TW202340420A - Liquid crystalline resin composition for planar connector, and planar connector obtained using same - Google Patents

Abstract

Provided are: a liquid crystalline resin composition which exhibits good fluidity and enables production of a planar connector which exhibits excellent crack resistance and mechanical strength and in which warping is suppressed; and a planar connector containing said liquid crystalline resin composition. This liquid crystalline resin composition for a planar connector contains: (A) a wholly aromatic polyester; (B) a fibrous inorganic filler; (C) mica; and (D) talc and/or silica. Component (A) contains constituent units (I) to (IV). Relative to the total amount of constituent units, the amount of (I) is 40-75 mol%, the amount of (II) is 0.5-7.5 mol%, the amount of (III) is 8.5-30 mol%, and the amount of (IV) is 8.5-30 mol%. The weight average fiber length of component (B) is 150-500 [mu]m. Relative to the total amount of the composition, the amount of component (A) is 45-70 mass%, the amount of component (B) is 5-20 mass%, the amount of component (C) is 7-27 mass%, the amount of component (D) is 5-25 mass%, and the total amount of components (B) to (D) is 30-55 mass%. Ar1 and Ar2 each independently denote an arylene group.

Description

Liquid crystalline resin composition for planar connectors and planar connector using same

The present invention relates to a liquid crystal resin composition for planar connectors and a planar connector using the same.

Liquid crystalline resins represented by liquid crystalline polyester resins have a good balance between excellent mechanical strength, heat resistance, chemical resistance, electrical properties, etc., and also have excellent dimensional stability, so they are used as high-performance engineering plastics. widely used. In addition, since liquid crystalline resins are also excellent in fluidity and the like, they have been conventionally used as materials for various electronic components. In particular, as electronic equipment becomes more advanced in performance in recent years, there is a demand for molded products (planar connectors, etc.) containing fine structures and the like. In order to meet such needs, for example, Patent Document 1 proposes a planar connector formed from a composite resin composition composed of a specific liquid crystalline polymer, an inorganic filler, and glass fiber. Its formability, flatness, It has excellent properties such as warpage deformation and heat resistance, and is unlikely to cause cracks (also called cracks) in the lattice portion or the like. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2012-214652

[Problem to be solved by the invention]

In recent years, with the shift from LTE to 5G, there is a need to improve the computing processing capabilities of communication terminals. For this reason, it is necessary to improve the performance of the CPU and realize high-speed calculation processing. As technologies for realizing high-speed calculation processing, technologies such as multi-core, multi-socket, and multi-pin technology can be cited.

In the installation of the CPU, the corresponding CPU socket is usually used. As CPUs become multi-pin, product design changes such as higher area and narrower pitch are produced in the CPU. Changes such as higher area and narrower pitch are also produced in the CPU socket. As a candidate for the CPU socket material, a liquid crystal resin composition can be cited. When a liquid crystalline resin composition is used to increase the area of a CPU socket, it is required to suppress warpage deformation caused by expansion of the size of the CPU socket. On the other hand, when the pitch of a CPU socket is narrowed using a liquid crystalline resin composition, it is required to suppress cracks and strength reduction caused by reductions in the distance between pitches and the thickness of electrode partitions.

However, according to the research of the present inventors, conventional liquid crystalline resin compositions have very high melt viscosity and poor fluidity, or even if conventional liquid crystalline resin compositions are used, high area of planar connectors such as CPU sockets is required. Even with smaller pitches and narrower pitches, warping deformation, crack generation, or reduction in mechanical strength cannot be fully suppressed. The present invention has been made to solve the above problems, and its object is to provide a liquid crystalline resin composition with good fluidity and a planar connector containing the liquid crystalline resin composition that can achieve Manufacturing of planar connectors with excellent crack resistance and mechanical strength and suppressed warpage deformation. [Methods to solve the problem]

The present inventors have conducted intensive research to solve the above-mentioned problems. As a result, by containing in a predetermined amount: a predetermined fully aromatic polyester containing a large amount of structural units derived from 6-hydroxy-2-naphthoic acid, and a fibrous inorganic filler with a weight average fiber length of 150 to 500 μm A liquid crystalline resin composition for a planar connector, mica, and one or more inorganic fillers selected from the group consisting of talc and silica can solve the above problems, and the present invention has been completed. More specifically, the present invention provides the following inventions.

(1) A liquid crystal resin composition for planar connectors, containing: (A) fully aromatic polyester; (B) fibrous inorganic filler; (C) mica; and (D) selected from talc and silica A group of more than one inorganic filler, The aforementioned fully aromatic poly(A) contains the following structural units (I) to (IV). Compared with all the structural units, the content of the structural unit (I) is 40 to 75 mol%, and the content of the structural unit (II) is 40 to 75 mol%. The content of the structural unit (III) is 0.5~7.5 mol%, the content of the structural unit (III) is 8.5~30 mol%, and the content of the structural unit (IV) is 8.5~30 mol%. The weight average fiber length of the aforementioned (B) fibrous inorganic filler is 150 to 500 μm, Compared with the entire liquid crystalline resin composition, the content of the aforementioned (A) fully aromatic polyester is 45 to 70% by mass; the content of the aforementioned (B) fibrous inorganic filler is 5 to 20% by mass; the aforementioned (C) The content of mica is 7 to 27% by mass; the content of the aforementioned (D) one or more inorganic fillers selected from the group consisting of talc and silica is 5 to 25% by mass, and the aforementioned (D) The total content of B) the fibrous inorganic filler, the aforementioned (C) mica, and the aforementioned (D) one or more inorganic fillers selected from the group consisting of talc and silica is 30 to 55% by mass.

[Chemical 1] (In the formula, Ar ₁ and Ar ₂ each independently represent an arylene group).

(2) The liquid crystal resin composition according to (1), wherein the fibrous inorganic filler (B) is at least one selected from the group consisting of glass fiber and ground glass fiber.

The liquid crystalline resin composition as described in (1) or (2) has a Rockwell hardness of M scale measured in accordance with JIS K 7202-2 of 140 or less.

