JP5172279B2 - Liquid crystal polymer composition and molded article comprising the same - Google Patents

Description

  The present invention relates to a liquid crystal polymer composition.

  Thermotropic liquid crystal polymers (hereinafter abbreviated as liquid crystal polymers or LCPs) are excellent in mechanical properties such as heat resistance and rigidity, chemical resistance, dimensional accuracy, etc. Its use is expanding to applications.

  Especially in the information / communication field such as personal computers and mobile phones, there is a rapid increase in the degree of integration, miniaturization, thinning, and low profile of parts, resulting in the formation of very thin parts. There are many. Therefore, the amount of LCP used is greatly increased by taking advantage of its excellent moldability, that is, good fluidity and no characteristics of other resins such as no burrs.

  However, in recent years, the reflow temperature has become higher in applications such as connectors due to lead-free soldering, and the warpage of molded products caused by reflow treatment at high temperatures has also become a problem in molded products of LCP. .

  As a method of solving such a problem of warping of a molded article, a method of blending a liquid crystal polymer with a plate-like filler is known. Thus, a method of blending a liquid crystal polymer with a plate-like filler such as talc, which has a specific shape and satisfies D / W ≦ 5 and 3 ≦ W / H ≦ 200 has been proposed (in Patent Document 1) , D is the maximum particle diameter of the plate-like filler, the direction is the x direction, W is the particle diameter perpendicular to the x direction (y direction), and H is the particle thickness in the z direction perpendicular to the xy plane. Is).

However, in Patent Document 1, as for talc, the D / W ratio is 1.0 to 1.3, and only talc having a substantially circular to square shape has been studied. Although an improvement was observed in the occurrence of warpage, the effect was not sufficient, and further improvement in the occurrence of warpage was required.
JP 2001-106923 A

  An object of the present invention is to provide a liquid crystal polymer composition with less warping of a molded product.

  The present invention provides a liquid crystal polymer composition comprising 1 to 200 parts by weight of talc having an average particle diameter of 5 to 100 μm and an aspect ratio of 3.0 to 5.0 with respect to 100 parts by weight of the liquid crystal polymer. To do.

  The liquid crystal polymer used in the present invention is a polyester or polyester amide that forms an anisotropic melt phase, and is not particularly limited as long as it is called a thermotropic liquid crystal polyester or a thermotropic liquid crystal polyester amide by those skilled in the art.

  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.

  As the repeating unit constituting the liquid crystal polymer used in the present invention, aromatic oxycarbonyl repeating unit, aromatic dicarbonyl repeating unit, aromatic dioxy repeating unit, aromatic aminooxy repeating unit, aromatic aminocarbonyl repeating unit, aromatic Examples thereof include a diamino repeating unit, an aromatic oxydicarbonyl repeating unit, and an aliphatic dioxy repeating unit.

  The liquid crystal polymer composed of each of these repeating units may or may not form an anisotropic molten phase depending on the constituent components, the composition ratio in the polymer, and the sequence distribution, but the liquid crystal used in the present invention. Polymers are limited to those that form an anisotropic melt phase.

  Specific examples of the monomer that gives an aromatic oxycarbonyl repeating unit include, for example, parahydroxybenzoic acid, metahydroxybenzoic acid, orthohydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 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, their alkyl, alkoxy or halogen Substituents and ester-forming derivatives thereof such as acylated products, ester derivatives, acid halides and the like can be mentioned. Among these, parahydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are preferable from the viewpoint of easy adjustment of characteristics and melting point of the liquid crystal polymer.

  Specific examples of the monomer giving the aromatic dicarbonyl repeating unit include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1, Examples thereof include aromatic dicarboxylic acids such as 4-naphthalenedicarboxylic acid and 4,4′-dicarboxybiphenyl, alkyl, alkoxy or halogen-substituted products thereof, and ester-forming derivatives such as ester derivatives and acid halides thereof. Among these, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferable because the liquid crystal polymer from which terephthalic acid and 2,6-naphthalenedicarboxylic acid are obtained can easily adjust the mechanical properties, heat resistance, melting point temperature, and moldability to appropriate levels.

  Specific examples of the monomer giving an aromatic dioxy repeating unit include, for example, hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4 Aromatic diols such as 4,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, alkyl, alkoxy or halogen substituents thereof, and Examples thereof include ester-forming derivatives such as acylated products. Among these, hydroquinone and 4,4'-dihydroxybiphenyl are preferable from the viewpoint of reactivity during polymerization, characteristics of the obtained liquid crystal polymer, and the like.

