Aromatic liquid crystal polyester resin, preparation method thereof and composite liquid crystal polymer material

Abstract

The invention relates to aromatic liquid crystal polyester resin, a preparation method thereof and a composite liquid crystal polymer material. The aromatic liquid crystal polyester resin is prepared from the following raw materials in parts by mole: 55 to 65 parts of p-hydroxybenzoic acid, 1 to 3 parts of 2-hydroxy-6-naphthoic acid, 14 to 16 parts of diphenol, 17 to 21 parts of phthalic acid and 3 to 5 parts of acetaminophen. The aromatic liquid crystal polyester resin has high mechanical strength, high fluidity, good toughness and high thermal deformation temperature, so that the aromatic liquid crystal polyester resin can be used for manufacturing precise electronic parts such as electronic connectors and the like, and can be well suitable for surface assembly technologies such as reflow soldering and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high molecular resin materials, in particular to an aromatic liquid crystal polyester resin, a preparation method thereof and a composite liquid crystal polymer material. BACKGROUND

[0002] Liquid crystal polyester resin (LCP) is a kind of high-performance engineering plastics, which has excellent processing fluidity and low shrinkage, and can be adapted to the molding of small and thin products. It has been widely used in the preparation of precision electronic components such as electronic connectors.

[0003] In the reflow soldering process of assembling electronic devices, the paster component and the circuit board pad need to be combined by high temperature, so the matrix material needs to have a high heat distortion temperature (above 240℃). However, if the liquid crystal polyester resin has a high heat distortion temperature, the processing fluidity of the liquid crystal polyester resin will usually become poor, which is not conducive to the molding of precision components. The traditional liquid crystal polyester resin cannot have both a high heat distortion temperature and a good processing fluidity. SUMMARY

[0004] Therefore, it is necessary to provide an aromatic liquid crystal polyester resin having a high heat distortion temperature and a good processing fluidity, and a preparation method thereof and a composite liquid crystal polymer material having excellent mechanical properties.

[0005] In a first aspect, the present application provides an aromatic liquid crystal polyester resin.

[0006] The aromatic liquid crystal polyester resin comprises the following preparation raw materials in mole fraction:

[0007] 55 parts to 65 parts of p-hydroxybenzoic acid;

[0008] 1 part to 3 parts of 2-hydroxy-6-naphthoic acid;

[0009] 14 parts to 16 parts of diphenylol;

[0010] 17 parts to 21 parts of phthalic acid; and

[0011] 3 parts to 5 parts of acetaminophen.

[0012] In some embodiments, the number average molecular weight of the aromatic liquid crystal polyester resin is 20,000 to 50,000.

[0013] In some embodiments, the phthalic acid comprises terephthalic acid and orthophthalic acid.

[0014] In some embodiments, the content of the terephthalic acid in the preparation raw materials of the aromatic liquid crystal polyester resin is 16 parts to 18 parts in mole fraction; and / or

[0015] The content of the phthalic acid is 1 part to 3 parts.

[0016] In some embodiments, the molar ratio of the p-hydroxybenzoic acid to the 2-hydroxy-6-naphthoic acid in the raw materials for preparing the aromatic liquid crystal polyester resin is 30: (0.8-1.2).

[0017] In the second aspect of the present application, a method for preparing the aromatic liquid crystal polyester resin is provided.

[0018] A method for preparing the aromatic liquid crystal polyester resin, comprising the following steps:

[0019] The p-hydroxybenzoic acid, the 2-hydroxy-6-naphthoic acid, the diphenylolpropane, the phthalic acid, the p-acetamidophenol and the first catalyst are mixed and subjected to a first heat treatment to prepare a first prepolymer, wherein the first catalyst comprises a metal catalyst.

[0020] The first prepolymer is mixed with a second catalyst and subjected to a second heat treatment to prepare a second prepolymer, wherein the second catalyst comprises an acid anhydride catalyst and / or an acid ester catalyst.

[0021] The second prepolymer is subjected to a third heat treatment to prepare the aromatic liquid crystal polyester resin.

[0022] The temperature of the first heat treatment is 120-160°C, the temperature of the second heat treatment is 160-350°C, and the temperature of the third heat treatment is 250-350°C.

