Liquid crystal polyester composition, pellet, and molded article

Abstract

A liquid crystal polyester composition containing: a liquid crystal polyester; and a carbodiimide compound having a carbodiimide group, wherein the liquid crystal polyester contains a first monomer unit having a fused aromatic ring, and the first monomer unit content is 30 mol% or more relative to the total of all monomer units constituting the liquid crystal polyester.

Description

Liquid crystal polyester composition, pellets and molded articles

[0001] The present disclosure relates to a liquid crystal polyester composition, pellets, and molded articles.

[0002] Liquid crystal polyesters have high fluidity and heat resistance, and the dimensional accuracy of the molded articles obtained is also high, and therefore they are used in a variety of applications.

[0003] When liquid crystal polyester is molded by injection molding, melt extrusion, etc., differences in physical properties may occur between the flow direction (MD) and the perpendicular direction (TD) (i.e., anisotropy may occur in the molded product.) For example, Patent Document 1 discloses a liquid crystal resin composition comprising more than 50 wt % but not more than 99.99 wt % of a liquid crystal resin and 0.01 wt % or more but less than 50 wt % of a cyclic olefin resin, with the aim of providing a composition with little anisotropy.

[0004] Japanese Patent Application Publication No. 10-316841

[0005] However, in the method described in the above publication, the addition of the cyclic olefin resin sometimes impairs the properties (for example, dielectric properties, heat resistance, etc.) of the liquid crystal polyester.

[0006] An object of the present disclosure is to provide a liquid crystal polyester composition that can achieve both good dielectric properties and small anisotropy, as well as pellets and molded articles that include the liquid crystal polyester composition.

[0007] The present disclosure provides, for example, the following: [1] A liquid crystal polyester composition comprising a liquid crystal polyester and a carbodiimide compound having a carbodiimide group, wherein the liquid crystal polyester comprises a first monomer unit having a condensed aromatic ring, and the content of the first monomer unit is 30 mol% or more relative to the total of all monomer units constituting the liquid crystal polyester. [2] A liquid crystal polyester composition, which is a melt-kneaded mixture of raw material components comprising a liquid crystal polyester and a carbodiimide compound having a carbodiimide group, wherein the liquid crystal polyester comprises a first monomer unit having a condensed aromatic ring, and the content of the first monomer unit is 30 mol% or more relative to the total of all monomer units constituting the liquid crystal polyester. [3] The liquid crystal polyester composition according to [1] or [2], wherein the liquid crystal polyester further comprises a second monomer unit having a benzene ring. [4] The liquid crystal polyester composition according to any one of [1] to [3], wherein the condensed aromatic ring is a naphthalene ring. [5] The liquid crystal polyester composition according to any one of [1] to [4], wherein the content of the carbodiimide compound is 0.05 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the total of the liquid crystal polyester and the carbodiimide compound. [6] A pellet comprising the liquid crystal polyester composition according to any one of [1] to [5]. [7] A molded article comprising the liquid crystal polyester composition according to any one of [1] to [5]. [8] The molded article according to [7], which is a film.

[0008] According to the present disclosure, a liquid crystal polyester composition capable of achieving both good dielectric properties and small anisotropy is provided. According to the present disclosure, a pellet containing the liquid crystal polyester composition and capable of achieving both good dielectric properties and small anisotropy is provided. According to the present disclosure, a molded article containing the liquid crystal polyester composition and capable of achieving both good dielectric properties and small anisotropy is provided.

[0009] Preferred embodiments of the present disclosure will be described in detail below.

[0010] The liquid crystal polyester composition of this embodiment (hereinafter also simply referred to as "liquid crystal polyester composition") contains a liquid crystal polyester and a carbodiimide compound. The liquid crystal polyester contains a first monomer unit having a condensed aromatic ring. The content of the first monomer unit in the liquid crystal polyester is 30 mol % or more based on the total of all monomer units constituting the liquid crystal polyester.

[0011] According to the liquid crystal polyester composition of the present embodiment, a molded article having both good dielectric properties and small anisotropy can be obtained.

[0012] The reason why the above effect is achieved is not entirely clear, but is thought to be as follows. Liquid crystal polyesters having fused aromatic rings are likely to be oriented due to interactions between the fused aromatic rings, and anisotropy is likely to occur in molded articles. Since the liquid crystal polyester composition of this embodiment contains a liquid crystal polyester and a carbodiimide compound, a terminal group (e.g., a carboxyl group) of the liquid crystal polyester reacts with a carbodiimide group of the carbodiimide compound to form a crosslinked structure. It is thought that the formation of this crosslinked structure suppresses the orientation of the liquid crystal polyester, thereby reducing the anisotropy of the molded article. In this embodiment, since a crosslinked structure is formed at the terminal group portion of the liquid crystal polyester, it is thought that anisotropy is reduced without impairing the dielectric properties due to the characteristics of the main chain portion of the liquid crystal polyester.

[0013] In the liquid crystal polyester composition of the present embodiment, the liquid crystal polyester and the carbodiimide compound may partially or completely react to form a crosslinked structure, i.e., the liquid crystal polyester composition of the present embodiment may contain a reaction product of the liquid crystal polyester and the carbodiimide compound.

[0014] In this specification, the phrase "the liquid crystal polyester composition comprises a liquid crystal polyester and a carbodiimide compound" also includes the case where the liquid crystal polyester composition comprises a reaction product of a liquid crystal polyester and a carbodiimide compound. The "content of liquid crystal polyester" refers to the total amount of unreacted liquid crystal polyester and the portion derived from the liquid crystal polyester in the reaction product. The "content of carbodiimide compound" refers to the total amount of unreacted carbodiimide compound and the portion derived from the carbodiimide compound in the reaction product.

[0015] The liquid crystal polyester composition of the present embodiment can also be considered as a mixture of raw material components containing a liquid crystal polyester and a carbodiimide compound. The liquid crystal polyester composition of the present embodiment may be a melt-kneaded product of the raw material components.

[0016] The liquid crystal polyester may be any polyester that exhibits liquid crystallinity in a molten state. The liquid crystal polyester may be a single polymer or a mixture of two or more polymers. When the liquid crystal polyester is a mixture of two or more polymers, the parameters related to the liquid crystal polyester described below refer to the parameters of the mixture (parameters measured using the mixture). Furthermore, the sum of all monomer units refers to the sum of the monomer units constituting each polymer.

[0017] The liquid crystal polyester has constituent units (monomer units) derived from raw material monomers. The liquid crystal polyester may have a main monomer unit (e.g., 90 mol % or more, 95 mol % or more, or 99 mol % or more of the monomer units, preferably all of the monomer units, based on the total of all the monomer units) derived from an aromatic compound.

[0018] The liquid crystal polyester has a first monomer unit having a condensed aromatic ring. The liquid crystal polyester may further have a second monomer unit having a benzene ring. The second monomer unit may be a monomer unit having a benzene ring but not having a condensed aromatic ring. The liquid crystal polyester may have one type of first monomer unit, or may have two or more types of first monomer units. The liquid crystal polyester may have one type of second monomer unit, or may have two or more types of second monomer units.

[0019] The first monomer unit may be a monomer unit derived from a first aromatic compound having a fused aromatic ring. The second monomer unit may be a monomer unit derived from a second aromatic compound having a benzene ring but no fused aromatic ring. The first aromatic compound and the second aromatic compound may be, for example, an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, or an aromatic diol.

