JP6837184B2 - Liquid crystal resin composition - Google Patents

Description

The present invention relates to a liquid crystal resin composition.

Liquid crystal resins represented by liquid crystal polyester resins have excellent mechanical strength, heat resistance, chemical resistance, electrical properties, etc. in a well-balanced manner, and also have excellent dimensional stability, so they are widely used as high-performance engineering plastics. It's being used. Recently, liquid crystal resins have come to be used for precision equipment parts by taking advantage of these features.

The liquid crystal resin composition may have a problem of blistering. That is, liquid crystal polymers 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, when 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 the decomposition gas generated when the liquid crystal polymer 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. As a liquid crystal resin composition in which the generation of blister generated due to such a cause is reduced, for example, a liquid crystal resin composition containing a liquid crystal polyester, a specific fatty acid ester, a filler, and a fatty acid metal salt is known. (Patent Document 1).

JP-A-2009-179693

Another cause of blister generation is that the cavities (delamination) caused by the distortion that occurs at the boundary between the skin layer and the core layer and the non-uniform layer structure caused by the complicated molded product shape expand thermally during reflow and soften by heating. The surface of the molded product is pushed up, and the pushed up part appears as a blister. Especially in the production of molded products with a large difference in wall thickness, the melted liquid crystal resin composition is sufficiently filled in the thick part due to the flow phenomenon peculiar to the liquid crystal resin in the process of flowing from the thin part to the thick part. There is a problem that a non-uniform layer structure is likely to be formed without being formed. The conventional liquid crystal composition is insufficient to solve the problem of blistering in a molded product having such a large difference in wall thickness.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal resin composition in which blister generation is suppressed in a molded product having a large wall thickness difference.

The present inventors have conducted intensive studies to solve the above problems. As a result, they have found that the above problems can be solved by adjusting the swell ratio of the liquid crystal resin composition to a specific range, and have completed the present invention. More specifically, the present invention provides the following.

A liquid crystal resin composition containing (1) (A) liquid crystal resin, (B) whisker, and (C) plate-like filler, and the swell ratio of the liquid crystal resin composition exceeds 1.00. Is a liquid crystal resin composition.

(2) The liquid crystal resin composition according to (1) for a connector, wherein the connector is a molded product of the liquid crystal resin composition, and the molded product has a thick portion and a thin portion. A liquid crystal resin composition having an unbalanced wall thickness difference of 0.5 mm or more, and having a shape in which a path from a gate portion of the molded product to the thick wall portion passes through the thin wall portion.

(3) The liquid crystal resin composition according to (1) or (2) for a connector that undergoes a reflow step, wherein the reflow step includes heating in a preheat zone and heating in a reflow zone, and the preheat. In the zone, the set temperature is 140 to 170 ° C. and the processing time is 1 to 3 minutes. In the reflow zone, the set temperature is 180 to 210 ° C., the processing time is 30 to 120 seconds, and the measured average temperature is A liquid crystal resin composition having a temperature of 183 ° C. or higher and a measured peak temperature of 220 to 270 ° C.

According to the present invention, it is possible to provide a liquid crystal resin composition in which blisters are suppressed in molded products having a large difference in wall thickness.

It is a figure which shows the DDR-DIMM connector molded in an Example. Note that A indicates a gate position. The unit of the numerical value in the figure is mm. It is a figure which shows the FPC connector molded in an Example. Note that A indicates a gate position. The unit of the numerical value in the figure is mm. It is a figure which shows the molded article which was molded in Example and used in the step sensitivity blister evaluation. Note that A indicates a gate position. The unit of the numerical value in the figure is mm.

<Liquid crystal resin composition>
The liquid crystal resin composition according to the present invention is a liquid crystal resin composition containing (A) a liquid crystal resin, (B) a whisker, and (C) a plate-like filler, and is the liquid crystal resin composition. The swell ratio is greater than 1.00. In the liquid crystal resin composition according to the present invention, when the swell ratio is more than 1.00, the generation of blisters in a molded product having a large wall thickness difference is effectively suppressed. Since the generation of blisters is suppressed more effectively, the swell ratio is preferably 1.02 or more, and more preferably 1.03 or more. The upper limit of the swell ratio is not particularly limited, and may be, for example, 1.2.

