Liquid crystal polyester resin composition, molded article, and electronic component material containing 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 impact strength and weld line impact strength, 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 fibril inhibitor, an esterification inhibitor, and fillers.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to liquid crystal polyester resin compositions, molded articles, and electronic component materials containing the same, and more specifically, to liquid crystal polyester resin compositions, molded articles, and electronic component materials containing the same that exhibit excellent weld line impact strength and low dust characteristics. [Background technology]

[0002] Liquid crystal polyester resin refers to a molten polyester resin in which the molecular chains within the polymer are arranged regularly and parallel to each other in a molten state. This state of each molecule in which it is arranged is usually called the liquid crystal state or the nematic phase of a liquid crystal material. The molecules in such a polymer are generally thin, long, and flat, and exhibit very high mechanical strength, electrical properties, and heat resistance along the long chains of the molecules.

[0003] Resin compositions containing liquid crystal polyester resin have high heat resistance and high fluidity properties and are widely used as materials for various electrical / electronic products. Furthermore, as small portable electronic products such as notebook computers are becoming thinner and lighter while maintaining excellent performance, the demand for liquid crystal polyester resin compositions with excellent moldability is increasing.

[0004] However, liquid crystal polyester resin compositions have the characteristic that the molten polymer does not lose its crystalline structure even while flowing. When injected into molded products with complex structures, weld lines are formed at the boundaries where the resins meet during the molding process. Since the strength of such weld lines is very weak, the molded product can be damaged by external or internal impacts and friction.

[0005] Furthermore, molded articles of liquid crystal polyester resin composition may undergo fibrillation, a phenomenon in which the surface peels off and fuzz forms due to ultrasonic cleaning or friction with other components. When molded articles of liquid crystal polyester resin composition are used as electronic components in electronic devices, foreign matter such as dust and fibrils that detach from the fibrillated areas can significantly degrade the performance of the electronic device.

[0006] For example, in the case of electronic components, especially optical equipment with lenses, dust and other particles adhering to the lens can significantly degrade its optical properties. Fibrillation can occur when assembling or operating camera modules. Specifically, when the camera autofocus function is activated, dust can be generated from the surface of the camera module components due to their sliding movement, and dust is also easily generated when the equipment is subjected to impact or dropped. In recent years, miniaturization of peripheral electronic devices and accessories used inside electronic equipment has become essential, and as a result, the need has emerged to manufacture dust-sensitive semiconductor and optical material components using electronic component materials that generate less dust.

[0007] In connection with this, Korean Patent Publication No. 10-2014-0007792 discloses a liquid crystal polyester resin composition that can yield molded articles that are less susceptible to fibrillation. [Overview of the project] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide a liquid crystal polyester composition and an electronic component material containing the same that can reduce physical damage caused by internal and external friction and internal and external impact, improve impact strength and impact strength at weld lines, and minimize the generation of fibrils and dust. [Means for solving the problem]

[0009] According to one aspect of the present invention, the present invention can provide a liquid crystal polyester resin composition comprising a liquid crystal polyester resin; a fibril inhibitor; an esterification reaction inhibitor; and a filler.

[0010] Preferably, the fibril inhibitor is a compound comprising repeating units derived from α-olefins and repeating units derived from α,β-unsaturated carboxylic acids or their esters, thereby providing a liquid crystal polyester resin composition.

[0011] Preferably, the fibril inhibitor is one or more selected from the group consisting of ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate methyl copolymer, ethylene-(meth)acrylate ethyl copolymer, and ethylene-(meth)acrylate butyl copolymer, thereby providing a liquid crystal polyester resin composition.

[0012] Preferably, the esterification reaction inhibitor is a phosphite compound, and a liquid crystal polyester resin composition can be provided.

[0013] Preferably, the filler can provide a liquid crystal polyester resin composition comprising a carbon-based filler and an inorganic filler.

