JP6951268B2 - Liquid crystal polyester resin composition - Google Patents

Description

The present invention relates to a liquid crystal polyester resin composition in which good fluidity, mechanical properties, and excellent flame retardancy are obtained, and the generation of particles is suppressed.

Liquid crystal polyester has the characteristics of good fluidity and less burrs, and is also excellent in mechanical properties such as heat resistance and rigidity, chemical resistance, dimensional accuracy, etc., so electricity with a complicated shape -The amount of electronic parts used is increasing.

In recent years, with the rapid growth of information and information technology (IT), in the information and communication field, the degree of integration, miniaturization, thinning, and reduction of height of electrical and electronic parts have progressed, and the thickness is very low of 0.5 mm or less. In many cases, a thin portion is formed, and even in such a portion (thin-walled portion), good fluidity is required so that the resin is completely filled. In general, liquid crystal polyester is superior in fluidity to other resins, but when such thinning is required, further improvement in fluidity and stricter flame retardancy are required. It's coming.

As a method for improving the flame retardancy of liquid crystal polyester, a method of adding a halogen-based flame retardant (Patent Document 1), silicone (Patent Document 2), a phosphorus-based compound (Patent Document 3), and red phosphorus (Patent Document 4) is available. Proposed.

Although the method of adding these substances has a certain effect of improving flame retardancy, the method of adding a halogen-based flame retardant or a phosphorus-based compound may corrode the mold due to the generation of gas. Further, the method of adding red phosphorus cannot be used for applications requiring white color, and the method of adding a phosphorus compound or silicone also has a problem that it causes mold stains and gas generation.

On the other hand, it is known that a molded product of liquid crystal polyester has a phenomenon in which the resin surface is peeled off and fluffed (hereinafter referred to as "fibrillation") due to ultrasonic cleaning or sliding with other members.

In the case of precision equipment, especially optical equipment with lenses, a small amount of dust or dirt affects the performance of the equipment. For example, in a component used in an optical device such as a camera module, if small dust, oil, dust, etc. adhere to the lens, it causes a significant deterioration in the optical characteristics of the camera module.

For the purpose of preventing such deterioration of optical characteristics, parts that usually constitute a camera module such as a lens barrel portion, a mount holder portion, a CMOS (image sensor) frame, a shutter and a shutter bobbin portion (hereinafter, "for camera module"). (Also referred to as "parts") are ultrasonically cleaned before assembly to remove small dust and dirt adhering to the surface.

However, in a molded product made of a liquid crystal polyester resin composition, the surface of the molded product is easily peeled off, and when ultrasonic cleaning is performed, the surface is easily peeled off and fibrillation is likely to occur. Then, small dust or dust (hereinafter referred to as particles) made of the resin composition is likely to be generated from the fibrillated portion. Then, even if the generated particles are extremely small, they become foreign substances when the camera module is assembled and when the camera is used, and there is a problem that the optical characteristics of the camera module are significantly deteriorated.

As a liquid crystal polyester resin that suppresses the generation of particles, a resin composition in which a liquid liquid polyester contains a specific filler (talc, glass fiber, carbon black, etc.), an olefin-based copolymer, or the like has been proposed (Patent Document 5). 10).

Japanese Unexamined Patent Publication No. 1-118567 Japanese Unexamined Patent Publication No. 2000-239503 Japanese Unexamined Patent Publication No. 7-109406 Japanese Unexamined Patent Publication No. 2000-154314 Japanese Patent No. 5826411 Japanese Unexamined Patent Publication No. 2015-021110 JP 2015-000949 Japanese Unexamined Patent Publication No. 2012-193270 Japanese Unexamined Patent Publication No. 2009-242453 JP-A-2009-242456

However, the resin compositions proposed in Patent Documents 5 to 10 have poor wettability between the inorganic filler and the liquid crystal polyester, and the effect of suppressing particle generation during ultrasonic cleaning is insufficient. Therefore, there has been a demand for a liquid crystal polyester resin composition in which the generation of particles is reduced during ultrasonic cleaning.
An object of the present invention is a liquid crystal polyester resin composition in which good fluidity, mechanical properties, and excellent flame retardancy are obtained, and the generation of particles is suppressed, and a molded product composed of the liquid crystal polyester resin composition. Is to provide.

As a result of diligent studies in view of the above problems, the present inventors have excellent mechanical properties such as fluidity, tensile strength and bending strength by blending fibrous titanium oxide with a liquid crystal polyester composed of a specific repeating unit. At the same time, they have found that a liquid crystal polyester resin composition having improved flame retardancy and suppressed generation of particles can be obtained, and have completed the present invention.

