Liquid crystal polyester resin, molded products, and electrical and electronic components

Abstract

[Problem] To provide a liquid crystal polyester resin having desired polymer properties. [Solution] The liquid crystal polyester resin according to the present invention is a liquid crystal polyester resin comprising constituent units derived from three or more types of hydroxycarboxylic acids, and the liquid crystal polyester resin is characterized by the following conditions: the ratio of ester bonds formed between the hydroxycarboxylic acid of the first most abundant constituent unit among the three or more types of hydroxycarboxylic acid-derived constituent units and the same type of hydroxycarboxylic acid is 12% or more and 60% or less with respect to the total ester bonds present in the liquid crystal polyester resin.

Description

Technology Field

[0001] The present invention relates to a liquid crystal polyester resin, a molded article comprising said liquid crystal polyester resin, and an electrical and electronic component having said molded article. Background Technology

[0002] Liquid crystal polymers (LCPs), such as liquid crystal polyesters and polyamides, possess high heat resistance derived from a rigid framework in which aromatic monomers are linked by strong ester or amide bonds. Liquid crystal polymers also exhibit excellent low viscosity and melt moldability as they express a liquid crystal phase in which molecules are oriented upon melting. In the synthesis of liquid crystal polyesters, p-hydroxybenzoic acid (HBA), the most basic repeating unit, can be homopolymerized; however, melt processing is impossible because the melting point of HBA homopolymers is considered to exceed the decomposition temperature of liquid crystal polymers. Therefore, melt processing was made possible by copolymerizing HBA with monomers other than HBA to form random copolymers, thereby reducing excessive crystallinity and lowering the melting point of the liquid crystal polymers. High-heat-resistant and positive-molding polymers have been developed by finding a balance that maintains even higher heat resistance. In particular, as an LCP with excellent heat resistance, an LCP obtained by copolymerizing a diol or a dicarboxylic acid with a hydroxycarboxylic acid is known.

[0003] There are many known methods for controlling the physical properties of LCP by changing the types of monomers constituting the LCP or their compositional ratios. In recent years, in response to the miniaturization of electronic components, designs for LCPs with an increased number of constituent monomer types have been reported to provide high fluidity and fillability during melt molding. Patent Document 1 achieves high fluidity and low warping by increasing the number of monomer types to five by increasing the number of hydroxycarboxylic acids to two. Similarly, Patent Document 2 reports an LCP with excellent fluidity and mechanical strength by using five types of monomers, including two types of hydroxycarboxylic acids. However, while both Patent Documents 1 and 2 improve moldability and other properties, there was a problem in that as the number of monomers used increased and the compositional ratio of their constituent units became closer to uniform, the melting point, which is the most basic heat resistance indicator of the obtained LCP, tended to decrease.

[0004] Increasing the types of monomers constituting the LCP—that is, equalizing the compositional ratio of the constituent monomers within the LCP among the monomers—increases the randomness of the LCP, which is a random copolymer; therefore, the problem of lowering the melting point mentioned above is essentially an unavoidable problem when increasing the types of monomers. This can also be seen from Non-Patent Literature 1, which indicates that when the compositional ratio of an LCP containing two types of hydroxycarboxylic acids, HBA and 2-hydroxy-6-naphthoic acid (HNA), is changed, the melting point decreases along with the equalization of the compositional ratios of each other. Prior art literature

[0005] Japanese Patent Publication No. 2017-137438, Japanese Patent Publication No. 2012-126842, International Publication No. 2011 / 18837

[0006] Journal of Applied Polymer Science, Vol.62, 1049-1056 (1996) The problem to be solved

[0007] Meanwhile, the physical properties of LCP can be controlled from perspectives other than the type of constituent unit and its composition ratio. For example, there are methods to control the sequence and chain length of specific monomers within the LCP. As an example, in LCPs that are copolymers of multiple types of monomers and become random polymers, the same specific monomer undergoes localized continuous polymerization, forming a single continuous sequence. This causes problems that affect the physical properties and quality of the polymer. In particular, the occurrence of a specific monomer's continuous sequence becomes a problem in LCPs using aromatic hydroxycarboxylic acid-based monomers that can be polymerized alone. When a specific aromatic hydroxycarboxylic acid undergoes homopolymerization exceeding a certain chain length, it creates a localized high-melting-point region with a significantly higher melting point compared to the surrounding area. Due to the presence of this high-melting-point region, a portion does not melt under the heating temperature set for the surrounding area during molding, leading to processing troubles such as blocking the flow path or the molding machine nozzle, especially in micro-molding. In addition, there is a concern that not only local occurrences but also the average chain length of specific monomers in the system may affect various physical properties of LCP. Patent Document 3 discloses that in copolymer LCP in which HNA is the main aromatic hydroxycarboxylic acid and an aromatic diol and an aromatic dicarboxylic acid are introduced, the average chain length of HNA is set to a certain short and desirable range, thereby allowing for desirable control of the fluidity and mechanical properties of the obtained polymer during processing. Here, even with LCPs of the same constituent unit and the same composition, the physical properties of LCP, including fluidity, are improved by controlling the average chain length of HNA. However, in the design of Patent Document 3, melting point control by controlling the average chain length at the same composition was not realized.

[0008] Patent Document 3 discloses that a method for controlling the continuous chain length of an actual HNA (more preferred condition) involves heating the melt polymerization endpoint temperature to a high temperature ranging from the melting point of the obtained LCP + 25°C to the melting point + 35°C. This is considered a method for controlling the continuous chain length of the aromatic hydroxycarboxylic acid in the system by raising the reaction endpoint temperature to a high temperature, thereby inducing ester exchange that attracts less reactive aromatic diols or aromatic dicarboxylic acids at the end of the reaction, because the reaction rate of the aromatic hydroxycarboxylic acid monomer during melt polymerization is faster than that of the aromatic diol or aromatic dicarboxylic acid. However, the method for controlling the average chain length when multiple types of hydroxycarboxylic acids with similar reactivity are used, and the control of various physical properties based on the average chain length, have not been elucidated.

[0009] The inventors increased the number of hydroxycarboxylic acid types from two to aim for further moldability and fillability during melting. By doing so, they investigated how to reduce the probability of specific hydroxycarboxylic acids bonding together. In conventional investigations, the evaluation of the chain lengths of hydroxycarboxylic acids synthesized using multiple hydroxycarboxylic acid species, changes in the sequence state of the main chain related to the polymerization conditions disclosed in Patent Document 1, and the control of polymer properties associated therewith have not been elucidated. Furthermore, in liquid crystal polyester resins using three or more types of hydroxycarboxylic acids, the optimization of polymer properties by controlling the sequence state of the main chain has not been achieved, and there has been a challenge in optimizing them from the perspective of material performance.

[0010] Therefore, the inventors evaluated the sequence state of the main chain (repetition pattern of constituent unit monomers) in liquid crystal polyester resins using three or more types of hydroxycarboxylic acids and compared it with the physical properties of the polymer. As a result, the inventors discovered a liquid crystal polyester resin with improved thermal properties of LCP with the same monomer composition ratio by controlling the ratio of ester bonds formed between the hydroxycarboxylic acid of the first most abundant constituent unit among the constituent units derived from three or more types of hydroxycarboxylic acids in the liquid crystal polyester resin. The present invention was completed based on the above findings.

[0011] Accordingly, the object of the present invention is to provide a liquid crystal polyester resin having desired polymer properties. Furthermore, another object of the present invention is to provide a molded article comprising this liquid crystal polyester resin and an electrical and electronic component having said molded article. means of solving the problem

[0012] That is, according to the present invention, the following invention is provided.

