JP2014237740A - Composite resin composition and planar connector molded from the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite resin composition which can obtain a planar connector excellent in flatness, weld strength, and crack resistance, and a planar connector molded from the composite resin composition.SOLUTION: A composite resin composition comprises (A) a liquid crystal polymer containing a predetermined component, (B) glass fiber, and (C) one or more plate-shaped inorganic fillers selected from the group consisting of mica and talc. The content of the liquid crystal polymer (A) is 45-60 mass% with respect to the total mass of the composite resin composition, the content of the glass fiber (B) is larger than 25 mass% and equal to or less than 30 mass% with respect to the total mass of the composite resin composition, and the total amount of the one or more plate-shaped inorganic fillers (C) selected from the group consisting of mica and talc is 15-20 mass% with respect to the total mass of the composite resin composition.

Description

  The present invention relates to a composite resin composition and a planar connector molded from the composite resin composition.

  Since liquid crystalline polymers are excellent in fluidity and the like, they have been conventionally used as materials for various electronic components.

  In particular, with the recent improvement in performance of electronic equipment, there is a need for electronic parts (connectors and the like) having a fine structure. In order to meet such needs, for example, Patent Document 1 discloses that a composite resin composition composed of a predetermined liquid crystalline polymer, an inorganic filler, and glass fiber is molded and cracked in a lattice portion of a planar connector (“ There has been disclosed a planar connector having crack resistance, which is less likely to cause cracks).

JP 2012-214652 A

  However, it has been difficult to stably obtain a planar connector having high crack resistance without sacrificing flatness. Further, as a result of studies by the present inventors, it has been found that the occurrence of cracks in a planar connector correlates with the weld strength of the connector. That is, in order to suppress the occurrence of cracks, it is necessary to increase the weld strength of the connector.

  The present invention has been made in view of such circumstances, and a composite resin composition from which a flat connector excellent in flatness, weld strength and crack resistance can be obtained, and a flat shape molded from the composite resin composition. The purpose is to provide a connector.

  The present inventors have found that the above problem can be solved by combining a liquid crystalline polymer containing a specific amount of a specific structural unit, glass fiber, and a predetermined plate-like inorganic filler. Specifically, the present invention provides the following.

(1) A composite resin composition comprising (A) a liquid crystalline polymer, (B) glass fiber, and (C) one or more plate-like inorganic fillers selected from the group consisting of mica and talc. ,
The (A) liquid crystalline polymer has the following constituent units as essential constituents: (I) 4-hydroxybenzoic acid, (II) 2-hydroxy-6-naphthoic acid, (III) terephthalic acid, (IV) Including isophthalic acid and (V) 4,4′-dihydroxybiphenyl,
The structural unit of (I) is 35 to 75 mol% with respect to all the structural units,
The structural unit of (II) is 2 to 8 mol% with respect to all the structural units,
The structural unit of (III) is 4.5 to 30.5 mol% with respect to all structural units,
The structural unit of (IV) is 2 to 8 mol% with respect to all the structural units,
The structural unit of (V) is 12.5 to 32.5 mol% with respect to all the structural units,
The total amount of the structural units (II) and (IV) is 4 to 10 mol% with respect to all the structural units,
Said (A) liquid crystalline polymer is 45-60 mass% with respect to the whole composite resin composition,
The (B) glass fiber is more than 25 mass% and 30 mass% or less with respect to the entire composite resin composition,
One or more plate-shaped inorganic fillers selected from the group consisting of (C) mica and talc are a composite resin composition having a total amount of 15 to 20% by mass with respect to the entire composite resin composition.

(2) Molded from the composite resin composition according to (1),
It has a lattice structure inside the outer frame part,
The planar connector whose pitch interval of the lattice part in the lattice structure is 1.5 mm or less.

  ADVANTAGE OF THE INVENTION According to this invention, the composite resin composition from which the planar connector excellent in flatness, weld strength, and crack resistance is obtained, and the planar connector shape | molded from the said composite resin composition are provided.

It is a figure which shows the planar connector shape | molded in the Example. (A) is a top view of a planar connector. (B) is the detail of the A section in (a). In addition, the unit of the numerical value in a figure is mm.

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

[Composite resin composition]
The composite resin composition of the present invention contains a predetermined amount of a specific liquid crystalline polymer, glass fiber, and a plate-like inorganic filler. Hereinafter, the components constituting the composite resin composition of the present invention will be described.