  Specific examples of the monomer that gives an aromatic aminooxy repeating unit include, for example, p-aminophenol, m-aminophenol, 4-amino-1-naphthol, 5-amino-1-naphthol, and 8-amino-2- Aromatic hydroxyamines such as naphthol and 4-amino-4′-hydroxybiphenyl, alkyl, alkoxy or halogen substituents thereof, and ester or amide-forming derivatives thereof such as acylated products thereof can be mentioned.

  Specific examples of the monomer that gives an aromatic aminocarbonyl repeating unit include aromatic aminocarboxylic acids such as p-aminobenzoic acid, m-aminobenzoic acid, and 6-amino-2-naphthoic acid, their alkyls, Examples thereof include alkoxy or halogen-substituted products, and ester or amide-forming derivatives thereof such as acylated products, ester derivatives, and acid halides.

  Specific examples of the monomer that gives an aromatic diamino repeating unit include aromatic diamines such as p-phenylenediamine, m-phenylenediamine, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, alkyls thereof, Examples include amide-forming derivatives such as alkoxy or halogen-substituted products, and acylated products thereof.

  Specific examples of monomers that give aromatic oxydicarbonyl repeating units include hydroxyaromatic dicarboxylic acids such as 3-hydroxy-2,7-naphthalenedicarboxylic acid, 4-hydroxyisophthalic acid, and 5-hydroxyisophthalic acid. And alkyl-substituted, alkoxy- or halogen-substituted products thereof, and ester-forming derivatives such as acylated products, ester derivatives, and acid halides thereof.

  Specific examples of the monomer giving the aliphatic dioxy repeating unit include aliphatic diols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and acylated products thereof. In addition, polyesters containing aliphatic dioxy repeating units such as polyethylene terephthalate and polybutylene terephthalate are mixed with the above aromatic oxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic hydroxyamine, aromatic aminocarboxylic acid, A liquid crystal polymer containing an aliphatic dioxy repeating unit can also be obtained by reacting with an aromatic diamine, a hydroxyaromatic dicarboxylic acid and an acylated product, an ester derivative, an acid halide, or the like thereof.

  The liquid crystal polymer used in the present invention may contain a thioester bond as long as the object of the present invention is not impaired. Examples of the monomer that gives such a bond include mercapto aromatic carboxylic acid, aromatic dithiol, and hydroxy aromatic thiol. These monomers are used in an aromatic oxycarbonyl repeating unit, an aromatic dicarbonyl repeating unit, an aromatic dioxy repeating unit, an aromatic aminooxy repeating unit, an aromatic aminocarbonyl repeating unit, an aromatic diamino repeating unit, The amount is preferably 10 mol% or less based on the total amount of monomers giving the aromatic oxydicarbonyl repeating unit and the aliphatic dioxy repeating unit.

  As mentioned above, although the repeating unit contained in the liquid crystal polymer used in this invention and the monomer which gives it were demonstrated, the liquid crystal polymer used in this invention is an aromatic oxycarbonyl repeating unit, 4-oxybenzoyl repeating unit, and / or Or it is more preferable to use what contains a 6-oxy-2- naphthoyl repeating unit.

  Among the liquid crystal polymers containing 4-oxybenzoyl repeating units and / or 6-oxy-2-naphthoyl repeating units, preferred are, for example, copolymers composed of the following monomer constituent units.

1) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid copolymer 2) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl copolymer 3) 4-hydroxybenzoic acid / terephthalic acid / Isophthalic acid / 4,4'-dihydroxybiphenyl copolymer 4) 4-hydroxybenzoic acid / terephthalic acid / isophthalic acid / 4,4'-dihydroxybiphenyl / hydroquinone copolymer 5) 4-hydroxybenzoic acid / terephthalic acid / Hydroquinone copolymer 6) 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone copolymer 7) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / 4,4′-dihydroxybiphenyl Copolymer 8) 6-hydroxy-2-naphthoic acid / terephthalic acid / 4,4'-dihydroxybi Phenyl copolymer 9) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone copolymer 10) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / 4,4′-dihydroxy Biphenyl copolymer 11) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer 12) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer 13) 4 -Hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer 14) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone / 4,4 '-Dihydroxybiphenyl copolymer 15) 4-hydroxybenzoic acid / tere Taric acid / 4-aminophenol copolymer 16) 6-hydroxy-2-naphthoic acid / terephthalic acid / 4-aminophenol copolymer 17) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / 4-aminophenol copolymer 18) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / 4-aminophenol copolymer 19) 4-hydroxybenzoic acid / terephthalic acid / ethylene glycol copolymer 20) 4-hydroxybenzoic acid / terephthalic acid / 4,4′-dihydroxybiphenyl / ethylene glycol copolymer 21) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / ethylene glycol copolymer 22 ) 4-Hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / Telef Taric acid / 4,4′-dihydroxybiphenyl / ethylene glycol copolymer.

