Polyamide resin composition and molded article thereof

Abstract

To provide a polyamide resin composition which can sufficiently enhance tensile elongation at break, and can enhance flowability under high temperature, and a molded body of the same.SOLUTION: A semi-aromatic polyamide resin composition contains a polyamide resin (A) and a styrenic thermoplastic elastomer (B), wherein the polyamide resin (A) includes a component unit containing an aromatic ring, a ratio of the total number of carbon atoms constituting the aromatic ring to the total number of carbon atoms constituting the component unit contained in the polyamide resin (A) is 30 to 60%, and a content of the styrenic thermoplastic elastomer (B) is 1 to 30 mass% to the total mass of the polyamide resin composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide resin composition and a molded article thereof. [Background technology]

[0002] Conventionally, various polyamide resin compositions have been known as molding materials. For example, Patent Document 1 describes: 40 to 90% by weight of units derived from terephthalic acid and hexamethylenediamine, Units derived from ε-caprolactam, 0 to 50% by weight, <c>It contains 0 to 60% by weight of adipic acid and a unit derived from hexamethylenediamine, and the above and / or <c>A partially aromatic (semi-aromatic) copolyamide is disclosed in which the copolyamide makes up at least 10% by weight of the total, and the copolyamide is less than 0.5% by weight of the triamine component. According to Patent Document 1, the above partially aromatic copolyamide was able to maintain mechanical strength while improving heat moldability.

[0003] Furthermore, Patent Document 2 discloses a polyamide resin composition comprising a crystalline copolyamide containing a predetermined amount of hexanemethylene terephthalamide units, and a predetermined amount of a modified or unmodified elastomer selected from polyolefin-based elastomers and diene-based elastomers. According to Patent Document 2, the above polyamide resin composition is said to have excellent mechanical properties, heat resistance, and moldability.

[0004] The polyamide resins described in these documents are significantly lighter than metals and possess excellent mechanical strength and heat resistance, making them suitable for use, for example, as resin materials for automotive parts. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-41318 [Patent Document 2] Japanese Patent Application Publication No. 5-98152 [Overview of the project] [Problems that the invention aims to solve]

[0006] Conventional polyamide resin compositions have high mechanical strength, but suffer from low flexibility and low tensile elongation at break. Low tensile elongation at break makes molded products prone to breakage during assembly. In contrast, while incorporating an elastomer, as described in Patent Document 2, can increase the tensile elongation at break of a molded product to some extent, it cannot sufficiently increase it. Furthermore, there is a demand to improve the fluidity of polyamide resin compositions at high temperatures during molding. This is because improving fluidity can reduce constraints on molding conditions and product shapes.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a polyamide resin composition and a molded article thereof that can more sufficiently increase tensile elongation at break and improve fluidity at high temperatures. [Means for solving the problem]

[0008] One aspect of the present invention, for solving the above problems, relates to the following polyamide resin compositions [1] to [9]. [1] A polyamide resin composition comprising a polyamide resin (A) and a styrene-based thermoplastic elastomer (B), wherein the polyamide resin (A) comprises component units including an aromatic ring, the ratio of the total number of carbon atoms constituting the aromatic ring to the total number of carbon atoms constituting the component units contained in the polyamide resin (A) is 30-60%, and the content of the styrene-based thermoplastic elastomer (B) is 1-30% by mass relative to the total mass of the polyamide resin composition. [2] The polyamide resin composition according to [1], wherein the styrene-based thermoplastic elastomer (B) is a styrene-based thermoplastic elastomer selected from the group consisting of styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene / butylene-styrene copolymer (SEBS), and styrene-ethylene / propylene-styrene copolymer (SEPS), or a modified version thereof. [3] The polyamide resin composition according to [1] or [2], wherein the styrene-based thermoplastic elastomer (B) comprises an elastomer modified with an unsaturated carboxylic acid or a derivative thereof, and the average content of component units derived from the unsaturated carboxylic acid or a derivative thereof relative to the total mass of the styrene-based thermoplastic elastomer (B) is 0.05 to 5.0% by mass. [4] The polyamide resin composition according to [3], wherein the amount of terminal amino groups of the polyamide resin (A) is 10 to 200 mmol / kg. [5] The polyamide resin composition according to [3] or [4], wherein [X] is the number of moles of terminal amino groups per unit mass of the polyamide resin composition, and [Y] is the number of moles of component units derived from the unsaturated carboxylic acid or its derivative contained in the styrene-based thermoplastic elastomer (B) per unit mass of the polyamide resin composition, and [X] / [Y] is 0.01 to 500. [6] The polyamide resin composition according to any one of [1] to [5], wherein the polyamide resin (A) comprises a component unit (a1) derived from a dicarboxylic acid and a component unit (a2) derived from a diamine, the component unit having an aromatic ring being a component unit derived from a dicarboxylic acid having an aromatic ring, and the content of the component unit having an aromatic ring is 60 mol% or more with respect to the total number of moles of the component unit (a1) derived from the dicarboxylic acid. [7] The polyamide resin composition according to [6], wherein the component unit (a1) derived from the dicarboxylic acid contains 45 to 100 mol% of component units derived from terephthalic acid with respect to the total number of moles of component units (a1) derived from the dicarboxylic acid, and the component unit (a2) derived from the diamine contains 40 to 100 mol% of component units derived from a linear alkylenediamine having 4 to 18 carbon atoms and 0 to 60 mol% of component units derived from a branched alkylenediamine having 4 to 18 carbon atoms with respect to the total number of moles of component units (a2) derived from the diamine. [8] The polyamide resin composition according to [7], wherein the component unit (a1) derived from the dicarboxylic acid contains 90 to 100 mol% of component units derived from terephthalic acid with respect to the total number of moles of component units (a1) derived from the dicarboxylic acid, and the component unit (a2) derived from the diamine contains 40 to 80 mol% of component units derived from a linear alkylenediamine having 4 to 18 carbon atoms and 20 to 60 mol% of component units derived from a branched alkylenediamine having 4 to 18 carbon atoms with respect to the total number of moles of component units (a2) derived from the diamine. [9] The component unit (a1) derived from the dicarboxylic acid comprises 20 to 80 mol% of component units derived from terephthalic acid and 20 to 80 mol% of component units derived from isophthalic acid, with respect to the total number of moles of component units (a1) derived from the dicarboxylic acid. The polyamide resin composition according to [7], wherein the component unit (a2) derived from the diamine comprises a component unit derived from an aliphatic diamine having 4 to 15 carbon atoms.

[0009] One aspect of the present invention, for solving the above problems, relates to the molded article described below

[10] . A molded article obtained by molding a polyamide resin composition as described in any of

[10] [1] to [9]. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a polyamide resin composition and a molded article thereof that can more sufficiently increase tensile elongation at break and improve fluidity at high temperatures. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments.

[0012] In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical ranges described in other stepwise descriptions.

[0013] As described above, by adding an elastomer to a polyamide resin, the flexibility of a molded body formed from a polyamide resin composition containing these can be enhanced, and the tensile elongation at break can be increased to a certain extent. However, in the polyamide resin composition described in Patent Document 2, the tensile elongation at break of the molded body did not increase sufficiently.

[0014] In contrast, the present inventors have found that by using a styrenic thermoplastic elastomer (B) with respect to a polyamide resin (A) having more aromatic rings in its molecular structure, the tensile elongation at break of the molded body can be increased more sufficiently than when using other elastomers with respect to the same type of polyamide resin (A), and the improvement rate (improvement ratio) is higher than when using a polyamide resin having fewer aromatic rings in its molecular structure.

[0015] Specifically, the above polyamide resin (A) contains a component unit containing an aromatic ring, and the ratio of the total number of carbon atoms constituting the aromatic ring to the total number of carbon atoms constituting the component units contained in the polyamide resin (A) is 30 to 60%. The reason why the tensile elongation at break and its improvement rate increase more sufficiently by using such a polyamide resin (A) and a styrenic thermoplastic elastomer (B) is considered as follows.

[0016] It is believed that interactions occur in the polyamide resin composition between the aromatic rings contained in the molecular structure of the polyamide resin (A) and the aromatic rings contained in the molecular structure of the styrene-based thermoplastic elastomer (B). In this case, it is believed that the more aromatic rings contained in the molecular structure of the polyamide resin (A), the easier it is for interactions to occur with the aromatic rings of the styrene-based thermoplastic elastomer (B). In the polyamide resin composition, it is believed that the molecules of the polyamide resin (A) and the styrene-based thermoplastic elastomer (B) can exist in close proximity to each other as a result of the above interaction. This is believed to increase the strength of the molded article and make it less likely for the molded article to break when tensile stress is applied. In a polyamide resin composition whose flexibility has been increased by the addition of elastomer, it is believed that the above-mentioned breakage is less likely to occur, and as a result, the tensile elongation at break can be increased more sufficiently when tensile stress is applied to the molded article.

[0017] Furthermore, the inventors have found that by using the above-mentioned polyamide resin (A) and styrene-based thermoplastic elastomer (B), the fluidity of the polyamide resin composition at high temperatures (hereinafter also simply referred to as fluidity) can be increased compared to when other elastomers are used with the same type of polyamide resin (A), and that the rate of improvement is higher than when using a polyamide resin with fewer aromatic rings in the molecular structure. The reason for this is thought to be as follows.

[0018] Under high-temperature conditions, the molecular motion of polyamide resin (A) and styrene-based thermoplastic elastomer (B) is activated. When molecular motion is activated, the aromatic rings of the polyamide resin (A) and styrene-based thermoplastic elastomer (B) are less likely to exist in close proximity to each other in their molecular structures. As a result, interaction between the aromatic rings of polyamide resin (A) and styrene-based thermoplastic elastomer (B) becomes less likely, and the molecules of polyamide resin (A) and styrene-based thermoplastic elastomer (B) are less likely to exist in close proximity to each other. Consequently, it is believed that the fluidity of the polyamide resin composition increases under high-temperature conditions.

