Polyamide resin composition

Abstract

Provided is a polyamide resin composition containing (A) a polyamide having a melting point of 280 DEG C or higher, (B) a brominated flame retardant, (C) an inorganic filler, and (D) a colorant, the polyamide (A) containing dicarboxylic acid units and diamine units, 50-100 mol% of the diamine units being aliphatic diamine units having 4-18 carbon atoms, the colorant (D) is at least one of an organic colorant and an inorganic colorant, and R1 represented by a specific formula (1) is less than 50.

Description

Technical Field

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

[0002] Polyamide resins are used in various applications, such as automotive parts and electrical / electronic components, due to their excellent mechanical properties and heat resistance. Additionally, halogenated flame retardants, such as brominated flame retardants, are sometimes combined with polyamide resin compositions as flame retardants (see Patent Documents 1-4). Polyamide resin compositions with enhanced flame retardancy in this way are also called flame-retardant polyamide resin compositions.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-138197

[0006] Patent Document 2: Japanese Patent Application Publication No. 2000-186206

[0007] Patent Document 3: Japanese Patent Application Publication No. 2002-309083

[0008] Patent Document 4: Japanese Patent Application Publication No. 8-127714 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] If the molded body of the flame-retardant polyamide resin composition is exposed to high temperatures during the reflow process, expansion, i.e., bubbling, will occur inside and on the surface of the molded body. However, patent documents 1 to 4 do not provide sufficient research on the above-mentioned bubbling.

[0011] Furthermore, flame-retardant polyamide resin compositions are sometimes used after coloring for applications such as automotive parts and electrical / electronic components. The inventors' research has shown that if a molded article containing a colorant-containing flame-retardant polyamide resin composition is exposed to high temperatures during a reflow process, the rate of blistering tends to increase further.

[0012] Therefore, there is a need for a flame-retardant polyamide resin composition that can produce molded articles with a low foaming rate even when exposed to high temperatures during the reflow process, i.e., excellent foaming resistance, as well as excellent flame retardancy and mechanical properties.

[0013] Therefore, the object of the present invention is to provide a polyamide resin composition that can produce a molded article with excellent foaming resistance, flame retardancy and mechanical properties even when exposed to high temperatures during the reflow process, as well as a method for manufacturing the polyamide resin composition and a molded article of the polyamide resin composition.

[0014] Methods for solving problems

[0015] In order to solve the above-mentioned problem, in-depth research was conducted, and as a result, the inventors came up with the following invention and found that it can solve the problem.

[0016] That is, the present invention is as follows.

[0017] [1] A polyamide resin composition comprising polyamide (A) with a melting point of 280°C or higher, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D).

[0018] The polyamide (A) described above comprises dicarboxylic acid units and diamine units, wherein 50 to 100 mol% of the diamine units are aliphatic diamine units having 4 to 18 carbon atoms.

[0019] The aforementioned colorant (D) is at least one of an organic colorant and an inorganic colorant.

[0020] R1 is less than 50 as expressed by the following formula (1).

[0021] [Mathematical Expression 1]

[0022]

[0023] [In formula (1), XA is the content (mass%) of the above-mentioned polyamide (A) relative to 100% by mass of the above-mentioned polyamide resin composition, XB is the content (mass%) of the above-mentioned brominated flame retardant (B) relative to 100% by mass of the above-mentioned 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 above-mentioned polyamide (A), and YB is the melt viscosity (Pa·s) of the above-mentioned brominated flame retardant (B) at a temperature 14°C higher than the melting point of the above-mentioned polyamide (A). Wherein, when there are two or more types of polyamide (A), the melting point of the above-mentioned polyamide (A) is a weighted average based on the content (mass%) of the above-mentioned polyamide (A) relative to 100% by mass of the above-mentioned polyamide resin composition. n and m are both integers of 1 or more.]

[0024] [2] A polyamide resin composition comprising polyamide (A) with a melting point of 280°C or higher, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D).

[0025] The polyamide (A) described above comprises dicarboxylic acid units and diamine units, wherein 50 to 100 mol% of the diamine units are aliphatic diamine units having 4 to 18 carbon atoms.

[0026] The colorant (D) mentioned above is at least one of organic and inorganic colorants, and R2 expressed by the following formula (2) is less than 20.

[0027] [Mathematical Expression 2]

[0028]

[0029] [In formula (2), ZA is the content (volume%) of the above-mentioned polyamide (A) relative to 100 volume% of the above-mentioned polyamide resin composition, ZB is the content (volume%) of the above-mentioned brominated flame retardant (B) relative to 100 volume% of the above-mentioned 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 above-mentioned polyamide (A), and YB is the melt viscosity (Pa·s) of the above-mentioned brominated flame retardant (B) at a temperature 14°C higher than the melting point of the above-mentioned polyamide (A). Wherein, when there are two or more types of polyamide (A), the melting point of the above-mentioned polyamide (A) is a weighted average based on the content (volume%) of the above-mentioned polyamide (A) relative to 100 volume% of the above-mentioned polyamide resin composition. n and m are both integers of 1 or more.]

[0030] [3] According to the polyamide resin composition described in [1] or [2] above, the content of the brominated flame retardant (B) is 25 to 70 parts by weight relative to 100 parts by weight of the polyamide (A).

[0031] [4] The polyamide resin composition described in any one of [1] to [3] above, wherein ΔE expressed by the following formula (3) is greater than 1.

[0032] [Mathematical Expression 3]

[0033]

[0034] [In equation (3), ΔE is derived from CIE1976 (L a b The color difference specified in the color system, L col a col and b col The above-mentioned polyamide resin composition is derived from CIE1976 (L a b The color system specified by L a and b L nat a nat and b nat A polyamide resin composition without colorant, having the same composition as the above-described polyamide resin composition except that it does not contain colorant (D), is formulated according to CIE 1976 (L). a b The color system specified by L a and b 。

[0035] [5] The polyamide resin composition according to any one of [1] to [4] above, wherein the organic colorant is at least one selected from anthraquinone dyes, violet ketone dyes, anthraquinone dyes and phthalocyanine dyes.

[0036] [6] The polyamide resin composition according to any one of [1] to [5] above, wherein the inorganic colorant is at least one selected from carbon black, metal oxide, metal sulfide and composite metal oxide.

[0037] [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% by mass relative to 100% by mass of the polyamide resin composition.

[0038] [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% by mass relative to 100% by mass of the polyamide resin composition.

[0039] [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 unit is a terephthalic acid unit, and the aliphatic diamine constituting the aliphatic diamine unit having 4 to 18 carbons is at least one selected from 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,10-decanediamine.

[0040]

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

[0041]

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

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

[0042]

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

[11] above further comprises an aromatic vinyl copolymer (E), wherein the aromatic vinyl copolymer (E) comprises at least one structural unit selected from styrene and α-methylstyrene and at least one structural unit selected from maleic anhydride and monoalkyl maleic anhydride having 1 or more and 3 or fewer carbon atoms.

[0043] The glass transition temperature of the above-mentioned aromatic vinyl copolymer (E) is above 140°C.

[0044]

[13] According to the polyamide resin composition described in

[12] above, the content of at least one structural unit in the aromatic vinyl copolymer (E) selected from maleic anhydride and monoalkyl maleic anhydride having 1 or more and 3 or fewer carbon atoms is 18 to 50 by mass.

[0045]

[14] According to the polyamide resin composition described in

[12] or

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

[0046]

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

[14] above further contains a flame retardant additive (F).

[0047]

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

[15] above, wherein,

[0048] Relative to 100 parts by weight of the above polyamide (A), it contains:

[0049] 25-70 parts by weight of the above-mentioned brominated flame retardant (B)

[0050] 30 to 250 parts by weight of the above-mentioned inorganic filler material (C)

[0051] 0.0005 to 20 parts by weight of the above colorant (D).

[0052]

[17] The polyamide resin composition described in

[16] above further contains an aromatic vinyl copolymer (E), and the content of the aromatic vinyl copolymer (E) is 0.1 to 10 parts by weight relative to 100 parts by weight of the polyamide (A).

[0053]

[18] The polyamide resin composition described in

[16] or

[17] above further contains a flame retardant (F), and the content of the flame retardant (F) is 1 to 20 parts by weight relative to 100 parts by weight of the polyamide (A) above.

[0054]

[19] A method for manufacturing the polyamide resin composition described in any one of [1] to

[18] above, wherein the polyamide (A), the brominated flame retardant (B), the inorganic filler (C), the colorant (D), and the aromatic vinyl copolymer (E) and the flame retardant additive (F) used as needed are melt-blended.

[0055]

[20] A molded body, which is a molded body of the polyamide resin composition described in any one of [1] to

[18] above.

[0056]

[21] According to the molded body described in

[20] , it is a connector.

[0057]

[22] The molded body described in

[20] or

[21] is a vehicle-mounted connector.

[0058] Invention Effects

[0059] According to the present invention, a polyamide resin composition that produces a molded article with excellent foaming resistance even when exposed to high temperatures during a reflow process, as well as excellent flame retardancy and mechanical properties, can be provided, along with a method for manufacturing the polyamide resin composition and a molded article of the polyamide resin composition. Detailed Implementation

[0060] The following description is based on an example of an embodiment of the present invention (hereinafter sometimes referred to as "this embodiment"). However, the embodiment shown below is an example for embodying the technical concept of the present invention, and the present invention is not limited to the following description.

