WO2018199159A1 - Method for producing liquid-crystal polyester composition, and liquid-crystal polyester composition - Google Patents

Abstract

A method for producing a liquid-crystal polyester composition having a flow initiation temperature of 330°C or higher, the method including melt-kneading a liquid-crystal polyester and fibrils made of glass having a number-average fiber length of 1 mm or greater until the fibrils become glass fibers having a number-average fiber length of 30-200 μm.

Description

Method for producing liquid crystal polyester composition and liquid crystal polyester composition

The present invention relates to a method for producing a liquid crystal polyester composition and a liquid crystal polyester composition.
This application claims priority based on Japanese Patent Application No. 2017-090718 filed in Japan on April 28, 2017, the contents of which are incorporated herein by reference.

Liquid crystal polyester is widely used mainly for electrical and electronic parts because of its excellent heat resistance, fluidity and dimensional stability. For such applications, a molded body using a liquid crystal polyester composition using liquid crystal polyester and glass fiber having high heat resistance as a forming material has been proposed (for example, Patent Document 1).

JP 2008-239950 A

However, when a thin product is manufactured using a liquid crystal polyester composition having high heat resistance as described in Patent Document 1, molding may be defective. Therefore, in such a liquid crystal polyester, further improvement in thin-wall fluidity is required.

The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid crystal polyester composition having high heat resistance and high thin-wall fluidity, and a method for producing the same.

Among liquid crystal polyester compositions, particularly liquid crystal polyester compositions having a flow start temperature of 330 ° C. or more tend to improve heat resistance. On the other hand, this liquid crystal polyester composition has a problem that the thin wall fluidity is low. The present inventors have found that this problem can be solved by the following aspects, and have completed the present invention.

In order to solve the above problems, one embodiment of the present invention includes a step of melt-kneading a liquid crystalline polyester and a glass fiber having a number average fiber length of 1 mm or more. However, it melt-kneads until it becomes a glass fiber whose number average fiber length is 30 micrometers or more and 200 micrometers or less, and provides the manufacturing method of the liquid crystal polyester composition whose flow start temperature of a liquid crystal polyester composition is 330 degreeC or more.

One embodiment of the present invention is a liquid crystal polyester composition comprising a liquid crystal polyester and glass fibers having a number average fiber length of 30 μm or more and 200 μm or less, and the flow start temperature of the liquid crystal polyester composition is 330 ° C. or more, In the case of measuring the melt viscosity at a shear rate of 35 / sec after the liquid crystal polyester composition is left in a furnace of a capillary rheometer set at a temperature 30 ° C. higher than the flow start temperature and then kept at the temperature. A liquid crystal polyester composition having a value of 100 × b / a of 50 or more and 200 or less when the melt viscosity measured after standing for 5 minutes is a and the melt viscosity measured after standing for 1 hour is b provide.
[0000]
That is, the present invention includes the following aspects.
[1] including melt-kneading a liquid crystalline polyester and a glass fiber having a number average fiber length of 1 mm or more until the fiber becomes a glass fiber having a number average fiber length of 30 μm or more and 200 μm or less,
The manufacturing method of the liquid-crystal polyester composition whose flow start temperature is 330 degreeC or more.
[2] A liquid crystal polyester composition comprising a liquid crystal polyester and glass fibers having a number average fiber length of 30 μm or more and 200 μm or less,
The flow start temperature of the liquid crystal polyester composition is 330 ° C. or higher,
The liquid crystal polyester composition is allowed to stand for 5 minutes or 1 hour in a capillary rheometer furnace set at a temperature 30 ° C. higher than the flow start temperature, and then held at the temperature to obtain a melt viscosity at a shear rate of 35 / sec. The melt viscosity of the liquid crystal polyester composition measured after being left in the furnace for 5 minutes, and the melt viscosity of the liquid crystal polyester composition measured after being left in the furnace for 1 hour. A liquid crystal polyester composition having a value of 100 × b / a, where b is 50 or more and 200 or less.

According to the method for producing a liquid crystal polyester composition which is an embodiment of the present invention, a liquid crystal polyester composition having high heat resistance and high thin-wall fluidity can be obtained. In addition, the liquid crystal polyester composition which is one embodiment of the present invention has high heat resistance and high thin-wall fluidity.

It is a schematic sectional drawing which shows an example of the extruder which concerns on the manufacturing method of the liquid-crystal polyester composition of 1st Embodiment of this invention. It is a schematic perspective view of the metal mold | die for thin wall flow length measurement in this embodiment.

Hereinafter, a method for producing a liquid crystal polyester composition according to an embodiment of the present invention will be described with reference to the drawings. In all the drawings below, the dimensions, ratios, etc. of the respective components are appropriately changed in order to make the drawings easy to see.

<< First Embodiment >>
<Method for producing liquid crystal polyester composition>
The manufacturing method (1st Embodiment) of the liquid-crystalline-polyester composition which is one Embodiment of this invention has the process of melt-kneading liquid crystalline polyester and the glass fibrils whose number average fiber length is 1 mm or more. The melt-kneading step includes melt-kneading until the number average fiber length of the fibrils is 30 μm or more and 200 μm or less.

[Liquid crystal polyester]
The liquid crystal polyester according to the method for producing the liquid crystal polyester composition of the present embodiment exhibits liquid crystallinity in a molten state. The liquid crystalline polyester may be a liquid crystalline polyester amide, a liquid crystalline polyester ether, a liquid crystalline polyester carbonate, or a liquid crystalline polyester imide.

The flow start temperature of the liquid crystal polyester according to the production method of the present embodiment is preferably 330 ° C. or higher. The flow initiation temperature of the liquid crystalline polyester is more preferably 330 ° C. or higher and 450 ° C. or lower, still more preferably 330 ° C. or higher and 400 ° C. or lower, and particularly preferably 330 ° C. or higher and 390 ° C. or lower. Further, the flow start temperature may be 340 ° C or higher, 350 ° C or higher, or 360 ° C or higher.
As one aspect, the flow start temperature may be 340 ° C. or higher and 450 ° C. or lower, 350 ° C. or higher and 400 ° C. or lower, or 360 ° C. or higher and 390 ° C. or lower.
As another aspect, the flow start temperature may be 340 ° C. or higher and 347 ° C. or lower.