In the present specification, the swell ratio is 1 mm in inner diameter when measuring the fluidity in accordance with ISO 11443 under the conditions of a cylinder temperature 10 to 20 ° C. higher than the melting point of the liquid crystal resin and a shear rate of 2432 sec ^-1. After being extruded from an orifice having a length of 20 mm, the outer diameter D of the extruded product having stable dimensions is measured, the ratio D / d to the inner diameter d of the orifice is calculated, and the obtained value is adopted.

The swell ratio represents the ease of swelling of the extruded liquid crystal resin composition. At first glance, it seems that the higher the fluidity, the higher the swell ratio, but the swell ratio is not necessarily determined only by the melt viscosity, and the liquid crystal resin compositions showing the same melt viscosity have different swell ratios. Can be done. The same applies to the type or content of fillers or polymers. The swell ratio also depends on the compound conditions when preparing the liquid crystal resin composition. That is, even liquid crystal resin compositions containing the same component in the same amount can exhibit different swell ratios under different compound conditions. In this way, the swell ratio is an index determined by the complex relationship of complex factors.

On the other hand, the generation of blisters is not determined only by the melt viscosity, and even if the liquid crystal resin compositions exhibit the same melt viscosity, it is possible that blisters are generated on one side and no blisters are generated on the other side. The same applies to the type or content of filler or polymer and compound conditions. In this way, the occurrence of blisters is also an index determined by the complex relationship of multiple factors. Here, as demonstrated in Examples and Comparative Examples, when the swell ratio exceeds 1.00, the occurrence of blisters in the molded product having a large wall thickness difference is suppressed, provided that the other requirements in the present invention are satisfied. Will be done. When molding a complicated molded product, for example, a mold is used in which a cavity branched in a direction perpendicular to the mainstream of the melt of the liquid crystal resin composition extends. When the swell ratio exceeds 1.00, the melt easily spreads even into the cavity extending in the vertical direction and fills the voids, so that the generation of blisters in the molded product having a large wall thickness difference is suppressed. Cheap.

[(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 anisotropic molten phase can be confirmed 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. Liquid crystalline polymers applicable to the present invention normally transmit polarized light and are optically anisotropy when inspected between orthogonal polarizers, even in the molten and resting 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 (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 include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, and 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 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 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 acetic anhydride and other anhydrous carboxylic acids.

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. Generally, one having a melt viscosity at a molding temperature of 1000 sec ^-1 and a shear rate of 10 MPa or more and 600 MPa 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. The 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 50 to 75% by mass. When the content of the component (A) is within the above range, the obtained composition tends to suppress the generation of blisters while maintaining the fluidity. The content of the component (A) is more preferably 53 to 70% by mass, and even more preferably 55 to 68% by mass.

[(B) Whisker]
The liquid crystal resin composition according to the present invention includes whiskers. By including the whiskers in the liquid crystal resin composition according to the present invention, the obtained composition tends to suppress the generation of blisters while maintaining the mechanical strength. The whiskers can be used alone or in combination of two or more.

(B) The average fiber length of the whiskers is preferably 50 to 200 μm, more preferably 100 to 170 μm, and even more preferably 120 to 150 μm. When the average fiber length is within the above range, the obtained composition is more likely to suppress the generation of blisters while maintaining the mechanical strength. The average fiber length is a value measured by an image processing method by an image measuring machine by capturing a stereomicroscopic image from a CCD camera into a PC.

(B) The whisker has a preferable average fiber diameter of 1 to 15 μm or less, and a more preferable average fiber diameter of 5 to 10 μm. When the average fiber diameter is within the above range, the obtained composition is more likely to suppress the generation of blisters while maintaining the mechanical strength. The average fiber diameter is a value measured by an image processing method using a stereomicroscope image taken from a CCD camera into a PC and an image measuring machine.

