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

Abstract

Disclosed are a liquid crystal polyester resin composition, and a molded article and an electronic component material comprising the same. The liquid crystal polyester resin composition has good mechanical properties, good weld line impact strength, high dimensional stability, and dust generation resistance.

Description

Technical Field

[0001] Embodiments of the present invention relate to a liquid crystal polyester resin composition, and a molded product and an electronic component material comprising the liquid crystal polyester resin composition, and more specifically, to a liquid crystal polyester resin composition having good mechanical properties, good weld line impact strength, high dimensional stability and resistance to dust generation, and a molded product and an electronic component material comprising the liquid crystal polyester resin composition. Background Art

[0002] Liquid crystal polyester resin refers to a molten polyester resin in which the molecular chains in the polymer are aligned in a highly ordered, parallel manner. This orderly arrangement of molecules is often referred to as the liquid crystal phase or nematic phase of liquid crystal. These polymer molecules are usually long, thin and flat, so that the long chains along the molecules have excellent mechanical strength, electrical properties and heat resistance.

[0003] Liquid crystal polyester resin-based compositions offer excellent heat resistance and high fluidity, making them ideal for a wide range of electrical / electronic applications. As small portable devices such as laptop computers become thinner, lighter, and more powerful, demand for liquid crystal polyester resin compositions with good moldability is increasing.

[0004] However, the liquid crystal polyester resin composition is characterized in that the molten polymer does not lose its crystal structure during flow. Therefore, during the molding process, when the resin composition is injection molded into a product with a complex shape, a weld line is formed at the interface where the resin flow intersects. These weld lines are very fragile, making the molded product susceptible to damage caused by internal / external impact or friction.

[0005] In addition, molded articles made from liquid crystal polyester resin compositions are prone to fibrillation, a phenomenon in which the surface of a molded article peels off due to ultrasonic cleaning or friction with other components to form fibrils. When these molded articles are used as electronic components of electronic products, foreign matter (e.g., dust or fibrils) falling off from the fibrillated area can greatly impair the performance of the electronic products.

[0006] For example, in the case of electronic components, especially optical devices with lenses, particulate contaminants such as dirt and dust adhering to the lenses can seriously impair the optical properties of the optical devices. Fibrillation can occur during assembly or operation of camera modules. The same applies to camera modules of mobile phones. In particular, when the autofocus function of the camera is activated, dust particles can be generated from the surface of the components of the camera module due to the sliding of the components. Dust particles can also be generated when the device is impacted or dropped. With the recent trend towards miniaturization of peripheral devices and accessories used in electronic products, there is an increasing demand for electronic component materials that resist dust generation and can therefore be used as materials for dust-sensitive semiconductors and optical components.

[0007] In this regard, Korean Patent Laid-Open Publication No. 10-2014-0007792 discloses a liquid crystal polyester resin composition designed to obtain a molded product having high resistance to fibrillation. Summary of the invention

[0008] Embodiments of the present invention provide a liquid crystal polyester composition and an electronic component material comprising the liquid crystal polyester composition, wherein the liquid crystal polyester composition resists physical damage caused by internal / external friction and internal / external impact, has improved mechanical properties in terms of tensile strength, impact strength and weld line impact strength, provides high dimensional stability due to its low shrinkage, and minimizes dust generation and fibril formation.

[0009] According to one aspect of the present invention, a liquid crystal polyester resin composition is provided, comprising: a liquid crystal polyester resin; a polyphenylene sulfide resin; a carbon-based filler; and an inorganic filler, wherein the inorganic filler comprises glass powder.

[0010] Preferably, the liquid crystal polyester resin composition comprises: 55 wt % to 85 wt % of a liquid crystal polyester resin; greater than or equal to 1 wt % and less than 15 wt % of a polyphenylene sulfide resin; 1 wt % to 5 wt % of a carbon-based filler; and 5 wt % to 30 wt % of an inorganic filler.

