Molding raw material and film

Abstract

The present disclosure relates to a molding raw material that contains a liquid crystal polyester and in which the full width at half maximum of a peak having a peak top at a diffraction angle 2θ=17° to 22° in the X-ray diffraction spectrum is from 5.00° to 9.00°. The present disclosure also relates to a film which is a molded article of the molding raw material.

Description

Molding materials and films

[0001] The present disclosure relates to a forming material and a film.

[0002] Liquid crystal polyesters have attracted attention as materials that can achieve excellent low moisture absorption, heat resistance, and mechanical strength.

[0003] Patent Document 1 discloses an aromatic liquid crystal polyester that can be used to produce a film with small thermal volume expansion, the liquid crystal polyester essentially consisting of 30 to 60 mol % of repeating structural units derived from hydroxycarboxylic acid, 35 to 20 mol % of repeating structural units derived from 4,4′-diphenol, and 35 to 20 mol % of repeating structural units derived from naphthalenedicarboxylic acid.

[0004] Japanese Patent Application Laid-Open No. 2004-244452

[0005] Conventionally, when a film is produced by forming a molding material containing a liquid crystal polyester, a large number of unmelted lumps may occur in the film.

[0006] An object of the present disclosure is to provide a forming raw material that generates few lumps during film formation. Another object of the present disclosure is to provide a film that is formed from the forming raw material and has few lumps.

[0007] The present disclosure provides, for example, the following: [1] A molding material comprising a liquid crystal polyester, wherein the full width at half maximum of a peak having a peak top at a diffraction angle 2θ=17° to 22° in an X-ray diffraction spectrum is 5.00° or more and 9.00° or less. [2] The molding material according to [1], wherein the content of the liquid crystal polyester in the molding material is 75% by mass or more. [3] The molding material according to [1] or [2], wherein, when the maximum diffraction intensity of the peak in the X-ray diffraction spectrum is taken as 1, the diffraction intensity at a diffraction angle 2θ=25° is 0.300 or more and 0.520 or less. [4] The molding material according to any one of [1] to [3], wherein the liquid crystal polyester contains a monomer unit (i) having a phenylene skeleton. [5] The molding material according to [4], wherein the content of the monomer unit (i) is 50 mol% or more relative to the total of all monomer units constituting the liquid crystal polyester. [6] The molding material according to any one of [1] to [5], wherein the liquid crystal polyester contains a monomer unit (a) derived from an aromatic hydroxycarboxylic acid. [7] The molding material according to [6], wherein the content of the monomer unit (a) is 50 mol% or more relative to the total of all monomer units constituting the liquid crystal polyester. [8] The molding material according to any one of [1] to [7], which is a pellet. [9] A film, which is a molded product of the molding material according to any one of [1] to [8].

[10] The film according to [9], which is a melt-extrusion molded product of the molding material.

[0008] According to the present disclosure, a forming raw material that generates few lumps during film formation is provided. Also, according to the present disclosure, a film with few lumps formed from the forming raw material is provided.

[0009] 1 is a diagram showing an X-ray diffraction spectrum of a forming raw material of Example 1. FIG. 2 is a diagram showing an X-ray diffraction spectrum of a forming raw material of Comparative Example 1. FIG. 3 is a diagram showing an X-ray diffraction spectrum of a forming raw material of Comparative Example 2. FIG. 4 is a diagram showing an X-ray diffraction spectrum of a forming raw material of Comparative Example 3.

[0010] Preferred embodiments of the present disclosure will be described in detail below.

[0011] The forming material of the present embodiment includes a liquid crystal polyester. In addition, the forming material of the present embodiment has an X-ray diffraction spectrum in which the full width at half maximum of a peak having a peak top at a diffraction angle 2θ of 17° to 22° is 5.00° or more and 9.00° or less.

[0012] The forming material of this embodiment generates few lumps during film formation, and therefore, a film with few lumps can be easily produced using the forming material of this embodiment.

