Polyamide composition, method for producing the same, and molded article

Abstract

The present invention relates to a polyamide composition, a method for producing the same, and a molded article. The present invention provides a polyamide composition that does not contain halogen, has excellent flame retardancy, and has good long-term heat resistance when formed into a molded article. A polyamide composition comprising: (A) an aliphatic polyamide; (B) a semi-aromatic polyamide containing diamine units and dicarboxylic acid units; (C) at least one phosphinate selected from the group consisting of phosphinates represented by the following general formula (1), phosphinates represented by the following general formula (2), and condensates thereof; and (D) a polymer having an oxygen index of 27% or more and having an aromatic group in the main chain, wherein the content of the polymer (D) is 0.1% by mass or more and 8% by mass or less based on the total mass of the aliphatic polyamide (A), the semi-aromatic polyamide (B), the phosphinates (C), and the polymer (D).

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of September 24, 2019 and an application number of 201910903204.9. Technical Field

[0002] The present invention relates to a polyamide composition, a method for manufacturing the same, and a molded article Background Art

[0003] Compositions based on aliphatic polyamides have excellent characteristic properties and are therefore used to manufacture molded articles in a very large number of applications. In particular, in order to ensure appropriate fire protection, polyamide compositions having flame retardant properties are essential for components in the electrical and electronic industries.

[0004] Polyamides are often flame retardant treated by adding halogen compounds. However, recently, various regulations have been established in accordance with harmful substance regulations such as RoHS (Restriction of Hazardous Substances Directive) and PoHS (Prohibition of Certain Hazardous Substances in Consumer Products) so that products containing halogen-containing compounds are not used in electrical and electronic components. Therefore, various halogen-free flame retardants for polyamides have been developed.

[0005] As the halogen-free flame retardant, for example, a phosphorus compound can be cited. In Patent Document 1, the use of calcium salts and aluminum salts of phosphinic acid or diphosphinic acid as flame retardants for polyamides is disclosed. A test piece having a specimen thickness of 1.2 mm manufactured from a polyamide composition containing these halogen-free flame retardants and reinforced with glass fiber at 30% by mass based on the total mass of the composition reaches a flammability rating of V-0 based on UL94.

[0006] In order to achieve a flammability rating of V-0 according to UL94, Patent Document 2 discloses that: in a glass fiber-reinforced polyamide composition having polyamide 6 as a main component, an amount of aluminum phosphinate far greater than 20% by mass based on the total mass of the composition is required; in a glass fiber-reinforced polyamide composition having polyamide 66 as a main component, more than 30% by mass of aluminum phosphinate is required. It can be seen that in order to achieve a flammability rating of V-0 using phosphinic acid-based flame retardants, a large amount must be added, and thus it becomes a problem that the mechanical properties are adversely affected.

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

[0008] In addition, Patent Document 4 discloses a polyamide composition using a phosphinate as a flame retardant and based on a mixture of a polyamide containing an aromatic polyamide and polyphenylene sulfide. It is reported that by adding polyphenylene sulfide with excellent flame retardancy to the polyamide containing an aromatic polyamide, the amount of the flame retardant used can be reduced, and the amount of outgassing from the flame retardant can be reduced.

[0009] Prior art documents

[0010] Patent documents

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

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

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

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

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

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

[0017] Patent Document 7: Japanese Patent Application Laid-Open No. 08-073720 Summary of the invention

[0018] Problems to be solved by the invention

[0019] However, although the polyamide composition described in Patent Document 3 improves the tensile elongation at break by reducing the amount of the flame retardant used, there is still room for improvement in terms of the flexural modulus of elasticity and long-term heat resistance under the atmospheric equilibrium moisture absorption required for automotive and various electrical components.

[0020] In addition, although the polyamide composition described in Patent Document 4 reduces the amount of the flame retardant used and reduces outgassing by adding polyphenylene sulfide, there are the following problems: when increasing the proportion of the aliphatic polyamide relative to the aromatic polyamide, it is difficult to maintain the flammability classification V-0 based on UL94. In addition, there is particular concern about the deterioration of the CTI (Comparative Tracking Index) required for electrical components.

[0021] Therefore, in the prior art, a polyamide composition that does not contain halogens, has excellent flame retardancy, and has good tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance is not known.

[0022] The present invention has been made in view of the above circumstances, and the present invention provides a polyamide composition that does not contain halogen, has excellent flame retardancy, and has good long-term heat resistance when formed into a molded article, a method for producing the same, and a molded article containing the above polyamide composition.

[0023] Means for Solving the Problems

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

[0025] The polyamide composition according to the first aspect of the present invention contains:

[0026] (A) an aliphatic polyamide;

[0027] (B) a semi-aromatic polyamide containing diamine units and dicarboxylic acid units;

[0028] (C) at least one phosphinate selected from the group consisting of phosphinates represented by the following general formula (1), bis(phosphinates) represented by the following general formula (2), and condensates thereof; and

[0029] (D) a polymer having an oxygen index of 27% or more and having an aromatic group in the main chain, wherein

[0030] the content of the polymer (D) is 0.1% by mass or more and 8% by mass or less based on the total mass of the aliphatic polyamide (A), the semi-aromatic polyamide (B), the phosphinates (C), and the polymer (D),

[0031]

[0032] (In the general formula (1), R 11 and R 12 are each independently an alkyl group having 1 or more and 6 or less carbon atoms or an aryl group having 6 or more and 10 or less carbon atoms. M n11+ is an n11-valent metal ion. 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, the plurality of R 11 and R 12 each may be the same or different.

[0033] In the general formula (2), R 21 and R 22 are each independently an alkyl group having 1 or more and 6 or less carbon atoms or an aryl group having 6 or more and 10 or less carbon atoms. Y 21 is an alkylene group having 1 or more and 10 or less carbon atoms or an arylene group having 6 or more and 10 or less carbon atoms. M' m21+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 of 1 or more and 3 or less. When n21 is 2 or 3, the plurality of Rs present 21 , R 22 and Y 21 may each be the same or different. m21 is 2 or 3. x is 1 or 2. When x is 2, the plurality of M's present may be the same or different. n21, x, and m21 are integers that satisfy the relational expression 2×n21 = m21×x.)

[0034] The (D) polymer may be polyphenylene sulfide, polyphenylene ether, or maleic anhydride-modified polyphenylene ether.

[0035] The (A) aliphatic polyamide may contain diamine units and dicarboxylic acid units.

[0036] The (A) aliphatic polyamide may be polyamide 66.

[0037] With respect to the total mass of the (A) aliphatic polyamide, the (B) semi-aromatic polyamide, the (C) hypophosphite salts, and the (D) polymer, the content of the (C) hypophosphite salts may be 0.1% by mass or more and 30% by mass or less.

[0038] The tanδ peak temperature of the polyamide composition may be 90°C or higher.

[0039] The (B) semi-aromatic polyamide may contain 50 mol% or more of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

[0040] The (B) semi-aromatic polyamide may contain 75 mol% or more of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

[0041] The (B) semi-aromatic polyamide may contain 100 mol% of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

[0042] The weight-average molecular weight of the polyamide composition may be 10,000 or more and 50,000 or less.

[0043] The polyamide composition according to the first aspect may further contain at least one (E) filler.

[0044] The molded article according to the second aspect of the present invention is obtained by molding the polyamide composition according to the first aspect.

[0045] The method for producing a polyamide composition according to the third aspect of the present invention is a method for producing the polyamide composition according to the first aspect, which is a method of melt-kneading raw material components containing the (A) aliphatic polyamide, the (B) semi-aromatic polyamide, the (C) phosphinate, and the (D) polymer.

[0046] Advantages of the Invention

[0047] According to the polyamide composition and the method for producing the same according to the above aspect, a molded article that does not contain halogen but has excellent flame retardancy and good long-term heat resistance can be obtained. The molded article according to the above aspect does not contain halogen, and although it does not contain halogen, it has excellent flame retardancy and good long-term heat resistance. Detailed Embodiments

[0048] Hereinafter, the mode for implementing the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an exemplification for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be implemented with appropriate modifications within the scope of its gist.

[0049] It should be noted that in this specification, "polyamide" refers to a polymer having an amide group (-NHCO-) in the main chain.

[0050] 《Polyamide Composition》

[0051] The polyamide composition of the present embodiment contains the following components (A) to (D).

[0052] (A) Aliphatic polyamide;

[0053] (B) Semi-aromatic polyamide containing diamine units and dicarboxylic acid units;

[0054] (C) Phosphinates;

[0055] (D) A polymer having an oxygen index of 27% or more and having an aromatic group in the main chain (hereinafter sometimes simply referred to as "(D) polymer").

[0056] In the polyamide composition of the present embodiment, the content of the (D) component is 0.1% by mass or more and 8.0% by mass or less based on the total mass of the components (A) to (D).

[0057] The above (C) phosphinates are at least one phosphinate selected from the group consisting of phosphinates represented by the following general formula (1) (hereinafter sometimes simply referred to as "phosphinate (1)"), bisphosphinates represented by the following general formula (2) (hereinafter sometimes simply referred to as "bisphosphinate (2)"), and condensates thereof.

[0058]

[0059] (In general formula (1), R 11 and R 12 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. M n11+ is an n11-valent metal ion. 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, the plurality of R 11 and R 12 may be the same or different from each other.

[0060] In general formula (2), R 21 and R 22 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. Y 21 is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms. M’ m21+ is an m21-valent metal ion. 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 of 1 or more and 3 or less. When n21 is 2 or 3, the plurality of R 21 , R 22 and Y 21 may be the same or different from each other. m21 is 2 or 3. x is 1 or 2. When x is 2, the plurality of M’ may be the same or different. n21, x, and m21 are integers satisfying the relational expression 2×n21 = m21×x).

[0061] By having the above-described configuration, the polyamide composition of the present embodiment can obtain a molded product that does not contain halogen, has excellent flame retardancy, and has good tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance.

[0062] <Properties of polyamide composition>

[0063] The molecular weight and tanδ peak temperature of the polyamide composition of the present embodiment can be set to the following configuration. Specifically, they can be measured by the method described in the examples below.

[0064] [Weight-average molecular weight (Mw) of polyamide composition]

[0065] As an index of the molecular weight of the polyamide composition, the weight-average molecular weight (Mw) can be used.

[0066] 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, still 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 35,000 or more and 40,000 or less.

[0067] By having the weight-average molecular weight (Mw) of the polyamide composition within the above range, a polyamide composition with more excellent mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, etc., can be obtained. In addition, a molded article obtained from a polyamide composition containing components typified by (E) filler becomes a molded article with more excellent tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance.

[0068] As a method for controlling the Mw of the polyamide composition within the above range, for example, (A) aliphatic polyamide, (B) semi-aromatic polyamide, and (D) polymer having an Mw within the ranges described later can be cited.

[0069] It should be noted that for the measurement of Mw (weight-average molecular weight), as described in the examples below, it can be measured using GPC (gel permeation chromatography).

[0070] [Tanδ peak temperature of polyamide composition]

[0071] The lower limit value of the tanδ peak temperature of the polyamide composition is preferably 90 °C, more preferably 105 °C, and still more preferably 110 °C.

[0072] On the other hand, the upper limit value of the tanδ peak temperature of the polyamide composition is preferably 150 °C, more preferably 140 °C, and still more preferably 130 °C.

[0073] That is, the tanδ peak temperature of the polyamide composition is 90 °C or more, preferably 105 °C or more and 150 °C or less, more preferably 110 °C or more and 140 °C or less, and still more preferably 110 °C or more and 130 °C or less.

[0074] By having the tanδ peak temperature of the polyamide composition be the above lower limit value or more, there is a tendency to obtain a polyamide composition with more excellent water absorption rigidity and thermal rigidity. On the other hand, by having the tanδ peak temperature of the polyamide composition be the above upper limit value or less, there is a tendency for a molded article obtained from a polyamide composition containing components typified by (E) filler to become a molded article with more excellent tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance.

[0075] As a method for controlling the tanδ peak temperature of the polyamide composition within the above range, for example, a method of controlling the contents of (A) aliphatic polyamide and (B) semi-aromatic polyamide within the ranges described below can be cited, etc.

[0076] Hereinafter, the details of each constituent of the polyamide composition of the present embodiment will be described.

[0077] <(A) Aliphatic polyamide>

[0078] The constituent units of the (A) aliphatic polyamide contained in the polyamide composition of the present embodiment preferably satisfy at least any one of the following conditions (1) and (2).

