Polyamide resin composition and molded article

Abstract

To provide a polyamide resin composition which can enhance reflow heat resistance while enhancing tracking resistance of a molded article and can suppress a decrease in fluidity during molding, and to provide a molded article thereof.SOLUTION: The polyamide resin composition contains a polyamide resin (A) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC), a phosphinic acid-based compound (B), and a borate compound (C). The ratio of the content of the borate compound (C) to the total mass of the phosphinic acid-based compound (B) is 1.5 or more and less than 10.0.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Polyamide resin compositions have been known as molding materials. Polyamide resin compositions are widely used as materials for various parts, such as automobile parts and electric / electronic parts, and are known to produce molded articles with excellent mechanical strength.

[0003] When polyamide resin compositions are used in automobile parts (such as bus bars) and electrical and electronic parts, tracking fracture may occur. Therefore, when polyamide resin compositions are used for these applications, it is required to improve the tracking resistance of the molded articles.

[0004] For example, Patent Document 1 discloses a flame-retardant resin composition comprising a polyamide resin, a halogen-based flame retardant, an organic phosphinic acid or its salt, and a flame-retardant assistant. According to Patent Document 1, the flame-retardant resin composition is said to have improved flame retardancy and tracking resistance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2006 / 090751 Summary of the Invention [Problem to be solved by the invention]

[0006] As described in Patent Document 1, a polyamide resin composition with improved tracking resistance is known.

[0007] When a molded article of a polyamide resin composition containing a semi-aromatic polyamide resin is used for automobile parts, electrical and electronic parts, etc., the molded article may be reflow soldered to a substrate. During this process, the moisture contained in the molded article evaporates due to heating in the reflow process, and the resulting vapor pressure can cause blisters (expansion) in the molded article. From the viewpoint of improving the appearance and dimensional accuracy of the molded article, it is desirable to use a polyamide resin composition that is less likely to cause blisters due to heating (high reflow heat resistance).

[0008] According to the investigations of the present inventors, when the polyamide resin composition described in Patent Document 1 was used, it was not possible to improve the reflow heat resistance of the molded article.

[0009] An object of the present invention is to provide a polyamide resin composition and a molded article thereof, which can improve the tracking resistance of the molded article while also improving the reflow heat resistance. [Means for solving the problem]

[0010] In order to solve the above problems, one aspect of the present invention relates to the following polyamide resin compositions [1] to [8]. [1] A polyamide resin (A) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC), a phosphinic acid compound (B); a borate compound (C), the ratio of the content of the borate compound (C) to the total mass of the phosphinic acid compound (B) is 1.5 or more and less than 10.0; Polyamide resin composition. [2] The content of the phosphinic acid compound (B) is 0.5 mass% or more and less than 10 mass% based on the total mass of the polyamide resin (A). [1] The polyamide resin composition according to [1]. [3] The polyamide resin (A) has an intrinsic viscosity [η] measured in 96.5% sulfuric acid at a temperature of 25°C of 0.7 dl / g or more and 0.9 dl / g or less. [1] or [2]. The polyamide resin composition. [4] The polyamide resin (A) contains a component unit (Aa) derived from a dicarboxylic acid and a component unit (Ab) derived from a diamine, The dicarboxylic acid-derived component units (Aa) include component units derived from terephthalic acid, the content of which is 60 mol % or more relative to the total number of moles of the dicarboxylic acid-derived component units (Aa), and component units derived from an aliphatic dicarboxylic acid having from 4 to 20 carbon atoms, the content of which is 40 mol % or less relative to the total number of moles of the dicarboxylic acid-derived component units (Aa). The polyamide resin composition according to any one of [1] to [3]. [5] The phosphinic acid compound (B) is aluminum diethylphosphinate. The polyamide resin composition according to any one of [1] to [4]. [6] The borate compound (C) is zinc borate. The polyamide resin composition according to any one of [1] to [5]. [7] further comprising a flame retardant that is a halogen-containing compound; The polyamide resin composition according to any one of [1] to [6]. [8] The halogen-containing compound is brominated polystyrene. [7] The polyamide resin composition according to [7].

[0011] Another aspect of the present invention for solving the above problems relates to the following molded article [9]. [9] A molded article obtained by molding the polyamide resin composition according to any one of [1] to [8]. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a polyamide resin composition that can improve the reflow heat resistance of a molded article and can suppress warping of the molded article after molding and reflow, and a molded article thereof. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing the relationship between the temperature and time of the reflow process in the reflow heat resistance test carried out in the examples of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0015] 1. Polyamide resin composition The polyamide resin composition according to the present embodiment comprises a polyamide resin (A) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC), a phosphinic acid compound (B), and a borate compound (C), and the ratio of the content of the borate compound (C) to the total mass of the phosphinic acid compound (B) is 1.5 or more and less than 10.0.

[0016] When a molded article of a polyamide resin composition is used as an insulating material for insulating conductive members in electrical and electronic components, a voltage is applied to the molded article of the polyamide resin composition. It is known that if a voltage is applied to the surface of a molded article of the polyamide resin composition with minute amounts of dirt and moisture attached, tracking breakdown can occur. Specifically, the dirt and moisture act as electrical pathways, causing leakage current to flow between electrodes and generating Joule heat. This Joule heat evaporates the moisture, forming a dry area (dry zone). Because the dry zone has high insulation resistance, applying a high voltage across the dry zone causes scintillation discharge. This supplies thermal energy to the surface of the molded article, causing carbonization and precipitation of char on the surface of the molded article. Repeated discharges then cause the char to grow from the char precipitated on the surface of the molded article, bridging the electrodes and resulting in tracking breakdown.

[0017] In contrast, the inclusion of a phosphinic acid compound (B) in the polyamide resin composition can improve tracking resistance. When heat is applied, the phosphinic acid compound (B) thermally decomposes to produce phosphoric acid. The produced phosphoric acid is thought to rapidly hydrolyze the polyamide resin (A). Since the hydrolysis of the polyamide resin (A) is an endothermic reaction, it is thought that the thermal energy generated by the scintillation discharge during the decomposition of the polyamide resin (A) is absorbed. This is thought to make it difficult for the surface of the molded article to be carbonized and improve tracking resistance.

[0018] On the other hand, the phosphinic acid compound (B) also thermally decomposes to produce phosphoric acid due to shear heat generated during kneading of the polyamide resin composition and heating to melt the polyamide resin composition during molding. Therefore, hydrolysis of the polyamide resin (A) may occur during production of the polyamide resin composition or during production of a molded article, resulting in a decrease in the molecular weight of the polyamide resin (A). As a result, the mechanical strength of the polyamide resin composition constituting the molded article is reduced, and the molded article may be unable to withstand the vapor pressure generated by the evaporation of water contained in the molded article during the reflow process performed to mount electrical and electronic components, making it more likely to develop blisters.

