Liquid crystal polyester composite material as well as preparation method and application thereof
By adding a specific proportion of filler to liquid crystal polyester and adjusting the difference between melt viscosity, melting point and crystallization temperature, the problem of decreased fluidity of thermally conductive LCP materials was solved, and a liquid crystal polyester composite material with high thermal conductivity and high fluidity was realized, which is suitable for applications such as drive motors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-04-07
AI Technical Summary
Existing thermally conductive LCP materials improve thermal conductivity but reduce fluidity, making it impossible to combine thermal conductivity and high fluidity, thus failing to meet the high winding fill factor and heat dissipation requirements of the insulation layer in drive motors.
By adding specific proportions of sheet-like, spherical, and fibrous fillers to liquid crystal polyester and adjusting the difference between melt viscosity, melting point, and crystallization temperature, liquid crystal polyester composite materials are prepared, ensuring that the material maintains good thermal conductivity while possessing excellent flow properties.
This invention achieves both high thermal conductivity and good flow properties in liquid crystal polyester composite materials, making them suitable for components requiring high flowability and thermal conductivity, such as robot motors and medical device motors.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of high molecular materials, and more particularly to a liquid crystal polyester composite material, a preparation method thereof and an application thereof. BACKGROUND
[0002] Liquid crystal polyester (LCP) material is a high molecular polymer with fast crystallization speed, high temperature resistance, self-flame retardancy, excellent dielectric performance, high modulus, high strength and strong anisotropy, which is widely used in electronic and electrical industries, home appliance industries and the like. Due to its unique high flowability, high temperature resistance and dimensional stability, the LCP material can be applied to precision electronic devices and the like.
[0003] The existing driving motor adopts a plastic framework and a film to make an insulating support for winding isolation of a copper coil. With the reduction of the size of the motor and the increase of the driving power demand, higher requirements are put forward for the full slot rate and heat dissipation efficiency of the motor. In order to obtain a higher winding full slot rate, the insulating isolation layer needs to be thinned as much as possible to save winding space. Meanwhile, with the increase of the number of turns and the increase of power, the requirement for heat dissipation is also increasing, and higher requirements are put forward for the thermal conductivity of the insulating isolation layer. In the current thermal conductive LCP material, the thermal conductivity is usually improved by adding thermal conductive fillers. However, the addition of the thermal conductive fillers will reduce the flowability of the composite material, and it is difficult to have both thermal conductivity and high flowability. SUMMARY
[0004] The present application aims at overcoming the defects or deficiencies of the LCP composite material in the prior art in terms of thermal conductivity and high flowability, and provides a liquid crystal polyester composite material.
[0005] Another object of the present application is to provide a preparation method of the liquid crystal polyester composite material.
[0006] Another object of the present application is to provide an application of the liquid crystal polyester composite material.
[0007] To achieve the above objects, the present application adopts the following technical solutions: liquid crystal polyester 82-115 parts; flaky filler 8-15 parts; spherical filler 3-10 parts; fibrous filler 0.2-1.2 parts; The difference between the melting point and the crystallization temperature of the liquid crystal polyester composite material is greater than or equal to 48℃, and the melt viscosity of the liquid crystal polyester composite material is less than or equal to 15 Pa·S.
[0008] The application provides a liquid crystal polyester composite material, three kinds of fillers are added in the liquid crystal polyester, and the amount of the fillers is controlled in a specific range, meanwhile, the melt viscosity of the liquid crystal polyester composite material and the difference between the melting point and the crystallization temperature of the liquid crystal polyester composite material are controlled, so that the liquid crystal polyester composite material has good heat conduction performance and good flow performance.
[0009] It should be noted that the content of the liquid crystal polyester in the liquid crystal polyester composite material is preferably not less than 75wt%.
[0010] It should be noted that the content of the flaky filler in the liquid crystal polyester composite material is 8-15 parts, for example, but not limited to, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12.5 parts, 13 parts, 13.5 parts, 14 parts, 14.5 parts or 15 parts, etc., and specific point values between the above point values. Due to the limitation of the length and the consideration of simplicity, the specific point values included in the range are not listed in the application.
[0011] The content of the spherical filler in the liquid crystal polyester composite material is 3-10 parts, for example, but not limited to, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts or 10 parts, etc., and specific point values between the above point values. Due to the limitation of the length and the consideration of simplicity, the specific point values included in the range are not listed in the application.
