Liquid crystal polymer, and liquid crystal composition, preparation method therefor and use thereof

Abstract

The present invention relates to a liquid crystal polymer, and a liquid crystal composition, a preparation method therefor and a use thereof. The liquid crystal polymer has a zero-shear viscosity of 3,500-8,000 Pa.s, and an enthalpy of fusion of greater than or equal to 1.2 J / g. The liquid crystal composition prepared from the liquid crystal polymer of the present invention is not prone to powder shedding under the action of ultrasound, has good flatness and good weld line strength, and is very suitable for preparing optical instrument components, especially camera module components.

Description

A liquid crystal polymer, a liquid crystal composition, a method for preparing the same, and its applications. Technical Field This invention relates to the field of polymer materials technology, and more specifically, to a liquid crystal polymer, a liquid crystal composition, a method for preparing the same, and its applications. Background Technology Liquid crystal polymers (LCPs) have excellent dimensional stability, heat resistance and flowability, and can be used to manufacture precision instrument components. In precision instruments, especially optical instruments with lenses, even minor dirt and dust can affect their performance. For example, in the optical components of a camera module, when tiny amounts of oil, dust, or grease adhere to the lens, the camera's optical characteristics significantly deteriorate, affecting image quality and aesthetics. To avoid this, camera module components are typically ultrasonically cleaned before assembly to remove minute dirt, oil, and dust from their surfaces. Due to their rigid molecular chain structure, liquid crystal polymers are prone to orientation along the flow direction, forming a distinct core-skin structure. This pronounced core-skin orientation makes the material surface susceptible to interlayer delamination under external forces. This results in the shedding of powder and the formation of microparticles during ultrasonic cleaning, a major cause of dirt buildup during ultrasonic cleaning. Furthermore, the falling dust can negatively impact the image resolution of cameras. In addition, since these are components of precision instruments, attention must be paid to the surface flatness and weld line strength of the liquid crystal polymer material to meet the precision and reliability requirements of the injection-molded components. CN107924039A provides a liquid crystal resin composition for a camera module, whose anti-powdering properties and flatness need further improvement. CN101981123A provides a liquid crystal polyester resin composition for camera modules, but its anti-powdering performance needs further improvement, and it does not focus on the flatness of the material. Summary of the Invention The primary objective of this invention is to overcome the technical problems existing in the prior art and to provide a liquid crystal polymer. A further object of the present invention is to provide a liquid crystal composition. A further object of the present invention is to provide a method for preparing the above-described liquid crystal composition. A further object of the present invention is to provide the application of the above-described liquid crystal composition in the manufacture of optical instrument components. The above-mentioned objective of the present invention is achieved through the following technical solution: A liquid crystal polymer, wherein the zero-shear viscosity of the liquid crystal polymer is 3500~8000 Pa·s and the enthalpy of melting is ≥1.2 J / g. The inventors of this invention have discovered that the liquid crystal composition made from the liquid crystal polymer of this invention is not prone to powder shedding under ultrasonic treatment, has good flatness, and also has good weld line strength, making it very suitable for manufacturing optical instrument components, especially camera module components. A liquid crystal composition comprising the following components in parts by weight: 60-75 parts of the above-mentioned liquid crystal polymer, 20-40 parts of filler. The addition of fillers in this invention can improve the basic mechanical properties of the liquid crystal composition. The inventors of this invention have discovered that controlling the zero-shear viscosity of the liquid crystal polymer within a certain range can not only improve the problem of powder shedding from the liquid crystal composition under ultrasound, but also improve the flatness of the liquid crystal composition to a certain extent. The principle is as follows: when the zero-shear viscosity of the liquid crystal polymer is within a certain range, the molecular chains of the liquid crystal polymer can reach a suitable length, which is beneficial for the entanglement between liquid crystal polymer molecules, slows down the delamination between layers of the liquid crystal