[0013] According to the findings of the present inventors, even if a liquid crystal polyester appears to be uniformly melted at first glance, there may be some unmelted portions, which may cause lumps during film formation.The present inventors have found that the above peak in the X-ray diffraction spectrum is effective as a means for observing the aggregation state of the liquid crystal polyester in the molding raw material, and further found that by selecting an appropriate aggregation state, the liquid crystal polyester melts more uniformly when the molding raw material is melted, making it less likely that unmelted portions will occur, and suppressing the occurrence of lumps.

[0014] In this embodiment, when the full width at half maximum of the peak is 5.00° or more and 9.00° or less, the liquid crystal polyester is in an appropriate aggregation state, and when the molding raw material is melted, the liquid crystal polyester melts more uniformly, making it less likely to produce unmelted parts and suppressing the occurrence of bumps. Note that when the peak is less than 5.00°, i.e., when the peak is too sharp, the crystallization of the liquid crystal polyester is significant, and it is thought that unmelted parts due to the crystalline structure are more likely to occur. Also, when the peak is more than 9.00°, i.e., when the peak is broad, it is thought that the aggregation state of the liquid crystal polyester is non-uniform, and due to the presence of a complex aggregation structure that is likely to produce unmelted parts, bumps are more likely to occur during film formation.

[0015] The liquid crystal polyester may be any polyester that exhibits liquid crystallinity in a molten state. The molding raw material may contain only one type of liquid crystal polyester, or may contain two or more types of liquid crystal polyester.

[0016] The flow initiation temperature of the liquid crystal polyester may be, for example, 250° C. or higher, or 260° C. or higher. The flow initiation temperature of the liquid crystal polyester may be 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, 260° C. or higher and 400° C. or lower, 260° C. or higher and 360° C. or lower, or 260° C. or higher and 340° C. or lower.

[0017] 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.

[0018] The liquid crystal polyester has constituent units (also referred to as monomer units) derived from raw material monomers. The liquid crystal polyester may have a main monomer unit (for example, 90 mol% or more, 95 mol% or more, or 99 mol% or more of the monomer units relative to the total of all monomer units, preferably all monomer units) derived from an aromatic compound. A liquid crystal polyester in which all monomer units are derived from an aromatic compound is also referred to as a wholly aromatic liquid crystal polyester.

[0019] 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).

[0020] The liquid crystal polyester may contain, for example, a monomer unit (i) having a phenylene skeleton. The liquid crystal polyester may also contain, for example, a monomer unit (ii) having a condensed aromatic ring.

[0021] The monomer unit (i) may be, for example, a monomer unit derived from a first aromatic compound having a benzene ring but no fused aromatic ring, and the monomer unit (ii) may be a monomer unit derived from a second aromatic compound having a fused aromatic ring.

[0022] 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. That is, the liquid crystal polyester may contain, for example, a monomer unit (a) derived from an aromatic hydroxycarboxylic acid. The liquid crystal polyester may also contain, for example, a monomer unit (b) derived from an aromatic dicarboxylic acid. The liquid crystal polyester may also contain, for example, a monomer unit (c) derived from an aromatic diol.

[0023] Examples of the monomer unit (i) include a monomer unit derived from an aromatic hydroxycarboxylic acid (i-a) having a benzene ring and no fused heterocyclic ring (hereinafter also referred to as monomer unit (i-a)), a monomer unit derived from an aromatic dicarboxylic acid (i-b) having a benzene ring and no fused heterocyclic ring (hereinafter also referred to as monomer unit (i-b)), and a monomer unit derived from an aromatic diol (i-c) having a benzene ring and no fused heterocyclic ring (hereinafter also referred to as monomer unit (i-c)).

[0024] The aromatic hydroxycarboxylic acid (ia) 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 (ib) may be a compound having a benzene ring and two carbonyl groups bonded to the benzene ring. The aromatic diol (ic) may be a compound having a benzene ring and two hydroxyl groups bonded to the benzene ring.

[0025] Examples of aromatic hydroxycarboxylic acids (ia) include p-hydroxybenzoic acid and m-hydroxybenzoic acid. Examples of aromatic dicarboxylic acids (ib) include terephthalic acid and isophthalic acid. Examples of aromatic diols (ic) include hydroquinone and 4,4'-biphenol.

