Liquid crystal polyester resin composition, molded article, and electronic component material including the same

Abstract

To provide: a liquid crystal polyester composition that can reduce physical damage caused by internal and external friction and internal and external impact, have improved mechanical properties such as tensile strength and impact strength, and improved weld line impact strength, provide dimensional stability due to low shrinkage, and minimize fibril and dust generation; and an electronic component material including the same.SOLUTION: A liquid crystal polyester resin composition comprises a liquid crystal polyester resin, a polyphenylene sulfide resin, carbon-based fillers, and inorganic fillers, where the inorganic fillers comprise glass powder.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a liquid crystal polyester resin composition, a molded article, and an electronic component material containing the same, and specifically, to a liquid crystal polyester resin composition, a molded article, and an electronic component material containing the same, which exhibit excellent mechanical properties, weld line impact strength, dimensional stability, and low dust characteristics.

Background Art

[0002] A liquid crystal polyester resin means a molten polyester resin having a property that molecular chains in the polymer are regularly arranged parallel to each other in a molten state. The state of each molecule arranged in this way is usually referred to as a liquid crystal state or a nematic phase of a liquid crystal substance. Such molecules in the polymer are generally thin, long, and flat, and exhibit very high mechanical strength, electrical properties, and heat resistance along the long chain of the molecule.

[0003] A resin composition containing a liquid crystal polyester resin has high heat resistance and high flow characteristics and is widely used as a material for various electric / electronic products. In addition, since small portable electronic products such as notebook computers tend to be thin and light while having excellent performance, the demand for a liquid crystal polyester resin composition having excellent moldability is increasing.

[0004] However, a liquid crystal polyester resin composition has a property that the molten polymer does not lose its crystal structure even during flow. When injecting into a molded article having a complex structure, a weld line, which is a boundary portion where the resins meet during the molding process, is formed. Since the strength of such a weld line is very weak, the molded article may be damaged by external or internal impacts and friction.

[0005] In addition, the molded article of the liquid crystal polyester resin composition may undergo fibrillation, in which the surface is peeled off and fuzz is generated due to ultrasonic cleaning or friction with other members. When the molded article of the liquid crystal polyester resin composition is used as an electronic component in an electronic device, foreign matter such as dust and fibrils that fall off from the fibrillated portion may significantly reduce the performance of the electronic device.

[0006] For example, in the case of electronic components, particularly optical devices with lenses, if dust such as dirt and dust adheres to the lens, the optical properties may be significantly degraded. When assembling a camera module or operating the camera module, fibrillation may progress, and this is also the case when assembling a camera module of a mobile phone or operating the camera module. Specifically, when the camera autofocus function is exercised, dust may be generated from the surface of the component due to the sliding movement of the camera module components, and dust is also likely to be generated when the device is impacted or dropped. In recent years, miniaturization of peripheral electronic devices and each accessory used inside electronic devices has become essential, and as a result, there has been an emerging need to manufacture semiconductor and optical material components that are sensitive to dust using electronic component materials that generate less dust.

[0007] In this regard, Korean Patent Publication No. 10-2014-0007792 discloses a liquid crystal polyester resin composition capable of obtaining a molded product that is difficult to fibrillate. Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide a liquid crystalline polyester composition which reduces physical damage caused by internal and external friction and internal and external impact, improves mechanical properties such as tensile strength and impact strength and impact strength at weld lines, has dimensional stability due to low shrinkage, and minimizes the generation of fibrils and dust, and an electronic component material containing the same. [Means for solving the problem]

[0009] In one aspect of the present invention, the present invention can provide a liquid crystal polyester resin composition comprising a liquid crystal polyester resin; a polyphenylene sulfide resin; a carbon-based filler; and an inorganic filler, wherein the inorganic filler includes glass powder.

[0010] Preferably, the liquid crystal polyester resin is 55% by weight or more and 85% by weight or less; the polyphenylene sulfide resin is 1% by weight or more and less than 15% by weight; the carbon-based filler is 1% by weight or more and 5% by weight or less; and the inorganic filler is 5% by weight or more and 30% by weight or less, and a liquid crystal polyester resin composition can be provided.

[0011] Preferably, the carbon-based filler is at least one selected from the group consisting of carbon black, graphite, and carbon nanotubes, and a liquid crystal polyester resin composition can be provided.

