Polyamide resin composition

Abstract

A polyamide resin composition comprising a polyamide (A) having a melting point of 280°C or higher, a bromine-compound flame retardant (B), an inorganic filler (C), and a colorant (D), wherein the polyamide (A) comprises dicarboxylic acid units and diamine units, 50-100 mol% of the diamine units are C4-C18 aliphatic diamine units, and the colorant (D) is at least one colorant selected from among organic colorants and inorganic colorants, and wherein R1 represented by specific expression (1) is less than 50.

Description

Polyamide resin composition

[0001] The present invention relates to a polyamide resin composition, a method for producing the polyamide resin composition, and a molded article of the polyamide resin composition.

[0002] Polyamide resins are used in a variety of applications, such as automobile parts and electrical and electronic parts, due to their excellent mechanical properties and heat resistance. Furthermore, polyamide resin compositions may contain a halogen-based flame retardant, such as a bromine-based flame retardant (see Patent Documents 1 to 4). Polyamide resin compositions with enhanced flame retardancy are also referred to as flame-retardant polyamide resin compositions.

[0003] Japanese Patent Application Laid-Open No. 2002-138197 Japanese Patent Application Laid-Open No. 2000-186206 Japanese Patent Application Laid-Open No. 2002-309083 Japanese Patent Application Laid-Open No. 8-127714

[0004] When a molded article of a flame-retardant polyamide resin composition is exposed to high temperatures during the reflow process, the interior or surface of the molded article may swell, i.e., blisters may occur. However, Patent Documents 1 to 4 do not fully consider the blisters. Furthermore, flame-retardant polyamide resin compositions are sometimes colored for use in the above-mentioned automotive parts and electrical and electronic parts. As a result of studies by the present inventors, it has been found that the incidence of blisters tends to increase when a molded article of a flame-retardant polyamide resin composition containing a colorant is exposed to high temperatures during the reflow process.

[0005] Therefore, there is a demand for a flame-retardant polyamide resin composition that has a low incidence of blistering even when exposed to high temperatures during the reflow process, i.e., that has excellent blister resistance and that can give molded articles that are excellent in flame retardancy and mechanical properties.

[0006] Therefore, an object of the present invention is to provide a polyamide resin composition that has excellent blister resistance even when exposed to high temperatures during a reflow process, and that can give a molded article that has excellent flame retardancy and mechanical properties, a method for producing the polyamide resin composition, and a molded article of the polyamide resin composition.

[0007] As a result of intensive research to solve the above problems, the present inventors have conceived the following invention and found that the above problems can be solved.

[0008] [1] A polyamide resin composition containing a polyamide (A) having a melting point of 280°C or higher, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D), wherein the polyamide (A) contains a dicarboxylic acid unit and a diamine unit, and 50 to 100 mol% of the diamine unit is an aliphatic diamine unit having 4 to 18 carbon atoms, and the colorant (D) is at least one of an organic colorant and an inorganic colorant, and R represented by the following formula (1): １ A polyamide resin composition having a molecular weight of less than 50.

[0009] [In formula (1), XA is the content (% by mass) of the polyamide (A) relative to 100% by mass of the polyamide resin composition, XB is the content (% by mass) of the brominated flame retardant (B) relative to 100% by mass of the polyamide resin composition, YA is the melt viscosity (Pa s) of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), and YB is the melt viscosity (Pa s) of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A). However, when two or more types of polyamide (A) are used, the melting point of the polyamide (A) is a weighted average value based on the content (% by mass) of the polyamide (A) relative to 100% by mass of the polyamide resin composition.] n and m are both integers of 1 or greater. [2] A polyamide resin composition containing a polyamide (A) having a melting point of 280°C or higher, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D), wherein the polyamide (A) contains a dicarboxylic acid unit and a diamine unit, and 50 to 100 mol% of the diamine unit is an aliphatic diamine unit having 4 to 18 carbon atoms, and the colorant (D) is at least one of an organic colorant and an inorganic colorant, and is represented by the following formula (2): ２ A polyamide resin composition having a molecular weight of less than 20.

[0010] [In formula (2), ZA is the content (vol%) of the polyamide (A) relative to 100% by volume of the polyamide resin composition, ZB is the content (vol%) of the brominated flame retardant (B) relative to 100% by volume of the polyamide resin composition, YA is the melt viscosity (Pa s) of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), and YB is the melt viscosity (Pa s) of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A). However, when two or more types of polyamide (A) are used, the melting point of the polyamide (A) is a weighted average value based on the content (vol%) of the polyamide (A) relative to 100% by volume of the polyamide resin composition. Both n and m are integers of 1 or greater. [3] The polyamide resin composition according to the above [1] or [2], wherein the content of the brominated flame retardant (B) is 25 to 70 parts by mass relative to 100 parts by mass of the polyamide (A). [4] The polyamide resin composition according to any one of the above [1] to [3], wherein ΔE represented by the following formula (3) is greater than 1:

[0011] [In formula (3), ΔE is CIE1976 (L ＊ a ＊ b ＊ ) is the color difference defined by the color system, and L ＊ ｃｏｌ , a ＊ ｃｏｌ , and b ＊ ｃｏｌ is the CIE1976 (L ＊ a ＊ b ＊ ) L defined by the color system ＊ , a ＊ , and b ＊ and L ＊ ｎａｔ , a ＊ ｎａｔ , and b ＊ ｎａｔ is a colorant-free polyamide resin composition having the same composition as the polyamide resin composition except that it does not contain the colorant (D), as measured by CIE1976 (L ＊ a ＊ b ＊ ) L defined by the color system＊ , a ＊ , and b ＊[5] The polyamide resin composition according to any one of [1] to [4] above, wherein the organic colorant is at least one selected from the group consisting of anthraquinone dyes, perinone dyes, anthrapyridone dyes, and phthalocyanine dyes. [6] The polyamide resin composition according to any one of [1] to [5] above, wherein the inorganic colorant is at least one selected from the group consisting of carbon black, metal oxides, metal sulfides, and complex metal oxides. [7] The polyamide resin composition according to any one of [1] to [6] above, wherein the colorant (D) comprises the organic colorant, and the content of the organic colorant is 0.0001 to 0.5 mass% relative to 100 mass% of the polyamide resin composition. [8] The polyamide resin composition according to any one of [1] to [7] above, wherein the colorant (D) comprises the inorganic colorant, and the content of the inorganic colorant is 0.001 to 5.0 mass% relative to 100 mass% of the polyamide resin composition. [9] The polyamide resin composition according to any one of [1] to [8] above, wherein in the polyamide (A), 50 mol% or more of the dicarboxylic acid units are terephthalic acid units, and the aliphatic diamine having 4 to 18 carbon atoms constituting the aliphatic diamine units having 4 to 18 carbon atoms is at least one selected from the group consisting of 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8octanediamine, and 1,10-decanediamine.

[10] The polyamide resin composition according to any one of the above [1] to [9], wherein the brominated flame retardant (B) is selected from the group consisting of brominated polystyrene and polybrominated styrene, and the brominated flame retardant (B) is two or more types having different melt viscosities at a temperature 14°C higher than the melting point of the polyamide (A).

[11] The polyamide resin composition according to any one of the above [1] to

[10] , wherein the inorganic filler (C) comprises glass fiber (C1).

[12] The polyamide resin composition according to any one of [1] to

[11] above, further comprising an aromatic vinyl copolymer (E), the aromatic vinyl copolymer (E) comprising structural units derived from at least one selected from the group consisting of styrene and α-methylstyrene, and structural units derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydrides having an alkyl group containing from 1 to 3 carbon atoms, wherein the aromatic vinyl copolymer (E) has a glass transition temperature of 140°C or higher.

[13] The polyamide resin composition according to

[12] above, wherein the content of structural units derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydrides having an alkyl group containing from 1 to 3 carbon atoms is 18 to 50 mass%.

[14] The polyamide resin composition according to

[12] or

[13] above, wherein the aromatic vinyl copolymer (E) has a weight average molecular weight (Mw) of 10,000 to 500,000.

[15] The polyamide resin composition according to any one of [1] to

[14] above, further comprising a flame retardant aid (F).

[16] The polyamide resin composition according to any one of [1] to

[15] above, further comprising, per 100 parts by mass of the polyamide (A): 25 to 70 parts by mass of the brominated flame retardant (B), 30 to 250 parts by mass of the inorganic filler (C), and 0.0005 to 20 parts by mass of the colorant (D).

[17] The polyamide resin composition according to

[16] above, further comprising an aromatic vinyl copolymer (E), the content of which is 0.1 to 10 parts by mass per 100 parts by mass of the polyamide (A).

[18] The polyamide resin composition according to

[16] or

[17] above, further comprising a flame retardant aid (F), the content of which is 1 to 20 parts by mass per 100 parts by mass of the polyamide (A).

[19] A method for producing the polyamide resin composition according to any one of [1] to

[18] above, comprising melt-kneading the polyamide (A), the brominated flame retardant (B), the inorganic filler (C), and the colorant (D), and, if necessary, the aromatic vinyl copolymer (E) and the flame retardant aid (F).

[20] A molded product of the polyamide resin composition according to any one of [1] to

[18] above.

[21] The molded article according to

[20] , which is a connector.

[22] The molded article according to

[20] or

[21] , which is an in-vehicle connector.

[0012] According to the present invention, it is possible to provide a polyamide resin composition that has excellent blister resistance even when exposed to high temperatures during a reflow process, and that can give a molded article that is excellent in flame retardancy and mechanical properties, as well as a method for producing the polyamide resin composition and a molded article of the polyamide resin composition.

[0013] The following describes an example of an embodiment of the present invention (hereinafter, sometimes referred to as "this embodiment"). However, the embodiment described below is merely an example for embodying the technical concept of the present invention, and the present invention is not limited to the following description. Furthermore, although preferred embodiments are shown in this specification, combinations of two or more of the individual preferred embodiments are also preferred. For matters indicated as numerical ranges, when there are several numerical ranges, the lower and upper limits can be selectively combined to form a preferred embodiment. In this specification, when a numerical range is described as "XX to YY," it means "XX or more and YY or less." Furthermore, in this specification, "units" (where "~" indicates a monomer) mean "structural units derived from ~," for example, "dicarboxylic acid units" mean "structural units derived from dicarboxylic acids," and "diamine units" mean "structural units derived from diamines."