[0026] Examples of the fused aromatic ring contained in the monomer unit (ii) 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. Among these, a naphthalene ring is preferred from the viewpoints of availability and cost.

[0027] Examples of the monomer unit (ii) include a monomer unit derived from an aromatic hydroxycarboxylic acid (ii-a) having a fused aromatic ring (hereinafter also referred to as a monomer unit (ii-a)), a monomer unit derived from an aromatic dicarboxylic acid (ii-b) having a fused aromatic ring (hereinafter also referred to as a monomer unit (ii-b)), and a monomer unit derived from an aromatic diol (ii-c) having a fused aromatic ring (hereinafter also referred to as a monomer unit (ii-c)).

[0028] The aromatic hydroxycarboxylic acid (ii-a) 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 (ii-b) may be a compound having a fused aromatic ring and two carbonyl groups bonded to the fused aromatic ring. The aromatic diol (ii-c) may be a compound having a fused aromatic ring and two hydroxyl groups bonded to the fused aromatic ring.

[0029] Examples of aromatic hydroxycarboxylic acids (ii-a) include 2-hydroxy-6-naphthoic acid, 2-hydroxy-3-naphthoic acid, and 1-hydroxy-5-naphthoic acid. Examples of aromatic dicarboxylic acids (ii-b) include 2,6-naphthalenedicarboxylic acid. Examples of aromatic diols (ii-c) include 2,6-dihydroxynaphthalene and 2,7-dihydroxynaphthalene.

[0030] Examples of the monomer unit contained in the liquid crystal polyester include a monomer unit represented by the following formula (a-1) (hereinafter also referred to as a monomer unit (a-1)), a monomer unit represented by the following formula (b-1) (hereinafter also referred to as a monomer unit (b-1)), and a monomer unit represented by the following formula (c-1) (hereinafter also referred to as a monomer unit (c-1)).１ -CO- (a-1) -CO-Ar ２ -CO- (b-1) -O-Ar ３ -O- (c-1) [wherein, Ar １ , Ar ２ and Ar ３ each independently represents a phenylene group, a biphenylene group, a condensed polycyclic aromatic hydrocarbon group, or a group represented by formula (z-1), 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 - (z-1) [wherein, Ar ４ and Ar ５ each 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.

[0031] 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.

[0032] The biphenylene group may be, for example, a 4,4'-biphenylene group.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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).

[0040] 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.

[0041] The monomer unit (i) is, for example, Ar １ is a phenylene group, a biphenylene group, or Ar４ and Ar ５ is a phenylene group, and may be a monomer unit represented by formula (a-1) (hereinafter also referred to as monomer unit (a-1-i)). ２ is a phenylene group, a biphenylene group, or Ar ４ and Ar ５ is a phenylene group, and a monomer unit represented by formula (b-1) (hereinafter also referred to as monomer unit (b-1-i)) ３ is a phenylene group, a biphenylene group, or Ar ４ and Ar ５ is a group represented by formula (z-1), which is a phenylene group (hereinafter also referred to as monomer unit (c-1-i)).

[0042] In the monomer unit (a-1-i), Ar １ is preferably a phenylene group or a biphenylene group, and more preferably a phenylene group. ２ is preferably a phenylene group or a biphenylene group, and more preferably a phenylene group. ３ is preferably a phenylene group or a biphenylene group, and more preferably a phenylene group.

[0043] The monomer unit (i) is preferably the monomer unit (a-1-i).

[0044] The monomer unit (ii) is, for example, 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 (a-1) (hereinafter also referred to as monomer unit (a-1-ii)), which is a group represented by formula (z-1) that is a condensed polycyclic aromatic hydrocarbon group; ２ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５at least one of Ar and Ar may be a monomer unit represented by formula (b-1) (hereinafter also referred to as monomer unit (b-1-ii)), which is a group represented by formula (z-1) that is a condensed polycyclic aromatic hydrocarbon group; ３ is a condensed polycyclic aromatic hydrocarbon group, or Ar ４ and Ar ５ and (c-1) (hereinafter also referred to as monomer unit (c-1-ii)), in which at least one of the monomer units (c-1) is a group represented by formula (z-1), which is a condensed polycyclic aromatic hydrocarbon group.

