Liquid crystal polymer composition as well as preparation method and application thereof

Abstract

The invention relates to a liquid crystal polymer composition as well as a preparation method and application thereof. The liquid crystal polymer composition comprises the following components in parts by weight: 37-49 parts of a liquid crystal polymer, 1-8 parts of an ultraviolet light absorber, 8-25 parts of a light screener and 8-21 parts of semi-aromatic polyester. The liquid crystal polymer composition has good ultraviolet yellowing resistance and high-frequency vibration attenuation performance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a liquid crystal polymer composition, its preparation method, and its application. Background Technology

[0002] Liquid crystal polymers (LCPs) possess excellent processing fluidity, high heat resistance, dimensional stability, superior mechanical properties, and good high-frequency vibration damping performance, making them widely used in consumer electronics and other fields. With industry development, simple black is no longer sufficient to meet product color requirements, necessitating various color matching treatments for the materials. Sunlight or the dazzling lights emitted by large gaming chassis contain ultraviolet rays. To ensure that the product's color remains unchanged under prolonged light exposure, stringent requirements are placed on the weather resistance of liquid crystal materials, especially their resistance to ultraviolet aging.

[0003] Liquid crystal polymers are highly sensitive to ultraviolet light, exhibiting a very pronounced yellowing characteristic. This is mainly because under prolonged ultraviolet irradiation, liquid crystal polymers readily undergo thermal-fries or photo-fries rearrangements, forming conjugated double bonds, generating chromophores, and producing yellow substances. The formation of yellow substances causes changes in product color, thus limiting their application in consumer electronics and other fields.

[0004] Adding ultraviolet light absorbers to liquid crystal materials is a common method to solve the problem of ultraviolet yellowing, but adding ultraviolet light absorbers alone has limited effect on improving this problem. Summary of the Invention

[0005] The primary objective of this invention is to overcome the technical problems existing in the prior art and to provide a liquid crystal polymer composition.

[0006] A further object of the present invention is to provide a method for preparing the above-described liquid crystal polymer composition.

[0007] A further object of the present invention is to provide the application of the above-described liquid crystal polymer composition in the manufacture of components for electronic products.

[0008] The above-mentioned objective of the present invention is achieved through the following technical solution: A liquid crystal polymer composition comprising the following components in parts by weight: 37-49 parts of liquid crystal polymer, 1-8 parts of ultraviolet light absorber 8-25 parts of light shielding agent 8-21 parts of semi-aromatic polyester; The intrinsic viscosity of the semi-aromatic polyester is 0.52~0.92 dL / g.

[0009] The inventors of this invention have discovered that by adding a semi-aromatic polyester to a liquid crystal polymer system and controlling the intrinsic viscosity of the semi-aromatic polyester within a certain range, it can not only uniformly disperse on the surface of the liquid crystal polymer composition during processing, but also drive the ultraviolet light absorber to accumulate on the surface of the liquid crystal polymer composition. The semi-aromatic polyester, in combination with the ultraviolet light absorber and light shielding agent accumulated on the surface of the liquid crystal polymer composition, endows the liquid crystal polymer composition with good resistance to ultraviolet yellowing.

[0010] If the intrinsic viscosity of the semi-aromatic polyester is too low, it will be difficult for the semi-aromatic polyester to carry the ultraviolet absorber to the surface of the liquid crystal polymer composition for enrichment; if the intrinsic viscosity of the semi-aromatic polyester is too high, it will be difficult for the semi-aromatic polyester to be uniformly dispersed on the surface of the liquid crystal polymer composition. Both of these situations will result in poor or poor UV yellowing resistance of the liquid crystal polymer composition.

[0011] In addition, the addition of semi-aromatic polyester has a certain negative impact on the high-frequency vibration damping performance of the liquid crystal polymer composition (i.e., the loss factor decreases to a certain extent). However, by adjusting the intrinsic viscosity of the semi-aromatic polyester within a certain range, the negative impact can be reduced, thereby maintaining the good high-frequency vibration damping performance of the liquid crystal polymer composition.

