Polyamide composition, process for the production thereof and molded article

Abstract

This invention relates to polyamide compositions, methods for manufacturing the same, and molded articles. The invention provides a polyamide composition capable of producing molded articles containing a halogen-free flame retardant and exhibiting good flame retardancy and long-term heat resistance, as well as a method for manufacturing the same. A polyamide composition comprises (A) a polyamide, (B) a phosphorus-containing flame retardant, and (C) a styrene copolymer, wherein the content of the (C) styrene copolymer is 0.1% by mass or more and 7.0% by mass or less relative to the total mass of the (A) polyamide, the (B) phosphorus-containing flame retardant, and the (C) styrene copolymer. The method for manufacturing the polyamide composition is a method for manufacturing the above-mentioned polyamide composition, wherein the raw material components containing the (A) polyamide, the (B) phosphorus-containing flame retardant, and the (C) styrene copolymer are melt-blended.

Description

[0001] This application is a divisional application of Chinese patent application No. 202010423271.3, filed on May 19, 2020. Technical Field

[0002] This invention relates to polyamide compositions, methods for manufacturing the same, and molded articles thereof. Background Technology

[0003] Compositions based on aliphatic polyamides possess excellent properties and are therefore used in a wide range of applications for manufacturing molded articles. In particular, polyamide compositions with flame-retardant properties are essential components in the electrical and electronics industries to ensure proper fire resistance.

[0004] Polyamides are often treated with halogen compounds to achieve flame retardancy. However, recently, various regulations have been established based on hazardous substance regulations such as RoHS (Restriction of Hazardous Substances Directive) and PoHS (Prohibition of Certain Hazardous Substances in Consumer Products) to prohibit the use of products containing halogen compounds in electrical and electronic components. Therefore, a variety of halogen-free flame retardants for polyamides have been developed.

[0005] Phosphorus compounds can be listed as examples of halogen-free flame retardants. Patent Document 1 discloses the use of calcium and aluminum salts of phosphonic acid or secondary phosphonic acid as flame retardants for polyamides. Test pieces with a thickness of 1.2 mm made from a polyamide composition containing these halogen-free flame retardants and reinforced with glass fiber at 30% by weight relative to the total mass of the composition achieved a flammability rating of V-0 based on UL94.

[0006] To achieve a UL94 flammability rating of V-0, Patent Document 2 discloses that in glass fiber reinforced polyamide compositions with polyamide 6 as the main component, an amount of aluminum hypophosphite far exceeding 20% ​​by mass relative to the total mass of the composition is required; and in glass fiber reinforced polyamide compositions with polyamide 66 as the main component, an amount exceeding 30% by mass of aluminum hypophosphite is required. It is evident that to achieve a flammability rating of V-0 using hypophosphite flame retardants, a large amount of hypophosphite flame retardant must be added, thereby adversely affecting mechanical properties, which is a problem.

[0007] Therefore, Patent Document 3 discloses a polyamide composition based on a mixture of aliphatic and semi-aromatic polyamides containing phosphonates as flame retardants. It is reported that by adding semi-aromatic polyamides, the amount of flame retardant used can be reduced, and the tensile elongation can be improved.

[0008] Furthermore, Patent Document 4 discloses a polyamide composition using phosphonates as flame retardants and based on a mixture of polyamide containing aromatic polyamide and polyphenylene sulfide. It is reported that by adding polyphenylene sulfide, which has excellent flame retardant properties, to the polyamide containing aromatic polyamide, the amount of flame retardant used can be reduced, and the amount of gas emitted from the flame retardant can also be reduced.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent No. 3947261

[0012] Patent Document 2: Japanese Patent No. 4698789

[0013] Patent Document 3: Japanese Patent No. 4614959

[0014] Patent Document 4: Japanese Patent Application Publication No. 2009-270107

[0015] Patent Document 5: Japanese Patent Application Publication No. 2005-179362

[0016] Patent Document 6: European Patent Application Publication No. 699708

[0017] Patent Document 7: Japanese Patent Application Publication No. 08-073720 Summary of the Invention

[0018] The problem that the invention aims to solve

[0019] However, although the polyamide composition described in Patent Document 3 improves the elongation at break by reducing the amount of flame retardant used, there is still room for improvement in terms of long-term heat resistance required by automobiles and various electrical components.

[0020] In addition, although the polyamide composition described in Patent Document 4 reduces the amount of flame retardant used and reduces gas release by adding polyphenylene sulfide, there are concerns that it will be difficult to maintain the UL94 flammability rating of V-0 when the proportion of aliphatic polyamide relative to aromatic polyamide is increased.

[0021] It is evident that, in the existing technology, there is no known polyamide composition that uses halogen-free flame retardants and possesses both flame retardancy and long-term heat resistance.

[0022] The present invention was made in view of the above circumstances. The present invention provides a polyamide composition capable of producing molded articles containing a halogen-free flame retardant and exhibiting good flame retardancy and long-term heat resistance, a method for manufacturing the same, and molded articles comprising the above-described polyamide composition. Furthermore, the present invention provides a method for adding a styrene copolymer as a flame retardant additive.

[0023] means for solving problems

[0024] That is, the present invention includes the following methods.

[0025] The polyamide composition according to the first aspect of the present invention comprises: (A) polyamide, (B) phosphorus-containing flame retardant, and (C) styrene copolymer, wherein the content of (C) styrene copolymer is 0.1% by mass or more and 7.0% by mass or less relative to the total mass of the (A) polyamide, the (B) phosphorus-containing flame retardant, and the (C) styrene copolymer.

[0026] The (A) polyamide may contain (A1) aliphatic polyamide and (A2) semi-aromatic polyamide, wherein the (A2) semi-aromatic polyamide contains a diamine unit and a dicarboxylic acid unit.

[0027] The (A2) semi-aromatic polyamide may contain more than 50 mol% isophthalic acid units in all the dicarboxylic acid units constituting the (A2) semi-aromatic polyamide.

[0028] The (A2) semi-aromatic polyamide may contain more than 75 mol% isophthalic acid units in all the dicarboxylic acid units constituting the (A2) semi-aromatic polyamide.

[0029] The (A2) semi-aromatic polyamide may contain 100 mol% of isophthalic acid units in all the dicarboxylic acid units constituting the (A2) semi-aromatic polyamide.

[0030] The (C) styrene copolymer may contain acrylonitrile units and styrene units.

[0031] The (C) styrene copolymer may contain acrylonitrile units and styrene units, and the content of acrylonitrile units may be 30% by mass or more relative to the total mass of the constituent units of the (C) styrene copolymer.

[0032] The phosphorus-containing flame retardant (B) may contain at least one phosphonate selected from the group consisting of phosphonates represented by general formula (1), secondary phosphonates represented by general formula (2), and their condensates.

[0033]

[0034] (In general formula (1), R) 11 and R 12 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; M n11+A metal ion with a valence of n11; M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum; n11 is 2 or 3; when n11 is 2 or 3, multiple Rs exist. 11 and multiple R 12 They can be the same or different;

[0035] In general formula (2), R 21 and R 22 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; Y 21 It is an alkylene group having 1 or more but less than 10 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; M' x m21+ M' is a metal ion with a valence of m21; M' is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum; n21 is an integer greater than or equal to 1 and less than or equal to 3; when n21 is 2 or 3, multiple R's exist. 21 Multiple R 22 and multiple Y 21 Each can be the same or different; m21 is 2 or 3; x is 1 or 2; when x is 2, there are multiple M's that can be the same or different; n21, x and m21 are integers that satisfy the relation 2 × n21 = m21 × x).

[0036] The content of the phosphorus-containing flame retardant (B) may be more than 0.1% by mass and less than 30% by mass relative to the total mass of the polyamide (A), the phosphorus-containing flame retardant (B), and the styrene copolymer (C).

[0037] The tanδ peak temperature of the polyamide composition can be above 90°C.

[0038] The weight-average molecular weight of the polyamide composition can be above 10,000 and below 50,000.

[0039] The polyamide composition involved in the first method described above may further contain at least one (D) filler material.

[0040] The molded article according to the second aspect of the present invention is obtained by molding the polyamide composition according to the first aspect described above.

[0041] The method for manufacturing the polyamide composition according to the third aspect of the present invention is the same as the method for manufacturing the polyamide composition according to the first aspect, wherein the raw material components containing the (A) polyamide, the (B) phosphorus-containing flame retardant and the (C) styrene copolymer are melt-blended.

[0042] The fourth aspect of the present invention relates to a method of adding a styrene copolymer as a flame retardant additive to a resin composition containing polyamide and a phosphorus-containing flame retardant.

[0043] Invention Effects

[0044] According to the polyamide composition and manufacturing method described above, it is possible to obtain molded articles containing halogen-free flame retardants and exhibiting good flame retardancy and long-term heat resistance. Detailed Implementation

[0045] Hereinafter, a method for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail. This embodiment is merely an example for illustrating the present invention and is not intended to limit the invention to its contents. The present invention can be implemented with appropriate modifications within its scope.

[0046] It should be noted that, in this specification, "polyamide" refers to a polymer having an amide group (-NHCO-) ​​in its main chain.

[0047] Polyamide Compositions

[0048] The polyamide composition of this embodiment contains the following components (A) to (C).

[0049] (A) Polyamide;

[0050] (B) Phosphorus-containing flame retardants;

[0051] (C) Styrene copolymer.

[0052] In the polyamide composition of this embodiment, the content of component (C) is 0.1% by mass or more and 7% by mass or less relative to the total mass of components (A) to (C).

[0053] The polyamide composition of this embodiment, by having the above-described structure, can produce molded articles containing halogen-free flame retardants and exhibiting good flame retardancy and long-term heat resistance.

[0054] Properties of Polyamide Compositions

[0055] The molecular weight and tanδ peak temperature of the polyamide composition of this embodiment can be set as follows, and specifically, they can be measured by the method described in the examples below.

[0056] [Weight-average molecular weight (Mw) of the polyamide composition]

[0057] The weight-average molecular weight (Mw) can be used as an indicator of the molecular weight of a polyamide composition.

[0058] The weight-average molecular weight (Mw) of the polyamide composition is preferably 10,000 or more and 50,000 or less, more preferably 17,000 or more and 45,000 or less, even more preferably 20,000 or more and 45,000 or less, even more preferably 25,000 or more and 45,000 or less, particularly preferably 30,000 or more and 42,000 or less, and most preferably 34,000 or more and 38,000 or less.

[0059] By ensuring that the weight-average molecular weight (Mw) of the polyamide composition is within the aforementioned range, polyamide compositions with superior mechanical properties, particularly water absorption rigidity, thermal rigidity, and flowability, can be obtained. Furthermore, molded articles obtained from polyamide compositions containing components represented by (D) filler materials exhibit superior tensile strength and long-term heat resistance.

[0060] As a method for controlling the Mw of the polyamide composition within the above-mentioned range, examples include using (A) polyamide, (C) styrene copolymer, etc., where the Mw is within the range described below.

[0061] It should be noted that the determination of Mw (weight-average molecular weight) can be performed using GPC (gel permeation chromatography) as described in the examples below.

[0062] [Peak tanδ temperature of the polyamide composition]

[0063] The lower limit of the tanδ peak temperature of the polyamide composition is preferably 90°C, more preferably 105°C, and even more preferably 110°C.

[0064] On the other hand, the upper limit of the tanδ peak temperature of the polyamide composition is preferably 150°C, more preferably 140°C, and even more preferably 130°C.

[0065] That is, the tanδ peak temperature of the polyamide composition is preferably 90°C or higher and 150°C or lower, more preferably 105°C or higher and 140°C or lower, and even more preferably 110°C or higher and 130°C or lower.

[0066] When the tanδ peak temperature of the polyamide composition is above the aforementioned lower limit, there is a tendency to obtain a polyamide composition with superior water absorption rigidity and thermal rigidity. On the other hand, when the tanδ peak temperature of the polyamide composition is below the aforementioned upper limit, there is a tendency for molded articles obtained from polyamide compositions containing components represented by (D) filler materials to have superior tensile strength and long-term heat resistance.