[0045] In the monomer unit (a-1-ii), Ar １ In the monomer unit (b-1-ii), Ar is preferably a condensed polycyclic aromatic hydrocarbon group. ２ In the monomer unit (c-1-ii), Ar is preferably a condensed polycyclic aromatic hydrocarbon group. ３ is preferably a condensed polycyclic aromatic hydrocarbon group.

[0046] The monomer unit (ii) is preferably the monomer unit (a-1-ii).

[0047] The liquid crystal polyester may contain the monomer unit (i). The liquid crystal polyester may also contain the monomer unit (ii).

[0048] In the liquid crystal polyester, the total amount of the monomer unit (i) and the monomer unit (ii) may be, for example, 90 mol% or more, 95 mol% or more, 99 mol% or more, or 100 mol% based on the total amount of all monomer units constituting the liquid crystal polyester.

[0049] In the liquid crystal polyester, the content of the monomer unit (i) may be, for example, 50 mol% or more relative to the total of all monomer units constituting the liquid crystal polyester, and from the viewpoint of processability, it may be 55 mol% or more, 60 mol% or more, 63 mol% or more, 66 mol% or more, or 68 mol% or more. Furthermore, the content of the monomer unit (i) may be, for example, 90 mol% or less relative to the total of all monomer units constituting the liquid crystal polyester, and from the viewpoint of dielectric properties, it may be 85 mol% or less, 80 mol% or less, 77 mol% or less, or 74 mol% or less. That is, the content of the monomer unit (i) relative to the total of all monomer units constituting the liquid crystal polyester is, for example, 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, 50 mol% or more and 77 mol% or less, 50 mol% or more and 74 mol% or less, 55 mol% or more and 90 mol% or less, 55 mol% or more and 85 mol% or less, 55 mol% or more and 80 mol% or less, 55 mol% or more and 77 mol% or less, 55 mol% or more and 74 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, 60 mol% or more and 77 mol% or less % or less, 60 mol% to 74 mol%, 63 mol% to 90 mol%, 63 mol% to 85 mol%, 63 mol% to 80 mol%, 63 mol% to 77 mol%, 63 mol% to 74 mol%, 66 mol% to 90 mol%, 66 mol% to 85 mol%, 66 mol% to 80 mol%, 66 mol% to 77 mol%, 66 mol% to 74 mol%, 68 mol% to 90 mol%, 68 mol% to 85 mol%, 68 mol% to 80 mol%, 68 mol% to 77 mol%, or 68 mol% to 74 mol%.

[0050] In the liquid crystal polyester, the content of the monomer unit (ii) may be, for example, 10 mol% or more relative to the total of all monomer units constituting the liquid crystal polyester, and from the viewpoint of dielectric properties, it may be 15 mol% or more, 20 mol% or more, 23 mol% or more, or 26 mol% or more. Furthermore, the content of the monomer unit (ii) may be, for example, 50 mol% or less relative to the total of all monomer units constituting the liquid crystal polyester, and from the viewpoint of processability, it may be 40 mol% or less, 37 mol% or less, 34 mol% or less, or 32 mol% or less. That is, the content of the monomer unit (ii) relative to the total of all monomer units constituting the liquid crystal polyester is, for example, 10 mol% or more and 50 mol% or less, 10 mol% or more and 40 mol% or less, 10 mol% or more and 37 mol% or less, 10 mol% or more and 34 mol% or less, 10 mol% or more and 32 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 37 mol% or less, 15 mol% or more and 34 mol% or less, 15 mol% or more and 32 mol% or less, 20 mol% or more and 50 ... mol% or more and 40 mol% or less, 20 mol% or more and 37 mol% or less, 20 mol% or more and 34 mol% or less, 20 mol% or more and 32 mol% or less, 23 mol% or more and 50 mol% or less, 23 mol% or more and 40 mol% or less, 23 mol% or more and 37 mol% or less, 23 mol% or more and 34 mol% or less, 23 mol% or more and 32 mol% or less, 26 mol% or more and 50 mol% or less, 26 mol% or more and 40 mol% or less, 26 mol% or more and 37 mol% or less, 26 mol% or more and 34 mol% or less, or 26 mol% or more and 32 mol% or less.

