JP2023152004A - Semi-aromatic polyamide resin composition, and molded body formed by molding the same - Google Patents

Abstract

To provide a semi-aromatic polyamide resin composition which is excellent in all of heat resistance, mechanical characteristics, thermal aging resistance, and chemical resistance.SOLUTION: There are provided: a semi-aromatic polyamide resin composition which contains 100 pts.mass of a semi-aromatic polyamide (A), containing an aromatic dicarboxylic acid component and an aliphatic diamine component and having a melting point of 280-350°C, 0.01-2 pts.mass of a copper compound (B), 0.05-10 pts.mass of a polyhydric alcohol (C) and 1-5 pts.mass of a phosphorus-based antioxidant (D), wherein the semi-aromatic polyamide resin composition further may contain 5-200 pts.mass of a fibrous reinforcement material (E); and a molded body formed by molding the semi-aromatic polyamide resin composition.SELECTED DRAWING: None

Description

The present invention relates to a semi-aromatic polyamide resin composition and a molded article formed from the same.

Semi-aromatic polyamides are widely used as molding materials because of their excellent heat resistance and mechanical properties. Among them, semi-aromatic polyamides with a melting point of 300° C. or higher are used in applications where heat resistance is particularly required, such as around automobile engines and LED lighting. It is generally known that the higher the melting point of a semi-aromatic polyamide, the more likely it is that its physical properties will deteriorate (heat aging) in a high-temperature environment, and there is a demand for improved heat aging resistance.

Patent Document 1 discloses that a resin composition with excellent heat aging resistance can be obtained by blending a semi-aromatic polyamide with a copper compound, an alkali metal halide compound, and a polyhydric alcohol. However, the resin composition of Patent Document 1 did not have sufficient chemical resistance.

JP2020-033548A

The present invention solves the above problems, and aims to provide a semi-aromatic polyamide resin composition that has excellent heat resistance, mechanical properties, heat aging resistance, and chemical resistance.

As a result of extensive research to solve the above problems, the present inventors have discovered that the above problems can be solved by blending specific amounts of a copper compound, polyhydric alcohol, and phosphorus antioxidant into a semi-aromatic polyamide. They discovered this and arrived at the present invention.
That is, the gist of the present invention is as follows.

(1) 100 parts by mass of a semi-aromatic polyamide (A) containing an aromatic dicarboxylic acid component and an aliphatic diamine component and having a melting point of 280 to 350°C, 0.01 to 2 parts by mass of a copper compound (B), A semi-aromatic polyamide resin composition containing 0.05 to 10 parts by mass of a polyhydric alcohol (C) and 1 to 5 parts by mass of a phosphorous antioxidant (D).
(2) The semi-aromatic polyamide resin composition according to claim 1, further comprising 5 to 200 parts by mass of a fibrous reinforcing material (E).
(3) A molded article obtained by molding the semi-aromatic polyamide resin composition according to (1) or (2).

According to the present invention, it is possible to provide a semi-aromatic polyamide resin composition that has excellent heat resistance, mechanical properties, heat aging resistance, and chemical resistance.
Furthermore, the resin composition of the present invention also has excellent heat aging resistance in oil (oil resistance).

The semi-aromatic polyamide resin composition of the present invention contains a semi-aromatic polyamide (A), a copper compound (B), a polyhydric alcohol (C), and a phosphorous antioxidant (D).

The semi-aromatic polyamide (A) constituting the semi-aromatic polyamide resin composition of the present invention contains an aromatic dicarboxylic acid component and an aliphatic diamine component as constituent components. Semi-aromatic polyamide (A) may contain a copolymer component, but from the viewpoints of excellent heat resistance, mechanical properties, and chemical resistance, rapid crystallization, and the ability to obtain molded products in low-temperature molds, etc. It is preferable that the composition is not copolymerized, that is, it consists of a single aromatic dicarboxylic acid component and a single aliphatic diamine component.

In the present invention, examples of the aromatic dicarboxylic acid component constituting the semi-aromatic polyamide (A) include terephthalic acid, phthalic acid, isophthalic acid, and naphthalene dicarboxylic acid. Among these, terephthalic acid is preferred because it can improve heat resistance.

Acid components to be copolymerized in addition to aromatic dicarboxylic acid components include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, etc. Examples include dicarboxylic acids such as aliphatic dicarboxylic acids and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. The copolymerization amount of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids other than terephthalic acid is determined based on the total number of moles of raw material monomers in order not to lower the melting point and heat resistance of the semi-aromatic polyamide (A). On the other hand, it is preferably 5 mol % or less, and more preferably substantially not contained.

In the present invention, examples of the aliphatic diamine component constituting the semi-aromatic polyamide (A) include 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, and 1,5-pentanediamine. , 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2 -Methyl-1,5-pentanediamine and 2-methyl-1,8-octanediamine. It is preferable to use one type of aliphatic diamine component alone rather than using a combination of the above-mentioned multiple types, and a molded article with a good balance of heat resistance and mechanical properties and excellent chemical resistance can be obtained. Therefore, it is preferable to use 1,10-decanediamine alone.

Examples of diamine components to be copolymerized other than the aliphatic diamine component include alicyclic diamines such as cyclohexane diamine, and aromatic diamines such as xylylene diamine and benzenediamine. The amount of copolymerization of alicyclic diamine and aromatic diamine other than the aliphatic diamine component should be 5 mol% or less based on the total number of moles of raw material monomers so as not to impair the above characteristics provided by the aliphatic diamine component. is preferable, and it is more preferable that it is substantially not included.

In the present invention, copolymer components other than those mentioned above constituting the semi-aromatic polyamide (A) include lactams such as caprolactam and laurolactam, and ω-aminocarboxylic acids such as aminocaproic acid and 11-aminoundecanoic acid. The amount of these copolymers is preferably 5 mol% or less based on the total number of moles of the raw material monomers, in order not to reduce the heat resistance, mechanical properties, and chemical resistance of the semiaromatic polyamide (A). More preferably, it is substantially not contained.