[0067] As a method for controlling the tanδ peak temperature of the polyamide composition within the above-mentioned range, examples include: a method containing (A1) aliphatic polyamide and (A2) semi-aromatic polyamide, the (A2) semi-aromatic polyamide containing diamine units and dicarboxylic acid units, and controlling their contents within the range described below.

[0068] The following describes in detail the components of the polyamide composition of this embodiment.

[0069] <(A) Polyamide>

[0070] From the viewpoint of improving flame retardancy, weld strength and laser welding strength, the polyamide composition of this embodiment preferably contains (A) aliphatic polyamide and (A2) semi-aromatic polyamide, wherein the (A2) semi-aromatic polyamide contains a diamine unit and a dicarboxylic acid unit.

[0071] [(A1) Aliphatic polyamide]

[0072] (A1) The constituent units of aliphatic polyamide preferably satisfy at least one of the following conditions (1) and (2).

[0073] (1) Contains (A1-a) aliphatic dicarboxylic acid units and (A1-b) aliphatic diamine units.

[0074] (2) Contains at least one of the group consisting of (A1-c) selected from lactam units and aminocarboxylic acid units.

[0075] In the polyamide composition of this embodiment, the (A1) aliphatic polyamide may contain one or more polyamides that satisfy at least one of the conditions in (1) and (2) above. Among them, the constituent units of the (A1) aliphatic polyamide contained in the polyamide composition of this embodiment particularly preferably satisfy (1) above.

[0076] ((A1-a) aliphatic dicarboxylic acid unit)

[0077] Aliphatic dicarboxylic acids that constitute (A1-a) aliphatic dicarboxylic acid units include, for example, straight-chain or branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms.

[0078] As straight-chain saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms, they are not limited to the following substances, such as: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, diethylene glycol acid, etc.

[0079] As branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms, they are not limited to the following substances, such as: dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methylhexanoic acid, trimethylhexanoic acid, etc.

[0080] These aliphatic dicarboxylic acids that constitute the (A1-a) aliphatic dicarboxylic acid unit can be used alone or in combination of two or more.

[0081] Among them, the aliphatic dicarboxylic acid constituting the (A1-a) aliphatic dicarboxylic acid unit is preferably a straight-chain saturated aliphatic dicarboxylic acid with 6 or more carbon atoms, because it tends to have better heat resistance, flowability, toughness, low water absorption and rigidity of the polyamide composition.

[0082] Preferred straight-chain saturated aliphatic dicarboxylic acids with 6 or more carbon atoms include, for example: adipic acid, sebacic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, etc.

[0083] Among them, adipic acid, sebacic acid, or dodecanoic acid are preferred as straight-chain saturated aliphatic dicarboxylic acids with 6 or more carbon atoms, considering the heat resistance of the polyamide composition.

[0084] Furthermore, (A1) the aliphatic polyamide may, as needed, contain units derived from three or more polycarboxylic acids, without impairing the effect of the polyamide composition of this embodiment. Examples of three or more polycarboxylic acids include trimellitic acid, pyromellitic acid, and pyromellitic tetroxide. These three or more polycarboxylic acids may be used alone or in combination of two or more.

[0085] (A1-b) Aliphatic diamine unit

[0086] Examples of aliphatic diamines that constitute (A1-b) aliphatic diamine units include straight-chain saturated aliphatic diamines with 2 or more carbon atoms and 20 or fewer carbon atoms, or branched-chain saturated aliphatic diamines with 3 or more carbon atoms and 20 or fewer carbon atoms.

[0087] As a straight-chain saturated aliphatic diamine with 2 or more but less than 20 carbon atoms, it is not limited to the following substances, for example: ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, etc.

[0088] As a branched saturated aliphatic diamine with 3 or more but less than 20 carbon atoms, it is not limited to the following substances, for example: 2-methylpentamethylenediamine (also known as 2-methyl-1,5-diaminopentane), 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyl-1,8-octanediamine (also known as 2-methyloctamethylenediamine), 2,4-dimethyloctamethylenediamine, etc.

[0089] These aliphatic diamines that constitute the (A1-b) aliphatic diamine unit can be used alone or in combination of two or more.

[0090] The aliphatic diamine constituting the (A1-b) aliphatic diamine unit preferably has 6 or more and 12 or less carbon atoms, more preferably 6 or more and 10 or less. When the number of carbon atoms in the aliphatic diamine constituting the (A1-b) aliphatic diamine unit is at or above the aforementioned lower limit, the resulting molded article exhibits superior heat resistance. Conversely, when the number of carbon atoms in the aliphatic diamine constituting the (A1-b) aliphatic diamine unit is at or below the aforementioned upper limit, the resulting molded article exhibits superior crystallinity and mold release properties.

[0091] Preferred straight-chain or branched saturated aliphatic diamines with 6 or more but less than 12 carbon atoms include, for example, hexamethylenediamine, 2-methylpentamethylenediamine, and 2-methyl-1,8-octanediamine.

[0092] Among them, hexamethylenediamine or 2-methylpentamethylenediamine is preferred as a straight-chain or branched saturated aliphatic diamine with 6 or more but less than 12 carbon atoms. By containing such (A1-b) aliphatic diamine units, the molded articles obtained from the polyamide composition have better heat resistance and rigidity.

[0093] Furthermore, (A1) the aliphatic polyamide may, as needed, contain units derived from ternary or higher aliphatic polyamines without impairing the effects of the polyamide composition of this embodiment. Examples of ternary or higher aliphatic polyamines include bis(hexamethylene)triamine.

[0094] ((A1-c) is selected from at least one constituent unit of the group consisting of lactam units and aminocarboxylic acid units)

[0095] (A1) Aliphatic polyamides may contain at least one constituent unit selected from the group consisting of lactam units and aminocarboxylic acid units (A1-c). By containing such units, there is a tendency to obtain polyamides with excellent toughness.

[0096] It should be noted that the so-called "lactam unit" and "aminocarboxylic acid unit" here refer to lactams and aminocarboxylic acids that have undergone polymerization (condensation).

[0097] Lactams that constitute the lactam unit are not limited to the following substances, such as butyrolactam, valproic acid lactam, ε-caprolactam, octyl lactam, heptalactam, undecyllactam, laurolactam (dodecyllactam), etc.

[0098] Among these, the lactam constituting the lactam unit is preferably ε-caprolactam or laurolactam, more preferably ε-caprolactam. By containing such a lactam, the molded article obtained from the polyamide composition tends to have better toughness.

[0099] Aminocarboxylic acids that constitute an aminocarboxylic acid unit are not limited to the following substances, for example, ω-aminocarboxylic acids, α,ω-amino acids, etc., which are compounds obtained by ring opening of lactams.

[0100] The aminocarboxylic acid constituting the aminocarboxylic acid unit is preferably a straight-chain or branched saturated aliphatic carboxylic acid with 4 or more but less than 14 carbon atoms substituted at the ω-position. Such aminocarboxylic acids are not limited to the following substances, for example: 6-aminohexanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, etc. Additionally, p-aminomethylbenzoic acid, etc., can also be listed as an aminocarboxylic acid.

[0101] These constituents (A1-c) are selected from at least one of the constituent units consisting of lactam units and aminocarboxylic acid units. Each of the lactam and aminocarboxylic acid units may be used alone or in combination of two or more.

[0102] Among them, from the viewpoint of mechanical properties, heat resistance, formability and toughness, polyamides containing dicarboxylic acid units and diamine units are preferred as (A1) aliphatic polyamides, and polyamide 66 (PA66) is more preferred. PA66 has excellent mechanical properties, heat resistance, formability and toughness, and is therefore considered a suitable material for automotive parts.

[0103] The content of (A1) aliphatic polyamide relative to the total mass of polyamide in the polyamide composition may be set to, for example, 50% by mass or more and 100% by mass or less, or 55% by mass or more and 100% by mass or less, or 57% by mass or more and 100% by mass or less.

[0104] ((A1) Weight-average molecular weight Mw(A1))

[0105] The weight-average molecular weight (Mw(A1)) of the aliphatic polyamide can be used as an indicator of its molecular weight. The weight-average molecular weight (Mw(A1)) of the aliphatic polyamide is preferably 10,000 or more and 50,000 or less, more preferably 17,000 or more and 45,000 or less, further preferably 20,000 or more and 45,000 or less, even more preferably 25,000 or more and 45,000 or less, particularly preferably 30,000 or more and 45,000 or less, and most preferably 35,000 or more and 40,000 or less.

[0106] By ensuring that the weight-average molecular weight Mw (A1) is within the above range, polyamide compositions with superior mechanical properties, especially water absorption rigidity, thermal rigidity, flowability, tensile strength when molded, flexural modulus when absorbing water, long-term heat resistance, and electrical tracking resistance, can be obtained.

[0107] It should be noted that the weight-average molecular weight Mw(A1) can be determined using GPC as described in the examples below.

[0108] [(A2) Semi-aromatic polyamide]

[0109] (A2) Semi-aromatic polyamides are polyamides containing diamine units and dicarboxylic acid units.

[0110] Relative to all the constituent units of the (A2) semi-aromatic polyamide, the (A2) semi-aromatic polyamide preferably contains 20 mol% or more and 80 mol% or less of aromatic constituent units, more preferably 30 mol% or more and 70 mol% or less of aromatic constituent units, and even more preferably 40 mol% or more and 60 mol% or less of aromatic constituent units. Here, "aromatic constituent units" refers to aromatic diamine units and aromatic dicarboxylic acid units.

[0111] Furthermore, the (A2) semi-aromatic polyamide is preferably a polyamide containing (A2-a) dicarboxylic acid units and (A2-b) diamine units, wherein, relative to all the dicarboxylic acid units of the (A2) semi-aromatic polyamide, the (A2-a) dicarboxylic acid units contain more than 50 mol% isophthalic acid units, and the (A2-b) diamine units contain diamine units with 4 or more and 10 or fewer carbon atoms.

[0112] Furthermore, at this time, relative to all the constituent units of the (A2) semi-aromatic polyamide, the total content of isophthalic acid units and diamine units with 4 or more and 10 or less carbon atoms in the (A2) semi-aromatic polyamide is preferably 50 mol% or more, more preferably 80 mol% or more and 100 mol% or less, further preferably 90 mol% or more and 100 mol% or less, and particularly preferably 100 mol%.

[0113] It should be noted that the proportion of the specified monomer units constituting (A2) semi-aromatic polyamide can be determined by nuclear magnetic resonance spectroscopy (NMR) or similar methods.

[0114] ((A2-a) dicarboxylic acid unit)

[0115] There are no particular restrictions on what constitutes an (A2-a) dicarboxylic acid unit; for example, aromatic dicarboxylic acid units, aliphatic dicarboxylic acid units, and alicyclic dicarboxylic acid units can be listed.

[0116] Of which, as a (A2-a) dicarboxylic acid unit, relative to the total number of moles of (A2-a) dicarboxylic acid units, it is preferable to contain 50 mol% or more of isophthalic acid units, more preferably 65 mol% or more and 100 mol% or less of isophthalic acid units, even more preferably 75 mol% or more and 100 mol% or less of isophthalic acid units, particularly preferably 80 mol% or more and 100 mol% or less of isophthalic acid units, and most preferably 100 mol% of isophthalic acid units.

[0117] When the proportion of isophthalic acid units in the (A2-a) dicarboxylic acid units is above the aforementioned lower limit, there is a tendency to obtain polyamide compositions that simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, and flowability. Furthermore, molded articles obtained from polyamide compositions tend to exhibit superior tensile strength, flexural modulus of elasticity upon water absorption, long-term heat resistance, and electrical tracking resistance.

