Low-temperature-resistant, wear-resistant and tear-resistant regenerated TPU material and preparation method thereof
By blending the modified TPU material and carrying out coating treatment, the problem of wear and tear of TPU recycled materials in low temperature and humid environments is solved, and the material has good wear and tear resistance in extreme environments is achieved.
Patent Information
- Application Number
- CN202411279609.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-12
- Publication Date
- 2025-02-11
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
TPU recycled materials are prone to wear and tear problems in low temperature and humid environments, which limits their application range.
By blending and modifying the recovered TPU with SAG, PTW, EBA, and coating it with a modified polyol and carboxy nitrile latex, combining filler and promoter, and curing and hot pressing, it has better low temperature resistance. , recycled TPU material with wear resistance and tear resistance.
The recycled TPU material maintains better wear resistance and tear resistance under low temperature, humidity and rainwater erosion, and improves its application performance in extreme environments.
Smart Images
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of polymer material processing, and more specifically, to a low-temperature-resistant, wear-resistant, and tear-resistant recycled TPU material and a preparation method thereof. Background Art
[0002] As society continues to progress and develop, natural resources are decreasing, and recycling and reusing waste TPU plastics is one of the important measures to achieve sustainable development. In addition, TPU recycling helps reduce waste generation and reduce environmental pollution.
[0003] However, the recycling and application of TPU recycled materials mainly encounter the following difficulties: First, the recycled TPU mainly comes from shoes, wire and cable materials, scraps and other sources. Therefore, the performance of the recycled materials obtained is uneven, which limits its scope of application. Second, during the use of TPU materials, its polymer chains will undergo irreversible changes, such as automatic chemical reactions caused by chemicals or radiation, resulting in the generation of various oxygen-containing compounds and unsaturated groups. These changes increase the complexity of recycled materials. Third, long-term use and exposure to harsh environments (such as sunlight and high temperatures) will accelerate the aging process of TPU, forming more new compounds and impurities, further increasing the difficulty of recycling. Fourth, the recycled TPU materials may also contain other types of plastics or impurities. Because their physical properties are different after recycling, they limit their wide application.
[0004] Based on the above problems, the physical properties of TPU are improved by blending thermoplastic elastomers such as TPR and TPE with recycled TPU, so that it can be used in outdoor equipment, automotive industry and other fields. However, when it is in extreme environments for a long time, such as low temperature and humid environments, it is still prone to wear and tear, so further research is needed. Summary of the invention
[0005] In order to further improve the wear resistance and tear resistance of TPU recycled materials, and at the same time maintain good wear resistance and tear resistance in a low temperature and humid environment for a long time, the present application provides a low-temperature resistant, wear-resistant and tear-resistant recycled TPU material and a preparation method thereof.
[0006] In a first aspect, the present application provides a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material, which is composed of the following raw materials in parts by weight: Recycle TPU 100 pieces 10-20 parts of carboxylated nitrile latex Modified polyol 2-10 parts PTW5-10 copies SAG 3-5 parts EBA10-18 copies Filler 1-5 parts Accelerator 13-15 parts.
[0007] In the above technical solution, carboxylated nitrile latex is a copolymer emulsion prepared by emulsion polymerization of two monomers, butadiene and acrylonitrile. It has good adhesion, cold resistance, wear resistance, weather resistance, etc. The modified polyol has good flexibility and dispersing activity. Under the action of the accelerator, it can further react with the carboxylated nitrile latex and promote the dispersibility of the raw material system.
[0008] PTW is ethylene-butyl acrylate-glycidyl ester copolymer, SAG is styrene-acrylonitrile-glycidyl methacrylate copolymer, and EBA is ethylene-butyl acrylate copolymer. When the three are compounded, the flexibility and tear resistance of the recycled TPU can be further improved, and the compatibility of the recycled TPU with nitrile rubber can be promoted. The resulting recycled TPU material has better low temperature resistance, wear resistance, tear resistance and other properties, and can maintain better wear resistance and tear resistance under low temperature, humidity and rain erosion for a long time. Improve the practicality of recycled TPU materials.