[0014] Preferably, a liquid crystal polyester resin composition can be provided, comprising: liquid crystal polyester resin in an amount of 55% to 85% by weight; fibril inhibitor in an amount of 2% to 8% by weight; esterification reaction inhibitor in an amount of 0.1% to 1.0% by weight; carbon-based filler in an amount of 1% to 5% by weight; and inorganic filler in an amount of 10% to 30% by weight.

[0015] Preferably, the carbon-based filler is one or more selected from the group consisting of carbon black, graphite, and carbon nanotubes, and a liquid crystal polyester resin composition can be provided.

[0016] Preferably, the inorganic filler is one or more selected from the group consisting of serpentine, montmorillonite, talc, mica (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, and potassium titanate, and a liquid crystal polyester resin composition can be provided.

[0017] Preferably, a liquid crystal polyester resin composition further containing a lubricant can be provided.

[0018] Preferably, a liquid crystal polyester resin composition can be provided in which the weld line impact strength of a molded product produced from the liquid crystal polyester resin composition exceeds 20 J / m.

[0019] Preferably, a liquid crystal polyester resin composition can be provided in which the dent depth of a molded product produced from the liquid crystal polyester resin composition is less than 21 μm.

[0020] Preferably, a liquid crystal polyester resin composition can be provided in which the dent volume of a molded product produced from the liquid crystal polyester resin composition is less than 11,000,000 μm ,

[0022] , , , , ,

[0020] , , , 3 , ,

[0021] , ,

[0023] A liquid crystal polyester resin composition can be provided.

[0021] In another aspect of the present invention, the present invention can provide a molded product produced from the liquid crystal polyester resin composition.

[0022] 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

[0023] The liquid crystal polyester resin composition according to the present invention can minimize the generation of dust due to internal and external impacts and friction while maintaining the original physical properties of the liquid crystal polyester resin, such as excellent mechanical, thermal, and electrical properties, and flame retardancy.

[0024] The liquid crystal polyester resin composition, molded product, and electronic component material containing the same according to the present invention have excellent impact strength and weld line impact strength, and the generation of dust and fibrils is suppressed against internal and external friction and impacts.

[0025] In addition, the liquid crystal polyester resin composition, molded product, and electronic component material containing the same according to the present invention minimize the number of generated dust and fibrils, have excellent weld line impact strength, and can be used as a component material 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.

Embodiments for Carrying Out the Invention

[0026] Hereinafter, the present invention will be described.

[0027] 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 overly interpreted unless clearly and specifically defined.

[0028] Also, throughout this specification, when one part "includes" one component, this means that, unless otherwise stated, it does not exclude other components but may further include other components.

[0029] As an example of an embodiment of the present invention, the liquid crystal polyester resin composition can include a liquid crystal polyester resin, a fibril inhibitor, an esterification reaction inhibitor, and a filler.

[0030] The liquid crystal polyester resin used in the present invention exhibits liquid crystal properties in a molten state, and is preferably melted at a temperature of 450°C or lower.

[0031] When considering its mechanical strength and injection moldability, liquid crystal polyester resin can have a weight-average molecular weight of approximately 10,000 to 300,000, preferably approximately 10,000 to 50,000. If the weight-average molecular weight of the liquid crystal polyester resin is less than 10,000, the mechanical strength will be poor and molded products may break, while if the weight-average molecular weight exceeds 300,000, the fluidity of the resin will decrease, making injection molding difficult.

[0032] The liquid crystal polyester resin may be included in an amount of about 55% by weight or more and about 85% by weight or less based on the total weight of the liquid crystal polyester resin composition, preferably about 60% by weight or more and about 80% by weight or less, and more preferably about 65% by weight or more and about 80% by weight or less. If the liquid crystal polyester resin component is included in an amount of less than about 55% by weight, the fluidity of the resin composition will decrease, which may make fine injection molding difficult. If the liquid crystal polyester resin component is included in an amount exceeding about 85% by weight, the fluidity of the resin composition will become excessively high, which may worsen the strength and heat resistance of molded articles and electronic components manufactured therefrom.