[0061] Furthermore, while preferred embodiments are given in this specification, combinations of two or more individual preferred embodiments are also preferred. For items given as numerical ranges, where several numerical ranges exist, their lower and upper limits can be selectively combined to determine a preferred embodiment.

[0062] In this specification, when a numerical range such as "XX~YY" is mentioned, it means "above XX and below YY".

[0063] In addition, in this specification, the term "~ unit" (where "~" represents a monomer) means "a structural unit derived from ~", for example, "dicarboxylic acid unit" means "a structural unit derived from dicarboxylic acid", and "diamine unit" means "a structural unit derived from diamine".

[0064] <Polyamide Resin Composition>

[0065] The polyamide resin composition of the first embodiment of the present invention is a polyamide resin composition containing polyamide (A) with a melting point of 280°C or higher, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D).

[0066] The polyamide (A) described above comprises dicarboxylic acid units and diamine units, wherein 50 to 100 mol% of the diamine units are aliphatic diamine units having 4 to 18 carbon atoms.

[0067] The aforementioned colorant (D) is at least one of an organic colorant and an inorganic colorant.

[0068] R1 is less than 50 as expressed by the following formula (1).

[0069] [Mathematical Expression 4]

[0070]

[0071] 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). Wherein, when there are two or more types of polyamide (A), the melting point of the polyamide (A) is a weighted average 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.

[0072] In other words, n refers to the number of types of polyamide (A) in the above-mentioned polyamide resin composition, and is an integer of 1 or more. XA ｋ It is the kth polyamide (A) in the order of its content from most to least among the above polyamides (A). kThe content (in mass%) is relative to 100% by mass of the above-mentioned polyamide resin composition. Additionally, m refers to the number of types of the above-mentioned brominated flame retardant (B) in the above-mentioned polyamide resin composition, and is an integer of 1 or more. XB k It is the kth brominated flame retardant (B) in the order of its content from most to least among the aforementioned brominated flame retardants (B). k The content (in mass%) relative to 100% by mass of the above polyamide resin composition. YA k It is the melting point of the weighted average of polyamide (A), that is, the melting point of the polyamide (A) present in the above polyamide resin composition. k The melting point of polyamide (A) at a temperature 14°C higher than the weighted average melting point of all (k = 1 to n) of the polyamide (A). k The melt viscosity (Pa·s) of YB k The above-mentioned brominated flame retardant (B) at a temperature 14°C higher than the weighted average melting point of the polyamide (A) mentioned above. k The melt viscosity (Pa·s) of .

[0073] The inventors focused on the contents of the polyamide (A) and the brominated flame retardant (B) and the melt viscosity of the polyamide (A) and the brominated flame retardant (B), and found that if R1, expressed by the above formula (1), is less than a specific value, a molded article with excellent foaming resistance, flame retardancy and mechanical properties can be obtained even when exposed to high temperature in the reflow process.

[0074] R1, expressed as in formula (1) above, is less than 50, preferably 40 or less, more preferably 30 or less, even more preferably 25 or less, and even more preferably 20 or less. If R1 is less than 50, a molded article with excellent foaming resistance, flame retardancy, and mechanical properties can be obtained even when exposed to high temperatures during the reflow process. The lower limit of R1 is not particularly limited; however, if the melt viscosity of the brominated flame retardant (B) is too high relative to the polyamide (A), it will cause poor dispersion of the brominated flame retardant (B), resulting in a decrease in foaming resistance. Therefore, it is preferably 0.02 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and even more preferably 0.5 or more.

[0075] 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 polyamide (A) and the melt viscosity (YB) of brominated flame retardant (B) at a temperature 14°C higher than the melting point of polyamide (A), the above-mentioned R1 can be set to the above-mentioned range.

[0076] Furthermore, the closer the values ​​of YA and YB are, the easier it is to mix the polyamide (A) and the brominated flame retardant (B). When the brominated flame retardant (B) is dispersed in the polyamide (A), the aggregation of the brominated flame retardant (B) is suppressed. Therefore, a molded body with better foaming resistance can be obtained even when exposed to high temperatures during the reflow process.

[0077] Regarding n, from the viewpoint of adjusting the mechanical properties and flowability of the resulting molded article, it is an integer of 1 or more, preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. It should be noted that when n = 1, the polyamide (A) contained in the polyamide resin composition is one type.

[0078] Regarding m, from the viewpoint that the melt viscosity of the polyamide composition can be adjusted to the optimal viscosity, it is an integer of 1 or more, preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. It should be noted that when m = 1, the polyamide resin composition contains only one type of brominated flame retardant (B).

[0079] The polyamide resin composition of the second embodiment of the present invention is a polyamide resin composition containing polyamide (A) with a melting point of 280°C or higher, a brominated flame retardant (B), an inorganic filler (C), and a colorant (D).

[0080] The polyamide (A) described above comprises dicarboxylic acid units and diamine units, wherein 50 to 100 mol% of the diamine units are aliphatic diamine units having 4 to 18 carbon atoms.

[0081] The aforementioned colorant (D) is at least one of an organic colorant and an inorganic colorant.

[0082] R² is less than 20, as expressed by the following formula (2).

[0083] [Mathematical Expression 5]

[0084]

[0085] In formula (2), ZA is the content (volume%) of the polyamide (A) relative to 100 volume% of the polyamide resin composition, ZB is the content (volume%) of the brominated flame retardant (B) relative to 100 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). Wherein, when there are two or more types of polyamide (A), the melting point of the polyamide (A) is a weighted average based on the content (volume%) of the polyamide (A) relative to 100 volume% of the polyamide resin composition. n and m are both integers of 1 or more.

[0086] In other words, n refers to the number of types of polyamide (A) in the above-mentioned polyamide resin composition, and is an integer greater than or equal to 1. k It is the kth polyamide (A) in the order of its content from most to least among the above polyamides (A). k The content (volume%) is relative to 100% of the above-mentioned polyamide resin composition. Additionally, m refers to the number of types of the above-mentioned brominated flame retardant (B) in the above-mentioned polyamide resin composition, and is an integer of 1 or more. ZB k It is the kth brominated flame retardant (B) in the order of its content from most to least among the aforementioned brominated flame retardants (B). k The content (volume%) relative to 100% of the above polyamide resin composition. YA k It is the melting point of the weighted average of polyamide (A), that is, the melting point of the polyamide (A) present in the above polyamide resin composition. k The melting point of polyamide (A) at a temperature 14°C higher than the weighted average melting point of all (k = 1 to n) of the polyamide (A). k The melt viscosity (Pa·s) of YB k The above-mentioned brominated flame retardant (B) at a temperature 14°C higher than the weighted average melting point of the polyamide (A) mentioned above. k The melt viscosity (Pa·s) of .

[0087] It should be noted that the preferred ranges for n and m are as described above.

[0088] R2, expressed in formula (2) above, is less than 20, preferably 18 or less, and more preferably 15 or less. If R2 is less than 20, a molded article with excellent foaming resistance, flame retardancy, and mechanical properties can be obtained even when exposed to high temperatures during the reflow process. The lower limit of R2 is not particularly limited, but from the viewpoint of suppressing shear heating during melt mixing and improving foaming resistance, it is preferably 0.05 or more, more preferably 0.07 or more, further preferably 0.1 or more, and even more preferably 0.5 or more.

[0089] 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 polyamide (A) and the melt viscosity (YB) of brominated flame retardant (B) at a temperature 14°C higher than the melting point of polyamide (A), the above-mentioned R2 can be set to the above-mentioned range.

[0090] Hereinafter, the components of the polyamide resin composition of the above embodiments will be described.

[0091] [Polyamide (A)]

[0092] The polyamide (A) used in this embodiment has a melting point of 280°C or higher and contains dicarboxylic acid units and diamine units.

[0093] The aforementioned diamine unit comprises 50-100 mol% of aliphatic diamine units having 4-18 carbon atoms. By comprising 50-100 mol% of aliphatic diamine units having 4-18 carbon atoms in the diamine unit, a molded article exhibiting excellent foaming resistance even when exposed to high temperatures during the reflow process can be obtained. The content of aliphatic diamine units having 4-18 carbon atoms in the aforementioned diamine unit is preferably 75-100 mol%, more preferably 85-100 mol%.

[0094] Polyamide (A) can be one type or two or more types.

[0095] Examples of aliphatic diamines with 4 to 18 carbon atoms that constitute the aliphatic diamine unit include straight-chain 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; and 1-butyl-1,2-ethylenediamine, 1,1-dimethyl-1,4-butanediamine, and 1-ethyl-1,4-butanediamine. Diamine, 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 Branched aliphatic diamines such as 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 them, from the viewpoint of excellent physical properties such as heat resistance and low water absorption, aliphatic diamines with 4 to 18 carbon atoms are preferably selected from at least one of 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,10-decanediamine, more preferably from at least one of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, even more preferably a combination of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, that is, even more preferably 1,9-nonanediamine and 2-methyl-1,8-octanediamine.

[0096] As an aliphatic diamine with 4 to 18 carbon atoms, when 1,9-nonanediamine and 2-methyl-1,8-octanediamine are used together, 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.

[0097] Polyamide (A) may contain diamine units other than aliphatic diamine units having 4 to 18 carbon atoms. Examples of diamines constituting these 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-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl ether. Examples of alicyclic diamines include cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, norbornenedimethylamine, and tricyclodecanedimethylamine.

