Flame-retardant polyamide resin composition and molded article thereof

Abstract

This invention provides a flame-retardant polyamide resin composition that exhibits UL94V-0 flame retardancy over a wide range of thicknesses, while also exhibiting low leaching of the flame retardant, excellent heat resistance, colorfastness, formability, and component fitability. A flame-retardant polyamide resin composition is characterized in that it contains polyamide resin (A) and melamine cyanurate (B), wherein, relative to a total of 100 parts by mass of said components (A) and (B), it contains 90 to 98 parts by mass of polyamide resin (A) and 2 to 10 parts by mass of melamine cyanurate (B); in said polyamide resin (A), the proportion of polyamide 66 resin (A1) is 55 to 85% by mass, and the proportion of polyamide 6 resin (A2) is 15 to 45% by mass; and relative to a total of 100 parts by mass of said components (A) and (B), it contains 0.01 to 1 part by mass of phosphorus-based antioxidant (C), 0.01 to 1 part by mass of hindered phenolic antioxidant (D), and 0.1 to 1 part by mass of fatty acid metal salt lubricant (E) having 22 or fewer carbon atoms.

Description

Technical Field

[0001] This invention relates to a non-halogenated flame-retardant polyamide resin composition. More specifically, it relates to a non-halogenated flame-retardant polyamide resin composition exhibiting high flame retardancy, good snap-fit ​​properties, and excellent heat resistance and colorfastness. Background Technology

[0002] Polyamide resins are used in various fields such as electrical / electronic components and automotive parts due to their excellent mechanical properties, electrical properties, and chemical resistance. In these fields, when flame retardancy is required using non-reinforced and non-halogenated flame retardants, melamine cyanurate (e.g., Patent Documents 1 and 2) is used as a flame retardant.

[0003] However, melamine cyanurate has poor dispersibility compared to polyamide resin. When the amount mixed in increases, it leads to a decrease in the mechanical properties of polyamide resin; polyamide resin exudation; and due to thermal decomposition, it easily decomposes and sublimates melamine and cyanuric acid. Under the influence of sublimated melamine and cyanuric acid, silver lines are generated on the surface of the molded product during molding and processing, and the mold surface is easily contaminated.

[0004] In recent years, the requirements for electrical / electronic components, automotive parts, and other components have become more stringent. At various thicknesses, flame retardancy needs to be at the UL94 V-0 level, while also expecting higher levels of flame retardant performance such as no leakage, heat resistance and color change, formability, and even better component fitability.

[0005] Existing technical documents

[0006] Patent Document 1: Japanese Patent Publication No. 58-25379

[0007] Patent Document 2: Japanese Patent Publication No. 58-35541 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] This invention provides a flame-retardant polyamide resin composition. It exhibits UL94 V-0 flame retardancy over a wide range of thicknesses, while also exhibiting low leaching of the flame retardant, excellent heat resistance, colorfastness, formability, and component fitability.

[0010] Problem-solving methods

[0011] The present invention was completed as a result of in-depth research conducted by the inventors to solve the above-mentioned problems.

[0012] That is, the present invention has the following structure.

[0013] [1] A flame-retardant polyamide resin composition comprising polyamide resin (A) and melamine cyanurate (B), wherein, relative to a total of 100 parts by mass of said components (A) and (B), it comprises 90 to 98 parts by mass of polyamide resin (A) and 2 to 10 parts by mass of melamine cyanurate (B); and comprises 0.01 to 1 part by mass of phosphorus-based antioxidant (C), 0.01 to 1 part by mass of hindered phenolic antioxidant (D) and 0.1 to 1 part by mass of fatty acid metal salt lubricant (E) having 22 or fewer carbon atoms, wherein the polyamide resin (A) comprises 55 to 85% by mass of polyamide 66 resin (A1) and 15 to 45% by mass of polyamide 6 resin (A2).

[0014] [2] The flame-retardant polyamide resin composition according to [1], wherein the fatty acid metal salt lubricant (E) is a metal salt of stearic acid.

[0015] [3] A molded article comprising the flame-retardant polyamide resin composition described in [1] or [2].

[0016] [4] According to [3], the molded article is any one of ferrite core cover, SC lock, cable tie, and electrical wiring protection component.

