JP2018188529A - Liquid crystal polyester composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal polyester composition having high heat resistance and high thin-wall fluidity.SOLUTION: A liquid crystal polyester composition contains a liquid crystal polyester and a glass fiber, and satisfies the following (i) and (ii) conditions. (i) The liquid crystal polyester composition has a flow starting temperature of 330°C or more. (ii) A product obtained by decomposing the liquid crystal polyester included in the liquid crystal polyester composition with n-butylamine is measured by liquid chromatography, to obtain a chromatogram, in which a value of 100×b/a is 50 or more and 200 or less, with a, b denoting the area ratios of a peak with a retention time of 21.90 minutes to a peak with a retention time of 2.50 minutes.SELECTED DRAWING: None

Description

  The present invention relates to a liquid crystal polyester composition.

  Liquid crystal polyesters are widely used mainly in electric and electronic parts because they are excellent in 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, in such prior art, the liquid crystal polyester composition has a problem that the heat resistance is high, but the thin-wall fluidity is low.

  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.

In order to solve the above problems, one embodiment of the present invention provides a liquid crystal polyester composition that includes liquid crystal polyester and glass fiber and satisfies the following conditions (i) and (ii).
(I) The flow start temperature of the liquid crystal polyester composition is 330 ° C. or higher.
(Ii) In the chromatogram obtained by measuring the decomposition product obtained by decomposing the liquid crystal polyester contained in the liquid crystal polyester composition with n-butylamine by the liquid chromatography method under the following conditions, the retention time is 2. The area ratio of the peak with a retention time of 21.90 minutes for the peak of 50 minutes is a,
In a chromatogram obtained by measuring in a similar manner a liquid crystal polyester composition held at a temperature 30 ° C. higher than the flow start temperature of the liquid crystal polyester composition for 1 hour, the retention time for a peak with a retention time of 2.50 minutes is 21.90. The value of 100 × b / a when the area ratio of the peak of the minute is b is 50 or more and 200 or less.

[conditions]
Sample injection volume: 10 μL
Column: manufactured by Sumika Chemical Analysis Co., Ltd., product name “sumipax ODS KP-06” (5 μm × 4.6 mmφ × 1250 mm)
Column temperature: 40 ° C
Measurement method: Gradient elution method Eluent flow rate: 1.0 mL / min Detector: UV-visible spectrophotometer (UV)
Detection wavelength: 240 nm
Eluent: (A) 0.1% acetic acid-added aqueous solution and (B) 0.1% acetic acid-added acetonitrile solution are used, and the composition of the eluent is changed under the following gradient conditions.

[Gradient condition]
First, the concentration of the solution (B) is linearly changed from 10% by volume to 15% by volume with respect to the total amount of the eluent over 15 minutes. Next, the concentration of the solution (B) is linearly changed from 15% by volume to 100% by volume over 10 minutes with respect to the total amount of the eluent.

  According to the liquid crystal polyester composition which is one embodiment of the present invention, the heat resistance is high and the thin wall fluidity is high.

The schematic sectional drawing which shows an example of the extruder used with the manufacturing method of the liquid crystalline polyester composition of this embodiment. The schematic block diagram of the metal mold | die for thin wall flow length measurement in this embodiment.

  Hereinafter, 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 and ratios of the constituent elements are appropriately changed in order to make the drawings easy to see.

<Liquid crystal polyester composition>
The liquid crystal polyester composition of this embodiment contains liquid crystal polyester and glass fiber.

[Liquid crystal polyester]
The liquid crystal polyester used in the present embodiment exhibits liquid crystallinity in a molten state. 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 flow start temperature of the liquid crystal polyester used in this embodiment is preferably 330 ° C. or higher. Preferably they are 330 degreeC or more and 450 degrees C or less, More preferably, they are 330 degreeC or more and 400 degrees C or less, More preferably, they are 330 degreeC or more and 390 degrees C or less. Further, the flow start temperature may be 340 ° C. or higher, 350 ° C. or higher, or 360 ° C. or higher.

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 a temperature at which a viscosity of 4800 Pa · s (48000 poise) is exhibited 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 crystal polyester. “Synthesis / Molding / Application—”, CMC Co., Ltd., June 5, 1987, p. 95).

