TW201945464A - Liquid-crystalline resin composition - Google Patents

Abstract

Provided is a liquid-crystalline resin composition in which the formation of blisters is suppressed in molded articles having large differences in thickness. The liquid-crystalline resin composition according to the present invention contains (A) a liquid-crystalline resin, (B) whiskers, and (C) a lamellar filler, wherein the swell ratio of the liquid-crystalline resin composition is more than 1.00. The liquid-crystalline resin composition according to the present invention is preferably for use in a connector; the connector comprises a molded product of the liquid-crystalline resin composition; the molded product has a non-uniform structure in which the difference in thickness between the thick part and the thin part is 0.5 mm or more; and a path from a gate part of the molded product to the thick part has a shape that traverses the thin part.

Description

Liquid crystal resin composition

The present invention relates to a liquid crystalline resin composition.

Liquid crystalline resins typified by liquid crystalline polyester resins are widely used as high-performance resins because they have excellent mechanical strength, heat resistance, chemical resistance, and electrical properties, as well as excellent dimensional stability. Functional engineering plastic. Recently, liquid crystal resins have been used in precision machine parts by taking advantage of these advantages.

The liquid crystal resin composition may cause a problem of foaming. That is, liquid crystal polymers such as liquid crystalline polyester and liquid crystal polyester amidine have good high-temperature thermal stability, so they are mostly used for materials that require heat treatment at high temperatures. However, when the molded article is left in a high-temperature air or liquid for a long time, a problem occurs in which a fine swelling called foaming occurs on the surface.

One cause of this phenomenon is that the decomposition gas or the like generated by the liquid crystalline polymer in the molten state is brought into the molded article, and then, when the high-temperature heat treatment is performed, the gas expands and pushes the surface of the molded article that is softened by heating up, The part pushed up appears as a bubble. As a liquid crystalline resin composition which reduces foaming caused by such a cause, for example, a liquid crystalline resin composition containing a liquid crystalline polyester, a specific fatty acid ester, a filler, and a fatty acid metal salt is known (Patent Document 1) ).
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-179693

[Questions to be Solved by the Invention]

The other cause of blistering is caused by strains at the boundary between the skin layer and the core layer, complex molded product shapes, and other voids (interlayer delamination) caused by uneven layer structures that thermally expand during reflow and heat up On the other hand, the surface of the softened molded product is pushed up, and the part pushed up appears as a bubble. In particular, when manufacturing a molded article having a large difference in wall thickness, the molten liquid crystal resin composition flows from a thin-walled portion to a thick-walled portion, and the thick-walled portion may not be filled sufficiently due to a flow phenomenon peculiar to the liquid crystal resin. The problem of uneven layer structure is liable to be formed in the subordinates. Conventional liquid crystalline compositions have been insufficient to solve the problem of foaming that occurs in such molded products having large wall thickness differences.

This invention is made in order to solve the said subject, The objective is to provide the liquid-crystalline resin composition which can suppress generation | occurrence | production of the foaming in the molded article with a large difference in wall thickness.
Means to solve the problem

In order to solve the above-mentioned problems, the present inventors repeated their intensive studies. As a result, it was found that the above-mentioned problem can be solved by adjusting the swell ratio of the liquid crystalline resin composition to a specific range, and the present invention has been completed. More specifically, the present invention provides the following matters.

(1) A liquid crystalline resin composition, which is a liquid crystalline resin composition containing (A) a liquid crystalline resin, (B) whiskers, and (C) a plate-like filler, and the expansion ratio of the liquid crystalline resin composition is Greater than 1.00.

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

(3) A liquid crystalline resin composition is a liquid crystalline resin composition as described in (1) or (2) for a connector subjected to a reflow step, wherein the reflow step includes heating in a preheating zone and heating in a reflow zone. Heating, the set temperature in the preheating zone is 140-170 ° C, the processing time is 1 to 3 minutes, the set temperature in the reflow zone is 180-210 ° C, the processing time is 30-120 seconds, and the average measured temperature The temperature is 183 ° C or higher, and the measured peak temperature is 220-270 ° C.
[Inventive effect]

According to the present invention, it is possible to provide a liquid crystalline resin composition that suppresses foaming in a molded article having a large difference in wall thickness.

[Forms for Implementing Invention]

> Liquid crystal resin composition>
The liquid crystalline resin composition of the present invention is a liquid crystalline resin composition containing (A) a liquid crystalline resin, (B) whiskers, and (C) a plate-like filler, and the expansion ratio of the liquid crystalline resin composition is greater than 1.00. . The liquid crystalline resin composition of the present invention can effectively suppress foaming in a molded product having a large difference in wall thickness when the expansion ratio is greater than 1.00. Since foaming can be more effectively suppressed, the aforementioned expansion ratio is preferably 1.02 or more, and more preferably 1.03 or more. The upper limit of the expansion ratio is not particularly limited, and may be 1.2, for example.

