JP2008013702A - Crystalline polyester composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal polyester composition improved in a mechanical property especially in a thin-walled portion, dimensional stability and heat resistance; and a molded product thereof. <P>SOLUTION: The liquid crystal polyester composition is prepared by mixing 100 pts.wt. of a liquid crystal polyester with 5-200 pts.wt. of at least two kinds of glass fibers, in which glass fibers having a non-circular cross sectional shape with a ratio of major axis/minor axis of 2.5-5 comprise 20-80 wt.% of the entire glass fibers, and glass fibers having a circular cross sectional shape comprise 80-20 wt.% of the entire glass fibers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystalline polyester composition capable of giving a molded article having excellent mechanical properties, dimensional stability and heat resistance, particularly in a thin portion.

  In recent years, there has been an increasing demand for higher performance of plastics, and many polymers with various new performances have been developed and put on the market. Among them, optically anisotropic liquid crystals characterized by parallel arrangement of molecular chains Liquid crystalline polymers such as water-soluble polyesters are attracting attention because of their excellent moldability and mechanical properties, and demand is growing for injection molded products, mainly for electrical and electronic parts. These liquid crystalline polyesters may be used alone in various molded products, but in many cases, various reinforcing agents and additives are blended for the purpose of improving heat resistance and mechanical strength. ing. For example, it is disclosed that glass fibers are blended for the purpose of improving the mechanical strength of liquid crystalline polyester (see, for example, Patent Documents 1 to 3).

On the other hand, for the purpose of improving the dimensional stability and mechanical strength of a crystalline or amorphous thermoplastic resin, a resin composition containing a flat cross-section glass fiber such as an eyebrow shape or an oval shape is disclosed. (For example, see Patent Documents 4 to 8).
Japanese Unexamined Patent Publication No. 7-304935 Japanese Patent Laid-Open No. 61-219732 JP-A-4-103656 JP-A-62-226836 Japanese Patent Laid-Open No. 62-268612 JP-A-8-259808 Japanese Patent Laid-Open No. 2-173047 JP-A-2003-268252

  As disclosed in the above-mentioned patent documents, the mechanical strength and dimensional stability of the resin are improved to some extent by using glass fiber as the reinforcing agent for the thermoplastic resin. However, in recent years, liquid crystalline polyester has not been able to provide a sufficient reinforcing effect at the thin-walled portion of the glass fiber in an extremely thin-walled molded product that makes use of the characteristic good fluidity, and the mechanical strength of the thin-walled portion can be sufficiently obtained. There is a problem that there is no problem, and a known method is insufficient for this problem.

  Therefore, in view of the background of such prior art, the present invention provides a liquid crystal polyester composition excellent in mechanical properties of a thin-walled portion, excellent in dimensional stability and heat resistance, and a molded product thereof. Is an issue.

  As a result of intensive studies to develop a liquid crystalline polyester with improved mechanical strength of the thin-walled portion of the injection molded product, the present inventors have determined that a glass fiber having an oval cross-sectional shape having a specific fiber diameter, By blending liquid crystal polyester with a specific proportion of glass fiber having a circular cross-sectional shape having a fiber diameter of, the mechanical strength of the thin-walled portion, in particular, impact strength and bending elastic modulus are specifically improved, and excellent The present inventors have found that a liquid crystalline polyester composition giving a molded product having dimensional stability and heat resistance can be obtained, and the present invention has been achieved.

That is, the present invention
(1) (A) With respect to 100 parts by weight of liquid crystalline polyester, at least (B1) a glass fiber having a non-circular cross-sectional shape having a major axis / minor axis ratio of 2.5 to 5 and (B2) a circular cross-sectional shape. A liquid crystalline polyester composition comprising 5 to 200 parts by weight of glass fiber containing glass fiber (total amount of glass fiber), (B1) non-circular having a major axis / minor axis ratio of 2.5 to 5 The glass fiber having a cross-sectional shape is 20 to 80% by weight of the total amount of glass fiber, and (B2) the glass fiber having a circular cross-sectional shape is 80 to 20% by weight of the total amount of glass fiber. Polyester composition,
(2) The liquid crystalline polyester composition according to the above (1), wherein the liquid crystalline polyester is a liquid crystalline polyester comprising the following structural units (I), (II), (III) and (IV):

(However, R ₁ in the formula is

1 or more groups selected from R ₂

1 or more types of groups selected from In the formula, X represents a hydrogen atom or a chlorine atom. )
(3) The liquid crystalline polyester composition according to the above (1), wherein the liquid crystalline polyester is a liquid crystalline polyester comprising the following structural units (I), (V), (VI), (VII), (VIII),

(4) (B1) Any one of the above (1) to (3), wherein the cross-sectional shape of the glass fiber is oval and the major axis / minor axis ratio is 3.5 to 4.5. Liquid crystalline polyester composition,
(5) A molded article comprising the liquid crystalline polyester composition according to any one of (1) to (4), and (6) a molded article according to (5), wherein the molded article is an injection molded article. It is.

  The liquid crystalline polyester of the present invention is a polyester capable of forming an anisotropic molten phase. For example, it comprises a structural unit selected from an aromatic oxycarbonyl unit (A1), an aromatic and / or aliphatic dioxy unit (A2), an aromatic and / or aliphatic dicarbonyl unit (A3), and is anisotropic. Examples thereof include liquid crystalline polyesters that form a melt phase.