[0012] The content of the fibrous filler in the liquid crystal polyester composite material is 0.2-1.2 parts, for example, but not limited to, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts, 0.6 parts, 0.65 parts, 0.7 parts, 0.75 parts, 0.8 parts, 0.85 parts, 0.9 parts, 0.95 parts, 1 part, 1.05 parts, 1.1 parts, 1.15 parts or 1.2 parts, etc., and specific point values between the above point values. Due to the limitation of the length and the consideration of simplicity, the specific point values included in the range are not listed in the application.
[0013] Further, the total content of the flaky filler, the spherical filler and the fibrous filler in the liquid crystal polyester composite material is 17-25wt% of the content of the liquid crystal polyester, for example, but not limited to, 17wt%, 17.5wt%, 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt%, 20.5wt%, 21wt%, 21.5wt%, 22wt%, 22.5wt%, 23wt%, 23.5wt%, 24wt%, 24.5wt% or 25wt%, etc., and specific point values between the above point values.
[0014] It should be noted that the difference between the melting viscosity and the melting point and the crystallization temperature of the liquid crystal polyester composite material in the present application can be controlled by the amount of liquid crystal polyester and each morphology filler added.
[0015] It should be noted that the difference between the melting point and the crystallization temperature of the liquid crystal polyester composite material in the present application is ≥48℃, such as but not limited to ≥48℃, 49℃, 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃, 65℃ or 66℃, etc., and specific point values between the above point values. Due to the consideration of space and simplicity, the specific point values included in the range are not listed in the present application.
[0016] Further, the difference between the melting point and the crystallization temperature of the liquid crystal polyester composite material is 50-65℃.
[0017] Specifically, the test standard of the melting point and the crystallization temperature of the liquid crystal polyester composite material is GB / T 19466.3-2004.
[0018] Specifically, the heating rate for determining the melting point and the crystallization temperature is 10℃ / min.
[0019] Further, the melting point of the liquid crystal polyester composite material is 340-355℃.
[0020] Further, the crystallization temperature of the liquid crystal polyester composite material is 285-320℃.
[0021] It should be noted that the melting viscosity of the liquid crystal polyester composite material in the present application is ≤15Pa·S, such as but not limited to ≤15, 14.5, 14, 13.5, 13, 12.5, 12, 11.5, 11, 10.5, 10, 9.5, 9, 8.5, 8, 7.5, 7, 6.5, 6, 5.5, 5, 4.5 or 4Pa·S, etc., and specific point values between the above point values. Due to the consideration of space and simplicity, the specific point values included in the range are not listed in the present application.
[0022] Further, the melting viscosity of the liquid crystal polyester composite material is 5-14Pa·S.
[0023] Specifically, the test standard of the melting viscosity of the liquid crystal polyester composite material is ISO 11443-2021.
[0024] Specifically, the melting viscosity of the liquid crystal polyester composite material is measured at a shear rate of 1000 -s 20℃ higher than the melting point.
[0025] Further, the liquid crystalline polyester is composed of at least two of terephthalic acid, isophthalic acid, hydroquinone, 6-hydroxy-2-naphthoic acid, and p-hydroxybenzoic acid as repeating units.
[0026] Further, the liquid crystalline polyester is composed of terephthalic acid, p-hydroxybenzoic acid, isophthalic acid, and hydroquinone as repeating units.
[0027] In some preferred embodiments, the molar ratio of terephthalic acid, p-hydroxybenzoic acid, isophthalic acid, and hydroquinone in the liquid crystalline polyester is (0.5-1.5):(2-4):(0.05-0.5):1; for example, but not limited to, 0.5:4:0.5:1, 0.6:3.8:0.45:1, 0.7:3.5:0.4:1, 0.8:3.2:0.35:1, 0.9:3:0.3:1, 1:2.8:0.25:1, 1.1:2.5:0.2:1, 1.2:2.2:0.15:1, 1.3:2:0.1:1, 1.4:2.5:0.05:1, 1.5:2:0.05:1, 1.5:3.5:0.3:1, and the like, and specific point values between the above point values, for the sake of brevity, the specific point values included in the range are not listed herein.
