JP7199853B2 - Liquid crystalline resin composition for sliding wear resistant member and sliding wear resistant member using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid crystalline resin composition for a sliding wear resistant member and a sliding wear resistant member using the same.

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

Examples of parts using liquid crystalline resins include connectors such as FPC connectors; sockets such as memory card sockets; camera module parts such as lens holders; and relays. These parts are required to have excellent mechanical strength and heat resistance, and are sometimes used in a form in which two or more members are in dynamic contact. It is also desired that the susceptibility to wear when two or more members are in dynamic contact is reduced. For example, in Patent Document 1, the object is to provide a molded article made of a liquid crystalline resin composition having excellent surface appearance and excellent slidability. is disclosed in a liquid crystalline resin composition containing in a specific ratio.

Japanese Patent No. 5087958

However, according to the studies of the present inventors, conventional liquid crystalline resin compositions do not sufficiently reduce sliding wear resistance. The present invention has been made to solve the above problems, and an object of the present invention is to provide a sliding wear resistant member having reduced sliding wear resistance while having mechanical strength and heat resistance equivalent to conventional ones. It is an object of the present invention to provide a liquid crystalline resin composition for a sliding and wear resistant member used for manufacturing and a sliding and wear resistant member using the same. In this specification, heat resistance refers to heat resistance evaluated by high-temperature rigidity, and high-temperature rigidity is defined as deflection temperature under load (hereinafter also referred to as "DTUL") in accordance with ISO 75-1, 2. Evaluated by measuring.

The present inventors have made intensive studies to solve the above problems. As a result, it was found that the above problems could be solved by using a liquid crystalline resin composition containing a liquid crystalline resin, barium sulfate having a specific median diameter, and an epoxy group-containing copolymer. Arrived. More specifically, the present invention provides the following.

(1) A sliding wear resistant member containing (A) a liquid crystalline resin, (B) barium sulfate, and (C) an epoxy group-containing copolymer, wherein the median diameter of (B) barium sulfate is 10 μm or less. Liquid crystalline resin composition for

(2) The content of the (A) liquid crystalline resin is 53.5 to 78% by mass, the content of the (B) barium sulfate is 20 to 40% by mass, and the (C) epoxy group The composition according to (1), wherein the content of the contained copolymer is 2.0 to 6.5% by mass.

(3) The composition according to (1), which further contains (D) a fibrous filler.

(4) The content of the (A) liquid crystalline resin is 33.5 to 73% by mass, the content of the (B) barium sulfate is 20 to 40% by mass, and the (C) epoxy group The composition according to (3), wherein the content of the contained copolymer is 2.0 to 6.5% by mass, and the content of the fibrous filler (D) is 5 to 20% by mass.

(5) A sliding wear resistant member comprising the composition according to any one of (1) to (4).

If a sliding wear resistant member is produced using the liquid crystalline resin composition for a sliding wear resistant member of the present invention as a raw material, the sliding wear resistance is reduced while maintaining the same mechanical strength and heat resistance as conventional ones. It is possible to obtain a sliding wear resistant member.

FIG. 1 is a diagram for explaining a method for evaluating the amount of sliding wear.

Embodiments of the present invention will be described below. In addition, this invention is not limited to the following embodiment.

<Liquid Crystalline Resin Composition for Sliding Wear Resistant Member>
The liquid crystalline resin composition for a sliding wear resistant member of the present invention contains (A) a liquid crystalline resin, (B) barium sulfate, and (C) an epoxy group-containing copolymer.

[(A) liquid crystalline resin]
The (A) liquid crystalline resin used in the present invention refers to a melt-processable polymer having a property capable of forming an optically anisotropic melt phase. The anisotropic melt phase properties can be confirmed by conventional polarimetry using crossed polarizers. More specifically, confirmation of the anisotropic molten phase can be carried out by using a Leitz polarizing microscope and observing the molten sample placed on a Leitz hot stage under a nitrogen atmosphere at a magnification of 40 times. A liquid crystalline polymer applicable to the present invention normally transmits polarized light and exhibits optical anisotropy when inspected between crossed polarizers even in a molten state.