[0011] Preferably, the carbon-based filler includes at least one selected from the group consisting of carbon black, graphite, and carbon nanotubes.

[0012] Preferably, the inorganic filler comprises at least one selected from the group consisting of serpentine, montmorillonite, talc, mica, chlorite, glass flakes, silicon dioxide, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, clay, siliceous earth, wollastonite, iron oxide, titanium oxide, zinc oxide, aluminum oxide, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, silicon carbide, silicon nitride, boron nitride, potassium titanate and molybdenum disulfide (MoS 2 ).

[0013] Preferably, a molded article made from the liquid crystal polyester resin composition has a weld line impact strength greater than 20 J / m.

[0014] Preferably, a molded article made from the liquid crystal polyester resin composition has a concave depth of less than 30 μm.

[0015] Preferably, the molded article made from the liquid crystal polyester resin composition has a diameter of 14,600,000 μm. 3 or less than 14,600,000 μm 3 The volume of the depression.

[0016] According to another aspect of the present invention, there is provided a liquid crystal polyester resin composition, comprising a liquid crystal polyester resin, a polyphenylene sulfide resin and a filler, wherein, when the tape is peeled off from a sample after being attached to the sample prepared from the liquid crystal polyester resin composition, the peeled area of ​​the sample is less than 15% of the total area of ​​a region of the sample to which the tape is attached.

[0017] According to another aspect of the present invention, there is provided a molded product, which is made from the above liquid crystal polyester resin composition.

[0018] According to another aspect of the present invention, an electronic component material is provided, wherein the electronic component material comprises the liquid crystal polyester resin composition.

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

[0020] Furthermore, the liquid crystal polyester resin composition according to the present invention has high dimensional stability because it has low shrinkage in both MD (resin flow direction) and TD (direction perpendicular to the resin flow direction).

[0021] Furthermore, the liquid crystal polyester resin composition according to the present invention and the molded article and electronic component material including the same resist dust generation and fibril formation caused by internal / external friction and impact.

[0022] In addition, the liquid crystal polyester resin composition according to the present invention resists peeling caused by internal / external factors (including stickiness, friction, vibration, etc.), thereby significantly reducing damage to molded products or electronic components made from the liquid crystal polyester resin composition and the generation of dust and fibrils.

[0023] In addition, the liquid crystal polyester resin composition according to the present invention and the molded article and electronic component material including the liquid crystal polyester resin composition can be used as materials for various components of electronic products that are sensitive to internal / external impact and internal / external friction because of its resistance to dust generation / fibrillation and good weld line impact strength. Specifically, when used as a material for a component of a camera module, especially a component of a camera module of a mobile phone, the liquid crystal polyester resin composition according to the present invention can help maintain or improve optical properties such as pixel count and image quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] none DETAILED DESCRIPTION

[0025] Hereinafter, exemplary embodiments of the present invention will be described.

[0026] Unless otherwise specified, the technical and scientific terms used herein have the meanings commonly understood by those skilled in the art. It should also be understood that terms (e.g., terms defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the specification and the relevant art, and should not be interpreted as an idealized or overly formal meaning unless explicitly defined herein.

[0027] Furthermore, it should be understood that when the terms “includes / comprises / including and / or comprising” are used in this specification, it specifies the presence of stated elements but does not exclude the presence or addition of one or more other elements.

[0028] According to one aspect of the present invention, a liquid crystal polyester resin composition may include a liquid crystal polyester resin, a polyphenylene sulfide resin, and a filler.

[0029] The liquid crystal polyester resin exhibits liquid crystallinity when melted, and preferably melts at a temperature of 450°C or lower.

