Preparation method and application of nylon heat-resistant agent

Abstract

The invention discloses a preparation method and application of a nylon heat-resistant agent. The nylon heat-resistant agent is prepared by reacting a maleic anhydride derivative and lactam under the action of an initiator. The heat-resistant effect is good; the preparation is simple, and the like. By adding the nylon heat-resistant agent into the nylon material, the heat resistance and mechanical properties of the nylon material can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a preparation method and application of a nylon heat-resistant agent. Background Art

[0002] Nylon (PA) is a type of polymer containing amide groups (-CO-NH-) in its molecular chain. It is currently the engineering plastic with the largest output and the widest application fields. Due to the amide groups in its molecular chain, it can form hydrogen bond interactions, and the molecular chain structure is regular, so it has relatively high strength and modulus. According to the different molecular structures of nylon, it can be divided into aliphatic nylon and aromatic nylon. Among them, the main component in the molecular chain of aliphatic nylon is methylene. It has good toughness, excellent processing performance, and high cost performance, and has been widely used in fields such as aerospace, electrical equipment, and the automotive industry. The main varieties include PA6, PA66, PA1010, PA11, PA12, etc. Compared with aromatic nylon, aliphatic nylon has a strong price advantage, high comprehensive performance, excellent processing performance, easy access to raw materials, and wider application. With the miniaturization and lightweight of automobiles and the high-performance of electrical equipment, higher requirements are put forward for its strength, heat resistance, etc. However, compared with other engineering plastics, aliphatic nylon has a lower heat distortion temperature and poor heat resistance, and cannot meet the application requirements in high-heat fields such as automotive engines, fuel systems, battery pack systems, and electrical equipment. Therefore, it is of great significance to carry out heat resistance modification on it. Commonly used nylon heat resistance modification methods at home and abroad are divided into two types: chemical method and physical method. The chemical method mainly uses synthetic methods to introduce aromatic heterocycles or polar groups into the nylon main chain to increase the molecular chain rigidity or carry out molecular chain cross-linking. For example, aromatic nylon is prepared by polycondensation. Due to the benzene ring structure in the molecular chain, the movement and rotation of the molecular chain are hindered, and it has relatively high mechanical strength, glass transition temperature, and heat distortion temperature. The main varieties include PA6T, PA9T, and PPTA, etc. However, aromatic nylon is expensive, has too high a melting point, is difficult to process and form, requires high production equipment, and most can only be used for the production of synthetic fibers, and it is difficult to achieve popularization and utilization. The radiation of the cross-linking method has relatively strict requirements for safety protection, which is not conducive to industrial production. The physical method usually uses a blending method, including fiber reinforcement, adding inorganic powders, blending with engineering plastics with higher heat resistance, heat-resistant agents or chain extenders with reactive groups such as PC, PPO, St-MAH, MPBO, BOZ, etc. However, the existing methods all have the problem of poor compatibility between the blend and PA. In particular, the addition of fibers, powders, etc. is likely to cause phenomena such as floating fibers and agglomeration, which greatly limits the application range of the products. For products with high surface requirements or extrusion molding, it is difficult to promote and apply. Based on the above research background, it becomes particularly important to prepare a PA heat-resistant agent with good compatibility, good heat resistance effect, and simple preparation and to prepare a high-heat-resistant PA composition. Summary of the Invention

[0003] The object of the present invention is to provide a preparation method of nylon and its application. The heat-resistant agent prepared by the present invention can be used in nylon materials, can significantly improve the heat resistance of nylon materials, and does not affect other properties of nylon materials, with a wide range of applications.

[0004] The present invention provides a preparation method of a nylon heat-resistant agent, in which a maleic anhydride (MAH) derivative and a lactam are reacted under the action of an initiator to prepare the nylon heat-resistant agent.

[0005] The maleic anhydride derivative includes N-phenylmaleimide, N-substituted phenylmaleimide, N-glycine-based maleimide, N-cyclohexylmaleimide.