[0019] The configuration of the present invention will be described below.

[0020] 1. Polyamide resin composition The polyamide resin composition of the present invention comprises a polyamide resin (A) and a styrene-based thermoplastic elastomer (B).

[0021] 1-1. Polyamide resin (A) As described above, the polyamide resin (A) contains a component unit that includes an aromatic ring. The aromatic ring is preferably a benzene ring.

[0022] The polyamide resin (A) can be, for example, a polyamide containing component units (a1) derived from a dicarboxylic acid and component units (a2) derived from a diamine. The following describes the case in which the polyamide resin (A) contains component units (a1) derived from a dicarboxylic acid and component units (a2) derived from a diamine.

[0023] (Component unit (a1) derived from dicarboxylic acid) The component unit (a1) derived from a dicarboxylic acid may include, for example, a component unit derived from a dicarboxylic acid having an aromatic ring.

[0024] The aromatic ring-containing component units in the polyamide resin (A) are preferably derived from a dicarboxylic acid having an aromatic ring. In this case, the content of the aromatic ring-containing component units is preferably 60 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more, relative to the total number of moles of the component units (a1) derived from the dicarboxylic acid. When the content is 60 mol% or more, it becomes easier to uniformly disperse the styrene-based thermoplastic elastomer (B) in the polyamide resin composition, and interaction between the aromatic ring of the polyamide resin (A) and the aromatic ring of the styrene-based thermoplastic elastomer (B) can be easily generated. The upper limit of the content is not particularly limited, but for example, it is preferably 100 mol% or less, and preferably 90 mol% or less.

[0025] Examples of dicarboxylic acids having the above-mentioned aromatic ring include aromatic dicarboxylic acids.

[0026] Examples of aromatic dicarboxylic acids include terephthalic acid and aromatic carboxylic acids other than terephthalic acid.

[0027] Examples of terephthalic acid include terephthalic acid and terephthalic acid esters. Of these, terephthalic acid is preferred.

[0028] The component units (a1) derived from dicarboxylic acid preferably contain 45 to 100 mol% of component units derived from terephthalic acid, and more preferably 90 to 100 mol% of component units derived from terephthalic acid, relative to the total number of moles of component units (a1) derived from dicarboxylic acid. When the content of component units derived from terephthalic acid is 45 mol% or more, the melting point of the polyamide resin (A) can be easily increased, and the heat resistance of the resulting molded article can be improved. Furthermore, the ratio of the total number of carbon atoms constituting the aromatic ring to the total number of carbon atoms constituting the component units contained in the polyamide resin (A) can be more easily increased. This makes it easier to induce interaction between the styrene-based thermoplastic elastomer (B) and the polyamide resin (A), and makes it easier to improve the tensile elongation at break and fluidity.

[0029] Examples of aromatic dicarboxylic acids other than terephthalic acid include isophthalic acid, 2-methylterephthalic acid, and naphthalenedicarboxylic acid. Of these, isophthalic acid is preferred.

[0030] When the component unit (a1) derived from dicarboxylic acid contains component units derived from isophthalic acid, the component unit (a1) derived from dicarboxylic acid preferably contains 20 to 80 mol% of component units derived from terephthalic acid and 20 to 80 mol% of component units derived from isophthalic acid, more preferably contains 25 to 75 mol% of component units derived from terephthalic acid and 25 to 75 mol% of component units derived from isophthalic acid, and even more preferably contains 55 to 75 mol% of component units derived from terephthalic acid and 25 to 45 mol% of component units derived from isophthalic acid. Having the content of terephthalic acid and isophthalic acid within the above ranges makes it possible to maintain the crystallinity of the polyamide resin (A) while improving its moldability.

[0031] The component unit (a1) derived from a dicarboxylic acid may further include component units derived from other dicarboxylic acids other than aromatic dicarboxylic acids, to the extent that the effects of the present invention are not impaired. Examples of component units derived from other dicarboxylic acids include component units derived from aliphatic dicarboxylic acids having 4 to 20 carbon atoms, and component units derived from alicyclic dicarboxylic acids having 4 to 20 carbon atoms.

[0032] The above aliphatic dicarboxylic acid is an aliphatic dicarboxylic acid having 4 to 20 carbon atoms, preferably 6 to 12 carbon atoms. Examples of such aliphatic dicarboxylic acids include adipic acid, azelaic acid, and sebacic acid. Among these, adipic acid and sebacic acid are preferred.

[0033] Examples of alicyclic dicarboxylic acids include 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid.

[0034] The content of component units derived from other dicarboxylic acids can be 0 to 40 mol%, preferably 0 to 30 mol%, and more preferably 0 to 10 mol%, relative to the total number of moles of component units (a1) derived from dicarboxylic acids.

[0035] (Component unit (a2) derived from diamine) The component unit (a2) derived from the diamine may include, for example, component units derived from aliphatic diamines having 4 to 18 carbon atoms, component units derived from alicyclic diamines having 4 to 20 carbon atoms, and aromatic diamines. Of these, it is preferable that the component unit (a2) derived from the diamine includes component units derived from aliphatic diamines having 4 to 18 carbon atoms.

[0036] The above aliphatic diamine is an aliphatic diamine having 4 to 18 carbon atoms, preferably 4 to 15 carbon atoms. Examples of such aliphatic diamines include linear alkylenediamines having 4 to 18 carbon atoms, and branched alkylenediamines (alkylenediamines having side chains) having 4 to 18 carbon atoms.

[0037] Examples of the linear alkylenediamines mentioned above include 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, and 1,12-diaminododecane. Among these, 1,6-diaminohexane, 1,9-nonanediamine, and 1,10-diaminodecane are preferred. The linear alkylenediamine may be present as a single type or as two or more types.

[0038] The content of component units derived from the linear alkylenediamine is preferably 40 to 100 mol%, and more preferably 40 to 80 mol%, relative to the total number of moles of component units (a2) derived from the diamine.

[0039] Examples of the above branched alkylenediamines include 1-butyl-1,2-diaminoethane, 2,2-dimethyldiaminopropane, 1,1-dimethyl-1,4-diaminobutane, 1-ethyl-1,4-diaminobutane, 1,2-dimethyl-1,4-diaminobutane, 1,3-dimethyl-1,4-diaminobutane, 1,4-dimethyl-1,4-diaminobutane, 2,3-dimethyl-1,4-diaminobutane, 2-methyl-1,5-diaminopentane, 2,5-dimethyl-1,6- Diaminohexane, 2,4-dimethyl-1,6-diaminohexane, 3,3-dimethyl-1,6-diaminohexane, 2,2-dimethyl-1,6-diaminohexane, 2,2,4-trimethyl-1,6-diaminohexane, 2,4,4-trimethyl-1,6-diaminohexane, 2,4-diethyl-1,6-diaminohexane, 2,3-dimethyl-1,7-diaminoheptane, 2,4-dimethyl-1,7-diaminoheptane, 2,5-dimethyl-1,7-diaminoheptane Butane, 2,2-dimethyl-1,7-diaminoheptane, 2-methyl-4-ethyl-1,7-diaminoheptane, 2-ethyl-4-methyl-1,7-diaminoheptane, 2,2,5,5-tetramethyl-1,7-diaminoheptane, 3-isopropyl-1,7-diaminoheptane, 3-isooctyl-1,7-diaminoheptane, 2-methyl-1,8-diaminooctane, 1,3-dimethyl-1,8-diaminooctane, 1,4-dimethyl-1,8-diaminooctane These include 2,4-dimethyl-1,8-diaminooctane, 3,4-dimethyl-1,8-diaminooctane, 4,5-dimethyl-1,8-diaminooctane, 2,2-dimethyl-1,8-diaminooctane, 3,3-dimethyl-1,8-diaminooctane, 4,4-dimethyl-1,8-diaminooctane, 3,3,5-trimethyl-1,8-diaminooctane, 2,4-diethyl-1,8-diaminooctane, and 5-methyl-1,9-diaminononane. Among these, 2-methyl-1,5-diaminopentane is more preferred.

[0040] The content of the component units derived from the branched alkylenediamine is preferably 0 to 60 mol%, and more preferably 20 to 60 mol%, relative to the total number of moles of component units (a2) derived from the diamine.

[0041] When the component unit (a2) derived from diamine contains component units derived from linear and branched alkylenediamine in the amounts described above, the melting point of the polyamide resin (A) can be lowered to a level that prevents gas burning of the polyamide resin composition during molding. Furthermore, the melt fluidity of the polyamide resin composition during molding can be further improved, and the creep resistance of the molded article at high temperatures can be enhanced.

[0042] When the component unit (a2) derived from the diamine contains both component units derived from linear alkylenediamines with 4 to 18 carbon atoms and component units derived from branched alkylenediamines with 4 to 18 carbon atoms, the melt fluidity during molding can be further improved if the content of the component units derived from the linear alkylenediamine is 99 mol% or less of the total number of moles of both. Furthermore, if the content of the component units derived from the branched alkylenediamine is 50 mol% or less of the total number of moles, the crystallization rate of the polyamide resin (A) is less likely to slow down, and sufficient heat resistance is more easily achieved.

[0043] When the component unit (a1) derived from the dicarboxylic acid contains a component unit derived from an aliphatic diamine having 4 to 15 carbon atoms, the component unit (a2) derived from the diamine preferably contains a component unit derived from an aliphatic diamine having 4 to 15 carbon atoms.