[0030] Considering the mechanical strength and injection moldability of the liquid crystal polyester resin, the liquid crystal polyester resin may have a weight average molecular weight of about 10,000 g / mol to 300,000 g / mol, preferably about 10,000 g / mol to 50,000 g / mol. If the weight average molecular weight of the liquid crystal polyester resin is less than 10,000 g / mol, the liquid crystal polyester resin composition may have poor mechanical strength, so that a molded product made from the liquid crystal polyester resin composition is easily damaged, and if the weight average molecular weight of the liquid crystal polyester resin exceeds 300,000 g / mol, the liquid crystal polyester resin composition may have poor fluidity and thus poor injection moldability.

[0031] The liquid crystal polyester resin may be present in an amount of about 55% to about 85% by weight, preferably about 60% to about 80% by weight, and more preferably about 65% to about 80% by weight, based on the total weight of the liquid crystal polyester resin composition. If the content of the liquid crystal polyester resin is less than about 55% by weight, the resin composition may have poor fluidity, making microinjection molding of the resin composition difficult. If the content of the liquid crystal polyester resin component exceeds about 85% by weight, the resin composition may have excessive fluidity, thereby deteriorating the strength and heat resistance of a molded product or electronic component made from the resin composition.

[0032] The liquid crystal polyester resin may include at least one selected from the group consisting of liquid crystal polyester amide, liquid crystal polyester ether, liquid crystal polyester carbonate, and liquid crystal polyester imide.

[0033] Preferably, the liquid crystal polyester resin includes a fully aromatic liquid crystal polyester prepared using only aromatic compounds as monomer materials. Typical examples of fully aromatic liquid crystal polyesters include: resins prepared by polymerization (polycondensation) of one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxylamines, and aromatic diamines; resins prepared by polymerization of two or more aromatic hydroxycarboxylic acids; resins prepared by polymerization of one or more compounds selected from the group consisting of aromatic dicarboxylic acids, aromatic diols, aromatic hydroxylamines, and aromatic diamines; and resins prepared by polymerization of polyesters (e.g., polyethylene terephthalate) and aromatic hydroxycarboxylic acids.

[0034] The liquid crystal polyester resin can be prepared by forming a liquid crystal polyester prepolymer by polycondensation of one or more aromatic monomers, followed by solid phase polycondensation of the prepolymer. The removal of byproducts of the solid phase polycondensation process can be achieved by purging or evacuating with an inert gas.

[0035] The liquid crystal polyester resin used in the resin composition according to the present invention can be prepared by polymerization of one or more monomers selected from the group consisting of, for example, hydroxybenzoic acid (HBA), hydroxynaphthoic acid (HNA), biphenol (BP), terephthalic acid (TPA) and hydroxyacetanilide (APAP).

[0036] For example, the liquid crystal polyester resin can be prepared by polymerization of a monomer mixture including 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). Within these content ranges of the above monomers, the liquid crystal polyester resin can ensure fluidity, and the resin composition including the liquid crystal polyester resin can improve the mechanical properties (e.g., impact strength) of the final product while minimizing the generation of dust and fibrils.

[0037] The polyphenylene sulfide resin (hereinafter referred to as "PPS resin") used in the resin composition according to the present invention may be used as an impact modifier.

[0038] The polyphenylene sulfide resin may include at least one of a linear polyphenylene sulfide resin or a cross-linked polyphenylene sulfide resin. Specifically, the polyphenylene sulfide resin may include a polyphenylene sulfide resin having a melt index (MI) of 10 g / 10 min to 300 g / 10 min at a temperature of 316° C. and a load of 2.16 kg in consideration of thermal stability and processability.

[0039] The polyphenylene sulfide resin may be present in an amount greater than or equal to 1% by weight and less than 15% by weight based on the total weight of the liquid crystal polyester resin composition. If the content of the polyphenylene sulfide resin is less than 1% by weight, fibrils may be formed on the surface of a molded article or electronic component made from the resin composition, thereby causing product failure. In addition, if the content of the polyphenylene sulfide resin exceeds 15% by weight, the liquid crystal polyester resin composition may have poor mechanical properties and poor dent resistance.

[0040] The filler may include both a carbon-based filler and an inorganic filler.