The type of the liquid crystalline resin (A) as described above is not particularly limited, and aromatic polyesters and/or aromatic polyesteramides are preferable. Polyesters that partially contain aromatic polyesters and/or aromatic polyesteramides in the same molecular chain are also within the scope. (A) The liquid crystalline resin is preferably at least about 2.0 dl/g, more preferably 2.0 to 10.0 dl/g when dissolved in pentafluorophenol at a concentration of 0.1% by mass at 60°C. of logarithmic viscosity (I.V.) is preferably used.

The aromatic polyester or aromatic polyester amide (A) as the liquid crystalline resin applicable to the present invention is particularly preferably at least one selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic hydroxylamines, and aromatic diamines. It is an aromatic polyester or aromatic polyester amide having repeating units derived from a compound as a constituent.

More specifically,
(1) Polyester mainly composed of repeating units derived from one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(2) a repeating unit mainly derived from (a) one or more of aromatic hydroxycarboxylic acids and derivatives thereof, and (b) one of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and derivatives thereof or a polyester consisting of repeating units derived from two or more types, and (c) repeating units derived from at least one or two or more of aromatic diols, alicyclic diols, aliphatic diols, and derivatives thereof;
(3) repeating units mainly derived from (a) one or more of aromatic hydroxycarboxylic acids and derivatives thereof; and (b) one or two of aromatic hydroxyamines, aromatic diamines, and derivatives thereof Polyesteramides comprising repeating units derived from at least one species and (c) repeating units derived from one or more of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and derivatives thereof;
(4) repeating units mainly derived from (a) one or more of aromatic hydroxycarboxylic acids and derivatives thereof; and (b) one or two of aromatic hydroxyamines, aromatic diamines, and derivatives thereof (c) repeating units derived from one or more of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and derivatives thereof; and (d) aromatic diols and alicyclic and polyester amides comprising repeating units derived from at least one or two or more of group diols, aliphatic diols, and derivatives thereof. Furthermore, a molecular weight modifier may be used in combination with the above constituents, if necessary.

（Ｘ：アルキレン（Ｃ_１～Ｃ_４）、アルキリデン、－Ｏ－、－ＳＯ－、－ＳＯ_２－、－Ｓ－、及び－ＣＯ－より選ばれる基である）

（Ｙ：－（ＣＨ_２）_ｎ－（ｎ＝１～４）及び－Ｏ（ＣＨ_２）_ｎＯ－（ｎ＝１～４）より選ばれる基である。） Preferable examples of specific compounds constituting the (A) liquid crystalline resin applicable to the present invention include p-hydroxybenzoic acid, aromatic hydroxycarboxylic acids such as 6-hydroxy-2-naphthoic acid, 2,6-dihydroxy Aromatic diols such as naphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcinol, compounds represented by the following general formula (I), and compounds represented by the following general formula (II) terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and aromatic dicarboxylic acids such as compounds represented by the following general formula (III); p-aminophenol, p- Aromatic amines such as phenylenediamine can be mentioned.

(X: a group selected from alkylene (C ₁ to C ₄ ), alkylidene, —O—, —SO—, —SO ₂ —, —S—, and —CO—)

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

The liquid crystalline resin (A) used in the present invention can be prepared by a known method using a direct polymerization method or a transesterification method from the above monomer compound (or a mixture of monomers), and usually a melt polymerization method. or slurry polymerization method is used. The above-mentioned compounds having ester-forming ability may be used for polymerization as they are, or may be modified from precursors to derivatives having said ester-forming ability in the pre-polymerization stage. Various catalysts can be used for these polymerizations. and alkaline earth metal salts, and Lewis acid salts such as _BF3 . The amount of catalyst used is generally about 0.001 to 1% by weight, preferably about 0.01 to 0.2% by weight, based on the total weight of the monomers. If necessary, the polymers produced by these polymerization methods can be subjected to solid phase polymerization under reduced pressure or by heating in an inert gas to increase the molecular weight.