In this specification, the expansion ratio is measured at a cylinder temperature of 10 to 20 ° C higher than the melting point of the liquid crystal resin and a shear rate of 2432 sec ^-1 . When measuring fluidity according to ISO 11443, the inner diameter is 1 mm. After an orifice having a length of 20 mm was extruded, the value obtained by measuring the ratio D / d to the inner diameter d of the orifice was measured by measuring the outer diameter D of the extruded product after the dimension was stabilized.

The swelling ratio indicates the ease of swelling of the extruded liquid crystal resin composition. At first glance, the higher the fluidity, the higher the expansion ratio, but the expansion ratio is not necessarily determined only by the melt viscosity. Liquid crystal resin compositions showing the same melt viscosity may have different expansion ratios from each other. The same applies to the type or content of filler or polymer. The expansion ratio is also controlled by the mixing conditions when preparing the liquid crystalline resin composition. That is, liquid crystal resin compositions containing the same components in the same amount may exhibit different expansion ratios when the mixing conditions are different. In this way, the expansion ratio is an index determined by a complex relationship between plural elements.

On the other hand, the occurrence of foaming is not determined only by the melt viscosity. The liquid crystal resin compositions exhibiting the same melt viscosity may cause foaming on one side and not foaming on the other. The same applies to the type or content of the filler or polymer and the mixing conditions. In this way, the generation of bubbling is also an index determined by a complex relationship between a plurality of elements. Here, as demonstrated in the examples and comparative examples, when the expansion ratio is more than 1.00 under the condition that the other necessary conditions of the present invention are provided, it is possible to suppress the occurrence of blistering in a molded product having a large difference in wall thickness. When molding a complex molded product, for example, a branched die groove can be used to extend the mold in a direction perpendicular to the mainstream of the molten material of the liquid crystal resin composition. When the expansion ratio is more than 1.00, the molten material is likely to be expanded to a mold groove extending in such a vertical direction, and it is easy to completely fill the gap, so it is easy to suppress the occurrence of blistering in a molded product having a large wall thickness difference.

[(A) Liquid crystalline resin]
The (A) liquid crystalline resin used in the present invention refers to a melt-processable polymer having properties capable of forming an optically anisotropic melt phase. The properties of the anisotropic molten phase can be confirmed by a common polarization inspection method using an orthogonal polarizer. More specifically, confirmation of the anisotropic molten phase can be performed by observing a molten sample placed on a Leitz hot stage at a Leitz hot stage at a magnification of 40 times using a Leitz polarizing microscope. In the liquid crystalline polymer to which the present invention can be applied, when the inspection is performed between the orthogonal polarizers, the polarized light is usually transmitted and optically shows anisotropy even in a molten still state.

The type of the (A) liquid crystalline resin is not particularly limited, and an aromatic polyester and / or an aromatic polyester amidine is preferred. In addition, polyesters which partially contain an aromatic polyester and / or an aromatic polyester amidine in the same molecular chain are also within the scope. As the liquid crystal resin (A), when it is dissolved in pentafluorophenol at a concentration of 0.1% by mass at 60 ° C, it can be preferably used to have a logarithmic viscosity (at least about 2.0 dl / g, more preferably 2.0 to 10.0 dl / g). IV).

As the aromatic polyester or aromatic polyester amide of the (A) liquid crystalline resin applicable to the present invention, it is particularly preferred that the aromatic polyester or aromatic polyester amine be selected from aromatic hydroxycarboxylic acids, aromatic hydroxylamines, and aromatic diamines. An aromatic polyester or an aromatic polyester amidamine having a repeating unit of at least one compound constituting a group as a constituent.

More specifically,
(1) Polyester mainly composed of one or more repeating units derived from aromatic hydroxycarboxylic acids and their derivatives;
(2) It is mainly composed of (a) one or two or more repeating units derived from aromatic hydroxycarboxylic acids and their derivatives, and (b) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, And such derivatives are polyesters consisting of one or more repeating units;
(3) It consists mainly of (a) one or two or more repeating units derived from aromatic hydroxycarboxylic acids and their derivatives, (b) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and One or two or more repeating units of these derivatives, and (c) at least one or two derived from aromatic diols, alicyclic diols, aliphatic diols, and derivatives thereof A polyester composed of more than one repeating unit;
(4) Mainly derived from (a) one or two or more repeating units derived from aromatic hydroxycarboxylic acids and their derivatives, (b) derived from aromatic hydroxylamines, aromatic diamines, and the like And (c) one or two or more repeating units derived from aromatic dicarboxylic acid, alicyclic dicarboxylic acid, and derivatives thereof. Polyester amide
(5) Mainly derived from (a) one or two or more repeating units derived from aromatic hydroxycarboxylic acids and their derivatives, (b) derived from aromatic hydroxylamines, aromatic diamines, and the like One or two or more repeating units of a substance, (c) one or two or more repeating units derived from an aromatic dicarboxylic acid, an alicyclic dicarboxylic acid, and derivatives thereof, and (d ) Polyesteramine and the like derived from at least one or two or more repeating units derived from aromatic diols, alicyclic diols, aliphatic diols, and derivatives thereof. Moreover, you may use a molecular weight modifier together with the said component as needed.