[0019] In contrast, by incorporating a certain amount or more of a borate compound (C) into a polyamide resin composition containing a phosphinic acid compound (B), it is possible to improve both tracking resistance and reflow heat resistance. The anions (e.g., borate ions) constituting the borate compound (C) have multiple hydroxyl groups that can form interactions (hydrogen bonds) with the terminal carboxyl groups and terminal amino groups of the polyamide resin (A). This allows multiple polyamide resin (A) molecules to be connected via the anions, forming a pseudo-crosslinked structure. As a result, the molecular weight reduction of the polyamide resin (A) due to hydrolysis is suppressed, and the mechanical strength of the polyamide resin composition constituting the molded article is suppressed, thereby suppressing the occurrence of blisters. In other words, the reflow heat resistance of the molded article can be improved.

[0020] As a result of investigations by the present inventors, it was found that the reflow heat resistance of the molded body can be improved by setting the ratio of the content of the borate compound (C) to the total mass of the phosphinic acid compound (B) to be 1.5 or more.

[0021] 1. Polyamide resin (A) The polyamide resin (A) is a polyamide resin having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC). The polyamide resin (A) forms crystals in the molded product, which can increase the mechanical strength (such as tensile strength) of the molded product. Furthermore, since the polyamide resin (A) has a high melting point, it can be prevented from melting during the reflow process. The method for measuring the melting point of the polyamide resin (A) will be described later.

[0022] The polyamide resin (A) is, for example, a polyamide resin containing a component unit (Aa) derived from a dicarboxylic acid and a component unit (Ab) derived from a diamine. Hereinafter, the polyamide resin containing the component unit (Aa) derived from a dicarboxylic acid and the component unit (Ab) derived from a diamine will be described.

[0023] (Component unit (Aa) derived from dicarboxylic acid) The dicarboxylic acid-derived component units (Aa) preferably include component units derived from aromatic dicarboxylic acids, and more preferably include component units derived from terephthalic acid.

[0024] The content of the component units derived from terephthalic acid is preferably 40 mol% to 100 mol%, more preferably 60 mol% to 99 mol%, even more preferably 60 mol% to 85 mol%, and particularly preferably 60 mol% to 65 mol%, based on the total number of moles of the component units (Aa) derived from dicarboxylic acids. When the content of the component units derived from terephthalic acid is 40 mol% or more, the crystallinity of the polyamide resin (A) is further increased, thereby improving the chemical resistance of the molded article. Furthermore, since terephthalic acid contains an aromatic ring in the molecule, the inclusion of a certain amount of component units derived from terephthalic acid tends to rigidify the molecular chain of the polyamide resin (A). Therefore, the amide groups of the polyamide resin (A) are less likely to come into contact with water molecules, making it difficult for hydrogen bonds to form between them. This further suppresses hydrolysis of the polyamide resin (A) by phosphoric acid generated from the phosphinic acid compound (B). As a result, the reflow heat resistance of the molded article is further improved. For the same reason, if the content of component units derived from terephthalic acid is 60 mol % or more, the reflow heat resistance of the molded article is more sufficiently improved.

[0025] The dicarboxylic acid-derived component unit (Aa) may contain other dicarboxylic acid-derived component units. Examples of other dicarboxylic acids include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids other than terephthalic acid. Of these, aliphatic dicarboxylic acids are preferred.

[0026] Examples of the aliphatic dicarboxylic acid include aliphatic dicarboxylic acids having 4 to 20 carbon atoms. The number of carbon atoms is preferably 6 to 12. Examples of such aliphatic dicarboxylic acids include adipic acid, azelaic acid, and sebacic acid. Among these, adipic acid and sebacic acid are preferred, and adipic acid is more preferred.

[0027] The content of the component units derived from the above aliphatic dicarboxylic acid is preferably 0 mol % or more and 60 mol % or less, and more preferably 0 mol % or more and 40 mol % or less, relative to the total number of moles of the component units (Aa) derived from the dicarboxylic acid.

[0028] Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acid and its esters.

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

[0030] The content of component units derived from alicyclic dicarboxylic acids and aromatic dicarboxylic acids other than terephthalic acid is preferably 20 mol % or more and 80 mol % or less, and more preferably 25 mol % or more and 75 mol % or less, based on the total number of moles of component units (Aa) derived from dicarboxylic acids.

[0031] The dicarboxylic acid-derived component units (Aa) preferably contain 60 mol% to 99 mol% of component units derived from terephthalic acid and 1 mol% to 40 mol% of component units derived from an aliphatic dicarboxylic acid having 4 to 20 carbon atoms, relative to the total number of moles of component units derived from dicarboxylic acid-derived component units (Aa), and more preferably contain 60 mol% to 85 mol% of component units derived from terephthalic acid and 15 mol% to 40 mol% of component units derived from an aliphatic dicarboxylic acid having 4 to 20 carbon atoms. By containing 60 mol% or more of component units derived from terephthalic acid, the reflow heat resistance of the molded article can be further improved. By containing 1 mol% or more of the component units derived from the aliphatic dicarboxylic acid, the aromatic ring concentration in the polyamide resin (A) is not too high, thereby suppressing a decrease in tracking resistance.

[0032] (Diamine-derived component unit (Ab)) The diamine-derived component unit (Ab) includes, for example, a component unit derived from an aliphatic diamine having from 4 to 15 carbon atoms, a component unit derived from an alicyclic diamine having from 4 to 20 carbon atoms, and a component unit derived from an aromatic diamine.

[0033] The number of carbon atoms in the aliphatic diamine is preferably 4 or more and 12 or less, and more preferably 6 or more and 12 or less. Examples of the aliphatic diamine include linear alkylenediamines and branched alkylenediamines.

[0034] Examples of the linear alkylenediamine 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, and 1,6-diaminohexane is more preferred. The linear alkylenediamine may be contained alone or in combination of two or more.

[0035] Examples of the branched alkylenediamine include 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, 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, 2, These include 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. Of these, 2-methyl-1,8-diaminooctane is preferred.

[0036] The content of the component units derived from the aliphatic diamine is preferably 30 mol % or more and 100 mol % or less, and more preferably 70 mol % or more and 100 mol % or less, based on the total number of moles of the component units (Ab) derived from the diamine.

[0037] Examples of the alicyclic diamine having 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 the aromatic diamine include metaxylylenediamine.

[0038] The content of the component units derived from the above alicyclic diamine and aromatic diamine is preferably 0 mol % or more and 70 mol % or less, and more preferably 0 mol % or more and 30 mol % or less, relative to the total number of moles of the component units (Ab) derived from diamine.