[0014] <Polyamide Resin Composition> A polyamide resin composition according to a first embodiment of the present invention is a polyamide resin composition containing a polyamide (A) having a melting point of 280°C or more, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D), wherein the polyamide (A) contains dicarboxylic acid units and diamine units, and 50 to 100 mol% of the diamine units are aliphatic diamine units having 4 to 18 carbon atoms, and the colorant (D) is at least one of an organic colorant and an inorganic colorant, and R represented by the following formula (1): １ The polyamide resin composition has a viscosity of less than 50.

[0015]

[0016] In formula (1), XA is the content (mass%) of the polyamide (A) relative to 100% by mass of the polyamide resin composition, XB is the content (mass%) of the brominated flame retardant (B) relative to 100% by mass of the polyamide resin composition, YA is the melt viscosity (Pa·s) of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), and YB is the melt viscosity (Pa·s) of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A). However, when two or more types of polyamide (A) are used, the melting point of the polyamide (A) is a weighted average value based on the content (mass%) of the polyamide (A) relative to 100% by mass of the polyamide resin composition. n and m are both integers of 1 or more. In other words, n means the number of types of polyamide (A) in the polyamide resin composition and is an integer of 1 or more. XA ｋ represents the kth polyamide (A) in descending order of content among the polyamides (A). ｋ ) relative to 100% by mass of the polyamide resin composition. m represents the number of types of the brominated flame retardant (B) in the polyamide resin composition and is an integer of 1 or more. ｋ is the kth brominated flame retardant (B) in descending order of content among the brominated flame retardants (B). ｋ ) is the content (% by mass) of the polyamide resin composition relative to 100% by mass of the polyamide resin composition. ｋ is the weighted average melting point of the polyamide (A), i.e., the melting point of the polyamide (A) present in the polyamide resin composition. ｋ ) at a temperature 14°C higher than the melting point of the weighted average of all (k = 1 to n) of the polyamide (A ｋ ) is the melt viscosity (Pa s) of YB ｋ is the melting point of the brominated flame retardant (B) at a temperature 14°C higher than the weighted average melting point of the polyamide (A). ｋ ) is the melt viscosity (Pa·s).

[0017] The present inventors focused on the contents of the polyamide (A) and the brominated flame retardant (B) and the melt viscosities of the polyamide (A) and the brominated flame retardant (B), and determined that the R１ It has been found that when the β-blocking coefficient is smaller than a specific value, a molded article having excellent blister resistance even when exposed to high temperatures during the reflow process, as well as excellent flame retardancy and mechanical properties can be obtained.

[0018] R represented by the formula (1) １ is smaller than 50, preferably 40 or less, more preferably 30 or less, even more preferably 25 or less, and even more preferably 20 or less. １ When R is less than 50, a molded article having excellent blister resistance and excellent flame retardancy and mechanical properties can be obtained even when exposed to high temperatures during the reflow process. １ The lower limit of is not particularly limited, but if the melt viscosity of the brominated flame retardant (B) is too high relative to that of the polyamide (A), poor dispersion of the brominated flame retardant (B) occurs, resulting in a decrease in blister resistance. Therefore, the lower limit is preferably 0.02 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and still more preferably 0.5 or more.

[0019] The R １ can be set within the above range by appropriately adjusting the content (XA) of polyamide (A) and the content (XB) of brominated flame retardant (B) in the polyamide composition, as well as the melt viscosity (YA) of the polyamide (A) and the melt viscosity (YB) of the brominated flame retardant (B) at a temperature 14° C. higher than the melting point of the polyamide (A). Furthermore, the closer the value of YA and the value of YB are, the easier the polyamide (A) and the brominated flame retardant (B) will be to mix, the more the brominated flame retardant (B) will be dispersed in the polyamide (A), and aggregation of the brominated flame retardant (B) will be suppressed, resulting in a molded product with superior blister resistance even when exposed to high temperatures during the reflow process.

[0020] From the viewpoint of adjusting the mechanical properties and flowability of the obtained molded article, n is an integer of 1 or more, and is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. When n = 1, the polyamide resin composition contains one type of polyamide (A). When m = 1, the polyamide resin composition contains one type of brominated flame retardant (B), and is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. When m = 1, the polyamide resin composition contains one type of brominated flame retardant (B).

[0021] A polyamide resin composition according to a second embodiment of the present invention is a polyamide resin composition containing a polyamide (A) having a melting point of 280°C or more, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D), wherein the polyamide (A) contains a dicarboxylic acid unit and a diamine unit, and 50 to 100 mol% of the diamine unit is an aliphatic diamine unit having 4 to 18 carbon atoms, and the colorant (D) is at least one of an organic colorant and an inorganic colorant, and R represented by the following formula (2): ２ is a polyamide resin composition having a molecular weight of less than 20.

[0022]

[0023] In formula (2), ZA is the content (vol %) of the polyamide (A) relative to 100% by volume of the polyamide resin composition, ZB is the content (vol %) of the brominated flame retardant (B) relative to 100% by volume of the polyamide resin composition, YA is the melt viscosity (Pa s) of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), and YB is the melt viscosity (Pa s) of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A). However, when two or more types of polyamide (A) are used, the melting point of the polyamide (A) is a weighted average value based on the content (vol %) of the polyamide (A) relative to 100% by volume of the polyamide resin composition. n and m are both integers of 1 or more. In other words, n means the number of types of polyamide (A) in the polyamide resin composition and is an integer of 1 or more. ZA ｋrepresents the kth polyamide (A) in descending order of content among the polyamides (A). ｋ ) relative to 100% by volume of the polyamide resin composition. m means the number of types of the brominated flame retardant (B) in the polyamide resin composition and is an integer of 1 or more. ｋ is the kth brominated flame retardant (B) in descending order of content among the brominated flame retardants (B). ｋ ) is the content (vol %) of the polyamide resin composition relative to 100% by volume. ｋ is the weighted average melting point of the polyamide (A), i.e., the melting point of the polyamide (A) present in the polyamide resin composition. ｋ ) at a temperature 14°C higher than the melting point of the weighted average of all (k = 1 to n) of the polyamide (A ｋ ) is the melt viscosity (Pa s) of YB ｋ is the melting point of the brominated flame retardant (B) at a temperature 14°C higher than the weighted average melting point of the polyamide (A). ｋ The preferred ranges of n and m are as described above.

[0024] R represented by the formula (2) ２ is smaller than 20, preferably 18 or less, more preferably 15 or less. ２ When R is less than 20, a molded article having excellent blister resistance and excellent flame retardancy and mechanical properties can be obtained even when exposed to high temperatures during the reflow process. ２ The lower limit of is not particularly limited, but from the viewpoint of suppressing shear heat generation during melt-kneading and improving blister resistance, it is preferably 0.05 or more, more preferably 0.07 or more, even more preferably 0.1 or more, and still more preferably 0.5 or more.

[0025] The R ２ can be set within the above-mentioned range by appropriately adjusting the content (ZA) of polyamide (A) and the content (ZB) of brominated flame retardant (B) in the polyamide composition, as well as the melt viscosity (YA) of the polyamide (A) and the melt viscosity (YB) of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A).

[0026] Each component of the polyamide resin composition of the above embodiment will be described below.

[0027] [Polyamide (A)] The polyamide (A) used in this embodiment has a melting point of 280°C or higher and contains dicarboxylic acid units and diamine units. The diamine units contain 50 to 100 mol% aliphatic diamine units having 4 to 18 carbon atoms. By containing 50 to 100 mol% aliphatic diamine units having 4 to 18 carbon atoms in the diamine units, a molded product with excellent blister resistance can be obtained even when exposed to high temperatures during the reflow process. The content of aliphatic diamine units having 4 to 18 carbon atoms in the diamine units is preferably 75 to 100 mol%, more preferably 85 to 100 mol%. Polyamide (A) may be one type or two or more types.

[0028] Examples of the aliphatic diamine having 4 to 18 carbon atoms that constitutes the aliphatic diamine unit having 4 to 18 carbon atoms include linear aliphatic diamines such as 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine; 1-butyl-1,2-ethanediamine, 1,1-dimethyl-1,4-butanediamine, and 1-ethyl-1,4-butanediamine; hexanediamine, 1,2-dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6- Hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-propyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptanediamine, 2,3-dimethyl-1,7-heptanediamine, 2,4-dimethyl-1,7-heptanediamine, 2,5-dimethyl-1,7-heptanediamine, 2-ethyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 4-methyl- Examples of branched chain aliphatic diamines include 1,8-octanediamine, 1,3-dimethyl-1,8-octanediamine, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1,8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine.Among these, from the viewpoint of excellent physical properties such as heat resistance and low water absorbency, the aliphatic diamine having 4 to 18 carbon atoms is preferably at least one selected from the group consisting of 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8octanediamine, and 1,10-decanediamine, more preferably at least one selected from the group consisting of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and even more preferably a combination of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, that is, 1,9-nonanediamine and 2-methyl-1,8-octanediamine.

[0029] When 1,9-nonanediamine and 2-methyl-1,8-octanediamine are used in combination as the aliphatic diamine having 4 to 18 carbon atoms, from the viewpoint of heat resistance, the molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine (1,9-nonanediamine / 2-methyl-1,8-octanediamine) is preferably in the range of 95 / 5 to 40 / 60, more preferably in the range of 90 / 10 to 50 / 50, and even more preferably in the range of 90 / 10 to 60 / 40.

