Low-thermal-conductivity nylon material and preparation method thereof

Abstract

The present invention relates to the technical field of engineering plastics, and discloses a low thermal conductivity nylon material and a preparation method thereof, the low thermal conductivity nylon material comprises the following raw materials by mass: 50%-95% of nylon slices; 1%-30% of a low thermal conductivity material; 5%-20% of a phase solvent; 0%-3% of a coupling agent; 0.1%-1% of an antioxidant; wherein the low-heat-conduction material is at least one of hollow inorganic particles, low-heat-conduction inorganic particles or organic particles; according to the preparation method, processing is performed through a twin-screw extrusion process, and the low-heat-conductivity material is uniformly dispersed in a side feeding manner, so that the material is ensured to keep good uniformity and stability in the processing process. The material disclosed by the invention has excellent low thermal conductivity while ensuring good mechanical properties, and is suitable for the application fields requiring high thermal stability and low thermal conductivity, such as automobile parts, electronic equipment shells and the like.

Description

Technical Field

[0001] The invention relates to the technical field of engineering plastics, in particular to a low thermal conductivity nylon material and a preparation method thereof. Background Art

[0002] With the widespread application of nylon materials in various fields, especially in the automotive, electronics and home appliance industries, nylon, as a high-performance engineering plastic, has increasing functional requirements. In addition to traditional properties such as high flame retardancy, heat resistance, and lightweight, modern applications have increasingly stringent requirements for the thermal conductivity of nylon materials, especially in areas that require heat dissipation or thermal stability, and existing technologies are also being deployed in these directions.

[0003] However, with the continuous expansion of application areas, some emerging scenarios have put forward higher requirements for the low thermal conductivity of nylon materials. For example, in automobile manufacturing, especially in the design of body parts, low thermal conductivity has become a key performance indicator. In some environments with large high temperature fluctuations, if the thermal conductivity of the material is too high, it is easy to cause thermal expansion and contraction caused by temperature changes, thereby affecting the dimensional stability of the material. In order to cope with this problem, it is particularly important to develop nylon materials that can both guarantee mechanical properties and effectively reduce thermal conductivity. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a low thermal conductivity nylon material and a preparation method thereof, which solves the problems of excessive thermal conductivity and dimensional instability caused by thermal expansion and contraction of the existing nylon materials in a high temperature fluctuating environment, while maintaining excellent mechanical properties.

[0005] To achieve the above objectives, the present invention is implemented by the following technical solutions: A low thermal conductivity nylon material comprises the following raw materials in percentage by mass: 50% to 95% nylon slices; 1% to 30% of low thermal conductivity materials; 5% to 20% compatibilizer; 0% to 3% coupling agent; 0.1% to 1% antioxidant; Wherein, the low thermal conductivity material is at least one of hollow inorganic particles, low thermal conductivity inorganic particles or organic particles.

[0006] Preferably, the nylon slices include one or a mixture of PA6, PA66, PA11, PA12 or PA1010.

[0007] Preferably, the low thermal conductivity material has a bulk density of 0.08-0.5 g / cm 3The hollow inorganic particles may be one or more of expanded perlite, aerogel particles, thermal expansion microspheres, rigid polyurethane foam particles or phenolic resin particles with a particle size of 0.1 mm to 5 mm.

[0008] Preferably, the compatibilizer is maleic anhydride grafted polyolefin elastomer.

[0009] Preferably, the maleic anhydride grafted polyolefin elastomer is maleic anhydride grafted POE, and the grafting rate is 0.5% to 1.5%.

[0010] Preferably, the coupling agent is a silane coupling agent, preferably a silane coupling agent containing an amino group.

[0011] Preferably, the antioxidant is one of 1098, 1010, 168 or 626.

[0012] The present invention also provides a method for preparing a low thermal conductivity nylon material, comprising the following steps: Mixing nylon chips, low thermal conductivity materials, compatibilizers, coupling agents and antioxidants; The mixture is extruded through a twin-screw extruder; The low thermal conductivity material is added by side feeding, and the side feeding position is 1 / 3-2 / 3 of the screw length away from the discharge port.

[0013] Preferably, the low thermal conductivity material is added by side feeding to ensure that the low thermal conductivity material is evenly dispersed.