A planar connector, including the liquid crystalline resin composition according to any one of (1) to (3), having an outer frame part and a lattice structure formed inside the outer frame part, the lattice part of the lattice structure The pitch interval is below 1.5mm. [Effects of the invention]

According to the present invention, it is possible to provide a liquid crystalline resin composition with good fluidity that can achieve excellent crack resistance, mechanical strength, and warpage, and a planar connector including the liquid crystalline resin composition. Manufacturing of flat connectors with suppressed bending deformation.

Hereinafter, embodiments of the present invention will be described. In addition, the present invention is not limited to the following embodiments.

<Liquid crystalline resin composition for planar connectors> The liquid crystal resin composition for planar connectors of the present invention contains: (A) fully aromatic polyester, (B) fibrous inorganic filler, (C) mica, and (D) selected from talc and silica. One or more inorganic fillers in the group, the (B) fibrous inorganic filler has a weight average fiber length of 150 to 500 μm.

[(A) Fully aromatic polyester] The liquid crystalline resin composition of the present invention contains (A) wholly aromatic polyester. (A) Fully aromatic polyester can be used individually by 1 type or in combination of 2 or more types. (A) Fully aromatic polyester contains the following structural units (I) to (IV), Compared with all constituent units, The content of structural unit (I) is 40~75 mol%, The content of structural unit (II) is 0.5~7.5 mol%, The content of structural unit (III) is 8.5~30 mol%, The content of the structural unit (IV) is 8.5 to 30 mol%.

[Chemicalization 2] (Ar ₁ and Ar ₂ each independently represent an aryl group in the formula)

The structural unit (I) is derived from 6-hydroxy-2-naphthoic acid (hereinafter also referred to as "HNA" (6-hydroxy-2-naphthoic acid)). The component (A) contains 40 to 75 mol% of the structural unit (I) based on all the structural units. When the content of the structural unit (I) is within the above range, heat resistance and manufacturability are likely to be improved. From the viewpoint of heat resistance and manufacturability, the content of the structural unit (I) is preferably 40 to 60 mol%, more preferably 45 to 60 mol% based on all the structural units.

The structural unit (II) is derived from 4-hydroxybenzoic acid (hereinafter also referred to as "HBA" (4-hydroxybenzoic acid)). The component (A) contains 0.5 to 7.5 mol% of the structural unit (II) based on all the structural units. When the content of the structural unit (II) is within the above range, heat resistance and manufacturability are likely to be improved. From the viewpoint of heat resistance and manufacturability, the content of the structural unit (II) is preferably 1 to 6 mol% based on the total structural units.

The structural unit (III) is a structural unit derived from a dicarboxylic acid. Examples of Ar ₁ include 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, and the like. From the viewpoint of heat resistance, the structural unit (III) is preferably derived from 1,4-phenylenedicarboxylic acid (hereinafter also referred to as "TA"). The content of the structural unit (III) is 8.5 to 30 mol%, preferably 17.5 to 30 mol%, based on all the structural units.

The structural unit (IV) is a structural unit derived from diol. As the diol, hydroquinone, dihydroxybiphenyl, etc. can be used. From the viewpoint of heat resistance, dihydroxybiphenyl, especially 4,4'-dihydroxybiphenyl (hereinafter also referred to as "BP") is relatively good. The content of the structural unit (IV) is 8.5 to 30 mol%, preferably 17.5 to 30 mol%, based on all the structural units.

Since component (A) contains a specific amount of specific structural units (I) to (IV) with respect to all structural units, it is excellent in both heat resistance and manufacturability. In addition, the component (A) preferably contains a total of 100 mol% of the structural units (I) to (IV) with respect to all the structural units.

Next, the method for producing the wholly aromatic polyester of the present invention will be described. The fully aromatic polyester in the present invention is polymerized using a direct polymerization method, a transesterification method, or the like. During polymerization, melt polymerization, solution polymerization, slurry polymerization, solid phase polymerization, etc. or a combination of two or more thereof can be used. Melt polymerization or melt polymerization and solid phase polymerization are preferably used. combination of laws.

In the present invention, during polymerization, a chelating agent, a terminally activated monomer that is a chloride compound derivative, or the like may be used for the polymerized monomer. Examples of the chelating agent include fatty acid anhydrides such as acetic anhydride and the like.

Various catalysts can be used for the polymerization of these. Typical catalysts include potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and antimony trioxide. Metal salt catalysts such as (2,4-pentanedionato)cobalt(III) (tris(2,4-pentanedionato)cobalt(III)), 1-methylimidazole, 4-dimethylaminopyridine, etc. Organic compounds are catalysts.

Reaction conditions include, for example, a reaction temperature of 200 to 380°C and a final pressure of 0.1 to 760 Torr (ie, 13 to 101,080 Pa). Especially in melting reactions, for example, the reaction temperature is 260~380℃, preferably 300~360℃, and the final pressure is 1~100 Torr (i.e. 133~13,300 Pa), preferably 1~50 Torr (i.e. 133~ 6,670Pa).

The reaction can be carried out by putting all the raw material monomers (HNA, HBA, TA, and BP), chelating agent, and catalyst into the same reaction vessel to start the reaction (one-step method), or the raw material monomers HNA, HBA, and BP can be After the hydroxyl group is chelated by a chelating agent, it reacts with the carboxyl group of TA (two-stage method).

After the melt polymerization reaches a predetermined temperature in the reaction system, the pressure is reduced to a predetermined degree of pressure reduction. After the torque of the mixer reaches a predetermined value, an inert gas is introduced, the pressure is increased from a reduced pressure state to a predetermined pressurized state, and the fully aromatic polyester is discharged from the reaction system.

The fully aromatic polyester produced by the above polymerization method can further achieve an increase in molecular weight by solid-state polymerization heated under normal pressure or reduced pressure in an inert gas. The preferred conditions for the solid-state polymerization reaction are a reaction temperature of 230~350°C, preferably 260~330°C, and a final pressure of 10~760 Torr (ie, 1330~101,080 Pa).

Next, the properties of wholly aromatic polyester will be described. The wholly aromatic polyester in the present invention exhibits optical anisotropy when melted. The fact that a certain resin exhibits optical anisotropy when melted means that the resin is a liquid crystalline resin. The fully aromatic polyester in the present invention has both thermal stability and ease of processing.