polymer under ultrasound, and improves the anti-powder shedding performance; furthermore, the anisotropy of the molecular chains of the liquid crystal polymer at this zero-shear viscosity is reduced, thus its flatness is also improved to a certain extent. However, the zero-shear viscosity of the liquid crystal polymer should not be further increased, otherwise the compatibility between the liquid crystal polymer and the filler will deteriorate, thereby worsening the anti-powdering performance and flatness. Further research by the inventors revealed that controlling the melting enthalpy of the liquid crystal polymer within a certain range can further improve the problem of easy powder shedding under ultrasonication in liquid crystal compositions, and effectively improve the flatness of the liquid crystal composition. This is because controlling the melting enthalpy within a certain range increases the degree of ordered and regular arrangement of the liquid crystal polymer molecular chains, reduces the free volume, enhances the inter-chain interaction forces, and improves the material's anti-powdering performance. Simultaneously, increasing the melting enthalpy can increase the material modulus, thereby improving the flatness of the liquid crystal polymer. Furthermore, by combining the specific zero-shear viscosity and melting enthalpy of the liquid crystal polymer, the weld line strength of the liquid crystal composition is improved, including the tensile strength and flexural strength of the weld line. In this invention, the liquid crystal polymer is used as the main resin; preferably, the liquid crystal polymer accounts for more than 50 wt% of the liquid crystal composition. In this invention, the zero-shear viscosity of the liquid crystal polymer can specifically be 3500, 3600, 3700, 3900, 4100, 4300, 4500, 4800, 5000, 5500, 6000, 6500, 7000, 7300, 7500, 7600, 7800 or 8000 Pa·s. Preferably, the zero-shear viscosity of the liquid crystal polymer is 5000~6450 Pa·s. Within this range, the properties of the obtained liquid crystal composition are better. Commonly used liquid crystal polymers in this field can be used in this invention. Preferably, the liquid crystal polymer is a liquid crystal polyester. More preferably, the liquid crystal polymer comprises the following repeating units: -O-Ar1-CO-50~60mol%, -CO-Ar2-CO-20~25mol%, -O-Ar3-O-20~25mol%; Wherein, Ar1 is at least one of phenylene or naphthylene, and Ar2 and Ar3 are independently at least one of phenylene, biphenylene, or naphthylene. More preferably, the preparation process of the liquid crystal polymer is as follows: the monomers corresponding to the -O-Ar1-CO- repeating unit, the monomers corresponding to the -CO-Ar2-CO- repeating unit, and the monomers corresponding to the -O-Ar3-O- repeating unit are subjected to acylation reaction, condensation reaction, and solid-state thickening reaction in sequence to obtain the polymer. More preferably, the monomer corresponding to the -O-Ar1-CO- repeating unit is at least one of p-hydroxybenzoic acid, m-hydroxybenzoic acid, o-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, or 1-hydroxy-2-naphthoic acid. More preferably, the monomer corresponding to the -CO-Ar2-CO- repeating unit is at least one of terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, or 4,4'-biphenyldicarboxylic acid. More preferably, the monomer corresponding to the -O-Ar3-O- repeating unit is at least one of hydroquinone, hydroquinone, or 2,6-naphthol. More preferably, the acylation reaction is carried out in the presence of an acylation agent. More preferably, the acylating agent is acetic anhydride. More preferably, the acylation reaction is carried out at a temperature of 140~190℃ for a time of 0.5~4 hours. More preferably, the temperature is increased from room temperature (20-30°C) to the temperature of the acylation reaction at a rate of 1.5-3°C / min. More preferably, the temperature of the polycondensation reaction is higher than the temperature of the acylation reaction, and the temperature of the polycondensation reaction is increased from the temperature of the acylation reaction to the temperature of the polycondensation reaction at a rate of 2.0~5.5℃ / min. More preferably, the temperature of the polycondensation reaction is 300~400℃ and the pressure is below 10 kPa. More preferably, the pressure is 1~10 kPa. More preferably, the polycondensation reaction is carried out in a reactor, and the polycondensation reaction is terminated when the power of the agitator in the reactor is increased to 1~10kw. More preferably, the solid-phase thickening temperature is 280~320℃ and the time is 11~16 hours. As a method for manufacturing the liquid crystal resin used in this invention, known methods can be used, such as a manufacturing method that uses only melt polymerization or a two-stage polymerization method that uses melt polymerization and solid-state polymerization. The zero-shear viscosity of the liquid crystal polymer of the present invention can