[0013] [1] A liquid crystal polyester resin containing constituent units derived from three or more types of hydroxycarboxylic acids, and

[0014] The above liquid crystal polyester resin is subject to the following conditions:

[0015] The ratio of ester bonds formed between the hydroxycarboxylic acid of the first most abundant constituent unit among the three or more types of hydroxycarboxylic acids and the same type of hydroxycarboxylic acid is 12% or more and 60% or less with respect to the total ester bonds present in the liquid crystal polyester resin.

[0016] A liquid crystal polyester resin characterized by satisfying [specific criteria].

[0017] [2] A liquid crystal polyester described in [1], wherein the composition ratio of constituent units derived from the three or more types of hydroxycarboxylic acids is 50 mol% or more relative to the total constituent units of the liquid crystal polyester resin.

[0018] [3] A liquid crystal polyester resin described in [1] or [2], wherein the composition ratio of the first most abundant constituent unit among the three or more hydroxycarboxylic acid-derived constituent units is 40 mol% or more and 98 mol% or less relative to the total of the three or more hydroxycarboxylic acid-derived constituent units.

[0019] [4] A liquid crystal polyester resin described in any one of [1] to [3], wherein the composition ratio of the second most abundant constituent unit among the three or more hydroxycarboxylic acid-derived constituent units is 1 mol% or more and 40 mol% or less relative to the total of the three or more hydroxycarboxylic acid-derived constituent units.

[0020] [5] A liquid crystal polyester resin described in any one of [1] to [4], wherein the composition ratio of the third most abundant constituent unit among the three or more hydroxycarboxylic acid-derived constituent units is 0.1 mol% or more and 20 mol% or less relative to the total of the three or more hydroxycarboxylic acid-derived constituent units.

[0021] [6] A liquid crystal polyester resin described in [3], wherein the first most abundant constituent unit among the three or more hydroxycarboxylic acid-derived constituent units is a constituent unit derived from p-hydroxybenzoic acid or a constituent unit derived from 6-hydroxy-2-naphthoic acid.

[0022] [7] A liquid crystal polyester resin described in [4], in which the second most abundant constituent unit among the three or more hydroxycarboxylic acid-derived constituent units is a constituent unit derived from p-hydroxybenzoic acid or a constituent unit derived from 6-hydroxy-2-naphthoic acid.

[0023] [8] A liquid crystal polyester resin having a melting point of 270°C or higher and 370°C or lower, as described in any one of [1] to [7].

[0024] [9] A liquid crystal polyester resin described in any one of [1] to [8], having a melt viscosity of 1 Pa·s or more measured at a temperature of the melting point of the liquid crystal polyester resin to the melting point + 30°C or higher and a shear rate of 1000 / s.

[0025]

[10] A liquid crystal polyester resin described in any one of [1] to [9], wherein the load deflection temperature of the liquid crystal polyester resin is 180°C or higher.

[0026]

[11] A fibrous molded article comprising a liquid crystal polyester resin as described in any of [1] to

[10] .

[0027]

[12] A sheet-shaped molded article comprising a liquid crystal polyester resin as described in any of [1] to

[10] .

[0028]

[13] An injection molded article comprising a liquid crystal polyester resin as described in any of [1] to

[10] .

[0029]

[14] An electrical and electronic component having the molded product described in

[11] .

[0030]

[15] An electrical and electronic component having the molded product described in

[12] .

[0031]

[16] An electrical and electronic component having the molded product described in

[13] . Effects of the invention

[0032] According to the present invention, a liquid crystal polyester resin having desired polymer properties can be provided. In addition, according to the present invention, a molded article comprising the liquid crystal polyester resin and an electrical and electronic component having said molded article can be provided.

[0033] In particular, in the present invention, by controlling the sequence state of the main chain within a specific range in a liquid crystal polyester resin using three or more types of hydroxycarboxylic acids, the thermal properties of the liquid crystal polyester resin having the same type of constituent unit and an equivalent degree of polymerization can be further improved. Brief explanation of the drawing

[0034] Figure 1 is of Reference Example 1. 13 This is the CNMR spectrum. Figure 2 is of Reference Example 2. 13 This is the CNMR spectrum. FIG. 3 is of Example 1-1. 13 This is the CNMR spectrum. FIG. 4 is of Example 1-2. 13 This is the CNMR spectrum. FIG. 5 is of Examples 1-3. 13 This is the CNMR spectrum. Fig. 6 is of Comparative Example 1-1. 13 This is the CNMR spectrum. Specific details for implementing the invention

[0035] (Liquid crystal polyester resin)

[0036] The liquid crystal polyester resin according to the present invention comprises a constituent unit (I) derived from three or more types of hydroxycarboxylic acids, and may further comprise a constituent unit (II) derived from a dicarboxylic acid and a constituent unit (III) derived from a diol. In addition, the liquid crystal polyester resin according to the present invention may be a single unit or a mixture (polymer blend).

[0037] In the liquid crystal polyester resin according to the present invention, the compositional ratio of constituent units (I) derived from three or more types of hydroxycarboxylic acids is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 90 mol% or more, and most preferably 95 mol% or more with respect to the total constituent units of the liquid crystal polyester resin. By appropriately setting the proportion of hydroxycarboxylic acids among the constituent units in the liquid crystal polyester resin to exceed the majority, the contribution to the liquid crystal polyester resin in which the effects exhibited by the present invention are obtained can be increased, thereby increasing the effect of controlling physical properties.

[0038] The liquid crystal polyester resin according to the present invention is subject to the following conditions:

[0039] The ratio of ester bonds formed between the hydroxycarboxylic acid of the first most abundant constituent unit among three or more types of hydroxycarboxylic acids and the same type of hydroxycarboxylic acid is 12% or more and 60% or less with respect to the total ester bonds present in the liquid crystal polyester resin.

[0040] It is characterized by satisfying [the condition].

[0041] The lower limit of the above ratio is preferably 20% or more, more preferably 30% or more, even more preferably 35% or more, and even more preferably 40% or more, and the upper limit is preferably 57% or less, more preferably 55% or less, even more preferably 53% or less, and even more preferably 50% or less.

[0042] In the present invention, "ratio of ester bonds formed between a hydroxycarboxylic acid and a homologous hydroxycarboxylic acid" refers to the ratio of ester bonds (self-linking) formed between a homologous hydroxycarboxylic acid and a constituent unit derived from three or more hydroxycarboxylic acids present in a liquid crystal polyester resin, relative to the total ester bonds present in the liquid crystal polyester resin.

[0043] If the above ratio is within the above numerical range, the thermal properties of a liquid crystal polyester resin having homogeneous constituent units and an equivalent degree of polymerization can be further improved. In addition, in order to control the sequence state of the above main chain, it is preferable that the liquid crystal polyester resin be obtained through solid-state polymerization.

[0044] In addition, the above "ratio of ester bonds formed between a hydroxycarboxylic acid and a homologous hydroxycarboxylic acid" can be calculated by measuring the total amount of ester bonds present in the liquid crystal polyester resin and the amount of ester bonds formed between homologous hydroxycarboxylic acids by NMR. For example, 13In the NMR spectrum obtained by C-NMR, the chemical shift value (ppm) of the carbonyl carbon of the ester bond in the liquid crystal polyester resin is identified. Typically, the carbonyl carbon (COO) of the ester bond tends to be detected at 165-175 ppm. By confirming the peak between the corresponding chemical shift values, the type of ester bond corresponding to that peak is identified. Accordingly, in the present invention, the “ratio of ester bonds formed between the hydroxycarboxylic acid of the first most abundant constituent unit among three or more types of hydroxycarboxylic acids” can be obtained by dividing the integral ratio of the peak of the carbonyl carbon of the ester bond between the hydroxycarboxylic acid of the first most abundant constituent unit and the hydroxycarboxylic acid of the same type by the sum of the integral ratios of all ester bond peaks present in the liquid crystal polyester resin, which are mainly detected at 165-175 ppm. In addition, specific identification methods will be explained in detail in the examples.