[0041] The carbon-based filler may include at least one selected from the group consisting of carbon black, graphite and carbon nanotubes. These carbon-based fillers may be used alone or in combination. Preferably, the carbon-based filler includes carbon black. The carbon-based filler may be present in an amount of about 1% by weight to about 5% by weight based on the total weight of the liquid crystal polyester resin composition. For example, carbon black may be used as a carbon-based filler to ensure light blocking properties. Carbon black may be present in an amount of about 1% by weight to about 5% by weight based on the total weight of the liquid crystal polyester resin composition. If the content of carbon black is less than about 1% by weight, the blackness of the liquid crystal polyester resin composition may be reduced, making it difficult to ensure sufficient light blocking properties. If the content of carbon black exceeds about 5% by weight, the carbon black particles may agglomerate together instead of being uniformly dispersed in the liquid crystal polyester resin composition, thereby causing the physical properties of the resin composition to deteriorate and increasing the possibility of the agglomerates falling off as dust.

[0042] Inorganic fillers can be used to improve the mechanical strength, heat resistance and resistance to impact-induced dents of the resin composition. The mixing of the inorganic filler with the liquid crystal polyester resin needs to be carried out without damaging the mechanical properties (strength, stiffness, hardness, etc.), heat resistance and electrical properties of the polyester resin. The inorganic filler may include any non-fibrous filler, such as a flaky filler, a particulate filler, etc.

[0043] The lamellar fillers may include serpentine, montmorillonite, talc, mica (biotite, muscovite, phlogopite, etc.), chlorite, glass flakes, and the like.

[0044] Particulate fillers may include: silicates, such as silicon dioxide, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, clay, siliceous earth and wollastonite; metal oxides, such as iron oxide, titanium oxide, zinc oxide and aluminum oxide; 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; potassium titanate; and the like.

[0045] The inorganic filler may include at least one selected from the above-mentioned flaky fillers, at least one selected from the above-mentioned particulate fillers, or a combination thereof. For example, the inorganic filler may include a combination of mica as a flaky filler and glass powder as a particulate filler.

[0046] As a flaky filler, mica can be used to improve the heat resistance and mechanical properties of the resin composition and to impart dimensional stability to a molded article made from the resin composition.

[0047] Generally, glass powder is difficult to be used in a liquid crystal polyester resin composition due to its amorphous nature. Advantageously, the liquid crystal polyester resin composition according to the present invention contains glass powder. By using glass powder, the liquid crystal polyester resin composition can provide improved weld line impact strength, obtain positive results in the tape test, inhibit dust generation and fibril formation, and provide improved dimensional stability due to its low shrinkage in both the MD and TD directions.

[0048] The glass powder may have an average particle diameter (D 50 ) of 2 μm to 40 μm.

[0049] Based on the total weight of the liquid crystal polyester resin composition, the inorganic filler may be present in an amount of 5% by weight to 35% by weight, preferably greater than or equal to 5% by weight and less than 30% by weight, more preferably 5% by weight to 25% by weight.

[0050] Preferably, the inorganic filler contains two or more types of inorganic fillers including glass powder. Here, based on the total weight of the liquid crystal polyester resin composition, the glass powder may be present in an amount of greater than or equal to about 1% by weight and less than about 18% by weight, preferably about 1% by weight to about 15% by weight. Based on the total weight of the liquid crystal polyester resin composition, the inorganic filler other than the glass powder may be present in an amount of about 4% by weight to about 17% by weight, preferably about 4% by weight to about 15% by weight.