[0017] Invention Effects

[0018] The flame-retardant polyamide resin composition of the present invention not only has excellent heat resistance and color change resistance and formability, but also does not significantly impair fracture strength and toughness, and has UL94 V-0 level flame retardancy over a wide range of thicknesses. Detailed Implementation

[0019] The present invention will be described in detail below.

[0020] [Polyamide resin (A)]

[0021] As for the polyamide resin (A) in this invention, there is no particular limitation as long as it is a polymer having an amide bond (-NHCO-) ​​in its main chain. The polyamide resin (A) is preferably crystalline, and examples include: polyamide 6 (PA6), polyamide 66 (PA66), polyamide 46 (PA46), polyamide 11 (PA11), polyamide 12 (PA12), polyamide 610 (PA610), polyamide 612 (PA612), poly(m-phenylene adipamide) (PAMXD6), hexamethylenediamine-terephthalic acid (PA6T), hexamethylenediamine-terephthalic acid and adipic acid polymer (PA6T / 66), hexamethylenediamine- crystalline polyamide resins, or blends thereof, including but not limited to copolymers of terephthalic acid and ε-caprolactam (PA6T / 6), trimethylhexamethylenediamine-terephthalic acid polymer (PATMD-T), isophthalic acid and adipic acid copolymer (PAMXD6 / MXDI), trimethylhexamethylenediamine and terephthalic acid and ε-caprolactam copolymer (PATMDT / 6), and diaminodicyclohexylmethane and isophthalic acid and dodecanoic acid copolymer.

[0022] When the total mass of polyamide resin (A) and melamine cyanurate (B) is 100 parts by mass, the mixing amount (content) of polyamide resin (A) is 90 to 98 parts by mass. Within this range, the exudation of the flame retardant is suppressed, and the composition maintains high flame retardancy. The mixing amount (content) of polyamide resin (A) is preferably 92 to 96 parts by mass, more preferably 93 to 95 parts by mass. In the flame-retardant polyamide resin composition of the present invention, the mixing amount of each component is directly referred to as the content.

[0023] From the viewpoints of excellent formability, melt flowability, and flame retardancy, the preferred form of the polyamide resin (A) in this invention is a mixture of polyamide 66 resin (A1) and polyamide 6 resin (A2).

[0024] As the polyamide 66 resin (A1) in this invention, an example is a polyamide 66 resin obtained by polycondensation of adipic acid and hexamethylenediamine as raw materials. The relative viscosity of the polyamide 66 resin (A1) is preferably 2.2 to 3.5, measured according to JIS K6810 in 98% sulfuric acid at a concentration of 1% and a temperature of 25°C. When the relative viscosity is below 2.2, the mechanical properties tend to decrease; when it exceeds 3.5, the melt flowability tends to be insufficient. The relative viscosity of the polyamide 66 resin (A1) is more preferably 2.3 to 3.0. Furthermore, the polyamide 66 resin (A1) can be mixed with polyamide 66 resins of different relative viscosities and adjusted to the preferred range of relative viscosity.

[0025] While there is no particular limitation on the concentration of terminal amino groups in polyamide 66 resin (A1), it is preferably 50 to 90 eq / ton, and more preferably 60 to 80 eq / ton from the viewpoint of heat resistance and color change.

[0026] When the polyamide resin (A) is 100 parts by weight, the mixing amount of polyamide 66 resin (A1) is preferably 55 to 85 parts by weight. When the mixing amount of polyamide 66 resin (A1) exceeds 85 parts by weight, the hingeability (fastening performance) decreases; when it is below 50 parts by weight, the molding processability tends to decrease. From the viewpoint of balancing fastening performance and molding processability, the mixing amount of polyamide 66 resin (A1) is more preferably 60 to 80 parts by weight.

[0027] The polyamide 6 resin (A2) used in this invention is a polyamide 6 resin obtained by polycondensation of ε-caprolactam. The relative viscosity of the polyamide 6 resin (A2), measured according to JIS K 6810 in 98% sulfuric acid at a concentration of 1% and a temperature of 25°C, is preferably 1.5 to 4.0. If the relative viscosity is below 1.5, the mechanical properties tend to decrease; if it exceeds 3.6, the melt flowability tends to be impaired. The relative viscosity of the polyamide 6 resin (A2) is more preferably 1.8 to 3.6. Furthermore, the polyamide 6 resin (A2) can be mixed with polyamide 6 resins of different relative viscosities and adjusted to the preferred relative viscosity range.