[0014] Preferably, the extrusion processing temperature is 210-260° C., wherein when heat-expandable microspheres are used as the low thermal conductivity material, the residence time is shortened and the processing temperature is reduced.

[0015] The present invention provides a low thermal conductivity nylon material and a preparation method thereof. The material has the following beneficial effects: 1. The low thermal conductivity nylon material provided by the present invention significantly reduces the thermal conductivity by rationally selecting low thermal conductivity fillers and optimizing the formula. The material can effectively hinder the conduction of heat and is particularly suitable for application scenarios requiring low thermal conductivity, such as automotive parts and electronic equipment housings. Low thermal conductivity enables the material to maintain dimensional stability in an environment with large temperature fluctuations and reduce deformation or damage caused by thermal expansion or thermal contraction.

[0016] 2. The low thermal conductivity nylon material of the present invention can maintain good mechanical properties, including tensile strength, flexural strength and impact strength, while maintaining low thermal conductivity. By optimizing the use of compatibilizers and coupling agents in the formula, the low thermal conductivity filler and the nylon matrix have good compatibility, ensuring the excellent performance of the material in high-load applications. Its high mechanical strength enables the material to withstand greater external pressure and impact, and is suitable for engineering applications with high strength requirements.

[0017] 3. The present invention adds antioxidants and other additives to the material, which significantly improves the thermal stability of the material. The use of antioxidants can effectively inhibit the oxidation reaction of the material under high temperature environment and maintain its long-term stability. This enables the low thermal conductivity nylon material of the present invention to maintain excellent physical properties and chemical stability under high temperature or long-term heat load, and prolongs its service life.

[0018] 4. The low thermal conductivity nylon material of the present invention adopts a twin-screw extrusion process and has good processability. During the molding process, by optimizing the process parameters and using appropriate compatibilizers and coupling agents, the material can be evenly dispersed and stably processed in common processing methods such as injection molding and extrusion. This makes the material of the present invention adaptable to the production needs of various complex shapes and can meet the requirements of large-scale industrial production.

[0019] 5. The low thermal conductivity fillers (such as hollow inorganic particles, aerogel particles, etc.) used in the present invention have low material density while ensuring low thermal conductivity, which reduces the amount of fillers used, thereby reducing the cost of raw materials. At the same time, most of these low thermal conductivity fillers are environmentally friendly materials, which not only help to reduce energy consumption in the production process, but also meet the requirements of modern society for environmental protection and sustainable development. This makes the low thermal conductivity nylon material of the present invention have good economic benefits and environmental protection while meeting the performance requirements. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The present invention provides a low thermal conductivity nylon material. The core innovation of the material lies in that the thermal conductivity of the material is successfully reduced by reasonably selecting and proportioning a nylon matrix and a low thermal conductivity filler, combined with specific compatibilizers, coupling agents and antioxidants, while ensuring a smooth hysteresis effect of internal temperature changes in an environment with large temperature fluctuations, thereby improving the thermal stability and dimensional stability of the material.

[0022] The composition of the low thermal conductivity nylon material of the present invention mainly includes the following components: Nylon chips (50% to 95%): As the main component of the matrix, nylon resins such as PA6, PA66, PA11, PA12, PA1010, or their mixtures are selected. These nylon resins have excellent performance in maintaining good mechanical properties, heat resistance, processability and other basic properties, and are the basis of composite materials.

[0023] Low thermal conductivity material (1% to 30%): This component is one of the core innovations of the present invention, and is intended to significantly reduce the thermal conductivity of the composite material. Low thermal conductivity materials include one or more of hollow inorganic particles, low thermal conductivity inorganic particles, and organic particles. In particular, it is preferred to use a bulk density of 0.08-0.5 g / cm 3 Hollow inorganic particles between 0.1mm and 5mm, as well as expanded perlite, aerogel particles, thermal expansion microspheres, rigid polyurethane foam particles, phenolic resin particles, etc. These low thermal conductivity particles can effectively reduce the thermal conductivity of the material through their unique structure (such as pore structure and low density) and play a role in thermal isolation.

[0024] Compatibilizer (5% to 20%): In order to ensure good compatibility between the low thermal conductivity material and the nylon matrix and avoid degradation of material performance due to poor interface, the present invention uses maleic anhydride grafted polyolefin elastomer and rubber, especially maleic anhydride grafted POE (grafting rate 0.5% to 1.5%). The compatibilizer not only improves the interaction between different components, but also helps to improve the processability and mechanical properties of the composite material.