As described above, the semi-aromatic polyamide (A) in the present invention preferably consists of a single aromatic dicarboxylic acid component and a single aliphatic diamine component, but the semi-aromatic polyamide resin composition of the present invention may contain two or more types of semi-aromatic polyamides (A) having different constituent monomer components.

In the present invention, the semi-aromatic polyamide (A) preferably contains a monocarboxylic acid component as a constituent component in order to improve heat aging resistance, fluidity, and mold release properties. The content of the monocarboxylic acid component is preferably 0.3 to 4.0 mol%, and 0.3 to 3.0 mol% based on the total monomer components constituting the semi-aromatic polyamide (A). It is more preferably 0.3 to 2.5 mol%, 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. When the molecular weight of the monocarboxylic acid is 140 or more, the heat aging resistance, fluidity, and mold releasability of the semi-aromatic polyamide (A) are further improved. Furthermore, by improving the fluidity during melt processing, it becomes possible to lower the processing temperature, and thermal deterioration during melt processing can be suppressed, resulting in improved heat aging resistance. In addition, when the resin composition contains a semi-aromatic polyamide (A) containing a monocarboxylic acid component having a molecular weight of 140 or more together with the polyhydric alcohol (C), the crystallization rate during molding remains unchanged; The crystallinity of the obtained molded body is improved. As a result, the chemical resistance of the molded article is synergistically improved. Even in the automotive field, chemical resistance is required for molded articles such as parts that come into contact with antifreeze, and the present invention is particularly useful for this purpose.

Examples of the monocarboxylic acid component include aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids, with aliphatic monocarboxylic acids being preferred from the viewpoint of fluidity and mold releasability.

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, and behenic acid. Among these, stearic acid is preferred because of its high versatility. Examples of the alicyclic monocarboxylic acid having a molecular weight of 140 or more include 4-ethylcyclohexanecarboxylic acid, 4-hexylcyclohexanecarboxylic acid, and 4-laurylcyclohexanecarboxylic acid. 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 like. Examples include derivatives.

The monocarboxylic acid component may be used alone or in combination. Further, 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 in combination. In addition, in the present invention, the molecular weight of monocarboxylic acid refers to the molecular weight of monocarboxylic acid as a raw material.

In the present invention, the semi-aromatic polyamide (A) needs to have a melting point of 280 to 350°C, preferably 300 to 350°C, more preferably 305 to 340°C, and more preferably 310 to 350°C. More preferably, the temperature is 335°C. If the melting point of the semi-aromatic polyamide (A) is less than 280°C, the resulting semi-aromatic polyamide resin composition may have insufficient crystallinity and thus may have poor heat aging resistance. On the other hand, when the melting point of semi-aromatic polyamide (A) exceeds 350°C, carbonization and decomposition progress during melt processing because the decomposition temperature of polyamide bonds is about 350°C. In the present invention, the melting point is defined as the top of the endothermic peak when the temperature is raised at a rate of 20° C./min using a differential scanning calorimeter (DSC).

In the present invention, the relative viscosity of the semi-aromatic polyamide (A) when measured in 96% sulfuric acid at 25°C at a concentration of 1 g/dL is preferably 1.8 or more from the viewpoint of mechanical properties. , more preferably from 1.8 to 3.5, and even more preferably from 2.2 to 3.1. When the relative viscosity of the semi-aromatic polyamide (A) exceeds 3.5, melt processing may become difficult.

The method for producing the semi-aromatic polyamide (A) is not particularly limited, but conventionally known heat polymerization methods and solution polymerization methods can be used. Among these, the heating polymerization method is preferably used because it is industrially advantageous. Examples of the heating polymerization method include a method comprising a step (i) of obtaining a reaction product from an aromatic dicarboxylic acid component and an aliphatic diamine component, and a step (ii) of polymerizing the obtained reaction product. .

In step (i), for example, aromatic dicarboxylic acid powder is heated in advance to a temperature above the melting point of the aliphatic diamine and below the melting point of the aromatic dicarboxylic acid; One method is to add an aliphatic diamine without substantially containing water so as to maintain the dicarboxylic acid powder state. Alternatively, as another method, a suspension consisting of a molten aliphatic diamine and a solid aromatic dicarboxylic acid is stirred and mixed to obtain a mixed solution, and then the melting point of the semi-aromatic polyamide that is finally produced is A method of obtaining a mixture of a salt and a low polymer by carrying out a salt production reaction by reacting an aromatic dicarboxylic acid with an aliphatic diamine and a low polymer production reaction by polymerizing the produced salt at a temperature below It will be done. In this case, the crushing may be carried out while the reaction is being carried out, or the crushing may be carried out after being taken out once after the reaction. In step (i), the former is preferred because the shape of the reaction product can be easily controlled.

In step (ii), for example, the reaction product obtained in step (i) is solid-phase polymerized at a temperature lower than the melting point of the semi-aromatic polyamide to be finally produced, and the molecular weight is increased to a predetermined molecular weight. , a method for obtaining a semi-aromatic polyamide. The solid phase polymerization is preferably carried out at a polymerization temperature of 180 to 270° C. and a reaction time of 0.5 to 10 hours in a stream of inert gas such as nitrogen.

The reaction apparatus for step (i) and step (ii) is not particularly limited, and any known apparatus may be used. Step (i) and step (ii) may be performed in the same device or in different devices.

In addition, heating methods in the thermal polymerization method include, but are not particularly limited to, a method of heating the reaction container with a medium such as water, steam, or heat transfer oil, a method of heating the reaction container with an electric heater, and a method of heating the reaction container by stirring. One example is a method that utilizes frictional heat accompanying the movement of the contents, such as heat. Furthermore, these methods may be combined.