[0030] The polyamide (A) may contain diamine units other than the aliphatic diamine units having 4 to 18 carbon atoms. Examples of diamines constituting such other diamine units include aliphatic diamines having 2 or 3 carbon atoms, aromatic diamines, and alicyclic diamines. Examples of aliphatic diamines having 2 or 3 carbon atoms include ethylenediamine, 1,2-propanediamine, and 1,3-propanediamine. Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl ether. Examples of alicyclic diamines include cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, norbornanedimethylamine, and tricyclodecanedimethylamine. These diamines can be used alone or in combination. The polyamide (A) may further contain a structural unit derived from a trivalent or higher polyvalent amine such as bis(hexamethylene)triamine, to the extent that melt molding is possible, as long as the effects of the present invention are not impaired.

[0031] When the polyamide (A) contains other diamine units, the content thereof is preferably 50 mol % or less, more preferably 30 mol % or less, even more preferably 20 mol % or less, and still more preferably 10 mol % or less, of the total diamine units contained in the polyamide (A).

[0032] The polyamide (A) contains any dicarboxylic acid unit. Examples of the dicarboxylic acid constituting the dicarboxylic acid unit include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, dimethylmalonic acid, 2,2-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, and trimethyladipic acid; 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and cycloheptanedicarboxylic acid. Examples of suitable dicarboxylic acids include alicyclic dicarboxylic acids such as cyclooctanedicarboxylic acid, cyclodecanedicarboxylic acid, and the like; and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, and 4,4'-biphenyldicarboxylic acid. These dicarboxylic acids can be used alone or in combination. The polyamide (A) may contain structural units derived from polycarboxylic acids, as long as the effects of the present invention are not impaired. Examples of structural units derived from polycarboxylic acids include trimellitic acid, trimesic acid, and pyromellitic acid. It is preferable to contain such structural units to the extent that melt molding is possible.

[0033] The dicarboxylic acid units preferably contain terephthalic acid units in an amount of 50 mol % or more, more preferably 60 mol % or more, even more preferably 75 mol % or more, and may even be 100 mol %. When the dicarboxylic acid units contain terephthalic acid units in an amount of 50 mol % or more, a molded article having excellent blister resistance can be obtained even when exposed to high temperatures during a reflow process.

[0034] The molar ratio of dicarboxylic acid units to diamine units in the polyamide (A) [dicarboxylic acid units / diamine units] is preferably 45 / 55 to 55 / 45, and more preferably 47 / 53 to 53 / 47, from the viewpoint of increasing the degree of polymerization. The molar ratio of dicarboxylic acid units to diamine units can be adjusted depending on the blending ratio (molar ratio) of the raw dicarboxylic acid and the raw diamine. The total content of dicarboxylic acid units and diamine units in 100 mol% of the polyamide (A) is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more, and may even be 100 mol%.

[0035] It is preferable that 10% or more of the terminal groups of the molecular chain of the polyamide (A) are blocked with a terminal blocking agent. The proportion of the terminal groups of the molecular chain blocked with the terminal blocking agent (terminal blocking rate) is more preferably 20% or more. As the terminal blocking agent, a monofunctional compound reactive with the amino or carboxyl group at the polyamide terminal can be used. From the viewpoints of reactivity and the stability of the blocked terminal, a monocarboxylic acid or a monoamine is preferred, and from the viewpoint of ease of handling, a monocarboxylic acid is more preferred. Other terminal blocking agents that can be used include monoisocyanates, monoacid halides, monoesters, and monoalcohols.

[0036] The monocarboxylic acid used as the end-capping agent may be one that is reactive with an amino group, and examples thereof include aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid; and any mixtures thereof. Among these, from the viewpoints of reactivity, stability of the blocked end, cost, and the like, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, and benzoic acid are preferred.

[0037] The monoamine used as the terminal blocking agent may be one that is reactive with a carboxyl group, and examples thereof include aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine; and any mixtures thereof. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferred from the standpoints of reactivity, boiling point, stability of the blocked terminals, cost, and the like.

[0038] The terminal capping rate of polyamide (A) is calculated by measuring the number of carboxyl terminals, amino terminals, and terminal groups capped with a terminal capping agent present in polyamide (A) and then calculating the terminal capping rate according to the following formula (I): １It is preferable to determine the terminal capping rate from the integrated value of the characteristic signal corresponding to each terminal group by H-NMR: Terminal capping rate (%) = [(T - S) / T] x 100 (I) (where T represents the total number of terminal groups in the molecular chain of polyamide (A) (this is usually equal to twice the number of polyamide molecules), and S represents the total number of carboxyl terminals and amino terminals that remain uncapped.)

[0039] The polyamide (A) can be produced by any known method for producing crystalline polyamides, such as a solution polymerization method or an interfacial polymerization method using dicarboxylic acid and diamine in the form of acid chloride as raw materials, a melt polymerization method, a solid-state polymerization method, or a melt extrusion polymerization method using dicarboxylic acid and diamine as raw materials.

[0040] The melting point of the polyamide (A) is 280°C or higher, preferably 290°C or higher, more preferably 300°C or higher, from the viewpoint of heat resistance and more significantly exhibiting the effects of the present invention. Furthermore, from the viewpoint of suppressing thermal decomposition of the polyamide during melt molding, the melting point is preferably 350°C or lower, more preferably 340°C or lower, and even more preferably 330°C or lower. When two or more polyamides (A) are used, the melting point of the polyamide (A) being 280°C or higher means that, on a mass basis, the weighted average melting point of the polyamide (A) is 280°C or higher, calculated based on the content (mass%) of the polyamide (A) relative to 100% by mass of the polyamide resin composition. Furthermore, on a volume basis, the weighted average melting point of the polyamide (A) is 280°C or higher, calculated based on the content (volume%) of the polyamide (A) relative to 100% by volume of the polyamide resin composition. The melting point of the polyamide (A) can be determined as the peak temperature of an endothermic peak that appears when the temperature is raised at a rate of 10° C. / min using a differential scanning calorimetry (DSC) analyzer.

[0041] From the viewpoint of heat resistance, the glass transition temperature of the polyamide (A) is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher. There is no particular upper limit to the glass transition temperature of the polyamide (A), but from the viewpoint of handleability, it is preferably 180°C or lower, more preferably 160°C or lower, and may be 150°C or lower. In other words, the glass transition temperature of the polyamide (A) is preferably 100 to 180°C, more preferably 110 to 160°C, and even more preferably 120 to 150°C. The glass transition temperature of the polyamide (A) can be determined using a differential scanning calorimetry (DSC) analyzer as the temperature of the inflection point that appears when the temperature is increased at a rate of 20°C / min.

[0042] The melt viscosity of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A) is preferably 10 to 300 Pa·s, more preferably 15 to 290 Pa·s, and even more preferably 20 to 280 Pa·s. When the melt viscosity is within the above range, the R １ and R represented by the above formula (2) ２ The melt viscosity of the polyamide (A) can be measured using a rotational rheometer, specifically by the method described in the examples.

[0043] The content (mass%) of polyamide (A) in the total amount of the polyamide resin composition of this embodiment is preferably 20 to 70 mass%, more preferably 25 to 70 mass%, even more preferably 30 to 65 mass%, and still more preferably 30 to 50 mass%. When the content (mass%) of polyamide (A) is within the above range, R represented by the above formula (1) １ can be in the above range.

[0044] The content (vol %) of polyamide (A) in the total amount of the polyamide resin composition of this embodiment is preferably 15 to 45% by volume, more preferably 18 to 40% by volume, and even more preferably 20 to 35% by volume. When the content (vol %) of polyamide (A) is within the above range, R represented by the above formula (2) can be obtained. ２can be in the above range.

[0045] [Brominated Flame Retardant (B)] The polyamide resin composition of this embodiment contains a brominated flame retardant (B). By containing the brominated flame retardant (B), the polyamide resin composition has improved flame retardancy.

[0046] Examples of the brominated flame retardant (B) used in this embodiment include hexabromocyclododecane, decabromodiphenyl oxide, octabromodiphenyl oxide, tetrabromobisphenol A, bis(tribromophenoxy)ethane, bis(pentabromophenoxy)ethane, tetrabromobisphenol A epoxy resin, tetrabromobisphenol A carbonate, ethylene(bistetrabromophthal)imide, ethylenebispentabromodiphenyl, tris(tribromophenoxy)triazine, bis(dibromopropyl)tetrabromobisphenol Examples of suitable brominated polyphenylene ethers include brominated phenol A, bis(dibromopropyl)tetrabromobisphenol S, and poly(di)bromophenylene ether; polydibromostyrene, polytribromostyrene, brominated polystyrene, polybrominated styrene, brominated crosslinked aromatic polymers, brominated epoxy resins, brominated phenoxy resins, brominated styrene-maleic anhydride polymers, tetrabromobisphenol S, tris(tribromoneopentyl)phosphate, polybromotrimethylphenylindane, and tris(dibromopropyl)isocyanurate. The brominated polystyrene may be at least one selected from the group consisting of uncrosslinked and unmodified brominated polystyrene, crosslinked brominated polystyrene, and modified brominated polystyrene to which a functional group has been added. Examples of suitable functional groups include functional groups containing an epoxy group, such as glycidyl methacrylate, and acid anhydride groups containing an α,β-unsaturated dicarboxylic acid anhydride, such as maleic anhydride and citraconic anhydride. The modification rate is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass. Similarly, the polybrominated styrene may be at least one selected from the group consisting of unmodified polybrominated styrene and modified polybrominated styrene to which a functional group has been added. The functional group and modification rate in the modified polybrominated styrene are the same as those described above for the modified brominated polystyrene. These brominated flame retardants (B) may be used alone or in combination of two or more.

[0047] It is preferable to use at least two brominated flame retardants (B) selected from the group consisting of brominated polystyrenes and polybrominated styrenes. Furthermore, it is preferable that these two or more brominated flame retardants (B) are two or more different in melt viscosity at a temperature 14°C higher than the melting point of the polyamide (A). For example, a brominated polystyrene and a modified polybrominated styrene having different melt viscosities at a temperature 14°C higher than the melting point of the polyamide (A) may be used in combination. This can improve blister resistance, flame retardancy, and mechanical properties. In addition, R represented by the above formula (1) １ and R represented by the above formula (2) ２ can be set within the above ranges.

