JPWO2020100618A1 - A connector containing a liquid crystal resin composition and a molded product of the liquid crystal resin composition. - Google Patents

Abstract

Provided are a liquid crystal resin composition having good fluidity, which is excellent in heat resistance and mechanical strength and can realize the production of a connector in which warpage deformation is suppressed, and a connector including a molded product of the liquid crystal resin composition. The liquid crystal resin composition according to the present invention contains (A) a liquid crystal resin, (B) fibrous wollastonite, and (C) mica, and has an aspect ratio of (B) fibrous wollastonite. Is 8 or more, and the content of the (A) liquid crystal resin is 62.5 to 72.5% by mass with respect to the entire liquid crystal resin composition, and the content of the (B) fibrous wollastonite is The content is 2.5 to 15% by mass, the content of the (C) mica is 17.5 to 30% by mass, and the total content of the (B) fibrous wollastonite and the (C) mica. Is 27.5 to 37.5% by mass.

Description

The present invention relates to a liquid crystal resin composition and a connector containing a molded product of the liquid crystal resin composition.

The liquid crystal resin is a thermoplastic resin having excellent dimensional accuracy, fluidity, and the like. Due to these characteristics, liquid crystal resins have been conventionally used as materials for various electronic components.

In particular, with the recent miniaturization and thinning of electronic devices, there is a need for lowering the height and narrowing the pitch of electronic components (connectors, etc.) constituting the electronic devices. For example, Patent Document 1 discloses a connector formed from a liquid crystal resin composition reinforced with mica and glass fiber. Such a connector is used to connect a substrate-to-board connector or a flexible printed circuit board (FPC) and a flexible flat cable (FFC), which are required to have heat resistance, suppression of warpage deformation, fluidity, dimensional stability, and the like. It is used as a connector for flexible printed circuit boards used in

Japanese Unexamined Patent Publication No. 2006-37061

However, when trying to mold a connector from a conventional liquid crystal resin composition, the heat resistance, mechanical strength, suppression of warpage deformation, and fluidity of the composition are not sufficient and the processability is inferior. It has been difficult to manufacture a low-profile narrow-pitch connector that meets the needs for narrow pitching.

The present invention has been made in view of such circumstances, and a liquid crystal resin composition having excellent fluidity, which is excellent in heat resistance and mechanical strength and can realize the production of a connector in which warpage deformation is suppressed, and the said liquid crystal resin composition. It is an object of the present invention to provide a connector including a molded product of a liquid crystal resin composition.

The present inventors have solved the above problems by combining a liquid crystal resin, a fibrous wollastonite, and mica with a predetermined content and setting the aspect ratio of the fibrous wollastonite within a predetermined range. I found that it could be solved. Specifically, the present invention provides the following.

(1) A liquid crystal resin composition containing (A) a liquid crystal resin, (B) fibrous wollastonite, and (C) mica.
The aspect ratio of the fibrous wollastonite (B) is 8 or more.
For the entire liquid crystal resin composition
The content of the liquid crystal resin (A) is 62.5 to 72.5% by mass.
The content of the fibrous wollastonite (B) is 2.5 to 15% by mass.
The content of (C) mica is 17.5 to 30% by mass.
The total content of the (B) fibrous wollastonite and the (C) mica is 27.5 to 37.5% by mass.
Is a liquid crystal resin composition.

(2) The liquid crystal resin composition according to (1) for a connector having a product total length of less than 30 mm and a product height of less than 5 mm.

(3) A connector comprising the molded product of the liquid crystal resin composition according to (1) or (2), having a product total length of less than 30 mm and a product height of less than 5 mm.

(4) The connector according to (3), which is a low profile narrow pitch connector.

(5) The distance between pitches is 0.5 mm or less.
The total length of the product is 3.5 mm or more and less than 30 mm.
The product height is 1.5 mm or less,
The connector according to (3) or (4), which is a low-profile narrow-pitch connector which is a board-to-board connector or a connector for a flexible printed circuit board.

According to the present invention, a liquid crystal resin composition having excellent fluidity, which is excellent in heat resistance and mechanical strength and can realize the production of a connector in which warpage deformation is suppressed, and a molded product of the liquid crystal resin composition can be obtained. Including connectors are provided.

It is a figure which shows the FPC connector molded in an Example. The unit of the numerical value in the figure is mm. It is a figure which shows the measurement point in the measurement of the warp of the FPC connector performed in an Example.

Hereinafter, embodiments of the present invention will be specifically described.