[0033] As the liquid crystal polyester resin, one or more may be selected from the group consisting of liquid crystal polyesteramide, liquid crystal polyester ether, liquid crystal polyester carbonate, and liquid crystal polyester imide.

[0034] Preferably, the liquid crystal polyester resin is a fully aromatic liquid crystal polyester composed using only aromatic compounds as monomer materials. Typical examples of the fully 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 with an aromatic hydroxycarboxylic acid.

[0035] Liquid crystal polyester resin can be produced by polycondensing one or more aromatic monomers to form a liquid crystal polyester prepolymer, and then by solid-phase polycondensation of the formed prepolymer. By-products generated during the solid-phase polycondensation reaction can be removed by purging with an inert gas or by vacuum.

[0036] The liquid crystal polyester resin that may 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).

[0037] For example, liquid crystal polyester resins can be polymerized containing 56 mol% to 66 mol% hydroxybenzoic acid (HBA), 2 mol% to 8 mol% hydroxynaphthoic acid (HNA), 9 mol% to 17 mol% biphenol (BP), 11 mol% to 21 mol% terephthalic acid (TPA), and 2 mol% to 8 mol% hydroxyacetanilide (APAP). Liquid crystal polyester resins polymerized with such mol% combinations can ensure fluidity, and resin compositions containing them can improve the mechanical properties of the product, such as impact strength, while minimizing the generation of dust and fibrils.

[0038] The fibril inhibitor in this invention can improve the impact resistance of liquid crystal polyester resin compositions to internal and external impacts and reduce fibril formation. As the fibril inhibitor, a copolymer containing repeating units derived from α-olefins and repeating units derived from α,β-unsaturated carboxylic acids or esters of α,β-unsaturated carboxylic acids can be used.

[0039] Examples of α-olefins include α-olefins with 2 to 10 carbon atoms, such as ethylene, propylene, butene, hexene, and octene, with ethylene being a typical example. Examples of α,β-unsaturated carboxylic acids or esters of α,β-unsaturated carboxylic acids include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate, with methacrylic acid being particularly preferred in some cases.

[0040] Examples of copolymers containing repeating units derived from α-olefins and repeating units derived from α,β-unsaturated carboxylic acids or their esters include ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate methyl copolymer, ethylene-(meth)acrylate ethyl copolymer, and ethylene-(meth)acrylate butyl copolymer. Preferably, ethylene-methacrylic acid copolymer can be used.

[0041] The fibril inhibitor may be included in an amount of approximately 2% by weight or more and approximately 8% by weight or less, based on the total weight of the liquid crystal polyester resin composition. If the amount of fibril inhibitor is less than approximately 2% by weight, the impact strength will be poor, and a large amount of fibril may be generated after cleaning the molded product. If the amount of fibril inhibitor exceeds approximately 8% by weight, it will be difficult to obtain a good molded product due to a change in fluidity caused by a decrease in the melt viscosity of the molded product, and the mechanical properties will be poor, resulting in dent depth (μm) and dent volume (μm). 3 An increase in ) can generate a lot of dust.

[0042] Esterification reaction inhibitors can be used to improve and enhance the melt viscosity and weld line impact strength of liquid crystal polyester resin compositions. Since the manufacturing and processing of liquid crystal polyester resin compositions are carried out at high temperatures of about 300°C to 400°C, additives including esterification reaction inhibitors must not decompose at high temperatures of about 300°C to 400°C. Examples of esterification reaction inhibitors include phosphite compounds, specifically pentadecyl phosphite, hexadecyl phosphite, heptadecyl phosphite, octadecyl phosphite, nonadecyl phosphite, and icosyl phosphite. Preferably, one or more selected from the group consisting of heptadecyl phosphite, octadecyl phosphite, and nonadecyl phosphite can be used.