In the production of semi-aromatic polyamide (A), a polymerization catalyst may be used to increase the efficiency of polymerization. Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid, or salts thereof. The amount of the polymerization catalyst added is preferably 2 mol % or less based on the total monomer components constituting the semi-aromatic polyamide (A).

The semi-aromatic polyamide resin composition of the present invention needs to contain a copper compound (B). Examples of the copper compound (B) used in the present invention include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, copper acetate, copper propionate, and benzoate. Examples include copper acid, copper adipate, copper terephthalate, copper isophthalate, copper sulfate, copper phosphate, copper borate, copper nitrate, copper stearate, and copper complex salts coordinated to a chelating agent. Among them, copper halides are preferred, and cuprous iodide and cuprous bromide are more preferred. The copper compound (B) may be used alone or in combination.

The content of the copper compound (B) needs to be 0.01 to 2 parts by mass, and 0.02 to 0.5 parts by mass, based on 100 parts by mass of the semiaromatic polyamide (A). It is preferable. When the content of the copper compound (B) is less than 0.01 part by mass, the resin composition does not show any improvement in heat aging resistance. On the other hand, when the content of the copper compound (B) exceeds 2 parts by mass, the effect is saturated, which is not only economically disadvantageous, but also the resulting molded product may be colored and spoil its appearance.

The semi-aromatic polyamide resin composition of the present invention preferably contains a halogenated alkali metal salt. Examples of the halogenated alkali metal compound used in the present invention include potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium bromide, and sodium chloride, with potassium iodide and potassium bromide being preferred. . The halogenated alkali metal compounds may be used alone or in combination.

The content of the alkali metal halide compound is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the semi-aromatic polyamide (A). When the content of the alkali metal halide compound is less than 0.1 part by mass, the resin composition does not show any improvement in heat aging resistance. On the other hand, when the content of the alkali metal halide compound exceeds 3 parts by mass, the effect is saturated, which is not only economically disadvantageous, but also may cause the resin composition to become brittle.

In the present invention, the mass ratio of the copper compound (B) to the alkali metal halide compound is preferably 1/2 to 1/20 from the viewpoint of improving mechanical strength and heat aging resistance.

The semi-aromatic polyamide resin composition of the present invention needs to contain polyhydric alcohol (C). The polyhydric alcohol (C) used in the present invention is a compound containing two or more hydroxyl groups. Examples of the polyhydric alcohol (C) include saturated aliphatic compounds, unsaturated aliphatic compounds, alicyclic compounds, aromatic compounds, and saccharides. Polyhydric alcohols may contain one or more heteroatoms, such as oxygen, nitrogen and/or sulfur. The polyhydric alcohol (C) may contain substituents other than hydroxyl groups, such as ether, carboxylic acid, amide, or ester groups. Further, the polyhydric alcohol may be a low molecular weight compound or a polymer type high molecular weight compound in which certain monomer units repeat. One type of polyhydric alcohol (C) may be used alone, or a plurality of types may be used in combination. The semi-aromatic polyamide resin composition of the present invention has improved heat aging resistance by containing the polyhydric alcohol (C). In addition, the semi-aromatic polyamide resin composition of the present invention has improved fluidity by containing polyhydric alcohol (C), so it is also possible to lower the processing temperature during melt processing. Thermal deterioration during melt processing can be suppressed.

Examples of saturated aliphatic compounds include ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3propanediol, and glycerin monomethacrylate. low molecular weight alcohol; glycerol, trimethylolpropane, hexane-1,2,6-triol, 1,1,1-tris-(hydroxymethyl)ethane, 3-(2'-hydroxyethoxy)-propane-1, 2-diol, 3-(2'-hydroxypropoxy)-propane-1,2-diol, 2-(2'-hydroxyethoxy)-hexane-1,2-diol, 6-(2'-hydroxypropoxy)- Hexane-1,2-diol, 1,1,1-tris-[(2'-hydroxyethoxy)-methyl]-ethane, 1,1,1-tris-[(2'-hydroxypropoxy)-methyl]- Trihydric low molecular weight alcohols such as propane, di-trimethylolpropane, trimethylolpropane ethoxylate, trimethylolpropane propoxylate; Quaternary or higher hydric low molecular weight alcohols such as pentaerythritol, dipentaerythritol, tripentaerythritol; polyethylene glycol , polyglycerin, polyvinyl alcohol, ethylene-vinyl alcohol copolymer resin, polyvinyl butyral (e.g. Mowital manufactured by Kuraray), polybutadiene with hydrogenated hydroxyl groups at both ends (e.g. GI series manufactured by Nippon Soda), polybutadiene with hydroxyl groups at both ends (e.g. , G series manufactured by Nippon Soda), dendritic polyalcohols (e.g. Boltorn manufactured by Perstorp), polycaprolactone polyols (e.g. Plaxel 200 series, 300 series, 400 series manufactured by Daicel), etc. Can be mentioned.

Examples of unsaturated aliphatic compounds include ricinoleyl alcohol. Examples of alicyclic compounds include 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,3,5-cyclohexanetriol, 2,3-di-(2'-hydroxy ethyl)-cyclohexan-1-ol. Examples of aromatic compounds include 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, hydrobenzoin, 1,1,2,2-tetraphenylethane-1,2 -diol, 1,1,1-tris-(4'-hydroxyphenyl)-ethane, 1,1,1-tris-(hydroxyphenyl)-propane, 1,1,3-tris-(dihydroxy-3-methyl phenyl)-propane, 1,1,4-tris-(dihydroxyphenyl)-butane, 1,1,5-tris-(hydroxyphenyl)-3-methylpentane, and bisphenoxyethanolfluorene. Examples of sugars include cyclodextrin, D-mannose, glucose, galactose, sucrose, fructose, xylose, arabinose, D-mannitol, D-sorbitol, D- or L-arabitol, xylitol, iditol, galactitol, talitol, Examples include allitol, althritol, giltol, erythritol, threitol, ribitol, and D-gulonic acid-γ-lactone.