(B) The whiskers are not particularly limited, and are, for example, potassium titanate whiskers, calcium silicate whiskers (wollastonite), calcium carbonate whiskers, zinc oxide whiskers, aluminum borate whiskers, silicon nitride whiskers, silicon trinitride whiskers. , Basic magnesium sulfate whiskers, barium whiskers titanate, silicon carbide whiskers, boron whiskers, etc. In terms of availability, potassium titanate whiskers, calcium silicate whiskers (wollastonite), calcium carbonate whiskers, zinc oxide Whiskers, aluminum borate whiskers and the like are preferable, and calcium silicate whiskers (wollastonite) are more preferable. The shape of the (B) whiskers in the liquid crystal resin composition of the present invention is different from the shape of the (B) whiskers before being blended. The shape of the whisker (B) described above is the shape before blending. If the shape before blending is as described above, it is easy to obtain a molded product in which blister generation is suppressed while maintaining mechanical strength.

In the liquid crystal resin composition of the present invention, the preferable content of (B) whiskers is 3 to 30% by mass. When the content of the component (B) is within the above range, the obtained composition tends to suppress the generation of blisters while maintaining the mechanical strength. The content of the component (B) is more preferably 4 to 30% by mass (for example, 5 to 30% by mass or 4 to 29% by mass), still more preferably 5 to 28% by mass (for example, 5 to 27.5% by mass). Mass%).

[(C) Plate-shaped filler]
The liquid crystal resin composition according to the present invention contains a plate-like filler. By including the plate-shaped filler in the liquid crystal resin composition according to the present invention, it is possible to obtain a molded product in which warpage deformation is suppressed. The plate-shaped filler can be used alone or in combination of two or more.

In the liquid crystal resin composition of the present invention, the preferable content of the (C) plate-like filler is 10 to 35% by mass. When the content of the component (C) is within the above range, it is easy to obtain a molded product in which warpage deformation is suppressed from the obtained composition. The content of the component (C) is more preferably 10 to 32% by mass (for example, 11 to 32% by mass), still more preferably 12 to 30% by mass (for example, 12.5 to 30% by mass).

Examples of the plate-like filler in the present invention include talc, mica, glass flakes, and various metal foils. One or more selected from talc and mica are preferable, and talc is more preferable, in that the warp deformation of the molded product obtained from the liquid crystal resin composition is suppressed without deteriorating the fluidity of the liquid crystal resin composition. preferable. The average particle size of the plate-shaped filler is not particularly limited, and a smaller one is desirable in consideration of the fluidity in the thin-walled portion. On the other hand, in order to reduce the warp deformation of a molded product such as a connector obtained from the liquid crystal resin composition, it is necessary to maintain a certain size. Specifically, 1 to 100 μm is preferable, and 5 to 50 μm is more preferable.

〔talc〕
As the talc that can be used in the present invention, _{the total content of Fe 2} O ₃ , Al ₂ O ₃ and Ca O is 2.5% by mass or less with _{respect to the total solid content of the talc, and Fe 2} O ₃ and Al _It is preferable that the total content of 2O ₃ is more than 1.0% by mass and 2.0% by mass or less, and the content of CaO is less than 0.5% by mass. That is, the talc that can be used in the present invention _{contains at least one of Fe 2} O ₃ , Al ₂ O _3, and CaO in addition to _{SiO 2} and MgO, which are the main components thereof, and each component is in the above content range. It may be contained in.

In the above talc, when _{the total content of Fe 2} O ₃ , Al ₂ O ₃ and CaO was 2.5% by mass or less, the liquid crystal resin composition was molded from the molding processability and the liquid crystal resin composition. The heat resistance of molded products such as connectors does not deteriorate easily. Therefore, _{the total content 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.