[0079] (1) Containing (A-a) aliphatic dicarboxylic acid units and (A-b) aliphatic diamine units.

[0080] (2) Containing at least one selected from the group consisting of (A-c) lactam units and aminocarboxylic acid units.

[0081] In the polyamide composition of the present embodiment, as the (A) aliphatic polyamide, one or more polyamides that satisfy at least any one of the above conditions (1) and (2) can be contained. Among them, the constituent units of the (A) aliphatic polyamide contained in the polyamide composition of the present embodiment particularly preferably satisfy the above (1).

[0082] [(A-a) Aliphatic dicarboxylic acid units]

[0083] As the aliphatic dicarboxylic acid constituting the (A-a) aliphatic dicarboxylic acid unit, for example, a linear or branched saturated aliphatic dicarboxylic acid having 3 or more and 20 or less carbon atoms can be cited, etc.

[0084] As the linear saturated aliphatic dicarboxylic acid having 3 or more and 20 or less carbon atoms, it is not limited to the following substances, and for example, it can be cited: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, icosanedioic acid, diglycolic acid, etc.

[0085] As the branched saturated aliphatic dicarboxylic acid having 3 or more and 20 or less carbon atoms, it is not limited to the following substances, and for example, it can be cited: dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid, etc.

[0086] These aliphatic dicarboxylic acids constituting the (A-a) aliphatic dicarboxylic acid unit can be used alone as only one kind, or two or more kinds can be used in combination.

[0087] Among them, as the aliphatic dicarboxylic acid constituting the (A-a) aliphatic dicarboxylic acid unit, a linear saturated aliphatic dicarboxylic acid having 6 or more carbon atoms is preferred because it has a more excellent tendency in terms of heat resistance, fluidity, toughness, low water absorption, and rigidity of the polyamide composition.

[0088] As the preferred linear saturated aliphatic dicarboxylic acid having 6 or more carbon atoms, specifically, for example, adipic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, icosanedioic acid, etc. can be cited.

[0089] Among them, as the linear saturated aliphatic dicarboxylic acid having 6 or more carbon atoms, from the viewpoints of heat resistance of the polyamide composition, etc., adipic acid, sebacic acid, or dodecanedioic acid is preferred.

[0090] In addition, the (A) aliphatic polyamide may further contain units derived from polycarboxylic acids having three or more carboxylic acid groups as needed within the range that does not impair the effects of the polyamide composition of the present embodiment. As the polycarboxylic acids having three or more carboxylic acid groups, for example, trimellitic acid, pyromellitic acid, pyromellitic dianhydride, etc. can be cited. These polycarboxylic acids having three or more carboxylic acid groups can be used alone or in combination of two or more.

[0091] [(A-b) aliphatic diamine unit]

[0092] As the aliphatic diamine constituting the (A-b) aliphatic diamine unit, for example, a linear saturated aliphatic diamine having 2 or more and 20 or less carbon atoms or a branched saturated aliphatic diamine having 3 or more and 20 or less carbon atoms, etc. can be cited.

[0093] As the linear saturated aliphatic diamine having 2 or more and 20 or less carbon atoms, it is not limited to the following substances. For example, ethylenediamine, propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, etc. can be cited.

[0094] As the branched saturated aliphatic diamine having 3 or more and 20 or less 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. can be cited.

[0095] These aliphatic diamines constituting the (A-b) aliphatic diamine unit can be used alone or in combination of two or more.

[0096] Among them, the number of carbon atoms of the aliphatic diamine constituting the (A-b) aliphatic diamine unit is preferably 6 or more and 12 or less, more preferably 6 or more and 10 or less. When the number of carbon atoms of the aliphatic diamine constituting the (A-b) aliphatic diamine unit is at least the above lower limit value, the heat resistance of the obtained molded product is more excellent. On the other hand, when the number of carbon atoms is at most the above upper limit value, the crystallinity and mold release property of the obtained molded product are more excellent.

[0097] As the linear or branched saturated aliphatic diamine having 6 or more and 12 or less carbon atoms, specifically, for example, hexamethylenediamine, 2-methylpentamethylenediamine, 2-methyl-1,8-octanediamine, etc. can be cited.

[0098] Among them, as the linear or branched saturated aliphatic diamine having 6 or more and 12 or less carbon atoms, hexamethylenediamine or 2-methylpentamethylenediamine is preferred. By containing such an (A-b) aliphatic diamine unit, the heat resistance, rigidity, etc. of the molded product obtained from the polyamide composition are more excellent.

[0099] In addition, the (A) aliphatic polyamide may contain, as needed, within the range not impairing the effects of the polyamide composition of the present embodiment, units derived from aliphatic polyamines having three or more functional groups. As the aliphatic polyamine having three or more functional groups, for example, bis(hexamethylene)triamine, etc. can be cited.

[0100] [(A-c) is at least one structural unit selected from the group consisting of lactam units and aminocarboxylic acid units]

[0101] The (A) aliphatic polyamide may contain (A-c) at least one structural unit selected from the group consisting of lactam units and aminocarboxylic acid units. By containing such units, there is a tendency to obtain a polyamide with excellent toughness.

[0102] It should be noted that the so-called "lactam unit" and "aminocarboxylic acid unit" herein refer to lactams and aminocarboxylic acids that have undergone polymerization (condensation).

[0103] The lactam constituting the lactam unit is not limited to the following substances, and for example, butyrolactam, valerolactam, ε-caprolactam, capryllactam, enantholactam, undecalactam, laurolactam (dodecanolactam), etc. can be cited.

[0104] Among them, as the lactam constituting the lactam unit, ε-caprolactam or laurolactam is preferred, and ε-caprolactam is more preferred. By containing such a lactam, there is a tendency for the toughness of the molded product obtained from the polyamide composition to be more excellent.

[0105] The aminocarboxylic acid that constitutes the aminocarboxylic acid unit is 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, can be cited.

[0106] As the aminocarboxylic acid that constitutes the aminocarboxylic acid unit, a linear or branched saturated aliphatic carboxylic acid having 4 or more and 14 or less carbon atoms with an amino group substituted at the ω-position is preferred. As such an aminocarboxylic acid, it is not limited to the following substances. For example, 6-aminohexanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, etc. can be cited. In addition, p-aminomethylbenzoic acid, etc. can also be cited as the aminocarboxylic acid.

[0107] Each of these lactams and aminocarboxylic acids, which constitute at least one of the constituent units selected from the group consisting of lactam units and aminocarboxylic acid units in (A-c), can be used alone or in combination of two or more.

[0108] Among them, as the (A) aliphatic polyamide contained in the polyamide composition of the present embodiment, from the viewpoints of mechanical properties, heat resistance, moldability, and toughness, a polyamide containing a dicarboxylic acid unit and a diamine unit is preferred, and polyamide 66 (PA66) is more preferred. PA66 has excellent mechanical properties, heat resistance, moldability, and toughness, and is therefore considered to be a suitable material for automotive parts.

[0109] With respect to the total mass of the polyamide in the polyamide composition, the content of the (A) aliphatic polyamide in the polyamide composition of the present embodiment can be set, for example, to 10% by mass or more and 100% by mass or less, can be set, for example, to 50% by mass or more and 100% by mass or less, can be set, for example, to 55% by mass or more and 100% by mass or less.

[0110] [(A) Weight-average molecular weight Mw(A) of aliphatic polyamide]

[0111] As an index of the molecular weight of the (A) aliphatic polyamide, the weight-average molecular weight Mw(A) can be used. The weight-average molecular weight Mw(A) 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, still further 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.

[0112] By having the weight-average molecular weight Mw(A) within the above range, a polyamide composition having more excellent mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, tensile strength when formed into a molded product, flexural elastic modulus when absorbing water, and long-term heat resistance, etc., can be obtained.

[0113] It should be noted that the measurement of the weight-average molecular weight Mw(A) can be carried out using GPC as described in the following examples.

[0114] <(B) Semi-aromatic polyamide>

[0115] The (B) semi-aromatic polyamide contained in the polyamide composition of the present embodiment is a polyamide containing diamine units and dicarboxylic acid units.

[0116] Relative to all the constituent units of the (B) semi-aromatic polyamide, the (B) semi-aromatic polyamide preferably contains 20 mol% or more and 80 mol% or less of aromatic constituent units, more preferably contains 30 mol% or more and 70 mol% or less of aromatic constituent units, and still more preferably contains 40 mol% or more and 60 mol% or less of aromatic constituent units. Herein, the so-called "aromatic constituent units" refer to aromatic diamine units and aromatic dicarboxylic acid units.

[0117] In addition, the (B) semi-aromatic polyamide is preferably a polyamide containing (B-a) dicarboxylic acid units and (B-b) diamine units. Relative to all the dicarboxylic acid units of the (B) semi-aromatic polyamide, the (B-a) dicarboxylic acid units contain 50 mol% or more of isophthalic acid units, and the (B-b) diamine units contain diamine units having 4 or more and 10 or less carbon atoms.

[0118] In addition, at this time, relative to all the constituent units of the (B) semi-aromatic polyamide, the total content of isophthalic acid units and diamine units having 4 or more and 10 or less carbon atoms in the (B) semi-aromatic polyamide is preferably 50 mol% or more, more preferably 80 mol% or more and 100 mol% or less, still more preferably 90 mol% or more and 100 mol% or less, and particularly preferably 100 mol%.

[0119] It should be noted that the proportion of the specified monomer units constituting the (B) semi-aromatic polyamide can be measured by nuclear magnetic resonance spectroscopy (NMR) or the like.

[0120] [(B-a) dicarboxylic acid units]

[0121] The (B-a) dicarboxylic acid units are not particularly limited, and examples thereof include aromatic dicarboxylic acid units, aliphatic dicarboxylic acid units, alicyclic dicarboxylic acid units, and the like.

[0122] Among them, as the (B-a) dicarboxylic acid unit, based on the total molar amount of the (B-a) dicarboxylic acid unit, it preferably contains 50 mol% or more of isophthalic acid units, more preferably 65 mol% or more and 100 mol% or less of isophthalic acid units, still 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.

[0123] When the proportion of isophthalic acid units in the (B-a) dicarboxylic acid unit is at or above the above lower limit value, there is a tendency to obtain a polyamide composition that can simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, etc. In addition, for the molded article obtained from the polyamide composition, there is a tendency for the tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance to be more excellent.

[0124] (Aromatic dicarboxylic acid unit)

[0125] The aromatic dicarboxylic acid constituting the aromatic dicarboxylic acid unit other than the isophthalic acid unit is not limited to the following substances, and for example, dicarboxylic acids having aromatic groups such as phenyl and naphthyl can be cited. The aromatic group of the aromatic dicarboxylic acid may be unsubstituted or may have a substituent.

[0126] As such a substituent, there is no particular limitation, and for example, an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an alkylaryl group having 7 to 10 carbon atoms, a halogen group, a silyl group having 1 to 6 carbon atoms, a sulfonic acid group and its salts (such as sodium salt), etc. can be cited.

[0127] As the alkyl group having 1 to 4 carbon atoms, it is not limited to the following groups, and for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. can be cited.

[0128] As the aryl group having 6 to 10 carbon atoms, it is not limited to the following groups, and for example, phenyl, naphthyl, etc. can be cited.

[0129] As the aralkyl group having 7 to 10 carbon atoms, it is not limited to the following groups, and for example, benzyl, etc. can be cited.

[0130] As the alkylaryl group having 7 to 10 carbon atoms, it is not limited to the following groups, and for example, tolyl, xylyl, etc. can be cited.

[0131] As the halogen group, it is not limited to the following groups, and for example, fluoro group, chloro group, bromo group, iodo group, etc. can be cited.

[0132] As the silyl group having 1 or more and 6 or less carbon atoms, it is not limited to the following groups, and for example, can be exemplified: trimethylsilyl group, tert-butyldimethylsilyl group, etc.

[0133] Among them, as the aromatic dicarboxylic acid constituting the aromatic dicarboxylic acid unit other than the isophthalic acid unit, an unsubstituted aromatic dicarboxylic acid having 8 or more and 20 or less carbon atoms or an aromatic dicarboxylic acid having 8 or more and 20 or less carbon atoms substituted with a specified substituent is preferred.

[0134] As the unsubstituted aromatic dicarboxylic acid having 8 or more and 20 or less carbon atoms or the aromatic dicarboxylic acid having 8 or more and 20 or less carbon atoms substituted with a specified substituent, specifically, it is not limited to the following substances, and for example, can be exemplified: terephthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, sodium isophthalate-5-sulfonate, etc.