[0044] In this case, the content of component units derived from aliphatic diamines having 4 to 15 carbon atoms is preferably 30 to 100 mol%, and more preferably 70 to 100 mol%, relative to the total number of moles of component units (a2) derived from diamines.

[0045] Examples of alicyclic diamines with 4 to 20 carbon atoms include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 2,5-bisaminomethylnorbornane, and 2,6-bisaminomethylnorbornane. Examples of aromatic diamines include metaxylylenediamine.

[0046] The content of component units derived from alicyclic diamines having 4 to 20 carbon atoms can be 0 to 75 mol%, and preferably 35 to 65 mol%, relative to the total number of moles of component units (a2) derived from diamines.

[0047] The content of component units derived from aromatic diamines can be 0 to 50 mol%, and preferably 0 to 30 mol%, relative to the total number of moles of component units derived from diamines.

[0048] The constituent units of polyamide resin (A) and their ratios can be calculated from the charging ratio during the preparation of polyamide resin (A), or measured by NMR spectroscopy.

[0049] 1 For H-NMR measurements, for example, a nuclear magnetic resonance spectrometer (ECX400 model, manufactured by JEOL Ltd.) is used, the solvent is deuterated orthodichlorobenzene, the sample concentration is 20 mg / 0.6 mL, the measurement temperature is 120°C, and the observed nucleus is 1 The conditions are as follows: H (400 MHz), sequence is single pulse, pulse width is 5.12 μs (45° pulse), repetition time is 7.0 seconds, and number of integrations is 500 or more. The reference chemical shift is set to 0 ppm for hydrogen of tetramethylsilane, but similar results can also be obtained by setting the peak derived from residual hydrogen of deuterated orthodichlorobenzene to 7.10 ppm as the reference value for the chemical shift. 1 Peaks such as H can be assigned using conventional methods.

[0050] 13 For 13C-NMR measurements, for example, a nuclear magnetic resonance spectrometer (ECP500 model, manufactured by JEOL Ltd.) is used as the measuring instrument, an orthodichlorobenzene / deuterated benzene (80 / 20 vol%) mixed solvent is used, the measurement temperature is 120°C, and the observed nucleus is 13 The conditions are as follows: C (125MHz), single-pulse proton decoupling, 45° pulse, repetition time 5.5 seconds, accumulation count of 10,000 or more, and chemical shift reference value of 27.50 ppm. Various signals are assigned based on conventional methods, and quantification can be performed based on the accumulated value of the signal intensity.

[0051] Specific examples of polyamide resin (A) include polyamide resins in which the component unit (a1) derived from dicarboxylic acid is derived from terephthalic acid and the component unit (a2) derived from diamine is derived from 1,6-diaminohexane and 2-methyl-1,5-pentanediamine; polyamide resins in which the component unit (a1) derived from dicarboxylic acid is derived from terephthalic acid and isophthalic acid and the component unit (a2) derived from diamine is derived from 1,6-diaminohexane; polyamide resins in which the component unit (a1) derived from dicarboxylic acid is derived from terephthalic acid and the component unit (a2) derived from diamine is derived from 1,9-diaminononane; and polyamide resins in which the component unit (a1) derived from dicarboxylic acid is derived from terephthalic acid and the component unit (a2) derived from diamine is derived from 1,10-diaminodecane.

[0052] (Physical properties of polyamide resin (A)) In the present invention, the polyamide resin preferably has a melting point (Tm) of 280°C or higher, more preferably 280 to 340°C, and even more preferably 300 to 330°C, as measured by a differential scanning calorimeter (DSC). When the melting point (Tm) is 280°C or higher, the tensile strength and heat resistance of the polyamide resin composition and molded article can be further increased. Furthermore, when the melting point (Tm) is 340°C or lower, the polyamide resin composition can be easily molded without excessively raising the molding temperature, and the moldability can be further improved. In addition, the thermal decomposition of the polyamide resin (A) and other components during melting can be further suppressed.

[0053] The melting point (Tm) of the polyamide resin (A) described above can be brought within the above range by adjusting the composition of the polyamide resin (A). For example, the melting point (Tm) can be increased by increasing the content ratio of the component units derived from terephthalic acid, which will be described later.

[0054] Furthermore, the polyamide resin (A) preferably has a glass transition temperature (Tg) of 90 to 145°C, and more preferably 100 to 145°C, as measured by a differential scanning calorimeter (DSC). When the glass transition temperature (Tg) is 90°C or higher, the temperature at which molecular mobility becomes active in a high-temperature environment increases, thereby suppressing molecular mobility and further improving the heat resistance of the polyamide resin composition and molded article. Also, when the glass transition temperature (Tg) is 145°C or lower, the cycle time during injection molding can be shortened when the molten polyamide resin composition is cooled during molding.

[0055] The heat of fusion (ΔH) of the polyamide resin (A), as measured by differential scanning calorimetry (DSC), is preferably 0 to 70 J / g, more preferably 20 to 65 J / g, and even more preferably 30 to 60 J / g. The heat of fusion is an indicator of the crystallinity of the resin; a higher heat of fusion indicates higher crystallinity of the polyamide resin (A). When the heat of fusion (ΔH) of the polyamide resin (A) is 30 J / g or higher, the crystallinity of the polyamide resin (A) is further increased, and the tensile strength of the polyamide resin composition and molded article can be increased.

[0056] The melting point (Tm), glass transition temperature (Tg), and heat of fusion (ΔH) of polyamide resin can be measured using a differential scanning calorimeter (DSC220C model, manufactured by Seiko Instruments Inc.).

[0057] Specifically, approximately 5 mg of polyamide resin is sealed in a measuring aluminum pan and heated from room temperature to 350°C at a rate of 10°C / min. To completely melt the resin, it is held at 350°C for 3 minutes, and then cooled to 30°C at a rate of 10°C / min. After being left at 30°C for 5 minutes, a second heating is performed to 350°C at a rate of 10°C / min. The temperature of the endothermic peak (°C) during this second heating is defined as the melting point (Tm) of the polyamide resin, and the displacement point corresponding to the glass transition is defined as the glass transition temperature (Tg). The heat of fusion (ΔH) is determined from the area of ​​the endothermic peak during melting in the first heating process, in accordance with JIS K7122:2012.

[0058] The intrinsic viscosity [η] of the polyamide resin (A), measured at a temperature of 25°C in concentrated sulfuric acid, is preferably 0.70 to 1.2 dl / g, and more preferably 0.75 to 1.1 dl / g. When the intrinsic viscosity [η] of the polyamide resin (A) is 0.75 dl / g or higher, the decrease in the tensile strength of the polyamide resin composition can be sufficiently suppressed. When the intrinsic viscosity [η] is 1.1 dl / g or lower, the fluidity of the polyamide resin composition during molding is less likely to be impaired.

[0059] The intrinsic viscosity [η] of the semi-aromatic polyamide resin (A) can be measured as follows: Dissolve 0.5 g of the semi-aromatic polyamide resin (A) in 50 ml of 96.5% sulfuric acid solution to prepare the sample solution. Measure the flow time of the obtained solution at 25°C ± 0.05°C using an Ubbelohde viscometer and calculate the intrinsic viscosity [η] based on the following formula. [η] = ηSP / (C * (1 + 0.205ηSP)) [η]: Intrinsic viscosity (dl / g) ηSP: Specific viscosity C: Sample concentration (g / dl) t: Number of seconds (seconds) the sample solution flows down. t0: Number of seconds (seconds) of the blank sulfuric acid flowing down the flow. ηSP = (t - t0) / t0

[0060] As described above, the polyamide resin (A) contains component units including aromatic rings, and the ratio of the total number of carbon atoms constituting the aromatic rings to the total number of carbon atoms constituting the component units in the polyamide resin (A) is 30-60%. If it is 30% or more, it can cause interaction with the aromatic rings of the styrene-based thermoplastic elastomer, thereby increasing the tensile elongation at break of the molded article and the fluidity of the polyamide resin composition. If it is 60% or less, it can suppress the occurrence of the above interaction excessively, thereby appropriately adjusting the melt viscosity of the polyamide resin composition. This can improve the moldability of the polyamide resin composition. From these viewpoints, the above ratio is preferably 35-55%, and more preferably 40-50%. The above ratio of carbon atoms can be adjusted by the combination of dicarboxylic acid and diamine used in the preparation of the polyamide resin (A), and the content ratio of aromatic dicarboxylic acid and aromatic diamine.

[0061] The amount of terminal amino groups in the polyamide resin (A) is preferably 10 mmol / kg or more, more preferably 20 mmol / kg or more, and even more preferably 40 mmol / kg or more. When the amount of terminal amino groups is 10 mmol / kg or more, when the styrene-based thermoplastic elastomer (B) contains a styrene-based thermoplastic elastomer modified with an unsaturated carboxylic acid or its derivative described later, interactions are more likely to occur between the modified portion of the modified styrene-based thermoplastic elastomer and the terminal amino groups of the polyamide resin (A). As a result, the molecules of the polyamide resin (A) and the styrene-based thermoplastic elastomer (B) can be more closely coupled, making the molded article less prone to breakage and increasing the tensile elongation at break of the polyamide resin composition. The upper limit of the amount of terminal amino groups is not particularly limited, but for example, it can be 200 mmol / kg or less.

[0062] The amount of terminal amino groups can be adjusted to the above range by adjusting the content of component units derived from dicarboxylic acid (a1) and component units derived from diamine (a2), or by using an end encapsulant during the synthesis of the polyamide resin.

[0063] The end-capturing agent is preferably a monoamine if the molecular end is a carboxyl group, and preferably a monocarboxylic acid if the molecular end is an amino group.