[0098] These diamines can be used alone or in combination with two or more.

[0099] The polyamide (A) may further include structural units of polyamines of 3 or more members, such as bis(hexamethylene)triamine, within the range that allows for melt forming, without impairing the effects of the present invention.

[0100] When the polyamide (A) contains other diamine units, their content is preferably 50 mol% or less, more preferably 30 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less of all the diamine units contained in the polyamide (A).

[0101] Polyamide (A) contains any dicarboxylic acid unit.

[0102] Examples of dicarboxylic acids that constitute dicarboxylic acid units include, for instance, malonic acid, succinic acid, glutaric acid, adipic acid, heptanoic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, dimethylmalonic acid, 2,2-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methylhexanoic acid, and trimethylhexanoic acid, which are aliphatic dicarboxylic acids; 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and cycloheptanoic acid. Alicyclic dicarboxylic acids such as alkyldicarboxylic acid, cyclooctanedicarboxylic acid, and cyclodecanedicarboxylic acid; 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-phenylene dioxydiacetic acid, 1,3-phenylene dioxydiacetic acid, biphenyl dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenyl sulfone-4,4'-dicarboxylic acid, and 4,4'-diphenyldicarboxylic acid. These dicarboxylic acids can be used alone or in combination of two or more.

[0103] The polyamide (A) may contain structural units derived from polycarboxylic acids to a extent that does not impair the effects of the present invention. Examples of structural units derived from polycarboxylic acids include trimellitic acid, pyromellitic acid, and pyromellitic tetracarboxylic acid. Preferably, it contains units within a range suitable for melt forming.

[0104] The dicarboxylic acid unit preferably contains 50 mol% or more of terephthalic acid units, more preferably 60 mol% or more of terephthalic acid units, and even more preferably 75 mol% or more of terephthalic acid units, and may also be 100 mol%. By making the dicarboxylic acid unit contain 50 mol% or more of terephthalic acid units, a molded article with better foaming resistance can be obtained even when exposed to high temperatures during the reflow process.

[0105] Regarding the molar ratio of dicarboxylic acid units to diamine units in polyamide (A) [dicarboxylic acid unit / diamine unit], from the viewpoint of increasing the degree of polymerization, it is preferably 45 / 55 to 55 / 45, and more preferably 47 / 53 to 53 / 47.

[0106] It should be noted that the molar ratio of dicarboxylic acid units to diamine units can be adjusted according to the mixing ratio (molar ratio) of dicarboxylic acid and diamine as raw materials.

[0107] The total content of dicarboxylic acid units and diamine units in 100 mol% of polyamide (A) is preferably 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, even more preferably 99 mol% or more, and may also be 100 mol%.

[0108] Polyamide (A) preferably has at least 10% of its terminal groups on its molecular chain capped by a capping agent. More preferably, the proportion of terminal groups on the molecular chain capped by a capping agent (capping rate) is 20% or more.

[0109] As capping agents, monofunctional compounds that react with the amino or carboxyl groups at the ends of polyamides can be used. From the viewpoints of reactivity and capping stability, monocarboxylic acids or monoamines are preferred, and monocarboxylic acids are more preferred from the viewpoints of ease of handling. In addition, monoisocyanates, monoacyl halides, monoesters, and monoalcohols can also be used as capping agents.

[0110] As monocarboxylic acids used as end-capping agents, monocarboxylic acids that react with amino groups can be used, such as aliphatic monocarboxylic acids like acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, octanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, tervaric acid, and isobutyric acid; alicyclic monocarboxylic acids like cyclohexanecarboxylic acid; aromatic monocarboxylic acids like benzoic acid, toluic acid, α-naphthoic acid, β-naphthoic acid, methylnaphthoic acid, and phenylacetic acid; and any mixtures thereof. Among these, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, octanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, and benzoic acid are preferred from the viewpoints of reactivity, end-capping stability, and price.

[0111] As monoamines used as end-capping agents, monoamines that are reactive with carboxyl groups can be used, such as aliphatic monoamines like methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine; alicyclic monoamines like cyclohexylamine and dicyclohexylamine; aromatic monoamines like aniline, toluidine, diphenylamine, and naphthylamine; and any mixtures thereof. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferred from the viewpoints of reactivity, boiling point, end-capping stability, and price.

[0112] Regarding the end-capping rate of polyamide (A), the number of carboxyl-terminal groups, amino-terminal groups, and end groups capped by the end-capping agent present in polyamide (A) can be determined separately according to the following formula (I). From the viewpoints of accuracy and simplicity, it is preferable to determine the number of each end group using... 1 H-NMR is determined by the integral value of the characteristic signal corresponding to each terminal group.

[0113] End capping rate (%) = [(TS) / T] × 100 (I)

[0114] [In the formula, T represents the total number of terminal groups in the molecular chain of polyamide (A) (this value is usually equal to twice the number of polyamide molecules), and S represents the total number of uncapped carboxyl and amino terminals remaining.]

[0115] Polyamide (A) can be manufactured using any method known as a method for manufacturing crystalline polyamide. For example, it can be manufactured using solution polymerization or interfacial polymerization using dicarboxylic acids and diamines as raw materials in the form of acyl chlorides, melt polymerization using dicarboxylic acids and diamines as raw materials, solid-state polymerization, melt extrusion polymerization, and other methods.

[0116] Regarding the melting point of polyamide (A), in addition to considering heat resistance, it is preferably 280°C or higher, more preferably 290°C or higher, and more preferably 300°C or higher, from the viewpoint of maximizing the effects of the present invention. Furthermore, from the viewpoint of suppressing the thermal decomposition of polyamide during melt molding, it is preferably 350°C or lower, more preferably 340°C or lower, and even more preferably 330°C or lower.

[0117] It should be noted that when there are two or more types of polyamide (A), the melting point of polyamide (A) being 280°C or higher, under mass-based conditions, means that the melting point of polyamide (A) is 280°C or higher based on the weighted average of the content (mass%) of polyamide (A) relative to 100% by mass of the polyamide resin composition. Furthermore, under volume-based conditions, it means that the melting point of polyamide (A) is 280°C or higher based on the weighted average of the content (volume%) of polyamide (A) relative to 100% by volume of the polyamide resin composition.

[0118] The melting point of polyamide (A) can be determined by the peak temperature of the endothermic peak that appears when the temperature is increased at a rate of 10 °C / min using a differential scanning calorimetry (DSC) instrument.

[0119] Regarding the glass transition temperature of polyamide (A), from the viewpoint of heat resistance, it 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 polyamide (A); however, from the viewpoint of operability, it is preferably 180°C or lower, more preferably 160°C or lower, and also preferably 150°C or lower. In other words, the glass transition temperature of polyamide (A) is preferably 100–180°C, more preferably 110–160°C, and even more preferably 120–150°C. The glass transition temperature of polyamide (A) can be determined as the temperature at which the inflection point occurs when the temperature is increased at a rate of 20°C / min using a differential scanning calorimetry (DSC) apparatus.

[0120] 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. If the melt viscosity is within the above range, R1 represented by the above formula (1) and R2 represented by the above formula (2) can be set to the above range respectively.

[0121] The melt viscosity of polyamide (A) can be determined using a rotational rheometer, specifically using the method described in the examples.

[0122] The content (mass%) of polyamide (A) in the total amount of the polyamide resin composition of this embodiment is preferably 20 to 70% by mass, more preferably 25 to 70% by mass, even more preferably 30 to 65% by mass, and even more preferably 30 to 50% by mass. If the content (mass%) of polyamide (A) is within the above range, R1, expressed by the above formula (1), can be set to the above range.

[0123] Furthermore, the content (volume %) of polyamide (A) in the total amount of the polyamide resin composition of this embodiment is preferably 15 to 45 vol%, more preferably 18 to 40 vol%, and even more preferably 20 to 35 vol%. If the content (volume %) of polyamide (A) is within the above range, then R2, expressed by the above formula (2), can be set to the above range.

[0124] [Brominated flame retardant (B)]

[0125] The polyamide resin composition of this embodiment contains a brominated flame retardant (B). By containing a brominated flame retardant (B), a polyamide resin composition with improved flame retardancy is obtained.

[0126] Examples of brominated flame retardants (B) used in this embodiment include hexabromocyclododecane, decabromodiphenyl ether, octabromodiphenyl ether, tetrabromobisphenol A, bis(tribromophenoxy)ethane, bis(pentabromophenoxy)ethane, tetrabromobisphenol A epoxy resin, tetrabromobisphenol A carbonate, ethylene(bistetrabromophthalimide), ethylenebispentabromobiphenyl, tris(tribromophenoxy)triazine, bis(dibromopropyl)tetrabromobisphenol A, bis(dibromopropyl)tetrabromobisphenol S, brominated polyphenylene ethers such as poly(di)bromophenyl ether, polydibromostyrene, polytribromostyrene, brominated polystyrene, polybromostyrene, brominated crosslinked aromatic polymers, brominated epoxy resins, brominated phenoxy resins, brominated styrene-maleic anhydride polymers, tetrabromobisphenol S, tris(tribromoneopentyl) phosphate, polybrominated trimethylphenylindane, tris(dibromopropyl)-isocyanurate, etc.

