JP6895032B1 - A connector containing a liquid crystal resin composition and a molded product of the liquid crystal resin composition. - Google Patents

Abstract

A liquid crystal resin composition having excellent fluidity, which is excellent in heat resistance and mechanical properties and can realize the manufacture of a connector in which warpage deformation and blister generation are suppressed, and a connector containing a molded product of the liquid crystal resin composition. provide. The liquid crystal resin composition according to the present invention is a liquid crystal resin composition containing (A) liquid crystal resin, (B) fibrous wollastonite, and (C) mica, and the fibrous wollastonite. The content of Al2O3 is 0.05 to 0.65% by mass and the content of Fe2O3 is 0.05 to 1.0% by mass. ) The content of the fibrous wollastonite is 2.5 to 15% by mass, the content of the (C) mica is 17.5 to 27.5% by mass, and the (B) fibrous wollastonite and the above. (C) The total content with mica is 20 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 molded from a liquid crystal resin composition reinforced with mica and glass fiber. Such a connector is for connecting a board-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 an attempt is made to mold a connector from a conventional liquid crystal resin composition, the heat resistance of the composition, maintenance of mechanical properties, suppression of warpage deformation, and inferior fluidity and workability are therefore low. It has been difficult to manufacture a low-profile narrow-pitch connector that meets the needs for narrow pitching and narrowing.

In addition, the liquid crystal resin composition may have a problem of blistering. That is, liquid crystal resins such as liquid crystal polyester and liquid crystal polyester amide are often used as materials that require heat treatment at high temperature because they have good high temperature thermal stability. However, if the molded product is left in high temperature air or liquid for a long time, there arises a problem that fine swelling called blister is generated on the surface.

One cause of this phenomenon is that decomposition gas or the like generated when the liquid crystal resin is in a molten state is brought into the molded product, and then the gas expands when heat treatment is performed at a high temperature, and the molded product is softened by heating. The surface is pushed up, and the pushed up part appears as a blister. The generation of blisters can also be reduced by sufficiently degassing the vent holes during melt extrusion of the material and by not allowing the material to stay in the molding machine for a long time during molding. However, the condition range is very narrow, and it is not sufficient to obtain a molded product in which the generation of blisters is suppressed, that is, a molded product having blister resistance. A fundamental solution to the generation of blisters requires improvement in the quality of the liquid crystal resin itself, and known liquid crystal resins and methods using the same are insufficient to solve the problem of blistering.

The present invention has been made to solve the above problems, and an object of the present invention is to realize the production of a connector having excellent heat resistance and mechanical properties and suppressing warpage deformation and blister generation, and having good fluidity. It is an object of the present invention to provide a liquid crystal resin composition and a connector containing a molded product of the liquid crystal resin composition.

The present inventors have conducted intensive studies to solve the above problems. As a result, a liquid crystal resin containing a liquid crystal resin, fibrous wollastonite having a specific composition, and mica, and the content of each of the fibrous wollastonite, mica, and the total of these is in a predetermined range. We have found that the above problems can be solved by using the composition, and have completed the present invention. More 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, which contains Al ₂ O _{3 in the fibrous wollastonite.} The amount is 0.05 to 0.65% by mass, _{the content of Fe 2} O ₃ is 0.05 to 1.0% by mass, and the fiber (B) is compared with the whole liquid resin composition. The content of the fibrous wollastonite is 2.5 to 15% by mass, the content of the (C) mica is 17.5 to 27.5% by mass, the fibrous wollastonite and the (C) fibrous wollastonite. ) A liquid crystal resin composition having a total content of 20 to 37.5% by mass with mica.

(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 heat resistance and mechanical properties, capable of producing a connector in which warpage deformation and blister generation are suppressed, and having good fluidity, and the liquid crystal resin composition. A connector including a molded product can be 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.

<Liquid crystal resin composition>
The liquid crystal resin composition according to the present invention is a liquid crystal resin composition containing (A) liquid crystal resin, (B) fibrous wollastonite, and (C) mica, and the fibrous wollastonite. The content of Al ₂ O ₃ is 0.05 to 0.65% by mass, and _{the content of Fe 2} O ₃ is 0.05 to 1.0% by mass. On the other hand, the content of the (B) fibrous wollastonite was 2.5 to 15% by mass, the content of the (C) mica was 17.5 to 27.5% by mass, and the content of the (B) fiber. The total content of the plastic wollastonite and the mica (C) is 20 to 37.5% by mass.