[0064] Examples of monoamines include aliphatic monoamines such as methylamine, ethylamine, propylamine, and butylamine; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; and aromatic monoamines such as aniline and toluidine. Examples of monocarboxylic acids include aliphatic monocarboxylic acids having 2 to 30 carbon atoms such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecyl acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid; and alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid. Aromatic monocarboxylic acids and alicyclic monocarboxylic acids may have substituents on the cyclic structure.

[0065] The amount of terminal amino groups mentioned above can be measured, for example, by the following method.

[0066] Dissolve 1 g of polyamide resin in 35 mL of phenol and mix with 2 mL of methanol to prepare the sample solution. Using thymol blue as an indicator, titrate the sample solution with a 0.01 N aqueous hydrochloric acid solution using a potentiometric titrator (Metrohm) until the solution changes from blue to yellow, and measure the amount of terminal amino groups ([NH2], unit: mmol / kg).

[0067] Polyamide resins can be produced in the same manner as known polyamide resins, for example, by polycondensation of a dicarboxylic acid and a diamine in a homogeneous solution. Specifically, a lower-order condensate can be obtained by heating a dicarboxylic acid and a diamine in the presence of a catalyst, as described in International Publication No. 03 / 085029, and then polycondensation can be carried out by applying shear stress to the molten lower-order condensate.

[0068] Furthermore, the component units derived from dicarboxylic acid in the polyamide resin (A1) may include component units derived from biomass-derived dicarboxylic acid, and the component units derived from diamine may include component units derived from biomass-derived diamine. In addition, the polyamide resin (A1) may be a biomass-derived polyamide resin (A1) obtained by polymerizing a group of raw materials including biomass-derived raw materials.

[0069] 1-2. Styrene-based thermoplastic elastomer (B) By incorporating the styrene-based thermoplastic elastomer (B) into a polyamide resin composition, the tensile elongation at break, tensile strength at break, flexural strength, flexural modulus, fluidity, etc., of the resulting molded article can be improved.

[0070] Examples of styrene-based thermoplastic elastomers (B) include styrene-butadiene-styrene copolymers (SBS), styrene-isoprene-styrene copolymers (SIS), styrene-ethylene / butylene-styrene copolymers (SEBS), and styrene-ethylene / propylene-styrene copolymers (SEPS), or modified versions thereof.

[0071] In the styrenic thermoplastic elastomer (B), the content of the component unit derived from styrene is preferably 20 to 80 mol%, more preferably 30 to 65 mol%, based on the total number of moles of all component units. When the above content is 20 mol% or more, more interaction can occur between the aromatic ring of the polyamide resin (A) and the aromatic ring of the styrenic thermoplastic elastomer, so that the tensile elongation at break and the fluidity at high temperature of the polyamide resin composition can be further increased. When the above content is 80 mol% or less, it is possible to suppress the excessive occurrence of the above interaction and appropriately adjust the melt viscosity of the polyamide resin composition. The content of the component unit derived from styrene can be calculated from the charging ratio during the preparation of the styrenic thermoplastic elastomer (B) or measured by the NMR method. The NMR method can be the same as that described for the polyamide resin (A).

[0072] The density of the styrenic thermoplastic elastomer (B) measured in accordance with JIS K7112:1999 is preferably 0.850 to 1.000 g / cm 3 and more preferably 0.890 to 0.980 g / cm 3 When the above density is 0.850 g / cm 3 or more, the strength of the obtained molded body is hardly impaired, and when it is 0.980 g / cm 3 or less, appropriate flexibility can be imparted to the obtained molded body, and a decrease in tensile elongation at break can be further suppressed. The density of the styrenic thermoplastic elastomer (B) can be adjusted by the composition of the raw materials used in the synthesis of the resin before modification, the polymerization temperature, the hydrogen concentration, etc., which are the raw materials.

[0073] The melt flow rate (MFR) of the styrene-based thermoplastic elastomer (B) is preferably 0.1 to 50 g / 10 min, and more preferably 0.2 to 20 g / 10 min, as measured by ASTM D1238 at 190°C and a 2.16 kg load. If the MFR is 0.1 g / 10 min or higher, the fluidity of the polyamide resin composition at high temperatures can be further increased, and if it is 50 g / 10 min or lower, the obtained polyamide resin composition can be easily injection molded.

[0074] The styrene-based thermoplastic elastomer (B) preferably contains a styrene-based thermoplastic elastomer modified with an unsaturated carboxylic acid or its derivative (hereinafter referred to as the modified elastomer). The inclusion of the modified elastomer in the styrene-based thermoplastic elastomer (B) allows it to react with the polyamide resin (A) more easily, thereby imparting greater flexibility. The modified elastomer contains component units derived from an unsaturated carboxylic acid or its derivative.

[0075] Modified elastomers are obtained by graft-modifying unmodified styrene-based thermoplastic elastomers with unsaturated carboxylic acids or their derivatives.

[0076] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. Examples of derivatives of unsaturated carboxylic acids include acid anhydrides, esters, amides, imides, and metal salts, specifically maleic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, glycidyl acrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, monomethyl itaconic acid, diethyl itaconic acid, acrylamide, and methacrylic acid. This includes maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethylamide, maleic acid-N,N-diethylamide, maleic acid-N-monobutylamide, maleic acid-N,N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monobutylamide, fumaric acid-N,N-dibutylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, etc. Among these, maleic anhydride is preferred.

[0077] Graft modification can be carried out by various conventionally known methods. For example, it may be carried out by a melt modification method in which an unmodified styrene-based thermoplastic elastomer is melted using an extruder and graft monomers are added to perform graft copolymerization. From the viewpoint of efficiently graft copolymerizing the graft monomers, it is preferable to carry out the reaction in the presence of a radical initiator.

[0078] Examples of radical initiators include organic peroxides and organic peresters, specifically organic peroxides such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxidebenzoate)hexyn-3, 1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-butyl peracetate, and 2,5-dimethyl-2,5-di(tert- This includes organic peresters such as butylperoxy)hexine-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylperbenzoate, tert-butylperphenylacetate, tert-butylperisobutyrate, tert-butylper-sec-octoate, tert-butylperpivalate, cumylpervivalate, and tert-butylperdiethylacetate, as well as azo compounds such as azoisobutyronitrile and dimethylazoisobutyrate. Among these, dialkyl peroxides such as dicumylperoxide, di-tert-butylperoxide, 2,5-dimethyl-2,5-di(peroxybenzoate)hexine-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 1,4-bis(tert-butylperoxyisopropyl)benzene are preferred. Radical initiators are typically used in a ratio of 0.001% to 1% by mass relative to the mass of the ethylene-α-olefin copolymer used as a raw material.

[0079] The average content of the unsaturated carboxylic acid or its derivatives (average modification amount of the modified elastomer) relative to the total mass of the styrene-based thermoplastic elastomer (B) is preferably 0.05 to 5.00% by mass, more preferably 0.10 to 3.00% by mass, even more preferably 0.10 to 2.00% by mass, and particularly preferably 0.30 to 2.00% by mass. When the above average content (average modification amount) is 0.05% by mass or more, the modified elastomer reacts more readily with the polyamide resin. Furthermore, when the above average content (average modification amount) is 5.00% by mass or less, molding defects due to thickening and gelation can be suppressed.

[0080] The above average content (average modification amount) may be determined by measurement, or it may be calculated from the composition of the styrene-based thermoplastic elastomer (B) used in the preparation of the polyamide resin composition.

[0081] For example, the average content of component units derived from unsaturated carboxylic acids or their derivatives in styrene-based thermoplastic elastomer (B) can be measured by NMR spectroscopy. The measurement conditions can be the same as those described in the examples below.

[0082] The styrene-based thermoplastic elastomer (B) may contain an unmodified elastomer. The unmodified elastomer is a styrene-based thermoplastic elastomer that has not been modified with an unsaturated carboxylic acid or its derivative. Including an unmodified elastomer in the styrene-based thermoplastic elastomer can further improve the melt fluidity of the polyamide resin composition.

[0083] The unmodified elastomer can be, for example, a styrene-based thermoplastic elastomer used as a raw material for modified elastomers. However, the unmodified elastomer may be different from the styrene-based thermoplastic elastomer used as a raw material for modified elastomers.

[0084] When the styrene-based thermoplastic elastomer (B) contains an unmodified elastomer, the above average content (amount of modification) can also be calculated from the following formula (1), where xi (mass%) is the content (amount of modification) of component units derived from unsaturated carboxylic acids or their derivatives in the modified and unmodified elastomers constituting the styrene-based thermoplastic elastomer (B), and Mi (parts by mass) is the content of the modified and unmodified elastomers in the styrene-based thermoplastic elastomer (B) (i is an integer of 2 or more). Formula (1): Average content (average denaturation amount) (mass%) = (Σxi*Mi / ΣMi)×100

[0085] 1-3. Other ingredients The semi-aromatic polyamide resin composition of the present invention may further contain other components not mentioned above, as long as they do not impair the effects of the present invention. Examples of other components include additives such as inorganic fillers, organic fillers, organic flame retardants, inorganic flame retardants, lubricants, antioxidants (heat stabilizers), heat stabilizers, weather stabilizers, antistatic agents, anti-slip agents, anti-blocking agents, anti-fogging agents, pigments, dyes, natural oils, synthetic oils, and waxes. Other elastomers and other heat-resistant resins may also be further included.

[0086] (Inorganic filler (C)) The inorganic filler (C) may be an inorganic filler having a fibrous, powdery, granular, plate-like, needle-like, cloth-like, or mat-like shape.

[0087] Examples of fibrous inorganic fillers include glass fibers, carbon fibers, asbestos fibers, and boron fibers. Among these, glass fibers are particularly preferred. Using glass fibers improves moldability and enhances the mechanical properties such as strength (elastic modulus) and heat resistance properties such as heat distortion temperature of the molded article containing the inorganic filler.