  The liquid crystal polyester used in the present embodiment includes a structural unit derived from p-hydroxybenzoic acid. Moreover, it is preferable that the liquid crystal polyester used in this embodiment is a wholly aromatic liquid crystal polyester formed using only an aromatic compound as a raw material monomer.

  As a typical example of liquid crystal polyester, at least one compound selected from the group consisting of aromatic diol, aromatic hydroxyamine and aromatic diamine, aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid are polymerized. (Polycondensation); Polymerization of plural kinds of aromatic hydroxycarboxylic acids; At least one compound selected from the group consisting of aromatic hydroxyamines and aromatic diamines, aromatic dicarboxylic acids, and aromatics 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 derivatives thereof. Also good.

  Examples of the polymerizable derivative of the compound having a carboxyl group such as aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid include those in which the carboxyl group is substituted with an alkoxycarbonyl group or an aryloxycarbonyl group (ester), carboxyl group In which is substituted with a haloformyl group (acid halide) and those in which a carboxyl group is substituted with an acyloxycarbonyl group (an acid anhydride).

  Examples of polymerizable derivatives of hydroxyl group-containing compounds such as aromatic hydroxycarboxylic acids, aromatic diols, and aromatic hydroxyamines include acylated hydroxyl groups substituted with acyloxyl groups (acylated products). Can be mentioned.

  Examples of the polymerizable derivative of the compound having an amino group such as aromatic hydroxyamine and aromatic diamine include those obtained by acylating the amino group and substituting the 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)”). And more preferably.

(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 represent an oxygen atom or an imino group (—NH—). The hydrogen atom 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 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.

  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.

  Examples of the alkyl group that can be substituted with a hydrogen atom include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, and an n-hexyl group. , 2-ethylhexyl group, n-octyl group and n-decyl group. Carbon number of the said alkyl group which can be substituted with a hydrogen atom is 1-10 normally.

  Examples of the aryl group that can be substituted with a hydrogen atom 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. In the aryl group, at least one of hydrogen atoms constituting the aryl group may be substituted, and the total carbon number of the aryl group including the substituent is usually 6 to 20.

When the hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is substituted with these groups, the number of substitutions is the same for each group represented by Ar ¹ , Ar ² or Ar ^3. Independently, it is usually 2 or less, preferably 1 or less.

  Examples of the alkylidene group include a methylene group, an ethylidene group, an isopropylidene group, an n-butylidene group, and a 2-ethylhexylidene group. Carbon number of the said alkylidene group is 1-10 normally.

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) of the liquid crystal polyester is usually 30 mol% or more, preferably 30 to 80 mol%, more preferably 40 to 70 mol%, based on the total amount of all 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) of the liquid crystal polyester is usually 35 mol% or less, preferably 10 to 35 mol%, more preferably 15 to 15 mol% with respect to the total amount of all repeating units constituting the liquid crystal polyester. It is 30 mol%, More preferably, it is 17.5-27.5 mol%.

  The content of the repeating unit (3) of the liquid crystal polyester is usually 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 17.5-27.5 mol%.

  The higher the content of the repeating unit (1), the easier it is for the liquid crystalline polyester to improve the melt fluidity, heat resistance, strength and rigidity. 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 of the present 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)]. ] (Mol% / mol%). The ratio of the content of the repeating unit (2) and the content of the repeating unit (3) is usually 0.9 to 1.11, preferably 0.95 to 1.05, more preferably 0.98 to 1. 02.

  The repeating units (1) to (3) of the liquid crystal polyester may be independently derived from one kind of raw material monomer or may be derived from two or more kinds of raw material monomers. Moreover, liquid crystalline polyester may have repeating units other than repeating unit (1)-(3). The content of repeating units other than the repeating units (1) to (3) is usually 10 mol% or less, preferably 5 mol% or less, based on the total amount of all repeating units constituting the liquid crystal polyester.

  The liquid crystal 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. It is more preferable that the repeating unit (3) has only those in which X and Y are each an oxygen atom.

  Liquid crystalline polyesters having the same repeating unit within the above range may be used in combination with different repeating unit contents.