[0135] The aromatic dicarboxylic acid constituting the aromatic dicarboxylic acid unit can be used alone or in combination of two or more.

[0136] (Aliphatic dicarboxylic acid unit)

[0137] As the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid unit, a linear or branched saturated aliphatic dicarboxylic acid having 3 or more and 20 or less carbon atoms can be exemplified, etc.

[0138] As the linear saturated aliphatic dicarboxylic acid having 3 or more and 20 or less carbon atoms, it is not limited to the following substances, and for example, can be exemplified: malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, icosanedioic acid, diglycolic acid, etc.

[0139] As the branched saturated aliphatic dicarboxylic acid having 3 or more and 20 or less carbon atoms, it is not limited to the following substances, and for example, can be exemplified: dimethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid, etc.

[0140] (Alicyclic dicarboxylic acid unit)

[0141] As the alicyclic dicarboxylic acid constituting the alicyclic dicarboxylic acid unit (hereinafter sometimes referred to as "alicyclic dicarboxylic acid unit"), it is not limited to the following substances, and for example, can be exemplified: alicyclic dicarboxylic acid having 3 or more and 10 or less carbon atoms in the alicyclic structure, etc. Among them, as the alicyclic dicarboxylic acid, an alicyclic dicarboxylic acid having 5 or more and 10 or less carbon atoms in the alicyclic structure is preferred.

[0142] As such alicyclic dicarboxylic acids, they are not limited to the following substances. For example, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, etc. can be cited. Among them, as the alicyclic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid is preferred.

[0143] It should be noted that the alicyclic dicarboxylic acid constituting the alicyclic dicarboxylic acid unit can be used alone only one kind, or two or more kinds can be used in combination.

[0144] The alicyclic group of the alicyclic dicarboxylic acid can be unsubstituted or can have a substituent. As the substituent, for example, an alkyl group having 1 or more and 4 or less carbon atoms, etc. can be cited. As the alkyl group having 1 or more and 4 or less carbon atoms, the same groups as those exemplified in the above "aromatic dicarboxylic acid unit" can be cited.

[0145] As the dicarboxylic acid unit other than the isophthalic acid unit, an aromatic dicarboxylic acid unit is preferably contained, and an aromatic dicarboxylic acid having 6 or more carbon atoms is more preferably contained.

[0146] By using such a dicarboxylic acid, there is a tendency to obtain a polyamide composition that can simultaneously satisfy mechanical properties, especially water absorption rigidity, thermal rigidity, fluidity, etc. In addition, for a molded article obtained from the polyamide composition, there is a tendency that the tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance are more excellent.

[0147] (B) In the semi-aromatic polyamide, as the dicarboxylic acid constituting the (B-a) dicarboxylic acid unit, it is not limited to the compounds described as the above dicarboxylic acids, and can also be a compound equivalent to the above dicarboxylic acids.

[0148] Herein, the "compound equivalent to the dicarboxylic acid" refers to a compound that can obtain a dicarboxylic acid structure identical to the dicarboxylic acid structure derived from the above dicarboxylic acid. As such compounds, they are not limited to the following substances. For example, acid anhydrides of dicarboxylic acids, acid halides of dicarboxylic acids, etc. can be cited.

[0149] In addition, (B) the semi-aromatic polyamide can also contain units derived from polycarboxylic acids having three or more carboxylic acid groups as needed within the range that does not impair the effects of the polyamide composition of the present embodiment.

[0150] As polycarboxylic acids having three or more carboxylic acid groups, for example, trimellitic acid, pyromellitic acid, pyromellitic dianhydride, etc. can be cited. These polycarboxylic acids having three or more carboxylic acid groups can be used alone only one kind, or two or more kinds can be used in combination.

[0151] [(B-b) diamine unit]

[0152] Regarding the (B-b) diamine unit that constitutes (B) semi-aromatic polyamide, there are no particular limitations. For example, it can include: aromatic diamine units, aliphatic diamine units, alicyclic diamine units, etc. Among them, as the (B-b) diamine unit that constitutes (B) semi-aromatic polyamide, a diamine unit having 4 or more and 10 or less carbon atoms is preferably included, and a diamine unit having 6 or more and 10 or less carbon atoms is more preferably included.

[0153] (Aliphatic diamine unit)

[0154] As the aliphatic diamine that constitutes the aliphatic diamine unit, for example, it can include: linear saturated aliphatic diamines having 4 or more and 20 or less carbon atoms, etc.

[0155] As the linear saturated aliphatic diamines having 4 or more and 20 or less carbon atoms, it is not limited to the following substances. For example, it can include: ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, etc.

[0156] (Alicyclic diamine unit)

[0157] As the alicyclic diamine that constitutes the alicyclic diamine unit (hereinafter sometimes referred to as "alicyclic diamine"), it is not limited to the following substances. For example, it can include: 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine, etc.

[0158] (Aromatic diamine unit)

[0159] As the aromatic diamine that constitutes the aromatic diamine unit, as long as it is a diamine containing an aromatic group, it is not limited to the following substances. Specifically, as the aromatic diamine, for example, it can include m-xylylenediamine, etc.

[0160] It should be noted that these diamines that constitute each diamine unit can be used alone only one kind, or two or more kinds can be used in combination.

[0161] Among them, as the (B-b) diamine unit, an aliphatic diamine unit is preferred, a linear saturated aliphatic diamine unit having 4 or more and 10 or less carbon atoms is more preferred, a linear saturated aliphatic diamine unit having 6 or more and 10 or less carbon atoms is further preferred, and a hexamethylenediamine unit is particularly preferred.

[0162] By using such a diamine, there is a tendency to obtain a polyamide composition that can simultaneously satisfy mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, etc. In addition, for a molded article obtained from the polyamide composition, there is a tendency for the tensile strength, flexural modulus of elasticity during water absorption, and long-term heat resistance to be more excellent.

[0163] As the (B) semi-aromatic polyamide contained in the polyamide composition of the present embodiment, polyamide 6I (polyhexamethylene isophthalamide), polyamide 9I, or polyamide 10I is preferable, and polyamide 6I is more preferable. Since polyamide 6I has excellent heat resistance, moldability, and flame retardancy, it is considered a suitable material for automotive parts.

[0164] With respect to the total mass of the polyamide in the polyamide composition, the content of the (B) semi-aromatic polyamide in the polyamide composition of the present embodiment can be set to 5% by mass or more and 90% by mass or less, preferably 10% by mass or more and 50% by mass or less, more preferably 15.0% by mass or more and 40% by mass or less, and further preferably 20% by mass or more and 45% by mass or less.

[0165] By setting the content of the (B) semi-aromatic polyamide within the above range, the mechanical properties of the molded article obtained from the polyamide composition are more excellent. In addition, by containing components typified by the (E) filler, there is a tendency for the tensile strength, flexural modulus of elasticity during water absorption, and long-term heat resistance of the molded article obtained from the polyamide composition to be more excellent.

[0166] [Weight-average molecular weight Mw(B) of (B) semi-aromatic polyamide]

[0167] As an index of the molecular weight of the (B) semi-aromatic polyamide, the weight-average molecular weight Mw(B) can be used. The weight-average molecular weight Mw(B) 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, further preferably 15,000 or more and 40,000 or less, still further 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.

[0168] By having the weight-average molecular weight Mw(B) within the above range, a polyamide composition with more excellent mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, and the tensile strength, flexural modulus of elasticity during water absorption, and long-term heat resistance when formed into a molded article, etc., can be obtained.

[0169] It should be noted that for the measurement of the weight-average molecular weight Mw(B), as described in the following examples, it can be measured using GPC.

[0170] <End-capping agent>

[0171] In the polyamide composition of the present embodiment, the terminals of the polyamides ((A) aliphatic polyamide and (B) semi-aromatic polyamide) contained therein can be end-capped using a known end-capping agent.

[0172] When producing a polyamide from the above-mentioned dicarboxylic acid and the above-mentioned diamine, or when producing a polyamide from at least one selected from the group consisting of the above-mentioned lactam and the above-mentioned aminocarboxylic acid, such an end-capping agent can be added as a molecular weight regulator.

[0173] The end-capping agent is not limited to the following substances. For example, it can include: monocarboxylic acids, monoamines, acid anhydrides (such as phthalic anhydride), monoisocyanates, monoesters, monoalcohols, etc. The end-capping agent can be used alone as only one kind, or two or more kinds can be used in combination.

[0174] Among them, as the end-capping agent, a monocarboxylic acid or a monoamine is preferred. By end-capping the terminals of the polyamide with an end-capping agent, the molded article obtained from the polyamide composition tends to have more excellent thermal stability.

[0175] As the monocarboxylic acid that can be used as an end-capping agent, any substance having reactivity with the amino group that may be present at the terminal of the polyamide is sufficient. As the monocarboxylic acid, it is not limited to the following substances. For example, it can include: aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids, etc.

[0176] As the aliphatic monocarboxylic acid, for example, it can include: formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, isobutyric acid, etc.

[0177] As the alicyclic monocarboxylic acid, for example, it can include: cyclohexanecarboxylic acid, etc.

[0178] As the aromatic monocarboxylic acid, for example, it can include: benzoic acid, toluic acid, α-naphthoic acid, β-naphthoic acid, methylnaphthoic acid, phenylacetic acid, etc.

[0179] These monocarboxylic acids can be used alone as only one kind, or two or more kinds can be used in combination.

[0180] In particular, from the viewpoints of fluidity and mechanical strength, the terminals of the (B) semi-aromatic polyamide are preferably end-capped with acetic acid.

[0181] As the monoamine that can be used as an end-capping agent, any substance having reactivity with the carboxyl group that may be present at the terminal of the polyamide is sufficient. As the monoamine, it is not limited to the following substances. For example, it can include: aliphatic monoamines, alicyclic monoamines, aromatic monoamines, etc.

[0182] As aliphatic primary amines, examples include: methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, etc.

[0183] As alicyclic primary amines, examples include: cyclohexylamine, dicyclohexylamine, etc.

[0184] As aromatic primary amines, examples include: aniline, toluidine, diphenylamine, naphthylamine, etc.

[0185] These primary amines can be used alone, or two or more of them can be used in combination.

[0186] For a polyamide composition containing a polyamide capped with a capping agent, it tends to have more excellent heat resistance, fluidity, toughness, low water absorption, and rigidity.

[0187] <Manufacturing methods of (A) aliphatic polyamide and (B) semi-aromatic polyamide>

[0188] When manufacturing the polyamides ((A) aliphatic polyamide and (B) semi-aromatic polyamide) contained in the polyamide composition of the present embodiment, the addition amounts of the dicarboxylic acid and the diamine are preferably about the same molar amount. For the molar ratio, considering the portion of the diamine that escapes from the reaction system during the polymerization reaction, relative to 1 of the molar amount of all the dicarboxylic acid, the molar amount of all the diamines is preferably 0.9 or more and 1.2 or less, more preferably 0.95 or more and 1.1 or less, and still more preferably 0.98 or more and 1.05 or less.

[0189] As a manufacturing method of the polyamide, it is not limited to the following methods, and for example, it includes the following polymerization steps (1) or (2).

[0190] (1) A step of polymerizing a combination of a dicarboxylic acid constituting a dicarboxylic acid unit and a diamine constituting a diamine unit to obtain a polymer.

[0191] (2) A step of polymerizing one or more selected from the group consisting of a lactam constituting a lactam unit and an aminocarboxylic acid constituting an aminocarboxylic acid unit to obtain a polymer.

[0192] In addition, as a manufacturing method of the polyamide, it is preferable to further include a step of increasing the degree of polymerization of the polyamide after the above polymerization step. In addition, according to need, a capping step of capping the terminals of the obtained polymer with a capping agent can be included after the above polymerization step and the above increasing step.

[0193] As specific manufacturing methods of the polyamide, for example, various methods exemplified in the following 1) to 4) can be listed.

[0194] 1) A method of heating an aqueous solution or aqueous suspension of one or more selected from the group consisting of a binary carboxylic acid-diamine salt, a mixture of a binary carboxylic acid and a diamine, a lactam, and an amino carboxylic acid, and polymerizing it while maintaining a molten state (hereinafter sometimes referred to as "thermal melt polymerization method").

[0195] 2) A method of increasing the degree of polymerization of a polyamide obtained by the thermal melt polymerization method at a temperature below the melting point while maintaining a solid state (hereinafter sometimes referred to as "thermal melt polymerization-solid phase polymerization method").