[Liquid crystal resin composition]
The liquid crystal resin composition according to the present invention contains a liquid crystal resin, fibrous wollastonite, and mica in predetermined amounts, and the aspect ratio of the fibrous wollastonite is 8 or more. Hereinafter, the components constituting the liquid crystal resin composition according to the present invention will be described.

[(A) Liquid crystal resin]
The liquid crystal resin (A) used in the present invention refers to a melt-processable polymer having a property of forming an optically anisotropic molten phase. The properties of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizing element. More specifically, the confirmation of the anisotropic molten phase can be carried out by observing the molten sample placed on the Leitz hot stage at a magnification of 40 times under a nitrogen atmosphere using a Leitz polarizing microscope. The liquid crystal resin applicable to the present invention normally transmits polarized light and exhibits optical anisotropy when inspected between orthogonal polarizers, even in a molten and stationary state.

The type of the liquid crystal resin (A) as described above is not particularly limited, and is preferably an aromatic polyester and / or an aromatic polyester amide. The range also includes polyesters that partially contain aromatic polyesters and / or aromatic polyester amides in the same molecular chain. The liquid crystal resin (A) preferably at least about 2.0 dl / g, more preferably 2.0 to 10.0 dl / g when dissolved in pentafluorophenol at 60 ° C. at a concentration of 0.1% by mass. Those having a logarithmic viscosity (IV) of are preferably used.

The aromatic polyester or aromatic polyesteramide as the liquid crystal resin (A) applicable to the present invention is particularly preferably an aromatic polyester or an aromatic polyesteramide having a repeating unit derived from an aromatic hydroxycarboxylic acid as a constituent component. Is.

More specifically
(1) Polyester consisting of repeating units mainly derived from one or more aromatic hydroxycarboxylic acids and their derivatives;
(2) Repeating units mainly derived from (a) one or more kinds of aromatic hydroxycarboxylic acids and their derivatives, and (b) one kind of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and their derivatives. Or a polyester consisting of repeating units derived from two or more species;
(3) Repeating units mainly derived from (a) one or more kinds of aromatic hydroxycarboxylic acids and their derivatives, and (b) one kind of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and their derivatives. Or a polyester consisting of a repeating unit derived from two or more kinds and (c) a repeating unit derived from at least one kind or two or more kinds of aromatic diols, alicyclic diols, aliphatic diols, and derivatives thereof;
(4) Repetitive units mainly derived from (a) one or more aromatic hydroxycarboxylic acids and their derivatives, and (b) one or two aromatic hydroxyamines, aromatic diamines, and their derivatives. A polyester amide consisting of a repeating unit derived from a species or more and (c) a repeating unit derived from one or more of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and derivatives thereof;
(5) Repetitive units mainly derived from (a) one or more aromatic hydroxycarboxylic acids and their derivatives, and (b) one or two aromatic hydroxyamines, aromatic diamines, and their derivatives. Repeating units derived from species or higher, (c) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and repeating units derived from one or more of their derivatives, and (d) aromatic diols, alicyclics. Examples thereof include polyesteramides composed of group diols, aliphatic diols, and repeating units derived from at least one or more of the derivatives thereof. Further, a molecular weight adjusting agent may be used in combination with the above-mentioned constituent components, if necessary.

（Ｘ：アルキレン（Ｃ_１〜Ｃ_４）、アルキリデン、−Ｏ−、−ＳＯ−、−ＳＯ_２−、−Ｓ−、及び−ＣＯ−より選ばれる基である）

（Ｙ：−（ＣＨ_２）_ｎ−（ｎ＝１〜４）及び−Ｏ（ＣＨ_２）_ｎＯ−（ｎ＝１〜４）より選ばれる基である。）Preferred examples of the specific compound constituting the (A) liquid crystal resin applicable to the present invention are aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; 2,6-dihydroxy. Aromatic diols such as naphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcin, compounds represented by the following general formula (I), and compounds represented by the following general formula (II). Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and compounds represented by the following general formula (III); p-aminophenol, p- Examples include aromatic amines such as phenylenediamine.

(X: A group selected from alkylene (C _{1 to} C ₄ ), alkylidene, -O-, -SO-, -SO _2- , -S-, and -CO-)

(Y: A group selected from − (CH ₂ ) _n − (n = 1-4) and −O (CH ₂ ) _n O − (n = 1-4).)