[0025] Coupling agent (0% to 3%): The role of the coupling agent is to enhance the interfacial adhesion between the low thermal conductivity material and the nylon resin, and improve the mechanical properties of the overall composite material. The coupling agent is preferably a silane coupling agent, especially a silane coupling agent containing an amino group. When using low thermal conductivity inorganic particles, the silane coupling agent can significantly improve its binding with the nylon matrix, thereby enhancing the stability of the composite material.

[0026] Antioxidant (0.1% to 1%): In order to improve the thermal stability of low thermal conductivity nylon materials and prevent oxidation reactions during high temperature processing that lead to performance degradation, the present invention adds common nylon antioxidants, such as 1098, 1010, 168 and 626. These antioxidants can effectively protect the stability of the material in a high temperature environment and extend its service life.

[0027] The low thermal conductivity nylon material of the present invention has an innovative formula design, which effectively reduces thermal conductivity and improves thermal stability while ensuring good mechanical properties. Its mechanism of action can be divided into the following aspects: Filling and thermal isolation of low thermal conductivity materials: Low thermal conductivity materials (such as hollow inorganic particles, aerogel particles and expanded perlite) are evenly distributed in the nylon matrix to form a porous, low-density structure. These low thermal conductivity particles form an effective thermal resistance path inside the material, significantly reducing the heat conduction rate. Specifically, hollow inorganic particles and aerogel particles effectively hinder the transfer of heat through their internal cavities and microporous structures, thereby achieving the purpose of reducing thermal conductivity.

[0028] Expansion effect of heat-expandable microspheres: The present invention specifically selects heat-expandable microspheres as one of the low thermal conductivity materials. The microspheres expand during heating to form a bubble structure. This expansion effect not only increases the volume of the material, but also further improves the thermal insulation of the material. Due to the presence of bubbles, the thermal conductivity path of the material is interrupted, thereby greatly reducing the thermal conductivity of the overall material.

[0029] Improvement effect of compatibilizer: Compatibilizer plays a key role in the present invention. It reduces the thermal resistance of the material interface by improving the interfacial adhesion between different components. During the heat treatment process, the good combination between the low thermal conductivity filler and the nylon matrix helps to enhance the overall mechanical properties of the material, while avoiding the material embrittlement or interface separation caused by poor compatibility.

[0030] Interface strengthening effect of coupling agent: coupling agent forms covalent bonds with the surface of nylon matrix and low thermal conductivity material through chemical reaction, thus strengthening the bonding force between interfaces. This enhanced interface bonding force helps to improve the tensile strength, heat resistance and stability of the material, ensures the uniform dispersion of low thermal conductivity particles in the whole material, and avoids the separation or shedding of low thermal conductivity particles from the matrix.

[0031] Thermal stability of antioxidants: During high-temperature processing, antioxidants can effectively inhibit the thermal oxidation reaction of materials and maintain the stability of the nylon matrix. Especially in a long-term high-temperature environment, the addition of antioxidants can extend the service life of the material and ensure its physical properties and chemical stability under high temperature conditions.

[0032] The present invention solves the problem of high thermal conductivity of traditional nylon materials while maintaining good mechanical properties, thermal stability and processability. In particular, in application scenarios with large temperature fluctuations (such as automotive parts, etc.), the low thermal conductivity nylon material of the present invention has significant advantages and can effectively improve the stability and durability of parts.

[0033] Accordingly, the present invention also provides a method for preparing the above-mentioned low thermal conductivity nylon material, which comprises the following specific implementation steps: Step 1: Mixing of raw materials In this step, nylon chips, low thermal conductivity materials, compatibilizers, coupling agents and antioxidants are first premixed in appropriate proportions. The specific steps are as follows: Nylon chips: Choose nylon resins such as PA6, PA66, PA11, PA12, PA1010, or their mixtures. Different nylon chips can be selected as needed to ensure the mechanical properties, processability and thermal stability of the final material.

