JP2022186617A - Semi-aromatic polyamide resin composition and sliding component obtained by molding the same - Google Patents

Abstract

To provide a semi-aromatic polyamide resin composition particularly excellent in slidability in addition to heat resistance and mechanical characteristics.SOLUTION: The semi-aromatic polyamide resin composition contains: 87-99 pts.mass of a semi-aromatic polyamide resin (A) which comprises an aromatic dicarboxylic acid component mainly composed of terephthalic acid and an aliphatic diamine component; 1-10 pts.mass of an aliphatic polyamide resin (B); and 40-100 pts.mass of a fibrous reinforcing material (C) based on 100 pts.mass of the total of (A) and (B). The semi-aromatic polyamide resin composition has a melt flow rate of 15 g/10 min or less as measured at the melting point of (A) plus 25°C under a load of 1.2 kgf according to JIS K 7210.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a semi-aromatic polyamide resin composition which is particularly excellent in slidability in addition to heat resistance and mechanical properties.

Polyamide resins are used as sliding parts such as gears, bearings, and cam bearings because of their excellent heat resistance, mechanical properties, and slidability.

For example, Patent Document 1 discloses a semi-aromatic polyamide resin composition containing nylon 10T (polyamide resin composed of terephthalic acid and 1,10-decanediamine) and a sliding improver such as fluororesin. Further, in Patent Document 2, polyamide 9T (polyamide composed of terephthalic acid, 2-methyl-1,8-octanediamine and 1,9-nonanediamine) contains various fillers such as fluororesins and polyolefins. A sliding component made of a polyamide resin composition is disclosed.

JP 2013-064420 A JP-A-2002-363404

In recent years, more advanced slidability has been required for sliding parts used in the field of electrical and electronic equipment and in the engine room of automobiles. However, the semi-aromatic polyamide resin compositions of Patent Documents 1 and 2 do not have high slidability, and their applications are limited.

The present inventors have made intensive studies to solve the above problems, and as a result, added a specific amount of an aliphatic polyamide resin to a semi-aromatic polyamide resin to have a specific melt flow rate. We have found that the object has been achieved, and arrived at the present invention.

An object of the present invention is to provide a semi-aromatic polyamide resin composition which is particularly excellent in slidability in addition to heat resistance and mechanical properties.

That is, the gist of the present invention is as follows.
(1) 87 to 99 parts by mass of a semi-aromatic polyamide resin (A) composed of an aromatic dicarboxylic acid component and an aliphatic diamine component containing terephthalic acid as a main component, and 1 to 10 parts by mass of an aliphatic polyamide resin (B) and a fibrous reinforcing material (C) containing 40 to 100 parts by mass with respect to a total of 100 parts by mass of (A) and (B),
A semi-aromatic polyamide resin composition having a melt flow rate of 20 g/10 minutes or less when measured under a load of 1.2 kgf according to JIS K 7210 (melting point of (A) +25°C).
(2) The semi-aromatic polyamide resin composition according to Claim 1, wherein the fibrous reinforcing material (C) is glass fiber.
(3) The semi-aromatic polyamide resin composition according to (1) or (2), wherein the aliphatic diamine component of the semi-aromatic polyamide resin (A) is 1,10-decanediamine.
(4) According to JIS K7218 A method, the specific wear amount is 20 mm ³ /(kN km) or less when a wear test is performed under the conditions of S45C steel as the mating material, a load of 0.75 MPa, and a sliding distance of 3 km. The semi-aromatic polyamide resin composition according to any one of (1) to (3).
(5) A molded article obtained by molding the semi-aromatic polyamide resin composition according to any one of (1) to (4).
(6) The molded article according to (5), which is a sliding component.

According to the present invention, it is possible to provide a semi-aromatic polyamide resin composition which is particularly excellent in slidability in addition to heat resistance and mechanical properties.
Molded articles made of the semi-aromatic polyamide resin composition of the present invention can be suitably used for sliding parts.

The semi-aromatic polyamide resin composition of the present invention contains a semi-aromatic polyamide resin (A), an aliphatic polyamide resin (B) and a fibrous reinforcing material (C).

