JP2023057673A - Thermoplastic polyester resin composition and molding including the same - Google Patents

Abstract

To provide a thermoplastic polyester resin composition that has excellent mechanical strength, toughness and low wear resistance, whose pellets can be reliably supplied to a molding machine during injection molding, and a molding including the same.SOLUTION: A resin composition comprises, relative to (A) thermoplastic polyester resin (A component) 100 pts.wt., (B) modified polyethylene resin (B component) 4-25 pts.wt., (C) wholly aromatic polyamide fiber (C component) 10-35 pts.wt. and (D) epoxy resin represented by the general formula (1) (D component) 0.5-8 pts.wt.SELECTED DRAWING: None

Description

The present invention provides a thermoplastic polyester resin composition which has excellent mechanical strength, toughness and low abrasion resistance, and which is excellent in feedability to a molding machine during injection molding of pellets of the resin composition, and molding using the same. Regarding the body.

Thermoplastic polyester resins and polyarylene sulfide resins have long been used for electric and electronic parts, home appliances, and automobiles because of their excellent low water absorbency and little change in mechanical properties and dimensions due to environmental changes. Widely used for parts. Among them, sliding member applications such as various gears and bearings are exposed to continuous or intermittent frictional force, so in addition to the above dimensional stability, excellent mechanical strength and toughness as members, is required to have low abrasion resistance when sliding against the mating material. In recent years, there has been a demand for components that can achieve a long life even in harsh environments such as high temperatures and high loads, and a higher degree of wear resistance than ever before is required.

Patent Document 1 proposes, as a sliding member for a conveying chain, a sliding member for a conveying chain molded from a resin composition comprising a thermoplastic resin, a fibrous filler, and a solid lubricant. Low abrasion resistance is not sufficient even at low temperatures, and further improvement is required. Patent Document 2 proposes a resin composition comprising an aromatic polyester resin, a polyolefin polymer and a fibrous reinforcing material as a resin composition having excellent low abrasion resistance and impact resistance. However, its toughness and low wear properties are not sufficient for use in current sliding member applications. Patent Document 3 proposes a resin composition comprising a polyarylene sulfide resin, a wholly aromatic polyamide fiber, a fluororesin, and a specific epoxy resin as a resin composition having excellent impact strength, tensile strength at break and tensile elongation at break. ing. However, there is no description of low abrasion properties, and the tensile strength at break is not sufficient for use as a sliding member. In addition, the pellets of the resin composition containing aramid fibers may interfere with each other on the surface of the aramid fibers, and may not be supplied while accumulated in the hopper of the injection molding machine. No method has been proposed that can be applied to a system containing such solid lubricants.

JP 2015-124056 A JP-A-5-222278 Japanese Patent Application Laid-Open No. 2020-41019

An object of the present invention is to provide a thermoplastic polyester resin composition which has excellent mechanical strength, toughness and low wear properties and which is excellent in feedability to a molding machine during injection molding of pellets of the resin composition, and the use thereof. It is an object of the present invention to provide a molded body with a

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, by blending a modified polyethylene resin, a wholly aromatic polyamide fiber and a specific epoxy resin in a specific ratio with a thermoplastic polyester resin, the above-mentioned objects can be achieved. The present invention has been achieved by finding that the

That is, the above problems are (A) thermoplastic polyester resin (A component) 100 parts by weight, (B) modified polyethylene resin (B component) 4 to 25 parts by weight, (C) wholly aromatic polyamide fiber (C 10 to 35 parts by weight of component) and (D) 0.5 to 8 parts by weight of an epoxy resin (component D) represented by the following general formula (1): .

(In Formula (1), m is an average value and is an integer of 1 or more. R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a trifluoromethyl group. Each X independently represents a hydrogen atom or a glycidyl group, and at least one of the multiple Xs is a glycidyl group.)

According to the present invention, there is provided a thermoplastic polyester resin composition which has excellent mechanical strength, toughness and low abrasion resistance, and which is excellent in feedability to a molding machine during injection molding of pellets of the resin composition. The molded article obtained from the resin composition of the present invention can be suitably used for, for example, sliding members used in the fields of electrical and electronic equipment, semiconductors, automobiles, industrial machinery, OA equipment and construction.

Further details of the present invention will be described below.

<About A component>
The thermoplastic polyester resin, which is component A of the present invention, can be produced using a dicarboxylic acid component mainly composed of a dicarboxylic acid and/or an ester-forming derivative of a dicarboxylic acid, and a glycol component mainly composed of a diol. .