[(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 melt 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 in a nitrogen atmosphere using a Leitz polarizing microscope. When inspected between orthogonal polarizers, the liquid crystal resin applicable to the present invention normally transmits polarized light even in a molten and stationary state, and exhibits optical anisotropy.

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 liquid crystal resin (A) may be a total aromatic polyester and / or a total aromatic polyester amide, or a liquid crystal resin partially containing a total aromatic polyester and / or an aromatic polyester amide in the same molecular chain, and is heat resistant. From the viewpoint of properties and the like, a total aromatic polyester and / or a total aromatic polyester amide is preferable. 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. A liquid crystal resin such as aromatic polyester and / or aromatic polyesteramide having a logarithmic viscosity (IV) of is also preferably used.

The aromatic polyester or aromatic polyesteramide as the (A) liquid crystal resin applicable to the present invention is particularly preferably at least one selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic hydroxyamines, and aromatic diamines. It is an aromatic polyester or an aromatic polyester amide having a repeating unit derived from a species compound as a constituent.

More specifically
(1) Polyester composed of repeating units mainly derived from one or more kinds of aromatic hydroxycarboxylic acids and their derivatives;
(2) Repeating units mainly derived from (a) one or more aromatic hydroxycarboxylic acids and their derivatives, and (b) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and one of their derivatives. Or 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) Repeating units mainly derived from (a) one or more of aromatic hydroxycarboxylic acids and their derivatives, and (b) one or two of aromatic hydroxyamines, aromatic diamines, and their derivatives. Polyester amides consisting of repeating units derived from species or higher and (c) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and repeating units derived from one or more of their derivatives;
(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 to 4) and −O (CH ₂ ) _n O − (n = 1 to 4).)

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 an ester exchange 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 for polymerization as they are, or may be modified from a precursor to a derivative having the ester-forming ability by using an acylating agent or the like in the pre-polymerization step. Good. Examples of the acylating agent include carboxylic acid anhydride such as acetic anhydride.

Various catalysts can be used for the polymerization. Typical usable catalysts are potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, tris (2,4-pentandionato) cobalt (III). ) And other metal salt-based catalysts, and organic compound-based catalysts such as N-methylimidazole and 4-dimethylaminopyridine. Generally, the amount of the catalyst used is preferably about 0.001 to 1% by mass, particularly preferably about 0.01 to 0.2% by mass, based on the total weight of the monomer.

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 10 Pa · s or more and 600 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.

(A) The melting point (hereinafter, also referred to as “Tm”) and the crystallization temperature (hereinafter, also referred to as “Tc”) of the liquid crystal resin are not particularly limited. Difference between Tm and Tc Tm-Tc is preferably 45 ° C. or lower, more preferably 42 ° C. or lower, and even more preferably 40 ° C. or lower, in that blister generation is easily suppressed and mechanical strength is easily maintained. The lower limit of Tm-Tc is not particularly limited, and may be any of 0 ° C, 1 ° C, 5 ° C, 10 ° C, 20 ° C, 30 ° C, and 37 ° C.

In the liquid crystal resin composition of the present invention, the preferable content of the liquid crystal resin (A) is 62.5 to 80% by mass. When the content of the component (A) is within the above range, the composition tends to suppress the generation of blisters while maintaining the fluidity. The content of the component (A) is more preferably 63.5 to 75% by mass, and even more preferably 65 to 70% by mass.

[(B) Fibrous wollastonite]
The component (B) is fibrous wollastonite, and in the component (B), the content of Al ₂ O ₃ is 0.05 to 0.65% by mass, and _{the content of Fe 2} O _{3 is 0.05.} ~ 1.0% by mass. That is, the component (B) contains _{Al 2} O ₃ and Fe ₂ O ₃ in an amount in the above range in addition to _{SiO 2 and CaO, which are the main components thereof. By containing Al 2} O ₃ and Fe ₂ O _{3 in the} component (B), the composition has a low melt viscosity and is easy to maintain fluidity, but Al ₂ O ₃ and Fe in the component (B) _If each content of 2 O ₃ is too large, a problem of blister generation may occur. _{By containing Al 2} O ₃ and Fe ₂ O _{3 in} the amount in the above range as the component (B), the composition tends to suppress the generation of blisters while maintaining the fluidity. In this specification, the values analyzed in accordance with JIS K 0119 are adopted as the respective contents _{of Al 2} O ₃ and Fe ₂ O _{3 in the component (B).}