[0012] The present invention adds a light-shielding agent to the liquid crystal polymer composition, which plays a role in blocking and reflecting ultraviolet light, thereby improving the resistance of the liquid crystal polymer composition to ultraviolet yellowing.

[0013] The liquid crystal polymer composition of the present invention has good resistance to ultraviolet yellowing and maintains good high-frequency vibration attenuation performance, making it very suitable for manufacturing components of electronic products.

[0014] In this invention, the amount of liquid crystal polymer can be 37, 39, 41, 43, 45, 47, or 49 parts by weight, or any two of the above values ​​within a range; the amount of ultraviolet light absorber can be 1, 3, 5, 7, or 8 parts by weight, or any two of the above values ​​within a range; the amount of light shielding agent can be 8, 10, 12, 15, 18, 20, 22, or 25 parts by weight, or any two of the above values ​​within a range; and the amount of semi-aromatic polyester can be 8, 10, 12, 15, 17, 19, or 21 parts by weight, or any two of the above values ​​within a range.

[0015] In this invention, a liquid crystal polymer is used as the main resin. Preferably, the liquid crystal polymer accounts for more than 30 wt% of the liquid crystal polymer composition.

[0016] Preferably, the liquid crystal polymer composition comprises the following components in parts by weight: 43-48.5 parts of liquid crystal polymer, 4-8 parts of ultraviolet light absorber 8-20 parts of light shielding agent 12-20 parts of semi-aromatic polyester.

[0017] By controlling the amount of each component within this range, the resulting liquid crystal polymer composition exhibits better resistance to UV yellowing.

[0018] Commonly used liquid crystal polymers in this art can be used in this invention. Preferably, the liquid crystal polymer is at least one of liquid crystal polyester or liquid crystal polyester polyamide; more preferably, the liquid crystal polymer is liquid crystal polyester.

[0019] Preferably, the liquid crystal polyester is at least one of the following polymers: a copolymer of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids and aromatic diols, a copolymer of different aromatic hydroxycarboxylic acids, and a copolymer of aromatic dicarboxylic acids and aromatic diols.

[0020] Preferably, the liquid crystal polyester polyamide is at least one of the following polymers: a copolymer of aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid and aromatic hydroxyamine, a copolymer of aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol and aromatic hydroxyamine, aromatic dicarboxylic acid and aromatic hydroxyamine, or a copolymer of aromatic dicarboxylic acid, aromatic diol and aromatic hydroxyamine.

[0021] More preferably, the aromatic hydroxycarboxylic acid includes, but is not limited to, 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.

[0022] More preferably, the aromatic dicarboxylic acid includes, but is not limited to, at least one of terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, or 4,4'-biphenyldicarboxylic acid.

[0023] More preferably, the aromatic diol includes, but is not limited to, at least one of hydroquinone, hydroquinone, or 2,6-naphthol.

[0024] More preferably, the aromatic hydroxylamine includes, but is not limited to, p-aminophenol.

[0025] Liquid crystal polymers can be manufactured in-house or purchased commercially.

[0026] The self-made method can be as follows: the monomers of the liquid crystal polymer first undergo an acylation reaction, and then undergo melt polymerization to obtain the liquid crystal polymer.

[0027] Preferably, the temperature of the acylation reaction is 230~250℃.

[0028] More preferably, the temperature of the acylation reaction is increased at a heating rate of 2~8℃ / min.

[0029] Preferably, the acylation reaction takes 1 to 3 hours.

[0030] Preferably, the acylation reaction is carried out in the presence of an acylation agent; the acylation agent includes, but is not limited to, acetic anhydride.

[0031] More preferably, the amount of the acylating agent is such that the ratio of the molar amount of the acylating agent to the sum of the molar amounts of the hydroxyl groups of the monomer is (1.01~1.1):1.

[0032] Preferably, the melt polymerization process is as follows: the temperature is increased from the acylation reaction temperature to temperature T at a heating rate of 2~8℃ / min, and then the power of the stirring paddle in the reactor is increased to 1~10kW at a pressure below 10 kPa (e.g., 1~10 kPa); the temperature T is 15~25℃ higher than the melting point of the liquid crystal polymer.