[0127] Furthermore, the aforementioned brominated polystyrene can be selected from at least one type selected from uncrosslinked and unmodified brominated polystyrene, crosslinked brominated polystyrene, and modified brominated polystyrene with added functional groups. As functional groups, examples include epoxy-containing functional groups such as glycidyl methacrylate, and anhydride groups containing α,β-unsaturated dicarboxylic acid anhydrides such as maleic anhydride and citrate anhydride. The modification rate is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass. Similarly, the aforementioned polybrominated polystyrene can be selected from at least one type selected from unmodified polybrominated polystyrene and modified polybrominated polystyrene with added functional groups. The functional groups and modification rate of the modified polybrominated polystyrene are the same as those described above for the modified brominated polystyrene.

[0128] These brominated flame retardants (B) can be used alone or in combination with two or more.

[0129] The brominated flame retardant (B) is preferably selected from at least two groups of brominated polystyrene and polybrominated polystyrene. Furthermore, these two or more brominated flame retardants (B) are preferably two or more with different melt viscosities at a temperature 14°C higher than the melting point of polyamide (A). For example, brominated polystyrene and modified polybrominated polystyrene with different melt viscosities at a temperature 14°C higher than the melting point of polyamide (A) can be used together. This improves foaming resistance, flame retardancy, and mechanical properties. Additionally, R1, expressed in formula (1), and R2, expressed in formula (2), can be set to the ranges described above.

[0130] Brominated polystyrene can be manufactured, for example, by brominating the benzene ring of polystyrene after polymerizing styrene monomers to produce polystyrene. Polybrominated polystyrene can also be manufactured by polymerizing brominated styrene monomers (bromostyrene, dibromostyrene, tribromostyrene, etc.).

[0131] The bromine content in both brominated polystyrene and polybrominated polystyrene is preferably 55-75% by mass, more preferably 55-70% by mass. By setting the bromine content to 55% by mass or more, the amount of bromine required for flame retardancy can be met with a smaller amount of brominated polystyrene and polybrominated polystyrene. In addition, the reduction in mechanical properties is suppressed, and molded articles with excellent mechanical properties and heat resistance can be obtained. Furthermore, by setting the bromine content to 75% by mass or less, thermal decomposition is less likely to occur during melt processing such as extrusion and molding, gas generation can be suppressed, and molded articles with excellent heat resistance and colorfastness can be obtained.

[0132] 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 1–80 Pa·s, more preferably 1–70 Pa·s, and even more preferably 2–60 Pa·s. If the melt viscosity is within the above range, R1, expressed in formula (1), and R2, expressed in formula (2), can each be set to the above range. When at least two brominated flame retardants (B) are included, it is preferable that the melt viscosity of at least one of them is within the above range.

[0133] The melt viscosity of the brominated flame retardant (B) can be determined using a rotational rheometer, specifically using the method described in the examples.

[0134] The content (mass%) of brominated flame retardant (B) in the total amount of the polyamide resin composition of this embodiment is preferably 10 to 40% by mass, more preferably 12 to 35% by mass, and even more preferably 15 to 30% by mass. If the content (mass%) of brominated flame retardant (B) is within the above range, R1 represented by the above formula (1) can be set to the above range.

[0135] Furthermore, the content (volume %) of the brominated flame retardant (B) in the total amount of the polyamide resin composition of this embodiment is preferably 10 to 40 vol%, more preferably 12 to 35 vol%, and even more preferably 15 to 30 vol%. If the content (volume %) of the brominated flame retardant (B) is within the above range, then R2 expressed by the above formula (2) can be set to the above range.

[0136] The content of the brominated flame retardant (B) relative to 100 parts by weight of polyamide (A) is preferably 25 to 70 parts by weight, more preferably 30 to 65 parts by weight, and even more preferably 35 to 60 parts by weight. If the content of the brominated flame retardant (B) is 25 parts by weight or more, a molded article with excellent flame retardancy can be obtained. Furthermore, if the content of the brominated flame retardant (B) is 70 parts by weight or less, a molded article with even better foaming resistance, flame retardancy, and mechanical properties, even when exposed to high temperatures during the reflow process, can be obtained. When using multiple brominated flame retardants (B), as long as their total amount is within the above range, it is acceptable.

[0137] [Inorganic filler material (C)]

[0138] The polyamide resin composition of this embodiment contains an inorganic filler (C). Examples of inorganic fillers (C) include carbon nanotubes, fullerenes, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, aluminum silicate, silicon dioxide, magnesium oxide, aluminum oxide, magnesium carbonate, dolomite, calcium sulfate, calcium hydroxide, magnesium hydroxide, abrasive fibers, glass powder, ceramic beads, boron nitride, silicon carbide, halloysite, vermiculite, and various clay minerals and glass fibers. These inorganic fillers (C) can be used individually or in combination of two or more.

[0139] From the viewpoint of improving the mechanical properties of the molded polyamide resin composition, the inorganic filler material (C) preferably contains glass fiber or wollastonite, more preferably glass fiber (C1), and even more preferably glass fiber (C1).

[0140] The glass fiber (C1) is preferably the glass fiber described below. The average fiber length of the glass fiber (C1) is preferably 1 to 10 mm, more preferably 1 to 7 mm, and even more preferably 2 to 4 mm.

[0141] Regarding the average fiber diameter of the glass fiber (C1), from the viewpoint of obtaining a molded article with better foam resistance and mechanical properties, it is preferably 6 to 20 μm, and more preferably 6 to 15 μm.

[0142] The average fiber length and average fiber diameter of glass fiber (C1) can be determined by analyzing images from 400 randomly selected glass fibers (C1) using an electron microscope, calculating their respective average values, and thus obtaining the average value.

[0143] In addition, the average fiber length and average fiber diameter of the glass fibers (C1) in the polyamide resin composition or the molded body can be determined, for example, by dissolving the polyamide resin composition or the molded body in an organic solvent, extracting the glass fibers (C1), and then using image analysis with an electron microscope as described above.

[0144] Examples of cross-sectional shapes for glass fibers (C1) include circular, rectangular, near-rectangular oval, elliptical, cocoon-shaped, and cocoon-shaped fibers that taper in the center along the length direction. Among these, glass fibers (C1) with a cross-sectional shape of circular, rectangular, near-rectangular oval, elliptical, or cocoon-shaped are preferred.

[0145] The glass fiber (C1) may contain at least one surface treatment agent selected from coupling agents and condensing agents. For example, the glass fiber (C1) may contain a condensing agent. Alternatively, the glass fiber (C1) may contain both coupling agents and condensing agents. Preferably, the glass fiber (C1) contains a surface treatment agent on its surface. The amount of surface treatment agent adhering to the surface is typically 0.01% by mass or more relative to the total mass of the glass fiber (C1) (i.e., the total mass of the glass fiber (C1) and the surface treatment agent).

[0146] Examples of coupling agents include silane coupling agents and titanium coupling agents. Examples of silane coupling agents include γ-methacryloyloxypropyltrimethoxysilane, γ-epoxypropoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0147] Examples of bridging agents include urethane resin-based bridging agents, acrylic resin-based bridging agents, epoxy resin-based bridging agents, and resin-based bridging agents containing anhydride groups. Among these, urethane resin-based bridging agents, acrylic resin-based bridging agents, and epoxy resin-based bridging agents containing anhydride groups are considered to be resin-based bridging agents containing anhydride groups. Resin-based bridging agents containing anhydride groups are composed of at least one resin containing anhydride groups, preferably a copolymer containing anhydride groups. From the viewpoint of obtaining a molded article with better foaming resistance and better mechanical properties, it is preferable that the bridging agent includes at least one selected from epoxy resin-based bridging agents and resin-based bridging agents containing anhydride groups. From the viewpoint of obtaining a molded article with further improved foaming resistance, it is preferable that the bridging agent includes an epoxy resin-based bridging agent. From the viewpoint of obtaining a molded article with further improved flowability, it is preferable that the bridging agent includes an urethane resin-based bridging agent. Choosing a surface treatment agent suitable for glass fiber (C1) is believed to help impart strength to the molded body, enabling it to withstand the internal pressure of water vapor even under the peak temperature conditions of the reflow process.

[0148] The content of inorganic filler (C) relative to 100 parts by weight of polyamide (A) is preferably 30 to 250 parts by weight, more preferably 35 to 200 parts by weight, further preferably 40 to 150 parts by weight, and even more preferably 45 to 100 parts by weight. If the content of inorganic filler (C) is 30 parts by weight or more, a molded article with better mechanical properties can be obtained; if it is 250 parts by weight or less, shear heating during melt mixing can be suppressed.

[0149] [Coloring agent (D)]

[0150] The polyamide resin composition of this embodiment is endowed with visibility and decorative properties due to the presence of a colorant (D).

[0151] The colorant (D) used in this embodiment is at least one of an organic colorant and an inorganic colorant. The colorant (D) can be used alone or in combination with two or more.

[0152] Examples of organic colorants include anthraquinone dyes, violet ketone dyes, anthraquinone dyes, methyl alkaloid dyes, azazine dyes, azo dyes, azomethyl alkaloid dyes, phthalocyanine dyes, quinone imine dyes, quinoline dyes, nitro dyes, indigo dyes, and oxazine dyes; azo lake pigments, insoluble monoazo pigments, insoluble diazo pigments, chelated azo pigments, phthalocyanine pigments, perylene pigments, violet ketone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindolinone pigments, isoindolineone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, benzimidazolone pigments, and vat pigments.

