Polyamide composition as well as preparation method and application thereof

Abstract

The invention discloses a polyamide composition as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The polyamide composition is prepared from the following components in parts by weight: 38 to 52 parts of polyterephthalamide resin; 13 to 56 parts of long carbon chain polyamide resin; 8-22 parts of a flame retardant; 10 to 45 parts of glass fiber; 8-42 parts of a flaky filler; the long carbon chain polyamide resin comprises at least one of PA610 (polyamide 610), PA612 (polyamide 612), PA1010 (polyamide 1010) and PA1012 (polyamide 1012); the relative viscosity of the poly-terephthalamide resin is less than 3.0, and the relative viscosity of the long carbon chain polyamide resin is less than 3.0. The polyamide composition disclosed by the invention has the characteristics of low CLTE, ultrahigh flatness and excellent impact cracking resistance.

Description

Technical Field

[0001] This invention relates to the technical field of polymer materials, and more particularly to a polyamide composition, its preparation method, and its application. Background Technology

[0002] Ultra-thin fans are commonly used in heat dissipation for electronic devices (such as laptops and mobile phone cooling clips), micro-home appliances (such as portable fans), and precision instrument cooling systems. They are characterized by their thin and light structure (the overall thickness of the fan is typically <10mm), high rotational speed (5000-10000rpm), and compact size. Therefore, nylon materials must simultaneously meet multiple requirements, including mechanical strength, heat dissipation efficiency, processing precision, and environmental adaptability. In particular, they must maintain extremely high flatness and impact crack resistance even under long-term temperature and humidity conditions.

[0003] Existing patents do not mention the application areas of ultra-thin fans, nor do they address how to maintain excellent flatness and impact crack resistance under long-term temperature and humidity conditions. For example, patent CN113549323B describes a high-strength, flat, continuous long glass fiber reinforced PA66 composite material, which is used to prepare industrial fan blades that meet the new development requirements of high mechanical properties, high dimensional stability, high surface quality, and low water absorption. The size and thickness of such industrial fan blades are much larger than those of laptop fans, and the requirements for the flatness and impact crack resistance of the composite material are much lower than those for laptop fan materials. Patent KR101535264B1 describes a polyamide molding composition comprising (A1) a semi-aromatic, semi-crystalline polyamide with a melting point of 250°C to 330°C, and (A2) a caprolactam-containing polyamide with a caprolactam content of at least 50% by weight; a filler and a reinforcing agent; a heat stabilizer; and an additive. The patent does not mention the key technical features required for the field of ultra-thin fans, nor does it specifically limit the fillers and reinforcing agents, making it difficult for the invented materials to be applied to the field of ultra-thin fans. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polyamide composition, its preparation method, and its application. The polyamide composition of this invention has the characteristics of low CLTE, ultra-high flatness, and excellent impact crack resistance.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a polyamide composition comprising the following components in parts by weight: 38-52 parts of poly(terephthalamide) resin; 13-56 parts of long-chain polyamide resin; 8-22 parts of flame retardant; 10-45 parts of glass fiber; 8-42 parts of sheet filler; The long-chain polyamide resin includes at least one of PA610, PA612, PA1010, and PA1012; The relative viscosity of the poly(terephthalamide) resin is <3.0, and the relative viscosity of the long-chain polyamide resin is <3.0.

[0006] This invention, by selecting and blending poly(terephthalamide) resin and long-chain polyamide resin (with ≥10 carbon atoms in the diacid unit) and controlling their relative viscosity range, retains the high crystallinity of poly(terephthalamide) resin, thus achieving high strength, while simultaneously obtaining the uniform shrinkage properties and excellent impact resistance of long-chain polyamide resin. Furthermore, the addition of glass fiber and sheet filler further enhances the impact crack resistance of the composition, resulting in a polyamide composition with ultra-high flatness and excellent dimensional stability, while also exhibiting superior impact crack resistance.

[0007] Preferably, the relative viscosity range of the poly(terephthalamide) resin is 1.8-2.8, and the relative viscosity range of the long-chain polyamide resin is 1.8-2.8.