Examples of polyhydric alcohols having two or more hydroxyl groups and ester groups as other substituents include esters consisting of pentaerythritol and fatty acids (for example, Unistar H series manufactured by NOF Corporation), dipentaerythritol and Examples include polyhydric alcohols that have an ester bond with a fatty acid while leaving two or more hydroxyl groups, such as esters made of dibasic acids (for example, Plenizer series manufactured by Ajinomoto Fine Techno).

The content of polyhydric alcohol (C) needs to be 0.05 to 10 parts by mass, and 0.1 to 8 parts by mass, based on 100 parts by mass of semi-aromatic polyamide (A). The amount is preferably 0.2 to 6 parts by mass, and more preferably 0.2 to 6 parts by mass. When the content of polyhydric alcohol (C) is less than 0.05 parts by mass, the resin composition does not show any effect of suppressing heat aging. On the other hand, when the mass amount of the polyhydric alcohol (C) exceeds 10 parts by mass, the effect of suppressing heat aging is saturated, and not only is no further effect expected to be produced, but the resin composition is The alcohol may vaporize and generate a large amount of gas, and the retention stability may be poor.Also, polyhydric alcohol may bleed out onto the surface of the molded product, impairing its appearance or having insufficient mechanical properties. It may become.

The semi-aromatic polyamide resin composition of the present invention needs to contain a phosphorus antioxidant (D). The phosphorus antioxidant (D) used in the present invention is an inorganic salt such as a phosphate or a phosphite, or an organic phosphorus compound such as a phosphite ester. Ester residues of phosphite esters include aliphatic compounds, aromatic compounds, polyhydric alcohol compounds, and the like.

The semi-aromatic polyamide resin composition of the present invention has improved heat aging resistance and chemical resistance by containing the phosphorus antioxidant (D). In addition, the semi-aromatic polyamide resin composition of the present invention has improved fluidity by containing the phosphorus antioxidant (D), so it is possible to lower the processing temperature during melt processing. Therefore, thermal deterioration during melt processing can be suppressed.

The phosphorus antioxidant may be either an inorganic compound or an organic compound. Examples of phosphorus antioxidants include inorganic phosphates such as monosodium phosphate, disodium phosphate, trisodium phosphate, sodium phosphite, calcium phosphite, magnesium phosphite, and manganese phosphite; Phenyl phosphite, triotadecyl phosphite, tridecyl phosphite, trinonylphenyl phosphite, diphenylisodecyl phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl)pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, distearylpentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite Phosphite, 1,1'-biphenyl-4,4'-diylbis[bis(2,4-di-tert-butylphenyl) phosphonite], tetrakis(2,4-di-tert-butylphenyl) 4, Organic phosphorus compounds such as 4'-biphenylene-di-phosphonite, tetra(tridecyl-4,4'-isopropylidene diphenyl diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite) Phosphorous antioxidants may be used alone or in combination. Commercially available phosphorus antioxidants include, for example, Adekastab PEP-8, PEP-36, and PEP manufactured by Adeka Corporation. -4C, PEP-24G, and Hostanox P-EPQ manufactured by Clariant Japan.

The content of the phosphorus antioxidant (D) is based on 100 parts by mass of the semi-aromatic polyamide (A),
It is necessary to use 1 to 5 parts by weight, and preferably 1 to 2 parts by weight. When the content of the phosphorus antioxidant (D) is less than 1 part by mass, the resin composition exhibits no effect of suppressing heat aging. On the other hand, if the content of the phosphorus-based antioxidant (D) exceeds 5 parts by mass, the effect of suppressing heat aging is saturated, which is not only economically disadvantageous, but also causes the resin composition to contain phosphorus-based antioxidants during melt processing. The antioxidant may decompose and generate a large amount of gas, the retention stability may become poor, and the molded product may have insufficient mechanical properties.

It is preferable that the semi-aromatic polyamide resin composition of the present invention further contains a fibrous reinforcing material (E). The fibrous reinforcing material (E) is not particularly limited, but includes, for example, glass fiber, carbon fiber, boron fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, wholly aromatic polyamide fiber, polybenzoxazole fiber, and polytetrafluorocarbon fiber. Examples include ethylene 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, and basalt fiber. Among these, glass fibers and carbon fibers are preferred because they are highly effective in improving mechanical properties, have heat resistance that can withstand the heating temperature during melt-kneading with the semi-aromatic polyamide resin, and are easily available. The fibrous reinforcing material (E) may be used alone or in combination.

The fibrous reinforcing material (E) such as glass fiber or carbon fiber is preferably treated with a surface treatment agent such as a sizing agent. The main component of the sizing agent is preferably a coupling agent or a film forming agent. Examples of the coupling agent include coupling agents such as vinyl silane, acrylic silane, epoxy silane, amino silane, and amino titanium. Among these, aminosilane coupling agents are preferred because they have a high adhesion effect between the semi-aromatic polyamide (A) and glass fibers or carbon fibers, and have excellent heat resistance. Examples of the film-forming agent include urethane-based, epoxy-based, and acrylic-based resins, among which urethane-based resins are preferred because they have a high adhesion effect with glass fibers or carbon fibers and are excellent in heat resistance. The film forming agent preferably contains an acid component since this improves the hydrolysis resistance of the resin composition. The acid component is preferably copolymerized with the resin that is the main component of the film forming agent. Examples of the acid component include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and cinnamic acid, unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and maleic anhydride.