The nature of the melt anisotropy can be confirmed by conventional polarization inspection methods using crossed polarizers. More specifically, the confirmation of melting anisotropy can be carried out by melting a sample placed on a hot stage made by LINKAM using a polarizing microscope made by OLYMPUS, and observing it at a magnification of 150 times in a nitrogen atmosphere. . Fully aromatic polyester is optically anisotropic, allowing light to pass through when inserted between crossed polarizers. If the sample is optically anisotropic, polarized light will be transmitted even in a molten and still liquid state, for example.

Since nematic fully aromatic polyester will have a significant decrease in viscosity above the melting point, liquid crystallinity at or above the melting point is generally used as an indicator of processability. From the viewpoint of heat resistance, the higher the melting point, the better. However, considering thermal degradation during melt processing of fully aromatic polyester, the heating capacity of the extruder, etc., the melting point is preferably 360°C or lower. In addition, 300~360°C is more preferred, and 320~358°C is still more preferred.

At the film forming temperature of the present invention and the shearing speed of 1000/second, the melt viscosity of the above-mentioned fully aromatic polyester is preferably 500 Pa·s or less, more preferably 50 to 400 Pa·s, and further preferably 100 to 300 Pa·s. s. When the melt viscosity is within the above range, the wholly aromatic polyester itself or the composition containing the wholly aromatic polyester can easily ensure film forming properties during extrusion. In addition, in this specification, the value measured based on ISO11443 is used as the said melt viscosity.

The content of component (A) is 45 to 70 mass%, preferably 50 to 65 mass%, more preferably 54 to 61 mass%, based on the entire liquid crystalline resin composition. If the content of component (A) is within the above range, it is easy to improve the crack resistance, mechanical strength and warpage of the molded article composed of the liquid crystalline resin composition while ensuring sufficient fluidity of the liquid crystalline resin composition. Deformation suppression effect.

[(B) Fibrous inorganic filler] When the liquid crystalline resin composition of the present invention contains a fibrous inorganic filler, the crack resistance of a molded article composed of the liquid crystalline resin composition is easily improved, and the mechanical strength such as mesh strength is easily improved. The fibrous inorganic filler can be used individually by 1 type or in combination of 2 or more types.

The average fiber length of the fibrous inorganic filler is 150~500 μm, preferably 200~450 μm, more preferably 250~400 μm. When the average fiber length is 150 μm or more, the crack resistance of the molded article composed of the liquid crystalline resin composition of the present invention is easily improved, and the mechanical strength such as mesh strength is easily improved. If the average fiber length is 500 μm or less, the warpage deformation suppressing effect of a molded article composed of the liquid crystalline resin composition can be easily improved. In addition, in this specification, the following is used as the average fiber length of the fibrous inorganic filler: 10 three-dimensional microscopic images of the fibrous inorganic filler are imported from a CCD camera to a PC, and image processing is performed by an image measuring machine. The method is to measure the average value of the fiber length for 100 fibrous inorganic fillers per one stereoscopic microscopic image, that is, 1000 fibrous inorganic fillers in total. The average fiber of the fibrous inorganic filler in the liquid crystalline resin composition was measured by applying the above method to the fibrous inorganic filler remaining in ashes by heating the liquid crystalline resin composition at 600° C. for 2 hours. long. In this specification, unless otherwise stated, the average fiber length refers to the weight average fiber length.

The fiber diameter of the fibrous inorganic filler material is not particularly limited, and may be, for example, 20 μm or less, or 5 to 15 μm. In addition, in this specification, as the fiber diameter of a fibrous inorganic filler, the following is used: the fibrous inorganic filler was observed with a scanning electron microscope, and the average value of the fiber diameter of 30 fibrous inorganic fillers was measured. The fiber diameter of the fibrous inorganic filler in the liquid crystalline resin composition was measured by applying the above method to the fibrous inorganic filler remaining in ashes by heating the liquid crystalline resin composition at 600° C. for 2 hours. .

Any fiber can be used as long as it is a fibrous inorganic filler that satisfies the above-mentioned shape. Examples of the fibrous inorganic filler include glass fiber, ground glass fiber, carbon fiber, asbestos fiber, silica fiber, silica/alumina fiber, zirconium dioxide fiber, and boron nitride fiber. , silicon nitride fiber, boron fiber, potassium titanate fiber, calcium silicate fiber (wollastonite), and inorganic substances such as fibrous materials of stainless steel, aluminum, titanium, copper, brass, etc. Fibrous material. In the present invention, from the viewpoint of crack resistance and mechanical strength, it is preferred to use at least one filler selected from the group consisting of glass fiber and ground glass fiber as the fibrous inorganic filler.

The content of component (B) is 5 to 20 mass %, preferably 7 to 18 mass %, more preferably 9 to 16 mass % with respect to the entire liquid crystalline resin composition. If the content of component (B) is within the above range, it is easy to improve the crack resistance, mechanical strength and warpage of the molded article composed of the liquid crystalline resin composition while ensuring sufficient fluidity of the liquid crystalline resin composition. Deformation suppression effect.

[(C)Mica] The liquid crystalline resin composition of the present invention contains mica. By containing mica in the liquid crystalline resin composition of the present invention, the fluidity of the liquid crystalline resin composition can be sufficiently ensured, and the warpage deformation suppressing effect of a molded article composed of the liquid crystalline resin composition can be easily improved. Mica can be used individually by 1 type or in combination of 2 or more types.

Mica is contained in an amount of 7 to 27% by mass relative to the entire liquid crystalline resin composition. When the mica content is less than 7% by mass relative to the entire liquid crystalline resin composition, the warpage deformation suppressing effect of the molded article composed of the liquid crystalline resin composition is insufficient, which is undesirable. When the content of mica exceeds 27% by mass relative to the entire liquid crystalline resin composition, the crack resistance or mechanical strength of the molded article composed of the liquid crystalline resin composition may decrease, which is undesirable. The mica content in the liquid crystalline resin composition is preferably 9 to 24% by mass, and more preferably 11 to 21% by mass relative to the entire liquid crystalline resin composition.