[0153] From the viewpoints of heat resistance, color rendering and compatibility, anthraquinone dyes, violet ketone dyes, anthraquinone dyes, phthalocyanine dyes, azo pigments and phthalocyanine pigments are preferred, and at least one of anthraquinone dyes, violet ketone dyes, anthraquinone dyes and phthalocyanine dyes is more preferred.

[0154] As inorganic colorants, examples include black inorganic pigments such as carbon black, lampblack, acetylene black, bone black, pyrolytic carbon black, channel black, furnace black, and titanium black; metal oxides such as titanium oxide (TiO, Ti2O3, TiO2), zinc oxide (Pb3O4), iron oxide (Fe2O3), antimony oxide, and zirconium 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 various 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 oxides.

[0155] From the viewpoint of heat resistance, at least one of the following is preferred: black inorganic pigments, metal oxides, metal sulfides and composite metal oxides; more preferably, at least one of carbon black, metal oxides, metal sulfides and composite metal oxides is selected.

[0156] When the colorant (D) contains an organic colorant, the content of the organic colorant, from the viewpoint of flame retardancy, coloring properties and mechanical properties, is preferably 0.0001 to 0.5% by mass relative to 100% by mass of the polyamide resin composition of this embodiment, more preferably 0.001 to 0.5% by mass, and even more preferably 0.005 to 0.5% by mass.

[0157] When the colorant (D) contains an inorganic colorant, the content of the inorganic colorant, from the viewpoint of flame retardancy, coloring properties and mechanical properties, is preferably 0.001 to 5.0% by mass relative to 100% by mass of the polyamide resin composition of this embodiment, more preferably 0.01 to 5.0% by mass, and even more preferably 0.1 to 5.0% by mass.

[0158] The content of colorant (D) relative to 100 parts by weight of polyamide (A) is preferably 0.0005 to 20 parts by weight, more preferably 0.001 to 15 parts by weight, even more preferably 0.01 to 10 parts by weight, even more preferably 0.1 to 5 parts by weight, and even more preferably 0.2 to 1 part by weight. If the content of colorant (D) is 0.0005 parts by weight or more, a highly visible color can be emitted; if it is 20 parts by weight or less, the reduction of the mechanical properties of the molded article can be suppressed.

[0159] [Aromatic vinyl copolymer (E)]

[0160] From the viewpoints of flame retardancy, heat resistance, and formability, 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 formability, the copolymer (E) preferably contains at least one structural unit selected from styrene and α-methylstyrene, and at least one structural unit selected from maleic anhydride and monoalkyl maleic anhydride having 1 or more and 3 or fewer carbon atoms, more preferably containing structural units from styrene and structural units from maleic anhydride.

[0161] Regarding the content of at least one structural unit in the copolymer (E) selected from maleic anhydride and monoalkyl maleic anhydride having 1 or more and 3 or fewer carbon atoms, from the viewpoint of flame retardancy, heat resistance and formability, it is preferably 3 to 50% by mass, more preferably 5 to 50% by mass, even more preferably 10 to 40% by mass, and may also be 18 to 50% by mass, 18 to 30% by mass, or 18 to 25% by mass.

[0162] The copolymer (E) may further have structural units other than at least one structural unit selected from styrene and α-methylstyrene, and at least one structural unit selected from maleic anhydride and monoalkyl maleic anhydride having 1 or more and 3 or fewer carbon atoms. However, the total content of the structural units selected from styrene and α-methylstyrene and at least one structural unit selected from maleic anhydride and monoalkyl maleic anhydride having 1 or more and 3 or fewer carbon atoms in the copolymer (E) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass.

[0163] The glass transition temperature of the copolymer (E) is preferably 140°C or higher, more preferably 140–200°C, even more preferably 145–180°C, and even more preferably 150–160°C. If the glass transition temperature of the copolymer (E) is 140°C or higher, the flame retardancy and heat resistance can be further improved; if it is below 200°C, the thermal decomposition of polyamide during melt molding can be suppressed.

[0164] The glass transition temperature of the copolymer (E) can be determined as the temperature at which the inflection point occurs when the temperature is increased at a rate of 20 °C / min using a differential scanning calorimeter (DSC).

[0165] From the viewpoint 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, further preferably 30,000 to 300,000, and even more preferably 50,000 to 200,000.

[0166] The weight-average molecular weight (Mw) of the copolymer (E) was determined by gel permeation chromatography (GPC) based on polystyrene conversion.

[0167] The copolymer (E) can be a commercially available product or a copolymer synthesized using known methods. In addition, there is no particular limitation on the bonding mode of at least one structural unit selected from styrene and α-methylstyrene and at least one structural unit selected from maleic anhydride and monoalkyl maleic anhydride having 1 or more and 3 or fewer carbon atoms, and it can be any of random polymerization, block polymerization, or graft polymerization.

[0168] In the case where the polyamide resin composition of this embodiment contains copolymer (E), the content of copolymer (E) is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of polyamide (A), more preferably 0.5 to 8 parts by mass, and even more preferably 0.8 to 5 parts by mass, from the viewpoint of flame retardancy, heat resistance and formability.

[0169] [Flame retardant additive (F)]

[0170] The polyamide resin composition of this embodiment may further contain a flame retardant additive (F). By using the flame retardant additive (F) in combination with a brominated flame retardant (B), the resulting molded article can exhibit even better flame retardancy.

[0171] Examples of flame retardant additives (F) include antimony compounds such as antimony oxides (antimony trioxide, antimony tetroxide, antimony pentoxide, etc.) and antimonates such as sodium antimonate; melamine compounds such as melamine orthophosphate, melamine pyrophosphate, melamine borate, and melamine polyphosphate; tin oxides such as tin monoxide and tin dioxide; iron oxides such as iron oxide and γ-iron oxide; metal oxides such as manganese oxide, molybdenum oxide, cobalt oxide, bismuth oxide, tin oxide, nickel oxide, copper oxide, and tungsten oxide; metal hydroxides such as aluminum hydroxide; metal powders of aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, tin, antimony, nickel, copper, and tungsten; metal carbonates such as zinc carbonate and barium carbonate; metal borates such as zinc borate and calcium borate; zinc stannate such as zinc tin trioxide; and silicones. However, substances that meet the criteria for inorganic fillers (C) and colorants (D) are not included. They can be used individually or in combination of two or more.

[0172] Of the above, preferably selected from at least one of antimony compounds, melamine compounds, metal oxides, metal hydroxides, metal borates, and zinc stannate, more preferably selected from at least one of antimony trioxide, antimony tetroxide, antimony pentoxide, sodium antimonate, melamine orthophosphate, melamine pyrophosphate, melamine borate, melamine polyphosphate, aluminum hydroxide, zinc borate, and zinc tin trioxide.

[0173] The flame retardant additive (F) is preferably contained in the polyamide resin composition of this embodiment in powder form. The upper limit of its average particle size is preferably 30 μm, more preferably 15 μm, further preferably 10 μm, and particularly preferably 7 μm. On the other hand, the lower limit of the average particle size of the flame retardant additive (F) is preferably 0.01 μm. When the average particle size is between 0.01 and 30 μm, the flame retardancy of the resulting molded article is improved.

[0174] It should be noted that in this specification, the term "average particle size" refers to the volume average particle size, which can be determined from the particle size distribution measured using a laser diffraction particle size distribution measuring device based on the particle size of 50% of the cumulative volume (50% particle size D50).

[0175] When the polyamide resin composition of this embodiment contains a flame retardant (F), the content of the flame retardant (F) relative to 100 parts by weight of polyamide (A) is preferably 1 to 20 parts by weight, more preferably 2 to 18 parts by weight, further preferably 3 to 15 parts by weight, and even more preferably 4 to 10 parts by weight. This significantly enhances the aforementioned effects.

[0176] [Other ingredients]

[0177] The polyamide resin composition of this embodiment may contain other components as needed, in addition to the polyamide (A), brominated flame retardant (B), inorganic filler (C), and colorant (D) described above, as well as aromatic vinyl copolymer (E) and flame retardant additive (F) used as needed.

[0178] Other components include, for example, stabilizers such as copper compounds; antioxidants such as hindered phenolic antioxidants, histamine antioxidants, phosphorus antioxidants, and sulfur antioxidants; ultraviolet absorbers; light stabilizers; antistatic agents; heat stabilizers; crystallizing nucleating agents; plasticizers; lubricants; release agents; slip agents; dispersants; oxygen absorbers; hydrogen sulfide adsorbents; crystallization delay agents; impact modifiers such as α-olefin copolymers and rubbers; and anti-drip agents such as fluoropolymers.

[0179] The content of the other components mentioned above is not particularly limited as long as it does not impair the effect of the present invention. However, the content of polyamide (A) is preferably 0.02 to 200 parts by weight, more preferably 0.03 to 100 parts by weight, further preferably 0.05 to 50 parts by weight, and even more preferably 0.1 to 20 parts by weight.

[0180] In this embodiment, the total content of polyamide (A), brominated flame retardant (B), inorganic filler (C), and colorant (D) in the polyamide resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0181] (Method for manufacturing polyamide resin composition)

[0182] There are no particular limitations on the manufacturing method of the polyamide resin composition, and known methods can be used. For example, a method can be described by melt-blending polyamide (A), brominated flame retardant (B), inorganic filler (C), colorant (D), and aromatic vinyl copolymer (E), flame retardant additive (F), and other components mentioned above, as needed.