The melt viscosity of (A) the liquid crystalline resin obtained by the above method is not particularly limited. In general, those having a melt viscosity at a molding temperature of 10 MPa or more and 600 MPa or less at a shear rate of 1000 sec ^-1 can be used. However, if the viscosity is too high per se, the fluidity will be greatly deteriorated, which is not preferable. The liquid crystalline resin (A) may be a mixture of two or more liquid crystalline resins.

In the liquid crystalline resin composition of the present invention, the content of (A) the liquid crystalline resin is preferably 53.5 to 78% by mass. When the content of component (A) is 53.5% by mass or more, it is preferable in terms of fluidity, and when the content of component (A) is 78% by mass or less, it is preferable in terms of heat resistance. Also, the content of component (A) is more preferably 59 to 71.5% by mass, still more preferably 62.5 to 67.5% by mass. However, when the liquid crystalline resin composition of the present invention contains (D) a fibrous filler, the content of (A) the liquid crystalline resin in the liquid crystalline resin composition is , preferably 33.5 to 73% by mass, more preferably 43 to 64.5% by mass, and even more preferably 50.5 to 58.5% by mass.

[(B) barium sulfate]
(B) barium sulfate is used in combination with (C) the epoxy group-containing copolymer to maintain the mechanical strength and heat resistance of the molded product obtained from the liquid crystalline resin composition of the present invention, It contributes to reducing the sliding wear resistance of the body. (B) Barium sulfate can be used individually by 1 type or in combination of 2 or more types.

(B) The median diameter of barium sulfate is 10 μm or less. When the median diameter is more than 10 μm, it is difficult to achieve both the maintenance of mechanical strength and heat resistance equivalent to those of the conventional art and the reduction of sliding wear resistance. The median diameter is preferably from 0.3 to 6 μm, more preferably from 0.5 to 3 μm, and even more preferably from 0.6 to 2 μm, because both of the above are easily achieved. In this specification, the median diameter refers to the volume-based median value measured by a laser diffraction/scattering particle size distribution measurement method.

The content of component (B) is preferably 20 to 40% by mass in the liquid crystalline composition of the present invention. When the content is 20 to 40% by mass, it is easy to achieve both maintenance of mechanical strength and heat resistance equivalent to conventional ones and reduction of sliding wear resistance. The above content is more preferably 25 to 35% by mass, and still more preferably 28 to 32% by mass, because it is easier to achieve both of the above.

[(C) epoxy group-containing copolymer]
The liquid crystalline resin composition of the present invention contains (C) an epoxy group-containing copolymer. (C) The epoxy group-containing copolymer can be used alone or in combination of two or more. (C) The epoxy group-containing copolymer is not particularly limited, and for example, at least one selected from the group consisting of (C1) an epoxy group-containing olefin copolymer and (C2) an epoxy group-containing styrenic copolymer 1 type is mentioned. (C) The epoxy group-containing copolymer, when used in combination with (B) barium sulfate, contributes to reducing the sliding abrasion resistance of the molded article obtained from the liquid crystalline resin composition of the present invention.

(C1) Epoxy group-containing olefinic copolymers include, for example, copolymers composed of repeating units derived from α-olefins and repeating units derived from glycidyl esters of α,β-unsaturated acids. be done.

The α-olefin is not particularly limited and includes, for example, ethylene, propylene, butene, etc. Among them, ethylene is preferably used. The α,β-unsaturated acid glycidyl ester is represented by the following general formula (IV). Examples of glycidyl esters of α,β-unsaturated acids include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, etc. Glycidyl methacrylate is particularly preferred.

In the epoxy group-containing olefin copolymer (C1), the content of repeating units derived from an α-olefin is 87 to 98% by mass, and the content of repeating units derived from a glycidyl ester of an α,β-unsaturated acid. Preferably the amount is between 13 and 2% by weight.