[0020] In this specification, "derived" means that in the monomer units of the liquid crystal polyester formed by polymerization of the raw material monomers, the chemical structure of the functional group that contributes to polymerization of the raw material monomers has changed, but other structural changes have not occurred. Here, "derived" is a concept that also includes cases where the monomer unit is derived from a polymerizable derivative of the raw material monomer (for example, a compound obtained by converting the functional group that contributes to polymerization of the raw material monomers into another polymerizable group).

[0021] Examples of the first monomer unit include a monomer unit derived from an aromatic hydroxycarboxylic acid (1-1) having a fused aromatic ring (hereinafter also referred to as a monomer unit (1-1)), a monomer unit derived from an aromatic dicarboxylic acid (1-2) having a fused aromatic ring (hereinafter also referred to as a monomer unit (1-2)), and a monomer unit derived from an aromatic diol (1-3) having a fused aromatic ring (hereinafter also referred to as a monomer unit (1-3)).

[0022] The aromatic hydroxycarboxylic acid (1-1) may be a compound having a fused aromatic ring, a hydroxyl group bonded to the fused aromatic ring, and a carbonyl group bonded to the fused aromatic ring. The aromatic dicarboxylic acid (1-2) may be a compound having a fused aromatic ring and two carbonyl groups bonded to the fused aromatic ring. The aromatic diol (1-3) may be a compound having a fused aromatic ring and two hydroxyl groups bonded to the fused aromatic ring.

[0023] Examples of the fused aromatic ring contained in the first monomer unit include a naphthalene ring, an anthracene ring, a phenanthrene ring, a tetracene ring, a pyrene ring, a triphenylene ring, a perylene ring, and a fluorene ring. Of these, a naphthalene ring is preferred from the viewpoints of availability and cost.

[0024] Examples of aromatic hydroxycarboxylic acids (1-1) include 2-hydroxy-6-naphthoic acid, 2-hydroxy-3-naphthoic acid, and 1-hydroxy-5-naphthoic acid. Examples of aromatic dicarboxylic acids (1-2) include 2,6-naphthalenedicarboxylic acid. Examples of aromatic diols (1-3) include 2,6-dihydroxynaphthalene and 2,7-dihydroxynaphthalene.

[0025] Examples of the second monomer unit include a monomer unit derived from an aromatic hydroxycarboxylic acid (2-1) having a benzene ring and no fused aromatic ring (hereinafter also referred to as a monomer unit (2-1)), a monomer unit derived from an aromatic dicarboxylic acid (2-2) having a benzene ring and no fused aromatic ring (hereinafter also referred to as a monomer unit (2-2)), and a monomer unit derived from an aromatic diol (2-3) having a benzene ring and no fused aromatic ring (hereinafter also referred to as a monomer unit (2-3)).

[0026] The aromatic hydroxycarboxylic acid (2-1) may be a compound having a benzene ring, a hydroxyl group bonded to the benzene ring, and a carbonyl group bonded to the benzene ring. The aromatic dicarboxylic acid (2-2) may be a compound having a benzene ring and two carbonyl groups bonded to the benzene ring. The aromatic diol (2-3) may be a compound having a benzene ring and two hydroxyl groups bonded to the benzene ring.

[0027] Examples of aromatic hydroxycarboxylic acids (2-1) include p-hydroxybenzoic acid and m-hydroxybenzoic acid. Examples of aromatic dicarboxylic acids (2-2) include terephthalic acid and isophthalic acid. Examples of aromatic diols (2-3) include hydroquinone and 4,4'-biphenol.

[0028] Examples of the monomer unit contained in the liquid crystal polyester include a monomer unit represented by the following formula (I) (hereinafter also referred to as monomer unit (I)), a monomer unit represented by the following formula (II) (hereinafter also referred to as monomer unit (II)), and a monomer unit represented by the following formula (III) (hereinafter also referred to as monomer unit (III)). １ -CO- (I) -CO-Ar ２ -CO- (II) -O-Ar ３ -O- (III) [wherein, Ar １ , Ar ２ and Ar ３ each independently represents a phenylene group, a biphenylylene group, a condensed polycyclic aromatic hydrocarbon group, or a group represented by formula (IV), Ar １ , Ar ２ and Ar ３ Some or all of the hydrogen atoms in —Ar may be substituted with halogen atoms, alkyl groups or aryl groups. ４ -Z-Ar ５ - (IV) [wherein, Ar ４ and Ar ５each independently represents a phenylene group or a condensed polycyclic aromatic hydrocarbon group, and Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkanediyl group.

[0029] The phenylene group may be, for example, a 1,4-phenylene group or a 1,3-phenylene group, and is preferably a 1,4-phenylene group.

[0030] The biphenylylene group may be, for example, a 4,4'-biphenylylene group.

[0031] The condensed polycyclic aromatic hydrocarbon group is a group in which two hydrogen atoms have been removed from a condensed polycyclic aromatic hydrocarbon. Examples of the condensed polycyclic aromatic hydrocarbon include naphthalene, anthracene, phenanthrene, tetracene, pyrene, triphenylene, perylene, and fluorene. Among these, naphthalene is preferred from the viewpoints of availability and cost.

[0032] The condensed polycyclic aromatic hydrocarbon group may be, for example, a naphthylene group. The naphthylene group may be a 2,6-naphthylene group or a 2,7-naphthylene group, and is preferably a 2,6-naphthylene group.

[0033] Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogen atom as a substituent may be a fluorine atom, a chlorine atom, or a bromine atom, or may be a fluorine atom, a chlorine atom, or a fluorine atom.

[0034] The alkyl group as a substituent may be linear, branched, or cyclic. The alkyl group may be, for example, an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, and an n-decyl group.

[0035] The aryl group as a substituent may be a monocyclic ring or a fused ring. The aryl group may be, for example, an aryl group having 6 to 20 carbon atoms. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group. The aryl group may be a group in which a hydrogen atom of an aromatic ring is substituted with an alkyl group, such as a tolyl group.

[0036] Ar １ , Ar ２ and Ar ３ The number of substituents that the has may be, for example, 0 to 2, or may be 0 or 1, or may be 0.

[0037] The alkanediyl group in Z may be linear or branched. The alkanediyl group may be an alkanediyl group having 1 to 10 carbon atoms. Examples of the alkanediyl group include a methylene group, an ethanediyl group, a propanediyl group (e.g., a propane-2,2-diyl group), a butanediyl group, and an octanediyl group (e.g., an octane-3,3-diyl group).

[0038] Z is preferably an oxygen atom, a sulfur atom, a methylene group, an ethanediyl group, or a propanediyl group, and more preferably an oxygen atom.

[0039] The first monomer unit is Ar １ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５ At least one of Ar and Ar may be a monomer unit represented by formula (I) (hereinafter also referred to as monomer unit (I-1)), which is a group represented by formula (IV) that is a condensed polycyclic aromatic hydrocarbon group, ２ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５ At least one of the monomer units represented by formula (II) (hereinafter referred to as monomer unit (II-1)) is a group represented by formula (IV), which is a condensed polycyclic aromatic hydrocarbon group, ３ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５and a monomer unit represented by formula (III) (hereinafter referred to as monomer unit (III-1)), in which at least one of Ar １ is a condensed polycyclic aromatic hydrocarbon group, and the monomer unit (II-1) is preferably a monomer unit represented by formula (I) ２ is a condensed polycyclic aromatic hydrocarbon group, and the monomer unit (III-1) is preferably a monomer unit represented by formula (II) ３ is a monomer unit represented by formula (I) in which R is a condensed polycyclic aromatic hydrocarbon group.