[0028] Further, the molar ratio of terephthalic acid, p-hydroxybenzoic acid, isophthalic acid, and hydroquinone in the liquid crystalline polyester is (0.7-1):(2.5-3.5):(0.1-0.3):1.
[0029] It should be noted that the liquid crystalline polyester can be a commercially available product or obtained by self-preparation.
[0030] Specifically, the self-preparation method is, for example, but not limited to: Under the condition of inert gas pressurization, acylation reaction is carried out under the action of the reaction monomers on the acylating agent, the pressure is maintained at 0.1-0.2 MPa, the reaction temperature is 100-180℃, and the reaction time is 30 minutes-10 hours; after the acylation reaction is completed, the pressure in the reaction kettle is reduced to normal pressure, and the temperature is raised to 200-400℃ at a rate of 0.1-150℃ / min, and acetic acid and unreacted anhydride are discharged from the rectification column; when the acetic acid receiving amount reaches more than 90% of the theoretical value, the pressure in the reaction kettle is reduced to 1-10 kPa, the pressure is maintained under this condition, and the reaction system is programmed to rise to the highest reaction temperature of 320-360℃, and a prepolymer is obtained by melt polycondensation; the prepolymer is cooled, solidified, and granulated, solid-phase polymerization is carried out in a solid-phase polymerization container to obtain liquid crystalline polyester particles, the vacuum degree is 0.1-50 kPa, the solid-phase polymerization temperature is 160-340℃, and the reaction time is 0.5-40 hours.
[0031] The acylating agent can be acetic anhydride, propionic anhydride, butyric anhydride, etc.
[0032] According to actual needs, 0-2 parts of an additive can be selected to be added or not, and the additive is at least one of an antioxidant and a lubricant.
[0033] Further, the flaky filler includes one or more of flaky boron nitride, flaky graphite, or aluminum nitride.
[0034] Further, the flaky filler includes flaky boron nitride and / or flaky graphite.
[0035] Further, the average particle size of the flaky filler is 10-45 μm.
[0036] Specifically, the average particle size of the flaky filler is tested according to the standard GB / T19077.1-2008 by using a laser particle size instrument.
[0037] Further, the spherical filler includes one or more of spherical alumina, spherical zinc oxide, spherical magnesium oxide, or spherical titanium white powder.
[0038] Further, the average particle size of the spherical filler is 2-20 μm.
[0039] Specifically, the average particle size of the spherical filler is tested according to the standard GB / T19077.1-2008 by using a laser particle size instrument.
[0040] Further, the fibrous filler includes carbon nanotubes.
[0041] Further, the average length of the fibrous filler is 30-50 μm.
[0042] Specifically, the carbon nanotubes include multi-walled carbon nanotubes and / or single-walled carbon nanotubes.
[0043] Further, the average diameter of the carbon nanotubes is 1-100 nm.
[0044] Specifically, the average diameter of the carbon nanotubes is tested by TEM transmission electron microscopy according to GB / T26826-2011.
[0045] Further, under the premise of not affecting the heat conduction performance and flow performance of the liquid crystal polyester composite material, the liquid crystal polyester composite material further includes 0.1-2 parts of an additive.
[0046] Specifically, the additive, for example but not limited to, includes one or more of an antioxidant, an ultraviolet absorber, or a lubricant.
[0047] The antioxidant in the present application can be selected from commonly used antioxidants, such as but not limited to one or more of hindered phenolic antioxidants, thioether antioxidants, hindered phenolic antioxidants, or diphenylamine antioxidants.
[0048] In the specific embodiment, the phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite (PEP-36), or Irgafos® 627A; the thioether antioxidant is one or more of distearyl thiodipropionate, dilauryl thiodipropionate, or pentaerythritol dodecylthiopropionate; the hindered phenolic antioxidant is one or more of N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide) (Irganox 1098), tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol (Irganox 1010), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 259), n-octadecyl β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Irganox 1076), or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylate]-1,1-dimethyl}-2,4,8,10-tetraoxaspiro[11.22]hexadecane (ADK AO-80); and the diphenylamine antioxidant is one of butyl / octyl diphenylamine or dioctyl diphenylamine.
[0049] The ultraviolet absorber in the present application can be selected from commonly used ultraviolet absorbers, such as but not limited to one or more of hydroxybenzoic acid ester ultraviolet absorbers, benzophenone ultraviolet absorbers, or benzotriazole ultraviolet absorbers.