The (C1) epoxy group-containing olefin copolymer used in the present invention contains acrylonitrile, acrylic acid ester, methacrylic acid ester, α-methylstyrene, and maleic anhydride as a third component in addition to the above two components within a range that does not impair the present invention. Repeating units derived from one or more olefinic unsaturated esters such as acids may be contained in an amount of 0 to 48 parts by mass per 100 parts by mass of the above two components.

The epoxy group-containing olefinic copolymer, which is the component (C1) of the present invention, can be easily prepared by a conventional radical polymerization method using monomers and radical polymerization catalysts corresponding to each component. More specifically, an α-olefin and a glycidyl ester of an α,β-unsaturated acid are usually heated in the presence of a radical generator at 500 to 4000 atmospheres at 100 to 300° C. in the presence of an appropriate solvent or chain transfer agent. It can be produced by a method of copolymerizing in the presence or absence of It can also be produced by a method of mixing an α-olefin with a glycidyl ester of an α,β-unsaturated acid and a radical generator, followed by melt-graft copolymerization in an extruder.

Examples of the epoxy group-containing styrenic copolymer (C2) include copolymers composed of repeating units derived from styrenes and repeating units derived from glycidyl esters of α,β-unsaturated acids. be done. The glycidyl ester of the α,β-unsaturated acid is the same as that explained for the component (C1), so the explanation is omitted.

Examples of styrenes include styrene, α-methylstyrene, brominated styrene, divinylbenzene and the like, and styrene is preferably used.

The (C2) epoxy group-containing styrenic copolymer used in the present invention is a multicomponent copolymer containing repeating units derived from one or more vinyl monomers as a third component in addition to the above two components. There may be. Preferred as the third component are repeating units derived from one or more of olefinically unsaturated esters such as acrylonitrile, acrylic acid esters, methacrylic acid esters and maleic anhydride. An epoxy group-containing styrenic copolymer containing 40 mass % or less of these repeating units in the copolymer is preferable as the component (C2).

(C2) In the epoxy group-containing styrene copolymer, the content of repeating units derived from glycidyl esters of α,β-unsaturated acids is 2 to 20% by mass, and the content of repeating units derived from styrenes is preferably 80 to 98% by mass.

(C2) Epoxy group-containing styrenic copolymer can be prepared by a conventional radical polymerization method using a monomer and a radical polymerization catalyst corresponding to each component. More specifically, styrenes and a glycidyl ester of an α,β-unsaturated acid are usually reacted in the presence of a radical generator at 500 to 4000 atmospheres at 100 to 300°C in the presence of an appropriate solvent or chain transfer agent. Alternatively, it can be produced by a method of copolymerization in the absence. It can also be produced by a method of mixing styrenes, a glycidyl ester of an α,β-unsaturated acid and a radical generator, and carrying out melt-graft copolymerization in an extruder.

As (C) epoxy group-containing copolymer, (C1) epoxy group-containing olefinic copolymer is preferable in terms of heat resistance. When the component (C1) and the component (C2) are used together, the proportions of these components can be appropriately selected according to the required properties.

(C) The content of the epoxy group-containing copolymer is 2.0 to 6.5% by mass in the liquid crystalline resin composition of the present invention. When the content of component (C) is within the above range, it is easy to obtain a molded article with reduced sliding wear resistance without impairing mechanical strength and heat resistance. A more preferable content is 3.5 to 6.0% by mass, and a still more preferable content is 4.5 to 5.5% by mass.

[(D) fibrous filler]
By containing (D) a fibrous filler, the liquid crystalline resin composition of the present invention can provide a molded article having even better heat resistance. (D) A fibrous filler can be used individually by 1 type or in combination of 2 or more types.

(D) The average fiber length of the fibrous filler is preferably 50-200 μm, more preferably 100-170 μm, still more preferably 120-150 μm. When the average fiber length is 200 μm or less, the fluidity of the liquid crystalline resin composition tends to be sufficient. When the average fiber length is 50 µm or more, the molded article obtained from the liquid crystalline resin composition of the present invention tends to have improved mechanical strength and heat resistance. For the average fiber length, a value obtained by reading a stereoscopic microscope image from a CCD camera into a PC and measuring it by an image processing method using an image measuring machine is adopted.