[0043] The esterification reaction inhibitor may be included in an amount of approximately 0.1% by weight or more and approximately 1.0% by weight or less, based on the total weight of the liquid crystal polyester resin composition. If the esterification reaction inhibitor is less than approximately 0.1% by weight, the melt viscosity will be low, making it difficult to obtain a good molded product due to reduced fluidity, and the molded product may break due to inferior impact strength and weld line impact strength. If the esterification reaction inhibitor exceeds approximately 1.0% by weight, the dent depth (μm) and dent volume (μm) may be affected. 3 As the amount of ) increases, the effect of suppressing fibril formation on the surface of the molded product also decreases, which can lead to problems caused by dust and fibril.

[0044] Molded articles made from liquid crystal polyester resin compositions to which fibril inhibitors and esterification reaction inhibitors have been added exhibit suppressed fibril formation on the surface and possess excellent weld line impact strength, thereby preventing damage to the molded articles due to internal and external impacts and friction.

[0045] The filler can include all carbon-based and inorganic fillers.

[0046] 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 included 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 included 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. If 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 ensure sufficient light shielding properties. If the amount of carbon black exceeds about 5% by weight, it may solidify without being uniformly dispersed in the liquid crystal polyester resin composition, which may cause a decrease in physical properties and may increase the likelihood of aggregates separating as dust.

[0047] Inorganic fillers can be used to improve mechanical strength, heat resistance, and impact dent resistance. The addition of inorganic fillers to liquid crystal polyester resins must be carried out in a manner that does not damage the mechanical properties (such as strength, rigidity, and hardness), heat resistance, and electrical properties of the polyester resin. Any non-fibrous filler can be used, including plate-type and granular fillers. The inorganic filler may be included in the liquid crystal polyester resin composition in an amount of approximately 10% to 30% by weight, based on the total weight.

[0048] Plate-shaped fillers can improve mechanical properties and heat resistance, and provide dimensional stability to molded products. Examples of plate-shaped fillers include serpentine, montmorillonite, talc, mica (biotite, muscovite, phlogopite), chlorite, and glass flakes.

[0049] Examples of granular fillers include silica, quartz powder, glass beads, glass powder, silicates such as 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; silicon carbide; silicon nitride; boron nitride; and potassium titanate.

[0050] As inorganic fillers, one or more plate-type fillers, one or more granular fillers, or one or more plate-type fillers and one or more granular fillers can be used.

[0051] The liquid crystal polyester resin composition of the present invention may further contain a lubricant. Examples of lubricants include transition metal compounds containing elements belonging to Group 6 of the periodic table, specifically molybdenum-based compounds, tungsten-based compounds, and chromium-based compounds.

[0052] When a lubricant is included, the fluidity during high-temperature injection increases, maximizing the polymer chain orientation of the liquid crystal polyester resin, improving flexural strength, flexural modulus, impact strength, and weld line impact strength, and minimizing the generation of dust and fibrils due to internal and external impacts and friction.

[0053] As a lubricant, transition metal sulfides containing elements belonging to Group 6 of the periodic table can be used. Specifically, one or more selected from the group consisting of molybdenum disulfide (MoS2), molybdenum diselenium (MoSe2), molybdenum selenide sulfide (MoSSe), molybdenum trioxide (MoO3), tungsten disulfide (WS2), tungsten selenide (WSe2), tungsten selenide sulfide (WSSe), tungsten trioxide (MoO3), chromium disulfide (CrS2), chromium diselenium (CrSe2), chromium selenide sulfide (CrSSe), and chromium trioxide (CrO3) can be used. Preferably, molybdenum disulfide (MoS2) or tungsten disulfide (WS2) can be used as a lubricant, and more preferably, molybdenum disulfide (MoS2) can be used.

[0054] Transition metal sulfides have a layered structure in a sandwich-like manner, with a transition metal layer situated between two layers of sulfur. A weak Van der Vals force acts between each layer, resulting in each layer being slippery and having a low coefficient of friction. For example, molybdenum disulfide, a type of transition metal sulfide, can be added to plastics to obtain composites with low frictional resistance and high strength, or it can be vacuum-deposited onto the surface of other materials to obtain self-lubricating composite materials for high temperatures.