[0033] Preferably, the melting point (Tm) of the liquid crystal polymer is 270~330℃.

[0034] The melting point of liquid crystal polymers can be determined using a differential scanning calorimeter. The testing procedure is as follows: the heating rate is 20℃ / min, the temperature is raised to 30℃ above the melting point and held for 5 minutes to eliminate thermal history, and the melting point Tm is obtained from the curve of the second heating.

[0035] Optionally, the intrinsic viscosity of the liquid crystal polymer is 3.0~7.0 dL / g (e.g., 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5 or 7.0 dL / g); the intrinsic viscosity of the liquid crystal polymer can be measured using a Uys viscometer at 80°C, and the solvent is pentafluorophenol.

[0036] Preferably, the light-shielding agent is at least one of titanium dioxide, zinc oxide, or silicon dioxide.

[0037] More preferably, the average particle size of the light-shielding agent is 15~500nm.

[0038] In this invention, the average particle size of the light-shielding agent can be measured by a particle size analyzer.

[0039] More preferably, the light-shielding agent is titanium dioxide; the titanium dioxide has a rutile crystal form.

[0040] Preferably, the ultraviolet absorber is at least one of triazine ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, or benzoxazine ultraviolet absorbers.

[0041] More preferably, the ultraviolet absorber comprises a first ultraviolet absorber and a second ultraviolet absorber in a mass ratio of 1:(0.4~1.2); the first ultraviolet absorber is a triazine ultraviolet absorber, and the second ultraviolet absorber is at least one of a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber, or a benzoxazine ultraviolet absorber.

[0042] Specifically, the mass ratio of the first ultraviolet absorber to the second ultraviolet absorber can be 1:0.4, 1:0.5, 1:0.8, 1:1, or 1:1.2.

[0043] More preferably, the triazine-based ultraviolet absorber is at least one selected from 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxyphenol, 2,4-bis(2,4-dihydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(2,4-dihydroxyphenyl)-6-phenyl-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-diphenyl-1,3,5-triazine, and 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine.

[0044] More preferably, the benzotriazole ultraviolet absorber is at least one of 2,2'-methylenebis(4-tert-octyl-6-benzotriazole phenol), 2-(3'-tert-butyl-2'-hydroxy-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-[2-hydroxy-5-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, etc.

[0045] More preferably, the benzophenone-based ultraviolet absorber is at least one of 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2,2',4,4'-tetrahydroxybenzophenone.

[0046] More preferably, the benzoxazine ultraviolet absorber includes, but is not limited to, 2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazine-4-one.

[0047] In this invention, semi-aromatic polyester refers to a copolymer of aromatic diacid and aliphatic diol. Semi-aromatic polyester can be commercially available or manufactured in-house.

[0048] The self-made process is as follows: Aromatic diacid and aliphatic diol are mixed, and esterification reaction occurs first, followed by polycondensation reaction, to obtain the semi-aromatic polyester.

[0049] Preferably, the esterification reaction is carried out at a temperature of 250~270°C.

[0050] Preferably, the esterification reaction takes 2 to 5 hours.

[0051] Preferably, the esterification reaction is carried out in the presence of a catalyst.

[0052] More preferably, the catalyst includes, but is not limited to, at least one of antimony trioxide, antimony acetate, germanium dioxide, tetrabutyl titanate, titanium glycol, or stannous zincate; wherein the catalyst accounts for 0.01 to 0.05 wt% of the sum of the masses of the aromatic diacid and the aliphatic diol.

[0053] Preferably, the esterification reaction is carried out in the presence of a stabilizer.

[0054] More preferably, the stabilizer includes, but is not limited to, at least one of triphenyl phosphate, trimethyl phosphate, or triphenyl phosphite; the stabilizer accounts for 0.001 to 0.015 wt% of the sum of the masses of the aromatic diacid and the aliphatic diol.

[0055] Preferably, the polycondensation reaction includes low-vacuum polycondensation and high-vacuum polycondensation in sequence.