[0028] While there is no particular limitation on the concentration of terminal amino groups in polyamide 6 resin (A2), it is preferably 50 to 90 eq / ton, and more preferably 60 to 80 eq / ton from the viewpoint of heat resistance and color change.

[0029] When the polyamide resin (A) is 100 parts by weight, the mixing amount of polyamide 6 resin (A2) is preferably 15 to 45 parts by weight. If the mixing amount of polyamide 6 resin (A2) is less than 15 parts by weight, the hingeability (fastening performance) tends to decrease; if it exceeds 45 parts by weight, the molding processability tends to decrease. From the viewpoint of balancing fastening performance and molding processability, the mixing amount of polyamide 6 resin (A2) is more preferably 20 to 40 parts by weight.

[0030] To improve the appearance of molded products, amorphous polyamide resin (A3) can also be mixed in.

[0031] Examples of amorphous polyamide resins include polymers, copolymers, or blends obtained by polycondensation of diamines such as 4,4'-diamino-3,3'-dimethyldicyclohexylmethane (CA), 4,4'-diaminodicyclohexylmethane (PACM), m-phenylenediamine (MXD), trimethylhexamethylenediamine (TMD), isophorone diamine (IA), 4,4'-diaminodicyclohexylpropane (PACP), and hexamethylenediamine, as well as dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, and dodecanoic acid, and lactams such as caprolactam and dodecanolactam. From the viewpoint of balancing fit and processability, the mixing amount of amorphous polyamide resin (A3) is more preferably 0 to 15 parts by mass.

[0032] [Melamine cyanurate (B)]

[0033] As the melamine cyanurate (B) in this invention, an equimolar reaction mixture of cyanuric acid and melamine is preferably cited. Furthermore, a portion of the amino or hydroxyl groups in the melamine cyanurate may be replaced by other substituents. Melamine cyanurate can be obtained, for example, by reacting an aqueous solution of cyanuric acid and an aqueous solution of melamine under stirring at 90–100°C, and filtering the resulting precipitate. While the obtained solid can be used as is, it is preferable to pulverize it as needed. Although there are no particular limitations on the particle size, from the viewpoint of flame retardancy and toughness, an average particle size of 0.5–20 μm is preferred, and more preferably 1–15 μm.

[0034] When the total amount of polyamide resin (A) and melamine cyanurate (B) is 100 parts by mass, the mixing amount (content) of melamine cyanurate (B) is 2 to 10 parts by mass. From the viewpoint of flame retardancy, it is 2 parts by mass or more; from the viewpoint of fastening and exudation, it is 10 parts by mass or less. More preferably, it is 3 to 9 parts by mass, and even more preferably, it is 4 to 8 parts by mass.

[0035] [Phosphorus-based antioxidants (C)]

[0036] The phosphorus-based antioxidant (C) in this invention can be an inorganic compound or an organic compound, without particular limitation. Preferred phosphorus-based compounds include: inorganic phosphates such as monosodium phosphate, disodium phosphate, trisodium phosphate, sodium phosphite, calcium phosphite, magnesium phosphite, and manganese phosphite; triphenyl phosphite, tri(octadecyl) phosphite, tridecyl phosphite, triisodecyl phosphite, trinonylphenyl phosphite, diphenylisodecyl phosphite, diphenylalkyl phosphite, phenyl dialkyl phosphite, tri(nonylphenyl) phosphite, trilauryl phosphite, distearyl pentaerythritol diphosphite, tri(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, and diisodecoxy pentaerythritol diphosphite. Alcohol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis(2,4,6-tris(tert-butylphenyl)) pentaerythritol diphosphite, tripearylsorbitol triphosphite, tetra(2,4-di-tert-butylphenyl)-4,4'-biphenyl diphosphite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g][1,3,2]-dioxophosphataoctane, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxophosphataoctane, bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite, and bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, etc., are mixed to improve heat resistance and color change.