[0196] 3) A method of polymerizing one or more selected from the group consisting of a binary carboxylic acid-diamine salt, a mixture of a binary carboxylic acid and a diamine, a lactam, and an amino carboxylic acid while maintaining a solid state (hereinafter sometimes referred to as "solid phase polymerization method").

[0197] 4) A method of using a binary carboxylic acid acyl halide component equivalent to a binary carboxylic acid and a diamine component and polymerizing them (hereinafter sometimes referred to as "solution method").

[0198] Among them, as a specific production method of polyamide, a production method including the thermal melt polymerization method is preferred. In addition, when producing polyamide by the thermal melt polymerization method, it is preferable to maintain the molten state until the polymerization is completed. In order to maintain the molten state, it is necessary to carry out the production under polymerization conditions suitable for the polyamide composition. As polymerization conditions, for example, the following conditions can be cited. First, control the polymerization pressure in the thermal melt polymerization method at 14 kg / cm 2 or more and 25 kg / cm 2 or less (gauge pressure), and continue heating. Then, reduce the pressure over a period of 30 minutes or more until the pressure in the tank reaches atmospheric pressure (gauge pressure is 0 kg / cm 2 ).

[0199] In the production method of polyamide, as the polymerization mode, there is no particular limitation, and it can be batch type or continuous type.

[0200] As the polymerization apparatus used in the production of polyamide, there is no particular limitation, and a publicly known apparatus can be used. As the polymerization apparatus, specifically, for example, an autoclave type reactor, a drum type reactor, an extruder type reactor (kneader, etc.) can be cited.

[0201] Hereinafter, as a production method of polyamide, a method of producing polyamide by the batch type thermal melt polymerization method is specifically shown, but the production method of polyamide is not limited thereto.

[0202] First, an aqueous solution containing a raw material component having 40% by mass or more and 60% by mass or less of polyamide (a combination of a dicarboxylic acid and a diamine, and at least one selected from the group consisting of lactam and aminocarboxylic acid as needed) is prepared. Next, in a concentrating tank operated at a temperature of 110°C or higher and 180°C or lower and a pressure of about 0.035 MPa or higher and about 0.6 MPa or lower (gauge pressure), the aqueous solution is concentrated to 65% by mass or more and 90% by mass or less, thereby obtaining a concentrated solution.

[0203] Next, the obtained concentrated solution is transferred to an autoclave and heated continuously until the pressure in the autoclave reaches about 1.2 MPa or higher and about 2.2 MPa or lower (gauge pressure).

[0204] Next, in the autoclave, while removing at least any one of water and gas components, the pressure is maintained at about 1.2 MPa or higher and about 2.2 MPa or lower (gauge pressure). Next, when the temperature reaches about 220°C or higher and about 260°C or lower, the pressure is reduced to atmospheric pressure (gauge pressure is 0 MPa). The pressure in the autoclave is reduced to atmospheric pressure, and then reduced pressure is performed as needed, whereby by-products of water can be effectively removed.

[0205] Next, the autoclave is pressurized with an inert gas such as nitrogen, and the polyamide melt is extruded from the autoclave in the form of a wire. The extruded wire is cooled and cut, thereby obtaining pellets of polyamide.

[0206] <Polymer terminal of polyamide>

[0207] As the polymer terminal of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) contained in the polyamide composition of the present embodiment, there is no particular limitation, and it can be classified and defined as the following 1) to 4).

[0208] That is, 1) amino terminal, 2) carboxyl terminal, 3) terminal formed by a capping agent, 4) other terminals.

[0209] 1) The amino terminal is a polymer terminal having an amino (-NH 2 group), and is derived from a diamine.

[0210] 2) The carboxyl terminal is a polymer terminal having a carboxyl (-COOH group), and is derived from a dicarboxylic acid.

[0211] 3) The terminal formed by a capping agent is a terminal formed when a capping agent is added during polymerization. As the capping agent, the above-mentioned capping agents can be cited.

[0212] 4) Other polymer terminals whose ends are not classified as the above 1) to 3). As other terminals, specifically, terminals generated by deamination reaction of amino terminals, terminals generated by decarboxylation reaction from carboxyl terminals, etc. can be cited.

[0213] <(C) Phosphonites>

[0214] As the (C) phosphonites contained in the polyamide composition of the present embodiment, it is at least one phosphonite selected from the group consisting of phosphonites represented by the following general formula (1) (phosphonite (1)), diphosphonites represented by the following general formula (2) (diphosphonite (2)), and their condensates.

[0215]

[0216] (In general formula (1), R 11 and R 12 are each independently an alkyl group having 1 or more and 6 or less carbon atoms or an aryl group having 6 or more and 10 or less carbon atoms. M n11+ is an n11-valent metal ion. 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, the plurality of R 11 and R 12 can be the same or different from each other.

[0217] In general formula (2), R 21 and R 22 are each independently an alkyl group having 1 or more and 6 or less carbon atoms or an aryl group having 6 or more and 10 or less carbon atoms. Y 21 is an alkylene group having 1 or more and 10 or less carbon atoms or an arylene group having 6 or more and 10 or less carbon atoms. M' m21+ is an m21-valent metal ion. 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 of 1 or more and 3 or less. When n21 is 2 or 3, the plurality of R 21 , R 22 and Y 21 can be the same or different from each other. m21 is 2 or 3. x is 1 or 2. When x is 2, the plurality of M' can be the same or different. n21, x, and m21 are integers that satisfy the relationship of 2×n21 = m21×x).

[0218] [R 11 , R 12 , R 21 and R 22

[0219] R​11 , R 12 , R 21 and R 22 are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. When n11 is 2 or 3, the plurality of R 11 and R 12 may be the same or different from each other, but are preferably the same from the viewpoint of ease of production. Further, when n21 is 2 or 3, the plurality of R 21 and R 22 may be the same or different from each other, but are preferably the same from the viewpoint of ease of production.

[0220] As the alkyl group, it may be linear or cyclic, but is preferably linear. As the linear alkyl group, for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, etc. may be mentioned. As the branched alkyl group, for example, 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. may be mentioned.

[0221] As the aryl group, for example, phenyl, naphthyl, etc. may be mentioned.

[0222] The alkyl group and the aryl group may have a substituent. As the substituent on the alkyl group, for example, an aryl group having 6 to 10 carbon atoms, etc. may be mentioned. As the substituent on the aryl group, an alkyl group having 1 to 6 carbon atoms, etc. may be mentioned.

[0223] As the alkyl group having a substituent, specifically, for example, benzyl, etc. may be mentioned.

[0224] As the aryl group having a substituent, specifically, for example, tolyl, xylyl, etc. may be mentioned.

[0225] Among them, as R 11 , R 12 , R 21 and R 22 , an alkyl group having 1 to 6 carbon atoms is preferred, and methyl or ethyl is more preferred.

[0226] [Y 21 ​

[0227] Y 21 is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms. When n21 is 2 or 3, the multiple Ys present 21 may be the same or different from each other, but are preferably the same from the viewpoint of ease of production.

[0228] As the alkylene group, it may be linear or cyclic, but is preferably linear. As the linear alkylene group, for example, methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, etc. can be mentioned. As the branched alkylene group, for example, 1-methylethylene, 1-methylpropyl, etc. can be mentioned.

[0229] As the arylene group, for example, phenylene, naphthylene, etc. can be mentioned.

[0230] The alkylene group and the arylene group may have substituents. As the substituent on the alkylene group, for example, an aryl group having 6 to 10 carbon atoms, etc. can be mentioned. As the substituent on the arylene group, an alkyl group having 1 to 6 carbon atoms, etc. can be mentioned.

[0231] As the alkylene group having substituents, specifically, for example, benzylidene, phenylethylene, phenyltrimethylene, phenyltetramethylene, etc. can be mentioned.

[0232] As the arylene group having substituents, specifically, for example, methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene, tert-butylnaphthylene, etc. can be mentioned.

[0233] Among them, as Y 21 , an alkylene group having 1 to 10 carbon atoms is preferred, and methylene or ethylene is more preferred.

[0234] [M and M']

[0235] M and M' are each independently an ion of an element belonging to Group 2 or Group 15 of the periodic table, an ion of a transition element, a zinc ion or an aluminum ion. As the ion of an element belonging to Group 2 of the periodic table, for example, calcium ion, magnesium ion, etc. can be mentioned. As the ion of an element belonging to Group 15 of the periodic table, for example, bismuth ion, etc. can be mentioned.

[0236] In addition, when x is 2, the multiple M's present may be the same or different from each other, but are preferably the same from the viewpoint of ease of production.

[0237] Among them, as M and M', calcium, zinc or aluminum is preferred, and calcium or aluminum is more preferred.

[0238] [x]

[0239] x represents the number of M', which is 1 or 2. x can be appropriately selected according to the type of M' and the amount of diphosphinic acid.

[0240] [n11 and n21]

[0241] n11 represents the number of phosphinic acids and the valence of M, and n11 is 2 or 3. n11 can be appropriately selected according to the type and valence of M.

[0242] n21 represents the number of diphosphinic acids, and n21 is an integer of 1 or more and 3 or less. n21 can be appropriately selected according to the type and amount of M'.

[0243] [m21]

[0244] m21 represents the valence of M', and m21 is 2 or 3.

[0245] n21, x, and m21 are integers that satisfy the relationship of 2×n21 = m21×x.

[0246] As the preferred phosphinate (1), specifically, for example, the following can be mentioned: calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium methylethylphosphinate, magnesium methylethylphosphinate, aluminum methylethylphosphinate, zinc methylethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, calcium methanedi(methylphosphinate), magnesium methanedi(methylphosphinate), aluminum methanedi(methylphosphinate), zinc methanedi(methylphosphinate), calcium benzene-1,4-di(methylphosphinate), magnesium benzene-1,4-di(methylphosphinate), aluminum benzene-1,4-di(methylphosphinate), zinc benzene-1,4-di(methylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, zinc diphenylphosphinate, etc. Among them, as the phosphinate (1), from the viewpoint of excellent flame retardancy, calcium dimethylphosphinate or aluminum dimethylphosphinate is particularly preferred.

[0247] As the preferred diphosphinate (2), specifically, for example, the following can be mentioned: calcium methanedi(methylphosphinate), magnesium methanedi(methylphosphinate), aluminum methanedi(methylphosphinate), zinc methanedi(methylphosphinate), calcium benzene-1,4-di(methylphosphinate), magnesium benzene-1,4-di(methylphosphinate), aluminum benzene-1,4-di(methylphosphinate), zinc benzene-1,4-di(methylphosphinate), etc.

[0248] As a method for producing phosphinates, there is no particular limitation, and examples thereof include the methods described in Patent Document 5, Patent Document 6, Patent Document 7, etc. Specifically, it is produced by using phosphinic acid and a metal carbonate, metal hydroxide, or metal oxide in an aqueous solution. Although these phosphinates are essentially monomeric compounds, depending on the reaction conditions, they sometimes contain polymeric phosphinates as condensates with a condensation degree of 1 or more and 3 or less depending on the environment.

[0249] Relative to the total mass of (A) aliphatic polyamide, (B) semi-aromatic polyamide, (C) phosphinates, and (D) polymer, the content of (C) phosphinates 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, still more preferably 5% by mass or more and 28% by mass or less, and particularly preferably 8% by mass or more and 25% by mass or less.

[0250] By setting the content of (C) phosphinates to be above the above lower limit value, a polyamide composition with more excellent flame retardancy can be obtained. On the other hand, by setting the content of (C) phosphinates to be below the above upper limit value, a polyamide composition can be obtained that does not impair the properties of the polyamide copolymer and has more excellent flame retardancy.

[0251] <(D) A polymer having an oxygen index of 27% or more and an aromatic group in the main chain>

[0252] As the (D) polymer contained in the polyamide composition of the present embodiment, as long as the oxygen index is 27% or more, there is no particular limitation. Specific examples of the (D) polymer include polyphenylene sulfide, polyphenylene ether, maleic anhydride-modified polyphenylene ether, polysulfone, polyether ether ketone, polyetherimide, polyamideimide, polyether sulfone, etc. Among them, as the (D) polymer, polyphenylene sulfide, polyphenylene ether, maleic anhydride-modified polyphenylene ether, or polysulfone is preferred, and polyphenylene sulfide, polyphenylene ether, or maleic anhydride-modified polyphenylene ether is particularly preferred.

[0253] It should be noted that generally, the "oxygen index" is an index of the flammability of a material and is expressed by the lowest oxygen concentration (volume %) required for the material to continue burning. The oxygen index can be measured according to ISO 4589-2.