[0012] Preferably, the inorganic filler further includes at least one selected from the group consisting of serpentine, montmorillonite, talc, micas (biotite, muscovite, phlogopite), chlorite, glass flakes, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, wollastonite, iron oxide, titanium oxide, zinc oxide, alumina, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, silicon carbide, silicon nitride, boron nitride, potassium titanate, and molybdenum disulfide (MoS 2 ) and a liquid crystal polyester resin composition can be provided.

[0013] Preferably, the weld line impact strength of a molded article produced from the liquid crystal polyester resin composition exceeds 20 J / m, and a liquid crystal polyester resin composition can be provided.

[0014] Preferably, the dent depth of a molded article produced from the liquid crystal polyester resin composition is less than 30 μm, and a liquid crystal polyester resin composition can be provided.

[0015] Preferably, the dent volume of the molded article produced from the liquid crystal polyester resin composition is 14,600,000 μm 3 or less, and a liquid crystal polyester resin composition can be provided.

[0016] In another aspect of the present invention, the present invention provides a liquid crystal polyester resin composition containing a liquid crystal polyester resin; a polyphenylene sulfide resin; and a filler, wherein when a tape is adhered to and then peeled off from a test piece produced from the liquid crystal polyester resin composition, the peeled area is less than 15% of the area of the test piece adhered to the tape.

[0017] In still another aspect of the present invention, the present invention can provide a molded article produced from the liquid crystal polyester resin composition.

[0018] In still another aspect of the present invention, the present invention can provide an electronic component material containing the liquid crystal polyester resin composition.

Advantages of the Invention

[0019] The liquid crystal polyester resin composition, molded article, and electronic component material containing the same according to the present invention have excellent mechanical properties in terms of tensile strength and impact strength, and also have improved weld line impact strength.

[0020] Also, the liquid crystal polyester resin composition according to the present invention has low shrinkage rates in the MD direction (resin flow direction) and TD direction (perpendicular direction to the resin flow), and thus has excellent dimensional stability.

[0021] Furthermore, the liquid crystal polyester resin composition, molded article, and electronic component material containing the same according to the present invention suppress the generation of dust and fibrils against internal and external friction and impact.

[0022] In addition, since the area peeled off by internal and external factors including stickiness, friction or vibration is small, damage to molded products and electronic components to be manufactured hereafter, and generation of dust and fibrils are significantly reduced.

[0023] Further, the liquid crystal polyester resin composition, molded product, and electronic component material including the same according to the present invention minimize the number of generated dust and fibrils, are excellent in weld line impact strength, and can be used as component materials for electronic products that are sensitive to internal and external impacts and internal and external friction. In particular, the present invention is applied to components for camera modules or components for camera modules of mobile phones, and can maintain or improve optical performance such as the number of pixels and image quality.

Mode for Carrying Out the Invention

[0024] Hereinafter, the present invention will be described.

[0025] All terms (including technical and scientific terms) used in this specification can be used in a meaning commonly understood by those having ordinary knowledge in the technical field to which the present invention pertains, unless otherwise defined. Also, each commonly used pre-defined term is not ideally or excessively interpreted unless clearly and specifically defined.

[0026] Also, throughout this specification, when one part includes one component, this means that, unless otherwise stated to the contrary, it can further include other components, rather than excluding other components.

[0027] As an embodiment of the present invention, the liquid crystal polyester resin composition can include a liquid crystal polyester resin, a polyphenylene sulfide resin, and a filler.

[0028] The liquid crystal polyester resin used in the present invention exhibits liquid crystallinity in a molten state, and is preferably melted at a temperature of 450°C or lower.

[0029] When considering its mechanical strength and injection moldability, the liquid crystal polyester resin can have a weight average molecular weight of about 10,000 to 300,000, preferably about 10,000 to 50,000. When the weight average molecular weight of the liquid crystal polyester resin is less than 10,000, the mechanical strength becomes poor and the molded product may be damaged. On the other hand, when the weight average molecular weight exceeds 300,000, injection molding may become difficult due to the decrease in the fluidity of the resin.

[0030] The liquid crystal polyester resin may be contained in an amount of about 55% by weight or more to about 85% by weight or less, preferably about 60% by weight or more to about 80% by weight or less, and more preferably about 65% by weight or more to about 80% by weight or less, based on the total weight of the liquid crystal polyester resin composition. When the liquid crystal polyester resin component is contained in an amount less than about 55% by weight, the fluidity of the resin composition decreases and micro injection molding may become difficult. When the liquid crystal polyester resin component is contained in an amount exceeding about 85% by weight, the fluidity of the resin composition becomes excessively large, and the strength and heat resistance of the molded products and electronic components manufactured therefrom may deteriorate.