[0088] The average length of the fibrous inorganic filler is usually 0.1 to 20.0 mm, and preferably 0.3 to 6.0 mm or less. The aspect ratio of the fibrous inorganic filler is usually 10 to 2000 and preferably 30 to 600.

[0089] In addition to fibrous inorganic fillers, other fillers in the form of powders, granules, plates, needles, cloths, or mats may also be used. Examples of such other fillers include powdered or plated inorganic compounds such as silica, silica-alumina, alumina, calcium carbonate, titanium dioxide, talc, wollastonite, diatomaceous earth, clay, kaolin, spherical glass, mica, gypsum, red iron oxide, magnesium oxide, and zinc oxide, as well as needle-shaped inorganic compounds such as potassium titanate. These fillers can also be used in mixtures of two or more types.

[0090] The average particle size of the other fillers is typically 0.1 to 200 μm, and preferably 1 to 100 μm.

[0091] Fibrous fillers and other fillers can also be used after being treated with silane coupling agents or titanium coupling agents.

[0092] The inorganic filler (C) preferably contains at least one of a fibrous filler and another filler, and more preferably contains at least one of a fibrous filler and talc.

[0093] (Lubricant (D)) The lubricant (D) can further enhance the fluidity of the semi-aromatic polyamide resin composition during melt kneading and reduce mold release resistance.

[0094] As a lubricant (D), higher fatty acids, their metal salts, esters, or amides can be used.

[0095] Higher fatty acids have 8 or more carbon atoms, and are preferably fatty acids with 8 to 40 carbon atoms. Fatty acids are preferably monocarboxylic acids. Examples of higher fatty acids include saturated fatty acids such as octic acid, lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, and sebacic acid, as well as unsaturated fatty acids such as erucic acid, oleic acid, and ricinoleic acid. Of these, montanic acid, 12-hydroxystearic acid, and behenic acid are preferred.

[0096] Metal salts of higher fatty acids are metal salts of the above-mentioned higher fatty acids. Examples of metal elements that form metal salts include Group 1 elements (alkali metals) such as sodium and potassium, Group 2 elements (alkaline earth metals) such as calcium, magnesium, and barium, and Group 3 elements such as zinc and aluminum, with calcium salts, magnesium salts, zinc salts, and aluminum salts being preferred. Examples of such metal salts of higher fatty acids include calcium 12-hydroxystearate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, aluminum 12-hydroxystearate, calcium behenate, zinc behenate, magnesium behenate, sodium montanaate, calcium montanaate, zinc montanaate, magnesium montanaate, and aluminum montanaate. Of these, metal salts of montanaate and metal salts of 12-hydroxystearate are preferred.

[0097] Higher fatty acid esters are esterified products of the above-mentioned higher fatty acids with alcohols (preferably aliphatic alcohols having 8 to 40 carbon atoms). Examples of aliphatic alcohols include stearyl alcohol, behenyl alcohol, and lauryl alcohol. Examples of higher fatty acid esters include stearyl stearate and behenyl behenate.

[0098] Examples of higher fatty acid amides include stearic acid amide, oleic acid amide, erucic acid amide, ethylenebisstearyl amide, ethylenebisoleyl amide, N-stearylstearyl amide, and N-stearylerucaamide.

[0099] (Antioxidant (E)) Examples of antioxidants (E) include phosphorus-based antioxidants, phenol-based antioxidants, amine-based antioxidants, and sulfur-based antioxidants.

[0100] Examples of phosphorus-based antioxidants include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, triphenyl phosphite, 2-ethylhexyl phosphate, dilauryl phosphite, tri-iso-octyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, trilauryl phosphite, trilauryl-di-thiophosphite, trilauryl-tri-thiophosphite, trisnonylphenyl phosphite, distearyl pentaerythritol diphosphite, tris(mononylphenyl) phosphite, tris(dinonylphenyl) phosphite, trioctadecyl phosphite, 1,1,3-tris(2-methyl-di-tridecyl phosphite-5-tert-butylphenyl)butane, and 4,4′-butylidene-bis(3-methyl-6-tert-butyl)tridecyl This includes syl phosphite, 4,4′-butylidene-bis(3-methyl-6-tert-butyl-di-tridecyl) phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol-diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol-diphosphite, tetrakis(2,4-di-tert-butylphenyl)4,4′-bisphenylenediphosphite, distearyl pentaerythritol diphosphite, tridecyl phosphite, tristearyl phosphite, 2,2′-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, sorbitol-tris-phosphite-distearyl-mono-C30-diol ester, and bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite. Among these are pentaerythritol-diphosphite-based phosphorus antioxidants such as bis(2,4-di-tert-butylphenyl)pentaerythritol-diphosphite and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol-diphosphite, as well as tetrakis(2,4-di-tert-butylphenyl)4,4′-bisphenylenediphosphite.

[0101] Examples of phenolic antioxidants include 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyl]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 2,6-di-tert-butyl-p-cresol, 2,4,6-tri-tert-butylphenol, n-octadecyl-3-(4′-hydroxy-3′,5′-di-tert-butylphenol)propionate, styrene-phenol, and 4-hydroxy-methyl-2,6-di-tert-butylphenol. Tylphenol, 2,5-di-tert-butyl-hydroquinone, cyclohexylphenol, butylhydroxyanisole, 2,2′-methylene-bis-(4-methyl-6-tert-butylphenol), 2,2′-methylene-bis-(4-ethyl-6-tert-butylphenol), 4,4′-iso-propylenebisphenol, 4,4′-butylidene-bis(3-methyl-6-tert-butylphenol), 1,1-bis-(4-hydrooxyphenyl)cyclohexane, 4,4′-methylene-bis-(2,6-di- tert-butylphenol), 2,6-bis(2′-hydrooxy-3′-tert-butyl-5′-methylmethylbenzyl)4-methylphenol, 1,1,3-tris(2-methyl-4-hydrooxy-5-tert-butyl-phenyl)butane, 1,3,5-tris-methyl-2,4,6-tris(3,5-di-tert-butyl-4-hydrooxybenzyl)benzene, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydrooxyphenyl)propionate]methane, tris(3,5-di-tert This includes (-butyl-4-hydroxyphenyl) isocyanurate, tris[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl-oxyethyl] isocyanate, 4,4′-thiobis(3-methyl-6-tert-butylphenol), 2,2′-thiobis(4-methyl-6-tert-butylphenol), 4,4′-thiobis(2-methyl-6-tert-butylphenol), and N,N′-hexamethylenebis(3,5-di-tert-butylphenol-4-hydroxycinnamamide).

[0102] Examples of amine antioxidants include 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine, N,N′-diphenyl-p-phenylenediamine, N,N′-di-β-naphthyl-p-phenylenediamine, N-cyclohexyl-N′-phenyl-p-phenylenediamine, N-phenyl-N′-isopropyl-p-phenylenediamine, aldol-α-naphthylamine, polymers of 2,2,4-trimethyl-1,2-dihydroquinone, and 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline.

[0103] Examples of sulfur-based antioxidants include thiobis(β-naphthol), thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, dodecyl mercaptan, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropyl xanthate, dilauryl thiodipropionate, and distearyl thiodipropionate.

[0104] (organic filler) Examples of organic fillers include poly-p-phenylene terephthalamide, poly-metaphenylene terephthalamide, poly-p-phenylene isophthalamide, poly-metaphenylene isophthalamide, all-aromatic polyamides such as condensates of diaminodiphenyl ether and terephthalic acid (isophthalic acid) and condensates of para(meth)aminobenzoic acid, all-aromatic polyamide-imides such as condensates of diaminodiphenyl ether and trimellitic anhydride or pyromellitic anhydride, all-aromatic polyesters, all-aromatic polyimides, heterocyclic compounds such as polybenzimidazole and polyimidazophenanthroline, and secondary processed products such as powders, plates, fibers or cloths formed from polytetrafluoroethylene and the like.

[0105] (Organic flame retardant) Organic flame retardants may be formulated with organic flame retardants such as polybrominated styrene, brominated polyethylene ether, and brominated polystyrene, which have as their main constituent component a component unit represented by the following formula [I], manufactured from a phosphinic acid compound or brominated styrene monomer. In the following formula, m is a number from 1 to 5. [ka]

[0106] Polybrominated styrene preferably contains 60% by mass or more of dibrominated styrene units, and particularly preferably 70% by mass or more. In addition to dibrominated styrene, polybrominated styrene may also be obtained by copolymerizing monobrominated styrene and / or tribrominated styrene in an amount of 40% by mass or less, preferably 30% by mass or less.

[0107] In the semi-aromatic polyamide resin composition of the present invention, in addition to the organic flame retardant, at least one flame retardant aid selected from antimony oxide, sodium antimonate, tin oxide, iron oxide, zinc oxide, and zinc nitrate can be used. Sodium antimonate is particularly preferred, and substantially anhydrous sodium antimonate heat-treated at a high temperature of 550°C or higher is especially preferred.

[0108] (Inorganic flame retardant) Examples of inorganic flame retardants include hydrated metal compounds, metal compounds, and metal oxides.

[0109] (Other elastomers) Other examples of elastomers include olefin polymers. Examples of olefin polymers include ethylene-α-olefin copolymers, ethylene-propylene-diene copolymers, ethylene-vinyl acetate copolymers, ethylene-vinyl acetate copolymer saponified products, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl acrylate copolymers, polyethylene, polypropylene, polybutadiene, and modified versions thereof. Of these, ethylene-α-olefin copolymers and their modified versions are preferred.