The fiber length and fiber diameter of the fibrous reinforcing material (E) are not particularly limited, but the fiber length is preferably 0.1 to 7 mm, more preferably 0.5 to 6 mm. Since the fiber length of the fibrous reinforcing material (E) is 0.1 to 7 mm, the resin composition can be reinforced without adversely affecting the moldability. Further, the fiber diameter of the fibrous reinforcing material (E) is preferably 3 to 20 μm, more preferably 5 to 14 μm. Since the fiber diameter of the fibrous reinforcing material (E) is 3 to 20 μm, the resin composition can be reinforced without breaking during melt-kneading. Examples of the cross-sectional shape of the fibrous reinforcing material (E) include circular, rectangular, elliptical, and other irregular cross-sectional shapes, and among them, circular is preferable.

When using the fibrous reinforcing material (E), its content is preferably 5 to 200 parts by mass, more preferably 10 to 180 parts by mass, based on 100 parts by mass of the semi-aromatic polyamide (A). The amount is preferably 20 to 150 parts by weight, more preferably 30 to 130 parts by weight. If the content of the fibrous reinforcing material (E) is less than 5 parts by mass, the effect of improving mechanical properties may be small. On the other hand, if the content exceeds 200 parts by mass, the effect of improving mechanical properties will be saturated, and not only will no further improvement be expected, but the workability during melt-kneading will decrease, and the semi-aromatic polyamide resin composition It may be difficult to obtain pellets of the product. Additionally, fluidity during melt processing is significantly impaired, resulting in higher resin temperatures due to shear heat generation, and situations in which the resin temperature has to be raised to improve fluidity. This may lead to a decrease in molecular weight, mechanical properties, and heat aging resistance.

The semi-aromatic polyamide resin composition of the present invention further improves melt stability by containing various stabilizers such as antioxidants other than the phosphorus antioxidant (D), light stabilizers, and heat stabilizers. and effectively suppress heat aging. Examples of the antioxidant include hindered phenolic antioxidants and sulfur-based antioxidants, and examples of the light stabilizer include hindered amine light stabilizers.

Examples of hindered phenolic antioxidants include n-octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)-propionate, n-octadecyl-3-(3'- Methyl-5'-t-butyl-4'-hydroxyphenyl)-propionate, n-tetradecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)-propionate, 1,6- Hexanediol-bis-[3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate], 1,4-butanediol-bis-[3-(3,5-di-t-butyl) -4-hydroxyphenyl)-propionate], 2,2'-methylenebis-(4-methyl-t-butylphenol), triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4-hydroxy) phenyl)-propionate], tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 3,9-bis[2-{3-(3-t -butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]2,4,8,10-tetraoxaspiro[5.5]undecane, N,N'-bis-3- (3',5'-di-t-butyl-4'-hydroxyphenyl)propionylhexamethylenediamine, N,N'-tetramethylene-bis-3-(3'-methyl-5'-t-butyl-4 '-hydroxyphenol)propionyldiamine, N,N'-bis-[3-(3,5-di-t-butyl-4-hydroxyphenol)propionyl]hydrazine, N-salicyloyl-N'-salicylidenehydrazine, 3-(N-salicyloyl)amino-1,2,4-triazole, N,N'-bis[2-{3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy}ethyl] Oxyamide, pentaerythrityl-tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis-(3,5-di-t-butyl-4 Among them, triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)-propionate], tetrakis[methylene-3-(3' , 5'-di-t-butyl-4'-hydroxyphenyl)propionate] methane, 1,6-hexanediol-bis-[3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate ], pentaerythrityl-tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis-(3,5-di-t-butyl-4 -hydroxy-hydrocinnamide is preferred. The hindered phenolic antioxidant may be used alone or in combination. Commercially available hindered phenolic antioxidants include, for example, Adekastab AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, AO-80, AO-330, manufactured by Adeka Corporation; Irganox 245, 259, 565, 1010, 1035, 1076, 1098, 1222, 1330, 1425, 1520, 3114, 5057 manufactured by Ciba Specialty Chemical Co., Ltd., Sumilizer BHT-R, MDP-S, BBM-S manufactured by Sumitomo Chemical Co., Ltd. , WX-R, NW, BP-76, BP-101, GA-80, GM, GS, and Cyanox CY-1790 manufactured by Cyanamid.

Examples of sulfur-based antioxidants include distearyl 3,3'-thiodipropionate, pentaerythrityl tetrakis (3-laurylthiopropionate), 2-mercaptobenzimidazole, and didodecyl 3,3'-thiodipropionate. pionate, dioctadecyl 3,3'-thiodipropionate, ditridecyl 3,4'-thiodipropionate, 2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]-1,3 - Propanediyl ester. Among these, distearyl 3,3'-thiodipropionate and pentaerythrityltetrakis (3-laurylthiopropionate) are preferred. Sulfur-based antioxidants may be used alone or in combination. Examples of commercially available sulfur-based antioxidants include Sumilizer TP-D and MB manufactured by Sumitomo Chemical.

Examples of hindered amine light stabilizers include tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, tetrakis(2,2,6,6- Tetramethyl-1-4-piperidyl)butane-1,2,3,4-tetracarboxylate, dimethyl succinate 1-(2hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethyl- 4-piperidine polycondensate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, poly[(6-morpholino-S-triazine-2,4-diyl)[2,2, Examples include 6,6-tetramethyl-4-piperidyl]imino]-hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl)imino]. The hindered amine light stabilizer may be used alone or in combination. Commercially available stabilizers include, for example, Nyrostab S-EED manufactured by Clariant Japan, Biosorb 04 manufactured by Kyodo Yakuhin, Cyasorb UV-3346 manufactured by Cytec, Adeka Stab LA-57, LA-63P, LA-68, and BASF manufactured by Adeka. Examples include Chimasorb 119, 944, and Tinuvin 622, 765.

The content of the stabilizer is preferably 0.005 to 3 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the semiaromatic polyamide (A).