[0039] The constituent units of the polyamide resin (A) and their ratios can be calculated from the charge ratios when the polyamide resin (A) is prepared, or can be measured by the NMR method.

[0040] 1 In the case of H-NMR measurement, for example, a nuclear magnetic resonance apparatus (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 observation nucleus is 1 The conditions are H (400 MHz), sequence is single pulse, pulse width is 5.12 μsec (45° pulse), repetition time is 7.0 sec, and the number of accumulations is 500 or more. The reference chemical shift is set to 0 ppm for hydrogen in tetramethylsilane, but similar results can also be obtained by setting the peak derived from residual hydrogen in deuterated orthodichlorobenzene at 7.10 ppm as the reference value for the chemical shift. 1 Peaks such as H can be assigned by conventional methods.

[0041] 13 In the case of C-NMR measurement, for example, a nuclear magnetic resonance spectrometer (ECP500 model manufactured by JEOL Ltd.) is used as the measurement device, a mixed solvent of ortho-dichlorobenzene / heavy benzene (80 / 20% by volume) is used as the solvent, the measurement temperature is 120°C, and the observation nucleus is13 The conditions were: C (125 MHz), single pulse proton decoupling, 45° pulse, repetition time 5.5 seconds, accumulation number 10,000 or more, and chemical shift reference value 27.50 ppm. Assignment of various signals was performed based on the standard method, and quantification could be performed based on the accumulated value of signal intensity.

[0042] Specific examples of the polyamide resin (A) include polyamide 6T6I, polyamide 6T66, polyamide 6TDT, polyamide 46, and the like.

[0043] The polyamide resin (A) may contain only one type of polyamide resin or two or more types of polyamide resins, but preferably contains only one type of polyamide resin. Using only one type of polyamide resin can enhance the crystallinity of the polyamide resin (A) compared to using two or more types of polyamide resins. This is thought to be because the resin molecules can be aligned to more easily form crystalline portions without causing mutual miscibility between the multiple types of polyamide resins. Furthermore, by increasing the crystallinity of the polyamide resin (A), molecular chain motion at high temperatures can be suppressed, thereby suppressing deformation of the molded product during reflow treatment. This suppresses the generation of blisters due to evaporation of moisture inside the molded product, thereby further improving reflow heat resistance. In this specification, polyamide resins (A) containing the same type of component units but with different amounts of the component units are considered to be two or more types of polyamide resins.

[0044] The dicarboxylic acid-derived component units of the polyamide resin (A) may include component units derived from biomass-derived dicarboxylic acids, and the diamine-derived component units may include component units derived from biomass-derived diamines. The polyamide resin (A) may also be a biomass-derived polyamide resin (A) obtained by polymerizing raw materials including biomass-derived raw materials.

[0045] In this embodiment, the ratio of the total number of carbon atoms constituting the aromatic rings to the total number of carbon atoms constituting the constituent units contained in the polyamide resin (A) is preferably 20% to 32%, more preferably 25% to 30%. A ratio of 20% or more can further increase the mechanical strength (such as tensile strength) of the molded article. Furthermore, a ratio of 32% or less can reduce the proportion of aromatic rings in the molecular chains of the polyamide resin (A) when a voltage is applied to the surface of a resin member, making carbonization of the surface of the resin member less likely to occur. This can further improve the tracking resistance of the molded article. The carbon atom ratio can be adjusted by the combination of dicarboxylic acid and diamine used to prepare the polyamide resin (A) and the content ratio of the aromatic dicarboxylic acid and aromatic diamine. The carbon atom ratio can be calculated from the charge ratio or measured by NMR. The NMR method can be the same as described above.

[0046] (Physical Properties) From the viewpoint of further increasing the mechanical strength of the molded article, the melting point of the polyamide resin (A) is 280° C. or higher, preferably 290° C. or higher, and more preferably 300° C. or higher. Furthermore, from the viewpoint of suppressing decomposition of the amide bond of the polyamide resin (A), the melting point of the polyamide resin (A) is preferably 320° C. or lower.

[0047] The melting point of the polyamide resin (A) can be adjusted to the above range by adjusting the composition of the polyamide resin (A). For example, the melting point can be increased by increasing the content of component units derived from terephthalic acid, which will be described later.

[0048] The polyamide resin (A) preferably has a glass transition temperature (Tg) measured by differential scanning calorimetry (DSC) of 70°C to 145°C, more preferably 75°C to 125°C, and even more preferably 80°C to 100°C. A glass transition temperature (Tg) of 70°C or higher increases the temperature at which molecular mobility becomes active in high-temperature environments, thereby suppressing molecular mobility and further improving the heat resistance of the polyamide resin composition and molded articles. A glass transition temperature (Tg) of 145°C or lower makes it easier to maintain the fluidity of the resin composition without excessively increasing the mold temperature during molding, thereby improving molding processability.

[0049] The heat of fusion (ΔH) of the polyamide resin (A) measured by differential scanning calorimetry (DSC) is preferably greater than 5 J / g. The heat of fusion is an index of the crystallinity of a resin, and a larger heat of fusion indicates higher crystallinity. When the heat of fusion (ΔH) of the polyamide resin (A) exceeds 5 J / g, the crystallinity is increased, and the mechanical strength (such as bending strength) of the resulting molded article can be increased.

[0050] The melting point and heat of fusion (ΔH) of the polyamide resin (A) can be measured using a differential scanning calorimeter (DSC220C model, manufactured by Seiko Instruments Inc.).

[0051] Specifically, approximately 5 mg of polyamide resin (A) is sealed in a measuring aluminum pan and heated from room temperature to 350°C at 10°C / min. To completely melt the resin, it is held at 350°C for 3 minutes and then cooled to 30°C at 10°C / min. After leaving it at 30°C for 5 minutes, it is heated a second time to 350°C at 10°C / min. The temperature (°C) of the endothermic peak during this second heating is taken as the melting point (Tm) of polyamide resin (A), and the inflection point corresponding to the glass transition is taken as the glass transition temperature (Tg). The heat of fusion (ΔH) is determined from the area of the endothermic peak during melting during the first heating process in accordance with JIS K7122.