The most preferable liquid crystal resin (A) applicable to the present invention comprises the following structural units (I) to (VI) as essential constituents.
The content of the structural unit (I) is 50 to 70 mol% with respect to all the structural units.
The content of the constituent unit (II) with respect to all the constituent units is 0.5 mol% or more and less than 4.5 mol%.
The content of the structural unit (III) is 10.25 to 22.25 mol% with respect to all the structural units.
The content of the structural unit (IV) with respect to all the structural units is 0.5 mol% or more and less than 4.5 mol%.
The content of the structural unit (V) with respect to all the structural units is 5.75 to 23.75 mol%.
The content of the structural unit (VI) is 1 to 7 mol% with respect to all the structural units.
The total content of the structural unit (II) and the structural unit (IV) with respect to all the structural units is 1 mol% or more and less than 5 mol%.
The total content of the constituent units (I) to (VI) is 100 mol% with respect to all the constituent units.
A total aromatic polyesteramide exhibiting optical anisotropy when melted, wherein the molar ratio of the constituent units (VI) to the sum of the constituent units (V) and the constituent units (VI) is 0.04 to 0.37. ..

The liquid crystal resin (A) used in the present invention can be prepared from the above-mentioned monomer compound (or mixture of monomers) by a known method using a direct polymerization method or a transesterification method, and is usually a melt polymerization method. , Solution polymerization method, slurry polymerization method, solid phase polymerization method, etc., or a combination of two or more of these is used, and a melt polymerization method or a combination of a melt polymerization method and a solid phase polymerization method is preferably used. The above compounds having an ester-forming ability may be used in the polymerization as they are, or may be modified from a precursor to a derivative having the ester-forming ability in the pre-polymerization step. Various catalysts can be used for these polymerizations, and typical ones are potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and tris (2). , 4-Pentandionato) Metal salt-based catalysts such as cobalt (III), and organic compound-based catalysts such as N-methylimidazole and 4-dimethylaminopyridine. The amount of the catalyst used is generally preferably about 0.001 to 1% by mass, particularly preferably about 0.01 to 0.2% by mass, based on the total mass of the monomer. If necessary, the polymer produced by these polymerization methods can be further increased in molecular weight by a solid phase polymerization method in which the polymer is heated under reduced pressure or in an inert gas.

The melt viscosity of the liquid crystal resin (A) obtained by the above method is not particularly limited. In general, those having a melt viscosity at a molding temperature of 1000 sec ^-1 and a shear rate of 3 Pa · s or more and 500 Pa · s or less can be used. However, the one having a very high viscosity by itself is not preferable because the fluidity is very deteriorated. The liquid crystal resin (A) may be a mixture of two or more kinds of liquid crystal resins.

The liquid crystal resin composition according to the present invention contains (A) the liquid crystal resin in the liquid crystal resin composition in an amount of 62.5 to 72.5% by mass based on the entire liquid crystal resin composition. When the content of the liquid crystal resin (A) is less than 62.5% by mass with respect to the entire liquid crystal resin composition, the fluidity of the liquid crystal resin composition tends to deteriorate, and the liquid crystal resin composition This is not preferable because the bending strain of the molded product such as the connector obtained from the above may be reduced. (A) When the content of the liquid crystal resin is more than 72.5% by mass with respect to the entire liquid crystal resin composition, the flexural modulus and warpage deformation of the molded product such as a connector obtained from the liquid crystal resin composition It is not preferable because the suppressing effect is reduced. The liquid crystal resin composition according to the present invention preferably contains (A) the liquid crystal resin in the liquid crystal resin composition in an amount of 63.5 to 71.5% by mass based on the entire liquid crystal resin composition. It is more preferable to contain 65 to 70% by mass.

[(B) Fibrous wollastonite]
(B) The aspect ratio of the fibrous wollastonite, that is, the value of the average fiber length / average fiber diameter is 8 or more. The aspect ratio is preferably 10 to 25, more preferably 15 to 20, from the viewpoint of the flexural modulus of the molded product such as the connector obtained from the liquid crystal resin composition according to the present invention and the effect of suppressing warpage deformation. Is.

The fibrous wollastonite (B) is not particularly limited, and for example, a known fibrous wollastonite can be used. (B) The fibrous wollastonite may be used alone or in combination of two or more having different aspect ratios, average fiber lengths, average fiber diameters and the like.

The average fiber diameter of (B) fibrous wollastonite is preferably 3.0 to 50 μm, and the more preferable average fiber diameter is 4.5 to 40 μm. When the average fiber diameter is 3.0 μm or more, a molded product such as a connector obtained from the liquid crystal resin composition according to the present invention tends to have sufficient mechanical strength and a deflection temperature under load. When the average fiber diameter is 50 μm or less, the effect of suppressing raising of the surface of the molded product tends to be high. In the present specification, as the average fiber diameter, the average of the values obtained by observing the fibrous wollastonite with a scanning electron microscope and measuring the fiber diameter of 100 fibrous wollastonite is adopted.