The semi-aromatic polyamide resin composition of the present invention may contain polyamides other than the semi-aromatic polyamide (A). Polyamides other than semi-aromatic polyamide (A) (hereinafter sometimes referred to as "other polyamides") are not particularly limited, but include semi-aromatics that are amorphous or have a melting point of less than 300°C. Examples include polyamide and aliphatic polyamide.

Examples of semi-aromatic polyamides other than the semi-aromatic polyamide (A) include copolymers of terephthalic acid, isophthalic acid, and aliphatic diamines.

Examples of aliphatic polyamides of polyamides other than semi-aromatic polyamide (A) include polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 410, polyamide 412, polyamide 510, polyamide 512, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, polyamide 6/66, polyamide 66/1010, polyamide 66/612, polyamide 2Me5C, polyamide 6C, polyamide 8C, polyamide 9C, polyamide 10C, and polyamide 12C. Note that C means 1,4-cyclohexanedicarboxylic acid, and 2Me5 means 2-methylpentamethylene diamine.

When the semi-aromatic polyamide resin composition contains another polyamide, the content thereof is preferably 1 to 100 parts by mass, and 3 to 80 parts by mass, based on 100 parts by mass of the semi-aromatic polyamide (A). The amount is more preferably 3 to 50 parts by weight, and even more preferably 3 to 50 parts by weight. By containing 1 to 100 parts by mass of other polyamides, the semi-aromatic polyamide resin composition of the present invention has improved flowability during melt processing, resulting in improved moldability and surface appearance of the resulting molded product. It also improves. Furthermore, because of its high fluidity, it is possible to lower the melt processing temperature, so by lowering the melt processing temperature and suppressing thermal deterioration during melt processing, it is possible to improve heat aging resistance. can. If the content is less than 1 part by mass, the above effects may not be obtained. On the other hand, if the content exceeds 100 parts by mass, the heat resistance and mechanical properties of the semi-aromatic polyamide (A) may be impaired.

If necessary, other additives such as fillers, colorants, and antistatic agents may be further added to the semi-aromatic polyamide resin composition of the present invention. Examples of fillers include swellable clay minerals, silica, alumina, glass beads, and graphite. Examples of the coloring agent include pigments such as titanium oxide and carbon black, and dyes such as nigrosine. In particular, by containing nigrosine, the fluidity of the semi-aromatic polyamide resin composition during melt processing can be improved, the melt processing temperature can be lowered, and the heat aging resistance can be improved. Improves appearance.

In the present invention, semi-aromatic polyamide (A), copper compound (B), polyhydric alcohol (C), phosphorus antioxidant (D), and fibrous reinforcing material (E) added as necessary, The method for producing the semi-aromatic polyamide resin composition of the present invention by adding other additives is not particularly limited, but a melt-kneading method is preferred. Examples of the melt-kneading method include methods 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 not particularly limited as long as the semi-aromatic polyamide (A) melts and does not decompose; however, if it is too high, the semi-aromatic polyamide (A) will decompose. The melting point is preferably -20°C) or more and (the melting point of the semi-aromatic polyamide +40°C) or less.

The molten resin composition can be extruded into strands to form pellets, hot cut or underwater cut to form pellets, extruded into sheets and cut, or extruded into blocks and pulverized. It can be processed into various shapes by, for example, making it into a powder shape.

The molded article of the present invention is obtained by molding the above-mentioned semi-aromatic polyamide resin composition. Examples of the molding method include injection molding, extrusion molding, blow molding, and sinter molding, and injection molding is preferred because it has a large effect of improving mechanical properties and moldability.

The injection molding machine is not particularly limited, and 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 an injection molding machine is weighed for each shot, injected in a molten state into a 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 more preferably at least (the melting point of the semi-aromatic polyamide -20°C) and less than (the melting point of the semi-aromatic polyamide +40°C). Since the resin composition of the present invention has excellent fluidity during melt processing, there is no need to raise the resin temperature during molding. Therefore, it is possible to lower the resin temperature during molding and reduce thermal deterioration during melt processing.

When melt processing a semi-aromatic polyamide resin composition, it is preferable to use sufficiently dried semi-aromatic polyamide resin composition pellets. If a semi-aromatic polyamide resin composition containing a large amount of water is used, the resin may foam within the cylinder of an injection molding machine, making it difficult to obtain an optimal molded product. The moisture content of the semi-aromatic polyamide resin composition pellets used for injection molding is preferably less than 0.3 parts by mass, and less than 0.1 parts by mass, based on 100 parts by mass of the semi-aromatic polyamide resin composition. It is more preferable that there be.

The semi-aromatic polyamide resin composition of the present invention can be used as a molding resin for a wide range of applications such as automobile parts, electrical and electronic parts, miscellaneous goods, industrial equipment parts, and civil engineering and construction supplies.

Examples of automotive parts include thermostat members, inverter IGBT module members, actuator members, insulators, motor insulators, radiator members, radiator hoses, various valves, exhaust finishers, power device housings, ECU housings, motor members, and coil members. , resolver parts, cable covering materials, automotive camera casings, automotive camera lens holders, automotive connectors, engine mounts, intercoolers, bearing retainers, oil seal rings, chain covers, ball joints, chain tensioners, clutch members, torsion Examples include seats, starter gears, reducer gears, internal gears, automotive lithium-ion battery trays, automotive high-voltage fuse housings, automotive electrical circuit breaker housings, and automotive turbocharger impellers.

