Polyamide composition material for automobile air conditioner pipe as well as preparation method and application of polyamide composition material

Abstract

The invention relates to a polyamide composition material for an automobile air conditioner pipe as well as a preparation method and application thereof, and the polyamide composition material for the automobile air conditioner pipe is prepared from the following components in parts by weight: 80-93.7 parts of polyamide resin, 0.1-2 parts of a chain extender, 0-6 parts of a plasticizer, 3-15 parts of a flexibilizer, 0.1-3 parts of an antioxidant, 0.1-2 parts of a lubricant and 0-3 parts of a light stabilizer. And 0-3 parts of color master batch. The polyamide composition material for the automobile air conditioner pipe is used for preparing an all-plastic polyamide air conditioner pipe, and compared with a common rubber / aluminum pipe combined air conditioner pipe at present, the weight is reduced by 50%, the cost is reduced by 25%, the crimping connection number is reduced, leakage is reduced, processing aids are not needed in the pipe manufacturing process, meanwhile, the refrigerant permeability can be greatly reduced, and the service life of the all-plastic polyamide air conditioner pipe is prolonged. And the use requirement of the refrigerant pipe can be met under the condition of thinner pipeline wall thickness.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a polyamide composite material for automobile air-conditioning pipes, a preparation method and application thereof. Background Art

[0002] With the rapid development of the new energy vehicle industry, the requirements for automotive thermal management systems are increasing. Among them, air conditioning cooling pipes are an important part of the thermal management system. Currently, the commonly used automotive air conditioning refrigerant pipes are mostly aluminum pipes + rubber / PA6 multi-layer braided pipe structures. However, this structure of pipe material is complex to process, heavy, and the refrigerant is prone to leakage.

[0003] At present, OEMs and material factories are actively developing all-plastic air conditioning pipe solutions. Since long-chain nylon has better refrigerant permeability resistance than rubber and PA6, long-chain nylon all-plastic pipe solutions have been disclosed. For example, the patent with publication number CN113502050A discloses a car air conditioning pipe material and its preparation method. The car air conditioning material uses PA1012 resin, adds compatibilizers, polypropylene resin and other additives, and the obtained car air conditioning pipe is light in weight and has a small inner surface roughness, which can effectively improve the circulation efficiency of the refrigerant. However, PA1012 resin itself has poor refrigerant permeability resistance and is prone to cause rapid loss of refrigerant. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a polyamide material for automobile air-conditioning pipes and a preparation method and application thereof. The polyamide composition material for automobile air-conditioning pipes is used to prepare all-plastic polyamide air-conditioning pipes. Compared with the currently common rubber / aluminum tube combined air-conditioning pipes, the weight is reduced by 50%, the cost is reduced by 25%, the number of crimped connections is reduced, and leakage is reduced. No processing aids are required in the pipe manufacturing process. At the same time, the refrigerant permeability can be greatly reduced, and the use requirements of the refrigerant pipe can be met under the condition of thinner pipe wall thickness.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a polyamide composite material for automobile air-conditioning pipes, which is prepared from the following components in parts by weight: 80-93.7 parts of polyamide resin, 0.1-2 parts of chain extender, 0-6 parts of plasticizer, 3-15 parts of toughening agent, 0.1-3 parts of antioxidant, 0.1-2 parts of lubricant, 0-3 parts of light stabilizer and 0-3 parts of masterbatch.

[0007] As a further improvement of the above solution of the present invention, the polyamide resin is a copolymerized polyamide resin, and the relative viscosity of the copolymerized polyamide resin is 2.2-3.6.

[0008] As a further improvement of the above scheme of the present invention, the copolymerized polyamide resin is at least one of PA610 / MXD6, PA612 / MXD6, PA614 / MXD6, PA1010 / MXD6, PA1012 / MXD6, and PA1014 / MXD6.