[Glass fiber]
The lower limit of the number average fiber length of the glass fibers contained in the liquid crystal polyester composition of the present embodiment is preferably 30 μm or more, more preferably 50 μm or more, further preferably 70 μm or more, and particularly 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 preferably 200 μm or less, more preferably 170 μm or less, further preferably 150 μm or less, and particularly preferably 100 μm or less.

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

  In the present embodiment, 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.

  Although the average fiber diameter of glass fiber is not specifically limited, Preferably it is 3 micrometers or more and 15 micrometers or less. When the average fiber diameter of the glass fibers 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 average fiber diameter of the glass fibers 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.

  The surface of the glass fiber used in this embodiment may be treated with a surface coating agent. Examples of the surface coating agent include coupling agents such as a titanium coupling agent, resins, and other surface coating agents generally used for surface coating.

  By using the glass fiber processed with the surface coating agent, it can suppress that gas is emitted from the molded object which shape | molded the liquid crystal polyester composition obtained. Therefore, the chemical stability of the molded body can be improved. Moreover, 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 glass fiber used in the present embodiment may be treated with an epoxy-based, urethane-based, acrylic-based coating agent or sizing agent.

[Other ingredients]
The liquid crystal polyester composition which is one embodiment of the present invention may contain one or more other components such as a filler, an additive, and a resin other than the liquid crystal polyester as necessary.

  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 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 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 in a liquid crystalline polyester composition is 0-20 mass parts normally with respect to 100 mass parts of liquid crystalline polyester.

[Liquid crystal polyester composition]
The flow start temperature of the liquid crystal polyester composition of the present embodiment is 330 ° C. or higher, 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, the liquid crystal polyester composition of the present embodiment having a flow start temperature of 330 ° C. or higher tends to improve heat resistance.

  In the liquid crystal polyester composition of the present embodiment, a value of 100 × b / a (hereinafter referred to as requirement (ii)) calculated based on the peak area ratio a and the peak area ratio b in the chromatograph of the liquid crystal polyester composition. Is 50 or more and 200 or less.

  The peak area ratio a and the peak area ratio b are measured by the following method. In the chromatogram obtained by measuring the decomposition product obtained by decomposing the liquid crystal polyester contained in the liquid crystal polyester composition with n-butylamine by the liquid chromatography method under the following conditions, the retention time is 2.50 minutes. Let a be the area ratio of a peak with a retention time of 21.90 minutes relative to the peak. Moreover, in the chromatogram obtained by measuring similarly about the liquid crystal polyester composition hold | maintained at the temperature 30 degreeC higher than the flow start temperature of a liquid crystal polyester composition for 1 hour, the retention time with respect to the peak whose retention time is 2.50 minutes is 21. Let b be the area ratio of the peak at 90 minutes.

[conditions]
Sample injection volume: 10 μL
Column: manufactured by Sumika Chemical Analysis Co., Ltd., product name “sumipax ODS KP-06” (5 μm × 4.6 mmφ × 1250 mm)
Column temperature: 40 ° C
Measurement method: Gradient elution method Eluent flow rate: 1.0 mL / min Detector: UV-visible spectrophotometer (UV)
Detection wavelength: 240 nm
Eluent: (A) 0.1% acetic acid-added aqueous solution and (B) 0.1% acetic acid-added acetonitrile solution are used, and the composition of the eluent is changed under the following gradient conditions.

[Gradient condition]
First, the concentration of the solution (B) is linearly changed from 10% by volume to 15% by volume with respect to the total amount of the eluent over 15 minutes. Next, the concentration of the solution (B) is linearly changed from 15% by volume to 100% by volume over 10 minutes with respect to the total amount of the eluent.

  Here, details of the requirement (ii) will be described.

  In this embodiment, before measuring a liquid crystal polyester composition by a liquid chromatography method, the liquid crystal polyester contained in the liquid crystal polyester composition is previously treated with n-butylamine. Thereby, the ester bond between the repeating units which comprise liquid crystal polyester can be decomposed | disassembled, and liquid crystal polyester can be decomposed | disassembled. In the chromatogram of the degradation product of the liquid crystal polyester, the component derived from each repeating unit is detected as a peak.

  The chromatogram of the degradation product of the liquid crystal polyester is measured by the liquid chromatography method under the above conditions after decomposing the liquid crystal polyester held for 1 hour at a temperature 30 ° C. higher than the flow start temperature of the liquid crystal polyester composition with n-butylamine. It is obtained by doing.