Preferred examples of specific compounds constituting the (A) liquid crystalline resin applicable to the present invention include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 2,6-dicarboxylic acid. Hydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcinol, compounds represented by the following general formula (I), and the following general formula (II) Aromatic diols such as compounds shown; terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and the following general formula (III) Aromatic dicarboxylic acids such as compounds; aromatic amines such as p-aminophenol and p-phenylenediamine.

(X: a group selected from alkylene (C ₁ to C ₄ ), alkylene, -O-, -SO-, SO _2- , -S-, and -CO-)


(Y: a base selected from-(CH ₂ ) _n- (n = 1 to 4) and -O (CH ₂ ) _n O- (n = 1 to 4)).

The preparation of the (A) liquid crystalline resin used in the present invention can be performed from the above-mentioned monomer compound (or a mixture of monomers) by a known method such as a direct polymerization method or a transesterification method, and usually melt polymerization can be used. Method, solution polymerization method, slurry polymerization method, solid phase polymerization method, etc., or a combination of two or more of these, and a melt polymerization method, or a combination of a melt polymerization method and a solid phase polymerization method is preferred. The aforementioned compounds having the ability to form an ester may be used in the original form for polymerization, or may be modified from a precursor to a derivative having the ability to form the ester by using an amidine agent or the like at the early stage of polymerization. Examples of the halogenating agent include carboxylic anhydrides such as acetic anhydride.

Various catalysts can be used during polymerization. Typical examples of usable catalysts include potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and ginseng (2,4-pentanedione). Metal salt catalysts such as acid (cobalt (III)) and organic compound catalysts such as N-methylimidazole and 4-dimethylaminopyridine. The amount of the catalyst used is usually about 0.001 to 1% by mass, and particularly preferably about 0.01 to 0.2% by mass relative to the total weight of the monomer.

The melt viscosity of the (A) liquid crystalline resin obtained by the method described above is not particularly limited. Generally, a melt viscosity at a molding temperature of 10 MPa to 600 MPa at a shear rate of 1000 sec ^-1 can be used. But it is too high viscosity in itself, because the fluidity becomes very poor. The liquid crystal resin (A) may be a mixture of two or more 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 crystalline resin are not particularly limited. In terms of easy suppression of foaming and easy maintenance of mechanical strength, 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. 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.

The liquid crystal resin composition of this invention WHEREIN: The preferable content of (A) liquid crystal resin is 50-75 mass%. When the content of the component (A) is within the above range, the resulting composition is likely to suppress foaming while maintaining fluidity. The content of the component (A) is preferably 53 to 70% by mass, and more preferably 55 to 68% by mass.

[(B) Whiskers]
The liquid crystalline resin composition of the present invention contains whiskers. By containing whiskers in the liquid crystalline resin composition of the present invention, it is easy to suppress the occurrence of foaming while maintaining the mechanical strength of the obtained composition. Whiskers can be used alone or in combination of two or more.

(B) The average fiber length of the whisker is preferably 50 to 200 μm, preferably 100 to 170 μm, and more preferably 120 to 150 μm. When the average fiber length is within the above range, the obtained composition can more easily suppress foaming while maintaining mechanical strength. The average fiber length is a value measured by inputting a solid microscope image from a CCD camera to a PC, using an image measuring machine, and using an image processing method.

(B) A good average fiber diameter of the whiskers is 1 to 15 μm or less, and an average fiber diameter is preferably 5 to 10 μm. When the average fiber diameter is within the above range, the obtained composition can more easily suppress foaming while maintaining mechanical strength. The average fiber diameter is a value measured by inputting a solid microscope image from a CCD camera to a PC, using an image measuring machine, and using an image processing method.

The (B) whiskers are not particularly limited, and examples thereof include 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 titanate whiskers, 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, etc. are preferred, and calcium silicate whiskers (wollastonite) are more preferred. 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 preparation. The shape of the (B) whisker is a shape before preparation. When the shape before blending is as described above, it is easy to obtain a molded product with suppressed foaming while maintaining the mechanical strength.

The content of (B) whiskers in the liquid crystalline resin composition of the present invention is preferably from 3 to 30% by mass. When the content of the component (B) is within the above range, the obtained composition is likely to suppress the occurrence of foaming while maintaining the mechanical strength. The content of the component (B) is preferably 4 to 30% by mass (for example, 5 to 30% by mass or 4 to 29% by mass), and more preferably 5 to 28% by mass (for example, 5 to 27.5% by mass).

[(C) Plate-shaped filler]
The liquid crystalline resin composition of the present invention contains a plate-like filler. By containing a plate-like filler in the liquid crystalline resin composition of the present invention, it is possible to obtain a molded article with suppressed warping deformation. The plate-like filler can be used alone or in combination of two or more.