The average fiber length of (B) fibrous wollastonite is preferably 30 to 800 μm, and the more preferable average fiber length is 50 to 600 μm. When the average fiber length is 30 μm or more, a molded product such as a connector obtained from the liquid crystal resin composition according to the present invention tends to have sufficient mechanical strength and a deflection temperature under load. When the average fiber length is 800 μm or less, the effect of suppressing raising of the surface of the molded product tends to be high. In the present specification, as the average fiber length, 10 stereomicroscopic images of fibrous wollastonite are captured from a CCD camera into a PC, and 100 stereomicroscopic images are taken for each stereomicroscopic image by an image processing method using an image measuring machine. Fibrous wollastonite, that is, the average of the measured fibrous lengths of a total of 1000 fibrous wollastonite is adopted.

The liquid crystal resin composition according to the present invention contains (B) fibrous wollastonite in the liquid crystal resin composition in an amount of 2.5 to 15% by mass based on the entire liquid crystal resin composition. (B) When the content of the fibrous wollastonite is less than 2.5% by mass with respect to the entire liquid crystal resin composition, warpage deformation of a molded product such as a connector obtained from the liquid crystal resin composition, particularly This is not preferable because the warp deformation after reflow may increase. When the content of the fibrous wollastonite (B) is more than 15% by mass with respect to the entire liquid crystal resin composition, the fluidity of the liquid crystal resin composition tends to deteriorate, and the liquid crystal resin composition It is not preferable because the bending strain of the molded body such as the connector obtained from the above may be reduced. The fibrous wollastonite (B) in the present invention is preferably contained in the liquid crystal resin composition in an amount of 3 to 13% by mass, preferably 5 to 10% by mass, based on the entire liquid crystal resin composition. More preferred.

[(C) Mica]
The liquid crystal resin composition according to the present invention includes mica. By including mica in the liquid crystal resin composition according to the present invention, it is possible to obtain a molded product having a sufficient flexural modulus and suppressed warpage deformation. Mica can be used alone or in combination of two or more.

Mica is contained in an amount of 17.5 to 30% by mass based on the entire liquid crystal resin composition. When the content of mica is less than 17.5% by mass with respect to the entire liquid crystal resin composition, it is preferable because the improvement of the flexural modulus and the suppression of warpage deformation of the molded product obtained from the liquid crystal resin composition are not sufficient. Absent. If the content of mica is more than 30% by mass with respect to the entire liquid crystal resin composition, the fluidity of the liquid crystal resin composition deteriorates, and molding of the liquid crystal resin composition may become difficult. Therefore, it is not preferable. Mica is preferably contained in the liquid crystal resin composition in an amount of 18.5 to 27.5% by mass, more preferably 20 to 25% by mass, based on the total amount of the liquid crystal resin composition.

[Mica]
Mica is a pulverized product of silicate minerals containing aluminum, potassium, magnesium, sodium, iron and the like. Examples of mica that can be used in the present invention include muscovite, phlogopite, biotite, and artificial mica. Of these, muscovite is preferable because it has a good hue and is inexpensive.

Further, in the production of mica, a wet pulverization method and a dry pulverization method are known as methods for pulverizing minerals. The wet pulverization method is a method in which rough mica is roughly pulverized by a dry pulverizer, water is added, and the 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 when the wet pulverization method is used, it is easier 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 size and thickness described later can be obtained. Therefore, in the present invention, it is preferable to use mica produced by the wet pulverization method.

Further, since the wet pulverization method requires a step of dispersing the object to be crushed in water, a coagulation sedimentation agent and / or a sedimentation aid is added to the object to be pulverized in order to improve the dispersion efficiency of the object to be pulverized. Is common. Examples of the coagulation sedimentation agent and sedimentation aid that can be used in the present invention include polyaluminum chloride, aluminum sulfate, ferrous sulfate, ferric sulfate, copper chloride, polyiron sulfate, ferric chloride, and iron-silica inorganic high. Examples thereof include a molecular flocculant, a ferric chloride-silica inorganic polymer flocculant, slaked lime (Ca (OH) ₂ ), caustic soda (NaOH), and soda ash (Na ₂ CO ₃ ). These coagulation sedimentation agents and sedimentation aids have an alkaline or acidic pH. The mica used in the present invention preferably does not use a coagulation sedimentation agent and / or a sedimentation aid during wet pulverization. When mica that has not been treated with a coagulation sedimentation agent and / or a sedimentation aid is used, decomposition of the polymer in the liquid crystal resin composition is unlikely to occur, and a large amount of gas is less likely to be generated or the molecular weight of the polymer is less likely to decrease. It is easy to maintain better performance of molded products such as connectors.