[0056] More preferably, the low-vacuum polycondensation is performed at a temperature of 270-280°C, a pressure of 1-10 kPa, and a time of 0.5-5 hours; the high-vacuum polycondensation is performed at a temperature of 280-290°C, a pressure of 0.05-0.1 kPa, and a time of 1.1-3 hours.

[0057] More preferably, the low-vacuum polycondensation is carried out at a temperature of 270~280℃, a pressure of 1~10 kPa, and a time of 0.5~1.5 hours; the high-vacuum polycondensation is carried out at a temperature of 280~290℃, a pressure of 0.05~0.1 kPa, and a time of 1.1~1.5 hours.

[0058] More preferably, the high-vacuum polycondensation is carried out in a reactor, and the high-vacuum polycondensation is terminated when the power of the agitator in the reactor reaches 1~10kw.

[0059] Preferably, the polycondensation reaction is followed by a solid-phase thickening step.

[0060] More preferably, the solid phase thickening temperature is 200~230℃ and the time is 0~12 hours.

[0061] Preferably, the molar ratio of the aromatic diacid to the aliphatic diol is 1:(1.05~1.4).

[0062] Preferably, the aromatic diacid includes, but is not limited to, terephthalic acid.

[0063] Preferably, the aliphatic diol includes, but is not limited to, at least one of ethylene glycol or butanediol.

[0064] Preferably, the semi-aromatic polyester is at least one of polyethylene terephthalate (PET) or polybutylene terephthalate (PBT).

[0065] More preferably, the semi-aromatic polyester is polyethylene terephthalate. Using this semi-aromatic polyester results in a liquid crystal polymer composition with better UV resistance.

[0066] In this invention, the intrinsic viscosity of the semi-aromatic polyester can specifically be 0.52, 0.55, 0.58, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, or 0.92 dL / g. The intrinsic viscosity of the semi-aromatic polyester is measured using a Uys viscometer at 25°C, with the solvent being a mixed solvent of phenol and tetrachloroethane (volume ratio of phenol to tetrachloroethane being 3:2) and the solution concentration being 2 mg / mL.

[0067] Preferably, the intrinsic viscosity of the semi-aromatic polyester is 0.73~0.85 dL / g. Adjusting the intrinsic viscosity of the semi-aromatic polyester within this range results in a liquid crystal polymer composition with better UV resistance.

[0068] Preferably, the mass ratio of the semi-aromatic polyester to the ultraviolet absorber is 2~9:1, more preferably 2~5:1, even more preferably 2.5~3.75:1, and even more preferably 3~3.75:1.

[0069] By adjusting the mass ratio of semi-aromatic polyester to ultraviolet absorber, the ultraviolet absorber can be better enriched on the surface of the liquid crystal polymer composition, resulting in better ultraviolet resistance of the liquid crystal polymer composition.

[0070] Depending on actual production needs, semi-aromatic polyester and ultraviolet absorber can be directly mixed with the remaining components, or they can be made into masterbatch and then mixed with the remaining components.

[0071] Preferably, the semi-aromatic polyester and ultraviolet absorber are first prepared into an ultraviolet absorber masterbatch, and then combined with the remaining components to form a liquid crystal polymer composition.

[0072] The semi-aromatic polyester and ultraviolet absorber are first prepared into an ultraviolet absorber masterbatch, and then mixed with the remaining components. This allows the ultraviolet absorber to be better enriched on the surface of the liquid crystal polymer composition, resulting in better ultraviolet resistance of the liquid crystal polymer composition.

[0073] Preferably, the liquid crystal polymer composition further includes 1 to 2 parts of a nucleating agent.

[0074] Adding a nucleating agent can regulate the crystallization rate of the semi-aromatic polyester, allowing the semi-aromatic polyester to be better enriched and distributed on the surface of the liquid crystal polymer composition, resulting in better UV resistance of the liquid crystal polymer composition.

[0075] More preferably, the liquid crystal polymer composition further includes 1.2 to 2 parts of a nucleating agent.

[0076] Preferably, the nucleating agent is at least one of organic carboxylate nucleating agents, mineral nucleating agents, or ionic polymer nucleating agents.