[0006] Preferably, the substituent in the N-substituted phenylmaleimide is a substituent with a molecular weight less than 300, selected from hydroxyl group, amino group, carboxyl group, alkoxy group, cyano group, halogen, amide group;

[0007] In the method of the present invention, the maleic anhydride derivative includes N-phenylmaleimide (NPMI), N-(4-hydroxyphenyl) maleimide (NBCBMI), N-(4-allyloxyphenyl) maleimide (NAPMI), N-(benzocyclobuten-4-yl) maleimide (NBBMI), cyano-containing N-substituted phenylmaleimide (NPPMI), 4-N-benzophenone-based maleimide (NBPMI), N-p-carboxyphenyl maleimide (NPCPMI), N-[4-(N'-substituted amide group)phenyl] maleimide (NNSAPMI), N-[4-N'-(benzylamino-carbonyl)phenyl] maleimide (NBACPMI), 1-[4-(dimethylamino)phenyl] maleimide (DYPMI), tribromophenyl maleimide (TBPMI), N-oxazolinylphenyl maleimide (NOAOPMI), N-glycine-based maleimide (NGMI), N-cyclohexylmaleimide (NCHMI).

[0008] In the method of the present invention, the lactam is selected from one or more of butyrolactam, valerolactam, caprolactam, enantholactam, caprylolactam, capric lactam, undecanolactam, laurolactam, and preferably caprolactam, caprylolactam, laurolactam.

[0009] In the method of the present invention, the initiator is an anionic initiator, selected from one or more of alkali metals, metal hydrides, metal hydroxides, and metal alkylates of alkali metals, and preferably metal hydroxides and metal alkylates of alkali metals.

[0010] In the method of the present invention, the molar ratio of the maleic anhydride derivative, the lactam, and the initiator is: (35 - 60):(35 - 60):(0.1 - 5), preferably (45 - 55):(45 - 55):(0.5 - 3).

[0011] In the present invention, the reaction of the maleic anhydride derivative and the lactam includes two stages: in the first stage, the reaction temperature is 200 - 300 °C, preferably 220 °C - 280 °C; the pressure is 1.0 - 2.0 MPa, preferably 1.3 - 1.6 MPa; the reaction time is 0.5 - 1 h, preferably 0.6 - 0.8 h. In the second stage, the reaction temperature is 250 - 350 °C, preferably 280 °C - 330 °C; the pressure is 1.5 - 2.5 MPa, preferably 1.7 - 2.4 MPa; the reaction time is 0.5 - 2 h, preferably 1 - 1.5 h.

[0012] The prepared PA heat-resistant agent is added to water, ultrasonically oscillated, and then dried under vacuum;

[0013] In the method of the present invention, the ultrasonic oscillation duration is 10 - 30 min, preferably 20 - 25 min; the vacuum drying temperature is 60 - 100 °C, preferably 80 - 90 °C; the vacuum drying duration is 2 - 4 h, preferably 2.5 - 3 h.

[0014] The present invention also provides the application of the nylon heat-resistant agent, which is used in nylon materials.

[0015] A nylon material, comprising the following components in parts by weight:

[0016] 60 - 95 parts by weight of PA resin,

[0017] 1 - 20 parts by weight of PA heat-resistant agent,

[0018] 0 - 30 parts by weight of toughening agent,

[0019] 0 - 5 parts by weight of chain extender,

[0020] 0 - 3 parts by weight of antioxidant,

[0021] 0 - 3 parts by weight of light stabilizer,

[0022] 0 - 3 parts by weight of lubricant.

[0023] 0 - 3 parts by weight of colorant

[0024] Preferably, the nylon material comprises the following components in parts by weight:

[0025] 65 - 90 parts by weight of PA resin,

[0026] 5 - 15 parts by weight of PA heat-resistant agent,

[0027] The toughening agent is 5 - 20 parts by weight,

[0028] The chain extender is 0.5 - 2 parts by weight,

[0029] The antioxidant is 0.1 - 2 parts by weight,

[0030] The light stabilizer is 0 - 2 parts by weight,

[0031] The lubricant is 0 - 2 parts by weight,

[0032] The colorant is 0 - 2 parts by weight.