[Mica] Mica is a crushed material of silicate minerals containing aluminum, potassium, magnesium, sodium, iron, etc. Examples of mica that can be used in the present invention include muscovite, phlogopite, biotite, artificial mica, and the like. Among them, muscovite is preferred from the viewpoint of good hue and low price.

In the production of mica, as methods for pulverizing minerals, wet pulverization and dry pulverization are known. The wet crushing method is a method in which raw mica is coarsely crushed in a dry crusher, then water is added, and the raw material is wet-pulverized in a slurry state, followed by dehydration and drying. Compared with the wet crushing method, the dry crushing method is a low-cost and common method, but it is easier to crush the minerals thinner and finer using the wet crushing method. Since mica having a preferable average particle diameter and thickness described below can be obtained, in the present invention, it is preferable to use a thin and fine pulverized material. Therefore, in the present invention, mica produced by a wet grinding method is preferably used.

In addition, in the wet grinding method, since a process of dispersing the object to be crushed in water is required, in order to improve the dispersion efficiency of the object to be crushed, a coagulation settling agent and/or a settling aid is generally added to the object to be crushed. Examples of coagulation settling agents and settling aids that can be used in the present invention include polyaluminum chloride, aluminum sulfate, ferrous sulfate, ferric sulfate, chlorinated copperas, polyferric sulfate, and polychlorinated copper. Iron, iron-silica inorganic polymer flocculant, ferric chloride-silica inorganic polymer flocculant, slaked lime (Ca(OH) ₂ ), sodium hydroxide (NaOH), soda ash (Na ₂ CO ₃ ) wait. The pH of these coagulant settling agents and settling aids is alkaline or acidic. The mica used in the present invention is preferably wet-pulverized without using a coagulation settling agent and/or a settling aid. If mica that has not been treated with a coagulation settling agent and/or a settling aid is used, it is difficult to decompose the liquid crystal resin in the liquid crystal resin composition, and it is difficult to generate a large amount of gas and reduce the molecular weight of the liquid crystal resin. Therefore, It is easy to better maintain the performance of the obtained molded body such as components for surface mount relays.

The median diameter of mica is preferably 10 to 100 μm, and particularly preferably 20 to 80 μm. When the median diameter of the mica is 10 μm or more, it is preferable because the effect of improving the rigidity of the molded body is likely to be sufficient. When the median diameter of the mica is 100 μm or less, the rigidity of the molded body is likely to be sufficiently improved, and the welding strength is also likely to be sufficient, so it is preferable. In addition, when the median diameter of the mica is 100 μm or less, it is easy to ensure fluidity sufficient for molding the planar connector or the like of the present invention. In addition, in this specification, the term "median diameter" means the center value based on the volume measured by the laser diffraction/scattering particle size distribution measuring method.

The thickness of the mica that can be used in the present invention is preferably 0.01 to 1 μm, and particularly preferably 0.03 to 0.3 μm, as measured by electron microscope observation. When the thickness of the mica is 0.01 μm or more, it is preferable because the mica is less likely to break during melt processing of the liquid crystalline resin composition and may easily increase the rigidity of the molded article. When the mica thickness is 1 μm or less, the effect of improving the rigidity of the molded body is likely to be sufficient, so it is preferable.

The mica that can be used in the present invention may be surface-treated with a silane coupling agent or the like, and/or may be granulated with a binder to form a granular form.

[(D) One or more inorganic fillers selected from the group consisting of talc and silica] The liquid crystalline resin composition of the present invention contains (D) one or more inorganic fillers selected from the group consisting of talc and silica. By containing the component (D) in the liquid crystalline resin composition of the present invention, the crack resistance and mechanical strength of the molded article composed of the liquid crystalline resin composition can be easily improved. Talc powder can be used individually by 1 type or in combination of 2 or more types. Silica can be used individually by 1 type or in combination of 2 or more types.

The median diameter of talc powder is preferably 50 μm or less. When the above-mentioned intermediate diameter is 50 μm or less, the melt viscosity of the liquid crystalline resin composition obtained is difficult to increase, and mold deposits (hereinafter also referred to as "MD") are difficult to occur when the liquid crystalline resin composition is molded. ”). From the perspective of easy reduction of melt viscosity and MD, the above-mentioned intermediate diameter is preferably 10~25 μm, more preferably 11~20 μm, and still more preferably 12~16 μm. In addition, the so-called mold deposit refers to the attachment on the metal mold during molding.

The median diameter of silica is not particularly limited, and may be, for example, 1.3 to 30.0 μm. If the above-mentioned intermediate diameter is within the above range, the formability of the liquid crystal resin molded article will be easily improved. The above-mentioned intermediate diameter is preferably 1.5~25.0 μm, more preferably 2.0~15.0 μm.

The content of component (D) is 5 to 25 mass %, preferably 7 to 23 mass %, more preferably 9 to 21 mass %, based on the entire liquid crystalline resin composition. When the content of component (D) is within the above range, it is easy to improve the crack resistance, mechanical strength and warpage of the molded article composed of the liquid crystalline resin composition while ensuring sufficient fluidity of the liquid crystalline resin composition. Deformation suppression effect.

The total content of (B) fibrous inorganic filler, (C) mica, and (D) one or more inorganic fillers selected from the group consisting of talc and silica, relative to the liquid crystalline resin combination The total content of the material is 30 to 55% by mass, preferably 35 to 50% by mass, and more preferably 39 to 46% by mass. If the total content is within the above range, the crack resistance, mechanical strength and warpage deformation suppressing effect of the molded article composed of the liquid crystalline resin composition can be easily improved while ensuring sufficient fluidity of the liquid crystalline resin composition. .

[(E) Inorganic fillers other than component (B), (C), and (D)] The liquid crystalline resin composition of the present invention may optionally contain (E) an inorganic filler other than the component (B), the component (C), and the component (D). When the liquid crystalline resin composition contains the component (D), the mechanical strength such as bending elastic modulus of the molded article of the liquid crystalline resin composition can be easily improved. (D) Component may be used individually or in combination of 2 or more types. Examples of the component (D) include plate-shaped fillers other than mica and talc, granular fillers other than silica, and the like.