Examples of dicarboxylic acid components include 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, aromatic dicarboxylic acids such as diphenylsulfone-4,4'-dicarboxylic acid and diphenyl ether-4,4'-dicarboxylic acid; aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid and oxalic acid; Alicyclic dicarboxylic acids and the like can be mentioned, and one or more of these may be used, and can be arbitrarily selected depending on the purpose. When two or more dicarboxylic acids are used, the amount of dicarboxylic acid used as the main component is preferably 70 mol % or more, more preferably 80 mol % or more, based on the total acid components. Ester-forming derivatives of dicarboxylic acids include, for example, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, diphenoxyethane-4,4 lower dialkyl esters of aromatic dicarboxylic acids such as ′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid and diphenyl ether-4,4′-dicarboxylic acid; lower dialkyl esters of alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; , lower dialkyl esters of aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid and oxalic acid. When two or more dicarboxylic acid ester-forming derivatives are used, the amount of the dicarboxylic acid ester-forming derivative used as the main component is preferably 70 mol% or more, more preferably 70 mol% or more, based on the ester-forming derivative component of the total dicarboxylic acid. is 80 mol % or more.

Also, a small amount of tri- or higher functional dicarboxylic acid component such as trimellitic acid may be used, and a small amount of acid anhydride such as trimellitic anhydride may be used. In addition, a small amount of hydroxycarboxylic acid such as lactic acid and glycolic acid or an alkyl ester thereof may be used, and can be arbitrarily selected depending on the purpose.

Examples of glycol components include ethylene glycol, 1,4-butanediol, 1,3-propylene glycol, 1,2-propylene glycol, neopentylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexanedimethanol, diethylene glycol, One or two or more alkylene glycols such as triethylene glycol, poly(oxy)ethylene glycol, poly(oxy)tetramethylene glycol, and poly(oxy)methylene glycol may be used, and can be arbitrarily selected depending on the purpose. . In addition, small amounts of polyhydric alcohol components such as glycerin may be used. The amount of the glycol component used as the main component is preferably 70 mol % or more, more preferably 80 mol % or more, based on the total glycol components.

The amount of the glycol component to be used is preferably 1.1 times or more and 1.4 times or less by mol with respect to the dicarboxylic acid or the ester-forming derivative of the dicarboxylic acid. If the amount of the glycol component used is less than 1.1 times by mole, the esterification or transesterification reaction may not proceed sufficiently, which is not preferred. If the molar ratio is more than 1.4 times, the reaction rate will be slowed for unknown reasons, and the excessive glycol component may generate a large amount of by-products such as tetrahydrofuran, which is not preferred.

In the production of the thermoplastic polyester resin, known polymerization catalysts can be used, such as titanium compounds, antimony compounds, germanium compounds, manganese compounds, aluminum compounds and the like, among which titanium compounds are preferred. As the titanium compound used as the polymerization catalyst, tetraalkyl titanate is preferable, and specifically tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-sec-butyl titanate, tetra-t-butyl titanate, tetra-n-hexyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, etc., and a mixed titanate thereof may be used. Among these titanium compounds, tetra-n-propyl titanate, tetraisopropyl titanate and tetra-n-butyl titanate are particularly preferred, and tetra-n-butyl titanate is most preferred. The amount of the titanium compound added is preferably 10 ppm or more and 60 ppm or less, more preferably 15 ppm or more and 30 ppm or less, in terms of the titanium atom content in the thermoplastic polyester resin produced. If the titanium atom content in the produced thermoplastic polyester resin exceeds 60 ppm, the color tone and thermal stability of the resin composition of the present invention may deteriorate, which is not preferred. On the other hand, when the titanium atom content is less than 10 ppm, good polymerization activity cannot be obtained, and a thermoplastic polyester resin having a sufficiently high intrinsic viscosity may not be obtained. The thermoplastic polyester resin of the present invention comprises a dicarboxylic acid and/or an ester-forming derivative thereof, and a dicarboxylic acid component and a glycol component in the presence of a polymerization catalyst for esterification or transesterification, followed by polymerization. The temperature at the end of the esterification or transesterification reaction is preferably in the range of 180° C. or higher and 230° C. or lower, more preferably 180° C. or higher and 220° C. or lower. is more preferable. When the temperature at the end of the esterification reaction or the transesterification reaction exceeds 230°C, the reaction rate increases, but it is not preferred because by-products such as tetrahydrofuran may increase. Also, if the temperature is less than 180°C, the reaction may not proceed. The reaction product (bisglycol ether and/or its low polymer) obtained by the esterification or transesterification reaction is 0.4 kPa (3 Torr) at a temperature above the melting point of the thermoplastic polyester resin and 290 ° C. or below. Polycondensation is preferably carried out under the following reduced pressure. If the polycondensation reaction temperature exceeds 290° C., the reaction rate may rather decrease and coloration may increase, which is not preferred.

