JP2018168320A - Liquid crystal polyester composition and molded body - Google Patents

Abstract

To provide a liquid crystal polyester composition which can stably produce a molded body even in a small-sized and thin molded body, and can produce a molded body with less warpage.SOLUTION: A liquid crystal polyester composition contains 5 pts.mass or more and 80 pts.mass or less of a glass flake with respect to 100 pts.mass of liquid crystal polyester, where a thickness of the glass flake is 0.1 μm or more and 1.0 μm or less, a volume average particle diameter of the glass flake measured by a laser diffraction method is 23 μm or more and 38 μm or less, the glass flake contains a large diameter component having a particle diameter of 100 μm or more and 400 μm or less, and a ratio of the large diameter component in 100 vol.% of the glass flake is 0.1 vol% or more and 2.3 vol% or less.SELECTED DRAWING: None

Description

  The present invention relates to a liquid crystal polyester composition and a molded body.

  Liquid crystalline polyester has excellent moldability and high heat resistance. Liquid crystalline polyesters are used for electronic parts such as connectors, relays, and bobbins by taking advantage of these characteristics. In recent years, electronic components have been highly integrated, miniaturized, thinned, and low profiled. In particular, connector components are prone to miniaturization and thinning.

  Representative examples of such connectors include board-to-board (B to B) connectors and flexible printed circuit board (FPC) connectors. B to B connectors are used to join printed wiring boards together. The FPC connector is used to connect an FPC and a flexible flat cable (FFC).

  As an example of the B to B connector or the connector for FPC, for example, a connector in which the pitch between the metal terminals of the connector is set to 0.35 mm or less. Moreover, the thickness dimension (what is called stacking height) in the state which fitted the connector is 0.6 mmt or less. In order to manufacture such a thinned connector, a material excellent in fluidity has been demanded.

  Further, as the thickness of the connector has been reduced, conventionally, a warp that is negligibly small has become more obvious.

  For this reason, a molding material for a thin connector typified by a B to B connector or an FPC connector is required to be able to reduce warpage of the molded product while having excellent fluidity.

  In response to such a requirement, Patent Document 1 discloses a liquid crystalline polyester resin composition having excellent low fluidity and excellent fluidity even in an extremely thin molded product. The liquid crystalline polyester resin composition disclosed in Patent Document 1 includes a liquid crystalline polyester resin and fine glass flakes. In the liquid crystalline polyester resin composition disclosed in Patent Document 1, fine glass flakes having a number average particle diameter of 5 to 50 μm and an aspect ratio of 100 or less are used.

JP 2011-074301 A

  However, when trying to produce a small and thin molded article using the liquid crystalline polyester resin composition disclosed in Patent Document 1, a short shot occurs and a desired shape may not be obtained. Moreover, the molded object obtained using this resin composition may warp. From the above, there has been a demand for a liquid crystal polyester composition that can stably produce a molded body and can produce a molded body with less warpage.

  The present invention has been made in view of such circumstances, and a liquid crystal polyester composition and a molded body that can stably produce a molded body even in a small and thin molded body and can produce a molded body with less warpage. The purpose is to provide.

  In order to solve the above problems, one embodiment of the present invention includes 5 to 80 parts by mass of glass flakes with respect to 100 parts by mass of liquid crystalline polyester, and the thickness of the glass flakes is 0.1 to 1.0 μm. The glass flake has a volume average particle size of 23 μm or more and 38 μm or less measured by a laser diffraction method, and the glass flake contains a large particle size component having a particle size of 100 μm or more and 400 μm or less and occupies 100% by volume of the glass flake. Provided is a liquid crystal polyester composition in which the proportion of the large particle size component is 0.1% by volume or more and 2.3% by volume or less.

  In one embodiment of the present invention, the ratio of the large particle size component in 100% by volume of the glass flakes may be 0.1% by volume or more and less than 1.0% by volume.

  One embodiment of the present invention provides a molded body using the above-described liquid crystal polyester composition as a forming material.

  According to one aspect of the present invention, there are provided a liquid crystal polyester composition and a molded product that can stably produce a molded product even in a small and thin molded product and can produce a molded product with less warpage.

The schematic perspective view which shows an example of the connector for FPC. The schematic sectional drawing of the extruder used in the Example.

<Liquid crystal polyester composition>
The liquid crystal polyester composition of the present embodiment includes liquid crystal polyester and glass flakes.

[Liquid crystal polyester]
The liquid crystalline polyester is a liquid crystalline polyester that exhibits liquid crystallinity in a molten state, and is preferably melted at a temperature of 450 ° C. or lower. The liquid crystal polyester may be a liquid crystal polyester amide, a liquid crystal polyester ether, a liquid crystal polyester carbonate, or a liquid crystal polyester imide. The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester using only an aromatic compound as a raw material monomer.