  Among these, it is particularly preferable to use the copolymers 1), 9), and 13) as liquid crystal polymers from the viewpoint of molding processability and mechanical properties.

  As the liquid crystal polymer in the present invention, a blend of two or more liquid crystal polymers may be used for the purpose of improving fluidity during molding.

Hereinafter, a method for producing a liquid crystal polymer used in the present invention will be described.
The production method of the liquid crystal polymer used in the present invention is not particularly limited, and a known polycondensation method for forming an ester bond or an amide bond composed of a combination of the above monomers, for example, a melt acidosis method, a slurry polymerization method, or the like is used. Can do.

  The melt acidosis method is a preferred method for use in the method for producing a liquid crystal polymer used in the present invention, and this method first heats a monomer to form a molten liquid of a reactant, and then performs a reaction. Subsequently, a molten polymer is obtained. 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 both cases of the melt acidification method and the slurry polymerization method, the polymerizable monomer component used in producing the liquid crystal polymer is a modified form in which hydroxyl groups and / or amino groups are acylated, that is, as a lower acylated product. It can also be used for the reaction. 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 organotin compounds such as dialkyltin oxide (for example, dibutyltin oxide) and diaryltin oxide; antimony trioxide; titanium dioxide; organotitanium compounds such as alkoxytitanium 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 200 ppm, based on the monomer weight.

  The liquid crystal polymers obtained by the polycondensation reaction in this way are each extracted from the polymerization reaction tank in a molten state, and then processed into pellets, flakes, or powders.

  The obtained liquid crystal polymer in the form of pellets, flakes, or powders is substantially a solid phase under reduced pressure or in an inert gas atmosphere such as nitrogen or helium for the purpose of increasing molecular weight and improving heat resistance. You may heat-process in a state.

  The treatment temperature in the case of performing the heat treatment in the solid phase is not particularly limited as long as the liquid crystal polymer is not melted, but it is preferably 260 to 350 ° C, preferably 280 to 320 ° C.

  The liquid crystal polymer thus obtained was blended with talc having an average particle diameter of 5 to 100 μm and an aspect ratio of 3.0 to 5.0, and then banbury mixer, kneader, uniaxial or biaxial extrusion. The liquid crystal polymer composition of the present invention is obtained by melting and kneading the liquid crystal polymer at a temperature close to the crystal melting temperature or the crystal melting temperature + 30 ° C. using a machine.

  The liquid crystal polymer used in the present invention preferably has a crystal melting temperature (Tm) measured by a differential scanning calorimeter of 270 to 380 ° C, more preferably 320 to 360 ° C.

The crystal melting temperature (Tm) is measured by the method described below.
<Method for measuring crystal melting temperature>
After measuring the endothermic peak temperature (Tm1) observed when a liquid crystal polymer sample is measured at room temperature to 20 ° C./min, the sample is held at a temperature 20 to 50 ° C. higher than Tm1 for 10 minutes. Next, the sample was cooled to room temperature under a temperature drop condition of 20 ° C./min, and an endothermic peak was measured again when measured under a temperature rise condition of 20 ° C./min. Let melting temperature (Tm).

Hereinafter, the talc used in the present invention will be described.
The talc used in the present invention has an average particle diameter of 5 to 100 μm, more preferably 5 to 75 μm, and most preferably 5 to 50 μm.

  In the present invention, the average particle diameter of talc is a median diameter measured by a laser diffraction method.

  The talc used in the present invention has an aspect ratio of 3.0 to 5.0, more preferably 3.0 to 4.5, and most preferably 3.0 to 4.0.

  In the present invention, the aspect ratio of talc is determined as follows based on measurement with a multi-image analyzer manufactured by Beckman Coulter, Inc. In the present invention, the aspect ratio of talc is determined by illuminating a strobe in response to a voltage pulse generated when particles pass through the pores when measuring particles of talc by the Coulter method, It is measured by image analysis. The aspect ratio of talc particles is determined by measuring the longest length (A) between any two points on the outer circumference of the projected image, and using two straight lines parallel to the line measuring the maximum length (A). It is determined by measuring the shortest length (B) between two straight lines when a projection image is sandwiched, and calculating the value of (A) ÷ (B).