The thermoplastic polyester resin may be used alone or in combination of two or more, and can be arbitrarily selected depending on the purpose. When two or more types are used, the feeding method is not particularly limited. A method of supplying independently is mentioned. By using a thermoplastic polyester resin, it is possible to improve the wear resistance, mechanical strength and toughness of the molded article, and the feedability to a molding machine during injection molding of pellets of the resin composition. Representative thermoplastic polyester resins include, for example, polybutylene naphthalate, polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, and copolymers thereof. Examples of copolymer components include the above-described dicarboxylic acid component and glycol component. Polybutylene naphthalate resins, copolymers of polybutylene naphthalate resins, and mixtures of polybutylene naphthalate resins with other thermoplastic polyester resins are particularly preferred, and polybutylene naphthalate resins are more preferred. . By using these preferred thermoplastic polyester resins, the abrasion resistance of the molded article may be further improved.

<About B component>
As the modified polyethylene resin which is the B component of the present invention, those known per se can be used. By using the modified polyethylene resin, the wear resistance and mechanical strength of the molded article can be improved. Examples of polyethylene used as a starting material for producing a modified polyethylene resin include high-density polyethylene, low-density polyethylene, ultra-high molecular weight polyethylene, and polyethylene wax with a viscosity-average molecular weight of tens of thousands or more. and mixtures of one or more of these. As a method for modifying polyethylene, various conventionally known methods can be employed, for example, a method of introducing a functional group by oxidation reaction by introducing air into the polyethylene in a molten state of 140 to 180 ° C., and a method of introducing a functional group by an oxidation reaction. Suspending or dissolving in a solvent, usually at a temperature of 80 to 200 ° C., adding and mixing a modifying monomer and a radical polymerization initiator etc. for graft copolymerization, or melting point or higher, for example, 180 A method of contacting a modifying monomer and a radical polymerization initiator under melt-kneading at a temperature of up to 300° C. may be mentioned. Examples of modifying monomers include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, nadic acid (endocis-bicyclo[2,2]hept-5-ene-2,3 -dicarboxylic acid) and the like, and its derivatives include acid halides, esters, amides, imides, anhydrides and the like, for example, malenyl chloride, maleimide, acrylic acid amide, methacrylic acid amide, glycidyl methacrylate, anhydrous Maleic acid, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like. Among these, modified polyethylene resins modified with maleic acid, maleic anhydride or a mixture thereof are preferred, and modified polyethylene resins modified with maleic anhydride are particularly preferred. By using these preferred modified polyethylene resins, it may be possible to further improve the mechanical strength and wear resistance of the molded article.

The preferred range of the viscosity average molecular weight (Mv) of component B is 100,000 to 1,000,000, more preferably 200,000 to 900,000, and particularly preferably 300,000 to 800,000. be. By using the modified polyethylene resin within this range, it may be possible to further improve the mechanical strength and wear resistance of the molded product. The viscosity-average molecular weight of component B is obtained from the following formula (1) using the intrinsic viscosity [η] measured in a decalinic acid solvent at 135°C.
Mv=5.37×10 ⁴ [η] ^1.37 (1)

The content of component B is 4 to 25 parts by weight, preferably 7 to 22 parts by weight, and more preferably 10 to 20 parts by weight, per 100 parts by weight of component A. If the content is less than 4 parts by weight, the amount of wear during sliding increases and the mechanical strength decreases. If it exceeds 25 parts by weight, the dispersibility of component B in the resin composition becomes insufficient, and a uniform molded article cannot be obtained.

<About C component>
As the wholly aromatic polyamide fiber used as the C component of the present invention, any fiber may be used as long as it belongs to the category called wholly aromatic aramid fiber. By using a wholly aromatic polyamide fiber, it is possible to ensure both the mechanical strength and toughness required for the sliding member, and to exhibit excellent low abrasion resistance. Examples of wholly aromatic aramid fibers include meta-aramid fibers and para-aramid fibers, among which para-aramid fibers are preferred.