  A typical example of the liquid crystal polyester is polymerization (polycondensation) of an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, and at least one compound selected from the group consisting of an aromatic diol, an aromatic hydroxyamine, and an aromatic diamine. At least one compound selected from the group consisting of aromatic dicarboxylic acids and aromatic diols, aromatic hydroxyamines and aromatic diamines, And those obtained by polymerizing a polyester such as polyethylene terephthalate and an aromatic hydroxycarboxylic acid. Here, the aromatic hydroxycarboxylic acid, the aromatic dicarboxylic acid, the aromatic diol, the aromatic hydroxyamine, and the aromatic diamine are each independently replaced with a part or all of the polymerizable derivative. Also good.

  Examples of polymerizable derivatives of a compound having a carboxyl group such as aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid include those obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group (ester), carboxyl Examples include those obtained by converting a group into a haloformyl group (acid halide), and those obtained by converting a carboxyl group into an acyloxycarbonyl group (acid anhydride). Examples of polymerizable derivatives of hydroxyl group-containing compounds such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines include those obtained by acylating hydroxyl groups and converting them to acyloxyl groups (acylated products) ). Examples of polymerizable derivatives of amino group-containing compounds such as aromatic hydroxyamines and aromatic diamines include those obtained by acylating an amino group and converting it to an acylamino group (acylated product).

  The liquid crystalline polyester preferably has a repeating unit represented by the following formula (1) (hereinafter sometimes referred to as “repeating unit (1)”), and the repeating unit (1) and the following formula (2) A repeating unit represented (hereinafter sometimes referred to as “repeating unit (2)”) and a repeating unit represented by the following formula (3) (hereinafter sometimes referred to as “repeating unit (3)”). It is more preferable to have.

（Ａｒ^１は、フェニレン基、ナフチレン基又はビフェニリレン基を表す。Ａｒ^２及びＡｒ^３は、それぞれ独立に、フェニレン基、ナフチレン基、ビフェニリレン基又は下記式（４）で表される基を表す。Ｘ及びＹは、それぞれ独立に、酸素原子又はイミノ基（−ＮＨ−）を表す。Ａｒ^１、Ａｒ^２又はＡｒ^３で表される前記基にある水素原子は、それぞれ独立に、ハロゲン原子、アルキル基又はアリール基で置換されていてもよい。）

(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group (—NH—), and each hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or an alkyl group. Alternatively, it may be substituted with an aryl group.)

（Ａｒ^４及びＡｒ^５は、それぞれ独立に、フェニレン基又はナフチレン基を表す。Ｚは、酸素原子、硫黄原子、カルボニル基、スルホニル基又はアルキリデン基を表す。）

(Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-hexyl group, 2-ethylhexyl group, An n-octyl group and n-decyl group are mentioned, The carbon number is 1-10 normally. 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, and the number of carbon atoms is usually 6 to 20. . When the hydrogen atom is substituted with these groups, the number is usually 2 or less for each of the groups represented by Ar ¹ , Ar ² or Ar ³ , and preferably 1 It is as follows.

  Examples of the alkylidene group include a methylene group, an ethylidene group, an isopropylidene group, an n-butylidene group, and a 2-ethylhexylidene group, and the number of carbon atoms is usually 1 to 10.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. As the repeating unit (1), Ar ¹ is a p-phenylene group (repeating unit derived from p-hydroxybenzoic acid), and Ar ¹ is a 2,6-naphthylene group (6-hydroxy-2). -Repeating units derived from naphthoic acid) are preferred.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), Ar ² is a p-phenylene group (a repeating unit derived from terephthalic acid), Ar ² is an m-phenylene group (a repeating unit derived from isophthalic acid), Ar ² Is a 2,6-naphthylene group (a repeating unit derived from 2,6-naphthalenedicarboxylic acid), and Ar ² is a diphenyl ether-4,4′-diyl group (diphenyl ether- 4,4′-dicarboxylic acid-derived repeating units) are preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine or aromatic diamine. As the repeating unit (3), Ar ³ is a p-phenylene group (a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4′-biphenylylene group. Those (4,4′-dihydroxybiphenyl, 4-amino-4′-hydroxybiphenyl or repeating units derived from 4,4′-diaminobiphenyl) are preferred.

  The content of the repeating unit (1) is the total amount of all repeating units (the mass equivalent amount of each repeating unit (moles by dividing the mass of each repeating unit constituting the liquid crystal polyester by the formula amount of each repeating unit). ) And the total value thereof) is usually 30 mol% or more, preferably 30 to 80 mol%, more preferably 40 to 70 mol%, still more preferably 45 to 65 mol%.

  The content of the repeating unit (2) is usually 35 mol% or less, preferably 10 to 35 mol%, more preferably 15 to 30 mol%, still more preferably 17.5 to the total amount of all repeating units. 27.5 mol%.

  The content of the repeating unit (3) is usually 35 mol% or less, preferably 10 to 35 mol%, more preferably 15 to 30 mol%, still more preferably 17.5 to the total amount of all repeating units. 27.5 mol%. The higher the content of the repeating unit (1), the easier it is to improve the melt fluidity, heat resistance, strength and rigidity. However, if it is too much, the melting temperature and melt viscosity are likely to increase, and the temperature required for molding increases. easy.