[0040] The second monomer unit is Ar １ is a phenylene group, a biphenylylene group, or Ar ４ and Ar ５ is a phenylene group, and the monomer unit represented by formula (I) (hereinafter also referred to as monomer unit (I-2)) may be a monomer unit represented by formula (IV) in which Ar ２ is a phenylene group, a biphenylylene group, or Ar ４ and Ar ５ is a group represented by formula (IV) in which Ar is a phenylene group.) It may also be a monomer unit represented by formula (II) (hereinafter also referred to as monomer unit (II-2)), ３ is a phenylene group, a biphenylylene group, or Ar ４ and Ar ５ The monomer unit (I-2) may be a monomer unit represented by formula (III) in which Ar is a group represented by formula (IV) in which Ar is a phenylene group (hereinafter, also referred to as monomer unit (III-2)). １ is a monomer unit represented by formula (I) in which Ar is a phenylene group or a biphenylylene group, and the monomer unit (II-2) is preferably a monomer unit represented by formula (I) in which Ar is a ２ is a monomer unit represented by formula (II) in which Ar is a phenylene group or a biphenylylene group, and the monomer unit (III-2) is preferably a monomer unit represented by formula (II) in which Ar is a phenylene group or a biphenylylene group. ３ is a monomer unit represented by formula (I) in which R is a phenylene group or a biphenylylene group.

[0041] In the liquid crystal polyester, the content of the first monomer unit is 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, or even 70 mol% or more, based on the total of all monomer units constituting the liquid crystal polyester. A high content of the first monomer unit tends to further improve dielectric properties. The content of the first monomer unit may be, for example, 90 mol% or less, 85 mol% or less, or even 80 mol% or less, based on the total of all monomer units constituting the liquid crystal polyester. This tends to improve moldability and processability at low temperatures. That is, the content of the first monomer unit relative to the total of all monomer units constituting the liquid crystal polyester may be, for example, 30 mol% to 90 mol%, 30 mol% to 85 mol%, 30 mol% to 80 mol%, 40 mol% to 90 mol%, 40 mol% to 85 mol%, 40 mol% to 80 mol%, 50 mol% to 90 mol%, 50 mol% to 85 mol%, 50 mol% to 80 mol%, 60 mol% to 90 mol%, 60 mol% to 85 mol%, 60 mol% to 80 mol%, 70 mol% to 90 mol%, 70 mol% to 85 mol%, or 70 mol% to 80 mol%.

[0042] In the liquid crystal polyester, the content of the second monomer unit may be, for example, 10 mol% or more, 15 mol% or more, or 20 mol% or more, relative to the total of all monomer units constituting the liquid crystal polyester. This tends to be advantageous in terms of cost. The content of the second monomer unit may be, for example, 70 mol% or less, 60 mol% or less, 50 mol% or less, 40 mol% or less, or 30 mol% or less, relative to the total of all monomer units constituting the liquid crystal polyester. That is, the content of the second monomer unit may be, for example, 10 mol% or more and 70 mol% or less, 10 mol% or more and 60 mol% or less, 10 mol% or more and 50 mol% or less, 10 mol% or more and 40 mol% or less, 10 mol% or more and 30 mol% or less, 15 mol% or more and 70 mol% or less, 15 mol% or more and 60 mol% or less, 15 mol% or more and 50 mol% or less, 15 mol% or more and 40 mol% or less, 15 mol% or more and 30 mol% or less, 20 mol% or more and 70 mol% or less, 20 mol% or more and 60 mol% or less, 20 mol% or more and 50 mol% or less, 20 mol% or more and 40 mol% or less, or 20 mol% or more and 30 mol% or less.

[0043] In the liquid crystal polyester, the total amount of the first monomer unit and the second monomer unit may be, for example, 90 mol% or more, 95 mol% or more, 99 mol% or more, or 100 mol% relative to the total of all monomer units constituting the liquid crystal polyester.

[0044] The liquid crystal polyester may be a polymer having two or more types of monomer unit (I), or may be a polymer having monomer unit (I), monomer unit (II), and monomer unit (III). When the liquid crystal polyester contains monomer unit (I), monomer unit (II), and monomer unit (III), the content of monomer unit (II) and the content of monomer unit (III) may be approximately the same (for example, the difference may be 3 mol % or less, 1 mol % or less, 0.5 mol % or less, or 0.1 mol % or less).

[0045] When the liquid crystal polyester has the monomer unit (I), the monomer unit (II) and the monomer unit (III), the content of the monomer unit (I) may be, for example, 30 mol% or more, 40 mol% or more, 45 mol% or more, 50 mol% or more, or 53 mol% or more, based on the total of all the monomer units of the liquid crystal polyester. When the liquid crystal polyester has the monomer unit (I), the monomer unit (II) and the monomer unit (III), the content of the monomer unit (I) may be, for example, 80 mol% or less, 75 mol% or less, or 70 mol% or less, based on the total of all the monomer units of the liquid crystal polyester. That is, when the liquid crystal polyester has the monomer unit (I), the monomer unit (II), and the monomer unit (III), the content of the monomer unit (I) relative to the total of all monomer units of the liquid crystal polyester may be, for example, 30 mol% to 80 mol%, 30 mol% to 75 mol%, 30 mol% to 70 mol%, 40 mol% to 80 mol%, 40 mol% to 75 mol%, 40 mol% to 70 mol%, 45 mol% to 80 mol%, 45 mol% to 75 mol%, 40 mol% to 70 mol%, 50 mol% to 80 mol%, 50 mol% to 75 mol%, 50 mol% to 70 mol%, 53 mol% to 80 mol%, 53 mol% to 75 mol%, or 53 mol% to 70 mol%.

[0046] When the liquid crystal polyester has the monomer unit (I), the monomer unit (II) and the monomer unit (III), the content of the monomer unit (II) and the content of the monomer unit (III) may each be, for example, 35 mol% or less, 30 mol% or less, 27 mol% or less, 25 mol% or less, or 23 mol% or less, relative to the total of all monomer units of the liquid crystal polyester. When the liquid crystal polyester has the monomer unit (I), the monomer unit (II) and the monomer unit (III), the content of the monomer unit (II) and the content of the monomer unit (III) may each be, for example, 5 mol% or more, 10 mol% or more, 12 mol% or more, or 15 mol% or more, relative to the total of all monomer units of the liquid crystal polyester. That is, when the liquid crystal polyester has the monomer unit (I), the monomer unit (II), and the monomer unit (III), the content of the monomer unit (II) and the content of the monomer unit (III) are, for example, 5 mol% or more and 35 mol% or less, 5 mol% or more and 30 mol% or less, 5 mol% or more and 27 mol% or less, 5 mol% or more and 25 mol% or less, 5 mol% or more and 23 mol% or less, 10 mol% or more and 35 mol% or less, 10 mol% or more and 30 mol% or less, based on the total of all the monomer units of the liquid crystal polyester. mol% or less, 10 mol% or more and 27 mol% or less, 10 mol% or more and 25 mol% or less, 10 mol% or more and 23 mol% or less, 12 mol% or more and 35 mol% or less, 12 mol% or more and 30 mol% or less, 12 mol% or more and 27 mol% or less, 12 mol% or more and 25 mol% or less, 12 mol% or more and 23 mol% or less, 15 mol% or more and 35 mol% or less, 15 mol% or more and 30 mol% or less, 15 mol% or more and 27 mol% or less, 15 mol% or more and 25 mol% or less, or 15 mol% or more and 23 mol% or less.

