JPH08231832A - Liquid crystalline polyester resin composition, method for producing the same and molded article thereof - Google Patents

Abstract

(57) [Abstract] [Problem] Having excellent moldability, heat resistance, mechanical properties,
Disclosed is a liquid crystal polyester resin composition suitable for use in electric and electronic parts, which can provide a molded product having excellent surface appearance and mechanical properties with small anisotropy. SOLUTION: The following structural units (I), (II), (III
), (IV) liquid crystalline polyester resin (A) 1
5 to 200 parts by weight of glass fiber (B) having an average fiber diameter of 3 to 15 μm is filled with respect to 00 parts by weight, and the number average fiber length of the glass fibers in the composition is 0.12 to 0. 25
mm, and the weight average fiber length is 0.25 to 0.60 mm, a liquid crystalline polyester resin composition. Embedded image (However, R ₁ in the formula is R ₂ is one or more groups selected from And one or more groups selected from X in the formula represents a hydrogen atom or a chlorine atom. )

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystalline polyester resin composition which is excellent in heat resistance, moldability, mechanical properties and surface appearance, and can give a molded product having mechanical properties with small anisotropy, and its production. The present invention relates to a method and its molded article.

[0002]

2. Description of the Related Art In recent years, the demand for higher performance of plastics has been increasing, and many polymers having various new properties have been developed and put on the market. Attention has been paid to the optically anisotropic liquid crystal polymer having excellent mechanical properties.

As a liquid crystal polymer forming an anisotropic melt phase, for example, a liquid crystal polymer obtained by copolymerizing polyethylene terephthalate with p-hydroxybenzoic acid (Japanese Patent Laid-Open No. 49-72).
393), a liquid crystal polymer obtained by copolymerizing p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid (JP-A-54-77691), and p-hydroxybenzoic acid containing 4,4'-dihydroxybiphenyl. Liquid crystal polymer copolymerized with terephthalic acid and isophthalic acid
No. -24407) is known.

It is also known to incorporate glass fibers for the purpose of improving the heat resistance and mechanical strength of liquid crystal polymers. Further, it is known that glass fibers having a weight average fiber diameter of 0.15 to 0.60 mm are blended for the purpose of improving the dimensional accuracy of the liquid crystal polymer (Japanese Patent Laid-Open No. 63-1014).
No. 48).

[0005]

However, the liquid crystal polymer known so far has a low deflection temperature under load of less than 190 ° C. and insufficient heat resistance.
Deflection temperature under load is 190 ° C or more, which is good in heat resistance, but liquid crystal polymer having a good balance between heat resistance and moldability, such as high melt viscosity, which cannot be molded unless the liquid crystal start temperature is too high and 400 ° C or higher. Was difficult.

[0006] In addition, when glass fibers are mixed with the liquid crystal polymer, mechanical strength and heat resistance are improved, but there are problems that the moldability is deteriorated and the surface appearance of the molded product is deteriorated.

Further, the molded product of the liquid crystal polymer having such optical anisotropy has problems that the strength of the weld portion is low and the mechanical property anisotropy is large. It was found that the strength of the weld portion and the anisotropy of mechanical properties were not sufficiently improved even when the fibers were mixed.

Therefore, the present invention solves the above problems and is excellent in heat resistance, moldability, and mechanical properties at high temperature, and in particular, the weld part strength and the anisotropy of mechanical properties peculiar to liquid crystalline polymers are improved. Another object is to obtain a liquid crystalline polyester resin composition.

[0009]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems.