[0051] According to another aspect of the present invention, a molded article or an electronic component material can be manufactured from the liquid crystal polyester resin composition containing the foregoing components. The molded article or the electronic component material according to the present invention has good properties in terms of tensile strength, impact strength, and weld line impact strength, can obtain positive results in the tape test (when the tape is peeled off from the sample after attaching the tape to the sample prepared from the resin composition, the peeled area of the sample is less than 15% of the total area of the region of the sample to which the tape is attached), has high resistance to dust generation and fibril formation, and has good dimensional stability due to its low shrinkage in both the MD and TD directions. Specifically, when used as a material for components of a camera module of a mobile device such as a smartphone, the liquid crystal polyester resin composition according to the present invention can help maintain or improve the optical performance of the camera module, such as the number of pixels and image quality.

[0052] Next, the present invention will be described in more detail with reference to some examples. However, it should be noted that these examples are provided only for illustration and should not be construed as a limitation of the present invention in any way.

[0053] Preparation Example: Preparation of Liquid Crystal Polyester Resin

[0054] 1. After 13,000 g (127.3 mol) of acetic anhydride was placed in a 200 L batch reactor, 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, 6,500 g (39.6 mol) of terephthalic acid (TPA) and 1,570 g (10.4 mol) of hydroxyacetanilide (APAP) as monomers were added to the reactor while rotating a stirrer, followed by further adding 12,300 g (120.5 mol) of acetic anhydride, and then the aforementioned components were mixed in the batch reactor.

[0055] 2. 2.7 g of potassium acetate and 10.8 g of magnesium acetate as catalysts were added to the reactor, followed by injection of nitrogen gas to create an inert atmosphere inside the reactor.

[0056] 3. After heating the reactor to a temperature that allows acetic anhydride to reflux in the batch reactor over a period of 1 hour, the hydroxyl groups of the monomers were acetylated at this temperature for 2 hours, and then the excess unreacted acetic anhydride and the acetic acid generated by the acetylation of the hydroxyl groups were removed. Thereafter, the reactor was heated to 320° C. at a heating rate of 0.5° C. / min to prepare a liquid crystal polyester prepolymer, which was then cooled and solidified while being discharged through a lower valve of the reactor, and then primarily pulverized to obtain 32,000 g of the liquid crystal polyester prepolymer.

[0057] 4. The liquid crystal polyester prepolymer was secondarily pulverized using a fine grinder and then introduced into a rotary heating device. Thereafter, the polycondensation of the liquid crystal polyester prepolymer was performed by heating the prepolymer to 200°C for 2 hours while injecting nitrogen into the rotary heating device at a flow rate of 25 L / min, maintaining the temperature of the prepolymer at 200°C for 2 hours, heating the prepolymer to 285°C at a heating rate of 0.2°C / min, and maintaining the temperature of the heating device at 285°C for 3 hours.

[0058] 5. After the polycondensation of the prepolymer is completed, a liquid crystal polyester resin is finally obtained. The obtained liquid crystal polyester resin has a melting point of 330°C.

[0059] Example 1: Preparation of liquid crystal polyester resin composition

[0060] 1. 76.7 wt % of the liquid crystal polyester resin prepared in Preparation Example (hereinafter referred to as "LCP resin") was mixed with 3 wt % of carbon black, 8 wt % of mica, 10 wt % of glass powder and 4 wt % of PPS resin. Details of the aforementioned components are shown in Table 1.

[0061] 2. The obtained mixture was melt-kneaded at a barrel temperature of 340° C. in a twin-screw extruder (L / D: 44, diameter: 30 mm), by-products were subsequently removed by evacuation, and the melt-kneaded mixture was then pelletized to prepare a liquid crystal polyester resin composition in pellet form.

[0062] 3. The prepared pellets were mixed in a mixer (JITD-50KW, JEIL Machinery Co., Ltd.) for 30 minutes, and then dried in a hot air dryer (JIB-100KW, JEIL Machinery Co., Ltd.) at 150° C. for 2 hours.

[0063] Table 1

[0064]

[0065] Examples 2 to 5: Preparation of Liquid Crystal Polyester Resin Compositions

[0066] A liquid crystal polyester resin composition was prepared in the same manner as in Example 1, except that the content of each component was changed as listed in Table 2.

