Low-cost high-performance automobile hose core rod material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of automobile accessory manufacturing, and particularly discloses a low-cost and high-performance automobile hose core rod material as well as a preparation method and application thereof. The low-cost and high-performance automobile hose core rod material is prepared from the following raw materials: a thermoplastic elastomer TPE, modified calcium carbonate, an antioxidant, a lubricant, an anti-aging additive and a polylactic acid-glycolic acid copolymer. Wherein calcium carbonate is modified by adopting long-chain saturated fatty acid, N, N '-carbonyldiimidazole, polyvinyl alcohol and a cross-linking agent, so that the dispersity of calcium carbonate particles is improved, the formation of aggregates is effectively reduced, the mechanical property of the material is enhanced, and the ageing resistance of the material is improved.

Description

Technical Field

[0001] This application relates to the technical field of automotive parts manufacturing, and particularly to a low-cost and high-performance core rod material for automotive hoses, its preparation method, and application. Background Art

[0002] In recent years, with the rapid development of the automotive industry, polymer hoses have been widely used in the field of automotive parts due to their characteristics such as lightweight, corrosion resistance, and easy processing, especially as the core components of air-conditioning pipes. However, during the hose forming process, a core rod material is required as a support to ensure its dimensional accuracy and shape stability. Traditionally, TPX material has been used as the core rod material, which has excellent dimensional stability and anti-aging performance and can meet the high standards required for hose production.

[0003] However, TPX material has significant limitations in practical applications. Due to the complex production process of TPX and limited global production capacity, its price remains high, significantly increasing the production cost of hoses. Despite its excellent performance, its high cost restricts the large-scale popularization of automotive hoses, especially hindering the market promotion of mid- to low-end vehicle models.

[0004] To address the high cost of TPX, attempts have been made in the market to replace TPX with materials such as PE, PP, PA, etc. However, these materials are prone to wear or aging after repeated use, shortening the service life of the core rod, and some materials are prone to sticking to the mold or poor fluidity during extrusion molding, affecting production efficiency. Existing alternative solutions are difficult to achieve a balance among cost, performance, and processability. Summary of the Invention

[0005] In order to reduce the cost of the core rod material, maintain the excellent performance of the hose core rod material, and improve the processing performance of the material, this application provides a low-cost and high-performance core rod material for automotive hoses, its preparation method, and application.

[0006] In the first aspect, a low-cost and high-performance core rod material for automotive hoses provided by this application adopts the following technical solution: A low-cost and high-performance core rod material for automotive hoses is prepared from the following raw materials by weight: 60 - 70 parts of thermoplastic elastomer TPE, 20 - 30 parts of modified calcium carbonate, 0.5 - 1 part of antioxidant, 0.5 - 1 part of lubricant, 1 - 2 parts of anti-aging agent, 5 - 10 parts of poly(lactic-co-glycolic acid); The modified calcium carbonate includes calcium carbonate powder, long-chain saturated fatty acid, N,N'-carbonyldiimidazole, polyvinyl alcohol and a crosslinking agent, and the weight ratio of the calcium carbonate powder, long-chain saturated fatty acid, N,N'-carbonyldiimidazole, polyvinyl alcohol and crosslinking agent is 10:(0.3-0.5):(0.3-0.5):(2-4):(0.13-0.17).

