JP3045065B2 - Liquid crystalline polyester resin composition, production method thereof and molded article thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystalline polyester resin composition which is excellent in heat resistance, moldability, mechanical properties and surface appearance, and which can give a molded article having mechanical properties with small anisotropy, and its production. The present invention relates to a method and a molded article thereof.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for higher performance of plastics, and a number of polymers having various new properties have been developed and marketed. Among them, the polymer is characterized by a parallel arrangement of molecular chains. Optically anisotropic liquid crystal polymers have attracted attention because of their excellent mechanical properties.

As a liquid crystal polymer forming an anisotropic molten phase, for example, a liquid crystal polymer obtained by copolymerizing p-hydroxybenzoic acid with polyethylene terephthalate (JP-A-49-72)
No. 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 added to 4,4'-dihydroxybiphenyl. Liquid crystal polymer obtained by copolymerizing terephthalic acid and isophthalic acid
-24407) and the like.

It is known that glass fibers are blended for the purpose of improving the heat resistance and mechanical strength of a liquid crystal polymer. 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, what has been known as this liquid crystal polymer, the deflection temperature under load is as low as less than 190 ° C., and the heat resistance is insufficient.
Deflection temperature under load is 190 ° C or higher and heat resistance is good, but liquid crystal starting temperature is too high and molding cannot be performed unless 400 ° C or higher and melt viscosity is high, and a liquid crystal polymer having a balance between heat resistance and moldability is obtained. Was difficult.

[0006] Incorporation of glass fibers into the liquid crystal polymer improves mechanical strength and heat resistance, but causes problems such as reduced moldability and poor surface appearance of molded products.

Also, such molded articles of liquid crystal polymer having optical anisotropy have problems such as low weld strength and large anisotropy of mechanical properties. It was found that even when the fibers were blended, the strength of the weld portion and the anisotropy of the mechanical properties were not sufficiently improved.

Accordingly, the present invention solves the above-mentioned problems, and is excellent in heat resistance, moldability, and mechanical properties at high temperatures, and in particular, has improved weld strength and anisotropy in mechanical properties peculiar to liquid crystalline polymers. It is an object to obtain a liquid crystalline polyester resin composition.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.

That is, the present invention relates to a 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), and the number average fiber length of the glass fiber 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,

Embedded image (However, R ₁ in the formula is

Embedded image R ₂ represents one or more groups selected from

Embedded image And at least one group selected from X in the formula represents a hydrogen atom or a chlorine atom. ) Liquid crystalline polyester resin (A) and glass fiber (B)
2. The liquid crystalline polyester resin composition according to claim 1, wherein when melt kneading using a screw extruder, the liquid crystalline polyester resin (A) and the glass fiber (B) are sequentially and continuously supplied to the extruder in this order. And a method for producing a liquid crystalline polyester resin composition, characterized by producing the liquid crystalline polyester resin composition described above, wherein the number average fiber length of the glass fibers in the molded article is 0.10 to 0.1. An object of the present invention is to provide a liquid crystalline polyester resin molded product having a length 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 a structural unit of a polyester formed from p-hydroxybenzoic acid, and the structural unit (II) is 4,4. Structural units formed from '-dihydroxybiphenyl, the structural unit (III) being 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
Structural units formed from '-dihydroxydiphenyl ether, wherein structural unit (IV) is 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.

In the above structural unit, R ₁ and R ₂ are

Embedded image And the structural unit (III) is preferably a structural unit generated 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 comprising the above 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 sum of the structural units (I) and (II) is
60 based on the sum of units (I), (II) and (III)
９５95 mol%, preferably 80-92 mol%
Is particularly preferred. The structural unit (III)
It is preferably from 40 to 5 mol%, particularly preferably from 20 to 8 mol% , based on the total of the structural units (I), (II) and (III) . The moles of the structural units (I) and (II)
The ratio [(I) / (II)] is preferably from 75/25 to 95/5, and the structural unit (IV) is substantially composed of the structural unit (II) and
It is equimolar to the sum of (III) .

Further, particularly preferred examples of the liquid crystalline polyester resin (A) used in the present invention include the following.

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

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

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

A process in which p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl is reacted with acetic anhydride, 2,6-diacetoxynaphthalene and terephthalic acid, and is produced by 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, and metallic magnesium. .

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

[0021] | Tm + 7.70x-374.4 | < 10 ... (1) structural unit of here in (1) x in the formula of the structural unit (III)
The ratio (mol%) to the total of (I), (II) and (III ) is shown.

