JP2007099786A - Liquid crystal polyester resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal polyester resin composition suitable as a molding material of components reduced in size, thickness and height that exhibits excellent flowability on molding, hardly generates burrs and gives a molded article improved in weld strengths and anisotropy. <P>SOLUTION: The liquid crystal polyester resin composition comprises 100 pts.wt. of a liquid crystal polyester resin that is constituted of recurring units of formulae (I)-(IV) (wherein Ar<SB>1</SB>and Ar<SB>2</SB>are each a bivalent aromatic group) and contains at least 0.5 mol% and less than 3 mol% of the recurring unit represented by formula (II) in all the recurring units and 1-100 pts.wt. of a whisker. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal polyester resin composition that is excellent in fluidity during molding and has few burrs.

  Thermotropic liquid crystal polyester resin (hereinafter abbreviated as liquid crystal polyester resin or LCP) is excellent in mechanical properties such as heat resistance and rigidity, chemical resistance, dimensional accuracy, etc. Its use is expanding in various applications.

  In particular, in the information / communication field such as personal computers and mobile phones, there are many cases where a thin-walled portion is formed due to high integration of components, miniaturization, thinning, low profile, and the like. Therefore, in such a field, the amount of the LCP used is greatly increased by taking advantage of the characteristics that LCP has excellent moldability, that is, good fluidity and does not have burrs.

  However, the miniaturization, thinning, and low profile of parts in the information / communication field are increasing day by day, and further improvements are required in terms of fluidity and difficulty in generating burrs during LCP molding. ing.

  Although LCP has excellent characteristics, weak weld strength and anisotropy of molded products due to strong molecular orientation during molding are recognized as defects, and methods for improving these defects are known. Various studies have been made.

  As a method for improving these drawbacks, for example, a method of blending a fibrous filler such as aluminum borate whisker, titanium oxide whisker, or potassium titanate whisker into a liquid crystal polyester resin is known (Patent Documents 1 to 4). See).

  Although these liquid crystalline polyester resin compositions have improved weld strength and anisotropy, there are current requirements for parts in the information and communication fields regarding fluidity during molding and the difficulty of burrs. Not satisfied.

JP-A-3-59067 JP-A-3-281656 JP 62-81448 A JP-A-61-195156

  It is an object of the present invention to be suitable as a molding material for parts that are reduced in size, thickness, and height, has excellent fluidity at the time of molding, has few burrs, and has a weld strength and anisotropy of a molded product. An object of the present invention is to provide an improved liquid crystal polyester resin composition.

  The present invention relates to a liquid crystal polyester resin composed of repeating units of the following formulas (I) to (IV), wherein the repeating unit represented by the formula (II) is contained in a total repeating unit of 0.5 mol% or more and less than 3 mol%. The present invention relates to a liquid crystal polyester resin composition containing 100 parts by weight and 1 to 100 parts by weight of whiskers.

［Ａｒ_１およびＡｒ_２はそれぞれ２価の芳香族基を表す。］

[Ar ₁ and Ar ₂ each represent a divalent aromatic group. ]

  We have a 4-oxybenzoyl repeat unit (formula (I)), an aromatic dicarbonyl repeat unit (formula (III)), an aromatic dioxy repeat unit (formula IV) and a small amount of 6-oxy-2. -When a liquid crystal polyester resin composed of a naphthoyl repeating unit (formula (II)) is blended with a specific amount of whisker to form a liquid crystal polyester resin composition, it has excellent fluidity at the time of molding, less burrs are produced, and The inventors have found that the weld strength and anisotropy of the molded article are improved, and have completed the present invention.

  The liquid crystal polyester resin used in the present invention is a polyester resin that forms an anisotropic molten phase, and is referred to by those skilled in the art as a thermotropic liquid crystal polyester resin, as long as it is within the scope of the present invention. There is no particular limitation.

  The property of the anisotropic molten phase can be confirmed by a normal deflection inspection method using an orthogonal deflector, that is, by observing a sample placed on a hot stage in a nitrogen atmosphere.

  The liquid crystalline polyester resin used in the present invention comprises 4-oxybenzoyl repeating unit (I), 6-oxy-2-naphthoyl repeating unit (II) represented by the following formulas (I) to (IV), aromatic dicarbonyl repeating It is composed of a unit (III) and an aromatic dioxy repeating unit (IV).