[0052] The intrinsic viscosity [η] of the polyamide resin (A), measured in 96.5% sulfuric acid at 25°C, is preferably 0.7 dL / g or more and 1.2 dL / g or less, more preferably 0.7 dL / g or more and 1.0 dL / g or less, and even more preferably 0.7 dL / g or more and 0.9 dL / g or less. When the intrinsic viscosity [η] of the polyamide resin (A) is 0.7 dL / g or more, the molecular weight of the polyamide resin (A) can be sufficiently increased, and the decrease in molecular weight of the polyamide resin (A) due to the phosphinic acid compound (B) can be more sufficiently suppressed. This can further improve the reflow heat resistance of the molded article. When the intrinsic viscosity [η] is 1.2 dL / g or less, the decrease in fluidity of the polyamide resin composition during molding can be more sufficiently suppressed. Furthermore, when the intrinsic viscosity [η] is 0.9 dL / g or less, the decrease in fluidity of the polyamide resin composition during molding can be more sufficiently suppressed. The intrinsic viscosity [η] can be adjusted by adjusting the molar ratio of the dicarboxylic acid-derived component unit (Aa) and the diamine-derived component unit (Ab). Specifically, the closer the molar ratio of the carboxylic acid-derived component unit (Aa) and the diamine-derived component unit (Ab) is to 1:1, the higher the intrinsic viscosity can be. It can also be adjusted by the amount of end-capping of the polyamide resin (A).

[0053] The intrinsic viscosity [η] of the semi-aromatic polyamide resin (A) can be measured as follows. 0.5 g of the polyamide resin (A) is dissolved in 50 ml of a 96.5% sulfuric acid solution to prepare a sample solution. The flow time of the obtained solution at 25°C ± 0.05°C is measured using an Ubbelohde viscometer, and the intrinsic viscosity [η] is calculated 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 for sample solution to flow down (seconds) t0: Number of seconds the blank sulfuric acid flows (seconds) ηSP=(t-t0) / t0

[0054] The polyamide resin (A) can be produced by the same method as that for known polyamide resins, for example, by polycondensing a dicarboxylic acid and a diamine in a homogeneous solution. Specifically, the polyamide resin (A) can be produced by heating a dicarboxylic acid and a diamine in the presence of a catalyst to obtain a low-order condensate, as described in WO 03 / 085029, and then applying shear stress to a melt of the low-order condensate to polycondense it.

[0055] The content of the polyamide resin (A) is preferably 25% by mass or more and 55% by mass or less, more preferably 30% by mass or more and 45% by mass or less, and more preferably 33% by mass or more and 43% by mass or less, based on the total mass of the polyamide resin composition. When the content is 33% by mass or more, the mechanical strength (such as tensile strength) of the polyamide resin composition can be further increased. When the content is 43% by mass or less, other components such as the phosphinic acid compound (B) and the borate compound (C), which will be described later, can be sufficiently contained in the polyamide resin composition.

[0056] 1-2. Phosphinic acid compounds (B) In this embodiment, the polyamide resin composition contains a phosphinic acid compound (B). In this specification, phosphinic acid and its salts correspond to the "phosphinic acid compound." The phosphinic acid compound (B) preferably contains at least one of phosphinic acid and a phosphinic acid salt compound. From the viewpoint of suppressing evaporation during kneading, the polyamide resin composition preferably contains a phosphinic acid salt compound.

[0057] The phosphinate compound is, for example, a compound represented by the following formula (I) or formula (II).

[0058] [ka]

[0059] In formula (I) and formula (II), R 1 and R 2R are each independently a linear or branched alkyl or aryl group having 1 to 6 carbon atoms. 3 is a linear or branched alkylene group having from 1 to 10 carbon atoms, an arylene group having from 6 to 10 carbon atoms, an alkylarylene group having from 6 to 10 carbon atoms, or an arylalkylene group having from 6 to 10 carbon atoms. M is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and / or a protonated nitrogen base. m, n, and x are each independently an integer of 1 to 4.

[0060] Specific examples of the phosphinate compound include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, and calcium methanedi(methylphosphinate). Methane di(methylphosphinate), magnesium methane di(methylphosphinate), aluminum methane di(methylphosphinate), zinc methane di(methylphosphinate), calcium benzene-1,4-(dimethylphosphinate), magnesium benzene-1,4-(dimethylphosphinate), aluminum benzene-1,4-(dimethylphosphinate), zinc benzene-1,4-(dimethylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, zinc diphenylphosphinate, etc. Among these, calcium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, aluminum diethylphosphinate, and zinc diethylphosphinate are preferred, with aluminum diethylphosphinate being more preferred.

[0061] The content of the phosphinic acid compound (B) is preferably 0.5% by mass or more and less than 10% by mass, more preferably 1% by mass or more and less than 10% by mass, even more preferably 2.5% by mass or more and less than 9% by mass, and particularly preferably 5% by mass or more and less than 8.5% by mass, relative to the total mass of the polyamide resin (A). When the content is 1% by mass or more, the tracking resistance of the molded article can be further improved. When the content is less than 10% by mass, decomposition of the polyamide resin (A) by phosphoric acid generated from the phosphinic acid compound (B) can be further suppressed, thereby further improving reflow heat resistance.

[0062] The content of the phosphinic acid compound (B) is preferably 0.5% by mass or more and 4.5% by mass or less, and more preferably 1% by mass or more and 3% by mass or less, based on the total mass of the polyamide resin composition. When the content is 0.5% by mass or more, the tracking resistance of the molded article can be further improved. When the content is less than 4.5% by mass, decomposition of the polyamide resin (A) by phosphoric acid generated from the phosphinic acid compound (B) can be further suppressed, and reflow heat resistance can be further improved.

[0063] 1-3.Borate Compounds (C) In this embodiment, the polyamide resin composition contains a borate compound (C).

[0064] Examples of anions that constitute borate compounds include borate ions, metaborate ions, triborate ions, tetraborate ions, and pentaborate ions. These anions have multiple hydroxyl groups in one molecule. Examples of cations that constitute borate compounds include sodium ions, potassium ions, lithium ions, magnesium ions, calcium ions, and ammonium ions.

[0065] Specific examples of borate compounds (C) include zinc borate (xZnO·yB2O3·zH2O), barium metaborate (Ba(BO2)2), sodium tetraborate (Na2B4O7), disodium octaboron oxide (Na2B8O13 ), borax (Na2B4O5(OH)4·8H2O / Na2B4O7·10H2O), etc. Of these, zinc borate is preferred, anhydrous zinc borate is more preferred, and among zinc borates, those where (x, y, z) = (2, 3, 0) (i.e., 2ZnO·3B2O3) are particularly preferred. These have high thermal stability and are not prone to thermal decomposition or evaporation during kneading or molding of the polyamide resin composition, so the borate compound (C) can more fully improve the reflow heat resistance. Furthermore, when z = 0, i.e., anhydrous zinc borate, hydrolysis of the polyamide resin due to moisture generated during kneading can be fully suppressed, and the reflow heat resistance can be more fully improved.