Examples of electrical/electronic parts include connectors, ECU connectors, main lock connectors, modular jacks, reflectors, LED reflectors, switches, sensors, sockets, pin sockets, capacitors, jacks, fuse holders, relays, coil bobbins, breakers, and circuits. Parts, electromagnetic switches, holders, covers, plugs, housing parts for electric and electronic equipment such as portable computers and word processors, impellers, vacuum cleaner impellers, resistors, variable resistors, ICs, LED housings, camera housings body, camera barrel, camera lens holder, tact switch, lighting tact switch, hair iron housing, hair iron comb, all-molded DC-only small switch, organic EL display switch, materials for 3D printers, bonded magnets for motors Materials include:

Examples of miscellaneous goods include trays, sheets, and cable ties.
Examples of industrial equipment parts include insulators, connectors, gears, switches, washers, bearing retainers, sensors, impellers, and plastic rail chains.
Examples of civil engineering and construction supplies include fences, storage boxes, construction switchboards, anchor bolt guides, anchor rivets, solar panel raising materials, and brake pads for wind power generation.

The semi-aromatic polyamide resin composition of the present invention has chemical resistance and highly suppressed thermal aging in high-temperature atmospheres, so it can be used for long periods in environments where it comes into contact with chemicals and under high-temperature environments. It can be particularly suitably used for molded articles such as automobile parts.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

1. Measurement Method The physical properties of the semi-aromatic polyamide and semi-aromatic polyamide resin composition were measured by the following method.
(1) Melting point Using a differential scanning calorimeter DSC-7 (manufactured by PerkinElmer), the temperature was raised to 360°C at a rate of 20°C/min in a nitrogen atmosphere, then held at 360°C for 5 minutes, and then lowered. The temperature was lowered to 25°C at a rate of 20°C/min, and after further holding at 25°C for 5 minutes, the temperature was measured again at a heating rate of 20°C/min, and the top of the endothermic peak was taken as the melting point.
In the present invention, a case of 280°C or higher was judged to be acceptable.

(2) Relative viscosity Measured at 25° C. using 96% by mass sulfuric acid at a concentration of 1 g/dL.

(3) Tensile strength, heat aging resistance (tensile strength retention rate)
Tensile strength was measured in accordance with ISO178 using test pieces 1 and 2 produced by the method described below. The tensile strength retention rate (%) of test piece 2 relative to test piece 1 was determined, and the heat aging resistance at 150°C was evaluated.
<Test piece 1> (Test piece prepared under standard conditions)
The semi-aromatic polyamide resin composition was molded using an injection molding machine S2000i-100B (manufactured by Fanuc Corporation) at a cylinder temperature (melting point of semi-aromatic polyamide +15°C) and a mold temperature (melting point of semi-aromatic polyamide -175°C). C) and a residence time in the cylinder of 10 seconds to produce a test piece 1 (ISO multipurpose test piece).
<Test piece 2> (Test piece for heat aging evaluation, heat treated at 150°C x 3000 hours)
Test piece 1 was heat-treated at 150° C. for 3000 hours in a hot air oven under atmospheric conditions to produce test piece 2.
In the present invention, when the tensile strength does not contain a fibrous reinforcing material, a tensile strength of 70 MPa or more is passed, and when a fibrous reinforcing material is contained, a tensile strength of 140 MPa or more is passed. Further, a case in which the heat aging resistance (tensile strength retention rate) was 70% or more was judged to be acceptable.

(4) Chemical resistance (tensile strength retention rate)
<Test piece 3> (Test piece for chemical resistance evaluation, sulfuric acid treatment)
Test piece 1 was treated under 50% sulfuric acid immersion at room temperature for 24 hours to produce test piece 3.
The tensile strength retention rate (%) of test piece 3 relative to test piece 1 was determined, and chemical resistance was evaluated.
In the present invention, a case in which the chemical resistance (tensile strength retention rate) is 80% or more is judged to be acceptable.

(5) Oil resistance (tensile strength retention rate)
<Test piece 4> (Test piece for oil resistance evaluation, heat treated at 150°C x 1000 hours)
Test piece 1 was immersed in ATF oil with the lid of the container closed, and heat treated in a hot air oven at 150°C for 1000 hours to produce test piece 4.
The tensile strength retention rate (%) of test piece 4 relative to test piece 1 was determined, and oil resistance was evaluated.
In the present invention, a case where the oil resistance (tensile strength retention rate) was 80% or more was judged to be acceptable.

2. Raw Materials The raw materials used in the Examples and Comparative Examples are shown below.
(1) Aromatic dicarboxylic acid component ・TPA: Terephthalic acid (2) Aliphatic diamine component ・DDA: 1,10-decanediamine ・NDA: 1,9-nonanediamine (3) Monocarboxylic acid ・STA: Stearic acid (molecular weight :284)

(4) Semi-aromatic polyamide (A)
・Semi-aromatic polyamide (A-1)
4.76 kg of powdered terephthalic acid (TPA) as an aromatic dicarboxylic acid component, 0.16 kg of stearic acid (STA) as a monocarboxylic acid component, and 9.3 g of sodium hypophosphite monohydrate as a polymerization catalyst. was placed in a ribbon blender type reactor and heated to 170° C. while stirring at a rotation speed of 30 rpm under nitrogen sealing. Thereafter, while keeping the temperature at 170°C and the rotation speed at 30 rpm, 5.02 kg of 1,10-decanediamine (DDA) heated to 100°C was added as the aliphatic diamine component using a liquid injection device. , was added continuously (continuous injection method) over 2.5 hours to obtain a reaction product. The molar ratio of the raw material monomers is TPA:DDA:STA=49.1:50.0:0.9 (the equivalent ratio of the functional groups of the raw material monomers is TPA:DDA:STA=49.3:50.2 :0.5).
Subsequently, the obtained reaction product was heated and polymerized in the same reaction apparatus under a nitrogen stream at 250° C. and a rotation speed of 30 rpm for 8 hours to produce a semi-aromatic polyamide powder.
Thereafter, the obtained semi-aromatic polyamide powder was formed into a strand using a twin-screw kneader, the strand was cooled and solidified by passing it through a water tank, and then cut with a pelletizer to form a semi-aromatic polyamide (A-1). Obtained pellets.