［式中、
Ａｒ_１およびＡｒ_２は、それぞれ１種または２種以上の２価の芳香族基を表し、ｐ、ｑおよびｒは、それぞれ、液晶ポリエステル中での各繰返し単位の組成比（モル％）であり、以下の条件を満たす：
３５≦ｐ≦９０、
５≦ｑ≦３０、および
５≦ｒ≦３０。］
で表される繰返し単位を含む液晶ポリエステル１００質量部、および繊維状酸化チタン１〜１５０質量部と
を含有する液晶ポリエステル樹脂組成物に関する。
本発明の好ましい態様は以下を包含する。
〔２〕繊維状酸化チタンは、数平均繊維長（Ｌ）が１μｍ〜５０μｍであり、数平均繊維径（Ｄ）が０．０５μｍ〜２．０μｍであり、かつＬ／Ｄが３〜５０である、〔１〕に記載の液晶ポリエステル樹脂組成物。
〔３〕〔１〕または〔２〕に記載の液晶ポリエステル樹脂組成物から構成される成形品。
〔４〕成形品は、コネクタ、スイッチ、リレー、コンデンサ、コイル、トランス、カメラモジュール、アンテナ、チップアンテナおよびミニブレーカからなる群から選択される一種を構成する部品である、〔３〕に記載の成形品。
That is, the present invention
[1] Equations (I) to (III)

[During the ceremony,
Ar ₁ and Ar ₂ represent one or more divalent aromatic groups, respectively, and p, q and r are composition ratios (mol%) of each repeating unit in the liquid crystal polyester, respectively. , Satisfy the following conditions:
35 ≤ p ≤ 90,
5 ≦ q ≦ 30, and 5 ≦ r ≦ 30. ]
The present invention relates to a liquid crystal polyester resin composition containing 100 parts by mass of a liquid crystal polyester containing a repeating unit represented by, and 1 to 150 parts by mass of fibrous titanium oxide.
Preferred embodiments of the present invention include:
[2] The fibrous titanium oxide has a number average fiber length (L) of 1 μm to 50 μm, a number average fiber diameter (D) of 0.05 μm to 2.0 μm, and an L / D of 3 to 50. The liquid crystal polyester resin composition according to [1].
[3] A molded product composed of the liquid crystal polyester resin composition according to [1] or [2].
[4] The component according to [3], wherein the molded product is a component selected from the group consisting of a connector, a switch, a relay, a capacitor, a coil, a transformer, a camera module, an antenna, a chip antenna, and a mini breaker. Molding.

Since the liquid crystal polyester resin composition of the present invention is excellent in fluidity and mechanical strength, it can be used in various applications such as housings and packages of electrical and electronic parts, various communication devices, electronic devices and the like. In particular, since the flame retardancy is improved and the generation of particles is suppressed, it is suitably used for applications such as optical electronic parts such as camera modules and device parts such as mini breakers.

It is a figure which shows typically the state which the test piece was placed in a cylindrical glass container in the measurement of the number of particles generated.

The liquid crystal polyester used in the liquid crystal polyester resin composition of the present invention is a liquid crystal polyester that forms an anisotropic molten phase, which is called a thermotropic liquid crystal polyester by those skilled in the art.

The anisotropic melt phase of the liquid crystal polyester is usually a polarization inspection method utilizing orthogonal polarization child, i.e., the sample on the hot stage can be confirmed by observing under a nitrogen atmosphere.

［式中、
Ａｒ_１およびＡｒ_２は、それぞれ１種または２種以上の２価の芳香族基を表し、ｐ、ｑおよびｒは、それぞれ、液晶ポリエステル中での各繰返し単位の組成比（モル％）であり、以下の条件を満たす：
３５≦ｐ≦９０、
５≦ｑ≦３０、および
５≦ｒ≦３０。］ In the present invention, the liquid crystal polyester contains a repeating unit represented by the formulas (I) to (III).

[During the ceremony,
Ar ₁ and Ar ₂ represent one or more divalent aromatic groups, respectively, and p, q and r are composition ratios (mol%) of each repeating unit in the liquid crystal polyester, respectively. , Satisfy the following conditions:
35 ≤ p ≤ 90,
5 ≦ q ≦ 30, and 5 ≦ r ≦ 30. ]

The composition ratio p according to the formula (I) is preferably 40 to 85 mol%, more preferably 45 to 80 mol%, still more preferably 50 to 65 mol%.

The composition ratio q according to the formula (II) and the composition ratio r according to the formula (III) are preferably 7.5 to 30 mol%, more preferably 10 to 27.5 mol%, and 17.5 to 25, respectively. More preferably mol%. It is preferable that q and r are equimolar quantities.