[0031] As the liquid crystal polyester resin, one or more selected from the group consisting of liquid crystal polyester amide, liquid crystal polyester ether, liquid crystal polyester carbonate, and liquid crystal polyester imide may be used.

[0032] The liquid crystal polyester resin is preferably an all-aromatic liquid crystal polyester composed only of aromatic compounds as monomer substances. Typical examples of the all-aromatic liquid crystal polyester resin include resins produced by polymerizing (polycondensing) one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxyamines, and aromatic diamines; resins produced by polymerizing two or more aromatic hydroxycarboxylic acids; resins produced by polymerizing one or more compounds selected from the group consisting of aromatic dicarboxylic acids, aromatic diols, aromatic hydroxyamines, and aromatic diamines; and resins produced by polymerizing a polyester such as polyethylene terephthalate and an aromatic hydroxycarboxylic acid.

[0033] The liquid crystal polyester resin can be produced by polycondensing one or more aromatic monomers to form a prepolymer of the liquid crystal polyester, and then subjecting the formed prepolymer to solid-phase polycondensation. By-products generated during the solid-phase polycondensation reaction can be removed by purging with an inert gas or by vacuum.

[0034] The liquid crystal polyester resin that can be included in the resin composition of the present invention can be produced, for example, by polymerizing one or more monomers selected from the group including hydroxybenzoic acid (HBA), hydroxynaphthoic acid (HNA), biphenol (BP), terephthalic acid (TPA), and hydroxyacetanilide (APAP).

[0035] For example, a liquid crystal polyester resin can be polymerized containing 56 mol% to 66 mol% of hydroxybenzoic acid (HBA), 2 mol% to 8 mol% of hydroxynaphthoic acid (HNA), 9 mol% to 17 mol% of biphenol (BP), 11 mol% to 21 mol% of terephthalic acid (TPA), and 2 mol% to 8 mol% of hydroxyacetanilide (APAP). The liquid crystal polyester resin polymerized in such a molar% combination can ensure fluidity, and the resin composition containing this can improve mechanical properties such as the impact strength of the product while minimizing the generation of dust and fibrils.

[0036] Polyphenylene sulfide resin (hereinafter referred to as PPS resin) is included in the resin composition of the present invention and can serve as an impact reinforcing agent.

[0037] As the polyphenylene sulfide resin, one or more of a linear resin and a crosslinked resin can be used. Specifically, in consideration of thermal stability and workability, a polyphenylene sulfide resin having a melt index (MI, Melt Index) of 10 g / 10 min to 300 g / 10 min under the load conditions of 316 °C and 2.16 kg can be used.

[0038] The polyphenylene sulfide resin may be contained in an amount of 1% by weight or more and less than 15% by weight based on the total weight of the liquid crystal polyester resin composition. If the polyphenylene sulfide resin is not contained or contained in an amount less than 1% by weight, fibrillation may occur on the surface of the produced molded product or electronic component, which may cause product defects. Further, when the polyphenylene sulfide resin is contained in an amount of 15% by weight or more, the mechanical properties and dent (DENT) properties of the liquid crystal polyester resin composition may deteriorate.

[0039] The filler can include all carbon-based fillers and inorganic fillers.

[0040] As the carbon-based filler, one or more selected from the group consisting of carbon black, graphite, and carbon nanotubes can be used alone or in combination, and preferably, carbon black can be used. The carbon-based filler may be contained in an amount of about 1% by weight or more to about 5% by weight or less based on the total weight of the liquid crystal polyester resin composition. For example, carbon black can be used to ensure light-shielding properties, and may be contained in an amount of about 1% by weight or more to about 5% by weight or less based on the total weight of the liquid crystal polyester resin composition. When the amount of carbon black is less than about 1% by weight, the jet blackness of the liquid crystal polyester resin composition may decrease, making it difficult to sufficiently ensure light-shielding properties. When the amount of carbon black exceeds about 5% by weight, it may not be uniformly dispersed in the liquid crystal polyester resin composition and may agglomerate, which may cause deterioration of physical properties and increase the possibility of separation of the aggregates as dust.