The flow initiation temperature refers to the use of a capillary rheometer (capillary rheometer) to melt the liquid crystalline polyester while increasing the temperature at a rate of 4 ° C./min under a load of 9.8 MPa (100 kg / cm ² ). This is the temperature at which a viscosity of 4800 Pa · s (48000 poise) is exerted when extruding from a nozzle having a length of 1 mm and a length of 10 mm, and is a measure of the molecular weight of the liquid crystalline polyester (“Nanoyuki Koide,“ Liquid Crystal Polymer— “Synthesis / Molding / Application—”, CMC Co., Ltd., June 5, 1987, p. 95).

The liquid crystal polyester according to this embodiment is preferably a wholly aromatic liquid crystal polyester in which only an aromatic compound is polymerized as a raw material monomer.

Typical examples of the liquid crystal polyester according to the present invention include at least one compound selected from the group consisting of aromatic diols, aromatic hydroxyamines and aromatic diamines, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acids. And at least one compound selected from the group consisting of aromatic hydroxyamines and aromatic diamines, and aromatic dicarboxylic acids Examples include those obtained by polymerizing an acid and an aromatic diol; 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 their polymerizable derivatives. Also good.

Examples of polymerizable derivatives of compounds having a carboxyl group such as aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids include those in which the carboxyl group is substituted with an alkoxycarbonyl group or an aryloxycarbonyl group (ie, esters), Examples include those in which a carboxyl group is substituted with a haloformyl group (that is, an acid halide), and those in which a carboxyl group is substituted with an acyloxycarbonyl group (that is, an acid anhydride).

Examples of polymerizable derivatives of compounds having hydroxyl groups, such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines, include those wherein the hydroxyl group is acylated and substituted with an acyloxyl group (ie, hydroxyl groups Acylated product).

Examples of polymerizable derivatives of compounds having amino groups such as aromatic hydroxyamines and aromatic diamines include those in which the amino group is acylated and substituted with an acylamino group (ie, acylated products of amino groups). .

The liquid crystalline polyester according to the present invention 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: The repeating unit represented by (2) (hereinafter sometimes referred to as “repeating unit (2)”) and the repeating unit represented by the following formula (3) (hereinafter referred to as “repeating unit (3)”) It is more preferable to have.

(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) —X—Ar ³ —Y—

In the above formulas (1) to (3), 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—). The hydrogen atom contained in the group represented by Ar ¹ , Ar ² or Ar ³ may be independently substituted with a halogen atom, an alkyl group or an aryl group.

(4) —Ar ⁴ —Z—Ar ⁵ —

In the formula (4), 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.
The hydrogen atom contained in the group represented by Ar ⁴ or Ar ⁵ may be independently substituted with a halogen atom, an alkyl group or an aryl group.

Examples of the halogen atom that can be substituted with a hydrogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group that can be substituted with a hydrogen atom is preferably an alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or an s-butyl group. Group, t-butyl group, n-hexyl group, 2-ethylhexyl group, n-octyl group and n-decyl group.

The aryl group that can be substituted with a hydrogen atom may be substituted with at least one hydrogen atom constituting the aryl group, and is preferably an aryl group having 6 to 20 carbon atoms in total including the substituent. , Phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 1-naphthyl group and 2-naphthyl group.

When the hydrogen atom contained in the group represented by Ar ¹ , Ar ² or Ar ³ is substituted with these groups, the number of substitutions is the group represented by Ar ¹ , Ar ² or Ar ^3. Each is independently 2 or less, preferably 1 or less.

The alkylidene group is preferably an alkylidene group having 1 to 10 carbon atoms, and examples thereof include a methylene group, an ethylidene group, an isopropylidene group, an n-butylidene group, and a 2-ethylhexylidene group.

When the hydrogen atom contained in the group represented by Ar ⁴ or Ar ⁵ is substituted with the halogen atom, the alkyl group, or the aryl group, the number of groups substituting the hydrogen atom is Ar ⁴ or Ar ⁵ For each group represented, it is preferably 2 or less, more preferably 1 independently of each other.

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 (for example, a repeating unit derived from p-hydroxybenzoic acid), and Ar ¹ is a 2,6-naphthylene group (for example, 6 Preferred is a repeating unit derived from -hydroxy-2-naphthoic acid.

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 (for example, a repeating unit derived from terephthalic acid), Ar ² is an m-phenylene group (for example, a repeating unit derived from isophthalic acid) ), Ar ² is a 2,6-naphthylene group (for example, a repeating unit derived from 2,6-naphthalenedicarboxylic acid), and Ar ² is a diphenyl ether-4,4′-diyl group (For example, repeating units derived from diphenyl ether-4,4′-dicarboxylic acid) 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 (for example, a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4′-biphenylylene group. Are preferred (for example, repeating units derived from 4,4′-dihydroxybiphenyl, 4-amino-4′-hydroxybiphenyl or 4,4′-diaminobiphenyl).
As used herein, “derived from” means that the chemical structure changes due to polymerization.

The content of the repeating unit (1) in the liquid crystal polyester is 30 mol% or more, preferably 30 to 80 mol%, more preferably 40 to 70 mol%, based on the total amount of all the repeating units constituting the liquid crystal polyester. More preferably, it is 45 to 65 mol%.

The total amount of all repeating units constituting the liquid crystal polyester is obtained by dividing the mass of each repeating unit constituting the liquid crystal polyester by the formula weight of each repeating unit, and obtaining the substance amount equivalent amount (mole) of each repeating unit. , The sum of them. The mass of each repeating unit constituting the liquid crystal polyester is calculated from the amount of the raw material monomer used, and this is a numerical value assuming that all the raw material monomers react.

Similarly, the content of the repeating unit (2) in the liquid crystal polyester is 35 mol% or less, preferably 10 to 35 mol%, more preferably 15 to 30 mol, based on the total amount of all repeating units constituting the liquid crystal polyester. The mol% is more preferably 17.5 to 27.5 mol%.

The content of the repeating unit (3) of the liquid crystal polyester is 35 mol% or less, preferably 10 to 35 mol%, more preferably 15 to 30 mol%, based on the total amount of all repeating units constituting the liquid crystal polyester. More preferably, it is 17.5 to 27.5 mol%.