  The ratio between the content of the repeating unit (2) and the content of the repeating unit (3) is expressed as [content of repeating unit (2)] / [content of repeating unit (3)] (mol / mol). The ratio is usually 0.9 / 1 to 1 / 0.9, preferably 0.95 / 1 to 1 / 0.95, and more preferably 0.98 / 1 to 1 / 0.98.

  In addition, liquid crystalline polyester may have 2 or more types of repeating units (1)-(3) each independently. Further, the liquid crystalline polyester may have a repeating unit other than the repeating units (1) to (3), but the content thereof is usually 10 mol% or less with respect to the total amount of all repeating units, preferably 5 mol% or less.

  Since the liquid crystal polyester has a repeating unit (3) in which X and Y are each an oxygen atom, that is, having a repeating unit derived from a predetermined aromatic diol, the melt viscosity tends to be low. It is more preferable that the repeating unit (3) has only those in which X and Y are each an oxygen atom.

  The liquid crystalline polyester can be produced by melt polymerizing raw material monomers corresponding to the repeating units constituting the liquid crystalline polyester and solid-phase polymerizing the obtained polymer (hereinafter sometimes referred to as “prepolymer”). preferable. Thereby, high molecular weight liquid crystal polyester having high heat resistance, strength and rigidity can be produced with good operability. Melt polymerization may be carried out in the presence of a catalyst. Examples of this catalyst include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide, And nitrogen-containing heterocyclic compounds such as 4- (dimethylamino) pyridine and 1-methylimidazole, and nitrogen-containing heterocyclic compounds are preferably used.

  The liquid polyester has a flow starting temperature of usually 270 ° C. or higher, preferably 270 to 400 ° C., more preferably 280 to 380 ° C. As the flow start temperature is higher, the heat resistance, strength and rigidity are more likely to be improved. However, if the flow start temperature is too high, the melting temperature and the melt viscosity are likely to be high, and the temperature required for the molding is likely to be high.

The flow start temperature is also called the flow temperature or flow temperature, and the liquid crystal polyester is heated at a rate of 4 ° C./min under a load of 9.8 MPa (100 kgf / cm ² ) using a capillary rheometer. Is a temperature showing a viscosity of 4800 Pa · s (48000 poise) when extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm, and is a measure of the molecular weight of the liquid crystalline polyester (Naide Koide, “ “Liquid Crystal Polymer—Synthesis / Molding / Application—”, CMC Co., Ltd., June 5, 1987, p. 95).

[Glass flakes]
The liquid crystal polyester composition of this embodiment contains 5 to 80 parts by mass of glass flakes with respect to 100 parts by mass of the liquid crystal polyester. When the content of the glass flake is 5 parts by mass or more, warpage of the obtained molded body can be sufficiently reduced. Further, when the glass flake content is 80 parts by mass or less, the liquid crystal polyester composition can be melt-kneaded. On the other hand, when the content of glass flakes exceeds 80 parts by mass, the viscosity of the liquid crystal polyester composition is too high, and melt kneading becomes difficult.

  The lower limit value of the glass flake content relative to 100 parts by mass of the liquid crystalline polyester is preferably 10 parts by mass or more, and more preferably 20 parts by mass or more. When the lower limit value of the glass flake content is within such a range, warpage of the obtained molded product can be further reduced.

  The upper limit value of the glass flake content relative to 100 parts by mass of the liquid crystalline polyester is preferably 70 parts by mass or less, and more preferably 60 parts by mass or less. When the upper limit value of the glass flake content is in such a range, the fluidity of the liquid crystal polyester composition during molding is sufficiently good. As a result, a compact can be stably manufactured even in a compact and thin molded body.

(Thickness)
The thickness of the glass flakes contained in the liquid crystal polyester composition of the present embodiment is 0.1 μm or more and 1.0 μm or less. When the thickness of the glass flake is 0.1 μm or more, the warp of the obtained molded body can be sufficiently reduced. Moreover, the fluidity | liquidity of the liquid crystalline polyester composition at the time of shaping | molding becomes it enough favorable that the thickness of glass flakes is 1.0 micrometer or less. As a result, a compact can be stably manufactured even in a compact and thin molded body.

  The lower limit value of the glass flake thickness is preferably 0.3 μm or more, and more preferably 0.5 μm or more. When the lower limit value of the thickness of the glass flake is in such a range, the warp of the obtained molded body can be further reduced.

  Moreover, it is preferable that the upper limit of the thickness of glass flakes is 0.9 micrometer or less, and it is more preferable that it is 0.8 micrometer or less. When the upper limit value of the thickness of the glass flake is within such a range, a molded product can be more stably produced even in a small and thin molded product.

  The upper limit value and the lower limit value can be arbitrarily combined.