[0023] In some embodiments, the processing time of the first heat treatment is 1-3 hours; and / or

[0024] The processing time of the second heat treatment is 2-8 hours; and / or

[0025] The processing time of the third heat treatment is 4-10 hours.

[0026] In the third aspect of the present application, a composite liquid crystal polymer material is provided.

[0027] The composite liquid crystal polymer material comprises the following raw materials in parts by mass:

[0028] The liquid crystal polyester resin is 50-70 parts;

[0029] The glass fiber is 5-15 parts; and

[0030] The filler is 20-40 parts.

[0031] The liquid crystal polyester resin includes the aromatic liquid crystal polyester resin described above or the aromatic liquid crystal polyester resin prepared by the above preparation method.

[0032] In some embodiments, the filler includes one or more of talc, wollastonite, mica, titanium dioxide, calcium carbonate, barium sulfate, and silicon dioxide.

[0033] In a fourth aspect, this application provides the application of the above-described aromatic liquid crystal polyester resin or the aromatic liquid crystal polyester resin prepared by the above-described preparation method or the above-described composite liquid crystal polymer material in the preparation of flexible circuit boards or precision electronic connectors.

[0034] The aromatic liquid crystal polyester resin of this application uses benzene derivatives as polymerization raw materials, which can endow the aromatic liquid crystal polyester resin with good rigidity and heat resistance. Furthermore, by copolymerizing p-hydroxybenzoic acid, phthalic acid, and biphenol as main raw materials in a specific ratio, the molecular chain segments of the aromatic liquid crystal polyester resin can maintain good flexibility, avoiding embrittlement due to excessive rigidity. Moreover, the further introduction of 2-hydroxy-6-naphthoic acid and acetaminophen gives the aromatic liquid crystal polyester resin both a high heat distortion temperature and good processing fluidity. The above-mentioned aromatic liquid crystal polyester resin possesses good mechanical properties and high fluidity, making it suitable for manufacturing precision electronic components such as electronic connectors. Furthermore, the above-mentioned aromatic liquid crystal polyester resin also has a high heat distortion temperature, making it well-suited for surface mount technologies such as reflow soldering. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0036] In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. In this application, "at least one" means one or more, such as one, two, or more than two. "Multiple" or "several" means at least two, such as two, three, etc.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0039] Unless otherwise specified, the percentage content mentioned in this application refers to mass percentage for solid-liquid mixtures and solid-to-solid mixtures, and volume percentage for liquid-to-liquid mixtures.

[0040] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0041] In this application, "above" or "below" includes the number itself. For example, "below 1" includes 1.

[0042] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0043] In the reflow soldering process of assembling electronic components, surface mount components need to be bonded to circuit board pads at high temperatures, thus requiring the substrate material to have a high heat distortion temperature (above 240°C). However, a high heat distortion temperature usually leads to poor processing fluidity of liquid crystal polyester resin, and traditional liquid crystal polyester resins are difficult to combine a high heat distortion temperature with good processing fluidity.

[0044] Based on this, the first aspect of this application provides an aromatic liquid crystal polyester resin that has both a high heat distortion temperature and good processing fluidity, as well as excellent mechanical properties.

[0045] For example, the aromatic liquid crystal polyester resin comprises the following raw materials in molar amounts:

[0046] p-hydroxybenzoic acid 55-65 parts;

[0047] 1 to 3 parts of 2-hydroxy-6-naphthoic acid;

[0048] 14 to 16 parts of biphenyl phenol;

[0049] 17 to 21 parts phthalic acid; and

[0050] 3 to 5 parts acetaminophen.

[0051] The aforementioned aromatic liquid crystal polyester resin uses benzene derivatives as polymerization raw materials, which can endow it with good rigidity and heat resistance. Furthermore, by copolymerizing p-hydroxybenzoic acid, phthalic acid, and biphenol as main raw materials in a specific ratio, the molecular chain segments of the aromatic liquid crystal polyester resin can maintain good flexibility, avoiding embrittlement due to excessive rigidity. Moreover, the further introduction of 2-hydroxy-6-naphthoic acid and acetaminophen gives the aromatic liquid crystal polyester resin both a high heat distortion temperature and good processing fluidity. The aforementioned aromatic liquid crystal polyester resin possesses high mechanical strength, high fluidity, good toughness, and a high heat distortion temperature, making it suitable for manufacturing precision electronic components such as electronic connectors, and well-suited for surface mount technologies such as reflow soldering.