[0118] (1) Aromatic dicarboxylic acid unit

[0119] Aromatic dicarboxylic acids, which constitute aromatic dicarboxylic acid units other than isophthalic acid units, are not limited to the following substances; for example, dicarboxylic acids having aromatic groups such as phenyl or naphthyl groups can be listed. The aromatic groups of aromatic dicarboxylic acids may be unsubstituted or substituents.

[0120] There are no particular restrictions on the substituents, and examples include: alkyl groups with 1 or more and 4 or less carbon atoms, aryl groups with 6 or more and 10 or less carbon atoms, aralkyl groups with 7 or more and 10 or less carbon atoms, alkylaryl groups with 7 or more and 10 or less carbon atoms, halogen groups, silyl groups with 1 or more and 6 or less carbon atoms, sulfonic acid groups and their salts (sodium salts, etc.).

[0121] As an alkyl group having 1 or more but less than 4 carbon atoms, it is not limited to the following groups, for example: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc.

[0122] As an aryl group with 6 or more but less than 10 carbon atoms, it is not limited to the following groups, such as phenyl, naphthyl, etc.

[0123] Aryl groups having 7 or more but less than 10 carbon atoms are not limited to the following groups, for example, benzyl, etc.

[0124] As an alkylaryl group with 7 or more but less than 10 carbon atoms, it is not limited to the following groups, for example: tolyl, xylyl, etc.

[0125] As a halogen group, it is not limited to the following groups, for example: fluorine group, chlorine group, bromine group, iodine group, etc.

[0126] As a silyl group with 1 to 6 carbon atoms, it is not limited to the following groups, for example: trimethylsilyl, tert-butyldimethylsilyl, etc.

[0127] Among them, the aromatic dicarboxylic acid constituting the aromatic dicarboxylic acid unit other than the isophthalic acid unit is preferably an aromatic dicarboxylic acid with 8 or more and 20 or less unsubstituted carbon atoms or an aromatic dicarboxylic acid with 8 or more and 20 or less carbon atoms substituted by a specified substituent.

[0128] As an aromatic dicarboxylic acid with 8 or more and 20 or fewer unsubstituted carbon atoms, or an aromatic dicarboxylic acid with 8 or more and 20 or fewer carbon atoms substituted by a specified substituent, specifically, it is not limited to the following substances, for example: terephthalic acid, naphthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, sodium isophthalate-5-sulfonate, etc.

[0129] Aromatic dicarboxylic acids that make up an aromatic dicarboxylic acid unit can be used alone or in combination of two or more.

[0130] (2) Aliphatic dicarboxylic acid unit

[0131] Aliphatic dicarboxylic acids, which constitute aliphatic dicarboxylic acid units, can be listed as straight-chain or branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms.

[0132] As straight-chain saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms, they are not limited to the following substances, such as: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, diethylene glycol acid, etc.

[0133] As branched saturated aliphatic dicarboxylic acids with 3 or more but less than 20 carbon atoms, they are not limited to the following substances, such as: dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methylhexanoic acid, trimethylhexanoic acid, etc.

[0134] (3) Alicyclic dicarboxylic acid unit

[0135] Alicyclic dicarboxylic acids, which constitute alicyclic dicarboxylic acid units (hereinafter sometimes referred to as "alicyclic dicarboxylic acid units"), are not limited to the following substances, but may include, for example, alicyclic dicarboxylic acids with 3 or more but less than 10 carbon atoms in their alicyclic structure. Among these, alicyclic dicarboxylic acids with 5 or more but less than 10 carbon atoms in their alicyclic structure are preferred.

[0136] Such alicyclic dicarboxylic acids are not limited to the following substances, but may include, for example, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, etc. Among them, 1,4-cyclohexanedicarboxylic acid is preferred as an alicyclic dicarboxylic acid.

[0137] It should be noted that the alicyclic dicarboxylic acid units that make up the alicyclic dicarboxylic acid units can be used alone or in combination of two or more.

[0138] The alicyclic group in alicyclic dicarboxylic acids may be unsubstituted or substituent. Examples of substituents include alkyl groups having 1 or more but less than 4 carbon atoms. Examples of alkyl groups having 1 or more but less than 4 carbon atoms include groups that are the same as those exemplified in the "Aromatic Dicarboxylic Acid Units" section above.

[0139] As a dicarboxylic acid unit other than isophthalic acid unit, it is preferred to contain aromatic dicarboxylic acid unit, and more preferably contains aromatic dicarboxylic acid with 6 or more carbon atoms.

[0140] By using such dicarboxylic acids, it is possible to obtain polyamide compositions that simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, and flowability. Furthermore, molded articles obtained from polyamide compositions tend to exhibit superior tensile strength, flexural modulus during water absorption, long-term heat resistance, and electrical tracking resistance.

[0141] In (A2) semi-aromatic polyamides, the dicarboxylic acid constituting the (A2-a) dicarboxylic acid unit is not limited to the compounds described above as dicarboxylic acids, but may also be compounds equivalent to the dicarboxylic acids described above.

[0142] The term "compound equivalent to a dicarboxylic acid" as used herein refers to a compound whose structure is identical to that of the dicarboxylic acid derived from the aforementioned dicarboxylic acid. Such compounds are not limited to the following substances, but may include, for example, acid anhydrides of dicarboxylic acids and acyl halides of dicarboxylic acids.

[0143] In addition, (A2) the semi-aromatic polyamide may, as needed, contain units derived from ternary or more polycarboxylic acids, within the range that does not impair the effect of the polyamide composition of this embodiment.

[0144] Examples of polycarboxylic acids with three or more nucleotides include trimellitic acid, pyromellitic acid, and pyromellitic tetracarboxylic acid. These polycarboxylic acids with three or more nucleotides can be used individually or in combination of two or more.

[0145] ((A2-b)diamine unit)

[0146] There are no particular limitations on the (A2-b) diamine unit constituting the (A2) semi-aromatic polyamide, and examples include aromatic diamine units, aliphatic diamine units, and alicyclic diamine units. Among these, the (A2-b) diamine unit constituting the (A2) semi-aromatic polyamide preferably contains a diamine unit with 4 or more but less than 10 carbon atoms, and more preferably contains a diamine unit with 6 or more but less than 10 carbon atoms.

[0147] (1) Aliphatic diamine unit

[0148] Examples of aliphatic diamines that constitute aliphatic diamine units include straight-chain saturated aliphatic diamines with 4 or more but less than 20 carbon atoms.

[0149] As a straight-chain saturated aliphatic diamine with 4 or more but less than 20 carbon atoms, it is not limited to the following substances, for example: ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, etc.

[0150] (2) Alicyclic diamine unit

[0151] Alicyclic diamines (hereinafter sometimes referred to as "alicyclic diamines"), which constitute alicyclic diamine units, are not limited to the following substances, such as 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine, etc.

[0152] (3) Aromatic diamine unit

[0153] As a constituent aromatic diamine unit, an aromatic diamine is any diamine containing an aromatic group, and is not limited to the following substances. Specifically, examples of aromatic diamines include m-phenylenediamine.

[0154] It should be noted that the diamines that make up each diamine unit can be used alone or in combination of two or more.

[0155] Among them, the (A2-b) diamine unit is preferably an aliphatic diamine unit, more preferably a straight-chain saturated aliphatic diamine unit with 4 or more and 10 or less carbon atoms, even more preferably a straight-chain saturated aliphatic diamine unit with 6 or more and 10 or less carbon atoms, and particularly preferably a hexamethylenediamine unit.

[0156] By using such a diamine, it is possible to obtain polyamide compositions that simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, and flowability. Furthermore, molded articles obtained from polyamide compositions tend to exhibit superior tensile strength, flexural modulus during water absorption, long-term heat resistance, and electrical tracking resistance.

[0157] As a (A2) semi-aromatic polyamide, polyamide 6I (poly(hexamethylene isophthalamide),) polyamide 9I or polyamide 10I are preferred, with polyamide 6I being more preferred. Polyamide 6I has excellent heat resistance, processability and flame retardancy, and is therefore considered a suitable material for automotive parts.

[0158] The content of (A2) semi-aromatic polyamide relative to the total mass of polyamide in the polyamide composition can be set to 0% by mass or more and 50.0% by mass or less, preferably 10.0% by mass or more and 45.0% by mass or less, more preferably 15.0% by mass or more and 43.0% by mass or less, and even more preferably 20.0% by mass or more and 41.0% by mass or less.

[0159] By setting the content of (A2) semi-aromatic polyamide within the above-mentioned range, the molded articles obtained from the polyamide composition exhibit superior mechanical properties. Furthermore, by including components represented by (D) filler materials, the molded articles obtained from the polyamide composition tend to have superior tensile strength, flexural modulus of elasticity upon water absorption, long-term heat resistance, and electrical tracking resistance.

[0160] ((A2) Weight-average molecular weight Mw(A2) of semi-aromatic polyamides)

[0161] The weight-average molecular weight (Mw(A2)) can be used as an indicator of the molecular weight of the (A2) semi-aromatic polyamide. The weight-average molecular weight (Mw(A2)) of the semi-aromatic polyamide is preferably 10,000 or more and 50,000 or less, more preferably 15,000 or more and 45,000 or less, even more preferably 15,000 or more and 40,000 or less, even more preferably 17,000 or more and 30,000 or less, particularly preferably 17,000 or more and 25,000 or less, and most preferably 18,000 or more and 22,000 or less.

[0162] By ensuring that the weight-average molecular weight Mw(A2) is within the above range, polyamide compositions with superior mechanical properties, especially water absorption rigidity, thermal rigidity, flowability, tensile strength when molded, flexural modulus when absorbing water, long-term heat resistance and electrical tracking resistance, can be obtained.

[0163] It should be noted that the weight-average molecular weight Mw(A2) can be determined using GPC as described in the examples below.

[0164] [End-capping agent]

[0165] The ends of the (A) polyamide contained in the polyamide composition of this embodiment can be capped using a known capping agent.

[0166] When polyamides are manufactured from the above-mentioned dicarboxylic acids and diamines, or from at least one of the groups selected from the above-mentioned lactams and aminocarboxylic acids, such end-capping agents may also be added as molecular weight regulators.

[0167] End-capping agents are not limited to the following substances, but may include: monocarboxylic acids, monoamines, acid anhydrides (phthalic anhydride, etc.), monoisocyanates, monoesters, monohydric alcohols, etc. A single end-capping agent can be used alone, or two or more can be used in combination.

[0168] Among these, monocarboxylic acids or monoamines are preferred as end-capping agents. By using end-capping agents to end the polyamide, the molded articles obtained from the polyamide compositions tend to have better thermal stability.

[0169] Any monocarboxylic acid that can be used as a capping agent is a substance that is reactive with an amino group that may be present at the end of a polyamide. Monocarboxylic acids are not limited to the following substances, but may include: aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids, etc.

[0170] Examples of aliphatic monocarboxylic acids include: formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, tertralic acid, isobutyric acid, etc.

[0171] Examples of alicyclic monocarboxylic acids include cyclohexanecarboxylic acid.

[0172] Examples of aromatic monocarboxylic acids include benzoic acid, toluene, α-naphthoic acid, β-naphthoic acid, methylnaphthoic acid, and phenylacetic acid.

[0173] These monocarboxylic acids can be used alone or in combination of two or more.

[0174] In particular, from the viewpoint of fluidity and mechanical strength, the ends of (A2) semi-aromatic polyamides are preferably capped with acetic acid.

[0175] As a monoamine that can be used as a capping agent, any substance that is reactive with the carboxyl group that may be present at the end of the polyamide can be used. Monoamines are not limited to the following substances, for example: aliphatic monoamines, alicyclic monoamines, aromatic monoamines, etc.

[0176] Examples of aliphatic monoamines include: methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, etc.

[0177] Examples of alicyclic monoamines include cyclohexylamine and dicyclohexylamine.