  The amount of talc used in the present invention is 1 to 200 parts by weight with respect to 100 parts by weight of the liquid crystal polymer, more preferably 5 to 150 parts by weight, and most preferably 10 to 100 parts by weight.

  The talc used in the present invention has a water content of 0.2% by weight or less because it is difficult to cause blistering on the surface of a molded product called a blister and is less affected by physical properties such as heat resistance of the molded product. It is preferable to use one. The water content of talc can be measured by the method described below using an infrared moisture meter manufactured by Kett Science Laboratory.

<Method for measuring water content of talc>
10 g of a sample of talc is weighed, heated to 105 ° C. and held at the same temperature, and the weight reduction rate when the weight loss of the sample ceases is taken as the water content of talc.

  When the water content of talc exceeds 0.2% by weight, for example, it may be used after drying at 100 to 150 ° C. and making the water content 0.2% by weight or less.

  The liquid crystal polymer composition of the present invention may contain a fibrous filler in addition to talc. The amount of the fibrous filler used is 1 to 200 parts by weight, more preferably 1 to 150 parts by weight, and most preferably 1 to 100 parts by weight with respect to 100 parts by weight of the liquid crystal polymer.

  The average fiber diameter of the fibrous filler used in the present invention is not particularly limited as long as the object of the present invention is not impaired, but is preferably 0.1 to 50 μm. When the cross section of the fibrous filler is not circular, the longest length between any two points on the outer periphery of the cross section of the fibrous filler is taken as the fiber diameter.

  Specific examples of the fibrous filler used in the present invention include glass fiber, elliptic glass fiber, eyebrow glass fiber, silica alumina fiber, alumina fiber, carbon fiber, aramid fiber, potassium titanate fiber, boric acid. Examples thereof include one or more selected from the group consisting of aluminum fibers and wollastonite.

  Among these fibrous fillers, at least one selected from the group consisting of glass fibers, elliptical glass fibers, and eyebrows-type glass fibers is used from the balance between physical properties and cost of the liquid crystal polymer composition. Is more preferable.

  In the claims and specification of the present application, “glass fiber” refers to a glass fiber having a circular cross section, and “elliptical glass fiber” refers to a glass fiber having an elliptical cross section. “Glass fiber” refers to a glass fiber having a cross-sectional shape in which two circles partially overlap each other. Here, in description of the cross-sectional shape of glass fiber, elliptic glass fiber, and eyebrow glass fiber, “circular” and “elliptical” do not indicate only a geometrical circular or elliptical, but a microscope or the like When the image is enlarged, it is meant to include shapes recognized as shapes similar to circles and ellipses (for example, circles include squares with rounded corners, etc. Including rounded rectangles).

  The liquid crystal polymer composition of the present invention may further contain a plate-like or powdery filler excluding talc as long as the object of the present invention is not impaired. The amount used in the case of using a plate-like or powder-like filler excluding talc is 1 to 200 parts by weight, more preferably 1 to 150 parts by weight, most preferably 100 parts by weight of the liquid crystal polymer. 1 to 100 parts by weight.

  Specific examples of the plate-like or powder-like filler excluding talc used in the present invention include mica, graphite, calcium carbonate, dolomite, clay, glass flakes, glass beads, barium sulfate, and titanium oxide. One or more selected ones may be mentioned.

  In the liquid crystal polymer composition of the present invention, in addition to talc, when one or more fillers selected from the group consisting of fibrous, plate-like, and powdery fillers other than talc are used, other than talc and talc The total amount of the filler is preferably 1 to 200 parts by weight with respect to 100 parts by weight of the liquid crystal polymer.

  In the liquid crystal polymer composition of the present invention, a release improver such as a higher fatty acid, a higher fatty acid ester, a higher fatty acid amide, a higher fatty acid metal salt, a polysiloxane, a fluororesin, and the like as long as the object of the present invention is not impaired; Colorants such as pigments, antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, and the like may be added alone or in combination.

Those having an external lubricant effect such as higher fatty acid, higher fatty acid ester, higher fatty acid metal salt, and fluorocarbon surfactant may be previously adhered to the surface of liquid crystal polymer pellets during molding.
Here, the higher fatty acid means one having 10 to 25 carbon atoms.