  In addition, it turns out that the thickness of the glass flake used for this embodiment does not change substantially with the manufacturing method of the below-mentioned liquid crystal polyester composition. Therefore, the thickness of the glass flakes contained in the liquid crystal polyester composition can be determined by measuring the thickness of the glass flakes used.

  The thickness of the glass flakes used in the present embodiment is to observe the glass flakes to be used with a scanning electron microscope (SEM), measure the thickness of 10 glass flakes randomly selected from the obtained images, The average value is adopted.

(Volume average particle diameter)
The volume average particle diameter of the glass flakes contained in the liquid crystal polyester composition of the present embodiment is 23 μm or more and 38 μm or less. When the volume average particle diameter of the glass flakes is 23 μm or more, the warp of the obtained molded body can be sufficiently reduced. Further, when the volume average particle diameter of the glass flakes is 38 μm or less, a molded product can be stably produced even in a small and thin molded product.

  The lower limit of the volume average particle diameter of the glass flakes is preferably 25 μm or more, and more preferably 27 μm or more. When the lower limit value of the volume average particle diameter of the glass flake is within such a range, the warp of the obtained molded product can be further reduced.

  The upper limit of the volume average particle diameter of the glass flakes is preferably 36 μm or less, and more preferably 34 μm or less. When the upper limit value of the volume average particle diameter of the glass flake is within such a range, a molded product can be more stably produced even in a small and thin molded product.

  The upper limit value and the lower limit value can be arbitrarily combined.

  The lower limit of the volume average particle diameter of the glass flakes used for melt-kneading with the liquid crystalline polyester is preferably 25 μm or more, more preferably 40 μm or more, and further preferably 50 μm or more. The volume average particle diameter of glass flakes is known to be reduced by melt kneading, but glass flakes contained in a liquid crystal polyester composition are melt kneaded using glass flakes having a volume average particle diameter of 25 μm or more. Can be easily adjusted to 23 μm or more. As a result, it is possible to further reduce the warp of the obtained molded body.

  On the other hand, the upper limit of the volume average particle diameter of the glass flakes used for melt-kneading with the liquid crystalline polyester is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. By melt-kneading using glass flakes having a volume average particle diameter of 300 μm or less, the volume average particle diameter of the glass flakes contained in the liquid crystal polyester composition can be easily adjusted to 38 μm or less. As a result, a compact can be stably manufactured even in a compact and thin molded body.

  The upper limit value and the lower limit value can be arbitrarily combined.

  The volume average particle diameter of the glass flakes contained in the liquid crystal polyester composition of the present embodiment is measured by the following method.

  First, 3 g of the pellet made of the liquid crystal polyester composition of the present embodiment is heated at 600 ° C. for 3 hours to remove the resin, and glass flakes are taken out.

  Next, the obtained glass flakes are measured by a laser diffraction method. Specifically, 100 mg of glass flakes are dispersed in water, and measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by Horiba, Ltd., “LA-950V2”) under the following measurement conditions.

[Measurement condition]
Particle refractive index: 1.56
Dispersion medium: water Dispersion medium refractive index: 1.33

(Large particle size component)
The glass flakes contained in the liquid crystal polyester composition of the present embodiment contain a large particle size component having a particle size of 100 μm or more and 400 μm or less. The ratio of the large particle size component in 100% by volume of the glass flakes is 0.1% by volume to 2.3% by volume.

  When the ratio of the large particle size component is 0.1% by volume or more, warpage of the obtained molded body can be sufficiently reduced. Moreover, a molded object can be stably manufactured also in a small and thin molded object as the ratio of a large particle size component is 2.3 volume% or less. On the other hand, if the proportion of the large particle size component exceeds 2.3% by volume, shot shots may occur during the production of small and thin molded articles, and the desired shape may not be obtained. This is presumably because the large particle size component hinders the flow of the liquid crystalline polyester.

  The lower limit of the ratio of the large particle size component in 100% by volume of glass flakes is preferably 0.4% by volume or more, and more preferably 0.6% by volume or more. When the lower limit value of the ratio of the large particle size component is within such a range, the warp of the obtained molded body can be further reduced.

  Moreover, 1.5 volume% or less is preferable and, as for the upper limit of the ratio of the large particle size component which occupies for 100 volume% of glass flakes, it is more preferable that it is less than 1.0 volume%. When the upper limit value of the ratio of the large particle size component is within such a range, a molded body can be more stably produced even in a small and thin molded body.

  The upper limit value and the lower limit value can be arbitrarily combined.

  The volume average particle diameter of the glass flakes contained in the liquid crystal polyester composition and the ratio of the large particle size component in the glass flakes can be adjusted by the particle diameter of the glass flakes used and the production conditions of the liquid crystal polyester composition described later. .

  The particle diameter of the glass flake to be used can be adjusted by a conventionally known production method. The glass flakes used in this embodiment can be produced by a blow method or a rotary method.