As one aspect, when the liquid crystal polyester includes the repeating unit (1), the repeating unit (2), and the repeating unit (3), the repeating unit (1) with respect to the total amount of all repeating units constituting the liquid crystal polyester. The content of is 30 to 80 mol%, preferably 40 to 70 mol%, more preferably 45 to 65 mol%; the content of the repeating unit (2) is 10 to 35 mol%, preferably 15 to 30 mol%, more preferably 17.5 to 27.5 mol%; content of repeating unit (3) is 10 to 35 mol%, preferably 15 to 30 mol%, more preferably 17.5 to 27.5 mol%. However, the total content of the repeating unit (1), the repeating unit (2) and the repeating unit (3) does not exceed 100 mol%.

In the liquid crystal polyester, as the content of the repeating unit (1) increases, the melt fluidity, heat resistance, strength and rigidity are easily improved. However, if the content of the repeating unit (1) is more than 80 mol%, the melting temperature and the melt viscosity tend to be high, and the temperature required for molding tends to be high.

In the liquid crystal polyester according to this embodiment, the ratio between the content of the repeating unit (2) and the content of the repeating unit (3) is [content of repeating unit (2)] / [content of repeating unit (3)]. It is calculated from the formula represented by [rate] (mol% / mol%). The ratio between the content of the repeating unit (2) and the content of the repeating unit (3) is 0.9 to 1.11, preferably 0.95 to 1.05, more preferably 0.98 to 1.02. It is.

The repeating units (1) to (3) possessed by the liquid crystal polyester may be independently derived from one type of raw material monomer or may be derived from two or more types of raw material monomers.
The liquid crystalline polyester may have a repeating unit other than the repeating units (1) to (3). The content of repeating units other than the repeating units (1) to (3) is 0 mol% or more and 10 mol% or less, preferably 0 mol% or more and 5 mol based on the total amount of all repeating units constituting the liquid crystal polyester. % Or less.
As another aspect, the content of at least one repeating unit selected from the group consisting of the repeating unit (1), the repeating unit (2), and the repeating unit (3) in the liquid crystal polyester according to the present invention is the above-mentioned liquid crystal polyester. Preferably it is 90 mol% or more and 100 mol% or less with respect to the total content rate of all the repeating units to comprise, More preferably, it is 95 mol% or more and 100 mol% or less.

The liquid crystalline polyester preferably has a repeating unit (3) in which X and Y are each an oxygen atom. That is, it is preferable to have a repeating unit derived from a predetermined aromatic diol because the melt viscosity tends to be low. Further, it is more preferable that the repeating unit (3) has only those in which X and Y are each an oxygen atom.

The liquid crystal polyester according to the method for producing the liquid crystal polyester composition of the present embodiment may be commercially available, or may be synthesized from raw material monomers corresponding to the repeating units constituting the liquid crystal polyester. .

When the liquid crystalline polyester is synthesized, it is preferably produced by melt polymerization of the raw material monomers and solid-phase polymerization of the obtained polymer (hereinafter sometimes referred to as “prepolymer”). Thereby, for example, a liquid crystal polyester having a flow start temperature of 330 ° C. or higher and a high flow start temperature can be produced with good operability.

Melt polymerization may be performed in the presence of a catalyst. Examples of catalysts that may be used in the melt polymerization include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, antimony trioxide, and 4- (dimethylamino) pyridine. And nitrogen-containing heterocyclic compounds such as 1-methylimidazole, and nitrogen-containing heterocyclic compounds are preferably used.

In the above range, the liquid crystalline polyester may have the same repeating unit, and those having different repeating unit contents may be used in combination.

[Glass fiber]
The glass fiber according to the method for producing a liquid crystal polyester composition of the present embodiment (hereinafter sometimes simply referred to as “fibril”) has a number average fiber length of 1 mm or more. Preferably they are 1 mm or more and 10 mm or less, More preferably, they are 1 mm or more and 6 mm or less. The number average fiber length may be 2 mm or more, or 3 mm or more. As one aspect, the number average fiber length may be 2 mm or more and 10 mm or less, 3 mm or more and 10 mm or less, 2 mm or more and 6 mm or less, or 3 mm or more and 6 mm or less.

As the fibrils according to this embodiment, chopped strands having a narrow fiber length distribution are preferable.

The number average fiber diameter of the fibrils according to the method for producing the liquid crystal polyester composition of the present embodiment is not particularly limited, but is preferably 3 μm or more and 15 μm or less. When the number average fiber diameter of the fibrils is 3 μm or more, the reinforcing effect of the molded body obtained by molding the obtained liquid crystal polyester composition can be more sufficiently obtained. Moreover, when the number average fiber diameter of the fibrils is 15 μm or less, the moldability of the obtained liquid crystal polyester composition is improved, and the appearance of the surface of the molded body obtained by molding the liquid crystal polyester composition becomes better.
In the present specification, the number average fiber diameter and the number average fiber length of the fibril can be measured by observing with a microscope such as a digital microscope.

The surface of the fibril according to this embodiment may be partially or entirely treated with a surface coating agent. Examples of the surface coating agent include coupling agents such as titanium coupling agents, resins, and other surface coating agents generally used for surface coating.

By using the fibrils treated with the surface coating agent, it is possible to suppress the generation of gas from the molded body obtained by molding the obtained liquid crystal polyester composition. Therefore, the chemical stability of the molded body can be improved. Further, when an electric / electronic device or an optical device is assembled, contamination of peripheral members due to gas generated from the molded body can be reduced.

The fibrils according to this embodiment may be treated with an epoxy-based, urethane-based, acrylic-based coating agent or sizing agent.

The fibrils according to the method for producing the liquid crystal polyester composition of the present embodiment may be commercially available or may be produced by a known method.

[Other ingredients]
The liquid crystal polyester composition obtained by the method for producing a liquid crystal polyester composition according to an embodiment of the present invention may further include other fillers other than glass fibers, additives, or resins other than liquid crystal polyester, if necessary. It may contain at least one component.
That is, the method for producing a liquid crystal polyester composition according to an embodiment of the present invention includes a liquid crystal polyester, a glass fibril having a number average fiber length of 1 mm or more, and optionally a filler other than glass fiber, addition Melting and kneading an agent and at least one component selected from the group consisting of resins other than the liquid crystalline polyester.
As another aspect, the liquid crystal polyester composition obtained by the production method of the present invention comprises a liquid crystal polyester, the fibrils, and optionally a filler other than the glass fiber, the additive, and a resin other than the liquid crystal polyester. And at least one component selected from the group consisting of:

Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, flame retardants, and colorants. The content of the additive in the liquid crystal polyester composition obtained by the present embodiment is usually 0 to 5 parts by mass with respect to 100 parts by mass of the liquid crystal polyester.