[0007] By adopting the above technical solution, compared with the TPX material, the core rod material of the present application uses thermoplastic elastomer TPE as the matrix material, significantly reducing the production cost of the core rod material, enabling hose manufacturers to mass-produce without being restricted by material costs, and by introducing modified calcium carbonate, improving the mechanical and aging resistance properties of the material to ensure reliable support during the forming process of automotive hoses. Specifically, the long-chain saturated fatty acid and polyvinyl alcohol play a synergistic modification role. Since the reaction activity of the long-chain saturated fatty acid is relatively low and it is difficult to form a strong chemical bond with calcium carbonate, N,N'-carbonyldiimidazole is used to activate the long-chain saturated fatty acid to improve its reaction activity. N,N'-carbonyldiimidazole reacts with the carboxyl group in the long-chain saturated fatty acid to form carbonyl imidazole, and at the same time reacts with the hydroxyl group on the surface of calcium carbonate to form ester imidazole, thereby grafting the long-chain saturated fatty acid onto the surface of calcium carbonate and forming a strong chemical bond, significantly increasing the grafting rate of the long-chain saturated fatty acid. The steric hindrance effect of the long carbon chain prevents the direct contact between calcium carbonate particles, improving the dispersion of calcium carbonate particles and effectively reducing the formation of aggregates. The hydroxyl group on the surface of calcium carbonate reacts with the hydroxyl group of polyvinyl alcohol, enabling polyvinyl alcohol to be successfully grafted onto the surface of calcium carbonate, and under the action of the crosslinking agent, polyvinyl alcohol reacts with the active groups on the TPE molecular chain to form a covalent bond connection, realizing the chemical crosslinking of the two, thereby enhancing the mechanical properties of the material and improving the processing performance, aging resistance, corrosion resistance, etc. of the material. In addition, by introducing poly(lactic-co-glycolic acid) copolymer, not only the biodegradability and environmental protection performance of the material are improved, but also the application field of the material is expanded, which is helpful for environmental protection. The present application achieves a balance among cost, performance and processability, providing a more competitive alternative for automotive hose core rod materials.

[0008] Preferably, the long-chain saturated fatty acid is selected from one or more of lauric acid, myristic acid, stearic acid, and palmitic acid.

[0009] By adopting the above technical solution, the long carbon chain in the molecular structure of the long-chain saturated fatty acid has a steric hindrance effect, which can prevent particles from approaching each other and agglomerating during the modification of calcium carbonate, enabling calcium carbonate to have good dispersion stability in the organic phase and reducing the sedimentation of calcium carbonate.

[0010] Preferably, the preparation method of the modified calcium carbonate is as follows: (1) Dissolve polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol solution. Add calcium carbonate powder and a crosslinking agent to the polyvinyl alcohol solution at 70 - 80 °C, stir and react for 2 - 3 h, and obtain polyvinyl alcohol grafted calcium carbonate after drying. (2) Dissolve long-chain saturated fatty acid in toluene, add N,N′-carbonyldiimidazole at 50 - 60 °C, stir and react for 3 - 4 h to obtain a toluene solution of activated long-chain saturated fatty acid. (3) Add polyvinyl alcohol grafted calcium carbonate to the toluene solution of activated long-chain saturated fatty acid, perform ultrasonic treatment for 25 - 35 min, then stir and react at 40 - 60 °C for 3 - 4 h. After filtration, washing, and drying, obtain modified calcium carbonate.

[0011] Preferably, the crosslinking agent is glyoxal.

[0012] By adopting the above technical scheme, calcium carbonate is modified with polyvinyl alcohol and long-chain saturated fatty acid. Among them, the activation treatment of long-chain saturated fatty acid by N,N′-carbonyldiimidazole helps to increase the grafting amount of long-chain saturated fatty acid on the surface of calcium carbonate, effectively enhancing the dispersibility and interfacial binding force of calcium carbonate in the matrix. The long-chain saturated fatty acid has a long carbon chain, and the steric hindrance effect generated by the long carbon chain can prevent the re-aggregation of calcium carbonate, and these long carbon chains can be fully entangled with the surrounding TPE molecular chains, improving the dispersion stability of calcium carbonate. Polyvinyl alcohol reacts with the active groups on the TPE molecular chain under the action of glutaraldehyde to form a stable crosslinked structure, making the modified calcium carbonate evenly distributed in the thermoplastic elastomer TPE matrix.

[0013] Preferably, the antioxidant is a phosphite antioxidant.

[0014] By adopting the above technical scheme, the phosphite antioxidant can effectively inhibit the oxidative degradation reaction of the material during processing and use. The phosphite antioxidant has excellent thermal stability and long-term antioxidant performance, can decompose peroxides under high-temperature conditions, and prevent the propagation of free radical chain reactions, thus significantly improving the heat aging performance of the material and ensuring the stable physical and mechanical properties of the mandrel material during repeated use.