［Ａｒ_１およびＡｒ_２はそれぞれ２価の芳香族基を表す。］

[Ar ₁ and Ar ₂ each represent a divalent aromatic group. ]

  The liquid crystalline polyester resin used in the present invention contains a 4-oxybenzoyl repeating unit represented by the formula (I), and the content thereof is preferably 30 to 90 mol% in all repeating units of the liquid crystalline polyester resin. Yes, 45 to 85 mol% is particularly preferable, and 50 to 80 mol% is most preferable.

  Examples of the monomer that gives the repeating unit represented by the formula (I) include 4-hydroxybenzoic acid and ester-forming derivatives such as acylated products, ester derivatives, and acid halides.

  The liquid crystal polyester resin used in the present invention contains a 6-oxy-2-naphthoyl repeating unit represented by the formula (II), and the content thereof is 0.5 mol in all repeating units of the liquid crystal polyester resin. % To less than 3 mol%, particularly preferably 0.5 to 2.7 mol%, and most preferably 0.5 to 2.5 mol%.

  When the content of the repeating unit represented by the formula (II) in all the repeating units of the liquid crystal polyester resin is less than 0.5 mol%, the fluidity at the time of molding is inferior, and the amount of burrs generated is There is a problem such as an increase, and when it is 3 mol% or more, the melt viscosity of the liquid crystal polyester resin is low, but when the whisker is blended, the composition cannot obtain sufficient fluidity at the time of molding. In addition, there are problems such as an increased amount of burrs and poor heat resistance.

  Examples of the monomer that gives the repeating unit represented by the formula (II) include 6-hydroxy-2-naphthoic acid and ester-forming derivatives such as acylated products, ester derivatives, and acid halides.

  The liquid crystalline polyester resin used in the present invention also contains an aromatic dicarbonyl repeating unit represented by the formula (III) and an aromatic dioxy repeating unit represented by the formula (IV). Even if the liquid crystalline polyester resin of the present invention contains only one type of aromatic dicarbonyl repeating unit represented by formula (III) and aromatic dioxy repeating unit represented by formula (IV), Two or more types may be included.

  The liquid crystalline polyester resin used in the present invention preferably contains 5 to 35 mol% of the total repeating units of the liquid crystalline polyester resin as the total amount of aromatic dicarbonyl repeating units and aromatic dioxy repeating units, and 7.5 to 27. Those containing 5 mol% are particularly preferred, and those containing 10 to 25 mol% are most preferred.

  In the liquid crystal polyester resin used in the present invention, the total amount of each of the repeating units represented by formula (III) and formula (IV) is preferably substantially equimolar%.

  Here, “substantially equimolar%” means the ratio of the total amount of repeating units represented by the formula (III) and the total amount of repeating units represented by the formula (IV) contained in the liquid crystal polyester resin. Is 1 / 1.1-1.1 / 1.

Specific examples of the divalent aromatic group Ar ₁ contained in the aromatic dicarbonyl repeating unit represented by the formula (III) include groups selected from the following group.

Of these, Ar ₁ is preferably selected from the following (1) to (4) in view of the ease of production of the liquid crystal polyester resin, and the mechanical properties, heat resistance, and crystals of the obtained liquid crystal polyester resin are preferred. Ar ₁ is particularly preferably a group represented by the following (4) because the melting temperature and moldability are easily adjusted to appropriate levels.

  Specific examples of the monomer that provides the above-mentioned preferred aromatic dicarbonyl repeating unit include, for example, terephthalic acid, isophthalic acid, 4,4′-dicarboxybiphenyl, 2,6-naphthalenedicarboxylic acid, and 1,6-naphthalene. Aromatic dicarboxylic acids such as dicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, alkyl, alkoxy or halogen-substituted products thereof, and ester derivatives such as ester derivatives and acid halides thereof Derivatives. Among these, it is preferable because the mechanical properties, heat resistance, crystal melting temperature, and moldability of the liquid crystalline polyester from which 2,6-naphthalenedicarboxylic acid can be obtained can be easily adjusted to an appropriate level.