The semi-aromatic polyamide resin (A) used in the present invention contains an aromatic dicarboxylic acid component containing terephthalic acid as a main component and an aliphatic diamine component. In the present invention, "mainly composed of terephthalic acid" means that the content of terephthalic acid in the aromatic dicarboxylic acid component is 70 mol% or more, preferably 90 mol% or more. Preferably it is 100 mol %.

Examples of aliphatic diamine components include 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and 1,7-heptanediamine. , 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine. Among the above aliphatic diamine components, one of them may be used alone or in combination, but from the viewpoint of heat resistance and mechanical properties, it is preferable to use them alone.

The semi-aromatic polyamide resin (A) may contain a dicarboxylic acid component other than terephthalic acid and a diamine component other than the aliphatic diamine component. Examples of dicarboxylic acid components other than terephthalic acid include aliphatic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. dicarboxylic acids; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and naphthalenedicarboxylic acid. Examples of diamine components other than the aliphatic diamine component include alicyclic diamines such as cyclohexanediamine; aromatic diamines such as xylylenediamine and benzenediamine.

The semi-aromatic polyamide resin (A) may optionally contain lactams such as caprolactam and laurolactam; ω-aminocarboxylic acids such as aminocaproic acid and 11-aminoundecanoic acid.

In the present invention, the semi-aromatic polyamide resin (A) preferably contains a monocarboxylic acid component as a constituent component. The content of the monocarboxylic acid component is preferably 0.3 to 4.0 mol%, more preferably 0.3 to 3.0 mol%, relative to the total monomer components constituting the semiaromatic polyamide (A). is more preferably 0.3 to 2.5 mol %, and particularly preferably 0.8 to 2.5 mol %.

The molecular weight of the monocarboxylic acid is preferably 140 or more, more preferably 170 or more. Examples of monocarboxylic acid components include aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids, among which aliphatic monocarboxylic acids are preferred. Examples of aliphatic monocarboxylic acids having a molecular weight of 140 or more include caprylic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid and derivatives thereof. Among them, stearic acid is preferred because of its high versatility. Alicyclic monocarboxylic acids having a molecular weight of 140 or more include, for example, 4-ethylcyclohexanecarboxylic acid, 4-hexylcyclohexanecarboxylic acid, 4-laurylcyclohexanecarboxylic acid and derivatives thereof. Examples of aromatic monocarboxylic acids having a molecular weight of 140 or more include 4-ethylbenzoic acid, 4-hexylbenzoic acid, 4-laurylbenzoic acid, alkylbenzoic acids, 1-naphthoic acid, 2-naphthoic acid and their derivatives. One of the above monocarboxylic acid components may be used alone or in combination. Moreover, a monocarboxylic acid having a molecular weight of 140 or more and a monocarboxylic acid having a molecular weight of less than 140 may be used together. In addition, in this invention, the molecular weight of monocarboxylic acid refers to the molecular weight of the monocarboxylic acid of a raw material.

In the present invention, the relative viscosity of the semi-aromatic polyamide resin (A) measured in 96% sulfuric acid at 25°C at a concentration of 1 g/dL is 2.3 or more from the viewpoint of mechanical properties and slidability. is preferably 2.5 to 3.5, and even more preferably 2.5 to 3.1. If the relative viscosity of the semi-aromatic polyamide resin (A) is less than 2.3, high slidability may not be obtained. It can be difficult.

The semi-aromatic polyamide resin (A) can be produced using a conventionally known heat polymerization method or solution polymerization method. Among them, the heat polymerization method is preferably used from the viewpoint of being industrially advantageous. Examples of the heat polymerization method include a method comprising a step (I) of obtaining a reactant from a dicarboxylic acid component and a diamine component and a step (II) of polymerizing the obtained reactant.