[0066] The content of the borate compound (C) is preferably more than 5% by mass and not more than 40% by mass, more preferably 3% by mass or more and not more than 25% by mass, relative to the total mass of the polyamide resin (A). A content of more than 5% by mass allows for a greater degree of formation of a pseudo-crosslinked structure linking the molecules of the polyamide resin (A). As a result, the decrease in molecular weight of the polyamide resin (A) due to the phosphoric acid is more effectively suppressed, thereby further improving the reflow heat resistance of the molded article. A content of not more than 40% by mass allows for more effectively suppressing a decrease in the flowability of the polyamide resin composition during molding.

[0067] The content of the borate compound (C) is preferably 1% by mass or more and 10% by mass or less, and more preferably 2% by mass or more and 6% by mass or less, relative to the total mass of the polyamide resin composition. A content of 1% by mass or more allows for the formation of a pseudo-crosslinked structure in which the molecules of the polyamide resin (A) are linked together. As a result, the decrease in molecular weight of the polyamide resin (A) due to the phosphoric acid can be further suppressed, and the reflow heat resistance of the molded product can be further improved. A content of 10% by mass or less allows for the decrease in fluidity of the polyamide resin composition during molding to be further suppressed.

[0068] The ratio of the content of the borate compound (C) to the total mass of the phosphinic acid compound (B) is 1.5 or more, preferably 1.5 or more but less than 10.0, more preferably 1.6 or more but less than 5.0, even more preferably 1.6 or more but less than 3.0, and particularly preferably 1.6 or more but less than 2.5. A ratio of 1.6 or more allows for the formation of a pseudo-crosslinked structure linking the molecules of the polyamide resin (A). As a result, the molecular weight reduction of the polyamide resin (A) due to the phosphoric acid is further suppressed, thereby further improving the reflow heat resistance of the molded article. Furthermore, a ratio of less than 10.0 prevents the molecular weight of the polyamide resin (A) from increasing too much due to the formation of the pseudo-crosslinked structure, thereby suppressing a decrease in the flowability of the polyamide resin composition during molding.

[0069] 1-4.Other ingredients The polyamide resin composition may contain other known components.

[0070] Examples of other components include flame retardants, flame retardant auxiliaries, nucleating agents, lubricants, reinforcing materials, polyolefin resins, styrene-based thermoplastic elastomers, anti-drip agents, halogen scavengers, colorants, heat stabilizers, corrosion resistance improvers, anti-drip agents, ion scavengers, elastomers (rubbers), antistatic agents, mold release agents, antioxidants (phenols, amines, sulfurs, phosphorus compounds, etc.), heat stabilizers other than those mentioned above (lactone compounds, vitamin E compounds, hydroquinones, etc.), light stabilizers (benzotriazoles, triazines, benzophenones, benzoates, hindered amines, oxanilides, etc.), and the like.

[0071] (Flame retardant) In this embodiment, when the polyamide resin composition contains a flame retardant, the flame retardant is a halogen-containing compound. The flame retardant can impart flame retardancy to a molded article of the polyamide resin composition. Examples of the halogen-containing compound include brominated polystyrene, polybrominated styrene, and brominated polyphenylene ether. Of these, the halogen-containing compound is preferably brominated polystyrene.

[0072] The content of the flame retardant is preferably 10% by mass or more and 25% by mass or less, and more preferably 12% by mass or more and 22% by mass or less, based on the total mass of the polyamide resin composition.

[0073] (Flame retardant synergist) Examples of the flame retardant synergist include anhydrous sodium antimonate, hydrotalcite, boehmite, zinc stannate, iron oxide, zinc oxide, tin oxide, and the like.

[0074] The content of the flame retardant aid is preferably 0.5% by mass or more and 5.0% by mass or less, and more preferably 1.0% by mass or more and 3.0% by mass or less, based on the total mass of the polyamide resin composition.

[0075] (nucleating agent) The nucleating agent can promote the crystallization of the polyamide resin (A), thereby further increasing the tensile strength and elastic modulus of the molded article.

[0076] Examples of nucleating agents include metal salt compounds such as sodium 2,2-methylenebis(4,6-di-t-butylphenyl)phosphate, aluminum tris(pt-butylbenzoate), and stearates; sorbitol compounds such as bis(p-methylbenzylidene)sorbitol and bis(4-ethylbenzylidene)sorbitol; and inorganic substances such as talc, calcium carbonate, and hydrotalcite. Among these, talc is preferred from the viewpoint of further increasing the crystallinity of the resin member. These nucleating agents may be used alone or in combination.

[0077] Talc generally contains hydrous magnesium silicate (SiO2: 58-64%, MgO: 28-32%, Al2O3: 0.5-5%, Fe2O3: 0.3-5%) as its main component. The average particle size of the talc is not particularly limited, but is preferably 1-15 μm. When the average particle size of the talc is within the above range, the talc can be easily dispersed in the polyamide resin (A) without impairing the fluidity of the polyamide resin composition. From the same viewpoint, the average particle size of the talc is more preferably 1-7.5 μm. The average particle size of the talc can be measured by a laser diffraction method, for example, using a Shimadzu particle size distribution analyzer (SALD-2000A) manufactured by Shimadzu Corporation.

[0078] The content of the nucleating agent is preferably 0.10% by mass or more and 5.00% by mass or less, and more preferably 0.10% by mass or more and 3.00% by mass or less, based on the total mass of the polyamide resin composition. When the content of the nucleating agent is within the above range, the crystallinity of the resin member is easily increased sufficiently, and sufficient mechanical strength is easily obtained.

[0079] (lubricant) The lubricant improves the injection flowability of the polyamide resin composition and improves the appearance of the resulting resin part. The lubricant can be a metal salt of a fatty acid, such as a metal salt of an oxycarboxylic acid or a metal salt of a higher fatty acid.

[0080] The hydroxycarboxylic acid constituting the hydroxycarboxylic acid metal salt may be an aliphatic hydroxycarboxylic acid or an aromatic hydroxycarboxylic acid. Examples of the aliphatic hydroxycarboxylic acid include aliphatic hydroxycarboxylic acids having 10 to 30 carbon atoms, such as α-hydroxymyristic acid, α-hydroxypalmitic acid, α-hydroxystearic acid, α-hydroxyeicosanoic acid, α-hydroxydocosanoic acid, α-hydroxytetraeicosanoic acid, α-hydroxyhexaeicosanoic acid, α-hydroxyoctaeicosanoic acid, α-hydroxytriacontanoic acid, β-hydroxymyristic acid, 10-hydroxydecanoic acid, 15-hydroxypentadecanoic acid, 16-hydroxyhexadecanoic acid, 12-hydroxystearic acid, and ricinoleic acid. Examples of the aromatic hydroxycarboxylic acid include salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, gallic acid, mandelic acid, and trovic acid.