・Semi-aromatic polyamide (A-2)
A semi-aromatic polyamide (A-2) was obtained in the same manner as the semi-aromatic polyamide (A-1) except that the resin composition was changed as shown in Table 1.

Table 1 shows the resin composition and characteristic values of the obtained semi-aromatic polyamide.

(5) Copper compound (B)
・B-1: Copper iodide (reagent special grade)
(6) Polyhydric alcohol (C)
・C-1: Dipentaerythritol (manufactured by Perstorp, DiPenta90)
・C-2: Ester consisting of dipentaerythritol and adipic acid (manufactured by Ajinomoto Fine Techno Co., Ltd., Prenlyzer ST-210)

(7) Phosphorous antioxidant (D)
・D-1: Adeka Stab PEP-36 (bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite) manufactured by Adeka Corporation
・D-2: Manufactured by Clariant, Hostanox P-EPQ (tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-di-phosphonite)

(8) Fibrous reinforcement (E)
・E-1: Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., ECS03T-262H, average fiber diameter 10.5 μm, average fiber length 3 mm)
・E-2: Carbon fiber (manufactured by Toho Tenax Co., Ltd., HTA-C6-NR, average fiber diameter 7 μm, average fiber length 6 mm)

(9) Alkali metal halide compound/KI: Potassium iodide (special grade reagent)

(10) Polyamide other than semi-aromatic polyamide (A) P-1: Polyamide 6T/6I (manufactured by M Chemie Japan, Grivory G21, amorphous)
・P-2: Polyamide 6 (manufactured by Unitika, A1030BRT, crystalline)

(11) Stabilizer・AO-1:3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]2, 4,8,10-tetraoxaspiro[5.5]undecane (hindered phenolic antioxidant, manufactured by Adeka, Adeka Stab AO-80)

Example 1
100 parts by mass of semi-aromatic polyamide (A-1), 0.05 parts by mass of copper compound (B-1), 1 part by mass of polyhydric alcohol (C-1), 2 parts by mass of phosphorus antioxidant (D-1) 1 part and 0.2 part by mass of potassium iodide (KI) were dry blended and weighed using a loss-in-weight continuous quantitative feeder CE-W-1 type (manufactured by Kubota Corporation), screw diameter 26 mm, L/D 50. The mixture was supplied to the main supply port of a codirectional twin-screw extruder TEM26SS model (manufactured by Shibaura Kikai Co., Ltd.) and melt-kneaded. During the course of the mixing, 45 parts by mass of the fibrous reinforcing material (E-1) was fed from a side feeder, and further kneading was performed. After taking the strand shape from the die, it was passed through a water bath to cool and solidify, and then cut with a pelletizer to obtain semi-aromatic polyamide resin composition pellets. The barrel temperature of the extruder was set to (melting point of semi-aromatic polyamide +5°C) to (melting point of semi-aromatic polyamide +15°C), screw rotation speed of 250 rpm, and discharge rate of 25 kg/h.

Examples 2 to 17, Comparative Examples 1 to 5
Semi-aromatic polyamide resin composition pellets were obtained by performing the same operation as in Example 1, except that the composition of the semi-aromatic polyamide resin composition was changed as shown in Table 2.

Various evaluation tests were conducted using the obtained semi-aromatic polyamide resin composition pellets. The results are shown in Table 2.

Since the resin compositions of Examples 1 to 17 meet all the requirements stipulated by the present invention, thermal aging in a temperature atmosphere of 150°C is highly suppressed, and the tensile strength retention after 3000 hours is were over 70% in all cases. Furthermore, the tensile strength retention rates after 24 hours of immersion in 50% sulfuric acid were all 80% or higher, and the tensile strength retention rates after 1000 hours of oil immersion were all 80% or higher.
By comparing Example 1 and Example 2 containing a copolymer component, it was found that the higher the crystallinity without the copolymer component, the higher the tensile strength retention after 3000 hours at 150°C and the 24 hour immersion in 50% sulfuric acid. It can be seen that the tensile strength retention rate after lapse of time and the tensile strength retention rate after 1000 hours of oil immersion become high.
By comparing Example 1, Examples 3 to 5, and 8 to 10, the higher the content of the copper compound and phosphorus antioxidant, the higher the tensile strength retention after 3000 hours at 150°C, 50%. It can be seen that the tensile strength retention rate after 24 hours of sulfuric acid immersion and the tensile strength retention rate after 1000 hours of oil immersion become high, and the effect is saturated in the high concentration region.
By comparing Example 1 and Example 11, it can be seen that the inclusion of carbon fiber increases the tensile strength.
By comparing Example 1 and Example 16, it can be seen that the inclusion of a stabilizer increases the tensile strength retention after 3000 hours at 150°C.

Since the resin compositions of Comparative Examples 1 to 5 did not contain any of copper compounds, polyhydric alcohols, and phosphorous antioxidants, the tensile strength retention after 3000 hours at 150°C and 50% sulfuric acid immersion were Either the tensile strength retention rate after 24 hours or the tensile strength retention rate after 1000 hours of oil immersion was low.

Claims (3)

100 parts by mass of a semi-aromatic polyamide (A) containing an aromatic dicarboxylic acid component and an aliphatic diamine component and having a melting point of 280 to 350°C, 0.01 to 2 parts by mass of a copper compound (B), polyhydric alcohol A semi-aromatic polyamide resin composition containing 0.05 to 10 parts by mass of (C) and 1 to 5 parts by mass of a phosphorous antioxidant (D). The semi-aromatic polyamide resin composition according to claim 1, further comprising 5 to 200 parts by mass of a fibrous reinforcing material (E). A molded article obtained by molding the semi-aromatic polyamide resin composition according to claim 1 or 2.