[0110] (Other heat-resistant resins) Other examples of heat-resistant resins include PPS (polyphenylene sulfide), PPE (polyphenyl ether), PES (polyethersulfone), PEI (polyetherimide), LCP (liquid crystal polymer), and modified versions of these resins. Of these, polyphenylene sulfide is preferred.

[0111] 1-4. Composition of polyamide resin composition The polyamide resin composition of the present invention comprises a polyamide resin (A) and a styrene-based thermoplastic elastomer (B).

[0112] The content of polyamide resin (A) is preferably 60 to 99% by mass, and more preferably 70 to 95% by mass, relative to the total mass of the polyamide resin composition. If the content is 70% by mass or more, the strength and heat resistance of the molded article can be further enhanced. If the content is 99% by mass or less, other components such as styrene-based thermoplastic elastomer (B) can be included in the polyamide resin composition, thereby improving the tensile elongation at break of the molded article and the fluidity of the polyamide resin composition at high temperatures.

[0113] The content of the styrene-based thermoplastic elastomer (B) is 1 to 30% by mass, preferably 5 to 30% by mass, and more preferably 10 to 25% by mass, relative to the total mass of the polyamide resin composition. A content of 1% by mass or more facilitates interaction between the polyamide resin (A) and the styrene-based thermoplastic elastomer (B), thereby increasing the tensile elongation at break and flow length of the polyamide resin composition. Furthermore, a content of 30% by mass or less allows for appropriate adjustment of the flexibility of the polyamide resin composition, thereby increasing the strength of the molded article. Additionally, a content of 30% by mass or less suppresses excessive interaction between the polyamide resin (A) and the styrene-based thermoplastic elastomer (B), allowing for appropriate adjustment of the melt viscosity of the polyamide resin composition. This improves the fluidity of the polyamide resin composition at high temperatures and enhances its moldability.

[0114] When [X] is the number of moles of terminal amino groups per unit mass of the polyamide resin composition, and [Y] is the number of moles of component units derived from unsaturated carboxylic acids or their derivatives contained in the styrene-based thermoplastic elastomer (B) per unit mass of the polyamide resin composition, then [X] / [Y] is preferably 0.01 to 1000, preferably 0.01 to 500, more preferably 0.05 to 500, even more preferably 0.1 to 500, even more preferably 0.5 to 500, even more preferably 0.5 to 50, particularly preferably 0.5 to 10, particularly preferably 0.5 to 4, and most preferably 0.5 to 3.

[0115] When [X] / [Y] is within the above range, interactions are more likely to occur between the terminal amino groups of the polyamide resin (A) and the component units derived from the unsaturated carboxylic acid or its derivatives in the modified elastomer, making it easier to improve the tensile elongation at break and fluidity of the polyamide resin composition.

[0116] When α is the number of moles of aromatic rings contained in the molecular structure of the polyamide resin (A) and β is the number of moles of aromatic rings contained in the molecular structure of the styrene-based thermoplastic elastomer, the ratio α / β is preferably 3.7 to 100, more preferably 3.7 to 30, even more preferably 3.7 to 10, and particularly preferably 3.7 to 7.5. When α / β is 3.7 or higher, excessive interaction between the polyamide resin (A) and the styrene-based thermoplastic elastomer (B) is suppressed, and the melt viscosity of the polyamide resin composition can be appropriately adjusted. As a result, the fluidity of the polyamide resin composition during melting can be further increased, and moldability can be further improved. Furthermore, when α / β is 100 or lower, the aromatic rings of the polyamide resin (A) and the aromatic rings of the styrene-based thermoplastic elastomer interact more easily, so the tensile elongation at break and fluidity of the polyamide resin composition can be further increased. The above molar numbers α and β can be calculated from the charging ratio of the aromatic ring-containing compound during the preparation of the polyamide resin (A) and the styrene-based thermoplastic elastomer (B), or they can be measured by NMR. The NMR method can be the same as that described for the polyamide resin (A).

[0117] When the polyamide resin composition contains an inorganic filler (C), the content of the inorganic filler (C) is preferably 0.01 to 100% by mass, and more preferably 1 to 50% by mass, relative to the total mass of the polyamide resin (A) and the styrene-based thermoplastic elastomer (B). If the content of the inorganic filler (C) is 0.01% by mass or more, the strength of the molded article is easily increased, and if it is 100% by mass or less, the melt flowability of the polyamide resin composition is not easily impaired.

[0118] When using a polyamide resin composition for components such as cable ties, from the viewpoint of further improving the flexibility of the molded product, the content of inorganic filler (C) is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less, relative to the total mass of the polyamide resin composition.

[0119] When the polyamide resin composition contains a lubricant (D), the content of the lubricant (D) can be 0.01 to 1.00% by mass, preferably 0.05 to 0.50% by mass, and more preferably 0.06 to 0.40% by mass, based on the total mass of the polyamide resin composition. If the content of the lubricant (D) is 0.06% by mass or more, the fluidity of the polyamide resin composition during melt kneading can be further increased, and if it is 0.4% by mass or less, the mechanical strength of the resulting molded article is less likely to be impaired, and defects in appearance due to bleed-out are less likely to occur.

[0120] When a polyamide resin composition contains an antioxidant (E), the content of the antioxidant (E) can be 0 to 2.0% by mass of the total mass of the polyamide resin composition, preferably 0.1 to 5.0% by mass, and more preferably 0.1 to 1.0% by mass. If the content of the antioxidant (E) is 0.1% by mass or more, thermal degradation of the molded article is easily suppressed, and if it is 5.0% by mass or less, discoloration is less likely to occur.

[0121] When the polyamide resin composition contains the other elastomers described above, the content of the other elastomers is preferably 0 to 30% by mass, more preferably 0 to 10% by mass, and even more preferably 0 to 3% by mass, relative to the total mass of all elastomers contained in the polyamide resin composition. When the content of the other elastomers is within the above range, the content of the styrene-based thermoplastic elastomer (B) can be increased, and the interaction between the aromatic rings of the styrene-based thermoplastic elastomer (B) and the aromatic rings of the polyamide resin (A) can more effectively enhance the tensile elongation at break of the molded article and the fluidity of the polyamide resin composition.

[0122] 1-5. Physical properties of polyamide resin compositions The polyamide resin composition according to the present invention is manufactured using a bar flow mold with a width of 10 mm and a thickness of 0.5 mm, with an injection pressure of 2000 kg / cm². 2 The cylinder temperature is set 10°C higher than the melting point of the polyamide resin (A), and the flow length in the mold when injected is 25 mm or more, preferably 28 mm or more, and more preferably 30 mm or more. The upper limit of the above flow length is not particularly limited, but for example, it is 80 mm or less.

[0123] 1-6. Method for producing polyamide resin composition The polyamide resin composition of the present invention can be manufactured by any method. For example, the polyamide resin composition of the present invention can be manufactured by a step of preparing a styrene-based thermoplastic elastomer (B), a step of melt-kneading the prepared styrene-based thermoplastic elastomer (B), a polyamide resin (A), and other optional components, and a step of further granulation or pulverization as necessary.

[0124] Furthermore, prior to the melt-kneading step, a step of mixing at least a polyamide resin (A) and a styrene-based thermoplastic elastomer (B) may be performed. As for the mixing method, for example, a mixing method using a Henschel mixer, V-blender, ribbon blender, or tumbler blender can be used.

[0125] 2. Molded body The molded article of the present invention is obtained by molding the polyamide resin composition of the present invention.

[0126] In other words, using the polyamide resin composition prepared as described above, a molded body of a desired shape can be manufactured by conventional melt molding methods, such as compression molding, injection molding, or extrusion molding.

[0127] For example, the polyamide resin composition of the present invention can be introduced into an injection molding machine where the cylinder temperature is adjusted to be above the melting point of the polyamide resin (A), for example, 300°C to 350°C, to melt it, and then introduced into a mold of a predetermined shape to produce a molded article.

[0128] The shape of the molded article produced using the polyamide resin composition of the present invention is not particularly limited and can take on various shapes depending on the application.

[0129] The polyamide resin composition of the present invention is also suitable as a resin for forming various molded articles, preferably automotive interior and exterior parts, engine compartment parts, and automotive electrical parts. Examples of molded articles obtained from the semi-aromatic polyamide resin composition of the present invention include automotive exterior parts such as radiator grilles, rear spoilers, wheel covers, wheel caps, cowl vent grilles, air outlet louvers, air scoops, hood bulges, fenders, and back doors; cylinder head covers, engine mounts, air intake manifolds, throttle bodies, air intake pipes, radiator tanks, radiator supports, water pump housings such as water pump inlets and water pump outlets, thermostat housings such as water jacket spacers and thermostat housings, cooling fans, fan shrouds, oil pans, oil filter housings, oil filler caps, oil level gauges, timing belts, timing belt covers, and engine covers; fuel caps, fuel filler tubes, automotive fuel tanks, and fuel sensors. Automotive fuel system components such as der modules, fuel cutoff valves, quick connectors, canisters, fuel delivery pipes, and fuel filler necks; automotive drivetrain components such as shift lever housings and propeller shafts; automotive chassis components such as stabilizer bar linkage rods; automotive functional components such as window regulators, door locks, door handles, outside door mirror stays, accelerator pedals, pedal modules, seal rings, bearings, bearing retainers, gears, and actuators; automotive electronic components such as wire harness connectors, relay blocks, sensor housings, enclosures, ignition coils, and distributor caps; fuel system components for general-purpose equipment such as fuel tanks for general-purpose equipment (brush cutters, lawnmowers, and chainsaws, etc.); and electrical and electronic components such as connectors and LED reflectors, building materials, various enclosures, and exterior components.