be adjusted by any method known in the art, such as by solid-phase thickening of the purchased or melt-polymerized liquid crystal polymer, and by adjusting the solid-phase thickening time and / or temperature, etc.; the melting enthalpy of the liquid crystal polymer of the present invention can be adjusted by any method known in the art, such as by adjusting parameters such as the type of monomer, the monomer ratio, the temperature and time of melt polymerization, the temperature and time of solid-phase thickening, and the heating rate of different stages (e.g., the heating rate from room temperature to the reaction temperature of acylation reaction, the heating rate from the reaction temperature of acylation reaction to the reaction temperature of polycondensation reaction). Regardless of the method used, as long as the final liquid crystal polymer meets the zero-shear viscosity and melting enthalpy range defined by this invention, the technical problem of this invention can be solved. Preferably, the zero-shear viscosity of the liquid crystal polymer is 5000~6500 Pa·s. Within this range, the problem of easy powder shedding under ultrasonic treatment of the liquid crystal composition is further improved, the flatness is better, and the weld line strength is also higher. In this invention, the melting enthalpy of the liquid crystal polymer can be 1.20, 1.25, 1.30, 1.40, 1.50, 1.60, 1.70 or 1.80 J / g. Preferably, the enthalpy of melting of the liquid crystal polymer is 1.2~1.7 J / g. More preferably, the enthalpy of melting of the liquid crystal polymer is 1.32~1.60 J / g. Within this range, the problem of powder shedding under ultrasonic treatment of the crystal composition is further improved, and the flatness is better. Preferably, the melting point of the liquid crystal polymer is 320~360℃. The melting point of liquid crystal polymers can be determined using a differential scanning calorimeter. Preferably, the average particle size of the filler is 0.1 to 30 micrometers. Preferably, the packing material is fibrous packing material or sheet packing material. More preferably, the filler comprises fibrous filler and sheet filler in a mass ratio of 1:(0.8~1.2). The planarity of the liquid crystal composition is improved by combining different fillers. More preferably, the fibrous filler is at least one of potassium titanate whiskers, silicon carbide whiskers, or wollastonite. More preferably, the fibrous filler is potassium titanate whiskers. Using potassium titanate whiskers results in a liquid crystal composition with better resistance to powder shedding. More preferably, the sheet-like filler is at least one of mica, talc, or boron nitride. Preferably, the filler is a filler modified with a silane coupling agent. More preferably, the silane coupling agent is at least one of alkane silane coupling agents or epoxy silane coupling agents. More preferably, the silane coupling agent is an alkane-based silane coupling agent. When using silane coupling agents to modify fillers, the use of alkane-based silane coupling agents can further improve the problem of easy powder shedding under ultrasonic treatment in liquid crystal compositions, and also improve the strength of weld lines. More preferably, the alkane-based silane coupling agent is at least one of n-propyltrimethoxysilane, n-octyltriethoxysilane, or n-octyltrimethoxysilane. More preferably, the epoxy silane coupling agent includes, but is not limited to, epoxytrimethoxysilane. Preferably, the liquid crystal composition further includes 0.2 to 5 parts of other additives. More preferably, the other additives are at least one of color powder, lubricant or toughening agent. More preferably, the pigment is carbon black. More preferably, the toughening agent is an olefin copolymer, including but not limited to at least one of ethylene-butyl acrylate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, or ethylene-methyl acrylate-glycidyl methacrylate copolymer. The method for preparing the above-mentioned liquid crystal composition includes the following steps: The components are mixed and melt-extruded to obtain the liquid crystal composition. The application of the above-mentioned liquid crystal composition in the manufacture of optical instrument components is also within the scope of protection of this invention. Preferably, the optical instrument component is a camera module component. An optical instrument component is made from the above-mentioned liquid crystal composition. Preferably, the optical instrument component is a camera module component. Compared with the prior art, the beneficial effects of the present invention are: (1) The liquid crystal composition prepared by the liquid crystal polymer of the present invention is not easy to shed powder under ultrasonic action, has good flatness, and also has good weld line strength, which is very suitable for the preparation of optical instrument components, especially camera module components. (2) The liquid crystal composition of the