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

Further, in the above-mentioned differential calorimetry, the polymer after completion of the polymerization is heated from room temperature to a temperature not lower 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 holding at a temperature of 20 ° C. for 5 minutes, once cooling to room temperature under a temperature lowering condition of 20 ° C./min, an endothermic peak temperature (hereinafter Tm ₂₎ observed when measured again at a temperature rising condition of 20 ° C./min.
| Tm ₁ −Tm ₂ | ≦ 10 ° C. is preferable, and | Tm ₁ −Tm ₂ | ≦ 6 ° C. is more preferable. When the temperature difference is 10 ° C. or less, it can be said that the polymer structure is in a uniform state.

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

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

The melt viscosity is calculated as (melting point (Tm) +1
0) This is a value measured by a Koka flow tester under the conditions of a shear rate of 1,000 s ^{-1 at} a temperature of ° C.

When the liquid crystalline polyester resin (A) used in the present invention is subjected to polycondensation, the above-mentioned structural units (I) to (I) are used.
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 dodecandioic acid Acid, alicyclic dicarboxylic acid such as hexahydroterephthalic acid, chlorohydroquinone, methylhydroquinone, 4,4 ′
Aromatic diols such as dihydroxydiphenyl sulfide and 4,4′-dihydroxybenzophenone,
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 aromatics A group imide compound or the like can be further copolymerized in a small proportion that does not impair the object of the present invention.

As the glass fiber (B) used in the liquid crystalline polyester resin composition of the present invention, a weakly alkaline glass fiber 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 epoxy, urethane or acrylic, and epoxy is particularly preferable. 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 fiber (B) used for producing the liquid crystalline polyester resin composition of the present invention is 3 to 15
μm, and the fiber length is preferably 30 to 10 ⁴ μm, more preferably ⁴ to 10 μm, and 1000 to 1000 μm, respectively.
4000 μm, the filling amount is 5 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the liquid crystalline polyester.
Parts by weight. If the average diameter of the glass fiber is less than 3 μm,
The reinforcing effect is small and the effect of reducing anisotropy is small, which is not preferable. On the other hand, if it is larger than 15 μm, the moldability decreases, the surface appearance deteriorates, 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 a weight average fiber length of 0.25 to 0.6
0 mm, in particular, the weight average fiber length is 0.2
It is preferably from 5 to 0.50 mm. Further, the average aspect ratio of the glass fibers in the composition is more preferably 35 to 80. Here, the average aspect ratio 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 number average fiber length of the glass fibers in the composition is less than 0.12 mm, or the weight average fiber length is 0.1 mm.
If it is less than 25 mm, the molded article has large anisotropy in mechanical properties, has insufficient mechanical strength, and has a number average fiber length of 0.2.
If it exceeds 5 mm, or if the weight average fiber length is more than 0.60 mm, the fluidity during molding and the appearance of the molded article are impaired, and either case is not preferred.

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

The fillers usable in the present invention include carbon fiber, aromatic polyamide fiber, potassium titanate fiber, masonry fiber, brass fiber, stainless fiber, steel fiber, ceramic fiber, boron whisker fiber, mica, and talc. , Silica, calcium carbonate, glass beads,
Examples of the filler include fibrous, powdery, granular, and plate-like inorganic fillers such as glass flakes, glass microballoons, clay, wollastenite, and titanium oxide.

Further, the composition of the present invention contains an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphites and substituted products thereof) to the extent that the object of the present invention is not impaired. UV absorbers (eg, resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants and release agents (eg, montanic acid and its salts, esters, half esters thereof, stearyl alcohol, stearamide, and polyethylene wax), dyes (eg, nigrosine) And other additives such as colorants, plasticizers, antistatic agents, flame retardants, and other thermoplastic resins, including pigments (e.g., cadmium sulfide, phthalocyanine, carbon black, etc.) and other thermoplastic resins. Can be granted.

Although it is possible to apply a known melt-kneading technique 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 having a specific range. Because of the need to have a long and weight average fiber length, it is often difficult to obtain the target with conventional simple extrusion techniques.

For example, when a liquid crystal polyester resin (A) and a glass fiber (B) are melt-kneaded using a usual single screw extruder to form a composition, there is a problem that the shape of the obtained pellet 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 number average fiber length and the weight average fiber length in the specific ranges described above.