[0055] The lubricant may be used in an amount exceeding about 0.5% by weight to less than about 10% by weight, preferably exceeding about 0.5% by weight to about 5% by weight or less, more preferably about 1% by weight or more to about 5% by weight or less, and very preferably about 1% by weight or more to about 3% by weight or less, based on the total weight of the liquid crystal polyester resin composition.

[0056] If the lubricant content exceeds approximately 10% by weight, proper dispersion in the liquid crystal polyester resin composition is not achieved, resulting in reduced extrusionability and potentially very poor mechanical properties. Furthermore, this deterioration in mechanical properties may lead to an increase in dust and fibril generation.

[0057] When a lubricant is included in an amount of approximately 0.5% by weight or less, the orientation of the polymer chains decreases above the melting point of the liquid crystal polyester resin, and the improvement effect on mechanical properties is not fully achieved. As a result, the amount of dust and fibril generated may also increase.

[0058] The liquid crystal polyester resin composition of the present invention comprises a fibril inhibitor, an esterification reaction inhibitor, and a filler, and can improve impact strength and dent characteristics, thereby minimizing and suppressing the number of dust particles and fibrils generated by internal and external impacts and friction. Furthermore, the liquid crystal polyester resin composition of the present invention can minimize the particle size of the generated dust particles and fibrils, and can have excellent weld line impact strength. In addition, the liquid crystal polyester resin composition of the present invention can improve the impact strength of weld lines appearing in molded products with complex structures, minimizing and preventing damage due to internal and external impacts, and in particular, when applied to camera module components, it can greatly contribute to maintaining and improving optical performance such as pixel count and image quality.

[0059] The present invention allows for the production of molded articles or electronic component materials from a liquid crystal polyester resin composition containing the above-described components. The liquid crystal polyester resin composition of the present invention has increased polymer chain orientation properties, thereby enabling the molded articles or electronic component materials of the present invention to have excellent mechanical strength, including weld line impact strength, and to minimize the generation of dust and fibrils. Specifically, the liquid crystal polyester resin composition of the present invention can be applied to camera module components of mobile phones or smartphones, contributing to the maintenance and improvement of optical performance such as pixel count and image quality.

[0060] After drying the liquid crystal polyester resin composition of the present invention, the melt viscosity evaluated using a melt viscosity measuring instrument can be in the range of 15 Pa·s or more to 20 Pa·s or less.

[0061] After drying the liquid crystal polyester resin composition of the present invention, the impact strength of test specimens fabricated using an injection molding machine and evaluated was 80 kJ / m². 2 It can exhibit improved impact strength exceeding the previous limit.

[0062] After drying the liquid crystal polyester resin composition of the present invention, the weld line impact strength, when evaluated by fabricating test specimens using an injection molding machine, can show improved impact strength exceeding 20 J / m.

[0063] After drying the liquid crystal polyester resin composition of the present invention, test specimens were prepared using an injection molding machine, and the depth (μm) and volume (μm) of the dents were measured using a dent simulating tester. 3 ) are less than 21 μm and 11,000,000 μm, respectively. 3 It can indicate a range less than or equal to.

[0064] The present invention will be specifically described below through the following embodiments, but the present invention is not limited by these embodiments.

[0065] Manufacturing example: Manufacturing of liquid crystal polyester resin

[0066] 13,000 g (127.3 mol) of acetic anhydride was added to a 1,200 L batch reactor. While stirring, 20,000 g (144.8 mol) of parahydroxybenzoic 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) were added. Then, 12,300 g (120.5 mol) of acetic anhydride was added, and these were mixed in the batch reactor.

[0067] 2. 2.7 g of potassium acetate catalyst and 10.8 g of magnesium acetate catalyst were added, and nitrogen was injected to create an inert state inside the reactor.

[0068] 3. The reactor temperature was raised over 1 hour to a temperature at which the acetic anhydride inside the batch reactor refluxed. At this temperature, the hydroxyl groups of each monomer were acetylated over 2 hours, and the acetic acid produced by the acetylation reaction and the excess unreacted acetic anhydride were removed. The reactor temperature was raised to 320°C at a rate of 0.5°C / min to produce a liquid crystal polyester prepolymer. After that, it was cooled and solidified while being discharged through the lower valve, and pulverized to obtain 32,000 g of liquid crystal polyester prepolymer.

