JP2018104527A - Liquid crystal polyester resin composition and molded article made of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal polyester resin composition having excellent dimensional stability, shape retention characteristics and characteristics in a welded part after heat treatment, and a molded article made of the composition.SOLUTION: The liquid crystal polyester resin composition contains an inorganic filler (a) by 40 parts by weight or more and 250 parts by weight or less with respect to 100 parts by weight of a liquid crystal polyester resin having a melting point (Tm) of 300°C or higher and 350°C or lower, and satisfies an expression (1) 0.35≤E/E≤1.00. In the expression (1), Erepresents a flexure elastic modulus (GPa) of a molded article made of the liquid crystal polyester resin composition, measured in accordance with ASTM D790 at an atmospheric temperature of 23°C; and Erepresents a flexure elastic modulus (GPa) of a molded article made of the liquid crystal polyester resin composition, measured in accordance with ASTM D790 at an atmospheric temperature of 200°C.SELECTED DRAWING: None

Description

  The present invention relates to a liquid crystal polyester resin composition and a molded article comprising the same. More specifically, the present invention relates to a liquid crystal polyester resin composition capable of obtaining a molded article excellent in dimensional stability, shape retention and weld characteristics after heat treatment, and a molded article comprising the same.

  Liquid crystal polyester is excellent in heat resistance, fluidity and dimensional stability because of its liquid crystal structure. For this reason, demand is expanding mainly for electrical and electronic parts such as connectors and relays that require these characteristics. In particular, along with the recent high performance of equipment, SMT (surface mounting technology) processing is increasing as the above-mentioned parts are becoming smaller and thinner. Especially in the case of heat treatment such as reflow processing, in the case of box-type thin molded products such as relays, defects such as changes in dimensions and deformation, and defects that break at the welds occur, so dimensional stability after heat treatment, Shape retention and weld characteristics are required. In order to satisfy such required characteristics, for example, a liquid crystalline resin composition in which a fibrous inorganic filler having a specific number average fiber length is blended with a liquid crystalline polymer has been proposed (for example, see Patent Document 1). Moreover, the liquid crystal polyester resin composition (for example, refer patent document 2) which mix | blended the specific epoxy compound, the liquid crystal polyester resin composition (for example, which mix | blended the glass fiber which has a non-circular cross-sectional shape by the cross-sectional area of a specific range) Patent Document 3), a liquid crystal polyester resin composition that satisfies specific temperature requirements (for example, see Patent Document 4), and a liquid crystal polyester resin composition in which an aluminum-based filler is blended with liquid crystal polyester that has improved heat resistance (for example, Patent Document 5) has been proposed.

JP 2009-191088 A JP 2016-183308 A JP 2013-35915 A Japanese Patent Laying-Open No. 2015-21063 JP-A-7-70422

  With recent downsizing and refinement of molded products, it has been demanded that the dimensional stability, shape retention and weld properties after heat treatment are expressed at a higher level. The composition was still not sufficient. In addition, since the resin composition disclosed in Patent Document 5 has a high melting point of the liquid crystalline polyester resin, the processing temperature is high, the resin deteriorates, the fluidity is inferior, and the processability is poor. The characteristics were not sufficient. Therefore, the present invention aims to solve the above-mentioned problems and provide a liquid crystal polyester resin composition capable of obtaining a molded product excellent in dimensional stability after heat treatment, shape retention and weld characteristics, and a molded product. And

  As a result of intensive studies in order to solve the above problems, the present inventors have found that the ratio of elastic modulus at room temperature and high temperature of a liquid crystal polyester resin composition comprising a liquid crystal polyester resin having a specific melting range and an inorganic filler is high. It has been found that by satisfying a specific range, a molded product having excellent dimensional stability, shape retention and weld characteristics after heat treatment can be obtained, and the present invention has been achieved.

That is, the present invention has been made to solve at least a part of the problems described above, and can be realized as the following forms.
(1) A liquid crystal containing 40 to 250 parts by weight of an inorganic filler (a) and satisfying the following formula (1) with respect to 100 parts by weight of a liquid crystal polyester resin having a melting point (Tm) of 300 to 350 ° C. Polyester resin composition.
0.35 ≦ E ₂₀₀ / E ₂₃ ≦ 1.00 − (1)
(E ₂₃ is a flexural modulus (GPa) of a molded product made of a liquid crystal polyester resin composition measured in accordance with ASTM D790 at an ambient temperature of 23 ° C., and E ₂₀₀ is a molded product made of a liquid crystal polyester resin composition. Is a flexural modulus (GPa) measured in accordance with ASTM D790 at an atmospheric temperature of 200 ° C.)
(2) The liquid crystalline polyester resin composition according to (1), wherein the inorganic filler (a) is a fibrous filler having a major axis / minor axis ratio of 1 or more and less than 2.
(3) The liquid crystal polyester resin composition according to (1) or (2), which contains 2 mol% or more and 20 mol% or less of a structural unit derived from hydroquinone with respect to 100 mol% of the total amount of structural units of the liquid crystal polyester resin. .
(4) In a content of 100% by weight of the inorganic filler (a), titanium oxide, magnesium carbonate, magnesium hydroxide, magnesium oxide, zinc oxide, zinc sulfide, barium sulfate, barium titanate, barium phosphate, oxidation (1) to (1) including at least 0.1 wt% and not more than 20 wt% of one or more powdery or granular inorganic fillers (a ′) selected from the group consisting of aluminum, lead carbonate, and calcium carbonate The liquid crystal polyester resin composition according to any one of 3).
(5) A molded article comprising the liquid crystal polyester resin composition according to any one of (1) to (4).
(6) The molded article according to (5), selected from the group consisting of a relay, a switch, a coil bobbin, a lamp socket, and a camera module.

  According to the liquid crystal polyester resin composition of the present invention, a molded product excellent in dimensional stability after heat treatment, shape retention and weld characteristics can be obtained. Such a resin composition is particularly suitable for electrical / electronic parts and mechanical parts such as relays, switches, coil bobbins, lamp sockets, camera modules and the like having fitting parts and windings with other parts.

  Hereinafter, the present invention will be described in detail. The weight in the present invention means mass.

  The liquid crystal polyester resin used in the present invention is a polyester that forms an anisotropic molten phase. Examples of the liquid crystal polyester resin include polyesters composed of structural units selected to form an anisotropic molten phase from oxycarbonyl units, dioxy units, dicarbonyl units and the like described later.

  Next, the structural unit which comprises liquid crystal polyester resin is demonstrated.