Examples of resins other than liquid crystal polyesters include polypropylene, polyamide, polyesters other than liquid crystal polyesters, thermoplastic resins other than liquid crystal polyesters such as polysulfone, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and polyetherimide; and phenol resins And thermosetting resins such as epoxy resins, polyimide resins, and cyanate resins. The content of the resin other than the liquid crystal polyester in the liquid crystal polyester composition obtained by the present embodiment is usually 0 to 20 parts by mass with respect to 100 parts by mass of the liquid crystal polyester.

Other components according to the method for producing the liquid crystal polyester composition of the present embodiment may be commercially available or may be produced by a known method.

[Melting and kneading]
FIG. 1 is a schematic cross-sectional view showing an example of an extruder used in melt-kneading according to the method for producing a liquid crystal polyester composition of the first embodiment. Hereinafter, the case where a liquid crystal polyester composition is manufactured using the extruder shown in FIG. 1 is demonstrated.

Hereinafter, in the manufacturing method of the liquid crystal polyester composition of this embodiment, it demonstrates as manufacturing liquid crystal polyester composition by melt-kneading liquid crystal polyester and a fibril using the extruder shown in FIG.

The extruder 10 shown in FIG. 1 includes a motor 1 housed in a motor box 1a, a cylinder 2 provided adjacent to the motor box 1a, a screw 3 inserted into the cylinder 2 and connected to the motor 1. ,have. An extruder 10 shown in FIG. 1 is a twin-screw extruder in which two screws 3 are inserted into a cylinder 2.

The cylinder 2 has a main feed port 5 for supplying liquid crystal polyester and fibrils into the cylinder 2, and a side feed for supplying liquid crystal polyester and fibrils into the cylinder 2 behind the main feed port 5 in the extrusion direction (downstream side). A mouth 7, a first vent portion 4 and a second vent portion 6 for discharging volatile components (gas) generated in the cylinder 2, and a discharge die 9 for molding a melt-kneaded liquid crystal polyester composition are provided. Moreover, the discharge die 9 is provided with a nozzle hole 9a.

The main feed port 5 and the side feed port 7 have a hopper connected to the inside of the cylinder 2 and a supply device for supplying liquid crystal polyester and fibrils (all not shown).

The screw 3 includes a transport unit 8 for transporting the liquid crystal polyester composition. Further, the screw 3 includes a first kneading section 11 between the main feed port 5 and the side feed port 7 for plasticizing and kneading the liquid crystalline polyester composition. Further, the screw 3 includes a second kneading part 12 that plasticizes and kneads the liquid crystal polyester composition between the side feed port 7 and the first vent part 4. Furthermore, the screw 3 includes a third kneading portion 13 that kneads the liquid crystal polyester composition between the first vent portion 4 and the second vent portion 6. A fourth kneading part and a fifth kneading part may be further provided between the first vent part 4 and the second vent part 6. At this time, it is preferable to sufficiently control the increase in the cylinder temperature due to shear heat generation.

In the melt-kneading step according to the manufacturing method of the present embodiment, the number average fiber length of the glass fibers contained in the liquid crystal polyester composition is controlled to 30 μm or more and 200 μm or less.

In order to control the number average fiber length of the glass fibers contained in the liquid crystal polyester composition to 30 μm or more and 200 μm or less, the temperature condition and shearing force at the time of melt-kneading may be appropriately adjusted.

The temperature condition of the melt-kneading is selected from the temperature conditions of [FT-100] ° C. or more and [FT + 80] ° C. or less based on the flow start temperature (sometimes abbreviated as FT) ± 0 (° C.) of the liquid crystal polyester.

The shearing force for melt kneading is appropriately adjusted depending on the type and scale of the extruder used. Specifically, the shearing force relating to the melt-kneading can be adjusted by appropriately changing the configuration of the screw and the kneading part in the extruder.

In this embodiment, after melt-kneading in advance on a trial basis to obtain a sample of a liquid crystal polyester composition, the temperature conditions and shearing force of the melt-kneading and the number average fiber length of the glass fibers in the obtained sample are Based on this, the melt-kneading conditions may be appropriately adjusted so that the number average fiber length of the glass fibers in the liquid crystal polyester composition becomes a target value. Thereby, the liquid crystal polyester composition containing the glass fiber which has the target number average fiber length can be obtained.

Note that the number average fiber diameter of the glass fibers is considered to have a very low possibility of changing in the melt-kneading process.

When the extruder 10 is used, as long as the number average fiber length of the glass fibers in the liquid crystal polyester composition can be controlled to 30 μm or more and 200 μm or less, the liquid crystal polyester to be supplied to the main feed port 5, fibrils, and necessary The supply ratio of the other components blended according to the above is not particularly limited. Similarly, the supply ratios of the liquid crystal polyester, fibrils, and other components blended as needed are not particularly limited.
As one aspect, 30 to 100% of the total amount of liquid crystal polyester may be supplied from the main feed port, and 0 to 70% of the total amount of liquid crystal polyester and the total amount of fibrils may be supplied from the side foot port.

The discharge amount of the liquid crystal polyester composition from the discharge die 9 of the extruder 10 is preferably 200 kg / hour to 400 kg / hour. Moreover, it is preferable that the rotation speed of the screw 3 of the extruder 10 shall be 500 rpm to 800 rpm. In addition, it is preferable to adjust these manufacturing conditions so that the torque of the motor 1 which the extruder 10 has becomes 60% or more with respect to the upper limit torque of an extruder.