[0052] Optionally, in the raw materials for preparing aromatic liquid crystal polyester resins, the molar amount of p-hydroxybenzoic acid can be, but is not limited to, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, or other values ​​within the range of 55 to 65 parts. p-Hydroxybenzoic acid (HBA) is one of the important monomers of liquid crystal polyesters, and its rigid benzene ring structure helps to improve the heat resistance and rigidity of the polymer. However, the homopolymer of HBA is highly crystalline and has a high melting point, making it difficult to use as a main matrix. To alleviate the inherent disadvantages of HBA in processing due to its high crystallinity and excessively high melting point, this application employs a strategy of copolymerizing various monomers with specific structures to optimize performance.

[0053] Optionally, in the raw materials for preparing aromatic liquid crystal polyester resins, the molar amount of 2-hydroxy-6-naphthoic acid can be, but is not limited to, 1 part, 2 parts, 3 parts, or other values ​​within the range of 1 to 3 parts. The naphthalene ring structure of 2,6-naphthalenedicarboxylic acid (HNA) can produce a significant steric hindrance effect, and its rigid structure also helps to improve the mechanical properties of aromatic liquid crystal polyester resins. Maintaining the above-mentioned amount of HNA helps to lower the melting point of the copolymer and improve its processing fluidity, while also having a good effect on improving thermal stability. However, if excessive HNA is added, it will actually reduce the mechanical properties of the material and affect its overall performance.

[0054] Optionally, in the raw materials for preparing aromatic liquid crystal polyester resin, the molar amount of biphenyl can be, but is not limited to, 14 parts, 15 parts, 16 parts, or other values ​​within the range of 14 to 16 parts.

[0055] Optionally, the molar amount of acetaminophen in the raw materials for preparing aromatic liquid crystal polyester resin can be, but is not limited to, 1 part, 2 parts, 3 parts, or other values ​​within the range of 3 to 5 parts. It has been verified that adding acetaminophen within the above range helps to lower the melting point and improve processing fluidity, and also has a certain promoting effect on the formation of the liquid crystal phase in the system. However, excessive acetaminophen will lead to a decrease in the liquid crystal properties of the material, narrowing the temperature range of the liquid crystal phase and deteriorating the stability of the liquid crystal state.

[0056] Optionally, in the raw materials for preparing aromatic liquid crystal polyester resin, the molar amount of phthalic acid can be, but is not limited to, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, or other values ​​within the range of 17 to 21 parts.

[0057] In some embodiments, phthalic acid includes terephthalic acid and phthalic acid. The combination of terephthalic acid and phthalic acid helps to reduce the symmetry of the molecular chain, thereby lowering the melting point and improving processing fluidity.

[0058] In some embodiments, the content of terephthalic acid in the raw materials for preparing the aromatic liquid crystal polyester resin is 16 to 18 parts by molar fraction. Optionally, the molar fraction of terephthalic acid in the raw materials for preparing the aromatic liquid crystal polyester resin can be, but is not limited to, 16, 17, 18 parts, or other values ​​within the range of 16 to 18 parts. In some embodiments, the content of phthalic acid in the raw materials for preparing the aromatic liquid crystal polyester resin is 1 to 3 parts by molar fraction. Optionally, the molar fraction of phthalic acid in the raw materials for preparing the aromatic liquid crystal polyester resin can be, but is not limited to, 1 part, 2 parts, 3 parts, or other values ​​within the range of 1 to 3 parts. Maintaining the above-mentioned amounts of terephthalic acid and phthalic acid helps to improve the mechanical properties of the aromatic liquid crystal polyester resin.

[0059] In some embodiments, the number average molecular weight of the aromatic liquid crystal polyester resin is 20,000 to 50,000.

[0060] In some embodiments, the molar ratio of p-hydroxybenzoic acid to 2-hydroxy-6-naphthoic acid in the raw materials for preparing the aromatic liquid crystal polyester resin is 30:(0.8~1.2). Optionally, the molar ratio of p-hydroxybenzoic acid to 2-hydroxy-6-naphthoic acid can be, but is not limited to, other values ​​within the range of 30:0.8, 30:0.9, 30:1, 30:1.1, 30:1.2, or 30:(0.8~1.2).