  Examples of the aromatic oxycarbonyl unit (A1) include a structural unit generated from p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and the like, and an aromatic and / or aliphatic dioxy unit (A2). , Hydroquinone, 4,4′-dihydroxybiphenyl, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl, t-butylhydroquinone, phenylhydroquinone, methylhydroquinone, 2,6-dihydroxynaphthalene, Structural units formed from 2,7-dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane and 4,4′-dihydroxydiphenyl ether, ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, etc. , Aromatic and / or aliphatic dicarls Examples of the nyl unit (A3) include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4′-dicarboxylic acid. , 1,2-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylic acid and 4,4′-diphenyl ether dicarboxylic acid, adipic acid, sebacic acid and the like.

  Specific examples of the liquid crystalline polyester include a liquid crystalline polyester composed of a structural unit generated from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, a structural unit generated from p-hydroxybenzoic acid, and 6-hydroxy-2. A structural unit produced from naphthoic acid, a liquid crystalline polyester comprising a structural unit produced from an aromatic dihydroxy compound, an aromatic dicarboxylic acid and / or an aliphatic dicarboxylic acid, a structural unit produced from p-hydroxybenzoic acid, 4, 4 A liquid crystalline polyester comprising a structural unit produced from a structural unit produced from '-dihydroxybiphenyl, an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid and / or an aliphatic dicarboxylic acid such as adipic acid or sebacic acid, p-hydroxybenzoic acid Structural units generated from acids, 4,4 ' Liquid crystalline polyester comprising structural units generated from dihydroxybiphenyl, structural units generated from hydroquinone, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid and / or structural units generated from aliphatic dicarboxylic acids such as adipic acid and sebacic acid , A structural unit produced from p-hydroxybenzoic acid, a structural unit produced from ethylene glycol, a liquid crystalline polyester comprising a structural unit produced from terephthalic acid and / or isophthalic acid, a structural unit produced from p-hydroxybenzoic acid, ethylene A liquid crystalline polyester comprising a structural unit produced from glycol, a structural unit produced from 4,4′-dihydroxybiphenyl, a structural unit produced from an aliphatic dicarboxylic such as terephthalic acid and / or adipic acid, sebacic acid, Structural units generated from loxybenzoic acid, structural units generated from ethylene glycol, structural units generated from aromatic dihydroxy compounds, structures generated from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid Examples thereof include liquid crystalline polyester composed of units.

  Particularly preferred are liquid crystal polyesters containing the following structures (I), (II), (III) and (IV) as structural units, or (I), (V), (VI), (VII) and (VIII) Is a liquid crystalline polyester containing as a structural unit.

(However, R ₁ in the formula is

1 or more groups selected from R ₂

1 or more types of groups selected from In the formula, X represents a hydrogen atom or a chlorine atom. )

  The structural unit (V) is preferable as the structural unit (II), and the structural unit (VII) is preferable as the structural unit (IV).

  The structural unit (I) is a structural unit generated from p-hydroxybenzoic acid, the structural unit (V) is a structural unit generated from 4,4′-dihydroxybiphenyl, and the structural unit (VI) is generated from hydroquinone. The structural unit is a structural unit generated from ethylene glycol, the structural unit (III) is a structural unit generated from terephthalic acid, and the structural unit (VIII) is a structural unit generated from isophthalic acid. .

  In the case of the liquid crystal polyester composed of the structural units (I), (V), (III) and (VII), the total of the structural units (I) and (V) is (I), (V) and (III). ) To 60 to 95 mol%, more preferably 80 to 93 mol%. Moreover, 40-5 mol% is preferable with respect to the sum total of structural unit (I), (V), and (III), and, as for structural unit (III), 20-7 mol% is more preferable. The molar ratio [(I) / (V)] of the structural units (I) and (V) is preferably 75/25 to 95/5, more preferably 78 from the viewpoint of the balance between heat resistance and fluidity. / 22 to 93/7. The structural unit (VII) is substantially equimolar to the total of the structural units (III) and (V).

    On the other hand, in the case of liquid crystal polyester composed of the structural units (I), (V), (VI), (VII) and (VIII), the structural unit (I) is the structural units (I), (V) and ( It is 65-80 mol% with respect to the sum total of VI), More preferably, it is 68-75 mol%. Further, the structural unit (V) is 60 to 75 mol%, more preferably 65 to 73 mol%, based on the total of the structural units (V) and (VI). The structural unit (VII) is 60 to 70 mol%, more preferably 62 to 68 mol%, based on the total of the structural units (VII) and (VIII).

  There is no restriction | limiting in particular in the manufacturing method of the said liquid crystalline polyester used in this invention, It can manufacture according to the well-known polyester polycondensation method.

  For example, in the production of the liquid crystalline polyester, the following production method is preferred.

As an example, a liquid crystal polyester composed of the structural units (I), (V), (VI), (VII) and (VIII) will be described.
(1) A method for producing a liquid crystalline polyester from p-acetoxybenzoic acid and 4,4′-diacetoxybiphenyl, diacetoxybenzene, terephthalic acid and isophthalic acid by a deacetic acid condensation polymerization reaction.
(2) p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone and terephthalic acid, isophthalic acid is reacted with acetic anhydride to acylate the phenolic hydroxyl group, and then the liquid crystalline polyester is subjected to deacetic acid polycondensation reaction. How to manufacture.
(3) A method for producing a liquid crystalline polyester from a phenyl ester of p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, and diphenyl ester of isophthalic acid by a dephenol polycondensation reaction.
(4) A predetermined amount of diphenyl carbonate is reacted with p-hydroxybenzoic acid and aromatic dicarboxylic acid such as terephthalic acid and isophthalic acid to form a diphenyl ester, and then aromatics such as 4,4'-dihydroxybiphenyl and hydroquinone. A method for producing a liquid crystalline polyester by adding a group dihydroxy compound and dephenol polycondensation reaction.