In the above repeating unit, for example, when Ar ₁ (or Ar ₂ ) represents two or more divalent aromatic groups, the repeating unit represented by the formula (II) (or (III)) is contained in the liquid crystal polyester. It means that two or more kinds are contained depending on the kind of divalent aromatic group. In this case, the composition ratio q according to the formula (II) (or the composition ratio r according to the formula (III)) represents the composition ratio obtained by summing up two or more repeating units.

Specific examples of the monomer giving the repeating unit represented by the formula (I) include 6-hydroxy-2-naphthoic acid, and ester-forming derivatives such as an acylated product, an ester derivative, and an acid halide. ..

Specific examples of the monomer giving the repeating unit represented by the formula (II) include, for example, aromatic diols hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 1,6-. Dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, etc., and their alkyl, alkoxy Alternatively, halogen-substituted products and ester-forming derivatives such as these acylated products can be mentioned.

Specific examples of the monomer giving the repeating unit represented by the formula (III) include terephthalic acid and isophthalic acid, which are aromatic dicarboxylic acids, 2,6-naphthalenedicarboxylic acid, and 1,6-naphthalenedicarboxylic acid. , 2,7-Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl and the like, and their alkyl, alkoxy or halogen substituents, and esters of these ester derivatives, acid halides and the like. Examples include forming derivatives.

_{Among them, as the liquid crystal polyester, Ar 1} and Ar ₂ related to the repeating unit represented by the formula (II) and the formula (III) are independently represented by the aromatics represented by the formulas (1) to (4). Those containing one or more selected from the group consisting of groups are preferably used.

Among these, as the repeating unit represented by the formula (II), the aromatic groups represented by the formulas (1) and (3) are the reactivity at the time of polymerization, the mechanical properties of the obtained liquid crystal polyester, and the heat resistance. It is more preferable because it is easy to adjust the properties, crystal melting temperature and molding processability to appropriate levels. Examples of the monomer giving these repeating units include 4,4'-dihydroxybiphenyl and hydroquinone, and ester-forming derivatives thereof.

Further, as the repeating unit represented by the formula (III), the aromatic group represented by the formula (1) has an appropriate level of mechanical properties, heat resistance, crystal melting temperature and molding processability of the obtained liquid crystal polyester. It is more preferable because it is easy to adjust. Examples of the monomer giving these repeating units include terephthalic acid and its ester-forming derivative.

Further, as the liquid crystal polyester, the repeating unit represented by the formula (II) includes at least two kinds of the repeating unit according to the formula (1) and the formula (3), and the repeating unit according to the formula (1) is the formula (1). Of the 100 mol% of the repeating unit represented by III), those containing preferably 80 to 99.9 mol%, more preferably 85 to 99 mol%, still more preferably 90 to 98 mol% are particularly preferably used.

In the liquid crystal polyester of the present invention, the total composition ratio of the repeating units [p + q + r] is preferably 100 mol%, but other repeating units may be further contained as long as the object of the present invention is not impaired.

Examples of the monomer giving another repeating unit include other aromatic hydroxycarboxylic acids, aromatic hydroxyamines, aromatic diamines, aromatic aminocarboxylic acids, aromatic hydroxydicarboxylic acids, aliphatic diols, and aliphatic dicarboxylic acids. Examples thereof include aromatic mercaptocarboxylic acid, aromatic dithiol, aromatic mercaptophenol and combinations thereof.

Specific examples of other aromatic hydroxycarboxylic acids include, for example, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 5-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid. 4, 4'-Hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid and their alkyl, alkoxy or halogen substituents, and their acylates, Examples thereof include ester derivatives and ester-forming derivatives such as acid halides.

The total composition ratio of the repeating units given from these other monomer components is preferably 10 mol% or less in the entire repeating units.

The crystal melting temperature of the liquid crystal polyester used in the present invention is not particularly limited, but is preferably 310 to 360 ° C.

In the present specification and claims, "crystal melting temperature" means crystal melting when measured at a heating rate of 20 ° C./min by a differential scanning calorimetry (hereinafter abbreviated as DSC). It is obtained from the peak temperature. More specifically, after observing the heat absorption peak temperature (Tm1) observed when the liquid crystal polyester sample is measured at a temperature rising condition of 20 ° C./min from room temperature, the temperature is 20 to 50 ° C. higher than Tm1. After holding for 1 minute and then cooling the sample to room temperature under the temperature lowering condition of 20 ° C./min, the heat absorption peak when measured again under the temperature rising condition of 20 ° C./min was observed, and the temperature indicating the peak top was set to the liquid crystal. Let it be the crystal melting temperature of polyester. As the measuring device, for example, Seiko Instruments Inc. Exstar6000 or the like can be used.