(Liquid crystal polymer)
The liquid crystalline polymer in the present invention contains, as essential constituents, the following constituent units: (I) 4-hydroxybenzoic acid (also referred to as “HBA”), (II) 2-hydroxy-6-naphthoic acid (“HNA”). (III) terephthalic acid (also referred to as “TA”), (IV) isophthalic acid (also referred to as “IA”) and (V) 4,4′-dihydroxybiphenyl (also referred to as “BP”).

  The liquid crystalline polymer in the present invention contains the above structural units in a specific ratio. That is, the structural unit of (I) is 35-75 mol% (preferably 40-65 mol%) with respect to all the structural units. The structural unit of (II) is 2 to 8 mol% (preferably 3 to 7 mol%) with respect to all the structural units. The structural unit of (III) is 4.5-30.5 mol% (preferably 13-26 mol%) with respect to all the structural units. The structural unit of (IV) is 2 to 8 mol% (preferably 3 to 7 mol%) with respect to all the structural units. The structural unit of (V) is 12.5 to 32.5 mol% (preferably 15.5 to 29 mol%) with respect to all the structural units. The total amount of the structural units (II) and (IV) is 4 to 10 mol% (preferably 5 to 10 mol%) with respect to all the structural units.

  When the constituent unit of (I) is less than 35 mol% or more than 75 mol% with respect to all the constituent units, the melting point of the liquid crystalline polymer becomes remarkably high, and liquid crystallinity is produced in the production of molded products such as planar connectors. This is not preferable because the polymer may solidify in the reactor and a liquid crystalline polymer having a desired molecular weight may not be produced.

  When the amount of the structural unit (II) is less than 2 mol% with respect to all the structural units, there is a possibility that cracks may occur in the lattice portion or the like when a molded product such as a planar connector is produced. Moreover, when the structural unit of (II) exceeds 8 mol% with respect to all the structural units, since the heat resistance of a liquid crystalline polymer will become low, it is unpreferable.

  When the constituent unit of (III) is less than 4.5 mol% or more than 30.5 mol% with respect to all the constituent units, the melting point of the liquid crystalline polymer becomes remarkably high, and a molded product such as a planar connector is produced. At this time, the liquid crystalline polymer is solidified in the reactor, and it may not be possible to produce a liquid crystalline polymer having a desired molecular weight.

  If the structural unit of (IV) is less than 2 mol% with respect to all the structural units, there is a possibility that cracks may occur in the lattice portion or the like when a molded product such as a planar connector is produced. Moreover, when the structural unit of (IV) exceeds 8 mol% with respect to all the structural units, since the heat resistance of a liquid crystalline polymer will become low, it is unpreferable.

  When the constituent unit of (V) is less than 12.5 mol% or more than 32.5 mol% with respect to all the constituent units, the melting point of the liquid crystalline polymer becomes remarkably high, and a molded product such as a planar connector is produced. At this time, the liquid crystalline polymer is solidified in the reactor, which makes it impossible to produce a liquid crystalline polymer having a desired molecular weight.

  When the total amount of the structural units (II) and (IV) is less than 4 mol% with respect to all the structural units, the crystallization heat amount of the liquid crystalline polymer can be 2.5 J / g or more. In this case, when a molded product such as a planar connector is manufactured, cracks may occur in the lattice portion or the like, which is not preferable. A preferable value for the heat of crystallization of the liquid crystalline polymer is 2.3 J / g or less, and more preferably 2.0 J / g or less. The crystallization heat quantity indicates the crystallization state of the liquid crystalline polymer, and is a value obtained by differential calorimetry. Specifically, after observing the endothermic peak temperature (Tm1) observed when the liquid crystalline polymer is measured from room temperature at a temperature rising condition of 20 ° C./min, the liquid crystal polymer is held at a temperature of Tm1 + 40 ° C. for 2 minutes, and then 20 ° C. It refers to the calorific value of the exothermic peak obtained from the peak of the exothermic peak temperature observed when measured under the temperature lowering condition per minute.

  Moreover, it is not preferable that the total amount of the structural units (II) and (IV) exceeds 10 mol% with respect to all the structural units because the heat resistance of the liquid crystalline polymer is lowered.