[0045] also, 13 There are no particular restrictions on the solvent used for C-NMR measurement as long as it dissolves the liquid crystal polyester resin, but for example, pentafluorophenol, a mixed solvent of pentafluorophenol and chloroform, etc., may be used.

[0046] In addition, regarding the concentration when dissolving the liquid crystal polyester resin in a solvent, there are no particular limitations on the concentration at which the liquid crystal polyester resin dissolves, but for example, it is preferable to be within the range of 1 to 10 mass%.

[0047] 13 Regarding the number of C-NMR measurements, there is no particular limit as long as a sufficient S / N ratio of the desired carbonyl carbon is obtained, but for example, it is desirable to have about 10,000 to 40,000 measurements.

[0048] 13Regarding the measurement temperature for C-NMR measurement, it is preferable to perform it at, for example, 20 to 120°C.

[0049] The lower limit of the melt viscosity measured at the melting point to the melting point + 30°C of the liquid crystal polyester resin according to the present invention under the condition of a shear rate of 1000 / s is 1 Pa·s or more, preferably 5 Pa·s or more, more preferably 10 Pa·s or more, even more preferably 20 Pa·s or more, and even more preferably 30 Pa·s or more. In addition, the upper limit of the melt viscosity is preferably 300 Pa·s or less, more preferably 200 Pa·s or less, even more preferably 100 Pa·s or less, and even more preferably 80 Pa·s or less. By making the melt viscosity of the liquid crystal polyester resin according to the present invention within the above numerical range, a liquid crystal polyester resin with excellent processability when melted under high temperature conditions is obtained.

[0050] In addition, in this specification, the viscosity of the liquid crystal polyester resin can be measured using a capillary rheometer viscometer in accordance with JIS K7199.

[0051] Considering heat resistance, the lower limit of the melting point of the liquid crystal polyester resin according to the present invention is preferably 270°C or higher, more preferably 280°C or higher, even more preferably 290°C or higher, even more preferably 300°C or higher, and most preferably 305°C or higher. Additionally, the upper limit is not particularly limited, but is preferably 370°C or lower, more preferably 360°C or lower, even more preferably 340°C or lower, and even more preferably 330°C or lower.

[0052] The lower limit of the crystallization point of the liquid crystal polyester resin according to the present invention is preferably 230°C or higher, more preferably 235°C or higher, even more preferably 240°C or higher, and even more preferably 245°C or higher, and the upper limit is preferably 290°C or lower, more preferably 280°C or lower, even more preferably 275°C or lower, and even more preferably 270°C or lower.

[0053] By setting the melting point and crystallization point of the liquid crystal polyester resin according to the present invention to within the above numerical range, it is easy to control the melt viscosity of 1000 / s at the melting point + (10 to 30)°C to within the above desired numerical range, and also improve the heat resistance of the molded article made using the liquid crystal polyester resin in heat processing or in a high temperature and high load environment.

[0054] In addition, in this specification, the melting point of the liquid crystal polyester resin is a value measured by differential scanning calorimetry (DSC). Specifically, the crystallization point (Tc) is defined as the peak of the exothermic peak obtained when the liquid crystal polyester resin is completely melted by heating from room temperature to 360°C at a heating rate of 10°C / min and then lowered to 30°C at a rate of 10°C / min, and the melting point (Tm) is defined as the peak of the endothermic peak obtained when heating to 360°C at a rate of 10°C / min.

[0055] The lower limit of the load deflection temperature (DTUL) of the liquid crystal polyester resin according to the present invention is preferably 180°C or higher, considering practical heat resistance.

[0056] By making the load deflection temperature (DTUL) of the liquid crystal polyester resin according to the present invention within the above numerical range, the practical heat resistance for heat processing of a molded article made using the liquid crystal polyester resin can be improved.

[0057] In addition, in this specification, the load deflection temperature (DTUL) of the liquid crystal polyester resin is a value measured with a load of 1.8 MPa in accordance with ASTM D648 using a bending test specimen (80 mm × 12 mm × 2 mm) made by injection molding.

[0058] The liquid crystal properties of the liquid crystal polyester resin according to the present invention can be confirmed by using a polarizing microscope (product name: DS-Ri2) manufactured by Nikon Inc. equipped with a microscope hot stage (product name: 10083L) manufactured by Japan Hitech Co., Ltd., and then heating and melting the liquid crystal polyester resin on the microscope heating stage and observing the presence or absence of optical anisotropy.

[0059] Hereinafter, each constituent unit included in the liquid crystal polyester resin according to the present invention will be described in detail.

[0060] (Constituent unit derived from hydroxycarboxylic acid (I))

[0061] The constituent unit (I) derived from hydroxycarboxylic acid includes constituent units derived from three or more types of hydroxycarboxylic acid. The compositional ratio of the first most abundant constituent unit among the three or more types of hydroxycarboxylic acid-derived constituent units is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, and even more preferably 65 mol% or more with respect to the total of the three or more types of hydroxycarboxylic acid-derived constituent units, and the upper limit is 98 mol% or less, more preferably 95 mol% or less, even more preferably 90 mol% or less, and even more preferably 85 mol% or less. By keeping the compositional ratio of the first most abundant constituent unit within this range, the heat resistance of the resulting liquid crystal polyester can be designed to be preferably high.

[0062] In addition, the composition ratio of the second most abundant constituent unit among the constituent units derived from three or more types of hydroxycarboxylic acids is, with respect to the total of constituent units derived from three or more types of hydroxycarboxylic acids, a lower limit value is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 8 mol% or more, and even more preferably 13 mol% or more, and an upper limit value is preferably 40 mol% or less, more preferably 34 mol% or less, even more preferably 32 mol% or less, and even more preferably 28 mol% or less.

[0063] In addition, among the constituent units derived from three or more types of hydroxycarboxylic acids, the composition ratio of the third most abundant constituent unit is, with respect to the total of the constituent units derived from three or more types of hydroxycarboxylic acids, preferably 0.1 mol% or more, more preferably 0.5 mol% or more, even more preferably 1.0 mol% or more, and even more preferably 1.5 mol% or more, and also preferably 10 mol% or less, more preferably 7.0 mol% or less, even more preferably 5.0 mol% or less, and even more preferably 3.0 mol% or less.

[0064] Among the constituent units derived from three or more types of hydroxycarboxylic acids, the first most abundant constituent unit is preferably a constituent unit derived from an aromatic hydroxycarboxylic acid, the second most abundant constituent unit is preferably a constituent unit derived from an aromatic hydroxycarboxylic acid, and the third most abundant constituent unit is preferably a constituent unit derived from an aromatic hydroxycarboxylic acid. In particular, it is preferable that all of the constituent units derived from three or more types of hydroxycarboxylic acids are constituent units derived from aromatic hydroxycarboxylic acids. Furthermore, the constituent unit (I) derived from a hydroxycarboxylic acid preferably includes at least a constituent unit (A) derived from p-hydroxybenzoic acid and a constituent unit (B) derived from 6-hydroxy-2-naphthoic acid, and it is more preferable to further include a constituent unit (C) derived from a hydroxycarboxylic acid other than constituent units (A) and (B). Among the constituent units derived from three or more types of hydroxycarboxylic acids, the first most abundant constituent unit is preferably a constituent unit (A) derived from p-hydroxybenzoic acid or a constituent unit (B) derived from 6-hydroxy-2-naphthoic acid. Among the constituent units derived from three or more types of hydroxycarboxylic acids, the second most abundant constituent unit is preferably a constituent unit (A) derived from p-hydroxybenzoic acid or a constituent unit (B) derived from 6-hydroxy-2-naphthoic acid. Among the constituent units derived from three or more types of hydroxycarboxylic acids, the third most abundant constituent unit is preferably a constituent unit (C) derived from a hydroxycarboxylic acid other than constituent units (A) and (B).