[0009] In summary, this application utilizes SAG, PTW, EBA and recycled TPU for blending and modification, and then coats them with modified polyols and carboxyl nitrile latex, and with the assistance of fillers and accelerators, after curing, the nitrile rubber is compatible with SAG, PTW, EBA and recycled TPU. The obtained recycled TPU material has better low temperature resistance, wear resistance, tear resistance and other properties, and can maintain better wear resistance and tear resistance under low temperature, humidity and rain erosion for a long time.
[0010] The TPU material of the present application can be made into film or sheet, which is mainly used for snowboard boots, mountaineering shoes, outdoor tents, mountaineering clothes, mountaineering gloves, flood control sandbags, etc. Its characteristics are that it can maintain good wear resistance and tear resistance under long-term use under extreme weather conditions. Extreme weather conditions mainly include low temperature environments such as long-term low temperature environments such as climbing snow-capped mountains, jungles, wetlands, tropical rainforests and other environments, especially having good tolerance to low temperature and rain erosion.
[0011] Preferably, the modified polyol is cashew nut shell oil diol and / or short-chain branched polyester polyol.
[0012] Cashew nut shell oil diol has good water resistance and dispersion promoting properties, and can promote the uniform dispersion of various materials in the raw material system. The hydroxyl groups contained in it further react with carboxyl nitrile latex under the action of the accelerator to improve the physical properties of nitrile rubber. At the same time, it can also promote the compatibility of nitrile rubber with TPU. The short-chain branched polyester polyol reacts with carboxyl nitrile latex under the action of the accelerator to improve the physical properties of nitrile rubber, further improve the wear resistance and tear resistance of the recycled TPU material, and has better tolerance to low temperature, rain erosion and other environments.
[0013] Preferably, the modified polyol is composed of cashew nut shell oil diol and short-chain branched polyester polyol in a weight ratio of (1-3):1.
[0014] When cashew nut shell oil diol and short-chain branched polyester polyol are compounded, they play a better synergistic role, thereby making the performance of the recycled TPU material better and having better tolerance to low temperature, rain erosion and other environments.
[0015] Preferably, the solid content of the carboxylated nitrile latex is 50-65%.
[0016] The carboxyl nitrile latex in the above solid content range, combined with the modified polyol to form a system, can easily be compatible with SAG, PTW, EBA, and recycled TPU for coating, and after curing, a stable dispersion system can be formed, and the TPU material can obtain better performance.
[0017] Preferably, the filler is one or more of silica microspheres, hexagonal boron nitride, and organosilicon microspheres.
[0018] The above fillers are used to fill and reinforce, and the recycled TPU material made by combining SAG, PTW, EBA, recycled TPU, carboxyl nitrile latex, and modified polyols has better wear resistance and tear resistance.
[0019] In a second aspect, the present application provides a method for preparing a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material, comprising the following steps: 1) Weighing recycled TPU, PTW, EBA, and SAG according to parts by weight, mixing them uniformly, heating them to completely melt, cooling and drying them, and grinding them to obtain a ground blend, and mixing the ground blend with a filler uniformly to obtain a mixture A; 2) Weighing nitrile rubber latex, modified polyol, and curing agent in parts by weight and mixing them evenly to obtain a mixture B; 3) adding all of the mixture A to the mixture B according to parts by weight, mixing evenly to obtain a semi-finished product; 4) preheating, reheating, heat preservation, hot pressing, baking, and cooling the semi-finished product to obtain a recycled TPU material.
[0020] In the above process, the ground blend obtained by melt blending of recycled TPU, PTW and EBA has good compatibility and is easy to process and shape, and a filler is added to obtain a mixture A; in step 2), a mixture B is formed by nitrile rubber latex, modified polyol and curing agent, and then the mixture A and the mixture B are fully mixed, and the mixture B covers the mixture A; in step 4), part of the solvent in the mixed system is removed by preheating to facilitate subsequent fusion, and then after hydraulic baking, a stable plastic-rubber blend system is obtained, so that the obtained TPU recycled material has better wear resistance and tear resistance, and has better tolerance to low temperature and rain.
[0021] Preferably, the particle size of the ground blend in step 1) is 0.01-2 microns.
[0022] Preferably, the preheating temperature in step 4 is 100-105° C., and the preheating time is 1-2 min.
[0023] Preferably, the heating temperature in step 4) is 175-181° C., and the holding time is 10-30 seconds.