Specific examples of the divalent aromatic group Ar ₂ contained in the aromatic dioxy repeating unit represented by the formula (IV) include groups selected from the following group.

Among these, it is preferable that Ar ₂ is a group selected from the following (1) to (4) from the viewpoint of easy production of the liquid crystal polyester resin. In addition, Ar ₂ is particularly preferably a group represented by the following (1) because the mechanical properties, heat resistance, crystal melting temperature, and moldability of the obtained liquid crystal polyester resin can be easily adjusted to appropriate levels.

  Specific examples of the monomer that gives an aromatic dioxy repeating unit include hydroquinone, resorcin, 4,4′-dihydroxybiphenyl, 3,3′-dihydroxybiphenyl, 3,4′-dihydroxybiphenyl, and 2,6-dihydroxy. Aromatic diols such as naphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4′-dihydroxybiphenyl ether, alkyl, alkoxy or halogen substituents thereof, and Examples thereof include ester-forming derivatives such as acylated products. Among these, hydroquinone is preferable from the viewpoints of reactivity during polymerization, characteristics of the obtained liquid crystal polyester resin, and the like.

  The liquid crystal polyester resin used in the present invention may contain an aromatic oxycarbonyl repeating unit other than the 4-oxybenzoyl repeating unit and the 6-oxy-2-naphthoyl repeating unit as long as the object of the present invention is not impaired. It may also contain an amide bond or a thioester bond.

  Specific examples of monomers that give an aromatic oxycarbonyl repeating unit other than 4-oxybenzoyl repeating unit and 6-oxy-2-naphthoyl repeating unit include, for example, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 5- Hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, these Alkyl-substituted, alkoxy- or halogen-substituted compounds thereof, and ester-forming derivatives thereof such as acylated products, ester derivatives, and acid halides.

  Examples of the monomer that gives an amide bond or a thioester bond include aromatic aminophenols, aromatic aminocarboxylic acids, aromatic diamines, mercaptoaromatic carboxylic acids, aromatic dithiols, and hydroxyaromatic thiols.

  In the liquid crystal polyester resin, the repeating units other than formulas (I) to (IV) are preferably 10 mol% or less based on the total amount of the repeating units represented by formulas (I) to (IV).

  The liquid crystal polyester resin in the present invention is composed of repeating units of the formulas (I) to (IV), and has a formula (II) of 0.5 mol% or more and less than 3 mol% in all repeating units of the liquid crystal polyester resin. ) May be used alone or in combination of two or more liquid crystal polyester resins having different types and / or constitutional ratios.

  The crystal melting temperature of the liquid crystal polyester resin in the present invention is not particularly limited as long as the object of the present invention is not impaired, but is preferably 280 to 360 ° C, particularly preferably 300 to 340 ° C.

The crystal melting temperature of the liquid crystal polyester resin can be measured by the following method.
<Method for measuring crystal melting temperature>
Using an Exstar 6000 manufactured by Seiko Instruments Inc. as a differential scanning calorimeter, after observing the endothermic peak temperature (Tm1) observed when measuring a liquid crystal polymer sample at a temperature rising condition of 20 ° C./min from room temperature, Hold at a temperature 20-50 ° C. higher than Tm1 for 10 minutes. Next, after the sample was cooled to room temperature under a temperature drop condition of 20 ° C./min, an endothermic peak was measured again when measured under a temperature rise condition of 20 ° C./min, and the temperature showing the peak top was determined as the crystal melting of the liquid crystal polymer. Let it be temperature.

  Further, the melt viscosity of the liquid crystalline polyester resin used in the present invention is not particularly limited as long as the object of the present invention is not impaired, but it is preferably 3 to 80 Pa · s, and particularly preferably 5 to 50 Pa · s.

The melt viscosity of the liquid crystal polyester resin can be measured by the following method.
<Measuring method of melt viscosity>
Using a melt viscosity measuring device (Capillograph 1A manufactured by Toyo Seiki Co., Ltd.), with a capillary of 0.7 mmφ × 10 mm, at a temperature about 30 ° C. higher than the crystal melting temperature of the liquid crystal polyester resin, at a shear rate of 10 ³ s ⁻¹ Is measured to obtain a melt viscosity.