  Here, Nn-butyl p-hydroxybenzoic acid amide, which is one of the decomposition products of liquid crystal polyester, is detected at the peak position where the retention time is 2.50 minutes. Further, another decomposition product (hereinafter also referred to as component X) is detected at the peak position where the retention time is 21.90 minutes.

  Here, it is considered that the component X detected at the peak position where the retention time is 21.90 minutes is derived from a cross-linking component generated by cross-linking of the liquid crystal polyester.

  In the present specification, requirement (ii) means the rate of change of component X of the crosslinking component when the liquid crystal polyester composition is held at a temperature 30 ° C. higher than its flow initiation temperature. When the value of requirement (ii) is 50 or more and 200 or less, when the liquid crystal polyester composition is held under the above conditions, it can be said that the component X is hardly generated and the structural change is small. That is, it can be said that the liquid crystal polyester composition of the present embodiment has a small structural change when held under the above conditions.

  The value of requirement (ii) is preferably 60 or more, and more preferably 70 or more. Further, the value of requirement (ii) is preferably 150 or less, and more preferably 120 or less.

  Since the liquid crystal polyester composition of the present embodiment has a value of requirement (ii) of 50 or more and 200 or less, it can be said that structural change due to crosslinking is small when held for 1 hour at a temperature 30 ° C. higher than the flow start temperature. . That is, 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 easily occurs in the liquid crystal polyester composition, a side reaction such as a crosslinking reaction or a decomposition reaction between liquid crystal polyester molecules. It can be said that it is hard to cause.

  As a factor which suppresses said side reaction, it is estimated that the interaction of the liquid crystal polyester and glass fiber which comprises the liquid crystal polyester composition of this 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 (ii) 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. And a liquid crystal polyester composition having high thin-wall fluidity is obtained.

  In this 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 the present embodiment, a thin film flow length measurement mold (0.3 mmt) shown in FIG. 2 is used, and the 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.

  Various molded bodies 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 Cited The

<Method for producing liquid crystal polyester composition>
The liquid crystal polyester composition described above can be obtained by melt-kneading at least liquid crystal polyester and glass fibrils (hereinafter sometimes simply referred to as “fibrils”) with an extruder.

  A 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 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.

  The liquid crystal polyester used in the production method of the present embodiment may be a commercially available one or may be synthesized using raw material monomers corresponding to the repeating units constituting the liquid crystal polyester.

  In the case of synthesizing a liquid crystal polyester, it is preferably produced by subjecting a raw material monomer to melt polymerization and subjecting the resulting polymer (hereinafter sometimes referred to as “prepolymer”) to solid phase polymerization. Thereby, high molecular weight liquid crystal polyester having high heat resistance, strength and rigidity can be produced with good operability.

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

The fibrils used in the production method of the present embodiment preferably have a number average fiber length of 1 mm or more, more preferably 1 mm or more and 10 mm or less, and even more preferably 1 mm or more and 6 mm or less. Further, the number average fiber length may be 2 mm or more, or 3 mm or more.
As the fibrils used in this embodiment, chopped strands having a narrow fiber length distribution are preferred.

[Melting and kneading]
Next, the process of melt-kneading liquid crystal polyester and fibrils will be described.

  FIG. 1 is a schematic cross-sectional view showing an example of an extruder used in the melt-kneading step of the first embodiment. Hereinafter, 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 that supplies liquid crystal polyester and fibrils into the cylinder 2, and a side feed that supplies 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.

  The method for producing a liquid crystal polyester composition of the present embodiment includes a step of melt-kneading a liquid crystal polyester having a flow start temperature of 330 ° C. or more and a fibril having a number average fiber length of 1 mm or more. In the step, it is preferable to melt knead until the number average fiber length is 30 μm or more and 200 μm or less.

  In the method for producing the liquid crystal polyester composition of the present embodiment, the number average fiber length is reduced to 30 μm or more and 200 μm or less by breaking the fibrils having a number average fiber length of 1 mm or more while kneading with the liquid crystal polyester. It can melt-knead until it becomes.

  The liquid crystal polyester composition of this embodiment is manufactured using the manufacturing method mentioned 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. Accordingly, it is considered that the glass fibers are 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.