[0077] More preferably, the organic carboxylate nucleating agent is at least one of a long-chain linear saturated carboxylate sodium salt or a long-chain linear saturated carboxylate calcium salt.

[0078] More preferably, the mineral nucleating agent is at least one of talc, calcium carbonate, or kaolin.

[0079] More preferably, the ionic polymer is at least one of a sodium salt of ethylene-methacrylic acid copolymer or a zinc salt of ethylene-methacrylic acid copolymer.

[0080] Preferably, the liquid crystal polymer composition further includes 10 to 30 parts of glass fiber.

[0081] More preferably, the liquid crystal polymer composition further includes 20 to 30 parts of glass fiber.

[0082] More preferably, the glass fiber has an average length of 1-3 mm and an average cross-sectional diameter of 7-16 μm.

[0083] In this invention, the average length and average diameter of the glass fiber cross-section can be measured by microscopy.

[0084] The preparation method of the above-mentioned liquid crystal polymer composition includes the following steps: mixing the components, melt extruding, and granulating to obtain the liquid crystal polymer composition.

[0085] Preferably, the glass fiber and light-shielding agent are added from the side feed port of the twin-screw extruder.

[0086] Preferably, the ultraviolet absorber and semi-aromatic polyester are first mixed, melt-extruded, and granulated to obtain ultraviolet absorber masterbatch, which is then mixed with other components.

[0087] Preferably, the temperature of the melt extrusion is Tm+20℃, where Tm is the melting point of the liquid crystal polymer; the screw speed of the twin-screw extruder in the melt extrusion is 300~500 rpm, and the length-to-diameter ratio of the screw is 35~50:1.

[0088] The application of the above-mentioned liquid crystal polymer composition in the manufacture of components for electronic products is also within the scope of protection of this invention.

[0089] Preferably, the electronic product is a server, a laptop computer, a gaming device, or an electronic connector.

[0090] A component of an electronic product is prepared from the above-mentioned liquid crystal polymer composition.

[0091] Preferably, the electronic product is a server, a laptop computer, a gaming device, or an electronic connector.

[0092] Compared with the prior art, the beneficial effects of the present invention are: The present invention adds an ultraviolet light absorber, a light shielding agent, and a semi-aromatic polyester with a certain intrinsic viscosity to a liquid crystal polymer, and the resulting liquid crystal polymer composition has good resistance to ultraviolet yellowing and high-frequency vibration attenuation performance. Detailed Implementation

[0093] 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.

[0094] The reagents used in the various embodiments and comparative examples of this invention are described below: Liquid crystal polymer #1: Purchased from Polyplastics Corporation of Japan, brand name Vectra A950, melting point 280℃, intrinsic viscosity 4.9dL / g.

[0095] Liquid crystal polymer 2#: Self-made, preparation process as follows: The monomers p-hydroxybenzoic acid (HBA) and 6-hydroxy-2-naphthoic acid (HNA) were added to a reaction vessel containing acetic anhydride acylation solution at a molar ratio of HBA / HNA=73 / 27. The reactor was then placed in a 240℃ salt bath for reflux for 2 hours. After the byproduct acetic acid stopped distilling, the reactor was heated to 300℃ (denoted as temperature T) at a heating rate of 5℃ / min. Acetic acid and unreacted small molecules of raw materials were discharged from the distillation column. The internal pressure of the reaction vessel was then reduced to below 10 kPa and maintained at this pressure until the power of the agitator reached 7 kW. The material was then discharged and granulated to obtain liquid crystal polymer 2#. The melting point of liquid crystal polymer 2# is 281.2℃ and the intrinsic viscosity is 4.8 dL / g.

[0096] Liquid crystal polymer 3#: Prepared in-house. The preparation process differs from that of liquid crystal polymer 2# in that p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and terephthalic acid are added in a molar ratio of 76:23.5:0.5 into a reaction vessel containing the acetic anhydride acylation agent. After reflux, the temperature T of the reaction vessel is raised to 320℃. Liquid crystal polymer 3# has a melting point of 300℃ and an intrinsic viscosity of 5.1 dL / g.