[0041] The inorganic filler can be used to improve mechanical strength, heat resistance, and dent resistance due to impact. The blending of the inorganic filler with the liquid crystal polyester resin must be carried out so as not to damage mechanical properties such as the strength, rigidity, and hardness of the polyester resin, heat resistance, and electrical properties. Any non-fibrous filler can be used as the inorganic filler, and examples of non-fibrous fillers include plate-like fillers and granular fillers.

[0042] Examples of the plate-like filler include serpentine, montmorillonite, talc, micas such as mica (biotite, muscovite, phlogopite), chlorite, and glass flakes.

[0043] Examples of the granular filler include silicates such as silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, and wollastonite; metal oxides such as iron oxide, titanium oxide, zinc oxide, and alumina; metal carbonates such as calcium carbonate and magnesium carbonate; metal sulfates such as calcium sulfate and barium sulfate; molybdenum disulfide; silicon carbide; silicon nitride; boron nitride; and potassium titanate.

[0044] As the inorganic filler, one or more of plate-like fillers or one or more of granular fillers can be used, or one or more of each of the plate-like filler and the granular filler can be used. For example, mica as a plate-like filler and glass powder as a granular filler can be used in combination.

[0045] For example, mica is a plate-like filler having a plate-like form and can play a role in improving mechanical properties and heat resistance and imparting dimensional stability to the molded article.

[0046] Conventionally, in the case of glass powder, since it had amorphous characteristics, it was difficult to be used in the liquid crystal polyester resin composition. The liquid crystal polyester resin composition of the present invention can preferably contain glass powder, and by containing glass powder, the weld line impact strength can be improved, good quality can be obtained in the tape test, the generation of dust and fibrils can be suppressed, and the shrinkage rate measured in the MD direction and the TD direction is low, so that the dimensional stability can be improved.

[0047] The D50 of the glass powder may be from 2 μm to 40 μm.

[0048] The inorganic filler can be contained in an amount of 5% by weight or more and 35% by weight or less, preferably 5% by weight or more and less than 30% by weight, more preferably 5% by weight or more and 25% by weight or less, based on the total weight of the liquid crystal polyester resin composition.

[0049] The inorganic filler preferably contains glass powder, and two or more kinds can be used. In this case, the glass powder may be contained in an amount of about 1% by weight or more and less than about 18% by weight, preferably about 1% by weight or more and about 15% by weight or less. The inorganic filler other than the glass powder may be contained in an amount of 4% by weight or more and about 17% by weight or less, preferably 4% by weight or more and about 15% by weight or less.

[0050] The present invention can produce molded articles or electronic component materials from a liquid crystal polyester resin composition containing the above-described respective components. The molded articles or electronic component materials of the present invention have improved tensile strength, impact strength, and weld line impact strength. When the tape is adhered and then peeled off in a tape test, a good quality can be obtained in which the peeled area is less than 15% of the area of the test piece adhered to the tape. The generation of dust and fibrils is suppressed, and the shrinkage rates measured in the MD direction and TD direction are low, so that the dimensional stability is excellent. Specifically, the liquid crystal polyester resin composition of the present invention is applied to camera module parts of mobile phones or camera module parts of smart phones, and can contribute to maintaining and improving optical performances such as the number of pixels and image quality.

[0051] Hereinafter, the present invention will be specifically described through the following examples, and the present invention is not limited by these examples.

[0052] Production Example: Production of Liquid Crystal Polyester Resin

[0053] 1. 13,000 g (127.3 mol) of acetic anhydride was charged into a 200 L batch reactor, and while rotating the stirrer, 20,000 g (144.8 mol) of p-hydroxybenzoic acid (HBA), 2,200 g (11.8 mol) of hydroxynaphthoic acid (HNA), 5,400 g (29.3 mol) of biphenol (BP), 6,500 g (39.6 mol) of terephthalic acid (TPA), and 1,570 g (10.4 mol) of hydroxyacetanilide (APAP) monomers were charged. Then, 12,300 g (120.5 mol) of acetic anhydride was further charged, and these were mixed in the batch reactor.

[0054] 2. 2.7 g of potassium acetate catalyst and 10.8 g of magnesium acetate catalyst were added, and nitrogen was injected to make the internal space of the reactor in an inert state.