[0050] Specifically, the hydroxybenzoate ultraviolet absorber can be selected from 3,5-diisobutyl-4-hydroxybenzoic acid cetyl ester, 3,5-di-tert-butyl-4-hydroxybenzoic acid-2,4-di-tert-butylphenyl ester, 3,5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl ester; the benzophenone ultraviolet absorber can be selected from 2,4-dihydroxybenzophenone, 2-hydroxy-4-alkyloxybenzophenone, 1,3-di(methoxy-3-hydroxy-4 benzophenone) benzene, 2-hydroxy-4-phenylalkyloxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-methyl methacrylate benzophenone; the benzotriazole ultraviolet absorber can be selected from 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, 2-(2'-hydroxy-5'-methyl) benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxy) benzotriazole, 2-(2'-hydroxy-3'-isobutyl-5'-tert-butyl) benzotriazole, 2-(2'-hydroxy-3',5'-bis(1,1-dimethylphenyl) benzotriazole, 2-(2'-hydroxy-5'-tert-octyl) benzotriazole, 2-(2'-hydroxy-3'-(1,1-dimethylphenyl)-5'-[1,1,3,3-tetramethylbutyl] benzotriazole, 2,2'-methylene-(6-(2H-benzotriazole)-4-tert-octyl) phenol.
[0051] The lubricant used in the present application can be a commonly used lubricant, such as but not limited to zinc stearate and / or calcium stearate.
[0052] Further, the liquid crystal polyester composite material comprises the following components in parts by weight: liquid crystal polyester 85-105 parts; flaky filler 10-15 parts; spherical filler 5-9 parts; fibrous filler 0.3-0.8 parts.
[0053] The present application also provides a preparation method of the above-mentioned liquid crystal polyester composite material, comprising the following steps: S1. uniformly mixing all components except the liquid crystal polyester to obtain a premix; S2. feeding the liquid crystal polyester through the main feeding port, feeding the premix of step S1 through the side feeding port, melt extruding and granulating to obtain the liquid crystal polyester composite material. Specifically, the temperature of melt extrusion is 10°C higher than the melting point.
[0054] The present application also protects the application of the above-mentioned liquid crystal polyester composite material in the preparation of household appliance parts, automobile parts, medical equipment parts, especially parts that require high flowability (ultra-thin molding) and heat conduction performance, such as robot motors, medical equipment motors and the like.
[0055] A motor component is made of the liquid crystal polyester composite material.
[0056] Compared with the prior art, the present application has the following advantages: The present application provides a liquid crystal polyester composite material, by compounding different morphology fillers, and adjusting the melt viscosity of the liquid crystal polyester composite material and the difference between the melting point and the crystallization temperature of the liquid crystal polyester composite material, the liquid crystal polyester composite material can have good heat conduction performance and good flow performance at the same time. DETAILED DESCRIPTION
[0057] The present application will be further described in conjunction with specific embodiments, but the embodiments do not limit the present application in any form. Unless otherwise specified, the raw materials used in the embodiments of the present application are conventional commercially available raw materials.
[0058] 1. Raw materials used in the embodiments and comparative examples of the present application: Liquid crystal polyester: Liquid crystal polyester 1: the repeating unit is terephthalic acid / p-hydroxybenzoic acid / isophthalic acid / diphenylol, the molar ratio is 1.6:6:0.4:2, the melt viscosity is 9 Pa·s, and it is self-made.
[0059] Liquid crystal polyester 2: the repeating unit is terephthalic acid / p-hydroxybenzoic acid / isophthalic acid / diphenylol, the molar ratio is 1.7:6:0.3:2, the melt viscosity is 9 Pa·s, and it is self-made.
[0060] Liquid crystal polyester 3: the repeating unit is terephthalic acid / p-hydroxybenzoic acid / isophthalic acid / diphenylol, the molar ratio is 1.8:6:0.2:2, the melt viscosity is 9 Pa·s, and it is self-made.
[0061] Liquid crystal polyester 4: the repeating unit is p-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid, the molar ratio is 7:3, the melt viscosity is 23 Pa·s, and it is self-made.
[0062] Liquid crystal polyester 5: the repeating unit is terephthalic acid / p-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / diphenylol, the molar ratio is 2.2:0.2:5.3:2.3, the melt viscosity is 9 Pa·s, and it is self-made.