[0065] (Constituent unit derived from hydroxycarboxylic acid (A))

[0066] The constituent unit (A) derived from a hydroxycarboxylic acid is a constituent unit derived from p-hydroxybenzoic acid (HBA). Monomers that provide the constituent unit (A) include p-hydroxybenzoic acid, its acetylated derivatives, ester derivatives, acid halides, etc.

[0067] (Constituent unit derived from hydroxycarboxylic acid (B))

[0068] The constituent unit (B) derived from hydroxycarboxylic acid is a constituent unit derived from 6-hydroxy-2-naphthoic acid (HNA). Monomers that provide the constituent unit (B) include 6-hydroxy-2-naphthoic acid, and its acetylated derivatives, ester derivatives, acid halides, etc.

[0069] (Constituent unit derived from hydroxycarboxylic acid (C))

[0070] The constituent unit (C) derived from a hydroxycarboxylic acid is a constituent unit derived from a hydroxycarboxylic acid other than constituent units (A) and (B). It is preferable that the constituent unit (C) is a constituent unit derived from at least one selected from the group comprising m-hydroxybenzoic acid (mHBA), 6-hydroxynicotinic acid (HNIA), and 4'-hydroxy-4-biphenylcarboxylic acid (HPBA). Among these, a constituent unit derived from m-hydroxybenzoic acid is more preferable. Examples of monomers imparting the constituent unit (C) include these monomers, and their acetylated products, ester derivatives, acid halides, etc.

[0071] The composition ratio (mol%) of constituent units (A) to (C) in the liquid crystal polyester resin is, with respect to the total of constituent unit (I) derived from hydroxycarboxylic acid, under the following conditions:

[0072] 1 mol% ≤ constituent unit (A) ≤ 40 mol%

[0073] 40 mol% ≤ constituent unit (B) ≤ 98 mol%

[0074] 0.1 mol% ≤ constituent unit (C) ≤ 10 mol%

[0075] It is desirable to satisfy, and the following conditions:

[0076] 3 mol% ≤ constituent unit (A) ≤ 34 mol%

[0077] 50 mol% ≤ constituent unit (B) ≤ 95 mol%

[0078] 0.5 mol% ≤ constituent unit (C) ≤ 7.0 mol%

[0079] It is more desirable to satisfy, and the following conditions:

[0080] 8 mol% ≤ constituent unit (A) ≤ 32 mol%

[0081] 60 mol% ≤ constituent unit (B) ≤ 90 mol%

[0082] 1.0 mol% ≤ constituent unit (C) ≤ 5.0 mol%

[0083] It is more desirable to satisfy , and the following conditions:

[0084] 13 mol% ≤ constituent unit (A) ≤ 28 mol%

[0085] 65 mol% ≤ constituent unit (B) ≤ 85 mol%

[0086] 1.5 mol% ≤ constituent unit (C) ≤ 3.0 mol%

[0087] It is more desirable to satisfy .

[0088] (Constituent unit derived from dicarboxylic acid (II))

[0089] The constituent unit (II) derived from a dicarboxylic acid is preferably a constituent unit derived from a dicarboxylic acid represented by the following formula (1), and is more preferably a constituent unit derived from an aromatic dicarboxylic acid. In addition, the constituent unit (II) may include only one type or two or more types.

[0090]

[0091] Among the above formulas, Ar 3The carbon atom is a divalent hydrocarbon group that may have a substituent, if desired, and is preferably a divalent hydrocarbon group having an aromatic ring. Examples of hydrocarbon groups having an aromatic ring include phenyl groups, biphenyl groups, 4,4'-isopropyridendiphenyl groups, naphthyl groups, anthryl groups, and phenanthryl groups. Examples of substituents include hydrogen, alkyl groups, alkoxy groups, and fluorine. The number of carbon atoms in the alkyl group is preferably 1 to 10, and more preferably 1 to 5. Additionally, it may be a straight-chain alkyl group or a branched-chain alkyl group. The number of carbon atoms in the alkoxy group is preferably 1 to 10, and more preferably 1 to 5.

[0092] Examples of monomers that provide the constituent unit (II) include terephthalic acid (TPA), isophthalic acid (IPA), 2,6-naphthalenedicarboxylic acid (NADA), and their acyls, ester derivatives, acid halides, etc. The constituent unit (II) is preferably a constituent unit derived from terephthalic acid.

[0093] The composition ratio (mol%) of constituent unit (II) in the liquid crystal polyester resin is, with respect to constituent unit (I), preferably greater than 0 mol%, more preferably greater than 0.1 mol%, even more preferably greater than 0.3 mol%, and even more preferably greater than 0.5 mol%, and also preferably greater than 2.0 mol%, more preferably less than 1.5 mol%, even more preferably less than 1.2 mol%, and even more preferably less than 1.0 mol%.

[0094] (Constituent unit derived from Dior (III))

[0095] The constituent unit (III) derived from the diol is preferably a constituent unit derived from the diol represented by the following formula (2), and is more preferably a constituent unit derived from an aromatic diol. In addition, the constituent unit (III) may include only one type or two or more types.

[0096]

[0097] Among the above formulas, Ar 1 The carbon atom is a divalent hydrocarbon group that may have a substituent, if desired, and is preferably a divalent hydrocarbon group having an aromatic ring. Examples of hydrocarbon groups having an aromatic ring include phenyl groups, biphenyl groups, 4,4'-isopropyridendiphenyl groups, naphthyl groups, anthryl groups, and phenanthryl groups. Examples of substituents include hydrogen, alkyl groups, alkoxy groups, and fluorine. The number of carbon atoms in the alkyl group is preferably 1 to 10, and more preferably 1 to 5. Additionally, it may be a straight-chain alkyl group or a branched-chain alkyl group. The number of carbon atoms in the alkoxy group is preferably 1 to 10, and more preferably 1 to 5.

[0098] Examples of monomers that provide the constituent unit (III) include 4,4'-dihydroxybiphenyl (BP), hydroquinone (HQ), methylhydroquinone (MeHQ), 4,4'-isopropyridendiphenol (BisPA), and their acyls, ester derivatives, acid halides, etc.

[0099] The composition ratio (mol%) of constituent unit (III) in the liquid crystal polyester resin is, with respect to constituent unit (I), preferably greater than 0 mol%, more preferably greater than 0.1 mol%, even more preferably greater than 0.3 mol%, and even more preferably greater than 0.5 mol%, and also preferably greater than 2.0 mol%, more preferably less than 1.5 mol%, even more preferably less than 1.2 mol%, and even more preferably less than 1.0 mol%.

[0100] (Method for manufacturing liquid crystal polyester resin)

[0101] A method for manufacturing a liquid crystal polyester resin according to the present invention comprises a process of obtaining a polymer by performing melt polymerization of three or more hydroxycarboxylic acids and, optionally, a dicarboxylic acid and / or a diol. A method for manufacturing a liquid crystal polyester resin according to the present invention may further comprise a process of performing solid-state polymerization of the polymer (two-stage polymerization).