[0008] More preferably, the relative viscosity of the poly(terephthalamide) resin is any one or a combination of 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, and 2.8.

[0009] Preferably, the relative viscosity of the long-chain polyamide resin is any one or a combination of 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, and 2.8.

[0010] More preferably, the relative viscosity ratio of the poly(terephthalamide) resin and the long-chain polyamide resin is (0.6-1.4):1, and even more preferably (0.85-1.25):1.

[0011] The test method for the relative viscosity of the polyamide resin described in this invention is as follows: the test is carried out in accordance with GB12006.1-89. The specific test method is as follows: the relative viscosity ηr of the polyamide with a concentration of 0.25 g / dl is measured in 98% concentrated sulfuric acid at 25±0.01℃.

[0012] Preferably, the diamine unit in the poly(terephthalamide) resin is derived from an aliphatic diamine; the aliphatic diamine unit has ≥8 carbon atoms; preferably, the aliphatic diamine has 9-12 carbon atoms.

[0013] More preferably, the poly(terephthalamide) resin includes at least one of poly(octyl terephthalamide), poly(nonyl terephthalamide), poly(decyl terephthalamide), poly(undecyl terephthalamide), and poly(dodecanoyl terephthalamide).

[0014] Preferably, the mass ratio of glass fiber to sheet filler is (0.2-4.5):1, more preferably (0.3-4):1.

[0015] The applicant discovered that by controlling the mass ratio of glass fiber and sheet filler within the above-mentioned range, the dimensional stability and impact crack resistance of the composition can be further improved.

[0016] Preferably, the glass fiber is a two-dimensional irregular glass fiber, and the fiber cross-section can be rectangular, elliptical, or trapezoidal.

[0017] More preferably, the glass fiber is a flat glass fiber, and the cross-section of the flat glass fiber is basically rectangular; the flatness ratio of the glass fiber is (2-6):1, preferably (4-6):1.

[0018] The testing standard for aspect ratio is ISO 1888:2022.

[0019] Preferably, the flat glass fiber is chopped glass fiber; the chopped length is 2-15 mm.

[0020] Preferably, the short axis of the cross-section of the flat glass fiber is 3-20 μm and the long axis is 5-40 μm.

[0021] Preferably, the sheet-like filler includes at least one of talc, mica, and boron nitride.

[0022] Preferably, the particle size range of the sheet-like filler is 5-50 μm, more preferably 5-15 μm.

[0023] Preferably, the diameter-to-thickness ratio of the sheet-like filler is (2-12):1.

[0024] More preferably, the diameter-to-thickness ratio of the sheet-like filler is any one or a range of two of the following: 2:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, and 12:1.

[0025] The particle size of the sheet-like filler described in this invention was measured by laser diffraction, and the aspect ratio of the sheet-like filler was measured by microscopic image analysis (SEM scanning electron microscopy).

[0026] Preferably, the flame retardant comprises an organophosphorus flame retardant.

[0027] More preferably, the organophosphite flame retardant includes dialkylphosphinate; preferably, the dialkylphosphinate includes at least one of aluminum diethylphosphinate, zinc diethylphosphinate, aluminum methyl ethylphosphinate, aluminum ethyl butylphosphinate, and aluminum ethylhexylphosphinate.

[0028] More preferably, the organic hypophosphite flame retardant is aluminum diethylphosphinate.

[0029] Preferably, the polyamide composition comprises the following components in parts by weight: 42-50 parts of poly(terephthalamide) resin; 30-50 parts of long-chain polyamide resin; 10-20 parts of flame retardant; 20-40 parts of glass fiber; 10-20 parts of sheet filler.

[0030] Preferably, the total mass percentage of the polyamide composition comprising poly(terephthalamide) resin and long-chain polyamide resin is not less than 30%.

[0031] Preferably, the total mass percentage of the sheet filler and flat glass fiber in the halogen-free flame-retardant polyamide composition of the present invention is in the range of 20-40%.

[0032] Preferably, the polyamide composition further includes 0-5 parts of other additives, including but not limited to lubricants, antioxidants, light stabilizers, etc.