[0097] Ultraviolet absorber 1#: obtained by mixing first ultraviolet absorber 1# and second ultraviolet absorber 1# in a 1:1 mass ratio; wherein, first ultraviolet absorber 1# is 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol (commercially available), and second ultraviolet absorber 1# is 2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol) (commercially available); Ultraviolet light absorber 2#: It is obtained by mixing the first ultraviolet light absorber 1# and the second ultraviolet light absorber 1# at a mass ratio of 1:0.4; UV absorber 3#: It is obtained by mixing the first UV absorber 1# and the second UV absorber 2# in a mass ratio of 1:1; the second UV absorber 2# is 2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazin-4-one (commercially available). UV absorber 4#: obtained by mixing first UV absorber 2# and second UV absorber 1# in a 1:1 mass ratio; wherein, first UV absorber 2# is 2,4-bis(2,4-dihydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine (commercially available); Light shielding agent 1#: It is obtained by mixing titanium dioxide and silicon dioxide in a mass ratio of 1:0.2; wherein: titanium dioxide: average particle size is about 300 nm, R-105, Chemours Titanium Dioxide Technology; silicon dioxide: average particle size is 30 nm, DK-SiO2-30, Beijing Deco Island Gold Technology Co., Ltd. Light shielding agent #2: Titanium dioxide, average particle size approximately 300 nm, R-105, Chemours Titanium Dioxide Technology; Semi-aromatic polyester 1#: PET resin, self-made, the process is as follows: terephthalic acid and ethylene glycol are added to a reactor containing a catalyst (antimony trioxide) and a stabilizer (triphenyl phosphite (TPPi)) at a molar ratio of 1.0:1.2 (0.03wt% and 0.008wt% of the sum of the masses of terephthalic acid and ethylene glycol, respectively) to form a uniform slurry. Then, the temperature of the plastic is increased to 260℃ at a rate of 2.5℃ / min and maintained at this temperature for 3.5 hours. After that, the temperature is increased to 275℃ at a rate of 2.5℃ / min. Then, the pressure of the reactor is reduced to below 10 kPa and maintained for 1 hour. The pressure in the reactor was further reduced to below 0.1 kPa, and the temperature was raised to 285°C and maintained for 1.5 hours (referred to as time t) until the power of the reactor increased to 8.5 kW. The material was then discharged and sliced ​​to obtain PET chips. The chips were then dried and pre-crystallized. The PET chips were then subjected to a solid-phase thickening process at 210°C for 6 hours to obtain semi-aromatic polyester 1#, which has an intrinsic viscosity of 0.75 dL / g. Semi-aromatic polyester 2#: PET resin, self-made. The process differs from that of semi-aromatic polyester 1# in that the residence time t in the high vacuum polycondensation stage is 1.1 hours, and no solid-phase thickening process is required. The intrinsic viscosity of semi-aromatic polyester 2# is 0.55 dL / g. Semi-aromatic polyester 3#: PET resin, self-made, the process differs from that of semi-aromatic polyester 1# in that: the solid phase thickening reaction time is 12 hours; the intrinsic viscosity of the obtained semi-aromatic polyester 3# is 0.85 dL / g; Semi-aromatic polyester 4#: PET resin, self-made. The process differs from that of semi-aromatic polyester 1# in that the residence time t in the high vacuum polycondensation stage is 0.95 hours, and no solid-phase thickening process is required. The intrinsic viscosity of semi-aromatic polyester 4# is 0.45 dL / g. Semi-aromatic polyester 5#: PET resin, PET resin, self-made, the process differs from that of semi-aromatic polyester 1# in that: the solid phase thickening reaction time is 24 hours; the intrinsic viscosity of the obtained semi-aromatic polyester 5# is 1.0 dL / g; Semi-aromatic polyester 6#: PBT resin, self-made, the process is as follows: Terephthalic acid and butanediol are added at a molar ratio of 1.0:1.4 to a reactor containing a catalyst (antimony trioxide) and a stabilizer (triphenyl phosphite (TPPi) in amounts of 0.015 wt% and 0.0075 wt% of the sum of the masses of terephthalic acid and butanediol, respectively), forming a homogeneous slurry. Then, the plastic is heated to 265℃ at a rate of 2.5℃ / min, maintained at this temperature for 3.5 hours, and then further heated at 2.5℃ / min... The temperature is raised to 275℃, then the pressure in the reactor is reduced to below 10 kPa and maintained for 1 hour; the pressure in the reactor is further reduced to below 0.1 kPa, and the temperature is raised to 287℃ and maintained for 1.5 hours until the power of the reactor increases to 8.5 kW. The material is then discharged and sliced ​​to obtain PBT chips. The PBT chips are then subjected to solid-phase thickening at 210℃ for 6 hours. The chips are then dried to obtain a semi-aromatic polyester 6# with an intrinsic viscosity of 0.73 dL / g. Nucleating agent 1#: Sodium salt of long-chain linear saturated carboxylate, Licomont NAV101, Klein GmbH, Switzerland; Nucleating agent #2: Ultrafine talc, HTP Ultra5L, Imfabi, Italy; Fiberglass: ECS10-03-584A, China Jushi Co., Ltd.; Unless otherwise specified, all components (e.g., glass fiber) used in the parallel embodiments and comparative examples are the same commercially available products.