The liquid crystal polyester used in the present invention uses a capillary rheometer (Capillograph 1D manufactured by Toyo Seiki Co., Ltd.) using a 0.7 mmφ × 10 mm capillary ^{under the condition of a shear rate of 1000 s -1} and a crystal melting temperature of + 30 ° C. The melt viscosity measured in 1 is preferably 1 to 1000 Pa · s, and more preferably 5 to 300 Pa · s.

Hereinafter, a method for producing the liquid crystal polyester used in the present invention will be described.
The method for producing the liquid crystal polyester used in the present invention is not particularly limited, and a known polycondensation method for forming an ester bond composed of a combination of the above-mentioned monomers, for example, a melt acidlysis method, a slurry polymerization method, or the like is used. Can be done.

The melt acidlysis method is a method suitable for producing the liquid crystal polyester used in the present invention, and this method first heats a monomer to form a melt of a reactant and continues the reaction. To obtain molten polyester. A vacuum may be applied to facilitate the removal of volatiles (eg, acetic acid, water, etc.) that are by-produced in the final stage of condensation.

The slurry polymerization method is a method of reacting in the presence of a heat exchange fluid, and the solid product is obtained in a state of being suspended in a heat exchange medium.

In both the melt acidlysis method and the slurry polymerization method, the polymerizable monomer component used in producing the liquid crystal polyester reacts at room temperature as a modified form in which a hydroxyl group is acylated, that is, a lower acylated product. It can also be provided. The lower acyl group preferably has 2 to 5 carbon atoms, and more preferably 2 or 3 carbon atoms. Particularly preferably, a method of using the acetylated product of the monomer component in the reaction can be mentioned.

As the lower acylated product of the monomer, a product that is separately acylated and synthesized in advance may be used, or an acylating agent such as acetic anhydride may be added to the monomer during the production of the liquid crystal polyester to produce the monomer in the reaction system. ..

In either case of the melt acidlysis method or the slurry polymerization method, a catalyst may be used at the time of the reaction, if necessary.

Specific examples of the catalyst include organic tin compounds (dialkyltin oxide such as dibutyltin oxide, diaryltin oxide, etc.), organic titanium compounds (titanium dioxide, antimony trioxide, alkoxytitanium silicate, titanium alkoxide, etc.), and carboxylic acids. Examples thereof include alkali and alkaline earth metal salts (potassium acetate, sodium acetate, etc.), Lewis acids (BF _3, etc.), gaseous acid catalysts such as hydrogen halide (HCl, etc.), and the like.

The amount of the catalyst used is preferably 10 to 1000 ppm, more preferably 20 to 200 ppm with respect to the mass of the monomer.

The liquid crystal polyester obtained by such a polycondensation reaction is extracted from the polymerization reaction tank in a molten state, processed into pellets, flakes, or powder, and subjected to molding and melt kneading.

Pellet-like, flake-like, or powder-like liquid crystal polyesters are substantially solid under reduced pressure, under vacuum, or in an atmosphere such as nitrogen or helium, which is an inert gas, for the purpose of increasing the molecular weight and improving heat resistance. The heat treatment may be performed in the phase state.

The content of fibrous titanium oxide in the liquid crystal polyester resin composition of the present invention is 1 to 150 parts by mass, preferably 2 to 120 parts by mass, and more preferably 5 to 5 parts by mass with respect to 100 parts by mass of the liquid crystal polyester. It is 110 parts by mass, more preferably 10 to 80 parts by mass.

When the content of the fibrous titanium oxide is less than the above lower limit value, it is difficult to obtain the effect of improving the strength and flame retardancy of the liquid crystal polyester resin composition, and the effect of suppressing particle generation may be insufficient. If the content of fibrous titanium oxide exceeds the above upper limit, the fluidity may become insufficient and the cylinder and mold of the molding machine may be worn out.

When the liquid crystal polyester contains fibrous titanium oxide, the wettability of the interface between the liquid crystal polyester and the fibrous titanium oxide is good, and it is considered that the generation of particles due to ultrasonic cleaning is suppressed. The particles include a resin and a filler peeled off from a molded product composed of the liquid crystal polyester resin composition of the present invention.

The number average fiber length (L) of the fibrous titanium oxide in the present invention is preferably 1 μm to 50 μm, more preferably 2 μm to 40 μm, and further preferably 3 μm to 30 μm. If the number average fiber length (L) of the fibrous titanium oxide is less than the above lower limit value, the mechanical strength tends to be unmaintainable, and if it exceeds the above upper limit value, the effect of suppressing particle generation tends to be insufficient.

The number average fiber diameter (D) of the fibrous titanium oxide is preferably 0.05 μm to 2.0 μm, more preferably 0.1 μm to 1.5 μm, and 0.1 μm to 1.0 μm. Is even more preferable. If the number average fiber diameter (D) of the fibrous titanium oxide is less than the above lower limit value, the mechanical strength tends to be unmaintainable, and if it exceeds the above upper limit value, the effect of suppressing particle generation tends to be insufficient.