[0081] Examples of the metal constituting the metal oxycarboxylic acid salt include alkali metals such as lithium, and alkaline earth metals such as magnesium, calcium and barium.

[0082] Of these, the metal oxycarboxylic acid salt is preferably a metal salt of 12-hydroxystearic acid, and more preferably magnesium 12-hydroxystearate and calcium 12-hydroxystearate.

[0083] Examples of the higher fatty acids that constitute the higher fatty acid metal salts include higher fatty acids having 15 to 30 carbon atoms, such as stearic acid, oleic acid, behenic acid, behenic acid, and montanic acid.

[0084] Examples of metals constituting the above higher fatty acid metal salts include calcium, magnesium, barium, lithium, aluminum, zinc, sodium, and potassium.

[0085] Of these, the higher fatty acid metal salts are preferably calcium stearate, magnesium stearate, barium stearate, calcium behenate, sodium montanate, and calcium montanate.

[0086] The content of the lubricant is preferably 0.01% by mass or more and 1.30% by mass or less relative to the total mass of the polyamide resin composition. When the content of the lubricant is 0.01% by mass or more, the fluidity during molding tends to be improved, and the appearance of the obtained molded product tends to be improved. When the content of the lubricant is 1.30% by mass or less, gas due to decomposition of the lubricant is unlikely to be generated during molding, and the appearance of the product tends to be good.

[0087] (Reinforcement material) The reinforcing material may be an inorganic filler. Examples of reinforcing materials include fibrous reinforcing materials such as glass fiber, wollastonite, potassium titanate whiskers, calcium carbonate whiskers, aluminum borate whiskers, magnesium sulfate whiskers, zinc oxide whiskers, milled fiber, and cut fiber, as well as granular reinforcing materials. One of these may be used alone, or two or more may be used in combination. Among these, wollastonite, glass fiber, and potassium titanate whiskers are preferred, as they can easily increase the mechanical strength of the resin member, and wollastonite and glass fiber are more preferred.

[0088] The average fiber length of the fibrous reinforcing material is preferably 1 μm or more and 20 mm or less, more preferably 5 μm or more and 10 mm or less, from the viewpoints of moldability of the polyamide resin composition and the mechanical strength and heat resistance of the resulting resin part.

[0089] The cross-sectional shape of the fibrous reinforcing material may be circular or non-circular, but is preferably circular from the viewpoint of increasing the tensile strength of the molded article. When the molded article has a thick portion, the fibers tend to be oriented in the thickness direction of the thick portion, so a circular shape can exert a stronger reinforcing effect (the effect of increasing the tensile strength of the molded article) against cracks that occur inside the thick portion. The above cross-sectional shape can be confirmed by observation with an optical microscope.

[0090] The average fiber length and average fiber diameter of the fibrous reinforcing material can be measured by the following method. 1) The polyamide resin composition is dissolved in a hexafluoroisopropanol / chloroform solution (0.1 / 0.9% by volume), and then filtered to obtain a filtrate. 2) Disperse the filtered material obtained in 1) above in water, and measure the fiber length (Li) and fiber diameter (di) of each of 300 randomly selected fibers using an optical microscope (magnification: 50x). The number of fibers with fiber length Li is taken as qi, and the weight-average length (Lw) is calculated using the following formula, which is the average fiber length of the fibrous reinforcement. Weight average length (Lw) = (Σqi × Li 2 ) / (Σqi×Li) Similarly, the number of fibers with a fiber diameter Di is taken as ri, and the weight average diameter (Dw) is calculated based on the following formula, and this is taken as the average fiber diameter of the fibrous reinforcing material. Weight average diameter (Dw)=(Σri×Di 2 ) / (Σri×Di)

[0091] The content of the reinforcing material is preferably 80% by mass or more and 120% by mass or less, and more preferably 85% by mass or more and 100% by mass or less, based on the total mass of the polyamide resin (A). A content of 80% by mass or more can further enhance the tracking resistance of the molded article. Furthermore, a content of 120% by mass or less can reduce the interface area between the reinforcing material and the polyamide resin (A), making it less likely for blisters to form.

[0092] (Polyolefin resin) Polyolefin resins can suppress the generation of droplets when a molded article of polyamide resin is burned. Examples of polyolefin resins include ethylene polymers, propylene polymers, butene polymers, and copolymers of these olefins (e.g., ethylene-α-olefin copolymers). Of these, ethylene polymers are preferred.

[0093] Examples of the α-olefin other than ethylene in the ethylene-α-olefin copolymer include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc. Among these, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred.

[0094] The polyolefin resin preferably includes a modified polyolefin resin. Specifically, the polyolefin resin preferably includes a modified polyolefin resin having a polyolefin unit and a functional group structural unit. The modified polyolefin resin can be obtained by modifying a polyolefin resin before modification with a compound containing a functional group structural unit.

[0095] Examples of the functional group structural unit include functional groups containing heteroatoms. Examples of functional groups containing heteroatoms include carboxylic acid groups (including carboxylic acid anhydride groups), ester groups, ether groups, aldehyde groups, and ketone groups. Among these, carboxylic acid groups (including carboxylic acid anhydride groups) are preferred. That is, the modified polyolefin resin is preferably modified with an unsaturated carboxylic acid or its derivatives.

[0096] Examples of compounds containing a carboxylic acid group include α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and phthalic acid. Examples of compounds containing a carboxylic acid anhydride group include dicarboxylic acid anhydrides having an α,β-unsaturated bond such as maleic anhydride, itaconic anhydride, and phthalic anhydride. Of these, maleic anhydride is preferred.

[0097] The content of the functional group structural unit (modification amount) of the modified polyolefin resin is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.2% by mass or more and 3.0% by mass or less, and even more preferably 0.5% by mass or more and 1.5% by mass or less. When the content of the functional group structural unit is within the above range, the impact resistance and elongation of the resin composition tend to be improved.

[0098] The content (modification amount) of the functional group structural unit of the modified polyolefin resin can be calculated from the charge ratio when preparing the modified polyolefin resin, or can be measured by the NMR method. For the NMR method, the same method as described for the polyamide resin (A) can be used.

[0099] The modified polyolefin resin is obtained by graft-modifying an unmodified polyolefin resin with a compound containing a functional group structural unit.

[0100] 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 the polyolefin resin before modification is melted using an extruder and a graft monomer is added to carry out graft copolymerization, or it may be carried out by a solution modification method in which the polyolefin resin before modification is dissolved in a solvent and a graft monomer is added to carry out graft copolymerization. In either case, it is preferable to carry out the reaction in the presence of a radical initiator in order to efficiently graft copolymerize the graft monomer.