[0009] As a further improvement of the above scheme of the present invention, the preparation method of the copolymer polyamide resin is: adding a polyamide salt solution and an MXD6 salt solution into a polymerization kettle, heating to 230-260°C, then keeping the temperature and purging with nitrogen at normal pressure for 2-5 hours, and then vacuuming and reacting for 1-2 hours at a pressure lower than 400 Pa to obtain a polymerization product, and then obtaining a copolymer polyamide resin by stranding, pelletizing and drying; wherein the polyamide salt solution is at least one of PA610 salt solution, PA612 salt solution, PA614 salt solution, PA1010 salt solution, PA1012 salt solution and PA1014 salt solution.

[0010] As a further improvement of the above scheme of the present invention, the weight ratio of the polyamide salt in the polyamide salt solution to the MXD6 salt in the MXD6 salt solution is 4-30:1.

[0011] As a further improvement of the above solution of the present invention, the concentration of the polyamide salt solution and the MXD6 salt solution is 30-70%.

[0012] As a further improvement of the above scheme of the present invention, the PA610 salt solution is prepared by weighing hexamethylenediamine and sebacic acid in equal molar ratios, adding them into deionized water, and heating and stirring;

[0013] And / or, the PA612 salt solution is prepared by adding ethylenediamine and dodecanedioic acid into deionized water, followed by heating and stirring;

[0014] And / or, the PA614 salt solution is prepared by weighing ethylenediamine and tetradecanedioic acid in equal molar ratios, adding the mixture into deionized water, and heating and stirring;

[0015] And / or, the PA1010 salt solution is prepared by weighing decanediamine and sebacic acid in equal molar ratios, adding the mixture into deionized water, and heating and stirring;

[0016] The PA1012 salt solution is prepared by weighing decanediamine and dodecanedioic acid in equal molar ratios, adding the mixture into deionized water, and heating and stirring the mixture;

[0017] The PA1014 salt solution is prepared by weighing decanediamine and tetradecanedioic acid in equal molar ratios, adding the mixture into deionized water, and heating and stirring the mixture.

[0018] As a further improvement of the above scheme of the present invention, the chain extender is a copolymer of ethylene and maleic anhydride, preferably ZeMac E60P;

[0019] And / or, the plasticizer is N-butylbenzenesulfonamide;

[0020] And / or, the toughening agent is at least one of maleic anhydride grafted POE, maleic anhydride grafted SEBS, and maleic anhydride grafted EPDM;

[0021] And / or, the antioxidant is one or two of BASF Irganox 245, BASF Irganox 1098, and BASF Irganox 168;

[0022] And / or, the lubricant is one or both of calcium stearate and pentaerythritol stearate;

[0023] And / or, the light stabilizer is one or both of BASF Tinuvin 234 and BASF Tinuvin 770;

[0024] And / or, the masterbatch is at least one of a PA masterbatch, a PP masterbatch, and a PE masterbatch.

[0025] The present invention also provides a method for preparing the polyamide composite material for automobile air-conditioning pipes as described above, comprising mixing polyamide resin, chain extender, toughening agent, antioxidant, lubricant, light stabilizer and masterbatch in proportion to obtain material one; feeding material one to zone one of an extruder through a loss-in-weight scale, feeding a plasticizer in proportion to zone six of the extruder through a liquid metering scale, melting, extruding, granulating and drying to obtain the polyamide composite material for automobile air-conditioning pipes.

[0026] As a further improvement of the above scheme of the present invention, the extruder is a twin-screw extruder with a ten-section barrel, and the temperatures of each zone of the twin-screw extruder are: the temperature of zone one is 120-200°C, the temperature of zone two is 230-290°C, the temperature of zone three is 230-290°C, the temperature of zone four is 230-290°C, the temperature of zone five is 230-290°C, the temperature of zone six is ​​230-290°C, the temperature of zone seven is 230-290°C, the temperature of zone eight is 230-290°C, the temperature of zone nine is 230-290°C, and the temperature of zone ten is 230-290°C; the head temperature is 230-290°C; the main engine speed of the twin-screw extruder is 200-1000r / min.