(D) The fibrous filler preferably has an average fiber diameter of 1 to 15 μm or less, more preferably 5 to 10 μm. When the average fiber diameter is within the above range, the molded article obtained from the liquid crystalline resin composition of the present invention tends to have improved mechanical strength and heat resistance. For the average fiber diameter, a value obtained by capturing an image of a stereoscopic microscope from a CCD camera into a PC and measuring it by an image processing method using an image measuring machine is adopted.

Any fiber can be used as long as it is a fibrous filler that satisfies the above shape. Examples of the fibrous filler (D) include glass fiber, milled fiber, carbon fiber, asbestos fiber, and silica fiber. , silica-alumina fiber, zirconia fiber, potassium titanate whisker, calcium silicate whisker (wollastonite), calcium carbonate whisker, zinc oxide whisker, aluminum borate whisker, boron nitride whisker, silicon trinitride whisker, base Examples include whiskers such as organic magnesium sulfate whiskers, barium titanate whiskers, silicon carbide whiskers and boron whiskers, and inorganic fibrous materials such as fibrous materials of metals such as stainless steel, aluminum, titanium, copper and brass. From the viewpoint of availability, component (D) is preferably potassium titanate whiskers, calcium silicate whiskers (wollastonite), calcium carbonate whiskers, zinc oxide whiskers, aluminum borate whiskers, etc. Whiskers (wollastonite) are more preferred. The shape of component (D) in the liquid crystalline resin composition of the present invention is different from the shape of component (D) before blending. The shape of the above component (D) is the shape before blending. If the shape before blending is as described above, it is easy to obtain a molded article having excellent heat resistance.

The content of component (D) in the liquid crystalline resin composition of the present invention is preferably 5 to 20% by mass, more preferably 7 to 16% by mass, and even more preferably 9 to 12% by mass. When the content of component (D) is within the above range, the fluidity of the liquid crystalline resin composition is sufficiently ensured, and the mechanical strength and heat resistance of the molded article obtained from the liquid crystalline resin composition are improved. Cheap.

[(E) carbon black]
(E) carbon black used as an optional component in the present invention is not particularly limited as long as it is generally available for coloring resins. Generally, (E) carbon black contains lumps formed by agglomeration of primary particles. Many bumps (fine bump-like projections (fine irregularities) in which carbon black is agglomerated) are less likely to occur on the surface of the formed body. When the content of particles having a particle diameter of 50 μm or more is 20 ppm or less, the effect of suppressing the raising of the surface of the molded product tends to be high. A preferable content is 5 ppm or less.

The amount of (E) carbon black to be blended is preferably in the range of 0.5 to 5% by mass in the liquid crystalline resin composition. When the blending amount of carbon black is 0.5% by mass or more, the jet-blackness of the obtained resin composition is less likely to deteriorate, and the light-shielding property is less likely to be disturbed. If the amount of carbon black is 5% by mass or less, it is less economical and less likely to cause lumps.

[Other ingredients]
The liquid crystalline resin composition of the present invention may contain other polymers, other fillers, and known substances generally added to synthetic resins, such as antioxidants and ultraviolet absorbers, as long as they do not impair the effects of the present invention. Stabilizers such as agents, antistatic agents, flame retardants, coloring agents such as dyes and pigments, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents, etc. can be appropriately added according to the required performance.

Other fillers refer to fillers other than (B) barium sulfate, (D) fibrous fillers, and (E) carbon black, and examples thereof include particulate fillers such as silica.

[Method for Preparing Liquid Crystalline Resin Composition for Sliding Wear Resistant Member]
The method for preparing the liquid crystalline resin composition for a sliding wear resistant member of the present invention is not particularly limited. For example, by blending the above components (A) to (C) and, optionally, component (D), and melt-kneading them using a single-screw or twin-screw extruder, a sliding wear resistant member A liquid crystalline resin composition is prepared.