[0047] The liquid crystal polyester may have a monomer unit other than the monomer unit (I), the monomer unit (II), and the monomer unit (III), and the content thereof may be 10 mol% or less, 5 mol% or less, 2 mol% or less, 1 mol% or less, or even 0 mol% relative to the total of all the monomer units of the liquid crystal polyester.

[0048] The liquid crystal polyester may have, as the first monomer unit, only one of the monomer unit (I-1), the monomer unit (II-1) and the monomer unit (III-1), or may have, as the first monomer unit, two or more of the monomer unit (I-1), the monomer unit (II-1) and the monomer unit (IV-1).

[0049] The liquid crystal polyester preferably has at least the monomer unit (I-1) as the first monomer unit, and may have the monomer unit (I-1) and at least one selected from the group consisting of the monomer unit (II-1) and the monomer unit (III-1), or may have the monomer unit (I-1) and the monomer unit (II-1).

[0050] The proportion of the monomer units (I-1) in the first monomer units may be, for example, 50 mol % or more, 60 mol % or more, or 70 mol % or more. The proportion of the monomer units (I) in the first monomer units may be, for example, 95 mol % or less, 90 mol % or less, 85 mol % or less, or 80 mol % or less. That is, the proportion of the monomer unit (I-1) in the first monomer unit may be, for example, 50 mol% or more and 95 mol% or less, 50 mol% or more and 90 mol% or less, 50 mol% or more and 85 mol% or less, 50 mol% or more and 80 mol% or less, 60 mol% or more and 95 mol% or less, 60 mol% or more and 90 mol% or less, 60 mol% or more and 85 mol% or less, 60 mol% or more and 80 mol% or less, 70 mol% or more and 95 mol% or less, 70 mol% or more and 90 mol% or less, 70 mol% or more and 85 mol% or less, or 70 mol% or more and 80 mol% or less.

[0051] The total of the monomer units (II-1) and (III-1) in the first monomer units (or the proportion of the monomer units (II-1)) may be, for example, 5 mol % or more, 10 mol % or more, 15 mol % or more, or 20 mol % or more. The total of the monomer units (II-1) and (III-1) in the first monomer units (or the proportion of the monomer units (II-1)) may be, for example, 50 mol % or less, 40 mol % or less, or 30 mol % or less. That is, the total of the monomer units (II-1) and (III-1) in the first monomer units (or the proportion of the monomer units (II-1)) may be, for example, 5 mol% or more and 50 mol% or less, 5 mol% or more and 40 mol% or less, 5 mol% or more and 30 mol% or less, 10 mol% or more and 50 mol% or less, 10 mol% or more and 40 mol% or less, 10 mol% or more and 30 mol% or less, 15 mol% or more and 50 mol% or less, 15 mol% or more and 40 mol% or less, 15 mol% or more and 30 mol% or less, 20 mol% or more and 50 mol% or less, 20 mol% or more and 40 mol% or less, or 20 mol% or more and 30 mol% or less.

[0052] The liquid crystal polyester may have, as the second monomer unit, only one of the monomer unit (I-2), the monomer unit (II-2) and the monomer unit (III-2), or may have, as the second monomer unit, two or more of the monomer unit (I-2), the monomer unit (II-2) and the monomer unit (III-2).

[0053] The liquid crystal polyester may have, as the second monomer unit, at least one selected from the group consisting of the monomer unit (II-2) and the monomer unit (III-2), or may have the monomer unit (II-2) and the monomer unit (III-2).

[0054] The proportion of the monomer units (II-2) in the second monomer units may be, for example, 3 mol % or more, 5 mol % or more, 10 mol % or more, or 15 mol % or more. The proportion of the monomer units (II-2) in the second monomer units may be, for example, 40 mol % or less, 30 mol % or less, 25 mol % or less, or 20 mol % or less. That is, the proportion of the monomer unit (II-2) in the second monomer unit may be, for example, 3 mol% or more and 40 mol% or less, 3 mol% or more and 30 mol% or less, 3 mol% or more and 25 mol% or less, 3 mol% or more and 20 mol% or less, 5 mol% or more and 40 mol% or less, 5 mol% or more and 30 mol% or less, 5 mol% or more and 25 mol% or less, 5 mol% or more and 20 mol% or less, 10 mol% or more and 40 mol% or less, 10 mol% or more and 30 mol% or less, 10 mol% or more and 25 mol% or less, 10 mol% or more and 20 mol% or less, 15 mol% or more and 40 mol% or less, 15 mol% or more and 30 mol% or less, 15 mol% or more and 25 mol% or less, or 15 mol% or more and 20 mol% or less.

[0055] The proportion of the monomer units (III-2) in the second monomer units may be, for example, 60 mol% or more, 70 mol% or more, 75 mol% or more, or 80 mol% or more. The proportion of the monomer units (III-2) in the second monomer units may be, for example, 97 mol% or less, 95 mol% or less, 90 mol% or less, or 85 mol% or less. That is, the proportion of the monomer unit (III-2) in the second monomer unit may be, for example, 60 mol% or more and 97 mol% or less, 60 mol% or more and 95 mol% or less, 60 mol% or more and 90 mol% or less, 60 mol% or more and 85 mol% or less, 70 mol% or more and 97 mol% or less, 70 mol% or more and 95 mol% or less, 70 mol% or more and 90 mol% or less, 70 mol% or more and 85 mol% or less, 75 mol% or more and 97 mol% or less, 75 mol% or more and 95 mol% or less, 75 mol% or more and 90 mol% or less, 75 mol% or more and 85 mol% or less, 80 mol% or more and 97 mol% or less, 80 mol% or more and 95 mol% or less, 80 mol% or more and 90 mol% or less, or 80 mol% or more and 85 mol% or less.

[0056] In this specification, the number of each monomer unit contained in the liquid crystal polyester is determined by the analytical method described in JP 2000-19168 A. Specifically, the liquid crystal polyester is depolymerized by reacting it with a lower alcohol in a supercritical state, and the depolymerization product (monomers that derive each monomer unit) is quantified by liquid chromatography, whereby the number of each monomer unit relative to the total monomer units can be calculated.

[0057] The liquid crystal polyester can be produced by polymerizing raw material monomers corresponding to the monomer units that constitute the polyester, for example, according to the method described in Japanese Patent No. 6439027.

[0058] The flow initiation temperature of the liquid crystal polyester may be, for example, 250° C. or higher, or 270° C. or higher. The flow initiation temperature of the liquid crystal polyester may be, for example, 400° C. or lower, 360° C. or lower, or 340° C. or lower. That is, the flow initiation temperature of the liquid crystal polyester may be, for example, 250° C. or higher and 400° C. or lower, 250° C. or higher and 360° C. or lower, 250° C. or higher and 340° C. or lower, 270° C. or higher and 400° C. or lower, 270° C. or higher and 360° C. or lower, or 270° C. or higher and 340° C. or lower.