That is, in the present invention, the average fiber diameter is 3 to 15 μm with respect to 100 parts by weight of the liquid crystalline polyester resin (A) comprising the following structural units (I), (II), (III) and (IV). 5 to 200 parts by weight of the glass fiber (B), the number average fiber length of the glass fibers in the composition is 0.12 to 0.25 mm, and the weight average fiber length is 0.2.
A liquid crystalline polyester resin composition of 5 to 0.60 mm,

[Chemical 6] (However, R ₁ in the formula is

[Chemical 7] R ₂ is one or more groups selected from

Embedded image And one or more groups selected from X in the formula represents a hydrogen atom or a chlorine atom. 2) Liquid crystalline polyester resin (A) and glass fiber (B)
The liquid crystalline polyester resin composition according to claim 1, wherein the liquid crystalline polyester resin (A) and the glass fiber (B) are sequentially and continuously supplied to the extruder in the order of melt kneading using the axial extruder. The method for producing a liquid crystalline polyester resin composition and the liquid crystalline polyester composition described above are molded, and the number average fiber length of the glass fibers in the molded article is 0.10 to 0. The present invention provides a liquid crystalline polyester resin molded product having a thickness of 20 mm and a weight average fiber length of 0.15 to 0.40 mm.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The structural unit (I) of the liquid crystalline polyester resin (A) in the present invention is the structural unit of polyester produced from p-hydroxybenzoic acid, and the structural unit (II) is 4,4. The structural unit formed from ′ -dihydroxybiphenyl has the structural unit (III) of 3,3
′, 5,5′-Tetramethyl-4,4′-dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, phenylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,2-
Bis (4-hydroxyphenyl) propane and 4,4
The structural unit (IV) is a terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bis (phenoxy) ethane- Produced from one or more aromatic dicarboxylic acids selected from 4,4'-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid and 4,4'-diphenyl ether dicarboxylic acid The structural units are shown below.

As R ₁ and R ₂ in the above structural unit,

[Chemical 9] The structural unit (III) is preferably a structural unit formed from 2,6-dihydroxynaphthalene, and the structural unit (IV) is preferably a structural unit generated from terephthalic acid.

The liquid crystalline polyester resin (A) in the present invention is a copolymer composed of the structural units (I), (II), (III) and (IV).

The copolymerization amount of the above structural units (I), (II), (III) and (IV) is arbitrary. However, the following copolymerization amount is preferable from the viewpoint of fluidity and heat resistance. That is, the above structural unit [(I) + (II)] is [(I) +
(II) + (III)] is preferably 60 to 95 mol%, particularly preferably 80 to 92 mol%.
In addition, the structural unit (III) is [(I) + (II) + (III
)] Is preferably 40 to 5 mol%, and particularly preferably 20 to 8 mol%. Further, the structural unit (I) / (I
The molar ratio of I) is preferably 75/25 to 95/5, and the structural unit (IV) is substantially equimolar to the structural unit [(II) + (III)].

Further, as the particularly preferable examples of the liquid crystalline polyester resin (A) used in the present invention, the following are specifically mentioned.

That is, the structural unit (III) is 2,6
A structural unit formed from dihydroxynaphthalene, and the structural unit (IV) is a structural unit formed from terephthalic acid (hereinafter, such a liquid crystalline polyester resin in the present invention is referred to as (A-1)) ,

[Chemical 10] The structural unit [(I) + (II)] is [(I) + (II)]
+ (III)] is preferably 80 to 99 mol%, and more preferably 88 to 98 mol%. The structural unit (III) is [(I) + (II) + (III)]
Is preferably 20 to 1 mol%, particularly preferably 12 to 2 mol%. The molar ratio of structural unit (I) / (II) is preferably 75/25 to 95/5, and 80/20 to
90/10 is more preferable. Furthermore, structural unit (II) /
The molar ratio of (III) is preferably 90/10 to 40/60, more preferably 85/15 to 45/55. Also in this case, the structural unit (IV) is substantially equimolar to the structural unit [(II) + (III)].

The method for producing the liquid crystalline polyester resin (A) used in the present invention is not particularly limited, and can be produced according to a known polyester polycondensation method, but a particularly preferable liquid crystalline polyester resin (A-1). Is preferably produced by the following method.

A process for producing p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, acetic anhydride, 2,6-diacetoxynaphthalene and terephthalic acid, and deacetic acid polymerization in a molten state.

Although these polycondensation reactions proceed without a catalyst, it is sometimes preferable to add a metal compound such as stannous acetate, tetrabutyl titanate, sodium acetate and potassium acetate, antimony trioxide, or magnesium metal. .