[0051] The liquid crystal polyester may contain a monomer unit (a) derived from an aromatic hydroxycarboxylic acid.

[0052] In the liquid crystal polyester, the content of the monomer unit (a) may be, for example, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, 95 mol% or more, or 99 mol% or more, or even 100 mol%. That is, the content of the monomer unit (a) may be, for example, 50 mol% or more and 100 mol% or less, 60 mol% or more and 100 mol% or less, 70 mol% or more and 100 mol% or less, 80 mol% or more and 100 mol% or less, 90 mol% or more and 100 mol% or less, 95 mol% or more and 100 mol% or less, or 99 mol% or more and 100 mol% or less, based on the total of all monomer units constituting the liquid crystal polyester.

[0053] The liquid crystal polyester may contain a monomer unit (b) derived from an aromatic dicarboxylic acid, or may contain a monomer unit (c) derived from an aromatic diol.

[0054] In the liquid crystal polyester, the total amount of the monomer unit (b) and the monomer unit (c) may be, for example, 50 mol% or less, 40 mol% or less, 30 mol% or less, 20 mol% or less, 10 mol% or less, 5 mol% or less, or 1 mol% or less, or may be 0 mol%, relative to the total of all monomer units constituting the liquid crystal polyester.

[0055] The liquid crystal polyester may contain, as the monomer unit (i), at least one selected from the group consisting of the monomer unit (ia), the monomer unit (ib) and the monomer unit (ic), and preferably contains the monomer unit (ia).

[0056] The proportion of the monomer unit (i-a) in the monomer unit (i) may be, for example, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, 95 mol% or more, or 99 mol% or more, or even 100 mol%. That is, the proportion of the monomer unit (i-a) in the monomer unit (i) may be, for example, 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 100 mol%, 80 mol% to 100 mol%, 90 mol% to 100 mol%, 95 mol% to 100 mol%, or 99 mol% to 100 mol%.

[0057] The liquid crystal polyester may contain, as the monomer unit (ii), at least one selected from the group consisting of the monomer unit (ii-a), the monomer unit (ii-b), and the monomer unit (ii-c), and preferably contains the monomer unit (ii-a).

[0058] The proportion of the monomer units (ii-a) in the monomer units (ii) may be, for example, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, 95 mol% or more, or 99 mol% or more, or even 100 mol%. That is, the proportion of the monomer units (ii-a) in the monomer units (ii) may be, for example, 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 100 mol%, 80 mol% to 100 mol%, 90 mol% to 100 mol%, 95 mol% to 100 mol%, or 99 mol% to 100 mol%.

[0059] The liquid crystal polyester may contain the monomer unit (ia) and the monomer unit (ii-a). In this case, the total content of the monomer unit (ia) and the monomer unit (ii-a) may be, for example, 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 100 mol%, 80 mol% to 100 mol%, 90 mol% to 100 mol%, 95 mol% to 100 mol%, or 99 mol% to 100 mol% with respect to the total of all monomer units constituting the liquid crystal polyester.

[0060] 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.

[0061] 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.

[0062] The content of the liquid crystal polyester may be, for example, 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more, based on the total amount of the molding raw materials, or may be 100% by mass.

[0063] The molding raw material may further contain components other than the liquid crystal polyester, such as fillers, colorants, dispersants, plasticizers, antioxidants, curing agents, flame retardants, heat stabilizers, UV absorbers, antistatic agents, surfactants, lubricants, and mold release agents.

[0064] The shape of the molding raw material is not particularly limited, and may be, for example, powder, granules (pellets), or the like.

[0065] The molding raw material is preferably in the form of pellets.