[0048] Brominated polystyrene can be produced, for example, by polymerizing a styrene monomer to produce polystyrene, and then brominating the benzene ring of the polystyrene. Polybrominated styrene can be produced by polymerizing a brominated styrene monomer (bromostyrene, dibromostyrene, tribromostyrene, etc.).

[0049] The bromine content in both the brominated polystyrene and the polybrominated styrene is preferably 55 to 75% by mass, more preferably 55 to 70% by mass. By setting the bromine content to 55% by mass or more, the amount of bromine required for flame retardancy can be satisfied with a small content of the brominated polystyrene and the polybrominated styrene, and deterioration of mechanical properties can be suppressed, resulting in a molded article with excellent mechanical properties and heat resistance. Furthermore, by setting the bromine content to 75% by mass or less, thermal decomposition during melt processing such as extrusion or molding is unlikely to occur, gas generation can be suppressed, and a molded article with excellent heat discoloration resistance can be obtained.

[0050] The melt viscosity of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A) is preferably 1 to 80 Pa·s, more preferably 1 to 70 Pa·s, and even more preferably 2 to 60 Pa·s. When the melt viscosity is within the above range, the R １ and R represented by the above formula (2) ２can be within the above-mentioned ranges. When at least two brominated flame retardants (B) are contained, it is preferable that the melt viscosity of at least one of them is within the above-mentioned range. The melt viscosity of the brominated flame retardant (B) can be measured using a rotational rheometer, and specifically, can be measured by the method described in the examples.

[0051] The content (mass%) of the brominated flame retardant (B) in the total amount of the polyamide resin composition of this embodiment is preferably 10 to 40 mass%, more preferably 12 to 35 mass%, and even more preferably 15 to 30 mass%. When the content (mass%) of the brominated flame retardant (B) is within the above range, R represented by the above formula (1) １ can be in the above range.

[0052] The content (vol %) of the brominated flame retardant (B) in the total amount of the polyamide resin composition of this embodiment is preferably 10 to 40% by volume, more preferably 12 to 35% by volume, and even more preferably 15 to 30% by volume. When the content (vol %) of the brominated flame retardant (B) is within the above range, the R ２ can be in the above range.

[0053] The content of the brominated flame retardant (B) is preferably 25 to 70 parts by mass, more preferably 30 to 65 parts by mass, and even more preferably 35 to 60 parts by mass, per 100 parts by mass of the polyamide (A). When the content of the brominated flame retardant (B) is 25 parts by mass or more, a molded article with excellent flame retardancy can be obtained. Furthermore, when the content of the brominated flame retardant (B) is 70 parts by mass or less, a molded article with excellent blister resistance, flame retardancy, and mechanical properties can be obtained, even when exposed to high temperatures during the reflow process. When multiple types of brominated flame retardants (B) are used, the total amount thereof should be within the above range.

[0054] [Inorganic Filler (C)] The polyamide resin composition of this embodiment contains an inorganic filler (C). Examples of the inorganic filler (C) include carbon nanotubes, fullerenes, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, alumina silicate, silicon oxide, magnesium oxide, alumina, magnesium carbonate, dolomite, calcium sulfate, calcium hydroxide, magnesium hydroxide, milled fiber, glass powder, ceramic beads, boron nitride, silicon carbide, various clay minerals such as halloysite and vermiculite, and glass fiber. These inorganic fillers (C) may be used alone or in combination of two or more. From the viewpoint of improving the mechanical properties of a molded article of the polyamide resin composition, the inorganic filler (C) preferably contains glass fiber or wollastonite, more preferably contains glass fiber (C1), and even more preferably is glass fiber (C1).

[0055] The glass fibers (C1) preferably have the following properties. The average fiber length of the glass fibers (C1) is preferably 1 to 10 mm, more preferably 1 to 7 mm, and even more preferably 2 to 4 mm. The average fiber diameter of the glass fibers (C1) is preferably 6 to 20 μm, more preferably 6 to 15 μm, from the viewpoint of obtaining a molded article having excellent blister resistance and mechanical properties. The average fiber length and average fiber diameter of the glass fibers (C1) can be determined by measuring the fiber lengths and fiber diameters of 400 arbitrarily selected glass fibers (C1) through image analysis using an electron microscope and calculating the respective average values. The average fiber length and average fiber diameter of the glass fibers (C1) in a polyamide resin composition or a molded article can be determined, for example, by dissolving the polyamide resin composition or the molded article in an organic solvent, extracting the glass fibers (C1), and then performing image analysis using an electron microscope in the same manner as described above.

[0056] Examples of the cross-sectional shape of the glass fiber (C1) include a circle, a rectangle, an oval close to a rectangle, an ellipse, a cocoon shape, a cocoon shape with a constricted central portion in the longitudinal direction, etc. Among these, the cross-sectional shape of the glass fiber (C1) is preferably a circle, a rectangle, an oval close to a rectangle, an ellipse, or a cocoon shape.

[0057] The glass fiber (C1) may contain at least one surface treatment agent selected from the group consisting of a coupling agent and a sizing agent. For example, the glass fiber (C1) may contain a sizing agent. The glass fiber (C1) may also contain a coupling agent and a sizing agent. The glass fiber (C1) preferably contains a surface treatment agent on its surface. The amount of the surface treatment agent attached is usually 0.01 mass% or more based on the total mass of the glass fiber (C1) (i.e., the total amount of the glass fiber (C1) and the surface treatment agent).

[0058] Examples of the coupling agent include silane coupling agents and titanium coupling agents, such as γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0059] Examples of sizing agents include urethane resin-based sizing agents, acrylic resin-based sizing agents, epoxy resin-based sizing agents, and acid anhydride group-containing resin-based sizing agents. However, when a urethane resin-based sizing agent, an acrylic resin-based sizing agent, or an epoxy resin-based sizing agent contains an acid anhydride group, it is considered to belong to the category of acid anhydride group-containing resin-based sizing agents. The acid anhydride group-containing resin-based sizing agent is composed of a resin containing at least an acid anhydride group, and preferably a copolymer containing an acid anhydride group. From the viewpoint of obtaining a molded product with better blister resistance and better mechanical properties, it is preferable that the sizing agent contains at least one selected from the group consisting of epoxy resin-based sizing agents and acid anhydride group-containing resin-based sizing agents. From the viewpoint of obtaining a molded product with even better blister resistance, it is preferable that the sizing agent contains an epoxy resin-based sizing agent. From the viewpoint of obtaining a molded product with even better fluidity, it is preferable that the sizing agent contains a urethane resin-based sizing agent. It is believed that selecting an appropriate surface treatment agent for the glass fiber (C1) contributes to imparting to the molded article strength that can withstand the internal pressure of water vapor even under the peak temperature conditions of the reflow process.

[0060] The content of the inorganic filler (C) is preferably 30 to 250 parts by mass, more preferably 35 to 200 parts by mass, even more preferably 40 to 150 parts by mass, and still more preferably 45 to 100 parts by mass, relative to 100 parts by mass of the polyamide (A). When the content of the inorganic filler (C) is 30 parts by mass or more, a molded product with more excellent mechanical properties can be obtained, and when the content is 250 parts by mass or less, shear heat generation during melt-kneading can be suppressed.

[0061] [Colorant (D)] The polyamide resin composition of this embodiment contains a colorant (D), which provides visibility and decorativeness. The colorant (D) used in this embodiment is at least one of an organic colorant and an inorganic colorant. The colorant (D) may be used alone or in combination of two or more.

[0062] Examples of organic colorants include organic dyes such as anthraquinone dyes, perinone dyes, anthrapyridone dyes, methine dyes, azine dyes, azo dyes, azomethine dyes, phthalocyanine dyes, quinoneimine dyes, quinoline dyes, nitro dyes, indigo dyes, and oxazine dyes; and organic pigments such as azo lake pigments, insoluble monoazo pigments, insoluble disazo pigments, and chelate azo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, benzimidazolone pigments, and threne pigments. Among these, from the viewpoints of heat resistance, color development, and compatibility, anthraquinone dyes, perinone dyes, anthrapyridone dyes, phthalocyanine dyes, azo pigments, and phthalocyanine pigments are preferred, and at least one dye selected from the group consisting of anthraquinone dyes, perinone dyes, anthrapyridone dyes, and phthalocyanine dyes is more preferred.

[0063] Examples of inorganic colorants include black inorganic pigments such as carbon black, lamp black, acetylene black, bone black, thermal black, channel black, furnace black, and titanium black; titanium oxide (TiO, Ti ２ O ３ , TiO ２ ), zinc oxide (Pb ３ O ４ ), iron oxide (Fe ２ O ３Examples of suitable pigments include metal oxides such as black inorganic pigments, antimony oxide, and zirconium oxide (zircon oxide), metal sulfides such as zinc sulfide, ultramarine (Pigment Blue 29), zinc phosphate, barium sulfate, manganese phosphate, cobalt aluminate, cobalt stannate, cobalt zincate, antimony oxide, antimony sulfide, cerium sulfide, lanthanum sulfide, chromium oxide, zinc chromate, and composite metal oxides containing a plurality of oxides such as nickel-based, bismuth-based, vanadium-based, molybdenum-based, cadmium-based, titanium-based, zinc-based, manganese-based, cobalt-based, iron-based, chromium-based, antimony-based, magnesium-based, and aluminum-based. Among these, from the viewpoint of heat resistance, at least one selected from the group consisting of black inorganic pigments, metal oxides, metal sulfides, and composite metal oxides is preferred, and at least one selected from the group consisting of carbon black, metal oxides, metal sulfides, and composite metal oxides is more preferred.

[0064] When the colorant (D) contains an organic colorant, the content of the organic colorant is preferably 0.0001 to 0.5 mass%, more preferably 0.001 to 0.5 mass%, and even more preferably 0.005 to 0.5 mass%, relative to 100 mass% of the polyamide resin composition of this embodiment, from the viewpoints of flame retardancy, color development, and mechanical properties.