[0102] From the perspective of efficiently obtaining a liquid crystal polyester resin, it is preferable to perform melt polymerization under acetic acid reflux with 1.03 to 1.15 molar equivalents of acetic anhydride relative to the total hydroxyl groups of the total monomer, and it is more preferable to perform it under acetic acid reflux with 1.03 to 1.10 molar equivalents of acetic anhydride.

[0103] The reaction cessation temperature (final temperature) of the melt polymerization is preferably within the temperature range of (melting point - 25) to (melting point + 25)°C, based on the melting point exhibited when the melt viscosity (temperature range in which the liquid crystal phase is expressed is also 1000 / s) exceeds 20 Pa·s, when the liquid crystal polyester resin being polymerized is polymerized separately and independently (solid-state polymerization may be included or only melt polymerization may be performed, but the reaction cessation temperature of the melt polymerization is 313°C). It is more preferable that the temperature range be within the temperature range of (melting point - 20)°C to (melting point + 20)°C. Since almost no change in the homopolymerization state occurs in solid-state polymerization compared to melt polymerization, by controlling the reaction cessation temperature of the melt polymerization to within the above numerical range, the state of the main chain sequence can be controlled, thereby obtaining a liquid crystal polyester resin with improved thermal properties.

[0104] It is preferable to perform melt polymerization in the presence of a catalyst and in the absence of a solvent. As a catalyst, conventionally known catalysts for polymerizing polymers may be used. Examples of catalysts include metal salt catalysts such as potassium acetate, magnesium acetate, tin(II) acetate, lead acetate, sodium acetate, tetrabutyl titanate, and antimony trioxide, as well as organic compound catalysts such as nitrogen-containing heterocyclic compounds such as N-methylimidazole. The amount of catalyst used is not particularly limited, but it is preferably (10 to 100) mg / mol × total moles of monomers.

[0105] When performing solid-state polymerization, the polymer obtained by melt polymerization may be ground into a powder or flake form after cooling and solidifying. Additionally, the polymer strand obtained by melt polymerization may be pelletized into a pellet form. The reaction temperature of the solid-state polymerization is preferably below the melting point, and preferably between (melting point - 100)°C and (melting point - 5)°C. The reaction temperature of the solid-state polymerization may be varied in stages, and the final reaction temperature of the solid-state polymerization is preferably between (melting point - 90)°C and (melting point - 10)°C, and more preferably between (melting point - 80)°C and (melting point - 15)°C. The solid-state polymerization may be performed while stirring, or it may be performed in a stationary state without stirring.

[0106] The polymerization reaction device is not particularly limited, but a reaction device used for the reaction of general high-viscosity fluids is preferably used. Examples of such reaction devices include, for instance, a stirring-type polymerization reaction device having a stirring device with stirring blades of various shapes such as anchor type, multi-stage type, spiral type, spiral shaft type, or modified versions thereof, or a mixing device generally used for mixing resins such as a kneader, roll mill, or Banbury mixer.

[0107] (Molded product)

[0108] The molded article according to the present invention comprises the liquid crystal polyester resin of the present invention, and may further comprise a liquid crystal polyester resin other than the liquid crystal polyester resin of the present invention, a resin other than the liquid crystal polyester resin, and a filler. The content of the resin component in the molded article (total content of the liquid crystal polyester resin of the present invention, a liquid crystal polyester resin other than the liquid crystal polyester resin of the present invention, and a resin other than the liquid crystal polyester resin) is preferably 30 mass% or more and 99 mass% or less with respect to the total amount of the molded article, more preferably 40 mass% or more and 95 mass% or less, even more preferably 50 mass% or more and 90 mass% or less, and even more preferably 55 mass% or more and 85 mass% or less.

[0109] (Filling)

[0110] Examples of fillers include carbon fiber, graphite, glass fiber, talc, mica, glass flakes, clay, sericite, calcium carbonate, calcium sulfate, calcium silicate, silica, alumina, aluminum hydroxide, calcium hydroxide, graphite, potassium titanate, titanium oxide, fluorocarbon resin fiber, fluorocarbon resin, barium sulfate, various whiskers, etc. These fillers may be used as a single type or as two or more types.

[0111] The content of the filler in the molded article is preferably 1 mass% or more and 70 mass% or less with respect to the total amount of the molded article, more preferably 5 mass% or more and 60 mass% or less, even more preferably 10 mass% or more and 50 mass% or less, and even more preferably 15 mass% or more and 45 mass% or less. If two or more types of fillers are included, it is preferable that their total content be within the above range. It is desirable that the content of the filler in the molded article be within the above range because a molded article with superior mechanical properties is obtained.

[0112] (Other liquid crystal polyester resins other than the liquid crystal polyester resin of the present invention)

[0113] As for other liquid crystal polyester resins, any liquid crystal polyester resin other than the liquid crystal polyester resin of the present invention may be used, provided that such resins are not particularly limited and are conventionally known liquid crystal polyester resins. As preferred embodiments of other liquid crystal polyester resins, for example, liquid crystal polyester resins having constituent units derived from hydroxycarboxylic acids may be cited. As particularly preferred embodiments, liquid crystal polyester resins containing 65 to 80 mol% (preferably 70 to 75 mol%) of p-hydroxybenzoic acid and 20 to 35 mol% (preferably 25 to 30 mol%) of 6-hydroxy-2-naphthoic acid may be cited. In addition, as another preferred embodiment, a liquid crystal polyester resin may be provided, for example, having a constituent unit derived from a hydroxycarboxylic acid, in addition to having at least one of a constituent unit derived from an aromatic dicarboxylic acid and a constituent unit derived from an aromatic diol. Particularly preferred forms may be a liquid crystal polyester resin containing 60 to 80 mol% (preferably 65 to 75 mol%) of p-hydroxybenzoic acid, 1 to 5 mol% of 6-hydroxy-2-naphthoic acid, 0 to 20 mol% (preferably 1 to 15 mol%) of a constituent unit derived from an aromatic dicarboxylic acid, and 0 to 20 mol% (preferably 1 to 15 mol%) of a constituent unit derived from an aromatic diol. Here, as a constituent unit derived from an aromatic dicarboxylic acid, a constituent unit derived from at least one of 4,4'-dihydroxybiphenyl and hydroquinone may be cited. Additionally, as a constituent unit derived from an aromatic diol, a constituent unit derived from at least one of terephthalic acid, isophthalic acid, and 4'-hydroxy-4-biphenylcarboxylic acid may be cited. The compositional ratio of each constituent unit is not limited to the above preferred form and can be appropriately adjusted. Furthermore, other liquid crystal polyester resins may be used as a single type or two or more types may be used.

[0114] The content of a liquid crystal polyester resin other than the liquid crystal polyester resin of the present invention in the molded article is, with respect to 100 parts by mass of the total of the liquid crystal polyester resin of the present invention and the other liquid crystal polyester resin, the upper limit is preferably 90 parts by mass or less, more preferably 75 parts by mass or less, and even more preferably 50 parts by mass or less, and the lower limit may be 1 part by mass or more, 3 parts by mass or more, or 5 parts by mass or more.

[0115] (Resins other than liquid crystal polyester resin)

[0116] The molded article according to the present invention may include a resin other than a liquid crystal polyester resin, provided that it does not deviate from the spirit of the present invention. Examples of other resins include polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polyarylate, polycyclohexylene dimethylene terephthalate, and polybutylene terephthalate; polyolefin resins such as polyethylene and polypropylene; cycloolefin polymers; vinyl resins such as polyvinyl chloride; (meth)acrylic resins such as polyacrylate, polymethacrylate, and polymethyl methacrylate; polyphenylene ether resin; polyacetal resin; polyamide resin; imide resins such as polyimide and polyetherimide; polystyrene resins such as polystyrene, high-impact polystyrene, AS resin, and ABS resin; thermosetting resins such as epoxy resin; cellulose resin; polyetheretherketone resin; fluoropolymer resin; and polycarbonate resin. These other resins may be used as a single type or as two or more types.