The wholly aromatic polyamide constituting the fiber of the present invention is substantially obtained by combining one or more aromatic diamines and one or more aromatic dicarboxylic acid halides. However, to one or more aromatic diamines and one or more aromatic dicarboxylic acids, it is also possible to add a condensing agent represented by, for example, the system of triphenylphosphite and pyridine. The wholly aromatic polyamide may be para-type or meta-type, but para-type is more preferable. Preferred aromatic diamines include p-phenylenediamine, benzidine, 4,4″-diamino-p-terphenyl, 2,7-diaminofluorene, 3,4-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 1, 4-bis-(4-aminophenoxy)benzene, 4,4'-bis-(4-aminophenoxy)biphenyl, 9,10-bis-(4-aminophenyl)anthracene, etc. Aromatic dicarboxylic acid halides As, acid chlorides are particularly preferred, and terephthalic acid chloride, 2,6-naphthalenedicarboxylic acid chloride, 4,4'-diphenyldicarboxylic acid chloride, and one or more lower alkyl groups, lower alkoxy groups, halogeno and those containing non-reactive functional groups such as groups, nitro groups, and the like.

Furthermore, when using an aromatic dicarboxylic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, and one or more lower alkyl groups, lower alkoxy groups, halogeno and those containing non-reactive functional groups such as groups, nitro groups, and the like. Furthermore, the structure of the wholly aromatic polyamide preferred in the present invention is one whose main skeleton is represented by the following formula.

(However, Ar ₁ and Ar ₂ represent at least one aromatic residue selected from the group consisting of the following general formulas [I] to [IV]. Note that Ar ₁ and Ar ₂ are the same or different In addition, some of the hydrogen atoms in these aromatic residues may be substituted with halogen atoms or lower alkyl groups.)

Among them, the total of general formula [I] and general formula [II], the total of general formula [I] and general formula [III], when the total of Ar ₁ and Ar ₂ is 100 mol%, The total of general formula [I] and general formula [IV], or the general formula [I] is preferably 80 mol % or more. More preferably, the total of general formula [I] and general formula [II] or the total of general formula [I] and general formula [III] is 80 mol% or more. More preferably, the total of general formula [I] and general formula [II] or the total of general formula [I] and general formula [III] is 80 mol% or more, and general formula [II] or general formula [III] is 1 to 20 mol %.

The aromatic polyamide dope, which is the spinning stock solution, may be obtained by solution polymerization or by dissolving a separately obtained wholly aromatic polyamide in a solvent, but it is preferably obtained by solution polymerization reaction. In order to improve solubility, a small amount of inorganic salt may be added as a dissolution aid. Examples of such inorganic salts include lithium chloride and calcium chloride.

As a polymerization solvent or re-dissolving solvent, generally known aprotic organic polar solvents are used. , N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropionamide, N,N-butyramide, N,N-dimethylisobutyramide, N-methylcaprolactam, N,N-dimethylmethoxyacetamide, N- Acetylpyrrolidine, N-acetylpiperidine, N-methylpiperidone-2,N,N'-dimethylethyleneurea, N,N'-dimethylpropyleneurea, N,N,N',N'-tetramethylmalonamide, N-acetyl Pyrrolidone, N,N,N',N'-tetramethylurea, dimethylsulfoxide, etc., and the re-dissolving solvent includes strong acids such as concentrated sulfuric acid and methanesulfonic acid.

Although the degree of polymerization of the wholly aromatic polyamide is not particularly limited, a higher degree of polymerization is preferable as long as it is soluble in a solvent. When the wholly aromatic polyamide is solution polymerized, the acid component and the diamine component are reacted at a substantially equimolar ratio, but either component can be used in excess for controlling the degree of polymerization. Moreover, you may use a monofunctional acid component and an amine component as a terminal blocking agent.

When a wholly aromatic polyamide is molded into a fibrous form, a method of wet molding a wholly aromatic polyamide dope is usually used. There is a way to eject inside. A poor solvent for the wholly aromatic polyamide is used in the coagulation bath, but in order to prevent the solvent from the wholly aromatic polyamide dope from escaping rapidly and causing defects in the wholly aromatic polyamide fiber, a good solvent is usually added to coagulate. Adjust speed. Generally, it is preferable to use water as the poor solvent and a solvent for the wholly aromatic polyamide dope as the good solvent. The good solvent/poor solvent ratio is preferably 15/85 to 40/60, depending on the solubility and coagulability of the wholly aromatic polyamide.