[0183] There are no particular limitations on the melt blending method, but methods that can uniformly mix the above components are preferred. For example, single-screw extruders, twin-screw extruders, kneaders, Banbury mixers, etc. are preferred. There are no particular limitations on the melt blending conditions; however, for example, a method of melt blending for about 1 to 30 minutes in a temperature range that is about 10 to 50°C higher than the melting point of polyamide (A) can be cited.

[0184] (Physical properties of polyamide resin compositions)

[0185] Regarding the polyamide resin composition of this embodiment, from the viewpoint of improving visibility, ΔE, expressed by the following formula (3), is preferably greater than 1, more preferably greater than 3, even more preferably greater than 10, and even more preferably greater than 30.

[0186] Furthermore, the inorganic filler (C) and colorant (D) contained in the polyamide resin composition of this embodiment are preferably selected in a manner that satisfies this requirement.

[0187] [Mathematical Expression 6]

[0188]

[0189] In equation (3), ΔE is derived from CIE1976 (L a b The color difference specified in the color system.

[0190] L col a col and b col The polyamide resin composition of this embodiment is derived from CIE1976 (L a b The color system specified by L a and b That is, the polyamide resin composition of this embodiment is conformed to CIE1976 (L... a b The color system specified by L For L col a For a col b For b col .

[0191] L nat a nat and b nat A polyamide resin composition without colorant, having the same composition as the above-described polyamide resin composition except that it does not contain colorant (D), is formulated according to CIE 1976 (L). a b The color system specified by L a and b That is, a polyamide resin composition without colorant that has the same composition as the above-described polyamide resin composition except that it does not contain colorant (D), as specified in CIE 1976 (L). a b The color system specified by L For L nat a For a nat b For b nat .

[0192] <Molded body>

[0193] After manufacturing the above-mentioned polyamide resin composition, a molded article can be obtained, for example, by providing the granulated polyamide resin composition to various molding methods. The molding method of the molded article can be appropriately selected according to the application, and methods such as injection molding, extrusion molding, blow molding, compression molding, pressing molding, and calendering can be used.

[0194] In particular, the polyamide resin composition of this embodiment can provide molded articles with excellent foaming resistance even when exposed to high temperatures during the reflow process, as well as excellent flame retardancy and mechanical properties, making it suitable for use as injection molded articles in applications with surface mounting processes.

[0195] <Uses>

[0196] The polyamide resin composition of this embodiment can be used as various molded articles of any shape and purpose, such as electrical components, electronic components, automotive components, industrial components, water supply switch components, fibers, films, sheets, household goods, leisure goods, etc.

[0197] As electrical and electronic components, examples include connectors such as FPC connectors, B2B connectors, card connectors, SMT connectors (coaxial connectors, etc.), and memory card connectors; SMT relays; SMT coil holders; memory slots, CPU slots, and other slots; command switches, SMT switches, and other switches; optical components such as fiber optic components and optical sensors; LED components such as LED reflectors; and electronic substrates such as solar cell substrates, LED mounting substrates, flexible printed circuit boards, and resin-molded circuit boards.

[0198] Examples of automotive components include: thermostat housings, coolant control valve housings, thermal management module housings, radiator tanks, radiator hoses, water outlets, water inlets, water pump housings, and rear connectors; intercooler tanks, intercooler housings, turbo pipes, EGR cooler housings, resonators, throttle bodies, intake manifolds, and exhaust tailpipes; fuel system components such as fuel delivery pipes, fuel tanks, quick connectors, activated carbon canisters, pump modules, fuel lines, oil filters, lock nuts, and sealing materials; structural components such as mounting brackets, torsion bars, and cylinder head covers; and bearing retainers, gear retainers, headlight actuator gears, throttle valve gears, and sliding door rollers. Drive system components such as rollers and clutch peripherals; braking system components such as air brake pipes; vehicle electrical components such as wiring harness connectors, motor components, sensors, ABS coil brackets, combination switches, and vehicle switches in the engine compartment; and interior and exterior components such as sliding door dampers, rearview mirror brackets, door rearview mirror brackets, inner rearview mirror brackets, upper side beams, engine mounting brackets, air filter inserts, door opening limiters, traction chains, vehicle emblems, clamps, buffer covers, cup holders, airbags, mudguards, spoilers, radiator vents, radiator grilles, louvers, air intakes, engine hood protrusions, rear doors, and fuel dispenser modules.

[0199] As industrial components, examples include gas pipelines, oilfield extraction pipes, hoses, termite-proof cables (communication cables, transmission cables, etc.), powder coatings (inner coatings of water pipes, etc.), subsea oilfield pipes, pressure hoses, hydraulic hoses, paint hoses, fuel pump housings and impellers, spacers, supercharging pipes, 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 yarns) for fishing nets, etc.

[0200] Examples of water supply switch components include, for instance, housings for water conveyance components, water storage components, filter housings, faucet housings, pipe housings, bathroom water supply switches (hot water switching valves, water flow switching valves, etc.), sanitary fixture housings, kitchen water supply switch housings, water heater housings, valve components (shut-off ball valves, slide valves, cylinder valves) and valve component housings, toilet shut-off switch housings, shower head housings, water heater valve housings, residential piping (underfloor piping, etc.) connectors, bathroom water supply switch connectors, and water supply piping... Connectors, pipe fittings, water meter housings, water meter components (bearings, impellers, pins), water meter and gas meter housings, distributor housings, valve / pump housings for household appliances, steam-resistant components for steam irons, internal containers for electric kettles, dishwasher components (washing tub, washing nozzles, baskets), pump housings, pump components (e.g., turbines, wheels, impellers), housings for water supply systems (warm water tanks, etc.), housings for heating systems, housings for cooling systems, water flow regulating valves, pressure reducing valves, release valves, solenoid valves, three-way valves, thermal valves, hot water temperature sensors, water flow sensors, bathtub adapters, etc.

[0201] Examples of household appliances include valve / pump housings for tea and coffee makers; valve / pump housings for cooking appliances such as rice cookers and steamers; steam-resistant components for cooking appliances such as rice cookers and steamers (e.g., the lid of a rice cooker); sliding components for cooking appliances such as rice cookers and steamers (e.g., gears); sliding components for commercial cooking appliances (e.g., gears for gear pumps); and steam-resistant components for commercial cooking appliances (e.g., pipes in commercial rice cookers).

[0202] As leisure products, examples include the insoles of athletic shoes, the frames and grommets of tennis rackets, the clubheads and sleeves of golf clubs, fishing reels and rods for fishing tackle, propellers for boats, suspensions, gears, saddles, and water bottle cages for bicycles.

[0203] The polyamide resin composition of this embodiment can be manufactured using injection molding, making it suitable for electrical and electronic components requiring the production of large quantities of parts in a short time. Specifically, it is suitable for electrical and electronic components involving SMT processes, and more specifically, for surface mount components such as SMT connectors, SMT relays, SMT wire guides, slots, command switches, SMT switches, camera modules, power supply components, sensors, capacitor banks, hard disk components, resistors, fuse holders, coil holders, and IC housings.

[0204] A particularly suitable example of the molded body of the polyamide resin composition of this embodiment is a part of an SMT-compatible automotive connector. SMT-compatible automotive connectors typically include a housing and terminals made of a resin composition using a resin with a melting point of 260°C or higher. SMT-compatible automotive connectors may also include sealing rings, gaskets, and housings. Automotive connectors are generally larger in size than connectors for consumer electronics. Furthermore, during the SMT process, blistering is prone to occur due to exposure to higher temperatures and difficulty in releasing moisture from the molded body during the preheating process. High flame retardancy is also required. Moreover, automotive applications have stringent quality requirements, making blistering unacceptable. Therefore, the molded body must exhibit excellent blistering resistance even when exposed to high temperatures during the SMT process. The molded body of the polyamide resin composition of this embodiment meets these requirements and is therefore suitable as a part of an automotive connector.

[0205] Example

[0206] The present invention will now be described in detail using examples and comparative examples; however, the present invention is not limited to these descriptions.

[0207] The evaluations of the embodiments and comparative examples were carried out according to the methods shown below.

[0208] <1. Determination of Melt Viscosity>

[0209] The melt viscosity of polyamide (A) and brominated flame retardant (B) at 320°C was determined using a rotational rheometer (HAAKE MARSIII, Thermo Fisher Scientific, Inc.) under the following test conditions.

[0210] (Measurement conditions)

[0211] • Geometric structure: Conical plate diameter: φ20mm (inclination angle: 4°)

[0212] • Shear rate: The shear rate is continuously varied from 0.001 [1 / s] to 1000 [1 / s], and the melt viscosity is read at the point of 0.5 [1 / s].

[0213] • Measurement time: 7 minutes

[0214] <2. Calculation of R1 in terms of equation (1)>

[0215] Based on the melt viscosity of polyamide (A) and brominated flame retardant (B) obtained in 1 above at 320°C, and the contents of polyamide (A) and brominated flame retardant (B) recorded in Table 1, R1 of the following formula (1) is calculated.

[0216] [Mathematical Expression 7]

[0217]

[0218] In formula (1), XA is the content (mass%) of polyamide (A) relative to 100% by mass of the polyamide resin composition, and XB is the content (mass%) of brominated flame retardant (B) relative to 100% by mass of the polyamide resin composition. Additionally, 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.