  In addition, the well-known other structural unit can also be introduce | transduced into the liquid crystalline polymer in this invention in the range which does not inhibit the objective of this invention.

  The liquid crystalline polymer in the present invention can be obtained by polymerizing the above structural units by a direct polymerization method, a transesterification method, a melt polymerization method, a solution polymerization method, a slurry polymerization method, a solid phase polymerization method or the like.

  In the polymerization of the above structural unit, in addition to the above structural unit, an acylating agent for the above structural unit or a monomer whose terminal is activated as an acid chloride derivative can be used in combination. Examples of the acylating agent include acid anhydrides such as acetic anhydride.

In the polymerization of the above structural units, various catalysts can be used, such as dialkyl tin oxide, diaryl tin oxide, titanium dioxide, alkoxy titanium silicates, titanium alcoholates, alkali metal salts of carboxylic acids, alkaline earths. Metal salts, Lewis acid salts (BF _{3 and the} like) and the like. The amount of the catalyst used may be about 0.001-1% by mass, preferably about 0.003-0.2% by mass, based on the total amount of the above structural units.

  The conditions for the polymerization reaction are not particularly limited as long as the polymerization of the above structural units proceeds. For example, the reaction temperature is 200 to 380 ° C., the final ultimate pressure is 0.1 to 760 Torr (that is, 13 to 101,080 Pa). ).

  The polymerization reaction may be a method (one-step system) in which all the raw material monomers, the acylating agent and the catalyst are charged in the same reaction vessel and the reaction is started, and the hydroxyl groups of the raw material monomers (I), (II) and (V) are acylated. A method of reacting with the carboxyl groups of (III) and (IV) (two-stage system) after acylation with an agent may be used.

  Some liquid crystalline polymers obtained from the structural units (I) to (V) do not form an anisotropic molten phase depending on the constituent components and the sequence distribution in the liquid crystalline polymer. In terms of having easy processability, the liquid crystalline polymer in the present invention is preferably one that forms an anisotropic molten phase, that is, a liquid crystalline polymer that exhibits optical anisotropy when melted.

  The property of melt anisotropy can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. Specifically, for melting anisotropy, a polarizing microscope (manufactured by Olympus Co., Ltd.) is used, a sample placed on a hot stage (manufactured by Linkham Co., Ltd.) is melted, and the magnification is 150 times under a nitrogen atmosphere. This can be confirmed by observation. Liquid crystalline polymers that exhibit optical anisotropy when melted are optically anisotropic and transmit light when inserted between crossed polarizers. When the sample is optically anisotropic, for example, polarized light is transmitted even in a molten stationary liquid state.

Furthermore, the melt viscosity of the liquid crystalline polymer at a shear rate of 1000 / second at a temperature 10 to 40 ° C. higher than the melting point is 1 × 10 ⁵ Pa · s or less (more preferably ⁵ Pa · s or more and 1 × 10 ² Pa · s. s or less) is preferable in that the fluidity of the composite resin composition is ensured and the filling pressure does not become excessive at the time of forming the lattice portion of the planar connector.

  The composite resin composition of this invention contains 45-60 mass% of said liquid crystalline polymer with respect to the whole composite resin composition in a composite resin composition. If the amount of the liquid crystalline polymer is less than 45% by mass with respect to the entire composite resin composition, the fluidity deteriorates, which is not preferable. When the amount of the liquid crystalline polymer is more than 60% by mass with respect to the entire composite resin composition, it is preferable because the bending elastic modulus and crack resistance of a molded product such as a planar connector obtained from the composite resin composition are decreased. Absent. It is preferable that the composite resin composition of this invention contains 50-60 mass% of said liquid crystalline polymer with respect to the whole composite resin composition in a composite resin composition.

(Glass fiber)
The composite resin composition of this invention contains glass fiber in more than 25 mass% and 30 mass% or less with respect to the whole composite resin composition in a composite resin composition.

  When the amount of the glass fiber is 25% by mass or less with respect to the entire composite resin composition, the weld strength of the molded product obtained from the composite resin composition is low, and when the molded product is a planar connector or the like, Cracks are likely to occur in the lattice portion.

  When the amount of the glass fiber is more than 30% by mass with respect to the entire composite resin composition, the fluidity of the composition deteriorates and the composite contains more than 30% by mass of glass fiber with respect to the entire composite resin composition. The flat connector obtained from the resin composition has poor flatness and may have distortion.