The content of the (C) plate-like filler in the liquid crystalline resin composition of the present invention is preferably from 10 to 35% by mass. When the content of the component (C) is within the above range, a molded product capable of suppressing warpage deformation can be easily obtained from the obtained composition. The content of the component (C) is preferably 10 to 32% by mass (for example, 11 to 32% by mass), and 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 fragments, and various metal foils. In order to prevent the liquidity of the liquid crystalline resin composition from being deteriorated, and to suppress warpage and deformation of a molded article obtained from the liquid crystalline resin composition, one or more members selected from talc and mica are preferred, and talc is used. Is better. The average particle diameter of the plate-shaped filler is not particularly limited, and when considering the fluidity of the thin-walled portion, it is preferably smaller. On the other hand, in order to reduce warpage and 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, it is preferably 1 to 100 μm, and more preferably 5 to 50 μm.

[talc]
As the talc in the present invention can be used, relative to the total solid content of the talc to Fe ₂ O _3, the total content of Al ₂ O ₃ and CaO is 2.5 mass% or less, Fe ₂ O ₃ and Al ₂ O ₃ is It is preferable that the total content 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 may contain at least one of Fe ₂ O ₃ , Al ₂ O ₃ and CaO in addition to SiO ₂ and MgO as its main components and may be contained in the above-mentioned content range. The ingredients.

When the above talc has a total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO of 2.5% by mass or less, the moldability of the liquid crystalline resin composition and molded articles such as connectors formed from the liquid crystalline resin composition The heat resistance is not easily deteriorated. 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, in the above-described talc, the total content of Fe ₂ O ₃ and Al ₂ O ₃ is more than 1.0 mass% talc easily accessible. When the total content of Fe ₂ O ₃ and Al ₂ O ₃ in the talc is 2.0% by mass or less, the moldability of the liquid crystalline resin composition and the molded product such as a connector molded from the liquid crystalline resin composition are reduced. Heat resistance is not easily deteriorated. Therefore, the total content of Fe ₂ O ₃ and Al ₂ O ₃ is preferably greater than 1.0% by mass and not more than 1.7% by mass.

When the content of CaO in the talc is less than 0.5% by mass, the moldability of the liquid crystal resin composition and the heat resistance of molded products such as connectors molded from the liquid crystal resin composition are not easily deteriorated. Therefore, the content of CaO is preferably 0.01 mass% or more and 0.4 mass% or less.

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

[Mica]
The so-called mica is a pulverized product of a silicate mineral containing aluminum, potassium, magnesium, sodium, iron, and the like. Examples of the mica that can be used in the present invention include muscovite, phlogopite, biotite, and artificial mica. Among them, muscovite is preferred in terms of good hue and low price.

Further, in the production of mica, as a method for pulverizing minerals, a wet pulverization method and a dry pulverization method are known. As a wet pulverization method, after rough pulverizing the mica raw stone using a dry pulverizer, water is added and the main pulverization is performed by wet pulverization in a slurry state, followed by dehydration and drying. Compared with the wet pulverization method, the dry pulverization method is a low-cost and common method, but when the wet pulverization method is used, it is easier to pulverize the mineral thinly and finely. In order to obtain the mica having a good average particle diameter and thickness described later, it is preferable to use a thin and finely ground material in the present invention. Therefore, in the present invention, it is preferable to use mica produced by a wet pulverization method.

In the wet pulverization method, a step of dispersing the pulverized material in water is necessary. In order to improve the dispersion efficiency of the pulverized material, a coagulation sedimentation agent and / or a sedimentation aid are usually added to the pulverized material. Examples of the coagulating sedimentation agent and sedimentation aid that can be used in the present invention include polyaluminum chloride, aluminum sulfate, ferrous sulfate, ferric sulfate, chlorinated copperas, polyferric sulfate, and polychlorinated Iron, iron-silica inorganic polymer coagulant, iron chloride-silica inorganic polymer coagulant, slaked lime (Ca (OH) ₂ ), caustic soda (NaOH), alkali ash (Na ₂ CO ₃ ), etc. The pH of these coagulating sedimentation agents and sedimentation aids is alkaline or acidic. The mica used in the present invention is preferably one that does not use a coacervation agent and / or a sedimentation aid during wet pulverization. When using mica that has not been treated with a coacervation and sedimentation agent and / or a sedimentation aid, the polymer in the liquid crystalline resin composition is less likely to decompose, a large amount of gas is not easily generated, and the molecular weight of the polymer is lowered. The performance of the obtained molded product such as a connector is maintained.

In the mica that can be used in the present invention, an average particle diameter measured by a Microtrac laser diffraction method is preferably a substance having an average particle diameter of 10 to 100 μm, and a substance having an average particle diameter of 20 to 80 μm is particularly preferable. When the average particle diameter of the mica is 10 μm or more, it is preferable because the effect of improving the rigidity of the molded product is likely to be sufficient. When the average particle diameter of the mica is 100 μm or less, it is preferable because the rigidity of the molded product can be sufficiently improved and the welding strength can be easily made sufficient. In addition, when the average particle diameter of the mica is 100 μm or less, it is easy to ensure sufficient fluidity for molding the connector and the like of the present invention.

The thickness of the mica that can be used in the present invention is preferably a thickness measured by observation with an electron microscope, preferably 0.01 to 1 μm, and particularly preferably 0.03 to 0.3 μm. When the thickness of the mica is 0.01 μm or more, it is preferable that the mica does not easily crack during melt processing of the liquid crystalline resin composition. Therefore, the rigidity of the molded product may be easily improved, which is preferable. When the thickness of the 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 by using a silane coupling agent or the like, and / or may be granulated by using a binder to be granulated.