[0033] Preferably, the PA resin is selected from one or more of PA6, PA66, PA1010, PA610, PA612, PA1010, PA1012, PA11, PA12, PA1212.

[0034] Preferably, the toughening agent is selected from thermoplastic elastomers, including polyolefin elastomers (POE) and their chemically grafted modified products such as maleic anhydride grafted POE, ethylene - vinyl acetate copolymer (EVA), ethylene - acrylic acid copolymer (EAA), thermoplastic polyurethane elastomer (TPU), nylon elastomer (PEBAX), rubbers including ethylene - propylene - diene monomer (EPDM) and its grafted modified products, polyolefins including polypropylene (PP) and its grafted modified products such as polypropylene grafted maleic anhydride, polyethylene (PE) and its grafted modified products such as polyethylene grafted maleic anhydride;

[0035] Preferably, the chain extender is selected from one or more of isocyanates, epoxies, and bicyclic heterocycles.

[0036] Preferably, the antioxidant is selected from one or more of phenols, amines, metal ion halides, thioesters, and phosphites;

[0037] Preferably, the light stabilizer is selected from ultraviolet light absorbers, radical scavengers, and light shields;

[0038] Preferably, the lubricant is selected from one or more of stearic acid complex esters, polyethylene wax, amide wax, and polyols;

[0039] Preferably, the colorant is selected from one or more of pigments, dyes, color masterbatches, and carbon black.

[0040] The present invention also provides a method for preparing the nylon material. The PA resin, PA heat - resistant agent, optional toughening agent, optional chain extender, optional antioxidant, optional ultraviolet light absorber, optional lubricant, and optional colorant are mixed evenly and then extruded and pelletized by a twin - screw extruder to obtain the nylon material.

[0041] In the present invention, the extrusion temperature of the twin-screw extruder is 180-270°C, preferably 180-220°C in zone 1, 190-250°C in zone 2-3, 200-270°C in zone 4-6, 210-270°C in zone 7-10, 200-260°C in zone 11-12, and 190-240°C in zone 13; the screw speed is 100-300rpm, preferably 150-250rpm.

[0042] The present invention also provides applications of the nylon material, which can be applied to the fields of automobile pipelines, joints, instruments and meters, hydrogen storage energy, electrical housings, cable coverings, etc.

[0043] The PA heat-resistant agent of the present invention has a simple preparation method, low cost and good heat-resistant effect. When used in nylon materials, it can significantly improve the heat resistance of the nylon materials and is beneficial to improving the mechanical properties of the nylon materials. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0045] Source of raw materials:

[0046] N-phenylmaleimide (NPMI), Nippon Electric Chemical Industry Co., Ltd.

[0047] Butyrolactam, Aladdin Chemical

[0048] Caprolactam, Aladdin Chemical

[0049] Capryllactam, Aladdin Chemical

[0050] Lauryl lactam, Wanhua Chemical Group Co., Ltd.

[0051] Potassium hydroxide, Aladdin reagent

[0052] Butyl lithium, Aladdin reagent

[0053] N-(Benzocyclobutene-4-yl)maleimide, Gaide Chemical

[0054] N-Cyclohexylmaleimide:Guide Chemical

[0055] 4-N-Benzophenone Maleimide:Gaide Chemical

[0056] N-Glycine Maleimide:Alpha Chemicals

[0057] PA12 resin: Wanamid L3000, Wanhua Chemical Group Co., Ltd.

[0058] PA610 resin: SMVO, Arkema

[0059] PA1010 resin: TMNO TLD, Arkema

[0060] PA6 resin: 5034B, Ube Industries, Ltd.

[0061] Toughening agent: FUSABOND N493, Dow Chemical

[0062] Chain extender: isophorone diisocyanate, IPDI, Wanhua Chemical Group Co., Ltd.