present invention is not easy to shed powder under ultrasonic action, has good flatness, and also has good weld line strength, making it very suitable for manufacturing optical instrument components, especially camera module components. Embodiments of the present invention To more clearly and completely describe the technical solution of the present invention, the present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention. The reagents used in the various embodiments and comparative examples of this invention are described below: Liquid Crystal Polymer 1#: Self-made, preparation process as follows: The monomers p-hydroxybenzoic acid (HBA), terephthalic acid (PTA), and biphenyl hydroquinone (BP) were mixed in a molar ratio of 60:20:20 and added to a reaction vessel containing acetic anhydride for acylation. The temperature was increased from room temperature (25℃) to 170℃ at a rate of 2.5℃ / min. After reflux at 170℃ for 2 hours, the reaction byproduct acetic acid was collected. After the acylation reaction was completed, the reactor was heated to 350℃ at a rate of 4℃ / min. Acetic acid and unreacted small molecules of the raw materials were discharged from the distillation column. Then, the internal pressure of the reactor was reduced to below 5 kPa and maintained at this pressure until the power of the agitator reached 3.5 kW. The material was then discharged and pelletized. The material was then transferred to a rotating drum at 300℃ and held at this temperature for 14 hours to obtain Liquid Crystal Polymer 1#. The zero-shear viscosity of liquid crystal polymer 1# is 5005 Pa·s, and the melting enthalpy is 1.35 J / g. Liquid crystal polymer 2#: self-made, the preparation process differs from that of liquid crystal polymer 1# in that the drum isothermal time is extended to 16 hours. The zero-shear viscosity of liquid crystal polymer 2# is 6400 Pa·s, and the enthalpy of melting is 1.34 J / g. Liquid crystal polymer 3#: Self-made, the preparation process differs from that of liquid crystal polymer 1# in that the drum isothermal time is shortened to 11 hours. The zero-shear viscosity of liquid crystal polymer 3# is 4430 Pa·s, and the enthalpy of melting is 1.28 J / g. Liquid crystal polymer 4#: Self-made. The preparation process differs from that of liquid crystal polymer 1# in that: after the acylation reaction is completed, the reactor is heated to 350°C at a heating rate of 2.5°C / min. The zero-shear viscosity of liquid crystal polymer 4# is 5015 Pa·s, and the enthalpy of melting is 1.58 J / g. Liquid crystal polymer 5#: self-made. The preparation process differs from that of liquid crystal polymer 1# in that: after the acylation reaction is completed, the reactor is heated to 350°C at a heating rate of 5°C / min. Liquid crystal polymer 4# has a zero-shear viscosity of 4959 Pa·s and a melting enthalpy of 1.26 J / g. Liquid crystal polymer 6#: Self-made. The preparation process differs from that of liquid crystal polymer 1# in that the monomer composition is different. The monomers 6-hydroxy-2-naphthoic acid (HNA), terephthalic acid (PTA), and biphenyl hydroquinone (BP) are mixed in a molar ratio of 60:20:20. Liquid crystal polymer 6# has a zero-shear viscosity of 6585 Pa·s and a melting enthalpy of 1.39 J / g. Liquid crystal polymer 7#: Self-made. The preparation process differs from that of liquid crystal polymer 1# in the amount of monomers used. The molar ratio of the monomers p-hydroxybenzoic acid (HBA), terephthalic acid (PTA), and biphenyl hydroquinone (BP) is 50:25:25. Liquid crystal polymer 7# has a zero-shear viscosity of 4546 Pa·s and a melting enthalpy of 1.42 J / g. Liquid crystal polymer 8#: Prepared in-house. The preparation process differs from that of liquid crystal polymer 1# in that, before the acylation reaction, the temperature was increased from room temperature (25°C) to 170°C at a rate of 1.5°C / min. The resulting liquid crystal polymer 8# has a zero-shear viscosity of 5078 Pa·s and a melting enthalpy of 1.45 J / g. Liquid crystal polymer 9#: Self-made. The preparation process differs from that of liquid crystal polymer 1# in that the drum isothermal time is shortened to 8 hours. The zero-shear viscosity of liquid crystal polymer 9# is 2355 Pa·s, and the enthalpy of melting is 1.32 J / g. Liquid crystal polymer 10#: Self-made. The preparation process differs from that of liquid crystal polymer 1# in that the drum temperature is increased to 310℃ and the drum isothermal time is extended to 18 hours. The zero-shear viscosity of liquid crystal polymer 10# is 9455 Pa·s, and the enthalpy of melting is 1.38 J / g. Liquid crystal polymer 11#: In-house prepared. The preparation process differs from that of liquid crystal polymer 1# in that: after the acylation reaction is completed, the reactor is heated to 350°C at a heating rate of 7.5°C / min. The zero-shear viscosity of liquid crystal polymer 11# is 5105 Pa·s, and the enthalpy of melting is 0.92 J / g. Liquid crystal polymer 12#: According to patent CN107924039 A