Such a wholly aromatic polyamide fiber exerts its effect regardless of whether it is bundled or not, but bundled fibers are preferable because they are easy to handle. Binders for bundling include polyester resins, polyurethane resins, polyethersulfone resins, etc. Among them, polyester resins and polyurethane resins are preferred, and polyester resins are more preferred. In the present invention, such wholly aromatic polyamide fibers can be used singly or as a mixture of two or more.

In addition, the wholly aromatic polyamide fiber preferably has a fiber length of 0.5 mm to 4.0 mm, more preferably 0.8 mm to 4.0 mm, and 2.0 mm to 4.0 mm before being added to the A component. is particularly preferred. If the fiber length is less than 0.5 mm, the reinforcing effect may not be sufficient, and the improvement in mechanical strength may be insufficient. may be inferior, resulting in poor moldability. The fiber length can be measured, for example, by taking out an arbitrary single fiber from the fiber bundle, enlarging it with a microscope, measuring the length of 50 fibers, and taking the average value as the fiber length.

The form of the wholly aromatic polyamide fiber is not particularly limited, and any form can be used, but it is preferable that the fiber is twisted from the viewpoint of handleability during production of the resin composition. By using a fiber bundle with a large twist number, the supply of the wholly aromatic polyamide fiber to the extruder may be stabilized. The twist number of the wholly aromatic polyamide fiber is preferably 10 to 500 twists/m, more preferably 50 to 450 twists/m, and still more preferably 100 to 400 twists/m.

The content of component C is 10 to 35 parts by weight, preferably 13 to 32 parts by weight, more preferably 15 to 30 parts by weight, and particularly preferably 18 to 27 parts by weight with respect to 100 parts by weight of component A. . If the content of the C component exceeds 35 parts by weight, handling during production becomes difficult, and feedability to a molding machine during injection molding of pellets of the resin composition is impaired, making continuous molding difficult. On the other hand, if the content is less than 10 parts by weight, the amount of wear during sliding increases and the mechanical strength also decreases.

<About D component>
The resin composition of the present invention contains an epoxy resin represented by the following formula (1) as component D.

(In Formula (1), m is an average value and is an integer of 1 or more. R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a trifluoromethyl group. Each X independently represents a hydrogen atom or a glycidyl group, and at least one of the multiple Xs is a glycidyl group.)

Although the upper limit of m in the above formula is not particularly limited, it is preferably 300 or less. 200 or less is more preferable. When an epoxy resin other than the epoxy resins described above is used, the feedability of pellets of the resin composition to a molding machine during injection molding is impaired, and molding pressure increases during injection molding, making molding difficult.

Specific examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin and the like, and bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferable. By using these epoxy resins, it may be possible to efficiently improve wear resistance and mechanical strength and to ensure feedability to a molding machine during injection molding of pellets of the resin composition. Component D can be used alone or in combination of two or more compounds. The above epoxy resins are commercially available as jER1001, jER1007, jER1010, jER1256, jER4004P, jER4010P from Mitsubishi Chemical Co., Ltd., YD-011, YD-013, YD-014, etc. from Nippon Steel & Sumikin Chemical Co., Ltd., and are readily available. is.

The epoxy equivalent of component D is preferably 1,000 to 10,000 g/eq, more preferably 2,000 to 9,500 g/eq, and more preferably 5,000 to 9,000 g/eq. More preferred. If the epoxy equivalent is less than 1,000 g/eq, thickening tends to occur during kneading and extrusion, and the molding pressure during injection molding increases, resulting in poor moldability. Sufficient low wear and mechanical strength may not be obtained. In addition, the epoxy equivalent of D component is measured according to JISK7236.

The content of component D is 0.5 to 8 parts by weight, preferably 1 to 6 parts by weight, more preferably 1 to 5 parts by weight, and particularly preferably 2 to 5 parts by weight, per 100 parts by weight of component A. is. When the content of component D exceeds 8 parts by weight, the molding pressure during injection molding becomes high, making molding difficult. On the other hand, if the content is less than 0.5 parts by weight, the amount of wear during sliding increases, and the feedability of resin composition pellets to a molding machine during injection molding is impaired, making continuous molding difficult. Become.