The thus obtained particularly preferred liquid crystalline polyester resin (A-1) used in the present invention has a melting point (T
m, ° C.) preferably satisfies the following formula (1).

| Tm + 7.70x−374.4 | <10 (1) where x in the formula (1) is [(I) + of the structural unit (III).
The ratio (mol%) to (II) + (III)] is shown.

In the particularly preferred liquid crystalline polyester resin (A-1) used in the present invention, structural units (I) to (I
When the composition ratio of V) satisfies the above conditions and satisfies the melting point of the above formula (1), the composition distribution and randomness of the polymer are in a preferable state, and the fluidity, heat resistance and mechanical properties of the molded product are obtained. Is extremely excellent, and the polymer is hardly decomposed even at high temperature, which is preferable. Here, the melting point (Tm) is measured by a differential scanning calorimeter,
An endothermic peak temperature observed when measured at a temperature rising rate of 20 ° C./min, and refers to Tm ₂ described later.

In addition, in the above-mentioned differential calorimetric measurement, the polymer which has completed the polymerization is heated from room temperature to a temperature equal to or higher than the melting point.
° C. / endothermic peak temperature (hereinafter abbreviated as Tm ₁₎ the partial is observed when measured at a Atsushi Nobori condition, Tm ₁ of the observation post Tm ₁ +
After being kept at a temperature of 20 ° C. for 5 minutes, once cooled to room temperature under a temperature lowering condition of 20 ° C./min, and then measured again under a temperature rising condition of 20 ° C./min, an endothermic peak temperature (hereinafter Tm ₂
It is preferable that there is a relationship of | Tm ₁ −Tm ₂ | ≦ 10 ° C., and more preferably | Tm ₁ −Tm ₂ | ≦ 6 ° C. When this temperature difference is 10 ° C. or less, it can be said that the structure of the polymer is uniform.

The logarithmic viscosity of the liquid crystalline polyester resin (A) used in the present invention is 0.1 g / dl concentration, 60.
The value measured in pentafluorophenol at 0.degree.
It is preferably 8 to 10.0 dl / g. The value of logarithmic viscosity is 0.
If it is less than 8 dl / g, the mechanical properties are insufficient, and 10.
If it exceeds 0 dl / g, the fluidity is impaired, and in any case, it tends to be undesirable. In the case of the particularly preferred liquid crystalline polyester resin (A-1), 3.0 to
10.0 dl / g is preferable, 3.5-7.5 dl / g
Is particularly preferable.

The melt viscosity of the liquid crystalline polyester resin (A) used in the present invention is preferably 100 to 2,000 poise, and particularly preferably 100 to 1,000 poise.

The melt viscosity is (melting point (Tm) +1)
It is a value measured by a Koka type flow tester under conditions of 0) ° C. and a shear rate of 1,000 s ⁻¹ .

When the liquid crystalline polyester resin (A) used in the present invention is polycondensed, the above structural units (I) to
In addition to the components constituting (IV), aromatic dicarboxylic acids such as 3,3′-diphenyldicarboxylic acid and 2,2′-diphenyldicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and dodecanedioic acid. Acids, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, methylhydroquinone, 4,4 '
-Aromatic diols such as dihydroxydiphenyl sulfide and 4,4'-dihydroxybenzophenone, 1,4-
Butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanediol,
Aliphatic and alicyclic diols such as 1,4-cyclohexanedimethanol and aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, p-aminophenol, p-aminobenzoic acid and aroma. Group imide compounds and the like can be further copolymerized in a small proportion within a range not impairing the object of the present invention.

As the glass fiber (B) used in the liquid crystalline polyester resin composition of the present invention, weakly alkaline one is excellent in mechanical strength and can be preferably used in the present invention.

The glass fiber is preferably treated with a coating or sizing agent such as an epoxy type, urethane type or acrylic type, and an epoxy type is particularly preferable. Further, it is preferably treated with a silane-based or titanate-based coupling agent or other surface treatment agent, and an epoxysilane- or aminosilane-based coupling agent is particularly preferable.