[0063] Antioxidant: Irganox1098, BASF SE

[0064] Antioxidant: Irganox168, BASF SE

[0065] Light stabilizer: UV-312, Rianlon

[0066] Lubricant: calcium stearate, Liyang Chemical Industry

[0067] Colorant: black masterbatch, Cabot

[0068] Example 1

[0069] A preparation method of a nylon heat-resistant agent, the steps include:

[0070] (1) Mix 202.4 g of N-phenylmaleimide and 250 g of butyrolactam evenly and add them to the reaction kettle, then add 9.52 g of potassium hydroxide, and purge the reaction kettle with nitrogen 8 times to completely displace the air therein; raise the temperature of the reaction kettle to 220 °C, raise the pressure to 1.0 MPa, and maintain the pressure for 0.5 h; continue to raise the temperature to 250 °C, raise the pressure to 1.5 MPa, and maintain the pressure for 1 h to obtain a crude PA heat-resistant agent;

[0071] (2) Take out the crude PA heat-resistant agent and put it into a beaker with water and pure water, use ultrasonic oscillation for 10 min, and finally put the product into a vacuum oven and vacuum dry it at 60 °C for 4 h to obtain a nylon heat-resistant agent;

[0072] (3) 6.5 kg of PA6 resin, 500 g of PA heat-resistant agent, 2000 g of toughening agent, 500 g of chain extender, 50 g of antioxidant Irganox1098, 50 g of antioxidant Irganox1098, 100 g of light stabilizer UV-312,

[0073] After 300 g of the lubricant calcium stearate was uniformly mixed using a high-speed mixer, it was added to a twin-screw extruder for extrusion granulation. The extrusion temperature of the twin-screw extruder was 200 °C in the first zone, 210 °C in the second to third zones, 250 °C in the fourth to sixth zones, 250 °C in the seventh to tenth zones, 240 °C in the eleventh to twelfth zones, and 230 °C in the thirteenth zone; the screw speed was 200 rpm.

[0074] Example 2

[0075] To prepare a nylon heat-resistant agent and its composition, the steps include:

[0076] (1) After 477.6 g of N-(benzocyclobutene-4-yl) maleimide and 226 g of caprolactam were uniformly mixed, they were added to a reaction kettle. Then, 2.464 g of KOH was added, and the reaction kettle was purged with nitrogen 7 times to completely displace the air therein; the temperature of the reaction kettle was raised to 250 °C, the pressure was raised to 1.5 MPa, and the pressure was maintained for 0.8 h; the temperature was continuously raised to 300 °C, the pressure was raised to 2 MPa, and the pressure was maintained for 1.5 h to obtain a crude PA heat-resistant agent;

[0077] (2) The crude PA heat-resistant agent was taken out and placed in a beaker of water with sufficient pure water, ultrasonically vibrated for 20 min, and finally the product was placed in a vacuum oven and vacuum-dried at 80 °C for 3 h to obtain a nylon heat-resistant agent;

[0078] (3) After 8.5 kg of PA610 resin, 800 g of PA heat-resistant agent, 100 g of toughening agent, 200 g of chain extender, 50 g of antioxidant Irganox1098, 50 g of antioxidant Irganox168, 100 g of light stabilizer UV-312, and 200 g of lubricant calcium stearate were uniformly mixed using a high-speed mixer, they were added to a twin-screw extruder for extrusion granulation. The extrusion temperature of the twin-screw extruder was 200 °C in the first zone, 210 °C in the second to third zones, 250 °C in the fourth to sixth zones, 250 °C in the seventh to tenth zones, 240 °C in the eleventh to twelfth zones, and 230 °C in the thirteenth zone; the screw speed was 200 rpm.

[0079] Example 3

[0080] To prepare a nylon heat-resistant agent and its composition, the steps include:

[0081] (1) After 532.5 g of N-cyclohexyl maleimide and 282 g of octanamide were uniformly mixed, they were added to a reaction kettle. Then, 1.6 g of butyllithium was added, and the reaction kettle was purged with nitrogen 5 - 10 times to completely displace the air therein; the temperature of the reaction kettle was raised to 265 °C, the pressure was raised to 1.65 MPa, and the pressure was maintained for 1 h; the temperature was continuously raised to 300 °C, the pressure was raised to 2.3 MPa, and the pressure was maintained for 2 h to obtain a crude PA heat-resistant agent;