[0219] <3. Calculation of R2 expressed in equation (2)>

[0220] Based on the melt viscosity of polyamide (A) and brominated flame retardant (B) at 320°C obtained in 1 above, and the content of polyamide (A) (volume%) and brominated flame retardant (B) (volume%) relative to 100 vol% of the polyamide resin composition calculated based on the content (parts by mass) and specific gravity of each component recorded in Table 1, R2 of the following formula (2) is calculated.

[0221] [Mathematical Expression 8]

[0222]

[0223] In formula (2), ZA represents the content of polyamide (A) relative to 100 vol% of the polyamide resin composition (volume%), and ZB represents the content of brominated flame retardant (B) relative to 100 vol% of the polyamide resin composition (volume%). Additionally, in this evaluation, YA represents the melt viscosity (Pa·s) of polyamide (A) at 320°C, and YB represents the melt viscosity (Pa·s) of brominated flame retardant (B) at 320°C. n and m are both integers greater than or equal to 1.

[0224] <4. Color value (L) a b , ΔE) >

[0225] The L value, as a color value, of the polyamide resin compositions obtained in each example and comparative example was determined using the apparatus and conditions described below. a b For the purpose of testing, test piece A was prepared from the polyamide resin compositions obtained in the various examples and comparative examples using dumbbell-shaped tensile test pieces (Type A1) according to the method of JIS K7139:2009. colIn addition, a polyamide resin composition with the same composition as the polyamide resin compositions obtained in the examples and comparative examples was prepared, except that it did not contain colorant (D), and dumbbell-shaped tensile test pieces (type A1) were also produced in the same manner (test piece A). nat ).

[0226] Measuring apparatus: RAL gGmbH colorimeter, RAL COLORCATCH NANO

[0227] Light source: CIE standard light source D65

[0228] Sensor: CCD camera (224×224 pixels)

[0229] Geometry measurement: 45° / 0° Software: RAL iCOLOURS (version 3.7.2)

[0230] Device used: Software on iPhone 8 (iOS 13.3)

[0231] According to the obtained L a b Calculate ΔE as expressed in the following formula (3).

[0232] [Mathematical Expression 9]

[0233]

[0234] It should be noted that in equation (3), L col a ncol and b col The polyamide resin compositions obtained in each example (test piece A) col ) by CIE1976 (L a b The color system specified by L a and b L nat a nat and b nat It is a polyamide resin composition (test piece A) with the same composition as the above-mentioned polyamide resin composition except that it does not contain colorant (D). nat ) by CIE1976 (L a b The color system specified by L a and b ΔE is shown in Table 1.

[0235] <5. Evaluation of foaming resistance>

[0236] Using an injection molding machine (clamping force: 18 tons, screw diameter: φ18 mm) manufactured by Sumitomo Heavy Industries, Ltd., the polyamide resin composition obtained in the examples and comparative examples was used. The barrel temperature was set to 320°C, which is 14°C higher than the melting point of the polyamide as component (A). Under the condition of mold temperature of 140°C, the polyamide resin composition was injected into a mold with a thin film gate with a width of 10 mm and a thickness of 0.9 mm to produce multiple sheet-shaped test pieces with a length of 30 mm, a width of 10 mm, and a thickness of 1 mm as polyamide molded bodies.

[0237] Injection molding was performed with an injection speed of 60 mm / s, a holding pressure of 60 MPa, a holding time of 1.0 second, a cooling time of 4.0 seconds, and a cycle time of 11.0 seconds. The result, although this varies depending on the composition, was an injection time of approximately 0.15 seconds and a filling pressure of approximately 60 MPa. Regarding the barrel temperature settings, they were sequentially set to 320℃, 320℃, 320℃, 320℃, and 300℃, starting from the nozzle.

[0238] The resulting test pieces were left to stand for 168 hours at 85°C and 85% relative humidity. Subsequently, a reflow test was performed on these test pieces using a reflow system (TNX25-30EM, manufactured by Tamura Corporation). In the reflow test, the temperature was increased from 25°C to 150°C in 60 seconds, then to 180°C in 90 seconds, and further increased to the peak temperature in 60 seconds, held at the peak temperature for 20 seconds. The peak temperature was set to 265°C.

[0239] After the reflow test, the appearance of each test piece was visually observed. Even a slight bulge on the surface of the test piece was considered as bubbling.

[0240] The bubbling rate was calculated based on the observations of 100 test pieces. Specifically, the bubbling rate was calculated as the percentage of test pieces out of 100 that had at least one instance of bubbling.

[0241] The following five levels of indicators are used to evaluate foaming resistance. An evaluation result of "A" or "B" indicates a level that does not impede practical use.

[0242] A: The foaming rate is 0% or higher and less than 10%.

[0243] B: The foaming rate is 10% or higher but less than 25%.

[0244] C: The foaming rate is above 25% but less than 50%.

[0245] D: The foaming rate is above 50% but less than 75%.

[0246] E: Foaming rate is above 75% and below 100%.

[0247] <6. Evaluation of Mechanical Properties>

[0248] Prepare test pieces as shown below, and use these test pieces to evaluate mechanical properties such as tensile and bending properties.

[0249] [6-1. Preparation of test pieces B and C]

[0250] Using an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. (clamping force: 100 tons, screw diameter: φ32 mm), the polyamide resin composition obtained in the examples and comparative examples was used. The barrel temperature was set to 320°C, which is 14°C higher than the melting point of the polyamide in component (A). The polyamide resin composition was molded using a T-runner mold at a mold temperature of 140°C to produce a multi-purpose test piece A1 type (dumbbell-shaped test piece as described in JIS K7139:2009: thickness 4 mm, total length 170 mm, parallel part length 80 mm, and central parallel part width 10 mm) (hereinafter also referred to as "test piece B").

[0251] In addition, a test piece (hereinafter also referred to as "test piece C") is formed with the same shape as test piece B and a weld is formed at the center of its parallel part in a direction perpendicular to the length direction of the parallel part.

[0252] [6-2. Tensile properties: tensile strength and tensile strain at break]

[0253] Using the test piece C prepared in 6-1 above, the tensile breaking strength (MPa) and tensile breaking strain (%) were determined using a universal testing machine (Instron) at a test speed of 1 mm / min and a clamping distance of 115 mm, in accordance with ISO 527-1 (2nd edition 2012).

[0254] [6-3. Tensile properties: tensile breaking strength of weld]

[0255] Using the test piece C prepared in 6-1 above, the tensile breaking strength (MPa) of the weld was determined using a universal testing machine (Instron) at a test speed of 1 mm / min and a fixture spacing of 115 mm, in accordance with ISO 527-1 (2nd edition 2012).

[0256] [6-4. Bending characteristics: bending strength and flexural modulus]

[0257] Using the test piece B prepared in 6-1 above, the flexural strength (MPa) and flexural modulus (GPa) were determined using a universal testing machine (Instron) at a test speed of 2 mm / min and a distance of 64 mm between support points, in accordance with ISO 178 (2nd edition, 2012).

[0258] <7. Evaluation of the length of strip flow>

[0259] Using an injection molding machine manufactured by Nissei Resin Kogyo Co., Ltd. (clamping force: 80 tons, screw diameter: φ26 mm), the polyamide resin composition obtained in the examples and comparative examples was used. The barrel temperature was set to 320°C, which is 14°C higher than the melting point of the polyamide in component (A). A mold with a width of 40 mm and a height of 0.5 mm was used. The polyamide resin composition was molded 5 times at 1000 kgf under a mold temperature of 140°C. Then, it was molded 10 times at 750 kgf. Then, it was molded 5 times at 750 kgf. The flow length (mm) of the resulting polyamide molded body was measured, and the average value was set as the strip flow length.

[0260] <8. Evaluation of Flame Retardancy>

[0261] Flame retardancy was evaluated in accordance with the UL-94 standard.

[0262] Using an injection molding machine manufactured by Nissei Resin Industries, Ltd. (clamping force: 80 tons, screw diameter: φ26 mm), the polyamide resin composition obtained in the examples and comparative examples was used. The barrel temperature (320°C) was set to be 14°C higher than the melting point of the polyamide in component (A). The polyamide resin composition was molded at a mold temperature of 140°C to obtain a test piece D with a thickness of 0.75 mm, a width of 13 mm, and a length of 125 mm.

[0263] Then, the test piece D was held vertically by clamping its upper end. A blue flame with a height of 20±1 mm was brought into contact with the lower end for 10 seconds and then removed. The burning time of the test piece D was measured (first time). After extinguishing the flame, it was immediately brought into contact with the lower end again and removed. The burning time of the test piece D was measured (second time). The same measurement was repeated for 5 pieces, obtaining 5 data points for the first burning time and 5 data points for the second burning time, for a total of 10 data points. The sum of the 10 data points was set as T, and the maximum value among the 10 data points was set as M. The evaluation was carried out according to the following evaluation criteria.

[0264] In addition, visually check for any dripping during flame contact.

[0265] [Evaluation Criteria]

[0266] V-0: T is less than 50 seconds and M is less than 10 seconds, no burning to the clamp, and even if molten material with flames falls, it does not ignite the cotton 12 inches below.

[0267] V-1: T is less than 250 seconds and M is less than 30 seconds, no burning to the holder, and even if molten material with flames falls, it does not ignite the cotton 12 inches below.

[0268] V-2: T is less than 250 seconds and M is less than 30 seconds, no burning to the clamp, melted material with flames falls and ignites the cotton 12 inches below.