  Among them, p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, and isophthalic acid are reacted with acetic anhydride to acylate the phenolic hydroxyl group, and then the liquid crystalline polyester is obtained by deacetic acid polycondensation reaction. The manufacturing method is preferred.

  Furthermore, the total amount of 4,4'-dihydroxybiphenyl and hydroquinone and the total amount of terephthalic acid and isophthalic acid are substantially equimolar. The amount of acetic anhydride to be used is preferably 1.15 equivalents or less, more preferably 1.12 equivalents or less of the total of the phenolic hydroxyl groups of p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl and hydroquinone. Preferably, the lower limit is 1.0 equivalent or more.

  When producing the liquid crystalline polyester of the present invention by a deacetic acid polycondensation reaction, a melt polymerization method in which the polycondensation reaction is completed by reacting under reduced pressure at a temperature at which the liquid crystalline polyester melts is preferable.

  For example, in a reaction vessel equipped with a predetermined amount of p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, isophthalic acid, acetic anhydride, a stirring blade, a distillation pipe, and a discharge port at the bottom. There is a method in which the reaction is completed after charging and heating under stirring in a nitrogen gas atmosphere to acetylate the hydroxyl group, raising the temperature to the melting temperature of the liquid crystalline polyester, and performing polycondensation under reduced pressure. The conditions for the acetylation are usually 130 to 300 ° C., preferably 135 to 200 ° C., usually 1 to 6 hours, more preferably 140 to 180 ° C. for 2 to 4 hours. The polycondensation temperature is a melting temperature of the liquid crystalline polyester, for example, in the range of 250 to 350 ° C., and preferably a melting point of the liquid crystalline polyester + 10 ° C. or higher. The degree of vacuum during polycondensation is usually 0.1 mmHg (13.3 Pa) to 20 mmHg (2660 Pa), preferably 10 mmHg (1330 Pa) or less, more preferably 5 mmHg (665 Pa) or less. In addition, although acetylation and polycondensation may be performed continuously in the same reaction vessel, acetylation and polycondensation may be performed in different reaction vessels.

The obtained polymer is pressurized in the reaction vessel to, for example, approximately 1.0 kg / cm ² (0.1 MPa) at a temperature at which it melts, and discharged in a strand form from the discharge port provided in the lower portion of the reaction vessel. Can do. The melt polymerization method is an advantageous method for producing a uniform polymer, and an excellent polymer with less gas generation can be obtained, which is preferable.

  When producing the liquid crystalline polyester of the present invention, the polycondensation reaction can be completed by a solid phase polymerization method. For example, the polymer or oligomer of the liquid crystalline polyester of the present invention is pulverized by a pulverizer and the melting point of the liquid crystalline polyester is −5 ° C. to the melting point −50 ° C. (for example, 200 to 300 ° C.) under a nitrogen stream or under reduced pressure. A method of heating in the range for 1 to 50 hours, polycondensing to a desired degree of polymerization, and completing the reaction can be mentioned. Solid phase polymerization is an advantageous method for producing polymers with a high degree of polymerization.

  The polycondensation reaction of the liquid crystalline polyester proceeds even without a catalyst, but metal compounds such as stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, and magnesium metal can also be used.

  The liquid crystalline polyester of the present invention preferably has a number average molecular weight of 3,000 to 25,000, more preferably 5,000 to 20,000, and more preferably 8,000 to 18,000. .

  The number average molecular weight can be measured as a standard polystyrene equivalent value by a GPC (gel permeation chromatography) method using a solvent in which the liquid crystalline polyester is soluble.

  The melt viscosity of the liquid crystalline polyester in the present invention is preferably 1 to 200 Pa · s, more preferably 10 to 200 Pa · s, and still more preferably 10 to 100 Pa · s.

  The melt viscosity is a value measured by a Koka flow tester under the conditions of a melting point of liquid crystalline polyester + 10 ° C., a nozzle diameter of 0.5 mmφ × 10 mm, and a shear rate of 1,000 / s.

  In the present invention, the melting point (Tm) refers to the endothermic peak temperature (Tm1) observed when the polymer having been polymerized is measured under a temperature rising condition from room temperature to 20 ° C./min in differential calorimetry. , After being held at a temperature of Tm1 + 20 ° C. for 5 minutes, once cooled to room temperature under a temperature decrease condition of 20 ° C./min, and then endothermic peak temperature (Tm2) observed when measured again under a temperature increase condition of 20 ° C./min Point to.

  In the present invention, the liquid crystalline polyester resin is conventionally used by combining glass fibers having a non-circular cross-sectional shape and glass fibers having a circular cross-sectional shape in combination with specific fiber diameters at a specific mixing ratio. Compared to the case where only glass fibers having a circular cross section or glass fibers having a flat cross section are blended, the mechanical strength of a molded product obtained by molding a liquid crystalline polyester, in particular, the thin-walled portion, It is characterized by a specific improvement in dimensional stability and heat resistance.

  Since glass fibers having a non-circular cross-sectional shape are laminated in the thickness direction in the fiber orientation direction as compared with glass fibers having an equivalent cross-sectional area and a circular cross-sectional shape, the number of glass fibers per unit thickness increases. As a result, the shearing force applied to the liquid crystalline polyester during injection molding is increased, which significantly promotes orientation and improves mechanical strength and dimensional stability. In addition, glass fibers having a circular cross-sectional shape are used in combination. By doing so, not only can the packing density of the glass fibers be further improved and the mechanical strength of the thin-walled portion, particularly the impact resistance, can be specifically improved, but also dimensional stability and heat resistance can be imparted.