[0117] The content of a resin other than the liquid crystal polyester resin in the molded article is, with respect to 100 parts by mass of the total liquid crystal polyester resin of the present invention and other liquid crystal polyester resins, preferably 10 parts by mass or less as an upper limit, and more preferably 5 parts by mass or less.

[0118] (Other additives)

[0119] The molded article according to the present invention may include other additives, for example, coloring agents, dispersants, plasticizers, antioxidants, curing agents, flame retardants, heat stabilizers, ultraviolet absorbers, antistatic agents, and surfactants, to the extent that it does not deviate from the spirit of the present invention. These other additives may be used as a single type or two or more types may be used.

[0120] The shape of the molded article may be appropriately changed according to the application and is not particularly limited. Examples of shapes of the molded article include fibrous, plate-like, sheet-like, and rod-like forms.

[0121] A molded article according to the present invention can be manufactured by a conventionally known molding method using a resin composition comprising a liquid crystal polyester resin and, if desired, a filler or other resin. As a molding method, any of the following may be used: melt spinning, solution spinning, injection molding, compression molding, injection compression molding, calendering, punching, etc.

[0122] (Electrical and electronic components)

[0123] The electrical and electronic component according to the present invention comprises a molded article (e.g., a fibrous molded article or an injection-molded article) containing a liquid crystal polyester resin. Examples of electrical and electronic components comprising the molded article include antennas used in electronic devices or communication devices such as ETC, GPS, wireless LAN, and mobile phones; high-speed transmission connectors; CPU sockets; circuit boards; flexible printed circuit boards (FPC); stacked circuit boards; millimeter-wave and quasi-millimeter-wave radars such as collision avoidance radars; RFID tags; capacitors; inverter components; cable sheathing materials; insulating materials for secondary batteries such as lithium-ion batteries; speaker diaphragms, etc.

[0124] Examples

[0125] The present invention will be explained more specifically below by way of examples, but the present invention is not limited to examples.

[0126] <Preparation Example 1 of Liquid Crystal Polyester Resin>

[0127] (Example 1-1)

[0128] 25 mol% of p-hydroxybenzoic acid (HBA), 73 mol% of 6-hydroxy-2-naphthoic acid (HNA), and 2 mol% of m-hydroxybenzoic acid (mHBA) were added to a polymerization vessel equipped with stirring blades, and 0.50 mol% of terephthalic acid (TPA) was added relative to the total amount (100 mol%) of these hydroxycarboxylic acids, potassium acetate was added as a catalyst, and after performing vacuum-nitrogen injection of the polymerization vessel three times, acetic anhydride (1.08 molar equivalents for hydroxyl groups) was further added, the temperature was raised to 160°C, and an acetylation reaction was carried out for 1.5 hours under reflux conditions.

[0129] After the acetylation was completed, the polymerization vessel, which was in an acetic acid effluent state, was heated at a rate of 0.6°C / min until the melting zone temperature inside the vessel reached 313°C. Then, the melt polymerization reaction was stopped after the amount of effluent acetic acid exceeded 95 mass% relative to the theoretical effluent amount. Afterward, the polymer was removed and cooled to solidify. The obtained polymer was crushed to a size that passes through a sieve with a mesh size of 2.0 mm to obtain the polymer. Next, the obtained polymer was heated in an inert oven (product name: DN411I) manufactured by Yamato Kagaku Co., Ltd. under the introduction of nitrogen gas at a flow rate of 30 L / min or more to perform solid-state polymerization. For solid-state polymerization, the temperature was raised from room temperature to 250°C, maintained at 250°C for 2 hours, and then raised to 270°C and maintained for 1 hour. In addition, "250-2h, 270-1h" in the solid-state polymerization conditions listed in Table 1 indicates that solid-state polymerization was performed at 250°C for 2 hours and at 270°C for 1 hour. Furthermore, the temperature transitions at each step of the solid-state polymerization were performed as quickly as possible within the limits of the equipment's capacity.

[0130] After that, the polymer was naturally heated at room temperature to obtain the polyester resin of the present invention. The polyester resin was heated and melted on a microscope heating stage equipped with a microscope hot stage (product name: 10083L) manufactured by Japan Hitech Co., Ltd. and a polarizing microscope (product name: DS-Ri2) manufactured by Nikon Inc., and the liquid crystal properties were confirmed from the presence or absence of optical anisotropy.

[0131] (Example 1-2)

[0132] A polyester resin was obtained in the same manner as in Example 1-1, except that the reaction cessation temperature of the melt polymerization was changed to 296°C and the conditions of the solid-state polymerization were changed as follows. In the solid-state polymerization, the temperature was raised from room temperature to 250°C and maintained for 2 hours, then raised to 270°C and maintained for 2 hours, and then raised to 290°C and maintained for 1 hour. Next, the liquid crystallization of the polyester resin was confirmed in the same manner as above.

[0133] (Examples 1-3)

[0134] A polyester resin was obtained in the same manner as in Example 1-1, except that the reaction cessation temperature of the melt polymerization was changed to 320°C and the conditions of the solid-state polymerization were changed as follows. In the solid-state polymerization, the temperature was raised from room temperature to 230°C and maintained for 1 hour, then raised to 250°C and maintained for 1 hour, and then raised to 270°C and maintained for 1.5 hours. Next, the liquid crystal properties of the polyester resin were confirmed in the same manner as above.

[0135] (Comparative Example 1-1)

[0136] As in Example 1-1, after the completion of acetylation, the temperature was raised until the melting zone temperature in the tank reached 350°C, and then the pressure was reduced to 10 hPa over 30 minutes while maintaining a constant temperature. The power consumption of the stirring motor driving the stirring of the reaction system was monitored, and the polymerization reaction was terminated at the point where the power consumption corresponding to a predetermined torque load indicating the attainment of the target viscosity was displayed. In addition, a polyester resin was obtained in the same manner as in Example 1-1, except that the conditions for solid-state polymerization were changed as follows. For solid-state polymerization, the temperature was raised from room temperature to 270°C and maintained for 0.95 hours. Next, the liquid crystallization of the polyester resin was confirmed in the same manner as above.

[0137] (Comparative Example 1-2)

[0138] A polyester resin was obtained in the same manner as in Example 1-1, except that the reaction cessation temperature of the melt polymerization was changed to 350°C and the conditions of the solid-state polymerization were changed as follows. In the solid-state polymerization, the temperature was raised from room temperature to 250°C and maintained for 2 hours, then raised to 270°C and maintained for 0.5 hours. Next, the liquid crystallization of the polyester resin was confirmed in the same manner as above.

[0139] (Example 2-1)

[0140] A polyester resin was obtained in the same manner as in Example 1-1, except that TPA was not added and the conditions of solid-state polymerization were changed as follows. In the solid-state polymerization, the temperature was raised from room temperature to 250°C and maintained for 4 hours. Next, the liquid crystallinity of the polyester resin was confirmed in the same manner as above.

[0141] (Comparative Example 2-1)

[0142] A polyester resin was obtained in the same manner as Comparative Example 1-1, except that TPA was not added and the conditions of solid-state polymerization were changed as follows. In the solid-state polymerization, the temperature was raised from room temperature to 290°C and maintained for 1 hour. Next, the liquid crystallinity of the polyester resin was confirmed in the same manner as above.