[0178] Examples of aromatic monoamines include aniline, toluidine, diphenylamine, and naphthylamine.

[0179] These monoamines can be used alone or in combination of two or more.

[0180] Polyamide compositions containing polyamides that have been capped with end-capping agents tend to have superior heat resistance, flowability, toughness, low water absorption, and rigidity.

[0181] <(A) Method for manufacturing polyamide>

[0182] When manufacturing the polyamide composition of this embodiment containing (A) polyamide ((A1) aliphatic polyamide and (A2) semi-aromatic polyamide), the amount of dicarboxylic acid added and the amount of diamine added are preferably about the same molar amount. Regarding the molar ratio, considering the portion of the diamine that escapes from the reaction system during the polymerization reaction, the molar amount of all diamine relative to the total molar amount of all dicarboxylic acid is preferably 0.9 or more and 1.2 or less, more preferably 0.95 or more and 1.1 or less, and even more preferably 0.98 or more and 1.05 or less.

[0183] The method of manufacturing polyamide is not limited to the following methods, such as the polymerization steps including (1) or (2) below.

[0184] (1) A process of polymerizing a combination of a dicarboxylic acid constituting a dicarboxylic acid unit and a diamine constituting a diamine unit to obtain a polymer.

[0185] (2) A process of polymerizing one or more of the group consisting of lactams constituting lactam units and aminocarboxylic acids constituting aminocarboxylic acid units to obtain a polymer.

[0186] Furthermore, as a method for manufacturing polyamide, it is preferable to include an increasing step after the above-described polymerization step to raise the degree of polymerization of the polyamide. Additionally, if necessary, an end-capping step may be included after the above-described polymerization step and the above-described increasing step to end the ends of the obtained polymer using an end-capping agent.

[0187] Specific methods for manufacturing polyamides include, for example, various methods illustrated in 1) to 4) below.

[0188] 1) A method of polymerizing an aqueous solution or aqueous suspension of one or more selected from the group consisting of dicarboxylic acid-diamine salts, mixtures of dicarboxylic acids and diamines, lactams and aminocarboxylic acids by heating while maintaining the molten state (hereinafter, sometimes referred to as "thermal melt polymerization").

[0189] 2) A method for increasing the degree of polymerization of polyamide obtained by hot melt polymerization at a temperature below its melting point while maintaining it in a solid state (hereinafter sometimes referred to as "hot melt polymerization / solid phase polymerization").

[0190] 3) A method of polymerizing one or more of the group consisting of dicarboxylic acid-diamine salts, mixtures of dicarboxylic acids and diamines, lactams and aminocarboxylic acids while maintaining a solid state (hereinafter, sometimes referred to as "solid-state polymerization").

[0191] 4) A method that uses a dicarboxylic acid acyl halide component equivalent to a dicarboxylic acid and a diamine component and polymerizes them (hereinafter, sometimes referred to as the "solution method").

[0192] Of these, a preferred method for manufacturing polyamide is a hot melt polymerization method. Furthermore, when manufacturing polyamide using hot melt polymerization, it is preferable to maintain the molten state until polymerization is complete. To maintain the molten state, manufacturing must be carried out under polymerization conditions suitable for the polyamide composition. Examples of polymerization conditions include those shown below. First, the polymerization pressure in the hot melt polymerization method is controlled at 14 kg / cm². 2 Above and 25kg / cm 2 Continue heating at the following gauge pressure. Then, depressurize for at least 30 minutes until the pressure inside the tank reaches atmospheric pressure (gauge pressure 0 kg / cm²). 2 ).

[0193] In the manufacturing process of polyamide, there are no particular restrictions on the polymerization method; it can be either batch or continuous.

[0194] There are no particular restrictions on the polymerization apparatus used in the manufacture of polyamides, and known apparatus can be used. Specifically, examples of polymerization apparatus include, for instance, autoclave reactors, drum reactors, and extruder-type reactors (kneaders, etc.).

[0195] The following describes a method for manufacturing polyamide using a batch hot melt polymerization method, but the method for manufacturing polyamide is not limited to this.

[0196] First, an aqueous solution containing at least 40% by mass and less than 60% by mass of a polyamide raw material component (a combination of dicarboxylic acids and diamines, and at least one selected from the group consisting of lactams and aminocarboxylic acids, as needed) is prepared. Next, the aqueous solution is concentrated in a concentration tank at a temperature of at least 110°C and less than 180°C and a pressure of at least 0.035 MPa and less than 0.6 MPa (gauge pressure) to obtain a concentrated solution.

[0197] Next, the obtained concentrated solution is transferred to an autoclave and heated until the pressure in the autoclave reaches about 1.2 MPa or higher and about 2.2 MPa or lower (gauge pressure).

[0198] Next, in the autoclave, while removing at least one of the water and gas components, the pressure is maintained at approximately 1.2 MPa or higher and approximately 2.2 MPa or lower (gauge pressure). Then, when the temperature reaches approximately 220°C or higher and approximately 260°C, the pressure is reduced to atmospheric pressure (gauge pressure 0 MPa). After reducing the pressure inside the autoclave to atmospheric pressure, further depressurization is performed as needed, thereby effectively removing water as a byproduct.

[0199] Next, the autoclave is pressurized using inert gases such as nitrogen, and the polyamide molten material is extruded from the autoclave in the form of wire. The extruded wire is cooled and cut to obtain polyamide granules.

[0200] <(A) Properties of Polyamide>

[0201] [(A) Polymer ends of polyamide]

[0202] The polymer terminus of (A) polyamide contained in the polyamide composition of this embodiment is not particularly limited and can be classified and defined as 1) to 4) below.

[0203] That is, 1) amino terminus, 2) carboxyl terminus, 3) terminus formed by end-capping agent, and 4) other terminus.

[0204] 1) The amino terminus is a polymer terminus with an amino (-NH2 group) and is derived from a diamine unit.

[0205] 2) The carboxyl terminus is a polymer terminus with a carboxyl group (-COOH group) and is derived from a dicarboxylic acid unit.

[0206] 3) The end formed by the end-capping agent is the end formed when an end-capping agent is added during polymerization. The end-capping agents mentioned above can be listed as examples.

[0207] 4) Other ends are polymer ends that are not classified as 1) to 3) above. Specifically, other ends can be listed as: ends generated by deamination of the amino terminus, ends generated by decarboxylation of the carboxyl terminus, etc.

[0208] [(A) Weight-average molecular weight of polyamide, Mw(A)]

[0209] The weight-average molecular weight (Mw(A)) of the polyamide can be used as an indicator of its molecular weight. The weight-average molecular weight (Mw(A)) of the polyamide is preferably 12,000 or more and 44,000 or less, more preferably 17,500 or more and 40,000 or less, further preferably 20,000 or more and 40,000 or less, even more preferably 24,000 or more and 40,000 or less, particularly preferably 28,000 or more and 37,500 or less, and most preferably 32,000 or more and 36,000 or less.

[0210] By ensuring that the weight-average molecular weight Mw(A) is within the above range, polyamide compositions with superior flame retardancy, long-term heat resistance, weld strength, and laser welding strength can be obtained.

[0211] It should be noted that the weight-average molecular weight Mw(A) can be determined using GPC as described in the examples below.

[0212] <(B) Phosphorus-containing flame retardants>

[0213] As for the phosphorus-containing flame retardant (B) contained in the polyamide composition of this embodiment, there are no particular limitations as long as it contains phosphorus and does not contain halogens. Examples of phosphorus-containing flame retardants (B) include: phosphate ester flame retardants, melamine polyphosphate flame retardants, phosphazene flame retardants, phosphonic acid flame retardants, red phosphorus flame retardants, etc.

[0214] Among them, as (B) phosphorus-containing flame retardant, it is preferably a phosphate ester flame retardant, a melamine polyphosphate flame retardant, a phosphazene flame retardant or a phosphonic acid flame retardant, and is particularly preferably a phosphonic acid flame retardant.

[0215] As a phosphonic acid flame retardant, specifically, it may include, for example, at least one phosphonate selected from the group consisting of phosphonates represented by the following general formula (1) (hereinafter sometimes simply referred to as "phosphonate (1)"), secondary phosphonates represented by the following general formula (2) (hereinafter sometimes simply referred to as "secondary phosphonate (2)"), and their condensates.

[0216]

[0217] (In general formula (1), R) 11 and R 12 Each is independently an alkyl group having 1 or more but 6 or fewer carbon atoms, or an aryl group having 6 or more but 10 or fewer carbon atoms. M n11+ A metal ion with a valence of n11. M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n11 is 2 or 3. When n11 is 2 or 3, multiple R ions exist. 11 and multiple R 12 They can be the same or different.

[0218] In general formula (2), R 21 and R 22 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms. 21 It is an alkylene group having 1 or more but less than 10 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms. M' m21+ A metal ion with a valence of m21. M' is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n21 is an integer greater than or equal to 1 and less than or equal to 3. When n21 is 2 or 3, multiple R's exist. 21 Multiple R 22 and multiple Y 21 Each can be the same or different. m21 is 2 or 3. x is 1 or 2. When x is 2, there are multiple M's that can be the same or different. n21, x, and m21 are integers that satisfy the relation 2 × n21 = m21 × x.

[0219] [R 11 R 12 R 21 and R 22 ]

[0220] R 11 R 12 R 21and R 22 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms. When n11 is 2 or 3, multiple R groups exist. 11 and multiple R 12 They can be the same or different, but from the point of view of ease of manufacture, it is preferable to be the same. Furthermore, when n21 is 2 or 3, there are multiple R... 21 and multiple R 22 They can be the same or different, but from the point of view of ease of manufacturing, it is preferable to be the same.

[0221] As an alkyl group, it can be chain-like or cyclic, but chain-like is preferred. As a chain-like alkyl group, it can be straight-chain or branched. Examples of straight-chain alkyl groups include: methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, etc. Examples of branched alkyl groups include: 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, etc.

[0222] Examples of aryl groups include phenyl and naphthyl groups.

[0223] Alkyl and aryl groups can have substituents. Examples of substituents on alkyl groups include aryl groups with 6 or more but less than 10 carbon atoms. Examples of substituents on aryl groups include alkyl groups with 1 or more but less than 6 carbon atoms.

[0224] Alkyl groups with substituents, specifically, examples include benzyl and the like.

[0225] Aryl groups with substituents include, for example, tolyl and xylyl.

[0226] Among them, as R 11 R 12 R 21 and R 22 Preferably, it is an alkyl group with 1 or more but less than 6 carbon atoms, and more preferably methyl or ethyl.

[0227] [Y 21 ]

[0228] Y 21It is an alkylene group having 1 or more but less than 10 carbon atoms, or an arylene group having 6 or more but less than 10 carbon atoms. When n21 is 2 or 3, multiple Y atoms exist. 21 They can be the same or different, but from the point of view of ease of manufacturing, it is preferable to be the same.

[0229] The alkylene group can be chain-like or cyclic, but chain-like is preferred. The chain-like alkylene group can be straight-chain or branched. Examples of straight-chain alkylene groups include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene. Examples of branched alkylene groups include 1-methylethylene and 1-methylpropylene.

[0230] Examples of aryl groups include phenylene and naphthylene.

[0231] Alkylenes and arylenes may have substituents. Examples of substituents on alkylenes include aryl groups with 6 or more but less than 10 carbon atoms. Examples of substituents on arylenes include alkyl groups with 1 or more but less than 6 carbon atoms.

[0232] As alkylene groups with substituents, examples include: phenylmethylene, phenylethylene, phenyltrimethylene, phenyltetramethylene, etc.

[0233] As arylene groups with substituents, examples include: methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene, tert-butylnaphthylene, etc.

[0234] Among them, as Y 21 Preferably, it is an alkylene group with 1 or more but less than 10 carbon atoms, and more preferably a methylene or ethylene group.