[0069] 4. The liquid crystal polyester prepolymer was secondarily pulverized using a fine pulverizer and then placed in a rotary heating device. The rotary heating device was heated to 200°C over 2 hours while nitrogen was flowed through it at a flow rate of 25 L / min, and maintained at 200°C for 2 hours. After that, the temperature was raised to 285°C at a rate of 0.2°C / min and maintained for 3 hours while carrying out the polycondensation reaction.

[0070] 5. After the polycondensation reaction, a liquid crystal polyester resin was finally obtained, and the melting point of the manufactured resin was 330°C.

[0071] Example 1. Production of a liquid crystal polyester resin composition

[0072] 1. The liquid crystal polyester resin (hereinafter referred to as LCP resin) produced in the manufacturing example was mixed with 76.7% by weight of carbon black, 3% by weight of mica, 2% by weight of ethylene-methacrylic acid copolymer as a fibril inhibitor, 1% by weight of molybdenum disulfide, and 0.3% by weight of an esterification reaction inhibitor. The components used are specifically shown in Table 1 below.

[0073] 2. The material was melted and kneaded in a twin-screw extruder (L / D: 44, diameter: 30 mm). The barrel temperature of the extruder during melting and kneading was 340°C. By-products were removed by passing the material through a vacuum before it was pelletized.

[0074] 3. The pelletized liquid crystal polyester resin composition was mixed for 30 minutes using a mixer (Daiichi Sangyo Kiki, JITD-50KW), and then dried at 150°C for 4 hours using a hot air dryer (Daiichi Sangyo Kiki, JIB-100KW).

[0075] [Table 1]

[0076] Production of the liquid crystal polyester resin compositions of Examples 2 to 6

[0077] The liquid crystal polyester resin compositions of Examples 2 to 6 were manufactured using the same method as in Example 1, and were produced in the composition ratios shown in Table 2 below.

[0078] [Table 2]

[0079] Production of the liquid crystal polyester resin compositions of Comparative Examples 1 to 4

[0080] The liquid crystal polyester resin compositions of Comparative Examples 1 to 4 were manufactured using the same method as in Example 1, with the components and compositional ratios listed in Table 3 below.

[0081] [Table 3]

[0082] Test Example 1. Melt viscosity of liquid crystal polyester resin composition

[0083] For each of the resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4, a capillary rheometer (GOETTFERT RG20) was used, with a cylinder temperature of 350°C and a shear rate of 1000 sec. -1 The melt viscosity was measured under the specified conditions. The measured results are shown in Table 4.

[0084] Test Example 2. Impact strength of liquid crystal polyester resin composition

[0085] For each of the resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4, test specimens measuring 12.7 mm in width, 65 mm in length, and 3.2 mm in thickness were prepared.

[0086] The impact strength of each manufactured test specimen was evaluated in an unnotched state according to ASTM D256, and the results are shown in Table 4.

[0087] Test Example 3. Weld line impact strength of liquid crystal polyester resin composition

[0088] For each of the resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4, test specimens measuring 12.4 mm in width, 80 mm in length, and 3 mm in thickness were prepared. During the preparation of the test specimens, the gates from which the resin composition was extruded were positioned in both directions, so that the resin met at the center of the specimen from both ends, thereby creating a weld line.

[0089] The weld line impact strength was measured by applying impact to each weld line portion of each manufactured test specimen using an IZOD impactor in an unnotched state according to ASTM D256, and the results are shown in Table 4.

[0090] Test Example 4. Dent evaluation of liquid crystal polyester resin composition

[0091] 1. Test specimens measuring 12.4 mm in width, 80 mm in length, and 3 mm in thickness were prepared by molding each of the resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4 using an injection molding machine.

[0092] 2. Each manufactured test specimen was mounted in a dust simulation test machine, and a 15g ball was dropped from a height of 10cm 70 times consecutively.