[0082] (2) Take out the crude PA heat-resistant agent, put it into a beaker of water, add sufficient pure water, use ultrasonic oscillation for 30 min, and finally put the product into a vacuum oven and vacuum-dry it at 90 °C for 2 h to obtain the nylon heat-resistant agent;

[0083] (3) Mix 7.8 kg of PA1010 resin, 1400 g of PA heat-resistant agent, 400 g of toughening agent, 100 g of chain extender, 50 g of antioxidant Irganox1098, 50 g of antioxidant Irganox168, 100 g of light stabilizer UV-312, and 100 g of lubricant calcium stearate evenly using a high-speed mixer, then add them into a twin-screw extruder for extrusion granulation. The extrusion temperature of the twin-screw extruder is 200 °C in the first zone, 210 °C in the second to third zones, 250 °C in the fourth to sixth zones, 250 °C in the seventh to tenth zones, 240 °C in the eleventh to twelfth zones, and 230 °C in the thirteenth zone; the screw speed is 200 rpm.

[0084] Example 4

[0085] The preparation of the nylon heat-resistant agent and its composition includes the following steps:

[0086] (1) Mix 498.2 g of 4-N-benzophenone maleimide and 394 g of dodecyl lactam evenly, then add them into a reaction kettle, and then add 7.68 g of butyl lithium. Purge the reaction kettle with nitrogen 5 - 10 times to completely displace the air inside; raise the temperature of the reaction kettle to 280 °C, raise the pressure to 1.8 MPa, and maintain the pressure for 1 h; continue to raise the temperature to 330 °C, raise the pressure to 2.5 MPa, and maintain the pressure for 2.5 h to obtain the crude PA heat-resistant agent;

[0087] (2) Take out the crude PA heat-resistant agent, put it into a beaker of water, add sufficient pure water, use ultrasonic oscillation for 30 min, and finally put the product into a vacuum oven and vacuum-dry it at 100 °C for 2 h to obtain the nylon heat-resistant agent;

[0088] (3) Mix 9 kg of PA12 resin, 200 g of PA heat-resistant agent, 200 g of toughening agent, 200 g of chain extender, 50 g of antioxidant Irganox1098, 50 g of antioxidant Irganox168, 100 g of light stabilizer UV-312, 100 g of lubricant calcium stearate, and 100 g of colorant evenly using a high-speed mixer, then add them into a twin-screw extruder for extrusion granulation. The extrusion temperature of the twin-screw extruder is 200 °C in the first zone, 210 °C in the second to third zones, 250 °C in the fourth to sixth zones, 250 °C in the seventh to tenth zones, 240 °C in the eleventh to twelfth zones, and 230 °C in the thirteenth zone; the screw speed is 200 rpm.

[0089] Example 5

[0090] The preparation of the nylon heat-resistant agent and its composition includes the following steps:

[0091] (1) Mix 310 g of N - glycine - based maleimide and 390 g of dodecyl lactam evenly, then add them to a reaction kettle. Next, add 2.56 g of butyllithium. Purge the reaction kettle with nitrogen 5 - 10 times to completely displace the air inside. Raise the temperature of the reaction kettle to 260 °C and the pressure to 1.5 MPa, and maintain the pressure for 1 h. Then continue to raise the temperature to 280 °C and the pressure to 2.0 MPa, and maintain the pressure for 2.5 h to obtain a crude PA heat - resistant agent.

[0092] (2) Take out the crude PA heat - resistant agent and put it into a beaker of water with sufficient pure water. Use ultrasonic oscillation for 30 min. Finally, put the product into a vacuum oven and dry it under vacuum at 100 °C for 2 h to obtain a nylon heat - resistant agent.

[0093] (3) Mix 9 kg of PA12 resin, 200 g of PA heat - resistant agent, 200 g of toughening agent, 200 g of chain extender, 50 g of antioxidant Irganox1098, 50 g of antioxidant Irganox168, 100 g of light stabilizer UV - 312, 100 g of lubricant calcium stearate, and 100 g of colorant evenly using a high - speed mixer. Then add them to a twin - screw extruder for extrusion granulation. The extrusion temperature of the twin - screw extruder is 200 °C in the first zone, 210 °C in the second - third zones, 250 °C in the fourth - sixth zones, 250 °C in the seventh - tenth zones, 240 °C in the eleventh - twelfth zones, and 230 °C in the thirteenth zone. The screw speed is 200 rpm.