The resin composition of the present invention may be blended with other thermoplastic resins within the scope of the present invention, and, if necessary, antioxidants, impact modifiers, plasticizers, and organic compounds other than the C component. , inorganic fillers, flame retardants, colorants, light stabilizers, heat stabilizers, antistatic agents, antiblocking agents, lubricants other than component B, dispersants, flow modifiers, crystal nucleating agents, etc. can contain

<Method for producing resin composition>
Any method may be employed to produce the resin composition of the present invention. For example, a method of premixing each component and optionally other components, followed by melt-kneading and pelletizing can be mentioned. Means for premixing include a Nauta mixer, a V-type blender, a Henschel mixer, a mechanochemical device, an extrusion mixer, and the like. In the pre-mixing, granulation can be performed by an extrusion granulator, a briquetting machine, or the like. After pre-mixing, the mixture is melt-kneaded by a melt-kneader typified by a vented twin-screw extruder, and pelletized by a device such as a pelletizer. Other examples of the melt-kneader include a Banbury mixer, a kneading roll, a constant temperature stirring vessel and the like, but a vented twin-screw extruder is preferred. Alternatively, each component and, optionally, other components may be supplied independently to a melt-kneader typified by a twin-screw extruder without being premixed.

<About the compact>
A molded article using the resin composition of the present invention can be obtained by molding the pellets produced as described above. It is preferably obtained by injection molding or extrusion molding. In injection molding, not only ordinary molding methods, but also injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including the method of injecting supercritical fluid), insert molding, in-mold coating molding, heat insulation metal Mold molding, rapid heating and cooling mold molding, two-color molding, multi-color molding, sandwich molding, ultra-high speed injection molding and the like can be mentioned. For molding, either cold runner method or hot runner method can be selected. In extrusion molding, a molded body can be obtained by extruding a round bar and then cutting it into a disk shape, or by extruding a thick sheet and then punching it into a predetermined shape. can.

[EXAMPLES] Hereafter, although the form which implements this invention is demonstrated by an Example, this invention is not limited to these. Moreover, evaluation of various physical properties was carried out by the following methods.
[Evaluation of Resin Composition]
Specific wear amount was measured as evaluation of low wear property, tensile strength at break was measured as evaluation of mechanical strength, and tensile elongation at break was measured as evaluation of toughness by the following methods.

(1) Specific wear amount After drying the pellets obtained by the following method at 120 ° C. for 7 hours, using an injection molding machine (EC130SXII-4Y manufactured by Toshiba Machine Co., Ltd.) at a cylinder temperature of 280 ° C. and a mold temperature of 120 ° C. A hollow cylindrical test piece having an outer diameter of 25.6 mm, an inner diameter of 20 mm and a height of 15 mm was obtained according to the JIS K7218A method. According to the JIS K7218A method, the test piece was subjected to a friction and wear tester (EFM) under the conditions of a test piece of the same shape made of carbon steel (S45C) and a surface pressure of 0.75 MPa, a sliding speed of 500 mm / s, and a sliding distance of 3000 m. -3-G, manufactured by Orientec Co., Ltd.). The weight loss of the test piece after sliding was weighed to the nearest 0.1 mg using an electronic balance, and the specific wear amount was calculated using the formula described in JIS K7218A method. The test was conducted three times, and the average value thereof was taken as the specific wear amount of the composition. The specific wear amount must be 2.0×10 ⁻⁶ mm ³ /N·m or less.

(2) Tensile strength at break Tensile strength at break was measured by a method based on ISO527. It is necessary that the tensile strength at break is 85 MPa or more.

(3) Tensile elongation at break Tensile elongation at break was measured by a method based on ISO527. It is necessary that the tensile elongation at break is 5% or more.

(4) Pellet feedability When a test piece for conducting the tensile test described in (2) and (3) was molded using an injection molding machine EC130SXII-4Y manufactured by Toshiba Machine Co., Ltd., 10 pieces of the test piece were continuously formed. "○" indicates that the pellets in the hopper are fed into the molding machine during molding, and continuous molding is possible. It was set as "x".

[Example 1-12, Comparative Example 1-10]
According to the addition amount shown in Table 1, A component, B component, D component and other components were separately supplied to the twin-screw extruder from the first supply port. Here, the first supply port is the root supply port. Component C was supplied separately from the second supply port using a side feeder. Extrusion is performed using a vented twin-screw extruder with a diameter of 30 mmΦ (manufactured by Japan Steel Works, Ltd.: TEX30α-31.5BW-2V), screw rotation speed of 200 rpm, discharge rate of 20 kg / h, vent vacuum degree of 3 kPa. It was melted and kneaded to obtain pellets. The extrusion temperature was 290°C.