[0015] Preferably, the lubricant is selected from one or more of zinc stearate, calcium stearate, paraffin wax, and polyethylene wax.

[0016] By adopting the above technical scheme, the selection of the lubricant can significantly improve the processing performance of the mandrel material, effectively reduce the frictional resistance of the material during the extrusion molding process, improve the production efficiency and reduce equipment wear. At the same time, the addition of these lubricants also endows the mandrel material with better surface finish, further enhancing its dimensional stability and demolding performance during the shaping process of automotive hoses.

[0017] Preferably, the anti-aging agent is selected as light stabilizer UV-P.

[0018] By adopting the above technical solution, light stabilizer UV-P can effectively absorb ultraviolet rays and convert them into heat energy for release, thus avoiding the direct action of ultraviolet rays on the molecular structure inside the material and reducing the molecular chain breakage and degradation phenomena caused by ultraviolet irradiation. In addition, light stabilizer UV-P can also inhibit the generation of free radicals, further delaying the aging process of the material, significantly improving the weather resistance and stability of the material during long-term use, reducing the replacement frequency of the mandrel material, and indirectly reducing the production cost.

[0019] Preferably, the fineness of the calcium carbonate powder is D97 < 10 μm.

[0020] By adopting the above technical solution, controlling the fineness of the calcium carbonate powder at D97 < 10 μm can enhance the dimensional stability and shape retention ability of the material, ensuring a better support effect of the mandrel during the shaping process of the automotive hose.

[0021] In a second aspect, a preparation method of a low-cost and high-performance automotive hose mandrel material provided by the present application adopts the following technical solution: A preparation method of a low-cost and high-performance automotive hose mandrel material includes the following steps: Weigh the raw materials according to the component ratio, mix the thermoplastic elastomer TPE, modified calcium carbonate, antioxidant, lubricant, anti-aging agent, and poly(lactic-co-glycolic acid) copolymer evenly, melt and extrude them at 150°C - 200°C using a twin-screw extruder, draw into strips, cool, granulate, then extrude a mandrel of a specified specification using a twin-screw extruder or a single-screw extruder, and finally cut it into the required length to obtain a low-cost and high-performance automotive hose mandrel material.

[0022] Preferably, the processing process of the twin-screw extruder is as follows: the temperature of the first section is 155 - 165°C, the temperature of the second section is 155 - 165°C, the temperature of the third section is 160 - 170°C, the temperature of the fourth section is 160 - 170°C, the temperature of the fifth section is 165 - 175°C, the temperature of the sixth section is 175 - 180°C, the temperature of the seventh section is 185 - 195°C, the temperature of the eighth section is 190 - 200°C, the temperature of the ninth section is 195 - 200°C; the rotational speed of the twin-screw extruder is 30 - 60 rmp, and the pressure is 4.0 - 5.0 MPa.

[0023] By adopting the above technical solutions, modified calcium carbonate is added to the thermoplastic elastomer TPE, endowing the material with good flexibility and dimensional stability, enhancing the overall mechanical properties and aging resistance of the material. The addition of antioxidants and anti-aging additives effectively inhibits the oxidation degradation and photoaging phenomena of the material during use, prolongs the service life of the mandrel. The addition of lubricants improves the fluidity of the material, avoids the problem of sticking to the mold during the extrusion process, and improves production efficiency. The introduction of poly(lactic-co-glycolic acid) further enhances the biodegradability and environmental performance of the material, meeting the trend of green manufacturing.

[0024] In the third aspect, the application of a low-cost and high-performance automotive hose mandrel material provided by the present application adopts the following technical solutions: The application of a low-cost and high-performance automotive hose mandrel material in the shaping process of automotive hoses.