[0059] In this specification, the flow initiation temperature of the liquid crystalline polyester is measured using a flow tester, and is the temperature at which the liquid crystalline polyester melts under a load of 9.8 MPa while increasing in temperature at a rate of 4°C / min, and the molten liquid crystalline polyester is extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm, and the viscosity of the extruded liquid crystalline polyester is 4800 Pa s.

[0060] The dielectric loss tangent of the liquid crystal polyester at 28 GHz may be, for example, 0.002 or less, preferably 0.0015 or less, more preferably 0.0012 or less, which makes it easier to obtain a liquid crystal polyester composition having a suitable dielectric loss tangent as described below.

[0061] The liquid crystal polyester may have a relative dielectric constant of, for example, 4.0 or less, or 3.8 or less at 28 GHz. The liquid crystal polyester may have a relative dielectric constant of, for example, 2.8 or more, or 3.0 or more at 28 GHz.

[0062] In this specification, the dielectric loss tangent and relative permittivity of the liquid crystal polyester at 28 GHz are measured by the following method. Using an injection molding machine (ROBOSHOT S-2000i 30B, manufactured by FANUC Corporation), a liquid crystal polyester is used as the molding material to obtain a test piece having a width of 30 mm, a length of 30 mm, and a thickness of 0.3 mm under conditions of a mold temperature of 130°C and an injection speed of 200 mm / s. The cylinder temperature is set to a temperature (e.g., 300 to 400°C) at which the liquid crystal polyester melts and can be poured into the mold. The relative permittivity and dielectric loss tangent of the obtained test piece at 28 GHz are measured using a vector network analyzer (N529A, manufactured by Keysight Technologies, Inc.) and a split cylinder resonator (CR710, manufactured by EM Lab Co., Ltd.). The measurement environment is 23°C and 50% RH.

[0063] The content of the liquid crystal polyester may be, for example, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 96% by mass or more, 97% by mass or more, 97.5% by mass or more, 98% by mass or more, 98.5% by mass or more, or 99% by mass or more, based on the total amount of the liquid crystal polyester composition. The content of the liquid crystal polyester may be, for example, 99.98% by mass or less, 99.95% by mass or less, 99.9% by mass or less, 99.8% by mass or less, or 99.5% by mass or less, based on the total amount of the liquid crystal polyester composition.

[0064] The carbodiimide compound is a compound having a carbodiimide group (—N═C═N—). The carbodiimide compound may be a compound having one carbodiimide group or a compound having multiple carbodiimide groups.

[0065] The carbodiimide compound may further have a polar group other than the carbodiimide group. The carbodiimide compound may have, for example, an isocyanate group. The aliphatic carbodiimide compound described below may have, for example, an isocyanate group, or may have isocyanate groups at both ends.

[0066] Examples of the carbodiimide compound include an aliphatic carbodiimide compound, an aromatic carbodiimide compound, and a cyclic carbodiimide compound. An aromatic carbodiimide compound or a cyclic carbodiimide compound is preferred, and an aromatic carbodiimide compound is more preferred.

[0067] The aliphatic carbodiimide compound is a compound having an aliphatic hydrocarbon group and a carbodiimide group bonded to the aliphatic hydrocarbon group. The aliphatic carbodiimide compound may have a chain structure in which the carbodiimide groups and the aliphatic hydrocarbon groups are alternately bonded.

[0068] Examples of the aliphatic carbodiimide compound include compounds having a structure represented by the following formula (i): [In the formula, R １ represents an alkanediyl group, and n represents an integer of 1 or more.

[0069] The alkanediyl group may be, for example, an alkanediyl group having 1 to 10 carbon atoms, or an alkanediyl group having 1 to 4 carbon atoms. Examples of the alkanediyl group include a methylene group, an ethylene group, a 1,3-propanediyl group, and a 1,4-butanediyl group.

[0070] n represents an integer of 1 or more, and may be, for example, 2 or more, 5 or more, 10 or more, or 15 or more. n may be, for example, 50 or less, 40 or less, or 30 or less.

[0071] The aliphatic carbodiimide compound may be, for example, a compound represented by the following formula (i-1): [In the formula, R １ and n has the same meaning as above.]

[0072] The aliphatic carbodiimide compound may be, for example, a commercially available product. Examples of the aliphatic carbodiimide compound include Carbodilite HMV-15CA (manufactured by Nisshinbo Chemical Inc.), Carbodilite HMV-8CA (manufactured by Nisshinbo Chemical Inc.), Carbodilite LA-1 (manufactured by Nisshinbo Chemical Inc.), Carbodilite V-02B (manufactured by Nisshinbo Chemical Inc.), Carbodilite V-03 (manufactured by Nisshinbo Chemical Inc.), Carbodilite V-04K (manufactured by Nisshinbo Chemical Inc.), Carbodilite V-07 (manufactured by Nisshinbo Chemical Inc.), and Carbodilite V-09 (manufactured by Nisshinbo Chemical Inc.).

[0073] The aromatic carbodiimide compound is a compound having an aromatic ring and a carbodiimide group bonded to the aromatic ring. The aromatic carbodiimide compound may have a structure in which the carbodiimide groups and the aromatic hydrocarbon groups are bonded alternately.

[0074] The aromatic ring contained in the aromatic carbodiimide compound is preferably a benzene ring.

[0075] Examples of the aromatic carbodiimide compound include compounds having a structure represented by the following formula (ii): [In the formula, Ar ６ represents a phenylene group, and m represents an integer of 1 or more. ６ Some or all of the hydrogen atoms of may be substituted with halogen atoms, alkyl groups or aryl groups.

[0076] The phenylene group may be, for example, a 1,3-phenylene group or a 1,4-phenylene group, and is preferably a 1,3-phenylene group. These may have a substituent.

[0077] Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogen atom as a substituent may be a fluorine atom, a chlorine atom, or a bromine atom, or may be a fluorine atom, a chlorine atom, or a fluorine atom.

[0078] The alkyl group as a substituent may be linear, branched, or cyclic. The alkyl group may be, for example, an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, and an n-decyl group.

[0079] The aryl group as a substituent may be a monocyclic ring or a fused ring. The aryl group may be, for example, an aryl group having 6 to 20 carbon atoms. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group. The aryl group may be a group in which a hydrogen atom of an aromatic ring is substituted with an alkyl group, such as a tolyl group.

[0080] Ar ６ The number of substituents may be, for example, 0 to 3.

[0081] Ar ６ Examples of the alkyl group include a 2,4,6-triisopropyl-1,3-phenylene group.

[0082] The aromatic carbodiimide compound may be, for example, a commercially available product, such as Stavaxol (registered trademark) P (manufactured by Lanxess K.K.), Stavaxol (registered trademark) P100 (manufactured by Lanxess K.K.), Stavaxol (registered trademark) P400 (manufactured by Lanxess K.K.), Stavaxol (registered trademark) I (manufactured by Lanxess K.K.), or Carbodilite V-05 (manufactured by Nisshinbo Chemical Inc.).