[0027] The present invention also provides a use of the above-mentioned polyamide composition material for automobile air-conditioning pipes in the preparation of automobile air-conditioning pipes.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The polyamide composite material for automobile air-conditioning pipes provided by the present invention can be used to prepare all-plastic polyamide air-conditioning pipes. Compared with the currently common rubber / aluminum tube combined air-conditioning pipes, the weight is reduced by 50%, the cost is reduced by 25%, the number of crimped connections is reduced, leakage is reduced, and no processing aids are required during the pipe manufacturing process.

[0030] 2. The polyamide composite material for automobile air-conditioning pipes provided by the present invention has a large number of benzene ring structures introduced into the molecular chain due to the copolymerization of the structure of MXD6 in the copolymerized polyamide resin. This structure makes the interaction between molecules strong, thereby forming a dense structure, effectively blocking the passage of gas molecules and reducing refrigerant penetration.

[0031] 3. The polyamide composition material for automobile air-conditioning pipes provided by the present invention adds a chain extender, which reduces the viscosity requirement for long-chain nylon resin, expands the application scope of long-chain nylon, and improves the stability of product pipe extrusion.

[0032] 4. In the polyamide composite material for automobile air-conditioning pipes provided by the present invention, by adding toughening agents such as maleic anhydride grafted POE, maleic anhydride grafted SEBS, and maleic anhydride grafted EPDM, the low-temperature impact performance of the pipe can be greatly improved; antioxidants and light stabilizers are added to improve weather resistance; and lubricants are added to improve the surface brightness of the pipe. DETAILED DESCRIPTION

[0033] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0035] The raw material information used in the following examples and comparative examples is as follows:

[0036] (1) Homemade copolyamide resin

[0037] Copolymer polyamide resin 1: weigh hexamethylenediamine and dodecanedioic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 70% concentration PA612 salt solution; weigh meta-phenylenediamine and adipic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 30% concentration MXD6 salt solution; according to the weight of the salt in the salt solution, the weight ratio of hexamethylenediamine dodecanedioic acid salt and MXD6 salt is controlled to be 30:1; add the two salt solutions into a polymerization kettle in sequence, heat to 230-260°C, keep the temperature and purge with nitrogen at normal pressure for 2-5h, then vacuum the reaction at a pressure lower than 400Pa for 1-2h to obtain a polymerization product, control the viscosity by controlling the stirring current, and obtain a copolymer resin 1 with a relative viscosity of 2.8 after stranding, pelletizing and drying;

[0038] Copolymer polyamide resin 2: weigh hexamethylenediamine and sebacic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 50% concentration PA610 salt solution; weigh meta-phenylenediamine and adipic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 50% concentration MXD6 salt solution; according to the weight of the salt in the salt solution, the weight ratio of hexamethylenediamine sebacic acid salt and MXD6 salt is controlled to be 20:1; add the two salt solutions into a polymerization kettle in sequence, heat to 230-260°C, keep the temperature and purge with nitrogen at normal pressure for 2-5h, then vacuum the reaction at a pressure lower than 400Pa for 1-2h to obtain a polymerization reaction product, control the viscosity by controlling the stirring current, and obtain a copolymer resin 2 with a relative viscosity of 2.2 after stranding, pelletizing and drying;

[0039] Copolymerized polyamide resin 3: weigh decanediamine and dodecanedioic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 70% concentration PA1012 salt solution; weigh meta-phenylenediamine and adipic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 50% concentration MXD6 salt solution; according to the weight of the salt in the salt solution, the weight ratio of decanediamine salt of dodecanedioic acid and MXD6 salt is controlled to be 10:1; add the two salt solutions into a polymerization kettle in sequence, heat to 230-260°C, keep the temperature and purge with nitrogen at normal pressure for 2-5h, then evacuate the reaction at a pressure lower than 400Pa for 1-2h to obtain a polymerization product, control the viscosity by controlling the stirring current, and obtain a copolymerized resin 3 with a relative viscosity of 3.2 after stranding, pelletizing and drying;