  The production method of the liquid crystalline polyester resin used in the present invention is not particularly limited, and a known polycondensation method for forming an ester bond, an amide bond, and a thioester bond composed of a combination of various monomers, such as a melt acidolysis method and a slurry polymerization method Can be used.

  The melt acidolysis method is a preferable method for use in the method for producing the liquid crystal polyester resin used in the present invention, and this method first heats the monomer to form a melt of the reactant, and then reacts. To obtain a molten polymer. Note that a vacuum may be applied to facilitate removal of volatiles (for example, acetic acid, water, etc.) by-produced in the final stage of the condensation.

  The slurry polymerization method is a method of reacting in the presence of a heat exchange fluid, and the solid product is obtained in a state suspended in a heat exchange medium.

  In any case of the melt acidosis method and the slurry polymerization method, the polymerizable monomer component used for producing the liquid crystal polyester resin is a modified form in which hydroxyl groups, amino groups, and mercapto groups are acylated at room temperature, that is, It can also be subjected to the reaction as a lower acylated product. The lower acyl group preferably has 2 to 5 carbon atoms, more preferably 2 or 3 carbon atoms. Particularly preferred is a method using an acetylated product of the monomer in the reaction.

  The acylated product of the monomer may be prepared by separately acylating and synthesized in advance, or it may be generated in the reaction system by adding an acylating agent such as acetic anhydride to the monomer during the production of the liquid crystal polymer. it can.

  In any case of the melt acidification method or the slurry polymerization method, a catalyst may be used as needed during the reaction.

  Specific examples of the catalyst include organic tin compounds such as dialkyltin oxide (for example, dibutyltin oxide) and diaryltin oxide; organic titanium compounds such as titanium dioxide, antimony trioxide, alkoxy titanium silicate, and titanium alkoxide; alkali or alkali of carboxylic acid Examples include earth metal salts (for example, potassium acetate); inorganic acid salts (for example, potassium sulfate); Lewis acid (for example, boron trifluoride); gaseous acid catalysts such as hydrogen halide (for example, hydrogen chloride).

  The ratio of the catalyst used is usually 10 to 1000 ppm, preferably 20 to 20 ppm, based on the monomer.

  The liquid crystal polyester resin thus obtained is extracted from the reaction vessel and processed into pellets, flakes or powders.

  In preparing the liquid crystalline polyester resin composition of the present invention, the liquid crystalline polyester resin processed into pellets, flakes, or powders is melted with whiskers using a Banbury mixer, kneader, uniaxial or biaxial extruder, etc. Kneaded to obtain the liquid crystal polymer composition of the present invention.

  The whisker content in the liquid crystal polyester composition of the present invention is 1 to 100 parts by weight, preferably 5 to 80 parts by weight, particularly preferably 10 to 60 parts by weight, based on 100 parts by weight of the liquid crystal polyester resin. It is.

  The whisker used in the liquid crystal polyester resin composition of the present invention preferably has an average fiber diameter of 0.1 to 2 μm, particularly preferably 0.1 to 1 μm. Moreover, it is preferable that average fiber length is 5-100 micrometers, it is especially preferable that it is 7-50, and it is most preferable that it is 10-30 micrometers.

  The whisker preferably has an aspect ratio of 10 to 150, particularly preferably 12 to 100, and most preferably 15 to 50.

  Suitable whiskers for the liquid crystal polyester resin composition of the present invention include aluminum borate whisker, potassium titanate whisker, titanium oxide whisker, zinc oxide whisker, magnesium borate whisker, silicon carbide whisker, and silicon nitride whisker. These whiskers may be used alone or in combination.

  Among these, it is preferable to use aluminum borate whiskers and / or potassium titanate whiskers from the viewpoint of balance between cost and physical properties of the obtained liquid crystal polyester resin composition.

  In the present invention, the whisker may be treated with a silane coupling agent such as aminosilane, epoxy silane, vinyl silane, methacryl silane, mercapto silane, phenyl silane, trialkoxy silane, dialkoxy silane, and trichloro silane. .

  The liquid crystalline polyester resin composition of the present invention may further contain other inorganic fillers and / or organic fillers together with whiskers as long as the object of the present invention is not impaired.