[Liquid Crystalline Resin Composition for Sliding Wear Resistant Member]
The liquid crystalline resin composition of the present invention obtained as described above preferably has a melt viscosity of less than 90 Pa·sec from the viewpoint of moldability. One of the features of the liquid crystalline resin composition of the present invention is that it has high fluidity when melted and is excellent in moldability. The melt viscosity is more preferably 80 Pa·sec or less, still more preferably 75 Pa·sec or less. The lower limit of the melt viscosity is not particularly limited, and may be, for example, 30 Pa·sec or more, or 40 Pa·sec. As used herein, the melt viscosity is a value obtained by a measurement method according to ISO 11443 under the conditions of a cylinder temperature 10 to 20° C. higher than the melting point of the liquid crystalline resin and a shear rate of 1000 sec ⁻¹ .

<Sliding Wear Resistant Member>
A sliding wear resistant member is produced using the liquid crystalline resin composition of the present invention. The sliding wear resistant member of the present invention has mechanical strength and heat resistance equivalent to those of the conventional ones, but has reduced sliding wear resistance. The sliding wear resistant member of the present invention can be used for parts in which two or more members are in dynamic contact during use. Specifically, connectors such as FPC connectors; memory card sockets and the like. It can be used for sockets, parts for camera modules such as lens holders, and relays.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

<Liquid crystal resin>
- Liquid crystalline polyesteramide resin After charging the following raw materials into a polymerization vessel, the temperature of the reaction system was raised to 140°C, and the reaction was carried out at 140°C for 1 hour. After that, the temperature is further raised to 340° C. over 4.5 hours, and the pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 minutes to distill off acetic acid, excess acetic anhydride, and other low-boiling components. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to increase the pressure from reduced pressure to normal pressure to pressurized state, the polymer was discharged from the bottom of the polymerization vessel, and the strand was pelletized to obtain pellets. The obtained pellets were heat-treated at 300° C. for 2 hours in a nitrogen stream to obtain the desired polymer. The obtained polymer had a melting point of 336° C. and a melt viscosity at 350° C. of 19.0 Pa·s. The melt viscosity of the polymer was measured in the same manner as the melt viscosity measurement method described below.
(I) 4-hydroxybenzoic acid (HBA); 1380 g (60 mol%)
(II) 2-hydroxy-6-naphthoic acid (HNA); 157 g (5 mol%)
(III) Terephthalic acid (TA); 484 g (17.5 mol%)
(IV) 4,4′-dihydroxybiphenyl (BP); 388 g (12.5 mol %)
(V) 4-acetoxyaminophenol (APAP); 126 g (5 mol%)
Metal catalyst (potassium acetate catalyst); 110 mg
Acylating agent (acetic anhydride); 1659g

<Materials other than liquid crystalline resin>
- Barium sulfate 1: (manufactured by Sakai Chemical Industry Co., Ltd., median diameter 0.6 μm)
・ Barium sulfate 2: (manufactured by Sakai Chemical Industry Co., Ltd., median diameter 2 μm)
Epoxy group-containing olefin copolymer: Bondfast 2C (manufactured by Sumitomo Chemical Co., Ltd., ethylene-glycidyl methacrylate copolymer, glycidyl methacrylate content 6% by mass)
-Fibrous filler: NYGLOS 8 (manufactured by NYCO Materials, calcium silicate whiskers (wollastonite), number average fiber length 136 µm, average fiber diameter 8 µm)
Carbon black: VULCAN XC305 (manufactured by Cabot Japan Co., Ltd., average particle size 20 nm, ratio of particles with a particle size of 50 μm or more is 20 ppm or less)
・ Release agent: Pentaerythritol tetrastearate (manufactured by Emery Oleochemicals Japan Co., Ltd.)

<Production of Liquid Crystalline Resin Composition for Sliding Wear Resistant Member>
The above components are melt-kneaded at a cylinder temperature of 350 ° C. using a twin-screw extruder (TEX30α type manufactured by Japan Steel Works, Ltd.) in the proportions shown in Table 1 to obtain a liquid crystalline resin composition for a sliding wear resistant member. A pellet was obtained.