In the step (I), for example, dicarboxylic acid powder is heated in advance to a temperature equal to or higher than the melting point of diamine and equal to or lower than the melting point of dicarboxylic acid, and the dicarboxylic acid powder at this temperature is maintained in a dicarboxylic acid powder state. A method of adding a diamine without substantially containing water is exemplified. Alternatively, as another method, a suspension consisting of a molten diamine and a solid dicarboxylic acid is stirred and mixed to obtain a mixed liquid, and then a temperature below the melting point of the finally produced semi-aromatic polyamide resin and a method of obtaining a mixture of the salt and the low polymer by carrying out a reaction of a dicarboxylic acid and a diamine to form a salt and a reaction of polymerizing the produced salt to form a low polymer. In this case, the crushing may be performed while reacting, or the crushing may be performed after taking out once after the reaction. As the step (I), the former is preferable because the shape of the reactant can be easily controlled.

In step (II), for example, the reaction product obtained in step (I) is solid-phase polymerized at a temperature below the melting point of the finally produced semiaromatic polyamide resin (A) to increase the molecular weight to a predetermined level. A method of obtaining a semi-aromatic polyamide resin (A) by molecular weighting may be mentioned. Solid state polymerization is preferably carried out at a polymerization temperature of 180 to 270° C. for a reaction time of 0.5 to 10 hours in an inert gas stream such as nitrogen.

There are no particular restrictions on the reactors used in steps (I) and (II), and known reactors may be used. Step (I) and step (II) may be performed in the same apparatus or in different apparatuses.

In the production of the semi-aromatic polyamide resin (A), a polymerization catalyst may be used in order to increase the efficiency of polymerization, or a terminal blocker may be used in order to adjust the degree of polymerization and suppress thermal decomposition and coloration.

Polymerization catalysts include, for example, phosphoric acid, phosphorous acid, hypophosphorous acid, or salts thereof. The amount of the polymerization catalyst to be added is generally preferably 2 mol % or less with respect to the total monomers constituting the semi-aromatic polyamide resin (A).

The content of the semi-aromatic polyamide resin (A) should be 87 to 99 parts by mass with respect to a total of 100 parts by mass of the semi-aromatic polyamide resin (A) and the aliphatic polyamide resin (B). It is preferably 87 to 98 parts by mass, more preferably 90 to 95 parts by mass. If the content is less than 87 parts by mass, or if it exceeds 99 parts by mass, the specific wear amount of the molded article increases, which is not preferable.

In the present invention, it is necessary to contain an aliphatic polyamide resin (B) in order to improve slidability. Aliphatic polyamide resin (B) is a polymer containing no aromatic component in the main chain, such as poly ε-capramide (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide amide (polyamide 66), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecamethylene adipamide (polyamide 116), polyundecanamide (polyamide 11), polydodecanamide ( Polyamide 12) and polyamide copolymers containing at least two different polyamide components of these, or mixtures thereof. Among them, polyamide 6 and polyamide 66 are more preferable from the viewpoint of economy.

The content of the aliphatic polyamide resin (B) should be 1 to 13 parts by mass with respect to the total 100 parts by mass of the semi-aromatic polyamide resin (A) and the aliphatic polyamide resin (B). It is preferably 13 parts by mass, more preferably 5 to 10 parts by mass. If the content is less than 1 part by mass, or if it exceeds 13 parts by mass, the specific wear amount of the molded article increases, which is not preferable. On the other hand, if the content exceeds 13 parts by mass, the heat resistance is lowered, which is not preferable. Furthermore, in recent years, chemical resistance, water absorption resistance, and calcium chloride resistance are sometimes required for parts used in and near the engine room of automobiles. The chemical properties, water absorption resistance, and calcium chloride resistance are lowered, and as a result of the reduction in water absorption resistance, the strength may be lowered and dimensional change due to water absorption may be increased.

The relative viscosity of the aliphatic polyamide resin (B) of the present invention is 1.2 kgf (the melting point of the semi-aromatic polyamide resin (A) + 25 ° C.) according to JIS K 7210 of the semi-aromatic polyamide resin composition obtained. It is not particularly limited as long as the melt flow rate is 20 g/10 minutes or less when measured with a load, and may be appropriately set according to the purpose. When obtaining a semi-aromatic polyamide resin composition that is easy to mold, the relative viscosity of (B) is preferably 1.9 to 4.0, more preferably 2.0 to 3.5. is more preferred. If the relative viscosity of (B) is less than 1.9, depending on the molded product, toughness may be insufficient and mechanical properties may be reduced. On the other hand, if the relative viscosity of (B) exceeds 4.0, molding may become difficult and the appearance may deteriorate.