[0033] More preferably, the lubricant includes at least one of fluoropolymer, linear low-density polyethylene (LLDPE), silicone oil, metal stearate, alkyl stearate, metal montanic acid, montanic ester wax, or polyethylene wax.

[0034] Secondly, the present invention also discloses a method for preparing a polyamide composition, comprising the following steps: The components are mixed and added to a twin-screw extruder, and then extruded and granulated to obtain a polyamide composition.

[0035] Preferably, the temperature of the twin-screw extruder is 250-350℃, and the screw speed is 200-600 rpm.

[0036] Thirdly, the present invention also discloses the application of a polyamide composition in an ultra-thin fan, specifically applicable to the field of ultra-thin fans.

[0037] Fourthly, the present invention also discloses an ultra-thin fan structure, which includes a fan frame and fan blades of an ultra-thin fan assembly.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention, by selecting and blending poly(terephthalamide) resin and long-chain polyamide resin (with ≥10 carbon atoms in the diacid unit) and controlling their relative viscosity range, retains the high crystallinity of poly(terephthalamide) resin, thus achieving high strength, while simultaneously obtaining the uniform shrinkage properties and excellent impact resistance of long-chain polyamide resin. Furthermore, the addition of glass fiber and sheet filler further enhances the impact crack resistance of the composition, resulting in a polyamide composition that simultaneously possesses ultra-high flatness and dimensional stability, along with excellent impact crack resistance. Detailed Implementation

[0039] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the scope of protection and implementation of the present invention are not limited thereto.

[0040] Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0041] Examples 1-16 Examples of the polyamide composition and its preparation method according to the present invention are shown in Table 1.

[0042] The method for preparing the polyamide composition includes the following steps: The components are mixed and added to a twin-screw extruder, and after granulation and cooling, a polyamide composition is obtained.

[0043] The temperature of the twin-screw extruder is 250-350℃, and the screw speed is 200-600 rpm.

[0044] Comparative Examples 1-7 The only difference between the comparative examples and the embodiments is the type and ratio of components, as shown in Table 2.

[0045] In the components described in each embodiment and comparative example: The poly(terephthalamide) resin 1 is PA10T: with a relative viscosity of 1.8; The preparation method of the poly(terephthalamide) resin 1 is as follows: (1) Add terephthalic acid and 1,10-decanediamine in a molar ratio of 1:1 to a pressure vessel equipped with a magnetic coupling stirrer, condenser, gas port, feed port and pressure explosion-proof port; (2) Add benzoic acid, sodium hypophosphite (catalyst) and deionized water; the amount of benzoic acid is 2.5% of the total amount of diamine and diacid, the weight of sodium hypophosphite is 0.1% of the weight of other feed ingredients except deionized water, and the weight of deionized water is 30% of the total feed ingredients. (3) Vacuum and fill with high-purity nitrogen as a protective gas. Heat to 220°C within 2 hours under stirring. Stir the reaction mixture at 220°C for 1 hour. Then raise the temperature of the reactants to 230°C under stirring. (4) The reaction was continued for 2 hours at a constant temperature of 230°C and a constant pressure of 2.2 MPa. The pressure was kept constant by removing the water formed. After the reaction was completed, the material was discharged and the prepolymer was vacuum dried at 80°C for 24 hours to obtain the prepolymer product. The prepolymer product was solid-phase thickened at 250°C and 50 Pa vacuum for 6 hours to obtain poly(terephthalamide) resin 1.