  Examples of the inorganic filler and / or organic filler that may be blended in the liquid crystal polyester resin composition of the present invention include glass fiber, silica alumina fiber, alumina fiber, carbon fiber, aramid fiber, talc, mica, graphite, Examples thereof include one or more selected from the group consisting of wollastonite, dolomite, clay, glass flakes, glass beads, glass balloons, calcium carbonate, barium sulfate, and titanium oxide. Among these, it is preferable to use glass fiber because it has a good balance between physical properties and cost.

  The blending amount of other inorganic fillers and / or organic fillers may be up to 40% by weight, more preferably up to 20% by weight of the total resin composition of the present invention.

  In the liquid crystal polyester resin composition of the present invention, higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid metal salts (here, higher fatty acids are those having 10 to 25 carbon atoms) as long as the effects of the present invention are not impaired. Mold release improvers such as polysiloxane and fluororesins; colorants such as dyes and pigments; antioxidants; thermal stabilizers; ultraviolet absorbers; antistatic agents; surfactants, etc. You may mix | blend 1 type or in combination of 2 or more types. These blending ratios are 0.005 to 1 part by weight, preferably 0.01 to 0.5 part by weight, based on 100 parts by weight of the liquid crystal polyester resin composition.

  For those having an external lubricant effect such as higher fatty acid, higher fatty acid ester, higher fatty acid metal salt, and fluorocarbon surfactant, pellets of the liquid crystal polyester resin composition of the present invention are formed in advance when molding the liquid crystal polyester resin composition. It may be attached to the surface.

  Moreover, you may mix | blend another resin component with the liquid-crystal polyester resin composition of this invention in the range which does not impair the objective of this invention. Examples of other resin components include polyamides, polyesters, polyacetals, polyphenylene ethers and modified products thereof, and thermoplastic resins such as polysulfone, polyethersulfone, polyetherimide, and polyamideimide, phenol resins, epoxy resins, and polyimide resins. And other thermosetting resins. Other resin components can be blended alone or in combination of two or more. The compounding amount of the other resin components is not particularly limited, and may be appropriately determined according to the use and purpose of the liquid crystal polymer composition. Typically, it is added in a range where the total blending amount of other resins with respect to 100 parts by weight of the liquid crystalline polyester resin is 0.1 to 100 parts by weight, particularly 0.1 to 80 parts by weight.

  Other inorganic fillers and / or organic fillers of whisker, various additives and other resin components may be blended in a liquid crystal polyester resin composition comprising liquid crystal polyester and whisker, and the liquid crystal polyester resin and whisker are melt-kneaded. You may mix | blend simultaneously.

  The liquid crystal polyester resin composition of the present invention thus obtained is processed into a molded product, a film, a sheet, a nonwoven fabric, and the like by a known molding method using an injection molding machine, an extruder, or the like.

  The liquid crystalline polyester resin composition of the present invention is excellent in fluidity at the time of molding and has few burrs, so that it can be used as a molding material for small, thin, and low-profile parts used in the information and communication fields. Preferably used.

  Hereinafter, the present invention will be described in detail by way of examples.

Hereinafter, the abbreviations in Synthesis Examples and Examples represent the following compounds.
[Liquid crystal polyester resin monomer]
POB: 4-hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid NDA: 2,6-naphthalenedicarboxylic acid HQ: hydroquinone

[Liquid crystal polyester resin synthesis example]
-Synthesis of LCP1

POB: 628.4 g (4.55 mol), BON 6: 24.5 g (0.13 mol), HQ: 100.2 g (0.91 mol), NDA: 196.7 g (0.91 mol) and acetic anhydride : 684.9 g (6.71 mol) was charged into a 2 L glass reaction vessel having a stirring blade and a heat exchanger, and the temperature was raised from room temperature to 145 ° C. over 1 hour in a nitrogen gas atmosphere. Hold at temperature for 1 hour.

Thereafter, the temperature was raised to 345 ° C. over 7 hours while acetic acid by-produced was distilled off. After performing the polymerization reaction at the same temperature for 30 minutes, the pressure was reduced to atmospheric pressure to 10 torr over 80 minutes. When further heating and stirring were performed for 1 hour under a reduced pressure of 10 torr, a predetermined stirring torque was reached. After the reaction vessel was sealed, the reaction vessel was returned to atmospheric pressure with nitrogen gas to complete the reaction. The contents were taken out in the molten state, cooled and pulverized to obtain a flaky polymer.
The obtained polymer had a crystal melting temperature measured by a differential scanning calorimeter of 323 ° C., and a melt viscosity at 350 ° C. of 20 Pa · s.