[0040] Copolymer polyamide resin 4: weigh decanediamine and sebacic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 30% concentration PA1010 salt solution; weigh meta-phenylenediamine and adipic acid in an equal molar ratio, add them into deionized water, heat and stir to prepare a 70% concentration MXD6 salt solution; according to the weight of the salt in the salt solution, the weight ratio of decanediamine sebacic acid salt and MXD6 salt is controlled to be 4:1; add the two salt solutions into a polymerization kettle in sequence, heat to 230-260°C, keep the temperature and purge with nitrogen at normal pressure for 2-5h, then vacuum the reaction at a pressure lower than 400Pa for 1-2h to obtain a polymerization reaction product, control the viscosity by controlling the stirring current, and obtain a copolymer resin 4 with a relative viscosity of 3.6 after stranding, pelletizing and drying;

[0041] (2) Chain extender: Fantelus ZeMac E60P;

[0042] (3) Plasticizer BBSA, Proviplast 024 from Belgium;

[0043] (4) Maleic anhydride grafted POE is FUSABONDN N216 from Dow Chemical, USA;

[0044] (5) Maleic anhydride grafted SEBS is Kraton polymer FG1901;.

[0045] (6) Maleic anhydride grafted EPDM is ExxonMobil EXXELOR VA1803;

[0046] (7) Calcium stearate is Italian calcium stearate;

[0047] (8) Pentaerythritol stearate PETS is Italian PETS-AP;

[0048] (9) PA612 was produced by Shandong Dongchen Ruisen New Material Technology Co., Ltd., with a relative viscosity of 2.8;

[0049] (10) Antioxidant 245, Antioxidant 1098, PA black masterbatch, light stabilizer BASF Tinuvin 234, and light stabilizer BASF Tinuvin 770 are all commercially available.

[0050] The above raw materials are only for illustrating the sources and components of the reagents used in the experiments of the present invention so as to fully disclose the information, and do not mean that the present invention cannot be realized by using other similar reagents or reagents provided by other suppliers.

[0051] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the present technical field.

[0052] Example 1

[0053] This embodiment provides a polyamide composite material for automobile air-conditioning pipes, which includes the following component raw materials in parts by weight: 86.8 parts of copolymerized polyamide resin 1, 0.5 parts of chain extender ZeMac E60P, 2 parts of plasticizer BBSA, 7 parts of maleic anhydride grafted POE, 0.5 parts of antioxidant 245, 0.5 parts of antioxidant 1098, 0.5 parts of antioxidant 168, 0.2 parts of calcium stearate, 1 part of light stabilizer BASF Tinuvin 234, and 1 part of PA black masterbatch.

[0054] The preparation method of the polyamide composite material for automobile air-conditioning pipes of this embodiment comprises the following steps: adding polyamide resin, chain extender, toughening agent, antioxidant, lubricant, light stabilizer and masterbatch into a high-speed mixer in proportion, mixing for 2-10 minutes, and obtaining material one; feeding material one to zone one of a twin-screw extruder through a loss-in-weight scale, feeding a plasticizer to zone six of the twin-screw extruder through a liquid metering scale in proportion, melting, extruding, granulating and drying to obtain the polyamide composite material for automobile air-conditioning pipes. The twin-screw extruder is a twin-screw extruder with a ten-section barrel. The temperatures of each zone of the twin-screw extruder are: the temperature of zone one is 120-200°C, the temperature of zone two is 230-290°C, the temperature of zone three is 230-290°C, the temperature of zone four is 230-290°C, the temperature of zone five is 230-290°C, the temperature of zone six is ​​230-290°C, the temperature of zone seven is 230-290°C, the temperature of zone eight is 230-290°C, the temperature of zone nine is 230-290°C, and the temperature of zone ten is 230-290°C; the head temperature is 230-290°C; the main engine speed of the twin-screw extruder is 200-1000r / min.