[0067] Comparative Examples 1 to 4: Preparation of Liquid Crystal Polyester Resin Compositions

[0068] A liquid crystal polyester resin composition was prepared in the same manner as in Example 1, except that the content of each component was changed as listed in Table 3.

[0069] Table 2

[0070] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 LCP resin 75 71 67 71 71 79 64 71 71 Carbon Black 3 3 3 3 3 3 3 3 3 Mica 8 8 8 13 5 8 8 18 0 Glass powder 10 10 10 5 13 10 10 0 18 PPS resin 4 8 12 8 8 0 15 8 8

[0071] Experimental Example 1: Tensile Strength of Liquid Crystal Polyester Resin Composition

[0072] From each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, a sample having a size of 19 mm×130 mm×3.2 mm (width×length×thickness) was prepared.

[0073] The tensile strength of the prepared samples was evaluated according to American Society for Testing Material (ASTM) D638. The results are shown in Table 3.

[0074] Experimental Example 2: Impact Strength of Liquid Crystal Polyester Resin Composition

[0075] From each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, a sample having a size of 12.7 mm×64 mm×3.2 mm (width×length×thickness) was prepared.

[0076] The unnotched impact strength of the prepared samples was evaluated according to ASTM D256. The results are shown in Table 3.

[0077] Experimental Example 3: Shrinkage of Liquid Crystal Polyester Resin Composition

[0078] A sample having a size of 12.4 mm×80 mm×3 mm (width×length×thickness) was prepared from each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 by injection molding, and then placed in a constant temperature / humidity chamber at 23° C. and 50% RH for 1 day.

[0079] The shrinkage of the samples was measured in both MD and TD. The results are shown in Table 3.

[0080] Experimental Example 4: Weld Line Impact Strength of Liquid Crystal Polyester Resin Composition

[0081] A sample having a size of 12.4 mm×80 mm×3 mm (width×length×thickness) was prepared from each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4. When preparing the sample, gates enabling the resin composition to be injected into the mold cavity were positioned on both sides of the mold cavity so that a weld line was formed at the center of the sample where the resin flows from the two gates met.

[0082] The weld line impact strength in an unnotched state was measured by applying an impact to the weld line region of the prepared sample using an Izod impact tester according to ASTM D256.

[0083] Experimental Example 5: Resistance of Liquid Crystal Polyester Resin Composition to Fibril Formation

[0084] 1. A sample having a size of 12.4 mm×80 mm×3 mm (width×length×thickness) was prepared from each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 by injection molding, and then the sample was conditioned in a constant temperature / humidity chamber at 23° C. and 50% RH for at least 8 hours.

[0085] 2. The sample was cleaned in an alkaline aqueous solution (1%) at room temperature for 8 minutes and in ultrapure water for 2 minutes using a 40 kHz ultrasonic cleaner, and then dried in a dryer at 80° C. for 30 minutes.

[0086] 3. The samples were aerated for 10 seconds at room temperature and then observed under an optical microscope (XY-GB2, Haoshi Co., Ltd.) for the presence of fibrils.

[0087] 4. For each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, 100 samples were tested.

[0088] 5. After the completion of processes 1 to 4, the number of samples showing fibril formation was counted. The results are shown in Table 3.

[0089] Experimental Example 6: Tape Test of Liquid Crystal Polyester Resin Composition

[0090] 1. A sample having a size of 12.7 mm×130 mm×3.2 mm (width×length×thickness) was prepared from each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 by injection molding.

[0091] 2. The surface of the sample was washed with ethanol and then dried naturally for about 10 minutes.

[0092] 3. The area is 12.7cm 2 A tape of (12.7 mm x 100 mm (width x length)) (Scotch Magic Tape 810, 3M Company) was attached to the sample.

[0093] 4. The taped area of ​​the sample was compressed five times using a 3.7 kg weight, and then the area remained compressed for about 10 minutes.