[0254] Relative to the total mass of (A) aliphatic polyamide, (B) semi-aromatic polyamide, (C) phosphinates, and (D) polymer, the content of (D) polymer is 0.1% by mass or more and 8.0% by mass or less, preferably 1.0% by mass or more and 8.0% by mass or less, more preferably 2.5% by mass or more and 8.0% by mass or less, and still more preferably 2.5% by mass or more and 6.5% by mass or less.

[0255] By setting the content of the (D) polymer to be above the above lower limit value, a polyamide composition with more excellent flame retardancy can be obtained. On the other hand, by setting the content of the (D) polymer to be below the above upper limit value, a polyamide composition with more excellent long-term heat resistance can be obtained.

[0256] In addition, by setting the content of the (D) polymer within the above range, a polyamide composition with more excellent flexural modulus of elasticity and long-term heat resistance when absorbing water can be obtained.

[0257] [Weight-average molecular weight Mw(D) of the (D) polymer]

[0258] As an index of the molecular weight of the (D) polymer, the weight-average molecular weight Mw(D) can be used. The weight-average molecular weight Mw(D) of the (D) polymer is preferably 10,000 or more and 70,000 or less, more preferably 15,000 or more and 60,000 or less, further preferably 20,000 or more and 60,000 or less, still further preferably 25,000 or more and 60,000 or less, particularly preferably 25,000 or more and 55,000 or less, and most preferably 30,000 or more and 55,000 or less.

[0259] By having the weight-average molecular weight Mw(D) within the above range, a polyamide composition with more excellent mechanical properties, particularly water absorption rigidity, thermal rigidity, fluidity, tensile strength when forming a molded article, flexural modulus of elasticity when absorbing water, and long-term heat resistance, etc., can be obtained.

[0260] It should be noted that for the measurement of the weight-average molecular weight Mw(D), as described in the following examples, it can be measured using GPC.

[0261] <(E) Filler>

[0262] In the polyamide composition of the present embodiment, in addition to the above components (A) to (D), an (E) filler may also be contained. By containing the (E) filler, a polyamide composition with more excellent mechanical properties such as toughness and rigidity can be obtained.

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

[0264] These (E) filling materials can be used alone, one type only, or in combination of two or more types.

[0265] Among them, as the (E) filling material, from the viewpoints of rigidity and strength, etc., glass fiber, carbon fiber, flaky glass, talc, kaolin, mica, monocalcium phosphate, wollastonite, carbon nanotube, graphite, calcium fluoride, montmorillonite, swelling fluorphlogopite or apatite are preferred. Further, as the (E) filling material, glass fiber or carbon fiber is more preferred, and glass fiber is further preferred.

[0266] When the (E) filling material is glass fiber or carbon fiber, the number-average fiber diameter (D) is preferably 3 μm or more and 30 μm or less. Further, 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 having the above-described constitution, higher characteristics can be exhibited.

[0267] Further, when the (E) filling material is glass fiber, the number-average fiber diameter (D) is more preferably 3 μm or more and 30 μm or less. The weight-average fiber length (L) is more preferably 103 μm or more and 500 μm or less. In addition, the aspect ratio ((L) / (D)) is more preferably 3 or more and 100 or less.

[0268] The number-average fiber diameter and the weight-average fiber length of the (E) filling material can be measured by the following method.

[0269] First, a molded article of the polyamide composition is dissolved using a solvent such as formic acid that can dissolve polyamide. Next, for example, 100 or more filling materials are arbitrarily selected from the obtained insoluble components. Next, it can be determined by observing the filling materials using an optical microscope, a scanning electron microscope, etc.

[0270] Relative to the total mass of the polyamide composition, the content of the (E) filling material in the polyamide composition is preferably 1% by mass or more and 80% by mass or less, more preferably 10% by mass or more and 70% by mass or less, further preferably 15% by mass or more and 60% by mass or less, particularly preferably 20% by mass or more and 50% by mass or less, and most preferably 25% by mass or more and 40% by mass or less.

[0271] When the content of the (E) filling material is at least the above lower limit value, there is a tendency that the mechanical properties such as the strength and rigidity of the polyamide composition are further improved. On the other hand, when the content of the (E) filling material is at most the above upper limit value, there is a tendency that a polyamide composition having more excellent moldability can be obtained.

[0272] In particular, (E) the filler is glass fiber, and the content of (E) the filler is within the above range with respect to the total mass of the polyamide composition, whereby there is a tendency for further improvement in mechanical properties such as the strength and rigidity of the polyamide composition.

[0273] <(F) Other additives>

[0274] In the polyamide composition of the present embodiment, in addition to the components (A) to (E) described above, (F) other additives commonly used in polyamides may be contained within a range that does not impair the effects of the polyamide composition of the present embodiment. Examples of (F) other additives include: (F1) molding improvers, (F2) deterioration inhibitors, (F3) nucleating agents, (F4) heat stabilizers, etc.

[0275] The content of (F) other additives in the polyamide composition of the present embodiment varies depending on their types, the uses of the polyamide composition, etc., and thus there is no particular limitation as long as it is within a range that does not impair the effects of the polyamide composition of the present embodiment.

[0276] [(F1) Molding improver]

[0277] There is no particular limitation on the (F1) molding improver contained in the polyamide composition of the present embodiment. Examples include: higher fatty acids, metal salts of higher fatty acids, esters of higher fatty acids, amides of higher fatty acids, etc. It should be noted that the molding improver is also used as a "lubricating material".

[0278] (Higher fatty acid)

[0279] Examples of higher fatty acids include straight-chain or branched-chain saturated or unsaturated aliphatic monocarboxylic acids having 8 or more and 40 or less carbon atoms.

[0280] Examples of straight-chain saturated aliphatic monocarboxylic acids having 8 or more and 40 or less carbon atoms include: lauric acid, palmitic acid, stearic acid, behenic acid, montanic acid, etc.

[0281] Examples of branched-chain saturated aliphatic monocarboxylic acids having 8 or more and 40 or less carbon atoms include: isopalmitic acid, isostearic acid, etc.

[0282] Examples of straight-chain unsaturated aliphatic monocarboxylic acids having 8 or more and 40 or less carbon atoms include: oleic acid, erucic acid, etc.

[0283] Examples of branched-chain unsaturated aliphatic monocarboxylic acids having 8 or more and 40 or less carbon atoms include: isooleic acid, etc.

[0284] Among them, as the higher fatty acid, stearic acid or montanic acid is preferred.

[0285] (Metal salts of higher fatty acids)

[0286] Metal salts of higher fatty acids refer to metal salts of higher fatty acids.

[0287] Examples of the metal element as the metal salt include: Group 1 elements, Group 2 elements and Group 3 elements of the periodic table, zinc, aluminum, etc.

[0288] Examples of Group 1 elements of the periodic table include: sodium, potassium, etc.

[0289] Examples of Group 2 elements of the periodic table include: calcium, magnesium, etc.

[0290] Examples of Group 3 elements of the periodic table include: scandium, yttrium, etc.

[0291] Among them, Group 1 elements and Group 2 elements of the periodic table or aluminum are preferred, and sodium, potassium, calcium, magnesium or aluminum are more preferred.

[0292] Examples of the metal salts of higher fatty acids specifically include: calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium montanate, sodium montanate, calcium palmitate, etc.

[0293] Among them, as the metal salts of higher fatty acids, metal montanates or metal stearates are preferred.

[0294] (Higher fatty acid esters)

[0295] Higher fatty acid esters refer to the ester compounds of higher fatty acids and alcohols.

[0296] As the higher fatty acid esters, esters of aliphatic carboxylic acids having 8 or more and 40 or less carbon atoms and aliphatic alcohols having 8 or more and 40 or less carbon atoms are preferred.

[0297] Examples of the aliphatic alcohols having 8 or more and 40 or less carbon atoms include: stearyl alcohol, sorbitol, lauryl alcohol, etc.

[0298] Examples of the higher fatty acid esters specifically include: stearyl stearate, behenyl behenate, etc.

[0299] (Higher fatty acid amides)

[0300] Higher fatty acid amides refer to amide compounds of higher fatty acids.

[0301] Examples of the higher fatty acid amides include: stearamide, oleamide, erucamide, ethylene bisstearamide, ethylene bisoleamide, N-stearyl stearamide, N-stearyl erucamide, etc.

[0302] These higher fatty acids, metal salts of higher fatty acids, esters of higher fatty acids, and amides of higher fatty acids can each be used alone or in combination of two or more.

[0303] [(F2) deterioration inhibitor]

[0304] The (F2) deterioration inhibitor contained in the polyamide composition of the present embodiment is used for the purpose of preventing thermal deterioration, thermal discoloration, and improving heat aging resistance.

[0305] There is no particular limitation on the (F2) deterioration inhibitor, and examples thereof include: copper compounds, phenolic stabilizers, phosphite stabilizers, hindered amine stabilizers, triazine stabilizers, benzotriazole stabilizers, benzophenone stabilizers, cyanoacrylate stabilizers, salicylate stabilizers, sulfur-containing stabilizers, etc.

[0306] Examples of the copper compound include: copper acetate, cuprous iodide, etc.

[0307] Examples of the phenolic stabilizer include: hindered phenol compounds, etc.

[0308] These (F2) deterioration inhibitors can be used alone or in combination of two or more.

[0309] [(F3) nucleating agent]

[0310] (F3) nucleating agent refers to a substance that obtains at least any one of the following effects (1) to (3) by addition.

[0311] (1) The effect of raising the crystallization peak temperature of the polyamide composition.

[0312] (2) The effect of reducing the difference between the extrapolated onset temperature and the extrapolated termination temperature of the crystallization peak.

[0313] (3) The effect of making the spherulites of the obtained molded product finer or the size uniform.

[0314] Examples of the (F3) nucleating agent are not limited to the following substances, and include: talc, boron nitride, mica, kaolin, silicon nitride, carbon black, potassium titanate, molybdenum disulfide, etc.

[0315] (F3) nucleating agent can be used alone or in combination of two or more.

[0316] Among them, as the (F3) nucleating agent, from the viewpoint of the nucleating agent effect, talc or boron nitride is preferred.

[0317] In addition, the number average particle diameter of the (F3) nucleating agent is preferably 0.01 μm or more and 10 μm or less because the effect of the nucleating agent is high.

[0318] The number average particle diameter of the nucleating agent can be measured by the following method. First, the molded product is dissolved using a solvent such as formic acid that can dissolve polyamide. Next, for example, 100 or more nucleating agents are arbitrarily selected from the obtained insoluble components. Then, the particle diameter can be determined by observing and measuring it using an optical microscope, a scanning electron microscope, or the like.

[0319] With respect to 100 parts by mass of polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide), the content of the nucleating agent in the polyamide composition of the present embodiment is preferably 0.001 part by mass or more and 1 part by mass or less, more preferably 0.001 part by mass or more and 0.5 part by mass or less, and still more preferably 0.001 part by mass or more and 0.09 part by mass or less.

[0320] By setting the content of the nucleating agent to be above the above lower limit value with respect to 100 parts by mass of polyamide, there is a tendency for the heat resistance of the polyamide composition to be further improved. In addition, by setting the content of the nucleating agent to be below the above upper limit value with respect to 100 parts by mass of polyamide, a polyamide composition having more excellent toughness can be obtained.

[0321] [(F4) Heat stabilizer]

[0322] As the (F4) heat stabilizer, it is not limited to the following substances, and for example, phenolic heat stabilizers, phosphorus-containing heat stabilizers, amine-based heat stabilizers, metal salts of elements in Groups 3, 4, and 11 to 14 of the periodic table, etc. can be cited.

[0323] (Phenolic heat stabilizer)

[0324] As the phenolic heat stabilizer, it is not limited to the following substances, and for example, hindered phenol compounds, etc. can be cited. Hindered phenol compounds have the property of imparting excellent heat resistance and light resistance to resins or fibers such as polyamide.

[0325] As the hindered phenol compound, it is not limited to the following substances. For example, it can include: N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propanoyloxy]-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.

[0326] These hindered phenol compounds can be used alone, only one kind, or two or more kinds can be used in combination.

[0327] When using a phenolic heat stabilizer, relative to the total mass of the polyamide composition, the content of the phenolic 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.

[0328] When the content of the phenolic heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the gas generation amount can be further reduced.