[0106] ~

[0113] The liquid crystal polymer 12# was obtained by segment preparation. The zero-shear viscosity was 2893 Pa·s, and the enthalpy of melting was 1.12 J / g. Liquid crystal polymer 13#: According to patent CN101981123A

[0112] ~

[0114] The liquid crystal polymer 13# was obtained by segmental preparation. The zero-shear viscosity was 3584 Pa·s, and the melting enthalpy was 1.09 J / g. Liquid crystal polymer 14#: Ueno A-2500, Ueno Pharmaceutical Co., Ltd., Japan. The zero-shear viscosity of liquid crystal polymer 14# is 3059 Pa·s, and the enthalpy of melting is 1.23 J / g. The zero-shear viscosity of the aforementioned liquid crystal polymer was measured using the following method: A resin disc with a diameter of 25 mm and a thickness of 2 mm was prepared as the test sample. A rotational rheometer was used to perform steady-state shear rate scanning on the sample. First, the sample was heated to its melting point (Tm + 30℃) and held at that temperature for 6 minutes to eliminate processing history. Then, the temperature was lowered to the set temperature (Tm + 20℃), with a fixed melt strain of 0.5%. The scanning frequency range was 0.001~100 s. -1 The sample was scanned to obtain the viscosity versus shear rate curve. The shear rate was then fixed at 0.005 s⁻¹. -1 The shear viscosity at that time is zero, η0. The melting enthalpy of the above-mentioned liquid crystal polymer was measured by the following method: the melting point was measured using a DSC 200 F3 manufactured by NETZSCH. The heating rate was 20℃ / min. The temperature was raised to Tm+30℃ and held for 5 minutes to eliminate thermal history. Then, the temperature was lowered to room temperature at 20℃ / min and then raised to Tm+40℃ at 20℃ / min. The temperature corresponding to the melting peak of the second heating curve was taken as the melting point of the material. The melting peak was integrated to obtain the melting enthalpy change. Silane Coupling Agent 1#: Alkane silane coupling agent, n-propyltrimethoxysilane, Nanjing Pinning Coupling Agent Co., Ltd., China; Silane coupling agent #2: Epoxy silane coupling agent, epoxytrimethoxysilane, Z-6040, Dow Corning, USA; Filler #1: Mica, GM-501, average particle size 15 micrometers, Chuzhou Gree Mining Co., Ltd., China; Filler #2: Potassium titanate whiskers, average particle size 3 micrometers, Nantong Aoxin Electronic Technology Co., Ltd., China; Filler #3: Talc powder, average particle size 12 micrometers, Guangxi Longsheng Huamei Talc Development Co., Ltd., China; Filler #4: Wollastonite, HK-5000F, average particle size 2.5 micrometers, Dalian Global Minerals Co., Ltd.; Filler #5: Boron nitride (BN), average particle size 13μm, Qinhuangdao Yinuo Advanced Materials Co., Ltd. Modified filler 1#: prepared by mixing filler 1# and silane coupling agent 1# in a high-speed mixer at a mass ratio of 1:0.02; Modified filler 2#: prepared by mixing filler 2# and silane coupling agent 1# in a high-speed mixer at a mass ratio of 1:0.02; Modified filler #3: prepared by mixing filler #3 and silane coupling agent #1 at a mass ratio of 1:0.02 in a high-speed mixer; Modified filler #4: prepared by mixing filler #1 and silane coupling agent #2 at a mass ratio of 1:0.02 in a high-speed mixer; Modified filler #5: It is obtained by mixing filler #4 and silane coupling agent #1 at a mass ratio of 1:0.02 in a high-speed mixer; Modified filler 6#: It is obtained by mixing filler 5# and silane coupling agent 1# in a high-speed mixer at a mass ratio of 1:0.02; Other additives #1: Toughening agent, PTW, ethylene-glycidyl methacrylate copolymer, DuPont, USA; Other additives #2: Colorant, carbon black, commercially available. Unless otherwise specified, all components (e.g., other additives 1#, etc.) used in each parallel embodiment and comparative example are the same commercially available products. The liquid crystal compositions provided in the embodiments and comparative examples of the present invention were subjected to performance testing according to the following test methods: 1) Dust shedding assessment method: Cut the above test piece into 10mm×10mm×1mm samples and place them in 20ml of room temperature water in an ultrasonic cleaner (300W power, 45kHz frequency) for 5 minutes. Afterwards, use a particle counter (RION Co., Ltd., Japan, Particle Counter KE-40B1 (PARTICLE COUNTER)) to measure the number of particles with a diameter of 10μm or larger present in the water. This number is used as the evaluation of the number of micro-dust generated. 