Further, in order to achieve a good balance between rigidity and suppression of particle generation, the L / D of the number average fiber length (L) and the number average fiber diameter (D) is preferably 3 to 50, and 3.5 to 40. Is more preferable, and 4 to 30 is even more preferable. If the L / D is below the above lower limit value, the mechanical strength tends to be unmaintainable, and if it exceeds the above upper limit value, the effect of suppressing particle generation tends to be insufficient.

The number average fiber length (L) and the number average fiber diameter (D) are measured by observing with a scanning electron microscope (S2100A manufactured by Hitachi, Ltd.), taking a picture at 10000 times, and sampling 500 at random. The number average value of the length of the longest part of each fiber (particle) was defined as the number average fiber length, and the number average value of the length of the shortest part was defined as the number average fiber diameter.

The crystal structure of fibrous titanium oxide used in the present invention is not particularly limited, but one or more selected from the group consisting of rutile type, anatase type and blusite type can be used. The rutile type is preferable because it is excellent in the effect of reducing particle generation during ultrasonic cleaning. Further, in order to improve the dispersion in the resin, other metal oxides such as magnesium and calcium may be doped.

Examples of the fibrous titanium oxide used in the present invention include needle-shaped titanium oxide and rod-shaped titanium oxide.

The surface of the fibrous titanium oxide used in the present invention is treated with a known coupling agent (for example, a silane-based coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, etc.) or another surface treatment agent. Can also be used.

The liquid crystal polyester resin composition of the present invention contains, for example, other fibrous, plate-like, granular inorganic fillers or organic fillers in addition to the above-mentioned needle-like titanium oxide, as long as the effects of the present invention are not impaired. You can do it. Preferably, the liquid crystal polyester resin composition of the present invention contains only fibrous titanium oxide as a filler.

When the liquid crystal polyester resin composition of the present invention contains an inorganic filler or an organic filler other than fibrous titanium oxide, the content thereof is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the liquid crystal polyester. , More preferably 0.5 to 20 parts by mass. When the content of these other additives exceeds the above upper limit value, the molding processability tends to decrease and the thermal stability tends to deteriorate.

Other fibrous fillers include, for example, milled glass, silica-alumina fiber, alumina fiber, carbon fiber, aramid fiber, polyarylate fiber, polybenzimidazole fiber, potassium titanate whiskers, aluminum borate whiskers, wollastonite and the like. These can be used alone or in combination of two or more.

Other plate-like fillers include, for example, talc, mica, kaolin, clay, vermiculite, calcium silicate, aluminum silicate, pebbles, acidic white clay, brazing clay, serisite, sillimanite, bentonite, glass flakes, slate powder, etc. Silicates such as silane, calcium carbonate, husk, carbonates such as barium carbonate, magnesium carbonate, dolomite, barite powder, precipitated calcium sulfate, sulfates such as calcined gypsum, barium sulfate, hydroxides such as hydrated alumina, Alumina, antimony oxide, magnesia, plate-shaped titanium oxide, zinc flower, silica, silica sand, quartz, white carbon, oxides such as diatomaceous earth, sulfides such as molybdenum disulfide, plate-shaped wollastonite, etc. are mentioned. Can be used alone or in combination of two or more.

Examples of other granular fillers include calcium carbonate, glass beads, barium sulfate, granular titanium oxide, and the like, and these can be used alone or in combination of two or more.

In addition, the liquid crystal polyester resin composition of the present invention may contain other additives as long as the effects of the present invention are not impaired.

Other additives include, for example, higher fatty acids that are lubricants, higher fatty acid esters, higher fatty acid amides, higher fatty acid metal salts (here, higher fatty acids refer to those having 10 to 25 carbon atoms, for example) and the like. Mold improvers such as polysiloxane and fluororesin, colorants such as dyes, pigments, carbon black, etc. Flame retardants, antioxidants, surfactants, antioxidants, phosphorus-based antioxidants, phenol-based antioxidants Examples include agents, sulfur-based antioxidants, weather resistant agents, heat stabilizers, neutralizers, and the like. These additives may be used alone or in combination of two or more.

The content of these other additives is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the liquid crystal polyester. When the content of these other additives exceeds the above upper limit value, the molding processability tends to decrease and the thermal stability tends to deteriorate.

For additives having an external lubricant effect such as higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon-based surfactants, the surface of the pellets of the liquid crystal polyester resin composition is prepared in advance when the liquid crystal polyester resin composition is molded. It may be attached to.