  As a result of the study by the present inventors, it has been found that there is a correlation between the weld strength of a molded product (such as a planar connector) and the number of cracks of the molded product. Specifically, using various composite resin compositions, for the planar connector and the test piece obtained by the method described in the following examples, the weld strength and the number of cracks were measured under the measurement conditions described in the following examples. investigated. As a result, the weld strength of the test piece obtained from the composite resin composition in which the amount of glass fiber is 25% by mass or less with respect to the entire composite resin composition is 10 kgf or less (in some cases, 8 kgf or less), and Many cracks were observed in the planar connector obtained from the composite resin composition. On the other hand, the weld strength of the test piece obtained from the composite resin composition containing glass fiber of more than 25% by mass and 30% by mass or less (27.5-30% by mass) with respect to the entire composite resin composition is more than 10 kgf. In addition, almost no cracks were observed in the planar connector obtained from the composite resin composition.

  Although the average fiber length of the glass fiber in this invention is not specifically limited, It is preferable that it is 250-800 micrometers. An average fiber length of less than 250 μm is not preferable because cracks may occur in a lattice portion or the like of a molded product such as a planar connector obtained from the composite resin composition. If the average fiber length is more than 800 μm, the fluidity is deteriorated and molding of the composite resin composition may be difficult, which is not preferable.

  In addition, the fiber diameter of the glass fiber in the present invention is not particularly limited, but generally about 5 to 15 μm is used.

(Plate-like inorganic filler)
The composite resin composition of the present invention includes one or more plate-like inorganic fillers selected from the group consisting of mica and talc. By including the plate-like inorganic filler in the composite resin composition together with the glass fiber, a composite that can form a molded article having excellent flatness, crack resistance and weld strength without deteriorating the fluidity of the composite resin composition. A resin composition is obtained.

  The total amount of the plate-like inorganic filler contained in the composite resin composition of the present invention is 15 to 20% by mass with respect to the entire composite resin composition. When the plate-like inorganic filler is contained in such a range in the composite resin composition, the effect of improving the weld strength and the effect of reducing the number of cracks of the molded body produced by the glass fiber are reinforced. Such a reinforcing effect is remarkably exhibited when the amount of the glass fiber in the composite resin composition of the present invention is a value close to the upper limit (that is, 30% by mass with respect to the entire composite resin composition).

[Mica]
Mica is a pulverized product of silicate mineral containing aluminum, potassium, magnesium, sodium, iron and the like. Examples of mica in the present invention include muscovite, phlogopite, biotite, and artificial mica. Of these, muscovite is preferable in terms of good hue and low price.

  In addition, in the production of mica, wet pulverization methods and dry pulverization methods are known as methods for pulverizing minerals. The wet pulverization method is a method in which raw mica is roughly pulverized with a dry pulverizer, then water is added and main pulverization is performed by wet pulverization in a slurry state, followed by dehydration and drying. Compared with the wet pulverization method, the dry pulverization method is a low-cost and general method, but it is difficult to pulverize the mineral thinly and finely. In the present invention, it is preferable to use a thin and fine pulverized product because mica having a preferable average particle diameter and thickness described later can be obtained. Therefore, in the present invention, it is preferable to use mica produced by a wet pulverization method.

In addition, since the wet pulverization method requires a step of dispersing the material to be pulverized in water, a coagulating sedimentation agent and / or settling aid is added to the material to be pulverized in order to increase the dispersion efficiency of the material to be crushed. Is common. Examples of the coagulating settling agent and settling aid include polyaluminum chloride, aluminum sulfate, ferrous sulfate, ferric sulfate, copper chloride, polyiron sulfate, polyferric chloride, iron-silica inorganic polymer flocculant, chloride A ferric-silica inorganic polymer flocculant, slaked lime (Ca (OH) ₂ ), caustic soda (NaOH), soda ash (Na ₂ CO ₃ ) and the like can be mentioned. However, these coagulating sedimentation agents and sedimentation aids are alkaline or acidic in pH. Therefore, in the present invention, if mica treated with a coagulating sedimentation agent and / or sedimentation aid is used, it may cause degradation of the polymer in the composite resin composition, causing a large amount of gas generation or a decrease in the molecular weight of the polymer. Can adversely affect the performance of the resulting molded article. Therefore, the mica used in the present invention is preferably one that does not use a coagulating sedimentation agent and / or a sedimentation aid when wet pulverizing.