  Specific examples of the oxycarbonyl unit include structural units generated from aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid, m-hydroxybenzoic acid, and 6-hydroxy-2-naphthoic acid. From the viewpoint of improving dimensional stability, shape retention and weld characteristics after heat treatment, a structural unit generated from an aromatic hydroxycarboxylic acid is preferable, and a structural unit generated from p-hydroxybenzoic acid is particularly preferable.

  Specific examples of the dioxy unit include 4,4′-dihydroxybiphenyl, hydroquinone, resorcinol, t-butylhydroquinone, phenylhydroquinone, chlorohydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 3,4′-. Dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxybenzophenone, etc. Produced from aliphatic diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc. Concrete unit, 1,4-cyclohexanediol, and structural unit derived from alicyclic diol such as 1,4-cyclohexanedimethanol. From the viewpoint of improving dimensional stability, shape retention and weld characteristics after heat treatment, a structural unit generated from an aromatic diol is preferable, and a structural unit generated from 4,4'-dihydroxybiphenyl and hydroquinone is particularly preferable.

  Specific examples of the dicarbonyl unit include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 3,3′-diphenyldicarboxylic acid, 2,2′-diphenyldicarboxylic acid, Fragrances such as 1,2-bis (phenoxy) ethane-4,4′-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid Structural units generated from aliphatic dicarboxylic acids, structural units generated from aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, hexahydroterephthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3- Examples include structural units generated from alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. From the viewpoint of improving dimensional stability, shape retention and weld properties after heat treatment, a structural unit generated from an aromatic dicarboxylic acid is preferable, and a structural unit generated from terephthalic acid or isophthalic acid is particularly preferable.

  Further, in addition to the above structural units, structural units generated from p-aminobenzoic acid, p-aminophenol, and the like can be further included in a range that does not impair liquid crystallinity and characteristics.

  Specific examples of the liquid crystal polyester resin include a structural unit generated from p-hydroxybenzoic acid, a structural unit generated from 4,4′-dihydroxybiphenyl, a structural unit generated from hydroquinone, and generated from terephthalic acid and / or isophthalic acid. Liquid crystalline polyester composed of structural units, structural units generated from p-hydroxybenzoic acid, structural units generated from ethylene glycol, structural units generated from 4,4′-dihydroxybiphenyl, structural units generated from hydroquinone, terephthalic acid and / or Or a liquid crystalline polyester comprising a structural unit produced from isophthalic acid, a structural unit produced from p-hydroxybenzoic acid, a structural unit produced from hydroquinone, a structural unit produced from 4,4′-dihydroxybiphenyl, 2,6-naphthalene Structural units generated from carboxylic acid, liquid crystalline polyesters consisting of structural units generated from terephthalic acid, structural units generated from p-hydroxybenzoic acid, structural units generated from 2,6-dihydroxynaphthalene, 4,4′-dihydroxybiphenyl And a liquid crystal polyester comprising a structural unit formed from terephthalic acid and / or isophthalic acid. Particularly preferred are structural units generated from p-hydroxybenzoic acid, structural units generated from 4,4′-dihydroxybiphenyl, structural units generated from hydroquinone, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. It is a liquid crystal polyester composed of structural units. By being comprised from said structural unit, it is excellent in the heat resistance of the liquid crystal polyester resin composition obtained, and the amount of gas generation is suppressed. Therefore, the dimensional stability, shape retention and weld characteristics after heat treatment are improved.

  The raw material monomer constituting each structural unit is not particularly limited as long as it is a structure that can form each structural unit. However, an acylated product of a hydroxyl group of each structural unit, an esterified product of a carboxyl group of each structural unit, an acid halide Carboxylic acid derivatives such as acid anhydrides may be used.

  The total of dioxy units constituting the liquid crystal polyester resin and the total of dicarbonyl units are substantially equimolar. Here, “substantially equimolar” means that the structural unit constituting the polymer main chain excluding the terminal is equimolar. For this reason, the aspect which does not necessarily become equimolar when it includes even the structural unit which comprises the terminal can satisfy the requirement of “substantially equimolar”.

  The liquid crystalline polyester resin of the present invention preferably has 2 mol% or more of structural units derived from hydroquinone with respect to 100 mol% of the total amount of structural units of the liquid crystalline polyester resin. With the above structure, the dimensional stability, shape retention and weld characteristics after heat treatment can be further improved. More preferably, it is 4 mol% or more, More preferably, it is 7.5 mol% or more. On the other hand, the structural unit derived from hydroquinone is preferably 20 mol% or less. By adopting the above structure, the crystallinity of the liquid crystal polyester resin does not become too low, and the rigidity of the molded product is improved, so that the dimensional stability after heat treatment, shape retention and weld characteristics can be further improved. . More preferably, it is 15 mol% or less, More preferably, it is 12 mol% or less.

  Moreover, it is preferable that the sum total of the structural unit derived from p-hydroxybenzoic acid and the structural unit derived from terephthalic acid is 70 mol% or more with respect to 100 mol% of the total structural unit of the liquid crystal polyester resin. By setting it as said structure, the crystallinity and melting | fusing point of liquid crystal polyester resin can be controlled, and the molded article excellent in heat resistance and moldability can be obtained. Thereby, the dimensional stability after heat processing, shape retention, and weld characteristic can be improved more. The total of the structural unit derived from p-hydroxybenzoic acid and the structural unit derived from terephthalic acid is more preferably 73 mol% or more, and further preferably 75.5 mol% or more. On the other hand, since the crystallinity and melting point of the liquid crystal polyester resin do not become too high and can be set to an appropriate molding processing temperature, the deterioration of the liquid crystal polyester resin composition during molding is suppressed, and a molded product having excellent mechanical strength is obtained. Since it can obtain, it is preferable that the sum total of the structural unit derived from p-hydroxybenzoic acid and the structural unit derived from terephthalic acid is 80 mol% or less. More preferably, it is 77.5 mol% or less. Moreover, the structural unit derived from p-hydroxybenzoic acid and the structural unit derived from terephthalic acid may have either one of the structural units, and the other structural unit may be 0 mol%. It is preferable to exceed 0 mol%.

About the liquid crystalline polyester resin of this invention, the calculation method of content of each structural unit is shown below. First, the liquid crystal polyester resin is weighed in an NMR (nuclear magnetic resonance) test tube and dissolved in a solvent in which the liquid crystal polyester resin is soluble (for example, a pentafluorophenol / heavy tetrachloroethane-d ₂ mixed solvent). Next, about a solution, < ¹ > H-NMR spectrum measurement can be performed and it can calculate from the peak area ratio derived from each structural unit.