The fibrous reinforcing material (C) used in the present invention is not particularly limited, but examples include glass fiber, carbon fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, wholly aromatic polyamide fiber, and polybenz. Oxazole fiber, polytetrafluoroethylene fiber, kenaf fiber, bamboo fiber, hemp fiber, bagasse fiber, high-strength polyethylene fiber, alumina fiber, silicon carbide fiber, potassium titanate fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber, basalt fiber, wollastonite. Among them, glass fiber and carbon fiber are preferable because they have a large effect of improving slidability and are easily available.

When glass fibers or carbon fibers are used, it is preferable that they are surface-treated with a silane coupling agent for the purpose of improving the dispersibility of the fibers in the thermoplastic resin. A silane coupling agent may be used in combination with a sizing agent. Silane coupling agents include, for example, vinylsilane-based, acrylsilane-based, epoxysilane-based, and aminosilane-based agents. Among them, when a polyamide resin is used as the thermoplastic resin (A), an aminosilane-based coupling agent is preferable because it has a high adhesion effect between the polyamide and glass fibers or carbon fibers.

The fiber length of the fibrous reinforcing material (C) is preferably 0.1 to 7 mm, more preferably 0.2 to 6 mm. If the fiber length of (C) is less than 0.1 mm, the reinforcing effect may be poor. On the other hand, if the fiber length of (C) exceeds 7 mm, the fiber length of (C) may adversely affect moldability. The fiber diameter of the fibrous reinforcing material (C) is preferably 3-20 μm, more preferably 5-13 μm. If the fiber diameter of (C) is less than 3 μm, it may easily break during melt-kneading. On the other hand, if the fiber diameter of (C) exceeds 20 μm, the reinforcing effect may be inferior. The cross-sectional shape may be circular, rectangular, elliptical, or other modified cross-sections, but circular is preferable from an economical point of view.

Antioxidants, heat stabilizers and other additives may be further added to the resin composition used in the present invention.

Examples of antioxidants include hindered phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. One of the above antioxidants may be used alone or in combination. The content of the antioxidant is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 1.0 parts by mass, per 100 parts by mass of the semi-aromatic polyamide (A).

Examples of heat stabilizers include cuprous, cupric bromide, cuprous iodide, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper sulfate, Copper phosphate, copper borate, copper nitrate, copper stearate, and a copper complex salt coordinated with a chelating agent can be mentioned. Among them, copper compounds are preferred, copper halides are more preferred, and cuprous iodide is even more preferred. A heat stabilizer may be used alone or in combination. When a copper compound is used, its content is preferably 0.01 to 3 parts by mass, and 0.02 to 0.5 parts by mass with respect to 100 parts by mass of the semi-aromatic polyamide resin (A). is more preferable.

The semi-aromatic polyamide resin composition of the present invention has a melt flow rate of 20 g/10 minutes when measured under a load of 1.2 kgf according to JIS K 7210 (melting point of the semi-aromatic polyamide resin (A) + 25 ° C.). 15 g/10 minutes or less is preferable, and 0.1 to 15 g/10 minutes or less is more preferable. If the melt flow rate exceeds 20 g/10 minutes, high slidability cannot be obtained, which is not preferable.

The semi-aromatic polyamide resin composition of the present invention was subjected to a wear test according to JIS K7218 A method, with S45C steel as the mating material, a load of 0.75 MPa, and a sliding distance of ³ km. /(kN·km) or less, more preferably 15 mm ³ /(kN·km) or less, and even more preferably 12 mm ³ /(kN·km) or less.