The method for producing a liquid crystal polyester composition that is one embodiment of the present invention may include a step of forming pellets made of the liquid crystal polyester composition after the step of melt-kneading.
As a molding method of the liquid crystal polyester composition pellets, a melt molding method is preferable. Examples of the melt molding method include an injection molding method, an extrusion molding method such as a T-die method and an inflation method, a compression molding method, a blow molding method, a vacuum molding method, and a press molding method. Of these, the injection molding method is preferable.
As one aspect, the method for producing a liquid crystal polyester composition according to one embodiment of the present invention supplies liquid crystal polyester and glass fibrils having a number average fiber length of 1 mm or more to an extruder;
Melt-kneading the liquid crystalline polyester and fibrils supplied to the extruder until the number average fiber length of the fibrils is 30 μm or more and 200 μm or less; and the liquid crystal polyester composition obtained by the melt kneading Forming pellets.
The melt-kneading is preferably performed at [FT-100] ° C. or more and [FT + 80] ° C. or less with the flow start temperature FT ± 0 (° C.) of the liquid crystal polyester as a base point.
The liquid crystal polyester composition pellets are preferably molded by a melt molding method.

Note that the extruder according to the method for producing a liquid crystal polyester composition which is one embodiment of the present invention is not limited to the extruder having the configuration shown in FIG. For example, a cylinder, at least one screw disposed in the cylinder, and two or more supply ports (main feed port and side feed port) provided in the cylinder are preferably used. Those provided with one or more vent portions are more preferably used.

Specific examples of the extruder applicable to one embodiment of the present invention may be a single screw extruder or a twin screw extruder. Examples of twin-screw extruders include those with one to three screws rotating in the same direction, parallel shaft types with different directions rotating, oblique shaft types, and incomplete meshing types. The twin screw extruder is preferred. If the number average fiber length of the glass fibers contained in the liquid crystal polyester composition (or pellets) is less than the target value, the liquid crystal polyester composition (or pellets) is again introduced from the supply port of the extruder and melt kneaded. The number average fiber length of the glass fibers can be repeated until the target value is reached. In addition, the measuring method of the number average fiber length of glass fiber is mentioned later.

Thus, the liquid crystal polyester composition according to one embodiment of the present invention is manufactured. From the above, in the method for producing a liquid crystal polyester composition according to an embodiment of the present invention, the number average fiber length is 1 mm or more, by breaking the fibrils while kneading with the liquid crystal polyester, the number average fibers Melting and kneading can be performed until the glass fiber has a length of 30 μm to 200 μm.

In the production method of the present embodiment, the liquid crystal polyester is preferably blended in an amount of 40 to 80% by mass with respect to the total mass of the liquid crystal polyester composition to be obtained.
The fibrils are preferably blended in an amount of 20 to 60% by mass based on the total mass of the liquid crystal polyester composition to be obtained.

<Liquid crystal polyester composition>
The liquid crystal polyester composition which is one embodiment of the present invention is produced by the production method described above. In the liquid crystal polyester composition of the present embodiment, the liquid crystal polyester and the fibril are strongly kneaded while the fibril is broken. Therefore, it is considered that the glass fiber is uniformly dispersed in the liquid crystal polyester composition of the present embodiment. Moreover, in the liquid crystal polyester composition of this embodiment, it is thought that liquid crystal polyester and glass fiber are interacting strongly. Thereby, it is thought that the liquid crystal polyester composition of this embodiment has high heat resistance and high thin-wall fluidity.

<< Second Embodiment >>
<Liquid crystal polyester composition>
The liquid crystal polyester composition according to the second embodiment of the present invention is a liquid crystal polyester composition comprising a liquid crystal polyester and glass fibers having a number average fiber length of 30 μm or more and 200 μm or less. The flow start temperature is 330 ° C. or higher, and the liquid crystal polyester composition is left in the capillary rheometer furnace set at a temperature 30 ° C. higher than the flow start temperature for 5 minutes or 1 hour, and then held at the above temperature. In the case of measuring the melt viscosity at a shear rate of 35 / sec, the melt viscosity of the liquid crystal polyester composition measured after being left in the furnace for 5 minutes is measured after being left in the furnace for 1 hour. When the melt viscosity of the liquid crystal polyester composition is b, the value of 100 × b / a is 50 or more and 200 or less.

The melt viscosity a and the melt viscosity b are measured as follows. First, it is left for a predetermined time (5 minutes or 1 hour) in a furnace of a capillary rheometer set at a temperature 30 ° C. higher than the flow start temperature of the liquid crystal polyester composition of the present embodiment. Thereafter, the melt viscosity at a shear rate of 35 / sec is measured while the temperature is maintained. At this time, the melt viscosity measured with the predetermined time left in the furnace as 5 minutes is defined as a. Further, b is a melt viscosity measured with a predetermined time left in the furnace as 1 hour.

The value of 100 × b / a means the rate of change in melt viscosity when the liquid crystal polyester composition is held at a temperature 30 ° C. higher than its flow start temperature. When this value is less than 50 or more than 200, it can be said that the melt viscosity of the liquid crystal polyester composition tends to change when the liquid crystal polyester composition is held under the above conditions.

In contrast, in the liquid crystal polyester composition of the present embodiment, the value of 100 × b / a is 50 or more and 200 or less. Therefore, it can be said that when the liquid crystal polyester composition of the present embodiment is held under the above conditions, the melt viscosity of the liquid crystal polyester composition hardly changes.

The value of 100 × b / a is preferably 55 or more. Further, the value of 100 × b / a is preferably 150 or less, and more preferably 120 or less.
As one aspect, the value of 100 × b / a is preferably 55 or more and 150 or less, more preferably 55 or more and 120 or less, and more preferably 55 or more and 65 or less.

When the liquid crystal polyester composition of the present embodiment is held at a high temperature (for example, 360 ° C. or higher) at which a side reaction is likely to occur in the liquid crystal polyester composition, a cross-linking reaction or decomposition between liquid crystal polyester molecules contributing to a change in melt viscosity. It can be said that side reactions such as reactions are unlikely to occur.

As a factor that suppresses the side reaction, it is estimated that the interaction between the liquid crystal polyester and the glass fiber constituting the liquid crystal polyester composition of the present embodiment is strong. That is, the liquid crystal polyester composition of the present embodiment is considered to be a composition having a strong interaction between the liquid crystal polyester and the glass fiber.

The inventors have found that a liquid crystal polyester composition satisfying the requirement that the value of 100 × b / a is 50 or more and 200 or less is excellent in thin-wall fluidity, and completed the present invention.

From the above, when the value of 100 × b / a, which is an index of the interaction strength between the liquid crystalline polyester and the glass fiber, is 50 or more and 200 or less, this interaction is sufficiently strong and the heat resistance is high. In addition, a liquid crystal polyester composition having high thin-wall fluidity can be obtained.