[0046] The poly(terephthalamide) resin 2 is PA10T: with a relative viscosity of 2.0; The preparation method of the poly(terephthalamide) resin 2 is as follows: (1) Add terephthalic acid and 1,10-decanediamine in a molar ratio of 1:1 to a pressure vessel equipped with a magnetic coupling stirrer, condenser, gas port, feed port and pressure explosion-proof port; (2) Add benzoic acid, sodium hypophosphite (catalyst) and deionized water; the amount of benzoic acid is 2.5% of the total amount of diamine and diacid, the weight of sodium hypophosphite is 0.1% of the weight of other feed ingredients except deionized water, and the weight of deionized water is 30% of the total feed ingredients. (3) Vacuum and fill with high-purity nitrogen as a protective gas. Heat to 220°C within 2 hours under stirring. Stir the reaction mixture at 220°C for 1 hour. Then raise the temperature of the reactants to 230°C under stirring. (4) The reaction was continued for 2 hours at a constant temperature of 230°C and a constant pressure of 2.2 MPa. The pressure was kept constant by removing the water formed. After the reaction was completed, the material was discharged and the prepolymer was vacuum dried at 80°C for 24 hours to obtain the prepolymer product. The prepolymer product was solid-phase thickened at 250°C and 50 Pa vacuum for 8 hours to obtain poly(terephthalamide) resin 2.

[0047] The poly(terephthalamide) resin 3 is PA10T: with a relative viscosity of 2.8; The preparation method of the poly(terephthalamide) resin 3 is as follows: (1) Add terephthalic acid and 1,10-decanediamine in a molar ratio of 1:1 to a pressure vessel equipped with a magnetic coupling stirrer, condenser, gas port, feed port and pressure explosion-proof port; (2) Add benzoic acid, sodium hypophosphite (catalyst) and deionized water; the amount of benzoic acid is 2.5% of the total amount of diamine and diacid, the weight of sodium hypophosphite is 0.1% of the weight of other feed ingredients except deionized water, and the weight of deionized water is 30% of the total feed ingredients. (3) Vacuum and fill with high-purity nitrogen as a protective gas. Heat to 220°C within 2 hours under stirring. Stir the reaction mixture at 220°C for 1 hour. Then raise the temperature of the reactants to 230°C under stirring. (4) The reaction was continued for 2 hours at a constant temperature of 230°C and a constant pressure of 2.2 MPa. The pressure was kept constant by removing the water formed. After the reaction was completed, the material was discharged and the prepolymer was vacuum dried at 80°C for 24 hours to obtain the prepolymer product. The prepolymer product was solid-phase thickened at 250°C and 50 Pa vacuum for 12 hours to obtain poly(terephthalamide) resin 3.

[0048] The poly(terephthalamide) resin 4 is PA10T with a relative viscosity of 3.0.

[0049] The preparation method of the poly(terephthalamide) resin 4 is as follows: (1) Add terephthalic acid and 1,10-decanediamine in a molar ratio of 1:1 to a pressure vessel equipped with a magnetic coupling stirrer, condenser, gas port, feed port and pressure explosion-proof port; (2) Add benzoic acid, sodium hypophosphite (catalyst) and deionized water; the amount of benzoic acid is 2.5% of the total amount of diamine and diacid, the weight of sodium hypophosphite is 0.1% of the weight of other feed ingredients except deionized water, and the weight of deionized water is 30% of the total feed ingredients. (3) Vacuum and fill with high-purity nitrogen as a protective gas. Heat to 220°C within 2 hours under stirring. Stir the reaction mixture at 220°C for 1 hour. Then raise the temperature of the reactants to 230°C under stirring. (4) The reaction was continued for 2 hours at a constant temperature of 230°C and a constant pressure of 2.2 MPa. The pressure was kept constant by removing the water formed. After the reaction was completed, the material was discharged and the prepolymer was vacuum dried at 80°C for 24 hours to obtain the prepolymer product. The prepolymer product was solid-phase thickened at 250°C and 50 Pa vacuum for 14 hours to obtain poly(terephthalamide) resin 4.

[0050] The long-chain polyamide resin 1 is PA610:F120, with a relative viscosity of 2.2, manufactured by Shandong Guangyin. The long-chain polyamide resin 2 is PA610:F150, with a relative viscosity of 2.5, manufactured by Shandong Guangyin. The long-chain polyamide resin 3 is PA610:F160, with a relative viscosity of 2.6, manufactured by Shandong Guangyin. The long-chain polyamide resin 4 is PA610: Zylel RS LC3090, with a relative viscosity of 3.0, manufactured by DuPont, USA. The long-chain polyamide resin 5 is PA1010: Shandong Huachuang Special Plastics New Material Technology Co., Ltd., with a relative viscosity of 2.4; The long-chain polyamide resin 6 is PA1012: Shandong Guangyin New Material Co., Ltd., with a relative viscosity of 2.4.