[0055] Example 2

[0056] This embodiment adopts the same implementation method as Example 1, and the difference from Example 1 is that the polyamide composition material for automobile air-conditioning pipes in this embodiment includes the following component raw materials in parts by weight: 85.8 parts of copolymerized polyamide resin 2, 2 parts of chain extender ZeMac E60P, 6 parts of plasticizer BBSA, 3 parts of maleic anhydride grafted EPDM, 0.1 parts of antioxidant 245, 0.1 parts of PETS, and 3 parts of PA black masterbatch.

[0057] Example 3

[0058] This embodiment adopts the same implementation method as Example 1, and the difference from Example 1 is that the polyamide composition material for automobile air-conditioning pipes in this embodiment includes the following component raw materials in parts by weight: 80 parts of copolymerized polyamide resin 3, 0.2 parts of chain extender ZeMac E60P, 15 parts of maleic anhydride grafted SEBS, 1 part of antioxidant 245, 1 part of antioxidant 1098, 1 part of antioxidant 168, 0.1 parts of calcium stearate, and 1.7 parts of PA black masterbatch.

[0059] Example 4

[0060] This embodiment adopts the same implementation method as Example 1, and the difference from Example 1 is that the polyamide composition material for automobile air-conditioning pipes in this embodiment includes the following component raw materials in parts by weight: 93.7 parts of copolymerized polyamide resin 4, 0.1 parts of chain extender ZeMac E60P, 3 parts of maleic anhydride grafted SEBS, 0.1 parts of antioxidant 245, 0.1 parts of calcium stearate, and 3 parts of light stabilizer BASF Tinuvin770.

[0061] Example 5

[0062] This embodiment adopts the same implementation method as Example 1, and the difference from Example 1 is that the polyamide composition material for automobile air-conditioning pipes in this embodiment includes the following component raw materials in parts by weight: 72.7 parts of copolymerized polyamide resin 1, 15 parts of copolymerized polyamide resin 3, 0.3 parts of chain extender ZeMac E60P, 4 parts of plasticizer BBSA, 3 parts of maleic anhydride grafted POE, 2 parts of maleic anhydride grafted EPDM, 1 part of antioxidant 245, 1 part of calcium stearate, and 1 part of PETS.

[0063] Comparative Example 1

[0064] This comparative example adopts the same implementation mode as Example 1, and the difference from Example 1 is that the polyamide composition material for automobile air-conditioning pipes in this example includes the following component raw materials in parts by weight: 86.8 parts of PA612, 0.5 parts of chain extender ZeMac E60P, 2 parts of plasticizer BBSA, 7 parts of maleic anhydride grafted POE, 0.5 parts of antioxidant 245, 0.5 parts of antioxidant 1098, 0.5 parts of antioxidant 168, 0.2 parts of calcium stearate, 1 part of BASF Tinuvin 234, and 1 part of PA black masterbatch.

[0065] Comparative Example 2

[0066] This comparative example adopts the same implementation as Example 1, and the difference from Example 1 is that the polyamide composition material for automobile air-conditioning pipes in this example includes the following component raw materials in parts by weight: 86.8 parts of copolymerized polyamide resin 1, 2 parts of plasticizer BBSA, 7 parts of maleic anhydride grafted POE, 0.5 parts of antioxidant 245, 0.5 parts of antioxidant 1098, 0.5 parts of antioxidant 168, 0.2 parts of calcium stearate, 1 part of BASF Tinuvin 234, and 1 part of PA black masterbatch.