In the component (B), the content of Al ₂ O ₃ is preferably 0.08 to 0.45% by mass, more preferably 0.11 to 0.30% by mass, and the content of _{Fe 2} O _{3 is} , It is preferably 0.1 to 0.5% by mass, and more preferably 0.18 to 0.23% by mass. When _{the content of Al 2} O _{3 and} the content of Fe ₂ O ₃ are within the above ranges, the composition is more likely to suppress the generation of blisters.

The average fiber length of the component (B) is preferably 50 to 200 μm, more preferably 70 to 180 μm, and even more preferably 90 to 160 μm. When the average fiber length is within the above range, the composition is more likely to suppress the generation of blisters. 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. The average of the measured fiber lengths of 1000 fibrous wollastonite, that is, a total of 1000 fibrous wollastonite, is adopted. The component (B) in the liquid crystal resin composition can be obtained by heating the liquid crystal resin composition at 600 ° C. for 2 hours to incinerate it.

The preferable average fiber diameter of the component (B) is 1 to 20 μm or less, and the more preferable average fiber diameter is 5 to 16 μm. When the average fiber diameter is within the above range, the composition is more likely to suppress the generation of blisters. 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.

In the liquid crystal resin composition of the present invention, the content of the component (B) is 2.5 to 15% by mass. When the content of the component (B) is within the above range, the composition is excellent in fluidity while maintaining mechanical properties, so that the minimum filling pressure at the time of molding is unlikely to become excessive, and further, blisters are generated. Easy to suppress. The content of the component (B) is more preferably 3.5 to 12.5% by mass, and even more preferably 5 to 10% by mass. The component (B) can be used alone or in combination of two or more.

[(C) Mica]
The component (C) is mica. Since the liquid crystal resin composition according to the present invention contains the component (C), it is easy to obtain a molded product in which warpage deformation is suppressed. The component (C) can be used alone or in combination of two or more.

In the liquid crystal resin composition of the present invention, the content of the component (C) is 17.5 to 27.5% by mass. When the content of the component (C) is within the above range, it is easier to obtain a molded product in which warpage deformation is suppressed from the composition. The content of the component (C) is more preferably 18.5 to 26.5% by mass, and even more preferably 20 to 25% by mass.

[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, and then dehydration and drying are performed. Although the dry pulverization method is a low-cost and general method as compared with the wet pulverization method, it is easier to pulverize the mineral thinly and finely by using the wet pulverization method. 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 is preferably one that 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 the performance of the molded product better.

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, 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.

Further, the total content of the component (B) and the component (C) is 20 to 37.5% by mass, preferably 25 to 36.5% by mass in the liquid crystal resin composition of the present invention. , More preferably 30 to 35% by mass. When the total content is 20% by mass or more, it is easy to obtain a molded product in which warpage deformation is suppressed. When the total content is 37.5% by mass or less, the composition is excellent in fluidity while maintaining mechanical properties, so that the minimum filling pressure at the time of molding is unlikely to become excessive, and blisters are generated. Is easy to suppress.

[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. Examples of other fillers include (B) fibrous wollastonite and (C) fillers other than mica, and examples thereof include (C) plate-like fillers other than mica; and granular fillers such as silica. (C) Examples of the plate-like filler other than mica include talc and the like. However, from the viewpoint of suppressing warpage deformation of the molded product, the liquid crystal resin composition of the present invention preferably does not contain a plate-like filler other than (C) mica, such as talc.

[Method for preparing liquid crystal resin composition]
The method for preparing the liquid crystal resin composition of the present invention is not particularly limited. For example, the liquid crystal resin composition can be obtained by blending the above components (A) to (C) and optionally other components and melt-kneading them using a single-screw or twin-screw extruder. Preparation is done.

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 is evaluated.

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, especially 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). (Also known as an "FPC connector"), etc. Among them, the low-profile narrow-pitch connector, which has a distance between pitches of 0.5 mm or less, a product overall length of 3.5 mm or more and less than 30 mm, a product height of 1.5 mm or less, and a board-to-board connector or a connector for a flexible printed circuit board. 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 connector. In order to lower the filling pressure and reduce the residual internal stress of the 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. May only be obtained.