[0065] When the colorant (D) contains an inorganic colorant, the content of the inorganic colorant is preferably 0.001 to 5.0 mass%, more preferably 0.01 to 5.0 mass%, and even more preferably 0.1 to 5.0 mass%, relative to 100 mass% of the polyamide resin composition of this embodiment, from the viewpoints of flame retardancy, color development, and mechanical properties.

[0066] The content of the colorant (D) is preferably 0.0005 to 20 parts by mass, more preferably 0.001 to 15 parts by mass, even more preferably 0.01 to 10 parts by mass, still more preferably 0.1 to 5 parts by mass, and even more preferably 0.2 to 1 part by mass, relative to 100 parts by mass of the polyamide (A). When the content of the colorant (D) is 0.0005 parts by mass or more, a color with high visibility can be developed, and when it is 20 parts by mass or less, a decrease in the mechanical properties of the molded article can be suppressed.

[0067] [Aromatic Vinyl Copolymer (E)] From the viewpoints of flame retardancy, heat resistance, and moldability, the polyamide resin composition of this embodiment preferably further contains an aromatic vinyl copolymer (E) (hereinafter also referred to as "copolymer (E)"). From the viewpoints of flame retardancy, heat resistance, and moldability, copolymer (E) preferably contains structural units derived from at least one selected from the group consisting of styrene and α-methylstyrene, and structural units derived from at least one selected from the group consisting of maleic anhydride and a monoalkyl maleic anhydride having an alkyl group having from 1 to 3 carbon atoms, and more preferably contains structural units derived from styrene and structural units derived from maleic anhydride.

[0068] The content of structural units derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydride having an alkyl group having from 1 to 3 carbon atoms in the copolymer (E) is, from the viewpoints of flame retardancy, heat resistance, and moldability, preferably from 3 to 50 mass%, more preferably from 5 to 50 mass%, and even more preferably from 10 to 40 mass%, and may be from 18 to 50 mass%, 18 to 30 mass%, or 18 to 25 mass%.

[0069] Copolymer (E) may further contain structural units other than structural units derived from at least one selected from the group consisting of styrene and α-methylstyrene, and structural units derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydrides having an alkyl group having from 1 to 3 carbon atoms. However, the total content of structural units derived from at least one selected from the group consisting of styrene and α-methylstyrene, and structural units derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydrides having an alkyl group having from 1 to 3 carbon atoms in copolymer (E) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass.

[0070] The glass transition temperature of copolymer (E) is preferably 140°C or higher, more preferably 140 to 200°C, even more preferably 145 to 180°C, and still more preferably 150 to 160°C. When the glass transition temperature of copolymer (E) is 140°C or higher, the flame retardancy and heat resistance can be further improved, and when it is 200°C or lower, thermal decomposition of polyamide during melt molding can be suppressed. The glass transition temperature of copolymer (E) can be determined as the temperature of the inflection point that appears when the temperature is increased at a rate of 20°C / min using a differential scanning calorimetry (DSC) analyzer.

[0071] From the viewpoints of flame retardancy and heat resistance, the weight average molecular weight (Mw) of the copolymer (E) is preferably 10,000 to 500,000, more preferably 20,000 to 400,000, even more preferably 30,000 to 300,000, and still more preferably 50,000 to 200,000. The weight average molecular weight (Mw) of the copolymer (E) is measured by gel permeation chromatography (GPC) in terms of polystyrene.

[0072] The copolymer (E) may be a commercially available product or may be synthesized by a known method. The bonding form between the structural unit derived from at least one selected from the group consisting of styrene and α-methylstyrene and the structural unit derived from at least one selected from the group consisting of maleic anhydride and a monoalkyl maleic anhydride having an alkyl group having from 1 to 3 carbon atoms is not particularly limited, and may be any of random polymerization, block polymerization, and graft polymerization.

[0073] When the polyamide resin composition of this embodiment contains copolymer (E), the content of copolymer (E) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and even more preferably 0.8 to 5 parts by mass, per 100 parts by mass of polyamide (A), from the viewpoints of flame retardancy, heat resistance, and moldability.

[0074] [Flame-retardant synergist (F)] The polyamide resin composition of this embodiment may further contain a flame-retardant synergist (F). By using the flame-retardant synergist (F) in combination with the brominated flame retardant (B), the resulting molded article can exhibit even more excellent flame retardancy.

[0075] Examples of the flame retardant aid (F) include antimony compounds such as antimony oxides (e.g., diantimony trioxide, diantimony tetraoxide, diantimony pentoxide), and antimonates (e.g., sodium antimonate); melamine compounds (e.g., melamine orthophosphate, melamine pyrophosphate, melamine borate, melamine polyphosphate); tin oxides (e.g., tin monoxide, tin dioxide); iron oxides (e.g., ferric oxide, γ-iron oxide); metal oxides (e.g., manganese oxide, molybdenum oxide, cobalt oxide, bismuth oxide, tin oxide, nickel oxide, copper oxide, tungsten oxide); metal hydroxides (e.g., aluminum hydroxide); metal powders (e.g., aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, tin, antimony, nickel, copper, tungsten, etc.); metal carbonates (e.g., zinc carbonate, barium carbonate); metal borates (e.g., zinc borate, calcium borate); zinc stannates (e.g., zinc tin trioxide); and silicones. However, those corresponding to the inorganic filler (C) and the colorant (D) are excluded. These may be used alone or in combination of two or more.

[0076] Among the above, at least one selected from the group consisting of antimony compounds, melamine compounds, metal oxides, metal hydroxides, metal borates, and zinc stannate is preferred, and at least one selected from the group consisting of diantimony trioxide, diantimony tetroxide, diantimony pentoxide, sodium antimonate, melamine orthophosphate, melamine pyrophosphate, melamine borate, melamine polyphosphate, aluminum hydroxide, zinc borate, and zinc tin trioxide is more preferred.

[0077] The flame retardant aid (F) is preferably contained in the polyamide resin composition of this embodiment in the form of a powder. The upper limit of its average particle size is preferably 30 μm, more preferably 15 μm, even more preferably 10 μm, and particularly preferably 7 μm. On the other hand, the lower limit of the average particle size of the flame retardant aid (F) is preferably 0.01 μm. When the average particle size is 0.01 to 30 μm, the flame retardancy of the resulting molded article is improved. In this specification, the "average particle size" refers to the volume-average particle size, and can be determined from the particle size at which the cumulative volume is 50% (50% particle size D50) in the particle size distribution measured using a laser diffraction particle size distribution analyzer.

[0078] When the polyamide resin composition of this embodiment contains the flame retardant synergist (F), the content of the flame retardant synergist (F) is preferably 1 to 20 parts by mass, more preferably 2 to 18 parts by mass, even more preferably 3 to 15 parts by mass, and still more preferably 4 to 10 parts by mass, per 100 parts by mass of the polyamide (A). This makes it possible to significantly achieve the above-mentioned effects.

[0079] [Other Components] The polyamide resin composition of the present embodiment may contain other components as needed in addition to the above-described polyamide (A), brominated flame retardant (B), inorganic filler (C), and colorant (D), as well as the aromatic vinyl copolymer (E) and flame retardant aid (F) used as needed.

[0080] Examples of other components include stabilizers such as copper compounds; antioxidants such as hindered phenol antioxidants, hindered amine antioxidants, phosphorus antioxidants, and thio antioxidants; ultraviolet absorbers; light stabilizers; antistatic agents; heat stabilizers; crystal nucleating agents; plasticizers; lubricants; mold release agents; glidants; dispersants; oxygen absorbers; hydrogen sulfide adsorbents; crystallization retarders; impact modifiers such as α-olefin copolymers and rubbers; and anti-drip agents such as fluororesins.

[0081] The content of the other components is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 0.02 to 200 parts by mass, more preferably 0.03 to 100 parts by mass, even more preferably 0.05 to 50 parts by mass, and still more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of polyamide (A).

[0082] In the total amount of the polyamide resin composition of this embodiment, the total content of the polyamide (A), the brominated flame retardant (B), the inorganic filler (C), and the colorant (D) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and still more preferably 90% by mass or more.

[0083] (Method for Producing Polyamide Resin Composition) The method for producing the polyamide resin composition is not particularly limited, and known methods can be used. For example, a method of melt-kneading polyamide (A), brominated flame retardant (B), inorganic filler (C), colorant (D), and optionally aromatic vinyl copolymer (E), flame retardant aid (F), and other components described above can be used. The melt-kneading method is not particularly limited, and any method that can uniformly mix the components described above can be preferably used. For example, a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or the like is preferably used. The melt-kneading conditions are not particularly limited, and an example is a method of melt-kneading for about 1 to 30 minutes at a temperature range about 10 to 50°C higher than the melting point of polyamide (A).

[0084] (Physical Properties of Polyamide Resin Composition) From the viewpoint of improving visibility, the polyamide resin composition of this embodiment preferably has a ΔE represented by the following formula (3) of greater than 1, more preferably greater than 3, even more preferably greater than 10, and even more preferably greater than 30. In addition, the inorganic filler (C) and colorant (D) contained in the polyamide resin composition of this embodiment are preferably selected so as to satisfy this requirement.

[0085]

[0086] In formula (3), ΔE is the CIE 1976 (L ＊ a ＊ b ＊ ) is the color difference defined by the color system. ＊ ｃｏｌ , a ＊ ｃｏｌ , and b ＊ ｃｏｌ The polyamide resin composition of this embodiment is CIE1976 (L ＊ a ＊ b ＊ ) L defined by the color system ＊ , a ＊ , and b ＊ That is, the polyamide resin composition of this embodiment has a CIE 1976 (L ＊ a ＊ b ＊ ) L defined by the color system＊ L ＊ ｃｏｌ and a ＊ Gaa ＊ ｃｏｌ and b ＊ Ga b ＊ ｃｏｌ It is. ＊ ｎａｔ , a ＊ ｎａｔ , and b ＊ ｎａｔ is a colorant-free polyamide resin composition having the same composition as the polyamide resin composition except that it does not contain the colorant (D), as measured by CIE1976 (L ＊ a ＊ b ＊ ) L defined by the color system ＊ , a ＊ , and b ＊ That is, the CIE1976 (L) of a colorant-free polyamide resin composition having the same composition as the polyamide resin composition except that it does not contain the colorant (D) is ＊ a ＊ b ＊ ) L defined by the color system ＊ L ＊ ｎａｔ and a ＊ Gaa ＊ ｎａｔ and b ＊ Ga b ＊ ｎａｔ is.