For the production of 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 to form a composition, a twin screw extruder is used, and the liquid crystalline polyester resin (A) and the glass fiber (B) are used. ), And sequentially and continuously supplied to the extruder. Specifically, another input port is provided at an arbitrary position between the material input port and the nozzle portion of the twin-screw extruder, and a liquid crystalline polyester resin (A) in a molten state is provided.
Glass fiber (B) is supplied continuously.

(B) The composition is obtained by melting and kneading at a resin temperature of not less than the melting point (Tm) of the liquid crystalline polyester resin (A) and not more than the melting point (Tm) + 20 ° C.

(C) At the time of extrusion, the screw arrangement and screw rotation speed of the twin-screw extruder may be changed,
Melt kneading is performed by a method such as mounting an 8 to 20 mesh screen that gives passage resistance before the die.

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

The thus obtained liquid crystalline polyester composition of the present invention has excellent heat resistance, moldability, mechanical properties and surface appearance by ordinary molding methods such as injection molding, extrusion molding and blow molding. It can be processed into three-dimensional molded products, sheets, containers, pipes and the like having small mechanical properties.

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 article is 0.10 mm to 0.20 mm and the weight average fiber length is 0.1 mm. Preferably 15 to 0.40 mm,
Further, the average aspect ratio of the glass fibers in the molded article is more preferably 20 to 40, and such a molded article has particularly excellent properties.

[0044]

The present invention will be further described with reference to the following examples.

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

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

[0047]

Embedded image The melting point of this polymer was measured at a rate of temperature rise of 20 ° C./min using a DSC-7 manufactured by Perkin Elmer Co., and the peak temperature of Tm1 was 326 ° C. and the peak temperature of Tm2 was 323 ° C.

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

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]

Embedded image Also, place this polyester on the sample stage of a polarizing microscope,
As a result of checking the optical anisotropy by raising the temperature, the liquid crystal onset temperature was 296 ° C.

The melting point of this polymer was measured at a rate of temperature rise of 20 ° C./min using a DSC-7 type manufactured by Perkin Elmer Co., and the peak temperature of Tm ₁ was 320 ° C. and Tm _{2 was}
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 a passing resistance, the extruded resin temperature (actual value) was 320 ° C., and the screw rotation speed was 180 rpm. Under the conditions described above, the liquid crystalline polyester resin (a) obtained by the same method as in Reference Example 1 was extruded, and glass fiber (10 μm diameter, 3 mm long chopped strand) was fed from the intermediate addition port to 100 parts by weight of the polymer (a). 42
The mixture was continuously supplied so as to be parts by weight, and was melt-kneaded and then pelletized.

The polymer component was burned off from the obtained composition pellets, and the weight-average fiber length of the remaining glass fibers was determined. Table 1 shows the results.

Next, the obtained pellets are supplied to a Sumitomo Nestal injection molding machine Promat (manufactured by Sumitomo Heavy Industries, Ltd.), and a cylinder having a temperature of 320 ° C. and a mold temperature of 90 ° C. is 2 mm thick × 70 mm × 70 mm. 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 described above.

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

As an evaluation of moldability, the flow length of a test piece having a thickness of 0.5 mm and a width of 12.7 mm (rod flow) was measured using the above molding machine at an injection speed of 99% and an injection pressure of 500 kgf / cm ^2. Head). Table 2 shows the results.

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 glass fibers ( 10 μm diameter,
(3 mm long chopped strands) were blended, melt-kneaded, and pelletized. Further, the same injection molding machine as in Example 1 was used, and the same molding as in Example 1 was performed under the molding conditions shown in Table 2, and evaluation was performed. Further, the weight average fiber length of the glass fibers in the composition pellets and the square plate molded product was determined in the same manner as in Example 1. Table 1 shows the glass fiber length in the composition.
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 was impaired in molding fluidity and appearance of the molded article. The glass fiber in the composition has a weight average fiber length of 0.25.
It can be seen that the compositions of Comparative Examples 2, 3 and 4 having a size of less than mm have larger anisotropy in mechanical properties than the composition 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 and then packaged in a 40 mmφ single screw extruder. And put in, screw rotation speed 80rpm
The melt kneading was performed under the conditions of m and an extruded resin temperature of 330 ° C. to obtain a composition pellet. The composition pellets were irregular in shape and low in bulk specific gravity, and were so-called defective products.