[0329] (Phosphorus-containing heat stabilizer)

[0330] As a phosphorus-containing heat stabilizer, it is not limited to the following substances. For example, it can include: pentaerythritol phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, trisisodecyl phosphite, phenyl diisodecyl phosphite, phenyl bis(tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(2,4-di-tert-butyl-5-methylphenyl) phosphite, tris(butoxyethyl) phosphite, 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl) diphosphite tetra(tridecyl) ester, 4,4'-isopropylidenediphenyl diphosphite tetra(C12-C15 mixed alkyl) ester, 4,4'-isopropylidene bis(2-tert-butylphenyl) phosphite bis(nonylphenyl) ester, tris(biphenyl) phosphite, 1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl) butane diphosphite tetra(tridecyl) ester, 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl) diphosphite tetra(tridecyl) ester, 4,4'-isopropylidenediphenyl diphosphite tetra(C1-C15 mixed alkyl) ester, tris(mono, di mixed nonylphenyl) phosphite, 4,4'-isopropylidene bis(2-tert-butylphenyl) phosphite bis(nonylphenyl) ester, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tris(3,5-di-tert-butyl-4-hydroxyphenyl) phosphite, hydrogenated 4,4'-isopropylidenediphenyl polyphosphite, bis(4,4'-butylidenebis(3-methyl-6-tert-butylphenyl))-1,6-hexanediol diphosphite bis(octylphenyl) ester, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl) butane diphosphite hexa(tridecyl) ester, tris(4,4'-isopropylidene bis(2-tert-butylphenyl)) phosphite, tris(1,3-stearoyloxyisopropyl) phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl) phosphite octyl ester, 2,2-methylenebis(3-methyl-4,6-di-tert-butylphenyl) phosphite 2-ethylhexyl ester, 4,4'-biphenylene diphosphite tetra(2,4-di-tert-butyl-5-methylphenyl) ester, 4,4'-biphenylene diphosphite tetra(2,4-di-tert-butylphenyl) ester, etc.

[0331] These phosphorus-containing heat stabilizers can be used alone, only one kind, or two or more kinds can be used in combination.

[0332] As a pentaerythritol phosphite compound, it is not limited to the following substances. For example, it can include: pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl phenyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl methyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl 2 - ethylhexyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl isodecyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl lauryl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl isotridecyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl stearyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl cyclohexyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl benzyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl ethyl cellosolve ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl butyl carbitol ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl octylphenyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl nonylphenyl ester, pentaerythritol diphosphite bis(2,6 - di - tert - butyl - 4 - methylphenyl) ester, pentaerythritol diphosphite bis(2,6 - di - tert - butyl - 4 - ethylphenyl) ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl 2,6 - di - tert - butylphenyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl 2,4 - di - tert - butylphenyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl 2,4 - di - tert - octylphenyl ester, pentaerythritol diphosphite 2,6 - di - tert - butyl - 4 - methylphenyl 2 - cyclohexylphenyl ester, pentaerythritol diphosphite 2,6 - di - tert - amyl - 4 - methylphenyl phenyl ester, pentaerythritol diphosphite bis(2,6 - di - tert - amyl - 4 - methylphenyl) ester, pentaerythritol diphosphite bis(2,6 - di - tert - octyl - 4 - methylphenyl) ester, etc.

[0333] These pentaerythritol phosphite compounds can be used alone, only one kind, or two or more kinds can be used in combination.

[0334] When using a phosphorus - containing heat stabilizer, relative to the total mass of the polyamide composition, 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.

[0335] When the content of the phosphorus - containing heat stabilizer is within the above range, the heat - aging resistance of the polyamide composition can be further improved, and the gas generation amount can be further reduced.

[0336] (Amine heat stabilizer)

[0337] As the amine heat stabilizer, it is not limited to the following substances. For example, the following can be listed: 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, bis(2,2,6,6-tetramethyl-4-piperidyl) carbonate, bis(2,2,6,6-tetramethyl-4-piperidyl) oxalate, bis(2,2,6,6-tetramethyl-4-piperidyl) malonate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl) adipate, bis(2,2,6,6-tetramethyl-4-piperidyl) terephthalate, 1,2-bis(2,2,6,6-tetramethyl-4-piperidyloxy)ethane, α,α'-bis(2,2,6,6-tetramethyl-4-piperidyloxy)p-xylene, toluene-2,4-dicarbamic acid bis(2,2,6,6-tetramethyl-4-piperidyl) ester, hexamethylene-1,6-dicarbamic acid bis(2,2,6,6-tetramethyl-4-piperidyl) ester, benzene-1,3,5-tricarboxylic acid tris(2,2,6,6-tetramethyl-4-piperidyl) ester, benzene-1,3,4-tricarboxylic acid tris(2,2,6,6-tetramethyl-4-piperidyl) ester, 1-[2-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyloxy}butyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyloxy]-2,2,6,6-tetramethylpiperidine, the condensate 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.

[0338] These amine heat stabilizers can be used alone, only one kind, or in combination of two or more kinds.

[0339] When using an amine-based heat stabilizer, the content of the amine-based 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, based on the total mass of the polyamide composition.

[0340] When the content of the amine-based heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the gas generation amount can be further reduced.

[0341] (Metal salts of the elements of Groups 3, 4, and 11-14 of the periodic table)

[0342] As the metal salts of the elements of Groups 3, 4, and 11-14 of the periodic table, there are no particular limitations as long as they are salts of metals belonging to these groups.

[0343] Among them, from the viewpoint of further improving the heat aging resistance of the polyamide composition, copper salts are preferred. As such copper salts, they are not limited to the following substances, and for example, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, and copper complex salts obtained by coordinating copper with a chelating agent can be cited.

[0344] As the chelating agent, for example, ethylenediamine, ethylenediaminetetraacetic acid, etc. can be cited.

[0345] These copper salts can be used alone or in combination of two or more.

[0346] Among them, as the copper salt, copper acetate is preferred. When using copper acetate, a polyamide composition with more excellent heat aging resistance and capable of more effectively suppressing metal corrosion (hereinafter sometimes simply referred to as "metal corrosion") of the screw or barrel part during extrusion can be obtained.

[0347] When using a copper salt as the (F4) heat stabilizer, the content of the copper salt in the polyamide composition is preferably 0.01% by mass or more and 0.60% by mass or less, more preferably 0.02% by mass or more and 0.40% by mass or less, based on the total mass of the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide).

[0348] When the content of the copper salt 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 suppressed.

[0349] In addition, from the viewpoint of improving the heat aging resistance of the polyamide composition, relative to the polyamide ((A) aliphatic polyamide and (B) semi-aromatic polyamide) 10 6The content fraction (in million content fractions) of copper element derived from the above copper salt is preferably 10 content fractions or more and 2000 content fractions or less, more preferably 30 content fractions or more and 1500 content fractions or less, and still more preferably 50 content fractions or more and 500 content fractions or less.

[0350] The components of the (F4) heat stabilizer described above can be used alone or in combination of two or more.

[0351] "Manufacturing Method of Polyamide Composition"

[0352] As the manufacturing method of the polyamide composition of the present embodiment, there is no particular limitation as long as it is a method of mixing (A) aliphatic polyamide with the components of (B) to (D) above and the components of (E) and (F) as needed.

[0353] As the mixing method of the components of (A) to (D) above and the components of (E) and (F) as needed, for example, the following methods (1) or (2) etc. can be cited.

[0354] (1) A method of mixing the components of (A) to (D) above and the components of (E) and (F) as needed using a Henschel mixer etc., and supplying them to a melt kneader for kneading.

[0355] (2) A method of previously mixing the components of (A) to (D) above and the component of (E) as needed using a Henschel mixer etc. to prepare a mixture containing the components of (A) to (D) and the component of (F) as needed, supplying this mixture to a melt kneader for kneading, and then optionally adding the component of (E) by a side feeder using a single-screw or twin-screw extruder.

[0356] Regarding the method of supplying the components constituting the polyamide composition to the melt kneader, all the constituent components can be supplied at once through the same supply port, or the constituent components can be supplied from different supply ports respectively.

[0357] The temperature of melt kneading is preferably about 1°C or more and about 100°C or less higher than the melting point of (A) aliphatic polyamide, and more preferably about 10°C or more and about 50°C or less higher than the melting point of (A) aliphatic polyamide.

[0358] The shear rate in the kneader is preferably about 100 seconds -1 or more. In addition, the average residence time during kneading is preferably about 0.5 minutes or more and about 5 minutes or less.

[0359] As a device for melt-kneading, any well-known device can be used, and for example, a single-screw or twin-screw extruder, Banbury mixer, melt-kneading machine (such as a mixing roll), etc. are preferably used.

[0360] The compounding amounts of the respective components in the production of the polyamide composition of the present embodiment are the same as the contents of the respective components in the above-described polyamide composition.

[0361] <Molded Article>

[0362] The molded article of the present embodiment is obtained by molding the polyamide composition of the above-described embodiment.

[0363] The molded article of the present embodiment does not contain halogens, has excellent flame retardancy, and has good tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance.

[0364] As a method for obtaining the molded article, there is no particular limitation, and well-known molding methods can be used.

[0365] As well-known molding methods, for example, extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, dissimilar material molding, gas-assisted injection molding, foam injection molding, low-pressure molding, ultra-thin wall injection molding (ultra-high speed injection molding), in-mold composite molding (insert molding, overmolding on insert), etc. can be cited.

[0366] <Use>

[0367] The molded article of the present embodiment contains the polyamide composition of the above-described embodiment, has excellent flame retardancy and mechanical properties (particularly flexural modulus of elasticity when absorbing water and long-term heat resistance), and can be used for various purposes.

[0368] As uses of the molded article of the present embodiment, for example, it can be suitably used in the fields of automobiles, electric and electronic devices, machinery and industry, office equipment, and aviation and aerospace.

[0369] [Examples]

[0370] Hereinafter, specific examples and comparative examples will be cited to illustrate the present invention in detail, but the present invention is not limited to the following examples.

[0371] Hereinafter, the respective constituent components of the polyamide compositions used in the examples and comparative examples will be described.

[0372] <Constituent Components>

[0373] [(A) Aliphatic Polyamide]

[0374] A-1: Polyamide 66

[0375] A-2: Polyamide 6 (manufactured by Ube Industries, Ltd., model: SF1013A, molecular weight: 33,000)

[0376] [(B) Semi-aromatic polyamide]

[0377] B-1: Polyamide 6I

[0378] B-2: Polyamide 6I / 6T (manufactured by EMS, model: G21, content of isophthalic acid unit in all dicarboxylic acid units: 70 mol%, molecular weight: 27,000)

[0379] B-3: Polyamide MXD6 (manufactured by Toyobo Co., Ltd., trade name: Toyobo Nylon, T-600)

[0380] [(C) Hypophosphite salts]

[0381] C-1: Hypophosphite flame retardant aluminum diethylphosphinate (manufactured by Clariant, trade name: "Exolit OP1230")

[0382] C-2: Hypophosphorous acid flame retardant calcium diethylphosphinate (manufactured by Taihei Chemical Industry Co., Ltd.)

[0383] [(C’) Flame retardants other than hypophosphite salts]

[0384] C’-1: Nitrogen-containing flame retardant melamine cyanurate (manufactured by Nissan Chemical Industries, Ltd.)

[0385] C’-2: Nitrogen- and phosphorus-containing flame retardant cyclic phenoxyphosphazene (manufactured by Otsuka Chemical Co., Ltd.)

[0386] [(D) Polymer with an oxygen index of 27% or more and having an aromatic group in the main chain]

[0387] D-1: Polyphenylene sulfide (PPS) (manufactured by DIC Corporation) (oxygen index: 46%, molecular weight: 30,000)

[0388] D-2: Maleic anhydride-modified polyphenylene ether (m-PPE) (manufactured by Asahi Kasei Corporation) (oxygen index: 28%, molecular weight: 54,000)

[0389] D-3: Polyphenylene ether (PPE) (manufactured by Asahi Kasei Corporation) (oxygen index: 28%, molecular weight: 30,000)

[0390] D-4: Polysulfone (PSF) (manufactured by Solvay) (oxygen index: 30%, molecular weight: 50,000)

[0391] [(D’) Polymer with an oxygen index less than 27% or not having an aromatic group in the main chain]

[0392] D'-1: Polycarbonate (PC) (manufactured by Teijin Limited) (Oxygen index: 25%, Molecular weight: 40,000)

[0393] D'-2: Polyvinyl chloride (PVC) (manufactured by Taiyo Polyvinyl Chloride Co., Ltd.) (Oxygen index: 30%, Molecular weight: 97,000)

[0394] It should be noted that the oxygen indices of the above (D) polymers and the above (D') polymers were measured according to ISO 4589-2.