  The blowing method is a method in which a nozzle is placed in a liquid tank in which molten glass is stored, air is blown from the nozzle to create a balloon, and this is pulled with a roller to obtain glass flakes. The rotary method is a method in which molten glass is continuously poured into a flat plate or cup-shaped container rotating at high speed and stretched from the flat plate or cup edge to obtain glass flakes.

  As a composition of the glass flakes used in the present embodiment, a generally known glass composition can be used. Specifically, a glass with little alkali metal oxide such as E glass can be suitably used. A typical composition of E glass is shown below. The unit of the following composition is mass%.

SiO _2: 52~56
Al ₂ O _3: 12~16
CaO: 16-25
MgO: 0-6
Na ₂ O + K ₂ O: 0 to 2 (preferably 0 to 0.8)
B ₂ O _3: 5~13
F _2: 0~0.5

  Moreover, the surface of the glass flakes used in the present embodiment may be covered with a thin film of one or both of a metal and a metal oxide. When the glass flakes used in the present embodiment contain an alkali component, the elution of the alkali components from the glass flakes can be prevented by coating the surface of the glass flakes with a thin film. As a result, it is possible to suppress disadvantages based on the elution of the alkali component, for example, a decrease in the adhesive strength between the resin (liquid crystal polyester) and the glass flake, and the discoloration of the resin (liquid crystal polyester).

  The glass flakes used in the present embodiment may be granular glass flakes granulated using a binder.

Granular glass flakes are made by adding a binder to the glass flakes, stirring and drying. The specific method of adding the binder, stirring and drying is not particularly limited.

  The binder is not particularly limited, but preferably includes an adhesive component and a coupling agent component, and a lubricant component such as an oil agent and a surfactant can also be used.

  The adhesive component is a component for granulating glass flakes and increasing the affinity between the glass flakes and the molding resin (liquid crystal polyester). The coupling agent component is a component that reacts with the surface of the glass flakes to increase the affinity between the surface of the glass and the molding resin (liquid crystal polyester).

  The adhesive component is not particularly limited, and organic and inorganic materials can be used. Examples of the organic adhesive component include methyl cellulose, carboxymethyl cellulose, starch, carboxymethyl starch, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, acrylic resin, epoxy resin, phenol resin, vinyl acetate, and polyurethane resin. Examples of the inorganic adhesive component include water glass, colloidal silica, and colloidal alumina.

  The coupling agent component is not particularly limited, and examples thereof include silane coupling agents, titanium coupling agents, aluminum coupling agents, zirconia coupling agents, and the like, and mixtures thereof can also be used. Examples of silane coupling agents include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltri Examples thereof include ethoxysilane and γ-methacryloxypropyltrimethoxysilane.

  The adhesion rate (adhesion amount) of the binder in the granular glass flakes can be controlled by the concentration and amount of the binder added or sprayed to the glass flakes. That is, a predetermined amount of binder solution is added or sprayed on a predetermined amount of flaky glass so that the solid content of the binder becomes a predetermined amount. Thereby, the granular glass flakes of a predetermined adhesion rate can be manufactured. The adhesion rate of the binder is preferably 1.0% by mass or less, more preferably 0.1% by mass or more and 0.5% by mass or less.

[Other ingredients]
The liquid crystal polyester composition may contain one or more other components such as a filler other than the glass flakes of the present embodiment, an additive, and a resin other than the liquid crystal polyester as long as the effects of the present invention are achieved.

  The filler may be a fibrous filler, a plate-like filler, or a spherical or other granular filler other than the fibrous and plate-like materials. The filler may be an inorganic filler or an organic filler.

  Examples of fibrous inorganic fillers include glass fibers; carbon fibers such as pan-based carbon fibers and pitch-based carbon fibers; ceramic fibers such as silica fibers, alumina fibers and silica-alumina fibers; and metal fibers such as stainless steel fibers. It is done. In addition, whiskers such as potassium titanate whisker, barium titanate whisker, wollastonite whisker, aluminum borate whisker, silicon nitride whisker, and silicon carbide whisker are also included.

  Examples of fibrous organic fillers include polyester fibers and aramid fibers.

  Examples of the plate-like inorganic filler include talc, mica, graphite, wollastonite, barium sulfate and calcium carbonate. Mica may be muscovite, phlogopite, fluorine phlogopite, or tetrasilicon mica.

  Examples of the particulate inorganic filler include silica, alumina, titanium oxide, glass beads, glass balloons, boron nitride, silicon carbide and calcium carbonate.

  Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, flame retardants, and colorants.

  Examples of resins other than liquid crystal polyester include polypropylene, polyamide, polyester other than liquid crystal polyester, thermoplastic resin other than liquid crystal polyester such as polysulfone, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and polyetherimide; and phenol resin And thermosetting resins such as epoxy resins, polyimide resins, and cyanate resins. Content of resin other than liquid crystalline polyester is 0-20 mass parts normally with respect to 100 mass parts of liquid crystalline polyester.

<Method for producing liquid crystal polyester composition>
The liquid crystal polyester composition is preferably prepared by melt-kneading a liquid crystal polyester, a glass component, and other components used as necessary using an extruder and extruding it into a pellet form.