The mica that can be used in the present invention preferably has an average particle size of 10 to 100 μm measured by a microtrack laser diffraction method, and particularly preferably an average particle size of 20 to 80 μm. When the average particle size of mica is 10 μm or more, the effect of improving the rigidity of the molded product tends to be sufficient, which is preferable. When the average particle size of mica is 100 μm or less, the rigidity of the molded product is likely to be sufficiently improved, and the weld strength is also likely to be sufficient, which is preferable. Further, when the average particle size of mica is 100 μm or less, it is easy to secure sufficient fluidity for molding the connector or the like of the present invention.

The thickness of 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 observation with an electron microscope. When the thickness of the mica is 0.01 μm or more, the mica is less likely to crack during the melt processing of the liquid crystal resin composition, and the rigidity of the molded product may be easily improved, which is preferable. When the thickness of mica is 1 μm or less, the effect of improving the rigidity of the molded product is likely to be sufficient, which 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 granules.

In the liquid crystal resin composition according to the present invention, the total content of (B) fibrous wollastonite and (C) mica is 27.5 to 37.5% by mass with respect to the entire liquid crystal resin composition. is there. If the content is less than 27.5% by mass with respect to the entire liquid crystal resin composition, the flexural modulus and the warp deformation suppressing effect of the molded product such as a connector obtained from the liquid crystal resin composition are lowered. Not preferable. When the content is more than 37.5% by mass with respect to the entire liquid crystal resin composition, the fluidity of the liquid crystal resin composition tends to deteriorate, and the connector or the like obtained from the liquid crystal resin composition This is not preferable because the bending strain of the molded product may be reduced. The content is preferably 28.0 to 36.5% by mass, more preferably 28.5 to 35% by mass, based on the entire liquid crystal resin composition.

[Other ingredients]
The liquid crystal resin composition according to the present invention includes other polymers, other fillers, and known substances generally added to synthetic resins, that is, antioxidants and ultraviolet rays, as long as the effects of the present invention are not impaired. Stabilizers such as absorbents, antistatic agents, flame retardants, colorants such as dyes and pigments, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents and other other components are also added as appropriate according to the required performance. be able to. Other components may be used alone or in combination of two or more.

The other filler refers to a filler other than fibrous talc talc, mica, and carbon black having an aspect ratio of 8 or more, and for example, a fibrous filler other than fibrous talc talc having an aspect ratio of 8 or more (for example). , Fibrous wollastonite with an aspect ratio of less than 8 and milled fiber), and plate-like fillers other than mica (for example, talc). However, from the viewpoint of improving the mechanical strength of the molded product, suppressing warpage deformation, etc., the liquid crystal resin composition according to the present invention may not contain fibrous wollastonite, milled fiber, and talc having an aspect ratio of less than 8. preferable.

The method for producing the liquid crystal resin composition according to the present invention is not particularly limited as long as the components in the liquid crystal resin composition can be uniformly mixed, and can be appropriately selected from the conventionally known methods for producing the liquid crystal resin composition. For example, each component is melt-kneaded and extruded using a melt-kneading device such as a single-screw or twin-screw extruder, and then the obtained liquid crystal resin composition is processed into a desired form such as powder, flakes, and pellets. There is a way to do it.

Since the liquid crystal resin composition according to the present invention has excellent fluidity, the minimum filling pressure during molding is unlikely to be excessive, and connectors, particularly parts having a small and complicated shape such as low-profile narrow pitch connectors and the like, etc. Can be preferably molded. The degree of fluidity is determined by the minimum filling pressure of the connector. That is, the minimum injection filling pressure at which a good molded body can be obtained when the FPC connector shown in FIG. 1 is injection molded is specified as the minimum filling pressure. The lower the minimum filling pressure, the better the fluidity.

At 10 to 30 ° C. above the melting point of the liquid resin, at a shear rate of 1000 / sec, the melt viscosity of the liquid resin composition was measured according to ISO11443, the following preferably 1 × ¹⁰ 5 Pa · s, more It is preferably 5 Pa · s or more and 1 × 10 ² Pa · s or less. When the melt viscosity is 1 × 10 ⁵ Pa · s or less, it is easy to secure the fluidity of the liquid crystal resin composition when molding the connector, particularly the low-profile narrow pitch connector, and the filling pressure is unlikely to become excessive. ..