[0130] Molded articles of the polyamide resin composition of the present invention have good strength and elongation at break. Therefore, they are suitable for automotive fuel tanks, quick connectors, bearing retainers, fuel tanks for general-purpose equipment, fuel caps, fuel filler necks, fuel sender modules, wheel caps, fenders, automotive clamps, automotive clips, cable ties or back doors, various housings, exterior parts, etc. Examples of various housings and exterior parts include small housings, exterior molded products, and mobile phone housings, and it is particularly preferable to use it as a mobile phone housing. Furthermore, the polyamide resin composition of the present invention is also preferably used as a resin for manufacturing connectors that connect electronic circuits to each other. [Examples]

[0131] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to the examples.

[0132] 1. Constituent materials 1-1. Polyamide resin (A) Preparation of polyamide resin (PA-1) (6T6I) 1,6-diaminohexane 2800g (24.1 mol), terephthalic acid 2774g (16.7 mol), isophthalic acid 1196g (7.2 mol), sodium hypophosphate monohydrate 5.7g (5.4 × 10⁻¹⁶) as catalyst -2 36.6 g (0.30 mol) of benzoic acid (as a molecular weight modifier) ​​and 545 g of distilled water were placed in a 13.6 L autoclave and purged with nitrogen. Stirring was started at 190°C, and the internal temperature was raised to 250°C over 3 hours. At this time, the internal pressure of the autoclave was increased to 3.02 MPa. After continuing the reaction for 1 hour, the lower condensate was extracted by releasing it into the atmosphere through a spray nozzle installed at the bottom of the autoclave. The lower condensate was then cooled to room temperature, pulverized to a particle size of 1.5 mm or less using a pulverizer, and dried at 110°C for 24 hours. The obtained lower condensate had a moisture content of 3000 ppm and an intrinsic viscosity [η] of 0.14 dl / g.

[0133] Next, this lower condensate was melt-polymerized using a twin-screw extruder with a screw diameter of 30 mm and an L / D ratio of 36, at a cylinder temperature of 330°C, a screw rotation speed of 200 rpm, and a resin supply rate of 6 kg / h to prepare polyamide (PA-1).

[0134] The composition of the obtained polyamide resin (PA-1) was such that the content of terephthalic acid-derived component units within the dicarboxylic acid-derived component units was 70 mol%, the content of isophthalic acid-derived component units was 30 mol%, and the content of 1,6-diaminohexane-derived component units within the diamine-derived component units was 100 mol%. Furthermore, the intrinsic viscosity [η] of the polyamide resin (PA-1) was 1.00 dl / g, the melting point Tm was 330°C, the glass transition temperature Tg was 125°C, the heat of fusion ΔH was 50 J / g, and the amount of terminal amino groups [X] was 30 mmol / kg.

[0135] <Preparation of polyamide resin (PA-2) (6TDT)> 1,6-diaminohexane 1312g (11.3 mol), 2-methyl-1,5-pentanediamine 1312g (11.3 mol), terephthalic acid 3655g (22.0 mol), sodium hypophosphite monohydrate as catalyst 5.5g (5.2 × 10⁻¹⁰) -2 (Mole) 640 mL of deionized water is placed in a 1.0 L reactor, and after nitrogen purging, the temperature is set to 250°C and the pressure to 35 kg / cm². 2 The reaction was carried out for 1 hour under these conditions. After 1 hour, the reaction product generated in the reactor was collected in a container connected to the reactor and under a pressure of 10 kg / cm². 2 The sample was extracted into a receiver with a low viscosity setting to obtain a polyamide precursor with an intrinsic viscosity [η] of 0.15 dl / g.

[0136] Next, after drying this polyamide precursor, polyamide (PA-2) was prepared by melt polymerization using a twin-screw extruder with a screw diameter of 30 mm and an L / D ratio of 36, at a cylinder temperature of 330°C, a screw rotation speed of 200 rpm, and a resin supply rate of 6 kg / h.

[0137] The composition of the obtained polyamide resin (PA-2) was such that the content of terephthalic acid-derived component units within the dicarboxylic acid-derived component units was 100 mol%, the content of 1,6-diaminohexane-derived component units within the diamine-derived component units was 50 mol%, and the content of 2-methyl-1,5-pentanediamine-derived component units was 50 mol%. Furthermore, the intrinsic viscosity [η] of the polyamide resin (PA-2) was 1.00 dl / g, the melting point Tm was 300°C, the glass transition temperature Tg was 140°C, the heat of fusion ΔH was 45 J / g, and the amount of terminal amino groups [X] was 50 mmol / kg.

[0138] <Polyamide resin (PA-3) (6T66)> 1,6-diaminohexane 2800g (24.1 mol), terephthalic acid 2093g (12.6 mol), adipic acid 1505g (10.3 mol), sodium hypophosphite monohydrate 5.67g (5.4 × 10⁻¹⁶) as catalyst -2 36.5 g (0.30 mol) of benzoic acid (as a molecular weight modifier) ​​and 409 ml of deionized water were placed in a 13.6 L autoclave and purged with nitrogen. Stirring was started at 190°C, and the internal temperature was raised to 250°C over 3 hours. At this time, the internal pressure of the autoclave was increased to 3.02 MPa. After continuing the reaction for 1 hour, the lower condensate was extracted by releasing it into the atmosphere through a spray nozzle installed at the bottom of the autoclave. The lower condensate was then cooled to room temperature, pulverized to a particle size of 1.5 mm or less using a pulverizer, and dried at 110°C for 24 hours. The resulting lower condensate yielded 5440 g of polyamide precursor with a moisture content of 3000 ppm and an intrinsic viscosity [η] of 0.15 dl / g.

[0139] Next, this polyamide precursor was dried and melt-polymerized using a twin-screw extruder with a screw diameter of 30 mm and an L / D ratio of 36, at a cylinder temperature of 330°C, a screw rotation speed of 200 rpm, and a resin supply rate of 6 kg / h to obtain polyamide (PA-3).

[0140] The composition of the obtained polyamide resin (PA-3) was such that the content of terephthalic acid-derived component units within the dicarboxylic acid-derived component units was 55 mol%, the content of adipic acid-derived component units was 45 mol%, and the content of 1,6-diaminohexane-derived component units within the diamine-derived component units was 100 mol%. Furthermore, the intrinsic viscosity [η] of polyamide (PA-3) was 0.80 dl / g, the melting point Tm was 310°C, the glass transition temperature Tg was 85°C, the heat of fusion ΔH was 50 J / g, and the amount of terminal amino groups [X] was 120 mmol / kg.

[0141] For polyamide resins (PA-1) to (PA-3), the ratio of the total number of carbon atoms constituting the aromatic rings in each polyamide resin to the total number of carbon atoms constituting the component units in each polyamide resin was determined (see Table 1).

[0142] [Intrinsic viscosity [η]] The intrinsic viscosity [η] of the obtained polyamide resins (PA-1) to (PA-3) was measured as follows: 0.5 g of semi-aromatic polyamide resin was dissolved in 50 ml of 96.5% sulfuric acid solution. The number of seconds the resulting solution flowed at 25°C ± 0.05°C was measured using an Ubbelohde viscometer, and the intrinsic viscosity [η] was calculated based on the formula: [η] = ηSP / (C(1 + 0.205ηSP)). [η]: Intrinsic viscosity (dl / g) ηSP: Specific viscosity C: Sample concentration (g / dl) t: Number of seconds (seconds) the sample solution flows down. t0: Number of seconds (seconds) of the blank sulfuric acid flowing down the flow. ηSP = (t - t0) / t0

[0143] [Melting point Tm, glass transition temperature Tg, heat of fusion ΔH] The melting point Tm, glass transition temperature Tg, and heat of fusion ΔH of polyamide resins (PA-1) to (PA-3) were measured as follows using a differential scanning calorimeter (DSC220C model, manufactured by Seiko Instruments Inc.).

[0144] Approximately 5 mg of polyamide resin was sealed in an aluminum pan for measurement and heated from room temperature to 350°C at a rate of 10°C / min. To completely melt the resin, it was held at 350°C for 3 minutes, then cooled to 30°C at a rate of 10°C / min. After being left at 30°C for 5 minutes, it was heated a second time to 350°C at a rate of 10°C / min. The temperature of the endothermic peak (°C) during this second heating was defined as the melting point (Tm) of the polyamide resin, and the displacement point corresponding to the glass transition was defined as the glass transition temperature (Tg). The heat of fusion ΔH was determined from the area of ​​the endothermic peak during melting in the first heating process, in accordance with JIS K7121:2012.

[0145] [Terminal amino group count [X]] The amount of terminal amino groups [X] of polyamide resins (PA-1) to (PA-3) was measured as follows.

[0146] One g of polyamide resin was dissolved in 35 mL of phenol, and 2 mL of methanol was mixed to prepare the sample solution. Using thymol blue as an indicator, the sample solution was titrated with a 0.01 N aqueous hydrochloric acid solution using a potentiometric titrator (Metrohm) until the solution changed from blue to yellow, and the amount of terminal amino groups ([NH2], unit: mmol / kg) was measured.

[0147] Table 1 summarizes the physical properties of polyamide resins (PA-1) to (PA-3).

[0148] [Table 1]

[0149] 1-2. Styrene-based thermoplastic elastomer (B) <Modified styrene-ethylene / butylene-styrene copolymer (B)> A modified styrene-ethylene / butylene-styrene copolymer (ToughTec M1913, manufactured by Asahi Kasei Corporation) was used. The average content of component units derived from maleic anhydride (modification amount) [Y] relative to the total mass of the copolymer was 0.9% by mass, and the molar ratio of styrene / ethylene-butylene was 30 / 70. The density of the copolymer was 0.920 g / cm³. 3 The MFR was 0.2g / 10min.