[0143] (Example 3-1)

[0144] A polyester resin was obtained in the same manner as in Example 1-1, except that TPA was not added, 1 mol% of 4,4'-dihydroxybiphenyl (BP) was added, and the conditions of solid-state polymerization were changed as follows. In the solid-state polymerization, the temperature was raised from room temperature to 250°C and maintained for 2 hours, then raised to 280°C and maintained for 2 hours. Next, the liquid crystallinity of the polyester resin was confirmed in the same manner as above.

[0145] (Comparative Example 3-1)

[0146] A polyester resin was obtained in the same manner as Comparative Example 1-1, except that TPA was not added, 1 mol% of 4,4'-dihydroxybiphenyl (BP) was added, and solid-state polymerization was not performed. Next, the liquid crystallization of the polyester resin was confirmed in the same manner as above.

[0147] (Example 4-1)

[0148] A polyester resin was obtained in the same manner as in Example 1-1, except that TPA was not added, 1 mol% of hydroquinone (HQ) was added, and the conditions of solid-state polymerization were changed as follows. In the solid-state polymerization, the temperature was raised from room temperature to 250°C and maintained for 4.5 hours. Next, the liquid crystallinity of the polyester resin was confirmed in the same manner as above.

[0149] (Comparative Example 4-1)

[0150] A polyester resin was obtained in the same manner as Comparative Example 1-1, except that TPA was not added, 1 mol% of hydroquinone (HQ) was added, and solid-state polymerization was not performed. Next, the liquid crystallization of the polyester resin was confirmed in the same manner as above.

[0151] (Reference Example 1-1)

[0152] The monomer input was changed to 73 mol% HBA and 27 mol% HNA, and after the acetylation was completed, the temperature was raised until the melting zone temperature in the tank reached 322°C, and then the pressure was reduced to 10 hPa over 30 minutes while maintaining a constant temperature. The polymerization reaction was terminated at the same point as in Comparative Example 1-1, and a polyester resin was obtained in the same manner as in Example 1-1, except that solid-state polymerization was not performed. Next, the liquid crystallization of the polyester resin was confirmed in the same manner as above.

[0153] (Reference Example 1-2)

[0154] A polyester resin was obtained in the same manner as in Example 1-1, except that the monomer input was changed to 27 mol% HBA and 73 mol% HNA, the reaction cessation temperature of melt polymerization was changed to 304°C, and the conditions of solid-state polymerization were changed as follows. In solid-state polymerization, the temperature was raised from room temperature to 270°C and maintained for 1 hour. Next, the liquid crystallization of the polyester resin was confirmed in the same manner as above.

[0155] Table 1 shows the composition ratio (mol%) of the constituent units and the polymerization conditions of the polyester resins prepared in the above examples, comparative examples, and reference examples.

[0156] <Performance Evaluation of Liquid Crystal Polyester Resin 1>

[0157] Measurement of Melting Point

[0158] The melting points of the liquid crystal polyester resins obtained in the examples and comparative examples were measured using a differential scanning calorimeter (DSC) manufactured by Hitachi High-Tech Science Co., Ltd. First, in accordance with JIS-7121, the liquid crystal polyester resin was completely melted by heating from room temperature to 360°C at a heating rate of 10°C / min, and then the peak of the exothermic peak obtained when the temperature was lowered to 30°C at a rate of 10°C / min was defined as the crystallization point (Tc), and the peak of the endothermic peak obtained when the temperature was raised to 360°C at a rate of 10°C / min was defined as the melting point (Tm). The melting point (Tm) and the crystallization point (Tc) are shown in Table 1.

[0159] Measurement of Melt Viscosity

[0160] For the liquid crystal polyester resins obtained in the examples and comparative examples, the melt viscosity (Pa·s) under the conditions of the temperature and shear rate of 1000 / s listed in Table 1 was measured in accordance with JIS K7199 using a capillary rheometer viscometer (Toyo Seiki Seisakusho Capirograph 1D) and a capillary with an inner diameter of 1 mm and a length of 40 mm (L / D = 40). The measurement results are shown in Table 1.

[0161]

[0162] <Performance Evaluation of Liquid Crystal Polyester Resin 2>

[0163] <Evaluation of the sequence state of the main chain>

[0164] For the liquid crystal polyester resins of Reference Examples 1 and 2, Examples 1-1 to 1-3, and Comparative Example 1-1 obtained above, under the following conditions 13 C-NMR measurements were performed to evaluate the sequence status of the main chain. The obtained 13 C-NMR spectra are shown in Figures 1 to 6, respectively.

[0165] ( 13 C-NMR conditions)

[0166] · Measuring device: Nihon Denshi ECZ500R-M3 500MHz NMR

[0167] · Detector: Φ10mm

[0168] · Measurement conditions

[0169] 13 C: ( 1 H-Complete Decoupling Method)

[0170] Accumulated count: 20,000 times

[0171] Waiting time: 2 seconds

[0172] Measured temperature: 100℃

[0173] Solvent: Pentafluorophenol

[0174] Liquid crystal polyester resin concentration: 3.5 mass%

[0175] Reference Chemical Shift: 134.86 ppm

[0176] First, the liquid crystal polyester resin of Reference Example 1 (composition: HBA73 / HNA27) and the liquid crystal polyester resin of Reference Example 2 (composition: HBA27 / HNA73) 13 In the C-NMR spectrum, four peaks were identified at chemical shift values ​​(165-175 ppm) of the carbonyl carbon (COO) of the ester, and peaks originating from homologous or heterologous hydroxycarboxylic acid ester bonds were identified based on the relationship between each chemical shift and their integration ratios. The ester bond modes of the hydroxycarboxylic acids include "HBA-COO-HBA" (homologous), "HBA-COO-HNA (HNA-COO-HBA)" (heterologous), and "HNA-COO-HNA" (homologous). The identification results are shown in Table 2.

[0177] Next, the liquid crystal polyester resin (composition: HBA25 / HNA73 / mHBA2) obtained from Examples 1-1 to 1-3 and Comparative Example 1-1 13In the C-NMR spectrum, as described above, peaks were identified at chemical shift values ​​(165-175 ppm) of the carbonyl carbon (COO) of the ester, and peaks originating from ester bonds involving mHBA were identified based on the sequence or equivalence of the integration ratios. The ester bond patterns involving mHBA include "HBA-COO-mHBA (mHBA-COO-HBA)" (heterogeneous), "HNA-COO-mHBA (mHBA-COO-HNA)" (heterogeneous), and "mHBA-COO-mHBA" (homogeneous); it was estimated that no peak appeared for "mHBA-COO-mHBA" (homogeneous) because the compositional ratio of mHBA is low. The identification results are shown in Table 2.

[0178]

[0179] From the values ​​of the integral ratios of the peaks present in the corresponding chemical shifts shown in Table 2 above, each bonding mode was quantified, and the parameters of the following formula (I) were calculated. Even for liquid crystal polyesters polymerized using homogeneous monomers, specific chemical shifts may not be present due to the influence of the homopolymerization state. In addition, depending on the measurement environment, the position of individual chemical shifts may show a slight shift. Therefore, the positions of the chemical shifts (peak peaks) in Table 2 are merely representative values ​​based on the measurement conditions.