[0024] Preferably, in step 4), the hot pressing temperature is 140-160° C., and the hot pressing pressure is 10-20N.
[0025] The melting point of the ground blend obtained in the present application is measured to be 168°C±2°C, and the softening point is 98°C±2°C. Therefore, when the preheating temperature is 100-105°C and the preheating time is 1-2min, the ground blend in mixture A will soften, and part of the solvent in mixture A will be volatilized. When the heating temperature is 175-181°C, the carboxyl nitrile latex in the raw material system of mixture A will solidify and react with the modified polyol. At the same time, the ground blend in compound A will react and fuse with the polymer formed by crosslinking the carboxyl nitrile latex and the modified polyol. At a hot pressing temperature of 140-160°C and a hot pressing pressure of 10-20N, their fusion is promoted to form a TPU recycled material with a tight structure, thereby improving its physical properties and tolerance to low temperature, rain, etc.
[0026] In summary, this application has the following beneficial effects: The present application utilizes SAG, PTW, EBA and recycled TPU for blending and modification, and then coats them with modified polyols and carboxyl nitrile latex, and with the assistance of fillers and accelerators, after curing, the nitrile rubber is compatible with SAG, PTW, EBA and recycled TPU. The obtained recycled TPU material has better low temperature resistance, wear resistance, tear resistance and other properties, and can maintain better wear resistance and tear resistance under low temperature, humidity and rain erosion for a long time. DETAILED DESCRIPTION
[0027] The present application is further described in detail below with reference to the embodiments.
[0028] Introduction of some raw materials; Table 1 Introduction of some raw materials Example
[0029] Example 1 7. A method for preparing a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material, characterized in that it comprises the following steps: 1) Weigh 10 kg of recycled TPU, 0.5 kg of PTW, 1.8 kg of EBA, and 0.5 kg of SAG, mix and heat until all are melted to make them fully uniform, cool to 30° C., put them into a grinder for grinding to obtain a grinding blend with a particle size of 2 μm, and mix all the grinding blends with 0.5 kg of filler to obtain a mixture A.
[0030] 2) Weigh 1 kg of nitrile rubber latex, 0.2 kg of modified polyol, and 0.01 kg of curing agent, put them into a stirring device, and stir them at a speed of 50 r / min for 10 min to fully mix them, thereby obtaining a mixture B.
[0031] 3) Add all of mixture A to mixture B and continue stirring for 30 minutes to fully mix the mixture to obtain a semi-finished product.
[0032] 4) Coat the semi-finished product on the release film, preheat it in an oven at 100°C for 2 minutes, put it in a vulcanization device, keep it at 175°C for 30 seconds, put it in a hot pressing device, hot press it at 10N and 150°C for 1 second, then put it in an oven at 138°C for baking for 30 minutes, cool it to 30°C, remove the release film, and obtain the recycled TPU material.
[0033] The solid content of the carboxyl nitrile latex is 50%, and the modified polyol is a short-chain branched polyester polyol.
[0034] Example 2 The difference between Example 2 and Example 1 is that the amount of raw materials used in steps 1)-2) is different, and the specific process is as follows: 1) Weigh 10 kg of recycled TPU, 0.8 kg of PTW, 1.5 kg of EBA, and 0.3 kg of SAG, mix and heat until all are melted to make them fully uniform, cool to 30° C., put them into a grinder for grinding to obtain a grinding blend with a particle size of 2 μm, and mix all the grinding blends with 0.3 kg of filler to obtain a mixture A.
[0035] 2) Weigh 1.5 kg of nitrile rubber latex, 0.5 kg of modified polyol, and 0.03 kg of curing agent, put them into a stirring device and stir them at a speed of 50 r / min for 10 min to fully mix them, thereby obtaining a mixture B.
[0036] Example 3 The difference between Example 3 and Example 1 is that the amount of raw materials used in steps 1)-2) is different, and the specific process is as follows: 1) Weigh 10 kg of recycled TPU, 1 kg of PTW, 1.0 kg of EBA, and 0.1 kg of SAG, mix and heat until all are melted to make them fully uniform, cool to 30° C., put them into a grinder for grinding to obtain a grinding blend with a particle size of 2 μm, and mix all the grinding blends with 0.3 kg of filler to obtain a mixture A.