[0055] 3. The temperature of the reactor was raised to the temperature at which acetic anhydride inside the batch reactor refluxed over 1 hour, and the hydroxy groups of each monomer were acetylated at this temperature over 2 hours. Acetic acid produced in the acetylation reaction and unreacted acetic anhydride introduced in excess were removed. The temperature of the reactor was raised to 320 °C at a rate of 0.5 °C / min to produce a liquid crystal polyester prepolymer, and then it was cooled and solidified while discharging through the lower valve and primarily pulverized to obtain 32,000 g of the liquid crystal polyester prepolymer.

[0056] 4. The liquid crystal polyester prepolymer was secondarily pulverized using a fine pulverizer and then charged into a rotary heating device. While flowing nitrogen through the rotary heating device at a flow rate of 25 L / min, the temperature was raised to 200 °C over 2 hours, maintained at 200 °C for 2 hours, then raised to 285 °C at a rate of 0.2 °C / min, and then a polycondensation reaction was carried out while maintaining for 3 hours.

[0057] 5. After the polycondensation reaction, a liquid crystal polyester resin was finally obtained, and the melting point of the produced resin was 330 °C.

[0058] Example 1. Production of Liquid Crystal Polyester Resin Composition

[0059] 1. 75% by weight of the liquid crystal polyester resin (hereinafter referred to as LCP resin) produced in the production example, 3% by weight of carbon black, 8% by weight of mica, 10% by weight of glass powder, and 4% by weight of PPS resin were mixed. The components used are specifically shown in Table 1 below.

[0060] 2. It was melted and kneaded with a twin-screw extruder (L / D: 44, diameter: 30 mm). The barrel temperature of the extruder during melt-kneading was 340 °C, and after removing by-products through a vacuum, it was pelletized.

[0061] 3. The pelletized liquid crystal polyester resin composition was mixed for 30 minutes using a mixer (First Industry Equipment, JITD-50KW), and then dried at 150 °C for 2 hours using a hot air dryer (First Industry Equipment, JIB-100KW).

[0062]

Table 1

[0063] Production of Liquid Crystal Polyester Resin Compositions of Examples 2 to 5

[0064] The liquid crystal polyester resin compositions of Examples 2 to 5 were produced in the same manner as in Example 1 and produced according to the composition ratios shown in Table 2 below.

[0065] Production of Liquid Crystal Polyester Resin Compositions of Comparative Examples 1 to 4

[0066] The liquid crystal polyester resin compositions of Comparative Examples 1 to 4 were produced in the same manner as in Example 1 and produced according to the components and composition ratios described in Table 2 below.

[0067]

Table 2

[0068] Test Example 1. Tensile Strength of Liquid Crystal Polyester Resin Composition

[0069] For each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, test pieces with a width of 19 mm, a length of 130 mm, and a thickness of 3.2 mm were produced.

[0070] For each of the produced test pieces, the tensile strength was evaluated according to ASTM D638, and the results are shown in Table 3.

[0071] Test Example 2. Impact Strength of Liquid Crystal Polyester Resin Composition

[0072] For each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, test pieces with a width of 12.7 mm, a length of 64 mm, and a thickness of 3.2 mm were produced.

[0073] For each of the produced test pieces, the impact strength in the un-notched state was evaluated according to ASTM D256, and the results are shown in Table 3.

[0074] Test Example 3. Shrinkage Rate of Liquid Crystal Polyester Resin Composition

[0075] For each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, after producing test pieces having a width of 12.4 mm, a length of 80 mm, and a thickness of 3 mm through injection molding, they were left in a thermo-hygrostat chamber at a humidity of 50% and a temperature of 23°C for 1 day.

[0076] For the produced test pieces, the shrinkage rates in the MD direction and the TD direction were measured, and the results are shown in Table 3.

[0077] Test Example 4. Weld Line Impact Strength of Liquid Crystal Polyester Resin Composition

[0078] For each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, test pieces having a width of 12.4 mm, a length of 80 mm, and a thickness of 3 mm were produced. When producing the test pieces, the gates through which the resin composition was discharged were in both directions, and the resin was made to meet from both ends of the test piece to the center of the test piece so that a weld line was formed.

[0079] For each weld line portion of each of the produced test pieces, the weld line impact strength was measured by applying an impact using an IZOD impact tester in an un-notched state in accordance with ASTM D256, and the results are shown in Table 3.

[0080] Test Example 5. Fibril Evaluation of Liquid Crystal Polyester Resin Composition

[0081] 1. For each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, after injecting test pieces having a width of 12.4 mm, a length of 80 mm, and a thickness of 3 mm, they were conditioned in a thermo-hygrostat chamber at a humidity of 50% and a temperature of 23°C for at least 8 hours.