[0037] As a phosphorus-based antioxidant (C), phosphite compounds are preferred. Among phosphite compounds, compounds having a pentaerythritol diphosphite skeleton are preferred. Specifically, from the viewpoint of not reducing flame retardancy, further improving mold release properties, and also having excellent fastening properties, compounds with a pentaerythritol diphosphite skeleton and a molecular weight of about 600 to 800, such as bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (“ADKSTAB PEP-36”, molecular weight 633), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (“ADK STAB PEP-24G”, molecular weight 604), distearate pentaerythritol diphosphite (“ADK STAB PEP-8”, molecular weight 733), and bis(nonylphenyl) pentaerythritol diphosphite (“ADK STAB PEP-4C”, molecular weight 633), are particularly preferred.

[0038] When the total amount of polyamide resin (A) and melamine cyanurate (B) is 100 parts by mass, the mixing amount (content) of phosphorus-based antioxidant (C) is 0.01 to 1 part by mass. Within this range, the mixing amount of phosphorus-based antioxidant (C) inhibits discoloration during extrusion processing and prevents secondary oxidative degradation caused by phosphorus free radicals. The preferred mixing amount of phosphorus-based antioxidant (C) is 0.1 to 0.5 parts by mass.

[0039] [Hindered phenolic antioxidants (D)]

[0040] Examples of hindered phenolic antioxidants (D) in this invention include: N,N'-hexamethylene-bis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide, bis(3,3-bis-(4'-hydroxy-3'-tert-butylphenyl)butyrate) glycol ester, 2,1'-thioethyl bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4,4'-butylene-bis(3-methyl-6-tert-butylphenol), triethylene glycol-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate ("SONGNOX2450", molecular weight 633), etc., or mixtures of two or more of these substances.

[0041] When the total amount of polyamide resin (A) and melamine cyanurate (B) is 100 parts by mass, the amount (content) of the hindered phenolic antioxidant (D) is 0.01 to 1 part by mass. The amount of phosphorus-based antioxidant (D) is within this range, thereby preventing oxidative degradation over time with an appropriate formulation amount corresponding to the coordination bonds of the polyamide composition. The amount of hindered phenolic antioxidant (D) is preferably 0.1 to 0.5 parts by mass.

[0042] [Fatty acid metal salt lubricants with 22 or fewer carbon atoms (E)]

[0043] Examples of fatty acid metal salt lubricants (E) with 22 or fewer carbon atoms in this invention include metal salts of fatty acids such as stearic acid, palmitic acid, and benzyl acid. By using a fatty acid metal salt lubricant with 22 or fewer carbon atoms, not only is mold release improved, but also, because the initial generation temperature of combustion gases from fatty acids during combustion is close to the initial generation temperature of non-flammable gases produced during the decomposition of melamine cyanurate, it can hinder the ignition of flammable gases, thus exhibiting a tendency to further enhance flame retardancy.

[0044] More preferably, metal salts of aliphatic carboxylic acids with 18 or fewer carbon atoms are preferred. From the viewpoint of combining mold release and flame retardancy, alkali metal or alkaline earth metal salts of stearic acid, palmitic acid, etc., are even more preferred. Examples of alkali metals or alkaline earth metals include lithium, sodium, magnesium, and calcium salts. In particular, alkali metal or alkaline earth metal salts of stearic acid have the same initial generation temperature during combustion, which is the same for both the combustible gas from the decomposition of fatty acid metal salts and the non-combustible gas generated from the decomposition of melamine cyanurate. Therefore, there is no decrease in flame retardancy due to the addition, and the mold release properties can be improved, making them the most preferred.

[0045] When the total amount of polyamide resin (A) and melamine cyanurate (B) is 100 parts by mass, the mixing amount (content) of fatty acid metal salt lubricant (E) is 0.1 to 1 part by mass. If it exceeds 1 part by mass, the flame retardancy will decrease. The mixing amount of fatty acid metal salt lubricant (E) is preferably 0.2 to 0.8 parts by mass.

[0046] [Other ingredients]

[0047] In the flame-retardant polyamide resin composition of the present invention, other components may be added besides (A), (B), (C), (D), and (E) described above, without prejudice to the purpose of the present invention. These may include colorants such as pigments and dyes, additives such as heat stabilizers, weather resistance improvers, nucleating agents, plasticizers, release agents, and antistatic agents, as well as other resin polymers. In the flame-retardant polyamide resin composition of the present invention, the total amount of components (A), (B), (C), (D), and (E) described above is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0048] As suitable molded parts obtained using the flame-retardant polyamide resin composition of the present invention, specifically, are molded parts used in the fields of electrical / electronic components, automotive components, etc., such as connectors, coil bobbins, circuit breakers, electromagnetic switches, holders, plugs, sockets, switches, housings, covers, etc., and more specifically, are parts requiring heat resistance, colorfastness, and fastening properties such as ferrite core covers, SC locks, cable ties, and electrical wiring protection components.