The average fiber diameter of the glass fibers (B) used in the production of the liquid crystalline polyester resin composition of the present invention is 3 to 15
The fiber length is preferably 30 to 10 ⁴ μm, more preferably ⁴ to 10 μm and 1000 to
4000 μm, the filling amount is 5 to 200 parts by weight, preferably 10 to 100 parts by weight with respect to 100 parts by weight of the liquid crystalline polyester.
Parts by weight. When the average diameter of glass fiber is less than 3 μm,
The reinforcing effect is small and the anisotropy reducing effect is small, which is not preferable. On the other hand, when it is larger than 15 μm, the moldability is deteriorated, the surface appearance is deteriorated, and the effect of reducing anisotropy is not sufficient, which is not preferable.

The liquid crystalline polyester resin composition of the present invention comprises the above liquid crystalline polyester resin (A) and glass fibers (B) having an average fiber diameter of 3 to 15 μm. Number average fiber length is 0.12
~ 0.25 mm, and weight average fiber length is 0.25-0.6
Must be 0 mm, especially the weight average fiber length is 0.2
It is preferably 5 to 0.50 mm. Further, the average aspect ratio of the glass fibers in the composition is more preferably 35-80. The average aspect ratio referred to herein means a value obtained by dividing the weight average fiber length of the glass fibers in the composition by the average fiber diameter of the glass fibers. The glass fiber in the composition has a number average fiber length of less than 0.12 mm or a weight average fiber length of 0.1.
If it is less than 25 mm, the anisotropy of the mechanical properties of the molded product is large, the mechanical strength is not sufficient, and the number average fiber length is 0.2.
If it exceeds 5 mm or if the weight average fiber length is larger than 0.60 mm, the fluidity at the time of molding and the appearance of the molded product will be impaired, and thus either case is not preferable.

The liquid crystalline polyester composition of the present invention may further contain a filler other than glass fiber.

As the filler which can be used in the present invention, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, gypsum fiber, brass fiber, stainless fiber, steel fiber, ceramic fiber, boron whisker fiber, mica, talc. , Silica, calcium carbonate, glass beads,
Examples thereof include fibrous, powdery, granular or plate-like inorganic fillers such as glass flakes, glass microballoons, clay, wollastonite and titanium oxide.

Furthermore, in the composition of the present invention, antioxidants and heat stabilizers (for example, hindered phenols, hydroquinones, phosphites and substitution products thereof, etc.) are used to the extent that the objects of the present invention are not impaired. , UV absorbers (eg resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants and mold release agents (montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide and polyethylene wax), dyes (eg nigrosine) Etc.) and pigments (eg cadmium sulfide, phthalocyanine, carbon black, etc.), colorants, plasticizers, antistatic agents, flame retardants and other usual additives and other thermoplastics Can be granted.

Although a known melt-kneading technique can be applied to the production of the liquid crystalline polyester resin composition of the present invention, the liquid crystalline polyester composition of the present invention is, as described above, a number average fiber within a specific range. It is often difficult to obtain the desired product by conventional simple extrusion techniques because of the need to have length and weight average fiber length.

For example, when a liquid crystal polyester resin (A) and glass fibers (B) are melt-kneaded into a composition by using an ordinary single-screw extruder, there is a problem that the shape of pellets obtained is not stable. Further, when a normal twin-screw extruder is used, there is a problem that the glass fibers in the composition often do not satisfy the above-mentioned specific range of number average fiber length and weight average fiber length.

For producing the liquid crystalline polyester resin composition of the present invention, it is more preferable to apply the melt-kneading method according to the following methods (a) to (c).

(A) When the liquid crystalline polyester resin (A) and the glass fiber (B) are melt-kneaded into a composition, a twin-screw extruder is used, and the liquid crystalline polyester resin (A) and the glass fiber (B) are used. In this order, it is manufactured by a method of supplying the extruder sequentially and continuously. Specifically, a liquid crystal polyester resin (A) in a molten state is provided by further providing another inlet at an arbitrary position between the raw material inlet of the twin-screw extruder and the nozzle portion.
The glass fiber (B) is continuously supplied to.