[0061] In a second aspect, this application provides a method for preparing the above-mentioned aromatic liquid crystal polyester resin.

[0062] For example, a method for preparing an aromatic liquid crystal polyester resin includes the following steps:

[0063] A first prepolymer is prepared by mixing p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, biphenol, phthalic acid, and acetaminophen with a first catalyst and subjecting the mixture to a first heat treatment. The first catalyst includes a metal catalyst.

[0064] The first prepolymer is mixed with the second catalyst and subjected to a second heat treatment to prepare the second prepolymer. The second catalyst includes an acid anhydride catalyst or an acid ester catalyst.

[0065] The second prepolymer is subjected to a third heat treatment to prepare an aromatic liquid crystal polyester resin.

[0066] The temperature of the first heat treatment is 120℃~160℃, the temperature of the second heat treatment is 160℃~350℃, and the temperature of the third heat treatment is 250℃~350℃.

[0067] Optionally, a third heat treatment may be carried out in a rotary kiln reactor.

[0068] In some embodiments, nitrogen gas is continuously purged during the first, second, and third heat treatments at a flow rate of 0.5 Nm³. 3 / hr~2Nm 3 / hr.

[0069] In some embodiments, the temperature of the first heat treatment is 120°C to 160°C. Optionally, the temperature of the first heat treatment can be, but is not limited to, 120°C, 130°C, 140°C, 150°C, 160°C, or other values ​​within the range of 120°C to 160°C. The first heat treatment is mainly used for pretreatment of the polycondensation reaction to activate the polycondensation reaction.

[0070] In some embodiments, the temperature of the second heat treatment is 160°C to 350°C. The second heat treatment is mainly used to initiate the esterification reaction. Optionally, the temperature of the second heat treatment can be, but is not limited to, 160°C, 200°C, 250°C, 300°C, 350°C, or other values ​​within the range of 160°C to 350°C.

[0071] In some embodiments, the temperature of the third heat treatment is 250°C to 350°C. Optionally, the temperature of the third heat treatment can be, but is not limited to, 250°C, 270°C, 290°C, 310°C, 330°C, 350°C, or other values ​​within the range of 250°C to 350°C.

[0072] In some embodiments, the first heat treatment lasts for 1.5 to 4 hours.

[0073] In some embodiments, the second heat treatment lasts for 4 to 8 hours.

[0074] In some embodiments, the third heat treatment lasts for 6 to 12 hours.

[0075] In some embodiments, 0.5L to 1.5L of a second catalyst is added for every 1kg of the first prepolymer.

[0076] In some embodiments, p-hydroxybenzoic acid, 2-hydroxy-6-naphtholic acid, biphenol, phthalic acid, and acetaminophen are mixed with a first catalyst and a second catalyst, and then subjected to a first heat treatment and a second heat treatment sequentially to prepare a second prepolymer. In this case, the byproduct acetic acid is removed by condensation before the second heat treatment.

[0077] The structural units of aromatic liquid crystal polyester resins are formed through substitution and condensation reactions between hydroxyl, carboxyl, and amide groups in the raw materials. Specifically, acetaminophen polymerizes to form -HN-Ar-O-, p-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid polymerize to form -O-Ar-CO-, phthalic acid polymerizes to form -OC-Ar-CO, and biphenol polymerizes to form -O-Ar-O-. This application utilizes a method of prior activation treatment followed by heating polymerization, which ensures high resin yield while allowing monomers to fully participate in the condensation reaction, reducing unreacted monomer residues, and ultimately yielding a liquid crystal polyester resin with a high degree of polymerization.

[0078] In some embodiments, the first catalyst comprises a metal catalyst, which can more effectively promote the reaction. Optionally, the metal catalyst comprises one or more of potassium acetate, magnesium acetate, calcium acetate, and zinc acetate.

[0079] In some embodiments, the amount of metal catalyst added is converted into the amount of metal element added, which is 50wtppm to 150wtppm.

[0080] In some embodiments, the second catalyst includes an anhydride catalyst or an acid ester catalyst, which can provide an excellent solvent environment and improve the reaction rate.