  The melting point (Tm) of the liquid crystalline polyester resin of the present invention is 300 ° C. or higher and 350 ° C. or lower. When the melting point of the liquid crystal polyester resin is less than 300 ° C., the flexural modulus at a high temperature is significantly lowered, and thus the dimensional stability, shape retention and weld characteristics after heat treatment are greatly lowered. From the viewpoint of improving dimensional stability, shape retention and weld characteristics after heat treatment, it is preferably 310 ° C. or higher, more preferably 315 ° C. or higher. Further, when the melting point of the liquid crystal polyester resin is higher than 350 ° C., the liquid crystal polyester resin is deteriorated during processing due to the high processing temperature, and the mechanical strength and the weld characteristics after heat treatment are greatly reduced. From the viewpoint of improving mechanical strength and weld characteristics after heat treatment, 345 ° C. or lower is preferable, and 340 ° C. or lower is more preferable.

The melting point (Tm) is measured by differential scanning calorimetry. Specifically, first, an endothermic peak temperature (Tm ₁ ) is observed by heating the polymer that has been polymerized from room temperature to a temperature rising condition of 20 ° C./min. After observation of an endothermic peak temperature (Tm _1), holding the polymer for 5 minutes at a temperature of the endothermic peak temperature _(Tm 1) + 20 ℃. Thereafter, the polymer is cooled to room temperature under a temperature drop condition of 20 ° C./min. Then, the endothermic peak temperature (Tm ₂ ) is observed by heating the polymer under a temperature rising condition of 20 ° C./min. The melting point (Tm) refers to the endothermic peak temperature (Tm ₂ ).

  The melt viscosity of the liquid crystalline polyester resin used in the present invention is preferably 5 Pa · s or more from the viewpoint of improving the flexural modulus at high temperature and improving the dimensional stability, shape retention and weld properties after heat treatment, 15 Pa · s or more is more preferable, and 20 Pa · s or more is more preferable. On the other hand, from the viewpoint of improving fluidity and obtaining a molded product without defects such as unfilling, the melt viscosity of the liquid crystal polyester resin is preferably 100 Pa · s or less, more preferably 50 Pa · s or less, and 40 Pa · s or less. Is more preferable.

  In addition, this melt viscosity is a value measured by a Koka flow tester under the condition of the melting point (Tm) of the liquid crystal polyester resin + 20 ° C. and the shear rate of 1000 / sec.

The method for producing the liquid crystal polyester resin used in the present invention is not particularly limited, and can be produced according to a known polyester polycondensation method. Known polyester polycondensation methods include structural units derived from p-hydroxybenzoic acid, structural units derived from 4,4′-dihydroxybiphenyl, structural units derived from hydroquinone, structural units derived from terephthalic acid, and The following is mentioned as an example of the liquid crystalline polyester resin which consists of a structural unit derived from isophthalic acid.
(1) A method for producing a liquid crystal polyester resin from p-acetoxybenzoic acid and 4,4′-diacetoxybiphenyl, diacetoxybenzene, terephthalic acid, and isophthalic acid by a deacetic acid condensation polymerization reaction.
(2) Liquid crystalline polyester by reacting acetic anhydride with p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, hydroquinone, terephthalic acid, and isophthalic acid to acetylate the phenolic hydroxyl group, followed by deacetic acid polymerization A method for producing a resin.
(3) A method for producing a liquid crystal polyester resin by dephenol polycondensation reaction from phenyl p-hydroxybenzoate and 4,4′-dihydroxybiphenyl, hydroquinone, diphenyl terephthalate, and diphenyl isophthalate.
(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 phenyl esters, respectively, and then aromatics such as 4,4′-dihydroxybiphenyl and hydroquinone. A method for producing a liquid crystal polyester resin by adding a group dihydroxy compound and dephenol polycondensation reaction.

  Among them, (2) p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, and isophthalic acid are reacted with acetic anhydride to acetylate the phenolic hydroxyl group and then deacetic acid polycondensation reaction. A method for producing a liquid crystal polyester resin is preferably used because it is industrially excellent in controlling the terminal structure of the liquid crystal polyester resin and controlling the degree of polymerization.

  As a method for producing the liquid crystal polyester resin used in the present invention, the polycondensation reaction can be completed by a solid phase polymerization method. Examples of the treatment by the solid phase polymerization method include the following methods. First, a polymer or oligomer of a liquid crystal polyester resin is pulverized by a pulverizer. The pulverized polymer or oligomer is heated under a nitrogen stream or under reduced pressure, and polycondensed to a desired degree of polymerization to complete the reaction. The said heating can be performed for 1 to 50 hours in the range of melting | fusing point-50 degreeC-melting point-5 degreeC (for example, 200-300 degreeC) of liquid crystalline polyester.

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

  The liquid crystalline polyester resin composition of the present invention contains 40 to 250 parts by weight of the inorganic filler (a) with respect to 100 parts by weight of the liquid crystalline polyester resin. If the content of the inorganic filler (a) is less than 40 parts by weight, the mechanical strength and heat resistance of the molded product will be greatly reduced, and the dimensional stability, shape retention and weld properties after heat treatment will be greatly reduced. . From the viewpoint of improving the mechanical strength and heat resistance of the molded product, dimensional stability after heat treatment, shape retention and weld characteristics, it is preferably 60 parts by weight or more, more preferably 75 parts by weight or more, and still more preferably 90 parts by weight or more. . On the other hand, when the content of the inorganic filler (a) exceeds 250 parts by weight, the fluidity and workability are greatly lowered, and a molded product cannot be obtained with high accuracy. In addition, the weld characteristics after heat treatment are greatly reduced. From the viewpoint of improving the weld characteristics, fluidity and workability after heat treatment, it is preferably 200 parts by weight or less, more preferably 150 parts by weight or less.

  Although the inorganic filler (a) used by this invention is not specifically limited, For example, inorganic fillers, such as a fiber form, a whisker form, plate shape, a powder form, a granular form, can be mentioned. Specifically, as fibrous and whisker-like inorganic fillers, glass fibers, stainless fibers, metal fibers such as aluminum fibers and brass fibers, gypsum fibers, ceramic fibers, asbestos fibers, zirconia fibers, alumina fibers, silica fibers, Examples include titanium oxide fibers, potassium titanate whiskers, barium titanate whiskers, aluminum borate whiskers, silicon nitride whiskers, and acicular titanium oxide. Examples of the plate-like inorganic filler include mica, talc, kaolin, glass flake, clay, molybdenum disulfide, and wollastonite. Powdered and granular inorganic fillers include titanium oxide, magnesium carbonate, magnesium hydroxide, magnesium oxide, zinc oxide, zinc sulfide, barium sulfate, barium titanate, barium phosphate, aluminum oxide, lead carbonate, calcium carbonate, Examples thereof include silica and glass beads. The surface of the inorganic filler used in the present invention may be treated with a known coupling agent (for example, a silane coupling agent or a titanate coupling agent) or other surface treatment agent. . Moreover, you may use 2 or more types together for said inorganic filler used for this invention.