(B) A composition is prepared by melt-kneading the liquid crystalline polyester resin (A) at a resin temperature not lower than the melting point (Tm) and not higher than the melting point (Tm) + 20 ° C.

(C) During extrusion, the screw arrangement and screw rotation speed of the twin-screw extruder can be changed,
Melt kneading is carried out by a method such as attaching a screen of 8 to 20 mesh which gives a passage resistance in front of the die.

At least one of the above methods (a) to (c)
Employing one facilitates the manufacture of the compositions of the present invention. Therefore, it can be said that the composition of the present invention can be easily manufactured for the first time by a special technique for curing.

The liquid crystalline polyester composition of the present invention thus obtained has excellent heat resistance, moldability, mechanical properties, and surface appearance by ordinary molding methods such as injection molding, extrusion molding, blow molding, and the like. It can be processed into a three-dimensional molded product, a sheet, a container, a pipe, etc., which has a mechanical property with a small degree of directionality.

In order to exhibit the excellent properties of the liquid crystalline polyester composition of the present invention, the number average fiber length of the glass fibers in the molded product is 0.10 mm to 0.20 mm, and the weight average fiber length is not more than 0. It is preferably 15 to 0.40 mm,
Further, it is more preferable that the average aspect ratio of the glass fiber in the molded product is 20 to 40, and such a molded product has particularly excellent properties.

[0044]

EXAMPLES The present invention will be further described below with reference to examples.

Reference Example 1 994 parts by weight of p-hydroxybenzoic acid, 223 parts by weight of 4,4'-dihydroxybiphenyl, and 2,6-diacetoxynaphthalene 147 were placed in a reaction vessel equipped with a distillation tube and a stirrer.
Parts by weight, 299 parts by weight terephthalic acid and 10 parts acetic anhydride
77 parts by weight were charged, and deacetic acid polymerization was carried out under the following conditions.

First, 100 to 250 in a nitrogen gas atmosphere.
After reacting at ℃ for 6 hours and at 250-330 ℃ for 2.0 hours, the pressure was reduced to 0.5 mmHg at 330 ℃ for 2 hours, and the reaction was continued for 1.5 hours to complete polycondensation. A quantity of acetic acid was distilled off to obtain a beige resin (a) having the following theoretical structural formula.

[0047]

[Chemical 11] The melting point of this polymer using a Perkin Elmer DSC-7 type, was measured at a heating rate of 20 ° C. / min conditions, the peak temperature of Tm ₁ is 326 ° C., a peak temperature of Tm ₂ is 323 ° C. met It was

The logarithmic viscosity of this polymer is 4.86d.
1 / g, melt viscosity 333 ° C., shear rate 1000
(1 / sec) was 460 poise and the fluidity was extremely good.

Reference Example 2 1296 parts by weight of p-acetoxybenzoic acid and 414 parts by weight of 6-acetoxy-2-naphthoic acid were subjected to a deacetic acid polymerization reaction to obtain a beige resin (b) having the following theoretical structural formula.

[0050]

[Chemical 12] Also, place this polyester on the sample stage of the polarizing microscope,
As a result of raising the temperature and confirming the optical anisotropy, the liquid crystal starting temperature was 296 ° C.

The melting point of this polymer was measured by using DSC-7 type manufactured by Perkin Elmer Co., Ltd. under the conditions of a temperature rising rate of 20 ° C./min. The peak temperature of Tm ₁ was 320 ° C. and Tm ₂
Had a peak temperature of 317 ° C. The logarithmic viscosity of this polymer was 4.06 dl / g.

Example 1 Using a 30 mmφ twin-screw extruder having an intermediate addition port, a 12-mesh screen was placed in front of the die to give passage resistance, and the extruded resin temperature (actual measurement value) was 320 ° C. and the screw rotation speed was 180 rpm. The liquid crystalline polyester resin (a) obtained by the same method as in Reference Example 1 was extruded under the conditions of, and glass fiber (10 μm diameter, 3 mm long chopped strand) was added to 100 parts by weight of the polymer (a) from the intermediate addition port. 42
It was continuously fed so that it would be part by weight, melt-kneaded, and pelletized.