[Other ingredients]
The liquid crystalline resin composition of the present invention can also appropriately add other polymers, other fillers, and conventional substances commonly added to synthetic resins, that is, antioxidants, within a range that does not impair the effects of the present invention, that is, antioxidants. , Stabilizers such as ultraviolet absorbers, antistatic agents, flame retardants, dyes, pigments and other coloring agents, lubricants, release agents, crystallization accelerators, crystallization nucleating agents, etc. The other fillers refer to fillers other than (B) whiskers and (C) plate-shaped fillers, and examples thereof include granular fillers such as silicon oxide.

[Method for preparing liquid crystalline resin composition]
The method for preparing the liquid crystalline resin composition of the present invention is not particularly limited. For example, the components (A) to (C) described above are prepared, and these are melt-kneaded using a uniaxial or biaxial extruder to prepare a liquid crystalline resin composition.

The liquid crystal resin composition of the present invention is preferably used for a connector. The connector is formed of a molded product of the liquid crystal resin composition, and the molded product has a thickness difference between a thick portion and a thin portion of 0.5 mm. In the above-mentioned uneven thickness structure, the path from the gate portion of the molded product to the thick-walled portion has a shape that passes through the thin-walled portion. Since the said molded article has the above-mentioned shape, the liquid crystalline resin composition melt | melted at the time of manufacture must flow from a thin-walled part to a thick-walled part. The liquid crystalline resin composition of the present invention not only has a uneven thickness structure in which the thickness difference between the thick portion and the thin portion is 0.5 mm or more, but the liquid crystal resin composition must flow from the thin portion to the thick portion. The connector made of the molded product can effectively suppress the occurrence of foaming. Moreover, as a representative example of such a connector, a memory module connector, such as a DDR connector, and an interface connector, such as a SATA connector, are mentioned. 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, and a DDR2-Micro-DIMM. Connectors, etc.

The liquid crystalline resin composition of the present invention is preferably used for a connector that has undergone a reflow step. The reflow step includes heating in a preheating zone and heating in the reflow zone. In the preheating zone, the set temperature is 140 to 170 ° C. The processing time is 1 to 3 minutes. In the reflow zone, the set temperature is 180 to 210 ° C, while the processing time is 30 to 120 seconds, the measured average temperature is 183 ° C or more, and the measured peak temperature is 220 to 270 ° C. In the aforementioned preheating zone, by heating the solder paste at a temperature of 140 to 170 ° C. for 1 to 3 minutes, the flux in the solder paste can appropriately clean the surface to be soldered. After heating in the preheating zone, for example, the temperature of the oven can be increased by 1 to 3 ° C. per second, so that it can be transferred to heating in the reflow zone. In the aforementioned reflow zone, by setting the temperature to 180 to 210 ° C, the processing time to 30 to 120 seconds, and the actual temperature of the connector to be at least 183 ° C (melting point of the solder) and at least 60 seconds, it can effectively prevent In addition to welding-induced strain, bridging, and connection at low temperatures, the processing time at the measured peak temperature of 220 to 260 ° C can be maintained for 30 to 120 seconds, so sufficient reflow can be completed. The liquid crystalline resin composition of the present invention can effectively suppress the occurrence of foaming in the connector that has undergone the reflow step.

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

(A) Liquid crystal resin
(Manufacturing method of liquid crystalline polymer 1)
In a polymerization vessel equipped with a stirrer, a reflux column, a monomer input port, a nitrogen introduction port, and a pressure reduction / outflow line, the following raw material monomers, metal catalysts, and hydrating agents were added and nitrogen substitution was started.
(I) 4-hydroxybenzoic acid: 1380g (60 mole%) (HBA)
(II) 6-hydroxy-2-naphthoic acid: 157 g (5 mole%) (HNA)
(III) Terephthalic acid: 484 g (17.5 mole%) (TA)
(IV) 4,4'-dihydroxybiphenyl: 388g (12.5 mole%) (BP)
(V) 4-Ethoxyaminoaminophenol: 17.2 g (5 mole%) (APAP)
Potassium acetate catalyst: 110mg
Acetic anhydride: 1659g

After the raw materials were added to the polymerization vessel, the temperature of the reaction system was raised to 140 ° C and allowed to react at 140 ° C for 1 hour. Subsequently, the temperature was further raised to 340 ° C. over 4.5 hours, and the pressure was reduced to 10 Torr (that is, 1330 Pa) in 15 minutes, and the acetic acid, excess acetic anhydride, and other low-boiling components were distilled while performing melt polymerization. After the stirring torque reaches a predetermined value, nitrogen gas is introduced, and the pressure state is changed from a reduced pressure state to normal pressure, and the polymer is discharged from the lower part of the polymerization container, and the strands are pelletized and pelletized. The melting point of the obtained pellet was 336 ° C, the difference between the melting point and the crystallization temperature Tm-Tc was 40 ° C, and the melt viscosity was 20 Pa 为 s.