  As the extruder, one having a cylinder, one or more screws arranged in the cylinder, and one or more supply ports provided in the cylinder is preferably used, and further one place provided in the cylinder What has the above vent part is used more preferably.

  In order to control the volume average particle size of the glass flakes contained in the liquid crystal polyester composition and the ratio of the large particle size component in the glass flakes, the configuration of the extruder used for melt kneading and the conditions of melt kneading are changed. To do.

  For example, when the volume average particle diameter of the glass flakes contained in the liquid crystal polyester composition is reduced, a means for changing the screw configuration so as to increase the shearing force is effective as the configuration of the extruder. Specifically, there is a means for changing the configuration of the kneading block to be incorporated.

  Usually, it is known that the shearing action increases in the order of the left-hand kneading block (L), the neutral kneading block (N), and the right-hand kneading block (R) (L> N> R).

  Further, when the extruder has a plurality of supply ports, it is also effective to supply glass flakes from the upstream supply port. Further, when the extruder has a kneading part, it is also effective to supply glass flakes from a supply port on the upstream side of the kneading part.

  As a condition for melt kneading, it is effective to increase the rotational speed of the screw used. Further, for example, means for lowering the cylinder temperature, increasing the melt viscosity of the molten resin, and increasing the shearing force are also effective.

  According to the liquid crystal polyester composition having the above-described configuration, a liquid crystal polyester composition that can stably produce a molded body even in a small and thin molded body and can produce a molded body with less warpage can be obtained.

<Molded body>
The molded body of the present embodiment uses the above-described liquid crystal polyester composition as a forming material.

  As a molding method of the liquid crystal polyester composition of the present embodiment, a melt molding method is preferable. Examples thereof include injection molding methods, extrusion molding methods such as T-die method and inflation method, compression molding methods, blow molding methods, vacuum molding methods and press molding. Of these, the injection molding method is preferable.

  Examples of products and parts that are molded products of liquid crystal polyester compositions include bobbins such as optical pickup bobbins and transformer bobbins; relay parts such as relay cases, relay bases, relay sprues, and relay armatures; RIMM, DDR, and CPU sockets. , S / O, DIMM, Board to Board connector, FPC connector, card connector, etc .; Lamp reflector, LED reflector, etc .; Lamp holder, heater holder, etc .; Speaker diaphragm, etc. Separation claws, separation claws for printers, etc .; camera module parts; switch parts; motor parts; sensor parts; hard disk drive parts; tableware such as ovenware; And a sealing member such as a coil sealing member.

  FIG. 1 is a schematic perspective view showing an example of an FPC connector obtained using the liquid crystal polyester composition of the present embodiment. As shown in FIG. 1, the external dimensions of the FPC connector 100 are 18 mm × 3.5 mm × 1.0 mm. The pitch P between the metal terminals of the FPC connector 100 is 0.3 mm. Moreover, the thickness of the minimum thickness part 201 is 0.1 mm.

  The liquid crystal polyester composition of the present embodiment can stably produce a molded body even in a small and thin molded body, and can produce a molded body with less warpage. By using such a liquid crystal polyester composition, it is possible to stably produce a molded body even with a small and thin molded body as shown in FIG. 1, and to obtain a molded body with less warpage.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Each measurement was performed as follows.

<Flow start temperature of liquid crystal polyester>
The flow start temperature of the liquid crystal polyester was measured using a flow characteristic evaluation apparatus (manufactured by Shimadzu Corporation, “Flow Tester CFT-500 type”).

First, about 2 g of a powdery sample (liquid crystal polyester) is filled into a capillary rheometer equipped with a die having an inner diameter of 1 mm and a length of 10 mm. Next, the liquid crystal polyester was melted while being heated at a rate of 4 ° C./min under a load of 9.8 MPa (100 kgf / cm ² ) and extruded from the nozzle. At this time, a temperature at which the melt viscosity was 4800 Pa · s (48000 poise) was measured, and this was used as the flow start temperature.

<Volume average particle diameter of glass flake>
100 mg of glass flakes are dispersed in water, and the volume average particle size of the glass flakes is measured under the following measurement conditions using a laser diffraction / scattering particle size distribution measuring device (manufactured by Horiba, Ltd., “LA-950V2”). It was measured.

[Measurement condition]
Particle refractive index: 1.56
Dispersion medium: water Dispersion medium refractive index: 1.33

<Volume average particle diameter of glass flake in liquid crystal polyester composition>
3 g of a pellet-shaped liquid crystal polyester composition described later was heated at 600 ° C. for 3 hours to remove the resin, and glass flakes were taken out. Next, the volume average particle diameter of the taken-out glass flakes was measured in the same manner as in the above <Volume average particle diameter of glass flakes>.

(Ratio of large particle size component)
The ratio of the large particle size component having a particle size of 100 μm or more and 400 μm or less in 100% by volume of the glass flakes was calculated from the volume cumulative particle size distribution curve obtained by the above measurement.