  Among these inorganic fillers (a), fibrous fillers and whisker-like fillers are used from the viewpoint of improving mechanical strength such as rigidity, dimensional stability after heat treatment, shape retention, and weld characteristics. It is preferable. Furthermore, from the viewpoint of improving the dimensional stability in the thickness direction after heat treatment and improving the shape retention and weld characteristics after heat treatment, among the fibrous fillers, a fibrous material having a major axis / minor axis ratio of 1 or more and less than 2. It is preferable to use a filler. The major axis / minor axis ratio of the fibrous filler is more preferably 1.5 or less, and further preferably 1.2 or less.

  The major axis / minor axis ratio of a fibrous filler having a non-circular cross-sectional shape is defined as the quotient of the longest linear dimension of the fibrous filler cross-section and the linear dimension passing through the central point of the major axis and orthogonal to the major axis. The cross section of the fibrous filler having a circular cross-sectional shape is observed with a scanning electron microscope, and for example, 100 fibrous fillers having a non-circular cross-sectional shape are selected and the number average of the major axis / minor axis ratio is calculated. This is the value obtained by

  Further, from the viewpoint of improving mechanical strength such as rigidity, dimensional stability after heat treatment, shape retention and weld characteristics, glass fiber is more preferable among the fibrous fillers. The type of glass fiber is not particularly limited as long as it is generally used for reinforcing resin, and can be selected from, for example, long fiber type or short fiber type chopped strands and milled fibers.

  The glass fiber used in the present invention is preferably weakly alkaline in terms of mechanical strength. In particular, glass fibers having a silicon oxide content of 50 to 80% by weight are preferably used, and more preferably glass fibers having a silicon oxide content of 65 to 77% by weight. Glass fiber is an epoxy-based, urethane-based, acrylic-based coating or converging agent; silane-based, titanate-based coupling agents; other surface treatment agents; thermoplastic resins such as α-olefin polymers; epoxy resins It may be coated or focused with a thermosetting resin such as.

  From the viewpoint of improving the weld characteristics after heat treatment, the liquid crystalline polyester resin composition of the present invention contains titanium oxide, magnesium carbonate, magnesium hydroxide, magnesium oxide, zinc oxide, zinc sulfide, in the inorganic filler (a). One or more powdery or granular inorganic fillers (a ′) selected from the group consisting of barium sulfate, barium titanate, barium phosphate, aluminum oxide, lead carbonate, and calcium carbonate (hereinafter referred to as powdery or granular) Inorganic filler (sometimes referred to as “a ′)”). More preferably, it is titanium oxide.

  As the titanium oxide, a rutile type, anatase type, rutile and anatase type mixture can be used. From the viewpoint of improving heat resistance, thermal deterioration, and weld characteristics after heat treatment, it is preferable to use a rutile type. The weight average particle diameter of the titanium oxide is preferably 0.05 μm or more, more preferably 0.1 μm or more, and further preferably 0.2 μm or more from the viewpoint of improving fluidity and weld characteristics after heat treatment. Further, from the viewpoint of improving the whiteness and weld characteristics after heat treatment, the thickness is preferably 0.5 μm or less, more preferably 0.4 μm or less, and further preferably 0.35 μm or less.

  The powdery or granular inorganic filler (a ′) is 0.1% by weight or more in the content of 100% by weight of the inorganic filler (a) from the viewpoint of improving the weld characteristics after heat treatment. It is preferable to include. More preferably, it is 0.5 weight% or more, More preferably, it is 1 weight% or more. On the other hand, the powdery or granular inorganic filler (a ′) is 20% in a content of 100% by weight of the inorganic filler (a) from the viewpoint of improving dimensional stability and shape retention after heat treatment. It is preferable to contain not more than wt%. More preferably, it is 15 weight% or less, More preferably, it is 10 weight% or less.

  In the liquid crystal polyester resin composition of the present invention, an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphite, thioethers, and substituted products thereof, etc.) as long as the effects of the present invention are not impaired. UV absorbers (eg, resorcinol, salicylate), anti-coloring agents such as phosphites, hypophosphites, lubricants and mold release agents (montanic acid and its metal salts, its esters, their half esters, stearyl alcohol, Stearamide and polyethylene wax), colorants containing dyes or pigments, carbon black, crystal nucleating agents, plasticizers, flame retardants (bromine flame retardants, phosphorus flame retardants, red phosphorus, silicone flame retardants) Combining conventional additives selected from flame retardants, flame retardant aids, and antistatic agents It can be.

  The method of blending the liquid crystalline polyester resin of the present invention with the inorganic filler (a), the powdery or granular inorganic filler (a ′), and other additives is not particularly limited. For example, a dry blend method in which a solid inorganic filler (a), a powdery or granular inorganic filler (a ′), and other additives are blended with a liquid crystalline polyester resin, a liquid crystalline polyester resin, and an inorganic filler (A), a solution blending method in which other liquid additives or the like are blended with the powdery or granular inorganic filler (a ′), an inorganic filler (a), a powdery or granular inorganic filler (a ′) ) And other additives during polymerization of the liquid crystalline polyester resin, and melt the liquid crystalline polyester resin and the inorganic filler (a), the powdery or granular inorganic filler (a ′), and other additives A kneading method can be used, and melt kneading is particularly preferable. A known method can be used for melt kneading. For example, using a Banbury mixer, a rubber roll machine, a kneader, a single-screw or twin-screw extruder, the liquid crystal polyester resin composition can be obtained by melt-kneading the liquid crystal polyester resin at a melting point or higher and a melting point + 50 ° C. or lower. Of these, a twin screw extruder is preferable. In the case of melt-kneading, from the viewpoint of suppressing deterioration of the liquid crystal polyester resin composition and improving mechanical strength, melt-kneading is preferably performed at 370 ° C. or less, and 360 ° C. or less is more preferable.

  About a biaxial extruder, from the point of the dispersibility of liquid crystalline polyester resin and an inorganic filler, it is preferable to provide one or more kneading parts, and it is more preferable to provide two or more places. For example, when the kneading part is added from the side feeder, the inorganic filler (a) or the powdery or granular inorganic filler (a ′) is inorganic in order to promote plasticization of the liquid crystal polyester resin. In order to improve the dispersibility of the liquid crystalline polyester resin and the inorganic filler at one or more locations upstream from the side feeder of the filler, it is preferable to install two or more locations in total, one or more locations downstream of the side feeder.