[0093] 3. After the continuous drop test, the dent depth (μm) and dent volume (μm) of each specimen were measured using 3D tiling techniques via an optical microscope (HIROX, XY-GB2). 3 ) was measured.

[0094] 4.1 processes to 3 processes were combined into one test and performed a total of 6 times for each test piece. The average dent depth (μm) and dent volume (μm 3 ) of each test piece are shown in Table 4.

[0095] Test Example 5. Fibril Evaluation of Liquid Crystal Polyester Resin Compositions

[0096] 1. For each of the resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4, after injecting test pieces with a width of 横向12.4mm, a length of 縦80mm, and a thickness of 3mm, they were conditioned in a thermo-hygrostat at a humidity of 50% and a temperature of 23°C for at least 8 hours.

[0097] 2. After washing with a 1% alkaline aqueous solution for 8 minutes and then with ultrapure water for 2 minutes using a 40 kHz ultrasonic cleaner at room temperature, they were dried in a dryer at 80°C for 30 minutes.

[0098] 3. After performing blowing at room temperature for 10 seconds, the presence or absence of fibrils was observed using an optical microscope (HIROX, XY-GB2).

[0099] 4. For the resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4, 100 test pieces were measured for each.

[0100] 5. After going through the above processes 1 to 3, if the number of test pieces with fibrils generated among 100 test pieces was 5 or less, it was evaluated as good; if it exceeded 5, it was evaluated as bad. The evaluation results are shown in Table 4.

[0101]

Table 4

[0102] It should be noted that there are some unclear expressions in the original text such as “横向12.4mm” and “縦80mm” which are tentatively translated in a literal way. You may need to check and correct them according to the actual situation.The liquid crystal polyester resin compositions of Examples 1 to 6 were confirmed to have a melt viscosity in the range of 15 Pa·s to 20 Pa·s. Within this melt viscosity range, the resin compositions have fluidity suitable for the manufacture of molded articles, making it possible to produce molded articles of good quality. On the other hand, Comparative Examples 2 and 3 did not show appropriate melt viscosity values. In the case of Comparative Example 2, it is considered that the appropriate melt viscosity value was not shown due to the presence of an excessive amount of fibril inhibitor, and in the case of Comparative Example 3, it is considered that the appropriate melt viscosity value was not shown due to the absence of an esterification reaction inhibitor.

[0103] The liquid crystal polyester resin compositions of Examples 1 to 6 have a concentration of 80 kJ / m². 2 Because it possesses the above impact strength, it was confirmed to have excellent impact strength characteristics, resistance to internal and external impacts, and the ability to suppress dust generation, as well as stability against external or internal impacts and friction. On the other hand, in the case of Comparative Example 1 and Comparative Example 3, the impact strength was approximately 61 kJ / m, respectively. 2 and approximately 44 kJ / m³ 2 And, 80 kJ / m³ 2 Because they possessed inferior impact strength, it was confirmed that molded products were prone to breakage due to internal and external impacts. In the case of Comparative Example 1, it is considered that the inferior impact strength was due to the absence of a fibril inhibitor, and in the case of Comparative Example 3, it is considered that the inferior impact strength was due to the absence of an esterification reaction inhibitor.

[0104] The liquid crystal polyester resin compositions of Examples 1 to 6 had weld line impact strength exceeding 20 J / m, demonstrating excellent weld line impact strength, resistance to internal and external impacts, and the ability to suppress dust generation, as well as stability against external or internal impacts and friction. On the other hand, Comparative Example 1 had a weld line impact strength of approximately 20 J / m, and Comparative Example 3 had a weld line impact strength of approximately 14 J / m, both below 20 J / m, indicating that molded articles were easily damaged by internal and external impacts. This is considered to be due to the absence of a fibril inhibitor in Comparative Example 1 and the absence of an esterification reaction inhibitor in Comparative Example 3.