<Thickness of glass flakes used>
The glass flakes used are observed with a scanning electron microscope (SEM), the thicknesses of 10 glass flakes randomly selected from the obtained images are measured, and the average value is the thickness of the glass flakes in the examples. It was.

<Manufacture of liquid crystal polyester 1 (LCP1)>
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 994.5 g (7.2 mol) of p-hydroxybenzoic acid, 446.9 g of 4,4′-dihydroxybiphenyl ( 2.4 mol), 299.0 g (1.8 mol) of terephthalic acid, 99.7 g (0.6 mol) of isophthalic acid, and 1347.6 g (13.2 mol) of acetic anhydride. .2 g was added, and the inside of the reactor was sufficiently replaced with nitrogen gas. Thereafter, the temperature was raised from room temperature to 150 ° C. over 30 minutes under a nitrogen gas stream, and the mixture was refluxed for 1 hour while maintaining 150 ° C.

  Next, 0.9 g of 1-methylimidazole was added, and the temperature was increased from 150 ° C. to 320 ° C. over 2 hours and 50 minutes while distilling off by-product acetic acid and unreacted acetic anhydride, and when an increase in torque was observed The reaction was completed to obtain a prepolymer.

The prepolymer thus obtained was cooled to room temperature and pulverized with a coarse pulverizer. This prepolymer powder was heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere, heated from 250 ° C. to 285 ° C. over 5 hours, and held at 285 ° C. for 3 hours. Polymerization was performed.
The flow starting temperature of the obtained LCP1 was 327 ° C.

<Manufacture of liquid crystal polyester 2 (LCP2)>
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 994.5 g (7.2 mol) of p-hydroxybenzoic acid, 446.9 g of 4,4′-dihydroxybiphenyl ( 2.4 mol), 239.2 g (1.44 mol) of terephthalic acid, 159.5 g (0.96 mol) of isophthalic acid, and 1347.6 g (13.2 mol) of acetic anhydride. 2 g was added, and the inside of the reactor was sufficiently replaced with nitrogen gas.
Thereafter, the temperature was raised from room temperature to 150 ° C. over 30 minutes under a nitrogen gas stream, and the mixture was refluxed for 1 hour while maintaining 150 ° C.

  Next, 0.9 g of 1-methylimidazole was added, and the temperature was raised from 150 ° C. to 320 ° C. over 2 hours and 50 minutes while distilling out by-product acetic acid and unreacted acetic anhydride, and when torque increase was observed The reaction was completed to obtain a prepolymer.

  The prepolymer thus obtained was cooled to room temperature and pulverized with a coarse pulverizer. By heating the prepolymer powder from room temperature to 220 ° C. over 1 hour in a nitrogen atmosphere, raising the temperature from 220 ° C. to 240 ° C. over 0.5 hour, and holding at 240 ° C. for 10 hours, Solid phase polymerization was performed. The flow starting temperature of the obtained LCP2 was 291 ° C.

<Glass flakes>
The following three types of glass flakes were used.
Glass flake 1: MEG160FY-M03
(Nippon Sheet Glass Co., Ltd., volume average particle size 103 μm, thickness 0.7 μm)
Glass flake 2: MEG040FY
(Nippon Sheet Glass Co., Ltd., volume average particle diameter 43 μm, thickness 0.7 μm)
Glass flake 3: FTD025FY-F02
(Nippon Sheet Glass Co., Ltd., volume average particle diameter 32 μm, thickness 0.5 μm)

<Production of liquid crystal polyester composition>
Using the liquid crystal polyester and glass flakes described above, the liquid crystal polyester compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were produced.

[Examples 1 to 4, Comparative Examples 1 to 5]
Liquid crystal polyester composition using “PCM-30 type” (screw diameter: 29 mm, effective screw length / screw diameter: 25) manufactured by Ikekai Tekko Co., Ltd. as shown in FIG. Got. The configuration of the extruder is as follows.
Hopper part 5: Supply port Cylinder 1 (C1): First kneading zone Cylinder 2 (C2): Second kneading zone Vent 4: Air vent Cylinder 3 (C3): Third kneading zone Cylinder head (CH): 3Φmm 1 hole

  Liquid crystal polyester and glass flakes were blended at the blending ratio shown in Table 1, and then supplied from the hopper part. The set temperatures of C1, C2, C3, and CH were the temperatures shown in Table 1. Three counterclockwise kneading blocks (L) or three counterclockwise kneading blocks (R) were appropriately incorporated into C1, C2, and C3 to obtain a screw configuration shown in Table 1. The amount of extrusion was 6 kg / hour, and the number of revolutions of the extruder was 150 rpm. After melt-kneading using the extruder having the above-described configuration, a pellet-like liquid crystal polyester composition was obtained with a strand cutter.

[Comparative Example 6]
When the rotational speed of the extruder was 150 rpm and melt-kneaded under the conditions shown in Table 1, the strands were brittle and a pellet-like liquid crystal polyester composition could not be obtained.