[0083] A cyclic carbodiimide compound is a compound having a ring structure, part of which is a carbodiimide group. That is, a cyclic carbodiimide compound can also be referred to as a compound having a ring structure containing a carbodiimide group. Examples of the cyclic carbodiimide compound include a compound represented by the following formula (iii-1) and a compound represented by the following formula (iii-2).

[0084] As the cyclic carbodiimide compound, for example, a commercially available product such as Carbodista (registered trademark) TCC-NP (manufactured by Teijin Limited) may be used.

[0085] The content of the carbodiimide compound may be, for example, 0.02 parts by mass or more, or 0.05 parts by mass or more, relative to 100 parts by mass of the total of the liquid crystal polyester and the carbodiimide compound, and from the viewpoint of anisotropy, it may be 0.1 parts by mass or more, 0.2 parts by mass or more, or 0.5 parts by mass or more. The content of the carbodiimide compound may be, for example, 5 parts by mass or less, relative to 100 parts by mass of the total of the liquid crystal polyester and the carbodiimide compound, and from the viewpoint of dielectric properties, it may be 4 parts by mass or less, 3 parts by mass or less, 2.5 parts by mass or less, 2 parts by mass or less, 1.5 parts by mass or less, or 1 part by mass or less.

[0086] The total amount of the liquid crystal polyester and the carbodiimide compound in the liquid crystal polyester composition may be, for example, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 97% by mass or more, or 99% by mass or more, or may be 100% by mass.

[0087] The liquid crystal polyester composition may further contain an organic component other than the liquid crystal polyester and the carbodiimide compound.

[0088] For example, the liquid crystal polyester composition may contain one or more resins other than the liquid crystal polyester, such as polyolefins, cyclic polyolefins, polyvinyl chloride, polysulfones, (meth)acrylic resins, polyphenylene ether resins, polyacetal resins, polyamide resins, imide resins, cellulose resins, polyether ether ketone resins, fluororesins, polycarbonate resins, styrene-based resins, and thermosetting resins.

[0089] The liquid crystal polyester composition may further contain a colorant, a dispersant, a plasticizer, an antioxidant, a curing agent, a flame retardant, a heat stabilizer, an ultraviolet absorber, an antistatic agent, a surfactant, a lubricant, a mold release agent, etc.

[0090] The content of other organic components in the liquid crystal polyester composition may be, for example, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, 3% by mass or less, or 1% by mass or less, or may be 0% by mass.

[0091] The liquid crystal polyester composition may further contain an inorganic filler, and examples of the inorganic filler include titanium oxide and silica.

[0092] The amount of inorganic filler to be blended is not particularly limited and can be appropriately adjusted depending on the application. The content of inorganic filler in the liquid crystal polyester composition may be, for example, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, 3% by mass or less, or 1% by mass or less, or may be 0% by mass.

[0093] The liquid crystal polyester composition of the present embodiment may be a mixture of raw material components containing a liquid crystal polyester and a carbodiimide compound. The liquid crystal polyester composition of the present embodiment may be a melt-kneaded product of raw material components containing a liquid crystal polyester and a carbodiimide compound. In the mixture or the melt-kneaded product, the liquid crystal polyester and the carbodiimide compound may react to form a crosslinked structure.

[0094] The raw material components may further contain other organic components other than the liquid crystal polyester and the carbodiimide compound. The raw material components may further contain an inorganic filler. Examples of other organic components and inorganic fillers that may be contained in the raw material components include the same organic components and inorganic fillers that may be contained in the liquid crystal polyester composition described above.

[0095] The range of the content of each component in the raw material components may be the same as the range of the content of each component in the liquid crystal polyester composition described above.

[0096] The method for mixing the raw material components is not particularly limited, and known methods can be used without particular limitation. Examples of the mixing method include melt-kneading. Among these, melt-kneading is preferred from the viewpoint that the reaction between the terminal group of the liquid crystal polyester and the carbodiimide group of the carbodiimide compound is easily progressed and a suitable crosslinked structure is easily formed by the reaction.

[0097] The melt-kneaded mixture of the raw material components is heated to a temperature T １ The raw material components are mixed and kneaded.

[0098] Liquid crystal polyester flow starting temperature FT (℃) and temperature T １ (℃) (T １ The difference (T −FT) may be, for example, 5° C. or more, and from the viewpoint of more uniform mixing of the raw material components, it may be 10° C. or more, or 20° C. or more. １ -FT) may be, for example, 80°C or lower, and from the viewpoint of suppressing decomposition of the raw material components, it may be 70°C or lower, 60°C or lower, or 50°C or lower.

[0099] The liquid crystal polyester composition of the present embodiment has excellent fluidity when melted, and therefore can be suitably used as a molding material. The liquid crystal polyester composition may be used, for example, in the form of pellets.

[0100] The molded article of the present embodiment contains the liquid crystal polyester composition described above.

[0101] The molded article of this embodiment may be a molded article molded by a molding method in which a machine direction (MD) and a perpendicular direction (TD) are generated. Since the molded article of this embodiment contains the liquid crystal polyester composition described above, even if it is molded by a molding method in which a machine direction (MD) and a perpendicular direction (TD) are generated, the anisotropy is reduced. Examples of such molding methods include injection molding, inflation molding, T-die molding, blow molding, calendar molding, etc.

[0102] The molded article of this embodiment may be a connector, a socket, a film, a relay part, a coil bobbin, an optical pickup, an oscillator, a semiconductor package, an IC tray, a wafer carrier, a household electrical appliance part, a lighting fixture part, an audio product part, a ferrule for an optical cable, a telephone part, a facsimile part, a modem part, a separation claw, a heater holder, an impeller, a fan gear, a gear, a bearing, a motor part, a motor case, an engine part, an engine room part, an electrical part, an automotive interior part, a microwave cooking pot, a heat-resistant tableware, a flooring material, a wall material, a beam, a pillar, a roofing material, an aircraft part, a spacecraft part, a space equipment part, a nuclear reactor, a marine facility member, a cleaning jig, an optical equipment part, a valve, a pipe, a nozzle, a filter, a medical equipment part, a medical material, a sensor part, a sanitary fixture, a sporting goods, or a leisure goods.

[0103] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments.

[0104] The invention according to the present disclosure will be explained in more detail below using examples, but the invention according to the present disclosure is not limited to these examples.

[0105] Example 1 (1) Production of Liquid Crystal Polyester 1035.0 g (5.5 mol) of 6-hydroxy-2-naphthoic acid, 255.2 g (2.32 mol) of hydroquinone, 378.3 g (1.75 mol) of 2,6-naphthalenedicarboxylic acid, 83.1 g (0.5 mol) of terephthalic acid, 1189.9 g (12 mol) of acetic anhydride, and 0.175 g of 1-methylimidazole as a catalyst were added to a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser. The mixture was stirred at room temperature for 15 minutes, and then heated with stirring. When the internal temperature reached 140°C, the mixture was stirred for 1 hour while maintaining the same temperature. Next, the temperature was raised from 140°C to 310°C over 4 hours and 40 minutes while distilling off the by-product acetic acid and unreacted acetic anhydride. The mixture was kept at 310°C for 1 hour and 30 minutes, and then cooled to room temperature to obtain a solid. The resulting solid was pulverized using a pulverizer to obtain a resin powder (particle diameter: approximately 0.1 mm to approximately 1 mm). The flow initiation temperature of this resin powder was measured using a flow tester and found to be 274°C. The resulting resin powder was heated under a nitrogen atmosphere from 30°C to 225°C over 50 minutes, then heated from 225°C to 250°C over 1 hour and 40 minutes, then heated from 250°C to 300°C over 8 hours and 20 minutes, and then maintained at 300°C for 10 hours to undergo solid-state polymerization. The solid-state polymerized powder was then cooled to obtain a liquid crystal polyester (hereinafter also referred to as LCP1). The flow initiation temperature (FT) of the liquid crystal polyester after cooling was measured using the method described below and found to be 326°C. The content of the first monomer unit relative to the total of all monomer units constituting LCP1 was 72.0 mol%.