[0067] Comparative Example 3

[0068] This comparative example adopts the same implementation method as Example 1, and the difference from Example 1 is that the polyamide composition material for automobile air-conditioning pipes in this example includes the following component raw materials in parts by weight: 86.8 parts of copolymerized polyamide resin 1, 0.5 parts of chain extender ZeMac E60P, 2 parts of plasticizer BBSA, 0.5 parts of antioxidant 245, 0.5 parts of antioxidant 1098, 0.5 parts of antioxidant 168, 0.2 parts of calcium stearate, 1 part of BASF Tinuvin234, and 1 part of PA black masterbatch.

[0069] The amounts of various raw materials used in the polyamide composition materials for automobile air-conditioning pipes of the above embodiments and comparative examples are shown in Table 1.

[0070] Table 1 Amount of each raw material in the polyamide composition material for automobile air conditioning pipe of the embodiment and comparative example

[0071]

[0072]

[0073] Test Case

[0074] The polyamide composition materials prepared in Examples 1-5 and Comparative Examples 1-3 were extruded into injection molded specimens and pipes, and the mechanical properties were tested; the test results are shown in Table 2. Among them, the tensile strength and elongation at break were tested in accordance with ISO527-1A, with a tensile speed of 50 mm / min; the -30°C low-temperature notched impact test was tested in accordance with ISO179; the melt index test was tested in accordance with ISO 1133; the burst pressure test was tested in accordance with GB 16897; and the permeability was tested in accordance with GB / T20025.

[0075] Table 2 Performance test results

[0076]

[0077]

[0078] From the results in Table 2, we can see that:

[0079] Compared with Comparative Example 1, Example 1 uses copolymerized polyamide resin 1, and the refrigerant permeability of Example 1 is increased from 1.8 kg / (m 2 *year) is reduced to 0.25kg / (m 2 *year), confirming that the refrigerant permeability can be reduced by copolymerizing the MXD6 structure;

[0080] Compared with Comparative Example 2, Example 1 uses a chain extender, and the melt index of Example 1 is reduced from 9.8 to 3.1, so that the pipe can be stably extruded;

[0081] Compared with Comparative Example 3, Example 1 uses a toughening agent, and the low-temperature simply supported beam notched impact strength of the material in Example 1 increases from 2.5 KJ / m 2 Rising to 9.3KJ / m 2 The pipe can withstand low temperature impact of -40℃ without breaking.

[0082] In summary, the overall performance of Examples 1, 2, 3, 4 and 5 of the present application is good and can meet the application requirements of high explosion resistance and low permeability air-conditioning pipelines for new energy vehicles.

[0083] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polyamide composition material for automobile air-conditioning pipes, characterized in that: The invention is prepared from the following components in parts by weight: 80-93.7 parts of polyamide resin, 0.1-2 parts of chain extender, 0-6 parts of plasticizer, 3-15 parts of toughening agent, 0.1-3 parts of antioxidant, 0.1-2 parts of lubricant, 0-3 parts of light stabilizer and 0-3 parts of masterbatch.

2. The polyamide composition material for automobile air-conditioning pipes according to claim 1, characterized in that: The polyamide resin is a copolymerized polyamide resin, and the relative viscosity of the copolymerized polyamide resin is 2.2-3.

6.

3. The polyamide composition material for automobile air-conditioning pipes according to claim 2, characterized in that: The copolymer polyamide resin is at least one of PA610 / MXD6, PA612 / MXD6, PA614 / MXD6, PA1010 / MXD6, PA1012 / MXD6, and PA1014 / MXD6.

4. The polyamide composition material for automobile air-conditioning pipes according to claim 3, characterized in that: The preparation method of the copolymer polyamide resin is as follows: adding a polyamide salt solution and an MXD6 salt solution into a polymerization kettle, heating to 230-260° C., maintaining the temperature, and then purging with nitrogen at normal pressure for a reaction of 2-5 hours, and then vacuumizing the reaction at a pressure lower than 400 Pa for a reaction of 1-2 hours to obtain a polymerization product, and then pelletizing and drying the product to obtain the copolymer polyamide resin; wherein the polyamide salt solution is at least one of a PA610 salt solution, a PA612 salt solution, a PA614 salt solution, a PA1010 salt solution, a PA1012 salt solution, and a PA1014 salt solution.