  The glass fiber having a noncircular cross-sectional shape that can be used in the present invention has an elliptical shape, an eyebrows shape, an elliptical shape, a semicircular shape, an arc shape, or a similar cross-sectional shape, preferably a long shape. It is circular or eyebrows, and more preferably is oval. The oval mentioned here is different from an ellipse, and two or more parallel straight portions such as a rounded quadrangular shape, an ellipse having parallel straight portions, or a shape formed by combining a rectangle and two semicircles. A shape having a part of a circle at two or more locations is included. The use of glass fibers having an oval cross-sectional shape is preferable because the strength and dimensional stability of the thin-walled portion are higher than those having an elliptical or eyebrow-shaped cross-sectional shape.

  The ratio of the major axis (longest diameter of the cross section) and the minor axis (shortest diameter passing through the center point of the major axis) of these cross sections is 2.5 to 5, preferably 3.5 to 4.5, and more preferably. 3.8 to 4.2. When the ratio of the major axis to the minor axis is smaller than 2, the combined effect with the circular cross section is small, and when it is larger than 5, the effect of improving the mechanical strength cannot be obtained.

  The major axis / minor axis ratio of a glass fiber having a non-circular cross-sectional shape is defined as the quotient of the longest linear dimension of the glass fiber cross section, the linear dimension passing through the central point of the major axis, and orthogonal to the major axis. Is a value obtained by calculating the number average of the major axis / minor axis ratio obtained for, for example, 100 glass fibers.

  The fiber diameter of the glass fiber having a non-circular cross-sectional shape is not particularly limited, but a fiber diameter that is a value corresponding to a cross-sectional area of a circle having a diameter of 5 to 20 μm is preferable, more preferably, The fiber diameter is a value corresponding to the cross-sectional area of a circle having a diameter of 6 to 18 μm, more preferably a fiber diameter corresponding to the cross-sectional area of a circle having a diameter of 10 to 16 μm.

  The fiber length of the glass fiber having a non-circular cross-sectional shape is not particularly limited, but is preferably 0.05 to 5 mm before blending, more preferably 1 to 4 mm, and still more preferably 2 to 3.5 mm. . The fiber length of the glass fiber before blending can be determined by observing the glass fiber dispersed in soapy water under an optical microscope and measuring the fiber length of the photographed glass fiber. Measure 500 or more and calculate the weight average.

  The fiber length after blending is preferably 0.02 to 1.0 mm, more preferably 0.08 to 0.8 mm, and still more preferably 0.2 to 0.5 mm, as the weight average fiber length. The fiber length of the glass fiber after blending is a method of measuring the glass fiber length before blending the glass fiber remaining after the pellet of the liquid crystalline polyester composition is placed in a crucible and incinerated in an electric furnace at 600 ° C. It can be obtained by the same method.

  Known glass fibers are used as the glass fibers having a circular cross-sectional shape that can be used in the present invention. Among them, chopped strands of E glass are preferable, and the fiber diameter is preferably 3 to 18 μm, more preferably 5 to 5 μm. It is 15 μm, more preferably 6 to 12 μm. The fiber length is preferably 0.05 to 5 mm before blending, more preferably 1 to 4 mm, and still more preferably 2 to 3.5 mm.

  The fiber length after blending is preferably 0.01 to 0.7 mm, more preferably 0.05 to 0.5 mm, and still more preferably 0.2 to 0.4 mm, as the weight average fiber length. .

  Since the fiber length after blending falls within this range, the fiber length before blending is preferable, and the breakage of the glass fiber during blending varies depending on blending conditions. From the viewpoint of strength and heat resistance, the above range is preferable.

  Although not limited, in the present invention, a glass fiber having a non-circular cross-sectional shape having a specific fiber diameter and a glass fiber having a circular cross-sectional shape having a specific fiber diameter are specified. A combination of the ratios is preferable because a specific effect can be obtained.

  As a specific combination, for example, when the fiber diameter of a glass fiber having a non-circular cross-sectional shape is a fiber diameter having a cross-sectional area corresponding to the cross-sectional area of a circle having a diameter of 10 to 16 μm, it is circular. It is preferable to combine with a glass fiber having a cross-sectional shape of 6 to 12 μm, more preferably a glass fiber having a non-circular cross-sectional shape having a diameter of a circle with a cross-sectional area of 12 to 15 μm. When the fiber diameter is a value corresponding to the cross-sectional area, the glass fiber having a circular cross-sectional shape has a fiber diameter of 6.5 to 11.5 μm.

  At least one type of glass fiber having a circular cross-sectional shape and at least one type of glass fiber having a non-circular cross-sectional shape is used, but two or more types may be used, for example, a 6.5 μm diameter circular fiber having a fiber length of 3 mm before blending. A glass fiber having a cross-sectional shape and a glass fiber having an oval non-circular cross-sectional shape in which the cross-sectional area of the length-to-short diameter ratio 4 of the fiber length of 3 mm before blending is equivalent to the cross-sectional area of a circular cross-section of 15 μm diameter; And a combination with a glass fiber having an oval non-circular cross-sectional shape in which the cross-sectional area of the fiber length of 0.1 mm before blending is equal to the cross-sectional area of a circular cross-section of 15 μm in diameter. it can.

  As a mixing ratio, in the present invention, the total amount of glass fibers in which both glass fibers having a non-circular cross-sectional shape and glass fibers having a circular cross-sectional shape are combined is 100 parts by weight of liquid crystalline polyester. Although 5 to 200 parts by weight is essential, it is more preferably 10 to 150 parts by weight, still more preferably 20 to 100 parts by weight. The ratio of the glass fiber which has a non-circular cross-sectional shape with respect to the whole glass fiber is 20 to 80 weight%, More preferably, it is 30 to 70%, More preferably, it is 40 to 60%. In the said range, since the mechanical characteristic of a thin part which is the effect of this invention, a dimensional stability, and the improvement effect of heat resistance are acquired remarkably, it is preferable.