[0025] By adopting the above technical solutions, the mandrel material is used in the shaping process of automotive hoses, playing a supporting role for the hoses, thereby improving the production quality of the hose finished products and reducing production costs at the same time.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: In the present application, compared with the TPX material, the mandrel material of the present application uses the thermoplastic elastomer TPE as the matrix material, significantly reducing the production cost of the mandrel material, enabling hose manufacturers to produce on a large scale without being restricted by material costs, and by introducing modified calcium carbonate, improving the mechanical and aging properties of the material to ensure reliable support during the forming process of automotive hoses. Specifically, long-chain saturated fatty acids and polyvinyl alcohol play a synergistic modification role. Since the reaction activity of long-chain saturated fatty acids is relatively low and it is difficult to form a strong chemical bond with calcium carbonate, N,N′-carbonyldiimidazole is used to activate long-chain saturated fatty acids to improve their reaction activity. N,N′-carbonyldiimidazole reacts with the carboxyl group in long-chain saturated fatty acids to form carbonyl imidazole, and at the same time reacts with the hydroxyl group on the surface of calcium carbonate to form ester imidazole, thereby grafting long-chain saturated fatty acids onto the surface of calcium carbonate and forming a strong chemical bond, significantly increasing the grafting rate of long-chain saturated fatty acids. The steric hindrance effect of the long carbon chain prevents the direct contact between calcium carbonate particles, improving the dispersibility of calcium carbonate particles, and thus effectively reducing the formation of aggregates. The hydroxyl group on the surface of calcium carbonate reacts with the hydroxyl group of polyvinyl alcohol, enabling polyvinyl alcohol to be successfully grafted onto the surface of calcium carbonate, and polyvinyl alcohol reacts with the active groups on the TPE molecular chain under the action of a cross-linking agent to form a covalent bond connection, realizing the chemical cross-linking of the two, thereby enhancing the mechanical properties of the material and improving the aging resistance, corrosion resistance, etc. of the material. In addition, by introducing poly(lactic-co-glycolic acid), not only the biodegradability and environmental performance of the material are enhanced, but also the application field of the material is expanded, contributing to environmental protection. Detailed implementation manners

[0027] The present application will be further described in detail below in conjunction with embodiments.

[0028] Preparation Example Preparation Example 1 Preparation of modified calcium carbonate: (1) Dissolve 40 g of polyvinyl alcohol in 100 mL of deionized water to obtain a polyvinyl alcohol solution. At 70 °C, add 200 g of calcium carbonate powder and 2.6 g of glyoxal to the polyvinyl alcohol solution, stir and react for 2 h, and obtain polyvinyl alcohol-grafted calcium carbonate after drying. (2) Dissolve 6 g of lauric acid (Yunsheng Chemical 015) in 50 mL of toluene, add 6 g of N,N′-carbonyldiimidazole at 50 °C, stir and react for 3 h to obtain an activated lauric acid toluene solution. (3) Add the polyvinyl alcohol-grafted calcium carbonate to the activated lauric acid toluene solution, perform ultrasonic treatment for 25 min, then stir and react at 40 °C for 3 h, filter, wash, and dry to obtain modified calcium carbonate.

[0029] Preparation Example 2 Preparation of modified calcium carbonate: (1) Dissolve 75 g of polyvinyl alcohol in 100 mL of deionized water to obtain a polyvinyl alcohol solution. At 75 °C, add 250 g of calcium carbonate powder and 3.75 g of glyoxal to the polyvinyl alcohol solution, stir and react for 2.5 h, and obtain polyvinyl alcohol-grafted calcium carbonate after drying. (2) Dissolve 10 g of stearic acid (Coconut Tree 57-11-4) in 50 mL of toluene, add 10 g of N,N′-carbonyldiimidazole at 55 °C, stir and react for 3.5 h to obtain an activated stearic acid toluene solution. (3) Add the polyvinyl alcohol-grafted calcium carbonate to the activated stearic acid toluene solution, perform ultrasonic treatment for 30 min, then stir and react at 50 °C for 3.5 h, filter, wash, and dry to obtain modified calcium carbonate.

[0030] Preparation Example 3 Preparation of modified calcium carbonate: (1) Dissolve 120 g of polyvinyl alcohol in 150 mL of deionized water to obtain a polyvinyl alcohol solution. At 80 °C, add 300 g of calcium carbonate powder and 5.1 g of glyoxal to the polyvinyl alcohol solution, stir and react for 3 h, and obtain polyvinyl alcohol-grafted calcium carbonate after drying. (2) Dissolve 15 g of palmitic acid (Haoshun 57-10-3) in 50 mL of toluene, add 15 g of N,N′-carbonyldiimidazole at 60 °C, stir and react for 4 h to obtain an activated palmitic acid toluene solution. (3) Add polyvinyl alcohol grafted calcium carbonate to the toluene solution of activated palmitic acid, sonicate for 35 min, then stir and react at 60 °C for 4 h. After filtration, washing, and drying, modified calcium carbonate is obtained.