The polymer component was burned and removed from the obtained composition pellets, and the weight average fiber length of the remaining glass fibers was determined. The results are shown in Table 1.

Next, the pellets thus obtained were subjected to a Sumitomo Nestal injection molding machine Promat (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 320.degree. A square plate was formed. Further, the weight average fiber length of the glass fibers in the square plate molded product was determined in the same manner as above.

This square plate was cut into a width of 14 mm in the direction of flow and at a right angle, and the flexural modulus was measured according to the ASTM D790 standard under the conditions of a strain rate of 1 mm / min and a span distance of 40 mm.

For the evaluation of the moldability, the flow length (bar flow) of a 0.5 mm thick × 12.7 mm wide test piece was measured under the conditions of an injection speed of 99% and an injection pressure of 500 kgf / cm ² using the above molding machine. Long). The results are shown in Table 2.

Comparative Examples 1-2 Using the liquid crystalline polyester resin (a) obtained by the method of Reference Example 1, the same 30 mmφ twin-screw extruder as in Example 1 was used and the glass fiber ( 10 μm diameter,
3 mm long chopped strand) was blended, melt-kneaded, and pelletized. Furthermore, the same injection molding machine as in Example 1 was used, and under the molding conditions shown in Table 2, the same molding as in Example 1 was carried out and evaluated. Further, the weight average fiber length of the glass fibers in the composition pellet and the square plate molded product was determined in the same manner as in Example 1. The glass fiber length in the composition is shown in Table 1,
Table 2 shows the evaluation results of the molded products.

[0058]

[Table 1]

[Table 2] As shown in Table 1, it was found that the composition of Comparative Example 1 in which the weight average fiber length of the glass fibers in the composition exceeded 0.60 mm impaired the molding fluidity and the appearance of the molded article. The weight average fiber length of the glass fibers in the composition is 0.25.
It can be seen that the compositions of Comparative Examples 2, 3 and 4 having a thickness of less than mm have greater anisotropy in mechanical properties than the compositions of the present invention.

Comparative Example 3 100 parts by weight of the liquid crystalline polyester resin (a) of Reference Example 1 and 42 parts by weight of glass fiber (B) (10 μm diameter, 3 mm long chopped strand) were dry-blended together into a 40 mmφ single screw extruder. Then, the screw rotation speed is 80 rp
m and the extruded resin temperature was 330 ° C., and melt kneading was performed to obtain composition pellets. The composition pellets were irregular in shape and had a low bulk specific gravity, and were so-called defective products.

Further, using the same molding machine as in Example 1 for this composition, the cylinder temperature was 320 ° C. and the mold temperature was 9
A 2 mm thick × 70 mm × 70 mm square plate was formed under the condition of 0 ° C., but the appearance of the formed product was uneven and remarkably defective. The results are also shown in Tables 1 and 2.

Comparative Example 4 100 parts by weight of the liquid crystalline polyester resin (b) of Reference Example 2 and 42 parts by weight of glass fiber (B) (10 μm diameter, 3 mm long chopped strand) were dry-blended together into a 40 mmφ single screw extruder. Then, the screw rotation speed is 80 rp
m and the extruded resin temperature was 335 ° C., and melt kneading was performed to obtain composition pellets. The pellets of this composition had irregular shapes, foaming was observed, and the bulk specific gravity was small, and the pellet was a so-called defective product. Furthermore, using the same molding machine as in Example 1 for this composition, the cylinder temperature was 330 ° C. and the mold temperature was 90 ° C.
A square plate having a thickness of 2 mm × 70 mm × 70 mm was molded under the above condition, but the appearance of the molded product was uneven and remarkably defective. The results are also shown in Tables 1 and 2.

[0062]

The liquid crystalline polyester composition of the present invention is
Since a molded product having excellent heat resistance, moldability, mechanical properties, and surface appearance, and particularly mechanical properties with small anisotropy is provided, it can be used for various applications such as electric and electronic parts.