[0098] The liquid crystal polymer compositions provided in the embodiments and comparative examples of the present invention were subjected to performance testing according to the following test methods: 1. UV resistance yellowing test: Each liquid crystal polymer composition was injection molded into a standard test plate and tested according to ISO48922 cycle 2 conditions. After 144h of irradiation, the color difference of the standard plate was tested. Each sample was tested three times and the average value of the three color differences was taken.

[0099] 2. Test of loss factor δ: A dynamic thermomechanical analyzer from TA Instruments (USA) was used. The three-point bending mode was adopted, the amplitude was fixed at 0.1%, and the test frequency was varied from 0.1 Hz to 100 Hz. The loss factor value at 100 Hz was taken as δ.

[0100] The preparation processes of the liquid crystal polymer compositions of Examples 1-16 and Comparative Examples 3-4 of the present invention are as follows: 1) Weigh each component according to the formula, first mix the ultraviolet absorber and semi-aromatic polyester, melt extrude and granulate to obtain ultraviolet absorber masterbatch; wherein, the temperature of each zone of melt extrusion is 180℃, 150℃, 240℃, 260℃, 250℃, 240℃, 240℃, 250℃, 260℃; the screw speed of the twin-screw extruder is 400 rpm, and the screw length-to-diameter ratio is 40:1; 2) Components other than glass fiber and light-shielding agent, along with the UV absorber masterbatch, are added through the main feed inlet of the twin-screw extruder. Glass fiber and light-shielding agent are added through the side feed inlet of the twin-screw extruder. The mixture is 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 polymer composition. The twin-screw extruder has a screw speed of 400 rpm and a screw length-to-diameter ratio of 40:1.

[0101] The preparation process of the liquid crystal polymer compositions in Examples 17 and Comparative Examples 1-2 is as follows: Each component was weighed according to the formula. Components other than glass fiber and light-shielding agent were added through the main feed inlet of a twin-screw extruder, while glass fiber and light-shielding agent were added through the side feed inlet. The mixture was 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 polymer composition. The screw speed of the twin-screw extruder was 400 rpm, and the screw length-to-diameter ratio was 40:1.

[0102] Examples 1-17 Examples 1-17 provide a series of liquid crystal polymer compositions, the formulations of which are shown in Tables 1 and 2.

[0103] Table 1. Formulations (parts by weight) for Examples 1-8

[0104] Table 2 Formulations (parts by weight) for Examples 9-17

[0105] Comparative Examples 1-4 Comparative Examples 1-4 provide a series of liquid crystal polymer compositions, the formulations of which are shown in Table 3.

[0106] Table 3. Formulations (parts by weight) for Comparative Examples 1-4

[0107] The properties of the liquid crystal polymer compositions of each embodiment and comparative example were determined according to the test methods mentioned above, and the test results are shown in Table 4.