  These glass fibers may be treated with an epoxy-based, urethane-based, acrylic-based coating or sizing agent, and the surface thereof is a coupling agent such as γ- (2-aminoethyl) aminopropyltrimethoxysilane. Γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, hydroxypropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, vinylacetoxysilane Silane coupling agents such as isopropyl tris isostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophoro) A coupling treatment may be performed with a titanium coupling agent such as sulfate) ethylene titanate, isopropyl tridecylbenzenesulfonyl titanate, isopropyl tri (dioctyl phosphate) titanate, or an aluminum coupling agent such as acetoalkoxyaluminum diisopropylate.

  The liquid crystalline polyester composition of the present invention may further contain a filler other than glass fiber as long as the characteristics are not deteriorated. The filler is not particularly limited, but fillers such as a fiber, a plate, a powder, and a granule can be used. Specifically, for example, PAN-based and pitch-based carbon fibers, stainless steel fibers, metal fibers such as aluminum fibers and brass fibers, organic fibers such as aromatic polyamide fibers and liquid crystalline polyester fibers, gypsum fibers, ceramic fibers, asbestos fibers , Zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whisker, barium titanate whisker, aluminum borate whisker, silicon nitride whisker, etc., whisker-like filler, mica , Talc, kaolin, silica, glass beads, glass flakes, glass microballoons, clay, molybdenum disulfide, wollastonite, titanium oxide, zinc oxide, calcium polyphosphate and graphite, etc. BeThe above-mentioned filler used in the present invention can also be used by treating the surface thereof with the above coupling agent or other surface treatment agent.

  Further, the liquid crystalline polyester of the present invention includes antioxidants and heat stabilizers (for example, hindered phenols, hydroquinones, phosphites and substituted products thereof), ultraviolet absorbers (for example, resorcinol, salicylate), phosphorous acid. Colorants including salts, anti-coloring agents such as hypophosphite, lubricants and mold release agents (such as montanic acid and its metal salts, its esters, their half esters, stearyl alcohol, stearamide and polyethylene wax), dyes and pigments Carbon black, crystal nucleating agent, plasticizer, flame retardant (bromine flame retardant, phosphorus flame retardant, red phosphorus, silicone flame retardant, etc.), flame retardant aid, antistatic agent, etc. The usual additives and polymers other than thermoplastic resins can be blended to further impart the prescribed characteristics. Kill.

  Although the manufacturing method of the liquid crystalline polyester composition of the present invention is not particularly limited, it is preferably by melt kneading, and a known method can be used. For example, using a Banbury mixer, rubber roll machine, kneader, single-screw or twin-screw extruder, etc., the liquid crystalline polyester is melt-kneaded at a temperature from the melting point (Tm) of −30 ° C. to Tm + 30 ° C. can do. Among these, a twin screw extruder is preferable.

  As the configuration of the twin screw extruder, a meshing type and a twin screw co-rotating screw are preferable, and the screw length / diameter ratio (L / D) is preferably 25 to 60, more preferably 30 to 50, and most preferably. 40-45. Moreover, it is preferable to have one or more vents, more preferably two or more vents, and the vent location can be installed behind the kneading block after the side feeder. More preferably, it is also preferable to install it before the kneading block before the side feeder because the generated gas of the resin can be efficiently removed.

The kneading method is not particularly limited, and any known method can be used. For example,
1) Batch kneading method with liquid crystalline polyester, optional filler and other additives,
2) First, a liquid crystalline polymer composition (master pellet) containing a high concentration of other additives in liquid crystalline polyester is prepared, and then other thermoplastic resins, fillers, and other additives so as to have a prescribed concentration. To add (master pellet method),
3) Split addition method in which a part of the liquid crystalline polymer and other additives are kneaded once, and then the remaining filler and other additives are added.
Any method can be used.

  The liquid crystal polyester composition obtained by the present invention has excellent moldability, mechanical properties, dimensional stability and heat resistance by ordinary molding methods such as injection molding, extrusion molding and blow molding, and has these characteristics. Various gears, sensors, LED lamps, connectors, sockets, resistors, relay cases, switches, coil hobbins, capacitors, variable capacitor cases, optical pickups, transmitters, various terminal boards, transformers, plugs, printed boards, tuners, speakers, microphones , Headphones, small motors, magnetic head bases, power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, magnetic tape cassette reels, motor brush holders, parabolic antennas, suitable for electrical and electronic parts such as computer-related parts Used for However, other uses such as VTR parts, VTR camera parts, TV parts, irons, hair dryers, shavers, electric fans, juicers, rice cooker parts, microwave oven parts, headphone stereos, radio cassettes, audio, compact disc parts, Lighting parts, refrigerator parts, air conditioner parts, typewriter parts, calculators, word processor parts, homes, office electrical product parts, office computer related parts, telephone related parts, facsimile related parts, copier related parts, cleaning jigs , Oilless bearings, stern bearings, submersible bearings, mechanical parts such as motor parts, microscopes, binoculars, cameras, optical equipments such as watches, precision machine parts, alternator terminals, alternators connector, C regulator, light meter potentiometer base, various valves such as exhaust gas valve, various pipes related to fuel, exhaust system, intake system, air intake nozzle snorkel, intake manifold, fuel pump, engine coolant joint, carburetor main body, Carburetor spacer, exhaust gas sensor, coolant sensor, oil temperature sensor, brake pad wear sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake pad wear sensor, thermostat base for air conditioner, heating hot air flow control valve, Brush holder for radiator motor, water pump impeller, turbine vane, wiper motor parts, distributor , Starter switch, Starter relay, Transmission wire harness, Air conditioner panel switch base, Fuel related electromagnetic valve coil, Fuse connector, Horn terminal, Electrical component insulation plate, Step motor rotor, Lamp socket, Lamp reflector, Lamp housing, Brake Piston, solenoid hobbin, engine oil filter, radiator drain cock, in-tank fuel pump, diaphragm valve, auto antenna gear case, door lock, blinker switch, wiper gear, wiper pivot bearing, speedometer gear, parts, housing, window glass bottom Channel, seat belt housing, seat belt retractor parts, heater control lever, inside Door handles, regulator handles, outer door handles, sun visor brackets, collapsible room mirror stays, seat hooks, fender mirror cases, fuel caps, window washer nozzles, ignition devices and other car / vehicle related parts, bicycles, lawn mowers, partitions Corner pieces, curtain liners, blind gears, doors, office furniture parts, various fasteners, piping systems, hose joints, valves, bindings, adjusters, various fasteners, meters, shoe parts, beauty parts such as toys, music boxes, combs, casters It can also be used for brackets, rollers, caps, major parts, lighters, aerosol bottles, sports equipment, and other various general equipment parts.