  As a kneading method, 1) a method in which a liquid crystal polyester resin, an inorganic filler (a), a powdery or granular inorganic filler (a ′), and other additives are added all at once from the original feeder and kneaded ( (Batch kneading method) 2) Liquid crystal polyester resin, and other additives are added from the original feeder and kneaded, and then inorganic filler (a), powdered or granular inorganic filler (a ′), and others Method of adding additives from side feeder and kneading (side feed method), 3) Producing master pellets containing liquid crystal polyester resin and other additives in high concentration, and then adding the master pellets to the specified concentration Which method such as liquid crystal polyester resin, inorganic filler (a), and method of kneading with powdered or granular inorganic filler (a ′) (master pellet method) It may be used.

  The liquid crystalline polyester resin composition of the present invention has an excellent surface appearance (color tone) and machine by performing known melt molding such as injection molding, injection compression molding, compression molding, extrusion molding, blow molding, press molding, and spinning. It can be processed into a molded product having mechanical properties, heat resistance and flame retardancy. Examples of the molded product include injection molded products, extrusion molded products, press molded products, sheets, pipes, unstretched films, uniaxially stretched films, various films such as biaxially stretched films, unstretched yarns, superstretched yarns, and the like. Examples include various fibers. In particular, injection molding is preferred from the viewpoint of processability. In the case of melt molding, from the viewpoint of suppressing deterioration of the liquid crystal polyester resin composition and improving mechanical strength, melt molding is preferably performed at 370 ° C. or less, and 360 ° C. or less is more preferable.

The liquid crystal polyester resin composition of the present invention satisfies the following formula (1).
0.35 ≦ E ₂₀₀ / E ₂₃ ≦ 1.00 − (1)
(E ₂₃ is a flexural modulus (GPa) of a molded product made of a liquid crystal polyester resin composition measured in accordance with ASTM D790 at an ambient temperature of 23 ° C., and E ₂₀₀ is a molded product made of a liquid crystal polyester resin composition. Is a flexural modulus (GPa) measured according to ASTM D790 at an atmospheric temperature of 200 ° C.).

The E ₂₃ and _{E 200,} the 12.7mm wide × 127 mm long × 3.2 mm thick flexural test piece can be measured according to ASTM D790 in an atmosphere of 23 ° C. or 200 ° C..

E ₂₀₀ / E ₂₃ indicates the ratio between the flexural modulus measured at high temperature (200 ° C.) and the flexural modulus measured at room temperature (23 ° C.), and is an index indicating the height of the elastic modulus at high temperature. . The larger E ₂₀₀ / E ₂₃ is, the higher the elastic modulus at high temperature is. When E ₂₀₀ / E ₂₃ is less than 0.35, the dimensional stability, shape retention, and weld characteristics after heat treatment are significantly reduced. From the viewpoint of improving dimensional stability, shape retention and weld characteristics after heat treatment, 0.38 or more is preferable, and 0.40 or more is more preferable. On the other hand, since the bending elastic modulus of the liquid crystalline polyester resin is usually smaller when measured at a high temperature, the maximum value of E ₂₀₀ / E ₂₃ is 1.00. Since the crystallinity and melting point of the liquid crystal polyester resin are appropriately controlled and become an appropriate molding processing temperature, deterioration of the liquid crystal polyester resin composition at the time of molding can be suppressed, and a molded product having excellent mechanical strength can be obtained. 0.80 or less is preferable, 0.70 or less is more preferable, and 0.60 or less is more preferable.

In order to set the value of E ₂₀₀ / E ₂₃ to 0.35 or more and 1.00 or less, for example, the above-described types of liquid crystal polyester resins and inorganic fillers are contained in the amounts described as preferable. Just do it.

For example, by adopting the following embodiment, the value of E ₂₀₀ / E ₂₃ can be set to 0.35 or more and 1.00 or less.
(1) When containing 60 to 250 parts by weight of the fibrous inorganic filler described above as preferable with respect to 100 parts by weight of the liquid crystalline polyester having a structural unit derived from hydroquinone and having the melting point described as preferable above .
(2) When containing 40 parts by weight or more of whisker-like inorganic filler with respect to 100 parts by weight of liquid crystalline polyester having a structural unit derived from hydroquinone.
(3) When containing 200 to 250 parts by weight of the inorganic filler (a) with respect to 100 parts by weight of the liquid crystalline polyester.

Further, from the viewpoint of improving dimensional stability, shape retention and weld characteristics after heat treatment, E ₂₀₀ is preferably 6.0 GPa or more, more preferably 6.5 GPa or more, and even more preferably 7.0 GPa. On the other hand, from the viewpoint of improving the mechanical strength of the molded _{article, E 23} is preferably more than 15.0GPa, more preferably at least 16.5GPa, and even more preferably 17.5GPa.

  Molded articles obtained by molding the liquid crystalline polyester resin composition of the present invention include, for example, various gears, various cases, sensors, LED lamps, connectors, sockets, resistors, relay cases, relay bases, relay spools, switches, Coil bobbin, condenser, variable capacitor case, optical pickup, oscillator, various terminal boards, transformer, plug, printed wiring board, tuner, speaker, microphone, headphones, small motor, magnetic head base, power module, housing, semiconductor, liquid crystal display Parts, FDD carriage, FDD chassis, HDD parts, motor brush holder, parabolic antenna, electric and electronic parts represented by computer-related parts; VTR parts, TV parts, irons, hair dryers, rice cookers Products, microwave oven parts, acoustic parts, audio equipment parts such as audio / laser discs (registered trademark) / compact discs, lighting parts, refrigerator parts, air conditioner parts, household electrical appliance parts, office computer related parts , Telephone related parts, facsimile related parts, copier related parts, cleaning jigs, oilless bearings, stern bearings, underwater bearings and other bearings, motor parts, machine related parts such as lighters, microscopes, binoculars, Optical equipment such as cameras and watches, precision machinery-related parts; alternator terminals, alternator connectors, IC regulators, light dimmer potentiometer bases, exhaust gas valves and other valves, fuel-related / exhaust / intake system pipes, air Intake nozzle snow Kell, intake manifold, fuel pump, engine coolant joint, carburetor main body, carburetor spacer, exhaust gas sensor, coolant sensor, oil temperature sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake butt wear sensor, Air-conditioner thermostat base, air-conditioner motor insulators, automotive motor insulators such as power windows, heating hot air flow control valves, brush holders for radiator motors, water pump impellers, turbine vanes, wiper motor related parts, distributors, starters Switch, starter relay, transmission wiring harness, window oscherno Slur, air conditioner panel switch board, coil for fuel related solenoid valve, fuse connector, horn terminal, electrical component insulation plate, step motor rotor, lamp bezel, lamp socket, lamp reflector, lamp housing, brake piston, solenoid bobbin, engine oil Automobile / vehicle-related parts such as filters and igniter cases; Bottles for various chemicals such as shampoos, rinses, liquid soaps, detergents; chemical storage tanks, gas storage tanks, cooling liquid tanks, oil transfer tanks, disinfectants Tanks for chemicals and gas storage such as tanks for blood pumps, transfusion pumps, fuel tanks, canisters, washer liquid tanks, oil reservoir tanks, medical equipment parts, seasonings such as soy sauce, sauces, ketchup, mayonnaise, dressings, miso Vinegar etc. Fermented foods, fats and oils such as salad oil, sake, beer, mirin, whiskey, shochu, wine and other alcoholic beverages, carbonated beverages, juice, sports drinks, milk, coffee beverages, oolong tea, tea, mineral water, etc. It can be used for food storage containers; and tanks as general household appliance parts, bottle-shaped molded products, or hollow containers such as those tanks. Electrical and electronic parts and mechanical parts such as relays, switches, coil bobbins, lamp sockets, camera modules, etc. that have fitting parts and windings with other parts because of excellent dimensional stability, shape retention and weld characteristics after heat treatment Useful for.

  EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not limited by an Example. In the examples, the composition and characteristic evaluation of the liquid crystal polyester resin were measured by the following methods.

(1) Composition analysis of the liquid crystal polyester resin composition analysis LCP ^was carried out by 1 H- nuclear magnetic resonance spectrum ⁽¹ H-NMR) measurement. 50 mg of liquid crystal polyester resin was weighed in an NMR sample tube, dissolved in 800 μL of a solvent (a mixed solvent of pentafluorophenol / 1,1,2,2-tetrachloroethane-d ₂ = 65/35 (weight ratio)), and unity INOVA500. ¹ H-NMR measurement was performed at an observation frequency of 500 MHz and a temperature of 80 ° C. using a type NMR apparatus (manufactured by Varian), and the composition was determined from the peak area ratio derived from each structural unit observed in the vicinity of 7 to 9.5 ppm. analyzed.

(2) Melting point (Tm) of liquid crystal polyester resin
After observation of the endothermic peak temperature (Tm ₁ ) observed when the liquid crystal polyester resin was heated from room temperature under a temperature rising condition of 20 ° C./min using a differential scanning calorimeter DSC-7 (manufactured by Perkin Elmer), Tm ₁ Endothermic peak temperature (Tm ₂ ) observed when the temperature is kept at + 20 ° C. for 5 minutes, then cooled to room temperature under a temperature drop condition of 20 ° C./min, and again raised under a temperature rise condition of 20 ° C./min. Was the melting point. In the following production examples, the melting point (Tm ₂ ) is described as Tm.

(3) Melt viscosity of liquid crystalline polyester resin Melting of liquid crystalline polyester resin under the conditions of Tm + 20 ° C. and shear rate of 1000 / s using Koka flow tester CFT-500D (orifice 0.5φ × 10 mm) (manufactured by Shimadzu Corporation) The viscosity was measured.

[Production Example 1]
945 parts by weight of p-hydroxybenzoic acid, 243 parts by weight of 4,4′-dihydroxybiphenyl, 99 parts by weight of hydroquinone, 284 parts by weight of terephthalic acid, 82 parts by weight of isophthalic acid in a 5 L reaction vessel equipped with a stirring blade and a distillation pipe And 1252 parts by weight of acetic anhydride (1.09 equivalents of the total phenolic hydroxyl groups) were allowed to react at 145 ° C. for 2 hours with stirring under a nitrogen gas atmosphere, and then heated from 145 ° C. to 350 ° C. over 4 hours. . Thereafter, the polymerization temperature was maintained at 350 ° C., the pressure was reduced to 1.0 mmHg in 1.0 hour, the reaction was continued for another 20 minutes, and the polymerization was completed when the torque required for stirring reached 20 kg · cm. Next, the inside of the reaction vessel is pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer is discharged onto a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-1) was obtained.

  The liquid crystal polyester resin (A-1) had a Tm of 330 ° C. and a melt viscosity of 28 Pa · s.

[Production Example 2]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 870 parts by weight of p-hydroxybenzoic acid, 352 parts by weight of 4,4′-dihydroxybiphenyl, 89 parts by weight of hydroquinone, 292 parts by weight of terephthalic acid, 157 parts by weight of isophthalic acid And 1278 parts by weight of acetic anhydride (1.07 equivalent of the total phenolic hydroxyl groups) were allowed to react at 145 ° C. for 2 hours with stirring under a nitrogen gas atmosphere, and then heated from 145 ° C. to 320 ° C. over 4 hours. . Thereafter, the polymerization temperature was maintained at 325 ° C., the pressure was reduced to 1.0 mmHg in 1.0 hour, the reaction was continued for another 30 minutes, and the polymerization was completed when the torque required for stirring reached 20 kg · cm. Next, the inside of the reaction vessel is pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer is discharged onto a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-2) was obtained.

  The liquid crystal polyester resin (A-2) had a Tm of 314 ° C. and a melt viscosity of 25 Pa · s.

[Production Example 3]
In a 5 L reaction vessel equipped with a stirring blade and a distillation pipe, 994 parts by weight of p-hydroxybenzoic acid, 126 parts by weight of 4,4′-dihydroxybiphenyl, 112 parts by weight of terephthalic acid, and an intrinsic viscosity of about 0.6 dl / g 216 parts by weight of polyethylene terephthalate and 960 parts by weight of acetic anhydride (1.10 equivalents of total phenolic hydroxyl groups) were charged, and the mixture was reacted at 145 ° C. for 2 hours with stirring under a nitrogen gas atmosphere. The temperature increased with time. Thereafter, the polymerization temperature was maintained at 325 ° C., the pressure was reduced to 1.0 mmHg in 1.0 hour, the reaction was continued for 60 minutes, and the polymerization was completed when the torque required for stirring reached 20 kg · cm. Next, the inside of the reaction vessel is pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer is discharged onto a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-3) was obtained.

  The liquid crystal polyester resin (A-3) had a Tm of 314 ° C. and a melt viscosity of 19 Pa · s.

[Production Example 4]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 522 parts by weight of p-hydroxybenzoic acid, 102 parts by weight of 6-hydroxy-2-naphthoic acid, 282 parts by weight of 4,4′-dihydroxybiphenyl, 190 parts by weight of hydroquinone , 538 parts by weight of terephthalic acid and 1136 parts by weight of acetic anhydride (1.03 equivalents of total phenolic hydroxyl groups) were allowed to react at 145 ° C. for 2 hours with stirring in a nitrogen gas atmosphere, and then from 145 ° C. to 350 ° C. The temperature was raised in 4 hours. Thereafter, the polymerization temperature was maintained at 350 ° C., the pressure was reduced to 1.0 mmHg in 1.0 hour, the reaction was continued for another 30 minutes, and the polymerization was completed when the torque required for stirring reached 20 kg · cm. Next, the inside of the reaction vessel is pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer is discharged onto a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-4) was obtained.