[0094] Comparative Example 1

[0095] According to the proportion, mix 9.2 kg of PA12 resin, 200 g of toughening agent, 200 g of chain extender, 50 g of antioxidant Irganox1098, 50 g of antioxidant Irganox168, 5100 g of light stabilizer UV - 312 (ultraviolet absorber), 100 g of lubricant calcium stearate, and 100 g of colorant evenly using a high - speed mixer. Then add them to a twin - screw extruder for extrusion granulation. The extrusion temperature of the twin - screw extruder is 200 °C in the first zone, 210 °C in the second - third zones, 250 °C in the fourth - sixth zones, 250 °C in the seventh - tenth zones, 240 °C in the eleventh - twelfth zones, and 230 °C in the thirteenth zone. The screw speed is 200 rpm.

[0096] Comparative Example 2

[0097] In proportion, 9.3 kg of PA6 resin, 100 g of toughening agent, 200 g of chain extender, 50 g of antioxidant Irganox 1098, 50 g of antioxidant Irganox 168, 100 g of light stabilizer UV-312, and 200 g of lubricant calcium stearate are mixed evenly using a high-speed mixer and then added to a twin-screw extruder for extrusion granulation. The extrusion temperature of the twin-screw extruder is 200 °C in the first zone, 210 °C in the second to third zones, 250 °C in the fourth to sixth zones, 250 °C in the seventh to tenth zones, 240 °C in the eleventh to twelfth zones, and 230 °C in the thirteenth zone; the screw speed is 200 rpm.

[0098] The products of this example are tested for their performance using ISO international standards, and the results are shown in Table 1.

[0099] Table 1 Test results of the examples and comparative examples

[0100]

[0101]

[0102] As can be seen from the examples, the high heat-resistant PA composition containing a PA heat-resistant agent still has good mechanical properties while having a relatively high heat distortion temperature.

Claims

1. A preparation method of a nylon heat-resistant agent, characterized in that, React maleic anhydride derivatives with lactams under the action of an initiator to prepare a nylon heat-resistant agent.

2. The preparation method according to claim 1, characterized in that, The maleic anhydride derivatives include N-phenylmaleimide, N-substituted phenylmaleimide, N-glycine maleimide, N-cyclohexylmaleimide, Preferably, the substituent in the N-substituted phenylmaleimide is a substituent with a molecular weight less than 300, selected from hydroxyl, amino, carboxyl, alkoxy, cyano, halogen, amide group; Preferably, the maleic anhydride derivatives include N-phenylmaleimide, N-(4-hydroxyphenyl)maleimide, N-(4-allyloxyphenyl)maleimide, N-(benzocyclobutene-4-yl)maleimide, cyano-containing N-substituted phenylmaleimide, 4-N-benzophenone maleimide, N-p-carboxyphenyl maleimide, N-[4-(N'-substituted amide group)phenyl]maleimide, N-[4-N'-(benzylamino-carbonyl)phenyl]maleimide, 1-[4-(dimethylamino)phenyl]maleimide, tribromophenyl maleimide, N-oxazolinylphenyl maleimide, N-glycine maleimide, N-cyclohexylmaleimide; Preferably, the lactam is selected from one or more of butyrolactam, valerolactam, caprolactam, enantholactam, caprylolactam, capric lactam, undecanolactam, laurolactam, and preferably caprolactam, caprylolactam, laurolactam; Preferably, the initiator is an anionic initiator, selected from one or more of alkali metals, alkali metal hydrides, alkali metal hydroxides, and alkali metal alkylates, and preferably alkali metal hydroxides, alkali metal alkylates.

3. The preparation method according to claim 1 or 2, characterized in that, The molar ratio of the maleic anhydride derivative, lactam, and initiator is: (35-60):(35-60):(0.1-5), preferably (45-55):(45-55):(0.5-3).