  Hereinafter, although an example explains the present invention still in detail, the gist of the present invention is not limited only to the following example.

Reference Example 1 Liquid crystalline polyester A-1
In a 5 L reaction vessel equipped with a stirring blade and a distillation pipe, 870 parts by weight of p-hydroxybenzoic acid (6.30 mol), 327 parts by weight of 4,4′-dihydroxybiphenyl (1.89 mol), 89 parts by weight of hydroquinone (0.81 mol), 292 parts by weight (1.76 mol) of terephthalic acid, 157 g (0.95 mol) of isophthalic acid, and 1367 parts by weight of acetic anhydride (1.03 equivalents of the total phenolic hydroxyl groups) were charged with nitrogen gas. The mixture was reacted at 145 ° C. for 2 hours with stirring in an atmosphere, and then heated to 320 ° C. in 4 hours. Thereafter, the polymerization temperature was maintained at 320 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) in 1.0 hour, the reaction was continued for 90 minutes, and the polycondensation was completed when the torque reached 15 kg · cm. Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer was discharged to a strand-like material via a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter. In this liquid crystalline polyester (A-1), the p-oxybenzoate unit was 70 mol% based on the total of the p-oxybenzoate unit, the 4,4′-dioxybiphenyl unit and the 1,4-dioxybenzene unit. , 4′-dioxybiphenyl units are 70 mol% based on the total of 4,4′-dioxybiphenyl units and 1,4-dioxybenzene units, and terephthalate units are based on the total of terephthalate units and isophthalate units. It comprised 65 mol%, Tm was 314 degreeC, and the liquid-crystal starting temperature was 295 degreeC. The number average molecular weight was 12,000, and the melt viscosity measured at a temperature of 324 ° C. and a shear rate of 1,000 / s using a Koka type flow tester (orifice 0.5φ × 10 mm) was 20 Pa · s.

  The melting point (Tm) is determined by differential calorimetry. After observing the endothermic peak temperature (Tm1) observed when the polymer is measured from room temperature to 40 ° C / min, the temperature is maintained at Tm1 + 20 ° C for 5 minutes. Then, after cooling to room temperature under a temperature drop condition of 20 ° C./minute, the endothermic peak temperature (Tm 2) observed when measured again under a temperature rise condition of 20 ° C./minute was used.

  The molecular weight was measured by GPC-LS (gel permeation chromatography-light scattering) method using pentafluorophenol which is a solvent in which liquid crystalline polyester is soluble, and the number average molecular weight was determined.

Reference Example 2 Liquid crystalline polyester A-2
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 994 parts by weight of p-hydroxybenzoic acid (7.20 mol), 181 parts by weight of 4,4′-dihydroxybiphenyl (0.97 mol), 161 wt. Of terephthalic acid Parts (0.97 mol), 159 parts by weight (0.83 mol) of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g and 1026 parts by weight of acetic anhydride (1.10 equivalents of total phenolic hydroxyl groups) The reaction was conducted at 145 ° C. for 2 hours with stirring in a nitrogen gas atmosphere, and then the temperature was raised to 335 ° C. over 4 hours. Thereafter, the polymerization temperature was maintained at 335 ° C., nitrogen was pressurized to 0.1 MPa, and the mixture was heated and stirred for 20 minutes. Thereafter, the pressure was released, the pressure was reduced to 133 Pa in 1.0 hour, and the reaction was continued for another 30 minutes. When the torque reached 12 kg · cm, the polycondensation was completed. Next, the inside of the reaction vessel was pressurized to 0.1 MPa, the polymer was discharged to a strand through a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter.

  This liquid crystalline polyester (A-2) has 72.2 mol% p-oxybenzoate units, 9.7 mol% 4,4'-dioxybiphenyl units, 9.7 mol% terephthalate units, ethylenedioxy The unit is 8.3 mol%, Tm is 326 ° C., liquid crystal starting temperature is 300 ° C., number average molecular weight is 12,300, and Koka flow tester (orifice 0.5φ × 10 mm) is used, and temperature is 335 ° C. The melt viscosity measured at a shear rate of 1000 / s was 13 Pa · s.

