0016] This invention improves the resilience, internal heat generation, and tear resistance of polyurethane by selecting polytetrahydrofuran ether diol / polycaprolactone polyol and diphenylmethane diisocyanate composite as raw materials. The larger molecular weight of polytetrahydrofuran ether diol increases the molecular chain length, resulting in a polyurethane with good flexibility. Wear-resistant fillers are used to fully leverage the synergistic reinforcing effect with the main filler, enhancing wear resistance. The resulting polyurethane composite material has a regular internal molecular structure, forming a three-dimensional network, with each group connected to many other groups, effectively improving the tear resistance and mechanical properties of polyurethane materials used in track plates.

[0017] According to performance test results, the stress-strain properties of the new polyurethane material are 9.4% higher than those of synthetic rubber; the right-angle tear strength is 85% higher; the trouser tear strength is 394% higher; the aging performance is 36.3% higher; and the abrasion resistance is three times higher. These improvements demonstrate a significant enhancement in the mechanical properties, tear resistance, aging performance, and abrasion resistance of the new formulation's grounding rubber block.

[0018] Table 1. Performance test results of high-modulus tear-resistant polyurethane material for track shoes The polyurethane material in this embodiment has a high modulus, which affects its bonding reliability with the track plate. The track plate structure mainly consists of a metal frame, anti-circumferential rotation screws, and lateral and longitudinal fixing studs. The anti-circumferential rotation components, lateral and longitudinal fixing components are vulcanized together with the rubber block to increase bonding reliability.

[0019] This embodiment provides a track plate mainly composed of a spring steel base plate (3), M18 screws (4), M10 studs (5), and M10 bolts. The spring steel base plate is formed by die stamping, the M18 screws are riveted to the spring steel base plate under pressure, and the M10 studs and M10 bolts are welded to the spring steel base plate. The polyurethane material in this embodiment has a high modulus. In order to solve the problem of reliable adhesion with the spring steel base plate, four M10 studs and two M10 bolts are welded to enhance the adhesion between the polyurethane material and the track plate. At the same time, the M10 bolts on both sides of the steel core are used to resist the friction with the ground when the vehicle is driving, turning, or turning.

[0020] This embodiment provides the process for manufacturing and processing track plates: S1: Track plate processing procedure: The track plates are ultrasonically cleaned using anhydrous ethanol or other volatile solvents as the cleaning agent. After the surface is dried, adhesive is sprayed on. The first coat needs to reach a thickness of 10-20 micrometers. After drying, a second coat is sprayed and dried. The total dry film thickness should reach 30-60 micrometers. After it is completely dry, it is placed in a pre-set oven at a temperature of 125±25℃ for later use.

[0021] S2: Raw material preparation: Add polytetrahydrofuran ether diol, polycaprolactone polyol, and diphenylmethyl alkyl diisocyanate to the casting machine, setting the temperature to 80±20℃; add the crosslinking agent to auxiliary material tank B of the casting machine, setting the temperature to 140±20℃; add the antistatic agent to auxiliary material tank C of the casting machine, at room temperature; add the catalyst to the dedicated material tank of the casting machine, at room temperature. All raw materials undergo degassing for 1-3 hours.

[0022] S3: Casting ratio measurement: After S2 is prepared, the ratio measurement is carried out first to confirm that the casting ratio is correct before starting the polyurethane casting process.

[0023] S4: Casting process: Once the vulcanizing machine reaches the set temperature, turn on the casting machine to cast the polyurethane. Use the casting pipe to cast the polyurethane into the mold cavity. After casting the required amount, turn off the casting machine and observe the changes in the polyurethane state. Turn on the vulcanizing machine at the appropriate time to automatically close the mold.

[0024] S5: Preparation of flat vulcanizing machine: Turn on the flat vulcanizing machine, set the temperature to the range of 70~150℃, and adjust the pressure to 5~15MPa. Place the track plate processed in S1 into the mold for vulcanization.

[0025] S6: Post-treatment of release agent: Perform the curing process in the vulcanizing machine for 1 to 4 hours. Set the vulcanization time and the machine can perform self-demolding. After that, put it into another oven as soon as possible for secondary vulcanization. The secondary vulcanization process temperature is 60℃~130℃ and the time is 20~36 hours. S7: After demolding and cooling, manual inspection is carried out, and edge defects are repaired. After repair, it is placed in a constant temperature and humidity warehouse for the third vulcanization process at room temperature, which takes about 1 to 3 months to reach the best state.