  The liquid crystal polymer used in the present invention is not limited to the purpose of the present invention, and other resin components such as polyamide, polyester, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and modified products thereof, polysulfone, poly Thermoplastic resins such as ether sulfone and polyether imide, and thermosetting resins such as phenol resin, epoxy resin, and polyimide resin may be added alone or in combination of two or more.

  The blending amount of other resin components is not particularly limited, and may be determined as appropriate according to the use and purpose of the resin. Typically, the resin component is blended in an amount of 1 to 200 parts by weight, particularly 10 to 100 parts by weight, based on 100 parts by weight of the liquid crystal polymer of the present invention.

  In addition to talc, fibrous, plate-like, or powdery fillers, additives, and other resin components are liquid crystal using a Banbury mixer, kneader, single-screw or twin-screw extruder, etc. What is necessary is just to melt-knead and mix | blend with liquid crystal polymer at the crystal melting temperature vicinity of a polymer thru | or crystal melting temperature +30 degreeC.

  The liquid crystal polymer composition of the present invention thus obtained has a warp amount of 6.0 mm or less, preferably 5. 5 mm or less measured by a warp amount measuring method described below using, for example, a disk-shaped test piece. The amount of warpage is as small as 5 mm or less, particularly preferably 5.0 mm or less.

<Measurement method of warpage>
A disk-shaped test piece having a thickness of 1.0 mm and a diameter of 100 mm is prepared using an injection molding machine (manufactured by Nissei Plastic Co., Ltd., UH-1000-110). The test piece was allowed to stand at 23 ° C. and a relative humidity of 50% for 24 hours, and then, using a height gauge (manufactured by Mitutoyo Corporation, HDM-30) on the surface plate, Measure the distance and use it as the amount of warpage.

  The liquid crystal polymer 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.

  In particular, the liquid crystal polymer composition of the present invention has excellent fluidity at the time of molding and hardly warps even at high temperatures. Therefore, switches, relays, connectors, chips, optical pickups, inverters processed at high temperatures such as reflow. It is suitably used as a molding material for transformers, coil bobbins and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to a following example at all.

Below, the symbol of the material used in the Example and the comparative example is demonstrated.
<Liquid crystal polymer>
LCP1: UENO LCP2500 (Ueno Pharmaceutical Co., Ltd., 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone copolymer, crystal melting temperature 335 ° C.)
LCP2: UENO LCP6700 (Ueno Pharmaceutical Co., Ltd., 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer, crystal melting temperature 330 ° C.)
<talc>
Talc1: manufactured by Fuji Talc Co., Ltd., HK-A (aspect ratio: 3.6, average particle size: 24.0 μm, water content: 0.13% by weight)
Talc2: manufactured by Fuji Talc Co., Ltd., FG1-A (aspect ratio: 3.6, average particle size: 26.1 μm, water content: 0.07% by weight)
Talc3: manufactured by Fuji Talc Co., Ltd., DS-34 (aspect ratio 2.6, average particle size 19.8 μm, water content 0.24% by weight)
<Fibrous filler>
GF1: Glass fiber, manufactured by Vetrotex, 10EC 3MM92C (average fiber diameter 10 μm)
GF2: elliptic glass fiber, manufactured by Nitto Boseki Co., Ltd., CSG 3PA 831S (average cross-sectional minor axis 7 μm, average sectional major axis 28 μm)

[Examples 1 to 5 and Comparative Examples 1 to 3]
Using LCP1 as the liquid crystal polymer, the amount of talc and the fibrous filler (GF1) shown in Table 2 are blended with 100 parts by weight of the liquid crystal polymer, and a twin-screw extruder (manufactured by Nippon Steel Works, TEX-30α). ) Was pelletized to prepare a liquid crystal polymer composition.
The obtained liquid crystal polymer composition pellets were injection-molded under the conditions shown in Table 1, to prepare a disk-shaped test piece for measuring the amount of warpage, and the warpage was evaluated.
Table 2 shows the measurement results of the warpage amount.

Table 1: Molding conditions of test piece for measuring warpage

Table 2: Evaluation of components and warpage of liquid crystal polymer composition

The warpage amount of the liquid crystal polymer composition of Example 1 containing talc alone was as small as 3 mm or less.
Moreover, Example 2 and Comparative Example 1, Example 3 and Comparative Example 2, Example 4 and Comparative Example 3 have the same blending amounts of talc and fibrous filler except that the type of talc used is different. In any case, the liquid crystal polymer compositions of Examples 2 to 4 using talc having a large aspect ratio are less warped than Comparative Examples 1 to 3 using talc having a small aspect ratio. showed that.