[0106] (2) Preparation of Pellets of Liquid Crystal Polyester Composition The LCP1 obtained in (1) above and an aliphatic carbodiimide compound (hereinafter also referred to as C1) (product name: Carbodilite HMV-15CA, manufactured by Nisshinbo Chemical Inc.) were prepared. LCP1 and C1 were mixed in a mass ratio of 99.5:0.5 and granulated in a twin-screw extruder (manufactured by Ikegai Corporation, PCM30) at a cylinder temperature of 340°C to obtain pellets of a liquid crystal polyester composition.

[0107] (3) Preparation of Test Pieces The pellets obtained in (2) above were injection molded using an injection molding machine (ROBOSHOT S-2000i 30B, manufactured by FANUC Corporation) under conditions of a mold temperature of 130°C, an injection speed of 200 mm / s, and a cylinder temperature of 350°C to obtain flat plate-shaped test pieces having a length in the injection molding direction (MD) of 30 mm, a width in the direction perpendicular thereto (TD) of 30 mm, and a thickness of 0.3 mm.

[0108] (4) Evaluation (4-1) Measurement of flow initiation temperature (FT) Using a flow tester (Shimadzu Corporation, CFT-500EX), approximately 2 g of sample was filled into a cylinder equipped with a die having a nozzle with an inner diameter of 1 mm and a length of 10 mm, and the sample was melted and extruded from the nozzle while increasing the temperature at a rate of 4°C / min under a load of 9.8 MPa. The temperature at which the sample showed a viscosity of 4800 Pa s was measured, and this temperature was taken as the flow initiation temperature. The flow initiation temperatures of the liquid crystal polyester compositions measured by this method are shown in Table 1.

[0109] (4-2) Measurement of coefficient of linear expansion (CTE) A thermomechanical analyzer (Rigaku Corporation, Thermo plus EVO2 series TMA8311) was used to measure the CTE. A measurement specimen with an MD length of 25 mm and a TD width of 4.5 mm was cut out from the flat test piece obtained in (3) above. The test piece for measurement was attached to the above-mentioned apparatus so that the distance between the chucks was 20 mm, and a tensile load of 25 mN was applied to both ends of the test piece. Next, the temperature was raised from room temperature to 250 ° C at a rate of 5 ° C / min, then cooled to 30 ° C at a rate of 20 ° C / min, and held at 30 ° C for 30 minutes. Thereafter, the temperature was raised again at a rate of 5 ° C / min, and the MD linear expansion coefficient CTE (unit: × 10 －５ (1 / K)) was calculated. Next, a measurement specimen having a TD length of 25 mm and a MD width of 4.5 mm was cut out from the flat plate specimen obtained in (3) above, and the linear expansion coefficient CTE of the TD was calculated in the same manner as in the MD. Then, the absolute value of the difference between the CTE of the MD and the CTE of the TD was calculated. The results are shown in Table 1.

[0110] (4-3) Method for measuring relative permittivity (Dk) and dielectric loss tangent (Df) The relative permittivity (Dk) and dielectric loss tangent (Df) at 28 GHz of the test specimen obtained in (3) above were measured using a vector network analyzer (N529A, manufactured by Keysight Technologies Inc.) and a split cylinder resonator (CR710, manufactured by EM Lab Co., Ltd.). The measurement environment was 23°C and 50% RH. The results are shown in Table 1.

[0111] Example 2 Except for mixing LCP1 and C1 in a mass ratio of 99:1, pellets were prepared, test pieces were prepared, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0112] (Example 3) An aliphatic carbodiimide compound (hereinafter also referred to as C2) (product name: Carbodilite LA-1, manufactured by Nisshinbo Chemical Inc.) was prepared. Pellets were prepared, test pieces were prepared, and evaluations were performed in the same manner as in Example 1, except that C2 was used instead of C1. The results are shown in Table 1.

[0113] (Example 4) Pellets and test pieces were prepared and evaluated in the same manner as in Example 3, except that LCP1 and C2 were mixed in a mass ratio of 99:1 and the cylinder temperature during pellet preparation was changed to 335° C. The results are shown in Table 1.

[0114] (Example 5) Pellets and test pieces were produced and evaluated in the same manner as in Example 3, except that LCP1 and C2 were mixed in a mass ratio of 98:2, the cylinder temperature during pellet production was changed to 330° C., and the cylinder temperature during test piece production was changed to 330° C. The results are shown in Table 1.

[0115] Example 6 An aromatic carbodiimide compound (hereinafter also referred to as C3) (product name: Stavaxol (registered trademark) P100, manufactured by Lanxess KK) was prepared. Pellets and test pieces were prepared and evaluated in the same manner as in Example 1, except that C3 was used instead of C1 and LCP1 and C3 were mixed in a mass ratio of 99.5:0.5. The results are shown in Table 1.

[0116] Example 7 Except for mixing LCP1 and C3 in a mass ratio of 99:1, pellets, test pieces, and evaluations were carried out in the same manner as in Example 6. The results are shown in Table 1.

[0117] (Example 8) Pellets and test pieces were prepared and evaluated in the same manner as in Example 6, except that LCP1 and C3 were mixed in a mass ratio of 98:2 and the cylinder temperature during test piece preparation was changed to 365° C. The results are shown in Table 1.

[0118] Example 9 A cyclic carbodiimide compound (hereinafter also referred to as C4) (product name: Carbodista TCC-NP, manufactured by Teijin Limited) was prepared. C4 was used instead of C1, LCP1 and C4 were mixed in a mass ratio of 99.5:0.5, and pellets, test pieces, and evaluation were carried out in the same manner as in Example 1, except that the cylinder temperature during test piece preparation was changed to 375°C. The results are shown in Table 1.

[0119] (Example 10) Pellets and test pieces were prepared and evaluated in the same manner as in Example 9, except that LCP1 and C4 were mixed in a mass ratio of 99:1 and the cylinder temperature during test piece preparation was changed to 380° C. The results are shown in Table 1.