[0235] [M and M']

[0236] M and M' are each independently an ion belonging to either Group 2 or Group 15 of the periodic table, an ion of a transition element, a zinc ion, or an aluminum ion. Examples of ions belonging to Group 2 include calcium ions and magnesium ions. Examples of ions belonging to Group 15 include bismuth ions.

[0237] Furthermore, when x is 2, the multiple M's can be the same or different, but from the point of view of ease of manufacture, it is preferable that they are the same.

[0238] Among them, calcium, zinc or aluminum are preferred as M and M', and calcium or aluminum are more preferred.

[0239] [x]

[0240] x represents the number of M's, which can be 1 or 2. x can be appropriately selected based on the type of M' and the amount of secondary phosphonic acid.

[0241] [n11 and n21]

[0242] n11 represents the number of phosphonic acids and the valence of M, and n11 can be 2 or 3. n11 can be appropriately selected according to the type and valence of M.

[0243] n21 represents the number of secondary phosphonic acids, and n21 is an integer greater than 1 and less than 3. n21 can be appropriately selected according to the type and quantity of M'.

[0244] [m21]

[0245] m21 represents the valence of M', where m21 is 2 or 3.

[0246] n21, x, and m21 are integers that satisfy the relation 2 × n21 = m21 × x.

[0247] Preferred phosphine salts (1) include, for example: calcium dimethyl phosphine, magnesium dimethyl phosphine, aluminum dimethyl phosphine, zinc dimethyl phosphine, calcium methyl ethyl phosphine, magnesium methyl ethyl phosphine, aluminum methyl ethyl phosphine, zinc methyl ethyl phosphine, calcium diethyl phosphine, magnesium diethyl phosphine, aluminum diethyl phosphine, zinc diethyl phosphine, calcium methyl n-propyl phosphine, magnesium methyl n-propyl phosphine, aluminum methyl n-propyl phosphine, zinc methyl n-propyl phosphine, methanedi(methyl phosphine) Calcium dimethylphosphine, magnesium dimethylphosphine, aluminum dimethylphosphine, zinc dimethylphosphine, calcium phenyl-1,4-(dimethylphosphine), magnesium phenyl-1,4-(dimethylphosphine), aluminum phenyl-1,4-(dimethylphosphine), zinc phenyl-1,4-(dimethylphosphine), calcium methylphenylphosphine, magnesium methylphenylphosphine, aluminum methylphenylphosphine, zinc methylphenylphosphine, calcium diphenylphosphine, magnesium diphenylphosphine, aluminum diphenylphosphine, zinc diphenylphosphine, etc. Among these, calcium dimethylphosphine or aluminum dimethylphosphine are particularly preferred as phosphinates (1) from the viewpoint of excellent flame retardancy.

[0248] Preferred secondary phosphonates (2) include, for example, calcium methanedi(methylphosphonic acid), magnesium methanedi(methylphosphonic acid), aluminum methanedi(methylphosphonic acid), zinc methanedi(methylphosphonic acid), calcium benzene-1,4-di(methylphosphonic acid), magnesium benzene-1,4-di(methylphosphonic acid), aluminum benzene-1,4-di(methylphosphonic acid), zinc benzene-1,4-di(methylphosphonic acid), etc.

[0249] There are no particular limitations on the methods for manufacturing hypophosphates; for example, methods described in Patent Documents 5, 6, and 7 can be cited. Specifically, they are manufactured using hypophosphonic acid and metal carbonates, metal hydroxides, or metal oxides in an aqueous solution. Although these hypophosphates are essentially monomeric compounds, depending on the reaction conditions and the environment, they sometimes also include polymeric hypophosphates as condensates with a degree of condensation of 1 or more and 3 or less.

[0250] Relative to the total mass of (A) polyamide, (B) phosphorus-containing flame retardant and (C) styrene copolymer, the content of (B) phosphorus-containing flame retardant is preferably 0.1% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 30% by mass or less, even more preferably 10% by mass or more and 29% by mass or less, and particularly preferably 15% by mass or more and 29% by mass or less.

[0251] By setting the content of phosphorus-containing flame retardant (B) to the lower limit or above mentioned above, a polyamide composition with superior flame retardancy can be obtained. On the other hand, by setting the amount of phosphorus-containing flame retardant (B) to the upper limit or below mentioned above, a polyamide composition with superior flame retardancy can be obtained without impairing the properties of the polyamide copolymer.

[0252] <(C)Styrene copolymer>

[0253] The (C) styrene copolymer contained in the polyamide composition of this embodiment refers to a styrene copolymer containing styrene at a content of 10% by mass or more. Specifically, examples of (C) styrene copolymers include: styrene-acrylonitrile copolymers (AS resins), copolymers of styrene monomers with maleimide monomers such as maleimide and N-phenylmaleimide, and copolymers with acrylamide monomers such as acrylamide. Furthermore, copolymers obtained by replacing a portion of the styrene in a styrene polymer with monomers such as α-methylstyrene, p-methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, p-tert-butylstyrene, ethylstyrene, and vinylnaphthalene may also be used. From the viewpoint of excellent flame retardancy and long-term heat resistance, styrene-acrylonitrile copolymers (AS resins) having both styrene and acrylonitrile units are preferred as (C) styrene copolymers. AS resins with an acrylonitrile unit content of 30% by mass or more relative to the total mass of the constituent units of the (C) styrene copolymer are particularly preferred, and AS resins with an acrylonitrile unit content of 35% by mass or more relative to the total mass of the constituent units of the (C) styrene copolymer are especially preferred.

[0254] The addition of styrene copolymer improves fluidity and enhances the dispersibility of the flame retardant, suggesting that a strong and dense char (a carbonized layer formed during combustion) can be formed during combustion, thus improving flame retardancy. Furthermore, the addition of styrene copolymer also improves fluidity and enhances the dispersibility of the heat stabilizer, suggesting that the free radical scavenging efficiency of the heat stabilizer is improved, leading to enhanced long-term heat resistance.

[0255] Relative to the total mass of (A) polyamide, (B) phosphorus-containing flame retardant and (C) styrene copolymer, the content of (C) styrene copolymer is 0.1% by mass or more and 7% by mass or less, preferably 0.5% by mass or more and 6% by mass or less, more preferably 1% by mass or more and 5% by mass or less, and even more preferably 1% by mass or more and 3% by mass or less.

[0256] By setting the content of (C) styrene copolymer within the above range, a polyamide composition with excellent flame retardancy and good weld strength and long-term heat resistance when made into molded articles can be obtained.

[0257] [(C) Weight-average molecular weight of styrene copolymers, Mw(C)]

[0258] The weight-average molecular weight (Mw(C)) of the (C) styrene copolymer can be used as an indicator of its molecular weight. The weight-average molecular weight (Mw(C)) of the (C) styrene copolymer is preferably 50,000 or more and 220,000 or less, more preferably 50,000 or more and 150,000 or less, even more preferably 70,000 or more and 150,000 or less, and most preferably 70,000 or more and 100,000 or less.

[0259] By ensuring that the weight-average molecular weight Mw(C) is within the above range, a polyamide composition that combines flame retardancy with weld strength and long-term heat resistance when molded into articles can be obtained.

[0260] It should be noted that the weight-average molecular weight Mw can be determined using GPC as described in the examples below.

[0261] <(D) Filling Material>

[0262] In addition to the components (A) to (C) described above, the polyamide composition of this embodiment may also contain filler material (D). By including filler material (D), a polyamide composition with superior mechanical properties such as toughness and rigidity can be obtained.

[0263] The filler material (D) contained in the polyamide composition of this embodiment is not particularly limited, and examples include: glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, flake glass, talc, kaolin, mica, hydrotalcite, zinc carbonate, dicalcium phosphate, wollastonite, zeolite, boehmite, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, Ketjen black, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swelling fluoromica, apatite, etc.

[0264] These (D) filler materials can be used alone or in combination of two or more.

[0265] Among these, from the viewpoint of rigidity and strength, glass fiber, carbon fiber, flake glass, talc, kaolin, mica, dicalcium phosphate, wollastonite, carbon nanotubes, graphite, calcium fluoride, montmorillonite, swelling fluoromica, or apatite are preferred as filler materials for (D). Furthermore, glass fiber or carbon fiber are more preferred as filler materials for (D), and glass fiber is even more preferred.

[0266] When the filler material (D) is glass fiber or carbon fiber, the number-average fiber diameter (D) is preferably 3 μm or more and 30 μm or less. Furthermore, the weight-average fiber length (L) is preferably 100 μm or more and 750 μm or less. In addition, the aspect ratio ((L) / (D)) of the weight-average fiber length (L) to the number-average fiber diameter (D) is preferably 10 or more and 100 or less. By using glass fiber or carbon fiber with the above-described structure, superior properties can be exhibited.

[0267] (D) The number-average fiber diameter and weight-average fiber length of the filler material can be determined using the following methods.

[0268] First, the molded polyamide composition is dissolved using a solvent such as formic acid that can dissolve polyamide. Next, at least 100 filler materials are arbitrarily selected from the obtained insoluble components. Then, the filler materials can be determined by observing them using an optical microscope, scanning electron microscope, or similar means.

[0269] The content of (D) filler material in the polyamide composition is preferably 1% or more and 80% or less by mass relative to the total mass of the polyamide composition, more preferably 10% or more and 70% or less by mass, further preferably 15% or more and 60% or less by mass, particularly preferably 20% or more and 55% or less by mass, and most preferably 25% or more and 50% or less by mass.

[0270] When the content of filler material (D) is above the aforementioned lower limit, the mechanical properties of the polyamide composition, such as strength and rigidity, tend to be further improved. On the other hand, when the content of filler material (D) is below the aforementioned upper limit, the polyamide composition tends to have superior laser welding strength.

[0271] In particular, (D) the filler material is glass fiber, and the content of (D) the filler material is within the above range relative to the total mass of the polyamide composition, thereby tending to further improve the mechanical properties of the polyamide composition, such as strength and rigidity.

[0272] <(E) Other Additives>

[0273] In addition to the components (A) to (C) described above, the polyamide composition of this embodiment may also contain other additives commonly used in polyamides (E), within a range that does not impair the effect of the polyamide composition of this embodiment. Examples of other additives (E) include: (E1) molding modifiers, (E2) degradation inhibitors, (E3) nucleating agents, and (E4) heat stabilizers.

[0274] The content of other additives (E) in the polyamide composition of this embodiment varies depending on their type, the application of the polyamide composition, etc., and therefore there are no particular limitations as long as they do not impair the effect of the polyamide composition of this embodiment.

[0275] [(E1) Molding property modifier]

[0276] There are no particular limitations on the (E1) molding modifier contained in the polyamide composition of this embodiment, and examples include: higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, higher fatty acid amides, etc. It should be noted that the molding modifier is also used as a "lubricating material".

[0277] (Higher fatty acids)

[0278] Examples of higher fatty acids include linear or branched saturated or unsaturated aliphatic monocarboxylic acids with 8 or more but less than 40 carbon atoms.

[0279] Examples of straight-chain saturated aliphatic monocarboxylic acids with 8 or more carbon atoms and less than 40 include: lauric acid, palmitic acid, stearic acid, behenic acid, and linalic acid.

[0280] Examples of branched saturated aliphatic monocarboxylic acids with 8 or more carbon atoms and less than 40 include isopalmitic acid and isostearic acid.

[0281] Examples of linear unsaturated aliphatic monocarboxylic acids with 8 or more but less than 40 carbon atoms include oleic acid and erucic acid.

[0282] Examples of branched unsaturated aliphatic monocarboxylic acids with 8 or more carbon atoms and less than 40 include isoleic acid.

[0283] Among them, stearic acid or linalic acid are preferred as higher fatty acids.

[0284] (Higher fatty acid metal salts)

[0285] Metal salts of higher fatty acids refer to metal salts of higher fatty acids.

[0286] Metallic elements that can be used as metal salts include, for example, elements in Group 1, Group 2 and Group 3 of the periodic table, zinc, aluminum, etc.