(Manufacturing method of liquid crystalline polymer 2)
In a polymerization vessel equipped with a stirrer, a reflux column, a monomer input port, a nitrogen introduction port, and a pressure reduction / outflow line, the following raw material monomers, fatty acid metal salt catalysts, and hydrating agents were added and nitrogen substitution was started.
(I) 4-hydroxybenzoic acid 1385g (60 mole%) (HBA)
(II) 6-hydroxy-2-naphthoic acid 88g (2.8 mole%) (HNA)
(III) 504 g of terephthalic acid (18.15 mole%) (TA)
(IV) 19 g of isophthalic acid (0.7 mol%) (IA)
(V) 4,4'-Dihydroxybiphenyl 415g (13.35 mole%) (BP)
(VI) N-Ethyl-p-aminophenol 126 g (5 mole%) (APAP)
Potassium acetate catalyst 120mg
Acetic anhydride 1662g
After the raw materials were added, the temperature of the reaction system was raised to 140 ° C and the reaction was allowed to proceed at 140 ° C for 1 hour. Subsequently, the temperature was further increased to 360 ° C. over 5.5 hours, and the pressure was reduced to 10 Torr (that is, 1330 Pa) over 20 minutes, and the acetic acid, excess acetic anhydride, and other low-boiling components were distilled and melt-polymerized. After the stirring torque reaches a predetermined value, nitrogen gas is introduced, and the pressure state is changed from a reduced pressure state to normal pressure, and the polymer is discharged from the lower part of the polymerization container, and the strands are pelletized and pelletized. The melting point of the obtained pellets was 345 ° C, Tm-Tc was 37 ° C, and the melt viscosity was 10 Pa ･ s.

(Manufacturing method of liquid crystalline polymer 3)
In a polymerization vessel equipped with a stirrer, a reflux column, a monomer input port, a nitrogen introduction port, and a pressure reduction / outflow line, the following raw material monomers, metal catalysts, and hydrating agents were added and nitrogen substitution was started.
(I) 4-hydroxybenzoic acid: 1040 g (48 mole%) (HBA)
(II) 6-hydroxy-2-naphthoic acid: 89 g (3 mole%) (HNA)
(III) Terephthalic acid: 547 g (21 mole%) (TA)
(IV) Isophthalic acid: 91g (3.5 mole%) (IA)
(V) 4,4'-dihydroxybiphenyl: 716g (24.5 mole%) (BP)
Potassium acetate catalyst: 110mg
Acetic anhydride: 1644g

After the raw materials were added to the polymerization vessel, the temperature of the reaction system was raised to 140 ° C and allowed to react at 140 ° C for 1 hour. Subsequently, the temperature was further increased to 360 ° C. over 5.5 hours, and the pressure was reduced to 5 Torr (that is, 667 Pa) over 20 minutes, and the acetic acid, excess acetic anhydride, and other low-boiling components were distilled while performing melt polymerization. After the stirring torque reaches a predetermined value, nitrogen gas is introduced, and the pressure state is changed from a reduced pressure state to normal pressure, and the polymer is discharged from the lower part of the polymerization container, and the strands are pelletized and pelletized. The melting point of the obtained pellets was 355 ° C, Tm-Tc was 48 ° C, and the melt viscosity was 10 Pa ･ s.
The melt viscosity of the liquid crystalline polymers 1 to 3 was measured and measured in the same manner as the method for measuring the melt viscosity of the liquid crystalline resin composition described later.

(Filler)
(B) Fibrous filler ground fiber: EPH150M-01M manufactured by Nippon Electric Glass Co., Ltd., fiber diameter 10.5 μm, number average fiber length 150 μm
Glass fiber: Chopped strand of ECS03T-786H made by Japan Electric Glass Co., Ltd., fiber diameter 10 μm, length 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 Industry Co., Ltd., average particle size 12.8 μm
(D) Spherical filler glass beads: EGB731 by Potters Ballotini (strand), average particle size 20.0 μm

[Manufacture of liquid crystal resin composition]
Liquid crystal resin was obtained by melt-kneading the above components at the ratios shown in Table 1, Table 2, or Table 3 using a biaxial extruder (TEX30α type manufactured by Nippon Steel) at a cylinder temperature of 350 ° C. Composition pellets. At this time, in Examples 1 to 11 and Comparative Examples 1 to 4, 6, and 7, the liquid crystal resin was supplied from the main feed port of the extruder, and the filler was installed closer to the main feed port than the main feed port. It is supplied from the side feed port in the extrusion direction. On the other hand, in Comparative Example 5, a liquid crystalline resin and a filler were supplied from the main feed port of the extruder. In addition, "%" in the table represents mass%.

[Determination of melting point]
A DSC manufactured by TA Instruments was used to observe the endothermic spike temperature (Tm1) that can be observed when the liquid crystalline polymer is measured at a temperature rising condition of 20 ° C / min from room temperature, and then at a temperature of (Tm1 + 40) ° C. After being held for 2 minutes, the temperature was temporarily cooled to room temperature under a temperature lowering condition of 20 ° C / minute, and then the endothermic spike temperature that was observed when the measurement was performed again under a temperature increasing condition of 20 ° C / minute was measured.