[0037] 2) Weigh 2 kg of nitrile rubber latex, 0.8 kg of modified polyol, and 0.05 kg of curing agent, put them into a stirring device, stir them at a speed of 50 r / min for 10 min to fully mix them, and obtain a mixture B.
[0038] Example 4 The difference between Example 4 and Example 3 is that the modified polyol is a short-chain branched polyester polyol.
[0039] Example 5 The difference between Example 5 and Example 3 is that the modified polyol is composed of cashew nut shell oil diol and short-chain branched polyester polyol in a weight ratio of 1:1.
[0040] Example 6 The difference between Example 6 and Example 3 is that the modified polyol is composed of cashew nut shell oil diol and short-chain branched polyester polyol in a weight ratio of 1:3.
[0041] Example 7 The difference between Example 7 and Example 6 is that the particle size of the ground blend is 0.1 micron.
[0042] Example 8 The difference between Example 8 and Example 6 is that the particle size of the ground blend is 0.01 micron.
[0043] Example 9 The difference between Example 9 and Example 7 is that the process conditions of step 4 are different, and the specific process is as follows: 4) Coat the semi-finished product on the release film, preheat it in an oven at 105°C for 1 min, put it in a vulcanization device, keep it at 181°C for 10s, put it in a hot pressing device, hot press it at 20N and 140°C for 1s, then put it in an oven at 138°C for baking for 30min, cool it to 30°C, remove the release film, and obtain the recycled TPU material.
[0044] Example 10 The difference between Example 10 and Example 7 is that the process conditions of step 4 are different, and the specific process is as follows: 4) Coat the semi-finished product on the release film, preheat it in an oven at 103°C for 1.5 minutes, put it in a vulcanization device, keep it at 178°C for 20 seconds, put it in a hot pressing device, hot press it at 20N and 160°C for 1 second, then put it in an oven at 138°C for baking for 30 minutes, cool it to 30°C, remove the release film, and obtain the recycled TPU material.
[0045] Embodiment 11 The difference between Example 11 and Example 1 is that there is no preheating process, and the specific process is as follows: 4) Coat the semi-finished product on a release film, keep it warm at 175°C for 30 seconds, put it into a hot pressing device, hot press it at 10N and 150°C for 1 second, then put it into an oven at 138°C for baking for 32 minutes, cool it to 30°C, remove the release film, and obtain the recycled TPU material.
[0046] Example 12 The difference between Example 12 and Example 1 is that there is no hot pressing, and the specific process is as follows: 4) Coat the semi-finished product on the release film, preheat it in an oven at 100°C for 2 minutes, put it in a vulcanization device, keep it at 175°C for 30 seconds, put it in an oven at 138°C for baking for 30 minutes, cool it to 30°C, remove the release film, and obtain the recycled TPU material.
[0047] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the carboxylated nitrile latex liquid is replaced with nitrile rubber powder.
[0048] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the modified polyol is replaced by an equal amount of carboxylated nitrile latex.
[0049] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that an equal amount of SAG is replaced by TPW powder.
[0050] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that EBA and TPW powder are replaced by SAG in equal amounts.
[0051] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that EBA, TPW powder and SAG are replaced by maleic anhydride grafted polypropylene in equal amounts.
[0052] Comparative Example 6 The difference between Comparative Example 6 and Example 14 is that the nitrile rubber, curing agent, and modified polyol are replaced by TPE in equal amounts.
[0053] Performance testing The thickness of the recycled TPU materials obtained in Examples 1-12 and Comparative Examples 1-6 is preferably 0.8 mm, and the following performance tests are performed. In addition, the recycled TPU is also made into samples with a thickness of 0.8 mm, and the following performance tests are performed.
[0054] Test method / test method Tear resistance: GBT 16578.1-2008 Determination of tear resistance of plastic films and sheets, trouser tear method.
[0055] Wear resistance: Refer to "GB / T5478-2008 Plastic Rolling Wear Test Method", the sample diameter should be 100mm round sample 3pcs, thickness 0.8mm. Load 1kg; running length 25.4mm; speed 45 cycles / min; friction medium Cs-17; running times 3000 times; test environment temperature 85℃, humidity 60%.