In the present invention, the semi-aromatic polyamide resin (A), the aliphatic polyamide resin (B), the fibrous reinforcing material (C), and optionally other additives are blended to form the semi-aromatic polyamide resin of the present invention. A method for producing a polyamide resin composition is not particularly limited, but a melt-kneading method is preferred. Examples of the melt-kneading method include a method using a batch kneader such as Brabender, a Banbury mixer, a Henschel mixer, a helical rotor, a roll, a single screw extruder, a twin screw extruder, and the like. The melt-kneading temperature is selected from a range in which the semi-aromatic polyamide resin (A) melts and does not decompose, and is usually (Tm-20°C) to (Tm+50°C), where Tm is the melting point of the semi-aromatic polyamide resin (A). is.

Methods for processing the semi-aromatic polyamide resin composition of the present invention include a method of extruding the molten mixture into strands to form pellets, a method of hot-cutting or underwater cutting the molten mixture to form pellets, and a method of extruding into sheets. Examples include a method of cutting, and a method of extruding into blocks and pulverizing them into a powder shape.

Examples of the method for molding the semi-aromatic polyamide resin composition of the present invention include injection molding, extrusion molding, blow molding, and sinter molding, and the effect of improving mechanical properties and moldability is large. Therefore, the injection molding method is preferred. Although the injection molding machine is not particularly limited, examples thereof include a screw in-line injection molding machine and a plunger injection molding machine. The semi-aromatic polyamide resin composition heated and melted in the cylinder of the injection molding machine is weighed for each shot, injected in a molten state into the mold, cooled and solidified in a predetermined shape, and then formed into a molded product. removed from the mold. The resin temperature during injection molding is preferably Tm or higher, more preferably lower than (Tm+50° C.), where Tm is the melting point of the semi-aromatic polyamide resin (A). When the semi-aromatic polyamide resin composition is heated and melted, it is preferable to use sufficiently dried pellets of the semi-aromatic polyamide resin composition. If the water content is large, the resin may foam in the cylinder of the injection molding machine, making it difficult to obtain an optimum molded product. The moisture content of the semi-aromatic polyamide resin composition pellets used in the injection molding method is preferably less than 0.3 parts by mass and less than 0.1 parts by mass with respect to 100 parts by mass of the semi-aromatic polyamide resin composition. is more preferable.

Molded articles obtained by molding the semi-aromatic polyamide resin composition of the present invention have particularly excellent slidability in addition to heat resistance and mechanical properties. , continuously variable transmissions (CVT), bearings for power equipment used in electrical and electronic equipment, various gears, cams, bearings, end face materials for mechanical seals, valve seats, V-rings, rod packing, piston rings, It can be suitably used as rotating shafts/sleeves of compressors, pistons, impellers, vanes, rotors, oil seals, fasteners, various switches, various buttons, bobbins, bushes, plastic chains, and the like.

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

1. Measurement Method Physical properties of the semi-aromatic polyamide resin and the semi-aromatic polyamide resin composition were measured by the following methods.
(1) Melting point 10 mg of sufficiently dried semi-aromatic polyamide (A) pellets were measured using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer under the following conditions in a nitrogen atmosphere.
Temperature was raised to 350°C at a temperature increase rate of 20°C/min (1st scan) → maintained at 350°C for 5 minutes → temperature decreased to 25°C at a temperature decrease rate of 20°C/min → maintained at 25°C for 5 minutes → temperature increase rate of 20°C again. / min (2nd scan)
The top of the endothermic peak on the 2nd scan was taken as the melting point (Tm).
The higher the melting point, the better the heat resistance.
The melting point is preferably 300° C. or higher, more preferably 310° C. or higher.

(2) Relative Viscosity Sufficiently dried semi-aromatic polyamide resin pellets were dissolved in 96% by mass sulfuric acid to prepare a resin component concentration of 1 g/dL. The relative viscosity was measured using an Ubbelohde viscometer at 25°C.
When measuring a resin composition containing a fibrous reinforcing material component other than a resin, the fibrous reinforcing material was filtered out with a G-3 glass filter in advance, and then measured.