(A component)
AI: Polybutylene naphthalate resin obtained in Production Example I <Production Example I>
315.0 parts of 2,6-naphthalene dicarboxylic acid dimethyl ester, 200 parts of 1.4-butanediol, and 0.062 parts of tetra-n-butyl titanate were placed in a transesterification reactor, and the temperature of the transesterification reactor was 210°C. The transesterification reaction was carried out for 150 minutes while raising the temperature to . Then, the obtained reaction product was transferred to a polycondensation reactor to initiate the polycondensation reaction. In the polycondensation reaction, the pressure in the polycondensation reaction layer is gradually reduced from normal pressure to 0.13 kPa (1 torr) or less over 40 minutes, and at the same time the temperature is raised to a predetermined reaction temperature of 260°C. C. and a pressure of 0.13 kPa (1 torr), the polycondensation reaction was carried out for 140 minutes. When 140 minutes had passed, the polycondensation reaction was terminated, and the polybutylene naphthalate resin was extracted in the form of strands, which were cut into chips using a cutter while cooling with water. Next, the obtained polybutylene naphthalate resin was solid-phase polymerized for 8 hours at a temperature of 213° C. and a pressure of 0.13 kPa (1 Torr) or less to obtain a polybutylene naphthalate resin.

A-II: Polyphenylene sulfide resin obtained in Production Example II <Production Example II>
A reactant containing 400 g of para-diiodobenzene, 34 g of sulfur and 1.0 g of 1,3-diiodo-4-nitrobenzene was melt mixed at 180°C. The mixed mixture was polymerized while the temperature was raised from 180° C. to 340° C. and the pressure was reduced from normal pressure to 10 torr. After 4 hours from the start of the polymerization, 0.5 g of sulfur was added, and after 5 hours of polymerization reaction, 0.5 g of sulfur was additionally added, and the polymerization reaction was performed for 1 hour. I got the molecule. The resulting polymer had a number average molecular weight (Mn) of 7,630 and a polydispersity (Mw/Mn) of 4.7. Also, the total chlorine content was 20 ppm or less (below the detection limit), and the total sodium content was 7 ppm.

(B component)
BI: Maleic anhydride-modified polyethylene resin obtained in Production Example III <Production Example III>
15% by weight of ultra-high molecular weight polyethylene (Hi-Zex Million 630M manufactured by Mitsui Chemicals, Inc.) with an intrinsic viscosity of 31 dl/g measured in a decalic acid solvent at 135°C and a limit measured in a decalic acid solvent at 135°C 100 parts by weight of a polyethylene resin mixture consisting of 85% by weight of polyethylene (Hi-Zex 2200J, manufactured by Prime Polymer Co., Ltd.) having a viscosity of 2 dl/g, 1 part by weight of maleic anhydride and an organic peroxide (perhexin manufactured by NOF Corporation) 25B) 0.07 part by weight was mixed with a Nauta mixer, and the resulting mixture was melt-kneaded with a single-screw extruder (EXT 40 m / m extruder manufactured by Isuzu Kakoki Co., Ltd.) set at 250 ° C. B- Component I was obtained. The resulting modified polyethylene resin had an intrinsic viscosity [η] measured in decalinic acid at 135°C of 5.5 dl/g and a viscosity average molecular weight Mv of 550,000.
B-II: Oxidized polyethylene wax: Hi-Wax 310MP (product name) (manufactured by Mitsui Chemicals, Inc., viscosity average molecular weight of about 3,000)
B-III (comparative example): Polytetrafluoroethylene: KT-600M (product name) (manufactured by Kitamura Co., Ltd., melting point 325 to 335 ° C., 50% particle size 14 μm)

(C component)
CI: Wholly aromatic polyamide fiber: T322EH (product name) (manufactured by Teijin Limited, para-aramid fiber, major diameter 12 μm, average fiber length 3 mm, polyester resin sizing agent, twist number 245 times / m)
C-II: Wholly aromatic polyamide fiber: T322UR (product name) (manufactured by Teijin Limited, para-aramid fiber, long diameter 12 μm, average fiber length 3 mm, polyurethane resin sizing agent, twist number 60 times / m)
C-III: Wholly aromatic polyamide fiber: T322EH (product name) (manufactured by Teijin Limited, para-aramid fiber, major diameter 12 μm, average fiber length 1 mm, polyester resin sizing agent, twist number 60 times / m)
C-IV (comparative example): Carbon fiber: PAN-based carbon fiber HT P722 (trade name) (manufactured by Teijin Limited, fiber length 3 mm, major diameter 7 μm, polyimide sizing agent)