Further, using the same molding machine as in Example 1 for this composition, a cylinder temperature of 320 ° C. and a mold temperature of 9
A 2 mm thick.times.70 mm.times.70 mm square plate was formed under the condition of 0.degree. C., but the appearance of the formed product was uneven and extremely poor. The results are 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 the glass fiber (B) (10 μm diameter, 3 mm long chopped strand) were dry-blended and then packaged in a 40 mmφ single screw extruder. And put in, screw rotation speed 80rpm
The mixture was melt-kneaded under conditions of m and extruded resin temperature of 335 ° C. to obtain a composition pellet. The composition pellets were irregular in shape, foamed, 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, a cylinder temperature of 330 ° C. and a mold temperature of 90 ° C.
A square plate having a thickness of 2 mm × 70 mm × 70 mm was molded under the conditions described above, but the appearance of the molded product was uneven and extremely poor. The results are shown in Tables 1 and 2.

[0062]

The liquid crystalline polyester composition of the present invention comprises:
A molded article having excellent heat resistance, moldability, mechanical properties, and surface appearance, and particularly having mechanical properties with small anisotropy, can be used for various applications such as electric and electronic parts.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 67/00-67/04

Claims (12)

(57) [Claims] 1. The following structural units (I), (II) and (III)
), Liquid crystalline polyester resin (A) 1 comprising (IV)
The glass fiber (B) having an average fiber diameter of 3 to 15 μm is filled in an amount of 5 to 200 parts by weight, and the number average fiber length of the glass fibers in the composition is 0.12 to 0. 25
A liquid crystalline polyester resin composition having a mm and a weight average fiber length of 0.25 to 0.60 mm. Embedded image (However, R ₁ in the formula is R ₂ represents one or more groups selected from And at least one group 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 the 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. Embedded image 4. R ₁ and R _{2 in the} structural units (III) and (IV) of the liquid crystalline polyester resin (A) are represented by the following formula: And the sum of the structural units (I) and (II) is the structural unit
80-9 based on the sum of (I), (II) and (III)
9 mol%, structural unit (III) is structural unit (I), (II)
And 20 to 1 mol% based on the total of (III), structural units
Molar ratio [(I) / (II)] between positions (I) and (II) is 75/2
5-95 / 5, molar ratio of (II) and (III) [(II) / (II
I)] is 90/10 to 40/60 and the melting point (T
m, ° C.) satisfies the expression (2), and the logarithmic viscosity is 3.0 to 1
The liquid crystalline polyester resin composition according to claim 1, wherein the content is 0.0 dl / g. | Tm + 7.70x-374.4 | < 10 ... (2) structural units here (2) x in the formula of the structural unit (III)
The ratio (mol%) to the total of (I) + (II) + (III ) is shown. 5. The liquid crystalline polyester resin (A) has a melt viscosity of 100 to 1000 poise measured at a melting point (Tm) + 10 ° C. and a shear rate of 1000 s ^−1.
The liquid crystalline polyester resin composition according to the above. 6. A resin temperature of not less than the melting point (Tm) of the liquid crystalline polyester resin (A) and not more than the melting point (Tm) + 20 ° C. of the liquid crystalline polyester resin (A) and the glass fiber (B) using a twin screw extruder. The liquid crystalline polyester resin composition according to claim 1, which is produced by melt-kneading in (1). 7. 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 arranged in this order. The liquid crystalline polyester resin composition according to claim 6, which is produced by supplying the extruder 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 successively and continuously successively. A method for producing a liquid crystalline polyester resin composition, comprising producing the liquid crystalline polyester resin composition according to claim 1 by supplying the liquid crystalline polyester resin composition to the extruder. 9. A twin-screw extruder is an extruder having a raw material input port and a second input port between the raw material input port and the nozzle, wherein the liquid crystal polyester resin (A) is supplied from the raw material input port, and The method for producing a liquid crystalline polyester resin composition according to claim 8, wherein the glass fiber (B) is supplied from an inlet. 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 charged into the mixture. 11. A liquid crystalline polyester composition according to claim 1, wherein the number average fiber length of the glass fibers in the molded article is 0.10 to 0.20 mm and the weight average fiber length is 0.1 mm. A liquid crystalline polyester resin molded product having a size of 15 to 0.40 mm. 12. A molded article of a liquid crystalline polyester resin obtained by molding the liquid crystalline polyester composition according to claim 1, wherein the average aspect ratio of the glass fibers in the molded article is 20 to 40.