Reference Example 3 Liquid crystalline polyester A-3
In a 5 L reaction vessel equipped with a stirring blade and a distillation pipe, 994 parts by weight of p-hydroxybenzoic acid (7.20 mol), 126 parts by weight of 4,4′-dihydroxybiphenyl (0.67 mol), 112 weights of terephthalic acid Parts (0.67 mol), 216 parts by weight (1.12 mol) of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g and 960 parts by weight of acetic anhydride (1.10 equivalents of total phenolic hydroxyl groups) The mixture was charged and reacted at 145 ° C. for 2 hours with stirring in a nitrogen gas atmosphere, and then heated to 325 ° C. in 4 hours. Thereafter, the polymerization temperature was maintained at 325 ° C., nitrogen was pressurized to 0.1 MPa, and the mixture was heated and stirred for 20 minutes. Thereafter, the pressure was released, the pressure was reduced to 133 Pa in 1.0 hour, and the reaction was continued for another 120 minutes. When the torque reached 12 kg · cm, the polycondensation was completed. Next, the inside of the reaction vessel was pressurized to 0.1 MPa, the polymer was discharged to a strand through a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter.

  This liquid crystalline polyester (A-3) has a p-oxybenzoate unit of 74.4 mol%, a 4,4'-dioxybiphenyl unit of 7 mol%, a terephthalate unit of 7 mol% and an ethylenedioxy unit of 11. 6 mol%, Tm of 314 ° C., liquid crystal starting temperature of 292 ° C., number average molecular weight of 11,100, using Koka flow tester (orifice 0.5φ × 10 mm), temperature of 325 ° C., shear rate of 1000 The melt viscosity measured at / s was 12 Pa · s.

Reference Example 4 Liquid crystalline polyester A-4
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 994 parts by weight (7.20 mol) of p-hydroxybenzoic acid, 338.7 parts by weight (1.80 mol) of 6-hydroxy-2-naphthoic acid, Then, 965 parts by weight of acetic anhydride (1.05 equivalent of the total phenolic hydroxyl group) was added, and the mixture was reacted at 145 ° C. for 2 hours with stirring in a nitrogen gas atmosphere, and then heated to 330 ° C. in 4 hours. Thereafter, the polymerization temperature was maintained at 330 ° C., nitrogen was pressurized to 0.1 MPa, and the mixture was heated and stirred for 20 minutes. Thereafter, the pressure was released, the pressure was reduced to 133 Pa in 1.0 hour, and the reaction was continued for another 120 minutes. When the torque reached 12 kg · cm, the polycondensation was completed. Next, the inside of the reaction vessel was pressurized to 0.1 MPa, the polymer was discharged to a strand through a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter.

  This liquid crystalline polyester (A-4) has 80 mol% of p-oxybenzoate units and 20 mol% of 6-oxy-2-naphthalate units, Tm (melting point of liquid crystalline polyester) is 320 ° C., liquid crystal starting temperature It had a number average molecular weight of 10,900 at 298 ° C., and a melt viscosity measured using a Koka flow tester (orifice 0.5φ × 10 mm) at a temperature of 330 ° C. and a shear rate of 1000 / s was 18 Pa · s. .

(Reference Example 5) Liquid crystalline polyester A-5
24.9 parts by weight (0.18 mol) of p-hydroxybenzoic acid and 812.9 parts by weight (4.32 mol) of 6-hydroxy-2-naphthoic acid were added to a 5 L reaction vessel equipped with a stirring blade and a distillation tube. ), 4,4′-dihydroxybiphenyl 419.0 parts by weight (2.25 moles), 373.8 parts by weight (2.25 moles) terephthalic acid, and 964.8 parts by weight acetic anhydride (1 total of phenolic hydroxyl groups) .05 equivalents) was allowed to react at 145 ° C. for 2 hours with stirring in a nitrogen gas atmosphere, and then heated to 360 ° C. over 4 hours. Thereafter, the polymerization temperature was maintained at 360 ° C., nitrogen was pressurized to 0.1 MPa, and the mixture was heated and stirred for 20 minutes. Thereafter, the pressure was released, the pressure was reduced to 133 Pa in 1.0 hour, and the reaction was continued for another 120 minutes. When the torque reached 12 kg · cm, the polycondensation was completed. Next, the inside of the reaction vessel was pressurized to 0.1 MPa, the polymer was discharged to a strand through a die having one circular discharge port having a diameter of 10 mm, and pelletized by a cutter.

  This liquid crystalline polyester (A-5) has 2 mol% of p-oxybenzoate units, 48 mol% of 6-oxy-2-naphthalate units, 25 mol% of 4,4′-dioxybiphenyl units, and terephthalate units. 25 mol%, Tm (melting point of liquid crystalline polyester) is 350 ° C., liquid crystal starting temperature is 305 ° C., number average molecular weight is 11,200, and Koka flow tester (orifice 0.5φ × 10 mm) is used. The melt viscosity measured at a temperature of 360 ° C. and a shear rate of 1000 / s was 25 Pa · s.

(Reference Example 6) Glass fiber B-1 Glass fiber having a circular cross-sectional shape Glass chopped strand ECS-03T-790DE / P made by Nippon Electric Glass, fiber length 3 mm, fiber diameter 6.5 μm
B-2 Glass fiber having a cross-sectional shape of an oval (track shape having parallel straight portions) Nittobo flat fiber CSG 3PA-820 (aminosilane coupling, urethane sizing agent treatment), fiber length 3 mm, major diameter (28 μm) / Short diameter (7 μm) ratio: 4 and 15 μm diameter circular cross-sectional glass fiber equivalent cross-sectional area B-3 Eyebrow-shaped cross-sectional glass fiber Nittobo flat fiber CSH 3PA 860 (aminosilane coupling, epoxy system) Converging agent treatment) Fiber length 3 mm, major diameter (20 μm) / minor diameter (10 μm) ratio 2, circular cross-sectional glass fiber equivalent to glass fiber with a diameter of 15 μm B-4 Milled fiber of B-2 Fiber length 0.1 mm
B-5 Ratio of major axis to minor axis of B-2 2.3 product B-6 Glass fiber having a circular cross-sectional shape Glass chopped strand ECS-03T-747H / P manufactured by Nippon Electric Glass, fiber length 3 mm, fiber diameter 10.5 μm
B-7 Glass fiber with circular cross-sectional shape Milled fiber 40M-10A manufactured by Nippon Electric Glass, fiber length 0.2 mm, fiber diameter 10.5 μm.