-Synthesis of LCP2

POB: 635.3 g (4.60 mol), BON6: 2.45 g (0.013 mol), HQ: 103.5 g (0.94 mol), NDA: 203.2 g (0.94 mol) and acetic anhydride : 684.9 g (6.71 mol) was charged into a 2 L glass reaction vessel having a stirring blade and a heat exchanger, and the temperature was raised from room temperature to 145 ° C. over 1 hour in a nitrogen gas atmosphere. Hold at temperature for 1 hour.

  Thereafter, the temperature was raised to 355 ° C. over 7.5 hours while acetic acid produced as a by-product was distilled off. After performing the polymerization reaction at the same temperature for 30 minutes, the pressure was reduced to atmospheric pressure to 10 torr over 80 minutes. When a further stirring and stirring was performed for 0.6 hours under a reduced pressure of 10 torr, a predetermined stirring torque was reached. After sealing the reaction vessel, the reaction vessel was returned to atmospheric pressure with nitrogen gas, and the reaction was terminated. The contents were taken out in the molten state, cooled and pulverized to obtain a flaky polymer.

  The crystal melting temperature of the obtained polymer measured by a differential scanning calorimeter was 331 ° C., and the melt viscosity at 360 ° C. was 27 Pa · s.

-Synthesis of LCP3

POB: 646.4 g (4.68 mol), BON 6: 147.00 g (0.78 mol), HQ: 57.3 g (0.52 mol), NDA: 112.4 g (0.52 mol) and acetic anhydride : 684.9 g (6.71 mol) was charged into a 2 L glass reaction vessel having a stirring blade and a heat exchanger, and the temperature was raised from room temperature to 145 ° C. over 1 hour in a nitrogen gas atmosphere. Hold at temperature for 1 hour.

  Thereafter, the temperature was further raised to 330 ° C. over 6.5 hours while acetic acid produced as a by-product was distilled off. After performing the polymerization reaction at the same temperature for 30 minutes, the pressure was reduced to atmospheric pressure to 10 torr over 80 minutes. When a further stirring and stirring were performed for 0.8 hours under a reduced pressure of 10 torr, a predetermined stirring torque was reached. After the reaction vessel was sealed, the reaction vessel was returned to atmospheric pressure with nitrogen gas and the reaction was terminated. The contents were taken out in the molten state, cooled, and pulverized to obtain a flaky polymer.

  The crystal melting temperature of the obtained polymer measured by a differential scanning calorimeter was 298 ° C., and the melt viscosity at 330 ° C. was 22 Pa · s.

Example 1
LCP1 (100 parts by weight) obtained by the liquid crystal polyester resin synthesis example and aluminum borate whisker (40 parts by weight, manufactured by Shikoku Kasei Kogyo Co., Ltd .: Arborex D) were mixed with a twin screw extruder (Ikegai Co., Ltd. -30) was melt kneaded at a cylinder temperature of 340-330-330-325 ° C. and a screw rotation speed of 150 rpm to obtain a pellet-like liquid crystal polyester resin composition.

  The obtained liquid crystal polyester resin composition was evaluated for fluidity and burr according to the method described below, and the results are shown in Table 1.

<Liquidity assessment>
Using a connector model mold with a thickness of 0.6 mm and side gate shown in FIG. 1, molding is performed under the following conditions, and the mold is based on the weight of the molded product when the mold is completely filled with resin. The filling rate of the resin into was determined.

Molding machine: Nissei Plastic Industry Co., Ltd., UH-1000
Clamping force: 110 tons Injection speed: 200mm / sec
Injection pressure: 1000kg / cm ₂
Cylinder temperature: 350 ° C
Mold temperature: 70 ℃

<Bali evaluation>
A 20 μm gap is provided at the flow end of a test mold of length 170 × width 12.7 × thickness 0.8 mm, and molding is performed with the minimum molding pressure that can be filled. Measured.