[0180]

[0181] Specifically, based on the above formula (I), the ratio of ester bonds between hydroxycarboxylic acids that have the highest constituent amount among all ester bonds (all carbonyl carbons) present in the liquid crystal polyester resin ("HNA-COO-HNA" in Examples 1-1 to 1-3, Comparative Example 1-1, and Reference Example 1-2, and "HBA-COO-HBA" in Reference Example 1-1) was calculated. This represents the ratio of the "self-linking" of hydroxycarboxylic acids that have the highest constituent amount and have the most influence on physical properties. The calculation results are shown in Table 3. In Table 3, peak (c) corresponds to the carbonyl of the "HNA-COO-HNA" bond, and peak (a) corresponds to "HBA-COO-HBA". Accordingly, the ratio of "self-linking" of the hydroxycarboxylic acid with the highest composition in Table 3 is a value obtained by dividing the integral ratio of peak (c) by the sum of the integral ratios of all ester bonds of 165-175 ppm in Examples 1-1 to 1-3, Comparative Example 1-1, and Reference Example 1-2, and a value obtained by dividing the integral ratio of peak (a) by the sum of the integral ratios of all ester bonds of 165-175 ppm in Reference Example 1-1.

[0182]

[0183] From the results in Table 3, by changing the polymerization conditions of the liquid crystal polyester resin (in particular, the reaction cessation temperature of melt polymerization), the amount of "self-linking" of the hydroxycarboxylic acid, which has the largest amount and most influences physical properties, can be controlled. Specifically, by stopping the melt polymerization within a specific temperature range, the "self-linking" of the hydroxycarboxylic acid, which has the largest amount, could be suppressed. This had the effect of raising the melting point of liquid crystal polyesters with the same monomer composition and equivalent melt viscosity under the same conditions, that is, with the same degree of polymerization. In addition, the obtained liquid crystal polyester resin was separately hydrolyzed, and the proton NMR of the hydrolysate was measured; it was confirmed that both the example and the comparative example had a monomer composition in proportion to the input ratio.

[0184] In addition, the ratio of all ester bonds present in the liquid crystal polyester resin of the first-largest hydroxycarboxylic acid “self-linking” (HBA-COO-HBA in Reference Example 1, HNA-COO-HNA in Reference Example 2), using the integral values ​​of FIGS. 1 and FIGS. 2, was 52% and 51%, respectively. From this, it was confirmed that the “self-linking” of the first-largest hydroxycarboxylic acid could be reduced by using three or more types of hydroxycarboxylic acids in the present invention.

[0185] <Performance Evaluation of Liquid Crystal Polyester Resin 3>

[0186] <Fabrication of Bending Test Specimens>

[0187] The liquid crystal polyester resin obtained in Example 1-1 and Comparative Example 1-1 was heated and melted (mold temperature 80°C) under conditions of melting point + 20°C and injection molded to produce a bending test specimen of 80 mm × 12 mm × 2 mm (thickness).

[0188] <Measurement of Load Deflection Temperature (DTUL)>

[0189] Using the bending test specimens prepared above, the load deflection temperature (DTUL) was measured under a load of 1.8 MPa in accordance with ASTM D648. Three independent measurements were taken, and the average value of the three measurements is shown in Table 4. A higher load deflection temperature indicates superior practical heat resistance.

[0190] <Izod 충격 강도의 측정>

[0191] Using the bending test specimens prepared above, and in accordance with ASTM D256, the Izod impact strength (kJ / m²) was measured using an impact tester (Toyo Seiki, Model No.: Izod Impact Tester No. 556) under conditions of room temperature, hammer 5.5 J, and no notch. 2 Measurements were performed. The measurements were taken independently five times, and the average value of the five measurements is shown in Table 4.

[0192] Measurement of mechanical strength

[0193] Using the bending test specimens prepared above, the bending modulus (GPa), bending strength (MPa), and bending elongation (%) were measured using a universal testing machine (manufactured by Toyo Seiki, Model No.: Strograph VG) in accordance with JIS K7171 at room temperature under conditions of R = 50 mm, distance between points 50 mm, and test speed 2.0 mm / min. Measurements were performed independently three times, and the average value of the three measurements is shown in Table 4.

[0194]

[0195] As shown in Table 4, the liquid crystal polyester resin of Example 1, in which the ratio of ester bonds between hydroxycarboxylic acids with the highest composition was controlled, had a higher load deflection temperature compared to the liquid crystal polyester resin of Comparative Example 1, thereby improving practical heat resistance. In addition, the Izod impact strength and bending strength of Example 1-1 and Comparative Example 1-1 were both equivalent. From this, the increase in load deflection temperature in Example 1-1 is largely due to the improvement in the thermal properties (increase in melting point) of the polymer resulting from the realization of a desirable self-linked state.

Claims

Claim 1 A liquid crystal polyester resin comprising constituent units derived from three or more types of hydroxycarboxylic acids, wherein the liquid crystal polyester resin satisfies the following condition: the ratio of ester bonds formed between the hydroxycarboxylic acid of the first most abundant constituent unit among the three or more types of hydroxycarboxylic acid-derived constituent units and the same type of hydroxycarboxylic acid is 12% or more and 60% or less with respect to the total ester bonds present in the liquid crystal polyester resin. Claim 2 A liquid crystal polyester according to claim 1, wherein the composition ratio of constituent units derived from the three or more types of hydroxycarboxylic acids is 50 mol% or more with respect to the total constituent units of the liquid crystal polyester resin. Claim 3 A liquid crystal polyester resin according to claim 1, wherein the composition ratio of the first most abundant constituent unit among the three or more constituent units derived from hydroxycarboxylic acids is 40 mol% or more and 98 mol% or less with respect to the total of the three or more constituent units derived from hydroxycarboxylic acids. Claim 4 A liquid crystal polyester resin according to claim 1, wherein the composition ratio of the second-largest constituent unit among the constituent units derived from the three or more types of hydroxycarboxylic acids is 1 mol% or more and 40 mol% or less with respect to the total constituent units derived from the three or more types of hydroxycarboxylic acids. Claim 5 A liquid crystal polyester resin according to claim 1, wherein the composition ratio of the third most abundant constituent unit among the three or more constituent units derived from the hydroxycarboxylic acids is 0.1 mol% or more and 20 mol% or less with respect to the total of the three or more constituent units derived from the hydroxycarboxylic acids. Claim 6 A liquid crystal polyester resin according to claim 3, wherein the first most abundant constituent unit among the three or more constituent units derived from hydroxycarboxylic acids is a constituent unit derived from p-hydroxybenzoic acid or a constituent unit derived from 6-hydroxy-2-naphthoic acid. Claim 7 A liquid crystal polyester resin according to claim 4, wherein the second most abundant constituent unit among the three or more constituent units derived from hydroxycarboxylic acids is a constituent unit derived from p-hydroxybenzoic acid or a constituent unit derived from 6-hydroxy-2-naphthoic acid. Claim 8 In claim 1, the liquid crystal polyester resin having a melting point of 270°C or higher and 370°C or lower. Claim 9 A liquid crystal polyester resin according to claim 1, wherein the melt viscosity measured under conditions of a shear rate of 1000 / s at a temperature of the melting point of the liquid crystal polyester resin to the melting point + 30°C or higher is 1 Pa·s or higher. Claim 10 A liquid crystal polyester resin according to claim 1, wherein the load deflection temperature of the liquid crystal polyester resin is 180°C or higher. Claim 11 A fibrous molded article comprising a liquid crystal polyester resin as described in any one of claims 1 to 10. Claim 12 A sheet-shaped molded article comprising a liquid crystal polyester resin as described in any one of claims 1 to 10. Claim 13 An injection molded article comprising a liquid crystal polyester resin as described in any one of claims 1 to 10. Claim 14 An electrical and electronic component having the molded product described in paragraph 11. Claim 15 An electrical and electronic component having the molded product described in Clause 12. Claim 16 An electrical and electronic component having the molded product described in Paragraph 13.

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