[0051] The polyamide resin 7 is PA66: PA66 EPR27, with a relative viscosity of 2.2.

[0052] The polyamide resin 8 is PA6I / 6T, Shandong Xianglong, GT35; wherein, 6I / 6T=70 / 30, and the relative viscosity is 2.2.

[0053] The glass fiber 1 is TFG835 with a flatness ratio of 4:1, and is made by Taishan Fiberglass.

[0054] The glass fiber 2 is TFG950 with a flatness ratio of 6:1, and is made by Taishan Fiberglass.

[0055] The diameter-to-thickness ratio of the sheet-like filler 1 is 2:1 to 3:1; The diameter-to-thickness ratio of the sheet-like filler 2 is 4:1 to 6:1; The diameter-to-thickness ratio of the sheet-like filler 3 is 8:1 to 12:1; The diameter-to-thickness ratio of the sheet-like filler 4 is ≥15:1.

[0056] The sheet-like fillers 1-4 are mica powder with an aspect ratio of 28-48 and a D50 of 20.37 μm. They are provided by Shenzhen Haiyang Powder and are obtained by grinding and classifying the filler particles with different aspect ratios.

[0057] The organic hypophosphite flame retardant is aluminum diethylphosphinate: OP 1230, Clariant Chemicals.

[0058] The lubricant is LLDPE 7042. (Guangzhou Petrochemical)

[0059] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0060] Table 1 Table 2 To verify the performance of the polyamide compositions described in this invention, the polyamide compositions prepared in the various examples and comparative examples were injection molded into specimens for testing the following properties.

[0061] Performance testing methods: 1. Linear thermal expansion coefficient (CLTE in the vertical flow direction): Tested according to ISO 11359-1 / -2 standard.

[0062] 2. Tensile properties: Tested according to ISO527-4-2023 standard, the tensile rate is 10 mm / min.

[0063] 3. Flatness Dimensions: An ultra-thin fan frame was injection molded, with dimensions of 120mm × 120mm × 15mm and a wall thickness of 1mm. It was placed at 85℃ and 85% relative humidity for 1000 hours, then removed and cooled to room temperature. The flatness of the ultra-thin fan frame surface was then tested. The flatness test method was as follows: the fan frame was laid flat naturally, and the height of each of the four apex corners from the flat surface was measured. The maximum value of the four heights was recorded as the flatness dimensional data.

[0064] 4. Impact crack resistance: The fan frame is injection molded into an ultra-thin fan frame with dimensions of 120mm×120mm×15mm and a wall thickness of 1mm. After being placed at 85℃ and 85% relative humidity for 1000 hours, the frame is removed and dropped freely from a height of 1.5m to the ground to observe the cracking of the fan frame.

[0065] The performance parameters obtained from the above tests are shown in Table 3.

[0066] Table 3 As shown in Table 3, the polyamide composition of the present invention has a CLTE of less than 85, a tensile strength of greater than 105 MPa, and a planar dimension of less than 0.35 mm, indicating that the polyamide composition of the present invention has the characteristics of low CLTE, ultra-high flatness, dimensional stability, and excellent impact crack resistance.

[0067] A comparison of Examples 8-10 with Example 1 shows that if the aspect ratio of the sheet filler is too small or too large, although the CLTE of the material is controlled to be relatively small, the tensile strength will decrease. Therefore, by further controlling the aspect ratio of the sheet filler within the preferred range of (4-12):1, the present invention enables the polyamide composition to better balance the characteristics of low CLTE, dimensional stability, and excellent mechanical properties.