Further, the liquid crystal polyester resin composition of the present invention may further contain other resin components as long as the object of the present invention is not impaired. Examples of other resin components include thermoplastic resins such as polyamide, polyester, polyacetal, polyphenylene ether and its modifications, polysulfone, polyethersulfone, polyetherimide, and polyamideimide, phenolic resin, epoxy resin, and polyimide resin. Examples of the heat-curable resin.

Other resin components can be contained alone or in combination of two or more. The content of the other resin components is not particularly limited, and may be appropriately determined according to the use and purpose of the liquid crystal polyester resin composition. Typically, the total content of the other resin with respect to 100 parts by mass of the liquid crystal polyester is preferably added in the range of 0.1 to 100 parts by mass, more preferably 0.1 to 80 parts by mass.

Liquid crystal polyester and fibrous titanium oxide, if desired, other inorganic fillers and / or organic fillers, other additives, other resin components, etc. are blended in a predetermined composition, and a Banbury mixer, kneader, uniaxial or biaxial. The liquid crystal polyester resin composition of the present invention can be obtained by melt-kneading using an extruder or the like.

The liquid crystal polyester resin composition of the present invention thus obtained can be molded or processed by a known molding method using an injection molding machine, an extruder, or the like to obtain a desired molded product.

The deflection temperature under load (ASTM D648, load 1.82 MPa) using a strip-shaped test piece (length 127 mm, width 12.7 mm, thickness 3.2 mm) of the liquid crystal polyester resin composition of the present invention is preferably 270. ° C. or higher, more preferably 275 ° C. or higher, still more preferably 280 ° C. or higher, and usually 320 ° C. or lower.

Further, the liquid crystal polyester resin composition of the present invention has a bending strength of preferably 195 MPa or more, more preferably 195 MPa or more, in a bending test using a strip-shaped test piece (length 127 mm, width 12.7 mm, thickness 0.5 mm). Is 200 MPa or more, more preferably 205 MPa or more, and the flexural modulus is preferably 11 GPa or more, more preferably 12 GPa or more. The upper limit of the bending strength is not particularly limited, but is, for example, 400 MPa. The upper limit of the flexural modulus is not particularly limited, but is, for example, 30 Gpa. Therefore, in the liquid crystal polyester resin composition of the present invention, the bending strength is, for example, 195 to 400 MPa, 200 to 400 MPa, 205 MPa to 400 MPa, and the bending elastic modulus is, for example, 11 to 30 GPa, 12 to 30 GPa, and the like.

The liquid crystal polyester resin composition of the present invention has excellent flame retardancy. In the present specification, the flame retardancy is determined by molding a bar flow shape test piece of 170.0 mm × 12.5 mm × 0.8 mm and allowing it to stand for 48 hours under the conditions of 23 ° C. and 50% relative humidity, and then UL-. Evaluated according to 94 standards. The liquid crystal polyester resin composition of the present invention is characterized by being equivalent to V-0 according to the above evaluation.

A molded product made of a liquid crystal polyester composition usually has a surface easily peeled off, and ultrasonic cleaning tends to cause the surface to peel off and become fibrillated, and the fibrillated portion is made of a resin composition. Small dust and dirt (hereinafter referred to as particles) are likely to be generated. According to the liquid crystal polyester resin composition of the present invention, the generation of particles is suppressed, so that the molded product can obtain good optical characteristics without becoming foreign matter during assembly and use in an optical member such as a camera module. can.

The number of particles generated in the liquid crystal polyester resin composition of the present invention can be evaluated as the number of particles generated when the molded product is ultrasonically cleaned, and the preferable number of particles generated is 1000 or less, more preferably 800. It is less than or equal to, more preferably 500 or less, and particularly preferably 300 or less. When the number of particles generated exceeds the above upper limit value, the optical characteristics of the electronic component tend to be insufficient. The details of the method for evaluating the number of generated particles are as described in the examples.

According to the liquid crystal polyester resin composition of the present invention, good fluidity and mechanical strength can be obtained, so that electronic components such as connectors, switches, relays, capacitors, coils, transformers, camera modules, antennas, chip antennas and mini breakers can be obtained. It is preferably used for. Further, since the flame retardancy is improved and the generation of particles is suppressed, it is particularly preferably used for applications such as optical electronic parts such as camera modules and device parts such as mini breakers.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to the following Examples. The crystal melting temperature, melt viscosity, deflection temperature under load, bending strength, flexural modulus, flame retardancy, and the number of particles generated in the examples were measured and evaluated by the methods described below.

<Crystal melting temperature>
Using Exstar6000 manufactured by Seiko Instruments Co., Ltd. as a differential scanning calorimeter, the endothermic peak temperature (Tm1) observed when the sample was measured at a temperature rising condition of 20 ° C./min from room temperature was measured, and then 50 ° C. from Tm1. It was held at a high temperature for 10 minutes. Next, the sample was cooled to room temperature under the temperature lowering condition of 20 ° C./min, and the endothermic peak when measured again under the temperature rising condition of 20 ° C./min was observed, and the temperature indicating the peak top was the crystal melting temperature (Tm). ).