(Plate fillers other than mica and talc) When the liquid crystalline resin composition of the present invention contains a plate-shaped filler, the molded article composed of the liquid crystalline resin composition can easily increase mechanical strength such as bending elastic modulus, and can easily suppress warpage. The plate-shaped filler may be used alone, or two or more types may be used in combination.

The preferred median diameter of the plate-shaped filler is 15~50 μm. If the above-mentioned median diameter is 15 μm or more, the necessary mechanical strength can be easily ensured, and the warpage suppressing effect of the molded article can be easily increased. If the above-mentioned median diameter is 50 μm or less, the fluidity of the composition when melted is easily improved. The preferred intermediate diameter is 20~30 μm.

The plate-shaped filler is not particularly limited, and examples thereof include glass flakes, graphite, and various metal foils (for example, aluminum foil, iron foil, copper foil), and the like.

(Granular fillers other than silica) When the liquid crystalline resin composition of the present invention contains a granular filler, the molded article composed of the liquid crystalline resin composition can easily increase mechanical strength such as bending elastic modulus, and can easily suppress surface whitening. A granular filler can be used individually by 1 type or in combination of 2 or more types.

The preferred median diameter of the granular filler is 0.3~5.0 μm. When the above-mentioned intermediate diameter is 0.3 μm or more, the impact resistance of the molded body can be easily maintained. When the above-mentioned intermediate diameter is 5.0 μm or less, the surface whitening suppressing effect of the molded article is likely to be high. The above-mentioned intermediate diameter is more preferably 0.5~5.0 μm, and more preferably 0.5~4.0 μm.

Examples of the granular filler include quartz powder, glass beads, glass powder, potassium aluminum silicate, diatomaceous earth, metal oxides such as iron oxide, titanium oxide, zinc oxide, and aluminum oxide; calcium carbonate, and magnesium carbonate. Metal carbonates such as calcium sulfate, barium sulfate, etc.; metal sulfates such as calcium pyrophosphate, anhydrous dicalcium phosphate, etc.; silicon carbide; silicon nitride; boron nitride, etc. In the present invention, barium sulfate is preferably used as the granular filler from the viewpoint of suppressing surface whitening of the molded article and reducing dust generation of the molded article.

The content of component (E) is preferably 0.1 to 5 mass %, more preferably 0.2 to 2 mass %, and still more preferably 0.5 to 1 mass %, based on the entire liquid crystalline resin composition. When the content of component (D) is within the above range, the fluidity of the liquid crystalline resin composition can be sufficiently ensured, and the mechanical strength of the molded article composed of the liquid crystalline resin composition can be easily improved.

[Other ingredients] In the range that does not impair the effects of the present invention, other polymers, other fillers, and known substances generally added to synthetic resins, that is, antioxidants, can also be appropriately added to the liquid crystalline resin composition of the present invention according to the required performance. Stabilizers such as ultraviolet absorbers, antistatic agents, flame retardants, colorants such as dyes and pigments, lubricants, release agents, crystallization accelerators, crystal nucleating agents, etc.

Other polymers refer to polymers other than (A) wholly aromatic polyester, and examples include epoxy group-containing copolymers. Other fillers refer to fillers other than component (B), component (C), component (D) and component (E), and examples thereof include organic fillers and carbon black.

[Preparation of liquid crystalline resin composition] The preparation of the liquid crystalline resin composition of the present invention is not particularly limited. For example, component (A), component (B), component (C), component (D), component (E) optionally, and other components are optionally blended, and these are melted using a 1-screw or 2-screw extruder. A kneading process is performed to prepare a liquid crystalline resin composition.

[Liquid crystalline resin composition] From the viewpoint of fluidity during melting and molding processability, the melt viscosity of the liquid crystalline resin composition of the present invention obtained as described above is preferably 80 Pa·sec or less, more preferably 75 Pa·sec or less, more preferably 73 Pa·sec or less. In this specification, the melt viscosity is obtained by the measurement method based on ISO 11443 under the conditions of a cylinder temperature 10 to 30°C higher than the melting point of the liquid crystal resin and a shear rate of 1000 sec ^-1 value.

From the viewpoint of crack resistance, the M-scale Rockwell hardness of the liquid crystalline resin composition of the present invention measured in accordance with JIS K 7202-2 is preferably 140 or less, more preferably 135 or less, and still more preferably 130 or less.

＜Planar Connector＞ By molding the liquid crystalline resin composition of the present invention, the planar connector of the present invention can be obtained. The shape of the planar connector is not particularly limited. The planar connector has an outer frame part and a lattice structure formed inside the outer frame part, and the pitch interval of the lattice parts in the lattice structure may be 1.5 mm or less. The planar connector may have openings inside the aforementioned lattice structure. The thickness ratio of the outer frame part and the grid part of the planar connector may be 1.0 or less. In addition, the planar connector may be a very thin-walled planar connector in which the width of the resin portion of the grid portion holding the terminals of the planar connector is 0.5 mm or less, and the height of the entire product is 5.00 mm or less.

As a shape of the planar connector of this invention, the shape shown in FIG. 1 is mentioned, for example. The overall size of the planar connector is 43.88 mm × 43.88 mm × 3 mmt, and has an outer frame part with a thickness of 3 mm or less, a grid part with a thickness of 1.5 mm or less, and an opening part of 13.88 mm x 13.88 mm in the center. In addition, in order to prevent the pins inserted into the planar connector from falling off, the width of the pin insertion holes of the planar connector may be partially narrowed.

The shape of the pin insertion holes in the grid portion of the planar connector of the present invention is not particularly limited, and may be square or circular.

The molding method for obtaining the planar connector of the present invention is not particularly limited. However, in order to prevent deformation of the obtained planar connector and obtain a planar connector with good flatness (described later), it is preferable to select a method that does not retain internal stress. forming conditions. In order to reduce the filling pressure and reduce the residual internal stress of the resulting planar connector, the temperature of the tube of the molding machine is preferably higher than the melting point of the liquid crystal polymer.