  The mica in the present invention preferably has an average particle size of 10 to 100 μm, particularly preferably 20 to 80 μm, as measured by a microtrack laser diffraction method. If the average particle diameter of mica is less than 10 μm, the molded product may not have sufficient rigidity, which is not preferable. If the average particle diameter of mica is more than 100 μm, the rigidity and weld strength of the molded product may not be sufficient. If the average particle diameter of mica is more than 100 μm, the fluidity of the composite resin composition may not be sufficient.

  The thickness of mica in the present invention is preferably 0.01 to 1 μm, particularly preferably 0.03 to 0.3 μm, as measured by observation with an electron microscope. If the thickness of the mica is less than 0.01 μm, the mica tends to break during the melt processing of the composite resin composition, which is not preferable. If the thickness of mica exceeds 1 μm, the molded product may not have sufficient rigidity.

  The mica in the present invention may be surface-treated with a silane coupling agent or the like and / or granulated with a binder.

〔talc〕
As the talc in the present invention, the total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is 2.5 mass% or less with respect to the total solid content of the talc, and Fe ₂ O ₃ and Al ₂ O The total content of ₃ is more than 1.0% by mass and 2.0% by mass or less, and the CaO content is preferably less than 0.5% by mass. That is, the talc in the present invention contains at least one of Fe ₂ O ₃ , Al ₂ O ₃ and CaO in addition to the main components SiO ₂ and MgO, and each component may be included in the above range. Good.

In the above talc, when the total amount of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is more than 2.5% by mass, the moldability of the composite resin composition and the heat resistance of the molded product molded from the composite resin composition Sexuality may deteriorate. Therefore, the total amount of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is preferably 1.0% by mass or more and 2.0% by mass or less.

The cumulative average particle size (D ₅₀ ) of talc measured by laser diffraction method in the present invention is 4.0 to 20.0 μm from the viewpoint of maintaining the fluidity of the composite resin composition. It is preferable that it is 10 to 18 μm.

(Other ingredients)
In addition to the above components, the composite resin composition of the present invention may contain a nucleating agent, carbon black, pigment, antioxidant, stabilizer, plasticizer, lubricant, mold release agent, flame retardant, and the like. . The amounts and types of these components can be appropriately adjusted according to the effect to be obtained.

(Production method of composite resin composition)
The method for producing the composite resin composition of the present invention is not particularly limited as long as the above liquid crystalline polymer and glass fiber can be uniformly mixed, and can be appropriately selected from conventionally known methods for producing resin compositions. For example, each component is melt-kneaded and extruded using a melt-kneader such as a single-screw or twin-screw extruder, and then the resulting composite resin composition is processed into a desired form such as powder, flakes, pellets, etc. A method is mentioned.

  Since the composite resin composition of the present invention is excellent in fluidity, the minimum filling pressure at the time of molding is hardly excessive, and a portion having a complicated shape such as a lattice portion of a planar connector can be preferably molded. The minimum filling pressure is specified as the minimum injection filling pressure at which a good molded product can be obtained at 365 ° C. when molding the composite resin composition.

[Flat connector]
By molding the composite 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, and may be a planar connector having a lattice structure inside the outer frame portion and a pitch interval of the lattice portions in the lattice structure being 1.5 mm or less. Further, the planar connector may be a very thin planar connector in which the width of the resin portion of the lattice portion holding the terminals in the planar connector is 0.5 mm or less and the total height of the product is 5.0 mm or less. Specific examples of the planar connector of the present invention include those shown in FIG.

  The shape of the pin insertion hole in the lattice part of the planar connector of the present invention is not particularly limited, and may be a square, a round, a deformed hole, or the like.

  The molding method for obtaining the planar connector of the present invention is not particularly limited, but molding conditions with little residual internal stress are required in order to obtain a planar connector having good flatness to prevent deformation of the obtained planar connector. Is preferred. In order to lower the filling pressure and reduce the residual internal stress of the planar connector obtained, the cylinder temperature of the molding machine is preferably a temperature equal to or higher than the melting point of the liquid crystalline polymer.