[0034] Low thermal conductivity materials: Select fillers with low thermal conductivity, such as hollow inorganic particles, expanded perlite, aerogel particles, thermal expansion microspheres, rigid polyurethane foam particles, etc. The addition amount of these low thermal conductivity materials is 1% to 30%, and they reduce the thermal conductivity of the material through physical action.

[0035] Compatibilizer: Maleic anhydride grafted polyolefin elastomer (such as maleic anhydride grafted POE) is used as a compatibilizer. Its main function is to improve the compatibility between the low thermal conductivity material and the nylon matrix and ensure the uniform dispersion of each component.

[0036] Coupling agent: such as silane coupling agent, preferably silane coupling agent containing amino group. The addition of coupling agent helps to enhance the interface bonding force between low thermal conductivity material and nylon matrix, and ensure the stability of the material during processing.

[0037] Antioxidant: Commonly used nylon antioxidants such as 1098, 1010, 168, 626, etc., are added in an amount of 0.1% to 1% to improve the thermal stability of the material at high temperatures and prevent oxidation reactions.

[0038] All these ingredients need to be fully mixed in a high-speed mixer to ensure uniform distribution of the raw materials. During the mixing process, the mixing time and speed should be adjusted according to the actual situation to ensure that the low thermal conductivity material can be evenly dispersed in the nylon matrix.

[0039] Step 2: Extrusion The mixture in step 1 is extruded through a twin-screw extruder. The specific operation is as follows: Twin-screw extruder: The mixed raw materials are fed into the main feed port of the twin-screw extruder. The twin-screw extruder has good mixing effect and efficient plasticizing ability, which helps to maintain the uniform dispersion of low thermal conductivity materials and nylon matrix.

[0040] Extrusion temperature: The temperature range during the extrusion process should be controlled between 210℃ and 260℃. The specific temperature control is adjusted according to the type of material used. Especially when the low thermal conductivity material is thermal expansion microspheres, excessive processing temperature should be avoided to prevent the microspheres from over-expanding or rupturing during the extrusion process, affecting the thermal conductivity of the final product.

[0041] Extrusion speed: The extrusion speed should be set according to the actual processing needs to ensure sufficient mixing of the low thermal conductivity material and the nylon matrix.

[0042] Step 3: Side feeding of low thermal conductivity material In this step, the low thermal conductivity material is added by side feeding. The specific operation is as follows: Side feeding method: low thermal conductivity material is added to the extruder through the side feeding port. This method can ensure that the low thermal conductivity material is evenly distributed during the extrusion process without causing agglomeration or sedimentation.

[0043] Side feeding position: The side feeding port should be set at 1 / 3 to 2 / 3 of the twin screw outlet. This position can ensure good dispersion of low thermal conductivity materials during extrusion and will not adversely affect the plasticization process of the nylon matrix.

[0044] Uniform dispersion of low thermal conductivity materials: Side feeding helps to evenly disperse low thermal conductivity materials into the nylon matrix, thus ensuring that the final composite material has good thermal isolation and mechanical properties.

[0045] Step 4: Cooling and forming The extruded mixture will be cooled and shaped. The specific steps are as follows: Cooling method: The extruded material is quickly cooled by cooling rollers or cooling water tanks to make it solidify quickly and maintain the desired shape.

[0046] Molding method: According to the actual application requirements, the cooled material can be further pelletized by a pelletizer to form particles of suitable size, or further molded by injection molding, extrusion, etc. to obtain the final product.

[0047] Step 5: Post-processing To ensure the performance of the final material, some post-processing steps such as heat treatment or aging treatment may be required. This helps to improve the thermal stability of the material and ensure the stability of the material when used in high temperature environments for a long time.

[0048] Through the above preparation method, the present invention can produce a nylon composite material with good low thermal conductivity, excellent mechanical properties and thermal stability. The twin-screw extrusion process combined with the side feeding method not only improves the dispersibility of the low thermal conductivity material, but also ensures the stability of the material during processing. The method is suitable for large-scale industrial production and has high production efficiency and good operability.

[0049] In order to better understand the present invention, the present invention is described in detail below in conjunction with specific embodiments.

[0050] Examples 1-6 and comparative examples 1-2 are listed in the table below, wherein the total weight of nylon chips, low thermal conductivity materials and compatibilizers is calculated as 100%, and coupling agents and antioxidants are used in smaller amounts and are used as a percentage of the total weight.