[0081] In some embodiments, after the first heat treatment, a step of condensation to remove acetic acid and carbonic acid byproducts is also included.

[0082] In some embodiments, to improve the crystallinity of the reaction and the purity of the product, it is preferable to weigh each component in a dust-free, enclosed space before feeding and mixing, and then discharge it after treatment by a dust collection and filtration device. Furthermore, during the feeding process, the raw materials are fed into a feeder through a dust-free feeding chamber for mixing.

[0083] In some embodiments, an inert gas is used to push a second catalyst into a liquid-phase reactor, and then the mixture is fed into the liquid-phase reactor to react.

[0084] In some embodiments, the reaction time for the first heat treatment is 1 to 3 hours.

[0085] In some embodiments, the reaction time for the second heat treatment is 2 to 8 hours. Optionally, the termination time of the second heat treatment is determined by the torque value of the stirrer, and the reaction is stopped when the torque value is 6.5 N·m to 8 N·m.

[0086] In some embodiments, the third heat treatment lasts for 4 to 10 hours. The third heat treatment primarily involves chain segment growth, and its duration can be set according to the desired molecular weight range. Optionally, a solid-state reactor is used for the third heat treatment.

[0087] In some embodiments, the aromatic liquid crystal polyester resin is crushed to obtain aromatic liquid crystal polyester resin powder with a particle size of 0.5 mm to 1 mm.

[0088] In a third aspect, this application provides a composite liquid crystal polymer material.

[0089] For example, the composite liquid crystal polymer material comprises the following raw materials in parts by weight:

[0090] 50-70 parts of liquid crystal polyester resin;

[0091] 5 to 15 parts glass fiber; and

[0092] 20 to 40 parts of filler;

[0093] The liquid crystal polyester resin includes the aromatic liquid crystal polyester resin described above or the aromatic liquid crystal polyester resin prepared by the above preparation method.

[0094] Optionally, in the raw materials for preparing the composite liquid crystal polymer material, the mass fraction of liquid crystal polyester resin can be, but is not limited to, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, or other values ​​within the range of 50 to 70 parts.

[0095] Optionally, in the raw materials for preparing the composite liquid crystal polymer material, the mass fraction of glass fiber can be, but is not limited to, 5 parts, 7 parts, 9 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, or other values ​​within the range of 5 to 15 parts.

[0096] Optionally, in the raw materials for preparing the composite liquid crystal polymer material, the mass fraction of the filler can be, but is not limited to, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, or other values ​​within the range of 20 to 40 parts.

[0097] In some embodiments, the filler includes one or more of talc, wollastonite, mica, titanium dioxide, calcium carbonate, barium sulfate, and silicon dioxide.

[0098] In some embodiments, a twin-screw extruder is used to prepare the composite liquid crystal polymer material, with the temperature set at 340°C to 380°C. The raw materials are melt-mixed and extruded to granulate.

[0099] In a fourth aspect, this application provides the application of the above-described aromatic liquid crystal polyester resin or the aromatic liquid crystal polyester resin prepared by the above-described preparation method or the above-described composite liquid crystal polymer material in the preparation of flexible circuit boards or precision electronic connectors.

[0100] The present application will be further described in detail below with reference to specific embodiments.

[0101] Unless otherwise specified, the raw materials used in the following specific embodiments and comparative examples are all commercially available products; the instruments used are all commercially available products; and the processes used are all conventionally selected by those skilled in the art unless otherwise specified.

[0102] Example 1

[0103] This embodiment provides an aromatic liquid crystal polyester resin.

[0104] The raw materials for preparing aromatic liquid crystal polyester resin are as follows, based on molar parts:

[0105] 60 parts of p-hydroxybenzoic acid;

[0106] 2 parts of 2-hydroxy-6-naphthoic acid;

[0107] 14 parts of biphenol;

[0108] 16 parts of terephthalic acid;

[0109] 3 parts isophthalic acid; and

[0110] Five portions of acetaminophen.