(connector)
The connector of the present invention can be obtained by molding the liquid crystal resin composition according to the present invention. The connector of the present invention is not particularly limited, and examples thereof include a connector having a product total length of less than 30 mm and a product height of less than 5 mm. The connector having a product total length of less than 30 mm and a product height of less than 5 mm is not particularly limited, and examples thereof include a low profile narrow pitch connector, a coaxial connector, a micro SIM connector, and a micro SD connector. Of these, a low profile narrow pitch connector is preferable. The low profile narrow pitch connector is not particularly limited, and includes, for example, a board-to-board connector (also known as a "BtoB connector"), a flexible printed circuit board connector (flexible printed circuit board (FPC), and a flexible flat cable (FFC). (Used to connect, also known as "FPC connector") and the like. Among them, the low-profile narrow-pitch connector, which is a board-to-board connector or a flexible printed circuit board connector, has a pitch-to-pitch distance of 0.5 mm or less, a product total length of 3.5 mm or more and less than 30 mm, and a product height of 1.5 mm or less. It is suitable.

The molding method for obtaining the connector of the present invention is not particularly limited, and it is preferable to select molding conditions without residual internal stress in order to prevent deformation of the obtained connector. In order to lower the filling pressure and reduce the residual internal stress of the obtained connector, the cylinder temperature of the molding machine is preferably a temperature equal to or higher than the melting point of the liquid crystal resin.

The mold temperature is preferably 70 to 100 ° C. If the mold temperature is low, the liquid crystal resin composition filled in the mold may cause poor flow, which is not preferable. If the mold temperature is high, problems such as burrs may occur, which is not preferable. The injection speed is preferably 150 mm / sec or more. If the injection rate is low, only an unfilled molded product may be obtained, and even if a completely filled molded product is obtained, the molded product has a high filling pressure and a large residual internal stress, resulting in poor flatness. You may only get it.

The connector of the present invention is suppressed from warpage deformation. The degree of warpage of the connector is determined as follows. That is, with the FPC connector shown in FIG. 1, the height is measured at a plurality of positions indicated by black circles in FIG. 2, and the difference between the maximum height and the minimum height from the least squares plane is used as a sled. In the connector of the present invention, the change in warpage is suppressed before and after performing IR reflow.

Further, the connector of the present invention is excellent in heat resistance, for example, heat resistance as evaluated by high temperature rigidity. High temperature rigidity is evaluated by measuring the deflection temperature under load in accordance with ISO75-1 and ISO75-1.

The connector of the present invention has excellent mechanical strength. Mechanical strength is evaluated by measuring bending strength, bending strain, and flexural modulus by a bending test according to ASTM D790.

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

<Examples 1 to 5, Comparative Examples 1 to 7>
In the following Examples and Comparative Examples, the liquid crystal resins LCP1 and 2 were produced as follows. At that time, the melting point and the melt viscosity of the pellets were measured under the following conditions, respectively.

[Measurement of melting point]
After observing the heat absorption peak temperature (Tm1) observed when the liquid crystal resin was measured at a temperature rising condition of 20 ° C./min from room temperature with a DSC manufactured by TA Instruments, 2 at a temperature of (Tm1 + 40) ° C. After holding for 1 minute, the temperature was once cooled to room temperature under the temperature lowering condition of 20 ° C./min, and then the temperature of the heat absorption peak observed when the measurement was performed again under the temperature rising condition of 20 ° C./min was measured.

[Measurement of melt viscosity]
Using Capillograph 1B type manufactured by Toyo Seiki Seisakusho Co., Ltd., using an orifice with an inner diameter of 1 mm and a length of 20 mm at a temperature 10 to 30 ° C higher than the melting point of the liquid crystal resin, to ISO11443 at a shear rate of 1000 / sec. According to this, the melt viscosity of the liquid crystal resin was measured. The measurement temperature was 360 ° C. for LCP1 and 380 ° C. for LCP2.