[0087] <Molded Article> After producing the polyamide resin composition, for example, pellets can be subjected to various molding methods to obtain a molded article. The molding method for the molded article may be appropriately selected depending on the application, and methods such as injection molding, extrusion molding, blow molding, compression molding, press molding, and calendar molding can be used. In particular, the polyamide resin composition of this embodiment provides a molded article that has excellent blister resistance even when exposed to high temperatures during the reflow process, and is excellent in flame retardancy and mechanical properties, making it suitable as an injection molded article used in applications that include a surface mounting process.

[0088] <Applications> A molded article of the polyamide resin composition of this embodiment can be used as an electric part, an electronic part, an automobile part, an industrial part, a faucet part, a fiber, a film, a sheet, a household product, a leisure product, or any other molded article of any shape and application.

[0089] Examples of electrical and electronic components include connectors such as FPC connectors, BtoB connectors, card connectors, SMT connectors (coaxial connectors, etc.), and memory card connectors; SMT relays; SMT bobbins; sockets such as memory sockets and CPU sockets; switches such as command switches and SMT switches; optical components such as optical fiber components and optical sensors; LED application components such as LED reflectors; and electronic substrates such as solar cell substrates, LED mounting substrates, flexible printed wiring boards, and resin molded circuit boards.

[0090] Automotive parts include, for example, cooling parts such as thermostat housings, coolant control valve housings, thermal management module housings, radiator tanks, radiator hoses, water outlets, water inlets, water pump housings, and rear joints; intake and exhaust system parts such as intercooler tanks, intercooler cases, turbo duct pipes, EGR cooler cases, resonators, throttle bodies, intake manifolds, and tail pipes; fuel system parts such as fuel delivery pipes, gasoline tanks, quick connectors, canisters, pump modules, fuel piping, oil strainers, lock nuts, and seals; structural parts such as mount brackets, torque rods, and cylinder head covers; bearing retainers, gear tensioners, and head seals. drivetrain parts such as headlamp actuator gears, throttle valve gears, sliding door rollers, and peripheral clutch parts; brake system parts such as air brake tubes; automotive electrical parts such as wire harness connectors in the engine compartment, motor parts, sensors, ABS bobbins, combination switches, and on-board switches; and interior and exterior parts such as sliding door dampers, door mirror stays, door mirror brackets, inner mirror stays, roof rails, engine mount brackets, air cleaner inlet pipes, door checkers, plastic chains, emblems, clips, breaker covers, cup holders, airbags, fenders, spoilers, radiator supports, radiator grilles, louvers, air scoops, hood bulges, back doors, and fuel sender modules.

[0091] Examples of industrial parts include gas pipes, oil field drilling pipes, hoses, anti-termite cables (communication cables, pass cables, etc.), paint parts of powder coated products (inner coatings of water pipes, etc.), undersea oil field pipes, pressure-resistant hoses, hydraulic tubes, paint tubes, fuel pump housings and impellers, separators, supercharger ducts, butterfly valves, conveyor roller bearings, railway sleeper spring supports, outboard motor engine covers, generator engine covers, wind turbine blades, irrigation valves, large switches, and monofilaments (extruded threads) for fishing nets, etc.

[0092] Examples of faucet parts include housings for parts that transport tap water, housings for parts that store tap water, filter casing housings, faucet housings, pipe housings, housings for bathroom faucets (hot and cold water switching valves, water volume switching valves, etc.), housings for sanitary parts, housings for kitchen faucets, housings for water heaters, valve parts (shut-off balls, slides, cylinders) and valve part housings, housings for toilet stop valves, housings inside shower heads, valve housings for water heaters, fittings for residential piping (underfloor piping, etc.), fittings for bathroom faucets, fittings for water piping, pipe joints, and housings for water meters. Housings, water meter parts (bearings, propellers, pins) and water meters, gas meter housings, distributor housings, valve / pump housings for household appliances, steam-resistant parts for steam irons, inner containers for electric kettles, dishwasher parts (washing tubs, washing nozzles, baskets), pump housings, pump parts (e.g. turbine wheels, impellers), housings for water supply systems (hot water tanks, etc.), housings for heating systems, housings for cooling systems, water volume control valves, pressure reducing valves, relief valves, solenoid valves, three-way valves, thermovalves, water temperature sensors, water volume sensors, bathtub adapters, etc.

[0093] Examples of household products include valve / pump housings for tea and coffee makers; valve / pump housings for cooking appliances such as rice cookers and steamers; steam-resistant parts for cooking appliances such as rice cookers and steamers (such as rice cooker lids); sliding parts for cooking appliances such as rice cookers and steamers (such as gears); sliding parts for commercial cooking appliances (such as gears for gear pumps); steam-resistant parts for commercial cooking appliances (such as pipes for commercial rice cookers).

[0094] Examples of leisure goods include inner soles for sports shoes, racket frames and grommets, golf club heads and sleeves, fishing reels and rods, boat propellers, bicycle suspensions, gears, saddles, and bottle cages.

[0095] The molded article of the polyamide resin composition of this embodiment can be produced by injection molding, and therefore can be suitably used for electrical and electronic components that require the production of a large number of parts in a short period of time. Specifically, the molded article can be suitably used for electrical and electronic components that involve an SMT process, more specifically, for surface-mounted components such as SMT-compatible connectors, SMT relays, SMT bobbins, sockets, command switches, SMT switches, camera modules, power supply components, sensors, capacitor base plates, hard disk components, resistors, fuse holders, coil bobbins, and IC housings.

[0096] A particularly suitable example of a molded article made from the polyamide resin composition of this embodiment is a part of an SMT-compatible automotive connector. SMT-compatible automotive connectors generally include a housing and terminals made from a resin composition using a resin with a melting point of 260°C or higher. SMT-compatible automotive connectors may also include a seal ring, gasket, shell, and the like. Automotive connectors typically have larger external dimensions than connectors for consumer electronics. Furthermore, automotive connectors are exposed to higher temperatures during the SMT process, and blistering is likely to occur during the preheating step of the SMT process due to the difficulty in releasing moisture from the molded article. Furthermore, high flame retardancy is required. Furthermore, blistering is not acceptable due to the strict quality requirements for automotive applications. Therefore, molded articles are required to have excellent blister resistance even when exposed to high temperatures during the SMT process. Molded articles made from the polyamide resin composition of this embodiment can meet these requirements and are therefore suitable for use as part of automotive connectors.

[0097] The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these.

[0098] The evaluations in the examples and comparative examples were carried out according to the methods shown below.

[0099] <1. Measurement of Melt Viscosity> The melt viscosity of the polyamide (A) and the brominated flame retardant (B) at 320°C was measured using a rotational rheometer (HAAKE MARSIII, manufactured by Thermo Fisher Scientific Co., Ltd.) under the following measurement conditions. (Measurement Conditions) Geometry: Cone-plate diameter: φ20 mm (inclination angle: 4°) Shear rate: The shear rate was continuously changed from 0.001 [1 / s] to 1000 [1 / s], and the melt viscosity was read at 0.5 [1 / s]. Measurement time: 7 minutes

[0100] <2. R represented by formula (1) １ Calculation of R in the following formula (1) was performed from the melt viscosity at 320°C of the polyamide (A) and the brominated flame retardant (B) obtained in 1 above, and the contents of the polyamide (A) and the brominated flame retardant (B) shown in Table 1. １ was calculated.

[0101]

[0102] In formula (1), XA is the content (% by mass) of polyamide (A) relative to 100% by mass of the polyamide resin composition, and XB is the content (% by mass) of brominated flame retardant (B) relative to 100% by mass of the polyamide resin composition. In this evaluation, YA is the melt viscosity (Pa s) of polyamide (A) at 320°C, and YB is the melt viscosity (Pa s) of brominated flame retardant (B) at 320°C. n and m are both integers of 1 or more.

[0103] <3. R represented by formula (2) ２ Calculation of R in the following formula (2) was calculated from the content (volume %) of polyamide (A) and the content (volume %) of brominated flame retardant (B) relative to 100% by volume of the polyamide resin composition calculated based on the melt viscosity at 320°C of the polyamide (A) and the brominated flame retardant (B) obtained in 1 above, and the content (parts by mass) and specific gravity of each component shown in Table 1: ２ was calculated.

[0104]

[0105] In formula (2), ZA is the content (vol %) of polyamide (A) relative to 100% by volume of the polyamide resin composition, and ZB is the content (vol %) of brominated flame retardant (B) relative to 100% by volume of the polyamide resin composition. In this evaluation, YA is the melt viscosity (Pa s) of polyamide (A) at 320°C, and YB is the melt viscosity (Pa s) of brominated flame retardant (B) at 320°C. n and m are both integers of 1 or more.

[0106] <4. Color value (L ＊ a ＊ b ＊ , ΔE)> L ＊ a ＊ b ＊ For the measurement, dumbbell-shaped tensile test pieces (type A1) were prepared from the polyamide resin compositions obtained in each Example and Comparative Example by a method in accordance with JIS K7139:2009. colIn addition, polyamide resin compositions having the same composition as the polyamide resin compositions obtained in the examples and comparative examples except that they did not contain the colorant (D) were prepared, and dumbbell-shaped tensile test pieces (Type A1) (Test Piece A) were prepared in the same manner. nat Measurement device: RAL COLORCATCH NANO colorimeter manufactured by RAL gGmbH Light source: CIE standard light source D65 Sensor: CCD camera (224 x 224 pixels) Measurement geometry: 45° / 0° Software: RAL iCOLOURS (version 3.7.2) Equipment used: Software was used on iPhone (registered trademark) 8 (iOS 13.3) The obtained L ＊ a ＊ b ＊ From this, ΔE was calculated using the following formula (3).