[0051] The details are as follows: Embodiment 1~6: Embodiment 1: Ingredients: Nylon chips: PA66 (EPR27) 90% Low thermal conductivity material: hollow glass microspheres 5% Compatibilizer: MAH-POE (grafting rate: 1.0%) 5% Coupling agent: silane coupling agent (KH-550) 0.5% Antioxidant: 1098 0.2%, 168 0.2% Preparation method: 1. Mixing process: Mix PA66 slices, 5% hollow glass microspheres, MAH-POE, coupling agent and antioxidant in a high-speed mixer. Ensure that the low thermal conductivity material is evenly dispersed in the nylon matrix to avoid particle agglomeration.

[0052] 2. Extrusion processing: Process the mixed material through a twin-screw extruder. Set the temperature of the extruder to 230°C to maintain a good melt state. The speed of the extruder should be moderate to ensure uniform mixing of the low thermal conductivity material and the nylon matrix.

[0053] 3. Side feeding: Add low thermal conductivity materials (such as hollow glass beads) into the extruder by side feeding. The side feeding port is set at 1 / 3 to 2 / 3 of the screw length of the discharge port to ensure uniform dispersion of the material.

[0054] 4. Cooling and forming: The extruded material is quickly cooled by the cooling roller to obtain the final formed product. It can be pelletized by the pelletizer as needed to form a suitable granular product.

[0055] Embodiment 2: Ingredients: Nylon chips: PA66 (EPR27) 80%, PA6 (P-027) 13% Low thermal conductivity material: Perlite particles (average particle size: 5mm) 15% Compatibilizer: MAH-POE (grafting rate: 1.0%) 5% Coupling agent: silane coupling agent (KH-550) 1.5% Antioxidant: 1098 0.2%, 168 0.2% The preparation method is the same as Example 1.

[0056] Embodiment 3: Ingredients: Nylon chips: PA66 (EPR27) 70%, PA6 (P-027) 19% Low thermal conductivity material: aerogel particles (average particle size: 1mm) 2% Compatibilizer: MAH-POE (grafting rate: 1.0%) 15% Coupling agent: silane coupling agent (KH-550) 1% Antioxidant: 1098 0.2%, 168 0.2% The preparation method is the same as Example 1.

[0057] Embodiment 4: Ingredients: Nylon chips: PA66 (EPR27) 60% Low thermal conductivity material: thermal expansion microspheres (average particle size: 0.1 mm) 2% Compatibilizer: MAH-POE (grafting rate: 1.0%) 20% Coupling agent: Silane coupling agent (KH-550) 0% Antioxidant: 1098 0.2%, 168 0.2% The preparation method is the same as Example 1.

[0058] 4. Cooling and forming: After cooling by the cooling roller, pelletizing is carried out to obtain low thermal conductivity nylon material of suitable particle size.

[0059] Embodiment 5: Ingredients: Nylon chips: PA6 (P-027) 70% Low thermal conductivity material: polyurethane particles (average particle size: 0.5mm) 1% Compatibilizer: MAH-POE (grafting rate: 1.0%) 10% Coupling agent: Silane coupling agent (KH-550) 0% Antioxidant: 1098 0.2%, 168 0.2% The preparation method is the same as Example 1.

[0060] Embodiment 6: Ingredients: Nylon chips: PA66 (EPR27) 50% Low thermal conductivity material: hollow glass microspheres (packing density: 150 g / cm³) 30% Compatibilizer: MAH-POE (grafting rate: 1.0%) 20% Coupling agent: silane coupling agent (KH-550) 3% Antioxidant: 1098 0.2%, 168 0.2% The preparation method is the same as Example 1.

[0061] Comparative Examples 1 to 3: Comparative Example 1: Ingredients: PA66 95%, hollow glass microspheres 5%, MAH-POE 5%, KH-550 0.5%, 1098 0.2%, 1680.2%.

[0062] The preparation method is the same as Example 1.

[0063] Comparative Example 2: Ingredients: PA66 90%, perlite particles 5%, MAH-POE 5%, KH-550 0%, 1098 0.2%, 168 0.2%.

[0064] The preparation method is the same as Example 1.

[0065] Comparative Example 3: Ingredients: PA66 95%, hollow glass microspheres 5%, MAH-POE 0%, KH-550 0.5%, 1098 0.2%, 1680.2%.