<Melting viscosity>
Melt viscosity of a sample at a crystal melting temperature (Tm) + 20 ° C. under a ^{shear rate of 1000 sec -1} using a 1.0 mmφ x 10 mm capillary with a melt viscosity measuring device (Capirograph 1D manufactured by Toyo Seiki Co., Ltd.). Were measured respectively.

<Deflection temperature under load>
A strip-shaped test piece (length 127 mm x width 12.7 mm x thickness 3.2 mm) was molded using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), and this was used to form ASTM D648. According to this, the temperature at which the predetermined deflection amount (0.254 mm) was measured at a load of 1.82 MPa and a heating rate of 2 ° C./min was measured.

<Bending strength, flexural modulus>
It was measured according to ASTM D790 using the same test piece as the test piece used for measuring the deflection temperature under load.

<Flame retardance>
Pellets of the resin composition were molded into a bar flow shape test piece having a length of 170 mm, a width of 12.7 mm and a thickness of 0.8 mm using an injection molding machine (PS40 manufactured by Nissei Resin Industry Co., Ltd.) at 23 ° C. After allowing to stand for 48 hours under the condition of relative humidity of 50%, it was evaluated according to the UL-94 standard.

<Number of particles generated>
Using an injection molding machine (MINIMAT M26 / 15 manufactured by Sumitomo Heavy Industries, Ltd.) with a mold clamping pressure of 15 tons for pellets of the resin composition, the cylinder temperature is 20 ° C higher than the crystal melting temperature (Tm), and the mold temperature is 70 ° C. Then, a strip-shaped bending test piece having a length of 64 mm, a width of 12.7 mm, and a thickness of 2 mm was prepared and used as a test piece for measuring the number of particles.
As shown in FIG. 1, one test piece is placed in a cylindrical glass container having an outer diameter of 50 mm, an inner diameter of 45 mm, and a height of 100 mm and containing 50 mL of pure water so that the gate portion is not immersed in water. Was installed in an ultrasonic cleaning tank having a length of 140 mm, a width of 240 mm, and a depth of 100 m, which was provided with 1000 mL of water.

After ultrasonic cleaning at an output of 38 kHz and 100 W for 10 minutes, the number of shed substances (particles) with a maximum diameter of 2 μm or more contained in 1 mL of pure water was determined using a particle counter (LiQuilaz-05 manufactured by Spectris). The measurement was performed three times, and the average value was used as the measurement result.

In Examples and Comparative Examples, the abbreviations below represent the following compounds.
POB: Parahydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid BP: 4,4'-dihydroxybiphenyl HQ: Hydroquinone TPA: Terephthalic acid NDA: 2,6-naphthalenedicarboxylic acid

[Synthesis Example 1 (LCP-1)]
In a reaction vessel equipped with a stirrer with a torque meter and a distillate, BON 6: 660.5 g (54.0 mol%), BP: 254.2 g (21.0 mol%), HQ: 14.3 g (2. 0 mol%) and TPA: 248.3 g (23.0 mol%) were charged, and 1.03 times the molar amount of acetic anhydride was charged with respect to the amount of hydroxyl groups (mol) of all the monomers, and deacetic anhydride was polymerized under the following conditions. Was done.

The temperature was raised from room temperature to 150 ° C. over 1 hour under a nitrogen gas atmosphere, and the temperature was maintained at 150 ° C. for 60 minutes. Then, the temperature was raised to 350 ° C. over 7 hours while distilling acetic acid produced as a by-product, and then the pressure was reduced to 10 mmHg over 90 minutes. When a predetermined torque was exhibited, the polymerization reaction was terminated, the contents were taken out from the reaction vessel, and pellets of liquid crystal polyester were obtained by a pulverizer. The amount of distillate acetic acid at the time of polymerization was almost the same as the theoretical value. The crystal melting temperature (Tm) of the obtained pellets was 338 ° C., and the melting viscosity was 23 Pa · s.

[Synthesis Example 2 (LCP-2)]
POB: 641.9 g (71.5 mol%), BON 6: 30.6 g (2.5 mol%), HQ: 93.0 g (13 mol) in a reaction vessel equipped with a stirrer with a torque meter and a distillate. %) And NDA: 182.7 g (13 mol%), and 1.03 times the molar amount of acetic anhydride with respect to the amount of hydroxyl groups (mol) of all the monomers was charged, and deacetic acid polymerization was carried out under the following conditions.