The lower limit of the number average fiber length of the glass fibers contained in the liquid crystal polyester composition is 30 μm or more, preferably 50 μm or more, more preferably 70 μm or more, and further preferably 80 μm or more.

Further, the upper limit of the number average fiber length of the glass fibers contained in the liquid crystal polyester composition is 200 μm or less, preferably 170 μm or less, more preferably 150 μm or less, and further preferably 100 μm or less.

The upper limit value and the lower limit value can be arbitrarily combined.
As one aspect, the number average fiber length of the glass fibers contained in the liquid crystal polyester composition is 30 μm to 200 μm, preferably 50 μm to 170 μm, more preferably 70 μm to 150 μm, and even more preferably 80 μm. It is not less than 100 μm and particularly preferably not less than 80 μm and not more than 86 μm.

In the present specification, the number average fiber length of the glass fibers in the liquid crystal polyester composition is measured by the following method. First, a predetermined amount of pellets made of a liquid crystal polyester composition is placed in a crucible and treated in an electric furnace at 600 ° C. for 6 hours for ashing. Next, a micrograph (magnification: 100 times) is taken with the obtained residue dispersed in methanol and developed on a slide glass. The number average fiber length of the glass fibers in the liquid crystal polyester composition is determined by directly reading the length of the glass fibers from the photograph and calculating the average value (for example, the average value when the parameter is 400). In addition, the fiber length here means the maximum length in the fiber.

The flow start temperature of the liquid crystal polyester composition of the present embodiment is 330 ° C. or higher and 450 ° C. or lower, which can be said to be sufficiently high. The higher the flow start temperature of the liquid crystal polyester composition, the easier it is to improve the heat resistance, strength and rigidity. That is, it can be said that the liquid crystal polyester composition of the present embodiment having a flow start temperature of 330 ° C. or higher has high heat resistance.
The flow start temperature of the liquid crystal polyester composition of the present embodiment may be 350 ° C. or more and 400 ° C. or less, or 360 ° C. or more and 390 ° C. or less, as one aspect. As another aspect, the flow start temperature may be 340 ° C. or higher and 347 ° C. or lower.

In addition, the liquid crystal polyester composition having a flow start temperature of 330 ° C. or higher can be obtained by using a liquid crystal polyester having a flow start temperature of 330 ° C. or higher and 450 ° C. or lower as a raw material. Moreover, the flow start temperature of a liquid crystal polyester composition can be measured by the same method as liquid crystal polyester.

In the present specification, the high thin-wall fluidity of the liquid crystal polyester composition means that the thin-wall flow length specifically obtained by the following method is long.

A method for measuring the thin-wall flow length of the liquid crystal polyester composition will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of a mold for measuring a thin wall flow length in the present embodiment. In this embodiment, a thin film flow length measurement mold (0.3 mmt) shown in FIG. 2 is used, and a liquid crystal polyester composition is subjected to a cylinder temperature of 380 ° C. with an injection molding machine (roboshot S2000i-30B manufactured by FANUC). Molding is performed under conditions of a mold temperature of 130 ° C. and an injection speed of 200 mm / second. The thin-wall flow length is determined by measuring the length of the removed molded body.
The thin wall flow length is preferably 20 mm or more.

The liquid crystal polyester composition of the second embodiment can be produced, for example, by the production method shown in the first embodiment.

As one aspect, in the liquid crystal polyester composition of the second embodiment of the present invention, the content of the liquid crystal polyester is preferably 40 to 80% by mass with respect to the total mass of the liquid crystal polyester composition; glass The fiber content is preferably 20 to 60% by mass relative to the total mass of the liquid crystal polyester composition.

Various molded products can be obtained by molding the liquid crystal polyester composition of the present embodiment. Examples of molded products include optical pickup bobbins, transformer bobbins and other bobbins; relay cases, relay bases, relay sprues, relay armatures and other relay parts; RIMM, DDR, CPU socket, S / O, DIMM, Board to Board Connectors, connectors such as FPC connectors, card connectors, etc .; reflectors such as lamp reflectors and LED reflectors; holders such as lamp holders and heater holders; diaphragms such as speaker diaphragms; separation claws for copying machines, separation claws for printers, etc. Camera module parts; switch parts; motor parts; sensor parts; hard disk drive parts; ovenware and other dishes; vehicle parts; aircraft parts; and sealing members such as semiconductor element sealing members and coil sealing members Raising It is.

According to the method for producing a liquid crystal polyester composition according to an embodiment of the present invention, a liquid crystal polyester composition having high heat resistance and high thin-wall fluidity can be obtained. Moreover, the liquid crystal polyester composition which is one embodiment of the present invention has high heat resistance and high thin-wall fluidity.

As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

Supplying liquid crystal polyester, glass fibrils, and optionally, at least one component selected from the group consisting of fillers other than glass fibers, additives, and resins other than the liquid crystal polyester; And the liquid crystalline polyester supplied to the extruder and the fibrils, the number average fiber length of the fibrils is 30 μm or more and 200 μm or less, preferably 50 μm or more and 170 μm or less, more preferably 70 μm or more and 150 μm or less, more preferably 80 μm. Including obtaining a liquid crystal polyester composition by melt-kneading until it is 100 μm or less, particularly preferably 80 μm or more and 86 μm or less;
The liquid crystal polyester is a liquid crystal polyester having a repeating unit represented by the general formulas (1) to (3), preferably a repeating unit derived from p-hydroxybenzoic acid, and 4,4′-dihydroxybiphenyl. A liquid crystalline polyester having a repeating unit, a repeating unit derived from terephthalic acid, and a repeating unit derived from isophthalic acid;
The number average fiber length of the fibrils supplied to the extruder is 1 mm or more and 10 mm or less, more preferably 1 mm or more and 6 mm or less;
The liquid crystal polyester composition obtained by melt kneading has a flow start temperature of 330 ° C or higher, preferably 350 ° C or higher and 400 ° C or lower, more preferably 360 ° C or higher and 390 ° C or lower, or 340 ° C or higher and 347 ° C or lower. A method for producing a polyester composition.
The melt-kneading is preferably performed at [FT-100] ° C. or more and [FT + 80] ° C. or less with the flow start temperature FT ± 0 (° C.) of the liquid crystal polyester as a base point;
The manufacturing method may further include forming a pellet of the liquid crystal polyester composition obtained by the melt kneading.