2) Flatness Assessment: The liquid crystal composition was molded using an injection molding machine under the following molding conditions to obtain a molded body with dimensions of 64mm × 64mm × 1.0mm. Using this molded body as a test piece, after high-temperature reflow soldering, the deformation in the vertical direction of the flow was tested using a two-dimensional method. Injection barrel temperature: 360℃; mold temperature: 100℃; injection speed: 50mm / s. 3) Weld line mechanical property test: Using a mold with a dumbbell-shaped cavity (two-point injection, fluid counter-flow forming the weld line), a mechanical specimen with a thickness of 0.8mm was injection molded. Tensile strength test: Tested under ISO 527-1 / -2 conditions at a tensile speed of 10mm / min, and the average of 5 test results was taken. Flexural modulus test: Tested under ISO 178 conditions at a bending speed of 2mm / min, and the average of 5 test results was taken. The preparation processes of the liquid crystal compositions in the embodiments and comparative examples of the present invention are as follows: Each component is weighed according to the formula, added to a twin-screw extruder, melt-extruded at a temperature 20°C higher than the melting point of the liquid crystal polymer, cooled, and granulated to obtain the liquid crystal composition. The screw speed of the twin-screw extruder is 400 rpm, and the screw length-to-diameter ratio is 40:1. Examples 1-17 Examples 1-17 provide a series of liquid crystal compositions, the formulations of which are shown in Table 1. Table 1. Formulations (parts by weight) for Examples 1-17 Continued from Table 1 Comparative Examples 1-6 Comparative Examples 1 to 6 provide a series of liquid crystal compositions, the formulations of which are shown in Table 2. Table 2. Formulations (parts by weight) for Comparative Examples 1-6 The performance of the liquid crystal compositions of each embodiment and comparative example was measured according to the test methods mentioned above, and the test results are shown in Table 3. Table 3 Performance test results of the liquid crystal compositions of each embodiment and comparative example As can be seen from Table 3: The number of microparticles in Examples 1-17 does not exceed 7, and the flatness is not higher than 0.28, indicating that the liquid crystal composition of the present invention is not prone to powder shedding under ultrasonic treatment and has good flatness. Furthermore, the tensile strength of the weld lines in Examples 1-17 is not less than 40 MPa, and the flexural strength of the weld lines is not less than 49 MPa, indicating that the weld line strength of the liquid crystal composition of the present invention is good. These features make the liquid crystal composition of the present invention suitable for manufacturing camera module components. The liquid crystal polymer added in Comparative Example 1 had too low a shear viscosity, resulting in easy powder shedding, poor weld line strength, and worse flatness compared to Example 1 under ultrasonic treatment. The liquid crystal polymer added in Comparative Example 2 had too high a shear viscosity, resulting in easy powder shedding and worse flatness compared to Example 1 under ultrasonic treatment. The liquid crystal composition added in Comparative Example 3 had too low a melting enthalpy, resulting in easy powder shedding, poor flatness, and poor weld line strength under ultrasonic treatment. The liquid crystal compositions used in Comparative Examples 4, 5, and 6 had unsuitable shear viscosity and / or melting enthalpy, resulting in inferior anti-powder shedding performance, flatness, and weld line strength compared to Examples 1 and 4-10. Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A liquid crystal polymer, characterized in that, The liquid crystal polymer has a zero-shear viscosity of 3500~8000 Pa·s and a melting enthalpy ≥1.2 J / g.