[0031] Preparation Example 4 The difference between this preparation example and Preparation Example 2 is that an equal amount of myristic acid is used to replace stearic acid.

[0032] Preparation Example 5 The difference between this preparation example and Preparation Example 2 is that an equal amount of capric acid is used to replace stearic acid.

[0033] Preparation Example 6 The difference between this preparation example and Preparation Example 2 is that an equal amount of acetic acid is used to replace stearic acid.

[0034] Preparation Example 7 The difference between this preparation example and Preparation Example 2 is that an equal amount of oleic acid is used to replace stearic acid.

[0035] Preparation Example 8 The difference between this preparation example and Preparation Example 2 is that an equal amount of acrylic acid is used to replace stearic acid.

[0036] Preparation Example 9 The difference between this preparation example and Preparation Example 2 is that only polyvinyl alcohol is used to modify calcium carbonate. Among them, the preparation method of modified calcium carbonate is as follows: Dissolve 75 g of polyvinyl alcohol in 100 mL of deionized water to obtain a polyvinyl alcohol solution. At 75 °C, add 250 g of calcium carbonate powder and 3.75 g of glyoxal to the polyvinyl alcohol solution, stir and react for 2.5 h. After filtration, washing, and drying, modified calcium carbonate is obtained.

[0037] Preparation Example 10 The difference between this preparation example and Preparation Example 2 is that only stearic acid is used to modify calcium carbonate. Among them, the preparation method of modified calcium carbonate is as follows: (1) Dissolve 10 g of stearic acid (Coconut tree 57-11-4) in 50 mL of toluene, add 10 g of N,N′-carbonyldiimidazole at 55 °C, and stir and react for 3.5 h to obtain a toluene solution of activated stearic acid; (2) Add 250 g of calcium carbonate powder to the toluene solution of activated stearic acid, sonicate for 30 min, then stir and react at 50 °C for 3.5 h. After filtration, washing, and drying, modified calcium carbonate is obtained.

[0038] Preparation Example 11 The difference between this preparation example and Preparation Example 2 is that unactivated stearic acid is used to modify calcium carbonate, that is, N,N′-carbonyldiimidazole is not added. Among them, the preparation method of modified calcium carbonate is as follows: (1) Dissolve 75 g of polyvinyl alcohol in 100 mL of deionized water to obtain a polyvinyl alcohol solution. Add 250 g of calcium carbonate powder and 3.75 g of glyoxal to the polyvinyl alcohol solution at 75 °C, stir and react for 2.5 h, and obtain polyvinyl alcohol grafted calcium carbonate after drying; (2) Dissolve 10 g of stearic acid (coconut tree 57-11-4) in 50 mL of toluene, stir evenly to obtain a toluene solution of stearic acid; (3) Add the polyvinyl alcohol grafted calcium carbonate to the toluene solution of stearic acid, perform ultrasonic treatment for 30 min, then stir and react at 50 °C for 3.5 h. After filtration, washing, and drying, obtain modified calcium carbonate. Example

[0039] Example 1 A low-cost and high-performance core rod material for automotive hoses, comprising the following raw materials: 600 g of thermoplastic elastomer TPE (TPE-S grade), 200 g of modified calcium carbonate (prepared in Preparation Example 1), 5 g of phosphite antioxidant, 5 g of calcium stearate, 10 g of light stabilizer UV-P, 50 g of poly(lactic acid - glycolic acid) copolymer.