[0287] Elements that are in Group 1 of the periodic table include, for example, sodium and potassium.

[0288] Elements that are in Group 2 of the periodic table include, for example, calcium and magnesium.

[0289] Elements that are in Group 3 of the periodic table include, for example, scandium and yttrium.

[0290] The preferred elements are elements from Group 1 and Group 2 of the periodic table or aluminum, and more preferably sodium, potassium, calcium, magnesium or aluminum.

[0291] As higher fatty acid metal salts, specific examples include: calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium lignite, sodium lignite, calcium palmitate, etc.

[0292] Among them, lignite metal salt or stearate metal salt are preferred as higher fatty acid metal salts.

[0293] (Higher fatty acid esters)

[0294] Higher fatty acid esters refer to esterifications of higher fatty acids and alcohols.

[0295] As higher fatty acid esters, esters of aliphatic carboxylic acids with 8 or more carbon atoms and aliphatic alcohols with 8 or more carbon atoms and 40 or fewer carbon atoms are preferred.

[0296] Examples of aliphatic alcohols with 8 or more but less than 40 carbon atoms include stearyl alcohol, sorbitol, and lauryl alcohol.

[0297] As higher fatty acid esters, specifically, examples include stearate stearate and behenate behenate.

[0298] (Advanced fatty acid amides)

[0299] Higher fatty acid amides refer to amide compounds of higher fatty acids.

[0300] Examples of high-grade fatty acid amides include: stearamide, oleamide, mustardamide, ethylene bis-stearamide, ethylene bis-oleamide, N-stearyl stearamide, N-stearyl mustardamide, etc.

[0301] These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides can each be used alone or in combination of two or more.

[0302] [(E2) Degradation Inhibitor]

[0303] The (E2) degradation inhibitor contained in the polyamide composition of this embodiment is used for the purpose of preventing thermal degradation, thermal discoloration and improving heat aging resistance.

[0304] As (E2) degradation inhibitors, there are no particular limitations. Examples include: copper compounds, phenolic stabilizers, phosphite stabilizers, hindered amine stabilizers, triazine stabilizers, benzotriazole stabilizers, benzophenone stabilizers, cyanoacrylate stabilizers, salicylate stabilizers, sulfur-containing stabilizers, etc.

[0305] Examples of copper compounds include copper acetate and cuprous iodide.

[0306] Examples of phenolic stabilizers include hindered phenolic compounds.

[0307] These (E2) degradation inhibitors can be used alone or in combination of two or more.

[0308] [(E3) nucleating agent]

[0309] (E3) Nucleating agent refers to a substance that, by addition, achieves at least one of the following effects (1) to (3).

[0310] (1) Effect of increasing the crystallization peak temperature of the polyamide composition.

[0311] (2) The effect of reducing the difference between the extrapolation start temperature and the extrapolation end temperature of the crystallization peak.

[0312] (3) To achieve the effect of miniaturizing or homogenizing the size of the spherulites in the molded product.

[0313] As (E3) nucleating agents, substances are not limited to the following, such as talc, boron nitride, mica, kaolin, silicon nitride, carbon black, potassium titanate, molybdenum disulfide, etc.

[0314] (E3) Nucleating agents can be used alone or in combination of two or more.

[0315] Among them, talc or boron nitride are preferred as (E3) nucleating agents from the viewpoint of nucleating agent effectiveness.

[0316] In addition, the number-average particle size of the (E3) nucleating agent is preferably 0.01 μm or more and 10 μm or less, because the nucleating agent has a high efficiency.

[0317] The number-average particle size of the nucleating agent can be determined using the following method. First, the molded article is dissolved in a solvent that can dissolve polyamide, such as formic acid. Next, arbitrarily select, for example, more than 100 nucleating agents from the resulting insoluble components. Then, the particle size can be determined by observing and measuring it using an optical microscope, scanning electron microscope, or similar method.

[0318] Relative to 100 parts by weight of polyamide ((A1) aliphatic polyamide and (A2) semi-aromatic polyamide), the nucleating agent content in the polyamide composition of this embodiment is preferably 0.001 parts by weight or more and 1 part by weight or less, more preferably 0.001 parts by weight or more and 0.5 parts by weight or less, and even more preferably 0.001 parts by weight or more and 0.09 parts by weight or less.

[0319] By setting the nucleating agent content to the lower limit or above relative to 100 parts by mass of polyamide, the heat resistance of the polyamide composition tends to be further improved. In addition, by setting the nucleating agent content to the upper limit or below relative to 100 parts by mass of polyamide, a polyamide composition with better toughness can be obtained.

[0320] [(E4) Heat stabilizer]

[0321] As (E4) heat stabilizers, they are not limited to the following substances, such as: phenolic heat stabilizers, phosphorus-containing heat stabilizers, amine heat stabilizers, and metal salts of elements in Groups 3, 4 and 11-14 of the periodic table.

[0322] (Phenolic heat stabilizers)

[0323] As a heat stabilizer for phenols, it is not limited to the following substances, such as hindered phenolic compounds. Hindered phenolic compounds have the property of imparting excellent heat resistance and light resistance to resins or fibers such as polyamides.

[0324] As hindered phenolic compounds, not limited to the following substances, examples include: N,N'-hexane-1,6-dimethylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), pentaerythritol tetratetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoamide), triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 3, 9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, etc.

[0325] These hindered phenolic compounds can be used alone or in combination of two or more.

[0326] When using phenolic heat stabilizers, the content of phenolic heat stabilizers in the polyamide composition is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, relative to the total mass of the polyamide composition.

[0327] When the content of phenolic heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the amount of gas generated can be further reduced.

[0328] (Phosphorus-containing heat stabilizer)

[0329] As a phosphorus-containing heat stabilizer, it is not limited to the following substances, but can include, for example: pentaerythritol-type phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, diphenyl octyl phosphite, triisodecyl phosphite, diisodecyl phosphite, di(tetrazyl) phosphite, isooctyl diphenyl phosphite, isodecyl diphenyl phosphite, triphenyl diphenyl phosphite, tri(tetrazyl) phosphite, tri(nonylphenyl) phosphite, tri(2,4-di-tert-butylphenyl) phosphite, and tri(2,4-di-tert-butyl-5-methylphenyl) phosphite. Tris(butoxyethyl) phosphite, 4,4'-butylenebis(3-methyl-6-tert-butylphenyl) diphosphite-tetra(tetrazyl) ester, 4,4'-isopropyl diphenyl phosphite-tetra(C12-C15 mixed alkyl) ester, 4,4'-isopropyl bis(2-tert-butylphenyl) phosphite-di(nonylphenyl) ester, tris(biphenyl) phosphite, 1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite-tetra(tetrazyl) ester, 4,4'-butylenebis(3-methyl-6-tert-butylphenyl) diphosphite-tetra(tetrazyl) ester 4,4'-isopropyl diphenyl phosphite-tetra(C1-C15 mixed alkyl) ester, tri(mono, di-mixed nonylphenyl) phosphite, 4,4'-isopropyl bis(2-tert-butylphenyl) phosphite-di(nonylphenyl) ester, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tri(3,5-di-tert-butyl-4-hydroxyphenyl) ester, hydrogenated 4,4'-isopropyl diphenyl polyphosphite, bis(4,4'-butylidene bis(3-methyl-6-tert-butylphenyl))-1,6-hexanediol diphosphite di(octylphenyl) ester, 1,1,3 Tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite hexa(tetrazyl) ester, tris(4,4'-isopropylidene bis(2-tert-butylphenyl)) ester, tris(1,3-stearoyloxyisopropyl) ester, octyl ester of 2,2-methylene bis(4,6-di-tert-butylphenyl) ester, 2-ethylhexyl ester of 2,2-methylene bis(3-methyl-4,6-di-tert-butylphenyl) ester, tetratetra(2,4-di-tert-butyl-5-methylphenyl) ester of 4,4'-biphenylene diphosphite, and tetratetra(2,4-di-tert-butylphenyl) ester, etc.

[0330] These phosphorus-containing heat stabilizers can be used alone or in combination of two or more.

[0331] As a pentaerythritol-type phosphite compound, it is not limited to the following substances, but can include, for example: pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-phenyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-methyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-2-ethylhexyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-isodecyl ester, pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-lauryl ester. Esters, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-isotridecyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-stearyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-cyclohexyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-benzyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-ethyl cellosolve ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl Ester-Butyl carbitol ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-octylphenyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-nonylphenyl ester, Pentaerythritol diphosphite di(2,6-di-tert-butyl-4-methylphenyl) ester, Pentaerythritol diphosphite di(2,6-di-tert-butyl-4-ethylphenyl) ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester-2,6-di-tert-butylphenyl ester, Pentaerythritol diphosphite 2,6-di-tert-butyl-4-methylphenyl ester Butyl-4-methylphenyl ester-2,4-di-tert-butylphenyl ester, pentaerythritol diphosphite ester 2,6-di-tert-butyl-4-methylphenyl ester-2,4-di-tert-octylphenyl ester, pentaerythritol diphosphite ester 2,6-di-tert-butyl-4-methylphenyl ester-2-cyclohexylphenyl ester, pentaerythritol diphosphite ester 2,6-di-tert-pentyl-4-methylphenyl ester-phenyl ester, pentaerythritol diphosphite ester di(2,6-di-tert-pentyl-4-methylphenyl) ester, pentaerythritol diphosphite ester di(2,6-di-tert-octyl-4-methylphenyl) ester, etc.

[0332] These pentaerythritol-type phosphite compounds can be used alone or in combination of two or more.

[0333] When using a phosphorus-containing heat stabilizer, the content of the phosphorus-containing heat stabilizer in the polyamide composition is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, relative to the total mass of the polyamide composition.

[0334] When the content of phosphorus-containing heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the amount of gas generated can be further reduced.

[0335] (Amine heat stabilizers)

[0336] As a heat stabilizer for amines, it is not limited to the following substances, but also includes, for example: 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(phenylacetoxy)-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2 2,6,6-Tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4-(ethylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(cyclohexylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, 4-(phenylcarbamoyloxy)-2,2,6,6-tetramethylpiperidine, di(2,2,6,6-tetramethyl-4-piperidinyl) carbonate, di(2,2,6,6-tetramethyl-4-piperidinyl) oxalate, di(2,2,6,6-tetramethyl-4-piperidinyl) malonate, di(2,2,6,6-tetramethyl-4-piperidinyl) sebacate Piperidinyl ester, di(2,2,6,6-tetramethyl-4-piperidinyl) adipic acid ester, di(2,2,6,6-tetramethyl-4-piperidinyl) ester of terephthalate, 1,2-bis(2,2,6,6-tetramethyl-4-piperidoxy)ethane, α,α'-bis(2,2,6,6-tetramethyl-4-piperidoxy)p-xylene, di(2,2,6,6-tetramethyl-4-piperidinyl) ester of toluene-2,4-dicarboxylate, di(2,2,6,6-tetramethyl-4-piperidinyl) hexamethylene-1,6-dicarboxylate, tri(2,2,6,6-tetramethyl-4-piperidinyl) ester of phenyl-1,3,5-tricarboxylate, Condensates of 6-tetramethyl-4-piperidinyl ester, tris(2,2,6,6-tetramethyl-4-piperidinyl) ester of phenyl-1,3,4-tricarboxylic acid, 1-[2-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy}butyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-2,2,6,6-tetramethylpiperidin, condensates of 1,2,3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethanol, etc.

[0337] These amine heat stabilizers can be used alone or in combination of two or more.

[0338] When using amine heat stabilizers, the content of amine heat stabilizers in the polyamide composition is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, relative to the total mass of the polyamide composition.

[0339] When the content of amine heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the amount of gas generated can be further reduced.

[0340] (Metal salts of elements in Groups 3, 4, and 11–14 of the periodic table)

[0341] There are no restrictions on whether the metal salts are salts of elements belonging to Groups 3, 4, and 11-14 of the periodic table.