(3) Mechanical properties Using an injection molding machine S2000i-100B type (manufactured by Fanuc), a sufficiently dried pellet of the resin composition is used, and the melting point of the semi-aromatic polyamide resin used is Tm, and the cylinder temperature (Tm + 25 ° C.) and mold temperature (Tm-185° C.) to prepare a test piece (dumbbell piece). Using the obtained test piece, bending strength and bending elastic modulus were measured according to ISO178.
The higher the bending strength and bending elastic modulus, the better the mechanical properties.
The bending strength is preferably 150 MPa or more, more preferably 200 MPa or more.
The bending elastic modulus is preferably 4.0 GPa or more, more preferably 10.0 GPa or more.

(4) Melt flow rate (MFR)
A semi-aromatic polyamide resin composition was used, and the melting point of the semi-aromatic polyamide resin used was Tm (Tm+25° C.), and a load of 1.2 kgf was applied according to JIS K 7210.

(5) Specific wear amount Injection molding was performed in the same manner as in (3) to prepare a molded piece of 40 mm x 40 mm x 3 mm. Using the obtained molded piece, according to the JIS K7218 A method, a Suzuki type friction and wear tester (EFM-III-E manufactured by Toyo Baldwin Co., Ltd.) was used to test S45C steel as the mating material, a load of 0.75 MPa, and a speed of 0.75 MPa. A wear test was conducted under conditions of 5 m/s and a sliding distance of 3 km. The specific wear amount was obtained from the difference between the mass of the molded piece before the wear test and the mass after the wear test.
The smaller the specific wear amount, the better the slidability.

(6) Calcium chloride resistance (chemical resistance)
The test piece obtained in (3) was allowed to absorb water in a thermo-hygrostat at 60° C. and 90% RH until equilibrium was reached. After that, 1) gauze impregnated with a saturated calcium chloride aqueous solution is wrapped around the test piece, 2) a load of cantilever bending stress of 30 MPa is applied and left for 1 hour, 3) the gauze is removed and exposed to an oven at 100 ° C. for 1 hour. 4) cooled at room temperature for 1 hour, 5) exposed to water again for 1 hour in a constant temperature and humidity chamber at 60° C. and 90% RH, and 6) visually checked for cracks. These cycles 1) to 6) were repeated until cracks were observed on the surface of the test piece (up to 40 cycles), and the number of cycles at which cracks began to be observed was evaluated.
As for the calcium chloride resistance, the greater the number of cycles, the better the calcium chloride resistance. Calcium chloride resistance can also be used as an indicator of chemical resistance and water absorption resistance.
Calcium chloride resistance is preferably 30 cycles or more, more preferably over 40 cycles.

2. Raw Materials Raw materials used in Examples and Comparative Examples are shown below.
(1) Dicarboxylic acid component, terephthalic acid (2) Aliphatic diamine component, 1,10-decanediamine (3) Monocarboxylic acid component, stearic acid

(4) Semi-aromatic polyamide resin (A)
・Semi-aromatic polyamide resin (A-1)
48.1 kg of powdered terephthalic acid (TPA) as an aromatic dicarboxylic acid component, 1.5 kg of stearic acid (STA) as a monocarboxylic acid component, and 93 g of sodium hypophosphite monohydrate as a polymerization catalyst, The mixture was placed in a ribbon blender type reactor and heated to 170° C. while being stirred at 30 rpm under nitrogen sealing. Thereafter, while maintaining the temperature at 170° C. and the rotational speed at 30 rpm, 50.4 kg of 1,10-decanediamine (DDA) heated to 100° C. as an aliphatic diamine component was added using a liquid injector. , was continuously added over 2.5 hours (continuous liquid injection method) to obtain a reaction product. The molar ratio of the raw material monomers was TPA:DDA:STA=49.3:49.8:0.9 (the equivalent ratio of the functional groups of the raw material monomers was TPA:DDA:STA=49.5:50.0 : 0.5).
Subsequently, the obtained reaction product was polymerized by heating in the same reactor at 250° C. and a rotation speed of 30 rpm for 8 hours under a nitrogen stream to prepare a semi-aromatic polyamide resin powder.
After that, the powder of the obtained semi-aromatic polyamide resin is made into strands using a twin-screw kneader, the strands are passed through a water tank to cool and solidify, and cut with a pelletizer to produce a semi-aromatic polyamide resin (A -1) pellets were obtained.