[0395] [(E) Filler]

[0396] E-1: Glass fiber (GF) (manufactured by Nippon Electric Glass Co., Ltd., trade name: "ECS03T275H", average fiber diameter: 10 μmφ, cut length: 3 mm)

[0397] [(F) Other additives]

[0398] F-1: Phenolic heat stabilizer (manufactured by Ciba Specialty Chemicals, trade name "Irganox 1098")

[0399] <Manufacture of polyamide>

[0400] The manufacturing methods of aliphatic polyamide A-1 and semi-aromatic polyamide B-1 are described in detail below. It should be noted that the aliphatic polyamide A-1 and semi-aromatic polyamide B-1 obtained by the following manufacturing methods were dried in a nitrogen gas 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.

[0401] [Synthesis Example 1] Synthesis of aliphatic polyamide A-1 (polyamide 66)

[0402] The polymerization reaction of polyamide was carried out by the "thermal melting polymerization method" as described below.

[0403] First, 1500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500 g of distilled water to prepare a 50 mass% homogeneous aqueous solution of an equimolar amount of the raw material monomers. This aqueous solution was charged into an autoclave with an internal volume of 5.4 L and purged with nitrogen. Then, while stirring at a temperature of about 110 °C or higher and about 150 °C or lower, water vapor was slowly discharged and concentrated to a solution concentration of 70 mass%. Next, the internal temperature was raised to 220 °C. At this time, the pressure in the autoclave was increased to 1.8 MPa. This state was maintained for 1 hour until the internal temperature reached 245 °C, and while slowly discharging water vapor and maintaining the pressure at 1.8 MPa, the reaction was carried out for 1 hour. Then, the pressure was reduced over 1 hour. Next, the inside of the autoclave was maintained at a reduced pressure of 650 Torr (86.66 kPa) for 10 minutes using a vacuum device. At this time, the final internal temperature of the polymerization was 265 °C. Then, it was pressurized with nitrogen and formed into a strand shape from the lower spinneret (nozzle), water-cooled, cut, and discharged in the form of pellets. Next, the pellets were dried at 100 °C in a nitrogen atmosphere for 12 hours to obtain an aliphatic polyamide A-1 (polyamide 66).

[0404] The obtained aliphatic polyamide A-1 (polyamide 66) had Mw(A) = 40000.

[0405] [Synthesis Example 2] Synthesis of semi-aromatic polyamide B-1 (polyamide 6I)

[0406] As described above, the polymerization reaction of polyamide was carried out by the "thermal melting polymerization method".

[0407] First, 1500 g of an equimolar salt of isophthalic acid and hexamethylenediamine, 1.5 mol% of adipic acid in excess relative to all the equimolar salt components, and 0.5 mol% of acetic acid were dissolved in 1500 g of distilled water to prepare a 50 mass% homogeneous aqueous solution of an equimolar amount of the raw material monomers. Then, while stirring at a temperature of about 110 °C or higher and about 150 °C or lower, water vapor was slowly discharged and concentrated to a solution concentration of 70 mass%. Next, the internal temperature was raised to 220 °C. At this time, the pressure in the autoclave was increased to 1.8 MPa. This state was maintained for 1 hour until the internal temperature reached 245 °C, and while slowly discharging water vapor and maintaining the pressure at 1.8 MPa, the reaction was carried out for 1 hour. Then, the pressure was reduced over 30 minutes. Next, the inside of the autoclave was maintained at a reduced pressure of 650 Torr (86.66 kPa) for 10 minutes using a vacuum device. At this time, the final internal temperature of the polymerization was 265 °C. Then, it was pressurized with nitrogen and formed into a strand shape from the lower spinneret (nozzle), water-cooled, cut, and discharged in the form of pellets. Next, the pellets were dried at 100 °C in a nitrogen atmosphere for 12 hours to obtain a semi-aromatic polyamide B-1 (polyamide 6I).

[0408] The content of isophthalic acid units in the dicarboxylic acid units of the resulting semi-aromatic polyamide B-1 (polyamide 6I) is 100 mol%. Mw = 20,000.

[0409] <Physical properties and evaluation>

[0410] First, the pellets of the polyamide compositions obtained in the examples and comparative examples were dried in a nitrogen gas stream to adjust the water content in the polyamide compositions to 500 ppm or less. Then, using the pellets of each polyamide composition with the adjusted water content, various physical property measurements and various evaluations were carried out by the following methods.

[0411] [Physical property 1] tanδ peak temperature

[0412] Using a PS40E injection molding machine manufactured by Nissei Plastic Industrial Co., Ltd., the barrel temperature was set at 290 °C, the mold temperature was set at 100 °C, and it was molded into a molded product according to JIS-K7139 under the injection molding conditions of an injection time of 10 seconds and a cooling time of 10 seconds. This molded product was measured under the following conditions using a dynamic viscoelasticity evaluation device (EPLEXOR500N, manufactured by GABO).

[0413] (Measurement conditions)

[0414] Measurement mode: Tensile

[0415] Measurement frequency: 8.00 Hz

[0416] Temperature increase rate: 3 °C / minute

[0417] Temperature range: -100 °C to 250 °C

[0418] The ratio of the loss elastic modulus E2 to the storage elastic modulus E1 (E2 / E1) was defined as tanδ, and the highest temperature was defined as the tanδ peak temperature.

[0419] [Physical property 2] Molecular weight (Mw) of the polyamide composition

[0420] The weight average molecular weight (Mw) of the polyamide compositions obtained in the examples and comparative examples was measured using GPC under the following measurement conditions.

[0421] (Measurement conditions)

[0422] Measurement device: HLC-8020, manufactured by Tosoh Corporation

[0423] Solvent: Hexafluoroisopropanol solvent

[0424] Standard sample: Converted to PMMA (polymethyl methacrylate) (manufactured by Polymer Laboratories Ltd.)

[0425] GPC columns: TSK-GEL GMHHR-M and G1000HHR

[0426] [Evaluation 1] Flame retardancy

[0427] It was measured using the method of UL94 (a standard formulated by Underwriters Laboratories Inc., USA). It should be noted that the test pieces (length 127 mm, width 12.7 mm, thickness 1.6 mm) were produced as follows: A mold for UL test pieces (mold temperature = 100 °C) was installed on an injection molding machine (PS40E manufactured by Nissei Plastic Industrial Co., Ltd.), and each polyamide composition was molded at a barrel temperature of 290 °C. Regarding the injection pressure, it was carried out at a pressure of the full filling pressure + 2% when molding the UL test pieces. The flame retardancy grade was evaluated according to the UL94 standard (vertical burning test) to see if it corresponded to any one of the grades V-0, V-1, or V-2. It should be noted that the smaller the grade value, the higher the flame retardancy.

[0428] [Evaluation 2] Tensile strength

[0429] Each polyamide composition was molded into a molded piece of multi-purpose test piece type A according to ISO 3167 using an injection molding machine "PS-40E: manufactured by Nissei Plastic Co., Ltd.". The specific molding conditions were: setting the injection + holding pressure time to 25 seconds, setting the cooling time to 15 seconds, setting the mold temperature to 80 °C, and setting the molten resin temperature to the melting peak temperature (Tm2) on the high-temperature side of the polyamide + 20 °C.

[0430] Using the obtained molded piece of multi-purpose test piece type A, a tensile test was carried out at a temperature of 23 °C and a pulling speed of 5 mm / min according to ISO 527, and the tensile yield stress was measured as the tensile strength.

[0431] [Evaluation 3] Flexural modulus of elasticity when absorbing water

[0432] ISO dumbbell-shaped test pieces with a thickness of 4 mm were produced as test pieces. Using the obtained test pieces, the flexural modulus of elasticity was measured according to ISO178. In addition, the ISO dumbbell-shaped test pieces were placed in an atmosphere of constant temperature and humidity (23 °C, 50RH%), and after reaching the water absorption equilibrium, the flexural modulus of elasticity was measured according to ISO 178.

[0433] [Evaluation 4] Long-term heat resistance

[0434] The multi-purpose test piece (type A) in the above tensile strength was heated at 150 °C in a hot air circulation oven to cause thermal aging.

[0435] After being placed in the oven for 1000 hours, it was taken out of the oven and cooled at 23°C for more than 24 hours. Then, according to ISO 527 and at a pulling speed of 5 mm / minute, a tensile test was performed on the cooled multi-purpose test piece (Type A) using the same method as above, and the tensile strength of each was measured. The heat aging retention rate was calculated using the following formula.

[0436] Heat aging retention rate (%) = Tensile strength after aging / Tensile strength before aging × 100

[0437] [Evaluation 5] Tracking resistance

[0438] A test piece of 30 mm × 30 mm with a thickness of 4 mm was produced, and the CTI was measured according to the IEC60112 standard. It should be noted that the applied voltage was in units of 50 V.

[0439] Based on the obtained comparative tracking index (TI), the grades were divided as follows.

[0440] (Grade division)

[0441] CTI Grade 0: 600 ≤ TI

[0442] CTI Grade 1: 400 ≤ TI < 600

[0443] CTI Grade 2: 250 ≤ TI < 400

[0444] CTI Grade 3: 175 ≤ TI < 250

[0445] CTI Grade 4: 100 ≤ TI < 175

[0446] CTI Grade 5: 0 ≤ TI < 100

[0447] [Example 1] Manufacture of polyamide composition P-1a

[0448] Using a TEM 35 mm twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (set temperature: 280 °C, screw rotation speed: 300 rpm), (A) aliphatic polyamide A-1 and a substance obtained by premixing (B) semi-aromatic polyamide B-1, (D) polymer D-1, and (F) other additive F-1 were supplied from the top feed port provided at the uppermost upstream part of the extruder. Further, (C) flame retardant C-1 and (E) filler E-1 were supplied from the side feed port on the downstream side of the extruder (in a state where the resin supplied from the top feed port was sufficiently melted). Subsequently, the melt-kneaded product extruded from the die head was cooled in the form of a strand and pelletized, thereby obtaining pellets of polyamide composition P-1a. The compounding amounts were set as follows: (A) aliphatic polyamide A-1: 46.0% by mass, (B) semi-aromatic polyamide B-1: 11.6% by mass, (C) flame retardant C-1: 16.0% by mass, (D) polymer D-1: 1.0% by mass, (E) filler E-1: 25.0% by mass, and (F) other additive F-1: 0.1% by mass.

[0449] [Example 2] Production of polyamide composition P-2a

[0450] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 45.2% by mass, (B) semi-aromatic polyamide B-1: 11.4% by mass, and (D) polymer D-1: 2.0% by mass, pellets of polyamide composition P-2a were obtained using the same method as in Example 1.

[0451] [Example 3] Production of polyamide composition P-3a

[0452] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 44.4% by mass, (B) semi-aromatic polyamide B-1: 11.2% by mass, and (D) polymer D-1: 3.0% by mass, pellets of polyamide composition P-3a were obtained using the same method as in Example 1.

[0453] [Example 4] Production of polyamide composition P-4a

[0454] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 43.6% by mass, (B) semi-aromatic polyamide B-1: 11.0% by mass, and (D) polymer D-1: 4.0% by mass, pellets of polyamide composition P-4a were obtained using the same method as in Example 1.

[0455] [Example 5] Production of polyamide composition P-5a

[0456] Granules of polyamide composition P-5a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 46.2% by mass, (B) semi-aromatic polyamide B-1: 11.6% by mass, and (D) polymer D-2: 1.0% by mass.

[0457] [Example 6] Production of polyamide composition P-6a

[0458] Granules of polyamide composition P-6a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 44.6% by mass, (B) semi-aromatic polyamide B-1: 11.2% by mass, and (D) polymer D-2: 3.0% by mass.

[0459] [Example 7] Production of polyamide composition P-7a

[0460] Granules of polyamide composition P-7a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 42.8% by mass, (B) semi-aromatic polyamide B-1: 10.8% by mass, and (D) polymer D-2: 5.0% by mass.

[0461] [Example 8] Production of polyamide composition P-8a

[0462] Granules of polyamide composition P-8a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 40.0% by mass, (B) semi-aromatic polyamide B-1: 10.0% by mass, and (D) polymer D-2: 5.7% by mass.

[0463] [Example 9] Production of polyamide composition P-9a

[0464] Granules of polyamide composition P-9a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 44.4% by mass, (B) semi-aromatic polyamide B-1: 11.2% by mass, and (D) polymer D-3: 3.0% by mass.