[0105] The liquid crystal polyester resin compositions of Examples 1 to 6 all had a dent depth of less than approximately 21 μm and a dent volume of approximately 11,000,000 μm². 3 The following was confirmed, and it was confirmed that the generation of dust due to impact can be effectively suppressed. On the other hand, in the case of Comparative Example 2, the dent depth was approximately 23.8 μm and the dent volume was approximately 14,840,811 μm 3 In the case of Comparative Example 4, the dent depth was approximately 25.5 μm and the dent volume was 16,482,994 μm 3 It was confirmed that this was the case, and that the dent characteristics were poor. In the case of Comparative Example 2, it is considered that the poor dent characteristics were due to the inclusion of an excessive amount of fibril inhibitor, and in the case of Comparative Example 4, it is considered that the poor dent characteristics were due to the inclusion of an excessive amount of esterification reaction inhibitor.

[0106] In each of the liquid crystal polyester resin compositions of Examples 1 to 6, five or fewer test pieces exhibited fibril formation out of 100 test pieces, thus confirming their excellent effect in suppressing fibril formation due to impact and friction. For example, if the number of fibrils exceeds five, many cases of fibril separation from the surface of components may occur during the camera module assembly process. If these separated fibrils adhere to camera lenses or other components, they can cause defects. Therefore, reducing the number of fibrils generated reduces defects during camera module assembly, thereby promoting the improvement of pixel count in line with the increased performance of cameras.

[0107] In comparison, fibril formation occurred in 37 test specimens in Comparative Example 1 and in 19 test specimens in Comparative Example 4. In the case of Comparative Example 1, the poor fibril evaluation is considered to be due to the absence of a fibril inhibitor, and in the case of Comparative Example 4, it is considered to be due to the excessive amount of esterification reaction inhibitor.

[0108] The present invention is not limited to the embodiments described above, and it is obvious to those with ordinary skill in the art to which the present invention pertains that it can be implemented in various ways by modification or alteration without departing from the technical spirit of the invention.

Claims

1. A liquid crystal polyester resin of 55% by weight or more and 85% by weight or less; A fibril inhibitor in an amount of 2% by weight or more and 8% by weight or less; Esterification reaction inhibitor in an amount of 0.1% by weight or more to 1.0% by weight or less; Carbon-based fillers in an amount of 1% by weight or more and 5% by weight or less; and A liquid crystal polyester resin composition comprising 10% by weight or more and 30% by weight or less of an inorganic filler.

2. The liquid crystal polyester resin composition according to claim 1, wherein the fibril inhibitor is a compound comprising repeating units derived from α-olefin and repeating units derived from α,β-unsaturated carboxylic acid or its ester.

3. The liquid crystal polyester resin composition according to claim 1, wherein the fibril inhibitor is one or more selected from the group consisting of ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate methyl copolymer, ethylene-(meth)acrylate ethyl copolymer, and ethylene-(meth)acrylate butyl copolymer.

4. The liquid crystal polyester resin composition according to claim 1, wherein the esterification reaction inhibitor is a phosphite compound.

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

6. The liquid crystal polyester resin composition according to claim 1, wherein the inorganic filler is one or more selected from the group consisting of serpentine, montmorillonite, talc, mica, chlorite, glass flakes, silica, quartz powder, glass bead, 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, and potassium titanate.

7. The liquid crystal polyester resin composition according to claim 1, further comprising a lubricant.

8. The liquid crystal polyester resin composition according to claim 1, wherein the weld line impact strength of a molded product manufactured from the liquid crystal polyester resin composition exceeds 20 J / m.

9. The liquid crystal polyester resin composition according to claim 1, wherein the dent depth of the molded article produced from the liquid crystal polyester resin composition is less than 21 μm.

10. The dent volume of the molded product manufactured from the aforementioned liquid crystal polyester resin composition is 11,000,000 μm³. ３ A liquid crystal polyester resin composition according to claim 1, wherein the value is less than [value missing].

11. A molded article manufactured from a liquid crystal polyester resin composition according to claim 1.

12. An electronic component material comprising a liquid crystal polyester resin composition according to claim 1.

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