[0101] The content of the polyolefin resin is preferably 2% by mass or more and 10% by mass or less, more preferably 3% by mass or more and 8% by mass or less, and even more preferably 3% by mass or more and 6% by mass or less, relative to the total mass of the polyamide resin composition.

[0102] (styrene-based thermoplastic elastomer) The styrene-based thermoplastic elastomer, when blended with the semi-aromatic polyamide resin composition, improves the tensile elongation at break, tensile strength at break, flexural strength, flexural modulus, fluidity, etc. of the resulting molded article.

[0103] Examples of styrene-based thermoplastic elastomers include styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene / butylene-styrene copolymer (SEBS), and styrene-ethylene / propylene-styrene copolymer (SEPS). Of these, styrene-ethylene / butylene-styrene copolymer (SEBS) is preferred from the viewpoint of improving fluidity and elongation at break.

[0104] The styrene-based thermoplastic elastomer is preferably a styrene-based thermoplastic elastomer modified with an unsaturated carboxylic acid or a derivative thereof.

[0105] 1-4. Method for producing polyamide resin composition The polyamide resin composition can be produced by a known resin mixing method, such as mixing the polyamide resin (A), phosphinic acid compound (B), borate compound (C), and other components as needed, using a Henschel mixer, V-blender, ribbon blender, or tumbler blender, or by melt-kneading the mixed components in a single-screw extruder, multi-screw extruder, kneader, or Banbury mixer, followed by granulation or pulverization. The melting temperature during melt-kneading is preferably at least 10°C above the melting point (Tm) of the polyamide resin (A) and at most 20°C above the melting point (Tm) of the polyamide resin (A).

[0106] The molded article can be produced using the polyamide resin composition by a conventional melt molding method, such as compression molding, injection molding, etc. For example, the polyamide resin composition of the present invention can be put into an injection molding machine whose cylinder temperature is adjusted to the melting point of the polyamide resin (A) or higher, for example, about 280°C to 350°C, to be in a molten state, and then introduced into a mold of a predetermined shape to produce a molded article.

[0107] The shape of the molded article produced using the polyamide resin composition of the present invention is not particularly limited, and may take various shapes depending on the application.

[0108] Examples of applications of molded articles of the polyamide resin composition in this embodiment include vehicle structural parts, vehicle-mounted items, housings for electronic devices, housings for home appliances, structural parts, machine parts, various automobile parts, electronic device parts, medical devices, etc. As described above, the polyamide resin composition can improve the tracking resistance and reflow heat resistance of molded articles, and therefore, among these applications, it can be particularly suitably used for electronic device parts. [Example]

[0109] The present invention will be described below with reference to examples, which should not be construed as limiting the scope of the present invention.

[0110] 1. Synthesis / preparation of materials 1-1. Synthesis of polyamide resin (A) <Polyamide resin PA-1 (6T66)> 2515 g (15.1 mol) of terephthalic acid, 2800 g (24.1 mol) of 1,6-diaminohexane, 1325 g (9.0 mol) of adipic acid, 5.7 g of sodium hypophosphite monohydrate, and 554 g of distilled water were placed in a 13.6 L autoclave and purged with nitrogen. Stirring was initiated 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 3.01 MPa. After the reaction was continued for 1 hour, the low-order condensation product was discharged into the atmosphere through a spray nozzle installed at the bottom of the autoclave and extracted. The extracted low-order condensation product was cooled to room temperature, then pulverized in a pulverizer to a particle size of 1.5 mm or less, and dried at 110°C for 24 hours.

[0111] Next, this low-order condensate was placed in a tray-type solid-state polymerization reactor, and after nitrogen substitution, the temperature was raised to 220°C over approximately 1 hour and 30 minutes. The low-order condensate was then reacted for 1 hour and cooled to room temperature. Subsequently, polyamide (high condensate) was further melt-polymerized in a twin-screw extruder with a screw diameter of 30 mm and L / D = 36 at a barrel setting temperature of 330°C, a screw rotation speed of 200 rpm, and a resin feed rate of 6 kg / hour to obtain polyamide resin PA-1.

[0112] The resulting polyamide resin PA-1 had an intrinsic viscosity [η] of 0.8 dl / g and a melting point (Tm) of 320°C. The resulting polyamide resin PA-1 had a composition in which the dicarboxylic acid-derived component units contained 62.5 mol% of component units derived from terephthalic acid, 37.5 mol% of component units derived from adipic acid, and 100 mol% of component units derived from 1,6-diaminohexane. The ratio of the total number of carbon atoms constituting aromatic rings to the total number of carbon atoms constituting component units contained in the polyamide resin PA-1 was 28.1%.

[0113] 1-2. Phosphinic acid compounds (B) Aluminum phosphinate (EXOLIT OP1230, manufactured by Clariant) was used.

[0114] 1-3.Borate Compounds (C) Zinc borate (Fire Brake ZB US Borax)

[0115] 1-4.Other ingredients 1-4-1.Flame retardants Brominated polystyrene (SAY TEX HP-3010G, manufactured by Albemarle Corporation) was used.

[0116] 1-4-2.Flame retardant synergists Flame retardant aid 1: Hydrotalcite (NAOX-33, manufactured by Toda Kogyo Co., Ltd.) was used. Flame retardant synergist 2: anhydrous sodium antimonate (SA-A, manufactured by Nippon Seiko Co., Ltd.)

[0117] 1-4-3. Nucleating agent Talc (ET-5, manufactured by Matsumura Sangyo Co., Ltd.) was used.

[0118] 1-4-4. Lubricants Sodium montanate (LICOMONT CAV 102, Clariant) was used.

[0119] 1-4-5. Reinforcement material Glass fiber (ECS03T-262H, manufactured by Nippon Electric Glass Co., Ltd.) was used.

[0120] 1-4-6.Polyolefin resin Tafmer MH5020 (manufactured by Mitsui Chemicals, Inc.) was used.

[0121] 1-4-7. Styrene-based thermoplastic elastomer Maleic acid-modified styrene-ethylene-butylene-styrene copolymer (m-SEBS) (Tuftec M1913, manufactured by Asahi Kasei Corporation) was used.

[0122] 2. Measurement The physical properties of each of the above resins were measured by the following methods.