[0108] Table 4 Performance test results of the liquid crystal polymer compositions of each example and comparative example

[0109] As can be seen from Table 4: The liquid crystal polymer compositions of Examples 1-17 all showed ΔE ≤ 4.6 and loss factors ≥ 0.23 in the UV yellowing resistance test, indicating that the liquid crystal polymer compositions of the present invention have good UV yellowing resistance and maintain high-frequency vibration attenuation performance.

[0110] Comparative Example 1, without the addition of semi-aromatic polyester, exhibited poor UV yellowing resistance in its liquid crystal polymer composition. Comparative Example 2, without the addition of semi-aromatic polyester but replacing it with an equal amount of liquid crystal polymer, also showed poor UV yellowing resistance in its liquid crystal polymer composition. In Comparative Examples 3 and 4, the viscosity of the added semi-aromatic polyester was either too low or too high, resulting in poor UV yellowing resistance in the liquid crystal polymer compositions, and Comparative Example 3's liquid crystal polymer composition also exhibited poor high-frequency vibration damping performance.

[0111] 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 can make other variations or modifications 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 composition, characterized in that, The components include the following parts by weight: 37-49 parts of liquid crystal polymer, 1-8 parts of ultraviolet light absorber 8-25 parts of light shielding agent 8-21 parts of semi-aromatic polyester; The intrinsic viscosity of the semi-aromatic polyester is 0.52~0.92 dL / g.

2. The liquid crystal polymer composition according to claim 1, characterized in that, The melting point of the liquid crystal polymer is 270~330℃; Preferably, the liquid crystal polymer is at least one of liquid crystal polyester or liquid crystal polyester polyamide; More preferably, the liquid crystal polymer is a liquid crystal polyester.

3. The liquid crystal polymer composition according to claim 1, characterized in that, The ultraviolet light absorber is at least one of triazine ultraviolet light absorbers, benzotriazole ultraviolet light absorbers, benzophenone ultraviolet light absorbers, or benzoxazine ultraviolet light absorbers; Preferably, the ultraviolet light absorber comprises a first ultraviolet light absorber and a second ultraviolet light absorber in a mass ratio of 1:(0.4~1.2), wherein the first ultraviolet light absorber is a triazine ultraviolet light absorber, and the second ultraviolet light absorber is at least one of a benzotriazole ultraviolet light absorber, a benzophenone ultraviolet light absorber, or a benzoxazine ultraviolet light absorber; More preferably, the ultraviolet absorber comprises a first ultraviolet absorber and a second ultraviolet absorber in a mass ratio of 1:(0.4~1.2), wherein the first ultraviolet absorber is a triazine ultraviolet absorber and the second ultraviolet absorber is a benzotriazole ultraviolet absorber.

4. The liquid crystal polymer composition according to claim 1, characterized in that, The semi-aromatic polyester and ultraviolet absorber are first prepared into ultraviolet absorber masterbatch, and then combined with the remaining components to form a liquid crystal polymer composition; and / or The mass ratio of the semi-aromatic polyester to the ultraviolet absorber is 2~9:

1.

5. The liquid crystal polymer composition according to claim 1, characterized in that, The light-shielding agent is at least one of titanium dioxide, zinc oxide, or silicon dioxide; and / or The semi-aromatic polyester is at least one of polyethylene terephthalate or polybutylene terephthalate.

6. The liquid crystal polymer composition according to claim 1, characterized in that, The liquid crystal polymer composition further includes 1-2 parts of a nucleating agent; preferably, the nucleating agent is at least one of an organic carboxylate nucleating agent, a mineral nucleating agent, or an ionic polymer nucleating agent.

7. The liquid crystal polymer composition according to claim 1, characterized in that, The liquid crystal polymer composition further includes 10 to 30 parts of glass fiber.

8. A method for preparing the liquid crystal polymer composition according to any one of claims 1 to 7, characterized in that, The process includes the following steps: mixing the components, melt extruding, and granulating to obtain the liquid crystal polymer composition.

9. The use of the liquid crystal polymer composition according to any one of claims 1 to 7 in the manufacture of components for electronic products.

10. A component of an electronic product, characterized in that, It is prepared from the liquid crystal polymer composition according to claims 1 to 7.

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