[0107]

[0108] In addition, in formula (3), L ＊ ｃｏｌ , a ＊ ｎｃｏｌ , and b ＊ ｃｏｌ indicates the polyamide resin composition obtained in each example (test piece A col ) CIE1976 (L ＊ a ＊ b ＊ ) L defined by the color system ＊ , a ＊ , and b ＊ and L ＊ ｎａｔ , a ＊ ｎａｔ , and b ＊ ｎａｔ A colorant-free polyamide resin composition (test piece A) has the same composition as the above polyamide resin composition except that it does not contain the colorant (D). nat ) CIE1976 (L ＊ a ＊ b ＊ ) L defined by the color system ＊ , a ＊ , and b ＊ Table 1 shows ΔE.

[0109] 5. Evaluation of Blister Resistance Using an injection molding machine (clamping force: 18 tons, screw diameter: φ18 mm) manufactured by Sumitomo Heavy Industries, Ltd., the polyamide resin compositions obtained in the Examples and Comparative Examples were injection-molded in a mold having a film gate with a width of 10 mm and a thickness of 0.9 mm at a cylinder temperature (320°C) 14°C higher than the melting point of the polyamide (A) component and a mold temperature of 140°C to produce a plurality of sheet-like test pieces with a length of 30 mm, a width of 10 mm, and a thickness of 1 mm as polyamide molded articles. The injection molding was performed under settings of an injection speed of 60 mm / s, a dwell pressure of 60 MPa, a dwell time of 1.0 second, a cooling time of 4.0 seconds, and a cycle time of 11.0 seconds. The injection time was approximately 0.15 seconds and the filling pressure was approximately 60 MPa, depending on the composition. The temperatures of the cylinder were set to 320°C, 320°C, 320°C, 320°C, and 300°C in that order from the cylinder nozzle.

[0110] The obtained test pieces were left to stand for 168 hours under conditions of a temperature of 85°C and a relative humidity of 85%. Then, a reflow test was performed on the test pieces using a reflow system (TNX25-30EM, manufactured by Tamura Corporation). In the reflow test, the temperature was raised from 25°C to 150°C over 60 seconds, then raised to 180°C over 90 seconds, and then raised to the peak temperature over 60 seconds and held at the peak temperature for 20 seconds. The peak temperature was 265°C.

[0111] After the reflow test, the appearance of each test piece was visually observed. If even a small blister occurred in one location on the surface of the test piece, it was determined that a blister had occurred on the test piece.

[0112] The blister incidence rate was calculated from the observation results of 100 test pieces. Specifically, the blister incidence rate was calculated as the ratio (percentage) of the number of test pieces on which a blister occurred at least at one location among the 100 test pieces.

[0113] Blister resistance was evaluated using the following five-level index. Evaluation results of "A" and "B" indicate acceptable levels for practical use. A: Blister occurrence rate is 0% or more and less than 10% B: Blister occurrence rate is 10% or more and less than 25% C: Blister occurrence rate is 25% or more and less than 50% D: Blister occurrence rate is 50% or more and less than 75% E: Blister occurrence rate is 75% or more and less than 100%

[0114] <6. Evaluation of Mechanical Properties> Test specimens were prepared as follows, and mechanical properties such as tensile properties and bending properties were evaluated using the test specimens.

[0115] [6-1. Preparation of Test Pieces B and C] Using an injection molding machine (clamping force: 100 tons, screw diameter: φ32 mm) manufactured by Sumitomo Heavy Industries, Ltd., the polyamide resin compositions obtained in the Examples and Comparative Examples were molded using a T-runner mold at a cylinder temperature (320°C) 14°C higher than the melting point of the polyamide (A) component, and a mold temperature of 140°C to prepare multipurpose test pieces Type A1 (dumbbell-shaped test pieces as described in JIS K7139:2009: thickness 4 mm, total length 170 mm, parallel portion length 80 mm, central parallel portion width 10 mm) (hereinafter also referred to as "Test Piece B"). A test piece (hereinafter also referred to as "Test Piece C") having the same shape as Test Piece B but with a weld in the center of the parallel portion perpendicular to the longitudinal direction of the parallel portion was also molded.

[0116] [6-2. Tensile Properties: Tensile Breaking Strength and Tensile Breaking Strain] Using the test piece C prepared in 6-1 above, the tensile breaking strength (MPa) and the tensile breaking strain (%) were measured using a universal testing machine (manufactured by Instron) under conditions of a test speed of 1 mm / min and a gripping distance of 115 mm in accordance with ISO 527-1 (2012, 2nd edition).

[0117] [6-3. Tensile Properties: Weld Tensile Breaking Strength] Using the test piece C prepared in 6-1 above, the weld tensile breaking strength (MPa) was measured using a universal testing machine (manufactured by Instron) under conditions of a test speed of 1 mm / min and a gripping distance of 115 mm in accordance with ISO 527-1 (2012, 2nd edition).

[0118] [6-4. Flexural Properties: Flexural Strength and Flexural Modulus] Using the test piece B prepared in 6-1 above, the flexural strength (MPa) and flexural modulus (GPa) were measured in accordance with ISO 178 (2012, 2nd edition) at a test speed of 2 mm / min and a support distance of 64 mm using a universal testing machine (manufactured by Instron).

[0119] 7. Evaluation of Bar Flow Length Using an injection molding machine (clamping force: 80 tons, screw diameter: φ26 mm) manufactured by Nissei Plastic Industrial Co., Ltd., the polyamide resin compositions obtained in the Examples and Comparative Examples were molded using a mold having a width of 40 mm and a height of 0.5 mm at a cylinder temperature of 14°C higher than the melting point of the polyamide of component (A) (320°C). The polyamide resin compositions were molded under conditions of a mold temperature of 140°C, with 5 shots at 1000 kgf, followed by 10 shots at 750 kgf, and then 5 shots at 750 kgf, to obtain polyamide molded products, and the flow lengths (mm) of the obtained polyamide molded products were measured, and the average value was taken as the bar flow length.

[0120] 8. Evaluation of Flame Retardancy Flame retardancy was evaluated in accordance with the provisions of the UL-94 standard. Using an injection molding machine (clamping force: 80 tons, screw diameter: φ26 mm) manufactured by Nissei Plastic Industrial Co., Ltd., the polyamide resin compositions obtained in the examples and comparative examples were molded at a cylinder temperature (320°C) 14°C higher than the melting point of the polyamide (A) component, and a mold temperature of 140°C, to obtain test pieces D having a thickness of 0.75 mm, a width of 13 mm, and a length of 125 mm.

[0121] Next, the upper end of the obtained test piece D was clamped to fix the test piece D vertically, and a predetermined blue flame 20±1 mm high was applied to the lower end for 10 seconds and then released, and the burning time of test piece D (first time) was measured. Immediately after the fire was extinguished, the flame was again applied to the lower end and released, and the burning time of test piece D (second time) was measured. The same measurement was repeated for five pieces, obtaining a total of 10 data points: five data points for the first burning time and five data points for the second burning time. The total of the 10 data points was designated T, and the maximum value of the 10 data points was designated M, and the results were evaluated according to the following evaluation criteria. The presence or absence of dripping during flame exposure was also visually confirmed.

[0122] [Evaluation criteria] V-0: T was 50 seconds or less and M was 10 seconds or less, the flame did not spread to the clamp, and even when the flaming molten material fell, it did not ignite the cotton 12 inches below. V-1: T was 250 seconds or less and M was 30 seconds or less, the flame did not spread to the clamp, and even when the flaming molten material fell, it did not ignite the cotton 12 inches below. V-2: T was 250 seconds or less and M was 30 seconds or less, the flame did not spread to the clamp, and even when the flaming molten material fell, it ignited the cotton 12 inches below. X: If none of the evaluation criteria of UL94 were met.

[0123] Example 1 100 parts by mass of polyamide (A-2) as polyamide (A), 58 parts by mass of brominated flame retardant (B-1) as brominated flame retardant (B), 0.5 parts by mass of colorant (D-1) as colorant (D), 8.3 parts by mass of flame retardant auxiliary (F-1) as flame retardant auxiliary (F), 0.5 parts by mass of antioxidant, 1.8 parts by mass of anti-drip agent, and 0.8 parts by mass of mold release agent were supplied from the most upstream hopper of a twin-screw extruder ("MEGA 32L" manufactured by STEER Engineering: screw φ31.6 mm, L / D=52, rotation speed 150 rpm, discharge rate 10 kg / h), and 83 parts by mass of glass fiber (C1-1) as inorganic filler (C) were supplied from a side feeder and melt-kneaded at 320°C. The melt-kneaded polyamide resin composition was extruded into a strand shape, cooled, and then cut to obtain pellets of the polyamide resin composition. Test pieces of predetermined shapes were prepared using the obtained pellets according to the above-mentioned methods, and various physical properties were evaluated. The results are shown in Table 1.

[0124] Examples 2 to 15 and Comparative Examples 1 to 5 Pellets of polyamide resin compositions of the examples and comparative examples were obtained in the same manner as in Example 1, except that the types and amounts of each component were changed as shown in Tables 1 and 2. Test pieces of predetermined shapes were prepared using the obtained pellets according to the methods described above, and various physical properties were evaluated. The results are shown in Tables 1 and 2. In Tables 1 and 2, blank spaces indicate no blending.