[Examples 6 to 8 and Comparative Example 4]
Using LCP2 as the liquid crystal polymer, blending talc and fibrous filler in the amounts shown in Table 4 with respect to 100 parts by weight of the liquid crystal polymer, and using a twin screw extruder (manufactured by Nippon Steel, TEX-30α). The melt-kneaded product was pelletized to prepare a liquid crystal polymer composition.
The obtained liquid crystal polymer composition pellets were injection-molded under the conditions shown in Table 1, to prepare a disk-shaped test piece for measuring the amount of warpage, and the warpage was evaluated.
In addition, a strip-shaped test piece having a length of 127 mm, a width of 12.7 mm, and a thickness of 3.2 mm was injection-molded under the conditions shown in Table 3, and this was used in accordance with ASTM D648, with a load of 1.82 MPa and a rise. The load deflection temperature (DTUL) was measured at a temperature rate of 2 ° C./min.
Table 4 shows the measurement results of the warpage amount and DTUL.

Table 3: Molding conditions of test piece for measuring load deflection temperature

Table 4: Evaluation of components of liquid crystal polymer composition and amount of warpage and DTUL

In Examples 6 to 8 using a large talc with an aspect ratio of 3.6, it was confirmed that a low warpage amount of 6.0 mm or less was shown, but a comparison using a small talc with an aspect ratio of 2.6 In Example 4, a high warpage amount exceeding 6.0 mm was shown.
Furthermore, by using elliptical glass fiber (GF2) as a fibrous filler together with talc having a large aspect ratio, the occurrence of warpage could be further reduced.
Further, in Comparative Example 4 using Talc3 having a water content of 0.24% by weight, the load was compared with Examples 6 and 7 using Talc1 and 2 having a water content of 0.2% by weight or less. There was a tendency for the deflection temperature (DTUL) to decrease slightly.

Claims (12)

  A liquid crystal polymer composition comprising 1 to 200 parts by weight of talc having an average particle diameter of 5 to 100 μm and an aspect ratio of 3.0 to less than 4.0 with respect to 100 parts by weight of the liquid crystal polymer.   The liquid crystal polymer composition according to claim 1, wherein the aspect ratio of talc is 3.0 or more and 3.6 or less. The liquid crystal polymer is 4 -hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone copolymer and 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / 2,6-naphthalenedicarboxylic The liquid crystal polymer composition according to claim 1 or 2, which is selected from the group consisting of an acid / hydroquinone copolymer.   The liquid crystal polymer composition according to claim 1, wherein the water content of talc is 0.2% by weight or less.   Furthermore, the liquid crystal polymer composition in any one of Claims 1-4 containing 1-200 weight part fibrous filler with respect to 100 weight part of liquid crystal polymers.   The group in which the fibrous filler is made of glass fiber, elliptic glass fiber, eyebrow glass fiber, silica alumina fiber, alumina fiber, carbon fiber, aramid fiber, potassium titanate fiber, aluminum borate fiber, and wollastonite The liquid crystal polymer composition according to claim 5, wherein the liquid crystal polymer composition is one or more selected.   The liquid crystal polymer composition according to claim 6, wherein the fibrous filler is at least one selected from the group consisting of glass fiber, elliptical glass fiber, and eyebrows type glass fiber.   Furthermore, the liquid crystal polymer composition in any one of Claims 1-7 containing the plate-shaped or powder-like filler except 1-200 weight part talc with respect to 100 weight part of liquid crystal polymers.   The plate-like or powdery filler is at least one selected from the group consisting of mica, graphite, calcium carbonate, dolomite, clay, glass flakes, glass beads, barium sulfate, and titanium oxide. 9. A liquid crystal polymer composition according to 8.   The amount of warpage after a disc-shaped test piece having a thickness of 1.0 mm and a diameter of 100 mm obtained by molding the liquid crystal polymer composition was allowed to stand for 24 hours at 23 ° C. and a relative humidity of 50%. The liquid crystal polymer composition according to claim 1, which is 0 mm or less.   A molded product obtained by molding the liquid crystal polymer composition according to claim 1.   The molded article according to claim 11, selected from a switch, a relay, a connector, a chip, an optical pickup, an inverter transformer, and a coil bobbin.