[0150] [Amount of denaturation] The average content (modification amount) (mass%) of component units derived from maleic anhydride in styrene-based thermoplastic elastomers was measured by NMR spectroscopy. The measurement conditions were as follows: Measurement equipment: Nuclear magnetic resonance spectrometer (ECP500 model, manufactured by JEOL Ltd.) Observation nucleus: 13 C(125MHz) Sequence: Single-pulse proton decoupling Pulse width: 4.7 μs (45° pulse) Repeat time: 5.5 seconds Total number of times: 10,000 or more Solvent: Orthodichlorobenzene / deuterated benzene (volume ratio: 80 / 20) mixed solvent Sample concentration: 55 mg / 0.6 mL Measurement temperature: 120℃ Chemical shift baseline: 27.50 ppm

[0151] [density] The density was measured at a temperature of 23°C using a density gradient tube in accordance with JIS K7112:1999.

[0152] [MFR] MFR was measured in accordance with ASTM D1238, at 190°C with a load of 2.16 kg.

[0153] 1-2. Olefin polymer (B') Ethylene-1-butene copolymer was prepared using a Ti-based catalyst.

[0154] The ethylene-1-butene copolymer prepared above has an ethylene content of 81 mol% and a density of 0.861 g / cm³. 3 The MFR (ASTM D 1238, 190°C, 2.16 kg load) was 0.5 g / 10 min.

[0155] 100 parts by mass of the ethylene-1-butene copolymer prepared above, 1.2 parts by mass of maleic anhydride, and 0.06 parts by mass of peroxide (perhexine-25B, manufactured by Nippon Oil & Fats Co., Ltd.) were mixed in a Henschel mixer, and the resulting mixture was melt-graft modified in a 65 mmφ single-screw extruder set to 230°C to obtain modified ethylene-1-butene copolymer (B').

[0156] 1-4. Other ingredients <Inorganic filler (C)> Talc (average particle size 1.6 μm)

[0157] <Sliding material (D)> sodium montanate

[0158] <Antioxidant (E)> Phenolic antioxidants

[0159] 2. Preparation of polyamide resin composition (Examples 1 and 2, and Comparative Examples 1-4) Polyamide resin (A), styrene-based thermoplastic elastomer (B), olefin polymer (B'), inorganic filler (C), lubricant (D), and antioxidant (E) were mixed in a tumbler blender to obtain the composition shown in Table 2. The mixture was then melt-kneaded using a 30 mmφ vented twin-screw extruder at a cylinder temperature of 310°C. The kneaded mixture was then extruded into strands and cooled in a water bath. The strands were then taken up and cut with a pelletizer to obtain pelletized polyamide resin composition.

[0160] The tensile breaking strength and tensile breaking elongation, flexural strength and flexural modulus, and injection flowability of the obtained polyamide resin composition were evaluated by the following methods.

[0161] [Tensile breaking strength, tensile elongation] The obtained polyamide resin composition was molded using the following injection molding machine under the following molding conditions to obtain an ASTM dumbbell-shaped test specimen Type I with a thickness of 3.2 mm. Molding machine: Toshiba Machine Co., Ltd. EC75N-2A Cylinder temperature: 335°C (Example 1, Comparative Example 1) 310℃ (Example 2, Comparative Example 2), 320℃ (Comparative Examples 3 and 4) Mold temperature: 160℃ (Examples 1 and 2, Comparative Examples 1 and 2) 120℃ (Comparative Examples 3 and 4) Injection setting speed: 100mm / sec

[0162] The obtained test specimens were left for 24 hours at a temperature of 23°C in a nitrogen atmosphere. Subsequently, tensile tests were performed in an atmosphere of 23°C and 50% relative humidity, and the tensile breaking strength (MPa) and tensile breaking elongation (%) were measured.

[0163] [Bending strength, bending modulus of elasticity] The obtained semi-aromatic polyamide resin composition was injection molded under the following molding conditions to produce test specimens with a length of 127 mm, a width of 12.7 mm, and a thickness of 3.2 mm. Molding machine: Toshiba Machine Co., Ltd. EC75N-2A Cylinder temperature: 335°C (Example 1, Comparative Example 1) 310℃ (Example 2, Comparative Example 2), 320℃ (Comparative Examples 3 and 4) Mold temperature: 160℃ (Examples 1 and 2, Comparative Examples 1 and 2) 120℃ (Comparative Examples 3 and 4)

[0164] The obtained test specimens were left for 24 hours at a temperature of 23°C in a nitrogen atmosphere. Subsequently, bending tests were performed at a temperature of 23°C and a relative humidity of 50% using a bending tester (NTESCO AB5), with a span of 51 mm and a bending speed of 5 mm / min, and the bending strength (MPa) and bending modulus (MPa) were measured.

[0165] [Flow length test (fluidity)] A bar flow mold with a width of 10 mm and a thickness of 0.5 mm was used, and injection molding was performed under the following conditions, and the flow length (mm) of the resin inside the mold was measured. Injection molding machine: Sodick Plastics Co., Ltd., Tupal TR40S3A Injection pressure setting: 2000 kg / cm² 2 Cylinder setting temperature: 335℃ (Example 1, Comparative Example 1) 310℃ (Example 2, Comparative Example 2), 320℃ (Comparative Examples 3 and 4) Mold temperature: 160℃ (Examples 1 and 2, Comparative Examples 1 and 2) 120℃ (Comparative Examples 3 and 4)

[0166] Table 2 shows the compositions and evaluation results of the polyamide resin compositions of Examples 1 and 2 and Comparative Examples 1 to 4.

[0167] In Table 2, the "improvement rate of tensile elongation at break" represents the ratio of the tensile elongation at break of Example 1 to the tensile elongation at break of Comparative Example 1 in Example 1, the ratio of the tensile elongation at break of Example 2 to the tensile elongation at break of Comparative Example 2 in Example 2, and the ratio of the tensile elongation at break of Comparative Example 4 to the tensile elongation at break of Comparative Example 3 in Comparative Example 4.

[0168] Furthermore, in Table 2, the "improvement rate of fluidity" represents the ratio of the flow length of Example 1 to the flow length of Comparative Example 1 in Example 1, the ratio of the flow length of Example 2 to the flow length of Comparative Example 2 in Example 2, and the ratio of the flow length of Comparative Example 4 to the flow length of Comparative Example 3 in Comparative Example 4.

[0169] [Table 2]

[0170] In Examples 1 and 2, which used styrene-based thermoplastic elastomers, tensile elongation at break and fluidity were improved compared to Comparative Examples 1 and 2, which used the same type of polyamide resin (A). Furthermore, in Examples 1 and 2, which used PA-1 and PA-2, in which the ratio of carbon atoms constituting the aromatic ring to the total number of carbon atoms constituting the component units contained in polyamide resin (A) was 30-60%, the improvement rate of tensile elongation at break and the improvement rate of fluidity were higher than in Comparative Example 4, which used PA-3, in which the above ratio was less than 30%.

[0171] In particular, in Example 2, where the above ratio was 30-60% and PA-2 had a greater number of terminal amino groups than PA-1, the improvement rate of tensile elongation at fracture was especially high. [Industrial applicability]

[0172] The polyamide resin composition and its molded articles of the present invention exhibit good tensile elongation and fluidity at high temperatures. Therefore, it is expected that this will broaden the applicability of the polyamide resin composition to various housings, exterior parts, etc., and contribute to the further popularization of polyamide resin compositions.< / c> < / c>

Claims

1. Polyamide resin (A), Styrene-based thermoplastic elastomer (B) and A polyamide resin composition comprising, The polyamide resin (A) contains a component unit including an aromatic ring, The ratio of the total number of carbon atoms constituting the aromatic ring to the total number of carbon atoms constituting the component units contained in the polyamide resin (A) is 30 to 60%. The content of the styrene-based thermoplastic elastomer (B) is 1 to 30% by mass relative to the total mass of the polyamide resin composition. The polyamide resin (A) comprises a component unit (a1) derived from a dicarboxylic acid and a component unit (a2) derived from a diamine. The component unit (a1) derived from the dicarboxylic acid contains 90 to 100 mol% of component units derived from terephthalic acid relative to the total number of moles of component units (a1) derived from the dicarboxylic acid. The component unit (a2) derived from the diamine comprises, with respect to the total number of moles of component units (a2) derived from the diamine, 40 to 80 mol% of component units derived from linear alkylenediamine having 4 to 18 carbon atoms and 20 to 60 mol% of component units derived from branched alkylenediamine having 4 to 18 carbon atoms. The styrene-based thermoplastic elastomer (B) includes an elastomer modified with an unsaturated carboxylic acid or a derivative thereof. The average content of the unsaturated carboxylic acid or its derivative relative to the total mass of the styrene-based thermoplastic elastomer (B) is 0.05 to 5.0% by mass. The amount of terminal amino groups in the polyamide resin (A) is 10 to 200 mmol / kg. Polyamide resin composition.

2. The styrene-based thermoplastic elastomer (B) includes a modified product obtained by modifying a styrene-based thermoplastic elastomer selected from the group consisting of styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene / butylene-styrene copolymer (SEBS), and styrene-ethylene / propylene-styrene copolymer (SEPS) with the unsaturated carboxylic acid or a derivative thereof. The polyamide resin composition according to claim 1.

3. Let [X] be the number of moles of terminal amino groups per unit mass of the polyamide resin composition, and [Y] be the number of moles of component units derived from the unsaturated carboxylic acid or its derivative contained in the styrene-based thermoplastic elastomer (B) per unit mass of the polyamide resin composition. Then, [X] / [Y] is between 0.01 and 500. The polyamide resin composition according to claim 1.

4. A molded article obtained by molding a polyamide resin composition according to any one of claims 1 to 3.

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