・Semi-aromatic polyamide resins (A-2), (A-3)
Semi-aromatic polyamide resins (A-2), (A -3) was manufactured.

Table 1 shows the resin composition and characteristic values of the semi-aromatic polyamide resin (A).

(5) Aliphatic polyamide resin (B)
・ B-1: Polyamide 6 (A1030BRT, manufactured by Unitika Ltd. Relative viscosity 3.51)
・ B-2: Polyamide 6 (A1030BRL, manufactured by Unitika, relative viscosity 2.50)

(5) fibrous reinforcing material (C)
・ C-1: Glass fiber (T-262H manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter 10 μm, average fiber length 3 mm)
・ C-2: Glass fiber (E8CS-10-568H manufactured by Kyoseki Glass Co., Ltd., average fiber diameter 10 μm, average fiber length 3 mm)

Example 1
99 parts by mass of the semi-aromatic polyamide resin (A-1) and 1 part by mass of the aliphatic polyamide resin (B-1) are dry blended, and a loss-in-weight type continuous quantitative feeder CE-W- manufactured by Kubota Corporation. It was weighed using type 1, fed to the main feed port of a co-rotating twin-screw extruder (TEM37BS type manufactured by Toshiba Machine Co., Ltd.) with a screw diameter of 37 mm and an L/D of 40, and melt-kneaded. On the way, 100 parts by mass of glass fiber was supplied from a side feeder, and further melted and kneaded. A strand was taken out from the die, passed through a water bath, cooled and solidified, and cut with a pelletizer to obtain semi-aromatic polyamide resin composition pellets. The barrel temperature setting of the extruder was 330° C., screw rotation speed was 250 rpm, and discharge rate was 30 kg/hour.

Examples 2-10, Comparative Examples 1-5
Semi-aromatic polyamide resin composition pellets were obtained in the same manner as in Example 1, except that the resin composition was changed as shown in Table 2.

Table 2 shows the resin composition and characteristic values of the semi-aromatic polyamide resin compositions obtained in Examples 1-10 and Comparative Examples 1-5.

The semi-aromatic polyamide resin compositions of Examples 1 to 10 have a high melting point, bending strength, bending elastic modulus, and calcium chloride resistance, a melt flow rate of 20 g/10 minutes or less, and a small specific wear amount. showed that.

Since the semi-aromatic polyamide resin composition of Comparative Example 1 did not contain an aliphatic polyamide resin, the specific wear amount showed a large value.
Since the semi-aromatic polyamide resin compositions of Comparative Examples 2 and 3 had a large content of the aliphatic polyamide resin, they exhibited a large specific wear amount and were inferior in calcium chloride resistance.
Since the semi-aromatic polyamide resin compositions of Comparative Examples 4 and 5 had high melt flow rates, they exhibited large values of specific wear.

Claims (6)

87 to 99 parts by mass of a semi-aromatic polyamide resin (A) composed of an aromatic dicarboxylic acid component and an aliphatic diamine component containing terephthalic acid as a main component, an aliphatic polyamide resin (B) of 1 to 10 parts by mass, and fibers 40 to 100 parts by mass of the reinforcing material (C) with respect to a total of 100 parts by mass of (A) and (B),
A semi-aromatic polyamide resin composition having a melt flow rate of 20 g/10 minutes or less when measured under a load of 1.2 kgf according to JIS K 7210 (melting point of (A) +25°C). 2. The semi-aromatic polyamide resin composition according to claim 1, wherein the fibrous reinforcing material (C) is glass fiber. 3. The semi-aromatic polyamide resin composition according to claim 1, wherein the aliphatic diamine component of the semi-aromatic polyamide resin (A) is 1,10-decanediamine. According to JIS K7218 A method, the specific wear amount is 20 mm ³ /(kN·km) or less when a wear test is performed under the conditions that the mating material is S45C steel, the load is 0.75 MPa, and the sliding distance is 3 km. 3. The semi-aromatic polyamide resin composition according to 2. A molded article obtained by molding the semi-aromatic polyamide resin composition according to claim 1 or 2. The molded article according to claim 5, which is a sliding part.