(Manufacturing method of LCP1)
The following raw material monomers, fatty acid metal salt catalysts, and acylating agents were charged into a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a depressurization / outflow line, and nitrogen substitution was started.
(I) 4-Hydroxybenzoic acid: 1385 g (60 mol%) (HBA)
(II) 6-Hydroxy-2-naphthoic acid: 88 g (2.8 mol%) (HNA)
(III) Terephthalic acid: 504 g (18.15 mol%) (TA)
(IV) Isophthalic acid: 19 g (0.7 mol%) (IA)
(V) 4,4'-Dihydroxybiphenyl: 415 g (13.35 mol%) (BP)
(VI) N-Acetyl-p-Aminophenol: 126 g (5 mol%) (APAP)
Potassium acetate catalyst: 120 mg
Acetic anhydride: 1662 g
After charging the raw materials 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. Then, the temperature is further raised to 360 ° C. over 5.5 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 20 minutes while distilling acetic acid, excess acetic anhydride, and other low boiling points. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the mixture from a reduced pressure state to a pressurized state through normal pressure, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized and pelletized. The melting point of the obtained pellet was 345 ° C., and the melt viscosity was 10 Pa · s.

(Manufacturing method of LCP2)
The following raw material monomers, fatty acid metal salt catalysts, and acylating agents were charged into a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a depressurization / outflow line, and nitrogen substitution was started.
(I) 4-Hydroxybenzoic acid: 1040 g (48 mol%) (HBA)
(II) 6-Hydroxy-2-naphthoic acid: 89 g (3 mol%) (HNA)
(III) Terephthalic acid: 547 g (21 mol%) (TA)
(IV) Isophthalic acid: 91 g (3.5 mol%) (IA)
(V) 4,4'-Dihydroxybiphenyl: 716 g (24.5 mol%) (BP)
Potassium acetate catalyst: 110 mg
Acetic anhydride: 1644 g

After charging the raw materials 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. Then, the temperature is further raised to 360 ° C. over 5.5 hours, and then the pressure is reduced to 5 Torr (that is, 667 Pa) over 20 minutes while distilling acetic acid, excess acetic anhydride, and other low boiling points. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the mixture from a reduced pressure state to a pressurized state through normal pressure, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized and pelletized. The melting point of the obtained pellet was 355 ° C., and the melt viscosity was 10 Pa · s.

(Ingredients other than liquid crystal resin)
Fibrous filler Wollastonite 1: NYGLOS 8 (manufactured by NYCO Materials, aspect ratio 17, average fiber length 136 μm, average fiber diameter 8 μm)
Wallastnite 2: NYAD 325 (manufactured by NYCO Materials, aspect ratio 5, average fiber length 50 μm, average fiber diameter 5 μm)
Mild fiber: PF70E001 manufactured by Nitto Boseki Co., Ltd., fiber diameter 10 μm, average fiber length 70 μm (manufacturer's nominal value)
-Plate-shaped filler Mica; AB-25S manufactured by Yamaguchi Mica Industry Co., Ltd., average particle diameter 25 μm
Talc; Crown Talc PP manufactured by Matsumura Sangyo Co., Ltd., average particle size 10 μm

Each liquid crystal resin obtained above and a component other than the liquid crystal resin described above were mixed using a twin-screw extruder to obtain a liquid crystal resin composition. The blending amount of each component is as shown in Tables 1 and 2. In the following, "%" regarding the blending amount in the table indicates mass%. The extrusion conditions for obtaining the liquid crystal resin composition are as follows.
[Extrusion conditions]
[Examples 1 to 4, Comparative Examples 1 to 7]
The temperature of the cylinder provided at the main feed port was 250 ° C., and the temperature of all other cylinders was 360 ° C. All liquid crystal resin was supplied from the main feed port. The filler was supplied from the side feed port.
[Example 5]
The temperature of the cylinder provided at the main feed port was 250 ° C., and the temperature of all other cylinders was 370 ° C. All liquid crystal resin was supplied from the main feed port. The filler was supplied from the side feed port.

(Measurement of melt viscosity of liquid crystal resin composition)
Using Capillograph 1B type manufactured by Toyo Seiki Seisakusho Co., Ltd., using an orifice with an inner diameter of 1 mm and a length of 20 mm at a temperature 10 to 30 ° C higher than the melting point of the liquid crystal resin, to ISO11443 at a shear rate of 1000 / sec. According to this, the melt viscosity of the liquid crystal resin composition was measured. The measurement temperature was 360 ° C. for the liquid crystal resin composition using LCP1 and 380 ° C. for the liquid crystal resin composition using LCP2. The results are shown in Tables 1 and 2.

Based on the following method, the physical characteristics of the connector including the molded product of the liquid crystal resin composition were measured. The evaluation results are shown in Tables 1 and 2.