<Melt viscosity>
The melt viscosities of the liquid crystalline resin compositions of Examples and Comparative Examples were measured using the above pellets. Specifically, using a capillary rheometer (manufactured by Toyo Seiki Seisakusho Co., Ltd., Capilograph 1D: piston diameter 10 mm), the apparent melt viscosity under the conditions of a cylinder temperature of 350 ° C. and a shear rate of 1000 sec ^-1 was measured according to ISO 11443. and measured. An orifice with an inner diameter of 1 mm and a length of 20 mm was used for the measurement. Table 1 shows the results.

<Bending test>
The pellets of Examples and Comparative Examples were molded under the following molding conditions using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) to prepare bending test pieces of 130 mm × 13 mm × 0.8 mm. . Using this test piece, flexural strength, flexural modulus and breaking strain were measured according to ASTM D790. Among them, Table 1 shows the measurement results of the flexural modulus and flexural strength.
〔Molding condition〕
Cylinder temperature: 350°C
Mold temperature: 90°C
Injection speed: 33mm/sec
Holding pressure: 50MPa

[Deflection temperature under load (DTUL)]
The pellets of Examples and Comparative Examples were molded under the following molding conditions using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) to obtain test pieces for measurement (4 mm × 10 mm × 80 mm). . Using this test piece, the deflection temperature under load was measured by a method conforming to ISO 75-1, 2. A bending stress of 1.8 MPa was used. Table 1 shows the results.
〔Molding condition〕
Cylinder temperature: 350°C
Mold temperature: 80°C
Injection speed: 33mm/sec

<Sliding wear amount>
The pellets of Examples and Comparative Examples were molded under the following molding conditions using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.), and a measuring pin (diameter 10 mm, length 10 mm) and a measuring pin A specimen (80 mm x 80 mm x 1 mm) was obtained. As shown in FIG. 1, a load was applied to the measuring pin on the measuring test piece, and after performing a reciprocating sliding test under the following reciprocating sliding conditions, the total mass reduction of the measuring pin and the measuring test piece was calculated. It was calculated and used as the amount of sliding wear. Table 1 shows the results.
〔Molding condition〕
Cylinder temperature: 350°C
Mold temperature: 80°C
Injection speed: 33mm/sec
[Reciprocating sliding conditions]
Sliding speed: 5cm/sec
Stroke: 20mm
Load: 9.8N (1kg weight)
Number of round trips: 3000 times

As is clear from the results shown in Table 1, it was confirmed that the molded articles of Examples had mechanical strength and heat resistance equivalent to those of the conventional ones, while their sliding wear resistance was reduced. Furthermore, it was confirmed that the molded articles of Examples containing fibrous fillers had even better heat resistance.

Claims (3)

(A) a liquid crystalline resin,
(B) barium sulfate, and (C) an epoxy group-containing copolymer,
The median diameter of the (B) barium sulfate is 10 μm or less ,
The content of the (A) liquid crystalline resin is 53.5 to 78% by mass,
The content of (B) barium sulfate is 20 to 40% by mass,
A liquid crystalline resin composition for a sliding wear resistant member, wherein the content of the epoxy group-containing copolymer (C) is 2.0 to 6.5% by mass . (A) a liquid crystalline resin,
(B) barium sulfate,
(C) an epoxy group-containing copolymer, and
( D) contains a fibrous filler,
The median diameter of the (B) barium sulfate is 10 μm or less,
The content of the (A) liquid crystalline resin is 33.5 to 73% by mass,
The content of (B) barium sulfate is 20 to 40% by mass,
The content of the epoxy group-containing copolymer (C) is 2.0 to 6.5% by mass,
The content of the fibrous filler (D) is 5 to 20% by mass in the liquid crystalline resin composition for a sliding wear resistant member . A sliding wear resistant member comprising the composition according to claim 1 or 2 .

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