[0068] Comparing Comparative Examples 1-3 with Example 1, it can be seen that the relative viscosity of the polyethylene terephthalate resin in Comparative Example 1 is too high, resulting in high internal stress in the injection-molded product, leading to dimensional discrepancies in flatness. Furthermore, the material's flowability is poor, failing to meet the injection molding requirements for ultra-thin fans. Similarly, the relative viscosity of the long-chain polyamide resin in Comparative Example 2 is too high, resulting in high internal stress in the injection-molded product, leading to dimensional discrepancies in flatness. Moreover, the material's flowability is poor, again failing to meet the injection molding requirements for ultra-thin fans. In Comparative Example 3, the relative viscosities of both the polyethylene terephthalate resin and the long-chain polyamide resin are too high, resulting in high internal stress in the injection-molded product, leading to dimensional discrepancies in flatness. Furthermore, the material's flowability is poor, also failing to meet the injection molding requirements for ultra-thin fans. Therefore, by controlling the relative viscosity of the polyethylene terephthalate resin and the long-chain polyamide resin within the range defined by this invention, the present invention is beneficial for improving the dimensional stability and impact crack resistance of the polyamide composition.

[0069] Comparing Comparative Example 4 with Example 1, it can be seen that in Comparative Example 4, PA66 was used instead of the long-chain polyamide resin. After moisture conditioning, the material absorbed water severely, its dimensional stability deteriorated significantly, CLTE increased, and its flatness seriously exceeded the standard. Therefore, not any polyamide resin can produce a polyamide composition with excellent dimensional stability, impact crack resistance, and low CLTE.

[0070] Comparing Comparative Examples 5-6 with Example 1, it can be seen that in Comparative Example 5, without the addition of glass fiber, the strength of the material is significantly reduced; in Comparative Example 6, without the addition of sheet filler, the CLTE of the material is significantly increased, the difference in transverse and longitudinal shrinkage rates is large, and the flatness dimensions exceed the standard. Therefore, the present invention, by using a combination of glass fiber and sheet filler, is beneficial to improving the dimensional stability and impact crack resistance of the polyamide composition.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polyamide composition, characterized in that, Includes the following components in parts by weight: 38-52 parts of poly(terephthalamide) resin; 13-56 parts of long-chain polyamide resin; 8-22 parts of flame retardant; 10-45 parts of glass fiber; 8-42 parts of sheet filler; The long-chain polyamide resin includes at least one of PA610, PA612, PA1010, and PA1012; The relative viscosity of the poly(terephthalamide) resin is <3.0, and the relative viscosity of the long-chain polyamide resin is <3.

0.

2. The polyamide composition according to claim 1, characterized in that, The relative viscosity range of the poly(terephthalamide) resin is 1.8-2.8, and the relative viscosity range of the long-chain polyamide resin is 1.8-2.

8.

3. The polyamide composition according to claim 1, characterized in that, The diameter-to-thickness ratio of the sheet-like filler is (2-12):

1.

4. The polyamide composition according to claim 1, characterized in that, The diamine unit in the poly(terephthalamide) resin is derived from an aliphatic diamine; the aliphatic diamine unit has ≥8 carbon atoms; preferably, the poly(terephthalamide) resin includes at least one of poly(octyl terephthalamide), poly(nonyl terephthalamide), poly(decyl terephthalamide), poly(undecyl terephthalamide), and poly(dodecanoyl terephthalamide).

5. The polyamide composition according to claim 1, characterized in that, The mass ratio of glass fiber to sheet filler is (0.2-4.5):

1.

6. The polyamide composition according to claim 1, characterized in that, The sheet-like filler includes at least one of talc, mica, and boron nitride.

7. The polyamide composition according to claim 1, characterized in that, The flame retardant includes an organic hypophosphite flame retardant; preferably, the organic hypophosphite flame retardant includes a dialkyl phosphite; preferably, the dialkyl phosphite includes at least one of aluminum diethyl phosphite, zinc diethyl phosphite, aluminum methyl ethyl phosphite, aluminum ethyl butyl phosphite, and aluminum ethylhexyl phosphite.

8. A method for preparing a polyamide composition according to any one of claims 1-7, characterized in that, Includes the following steps: The components are mixed and added to a twin-screw extruder, and then extruded and granulated to obtain a polyamide composition.

9. The use of a polyamide composition as described in any one of claims 1-7 in an ultra-thin fan.

10. An ultra-thin fan structure, prepared using the polyamide composition as described in any one of claims 1-7.

Images