Further, among the above talcs, talc _{having a total content of Fe 2} O ₃ and Al ₂ O ₃ of more than 1.0% by mass is easily available. Further, in the above talc, when _{the total content of Fe 2} O ₃ and Al ₂ O ₃ is 2.0% by mass or less, the liquid crystal resin composition is molded from the moldability and the liquid crystal resin composition. The heat resistance of molded products such as connectors does not deteriorate easily. Therefore, _{the total content of Fe 2} O ₃ and Al ₂ O ₃ is preferably more than 1.0% by mass and 1.7% by mass or less.

Further, in the above talc, when the CaO content is less than 0.5% by mass, the molding processability of the liquid crystal resin composition and the heat resistance of the molded product such as the connector molded from the liquid crystal resin composition are deteriorated. It is hard to get worse. Therefore, the CaO content is preferably 0.01% by mass or more and 0.4% by mass or less.

The mass-based or volume-based cumulative average particle diameter (D ₅₀ ) of talc in the present invention measured by a laser diffraction method is determined from the viewpoint of preventing warpage deformation of the molded product and maintaining the fluidity of the liquid crystal resin composition. It is preferably 4.0 to 20.0 μm, more preferably 10 to 18 μm.

[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 not treated with the coagulation sedimentation agent and / or the sedimentation aid is used, the polymer in the liquid crystal resin composition is less likely to be decomposed, 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 is likely 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.

[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 the like can also be appropriately added depending on the required performance. The other fillers refer to fillers other than (B) whiskers and (C) plate-shaped fillers, and examples thereof include granular fillers such as silica.

[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 is prepared by blending the above components (A) to (C) and melt-kneading them with a single-screw or twin-screw extruder.

The liquid crystal resin composition of the present invention is preferably for a connector, the connector is made of a molded product of the liquid crystal resin composition, and the molded product has a wall thickness difference between a thick portion and a thin portion. It has an uneven wall structure of 0.5 mm or more, and has a shape in which the path from the gate portion of the molded product to the thick portion passes through the thin portion. Since the molded product has the above-mentioned shape, it is necessary for the molten liquid crystal resin composition to flow from the thin portion to the thick portion at the time of its production. The liquid crystal resin composition of the present invention not only has an unbalanced wall structure in which the wall thickness difference between the thick portion and the thin portion is 0.5 mm or more, but also the liquid crystal resin from the thin portion to the thick portion. In a connector made of a molded product that requires the flow of the composition, the generation of blisters can be effectively suppressed. A typical example of such a connector is a connector for a memory module such as a DDR connector; an interface connector such as a SATA connector. Examples of the DDR connector include a DDR-DIMM connector, a DDR2-DIMM connector, a DDR-SO-DIMM connector, a DDR2-SO-DIMM connector, a DDR-Micro-DIMM connector, a DDR2-Micro-DIMM connector and the like.

Further, the liquid crystal resin composition of the present invention is preferably for a connector that undergoes a reflow step, and the reflow step includes heating in the preheat zone and heating in the reflow zone, and the set temperature is 140 in the preheat zone. The temperature is ~ 170 ° C. and the treatment time is 1 to 3 minutes. In the reflow zone, the set temperature is 180 to 210 ° C., the treatment time is 30 to 120 seconds, the average temperature of the actual measurement is 183 ° C. or higher, and the peak of the actual measurement. The temperature is 220 to 270 ° C. In the preheat zone, by maintaining the temperature at 140 to 170 ° C. for 1 to 3 minutes, the solder paste is heated, and the surface to which the flux in the paste is soldered can be appropriately cleaned. After heating in the preheat zone, the transition to heating in the reflow zone can be made, for example, by raising the oven temperature at 1-3 ° C. per second. In the reflow zone, since the set temperature is 180 to 210 ° C. and the processing time is 30 to 120 seconds, the actual temperature of the connector becomes at least 60 seconds or more and 183 ° C. (melting point of solder) or more, resulting in soldering. In addition to being able to effectively prevent distortion, bridging, connection in low temperature conditions, etc., the processing time at the measured peak temperature of 220 to 260 ° C is maintained for 30 to 120 seconds, so sufficient reflow should be completed. Can be done. The liquid crystal resin composition of the present invention can effectively suppress the generation of blisters in the connector that has undergone the above reflow process.