[0082] 2. For each test piece, after washing with a 1% alkaline aqueous solution for 8 minutes and with ultrapure water for 2 minutes using a 40 kHz ultrasonic cleaner at normal temperature, they were dried in a dryer at 80°C for 30 minutes.

[0083] 3. After blowing air at room temperature for 10 seconds, the presence or absence of fibrils was observed using an optical microscope (HIROX, XY-GB2).

[0084] 4. For the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, 100 test pieces were measured for each.

[0085] 5. After going through the above steps 1 to 4, the number of test pieces with fibrils generated among the 100 test pieces was shown in Table 3.

[0086] Test Example 6. Tape Test of Liquid Crystal Polyester Resin Composition

[0087] 1. For each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, test pieces with a width of 12.7 mm, a length of 130 mm, and a thickness of 3.2 mm were manufactured through injection molding.

[0088] 2. The surfaces of the respective test pieces were washed with ethanol and dried naturally for about 10 minutes.

[0089] 3. A tape (3M, Scotch Magic Tape 810) with an area of 12.7 cm 2 (width 12.7 mm, length 100 mm) was adhered to each test piece.

[0090] 4. Using a weight of about 3.7 kg, the portion where the tape was adhered was crimped 5 times and the crimped state was maintained for about 10 minutes.

[0091] 5. A weight of about 2.6 kg was attached to the tape adhered to each test piece, the weight was allowed to fall freely, and the adhered tape was separated from each test piece.

[0092] 6. The area of the black resin composition attached to the peeled tape was observed and calculated under a microscope, and the results were shown in Table 3.

[0093] Test Example 7. Dent Evaluation of Liquid Crystal Polyester Resin Composition

[0094] 1. Test pieces with a width of 12.4 mm, a length of 80 mm, and a thickness of 3 mm were manufactured by molding each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 using an injection molding machine.

[0095] 2. Each of the manufactured test pieces was attached to a dust reproduction tester, and a 15 g ball was continuously dropped 70 times from a height of 15 cm.

[0096] 3. After the continuous drop test, the dent depth (μm) and dent volume (μm 3 ) of each test piece were measured using a 3D tiling technique through an optical microscope (HIROX, XY-GB2).

[0097] 4. Processes 1 to 3 were regarded as one test, and this was performed a total of 4 times for each test piece. The averages of the dent depth (μm) and dent volume (μm 3 ) of each test piece are shown in Table 3.

[0098]

Table 3

[0099] The liquid crystal polyester resin compositions of Examples 1 to 5 have a tensile strength of 100 MPa or more and an impact strength of 80 kJ / m 2 or more, so it was confirmed that they have excellent mechanical properties. Further, it can be judged that the liquid crystal polyester resin compositions of Examples 1 to 5 have resistance to external and internal impacts and the possibility of suppressing dust generation, and have stability against external or internal impacts and friction. In comparison, in the case of Comparative Example 2, both the tensile strength and the impact strength were poor. This is considered to be because the composition of Comparative Example 2 contains an excessive amount of PPS resin, resulting in a decrease in compatibility with the LCP resin and both the tensile strength and the impact strength becoming poor.

[0100] The liquid crystal polyester resin compositions of Examples 1 to 5 exhibited a shrinkage rate in the MD direction of less than 0.08% and a shrinkage rate in the TD direction of less than 1.13%. On the other hand, in the case of Comparative Example 2, a shrinkage rate in the MD direction of about 0.08% was shown, and in the cases of Comparative Examples 1 and 4, a shrinkage rate in the TD direction of about 1.13% or more was shown. In the cases of Comparative Examples 1 and 2, although they do not contain PPS resin, it is considered that the above results appeared due to excessive content. In the case of Comparative Example 4, since it does not contain inorganic fillers other than glass powder and contains an excessive amount of glass powder, it is expected that the above results appeared.

[0101] Since the liquid crystal polyester resin compositions of Examples 1 to 5 have a weld line impact strength exceeding 20 J / m, they have excellent weld line impact strength, resistance to internal and external impacts, and the possibility of suppressing dust generation, and it has been confirmed that they have stability against external or internal impacts and friction. On the other hand, in the cases of Comparative Examples 1 and 3, since they have a poor weld line impact strength of 20 J / m or less, it has been confirmed that there is a possibility that the molded products are easily damaged by internal and external impacts. This is considered to be due to the fact that Comparative Example 1 does not contain PPS resin and Comparative Example 3 does not contain glass powder.