A liquid crystal polyester composition comprising liquid crystal polyester, glass fiber, and, if desired, at least one component selected from the group consisting of a filler other than glass fiber, an additive, and a resin other than liquid crystal polyester,
The number average fiber length of the glass fibers is 30 μm or more and 200 μm or less, preferably 50 μm or more and 170 μm or less, more preferably 70 μm or more and 150 μm or less, further preferably 80 μm or more and 100 μm or less, and particularly preferably 80 μm or more and 86 μm or less;
The liquid crystal polyester is a liquid crystal polyester having a repeating unit represented by the general formulas (1) to (3), preferably a repeating unit derived from p-hydroxybenzoic acid, and 4,4′-dihydroxybiphenyl. A liquid crystalline polyester having a repeating unit, a repeating unit derived from terephthalic acid, and a repeating unit derived from isophthalic acid;
The liquid crystal polyester composition has a flow start temperature of 330 ° C. or higher, preferably 350 ° C. or higher and 400 ° C. or lower, more preferably 360 ° C. or higher and 390 ° C. or lower, or 340 ° C. or higher and 347 ° C. or lower;
The liquid crystal polyester composition is allowed to stand for 5 minutes or 1 hour in a capillary rheometer furnace set at a temperature 30 ° C. higher than the flow start temperature, and then held at the temperature to obtain a melt viscosity at a shear rate of 35 / sec. When measuring
100 when the melt viscosity of the liquid crystal polyester composition measured after being left in the furnace for 5 minutes is a, and the melt viscosity of the liquid crystal polyester composition measured after being left in the furnace for 1 hour is b. The value of xb / a is 50 or more and 200 or less, preferably 55 or more and 150 or less, more preferably 55 or more and 120 or less, and still more preferably 55 or more and 65 or less;
The content of the liquid crystal polyester is 40 to 80% by mass with respect to the total mass of the liquid crystal polyester composition;
The glass fiber content is 20 to 60% by mass with respect to the total mass of the liquid crystal polyester composition.
Liquid crystal polyester composition.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples. In addition, about the physical property of liquid crystal polyester and a liquid crystal polyester composition, and the number average fiber length of the glass fiber in a liquid crystal polyester composition, it measured with the following method.

[Measurement of flow start temperature of liquid crystal polyester]
Using a flow tester (“CFT-500 type” manufactured by Shimadzu Corporation), about 2 g of liquid crystalline polyester was filled into a cylinder equipped with a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm, and 9.8 MPa (100 kg / The liquid crystal polyester was melted while being heated at a rate of 4 ° C./minute under a load of cm ² ), extruded from a nozzle, and a temperature showing a viscosity of 4800 Pa · s (48000 poise) was measured.

[Measurement of number average fiber length of glass fibers in liquid crystal polyester composition]
1 g of the pellet made of the liquid crystal polyester composition was placed in a crucible and treated in an electric furnace at 600 ° C. for 6 hours for ashing. Subsequently, a micrograph (magnification: 100 times) was taken in a state where the obtained residue was dispersed in methanol and developed on a slide glass. The length of the glass fiber was directly read from the photograph and the average value was calculated. In calculating the average, the parameter was 400.

[Measurement of thin wall flow length of liquid crystal polyester composition]
The thin-wall fluidity of the liquid crystal polyester composition was evaluated by measuring the thin-wall flow length of the liquid crystal polyester composition by the following method. In this evaluation, it can be said that the longer the thin film flow length of the liquid crystal polyester composition, the better the liquid crystal polyester composition is.

Using a mold (0.3 mmt) for thin-wall flow length measurement shown in FIG. 2, the liquid crystal polyester composition was subjected to a cylinder temperature of 380 ° C. and a mold temperature of 130 ° C. using an injection molding machine (roboshot S2000i-30B manufactured by FANUC). Molding was performed under the conditions of an injection speed of 200 mm / sec.
Measurement of the length of the cavity portion of the molded body taken out was performed on five molded bodies, and the average value was defined as the thin-wall flow length. At this time, the residence time in the molding machine of the liquid crystalline polyester composition was within 5 minutes.

[Measurement of change rate (100 × b / a) of melt viscosity in liquid crystal polyester composition]
The set temperature of the capillary rheometer (“Capillograph 1B” manufactured by Toyo Seiki Co., Ltd.) was set to a temperature 30 ° C. higher than the flow start temperature of the liquid crystal polyester composition. Into the furnace of the capillary rheometer, the pellets obtained by molding the liquid crystal polyester composition were put and held for 5 minutes to melt the liquid crystal polyester composition. The melted liquid crystal polyester composition was measured for melt viscosity at a shear rate of 35 / second. The melt viscosity obtained here was defined as a. Similarly, the melt viscosity was measured at a shear rate of 35 / sec for the liquid crystal polyester composition held in a capillary rheometer furnace for 1 hour. The melt viscosity obtained here was defined as b. Based on these melt viscosity values, 100 × b / a was determined. In this example, the value of 100 × b / a means the rate of change in melt viscosity when the liquid crystalline polyester composition stays inside the extruder.

<Manufacture of liquid crystal polyester>
[Production Example 1]
A reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 994.5 g (7.2 mol) of parahydroxybenzoic acid, 446.9 g of 2,4′-dihydroxybiphenyl (2 .4 mol), 365.4 g (2.2 mol) of terephthalic acid, 33.2 g (0.2 mol) of isophthalic acid and 1347.6 g (13.2 mol) of acetic anhydride and 0.194 g of 1-methylimidazole as a catalyst. Was added and stirred at room temperature for 15 minutes to sufficiently replace the inside of the reactor with nitrogen gas, and then heated while stirring. When the internal temperature reached 145 ° C., the mixture was stirred for 1 hour while maintaining the same temperature.

Thereafter, while distilling off by-product acetic acid and unreacted acetic anhydride, the temperature was raised to 320 ° C. over 2 hours and 50 minutes, and when the increase in torque was observed, the reaction was completed and a prepolymer was obtained.
The flow initiation temperature of the prepolymer was 263 ° C.

The obtained prepolymer was cooled to room temperature and pulverized with a coarse pulverizer to obtain a liquid crystalline polyester powder (particle diameter of about 0.1 mm to about 1 mm). Thereafter, the liquid crystal polyester powder was heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere, heated from 250 ° C. to 300 ° C. over 5 hours, and held at 300 ° C. for 3 hours. The polymerization reaction proceeded at. The flow starting temperature of the obtained liquid crystal polyester was 361 ° C.