[0066] The X-ray diffraction spectrum of the forming raw material is measured by the following method. <Measurement of X-ray diffraction spectrum> 1.5 g of sample and a steel ball are placed in a sample container (75 mL) of a frozen grinder JFC-2000 (manufactured by Japan Analytical Industry Co., Ltd.). The sample container is attached to a grinding rod, immersed in liquid nitrogen, and held for 10 minutes. After that, the rod is vibrated up and down at a frequency of 75 Hz for 10 minutes to grind the sample, thereby obtaining a sample for XRD measurement. The sample for XRD measurement is measured under the following conditions to obtain an X-ray diffraction spectrum. <Apparatus conditions> Measurement apparatus: X'Pert Pro MPD Target: Cu Detector: X'Celerator Active Length (2θ) (°): 2.122 (°) Sample stage: Spinner Stage Revolution time (sec): 1 (sec) <Sample conditions> Sample holder: φ27 mm, depth 2.5 mm Sample rotation during measurement: Yes <Measurement conditions> Scan axis: 2θ / θ Mode: Continuous Start (°): 10° End (°): 35° Step (°): 0.0167113 (°) Time per Step (sec): 1000.125 sec Tube voltage (kV): 45 (kV) Tube current (mA): 40 (mA) Sample stage: Spinner Stage Revolution Time: 1 (second) Number of repetitions: 6 Measurement temperature: Room temperature (approx. 23°C) <Primary optical system> Filter: Ni Soller slit: 0.04 (rad) PDS (programmable divergence slit): Fixed 1 / 2, Offset 0 Mask: 10 mm ASS (anti-scatter slit): 1 (°) Attenuator: None <Receiving optical system> ASS (anti-scatter slit): None Soller slit: None Filter: None Attenuator: None Collimator: None Receiving slit: None Monochromator: X'Celerator monochromator, Offset -0.020

[0067] In this embodiment, the aggregation state of the liquid crystal polyester in the molding raw material is evaluated by a peak (hereinafter also referred to as peak (I)) having a peak top at a diffraction angle 2θ of 17° to 22° in the X-ray diffraction spectrum.

[0068] In the forming raw material of this embodiment, the full width at half maximum of Peak (I) is 5.00° or more and 9.00° or less. From the viewpoint of obtaining the above-mentioned effects more significantly, the full width at half maximum of Peak (I) may be 6.00° or more, 6.50° or more, or 7.00° or more. Furthermore, from the viewpoint of obtaining the above-mentioned effects more significantly, the full width at half maximum of Peak (I) may be 8.75° or less, 8.50° or less, or 8.25° or less.

[0069] When the maximum diffraction intensity of peak (I) is taken as 1, the diffraction intensity at a diffraction angle 2θ=25° may be, for example, 0.300 or more, and from the viewpoint of making it more difficult for unmelted portions due to the crystalline structure of the liquid crystal polyester to occur, it may be 0.400 or more, 0.425 or more, 0.450 or more, or 0.470 or more. Moreover, the diffraction intensity may be, for example, 0.520 or less, and from the viewpoint of making the aggregation state of the liquid crystal polyester more uniform and making it more difficult for unmelted portions to occur, it may be 0.510 or less, 0.505 or less, 0.500 or less, or 0.495 or less.

[0070] The molding raw material of this embodiment can be obtained, for example, by melting a raw material containing a liquid crystal polyester and molding the melt into pellets or the like. At this time, the melt may be subjected to a treatment so that the peak (I) of the molding raw material satisfies the above-mentioned full width at half maximum numerical range. The treatment may be, for example, a treatment of applying a shear force to the melt.

[0071] The treatment of applying shear force to the melt can be, for example, a method of passing the melt through a filter. According to such a method, when the melt passes through the pores of the filter, shear force is applied to the melt, and the liquid crystalline polyester in the melt is more uniformly dispersed, making it easier to obtain a molding material containing the liquid crystalline polyester in a good agglomerated state. The filter is not particularly limited, but, for example, a polymer filter containing a nonwoven fabric of sintered metal fiber is preferred.

[0072] The conditions for the above treatment are not particularly limited, and may be appropriately changed so that the peak (I) of the forming raw material satisfies the above-mentioned numerical range of full width at half maximum.