Claims (12)

[Claims] 1. The following structural units (I), (II) and (III)
), (IV) liquid crystalline polyester resin (A) 1
5 to 200 parts by weight of glass fiber (B) having an average fiber diameter of 3 to 15 μm is filled with respect to 00 parts by weight, and the number average fiber length of the glass fibers in the composition is 0.12 to 0. 25
mm, and a liquid crystal polyester resin composition having a weight average fiber length of 0.25 to 0.60 mm. Embedded image (However, R ₁ in the formula is R ₂ is one or more groups selected from And one or more groups selected from X in the formula represents a hydrogen atom or a chlorine atom. ) 2. The liquid crystalline polyester resin composition according to claim 1, wherein the glass fiber (B) in the composition has an average aspect ratio of 35 to 80.
It means a value obtained by dividing the weight average fiber length of the glass fibers in the composition by the average fiber diameter). 3. The liquid crystal according to claim ₁ , wherein R ₁ and R _{2 in the} structural units (III) and (IV) of the liquid crystalline polyester resin (A) are one or more selected from the following structural units. Polyester resin composition. [Chemical 4] 4. R ₁ and R _{2 in the} structural units (III) and (IV) of the liquid crystalline polyester resin (A) are as follows: And the structural unit [(I) + (II)] is [(I) + (I
I) + (III)], the structural unit (III
) Is 20 to 1 mol% of [(I) + (II) + (III)], and the molar ratio of structural units (I) / (II) is 75/25 to 9
5/5, (II) / (III) molar ratio 90 / 10-40
The liquid crystalline polyester resin composition according to claim 1, wherein the liquid crystal polyester resin composition has a melting point (Tm, ° C) satisfying the formula (2) and an inherent viscosity of 3.0 to 10.0 dl / g. | Tm + 7.70x-374.4 | <10 (2) where x in the formula (2) is [(I) + of the structural unit (III).
The ratio (mol%) to (II) + (III)] is shown. 5. The melt viscosity of the liquid crystalline polyester resin (A) measured at a temperature of melting point (Tm) + 10 ° C. and a shear rate of 1000 s ⁻¹ is 100 to 1000 poise.
The liquid crystalline polyester resin composition described. 6. A resin temperature of the liquid crystalline polyester resin (A) and the glass fiber (B) at a melting point (Tm) or more and a melting point (Tm) + 20 ° C. or less of the liquid crystalline polyester resin (A) using a twin-screw extruder. The liquid crystalline polyester resin composition according to claim 1, which is produced by melt-kneading with. 7. When the liquid crystalline polyester resin (A) and the glass fiber (B) are melt-kneaded by using a twin-screw extruder, the liquid crystalline polyester resin (A) and the glass fiber (B) are sequentially and continuously in order. The liquid crystalline polyester resin composition according to claim 6, which is produced by feeding the liquid crystalline polyester resin composition to the extruder. 8. When the liquid crystalline polyester resin (A) and the glass fiber (B) are melt-kneaded using a twin-screw extruder, the liquid crystalline polyester resin (A) and the glass fiber (B) are sequentially and continuously in order. The liquid crystalline polyester resin composition according to claim 1, which is produced by feeding the liquid crystalline polyester resin composition to the extruder. 9. A twin-screw extruder having a raw material charging port and a second charging port between the raw material charging port and the nozzle part, wherein the liquid crystal polyester resin (A) is fed from the raw material charging port, The method for producing a liquid crystalline polyester resin composition according to claim 8, wherein the glass fiber (B) is supplied from a charging port. 10. A liquid crystalline polyester resin (A) in a molten state
The method for producing a liquid crystalline polyester resin composition according to claim 7, wherein the glass fiber (B) is added to the mixture. 11. A liquid crystalline polyester composition according to claim 1, which is molded and has a number average fiber length of 0.10 to 0.20 mm and a weight average fiber length of 0.10 to 0.20 mm. Liquid crystalline polyester resin molded product having a size of 15 to 0.40 mm. 12. A liquid crystalline polyester resin molded product obtained by molding the liquid crystalline polyester composition according to claim 1, wherein the glass fiber in the molded product has an average aspect ratio of 20 to 40.