[0040] Among them, the preparation method of the low-cost and high-performance core rod material for automotive hoses in this example includes the following steps: Weigh the raw materials according to the above component ratio, mix the thermoplastic elastomer TPE, modified calcium carbonate, phosphite antioxidant, calcium stearate, light stabilizer UV-P, and poly(lactic acid - glycolic acid) copolymer evenly, and use a twin-screw extruder to melt and extrude at 150 °C, draw into strips, cool, and granulate. Then use a twin-screw extruder or a single-screw extruder to extrude a core rod of a specified specification, and finally cut it into the required length to obtain a low-cost and high-performance core rod material for automotive hoses. Among them, the processing technology of the twin-screw extruder is: the temperature of the first section is 155 °C, the temperature of the second section is 155 °C, the temperature of the third section is 160 °C, the temperature of the fourth section is 160 °C, the temperature of the fifth section is 165 °C, the temperature of the sixth section is 175 °C, the temperature of the seventh section is 185 °C, the temperature of the eighth section is 190 °C, and the temperature of the ninth section is 195 °C; the rotation speed of the twin-screw extruder is 30 rmp, and the pressure is 4.0 MPa.

[0041] Example 2 A low-cost and high-performance core rod material for automotive hoses, comprising the following raw materials: 650 g of thermoplastic elastomer TPE (TPE-S grade), 250 g of modified calcium carbonate (prepared in Preparation Example 2), 7 g of phosphite antioxidant, 7 g of zinc stearate, 15 g of light stabilizer UV-P, 75 g of poly(lactic acid - glycolic acid) copolymer.

[0042] Among them, the preparation method of the low-cost and high-performance core rod material for automotive hoses in this example includes the following steps: Weigh the raw materials according to the stated component ratios. Mix the thermoplastic elastomer TPE, modified calcium carbonate, phosphite antioxidant, zinc stearate, light stabilizer UV-P, and poly(lactic-co-glycolic acid) copolymer evenly. Then, use a twin-screw extruder to melt and extrude at 180 °C, draw into strands, cool, and pelletize. Next, use a twin-screw extruder or a single-screw extruder to extrude a mandrel of the specified size, and finally cut it into the required length to obtain a low-cost and high-performance automotive hose mandrel material. Among them, the processing technology of the twin-screw extruder is as follows: the temperature of the first section is 160 °C, the second section is 160 °C, the third section is 165 °C, the fourth section is 165 °C, the fifth section is 170 °C, the sixth section is 178 °C, the seventh section is 190 °C, the eighth section is 195 °C, and the ninth section is 200 °C; the rotational speed of the twin-screw extruder is 45 rmp, and the pressure is 4.5 MPa.

[0043] Example 3 A low-cost and high-performance automotive hose mandrel material, comprising the following raw materials: 700 g of thermoplastic elastomer TPE (TPE-S grade), 300 g of modified calcium carbonate (prepared in Preparation Example 3), 10 g of phosphite antioxidant, 10 g of polyethylene wax, 20 g of light stabilizer UV-P, and 100 g of poly(lactic-co-glycolic acid) copolymer.

[0044] Among them, the preparation method of the low-cost and high-performance automotive hose mandrel material in this example includes the following steps: Weigh the raw materials according to the stated component ratios. Mix the thermoplastic elastomer TPE, modified calcium carbonate, phosphite antioxidant, polyethylene wax, light stabilizer UV-P, and poly(lactic-co-glycolic acid) copolymer evenly. Then, use a twin-screw extruder to melt and extrude at 200 °C, draw into strands, cool, and pelletize. Next, use a twin-screw extruder or a single-screw extruder to extrude a mandrel of the specified size, and finally cut it into the required length to obtain a low-cost and high-performance automotive hose mandrel material. Among them, the processing technology of the twin-screw extruder is as follows: the temperature of the first section is 165 °C, the second section is 165 °C, the third section is 170 °C, the fourth section is 170 °C, the fifth section is 175 °C, the sixth section is 180 °C, the seventh section is 195 °C, the eighth section is 200 °C, and the ninth section is 200 °C; the rotational speed of the twin-screw extruder is 60 rmp, and the pressure is 5.0 MPa.

[0045] Example 4 The difference between this example and Example 2 is that the modified calcium carbonate prepared in Preparation Example 4 is used.