[0056] 1) The recycled TPU materials obtained in Examples 1-12 and Comparative Examples 1-6 were subjected to tear resistance and wear resistance tests after obtaining corresponding test samples according to the above method, and the tear strength and wear amount were recorded, and the mass loss rate was calculated.
[0057] 2) After the test specimens obtained in 1) are aged, they are subjected to tear resistance and wear resistance tests under the same test conditions as in 1), and then tear resistance and wear resistance tests are performed, and the corresponding tear strength and wear amount are recorded. At the same time, the tear strength residual rate and mass loss rate are calculated. The tear strength residual rate is equal to the tear strength after aging divided by the tear strength before aging, multiplied by 100%; and the mass loss rate is equal to the wear amount divided by the original weight, multiplied by 100%, and then the mass loss rate after aging is subtracted from the mass loss rate before aging to obtain the mass loss increment.
[0058] Aging treatment condition (I): placed in an environment of -40°C and 60% humidity for 7 days. Aging treatment condition (II): soaked in artificial rainwater for 1 month, the pH of rainwater is 5.6, and the temperature is maintained at 15°C.
[0059] Table 2 Experimental data of Examples 1-12 and Comparative Examples 1-6 Combining Example 1 and Comparative Examples 1-6 and Table 2, it can be seen that the tear strength, tear strength residual, and mass loss rate increase of Comparative Examples 1-6 are all less than the tear strength of Example 1, indicating that the present application has better physical properties and tolerance, and the resulting recycled TPU material is not easily damaged during use, thereby improving its practicality.
[0060] Combining Example 10 and Comparative Examples 1-6 and Table 2, it can be seen that the tear strength, tear strength residual, and mass loss rate increase of Comparative Examples 1-6 are all less than the tear strength of Example 1, indicating that the present application has better physical properties and tolerance.
[0061] Combining Example 1 and Example 12 and Table 2, it can be seen that the tear strength, tear strength residual, and mass loss rate increase of Example 12 are all less than the tear strength of Example 1, indicating that the application has better physical properties and tolerance, so that the recycled TPU material obtained has better physical properties and better tolerance to low temperature, rain, etc.
[0062] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.
Claims
1. A low temperature resistant, wear resistant and tear resistant recycled TPU material, characterized in that: It is composed of the following raw materials in parts by weight: Recycle TPU 100 pieces 10-20 parts of carboxylated nitrile latex Modified polyol 2-10 parts PTW5-10 copies SAG 3-5 parts EBA10-18 copies Filler 1-5 parts Accelerator 0.1-0.5 parts.
2. The low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 1, characterized in that: The modified polyol is cashew nut shell oil diol and / or short-chain branched polyester polyol.
3. The low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 2, characterized in that: The modified polyol is composed of cashew nut shell oil diol and short-chain branched polyester polyol in a weight ratio of (1-3):
1.
4. The low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 1, characterized in that: The solid content of the carboxyl nitrile latex is 50-65%.
5. The low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 1, characterized in that: The filler is one or more of silicon dioxide microspheres, hexagonal boron nitride, and organic silicon microspheres.
6. A method for preparing a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) Weigh the recovered TPU, PTW, EBA and SAG according to parts by weight, mix them evenly, heat them to melt them completely, cool them to dry them, grind them to obtain a grinding blend, and mix the grinding blend with the filler evenly to obtain a mixture A; 2) Weigh the nitrile rubber latex, modified polyol and curing agent according to parts by weight and mix them evenly to obtain a mixture B; 3) Add all of mixture A to mixture B according to parts by weight, mix well, and obtain a semi-finished product; 4) Preheating, reheating, heat preservation, hot pressing, baking and cooling the semi-finished product to obtain recycled TPU material.
7. The method for preparing a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 6, characterized in that: The particle size of the ground blend in step 1) is 0.01-2 microns.
8. The method for preparing a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 6, characterized in that: The preheating temperature in step 4 is 100-105° C., and the preheating time is 1-2 minutes.
9. The method for preparing a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 6, characterized in that: The heating temperature in step 4) is 175-181° C., and the holding time is 10-30 seconds.
10. The method for preparing a low-temperature-resistant, wear-resistant and tear-resistant recycled TPU material according to claim 6, characterized in that: In step 4), the hot pressing temperature is 140-160° C. and the hot pressing pressure is 10-20N.