[0063] The preparation method of the liquid crystal polyester 1-5 is as follows: Under the condition of inert gas pressurization, acylation reaction is carried out under the action of reaction monomers in acylating agent (acetic anhydride), the pressure is kept at 0.1 MPa~0.2 MPa, the reaction temperature is 100℃~180℃, and the reaction time is 30 minutes~10 hours; after the acylation reaction is completed, the pressure in the reaction kettle is reduced to normal pressure, and the temperature is raised to 200℃~400℃ at a rate of 0.1℃ / min~150℃ / min, acetic acid and unreacted acetic anhydride are discharged from the rectification column, when the acetic acid receiving amount reaches more than 90% of the theoretical value, the pressure in the reaction kettle is reduced to 1~10kPa, the reaction system is programmed to the highest reaction temperature of 320~360℃ under the condition of maintaining the reduced pressure, and the prepolymer is obtained by melt polycondensation; the prepolymer is cooled, solidified and granulated, and the liquid crystal polyester particles are obtained by solid phase polymerization in a solid phase polymerization container, the vacuum degree is 0.1Pa~50kPa, the solid phase polymerization temperature is 160~340℃, and the reaction time is 0.5 hours~40 hours.
[0064] Thermal conductive filler: Flaky filler 1: boron nitride, H-BN-E, average particle size of 21~25μm (obtained by sieving), purchased from Tianyuan Aviation Material; Flaky filler 2: flaky graphite, average particle size of 18~36μm (obtained by sieving), purchased from Qingdao Tianhe Da Graphite Co., Ltd.; Spherical filler 1: spherical alumina, W235, average particle size of 5~9μm (obtained by sieving), purchased from Qimingxing; Spherical filler 2: spherical zinc oxide, average particle size of 3~9μm (obtained by sieving), purchased from Jiangsu Shenlong Zinc Industry; Fibrous filler 1: multi-walled carbon nanotube, TNMH5, average diameter of 20~30nm, purchased from Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences; Fibrous filler 2: multi-walled carbon nanotube, TNMH8, average diameter of 50~100nm, purchased from Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences; Fibrous filler 3: single-walled carbon nanotube, average diameter of 1~2nm, purchased from Ningbo Enwo New Material Technology Co., Ltd.; Auxiliary agent: Lubricant: zinc stearate, commercially available; It should be noted that the same raw materials are used for parallel experiments of each embodiment and comparative example in the present application.
[0065] 2. The liquid crystal polyester composite material in each embodiment and comparative example is prepared according to the formula in Tables 1~2 by the following preparation method: S1. Mix other components except liquid crystal polyester uniformly to obtain a premix; S2. The liquid crystal polyester is fed through the main feeding port, and the premix described in step S1 is fed through the side feeding port, the melt extrusion temperature is 10 ℃ higher than the melting point, the rotating speed is 350 rpm, and granulation is performed to obtain the liquid crystal polyester composite material.
[0066] 3. Performance test (1) Thermal conductivity test: the liquid crystal polyester composite material prepared in each example and the comparative example is injected into a 60 mm*60 mm square sample with a thickness of 1 mm by using an injection molding machine, and the thermal conductivity is tested by using a laser flash method according to the standard GB / T22588-2008 under room temperature conditions; (2) Thin-wall flowability test: the liquid crystal polyester composite material prepared in each example and the comparative example is injection molded by using an injection molding machine under standard injection molding conditions (15 ℃ higher than the melting point of the composite material, 200 mm / s), the mold thickness is 0.2 mm, the width is 5 mm, the flow length is observed, the flow length is used to characterize the flowability of the material, and the flow length > 80 mm can be used for thin-wall injection molding; (3) Crystallization temperature and melting point test: the liquid crystal polyester composite material prepared in each example and the comparative example is used to test the crystallization temperature and melting point of the material by using DSC, and the heating rate is 10 ℃ / min; (4) Melt viscosity test: the liquid crystal polyester composite material prepared in each example and the comparative example is tested according to the standard ISO 11443-2021.