Example 2
A pellet-like liquid crystal polyester resin composition was obtained in the same manner as in Example 1 except that the type of resin, the type of filler, and the amount of filler used were changed as described in Table 1.
The obtained liquid crystal polyester resin composition was evaluated for fluidity and burr, and the results are shown in Table 1.

Comparative Example 1
In the same manner as in Example 1 except that the type of resin, the type of filler, and the amount of filler used are changed as described in Table 1, and the cylinder temperature is 350-340-340-335 ° C. A pellet-like liquid crystal polyester resin composition was obtained.
The obtained liquid crystal polyester resin composition was evaluated for fluidity and burr, and the results are shown in Table 1. However, fluidity was evaluated at a cylinder temperature of 360 ° C.

Comparative Example 2
The resin type, the type of filler, and the amount of filler used were changed according to the description in Table 1, and the cylinder temperature was set to 320-310-310-305 ° C., as in Example 1, A pellet-like liquid crystal polyester resin composition was obtained.
The obtained liquid crystal polyester resin composition was evaluated for fluidity and burr, and the results are shown in Table 1. However, the fluidity was evaluated at a cylinder temperature of 330 ° C.

Comparative Example 3 and Comparative Example 4
A pellet-like liquid crystal polyester resin composition was obtained in the same manner as in Example 1 except that the type of resin, the type of filler, and the amount of filler used were changed as described in Table 1.
The obtained liquid crystal polyester resin composition was evaluated for fluidity and burr, and the results are shown in Table 1.

ＡＢ；硼酸アルミニウムウィスカ（四国化成工業株式会社製アルボレックスＤ）
ＴＩ；チタン酸カリウムウィスカ（大塚化学化学株式会社ティスモＮ）
ＧＦ；ガラス繊維（旭ファイバーグラス社製ＣＳ０３ＦＴ５９１）
ＭＦ；ミルドガラス（セントラル硝子社製ＥＦＨ７５−３１）
＊ガラス繊維については、溶融混練時に押出機内で折れることにより、液晶ポリエステル樹脂組成物中においては３００μｍ程度の繊維長となっている。

AB: Aluminum borate whisker (Arbolex D manufactured by Shikoku Chemicals Co., Ltd.)
TI: Potassium titanate whisker (Otsuka Chemical Co., Ltd. Tismo N)
GF: Glass fiber (CS03FT591 manufactured by Asahi Fiber Glass Co., Ltd.)
MF: Milled glass (Central Glass Co., Ltd. EFH75-31)
* The glass fiber has a fiber length of about 300 μm in the liquid crystal polyester resin composition by being broken in the extruder during melt-kneading.

It is a figure of a connector model type used for fluidity evaluation.

Claims (8)

100 parts by weight of a liquid crystal polyester resin composed of repeating units of the following formulas (I) to (IV) and containing 0.5 mol% or more and less than 3 mol% of repeating units represented by formula (II) in all repeating units; And a liquid crystal polyester resin composition containing 1 to 100 parts by weight of whiskers.

[Ar ₁ and Ar ₂ each represent a divalent aromatic group. ]   The liquid crystalline polyester resin contains 30 to 90 mol% of repeating units represented by the formula (I) in all repeating units, and substantially equimolar repeating units represented by the formulas (III) and (IV). The liquid crystal polyester resin composition according to claim 1, comprising: The liquid crystal polyester resin composition according to claim 2, wherein Ar ₁ and Ar ₂ are one or more selected from the following aromatic groups (1) to (4).

The liquid crystal polyester resin composition according to claim 3, wherein Ar ₁ is an aromatic group represented by formula (4), and Ar ₂ is an aromatic group represented by formula (1).   The liquid crystal polyester resin composition according to any one of claims 1 to 4, wherein the whisker is an aluminum borate whisker and / or a potassium titanate whisker.   The liquid crystal polyester resin composition according to any one of claims 1 to 5, wherein the whisker has an average fiber diameter of 0.1 to 2.0 µm, an average fiber length of 5 to 100 µm, and an aspect ratio of 10 to 150.   The liquid crystal polyester resin composition according to claim 1, wherein the melt viscosity of the liquid crystal polyester resin is 3 to 80 Pa · s. A molded product formed by molding the liquid crystal polyester resin composition according to claim 1.

Images