[0342] From the viewpoint of further improving the heat aging resistance of the polyamide composition, copper salts are preferred. The copper salt is not limited to the following substances, but may include, for example: copper acetate, copper propionate, copper benzoate, copper adipic acid, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, and copper complex salts obtained by coordination of copper with a chelating agent.

[0343] Examples of chelating agents include ethylenediamine and ethylenediaminetetraacetic acid.

[0344] These copper salts can be used alone or in combination of two or more.

[0345] Copper acetate is preferred as the copper salt. When using copper acetate, a polyamide composition with better heat aging resistance and more effective suppression of metal corrosion (hereinafter sometimes simply referred to as "metal corrosion") of the screw or barrel during extrusion can be obtained.

[0346] When copper salt is used as the (E4) heat stabilizer, the content of copper salt in the polyamide composition is preferably 0.01% by mass or more and 0.60% by mass or less relative to the total mass of (A) polyamide, more preferably 0.02% by mass or more and 0.40% by mass or less.

[0347] When the copper salt content is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the precipitation of copper and metal corrosion can be more effectively inhibited.

[0348] Furthermore, from the viewpoint of improving the heat aging resistance of the polyamide composition, compared to (A) polyamide 10 6The concentration of copper element in the copper salt is preferably 10 parts by mass or more and 2,000 parts by mass or less, more preferably 30 parts by mass or more and 1,500 parts by mass or less, and even more preferably 50 parts by mass or more and 500 parts by mass or less, per 1,000 parts by mass.

[0349] The components of the (E4) heat stabilizer described above can be used alone or in combination of two or more.

[0350] Methods for manufacturing polyamide compositions

[0351] The method for manufacturing the polyamide composition of this embodiment is not particularly limited as long as it is a method of mixing (A) polyamide with each of the above-mentioned components (B) to (C) and each of the required components (D) and (E).

[0352] As for the mixing methods of the components (A) to (C) above, and the components (D) and (E) as needed, the following methods (1) or (2) can be listed as examples.

[0353] (1) A method of mixing the components (A) to (C) above, as well as the components (D) and (E) as needed, using a Henschel mixer or the like, and feeding them to a melt mixer for mixing.

[0354] (2) A mixture containing components (A) to (C) and component (E) as needed is prepared by mixing the components (A) to (C) above and the required component (E) in advance using a Henschel mixer or the like, the mixture is fed to a melt mixer and kneaded, and then component (D) is optionally fed by a side feeder using a single screw or twin screw extruder.

[0355] Regarding the method of supplying the components constituting the polyamide composition to the melt mixer, all the components can be supplied at once from the same supply port, or the components can be supplied separately from different supply ports.

[0356] When (A) polyamide contains (A1) aliphatic polyamide, the melt mixing temperature is preferably a temperature that is about 1°C higher than the melting point of (A1) aliphatic polyamide and about 100°C lower, and more preferably a temperature that is about 10°C higher than the melting point of (A1) aliphatic polyamide and about 50°C lower.

[0357] The preferred shearing speed in the mixer is approximately 100 seconds. -1 That's all. Additionally, the average dwell time during mixed practice is preferably between approximately 0.5 minutes and 5 minutes.

[0358] The apparatus used for melt mixing can be any known apparatus, such as a single-screw or twin-screw extruder, a Banbury internal mixer, a melt mixing mill (mixing rollers, etc.).

[0359] The proportions of each component in the polyamide composition of this embodiment are the same as the proportions of each component in the polyamide composition described above.

[0360] Molded Products

[0361] The molded article of this embodiment is obtained by molding the polyamide composition of the above embodiment.

[0362] The molded article of this embodiment contains halogen-free flame retardant and has excellent flame retardancy and long-term heat resistance.

[0363] There are no particular restrictions on the method for obtaining the molded article; well-known molding methods can be used.

[0364] Commonly known molding methods include, for example: extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, heterogeneous material molding, gas-assisted injection molding, foam injection molding, low-pressure molding, ultra-thin wall injection molding (ultra-high speed injection molding), and in-mold composite molding (insert molding, injection molding on substrate), etc.

[0365] <Applications>

[0366] The molded article of this embodiment contains the polyamide composition of the above embodiment and has excellent flame retardancy and long-term heat resistance, and can be used for various purposes.

[0367] As for the applications of the molded articles of this embodiment, they can be suitable for use in the automotive, electrical and electronic, machinery and industrial, office equipment, and aerospace fields.

[0368] Adding Method

[0369] The method of this embodiment involves adding (C) a styrene copolymer as a flame retardant additive to a resin composition containing (A) polyamide and (B) a phosphorus-containing flame retardant. As described above, by adding (C) a styrene copolymer to the resin composition containing (A) polyamide and (B) a phosphorus-containing flame retardant, the fluidity of the resin composition is improved, and the dispersibility of (B) a phosphorus-containing flame retardant becomes better. Therefore, it is speculated that a strong and dense char (a carbonized layer formed through combustion) can be formed during combustion, thus improving flame retardancy. In addition, by adding (C) a styrene copolymer to the resin composition containing (A) polyamide and (B) a phosphorus-containing flame retardant, the fluidity of the resin composition is improved, and the dispersibility of the heat stabilizer becomes better. Therefore, it is speculated that the free radical scavenging efficiency of the heat stabilizer is improved, and the long-term heat resistance is improved.

[0370] In addition to components (A) and (B), the above-described resin composition may also contain components (D) and (E). Regarding components (A) to (E), examples may be found that are identical to those exemplified in the above-described polyamide composition.

[0371] [Example]

[0372] The present invention will now be described in detail with specific embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0373] The components of the polyamide compositions used in this embodiment and comparative example will be described below.

[0374] <Components>

[0375] [(A1) Aliphatic polyamide]

[0376] A1-1: Polyamide 66

[0377] [(A2) Semi-aromatic polyamide]

[0378] A2-1: Polyamide 6I

[0379] A2-2: Polyamide 6I / 6T (manufactured by EMS, model: G21, isophthalic acid unit content in all dicarboxylic acid units is 70 mol%, molecular weight: 27000)

[0380] (B) Phosphorus-containing flame retardants

[0381] B-1: Phosphine-based flame retardant diethyl phosphinate (manufactured by Clariant, trade name: "Exolit OP1230")

[0382] B-2: Diethylphosphonic acid flame retardant calcium diethylphosphonate (manufactured by Taiping Chemical Industry Co., Ltd.)

[0383] [(B') Flame retardants other than phosphorus-containing flame retardants]

[0384] B'-1: Melamine cyanurate, a nitrogen-containing flame retardant (manufactured by Nissan Chemical Industries, Ltd.)

[0385] [(C) Styrene copolymer]

[0386] C-1: Styrene-acrylonitrile copolymer (AS) (manufactured by Asahi Kasei Corporation) (acrylonitrile content: 40% by mass, molecular weight: 80,000)

[0387] C-2: Styrene-acrylonitrile copolymer (AS) (manufactured by Asahi Kasei Corporation) (acrylonitrile content: 25% by mass, molecular weight: 140,000)

[0388] C-3: Styrene-acrylonitrile copolymer (AS) (manufactured by Asahi Kasei Corporation) (acrylonitrile content: 30% by mass, molecular weight: 130,000)

[0389] [(D) Filling material]

[0390] D-1: Glass fiber (GF) (manufactured by Nippon Electric Glass, trade name: "ECS03T275H", average fiber diameter: 10μmφ, cutting length: 3mm)

[0391] [(E) Other Additives]

[0392] E-1: Phenolic heat stabilizer (manufactured by Ciba Specialty Chemicals, trade name "Irganox 1098")

[0393] <Manufacturing of Polyamides>

[0394] The manufacturing methods of aliphatic polyamide A1-1 and semi-aromatic polyamide A2-1 are described in detail below. It should be noted that the aliphatic polyamide A1-1 and semi-aromatic polyamide A2-1 obtained by the manufacturing methods described below are dried in a nitrogen stream to adjust the moisture content to about 0.2% by mass, and then used as raw materials for the polyamide compositions in the examples and comparative examples described later.

[0395] [Synthetic Example 1] Synthesis of Aliphatic Polyamide A1-1 (Polyamide 66)

[0396] The polymerization reaction of polyamide was carried out using the "thermal melt polymerization method" as described below.

[0397] First, 1500g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500g of distilled water to prepare a homogeneous aqueous solution of 50% by mass of the raw monomers. This aqueous solution was then placed in a 5.4L autoclave and purged with nitrogen. Next, while stirring at a temperature above approximately 110°C and below approximately 150°C, water vapor was slowly vented to concentrate the solution to a concentration of 70% by mass. The internal temperature was then raised to 220°C. At this point, the autoclave was pressurized to 1.8 MPa. This pressure was maintained for 1 hour until the internal temperature reached 245°C, and the reaction continued for 1 hour while slowly venting water vapor and maintaining the pressure at 1.8 MPa. The pressure was then reduced for 1 hour. Finally, the autoclave was maintained at a reduced pressure of 650 Torr (86.66 kPa) for 10 minutes using a vacuum device. At this point, the final internal temperature of the polymerization was 265°C. Next, nitrogen gas is used to pressurize the material and form it into a filament from the lower spinneret (nozzle). This filament is then water-cooled, cut, and discharged as granules. The granules are then dried at 100°C under a nitrogen atmosphere for 12 hours to obtain aliphatic polyamide A1-1 (polyamide 66).

[0398] The Mw(A1) of the obtained aliphatic polyamide A1-1 (polyamide 66) is 40000.

[0399] [Synthetic Example 2] Synthesis of semi-aromatic polyamide A2-1 (polyamide 6I)

[0400] The polymerization reaction of polyamide was carried out using the "thermal melt polymerization method" as described below.

[0401] First, 1500 g of an equimolar salt of isophthalic acid and hexamethylenediamine, along with 1.5 mol% excess adipic acid relative to the total equimolar salt composition and 0.5 mol% acetic acid, were dissolved in 1500 g of distilled water to prepare a homogeneous aqueous solution of the raw monomers at an equimolar 50% by mass. Next, while stirring at a temperature above approximately 110°C and below approximately 150°C, the solution was concentrated to a concentration of 70% by mass by slowly venting water vapor. Then, the internal temperature was raised to 220°C. At this point, the autoclave was pressurized to 1.8 MPa. This pressure was maintained for 1 hour until the internal temperature reached 245°C, and the reaction continued for 1 hour while slowly venting water vapor and maintaining the pressure at 1.8 MPa. Next, the pressure was reduced over 30 minutes. Then, the autoclave was maintained at a reduced pressure of 650 Torr (86.66 kPa) for 10 minutes using a vacuum device. At this point, the final internal temperature of the polymerization was 265°C. Next, nitrogen gas is used to pressurize the material and form it into a filament from the lower spinneret (nozzle). This filament is then water-cooled, cut, and discharged as granules. The granules are then dried at 100°C under a nitrogen atmosphere for 12 hours to obtain semi-aromatic polyamide A2-1 (polyamide 6I).

[0402] The obtained semi-aromatic polyamide A2-1 (polyamide 6I) has an isophthalic acid unit content of 100 mol% in the dicarboxylic acid unit, and Mw(A2) = 20000.

[0403] <Physical Properties and Evaluation>

[0404] First, the granules of the polyamide compositions obtained in the examples and comparative examples were dried in a nitrogen stream to adjust the moisture content of the polyamide compositions to below 500 ppm. Then, using the granules of each polyamide composition with adjusted moisture content, various physical properties were measured and evaluated using the methods described below.

[0405] [Physical Property 1] tanδ Peak Temperature

[0406] Using a PS40E injection molding machine manufactured by Nissei Kogyo Co., Ltd., the barrel temperature was set to 290°C and the mold temperature to 100°C. The injection molding process was carried out according to JIS-K7139, with an injection time of 10 seconds and a cooling time of 10 seconds. The molded product was then measured using a dynamic viscoelasticity evaluation device (GABO EPLEXOR500N) under the following conditions.