[0049] While the method for manufacturing the flame-retardant polyamide resin composition of the present invention is not particularly limited, and a general single-screw extruder, twin-screw extruder, or pressure kneader can be used as the mixing apparatus, a twin-screw extruder is particularly preferred in the present invention. As one embodiment, the above-mentioned (A), (B), (C), (D), and (E), along with pigments according to the intended use, are mixed and fed into a twin-screw extruder. Through uniform mixing in the twin-screw extruder, a polyamide resin composition with high toughness and excellent flame retardancy can be obtained. Preferably, the mixing temperature of the twin-screw extruder is between 220 and 300°C, and the mixing time is preferably about 2 to 15 minutes.

[0050] Example

[0051] The present invention will be further described in detail below through embodiments, but the present invention is not limited to these embodiments in any way.

[0052] The following substances are used for each component.

[0053] Polyamide resin (A)

[0054] A1-1: Polyamide 66 (RV=2.8) Vydyne 21Z (manufactured by Ascend), melting point 265℃

[0055] A1-2: Polyamide 66 (RV=2.4) EPR24 (manufactured by Shanghai Shenma Plastics Technology Co., Ltd.), melting point 265℃

[0056] A2-1: Polyamide 6 (RV=2.0) M2000 (manufactured by MEIDA), melting point 225℃

[0057] A2-2: Polyamide 6 (RV=3.6) ZISAMIDE TP6603 (manufactured by Jisheng Company), melting point 225℃

[0058] Melamine cyanurate (B)

[0059] B: MC6000 (manufactured by Nissan Chemical Co., Ltd.)

[0060] Phosphorus-based antioxidants (C)

[0061] C: ADK STAB PEP-36 (manufactured by ADEKA Co., Ltd.)

[0062] Hindered phenolic antioxidants (D)

[0063] D: SONGNOX2450 (manufactured by SONGWON International Japan)

[0064] Fatty acid metal salt lubricants (E)

[0065] E1: Magnesium stearate NP-1500S (manufactured by Tamnan Chemical Industry Co., Ltd.)

[0066] Other release agents:

[0067] E2: Calcium lignite CS-8-CP (manufactured by Nitto Kasei Corporation)

[0068] E3: Fatty acid ester Licolub WE-40 (manufactured by Clariant Japan Co., Ltd.)

[0069] [Examples 1-12, Comparative Examples 1-7]

[0070] Evaluation samples were manufactured as follows: Raw materials were measured according to the mixing ratios of the polyamide resin compositions shown in Table 1, mixed in a tumbler, and then fed into a twin-screw extruder. The twin-screw extruder was set to a temperature of 250–300°C and a mixing time of 5–10 minutes. The resulting granules were then injection molded into various evaluation samples. The injection molding machine was set to a barrel temperature of 250–280°C and a die temperature of 80°C.

[0071] The various evaluation methods are shown below. The evaluation results are shown in Table 1.

[0072] 1. Relative viscosity [RV] of polyamide resin (98% sulfuric acid solution method)

[0073] The relative viscosity was measured at 25°C in a 98% sulfuric acid solution with a polyamide resin concentration of 1 g / dl.

[0074] 2. Melting point of polyamide resin

[0075] The melting point was determined using a differential scanning calorimeter (Seiko Instruments EXSTAR 6000) at a heating rate of 20°C / min, with the peak temperature of the endothermic peak as the melting point.

[0076] 3. Fit (tensile strength, elongation): Measured according to ISO 527, the tensile strength and elongation (tensile fracture deformation) are obtained.

[0077] 4. Flammability: Determined according to UL94, vertical burning test. V-0 indicates the highest flame retardancy.

[0078] 5. Exudation: Place a 100mm×100mm molded product with a thickness of 2mm in a constant temperature and humidity bath set at 80℃ and 95%RH for 96 hours. Repeat this operation at least twice. After that, return to room temperature and visually confirm the presence of exudates on the surface under a stereomicroscope.