  The liquid crystal polyester resin (A-4) had a Tm of 333 ° C. and a melt viscosity of 27 Pa · s.

[Production Example 5]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 994 parts by weight of p-hydroxybenzoic acid, 447 parts by weight of 4,4′-dihydroxybiphenyl, 359 parts by weight of terephthalic acid, 40 parts by weight of isophthalic acid and 1348 parts by weight of acetic anhydride. Parts (1.10 equivalents of total phenolic hydroxyl groups) and the reactor was sufficiently substituted with nitrogen gas, then 0.18 parts by weight of 1-methylimidazole was added, and the mixture was added under a nitrogen gas stream over 30 minutes. The temperature was raised to 150 ° C., and the temperature was maintained and refluxed for 30 minutes. Thereafter, 2.4 parts by weight of 1-methylimidazole was added, and then the temperature was raised to 320 ° C. over 2 hours and 50 minutes while distilling off the by-product acetic acid to be distilled off and unreacted acetic anhydride. When observed, the contents were removed and cooled to room temperature. The obtained solid was pulverized by a coarse pulverizer, heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere, heated from 250 ° C. to 295 ° C. over 5 hours, and then heated at 295 ° C. for 3 hours. By holding, solid phase polymerization was performed. After solid phase polymerization, the mixture was cooled to obtain a liquid crystal polyester resin (A-5).

  The liquid crystal polyester resin (A-5) had a Tm of 371 ° C. and a melt viscosity of 75 Pa · s.

[Production Example 6]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 994 parts by weight of p-hydroxybenzoic acid, 447 parts by weight of 4,4′-dihydroxybiphenyl, 299 parts by weight of terephthalic acid, 100 parts by weight of isophthalic acid, and 1168 parts by weight of acetic anhydride. Parts (1.10 equivalents of total phenolic hydroxyl groups) and the reactor was sufficiently substituted with nitrogen gas, then 0.18 parts by weight of 1-methylimidazole was added, and the mixture was added under a nitrogen gas stream over 30 minutes. The temperature was raised to 150 ° C., and the temperature was maintained and refluxed for 30 minutes. Thereafter, 2.4 parts by weight of 1-methylimidazole was added, and then the temperature was raised to 320 ° C. over 2 hours and 50 minutes while distilling off the by-product acetic acid to be distilled off and unreacted acetic anhydride. When observed, the contents were removed and cooled to room temperature. The obtained solid was pulverized with a coarse pulverizer, then heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere, heated from 250 ° C. to 295 ° C. over 5 hours, and heated at 295 ° C. for 2 hours. By holding, solid phase polymerization was performed. After solid phase polymerization, the mixture was cooled to obtain a liquid crystal polyester resin (A-6).

  The liquid crystal polyester resin (A-6) had a Tm of 343 ° C. and a melt viscosity of 26 Pa · s.

[Production Example 7]
In a 5 L reaction vessel equipped with a stirring blade and a distillation pipe, 1105 parts by weight of p-hydroxybenzoic acid, 186 parts by weight of 4,4′-dihydroxybiphenyl, 249 parts by weight of terephthalic acid, 0.27 parts by weight of sodium acetate and acetic anhydride 1051 parts by weight (1.03 equivalent of the total phenolic hydroxyl groups) was charged, and the mixture was reacted at 145 ° C. for 2 hours with stirring in a nitrogen gas atmosphere, and then heated from 145 ° C. to 350 ° C. over 3.5 hours. Thereafter, the polymerization temperature was maintained at 350 ° C., the pressure was reduced to 1.0 mmHg in 1.5 hours, and the reaction was further continued for 90 minutes. When the torque required for stirring reached 20 kg · cm, the polymerization was completed. Next, the inside of the reaction vessel is pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer is discharged onto a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-7) was obtained.

  The liquid crystal polyester resin (A-7) had a Tm of 332 ° C. and a melt viscosity of 22 Pa · s.

  According to the above (1), the composition analysis of the liquid crystal polyester resin obtained in each production example was performed. The results are shown in Table 1.

The inorganic fillers (a), powdery or granular inorganic fillers (a ′) and other additives (b) used in the examples and comparative examples are shown below.
(A-1): Nippon Electric Glass Co., Ltd. glass chopped strand “ECS03T790G” (circular cross-sectional shape (major axis / minor axis ratio 1), average cut length of 3000 μm, fiber diameter of 9 μm)
(A-2): Nippon Electric Glass Co., Ltd. milled fiber “EPG40M-10A” (circular cross-sectional shape (major axis / minor axis ratio 1), average fiber length 40 μm, fiber diameter 9 μm)
(A-3): Nittobo flat fiber “CSG3J-831” (oval (track shape having parallel straight portions), long diameter (20 μm) / short diameter (5 μm) ratio of 4 and diameter of 11 μm ) Cross-sectional area equivalent to glass fiber with an average cut length of 3 mm)
(A-4): Fiber inorganic filler obtained by sieving “MF20JH1-20” manufactured by Asahi Fiber Glass Co., Ltd. with a sieve so that the maximum fiber length is 400 μm or less (circular cross-sectional shape (major axis / minor axis ratio 1) ), Average fiber length 142 μm, fiber diameter 10 μm)
(A-5): Talc “RL217” manufactured by Fuji Talc Industry Co., Ltd.
(A-6): Mica “NJ-030” manufactured by Yamaguchi Mica Co., Ltd.
(A-7): Aluminum borate whisker “Arbolex Y” manufactured by Shikoku Chemicals Co., Ltd.
(A′-8): Titanium oxide “CR-63” manufactured by Ishihara Sangyo Co., Ltd. (weight average particle diameter: 0.21 μm)
(A′-9): Barium sulfate “B-55” manufactured by Sakai Chemical Industry Co., Ltd.
(B-1): Nippon Kayaku novolak type epoxy compound “XD-1000”.