In addition, the metal mold temperature is preferably 70~100℃. If the metal mold temperature is low, the composite resin composition filled in the metal mold may cause flow failure, so it is not preferable. If the temperature of the metal mold is high, problems such as burrs may occur, which is not preferable. Regarding the injection speed, it is preferably 150 mm/second or more for molding. If the injection speed is low, an unfilled molded product may be obtained. Even if a fully filled molded product is obtained, the molded product may have high filling pressure and high residual internal stress, resulting in a connector with poor flatness.

The planar connector of the present invention is excellent in crack resistance and mechanical strength. The bending elastic modulus of the planar connector of the present invention may be 13 GPa or more, or may be 13.5 GPa or more. A planar connector with an elastic modulus of 13 GPa or more is less likely to crack even if it has a thin-walled lattice portion, and has excellent crack resistance. In addition, the flexural elastic modulus is measured according to ISO178.

In addition, warping deformation of the planar connector of the present invention is suppressed. The degree of deformation of a planar connector is judged by the flatness of the planar connector as an index. Specifically, place the planar connector on a horizontal table, measure the height of the planar connector with an image measuring device, and measure the position 0.5mm from the end face of the connector at 10mm intervals. Calculate the height between the maximum height and the minimum height. The difference is taken as flatness. The flat planar connector of the present invention suppresses changes in flatness before and after IR reflow. [Example]

The present invention will be explained in more detail below using examples, but the present invention is not limited only to these examples. ＜Fully aromatic polyester＞

・Fully aromatic polyester 1 After the following raw materials were put into the polymerization vessel, the temperature of the reaction system was raised to 140°C, and the reaction was carried out at 140°C for 1 hour. Thereafter, the temperature was raised to 360°C over another 5.5 hours, and then the pressure was reduced to 5 Torr (ie, 667 Pa) over 30 minutes, and melt polymerization was performed while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reaches a predetermined value, nitrogen gas is introduced and the pressure is constantly increased from a reduced pressure state to a pressurized state. The polymer is discharged from the lower part of the polymerization vessel, and the strands are granulated and granulated. The obtained pellets were heat-treated at 300° C. for 3 hours under a nitrogen flow to obtain pellets of wholly aromatic polyester 1. The melting point of the particles is 348°C and the melt viscosity is 9 Pa·s. In addition, the melting point of the wholly aromatic polyester 1 was measured according to the method for measuring the melting point described below, and the melt viscosity of the wholly aromatic polyester 1 was measured in the same manner as the method for measuring the melt viscosity described below. 6-Hydroxy-2-naphthoic acid (HNA): 1218g (48 mol%) 4-Hydroxybenzoic acid (HBA): 37g (2 mol%) 1,4-phenylenedicarboxylic acid: 560g (TA): (25 mol%) 4,4’-dihydroxybiphenyl (BP): 628g (25 mol%) Metal catalyst (potassium acetate catalyst): 165mg Chelating agent (acetic anhydride): 1432g

・Fully aromatic polyester 2 After the following raw materials were put into the polymerization vessel, the temperature of the reaction system was raised to 140°C, and the reaction was carried out at 140°C for 3 hours. Thereafter, the temperature was raised to 360°C over another 4.5 hours, and then the pressure was reduced to 10 Torr (i.e., 1330 Pa) over 15 minutes, and melt polymerization was performed while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reaches a predetermined value, nitrogen gas is introduced, the pressure is increased from a reduced pressure state to a pressurized state, the polymer is discharged from the lower part of the polymerization vessel, and the strands are granulated to obtain fully aromatic polyester 2. Particles. The melting point of the particles is 320°C and the melt viscosity is 20 Pa·s. In addition, the melting point of the wholly aromatic polyester 2 was measured according to the method for measuring the melting point described below, and the melt viscosity of the wholly aromatic polyester 2 was measured in the same manner as the method for measuring the melt viscosity described below. 4-Hydroxybenzoic acid (HBA): 1347g (60 mol%) 1,4-phenylenedicarboxylic acid (TA): 378g (14 mol%) 1,3-phenylenedicarboxylic acid (IA): 162g (6 mol%) 4,4’-dihydroxybiphenyl (BP): 605g (20 mol%) Metal catalyst (potassium acetate catalyst): 110mg Chelating agent (acetic anhydride): 1704g

[Measurement method of melting point] In a DSC manufactured by TA Instruments, the endothermic peak temperature (Tm1) observed when a fully aromatic polyester is heated from room temperature at a temperature rise condition of 20°C/min is measured, and then maintained at a temperature of (Tm1+40)°C. After 2 minutes, the polymer was temporarily cooled to room temperature under a temperature lowering condition of 20° C./min, and then the temperature of the endothermic peak observed during heating under a temperature increasing condition of 20° C./min was measured again, and was used as the melting point of the polymer.

＜Materials other than fully aromatic polyester＞ ・Glass fiber: ECS03T-786H (manufactured by Nippon Electric Glass Co., Ltd., chopped strands, fiber diameter 10μm, length 3mm, true specific gravity 2.6) ・Ground glass fiber: PF70E001 (manufactured by Nittobo Co., Ltd., fiber diameter 10 μm, average fiber length 70 μm (manufacturer’s nominal value)) ・Mica: AB-25S (manufactured by Yamaguchi Mica Industry Co., Ltd., mica, medium diameter 25 μm) ・Talc: ROWN TALC PP (manufactured by Matsumura Industrial Co., Ltd., talc, median diameter 14.6 μm) ・Silica: FB-5SDC (manufactured by Denka Co., Ltd., silica, median diameter 5.0 μm)

<Manufacture of liquid crystalline resin composition> Using a twin-screw extruder (TEX30α model manufactured by Nippon Steel Works Co., Ltd.), the above components were melt-kneaded at the ratio shown in Table 1 at the following tube temperature to obtain liquid crystalline resin composition pellets. [Manufacturing conditions] Material tube temperature: 370°C: Case of liquid crystalline resin composition containing wholly aromatic polyester 1 350°C: Case of liquid crystalline resin composition containing fully aromatic polyester 2

＜Melt viscosity＞ Capilograph 1B type manufactured by Toyo Seiki Seisakusho Co., Ltd. is used. At a temperature of 10 to 30°C higher than the melting point of liquid crystal resin, an orifice with an inner diameter of 1 mm and a length of 20 mm is used at 1000/second. The melt viscosity of the liquid crystalline resin composition is measured according to ISO 11443 at a shear rate of . Among them, the specific measurement temperatures are: 370°C for the liquid crystalline resin composition containing the wholly aromatic polyester 1, and 350°C for the liquid crystalline resin composition containing the wholly aromatic polyester 2. The results are shown in Table 1.