[0079] 6. Thermochromic properties: Calculate the color difference (ΔE) between the particles after being placed in an oven at 120°C for 8 hours and the particles before treatment.

[0080] 7. Formability: Using a mold equipped with a release force measuring device, molding is performed under the above-mentioned molding temperature conditions. The release force is measured from the 31st injection to the 35th injection, and the release resistance value is obtained.

[0081] [Table 1]

[0082]

[0083] The tensile strength of Examples 1-12 is equivalent to that of general polyamide 6 and 66 resins, and the elongation at break is also above 5%. Even exceeding the tensile yield point, no fracture occurred, and no severe embrittlement was observed, thus good fastening properties can be expected. In flame retardancy tests at thicknesses of 0.4, 0.8, 1.6, and 3.0 mm, Examples 1-12 also achieved a UL94 V-0 rating, indicating high flame retardancy over a wide range of thicknesses. In thermochromic tests, the ΔE of Examples 1-12 at 120°C for 8 hours was below 20, indicating suppressed thermochromic behavior under thermal conditions. In the formability evaluation, the demolding resistance of the molded articles was below 1 MPa, making it a composition with minimal possibility of deformation and adhesion during demolding, even with continuous molding.

[0084] On the other hand, although Comparative Examples 1 to 7 partially meet the characteristics, Comparative Example 1 is not preferred because its flame retardancy is rated as UL94 V-2 at thicknesses of 0.4, 0.8, 1.6, and 3.0 mm, indicating a significant decrease in flame retardancy. Comparative Example 2 has a tensile strength of 3%, which does not suppress embrittlement and is therefore not preferred. Comparative Example 3, while rated as UL94 V-2 at thicknesses of 0.4, 0.8, 1.6, and 3.0 mm, has a tensile strength of 3%, making it difficult to say that it possesses both sufficient flame retardancy and good fastening properties. Comparative Examples 4, 5, and 7 are rated as UL94 V-2 at thicknesses of 0.8, 1.6, and 3.0 mm, making it difficult to say that they exhibit high flame retardancy over a wide range of thicknesses. Furthermore, Comparative Example 7 has a demolding resistance value exceeding 1 MPa, which does not indicate good formability and is also not preferred in this respect. Finally, Comparative Example 6, in addition to having a flame retardancy rating of UL94 V-2 at thicknesses of 0.8, 1.6, and 3.0 mm, had a tensile strength of 3%, which makes it difficult to say that it possesses both sufficient flame retardancy and fastening properties, so it is not preferred.

[0085] Industrial utilization potential

[0086] The flame-retardant polyamide resin composition of the present invention has a wide range of article thicknesses and is suitable for molded articles with hinge portions. The resulting molded articles have high flame retardancy over a wide range of article thicknesses and excellent fastening properties, and are therefore preferably used in electrical / electronic components, automotive parts, etc., where both high flame retardancy and fastening properties are desired.

Claims

1. A flame-retardant polyamide resin composition comprising polyamide resin (A) and melamine cyanurate (B), wherein, relative to a total of 100 parts by weight of said components (A) and (B), the composition comprises 90-98 parts by weight of polyamide resin (A), 2-8 parts by weight of melamine cyanurate (B), 0.01-1 parts by weight of phosphorus-based antioxidant (C), 0.01-1 parts by weight of hindered phenolic antioxidant (D), and 0.1-1 parts by weight of alkaline earth metal salt stearic acid lubricant (E), wherein said polyamide resin (A) comprises 55-85% by weight of polyamide 66 resin (A1) and 15-45% by weight of polyamide 6 resin (A2). In the flame-retardant polyamide resin composition, the total of components (A), (B), (C), (D), and (E) is 80% by mass or more. When other components are included besides components (A), (B), (C), (D), and (E), the other components are at least one of additives selected from colorants, heat stabilizers, weather resistance improvers, nucleating agents, plasticizers, release agents, and antistatic agents, as well as resin polymers other than component (A).

2. A molded article comprising the flame-retardant polyamide resin composition of claim 1.

3. The molded article according to claim 2, wherein the molded article is any one of ferrite core cover, SC lock, cable tie, and electrical wiring protection component.

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