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 (method for producing liquid crystal polymer 1)
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 melting point of the obtained pellet was 336 ° C., the difference Tm-Tc between the melting point and the crystallization temperature was 40 ° C., and the melt viscosity was 20 Pa · s.

(Manufacturing method of liquid crystal polymer 2)
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) 4,4'-Dihydroxybiphenyl 415 g (13.35 mol%) (BP)
(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, 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 points. 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 345 ° C., a Tm-Tc of 37 ° C., and a melt viscosity of 10 Pa · s.

(Manufacturing method of liquid crystal polymer 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) 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, Tm-Tc was 48 ° C, and the melt viscosity was 10 Pa · s.
The melt viscosities of the liquid crystal polymers 1 to 3 were measured in the same manner as the method for measuring the melt viscosity of the liquid crystal resin composition described later.

(filler)
(B) Fibrous filler Mild fiber: EPH150M-01M manufactured by Nippon Electric Glass Co., Ltd., fiber diameter 10.5 μm, number average fiber length 150 μm
Glass fiber: ECS03T-786H manufactured by Nippon Electric Glass Co., Ltd., chopped strand with fiber diameter of 10 μm and length of 3 mm Calcium silicate whiskers: NYGLOS 8 manufactured by NYCO Materials, number average fiber length 136 μm, average fiber diameter 8 μm
(C) Plate-shaped filler talc: Crown talc PP manufactured by Matsumura Sangyo Co., Ltd., average particle size 12.8 μm
(D) Spherical filler Glass beads: EGB731 manufactured by Potters Barotini Co., Ltd., average particle diameter 20.0 μm

[Manufacturing of liquid crystal resin composition]
The above components are melt-kneaded at a cylinder temperature of 350 ° C. using a twin-screw extruder (TEX30α type manufactured by Japan Steel Works, Ltd.) at the ratio shown in Table 1, Table 2, or Table 3 to form a liquid crystal resin composition. A product pellet was obtained. At that time, in Examples 1 to 11 and Comparative Examples 1 to 4, 6 and 7, the liquid crystal resin is supplied from the main feed port of the extruder, and the side feed port provided behind the main feed port in the extrusion direction. The filler was supplied from. On the other hand, in Comparative Example 5, the liquid crystal resin and the filler were supplied from the main feed port of the extruder. In addition, "%" in the table shows mass%.

[Measurement of melting point]
After observing the heat absorption peak temperature (Tm1) observed when the liquid crystal polymer 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 crystallization temperature]
After observing the heat absorption peak temperature (Tm1) observed when the liquid crystal polymer 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 swell ratio]
The swell ratio of the liquid crystal resin composition was measured using the above pellets. Specifically, the fluidity is measured in accordance with ISO 11443 under the following conditions of ^{cylinder temperature and shear rate 2432sec -1} by a capillary type Reometer (manufactured by Toyo Seiki Seisakusho Co., Ltd., Capillograph 1D: piston diameter 10 mm). The outer diameter D of the extruded product was measured when the dimensions became stable after being extruded from an orifice having an inner diameter of 1 mm and a length of 20 mm to expand or contract. When the inner diameter of the orifice was d, D / d was calculated and the obtained value was taken as the swell ratio. The results are shown in Table 1 or Table 2.
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)

[Measurement of melt viscosity]
The melt viscosity of the liquid crystal resin composition was measured using the pellets. Specifically, using a capillary rheometer (manufactured by Toyo Seiki Seisakusho Co., Ltd., Capillary Graph 1D: piston diameter 10 mm), the apparent melt viscosity under the ^{following cylinder temperature and shear rate of 1000 sec -1 is based on ISO 11443.} Was measured. An orifice having an inner diameter of 1 mm and a length of 20 mm was used for the measurement. The results are shown in Table 1 or Table 2.
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)