[0066] The preparation method is the same as Example 1.

[0067] Performance Test: In order to verify the performance of the low thermal conductivity nylon material of the present invention, the present invention adopts the following standardized test method to test the performance of the low thermal conductivity nylon materials in Examples 1 to 6 and Comparative Examples 1 to 3.

[0068] 1. Density test The density of low thermal conductivity nylon materials is tested using the density bottle method or the gas buoyancy method according to ISO 1183. The density of the material is obtained by weighing a certain volume of the material and calculating the ratio of its mass to volume. This test helps to understand the structural characteristics of the material, such as porosity and its effect on thermal conductivity.

[0069] 2. Tensile strength test According to ISO 527-2 standard, the tensile properties of low thermal conductivity nylon materials are tested by using a universal testing machine. The specimen is stressed until it breaks during the stretching process, and the tensile strength (maximum stress) and tensile elongation at break are tested. This test can evaluate the strength of the material under tensile load and its elastic deformation ability, reflecting the mechanical properties of the material, especially its applicability in high stress applications.

[0070] 3. Bending strength test The three-point bending method is used to perform bending tests on low thermal conductivity nylon materials in accordance with ISO 178. During the test, the standard specimen is placed between the support points and a central load is applied to measure its bending strength. This test can be used to evaluate the material's ability to resist bending, especially in scenarios where it is subjected to external pressure or heavy objects.

[0071] 4. Simply supported beam notched impact strength test The ISO 179 standard is used to test the simply supported beam notched impact strength of low thermal conductivity nylon materials. This test method mainly tests the energy absorption capacity and resistance to rupture of the material when it is impacted by applying an impact load at the notch of the specimen. This test can be used to evaluate the toughness of the material when it is subjected to sudden changes in force or impact.

[0072] 5. Thermal conductivity test According to GB / T 10297 standard, the thermal conductivity of low thermal conductivity nylon materials is tested by heat flow meter method or laser flash method. The thermal conductivity of the material is calculated by measuring the heat flow conduction of the material at a specific temperature. This test can evaluate the thermal isolation performance of the material, that is, its thermal stability and application potential under different ambient temperature changes.

[0073] The performance test results are shown in the following table: Based on the above performance test results, the following conclusions can be drawn: 1. Density: The density of the examples of the present invention is generally low, especially Example 6 (0.53 g / cm 6 ) shows an extremely low density, indicating that it has a high foaming and low filler density. This is because the present invention uses a specific low thermal conductivity filler (such as hollow glass microspheres, thermal expansion microspheres, etc.), whose low density helps to reduce the thermal conductivity of the material.

[0074] The density of the comparative samples (Comparative Examples 1, 2, and 3) is generally higher, especially that of Comparative Example 1 (1.14 g / cm 6 ), indicating that the filler dispersion in these samples was poor or the filler content was high, resulting in a higher density and poorer thermal isolation effect.

[0075] 2. Tensile strength: Example 5 (66 MPa) and Example 3 (65 MPa) have higher tensile strength, show good mechanical properties, and are suitable for applications requiring higher mechanical strength.

[0076] Comparative Example 1 (86 MPa) exhibits a higher tensile strength, but this is mainly due to the high content of nylon matrix used and the lack of low thermal conductivity filler, which limits its performance in terms of low thermal conductivity requirements.

[0077] The tensile strength of other comparative samples is lower (such as 55 MPa for comparative example 2), indicating that the mechanical properties are inferior to those of the embodiments of the present invention.

[0078] 3. Bending strength: Example 5 (81 MPa) and Example 3 (79 MPa) have higher flexural strength, indicating that these materials can maintain good stability and structural integrity when subjected to bending.

[0079] Comparative Example 1 (97 MPa) and Comparative Example 2 (68 MPa) have higher flexural strength, but also have low thermal conductivity due to the high nylon matrix ratio. Although the flexural strength of the comparative samples is higher, they may have disadvantages in thermal stability and thermal isolation performance in practical applications.

[0080] Simple supported beam notched impact strength: Example 4 (13 kJ / m 2 ) and Example 3 (9 kJ / m 2 ) have a high impact strength, indicating that these materials have good toughness when impacted and can effectively absorb impact energy and avoid cracking.