  The mold temperature is preferably 70 to 100 ° C. If the mold temperature is low, the composite resin composition filled in the mold may cause flow failure, which is not preferable. If the mold temperature is high, problems such as the occurrence of burrs may occur, which is not preferable. The injection speed is preferably 150 mm / second or more. If the injection speed is low, there is a possibility that only an unfilled molded product can be obtained. Even if a completely filled molded product is obtained, it becomes a molded product with a high filling pressure and a large residual internal stress, resulting in a poor flatness. May only be obtained.

  In addition, the planar connector of the present invention is excellent in flatness because deformation and warpage are suppressed. The flatness of the connector is measured by placing the connector on a horizontal desk, measuring the height of the flat connector with an image measuring instrument, and measuring 0.5 mm from the connector end face at 10 mm intervals. And the minimum height difference.

  The planar connector of the present invention is excellent in weld strength and crack resistance. As described above, the weld strength and crack resistance of the molded product are correlated, but according to the present invention, a planar connector having good weld strength and crack resistance can be obtained.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(Method for producing liquid crystalline polymer)
A polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a pressure reduction / outflow line was charged with the following raw material monomers, a metal catalyst, and an acylating agent, and nitrogen substitution was started.
(I) 4-hydroxybenzoic acid; 1041 g (48 mol%)
(II) 2-hydroxy-6-naphthoic acid; 89 g (3 mol%)
(III) terephthalic acid; 565 g (21.7 mol%)
(IV) Isophthalic acid; 78 g (3 mol%)
(V) 4,4′-dihydroxybiphenyl; 711 g (24.3 mol%)
110 mg of metal catalyst (potassium acetate catalyst)
Acylating agent (acetic anhydride); 1645 g

  After the raw materials were charged into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C. and reacted at 140 ° C. for 1 hour. Thereafter, the temperature is further increased to 360 ° C. over 5.5 hours, and then reduced to 5 Torr (ie, 667 Pa) over 30 minutes to melt while distilling acetic acid, excess acetic anhydride, and other low-boiling components. Polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to change from a reduced pressure state to a normal pressure through a normal pressure, the polymer was discharged from the lower part of the polymerization vessel, and the strand was pelletized to pelletize. The obtained pellets were heat-treated at 300 ° C. for 8 hours under a nitrogen stream. The pellet had a melting point of 358 ° C., a heat of crystallization of 1.6 J / g, and a melt viscosity of 9 Pa · s.

In this example, the melt viscosity was measured under the following conditions.
A Capillograph Type 1B manufactured by Toyo Seiki Co., Ltd. with L = 20 mm and d = 1 mm was used, and the liquid crystal was liquid crystallized in conformity with ISO 11443 at a shear rate of 1000 / sec. The melt viscosity of the conductive polymer was measured.

(Components other than liquid crystalline polymers)
The liquid crystalline polymer obtained above and the following components were mixed using a twin screw extruder to obtain a composite resin composition. The amount of each component is as shown in Tables 1 and 2.
Glass fiber; ECS03T-786H manufactured by Nippon Electric Glass Co., Ltd., chopped strand mica having a fiber diameter of 10 μm and length of 3 mm; AB-25S manufactured by Yamaguchi Mica Co., Ltd., average particle diameter of 25 μm
Talc: Crown Talc PP manufactured by Matsumura Sangyo Co., Ltd., average particle size 10 μm

  Based on the following method, the physical properties of the obtained composite resin composition or planar connector were measured. Each evaluation result is shown in Tables 1 and 2.

(Connector flatness)
The composite resin composition has a shape shown in FIG. 1 and is a planar connector (pin hole number 750) having an overall size of 39.82 mm × 39.82 mm × 1 mmt and a lattice pitch interval of 1.2 mm. The pin was injection molded under the following molding conditions. In addition, the gate used the film gate from the long side of a grating | lattice part, and the gate thickness was 0.3 mm.
[Molding condition]
Molding machine; Sumitomo Heavy Industries SE100DUZ
Cylinder temperature: 365 ° C-365 ° C-365 ° C-360 ° C
Mold temperature: 80 ℃
Injection speed: 200mm / sec
Holding pressure: 50 MPa
Holding pressure time: 1 sec
Cooling time: 5 sec
Screw rotation speed: 120rpm
Screw back pressure: 2MPa

  The obtained connector was allowed to stand on a horizontal desk, and the height of the connector was measured with a Mitutoyo Quick Vision 404 PROCNC image measuring device. At that time, 0.5 mm positions were measured at 10 mm intervals from the connector end face, and the difference between the maximum height and the minimum height was specified as flatness. A lower flatness value indicates that the connector is flat.