[0125] The components shown in Tables 1 and 2 are as follows: [Polyamide (A)] Polyamide (A-1): A polyamide in which the dicarboxylic acid units are terephthalic acid units and the diamine units are 1,9-nonanediamine units and 2-methyl-1,8-octanediamine units (molar ratio 85 / 15), melting point: 306°C, glass transition temperature: 125°C, melt viscosity at 320°C: 20 Pa s, specific gravity: 1.1. Polyamide (A-2): A polyamide in which the dicarboxylic acid units are terephthalic acid units and the diamine units are 1,9-nonanediamine units and 2-methyl-1,8-octanediamine units (molar ratio 85 / 15), melting point: 306°C, glass transition temperature: 125°C, melt viscosity at 320°C: 40 Pa s, specific gravity: 1.1. Polyamide (A-3): A polyamide in which the dicarboxylic acid units are terephthalic acid units and the diamine units are 1,9-nonanediamine units and 2-methyl-1,8-octanediamine units (molar ratio 85 / 15), melting point: 306°C, glass transition temperature: 125°C, melt viscosity at 320°C: 270 Pa s, specific gravity: 1.1.

[0126] [Brominated Flame Retardants (B)] Brominated flame retardant (B-1): manufactured by LANXESS, trade name "Firemaster CP-44HF" (glycidyl methacrylate modified polybrominated styrene), melt viscosity at 320°C 5 Pa·s, specific gravity: 2.0. Brominated flame retardant (B-2): manufactured by Albemarle, trade name "SAYTEX HP-7010" (brominated polystyrene), melt viscosity at 320°C 49 Pa·s, specific gravity: 2.2. Brominated flame retardant (B-3): manufactured by Albemarle, trade name "SAYTEX HP-3010" (brominated polystyrene), melt viscosity at 320°C 2 Pa·s, specific gravity: 2.2.

[0127] [Inorganic filler (C)] Glass fiber (C1-1): Central Glass Co., Ltd., product name "ECS03-615" (glass fiber, cross-sectional shape: round, average fiber diameter: 9 μm, average fiber length: 3 mm, silane treatment, specific gravity: 2.6)

[0128] [Colorant (D)] Colorant (D-1): Product name "#980B" (carbon black), manufactured by Mitsubishi Chemical Corporation, specific gravity: 1.8.

[0129] Aromatic vinyl copolymer (E) Aromatic vinyl copolymer (E-1): Polyscope, trade name "XIBOND 160" (styrene-maleic anhydride copolymer, acid value: 250 mg KOH / g, glass transition temperature: 150°C, weight average molecular weight (Mw): 115,000, specific gravity: 1.2, maleic anhydride content: 23% by mass)

[0130] [Flame Retardant Synergist (F)] Flame retardant synergist (F-1): Nippon Light Metal Co., Ltd., trade name "Flamtard S" (zinc stannate), specific gravity: 3.9.

[0131] [Other ingredients] Antioxidant: Sumitomo Chemical Co., Ltd., trade name "Sumilizer GA-80" (3,9-bis{1,1-dimethyl-2-[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane), specific gravity: 1.2. Anti-drip agent: Mitsui-DuPont Fluorochemicals Co., Ltd., trade name "640-J" (polytetrafluoroethylene powder), specific gravity: 2.2. Mold release agent: Mitsui Chemicals, Inc., trade name "Hiwax 200P" (polyolefin wax), specific gravity: 0.95.

[0132]

[0133]

[0134] It can be seen that all of the polyamide resin compositions obtained in Examples 1 to 15 have excellent blister resistance even when exposed to high temperatures during the reflow process, and that all of the molded articles of the polyamide resin compositions have excellent flame retardancy and mechanical properties.

[0135] Molded articles of the polyamide resin composition of the present invention are useful for various molded articles that require high reliability of electrical connections.

Claims

1. A polyamide resin composition comprising a polyamide (A) having a melting point of 280°C or higher, a bromine-based flame retardant (B), an inorganic filler (C), and a colorant (D), wherein the polyamide (A) contains a dicarboxylic acid unit and a diamine unit, and 50 to 100 mol% of the diamine unit is an aliphatic diamine unit having 4 to 18 carbon atoms, and the colorant (D) is at least one of an organic colorant and an inorganic colorant, and R represented by the following formula (1) is １ The polyamide resin composition according to claim 1, [In formula (1), XA is the content (mass%) of the polyamide (A) relative to 100% by mass of the polyamide resin composition, XB is the content (mass%) of the brominated flame retardant (B) relative to 100% by mass of the polyamide resin composition, YA is the melt viscosity (Pa·s) of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), and YB is the melt viscosity (Pa·s) of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A). However, when the polyamide (A) is two or more types, the melting point of the polyamide (A) is a weighted average value based on the content (mass%) of the polyamide (A) relative to 100% by mass of the polyamide resin composition. n and m are both integers of 1 or more.] 2. A polyamide resin composition comprising a polyamide (A) having a melting point of 280°C or higher, a bromine-based flame retardant (B), an inorganic filler (C), and a colorant (D), wherein the polyamide (A) contains a dicarboxylic acid unit and a diamine unit, and 50 to 100 mol% of the diamine unit is an aliphatic diamine unit having 4 to 18 carbon atoms, and the colorant (D) is at least one of an organic colorant and an inorganic colorant, and R represented by the following formula (2) is ２ The polyamide resin composition according to claim 1, [In formula (2), ZA is the content (volume %) of the polyamide (A) relative to 100% by volume of the polyamide resin composition, ZB is the content (volume %) of the brominated flame retardant (B) relative to 100% by volume of the polyamide resin composition, YA is the melt viscosity (Pa·s) of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), and YB is the melt viscosity (Pa·s) of the brominated flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A). However, when the polyamide (A) is two or more types, the melting point of the polyamide (A) is a weighted average value based on the content (volume %) of the polyamide (A) relative to 100% by volume of the polyamide resin composition. n and m are both integers of 1 or more.] 3. The polyamide resin composition according to claim 1 or 2, wherein the content of the brominated flame retardant (B) is 25 to 70 parts by mass per 100 parts by mass of the polyamide (A).

4. The polyamide resin composition according to any one of claims 1 to 3, wherein ΔE represented by the following formula (3) is greater than 1: [In formula (3), ΔE is CIE1976 (L ＊ a ＊ b ＊ ) color difference defined by the color system, L ＊ ｃｏｌ , a ＊ ｃｏｌ , and b ＊ ｃｏｌ The polyamide resin composition is CIE1976 (L ＊ a ＊ b ＊ ) L defined by the color system ＊ , a ＊ , and b ＊ And L ＊ ｎａｔ , a ＊ ｎａｔ , and b ＊ ｎａｔ The CIE1976 (L) of a colorant-free polyamide resin composition having the same composition as the polyamide resin composition except that it does not contain a colorant (D) is shown. ＊ a ＊ b ＊ ) L defined by the color system ＊ , a ＊ , and b ＊ It is.] 5. The polyamide resin composition according to any one of claims 1 to 4, wherein the organic colorant is at least one selected from the group consisting of anthraquinone dyes, perinone dyes, anthrapyridone dyes, and phthalocyanine dyes.

6. The polyamide resin composition according to any one of claims 1 to 5, wherein the inorganic colorant is at least one selected from the group consisting of carbon black, metal oxides, metal sulfides and composite metal oxides.

7. The polyamide resin composition according to any one of claims 1 to 6, wherein the colorant (D) contains the organic colorant, and the content of the organic colorant is 0.0001 to 0.5 mass% relative to 100 mass% of the polyamide resin composition.

8. The polyamide resin composition according to any one of claims 1 to 7, wherein the colorant (D) contains the inorganic colorant, and the content of the inorganic colorant is 0.001 to 5.0 mass% relative to 100 mass% of the polyamide resin composition.

9. The polyamide resin composition according to any one of claims 1 to 8, wherein in said polyamide (A), 50 mol % or more of the dicarboxylic acid units are terephthalic acid units, and the aliphatic diamine having 4 to 18 carbon atoms constituting the aliphatic diamine units having 4 to 18 carbon atoms is at least one selected from the group consisting of 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8octanediamine, and 1,10-decanediamine.

10. The polyamide resin composition according to any one of claims 1 to 9, wherein the brominated flame retardant (B) is selected from the group consisting of brominated polystyrene and polybrominated styrene, and is two or more types having different melt viscosities at a temperature 14°C higher than the melting point of the polyamide (A).

11. The polyamide resin composition according to any one of claims 1 to 10, wherein the inorganic filler (C) comprises glass fiber (C1).

12. The polyamide resin composition according to any one of claims 1 to 11, further comprising an aromatic vinyl copolymer (E) which comprises structural units derived from at least one selected from the group consisting of styrene and α-methylstyrene, and structural units derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydride having an alkyl group having from 1 to 3 carbon atoms, and the glass transition temperature of the aromatic vinyl copolymer (E) is 140°C or higher.

13. The polyamide resin composition according to claim 12, wherein the content of structural units derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydride having an alkyl group having from 1 to 3 carbon atoms in the aromatic vinyl copolymer (E) is 18 to 50 mass%.

14. The polyamide resin composition according to claim 12 or 13, wherein the weight average molecular weight (Mw) of the aromatic vinyl copolymer (E) is 10,000 to 500,000.

15. The polyamide resin composition according to any one of claims 1 to 14, further comprising a flame retardant auxiliary (F).

16. The polyamide resin composition according to any one of claims 1 to 15, comprising, relative to 100 parts by mass of the polyamide (A), 25 to 70 parts by mass of the brominated flame retardant (B), 30 to 250 parts by mass of the inorganic filler (C), and 0.0005 to 20 parts by mass of the colorant (D).

17. The polyamide resin composition according to claim 16, further comprising an aromatic vinyl copolymer (E), the content of which is 0.1 to 10 parts by mass per 100 parts by mass of the polyamide (A).

18. The polyamide resin composition according to claim 16 or 17, further comprising a flame retardant auxiliary (F), the content of which is 1 to 20 parts by mass per 100 parts by mass of the polyamide (A).

19. A method for producing a polyamide resin composition according to any one of claims 1 to 18, comprising melt-kneading the polyamide (A), the bromine-based flame retardant (B), the inorganic filler (C), and the colorant (D), and, where necessary, the aromatic vinyl copolymer (E) and the flame retardant auxiliary (F).

20. A molded article made from the polyamide resin composition according to any one of claims 1 to 18.

21. The molded article according to claim 20, which is a connector.

22. The molded article according to claim 20 or 21, which is an on-board connector.

Images