  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 a desired length, the liquid crystal polyester supplied to the main feed port 5, the fibrils, and as necessary The supply ratio of the components to be blended is not particularly limited. Similarly, the supply ratio of liquid crystal polyester, fibrils, and components to be blended as needed is not particularly limited.

  The cylinder 2 of the extruder 10 is preferably kneaded at a temperature at which the liquid crystalline polyester melts (for example, 340 ° C. to 400 ° C.). Moreover, in order to suppress the excessive temperature rise of the molten resin due to shearing heat generation, the temperature of the cylinder 2 may be lowered to 120 ° C. lower than the temperature at which the liquid crystal polyester melts downstream from the side feed port 7.

  The discharge rate 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 will be 60% or more.

The manufacturing method of the liquid crystal polyester composition of this embodiment may form the pellet which consists of a liquid crystal polyester composition, after melt-kneading liquid crystal polyester and a fibril.
As a molding method of the liquid crystal polyester composition, 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.

  In addition, as an extruder used for the manufacturing method of the liquid crystal polyester composition which is 1 aspect of this invention, it is not limited to the extruder of the structure shown in FIG. For example, a cylinder, one or more screws 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.

  In addition, as an extruder applicable to one embodiment of the present invention, specifically, either a single screw extruder or a twin screw extruder may be used. Examples of twin-screw extruders include those with a single screw rotating in the same direction to those with a triple screw, parallel shaft type with different direction rotation, oblique shaft type or incomplete meshing type, etc. 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.

  According to the liquid crystal polyester composition of the present embodiment, the heat resistance is high and the thin wall fluidity is high. Moreover, according to the manufacturing method of the liquid crystal polyester composition of this embodiment, the liquid crystal polyester composition having high heat resistance and high thin-wall fluidity can be obtained.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that 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.

  EXAMPLES The present invention will be described below with reference to 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 crystal 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 / 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 (robot 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.

[Measurement of change ratio of peak area ratio derived from component X to peak derived from Nn-butyl p-hydroxybenzoic acid amide (100 × b / a)]
An apparatus having the following configuration was used to measure the rate of change (100 × b / a) of the peak area ratio derived from component X relative to the peak derived from Nn-butyl p-hydroxybenzoic acid amide.

[Constitution]
Equipment: High-performance liquid chromatography system manufactured by Tosoh Corporation Pump: LC-20AD
Pump controller: CMB-20A
Autosampler: SIL-20AHT
Column oven: CTO-20A

(Sample preparation)
The liquid crystal polyester composition was put into an eggplant-shaped flask containing n-butylamine of N-methylpyrrolidone, and a sample was dissolved in a 200 ° C. sand bath with a cooling tube, and further decomposed for 2 hours. Thereafter, excess n-butylamine was removed with an evaporator in a sand bath at 80 ° C., neutralized by adding formic acid, and then added with N-methylpyrrolidone and anisic acid as a sample solution.

(Measurement)
The prepared sample was measured by a liquid chromatography method under the following conditions, and the area ratio of the peak with a retention time of 21.90 minutes to the peak with a retention time of 2.50 minutes in the obtained chromatogram was obtained. The area ratio was a. Similarly, the liquid crystal polyester composition was measured for 1 hour at a temperature 30 ° C. higher than the flow start temperature of the liquid crystal polyester composition, and the retention time for the peak in the resulting chromatogram was 2.50 minutes. The area ratio of the peak at 90 minutes was determined and this was defined as the peak area ratio b. A value of 100 × b / a was calculated based on these peak area ratio values. In this example, the value of 100 × b / a means the rate of change of the peak area ratio derived from component X with respect to the peak derived from Nn-butyl p-hydroxybenzoic acid amide.

[conditions]
Sample injection volume: 10 μL
Column: manufactured by Sumika Chemical Analysis Co., Ltd., product name “sumipax ODS KP-06” (5 μm × 4.6 mmφ × 1250 mm)
Column temperature: 40 ° C
Measurement method: Gradient elution method Eluent flow rate: 1.0 mL / min Detector: UV-visible spectrophotometer (UV)
Detection wavelength: 240 nm
Eluent: (A) 0.1% acetic acid-added aqueous solution and (B) 0.1% acetic acid-added acetonitrile solution were used, and the composition of the eluent was changed under the following gradient conditions.