[0094] 5. Attach a 2.6 kg weight to the tape on the sample, and then let the weight fall freely to remove the tape from the sample.

[0095] 6. The area of ​​the black resin composition on the removed tape was measured by microscopic observation. The results are shown in Table 3.

[0096] Experimental Example 7: Depression resistance of liquid crystal polyester resin composition

[0097] 1. A sample having a size of 12.4 mm×80 mm×3 mm (width×length×thickness) was prepared from each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 by injection molding.

[0098] 2. The prepared sample was mounted on a dust simulator, and then a 15 g ball was dropped on the sample from a height of 10 cm 70 times continuously.

[0099] 3. After the continuous drop test, the depression depth (μm) and depression volume (μm) of the samples were measured using an optical microscope (XY-GB2, HIROX Co., Ltd.) using 3D tiling technique. 3 ).

[0100] 4. Processes 1 to 3 constitute a single test. Six single tests are performed on each sample, and then the average pit depth (μm) and average pit volume (μm) are calculated. 3 The results are shown in Table 3.

[0101] Table 3

[0102]

[0103]

[0104] The liquid crystal polyester resin compositions of Examples 1 to 5 have a tensile strength of 100 MPa or more and a thermal conductivity of 80 kJ / m 2 or greater than 80kJ / m 2 The impact strength of the liquid crystal polyester resin composition of Examples 1 to 5 was excellent, thereby exhibiting good mechanical properties. In addition, these results show that the liquid crystal polyester resin compositions of Examples 1 to 5 have resistance to internal / external impact, resistance to dust generation, and stability to internal / external impact or friction. In contrast, the liquid crystal polyester resin composition of Comparative Example 2 exhibited poor properties in terms of both tensile strength and impact strength, which can be attributed to the poor compatibility between the LCP resin and the PPS resin due to the excessive presence of the PPS resin.

[0105] The liquid crystal polyester resin compositions of Examples 1 to 5 exhibited a shrinkage of less than 0.08% in MD and a shrinkage of less than 1.13% in TD. In contrast, the liquid crystal polyester resin composition of Comparative Example 2 exhibited a shrinkage of about 0.08% in MD, and the liquid crystal polyester resin compositions of Comparative Examples 1 and 4 exhibited a shrinkage of about 1.13% or more in TD. The high shrinkage of the resin compositions of Comparative Examples 1 and 2 can be attributed to the absence or excessive presence of PPS resin, while the high shrinkage of the resin composition of Comparative Example 4 can be attributed to the excessive presence of glass powder and the absence of other inorganic fillers.

[0106] The liquid crystal polyester resin compositions of Examples 1 to 5 exhibited good weld line impact strengths exceeding 20 J / m, thereby demonstrating resistance to internal / external impact, resistance to dust generation, and stability to internal / external impact or friction. In contrast, the liquid crystal polyester resin compositions of Comparative Examples 1 and 3 exhibited poor weld line impact strengths of 20 J / m or less, indicating that the molded articles made of the liquid crystal polyester resin compositions were more susceptible to damage due to internal / external impacts. The poor weld line impact strength of the resin composition of Comparative Example 1 can be attributed to the absence of PPS resin, while the poor weld line impact strength of the resin composition of Comparative Example 3 can be attributed to the absence of glass powder.

[0107] In the tape test, the liquid crystal polyester resin composition of Example 4 showed a 1.69 cm 2 The peeling area is the largest in each example, accounting for the total area of ​​the sample with the tape attached (12.7 cm 2 ) is less than about 15%. In addition, in the tape test, the liquid crystal polyester resin compositions of Examples 1 to 3 and 5 exhibited a 0.79 cm 2 To 1.16cm 2 The peeling area accounts for 5% to 10% of the total area of ​​the area where the tape is attached to the sample. In contrast, the liquid crystal polyester resin composition of Comparative Example 3 exhibits a peeling area of ​​about 10.48 cm 2 The peeling area of ​​1.34 mm / s was about 83% of the total area of ​​the area on which the tape was attached to the sample. The poor peeling resistance of the resin composition of Comparative Example 3 can be attributed to the absence of the glass frit.