[0081] Comparative Example 1 (15 kJ / m 2 ) Although it has high impact strength, its low thermal conductivity is poor, so in practical applications it may not be able to achieve the desired thermal isolation effect of the present invention.

[0082] Comparative Example 2 (3 kJ / m 2 ) and Comparative Example 3 (4 kJ / m 2 ) have a lower impact strength, indicating that these comparison samples have poor toughness and may be prone to cracking or damage during actual use.

[0083] 5. Thermal conductivity: The thermal conductivity of the embodiments of the present invention (such as embodiment 2: 0.20 W / (m·K), embodiment 6: 0.14 W / (m·K)) is lower than 0.30 W / (m·K), showing its excellent thermal isolation performance. The low thermal conductivity of embodiment 6 is particularly prominent, indicating that it has excellent thermal isolation characteristics and is suitable for use in an environment with large high temperature fluctuations.

[0084] The thermal conductivity coefficients of Comparative Example 1 (0.29 W / (m·K)) and Comparative Example 3 (0.24 W / (m·K)) are relatively high. Although they perform well in some test items, their thermal conductivity is much lower than that of the embodiments of the present invention and cannot meet the demand for low thermal conductivity materials.

[0085] By comparing the performance test results, it can be seen that the low thermal conductivity nylon material of the present invention has significant advantages in density, tensile strength, bending strength, impact strength and thermal conductivity, especially in terms of thermal conductivity, the performance of the material of the present invention is significantly better than that of the comparative sample. At the same time, the mechanical properties of the embodiments (such as tensile strength, bending strength, impact strength, etc.) also show good comprehensive performance, which can meet the requirements of application environments with large temperature changes and strong forces. In contrast, although the traditional materials (Comparative Examples 1, 2, and 3) have higher performance in certain mechanical properties, they cannot provide the required thermal isolation performance due to their high thermal conductivity. Therefore, the low thermal conductivity nylon material of the present invention has good prospects in practical applications.

[0086] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low thermal conductivity nylon material, characterized in that: The following raw materials are included in percentage by mass: 50% to 95% nylon slices; 1% to 30% of low thermal conductivity materials; 5% to 20% compatibilizer; 0% to 3% coupling agent; 0.1% to 1% antioxidant; Wherein, the low thermal conductivity material is at least one of hollow inorganic particles, low thermal conductivity inorganic particles or organic particles.

2. The low thermal conductivity nylon material according to claim 1, characterized in that: The nylon slices include one or a mixture of PA6, PA66, PA11, PA12 or PA1010.

3. The low thermal conductivity nylon material according to claim 1, characterized in that: The low thermal conductivity material has a bulk density of 0.08-0.5 g / cm 3 The hollow inorganic particles may be one or more of expanded perlite, aerogel particles, thermal expansion microspheres, rigid polyurethane foam particles or phenolic resin particles with a particle size of 0.1 mm to 5 mm.

4. The low thermal conductivity nylon material according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted polyolefin elastomer.

5. The low thermal conductivity nylon material according to claim 4, characterized in that: The maleic anhydride grafted polyolefin elastomer is maleic anhydride grafted POE, and the grafting rate is 0.5% to 1.5%.

6. The low thermal conductivity nylon material according to claim 1, characterized in that: The coupling agent is a silane coupling agent, preferably a silane coupling agent containing an amino group.

7. The low thermal conductivity nylon material according to claim 1, characterized in that: The antioxidant is one of 1098, 1010, 168 or 626.

8. A method for preparing a low thermal conductivity nylon material, used for preparing the low thermal conductivity nylon material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Mixing nylon chips, low thermal conductivity materials, compatibilizers, coupling agents and antioxidants; The mixture is extruded through a twin-screw extruder; The low thermal conductivity material is added by side feeding, and the side feeding position is 1 / 3-2 / 3 of the screw length away from the discharge port.

9. The method for preparing a low thermal conductivity nylon material according to claim 8, characterized in that: The low thermal conductivity material is added by side feeding to ensure uniform dispersion of the low thermal conductivity material.

10. The method for preparing a low thermal conductivity nylon material according to claim 8, characterized in that: The extrusion processing temperature is 210-260° C., wherein when the low thermal conductivity material uses thermal expansion microspheres, the residence time is shortened and the processing temperature is reduced.

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