[0123] <Melting point (Tm), glass transition temperature (Tg)> The melting point (Tm) and glass transition temperature (Tg) of polyamide resin (A) were measured using a differential scanning calorimeter (DSC220C, manufactured by Seiko Instruments Inc.). Specifically, approximately 5 mg of polyamide resin was sealed in an aluminum pan for measurement and set in the differential scanning calorimeter. The polyamide resin was then heated from room temperature to 350°C at 10°C / min. To completely melt the resin, it was held at 350°C for 3 minutes and then cooled to 30°C at 10°C / min. After leaving it at 30°C for 5 minutes, it was heated a second time to 350°C at 10°C / min. The temperature (°C) of the endothermic peak during this second heating was taken as the melting point (Tm) of the polyamide resin, and the inflection point corresponding to the glass transition was taken as the glass transition temperature (Tg).

[0124] <Heat of fusion (ΔH)> The heat of fusion (ΔH) of the polyamide resin was calculated from the area of the exothermic peak of crystallization during the first heating process in accordance with JIS K 7122 (2012).

[0125] <Intrinsic viscosity [η]> The intrinsic viscosity [η] of the polyamide resin was calculated by dissolving 0.5 g of the polyamide resin in 50 ml of a 96.5% sulfuric acid solution, measuring the flow time of the resulting solution at 25°C ± 0.05°C using an Ubbelohde viscometer, and then calculating the intrinsic viscosity [η] 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 for sample solution to flow down (seconds) t0: Number of seconds the blank sulfuric acid flows (seconds) ηSP=(t-t0) / t0

[0126] 3. Preparation of polyamide resin composition The above materials were mixed in a tumbler blender in the composition ratios (unit: parts by mass) shown in Table 1, and melt-kneaded using a 30 mmφ vented twin-screw extruder at a cylinder temperature of 300 to 335°C. The kneaded mixture was then extruded into strands and cooled in a water bath. The strands were then taken up in a pelletizer and cut to obtain pellet-shaped polyamide resin compositions 1 to 8.

[0127] 4. Evaluation <Tracking resistance> The obtained polyamide resin composition was molded using the following injection molding machine under the following molding conditions to obtain a test piece of 200 mm x 130 mm x 3 mm. Molding machine: EC75N-2A, manufactured by Toshiba Machine Co., Ltd. Cylinder temperature: Polyamide resin melting point + 10°C Mold temperature: 160℃ Injection setting speed: 100mm / sec

[0128] The comparative tracking index (CTI) [V], which is an index of tracking resistance, was measured for the obtained test piece in accordance with IEC 60112 under the following conditions. Test solution: Ammonium chloride (0.1% concentration) aqueous solution Testing machine: YST-1000V (Yamayo Testing Instruments Co., Ltd.) Test room temperature: 23℃

[0129] The PLC (Performance Level Category) was evaluated based on the measured CTI [V] and the following criteria: 0: CTI is 600V or more 1: CTI is between 400V and 600V 2: CTI is between 250V and 400V 3: CTI is 175V or more and less than 250V 4: CTI is 100V or more and less than 175V 5: CTI is less than 100V

[0130] <Flame retardancy> Each polyamide resin composition was injection molded under the following conditions to prepare 1 / 32 inch x 1 / 2 x 5 inch test pieces. Using the prepared test pieces, a vertical flame test was carried out in accordance with the UL94 standard (UL Test No. UL94 dated June 18, 1991) to evaluate flame retardancy. Molding machine: Tupearl TR40S3A (manufactured by Sodick Plastic Co., Ltd.) Molding machine cylinder temperature: Polyamide resin melting point + 10°C Mold temperature: 120℃

[0131] <Reflow heat resistance temperature> Each polyamide resin composition was injection molded under the following conditions to prepare a test piece having a length of 64 mm, a width of 6 mm and a thickness of 0.8 mm. Molding machine: Tupearl TR40S3A (manufactured by Sodick Plastic Co., Ltd.) Molding machine cylinder temperature: Polyamide resin melting point + 10°C Mold temperature: 100℃

[0132] The prepared test specimens were conditioned at a temperature of 40°C and a relative humidity of 95% for 96 hours. The conditioned test specimens were placed on a 1 mm-thick glass epoxy substrate. A temperature sensor was installed on this substrate. The glass epoxy substrate with the test specimen mounted thereon was set in an air reflow soldering machine (AIS-20-82-C, manufactured by Atec Techtron Co., Ltd.) and subjected to a reflow process according to the temperature profile shown in Figure 1. As shown in Figure 1, the temperature was raised to 230°C at a predetermined rate; then, the temperature was raised to a predetermined set temperature (a: 270°C, b: 265°C, c: 260°C, d: 255°C, and e: 235°C) over 20 seconds, and then lowered to 230°C. The maximum set temperature at which the test specimen did not melt and no blisters formed on the surface was determined, and this maximum set temperature was defined as the reflow heat resistance temperature.

[0133] The composition and evaluation results of each polyamide resin composition are shown in Table 1. The composition values in Table 1 represent parts by mass.

[0134] [Table 1]

[0135] From the results of polyamide resin compositions 1 and 2, it was found that when a polyamide resin composition contains a phosphinic acid compound (B) and a borate compound (C) and the ratio thereof ((C / (B))) is 1.5 or more, it is possible to improve both tracking resistance and reflow heat resistance.

Claims

1. a polyamide resin (A) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC); a phosphinic acid compound (B); a borate compound (C); the ratio of the content of the borate compound (C) to the total mass of the phosphinic acid compound (B) is 1.5 or more; Polyamide resin composition.

2. The content of the phosphinic acid compound (B) is 0.5 mass% or more and less than 10 mass% based on the total mass of the polyamide resin (A). The polyamide resin composition according to claim 1.

3. The polyamide resin (A) has an intrinsic viscosity [η] of 0.7 dl / g or more and 0.9 dl / g or less, as measured in 96.5% sulfuric acid at a temperature of 25°C. The polyamide resin composition according to claim 1.

4. The polyamide resin (A) contains a component unit (Aa) derived from a dicarboxylic acid and a component unit (Ab) derived from a diamine, The dicarboxylic acid-derived component units (Aa) include component units derived from terephthalic acid, the content of which is 60 mol% or more relative to the total number of moles of the dicarboxylic acid-derived component units (Aa), and component units derived from an aliphatic dicarboxylic acid having from 4 to 20 carbon atoms, the content of which is 40 mol% or less relative to the total number of moles of the dicarboxylic acid-derived component units (Aa). The polyamide resin composition according to claim 1.

5. The phosphinic acid compound (B) is aluminum diethylphosphinate. The polyamide resin composition according to claim 1.

6. The borate compound (C) is zinc borate. The polyamide resin composition according to claim 1.

7. further comprising a flame retardant that is a halogen-containing compound; The polyamide resin composition according to claim 1.

8. the halogen-containing compound is brominated polystyrene; The polyamide resin composition according to claim 7.

9. A molded article obtained by molding the polyamide resin composition according to any one of claims 1 to 8.

Images