[0073] In addition, the molten state of the liquid crystal polyester when melted and the aggregation state in the molding raw material can change significantly depending on the state before melting, melting conditions, etc. And, a means for confirming the molten state of the liquid crystal polyester when melted and the aggregation state of the liquid crystal polyester in the molding raw material has not been known in the past, and it has been difficult to stably melt the liquid crystal polyester uniformly and use it as a molding raw material in a good aggregation state. In this embodiment, the aggregation state in the molding raw material can be evaluated by the full width at half maximum of the peak (I) (and the diffraction intensity), so that a molding raw material containing the liquid crystal polyester in a good aggregation state can be stably obtained, and a film with few lumps can be stably produced.

[0074] The forming raw material of this embodiment can be suitably used for forming a film, etc.

[0075] Examples of a method for obtaining a molded product (e.g., a film) from the molding raw material of this embodiment include melt extrusion, etc. Examples of molding conditions include conditions for obtaining a molded product containing a known liquid crystal polyester.

[0076] The film formed from the forming raw material of this embodiment has few lumps and therefore has excellent adhesion to flat surfaces, making it suitable for use in applications such as circuit boards.

[0077] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

[0078] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0079] Example 1 (1) Production of Liquid Crystal Polyester (A1) 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 placed in a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser. After thoroughly purging the reactor with nitrogen gas, the temperature was raised to 140°C over 30 minutes under a nitrogen gas stream, and the temperature was maintained while refluxing for 1 hour. Next, the temperature was raised from 140°C to 280°C over 4 hours while distilling off the by-product acetic acid. Thereafter, the reaction was deemed 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 grinder to obtain a resin powder (particle diameter of approximately 0.1 mm to approximately 1 mm). The obtained resin powder was heated in a nitrogen atmosphere from room temperature to 230°C over 1 hour, then from 230°C to 259°C over approximately 28 hours, and maintained at 259°C for 5 hours to allow a solid-phase polymerization reaction to proceed, thereby obtaining a liquid crystal polyester (A1). The liquid crystal polyester (A1) had a flow initiation temperature of 286°C.

[0080] (2) Production of molding raw material (pellets) A pleated filter (manufactured by Fuji Filter Industrial Co., Ltd., filter material: nonwoven fabric of sintered metal fiber, filtration accuracy: 20 μm) was connected to the outlet of a twin-screw extruder, and the powder of liquid crystal polyester (A1) was extruded from the twin-screw extruder at a cylinder heating temperature of 300°C, passed through the filter, and then granulated to obtain a molding raw material in the form of pellets.

[0081] The X-ray diffraction spectrum of the obtained forming raw material was measured by the method described above in <Measurement of X-ray diffraction spectrum>. The results are shown in Figure 1. In Figure 1, the horizontal axis represents 2θ (°), and the vertical axis represents the diffraction intensity when the maximum diffraction intensity of the peak (peak (I)) having a peak top at a diffraction angle 2θ of 17° to 22° is set to 1. The horizontal and vertical axes in Figures 2 to 4 described below are the same.

[0082] From the obtained X-ray diffraction spectrum, the full width at half maximum of the peak (peak (I)) having a peak top at a diffraction angle 2θ of 17° to 22°, and the diffraction intensity at a diffraction angle 2θ of 25° were determined, with the maximum diffraction intensity of peak (I) being taken as 1. The results are shown in Table 1.

[0083] The filter inlet pressure was 5.8 MPa at the start of extrusion and 5.9 MPa after granulation (7 hours after the start of extrusion). Since there was almost no increase in the filter inlet pressure, it was confirmed that the filter was not clogged and that the effect of reducing particles, which will be described later, was not due to the removal of impurities by the filter but was due to a change in the molten state of the liquid crystal polyester caused by the filter.

[0084] (3) Production of Film The above-mentioned raw material for molding was charged into the cylinder of a single-screw extruder, and a film was obtained by T-die extrusion molding. The screw shape of the single-screw extruder was full flight.