＜Weight average fiber length＞ The weight average fiber length of the fibrous inorganic filler in the liquid crystalline resin composition is measured by the following method. 5 g of liquid crystalline resin composition particles were heated at 600° C. for 2 hours to ashes. After the ashed residue was fully dispersed in a 5% by mass polyethylene glycol aqueous solution, it was moved to a petri dish with a dropper, and the fibrous inorganic filler was observed with a stereomicroscope. The following weight average fiber length of the fibrous inorganic filler was used: 10 stereoscopic microscope images of the fibrous inorganic filler were imported from a CCD camera to a PC, and image processing was performed with an image measuring machine (LUZEXFS manufactured by NIRECO Co., Ltd.) In this method, the average value of the fiber length is measured for 100 fibrous inorganic fillers per one stereoscopic microscope image, that is, a total of 1,000 fibrous inorganic fillers. The results are shown in Table 1.

＜Load deflection temperature＞ The liquid crystalline resin composition was injection molded under the following molding conditions to obtain ISO test piece A-shaped. The test piece was cut into 80 mm×10 mm×4 mm to prepare a test piece. Using the test piece, the load deflection temperature was measured in accordance with ISO75-1 and 2. The deflection temperature under load is used as an index indicating the heat resistance of the molded article. The results are shown in Table 1. [Forming conditions] Forming machine: Sumitomo Heavy Industries, Ltd., SE100DU Material tube temperature: 370°C (Examples 1 to 5 and Comparative Examples 1 to 3, 5 and 6) 350℃(Comparative Example 4) Metal mold temperature: 90℃ Injection speed: 33mm/sec

＜Bending test＞ The liquid crystalline resin composition was injection molded under the following molding conditions to obtain ISO test piece A-shaped. The test piece was cut into 80 mm×10 mm×4 mm to prepare a bending test piece. Using the test piece, the bending strength, bending elastic modulus, and bending strain were measured in accordance with ISO178. The results are shown in Table 1. [Forming conditions] Forming machine: Sumitomo Heavy Industries, Ltd. SE100DU Material tube temperature: 370°C (Examples 1 to 5 and Comparative Examples 1 to 3, 5 and 6) 350℃(Comparative Example 4) Metal mold temperature: 90℃ Injection speed: 33mm/sec

＜Rockwell Hardness＞ The liquid crystalline resin composition was injection molded under the following molding conditions to obtain a test piece for measurement (100 mm × 10 mm × 4 mm). Two of these test pieces were stacked to make a test piece with a thickness of 8 mm, and measured under M-scale conditions (standard load: 10 kg, test load: 100 kg) using a Rockwell hardness tester (Toyo Seiki Manufacturing Co., Ltd.) in accordance with JIS K 7202-2. , steel ball indenter diameter: 1/2 in) Rockwell hardness. The results are shown in Table 1. [Forming conditions] Forming machine: Sumitomo Heavy Industries, Ltd., SE100DU Material tube temperature: 370°C (Examples 1 to 5 and Comparative Examples 1 to 3, 5 and 6) 350℃(Comparative Example 4) Metal mold temperature: 80℃ Injection speed: 33mm/sec

＜Flatness＞ The liquid crystalline resin composition was injection molded under the following molding conditions to prepare five flat test pieces of 80 mm×80 mm×1 mm. The obtained first flat test piece was placed on a horizontal surface, and the height from the horizontal surface was measured at 9 locations on the flat test piece using a CNC image measuring machine (Quick Vision 404PRO) manufactured by Mitutoyo Co., Ltd. And calculate the average height based on the measured values obtained. To measure the height position, a square with a side of 74 mm is placed on the main plane of the flat test piece so that the distance between the square and each side of the main plane is 3 mm. The corresponding positions of the midpoint of the side and the intersection of the two diagonals of the square. The height from the above-mentioned horizontal plane is the same as the above-mentioned average height, and the plane parallel to the above-mentioned horizontal plane is used as the reference plane. From the heights measured at the above nine places, select the maximum height and the minimum height from the reference plane, and calculate the difference between the two. Similarly, the above-mentioned difference was calculated for the other four flat test pieces, and the five obtained values were averaged and used as the flatness value before reflow. The results are shown in Table 1 [Forming conditions] Forming machine: Sumitomo Heavy Industries, Ltd., SE-100DUZ Material tube (cylinder) temperature: 370°C (Examples 1 to 5 and Comparative Examples 1 to 3, 5 and 6) 350℃(Comparative Example 4) Metal mold temperature: 80℃ Injection speed: 33mm/sec Maintaining pressure: 60MPa

IR reflow (IR reflow) under the following conditions was performed, and the flatness was measured by the above method, and was used as the flatness after reflow (reflow). The results are shown in Table 1. [IR reflow conditions] Measuring device: Large desktop reflow soldering device RF-300 manufactured by Japan Pulse Technology Research Institute (using far infrared heater) Sample conveying speed: 140mm/second Reflow oven pass time: 5 minutes Temperature condition of preheating zone: 150℃ Temperature conditions in the reflow area: 225°C Peak temperature: 287℃

＜Screen strength＞ Under the following molding conditions, the liquid crystalline resin composition was injection molded into a planar connector (number of pin holes: 1248 pins) as shown in Figure 1, with an overall size of 43.88mm × 43.88mm × 3mmt, and a central portion It has an opening of 13.88mm×13.88mm, and the grid portion has a pitch interval of 1.0mm. In addition, a special gate (overflow) as shown in Figure 2 is used as the gate. [Forming conditions] Forming machine: Sumitomo Heavy Industries, Ltd. SE30DUZ Material pipe temperature (indicated by the temperature from the nozzle side): 370℃-370℃-370℃-380℃(Examples 1~5 and Comparative Examples 1~3, 5 and 6) 350℃-350℃-350℃-340℃(Comparative Example 4) Metal mold temperature: 80℃ Injection speed: 300mm/sec Maintaining pressure: 50MPa Holding time: 2sec Cooling time: 10sec Screw speed: 120rpm Screw back pressure: 1.2Mpa