[Measurement of deflection temperature under load (DTUL)]
The pellet was molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain a test piece for measurement (80 mm × 10 mm × 4 mm). Using this test piece, the deflection temperature under load was measured by a method compliant with ISO75-1 and ISO75-1. As the bending stress, 1.8 MPa was used. The results are shown in Table 1 or Table 2.
〔Molding condition〕
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)
Mold temperature: 90 ° C
Injection speed: 33 mm / sec

[Bending test]
The pellet was molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to prepare a bending test piece of 80 mm × 10 mm × 4 mm. Using this test piece, bending strength and flexural modulus were measured according to ISO178. The results are shown in Table 1 or Table 2.
〔Molding condition〕
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)
Mold temperature: 90 ° C
Injection speed: 33 mm / sec
Holding pressure: 50 MPa

[Measurement of flatness]
The pellets were molded using a molding machine (“SE-100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to prepare five flat test pieces of 80 mm × 80 mm × 1 mm. The first plate-shaped test piece was allowed to stand on a horizontal surface, and using a CNC image measuring machine (model: QVBHU404-PRO1F) manufactured by Mitutoyo Co., Ltd., at nine locations on the flat plate-shaped test piece, from the horizontal surface. The height was measured, and the average height was calculated from the obtained measured values. The position where the height was measured is when a square with a side of 74 mm is placed on the main plane of the flat plate-shaped test piece so that the distance from each side of this main plane is 3 mm, and each vertex of this square is placed. , The midpoint of each side of this square, and the position corresponding to the intersection of the two diagonal lines of this square. The height from the horizontal plane is the same as the average height, and a plane parallel to the horizontal plane is used as a reference plane. From the heights measured at the above nine points, the maximum height and the minimum height from the reference plane were selected, and the difference between the two was calculated. Similarly, the above difference was calculated for the other four flat plate-shaped test pieces, and the five values obtained were averaged to obtain the flatness value. The results are shown in Table 1 or Table 2.
〔Molding condition〕
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)
Mold temperature: 90 ° C
Injection speed: 33 mm / sec
Holding pressure: 60 MPa

[Measurement of blister temperature]
The pellet was molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain a molded product of 12.5 mm × 120 mm × 0.8 mm having a weld portion. .. A fragment obtained by dividing this molded product into two parts at the weld portion was used as one sample and sandwiched in a hot press at a predetermined temperature for 5 minutes. Then, it was visually examined whether or not blisters were generated on the surface of the sample. The blister temperature was set to the maximum temperature at which the number of blisters generated was zero. The predetermined temperature was set in the range of 250 to 300 ° C. in increments of 10 ° C.
〔Molding condition〕
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)
Mold temperature: 90 ° C
Injection speed: 33 mm / sec

[Step sensitivity blister evaluation]
The pellets were molded using a molding machine (“TR100EH” manufactured by Sodick Co., Ltd.) under the following molding conditions, and as shown in FIG. 3, a step of 0.5 mm / 0.4 mm or a step of 0.2 mm / 0. A 12.9 mm × 73.0 mm × 0.8 mm molded product having a thickness of 0.3 mm was obtained.
〔Molding condition〕
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)
Mold temperature: 80 ° C
Injection rate: 100, 200, 300, or 400 mm / sec

The obtained molded product was subjected to IR reflow under the following conditions, and the presence or absence of blisters was visually observed. Since the molded product has different steps at the gate, each step was regarded as an independent sample in this evaluation. Ten samples were evaluated for each of a total of 16 conditions (4 steps 4 conditions × 4 injection speed conditions), and the number of samples in which blister was generated was counted out of a total of 160 samples. The results are shown in Table 1 or Table 2.
[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 set temperature: 150 ° C (processing time: 60 seconds)
Measured average temperature: 150 ° C
Reflow zone set temperature: 190 ° C (processing time: 60 seconds)
Measured average temperature: 230 ° C or higher Actual peak temperature: 251 ° C