4. The preparation method according to any one of claims 1-3, characterized in that, The reaction of maleic anhydride derivatives and lactams includes two stages: the reaction temperature in the first stage is 200-300 °C, preferably 220 °C - 280 °C; the pressure is 1.0-2.0 MPa, preferably 1.3-1.6 MPa; the reaction time is 0.5-1 h, preferably 0.6-0.8 h. The reaction temperature in the second stage is 250-350 °C, preferably 280 °C - 330 °C; the pressure is 1.5-2.5 MPa, preferably 1.7-2.4 MPa; the reaction time is 0.5-2 h, preferably 1-1.5 h.

5. The preparation method according to any one of claims 1-4, characterized in that, The prepared PA heat-resistant agent is added to water, ultrasonically oscillated, and then dried in vacuum; Preferably, the ultrasonic oscillation time is 10-30 min, preferably 20-25 min; the vacuum drying temperature is 60-100 °C, preferably 80-90 °C; the vacuum drying time is 2-4 h, preferably 2.5-3 h.

6. Use of the nylon heat-resistant agent prepared by the preparation method according to any one of claims 1-5, which is used in nylon materials.

7. A nylon material, comprising the following components in parts by weight: 60-95 parts by weight of PA resin, 1 - 20 parts by weight of the nylon heat-resistant agent prepared by the preparation method according to any one of claims 1 - 5, 0 - 30 parts by weight of the toughening agent, 0 - 5 parts by weight of the chain extender, 0 - 3 parts by weight of the antioxidant, 0 - 3 parts by weight of the light stabilizer, 0 - 3 parts by weight of the lubricant. 0 - 3 parts by weight of the colorant; Preferably, the nylon material comprises the following components in parts by weight: 65 - 90 parts by weight of PA resin, 5 - 15 parts by weight of PA heat-resistant agent, 5 - 20 parts by weight of the toughening agent, 0.5 - 2 parts by weight of the chain extender, 0.1 - 2 parts by weight of the antioxidant, 0 - 2 parts by weight of the light stabilizer, 0 - 2 parts by weight of the lubricant, 0 - 2 parts by weight of the colorant.

8. According to the preparation method of claim 7, the PA resin is selected from one or more of PA6, PA66, PA1010, PA610, PA612, PA1010, PA1012, PA11, PA12, PA1212; Preferably, the toughening agent is selected from thermoplastic elastomers, including polyolefin elastomers and their chemically grafted modified products, thermoplastic polyurethane elastomers, nylon elastomers, ethylene propylene diene monomer rubber and its grafted modified products, polyolefins and their grafted modified products, one or more of them; Preferably, the chain extender is selected from one or more of isocyanates, epoxies, and bicyclic heterocycles; Preferably, the antioxidant is selected from one or more of phenols, amines, metal ion halides, thioesters, and phosphites; Preferably, the light stabilizer is selected from ultraviolet light absorbers, free radical scavengers, and light shielding agents; Preferably, the lubricant is selected from one or more of stearic acid complex esters, polyethylene wax, amide wax, and polyols; Preferably, the colorant is selected from one or more of pigments, dyes, color masterbatches, and carbon black.

9. According to the preparation method of the nylon material of claim 7 or 8, the PA resin, PA heat-resistant agent, optional toughening agent, optional chain extender, optional antioxidant, optional ultraviolet light absorber, optional lubricant, and optional colorant are mixed evenly and then extruded and pelletized by a twin-screw extruder to obtain the nylon material; Preferably, the extrusion temperature of the twin-screw extruder is 180 - 270 °C, preferably 180 - 220 °C in the first zone, 190 - 250 °C in the second - third zones, 200 - 270 °C in the fourth - sixth zones, 210 - 270 °C in the seventh - tenth zones, 200 - 260 °C in the eleventh - twelfth zones, and 190 - 240 °C in the thirteenth zone; the screw speed is 100 - 300 rpm, preferably 150 - 250 rpm.

10. An application of the nylon material according to any one of claims 7 - 9, which can be applied to the fields of automotive pipelines, joints, instruments, hydrogen storage energy, electrical enclosures, and cable coatings.

Images