<< Evaluation 1 >>
<Granulation>
The granulation properties of the liquid crystal polyester compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were evaluated. What was pelletized with the above-mentioned extruder was set as "(circle)", and what was not pelletized was set as "*".

  The obtained pellet-like liquid crystal polyester composition was evaluated by the following methods. The results are shown in Table 2.

<< Evaluation 2 >>
<Standard deviation of filling peak pressure>
A pellet-shaped liquid crystal polyester composition was used for injection molding under the following molding conditions to obtain an FPC connector shown in FIG. The filling peak pressure when this FPC connector was molded was measured. This measurement was performed for 10 moldings to determine the standard deviation of the filling peak pressure. It can be said that the smaller this standard deviation, the smaller the variation in the filling peak pressure, and the lower the possibility of short shots during molding.

[Molding condition]
Molding machine: “ROBOSHOT S-2000i30B” manufactured by FANUC
Cylinder temperature: 350 ° C
Mold temperature: 70 ℃
Injection speed: 200 mm / sec Holding pressure: 200 kgf / cm ²
Holding time: 1 second Cooling time: 7 seconds Screw rotation speed: 100 rpm
Screw back pressure: 40 kgf / cm ²

<War amount of FPC connector>
Using the three FPC connectors obtained in the above-mentioned <Standard deviation of filling peak pressure>, the measurement table (glass substrate) of the flatness measurement module “core9030c” manufactured by Cores Co., Ltd. is formed so that the surface 100A is the bottom surface. ). Next, the warpage amount from the glass substrate is measured every 0.5 mm along the long side 100a, the maximum value of the warpage amount of each FPC connector is obtained, and the average value of the obtained maximum values is the maximum warpage amount. It was.

About the liquid crystal polyester composition of Examples 1-4 and Comparative Examples 1-6, it evaluated comprehensively on the following references | standards.
○: The standard deviation of the filling peak pressure is 50 kgf / cm ² or less and the maximum warpage amount is less than 0.08 mm.
X: The standard deviation of the filling peak pressure exceeds 50 kgf / cm ² , or the maximum warpage amount is 0.08 mm or more.

As shown in Table 2, in the liquid crystal polyester compositions of Examples 1 to 4 to which the present invention was applied, the standard deviation of the filling peak pressure was sufficiently small as 50 kgf / cm ² or less.

  In the liquid crystal polyester compositions of Examples 1 to 4, the volume average particle diameter of the glass flakes was 38 μm or less. Moreover, the ratio of the large particle size component which occupies 100 volume% of glass flakes was 2.3 volume% or less. For this reason, it is considered that the glass flakes hardly disturb the flow of the liquid crystalline polyester and the filling peak pressure is stable. Accordingly, the liquid crystal polyester compositions of Examples 1 to 4 to which the present invention is applied are less likely to cause short shots during molding, and can be stably produced.

  Moreover, the connector for FPC obtained using the liquid crystal polyester composition of Examples 1-4 was sufficiently small with the largest curvature amount being less than 0.08 mm.

  In the liquid crystal polyester compositions of Examples 1 to 4, the volume average particle diameter of the glass flakes was 23 μm or more. Moreover, the ratio of the large particle diameter component which occupies 100 volume% of glass flakes was 0.1 volume% or more. It is considered that the warpage of the obtained FPC connector was suppressed by these.

On the other hand, the FPC connector obtained using the liquid crystal polyester compositions of Comparative Examples 1 to 3 had a sufficiently small maximum warpage of less than 0.08 mm. However, the standard deviation of the filling peak pressure of this liquid crystal polyester composition exceeded 50 kgf / cm ^{2 and} was large.

In addition, the liquid crystal polyester compositions of Comparative Example 4 and Comparative Example 5 had a sufficiently small standard deviation of the filling peak pressure of 50 kgf / cm ² or less. However, the FPC connector obtained using this liquid crystal polyester composition has a large maximum warpage amount of 0.08 mm or more.

  From the above results, it was confirmed that the present invention is useful.

Claims (3)

The glass flake is contained in an amount of 5 parts by weight to 80 parts by weight with respect to 100 parts by weight of the liquid crystalline polyester,
The glass flake has a thickness of 0.1 μm or more and 1.0 μm or less,
The volume average particle diameter of the glass flakes measured by a laser diffraction method is 23 μm or more and 38 μm or less,
The glass flake includes a large particle size component having a particle size of 100 μm or more and 400 μm or less,
The liquid-crystal polyester composition whose ratio of the said large-particle-size component which occupies for 100 volume% of said glass flakes is 0.1 volume% or more and 2.3 volume% or less.   2. The liquid crystal polyester composition according to claim 1, wherein a ratio of the large particle diameter component in 100% by volume of the glass flakes is 0.1% by volume or more and less than 1.0% by volume.   The molded object which uses the liquid-crystal polyester composition of Claim 1 or 2 as a forming material.

Images