The temperature was raised from room temperature to 145 ° C. over 1 hour under a nitrogen gas atmosphere, and the temperature was maintained at 145 ° C. for 30 minutes. Then, the temperature was raised to 345 ° C. over 7 hours while distilling acetic acid produced as a by-product, and then the pressure was reduced to 10 mmHg over 80 minutes. When a predetermined torque was exhibited, the polymerization reaction was terminated, the contents were taken out from the reaction vessel, and pellets of liquid crystal polyester were obtained by a pulverizer. The amount of distillate acetic acid at the time of polymerization was almost the same as the theoretical value. The crystal melting temperature (Tm) of the obtained pellets was 321 ° C., and the melting viscosity was 23 Pa · s.

The filler used in the following examples and comparative examples is shown.
Fibrous titanium oxide (A-1): Needle-shaped titanium oxide "FTL-400" manufactured by Ishihara Sangyo Co., Ltd. (number average fiber length (L) = 10.1 μm, number average fiber diameter (D) = 0. 5 μm, L / D = 20)
Fibrous titanium oxide (A-2): Rod-shaped titanium oxide "PFR404" manufactured by Ishihara Sangyo Co., Ltd. (number average fiber length (L) = 2.91 μm, number average fiber diameter (D) = 0.4 μm, L / D = 7)
Glass fiber: ECS3010A manufactured by CPIC ( number average fiber diameter 10.5 μm)
Talc: "DS-34" manufactured by Fuji Talc Co., Ltd. (number average particle size 23 μm)

Example 1
LCP-1 is blended in a ratio of 100 parts by mass and fibrous titanium oxide (A-1) in a ratio of 5.4 parts by mass, and 350 by using a twin-screw extruder (TEX-30 manufactured by Japan Steel Works, Ltd.). Melt kneading was carried out at ° C. to obtain pellets of a liquid crystal polyester resin composition. By the above method, the melt viscosity, deflection temperature under load, bending strength, flexural modulus, flame retardancy and the number of particles generated were measured and evaluated. The results are shown in Table 1.

Examples 2-5, Comparative Examples 1-5
LCP-1 to 2, fibrous titanium oxide (A-1, A-2), glass fiber and talc were blended so as to have the contents shown in Table 1, and pellets were obtained in the same manner as in Example 1. Then, the measurement and evaluation were performed by the above method. The results are shown in Table 1.

As shown in Table 1, the liquid crystal polyester resin compositions of the present invention (Examples 1 to 5) have a deflection temperature under load of 280 ° C. or higher, a bending strength of 210 MPa or higher, and a flexural modulus of 13 GPa or higher. Moreover, it showed good flame retardancy and evaluation results of the number of particles generated.

On the other hand, when the technical features of the present invention are not satisfied as in Comparative Examples 1 to 5, the bending strength, the bending elastic modulus or the balance thereof is insufficient, and the flame retardancy and the number of particles generated are evaluated. The results were also unfavorable.

1 Cylindrical glass container 2 Pure water 3 Test piece 4 Gate

Claims (6)

Equations (I)-(III)

[During the ceremony,
Ar ₁ and Ar ₂ represent one or more divalent aromatic groups, respectively, and p, q and r are composition ratios (mol%) of each repeating unit in the liquid crystal polyester, respectively. , Satisfy the following conditions:
35 ≤ p ≤ 65 ,
5 ≦ q ≦ 30, and 5 ≦ r ≦ 30]
Contains 100 parts by mass of liquid crystal polyester having a crystal melting temperature of 310 to 360 ° C. and 1 to 150 parts by mass of fibrous titanium oxide, including the repeating unit represented by.
The repeating unit represented by the formula (I) is derived from 6-hydroxy-2-naphthoic acid or an ester-forming derivative thereof.
The repeating unit represented by the formula (II) is derived from one or more selected from the group consisting of hydroquinone, 4,4'-dihydroxybiphenyl and ester-forming derivatives thereof.
The repeating unit represented by the formula (III) is derived from terephthalic acid or an ester-forming derivative thereof.
Liquid crystal polyester resin composition. The fibrous titanium oxide has a number average fiber length (L) of 1 μm to 50 μm, a number average fiber diameter (D) of 0.05 μm to 2.0 μm, and an L / D of 3 to 50. Item 2. The liquid crystal polyester resin composition according to Item 1. The liquid crystal polyester resin composition according to claim 1 or 2, wherein the number of particles generated is 1000 or less. The liquid crystal polyester resin composition according to any one of claims 1 to 3, wherein the flame retardancy evaluated in accordance with the UL-94 standard is V-0. A molded product composed of the liquid crystal polyester resin composition according to any one of claims 1 to 4. Moldings are components of the one selected from the group consisting of mosquitoes Meramoju Le Contact and mini breaker, molded article according to claim 5.

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