2. A liquid crystal composition, characterized in that, The components include the following parts by weight: 60-75 parts of liquid crystal polymer, 20-40 parts of filler; The liquid crystal polymer has a zero-shear viscosity of 3500~8000 Pa·s and a melting enthalpy ≥1.2 J / g.

3. The liquid crystal composition according to claim 2, characterized in that, The liquid crystal polymer is a liquid crystal polyester.

4. The liquid crystal composition according to claim 2, characterized in that, The enthalpy of melting of the liquid crystal polymer is 1.2~1.8 J / g.

5. The liquid crystal composition according to claim 2, characterized in that, The filler is a filler modified with a silane coupling agent.

6. The liquid crystal composition according to claim 2, characterized in that, The filler is at least one of fibrous filler or sheet filler; preferably, the fibrous filler is at least one of potassium titanate whiskers, silicon carbide whiskers or wollastonite, and the sheet filler is at least one of mica, talc or boron nitride.

7. The liquid crystal composition according to claim 2, characterized in that, The liquid crystal composition also includes 0.2 to 5 parts of other additives.

8. A method for preparing the liquid crystal composition according to any one of claims 2 to 7, characterized in that, Includes the following steps: The components are mixed and melt-extruded to obtain the liquid crystal composition.

9. The use of the liquid crystal composition according to any one of claims 2 to 7 in the preparation of optical instrument components; preferably, the optical instrument component is a camera module component.

10. An optical instrument component, characterized in that, It is prepared from any one of the liquid crystal compositions of claims 2 to 7; preferably, the optical instrument component is a camera module component.

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