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 suppresses the generation of blisters. The degree of blister generation is determined by the blister temperature. That is, the presence or absence of blister generation on the surface of the molded product immersed in silicone oil at a predetermined temperature is visually observed, and the maximum temperature at which the number of blister generation is zero among the 30 molded products is defined as the blister temperature. It is evaluated that the higher the blister temperature, the more the blister generation is suppressed.

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, breaking strain, and flexural modulus by a bending test according to ASTM D790.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

(A) Liquid crystal resin (Manufacturing method of liquid crystal resin 1)
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) 504 g (18.15 mol%) of terephthalic acid (TA)
(IV) Isophthalic acid 19 g (0.7 mol%) (IA)
(V) 415 g (13.35 mol%) (BP) of 4,4'-dihydroxybiphenyl
(VI) 126 g (5 mol%) of N-acetyl-p-aminophenol (APAP)
Potassium acetate catalyst 120 mg
1662 g of acetic anhydride
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 to melt acetic acid, excess acetic anhydride, and other low boiling components while distilling. 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., the difference Tm-Tc between the melting point and the crystallization temperature was 37 ° C., and the melt viscosity was 10 Pa · s.

(Manufacturing method of liquid crystal resin 2)
The following raw material monomers, metal 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: 1380 g (60 mol%) (HBA)
(II) 6-Hydroxy-2-naphthoic acid: 157 g (5 mol%) (HNA)
(III) Terephthalic acid: 484 g (17.5 mol%) (TA)
(IV) 4,4'-dihydroxybiphenyl: 388 g (12.5 mol%) (BP)
(V) 4-acetoxyaminophenol: 17.2 g (5 mol%) (APAP)
Potassium acetate catalyst: 110 mg
Acetic anhydride: 1659 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 340 ° C. over 4.5 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 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 obtained pellet had a melting point of 336 ° C, a Tm-Tc of 40 ° C, and a melt viscosity of 20 Pa · s.

(Manufacturing method of liquid crystal resin 3)
The following raw material monomers, metal 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) 2-Hydroxy-6-naphthoic acid 166 g (48 mol%) (HNA)
(II) 76 g (25 mol%) of terephthalic acid (TA)
(III) 4,4'-Dihydroxybiphenyl 86 g (25 mol%) (BP)
(IV) 4-Hydroxybenzoic acid 5 g (2 mol%) (HBA)
Potassium acetate catalyst 22.5 mg
Acetic anhydride 191g
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 30 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 obtained pellets were heat-treated at 300 ° C. for 8 hours under a nitrogen stream. The melting point of the pellet was 352 ° C, the Tm-Tc was 25 ° C, and the melt viscosity was 23 Pa · s.
The melt viscosities of the liquid crystal resins 1 to 3 were measured in the same manner as the method for measuring the melt viscosities of the liquid crystal resin compositions described later.

(filler)
(B) Fibrous Wollastonite Fibrous Wollastonite 1: SH-1250BJ manufactured by Kinsei Matek Co., Ltd.
Fibrous Wollastonite 2: NYGLOS 8 manufactured by NYCO Materials
Fibrous Wollastonite 3: FPW # 150 manufactured by Kinsei Matek Co., Ltd.
Fibrous Wollastonite 4: SH-800 manufactured by Kinsei Matek Co., Ltd.
The composition, average fiber length, and average fiber diameter of the fibrous wollastonites 1 to 4 are as shown in Table 1. The contents of SiO ₂ , CaO, Al ₂ O ₃ , and Fe ₂ O _{3 in} the fibrous wollastonite are about 3 g of the fibrous wollastonite and cellulose powder (manufactured by GE Healthcare Bioscience Co., Ltd.). About 3 g of Whatman CC31) was mixed and pressed, and the tablet-shaped sample was obtained in accordance with JIS K 0119 using a fully automatic fluorescent X-ray analyzer (MagiX Pro Pw2540/00, manufactured by Spectris Co., Ltd.). Then, quantitative analysis was performed by the fundamental parameter (FP) method, and the calculation was performed.