Examples 1-9, Comparative Examples 1-13
A TEM35B type twin screw extruder manufactured by Toshiba Machine equipped with a side feeder. A side feeder is installed in C3 of cylinder C1 (original feeder heater) to C6 (die heater), and a vacuum vent is installed in C5. did. Table 2 shows liquid crystal polyester resins (A-1) to (A-7) and other additives (b-1) obtained in the respective production examples using a screw arrangement in which kneading blocks are incorporated in C2 part and C4 part. In addition, the inorganic fillers (a-1) to (a-7) and the powdery or granular fillers (a′-8) to (a′-9) are charged from the original feeder at the blending amounts shown in Table 3. Were added from the side feeder in the amounts shown in Table 2 and Table 3, the cylinder temperature was set to the melting point of the liquid crystalline polyester resin + 10 ° C., the screw rotation speed was set to 200 rpm, and melt-kneaded to form pellets. About the obtained liquid crystal polyester resin composition pellets, the liquid crystal polyester resin compositions obtained in the examples and comparative examples were hot-air dried at 150 ° C. for 3 hours using a hot-air dryer, and then the following (4) to ( 7) was evaluated. The results are shown in Table 2 and Table 3.

_{(4) E} 200 _/ E ₂₃
FANUC ROBOSHOT α-30C (manufactured by FANUC Co., Ltd.) injection molding machine, setting the resin temperature to the melting point of liquid crystal polyester resin + 20 ° C., mold temperature: 90 ° C., injection speed: 120 mm / sec, injection pressure: 80 MPa Then, a bending test piece having a width of 12.7 mm × 127 mm length × 3.2 mm thickness was produced, and the bending elastic modulus was measured in accordance with ASTM D790 at an ambient temperature of 23 ° C. with a test number n = 3. and, and the average value _{E 23.} In the above bending ambient temperature 200 ° C. The specimens in conformity with ASTM D790, measured flexural modulus at a test number n = 3, and the average value _{E 200.} Divided by _{E 23} and E _{200 is} an _E 200 _/ E _23.

(5) Dimensional stability after heat treatment (Dimensional change rate before and after heat treatment)
FANUC ROBOSHOT α-30C (manufactured by FANUC CORPORATION) with a cylinder temperature of melting point of liquid crystal polyester resin + 20 ° C. and mold temperature: 90 ° C., 100 mm long × 12.7 mm wide × 0.5 mm thick Ten rod-shaped test pieces were molded, and the dimension in the thickness direction of the central part of the molded product was measured using a micrometer. Thereafter, the molded product was heat-treated at 270 ° C. for 10 minutes using a hot air dryer, and the dimension in the thickness direction of the central part of the molded product was measured again using a micrometer. The dimension after the heat treatment was divided by the dimension before the heat treatment, and the average of 10 pieces was taken as the dimensional change rate. The lower the dimensional change rate, the better the dimensional stability in the thickness direction after heat treatment.

(6) Shape retention after heat treatment With a FANUC ROBOSHOT α-30C (manufactured by FANUC CORPORATION) injection molding machine, the cylinder temperature is the melting point of the liquid crystalline polyester resin + 20 ° C., the mold temperature is 90 ° C., 100 mm length × 12 A rod-shaped test piece having a width of 7 mm and a thickness of 0.5 mm was formed. One end of the obtained molded product was held and fixed with a special jig, leaving a length of 80 mm, and heat-treated at 270 ° C. for 5 minutes using a hot air dryer, and then the amount of deflection at the other end was determined by the number of tests n. = 3 and measured as an average value. The smaller the amount of deflection, the better the shape retention after heat treatment.

(7) Weld characteristics after heat treatment (number of weld cracks after heat treatment)
FANUC ROBOSHOT α-30C (manufactured by FANUC Co., Ltd.) injection molding machine with cylinder temperature + 20 ° C melting point of liquid crystal polyester resin, mold temperature: 90 ° C, bottom of molded product released, inner diameter length 30mm x width 50 box-shaped molded products 30 mm × height 30 mm and thickness 0.5 mm were molded. In addition, as the same cylinder temperature and mold temperature, 50 molded products having a length of 30 mm × width of 30 mm and a thickness of 0.5 mm were molded and fitted into each box-shaped molded product. The obtained molded product was heat-treated at 270 ° C. for 10 minutes using a hot air dryer, and then left to stand at 23 ° C. and 50% RH for 1 hour, and the number of cracks at the weld portion of the box-formed product portion. I investigated. The smaller the number of cracks at the weld, the better the weld characteristics after heat treatment.

  From the results of Tables 2 and 3, it can be seen that the liquid crystal polyester resin composition of the present invention is excellent in dimensional stability, shape retention and weld properties after heat treatment. Therefore, it can be said that it is suitable for use in electrical / electronic parts and mechanical parts such as relays, switches, coil bobbins, lamp sockets, camera modules, etc. having fitting parts and windings with other parts.

  Since the liquid crystalline polyester resin composition of the present invention can obtain a molded product having excellent dimensional stability, shape retention and weld characteristics after heat treatment, a relay, switch having a fitting part or winding with other parts, It is suitable for electrical / electronic parts and machine parts such as coil bobbins, lamp sockets and camera modules.

Claims (6)

A liquid crystal polyester resin composition containing 40 to 250 parts by weight of an inorganic filler (a) and satisfying the following formula (1) with respect to 100 parts by weight of a liquid crystal polyester resin having a melting point (Tm) of 300 ° C. or higher and 350 ° C. or lower. object.
0.35 ≦ E ₂₀₀ / E ₂₃ ≦ 1.00 − (1)
(E ₂₃ is a flexural modulus (GPa) of a molded product made of a liquid crystal polyester resin composition measured in accordance with ASTM D790 at an ambient temperature of 23 ° C., and E ₂₀₀ is a molded product made of a liquid crystal polyester resin composition. Is a flexural modulus (GPa) measured in accordance with ASTM D790 at an atmospheric temperature of 200 ° C.) The liquid crystalline polyester resin composition according to claim 1, wherein the inorganic filler (a) is a fibrous filler having a major axis / minor axis ratio of 1 or more and less than 2. 3. The liquid crystal polyester resin composition according to claim 1, comprising a hydroquinone-derived structural unit of 2 mol% or more and 20 mol% or less with respect to 100 mol% of the total amount of the structural units of the liquid crystal polyester resin. In the content of 100% by weight of the inorganic filler (a), titanium oxide, magnesium carbonate, magnesium hydroxide, magnesium oxide, zinc oxide, zinc sulfide, barium sulfate, barium titanate, barium phosphate, aluminum oxide, carbonic acid 4. One or more powdery or granular inorganic fillers (a ′) selected from the group consisting of lead and calcium carbonate are contained in an amount of 0.1 wt% to 20 wt%. Liquid crystal polyester resin composition as described in 2. The molded article which consists of a liquid-crystal polyester resin composition in any one of Claims 1-4. The molded article according to claim 5, wherein the molded article is selected from the group consisting of a relay, a switch, a coil bobbin, a lamp socket, and a camera module.