(D component)
DI: Bisphenol A type epoxy resin: jER1256 (product name) (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 7,500 to 8,500 g/eq)
D-II: Bisphenol A type epoxy resin: jER1010 (product name) (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 3,000 to 5,000 g/eq)
D-III (Comparative Example): Trisphenolmethane type epoxy resin: EPPN-501H (product name) (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 162 to 172 g / eq)

(Other ingredients)
EI: Talc: Upn HS-T0.8 (product name) (manufactured by Hayashi Kasei Co., Ltd., average particle size 5 μm)
E-II: Polycarbonate resin: carbon black = 60% by weight: Resin composition blended at a ratio of 40% by weight

<Examples 1 to 12>
Since the resin composition falls within the scope of the present claims, it exhibits excellent mechanical strength, toughness, and low abrasion resistance, and is excellent in feedability to a molding machine during injection molding of pellets of the resin composition. rice field.

<Comparative Example 1>
Since the content of the B component was less than the lower limit, the specific wear amount was large and the tensile strength at break was low.

<Comparative Example 2>
Since the content of the B component exceeded the upper limit, the components in the resin composition were separated, and a uniform molded article could not be obtained.

<Comparative Example 3>
Since the content of the C component was less than the lower limit, the specific wear amount was large and the tensile strength at break was low.

<Comparative Example 4>
Since the content of the C component exceeded the upper limit, the feedability of pellets was poor, and continuous molding was difficult.

<Comparative Example 5>
Since the content of component D exceeded the upper limit, the molding pressure during injection molding was increased, and a test piece having a predetermined shape could not be obtained.

<Comparative Example 6>
Since the content of component D was less than the lower limit, the specific wear amount was large, the feedability of pellets was poor, and continuous molding was difficult.

<Comparative Example 7>
Since the D component was different from the epoxy resin represented by the formula (1), the molding pressure during injection molding was increased, and a test piece having a predetermined shape could not be obtained.

<Comparative Example 8>
Since the B component was not a modified polyethylene resin, the specific wear amount was large and the tensile strength at break was low.

<Comparative Example 9>
Since the C component was not a wholly aromatic polyamide fiber, the specific abrasion amount was large and the tensile elongation at break was low.

<Comparative Example 10>
Since the A component was not a thermoplastic polyester resin, the tensile strength at break and the tensile elongation at break were low, the feedability of pellets was poor, and continuous molding was difficult.

Claims (8)

(A) Thermoplastic polyester resin (component A) 100 parts by weight, (B) modified polyethylene resin (component B) 4 to 25 parts by weight, (C) wholly aromatic polyamide fiber (component C) 10 to 35 parts Parts by weight and (D) a resin composition containing 0.5 to 8 parts by weight of an epoxy resin (component D) represented by the following general formula (1).

(In Formula (1), m is an average value and is an integer of 1 or more. R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a trifluoromethyl group. Each X independently represents a hydrogen atom or a glycidyl group, and at least one of the multiple Xs is a glycidyl group.) Component B is a modified polyethylene resin modified with at least one compound selected from the group consisting of maleic acid and maleic anhydride and having a viscosity average molecular weight of 100,000 to 1,000,000. The described resin composition. 3. The resin composition according to claim 1, wherein component D is a bisphenol A type epoxy resin or a bisphenol F type epoxy resin having an epoxy equivalent of 1,000 to 10,000 g/eq. The resin composition according to any one of claims 1 to 3, wherein component A is a polybutylene naphthalate resin. The resin composition according to any one of claims 1 to 4, wherein the C component is a wholly aromatic polyamide fiber bundled with at least one sizing agent selected from the group consisting of polyester resins and polyurethane resins. The resin composition according to any one of claims 1 to 5, wherein the C component is a wholly aromatic polyamide fiber having an average fiber length of 0.5 to 4.0 mm before being added to the A component. The resin composition according to any one of claims 1 to 6, wherein the C component is a para-type wholly aromatic polyamide fiber. A molded article made of the resin composition according to any one of claims 1 to 7.