[0111] The preparation method of aromatic liquid crystal polyester resin is as follows:

[0112] The above-mentioned proportions of p-hydroxybenzoic acid, 2-hydroxy-6-naphtholic acid, biphenol, terephthalic acid, isophthalic acid, and acetaminophen (total 4 kg) were mixed with 2.5 g of potassium acetate and 3.5 L of acetic anhydride and subjected to a first heat treatment. The mixture was refluxed at 150 °C for 2 h under a nitrogen atmosphere, and the byproducts acetic acid and carbonic acid were removed by condensation to obtain the first prepolymer. Then, the reactor temperature was increased to 280 °C at a rate of 1 °C / min and maintained at 280 °C for 2 h to obtain the second prepolymer, which was then pulverized using a pulverizer.

[0113] 3 kg of the second prepolymer was added to a 10 L rotary kiln reactor, and 1 Nm³ of gas was continuously introduced. 3 Nitrogen gas was applied at 300°C for 8 hours, and the reaction was continued at 300°C to obtain an aromatic liquid crystal polyester resin.

[0114] Example 2

[0115] This embodiment provides an aromatic liquid crystal polyester resin.

[0116] The preparation method of the aromatic liquid crystal polyester resin in this embodiment is the same as that in Example 1.

[0117] The raw materials for preparing aromatic liquid crystal polyester resin are as follows, based on molar parts:

[0118] 60 parts of p-hydroxybenzoic acid;

[0119] 2 parts of 2-hydroxy-6-naphthoic acid;

[0120] 14 parts of biphenyl phenol;

[0121] 18 parts of terephthalic acid;

[0122] 1 part isophthalic acid; and

[0123] Five portions of acetaminophen.

[0124] Example 3

[0125] This embodiment provides an aromatic liquid crystal polyester resin.

[0126] The preparation method of the aromatic liquid crystal polyester resin in this embodiment is the same as that in Example 1.

[0127] The raw materials for preparing aromatic liquid crystal polyester resin are as follows, based on molar parts:

[0128] 60 parts of p-hydroxybenzoic acid;

[0129] 2 parts of 2-hydroxy-6-naphthoic acid;

[0130] 16 parts of biphenol;

[0131] 16 parts of terephthalic acid;

[0132] 3 parts isophthalic acid; and

[0133] Three portions of acetaminophen.

[0134] Comparative Example 1

[0135] This comparative example provides an aromatic liquid crystal polyester resin.

[0136] The preparation method of the aromatic liquid crystal polyester resin in this comparative example is basically the same as that in Example 1.

[0137] The raw materials for preparing aromatic liquid crystal polyester resin are as follows, based on molar parts:

[0138] 60 parts of p-hydroxybenzoic acid;

[0139] 16 parts of biphenol;

[0140] 16 parts of terephthalic acid; and

[0141] 3 parts isophthalic acid.

[0142] Comparative Example 2

[0143] This comparative example provides an aromatic liquid crystal polyester resin.

[0144] The preparation method of the aromatic liquid crystal polyester resin in this comparative example is basically the same as that in Example 1.

[0145] The raw materials for preparing aromatic liquid crystal polyester resin are as follows, based on molar parts:

[0146] 60 parts of p-hydroxybenzoic acid;

[0147] 2 parts of 2-hydroxy-6-naphthoic acid;

[0148] 19 parts of biphenol;

[0149] 16 parts of terephthalic acid; and

[0150] 3 parts isophthalic acid.

[0151] Comparative Example 3

[0152] This comparative example provides an aromatic liquid crystal polyester resin.

[0153] The preparation method of the aromatic liquid crystal polyester resin in this comparative example is basically the same as that in Example 1.

[0154] The raw materials for preparing aromatic liquid crystal polyester resin are as follows, based on molar parts:

[0155] 60 parts of p-hydroxybenzoic acid;

[0156] 2 parts of 2-hydroxy-6-naphthoic acid;

[0157] 9 parts of biphenyl phenol;

[0158] 16 parts of terephthalic acid;

[0159] 3 parts isophthalic acid; and

[0160] 10 parts of acetaminophen.

[0161] Test case

[0162] Composite liquid crystal polymer materials were prepared using the aromatic liquid crystal polyester resins from the examples and comparative examples, respectively. The thermal stability and mechanical properties of the composite liquid crystal polymer materials were tested, and the test results are shown in Table 1.