(Examples 1-12, Comparative Examples 1-9)
Table 1 shows liquid crystal polyesters (A1 to A4), circular glass fibers (B-1) and / or non-circular glass fibers (B-2, B-3, B-4) obtained in Reference Examples 1 to 4. After dry blending at a rate of, the cylinder heater set temperature was adjusted so that the resin temperature would be the melting point + 10 ° C. with a TEM35B type twin screw extruder manufactured by Toshiba Machine. Melt-kneaded into pellets. The following evaluation was performed after hot air drying. The measurement results are shown in Table 1.

(1) Thin-wall bending strength and flexural modulus The pellets were subjected to a FANUC Co., Ltd. Roboshot α30c injection molding machine, set to a mold temperature of 90 ° C and a cylinder temperature melting point of + 10 ° C. A molded article having a width of 12.7 mm, a length of 150 mm, and a thickness of 0.3 mm was injection-molded at a rate of 99% and an injection pressure of the minimum filling pressure + 5 kgf / cm ² ), and the bending strength and the flexural modulus were measured in accordance with ASTM D790.

(2) Izod impact strength A square plate type test piece having a thickness of 62 mm × 62 mm × 3.2 mm was prepared using the above molding machine, cut to a width of 12.7 mm in the direction perpendicular to the flow direction, and ASTM notched. Measured according to D256.

(3) Dip solder heat resistance Using the above molding machine, a 127 mm × 12.7 mm × 0.3 mm thick rectangular test piece was prepared and subjected to a 10-second immersion test in a solder bath to determine whether the surface was rough or deformed. .

(4) Warp Deformability Using the above molding machine, mold temperature is set to 135 ° C, cylinder temperature melting point + 10 ° C, and 100-core fine pitch connector (insulator) measuring 48mm x 3mm x 4mm (side wall thickness 0.2mm) is molded. The connector was placed on a horizontal surface plate and observed using a universal projector. The maximum displacement of the connector bottom surface relative to the horizontal surface plate was defined as the amount of warpage deformation, and the maximum displacement amount of the inner wall surface relative to the horizontal surface plate was defined as the amount of internal warpage.

(5) Fiber length after blending The fiber length of the glass fiber after blending was determined by taking the pellets of the liquid crystalline polyester composition in a crucible and ashing them in an electric furnace at 600 ° C. It was obtained by observing under an optical microscope and measuring the fiber length of the photographed glass fiber. 500 or more were measured and the weight average was calculated.

  As is clear from Table 1, Examples 1 to 12 using a glass fiber having a non-circular cross-sectional shape and a glass fiber having a circular cross-sectional shape are glass fibers (B-1) having a circular cross-sectional shape. Compared with liquid crystalline polyesters (Comparative Examples 1, 5, and 8) blended only with the same liquid crystalline polyester, the mechanical properties, dimensional stability, and heat resistance of the thin-walled portion are improved in a well-balanced manner when compared with the same liquid crystalline polymer. A functional polyester composition is obtained. In particular, when glass fibers having a circular cross-sectional shape and glass fibers having a non-circular cross-sectional shape are blended with equal weight, the effect of improving physical properties is greatest.

  It can also be seen that when the ratio of major axis / minor axis is within a preferred range, a higher effect can be obtained.

Since the effects of the present invention as described above cannot be obtained by blending only glass fibers having a non-circular cross-sectional shape or glass fibers having a circular cross-sectional shape with liquid crystalline polyester, the specific cross-sectional shapes are different. It turns out that it expresses specifically by using glass fiber together in a specific ratio.

Claims (6)

(A) At least (B1) a glass fiber having a non-circular cross-sectional shape having a major axis / minor axis ratio of 2.5 to 5 and (B2) a glass fiber having a circular cross-sectional shape with respect to 100 parts by weight of liquid crystalline polyester. It is a liquid crystalline polyester composition comprising 5 to 200 parts by weight of glass fiber (total amount of glass fiber), and (B1) has a non-circular cross-sectional shape having a major axis / minor axis ratio of 2.5 to 5. The glass fiber having 20 to 80% by weight of the total amount of glass fiber, and (B2) the glass fiber having a circular cross-sectional shape is 80 to 20% by weight of the total amount of glass fiber. . The liquid crystalline polyester composition according to claim 1, wherein the liquid crystalline polyester is a liquid crystalline polyester comprising the following structural units (I), (II), (III) and (IV).

(However, R ₁ in the formula is

1 or more groups selected from R ₂

1 or more types of groups selected from In the formula, X represents a hydrogen atom or a chlorine atom. ) The liquid crystalline polyester composition according to claim 1, wherein the liquid crystalline polyester is a liquid crystalline polyester comprising the following structural units (I), (V), (VI), (VII), and (VIII).

(B1) The liquid crystalline polyester composition according to any one of claims 1 to 3, wherein the cross-sectional shape of the glass fiber is oval and the major axis / minor axis ratio is 3.5 to 4.5. . The molded article which consists of a liquid crystalline polyester composition in any one of Claims 1-4. The molded product according to claim 5, wherein the molded product is an injection molded product.