Using the obtained planar connector, the strength at the position shown in Figure 3 (blacked-out part) was measured under the following measurement conditions, and was used as the mesh strength. The results are shown in Table 1. [Measurement conditions] Testing machine: Tensilon RTA-250 made by ORIENTEC Span distance: 6mm Test speed: 1mm/min

＜Crack resistance＞ The planar connector in Figure 1 obtained as described above was subjected to IR reflow under the following conditions, the grid portion was observed with an optical microscope, and the number of cracks was measured. The smaller the number of cracks, the higher the crack resistance. Specifically, the number of cracks generated in one planar connector was counted, and the crack resistance was evaluated based on the following criteria. ○ (Good): The number of cracks is less than 8. × (Defect): The number of cracks is 8 or more. [IR reflow conditions] Measuring machine: Large desktop reflow soldering device RF-300 manufactured by Japan Pulse Technology Research Institute (using far infrared heater) Sample conveying speed: 140mm/sec Reflow oven passing time: 5min temperature conditions; Preheating zone: 150℃ Reflow zone: 240℃ Peak temperature: 260℃

[Table 1] Example Example Example Example Example Comparative example Comparative example Comparative example Comparative example Comparative example Comparative example 1 2 3 4 5 1 2 3 4 5 6 Fully aromatic polyester Monomeric composition HNA Mol% 48 48 48 48 48 48 48 48 48 48 HBA Mol% 2 2 2 2 2 2 2 2 60 2 2 TA Mol% 25 25 25 25 25 25 25 25 14 25 25 IA Mol% 6 BP Mol% 25 25 25 25 25 25 25 25 20 25 25 total Mol% 100 100 100 100 100 100 100 100 100 100 100 Resin composition Fully aromatic polyester mass % 60 55 55 55 55 55 55 55 55 55 60 filler fiberglass mass % 10 15 15 15 15 15 15 15 15 twenty two ground fiberglass mass % 15 mica mass % 20 20 10 20 20 30 20 20 4 talc mass % 10 10 20 10 30 10 10 14 Silicon dioxide mass % 10 30 total mass % 40 45 45 45 45 45 45 45 45 45 40 total mass % 100 100 100 100 100 100 100 100 100 100 100 Melt viscosity Pa・s 28 32 33 29 34 33 30 38 27 twenty four 28 Weight average fiber length of fibrous inorganic filler μm 280 280 280 280 380 280 280 280 280 100 280 Load deflection temperature ℃ 307 319 308 303 326 315 320 301 260 290 305 Bending strength MPa 153 174 155 164 189 164 188 165 145 135 158 bending elastic modulus MPa 16200 17300 13800 16500 18300 12800 19500 11000 10000 15500 14500 bending strain % 1.9 1.5 1.5 1.4 1.3 2.0 1.1 2.5 3.0 1.9 2.0 Rockwell hardness (M scale) - 122 128 122 115 127 121 149 95 128 127 122 Flatness Before reflow mm 0.10 0.05 0.12 0.07 0.05 0.11 0.04 3.78 0.25 0.08 0.24 After reflow mm 0.22 0.17 0.34 0.81 0.15 2.07 0.14 3.89 2.90 0.20 4.28 Screen strength N 16.1 14.5 16.8 14.4 15.3 14.8 9.8 16.0 13.2 10.1 14.5 Crack resistance - 〇 〇 〇 〇 〇 〇 × 〇 〇 × 〇

As shown by the results shown in Table 1, the liquid crystalline resin compositions of the Examples enable the production of planar connectors with excellent crack resistance and mechanical strength, suppressed bending deformation, and have good fluidity.

without

Figure 1 is a diagram showing a planar connector formed according to the embodiment, (a) is a plan view, and (b) is a right side view. Among them, the unit of the values in the figure is mm. Figure 2 is a diagram showing the gate of the planar connector formed according to the embodiment. (a) is a plan view and (b) is a right side view. Among them, the unit of the values in the figure is mm. Figure 3 is a diagram showing measurement locations in the measurement of mesh strength performed in Examples. Among them, the unit of the values in the figure is mm.

Claims (4)

A liquid crystal resin composition for planar connectors, containing: (A) fully aromatic polyester; (B) fibrous inorganic filler; (C) mica; and (D) selected from talc and silicon dioxide. One or more inorganic fillers of the group, wherein the aforementioned (A) fully aromatic poly contains the following structural units (I) to (IV), and the content of the structural unit (I) is compared to all the structural units. The content of structural unit (II) is 0.5~7.5 mol%; the content of structural unit (III) is 8.5~30 mol%; the content of structural unit (IV) is 8.5 ~30 mol%, the weight average fiber length of the aforementioned (B) fibrous inorganic filler is 150 ~ 500 μm, and the content of the aforementioned (A) fully aromatic polyester is 45 compared to the entire liquid crystalline resin composition. ~70 mass%; the content of the aforementioned (B) fibrous inorganic filler is 5-20 mass%; the content of the aforementioned (C) mica is 7-27 mass%; the aforementioned (D) is selected from talc and silicon dioxide The content of one or more inorganic fillers in the group is 5 to 25% by mass, and the aforementioned (B) fibrous inorganic filler, the aforementioned (C) mica, and the aforementioned (D) are selected from talc and dioxide. The total content of one or more inorganic fillers in the group consisting of silicon is 30 to 55% by mass, [Chemical 1] (In the formula, Ar ₁ and Ar ₂ each independently represent an aryl group). The liquid crystal resin composition according to claim 1, wherein the (B) fibrous inorganic filler is at least one selected from the group consisting of glass fiber and ground glass fiber. The liquid crystalline resin composition according to claim 1 or 2 has a Rockwell hardness of M scale measured in accordance with JIS K 7202-2 of 140 or less. A planar connector, including the liquid crystalline resin composition according to any one of claims 1 to 3, having an outer frame and a lattice structure formed inside the outer frame, and the nodes of the lattice portion of the lattice structure The distance is less than 1.5mm.

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