5. The polyamide composition material for automobile air-conditioning pipes according to claim 4, characterized in that: The weight ratio of the polyamide salt in the polyamide salt solution to the MXD6 salt in the MXD6 salt solution is 4-30:1; And / or, the concentration of the polyamide salt solution and the MXD6 salt solution is 30-70%.

6. The polyamide composition material for automobile air-conditioning pipes according to claim 4, characterized in that: The PA610 salt solution is prepared by weighing hexamethylenediamine and sebacic acid in an equal molar ratio, adding them into deionized water, and heating and stirring; And / or, the PA612 salt solution is prepared by weighing ethylenediamine and dodecanedioic acid in an equal molar ratio, adding them into deionized water, and heating and stirring; And / or, the PA614 salt solution is prepared by weighing ethylenediamine and tetradecanedioic acid in an equal molar ratio, adding them into deionized water, and heating and stirring; And / or, the PA1010 salt solution is prepared by weighing decanediamine and sebacic acid in an equal molar ratio, adding them into deionized water, and heating and stirring; The PA1012 salt solution is prepared by weighing decanediamine and dodecanedioic acid in an equal molar ratio, adding them into deionized water, and heating and stirring; The PA1014 salt solution is prepared by weighing decanediamine and tetradecanedioic acid in an equal molar ratio, adding the mixture into deionized water, and heating and stirring the mixture.

7. The polyamide composition material for automobile air-conditioning pipes according to claim 1, characterized in that: The chain extender is a copolymer of ethylene and maleic anhydride; And / or, the plasticizer is N-butylbenzenesulfonamide; And / or, the toughening agent is at least one of maleic anhydride grafted POE, maleic anhydride grafted SEBS, and maleic anhydride grafted EPDM; And / or, the antioxidant is one or two of BASF Irganox 245, BASF Irganox 1098, and BASF Irganox 168; And / or, the lubricant is one or both of calcium stearate and pentaerythritol stearate; And / or, the light stabilizer is one or both of BASF Tinuvin 234 and BASF Tinuvin 770; And / or, the masterbatch is at least one of a PA masterbatch, a PP masterbatch, and a PE masterbatch.

8. A method for preparing the polyamide composition material for automobile air-conditioning pipes according to any one of claims 1 to 7, characterized in that: The polyamide resin, chain extender, toughening agent, antioxidant, lubricant, light stabilizer and masterbatch are mixed in proportion to obtain material one; material one is fed to zone one of the extruder through a loss-in-weight scale, and the plasticizer is fed to zone six of the extruder through a liquid metering scale in proportion, and the materials are melted, extruded, granulated and dried to obtain a polyamide composite material for automobile air-conditioning pipes.

9. The method for preparing the polyamide composition material for automobile air-conditioning pipes according to claim 8, characterized in that: The extruder is a twin-screw extruder with a ten-section barrel, and the temperatures of each zone of the twin-screw extruder are: the temperature of zone one is 120-200°C, the temperature of zone two is 230-290°C, the temperature of zone three is 230-290°C, the temperature of zone four is 230-290°C, the temperature of zone five is 230-290°C, the temperature of zone six is ​​230-290°C, the temperature of zone seven is 230-290°C, the temperature of zone eight is 230-290°C, the temperature of zone nine is 230-290°C, and the temperature of zone ten is 230-290°C; the head temperature is 230-290°C; the main engine speed of the twin-screw extruder is 200-1000r / min.

10. Use of the polyamide composition material for automobile air-conditioning pipes according to any one of claims 1 to 7 in the preparation of automobile air-conditioning pipes.

Images