[0163] The preparation method and raw materials for the composite liquid crystal polymer material are as follows:

[0164] By mass, the raw materials for preparing the composite liquid crystal polymer material consist of 60 parts of aromatic liquid crystal polyester resin, 10 parts of glass fiber and 30 parts of talc. The glass fiber is Taishan Glass Fiber T443 with a length of 3mm to 6mm.

[0165] The preparation method of the composite liquid crystal polymer material is as follows: the raw materials are melted and mixed using a twin-screw extruder, and the composite liquid crystal polymer material is obtained after extrusion.

[0166] Table 1 Performance test results of composite liquid crystal polymer materials

[0167]

[0168] As shown in Table 1, this application introduces modified monomers such as HNA, BP, IPA, TPA and APAP to copolymerize with HBA, which enables the liquid crystal polymer material to maintain excellent processing fluidity while having a high heat distortion temperature, and also has good mechanical properties, making it particularly suitable for precision parts formed by SMT process.

[0169] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0170] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. An aromatic liquid crystal polyester resin, characterized in that, The preparation materials include the following in molar parts: p-hydroxybenzoic acid 55-65 parts; 1 to 3 parts of 2-hydroxy-6-naphthoic acid; 14 to 16 parts of biphenyl phenol; 17 to 21 parts phthalic acid; as well as 3 to 5 parts acetaminophen.

2. The aromatic liquid crystal polyester resin according to claim 1, characterized in that, The number-average molecular weight of the aromatic liquid crystal polyester resin is 20,000 to 50,000.

3. The aromatic liquid crystal polyester resin according to claim 1, characterized in that, The phthalic acid includes terephthalic acid and phthalic acid.

4. The aromatic liquid crystal polyester resin according to claim 3, characterized in that, The content of terephthalic acid in the raw materials for preparing the aromatic liquid crystal polyester resin is 16 to 18 parts by molar fraction; and / or The content of phthalic acid is 1 to 3 parts.

5. The aromatic liquid crystal polyester resin according to any one of claims 1 to 4, characterized in that, In the raw materials for preparing the aromatic liquid crystal polyester resin, the molar ratio of p-hydroxybenzoic acid to 2-hydroxy-6-naphthoic acid is 30:(0.8~1.2).

6. A method for preparing the aromatic liquid crystal polyester resin according to any one of claims 1 to 5, characterized in that, Includes the following steps: A first prepolymer is prepared by mixing p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, biphenol, phthalic acid, and acetaminophen with a first catalyst and subjecting the mixture to a first heat treatment, wherein the first catalyst comprises a metal catalyst. The first prepolymer is mixed with the second catalyst and subjected to a second heat treatment to prepare the second prepolymer, wherein the second catalyst includes an anhydride catalyst and / or an acid ester catalyst. The second prepolymer is subjected to a third heat treatment to prepare the aromatic liquid crystal polyester resin; The temperature of the first heat treatment is 120℃~160℃, the temperature of the second heat treatment is 160℃~350℃, and the temperature of the third heat treatment is 250℃~350℃.

7. The method for preparing the aromatic liquid crystal polyester resin according to claim 6, characterized in that, The processing time for the first heat treatment is 1 hour to 3 hours; and / or The second heat treatment lasts for 2 hours to 8 hours; and / or The processing time for the third heat treatment is 4 to 10 hours.

8. A composite liquid crystal polymer material, characterized in that, The preparation materials include the following ingredients in parts by weight: 50-70 parts of liquid crystal polyester resin; 5 to 15 parts glass fiber; and 20 to 40 parts of filler; The liquid crystal polyester resin includes the aromatic liquid crystal polyester resin according to any one of claims 1 to 5 or the aromatic liquid crystal polyester resin prepared by the preparation method according to any one of claims 6 to 7.

9. The composite liquid crystal polymer material according to claim 8, characterized in that, The filler includes one or more of talc, wollastonite, mica, titanium dioxide, calcium carbonate, barium sulfate, and silicon dioxide.

10. The application of an aromatic liquid crystal polyester resin according to any one of claims 1 to 5, or an aromatic liquid crystal polyester resin prepared by the preparation method according to any one of claims 6 to 7, or a composite liquid crystal polymer material according to any one of claims 8 to 9, in the preparation of flexible circuit boards or precision electronic connectors.

Images