[Measurement of crystallization temperature]
A DSC manufactured by TA Instruments was used to observe the endothermic spike temperature (Tm1) that can be observed when the liquid crystalline polymer is measured at a temperature rising condition of 20 ° C / min from room temperature, and then at a temperature of (Tm1 + 40) ° C. After holding for 2 minutes, the exothermic peak temperature that can be observed when the measurement is performed under a temperature-lowering condition of 20 ° C / minute is measured.

[Determination of expansion ratio]
The swelling ratio of the liquid crystalline resin composition was measured using the pellets. Specifically, when using a capillary rheometer (capillography 1D, manufactured by Toyo Seiki Seisakusho, CAPILLOGRAPHY1D: piston diameter 10mm), the fluidity was measured according to ISO 11443 under the conditions of the following cylinder temperature and shear rate 2432sec ^-1 , After being extruded and expanded or contracted from an orifice having an inner diameter of 1 mm and a length of 20 mm, the outer diameter D of the extruded product was measured at a time when the dimension was stable. When the inner diameter of the orifice is d, D / d is calculated and the obtained value is used as the expansion 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)

[Determination of melt viscosity]
The pellets were used to measure the melt viscosity of the liquid crystalline resin composition. Specifically, a capillary rheometer (capillography 1D manufactured by Toyo Seiki Co., Ltd .: piston diameter 10 mm) was used to measure the apparent temperature in accordance with ISO 11443 under the conditions of the following cylinder temperature and a shear rate of 1000 sec ^-1 Melt viscosity. The measurement system used an orifice having an inner diameter of 1 mm and a length of 20 mm. 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)

[Determination of load deflection temperature (DTUL)]
The pellets were molded using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain test pieces (80 mm x 10 mm x 4 mm) for measurement. Using this test piece, the deflection temperature under load was measured according to the method of ISO75-1, 2. As the bending stress, 1.8 MPa was used. The results are shown in Table 1 or Table 2.
[Forming conditions]
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: 33mm / sec

[Bending test]
The pellets were molded using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to produce a curved test piece of 80 mm x 10 mm x 4 mm. Using this test piece, flexural strength and flexural modulus of elasticity were measured in accordance with ISO178. The results are shown in Table 1 or Table 2.
[Forming conditions]
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: 33mm / sec
Holding pressure: 50MPa

[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 produce five flat test pieces of 80 mm x 80 mm x 1 mm. The first flat test piece was left to stand on a horizontal plane, and a CNC image measuring machine (type: QVBHU404-PRO1F) manufactured by Mitutoyo was used to measure the height from the horizontal plane at 9 places on the flat test piece to measure the height. The obtained value calculates the average height. The position for measuring the height is on the main plane of the flat test piece, and the distance from each side of the main plane is 3 mm. When a square with a side of 74 mm is placed, the vertices corresponding to the square and the square are placed. The midpoint of each side of the square and the intersection of the two diagonals of the square. A reference plane is a plane whose height from the horizontal plane is the same as the average height and is parallel to the horizontal plane. From the heights measured at the above 9 points, the maximum height and the minimum height from the reference plane are selected and the difference between the two is calculated. The above-mentioned difference was calculated similarly for the other four flat test pieces, and the obtained five values were averaged and set to the value of flatness. The results are shown in Table 1 or Table 2.
[Forming conditions]
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: 33mm / sec
Holding pressure: 60MPa

[Determination of foaming temperature]
The pellets were molded under the following molding conditions using a molding machine ("SE-100DU" manufactured by Sumitomo Heavy Industries, Ltd.) to obtain a molded product having a welded portion of 12.5 mm x 120 mm x 0.8 mm. A piece obtained by dividing the formed article into two pieces in the above-mentioned welded portion was taken as one sample and sandwiched by a hot press at a predetermined temperature for 5 minutes. Subsequently, it was visually inspected whether or not foaming occurred on the surface of the sample. The foaming temperature is set to the highest temperature at which the number of foaming is zero. The predetermined temperature is set in a range of 250 to 300 ° C with a pitch of 10 ° C.
[Forming conditions]
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: 33mm / sec

[Segmentation sensitivity blistering evaluation]
The pellets were formed using a molding machine ((TR100EH) manufactured by SODICK) under the following molding conditions to obtain 12.9 having a step difference of 0.5 mm / 0.4 mm or a step difference of 0.2 mm / 0.3 mm as shown in FIG. 3. A molded product of mm × 73.0mm × 0.8mm.
[Forming conditions]
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 ℃
Injection speed: 100, 200, 300, or 400mm / sec