[0046] Example 5 The difference between this example and Example 2 is that the modified calcium carbonate prepared in Preparation Example 5 is used.

[0047] Comparative Example Comparative Example 1 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that the modified calcium carbonate prepared in Preparation Example 6 is used.

[0048] Comparative Example 2 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that the modified calcium carbonate prepared in Preparation Example 7 is used.

[0049] Comparative Example 3 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that the modified calcium carbonate prepared in Preparation Example 8 is used.

[0050] Comparative Example 4 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that the modified calcium carbonate prepared in Preparation Example 9 is used.

[0051] Comparative Example 5 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that the modified calcium carbonate prepared in Preparation Example 10 is used.

[0052] Comparative Example 6 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that the modified calcium carbonate prepared in Preparation Example 11 is used.

[0053] Comparative Example 7 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that unmodified calcium carbonate of equal amount is used to replace the modified calcium carbonate.

[0054] Comparative Example 8 A low-cost and high-performance mandrel material for automotive hoses, which is different from Example 2 in that polylactic acid-glycolic acid is not added.

[0055] Performance detection test Using the mandrel materials obtained in Examples 1-5 and Comparative Examples 1-8 as test samples, their corrosion resistance, elongation at break, artificial accelerated aging, and home compost degradation rate (180 days) were tested, and the results were recorded in Table 1.

[0056] Table 1 According to Example 2, Comparative Examples 1-3 and the data in Table 1: In Comparative Example 1, the carbon chain length of acetic acid is short and the steric hindrance effect is small, so it cannot play a good dispersion role; oleic acid in Comparative Example 2 is an unsaturated fatty acid, and its molecular structure contains carbon-carbon double bonds, resulting in poor anti-aging performance of the material. Moreover, the carbon-carbon double bonds may lead to an increase in the intermolecular attraction of oleic acid molecules. Although it can still reduce the primary particle size of calcium carbonate, it can cause the calcium carbonate particles to aggregate and fuse with each other, increasing the degree of agglomeration and deteriorating the particle dispersion; acrylic acid in Comparative Example 3 is a short-chain unsaturated fatty acid, resulting in poor mechanical properties and anti-aging performance of the mandrel material. In this application, long-chain saturated fatty acids are used to modify calcium carbonate. The long carbon chain in the molecular structure of long-chain saturated fatty acids has a steric hindrance effect. When modifying calcium carbonate, it can prevent particles from approaching each other and agglomerating, enabling calcium carbonate to have good dispersion stability in the organic phase and reducing the sedimentation of calcium carbonate. Moreover, its molecular structure does not contain double bonds, which can improve the anti-aging performance of the material and extend the service life of the mandrel material.

[0057] According to Example 2, Comparative Examples 4-5 and the data in Table 1: Modifying calcium carbonate only with polyvinyl alcohol or only with stearic acid has an unsatisfactory modification effect. In this application, by using long-chain saturated fatty acids and polyvinyl alcohol for synergistic modification, the steric hindrance effect of the long carbon chain of the long-chain saturated fatty acids prevents direct contact between calcium carbonate particles, improving the dispersion of calcium carbonate particles, thereby effectively reducing the formation of aggregates. And polyvinyl alcohol reacts with the active groups on the TPE molecular chain under the action of a cross-linking agent to form a covalent bond connection, realizing the chemical cross-linking of the two, thereby enhancing the mechanical properties of the material and improving the anti-aging performance of the material.

[0058] According to Example 2, Comparative Example 6 and the data in Table 1: The activity of stearic acid in Comparative Example 6 is low. In this application, stearic acid or other long-chain saturated fatty acids can be activated by N,N′-carbonyldiimidazole, which can significantly improve the activity of stearic acid or other long-chain saturated fatty acids, form strong chemical bonds, thereby increasing the grafting rate, further increasing the steric hindrance effect, and being able to more effectively prevent calcium carbonate agglomeration, which is beneficial to improving the mechanical properties and anti-aging performance of the mandrel material.