[0269] X: Cases that do not meet any of the evaluation criteria of UL94 mentioned above.

[0270] <Example 1>

[0271] 100 parts by mass of polyamide (A-2) as polyamide (A), 58 parts by mass of bromine-based flame retardant (B-1) as bromine-based 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 hopper at the top of a twin-screw extruder (MEGA 32L manufactured by STEER Engineering: screw φ31.6mm, L / D=52, speed 150rpm, discharge 10kg / h). In addition, 83 parts by mass of glass fiber (C1-1) as inorganic filler (C) were supplied from a side feeder and melt-blended at 320°C. The melt-blended polyamide resin composition was extruded in a wire, cooled, and then cut to obtain granules of the polyamide resin composition. Using the obtained granules, test pieces of a given shape were prepared according to the method described above, and various physical properties were evaluated. The results are shown in Table 1.

[0272] <Examples 2-15 and Comparative Examples 1-5>

[0273] Except for the components being changed to the types and proportions listed in Tables 1 and 2, granules of the polyamide resin compositions of each example and comparative example were obtained in the same manner as in Example 1. Furthermore, using the obtained granules, test pieces of given shapes were prepared according to the method described above, and various physical properties were evaluated. The results are shown in Tables 1 and 2. It should be noted that in Tables 1 and 2, empty columns indicate no formulation.

[0274] It should be noted that the components in Tables 1 and 2 are as follows.

[0275] [Polyamide (A)]

[0276] • Polyamide (A-1): A polyamide with dicarboxylic acid unit of terephthalic acid unit, diamine unit of 1,9-nonanediamine unit and 2-methyl-1,8-octanediamine unit (molar ratio 85 / 15), melting point: 306℃, glass transition temperature: 125℃, melt viscosity at 320℃: 20 Pa·s, specific gravity: 1.1.

[0277] • Polyamide (A-2): A polyamide with dicarboxylic acid unit of terephthalic acid unit, diamine unit of 1,9-nonanediamine unit and 2-methyl-1,8-octanediamine unit (molar ratio 85 / 15), melting point: 306℃, glass transition temperature: 125℃, melt viscosity at 320℃: 40 Pa·s, specific gravity: 1.1.

[0278] • Polyamide (A-3): A polyamide with dicarboxylic acid unit of terephthalic acid unit, diamine unit of 1,9-nonanediamine unit and 2-methyl-1,8-octanediamine unit (molar ratio 85 / 15), melting point: 306℃, glass transition temperature: 125℃, melt viscosity at 320℃: 270 Pa·s, specific gravity: 1.1.

[0279] [Brominated flame retardant (B)]

[0280] • Bromine-based 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.

[0281] • 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.

[0282] • 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.

[0283] [Inorganic filler material (C)]

[0284] • Glass fiber (C1-1): Manufactured by Chuo Glass Co., Ltd., trade name "ECS03-615" (glass fiber, cross-sectional shape: circular, average fiber diameter: 9μm, average fiber length: 3mm, silane-based treatment, specific gravity: 2.6)

[0285] [Coloring agent (D)]

[0286] • Colorant (D-1): Manufactured by Mitsubishi Chemical Corporation, trade name "#980B" (carbon black), specific gravity: 1.8.

[0287] [Aromatic vinyl copolymers (E)]

[0288] • Aromatic vinyl copolymer (E-1): Polyscope, trade name "XIBOND 160" (styrene-maleic anhydride copolymer, acid value: 250 mg KOH / g, glass transition temperature: 150℃, weight-average molecular weight (Mw): 115000, specific gravity: 1.2, maleic anhydride content: 23% by mass)

[0289] [Flame retardant additive (F)]

[0290] • Flame retardant additive (F-1): Manufactured by Japan Light Metals Co., Ltd., trade name "FlamtardS" (zinc stannate), specific gravity: 3.9.

[0291] [Other ingredients]

[0292] • Antioxidant: Sumitomo Chemical Co., Ltd., trade name "Sumilizer GA-80" (3,9-bis{1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane), specific gravity: 1.2.

[0293] • Anti-drip agent: Manufactured by Mitsui DuPont Fluorochemicals Co., Ltd., trade name "640-J" (polytetrafluoroethylene powder), specific gravity: 2.2.

[0294] • Release agent: Manufactured by Mitsui Chemicals Co., Ltd., trade name "Hi-WAX200P" (polyolefin wax), specific gravity: 0.95.

[0295]

[0296]

[0297] It can be seen that the polyamide resin compositions obtained in Examples 1 to 15 exhibit excellent foaming resistance even when exposed to high temperatures during the reflow process. In addition, the molded articles of these polyamide resin compositions also exhibit excellent flame retardancy and mechanical properties.

[0298] Industrial availability

[0299] The molded articles of the polyamide resin composition of the present invention are useful for various molded articles requiring a high degree of reliability in electrical connections.

Claims

1. A polyamide resin composition containing 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), the polyamide (A) contains dicarboxylic acid units and diamine units, 50 to 100 mole% of the diamine units being aliphatic diamine units having 4 to 18 carbon atoms, the colorant (D) is at least one of an organic colorant and an inorganic colorant, R1 represented by the following formula (1) is less than 50; in formula (1), XA is the content of the polyamide (A) in terms of mass% relative to 100 mass% of the polyamide resin composition, XB is the content of the bromine-based flame retardant (B) in terms of mass% relative to 100 mass% of the polyamide resin composition, YA is the melt viscosity of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), the unit of the melt viscosity being Pa-s, YB is the melt viscosity of the bromine-based flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A), the unit of the melt viscosity being Pa-s; wherein in the case where the polyamide (A) is two or more, the melting point of the polyamide (A) is a weighted average based on the content of the polyamide (A) in terms of mass% relative to 100 mass% of the polyamide resin composition; both n and m are integers of 1 or more.

2. A polyamide resin composition containing 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), the polyamide (A) contains dicarboxylic acid units and diamine units, 50 to 100 mole% of the diamine units being aliphatic diamine units having 4 to 18 carbon atoms, the colorant (D) is at least one of an organic colorant and an inorganic colorant, R2 represented by the following formula (2) is less than 20; in formula (2), ZA is the content of the polyamide (A) in terms of volume% relative to 100 volume% of the polyamide resin composition, ZB is the content of the bromine-based flame retardant (B) in terms of volume% relative to 100 volume% of the polyamide resin composition, YA is the melt viscosity of the polyamide (A) at a temperature 14°C higher than the melting point of the polyamide (A), the unit of the melt viscosity being Pa-s, YB is the melt viscosity of the bromine-based flame retardant (B) at a temperature 14°C higher than the melting point of the polyamide (A), the unit of the melt viscosity being Pa-s; wherein in the case where the polyamide (A) is two or more, the melting point of the polyamide (A) is a weighted average based on the content of the polyamide (A) in terms of volume% relative to 100 volume% of the polyamide resin composition; both n and m are integers of 1 or more.

3. The polyamide resin composition according to claim 1 or 2, wherein the content of the bromine-based 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 claims 1 to 3, wherein the polyamide (A) is a polyamide having a melting point of 280°C or higher and containing dicarboxylic acid units and diamine units, 50 to 100 mole% of the diamine units being aliphatic diamine units having 4 to 18 carbon atoms. ​ ΔE represented by the following formula (3) is greater than 1; In formula (3), ΔΕ is the color difference as defined by the CIE 1976 (L a b ) color system, L col a col and b col The polyamide resin composition is derived from CIE1976 (L a b The color system specified by L a and b , L nat a nat and b nat A polyamide resin composition that is identical in composition to the polyamide resin composition except that it does not contain colorant (D), and is free of colorant, as defined by CIE 1976 (L). a b The color system specified by L a and b .

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-based dyes, perinone-based dyes, anthrapyridone-based dyes, and phthalocyanine-based 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% with respect 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% with respect to 100 mass% of the polyamide resin composition.

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

10. The polyamide resin composition according to any one of claims 1 to 9, wherein The bromine-based flame retardant (B) is selected from the group consisting of brominated polystyrene and polybromostyrene, and is two or more kinds different in the melt viscosity 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 material (C) contains glass fibers (C1).

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

13. The polyamide resin composition according to claim 12, wherein The content of the structural unit derived from at least one selected from the group consisting of maleic anhydride and monoalkyl maleic anhydride having an alkyl group having a carbon number of 1 or more and 3 or less in the aromatic vinyl-based 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-based copolymer (E) is 10,000 to 500,000.

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

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

17. The polyamide resin composition according to claim 16, further containing an aromatic vinyl-based copolymer (E), and the content of the aromatic vinyl-based copolymer (E) is 0.1 parts by mass to 10 parts by mass relative to 100 parts by mass of the polyamide (A).

18. The polyamide resin composition according to claim 16 or 17, further containing a flame retardant aid (F), and the content of the flame retardant aid (F) is 1 part by mass to 20 parts by mass relative to 100 parts by mass of the polyamide (A).

19. A method for producing the polyamide resin composition according to any one of claims 1 to 18, wherein, The polyamide (A), the bromine-based flame retardant (B), the inorganic filler (C), and the colorant (D), and the aromatic vinyl-based copolymer (E) and the flame retardant aid (F) used as necessary are melt-kneaded.

20. A molded body which is a molded body of the polyamide resin composition according to any one of claims 1 to 18.

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

22. The molded body according to claim 20 or 21, which is a connector for use in a vehicle.

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