[0108] The liquid crystal polyester resin compositions of Examples 1 to 5 exhibited high resistance to fibril formation, with 31 or less samples exhibiting fibril formation out of 100. In contrast, the liquid crystal polyester resin composition of Comparative Example 1 exhibited poor resistance to fibril formation, with 75 samples exhibiting fibril formation out of 100. The poor resistance of the resin composition of Comparative Example 1 to fibril formation may be attributed to the fact that the resin composition consists only of an LCP resin and does not contain a PPS resin.

[0109] The liquid crystal polyester resin compositions of Examples 1 to 5 exhibited a concave depth of less than about 30 μm and a depth of about 14,600,000 μm. 3 or less than 14,600,000 μm 3 In contrast, the liquid crystal polyester resin composition of Comparative Example 2 exhibited a depression depth greater than 30 μm, and the liquid crystal polyester resin compositions of Comparative Examples 2 to 4 exhibited a depression depth greater than 14,600,000 μm. 3The poor dent resistance of the resin composition of Comparative Example 2 may be attributed to the excessive presence of PPS resin, the poor dent resistance of the resin composition of Comparative Example 3 may be attributed to the absence of glass powder, and the poor dent resistance of Comparative Example 4 may be attributed to the excessive presence of glass powder and the absence of other inorganic fillers.

[0110] Although some embodiments have been described herein, it should be understood that these embodiments are provided for illustration only and should not be construed as limiting the present invention in any way, and that various modifications, changes, variations, and equivalent embodiments may be made by those skilled in the art without departing from the spirit and scope of the present invention.

[0111] [Explanation of Symbols]

[0112] none

Claims

1. A liquid crystal polyester resin composition, comprising: Liquid crystal polyester resin; Polyphenylene sulfide resin; Carbon-based fillers; and Inorganic fillers, The inorganic filler comprises glass powder.

2. The liquid crystal polyester resin composition according to claim 1, comprising: 55 wt % to 85 wt % of the liquid crystal polyester resin; greater than or equal to 1 wt % and less than 15 wt % of the polyphenylene sulfide resin; 1 wt % to 5 wt % of the carbon-based filler; as well as 5 wt % to 30 wt % of the inorganic filler. 3 . The liquid crystal polyester resin composition according to claim 1 , wherein the carbon-based filler comprises at least one selected from the group consisting of carbon black, graphite, and carbon nanotubes.

4. The liquid crystal polyester resin composition according to claim 1, wherein the inorganic filler comprises at least one selected from the group consisting of serpentine, montmorillonite, talc, mica, chlorite, glass flakes, silicon dioxide, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, clay, siliceous earth, wollastonite, iron oxide, titanium oxide, zinc oxide, aluminum oxide, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, silicon carbide, silicon nitride, boron nitride, potassium titanate and molybdenum disulfide (MoS2). 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 greater than 20 J / m. 6 . The liquid crystal polyester resin composition according to claim 1 , wherein a molded article made from the liquid crystal polyester resin composition has a concave depth of less than 30 μm.

7. The liquid crystal polyester resin composition according to claim 1, wherein a molded article made from the liquid crystal polyester resin composition has a diameter of 14,600,000 μm. 3 or less than 14,600,000 μm 3 The volume of the depression.

8. A liquid crystal polyester resin composition comprising a liquid crystal polyester resin, a polyphenylene sulfide resin and a filler, in, When the tape is peeled off from the sample prepared from the liquid crystal polyester resin composition after being attached to the sample, the peeled area of ​​the sample is less than 15% of the total area of ​​the region of the sample to which the tape is attached.

9. A molded product produced from the liquid crystal polyester resin composition according to claim 1. 10 . An electronic component material comprising the liquid crystal polyester resin composition according to claim 1 .

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