The obtained molded article was subjected to IR reflow under the following conditions and visually observed whether or not foaming occurred. In addition, when the said molded product has a different level | step difference using a gate as a boundary line, a level | step difference is considered as an independent sample in this evaluation. For each of a total of 16 conditions of 4 steps × 4 injection speeds, 10 samples were evaluated, and the number of samples that caused blistering out of the 160 samples was calculated. The results are shown in Table 1 or Table 2.
[IR reflow conditions]
Measuring machine: Large-scale desktop reflow soldering device RF-300 (using far-infrared heater) made by Japan PULSE Technology Research Institute
Sample conveying speed: 140mm / second reflow furnace passing time: 5 minutes set temperature in preheating zone: 150 ° C (processing time: 60 seconds)
Measured average temperature: 150 ° C
Set temperature in the reflow zone: 190 ° C (processing time: 60 seconds)
Measured average temperature: 230 ℃ or higher Measured peak temperature: 251 ℃

[DDR type blister evaluation]
Under the following molding conditions, the liquid crystalline resin composition was injection-molded (gate: tunnel gate, gate size: ψ0.75mm) to obtain an overall size of 70.0mm × 26.0mm × as shown in FIG. 1. DDR-DIMM connector with 4.0mmt, 0.6mm pitch and 100 × 2 pin holes.
[Forming conditions]
Forming 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 ℃
Injection speed: 200mm / sec

The obtained connector was subjected to IR reflow under the following conditions and visually observed whether or not foaming occurred. The results are shown in Table 1 or Table 2. In the table, no foaming was evaluated as "○", and foaming was evaluated as "x".
[IR reflow conditions]
Measuring machine: Large-scale desktop reflow soldering device RF-300 (using far-infrared heater) made by Japan PULSE Technology Research Institute
Sample conveying speed: 140mm / sec
Reflow furnace transit time: 5 minutes Set temperature in preheating zone: 150 ° C (Processing time: 60 seconds)
Measured average temperature: 150 ° C
Set temperature in the reflow zone: 190 ° C (processing time: 60 seconds)
Measured average temperature: 230 ℃ or higher Measured peak temperature: 251 ℃

[FPC-type blister evaluation]
The liquid crystal resin composition was injection-molded under the following molding conditions (gate: tunnel gate, gate size: ψ0.4mm) to obtain an overall size of 17.6mm × 4.00mm × as shown in FIG. 2. FPC connector with 1.16mm, 0.5mm pitch, 30 × 2 pin holes, minimum wall thickness: 0.12mm.
[Forming conditions]
Forming 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 ℃
Injection speed: 200mm / sec
Holding pressure: 50MPa
Holding time: 0.5 seconds Cooling time: 10 seconds Screw revolutions: 120rpm
Screw back pressure: 1.2MPa

The obtained connector was subjected to IR reflow under the following conditions and visually observed whether or not foaming occurred. The results are shown in Table 1 or Table 2. In the table, no foaming was evaluated as "○", and foaming was evaluated as "x".
[IR reflow conditions]
Measuring machine: Large-scale desktop reflow soldering device RF-300 (using far-infrared heater) made by Japan PULSE Technology Research Institute
Sample conveying speed: 140mm / sec
Reflow furnace transit time: 5 minutes Set temperature in preheating zone: 150 ° C (Processing time: 60 seconds)
Measured average temperature: 150 ° C
Set temperature in the reflow zone: 190 ° C (processing time: 60 seconds)
Measured average temperature: 230 ℃ or higher Measured peak temperature: 251 ℃

[Table 1]

[Table 2]

[table 3]

As can be seen from Tables 1, 2, and 3, the liquid crystal resin composition of the present invention contains (A) a liquid crystalline resin, (B) whiskers, and (C) a plate-like filler, and has an expansion ratio of More than 1.00, a molded article capable of suppressing generation of bubbles while maintaining mechanical strength and suppressing warpage and deformation is provided.

no.

FIG. 1 is a diagram showing a DDR-DIMM connector formed in the embodiment. In addition, A represents a gate position. The unit of the value in the figure is mm.

Fig. 2 is a view showing an FPC connector formed in the embodiment. In addition, A represents a gate position. The unit of the value in the figure is mm.

FIG. 3 is a diagram showing a molded product used in the step sensitivity sensitivity blister evaluation formed in the example. In addition, A represents a gate position. The unit of the value in the figure is mm.

Claims (3)

A liquid crystalline resin composition is a liquid crystalline resin composition including (A) a liquid crystalline resin, (B) whiskers, and (C) a plate-shaped filler, and an expansion ratio of the liquid crystalline resin composition is greater than 1.00. A liquid crystal resin composition is a liquid crystal resin composition for a connector, as described in item 1 of the scope of patent application, and the connector is formed of a molded product of the liquid crystal resin composition. The molded product has a uneven thickness structure in which the thickness difference between the thick wall 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-walled portion has a shape that passes through the thin-walled portion. A liquid crystal resin composition is a liquid crystal resin composition as described in item 1 or 2 of a patent application scope for a connector that has undergone a reflow step. The aforementioned reflow step includes heating in a preheating zone and heating in a reflow zone, The set temperature in the preheating zone is 140-170 ° C, and the processing time is 1-3 minutes. In the aforementioned reflow zone, the set temperature is 180-210 ° C, the processing time is 30-120 seconds, and the measured average temperature is 183 ° C or more, and the measured peak temperature is 220-270 ° C.