[0059] According to Example 2, Comparative Example 7 and the data in Table 1: Directly filling unmodified nano-calcium carbonate particles into organic polymer materials will cause uneven dispersion and poor compatibility between different components, resulting in poor toughness and low tensile strength of the final mandrel material. However, the modified nano-calcium carbonate not only plays a role in increasing volume and weight, but also can improve the mechanical properties, anti-aging properties, etc. of the material.

[0060] According to Example 2, Comparative Example 8, and the data in Table 1, it can be seen that the biodegradability of the mandrel material without adding polylactic acid-glycolic acid is poor. By adding polylactic acid-glycolic acid in the present application, not only the biodegradability and environmental protection performance of the material are improved, but also the application fields of the material are expanded, which is helpful for environmental protection.

[0061] This specific embodiment is only an explanation of the present application, and it does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A low-cost and high-performance mandrel material for automotive hoses, characterized in that, It is prepared from the following raw materials by weight parts: 60-70 parts of thermoplastic elastomer TPE, 20-30 parts of modified calcium carbonate, 0.5-1 part of antioxidant, 0.5-1 part of lubricant, 1-2 parts of anti-aging agent, 5-10 parts of poly(lactic-co-glycolic acid); The modified calcium carbonate includes calcium carbonate powder, long-chain saturated fatty acid, N,N′-carbonyldiimidazole, polyvinyl alcohol and crosslinking agent, and the weight ratio of the calcium carbonate powder, long-chain saturated fatty acid, N,N′-carbonyldiimidazole, polyvinyl alcohol and crosslinking agent is 10:(0.3-0.5):(0.3-0.5):(2-4):(0.13-0.17).

2. A low-cost and high-performance mandrel material for automotive hoses according to claim 1, characterized in that, The long-chain saturated fatty acid is selected from one or more of lauric acid, myristic acid, stearic acid, palmitic acid.

3. A low-cost and high-performance mandrel material for automotive hoses according to claim 1, characterized in that, The preparation method of the modified calcium carbonate is as follows: (1) Dissolve polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol solution, add calcium carbonate powder and crosslinking agent to the polyvinyl alcohol solution under the condition of 70-80 °C, stir and react for 2-3 h, and obtain polyvinyl alcohol grafted calcium carbonate after drying; (2) Dissolve long-chain saturated fatty acid in toluene, add N,N′-carbonyldiimidazole at 50-60 °C, stir and react for 3-4 h to obtain a toluene solution of activated long-chain saturated fatty acid; (3) Add polyvinyl alcohol grafted calcium carbonate to the toluene solution of activated long-chain saturated fatty acid, perform ultrasonic treatment for 25-35 min, then stir and react at 40-60 °C for 3-4 h, filter, wash and dry to obtain modified calcium carbonate.

4. A low-cost and high-performance mandrel material for automotive hoses according to claim 1, characterized in that, The crosslinking agent is glyoxal.

5. A low-cost and high-performance mandrel material for automotive hoses according to claim 1, characterized in that, The antioxidant is a phosphite antioxidant.

6. A low-cost and high-performance mandrel material for automotive hoses according to claim 1, characterized in that, The lubricant is selected from one or more of zinc stearate, calcium stearate, paraffin wax, polyethylene wax.

7. A low-cost and high-performance mandrel material for automotive hoses according to claim 1, characterized in that, The anti-aging agent is selected from light stabilizer UV-P.

8. A low-cost and high-performance mandrel material for automotive hoses according to claim 1, characterized in that The fineness of the calcium carbonate powder is D97<10 μm.

9. The preparation method of the low-cost and high-performance automotive hose mandrel material according to any one of claims 1-8, characterized in that, It includes the following steps: Weigh the raw materials according to the component ratio, mix the thermoplastic elastomer TPE, modified calcium carbonate, antioxidant, lubricant, anti-aging agent, poly(lactic-co-glycolic acid) evenly, melt and extrude at 150 °C - 200 °C by a twin-screw extruder, draw into strips, cool and pelletize, then extrude a mandrel of specified specification by a twin-screw extruder or a single-screw extruder, and finally cut it into the required length to obtain a low-cost and high-performance automotive hose mandrel material.

10. Application of the low-cost and high-performance automotive hose mandrel material according to any one of claims 1-8 in the process of shaping automotive hoses.

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