[0026] This invention provides a test method for high-modulus tear-resistant polyurethane materials for track plates: The tests were conducted according to the methods in GB / T531 "Test Method for Indentation Hardness of Vulcanized Rubber or Thermoplastic Rubber", GB / T528 "Standard for Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber", GB / T1689 "Determination of Abrasion Resistance of Vulcanized Rubber", GB / T1681 "Determination of Resilience of Vulcanized Rubber", GB / T529 "Determination of Tear Strength of Vulcanized Rubber or Thermoplastic Rubber (Pants-shaped, Right-angled and Crescent-shaped Specimens)", GB / T533 "Determination of Density of Vulcanized Rubber or Thermoplastic Rubber", GB / T3512 "Accelerated Aging and Heat Resistance Test of Vulcanized Rubber or Thermoplastic Rubber in Hot Air", GB / T1682 "Determination of Low-Temperature Brittleness of Vulcanized Rubber - Single Specimen Method", GB / T7762 "Static Tensile Test for Ozone Cracking Resistance of Vulcanized Rubber or Thermoplastic Rubber", and GB / T528 "Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber". The test results are shown in Table 1.

[0027] The track of this invention uses polyurethane grounding blocks. It underwent 2000km of chassis reliability testing along with the vehicle, including a 500km continuous driving test, a 100km continuous driving test on paved roads, and a four-hour continuous driving test with fire control capabilities. The track traveled 1400km on sand and gravel roads and approximately 600km on paved roads. During the tests, the track and grounding blocks maintained good overall condition, with no chipping, breakage, or large-scale delamination. The grounding blocks showed good performance at different mileage stages. Figure 2 As shown, the grounding rubber blocks were replaced without any replacements during the test, which improved the service life of the grounding rubber blocks on the tracks and has good application prospects.

[0028] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art will be able to make various modifications and improvements without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the scope of protection of the present invention.

Claims

1. A high-modulus tear-resistant polyurethane material for track plates, characterized in that, The components and their mass fractions in the preparation of the polyurethane material are as follows: 60-80 parts of polytetrahydrofuran ether diol / polycaprolactone polyol; 20-40 parts of diphenylmethyl alkyl diisocyanate; 2-5 parts catalyst; 1-5 parts of defoamer; 1-5 parts of wear-resistant reinforcing agent; Toughening agent 1-5 parts; 8-25 parts of crosslinking agent; 3 to 8 parts of antistatic agent.

2. A track plate using the high-modulus tear-resistant polyurethane material of claim 1, characterized in that, The track plate consists of a metal frame, anti-circumferential rotation components, and lateral and longitudinal fixing components. The anti-circumferential rotation components, lateral and longitudinal fixing components are fixed to the metal frame and vulcanized together with a rubber block made of high modulus tear-resistant polyurethane material to increase the bonding reliability.

3. The track plate according to claim 2, characterized in that, The processing procedure for the track plates is as follows: S1: Track plate processing: Ultrasonic cleaning of the track plates using a volatile solvent as the cleaning agent. After the surface is dried, adhesive is sprayed on. The first coat needs to reach a thickness of 10-20 micrometers. After drying, a second coat is sprayed and dried. The overall dry film thickness reaches 30-60 micrometers. Then, the track plates are placed in a pre-set oven at a temperature of 125±25℃ for later use. S2: Raw material preparation: Add polytetrahydrofuran ether diol, polycaprolactone polyol, and diphenylmethyl alkyl diisocyanate to the casting machine, setting the temperature to 80±20℃; add the crosslinking agent to the auxiliary material tank B of the casting machine, setting the temperature to 140±20℃; add the antistatic agent to the auxiliary material tank C of the casting machine, at room temperature; add the catalyst to the special material tank of the casting machine, at room temperature; degas all raw materials for 1~3 hours. S3: Casting ratio measurement: After S2 is prepared, the ratio measurement is carried out first to confirm that the casting ratio is correct before starting the polyurethane casting process. S4: Casting process: Once the vulcanizing machine reaches the set temperature, turn on the casting machine to cast the polyurethane. Use the casting pipe to cast the polyurethane into the mold cavity. Once the required amount has been cast, turn off the casting machine and observe the changes in the polyurethane state. Turn on the vulcanizing machine at the appropriate time to automatically close the mold. S5: Flat vulcanizing machine preparation: Turn on the flat vulcanizing machine, set the temperature to the range of 70~150℃, and adjust the pressure to 5~15MPa. Place the track plate processed in S1 into the mold for vulcanization. S6: Post-treatment of release agent: Vulcanize in a vulcanizing machine for 1 to 4 hours. Set the vulcanization time and perform self-release treatment. Then place it in another oven for secondary vulcanization. S7: After demolding and cooling, manual inspection is carried out, and edge defects are repaired. After repair, the product is placed in a constant temperature and humidity warehouse for the third vulcanization process at room temperature.

4. The track plate according to claim 3, characterized in that, In step S6, the secondary vulcanization process is carried out at a temperature of 60℃~130℃ for 20~36 hours.

5. The track plate according to claim 3, characterized in that, The third vulcanization process in step S7 takes 1 to 3 months.

6. The track plate according to claim 2, characterized in that, The metal frame is a spring steel base plate, which is formed by stamping with a mold.

7. The track plate according to claim 2, characterized in that, The anti-circumferential rotation components, as well as the lateral and longitudinal fixing components, are bolts or studs.

Images