[DDR type blister evaluation]
The liquid crystal resin composition is injection-molded under the following molding conditions (gate: tunnel gate, gate size: φ0.75 mm), and the overall size is 70.0 mm × 26.0 mm × 4.0 mmt as shown in FIG. , A DDR-DIMM connector having a pitch-to-pitch distance of 0.6 mm and a pin hole number of 100 × 2 was obtained.
〔Molding condition〕
Molding machine: Sumitomo Heavy Industries SE30DUZ
Cylinder temperature:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)
Mold temperature: 80 ° C
Injection speed: 200 mm / sec

The obtained connector was subjected to IR reflow under the following conditions, and the presence or absence of blisters was visually observed. The results are shown in Table 1 or Table 2. In the table, "○" indicates that no blisters have occurred, and "x" indicates that blisters have occurred.
[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 set temperature: 150 ° C (processing time: 60 seconds)
Measured average temperature: 150 ° C
Reflow zone set temperature: 190 ° C (processing time: 60 seconds)
Measured average temperature: 230 ° C or higher Measured peak temperature: 251 ° C

[FPC type blister evaluation]
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:
350 ° C (Examples 1, 2, 4 to 11, Comparative Examples 2 to 7)
360 ° C (Example 3)
370 ° C (Comparative Example 1)
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 subjected to IR reflow under the following conditions, and the presence or absence of blisters was visually observed. The results are shown in Table 1 or Table 2. In the table, "○" indicates that no blisters have occurred, and "x" indicates that blisters have occurred.
[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 set temperature: 150 ° C (processing time: 60 seconds)
Measured average temperature: 150 ° C
Reflow zone set temperature: 190 ° C (processing time: 60 seconds)
Measured average temperature: 230 ° C or higher Measured peak temperature: 251 ° C

As can be seen from Tables 1, 2 and 3, the liquid crystal resin composition of the present invention contains (A) a liquid crystal resin, (B) a whiskers, and (C) a plate-like filler, and has a swell ratio. When the content exceeds 1.00, the mechanical strength is maintained, warpage deformation is suppressed, and blister generation is suppressed to give a molded product.

Claims (3)

(A) Liquid crystal resin,
A liquid crystal resin composition for a connector containing (B) a whisker and (C) a plate-like filler.
The liquid crystal resin (A) is an aromatic polyester amide.
The average fiber length of the whiskers (B) is 50 to 200 μm.
The swell ratio of the liquid crystal resin composition is more than 1.00.
The swell ratio has an inner diameter of 1 mm when measuring the fluidity in accordance with ISO 11443 under the conditions of a cylinder temperature 10 to 20 ° C. higher than the melting point of the liquid crystal resin (A) and a shear rate of 2432 sec ^-1. After being extruded from an orifice having a length of 20 mm, the outer diameter D of the extruded product having stable dimensions was measured, the ratio D / d to the inner diameter d of the orifice was calculated, and the liquid crystal resin composition was obtained. Stuff. A connector for a liquid crystal resin composition according to請Motomeko 1,
The connector is made of a molded product of the liquid crystal resin composition.
The molded product has an uneven wall thickness structure in which the wall thickness difference between the thick portion and the thin wall portion is 0.5 mm or more, and the path from the gate portion of the molded product to the thick wall portion passes through the thin wall portion. A liquid crystal resin composition having a shape to be molded. A請Motomeko 1 or connector for a liquid crystal resin composition according to 2,
The connector is a connector that undergoes a reflow process.
The reflow step includes heating in the preheat zone and heating in the reflow zone.
In the preheat zone, the set temperature is 140 to 170 ° C. and the processing time is 1 to 3 minutes.
In the reflow zone, the liquid crystal resin composition has a set temperature of 180 to 210 ° C., a treatment time of 30 to 120 seconds, an actually measured average temperature of 183 ° C. or higher, and an actually measured peak temperature of 220 to 270 ° C.

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