(Connector minimum filling pressure)
When the planar connector of FIG. 1 was injection molded at 365 ° C., the minimum injection filling pressure at which a good molded product was obtained was measured as the minimum filling pressure.

(Crack resistance)
IR reflow was performed on the planar connector of FIG. 1 under the following conditions, the lattice portion was observed with an optical microscope, and the number of cracks was measured. A smaller number of cracks indicates higher crack resistance.
[IR reflow conditions]
Measuring instrument: RF-300 (using far infrared heater)
Sample feed rate: 140 mm / sec
Reflow furnace transit time: 5 min
Temperature conditions;
Preheat zone: 150 ° C
Reflow zone: 240 ° C
Peak temperature: 260 ° C

(Weld strength)
The composite resin composition was injection molded under the following molding conditions on a test specimen for measurement (125 mm × 13 mm × 0.4 mm, two-point film gate). The weld strength of the obtained test piece was measured under the following measurement conditions.
[Molding condition]
Molding machine: Sumitomo Heavy Industries SE100DU
Cylinder temperature: 365 ° C.-365 ° C.-365 ° C.-365 ° C.-365 ° C.-365 ° C.
Mold temperature: 90 ° C
Injection speed: 200mm / sec
Holding pressure: 70 MPa
Holding pressure time: 5 sec
Cooling time: 8 sec
Screw rotation speed: 150rpm
Screw back pressure: 1MPa
[Measurement condition]
Measuring machine: Orientec Tensilon Universal Tester RTM-100
Load cell: 100kg
Mold temperature: 90 ° C
Distance between chucks: 2.5 mm
Chuck force: 2.0 kgf / cm ²
Tensile speed: 0.5 mm / min

(Load deflection temperature)
The composite resin composition was injection-molded on a test specimen for measurement (4 mm × 10 mm × 80 mm) under the following molding conditions. The deflection temperature under load of the obtained test piece was measured according to ISO75-1,2.
[Molding condition]
Molding machine: Sumitomo Heavy Industries SE100DU
Cylinder temperature: 360 ° C-370 ° C-370 ° C-360 ° C-340 ° C-330 ° C
Mold temperature: 80 ℃
Injection speed: 33mm / sec
Holding pressure: 50 MPa
Holding time: 2 sec
Cooling time: 10 sec
Screw rotation speed: 120rpm

  As shown in Tables 1 and 2, the planar connector of the present invention is excellent in all of flatness, crack resistance and weld strength. The crack resistance and weld strength of the planar connectors in Comparative Examples 8 and 9 were equivalent to the present invention, but the flatness was inferior. According to the present invention, a planar connector having good flatness, crack resistance and weld strength can be obtained.

Claims (2)

A composite resin composition comprising (A) a liquid crystalline polymer, (B) glass fiber, and (C) one or more plate-like inorganic fillers selected from the group consisting of mica and talc,
The (A) liquid crystalline polymer has the following constituent units as essential constituents: (I) 4-hydroxybenzoic acid, (II) 2-hydroxy-6-naphthoic acid, (III) terephthalic acid, (IV) Including isophthalic acid and (V) 4,4′-dihydroxybiphenyl,
The structural unit of (I) is 35 to 75 mol% with respect to all the structural units,
The structural unit of (II) is 2 to 8 mol% with respect to all the structural units,
The structural unit of (III) is 4.5 to 30.5 mol% with respect to all structural units,
The structural unit of (IV) is 2 to 8 mol% with respect to all the structural units,
The structural unit of (V) is 12.5 to 32.5 mol% with respect to all the structural units,
The total amount of the structural units (II) and (IV) is 4 to 10 mol% with respect to all the structural units,
Said (A) liquid crystalline polymer is 45-60 mass% with respect to the whole composite resin composition,
The (B) glass fiber is more than 25 mass% and 30 mass% or less with respect to the entire composite resin composition,
One or more plate-shaped inorganic fillers selected from the group consisting of (C) mica and talc are a composite resin composition having a total amount of 15 to 20% by mass with respect to the entire composite resin composition. Molded from the composite resin composition according to claim 1,
It has a lattice structure inside the outer frame part,
The planar connector whose pitch interval of the lattice part in the lattice structure is 1.5 mm or less.

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