<Production of liquid crystal polyester composition>
In the following examples and comparative examples, the following materials were used as fibrils.
Fiber A: Nitto Boseki Co., Ltd., trade name “CS-3J-260S” (number average fiber length: 3 mm)
Fiber B: Central Glass Co., Ltd., trade name “Milled Fiber EFH75-01” (number average fiber length: 91 μm)

Further, a twin screw extruder (manufactured by Toshiba Machine Co., Ltd., model number “TEM-41SS”) was used as an extruder. This twin-screw extruder has a configuration in which a fourth kneading portion is added to the first vent portion and a fifth kneading portion is added to the second vent portion to the extruder having the configuration shown in FIG.

[Example 1]
A liquid crystal polyester composition was produced by a twin screw extruder using 45 parts by mass of the fibril A and 55 parts by mass of the liquid crystal polyester obtained in Production Example 1.

80% of the total amount of liquid crystal polyester was supplied from the main feed port of this twin-screw extruder, and 20% of the total amount of liquid crystal polyester and fibril A were supplied from the side feed port. The second kneading part to the fifth kneading part were set at 280 ° C. in order to suppress an increase in the cylinder temperature due to shearing heat generation. Other than that, it was 360 degreeC. A screw with a diameter of 41 mm was used, and the second vent was held by a water pump so that the degree of vacuum was -0.09 MPa (atmospheric pressure was 0 MPa) as a gauge pressure. A screw having the same direction (right rotation) in two axes was used, the screw rotation speed was 650 rpm, and the extrusion rate was 300 kg / hour. Under such conditions, the liquid crystal polyester and the fibril A were melt-kneaded to obtain a liquid crystal polyester composition.

The flow starting temperature of the liquid crystal polyester composition obtained in Example 1 was 347 ° C. The number average fiber length of the glass fibers in the liquid crystal polyester composition was 86 μm.

[Comparative Example 1]
A liquid crystal polyester composition was produced by a twin screw extruder using 45 parts by mass of the basic fiber B and 55 parts by mass of the liquid crystal polyester obtained in Production Example 1. It was manufactured in the same manner as in Example 1 except that the entire amount of liquid crystal polyester was supplied from the main feed port of this twin-screw extruder, the fibril B was supplied from the side feed port, and the processing temperature was uniformly set to 360 ° C.

The flow start temperature of the liquid crystal polyester composition obtained in Comparative Example 1 was 347 ° C. The number average fiber length of the glass fibers in the liquid crystal polyester composition was 87 μm.

[Comparative Example 2]
Compared with 40 parts by mass of fibril A and 60 parts by mass of the liquid crystalline polyester obtained in Production Example 1, except that a twin screw extruder was used in which the screw elements were adjusted in advance so that the shear stress was smaller than in Example 1. Prepared in the same manner as in Example 1.

The flow starting temperature of the liquid crystal polyester composition obtained in Comparative Example 2 was 349 ° C. The number average fiber length of the glass fibers in the liquid crystal polyester composition was 243 μm.

Table 1 summarizes the blending ratios and physical property values of the liquid crystal polyester compositions of Examples and Comparative Examples, and the number average fiber length of the glass fibers in the liquid crystal polyester composition after melt kneading.

In Example 1 to which an aspect of the present invention was applied, a fibril having a number average fiber length longer than that of the fibril used in Comparative Example 1 was used as a raw material. As a result, as shown in Table 1, the number average fiber length of the glass fibers contained in the liquid crystal polyester composition was about the same in Example 1 and Comparative Example 1. On the other hand, the liquid crystal polyester composition of Example 1 showed higher thin-wall fluidity than Comparative Example 1.

In Example 1, the same fibrils as those in Comparative Example 2 were used as raw materials. However, the number average fiber length of the glass fibers contained in the liquid crystal polyester composition was 200 μm or less in Example 1, whereas it was longer than 200 μm in Comparative Example 2. Such a liquid crystal polyester composition of Example 1 showed high thin-wall fluidity as compared with Comparative Example 2.

Moreover, as shown in Table 1, in Example 1, Comparative Example 1 and Comparative Example 2, although the flow start temperature of the liquid crystal polyester used was about the same, 100 × b / a in Example 1 The value was as low as 200 or less. Such a liquid crystal polyester composition of Example 1 showed high thin-wall fluidity as compared with Comparative Example 1 and Comparative Example 2.

Therefore, as in Example 1, the liquid crystal polyester composition having 100 × b / a of 50 or more and 200 or less has a higher thin-wall flow than the conventional liquid crystal polyester compositions such as Comparative Example 1 and Comparative Example 2. It is considered to indicate the length.

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

Since the present invention can provide a liquid crystal polyester composition having high heat resistance and high thin-wall fluidity and a method for producing the same, it is extremely useful industrially.

DESCRIPTION OF SYMBOLS 1 ... Motor 1a ... Motor box 2 ... Cylinder 3 ... Screw 4 ... 1st vent part 5 ... Main feed port,
6 ... 2nd vent part 7 ... Side feed port 8 ... Conveyance

Claims (2)

Including melt-kneading liquid crystalline polyester and glass fibrils having a number average fiber length of 1 mm or more until the fibrils become glass fibers having a number average fiber length of 30 μm or more and 200 μm or less,
The manufacturing method of the liquid-crystal polyester composition whose flow start temperature is 330 degreeC or more. A liquid crystal polyester composition comprising a liquid crystal polyester and a glass fiber having a number average fiber length of 30 μm or more and 200 μm or less,
The flow start temperature of the liquid crystal polyester composition is 330 ° C. or higher,
The liquid crystal polyester composition is allowed to stand for 5 minutes or 1 hour in a capillary rheometer furnace set at a temperature 30 ° C. higher than the flow start temperature, and then held at the temperature to obtain a melt viscosity at a shear rate of 35 / sec. When measuring
100 when the melt viscosity of the liquid crystal polyester composition measured after being left in the furnace for 5 minutes is a, and the melt viscosity of the liquid crystal polyester composition measured after being left in the furnace for 1 hour is b. The liquid crystal polyester composition whose value of xb / a is 50 or more and 200 or less.

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