(Deflection temperature under load)
Under the following molding conditions, the liquid crystal resin composition was injection-molded to obtain a molded product, and the deflection temperature under load was measured in accordance with ISO75-1 and ISO75-1.
[Molding condition]
Molding machine: Sumitomo Heavy Industries, SE100DU
Cylinder temperature:
360 ° C. (Examples 1 to 4, Comparative Examples 1 to 7)
370 ° C (Example 5)
Mold temperature: 80 ° C
Injection speed: 33 mm / sec

(Bending test)
The liquid crystal resin composition was injection-molded under the following molding conditions to obtain a molded product having a thickness of 0.8 mm, and the bending strength, bending strain, and flexural modulus were measured in accordance with ASTM D790.
[Molding condition]
Molding machine: Sumitomo Heavy Industries, SE100DU
Cylinder temperature:
360 ° C. (Examples 1 to 4, Comparative Examples 1 to 7)
370 ° C (Example 5)
Mold temperature: 80 ° C
Injection speed: 33 mm / sec

(FPC connector sled)
The liquid crystal resin composition is injection-molded under the following molding conditions (gate: tunnel gate, gate size: φ0.4 mm), and the overall size is 17.6 mm × 4.00 mm × 1.16 mm as shown in FIG. An FPC connector having a distance between pitches of 0.5 mm, a number of pin holes of 30 × 2 pins, and a minimum wall thickness of 0.12 mm was obtained.
[Molding condition]
Molding machine: Sumitomo Heavy Industries, SE30DUZ
Cylinder temperature (indicates the temperature from the nozzle side):
360 ° C-360 ° C-350 ° C-340 ° C (Examples 1 to 4, Comparative Examples 1 to 7)
370 ° C-370 ° C-360 ° C-350 ° C (Example 5)
Mold temperature: 80 ° C
Injection speed: 200 mm / sec
Holding pressure: 50 MPa
Holding time: 0.5 seconds Cooling time: 10 seconds Screw rotation speed: 120 rpm
Screw back pressure: 1.2 MPa

The obtained connector was allowed to stand on a horizontal desk, and the height of the connector was measured by a Mitutoyo Quick Vision 404PROCNC image measuring machine. At that time, the heights were measured at a plurality of positions indicated by black circles in FIG. 2, and the difference between the maximum height and the minimum height from the least squares plane was defined as the warp of the FPC connector. The warp was measured before and after the IR reflow performed under the following conditions.
[IR reflow conditions]
Measuring machine: Large desktop reflow soldering device RF-300 manufactured by Japan Pulse Technology Laboratory (using far infrared heater)
Sample feed rate: 140 mm / sec
Reflow furnace transit time: 5 minutes Preheat zone temperature condition: 150 ° C
Reflow zone temperature conditions: 190 ° C
Peak temperature: 251 ° C

(Minimum filling pressure of FPC connector)
When the FPC connector of FIG. 1 was injection-molded, the minimum injection-filling pressure at which a good molded product could be obtained was measured as the minimum filling pressure.

As shown in Tables 1 and 2, in the examples, the deflection temperature under load is 245 ° C or higher, the bending strain is 2.0% or higher, the flexural modulus is 14000 MPa or higher, and the FPC connector warp before reflow is less than 0.030 mm. The FPC connector warp after reflow was less than 0.090 mm, and the minimum filling pressure of the FPC connector was less than 75 MPa. Therefore, the liquid crystal resin composition according to the present invention has excellent fluidity, and the connector containing the molded product of this liquid crystal resin composition has excellent heat resistance and mechanical strength, and warpage deformation is suppressed. confirmed.

Claims (5)

A liquid crystal resin composition containing (A) a liquid crystal resin, (B) fibrous wollastonite, and (C) mica.
The aspect ratio of the fibrous wollastonite (B) is 8 or more.
For the entire liquid crystal resin composition
The content of the liquid crystal resin (A) is 62.5 to 72.5% by mass.
The content of the fibrous wollastonite (B) is 2.5 to 15% by mass.
The content of (C) mica is 17.5 to 30% by mass.
The total content of the (B) fibrous wollastonite and the (C) mica is 27.5 to 37.5% by mass.
Is a liquid crystal resin composition. The liquid crystal resin composition according to claim 1, wherein the liquid crystal resin composition is for a connector having a product total length of less than 30 mm and a product height of less than 5 mm. A connector comprising the molded product of the liquid crystal resin composition according to claim 1 or 2, having a product total length of less than 30 mm and a product height of less than 5 mm. The connector according to claim 3, which is a low profile narrow pitch connector. The distance between pitches is 0.5 mm or less,
The total length of the product is 3.5 mm or more and less than 30 mm.
The product height is 1.5 mm or less,
The connector according to claim 3 or 4, which is a low-profile narrow-pitch connector that is a board-to-board connector or a connector for a flexible printed circuit board.

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