[Gradient condition]
First, the concentration of the solution (B) was linearly changed from 10% to 15% by volume with respect to the total amount of the eluent over 15 minutes. Next, the concentration of the solution (B) was linearly changed from 15% by volume to 100% by volume with respect to the total amount of the eluent over 10 minutes.

<Manufacture of liquid crystal polyester>
[Production Example 1]
To 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 parahydroxybenzoic acid, 446.9 g of 4,4′-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 liquid crystal 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)
Original fiber B: manufactured by Central Glass Co., Ltd., trade name “Milded Fiber EFH75-01” (number average fiber length: 91 μm)

  Further, as the extruder, a twin screw extruder (manufactured by Toshiba Machine Co., Ltd., model number “TEM-41SS”) was used. 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 having a diameter of 41 mm was used, and the second vent portion was held by a water pump so that the degree of vacuum was -0.09 MPa (the 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 initiation 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.

  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 lengths of the glass fibers in the liquid crystal polyester compositions.

  As shown in Table 1, in the liquid crystal polyester composition of Example 1 manufactured by the manufacturing method according to one aspect of the present invention, the comparative example 1 and the flow start temperature were similar to those of Comparative Example 1. In comparison, the value of 100 × b / a was low. That is, while the liquid crystal polyester composition of Example 1 shows the same heat resistance as Comparative Example 1, it is derived from Component X relative to the peak derived from Nn-butyl p-hydroxybenzoic acid amide compared to Comparative Example 1. The rate of change in the peak area ratio was small. Furthermore, in other words, while the liquid crystal polyester composition of Example 1 shows the same heat resistance as that of Comparative Example 1, it can be said that the cross-linking reaction between the molecular chains of the liquid crystal polyester did not proceed as compared with Comparative Example 1. .

  Further, as shown in Table 1, the liquid crystal polyester composition of Example 1 had a long thin flow length as compared with Comparative Example 1. That is, the liquid crystal polyester composition of Example 1 exhibited the same heat resistance as that of Comparative Example 1, but was superior in thin-wall fluidity as compared with Comparative Example 1.

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

  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 part, 9 ... Discharge die, 9a ... nozzle hole, 10 ... extruder, 11 ... first kneading section, 12 ... second kneading section, 13 ... third kneading section

Claims (1)

Including liquid crystal polyester and glass fiber,
A liquid crystal polyester composition satisfying the following conditions (i) and (ii).
(I) The flow start temperature of the liquid crystal polyester composition is 330 ° C. or higher.
(Ii) In the chromatogram obtained by measuring the decomposition product obtained by decomposing the liquid crystal polyester contained in the liquid crystal polyester composition with n-butylamine by the liquid chromatography method under the following conditions, the retention time is 2. Retention time with respect to 50 minutes peak is 21.90 minutes peak area ratio a,
In the chromatogram obtained by measuring in the same manner the liquid crystal polyester composition held at a temperature 30 ° C. higher than the flow start temperature of the liquid crystal polyester composition for 1 hour, the retention time with respect to the peak with a retention time of 2.50 minutes is 21. When the area ratio of the peak at 90 minutes is b, the value of 100 × b / a is 50 or more and 200 or less.
[conditions]
Sample injection volume: 10 μL
Column: manufactured by Sumika Chemical Analysis Co., Ltd., product name “sumipax ODS KP-06” (5 μm × 4.6 mmφ × 1250 mm)
Column temperature: 40 ° C
Measurement method: Gradient elution method Eluent flow rate: 1.0 mL / min Detector: UV-visible spectrophotometer (UV)
Detection wavelength: 240 nm
Eluent: (A) 0.1% acetic acid-added aqueous solution and (B) 0.1% acetic acid-added acetonitrile solution are used, and the composition of the eluent is changed under the following gradient conditions.
[Gradient condition]
First, the concentration of the solution (B) is linearly changed from 10% by volume to 15% by volume with respect to the total amount of the eluent over 15 minutes. Next, the concentration of the solution (B) is linearly changed from 15% by volume to 100% by volume over 10 minutes with respect to the total amount of the eluent.

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