(C) Plate-shaped filler Mica: AB-25S manufactured by Yamaguchi Mica Co., Ltd., average particle size 25.0 μm
Talc: Crown Talc PP manufactured by Matsumura Sangyo Co., Ltd., average particle size 12.8 μm

[Manufacturing of liquid crystal resin composition]
The above components are melt-kneaded at the following cylinder temperature using a twin-screw extruder (TEX30α type manufactured by Japan Steel Works, Ltd.) at the ratio (unit: mass%) shown in Table 2 or Table 3, and are liquid crystal resins. Composition pellets were obtained. At that time, the liquid crystal resin was supplied from the main feed port of the extruder, and the filler was supplied from the side feed port provided behind the main feed port in the extrusion direction.
Cylinder temperature:
360 ° C. (Examples 1 to 4, 7, and 8, Comparative Examples 1 to 7)
350 ° C (Example 5)
370 ° C (Example 6)

[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 a temperature lowering condition of 20 ° C./min, and then the temperature of the heat absorption peak observed when measured again under a temperature rising condition of 20 ° C./min was measured.

[Measurement of crystallization temperature]
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 exothermic peak temperature observed when measured under the temperature lowering condition of 20 ° C./min was measured.

[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 350 ° C. for the liquid crystal resin composition using the liquid crystal resin 1, 360 ° C for the liquid crystal resin composition using the liquid crystal resin 2, and the liquid crystal resin using the liquid crystal resin 3. The temperature of the composition was 380 ° C. The results are shown in Tables 2 and 3.

[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, breaking strain, and flexural modulus were measured in accordance with ASTM D790. The results are shown in Tables 2 and 3.

[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. As the bending stress, 1.8 MPa was used. The results are shown in Tables 2 and 3.

[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.

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. The results are shown in Tables 2 and 3.
(IR reflow condition)
Measuring machine: Large desktop reflow soldering device RF-300 (using far-infrared heater) manufactured by Japan Pulse Technology Research Institute
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. The results are shown in Tables 2 and 3.

[Blister temperature]
Under the following molding conditions, the liquid crystal resin composition is injection-molded to obtain a molded product having a size of 12.5 mm × 120 mm × 0.8 mm, and 30 of these molded products are immersed in silicone oil at a predetermined temperature and washed with a detergent. After drying naturally, it was visually examined whether or not blisters were generated on the surface. The blister temperature was set to the maximum temperature at which the number of blisters generated was zero among the 30 molded products, and was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
◯ (Good): The blister temperature was 260 ° C. or higher.
X (defective): The blister temperature was less than 260 ° C.

[Molding condition]
Molding machine:
SE100DU manufactured by Sumitomo Heavy Industries, Ltd. (for bending test, deflection temperature under load, blister temperature)
SE30DUZ manufactured by Sumitomo Heavy Industries, Ltd. (for FPC connector sled)
Cylinder temperature:
360 ° C. (Examples 1 to 4, 7, and 8, Comparative Examples 1 to 7)
350 ° C (Example 5)
370 ° C (Example 6)
Mold temperature: 90 ° C
Injection speed: 33 mm / sec

As can be seen from Tables 2 and 3, in the examples, the melt viscosity is 35 Pa · s or less, the bending strength is 140 MPa or more, the flexural modulus is more than 10,000 MPa, the fracture strain is more than 2.0%, and the deflection temperature under load is 230 ° C. or more. The FPC connector warp before reflow was 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, and the evaluation of the blister temperature was good. 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 properties, and warpage deformation and blister generation are suppressed. It was confirmed that there was.

Claims (5)

(A) Liquid crystal resin,
A liquid crystal resin composition containing (B) fibrous wollastonite and (C) mica.
The liquid crystal resin (A) is an aromatic polyester or an aromatic polyester amide having a repeating unit derived from an aromatic hydroxycarboxylic acid as a constituent component.
In the fibrous wollastonite, _{the content of Al 2} O ₃ is 0.05 to 0.65% by mass, and _{the content of Fe 2} O ₃ is 0.05 to 1.0% by mass.
For the entire liquid crystal resin composition
The content of the fibrous wollastonite (B) is 2.5 to 15% by mass.
The content of (C) mica was 17.5 to 27.5% by mass.
The total content of the (B) fibrous wollastonite and the (C) mica is 20 to 37.5% by mass.
Is a liquid crystal resin composition. The liquid crystal resin composition according to claim 1, which 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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