[0120] Example 11 (1) Production of Liquid Crystal Polyester (LCP2) (1-1) Production of Liquid Crystal Polyester (a-1) A reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer, and a reflux condenser was charged with 1035.0 g (5.5 mol) of 6-hydroxy-2-naphthoic acid, 255.2 g (2.32 mol) of hydroquinone, 378.3 g (1.75 mol) of 2,6-naphthalenedicarboxylic acid, 83.1 g (0.5 mol) of terephthalic acid, 1226.87 g (12 mol) of acetic anhydride, and 0.175 g of 1-methylimidazole as a catalyst, and the mixture was stirred at room temperature for 15 minutes. The mixture was then heated to 140°C over 30 minutes while stirring under a nitrogen gas stream. The mixture was then refluxed for 1 hour while maintaining the same temperature. Next, the temperature was increased from 140°C to 310°C over 4 hours and 35 minutes while distilling off the by-product acetic acid and unreacted acetic anhydride. The reaction was considered complete when an increase in torque was observed, and the contents were removed. The resulting solid was cooled to room temperature and pulverized in a grinder to obtain an aromatic polyester powder (particle diameter: approximately 0.1 mm to approximately 1 mm). The flow temperature (FT) of this resin powder was measured using a flow tester and found to be 270°C. The resulting resin powder was heated from room temperature to 225°C over 1 hour, then heated from 225°C to 250°C over 1 hour and 40 minutes, then heated from 250°C to 306°C over 9 hours and 20 minutes, and then maintained at 306°C for 6 hours to undergo solid-state polymerization. The powder after solid-state polymerization was then cooled to obtain a liquid crystalline polyester (a-1). The flow temperature (FT) of the resulting liquid crystalline polyester (a-1) was 330°C.

[0121] (1-2) Preparation of Liquid Crystal Polyester (a-2) 1511.1 g (8.03 mol) of 6-hydroxy-2-naphthoic acid, 410.2 g (2.97 mol) of p-hydroxybenzoic acid, 1291.4 g (12.65 mol) of acetic anhydride, and 0.058 g of 1-methylimidazole as a catalyst were added to a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser. After stirring at room temperature for 15 minutes, the temperature was raised to 140 ° C. over 30 minutes while stirring under a nitrogen gas stream. The mixture was then refluxed for 1 hour while maintaining the same temperature. Next, the temperature was raised from 140 ° C. to 275 ° C. over 2 hours and 50 minutes while distilling off the by-product acetic acid and unreacted acetic anhydride. The reaction was considered complete when an increase in torque was observed, and the contents were removed. The resulting solid was cooled to room temperature and pulverized in a pulverizer to obtain an aromatic polyester powder (particle diameter: approximately 0.1 mm to approximately 1 mm). The flow initiation temperature (FT) of this resin powder was measured using a flow tester and found to be 217°C. The resulting resin powder was heated from room temperature to 190°C over 1 hour and 10 minutes, then heated from the same temperature (190°C) to 258°C over 9 hours and 50 minutes, and maintained at the same temperature of 258°C for 10 hours to undergo solid-state polymerization. The powder after solid-state polymerization was then cooled to obtain a liquid crystal polyester (a-2). The flow initiation temperature (FT) of the resulting liquid crystal polyester (a-2) was 318°C.

[0122] (1-3) Preparation of Liquid Crystal Polyester (LCP2) Liquid crystal polyester (a-1) and liquid crystal polyester (a-2) were dry blended in a mass ratio of 60:40 to obtain liquid crystal polyester (LCP2). The content of the first monomer unit relative to the total of all monomer units constituting LCP2 was 73.1 mol%.

[0123] (2) Preparation of pellets, preparation of test pieces, and evaluation The preparation of pellets, preparation of test pieces, and evaluation were carried out in the same manner as in Example 9, except that LCP2 and C4 were mixed in a mass ratio of 99.9:0.1, the cylinder temperature during pellet preparation was changed to 360° C., and the cylinder temperature during test piece preparation was changed to 340° C. The results are shown in Table 1.

[0124] Comparative Example 1 Pellets and test pieces were prepared and evaluated in the same manner as in Example 1, except that C1 was not used and the cylinder temperature during pellet preparation was changed to 345° C. The results are shown in Table 1.

[0125]

[0126] As shown in Table 1, in Examples 1 to 11, while maintaining good dielectric properties, the difference between the CTE in the machine direction (MD) and the CTE in the transverse direction (TD) is smaller than in Comparative Example 1 and Comparative Example 2 described later. From these results, it was confirmed that the liquid crystal polyester composition according to the present disclosure can achieve both good dielectric properties and small anisotropy.

[0127] (Comparative Example 2) (1) Production of Liquid Crystal Polyester (LCP3) 600.3 g (3.19 mol) of 2-hydroxy-6-naphthoic acid, 1078.7 g (7.81 mol) of p-hydroxybenzoic acid, 1235.3 g (12.1 mol) of acetic anhydride, and 0.168 g of 1-methylimidazole as a catalyst were added to a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser. After stirring at room temperature for 15 minutes, the temperature was raised to 140 ° C. over 30 minutes while stirring under a nitrogen gas stream. Thereafter, the mixture was refluxed for 1 hour while maintaining the same temperature. Next, the temperature was raised from 140 ° C. to 280 ° C. over 4 hours while distilling off the by-product acetic acid and unreacted acetic anhydride. Thereafter, the reaction was deemed to be complete when an increase in torque was observed, and the contents were removed and cooled to room temperature to obtain a solid. The resulting solid was pulverized in a pulverizer to obtain an aromatic polyester powder (particle diameter: approximately 0.1 mm to approximately 1 mm). The flow temperature (FT) of this resin powder was measured using a flow tester and found to be 234°C. The resulting resin powder was heated from room temperature to 230°C over 1 hour in a nitrogen atmosphere, then heated from 230°C to 250°C over 16 hours and 40 minutes, and held at 250°C for 10 hours, allowing the polymerization reaction to proceed in a solid phase. The flow temperature (FT) of the resulting resin (hereinafter also referred to as LCP3) was 283°C. The content of the first monomer unit relative to the total of all monomer units constituting LCP3 was 29.0 mol%.

[0128] (2) Preparation of pellets, preparation of test pieces, and evaluation The preparation of pellets, preparation of test pieces, and evaluation were carried out in the same manner as in Example 1, except that LCP3 was used instead of LCP1, LCP3 and C1 were mixed in a mass ratio of 99.5:0.5, the cylinder temperature during pellet preparation was changed to 300° C., and the cylinder temperature during test piece preparation was changed to 310° C. The results are shown in Table 2.

[0129]

Claims

1. A liquid crystal polyester composition comprising a liquid crystal polyester and a carbodiimide compound having a carbodiimide group, wherein the liquid crystal polyester contains a first monomer unit having a condensed aromatic ring, and the content of the first monomer unit is 30 mol% or more based on the total of all monomer units constituting the liquid crystal polyester.

2. A melt-kneaded product of raw material components containing a liquid crystal polyester and a carbodiimide compound having a carbodiimide group, wherein the liquid crystal polyester contains a first monomer unit having a condensed aromatic ring, and the content of the first monomer unit is 30 mol% or more based on the total of all monomer units constituting the liquid crystal polyester.

3. The liquid crystal polyester composition according to claim 1 or 2, wherein the liquid crystal polyester further contains a second monomer unit having a benzene ring.

4. The liquid crystal polyester composition according to claim 1 or 2, wherein the condensed aromatic ring is a naphthalene ring.

5. The liquid crystal polyester composition according to claim 1 or 2, wherein the content of the carbodiimide compound is 0.05 parts by mass or more and 5 parts by mass or less based on 100 parts by mass in total of the liquid crystal polyester and the carbodiimide compound.

6. A pellet containing the liquid crystal polyester composition according to claim 1 or 2.

7. A molded article containing the liquid crystal polyester composition according to claim 1 or 2.

8. The molded article according to claim 7, which is a film.

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