[0085] (4) Film Evaluation The obtained films were evaluated for the presence or absence of particles by the following method. The film was cut into pieces with a mass of approximately 0.5 g. The number of particles on the cut film was visually counted. From the results, the number of particles per 1 g of film was calculated. The results are shown in Table 1.

[0086] (Comparative Example 1) Production of a molding raw material, production of a film, and evaluation of the film were carried out in the same manner as in Example 1, except that the pleated filter was not used in (2) of Example 1. The results are shown in Table 1. The X-ray diffraction spectrum of the molding raw material of Comparative Example 1 was as shown in Figure 2.

[0087] Comparative Example 2 A liquid crystal polyester (A1) was obtained in the same manner as in Example 1 (1). This liquid crystal polyester (A1) was subjected to X-ray diffraction spectrum measurement without performing Example 1 (2). The X-ray diffraction spectrum was measured in the same manner as in the above-described <Measurement of X-ray Diffraction Spectrum>. However, the measurement conditions were changed: the end (°) was set to 90°, the time per step was set to 29.845 (seconds), and the number of repetitions was set to 1. The results are shown in FIG. 3. Furthermore, from the obtained X-ray diffraction spectrum, the full width at half maximum of the peak (Peak (I)) having a peak top at a diffraction angle 2θ of 17° to 22°, and the diffraction intensity at a diffraction angle 2θ of 25°, where the maximum diffraction intensity of Peak (I) is set to 1, were determined. The results are shown in Table 1.

[0088] (Example 2) The molding raw material obtained in Example 1 was charged into the cylinder of a single-screw extruder and a film was obtained by inflation molding. The screw shape of the single-screw extruder was full flight. The obtained film was evaluated in the same manner as in Example 1 (4). The results are shown in Table 2.

[0089] Comparative Example 3 A pellet-shaped molding raw material was obtained in the same manner as in Example 1, except that a twin-screw extruder with a screw diameter of about 1.5 times and a screw length to screw diameter ratio of about 1.1 times was used. The X-ray diffraction spectrum of the obtained molding raw material was measured by the method described above in <Measurement of X-ray diffraction spectrum>. The results are shown in Figure 4. Using the obtained molding raw material, a film was produced by inflation molding in the same manner as in Example 2, and the film was evaluated. The results are shown in Table 2.

[0090] In the following tables, "full width at half maximum" indicates the full width at half maximum of peak (I), and "diffraction intensity at 2θ=25°" indicates the diffraction intensity at a diffraction angle 2θ=25° when the maximum diffraction intensity of peak (I) is set to 1.

[0091] The "number of lumps" in the table was evaluated according to the following evaluation criteria: AA: The number of lumps is less than 2 / g. A: The number of lumps is 2 / g or more and less than 5 / g. C: The number of lumps is 5 / g or more.

[0092]

[0093]

Claims

1. A molding material containing a liquid crystal polyester, in which in an X-ray diffraction spectrum, the full width at half maximum of a peak having a peak top at a diffraction angle 2θ = 17° to 22° is 5.00° or more and 9.00° or less.

2. The molding material according to claim 1, wherein the content of the liquid crystal polyester in the molding material is 75% by mass or more.

3. The forming material according to claim 1, wherein, in the X-ray diffraction spectrum, when the maximum diffraction intensity of the peak is taken as 1, the diffraction intensity at a diffraction angle 2θ = 25° is 0.300 or more and 0.520 or less.

4. The molding material according to claim 1, wherein the liquid crystal polyester contains a monomer unit (i) having a phenylene skeleton.

5. The molding material according to claim 4, wherein the content of the monomer unit (i) is 50 mol % or more based on the total of all monomer units constituting the liquid crystal polyester.

6. The molding material according to claim 1, wherein the liquid crystal polyester contains a monomer unit (a) derived from an aromatic hydroxycarboxylic acid.

7. The molding material according to claim 6, wherein the content of the monomer unit (a) is 50 mol % or more based on the total of all monomer units constituting the liquid crystal polyester.

8. The molding material according to claim 1, which is in the form of pellets.

9. A film formed from the molding material according to any one of claims 1 to 8.

10. The film of claim 9, which is a melt extrusion of said forming material.

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