[0102] The area where the tape was peeled off at the portion where the tape was adhered to the test piece of the liquid crystal polyester resin composition of Example 4 was 1.69 cm 2 , which showed the largest peeled area among the examples, and the peeled area was less than about 15% of the area of the test piece adhered to the tape (12.7 cm 2 ). Also, the liquid crystal polyester resin compositions of Examples 1 to 3 and Example 5 were peeled off in an area of 0.79 cm 2 to 1.16 cm 2 , and were peeled off in the range of about 5% or more to less than 10% of the area of the test piece adhered to the tape. In comparison with this, in the case of Comparative Example 3, an area of about 10.48 cm 2 was peeled off, and about 83% of the area of the test piece adhered to the tape was peeled off. In the case of Comparative Example 3, since it does not contain glass powder, it is considered that peeling from the tape has occurred considerably.

[0103] In any of the liquid crystal polyester resin compositions of Examples 1 to 5, the number of test pieces in which fibrils occurred was 31 or less out of 100 test pieces. However, in the case of Comparative Example 1, fibrils occurred in 75 test pieces. In this case, Comparative Example 1 is considered to have fibrils occurring in a large number of test pieces because it is composed of only an LCP resin without containing a PPS resin.

[0104] The liquid crystal polyester resin compositions of Examples 1 to 5 were all confirmed to have a dent depth of less than about 30 μm and a dent volume of about 14,600,000 μm 3 as follows. On the other hand, the dent depth of Comparative Example 2 exceeded 30 μm, and the dent volumes of Comparative Examples 2 to 4 exceeded 14,600,000 μm 3 . In the case of Comparative Example 2, by containing an excessive amount of PPS resin, in the case of Comparative Example 3, by not containing glass powder, and in the case of Comparative Example 4, by not containing inorganic fillers other than glass powder and using an excessive amount of glass powder, it is considered to have shown poor dent characteristics.

[0105] The present invention is not limited to the above-described examples, and it is obvious to those having ordinary knowledge in the technical field to which the present invention pertains that various modifications or deformations can be made and implemented without departing from the technical gist of the present invention.

Claims

1. Liquid crystal polyester resin; Polyphenylene sulfide resin; Carbon-based fillers; and an inorganic filler; The liquid crystal polyester resin composition, wherein the inorganic filler includes glass powder.

2. The liquid crystal polyester resin is 55% by weight or more and 85% by weight or less; the polyphenylene sulfide resin is 1% by weight or more and less than 15% by weight; the carbon-based filler is from 1% to 5% by weight; and The liquid crystal polyester resin composition according to claim 1 , wherein the inorganic filler is contained in an amount of 5% by weight or more and 30% by weight or less.

3. The liquid crystal polyester resin composition according to claim 1, wherein the carbon-based filler is at least one selected from the group consisting of carbon black, graphite, and carbon nanotubes.

4. The inorganic filler may be selected from the group consisting of serpentine, montmorillonite, talc, micas, chlorite, glass flakes, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, wollastonite, iron oxide, titanium oxide, zinc oxide, alumina, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, silicon carbide, silicon nitride, boron nitride, potassium titanate, and molybdenum disulfide (MoS ２ The liquid crystal polyester resin composition according to claim 1, further comprising at least one selected from the group consisting of:

5. The liquid crystal polyester resin composition according to claim 1, wherein a molded article produced from the liquid crystal polyester resin composition has a weld line impact strength of more than 20 J / m.

6. The liquid crystal polyester resin composition according to claim 1, wherein a molded article produced from the liquid crystal polyester resin composition has a dent depth of less than 30 μm.

7. The dent volume of a molded product produced from the liquid crystal polyester resin composition is 14,600,000 μm ３ The liquid crystal polyester resin composition according to claim 1, wherein:

8. A liquid crystal polyester resin composition comprising a liquid crystal polyester resin; a polyphenylene sulfide resin; and a filler, A liquid crystal polyester resin composition, wherein when a tape is adhered to a test piece made from the liquid crystal polyester resin composition and then peeled off, the peeled area is less than 15% of the area of ​​the test piece adhered to the tape.

9. A molded article produced from the liquid crystal polyester resin composition according to claim 1.

10. A material for electronic parts, comprising the liquid crystal polyester resin composition according to claim 1.

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