[0407] (Measurement conditions)

[0408] Measurement mode: Tension

[0409] Measurement frequency: 8.00Hz

[0410] Heating rate: 3℃ / minute

[0411] Temperature range: above -100℃ and below 250℃

[0412] The ratio of the loss elastic modulus E2 to the energy storage elastic modulus E1 (E2 / E1) is set as tanδ, and the highest temperature is set as the tanδ peak temperature.

[0413] [Physical Property 2] Molecular Weight (Mw) of the Polyamide Composition

[0414] The weight-average molecular weight (Mw) of the polyamide compositions obtained in the Examples and Comparative Examples was determined using GPC under the following test conditions.

[0415] (Measurement conditions)

[0416] Measuring device: HLC-8020, manufactured by Tosoh Corporation.

[0417] Solvent: Hexafluoroisopropanol

[0418] Standard sample: PMMA (polymethyl methacrylate) (manufactured by Polymer Labs) conversion

[0419] GPC pillars: TSK-GEL GMHHR-M and G1000HHR

[0420] [Evaluation 1] Flame retardancy

[0421] The tests were conducted using the UL94 method (a standard established by Underwriters Laboratories, Inc.). It should be noted that the test pieces (127 mm in length, 12.7 mm in width, and 1.6 mm in thickness) were fabricated as follows: A mold for the UL test piece was mounted on an injection molding machine (PS40E manufactured by Nissei Kogyo Co., Ltd.) with a mold temperature of 100°C, and each polyamide composition was molded at a barrel temperature of 290°C. The injection pressure was set at the full filling pressure used when molding the UL test piece plus 2%. The flame retardancy rating was evaluated according to the UL94 standard (vertical burning test) to determine if it was equivalent to any one of the V-0, V-1, or V-2 ratings. It should be noted that the lower the rating number, the higher the flame retardancy.

[0422] [Evaluation 2] Weld strength

[0423] Test pieces were obtained using an injection molding machine (Nissei Kogyo Co., Ltd. PS40E) equipped with a mold in which molten resin flows from both ends along the length of a shape measuring 127 mm in length, 12.7 mm in width, and 1.6 mm in thickness, and a weld seam is to be formed in the center along the length. Specific molding conditions were as follows: injection + holding time set to 25 seconds, cooling time set to 15 seconds, mold temperature set to 80°C, and molten resin temperature set to the melt peak temperature (Tm2) of the high-temperature side of the polyamide + 20°C. Except for setting the clamping distance to 50 mm and the pulling speed to 50 mm / min, tensile tests were performed on the molded test pieces according to ASTM D638, and the tensile strength was determined.

[0424] [Evaluation 3] Long-term heat resistance

[0425] The multi-purpose test piece (Type A) with the above tensile strength was heated at 120°C in a hot air circulating oven to achieve thermal aging.

[0426] After being placed in the oven for 1000 hours, the specimens were removed and cooled at 23°C for at least 24 hours. Then, tensile tests were performed on the cooled multipurpose test specimens (Type A) according to ISO 527 and at a pulling speed of 5 mm / min using the same method as described above, and the tensile strengths were determined. The heat aging retention rate was calculated using the following formula.

[0427] Heat resistance aging retention rate (%) = Tensile strength after aging / Tensile strength before aging × 100

[0428] [Evaluation 4] Laser welding strength

[0429] Laser welding coloring masterbatch (Orient Chemical Industry: eBIND ACW-9871, hereinafter referred to as ACW) was dry-mixed with various polyamide resin compositions at a dilution ratio of 60 times. A 60mm × 60mm × 2.0mm thick plate was formed and then cut into 28mm × 60mm × 2.0mm thick plates to produce component A. The specific molding conditions were: the mold temperature was set to 80℃, and the molten resin temperature was set to the melt peak temperature (Tm2) of the high-temperature side of the polyamide + 20℃.

[0430] In addition, relative to 100 parts by weight of polyamide resin composition, 1500 ppm of carbon black (with a primary particle size of 27 nm) was dry-mixed to form a 60 mm × 60 mm × 2.0 mm thick plate, which was then cut into 25 mm × 60 mm × 2.0 mm thick plates to produce component B.

[0431] With component A and component B fixed in a manner that overlaps by 20mm along the long side of each component, and under the conditions of a scanning speed of 50.0mm / second and an output power of 150W, the welding head of the laser welding machine is used to irradiate the test piece from one end to the other, starting from one side of component A and parallel to the short side of the test piece, while air is used to cool this part, thus creating the test piece.

[0432] Using a universal testing machine manufactured by Instron Corporation and a 30kN force sensor, the two ends of component A and component B of the test piece were clamped between the clamps. The test piece was subjected to a tensile test under the test conditions of a clamping distance of 30mm and a pulling speed of 5.0mm / min, and the maximum point load was measured.

[0433] <Preparation of Polyamide Compositions>

[0434] [Example 1]

[0435] Using a TEM35mm twin-screw extruder (set temperature: 280°C, screw speed: 300 rpm) manufactured by Toshiba Machine Co., Ltd., a mixture of (A) polyamide A-1, (C) styrene copolymer C-1, and (E) other additives E-1 was supplied through a top feed port located at the very top of the extruder. Additionally, (B) phosphorus-containing flame retardant B-1 and (D) filler D-1 were supplied through a side feed port on the downstream side of the extruder (where the resin supplied from the top feed port was fully molten). The molten compound extruded from the die was then cooled in a filament and granulated to obtain granules of the polyamide composition. The proportions are shown in Table 1.

[0436] Furthermore, using the obtained polyamide composition granules, molded articles were manufactured by the above method, and various physical properties were measured and evaluated. The evaluation results are shown in Table 1.

[0437] [Examples 2-12, Comparative Examples 1-6]

[0438] Regarding components (A) to (E), the composition shown in Table 1 was used, except that they were manufactured using the same method as in Example 1. The evaluation results are shown in Tables 1 and 2. It should be noted that in Table 2, "ND" is an abbreviation for No Data, indicating that the strength of the prepared test piece was too low to be measured.

[0439]

[0440]

[0441] As shown in Table 1, polyamide compositions (Examples 1-12) containing (A) polyamide, (B) phosphorus-containing flame retardant and (C) styrene copolymer, and in which the content of (C) styrene copolymer relative to the total mass of components (A) to (C) is in the range of 0.1% by mass or more and 7% by mass or less, yielded molded articles that can combine flame retardancy and long-term heat resistance.

[0442] In addition, for polyamide compositions containing (A1) aliphatic polyamide A1-1 and (A2) semi-aromatic polyamide A2-1 or A2-2 (Examples 2 to 12), the resulting molded articles have particularly good laser welding strength.

[0443] In addition, polyamide compositions containing high acrylonitrile content styrene copolymer C-1 (Examples 2, 3, 6-10) yielded molded articles with particularly good flame retardancy and long-term heat resistance.

[0444] On the other hand, polyamide compositions (Comparative Examples 1-6) that do not contain (C) styrene copolymer or contain more than 7% by mass of (C) styrene copolymer relative to the total mass of components (A) to (C) did not produce molded articles that could combine flame retardancy and long-term heat resistance.

[0445] As can be seen from the above, the polyamide composition according to this embodiment can yield a molded article containing a halogen-free flame retardant and possessing both flame retardancy and long-term heat resistance.

[0446] [Industry Applicability]

[0447] According to the polyamide composition of this embodiment, molded articles containing halogen-free flame retardants and possessing both flame retardancy and long-term heat resistance can be obtained. The molded articles of this embodiment are suitable for use in the automotive, electrical and electronic, machinery and industrial, office equipment, and aerospace industries.

Claims

1. A polyamide composition comprising: (A) Polyamide, (B) Phosphorus-containing flame retardants, and (C) Styrene copolymer, wherein The content of the styrene copolymer (C) is 0.1% by mass or more and 7.0% by mass or less, relative to the total mass of the polyamide (A), the phosphorus-containing flame retardant (B), and the styrene copolymer (C). The (A) polyamide contains (A1) aliphatic polyamide and (A2) semi-aromatic polyamide, wherein the (A2) semi-aromatic polyamide contains a diamine unit and a dicarboxylic acid unit. The (A2) semi-aromatic polyamide contains more than 75 mol% isophthalic acid units in all the dicarboxylic acid units constituting the (A2) semi-aromatic polyamide.

2. The polyamide composition according to claim 1, wherein, The (A2) semi-aromatic polyamide contains 100 mol% isophthalic acid units in all the dicarboxylic acid units constituting the (A2) semi-aromatic polyamide.

3. The polyamide composition according to claim 1 or 2, wherein, The (C) styrene copolymer contains acrylonitrile units and styrene units.

4. The polyamide composition according to claim 1 or 2, wherein, The (C) styrene copolymer contains acrylonitrile units and styrene units, and The content of the acrylonitrile unit is 30% by mass or more relative to the total mass of the constituent units of the (C) styrene copolymer.

5. The polyamide composition according to claim 1 or 2, wherein, The phosphorus-containing flame retardant (B) contains at least one phosphonate selected from the group consisting of phosphonates represented by general formula (1), secondary phosphonates represented by general formula (2), and their condensates. In general formula (1), R 11 and R 12 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; M n11+ The metal ion is n11; M is an element belonging to Group IIA or Group VA of the periodic table, a transition element, or aluminum; n11 is 2 or 3; when n11 is 2 or 3, multiple R exist. 11 and multiple R 12 They are the same or different; In general formula (2), R 21 and R 22 Each is independently an alkyl group having 1 or more but less than 6 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; Y 21 It is an alkylene group having 1 or more but less than 10 carbon atoms, or an aryl group having 6 or more but less than 10 carbon atoms; M' x m21+ M' is a metal ion with a valence of m21; M' is an element belonging to Group IIA or Group VA of the periodic table, a transition element, or aluminum; n21 is an integer greater than or equal to 1 and less than or equal to 3; when n21 is 2 or 3, there are multiple R's. 21 Multiple R 22 and multiple Y 21 Each can be the same or different; m21 is 2 or 3; x is 1 or 2; when x is 2, there are multiple M' that are the same or different; n21, x and m21 are integers that satisfy the relation 2×n21=m21×x.

6. The polyamide composition according to claim 1 or 2, wherein, The content of the phosphorus-containing flame retardant (B) is 0.1% by mass or more and 30% by mass or less relative to the total mass of the polyamide (A), the phosphorus-containing flame retardant (B), and the styrene copolymer (C).

7. The polyamide composition according to claim 1 or 2, wherein, The polyamide composition has a tanδ peak temperature of 90°C or higher.

8. The polyamide composition according to claim 1 or 2, wherein, The polyamide composition has a weight-average molecular weight of 10,000 or more and 50,000 or less.

9. The polyamide composition according to claim 1 or 2, wherein, The polyamide composition also contains at least one (D) filler material.

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

11. A method for manufacturing a polyamide composition, comprising the method for manufacturing the polyamide composition according to any one of claims 1 to 9, wherein, The raw material components containing (A) polyamide, (B) phosphorus-containing flame retardant and (C) styrene copolymer are melt-blended.

12. A method, wherein, Styrene copolymers are added as flame retardant additives to resin compositions containing polyamides and phosphorus-containing flame retardants. The content of the styrene copolymer is 0.1% by mass or more and 7.0% by mass or less relative to the total mass of the polyamide, the phosphorus-containing flame retardant, and the styrene copolymer. The polyamide contains (A1) aliphatic polyamide and (A2) semi-aromatic polyamide, wherein the (A2) semi-aromatic polyamide contains a diamine unit and a dicarboxylic acid unit. The (A2) semi-aromatic polyamide contains more than 75 mol% isophthalic acid units in all the dicarboxylic acid units constituting the (A2) semi-aromatic polyamide.

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