[0067] Examples 1-11 and Comparative Examples 1-6 Table 1: The amount of each component in the liquid crystal polyester composite material in each example (unit: weight parts) and performance
[0068] Table 2: The amount of each component in the liquid crystal polyester composite material in each comparative example (unit: weight parts) and performance
[0069] As can be seen from Table 1, the liquid crystal polyester composite material prepared by the application has good thermal conductivity and flowability, specifically: the thermal conductivity is ≥0.8, and the thin-wall flowability is >80 mm; preferably, the thermal conductivity is ≥0.85, and the thin-wall flowability is >110 mm.
[0070] As can be seen from Comparative Examples 1-2, if the difference between the melt viscosity or the melting point and the crystallization temperature of the liquid crystal polyester composite material is not controlled, even if the thermal conductive filler described in the application is used, the thin-wall flowability of the prepared liquid crystal polyester composite material cannot meet the requirements, and even the thermal conductivity cannot meet the requirements.
[0071] From the comparative example 3 and the comparative example 4, it can be seen that if the heat-conducting filler is not used according to the present application, even if the difference between the melt viscosity or the melting point and the crystallization temperature of the liquid crystal polyester composite material is regulated, the thermal conductivity of the prepared liquid crystal polyester composite material cannot obviously meet the requirements.
[0072] From the comparative example 5, it can be seen that if the fibrous filler is too much, the comprehensive performance of the prepared liquid crystal polyester composite material is poor.
[0073] From the comparative example 6, it can be seen that if the heat-conducting filler is not within the scope of the present application, the comprehensive performance of the prepared liquid crystal polyester composite material is poor.
[0074] Obviously, the above examples of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and also impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.
Claims
1. A liquid crystal polyester composite material, characterized in that, Includes the following components, calculated in parts by weight: 82-115 parts of liquid crystal polyester; 8-15 parts of sheet filler; 3-10 parts of spherical packing material; 0.2~1.2 parts of fibrous filler; The difference between the melting point and crystallization temperature of the liquid crystal polyester composite material is ≥48℃; the melt viscosity of the liquid crystal polyester composite material is ≤15Pa·S.
2. The liquid crystal polyester composite material according to claim 1, characterized in that, At least one of the following three conditions must be met: (a) The difference between the melting point and crystallization temperature of the liquid crystal polyester composite material is 50~65℃; (b) The melt viscosity of the liquid crystal polyester composite material is 5~14 Pa·s; (c) The liquid crystal polyester is composed of repeating units of terephthalic acid, p-hydroxybenzoic acid, isophthalic acid, and biphenyl, and the molar ratio of terephthalic acid, p-hydroxybenzoic acid, isophthalic acid and biphenyl in the liquid crystal polyester is (0.5~1.5):(2~4):(0.05~0.5):
1.
3. The liquid crystal polyester composite material according to claim 1, characterized in that, The sheet-like filler includes one or more of sheet-like boron nitride, flake graphite, or aluminum nitride; the average particle size of the sheet-like filler is 10~45μm.
4. The liquid crystal polyester composite material according to claim 1, characterized in that, The spherical filler includes one or more of spherical alumina, spherical zinc oxide, spherical magnesium oxide, or spherical titanium dioxide; the average particle size of the spherical filler is 2~20μm.
5. The liquid crystal polyester composite material according to claim 1, characterized in that, The fibrous filler includes carbon nanotubes; the length of the fibrous filler is 30~50μm; and the average diameter of the carbon nanotubes is 1~100nm.
6. The liquid crystal polyester composite material according to claim 1, characterized in that, Includes the following components, calculated in parts by weight: 85-105 parts of liquid crystal polyester; 10-15 parts of sheet filler; 5-9 parts of spherical packing material; 0.3 to 0.8 parts of fibrous filler.
7. The liquid crystal polyester composite material according to claim 1, characterized in that, It also includes 0.1 to 2 parts of additives; the additives include one or more of antioxidants, ultraviolet absorbers, antistatic agents, flame retardants or lubricants.
8. A method for preparing the liquid crystal polyester composite material according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Mix all components except liquid crystal polyester evenly to obtain a premix; S2. The liquid crystal polyester is fed in through the main feed port, and the premixed material described in step S1 is fed in through the side feed port. The mixture is then melt-extruded and granulated to obtain the liquid crystal polyester composite material.
9. The use of the liquid crystal polyester composite material according to any one of claims 1 to 7 in the preparation of robot parts and / or medical device parts.
10. A motor accessory, characterized in that, It is prepared using the liquid crystal polyester composite material described in any one of claims 1 to 7.