[0465] [Example 10] Production of polyamide composition P-10a

[0466] Granules of polyamide composition P-10a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 44.4% by mass, (B) semi-aromatic polyamide B-1: 11.2% by mass, and (D) polymer D-4: 3.0% by mass.

[0467] [Example 11] Manufacture of Polyamide Composition P-11a

[0468] Granules of polyamide composition P-11a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 45.2% by mass, (B) semi-aromatic polyamide B-2: 11.4% by mass, and (D) polymer D-1: 2.0% by mass.

[0469] [Example 12] Manufacture of Polyamide Composition P-12a

[0470] Granules of polyamide composition P-12a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 42.8% by mass, (B) semi-aromatic polyamide B-2: 10.8% by mass, and (D) polymer D-2: 5.0% by mass.

[0471] [Example 13] Manufacture of Polyamide Composition P-13a

[0472] Granules of polyamide composition P-13a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-2: 45.2% by mass, (B) semi-aromatic polyamide B-1: 11.4% by mass, and (D) polymer D-1: 2.0% by mass.

[0473] [Example 14] Manufacture of Polyamide Composition P-14a

[0474] Granules of polyamide composition P-14a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-2: 42.8% by mass, (B) semi-aromatic polyamide B-1: 10.8% by mass, and (D) polymer D-2: 5.0% by mass.

[0475] [Example 15] Manufacture of Polyamide Composition P-15a

[0476] Granules of polyamide composition P-15a were obtained in the same manner as in Example 1, except that the compounding amounts were changed to (A) aliphatic polyamide A-1: 48.2% by mass, (B) semi-aromatic polyamide B-1: 5.4% by mass, and (D) polymer D-2: 5.0% by mass.

[0477] [Example 16] Manufacture of Polyamide Composition P-16a

[0478] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 37.5% by mass, (B) semi-aromatic polyamide B-1: 16.1% by mass, and (D) polymer D-2: 5.0% by mass, pellets of polyamide composition P-16a were obtained in the same manner as in Example 1.

[0479] [Example 17] Production of polyamide composition P-17a

[0480] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 32.2% by mass, (B) semi-aromatic polyamide B-1: 21.4% by mass, and (D) polymer D-2: 5.0% by mass, pellets of polyamide composition P-17a were obtained in the same manner as in Example 1.

[0481] [Example 18] Production of polyamide composition P-18a

[0482] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 29.4% by mass, (B) semi-aromatic polyamide B-1: 7.4% by mass, (C) phosphinate C-1: 9.0% by mass, (D) polymer D-2: 3.8% by mass, and (E) filler: 50% by mass, pellets of polyamide composition P-18a were obtained in the same manner as in Example 1.

[0483] [Example 19] Production of polyamide composition P-19a

[0484] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 22.2% by mass, (B) semi-aromatic polyamide B-1: 14.6% by mass, (C) phosphinate C-1: 9.0% by mass, (D) polymer D-2: 3.8% by mass, and (E) filler: 50.0% by mass, pellets of polyamide composition P-19a were obtained in the same manner as in Example 1.

[0485] [Example 20] Production of polyamide composition P-20a

[0486] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 39.6% by mass, (B) semi-aromatic polyamide B-1: 10.0% by mass, (C) phosphinate C-2: 20.0% by mass, (D) polymer D-2: 5.0% by mass, pellets of polyamide composition P-20a were obtained in the same manner as in Example 1.

[0487] [Example 21] Production of polyamide composition P-21a

[0488] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 7.0% by mass, (B) semi-aromatic polyamide B-3: 46.6% by mass, (C) hypophosphite C-1: 16.0% by mass, and (D) polymer D-2: 5.0% by mass, pellets of polyamide composition P-21a were obtained in the same manner as in Example 1.

[0489] [Comparative Example 1] Production of polyamide composition P-1b

[0490] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 46.8% by mass, (B) semi-aromatic polyamide B-1: 11.8% by mass, and (D) polymer D-1: 0% by mass, pellets of polyamide composition P-1b were obtained in the same manner as in Example 1.

[0491] [Comparative Example 2] Production of polyamide composition P-2b

[0492] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 46.8% by mass, (B) semi-aromatic polyamide B-2: 11.8% by mass, and (D) polymer D-1: 0% by mass, pellets of polyamide composition P-2b were obtained in the same manner as in Example 1.

[0493] [Comparative Example 3] Production of polyamide composition P-3b

[0494] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 41.7% by mass, (B) semi-aromatic polyamide B-1: 10.4% by mass, and (D) polymer D-1: 6.5% by mass, pellets of polyamide composition P-3b were obtained in the same manner as in Example 1.

[0495] [Comparative Example 4] Production of polyamide composition P-4b

[0496] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 41.7% by mass, (B) semi-aromatic polyamide B-1: 10.4% by mass, and (D) polymer D-2: 6.5% by mass, pellets of polyamide composition P-4b were obtained in the same manner as in Example 1.

[0497] [Comparative Example 5] Production of polyamide composition P-5b

[0498] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 42.8% by mass, (B) semi-aromatic polyamide B-1: 10.8% by mass, and (D') polymer D'-1: 5.0% by mass, pellets of polyamide composition P-5b were obtained in the same manner as in Example 1.

[0499] [Comparative Example 6] Production of Polyamide Composition P-6b

[0500] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 42.8% by mass, (B) semi-aromatic polyamide B-1: 10.8% by mass, and (D’) polymer D’-2: 5.0% by mass, pellets of polyamide composition P-6b were obtained in the same manner as in Example 1.

[0501] [Comparative Example 7] Production of Polyamide Composition P-7b

[0502] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 24.3% by mass, (B) semi-aromatic polyamide B-1: 16.3% by mass, (C) phosphinate C-1: 9.0% by mass, and (D) polymer D-1: 0% by mass, pellets of polyamide composition P-7b were obtained in the same manner as in Example 1.

[0503] [Comparative Example 8] Production of Polyamide Composition P-8b

[0504] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 42.8% by mass, (B) semi-aromatic polyamide B-1: 10.8% by mass, (C’) flame retardant C’-1 other than phosphinate: 16.0% by mass, and (D) polymer D-2: 5.0% by mass, pellets of polyamide composition P-8b were obtained in the same manner as in Example 1.

[0505] [Comparative Example 9] Production of Polyamide Composition P-9b

[0506] Except for changing the compounding amounts to (A) aliphatic polyamide A-1: 42.8% by mass, (B) semi-aromatic polyamide B-1: 10.8% by mass, (C’) flame retardant C’-2 other than phosphinate: 16.0% by mass, and (D) polymer D-2: 5.0% by mass, pellets of polyamide composition P-9b were obtained in the same manner as in Example 1.

[0507] In addition, molded articles were manufactured from the pellets of each polyamide composition obtained using the above method, and various physical properties were measured and evaluated. The evaluation results are shown in Tables 1 to 5 below.

[0508] Table 1

[0509]

[0510] Table 2

[0511]

[0512] Table 3

[0513]

[0514] Table 4

[0515]

[0516] Table 5

[0517]

[0518] As can be seen from Tables 1 to 3, the molded articles obtained from polyamide compositions P-1a to P-21a (Examples 1 to 21) containing (A) aliphatic polyamide, (B) semi-aromatic polyamide, (C) hypophosphite salts, and (D) polymer, and having the content of the (D) polymer in the range of 0.1% by mass or more and 8.0% by mass or less relative to the total mass of the components (A) to (D) have excellent flame retardancy, and excellent tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance.

[0519] In addition, among the polyamide compositions P-3a, P-6a, P-9a, and P-10a (Examples 3, 6, 9, and 10) containing different types of (D) polymer, the molded articles obtained from the polyamide compositions P-3a, P-6a, and P-9a (Examples 3, 6, and 9) containing D-1, D-2, and D-3 have particularly good tensile strength and long-term heat resistance compared to the molded articles obtained from the polyamide composition P-10a (Example 10) containing D-4.

[0520] In addition, among the polyamide compositions P-2a and P-11a (Examples 2 and 11) and P-7a and P-12a (Examples 7 and 12) containing different types of (B) semi-aromatic polyamide, the molded articles obtained from the polyamide compositions P-2a and P-7a (Examples 2 and 7) containing B-1 have particularly good tensile strength and flexural modulus of elasticity when absorbing water compared to the molded articles obtained from the polyamide compositions (Examples 11 and 12) containing B-2.

[0521] In addition, among the polyamide compositions P-2a and P-13a (Examples 2 and 13) and P-7a and P-14a (Examples 7 and 14) containing different types of (A) aliphatic polyamide, the molded articles obtained from the polyamide compositions P-2a and P-7a (Examples 2 and 7) containing A-1 have particularly good tensile strength and flexural modulus of elasticity when absorbing water compared to the molded articles obtained from the polyamide compositions P-13a and P-14a (Examples 13 and 14) containing A-2.

[0522] In addition, in polyamide compositions P-8a and P-20a (Examples 8 and 20) containing different types of (C) phosphinates, the molded article obtained from the polyamide composition P-8a (Example 8) containing C-1 has particularly good tensile strength and flexural modulus of elasticity when absorbing water compared to the molded article obtained from the polyamide composition P-20a (Example 20) containing C-2.

[0523] In contrast, as can be seen from Tables 4 to 5, the molded articles obtained from polyamide compositions P-1b, P-2b, and P-7b (Comparative Examples 1, 2, and 7) that do not contain (D) polymer have poor flame retardancy, flexural modulus of elasticity when absorbing water, and long-term heat resistance.

[0524] In addition, the molded articles obtained from polyamide compositions P-3b and P-4b (Comparative Examples 3 and 4) in which the content of (D) polymer is greater than 8.0% by mass relative to the total mass of components (A) to (D) have poor flame retardancy and tracking resistance.

[0525] In addition, the molded article obtained from polyamide composition P-5b (Comparative Example 5) in which the content of (D’) polymer is 0.1% by mass or more and 8.0% by mass or less relative to the total mass of components (A) to (D’), but contains a (D’) polymer having an oxygen index of less than 27% and no aromatic group in the main chain, has poor flame retardancy.

[0526] In addition, the molded articles obtained from polyamide composition P-6b (Comparative Example 6) in which the content of (D’) polymer is 0.1% by mass or more and 8.0% by mass or less relative to the total mass of components (A) to (D’), but contains a (D’) polymer having no aromatic group in the main chain, have poor flexural modulus of elasticity when absorbing water, long-term heat resistance, and tracking resistance.

[0527] In addition, the molded articles obtained from polyamide composition P-8b (Comparative Example 8) in which a nitrogen-containing flame retardant C’-1 is used as a halogen-free flame retardant other than (C) phosphinates to replace (C) phosphinates, and from polyamide composition P-9b (Comparative Example 9) in which a nitrogen- and phosphorus-containing flame retardant C’-2 is used as a halogen-free flame retardant other than (C) phosphinates to replace (C) phosphinates, have poor flame retardancy, tensile strength, and flexural modulus of elasticity when absorbing water, and the molded article obtained from polyamide composition P-9b (Comparative Example 9) also has poor tracking resistance.

[0528] From the above, it can be seen that a molded article excellent in halogen-free property, flame retardancy, tensile strength, flexural modulus of elasticity when absorbing water, and long-term heat resistance can be obtained from the polyamide composition according to the present embodiment.

[0529] [Industrial Applicability]

[0530] According to the polyamide composition of the present embodiment, a molded article that does not contain halogen but has excellent flame retardancy and excellent long-term heat resistance can be obtained. The molded article of the present embodiment can be suitably used in the fields of automobiles, electric and electronic fields, mechanical and industrial fields, office equipment fields, and aviation and aerospace fields.

Claims

1. A polyamide composition, comprising: (A) an aliphatic polyamide; (B) a semi-aromatic polyamide containing diamine units and dicarboxylic acid units; (C) at least one phosphinate selected from the group consisting of phosphinates represented by the following general formula (1), bis(phosphinates) represented by the following general formula (2), and condensates thereof; and (D) a polymer having an oxygen index of 27% or more and having an aromatic group in the main chain, the oxygen index being measured according to ISO4589-2, wherein, relative to the total mass of the (A) aliphatic polyamide, the (B) semi-aromatic polyamide, the (C) phosphinates, and the (D) polymer, the content of the (D) polymer is 2.5% by mass or more and 8% by mass or less, relative to the total mass of the (A) aliphatic polyamide, the (B) semi-aromatic polyamide, the (C) phosphinates, and the (D) polymer, the content of the (C) phosphinates is 0.1% by mass or more and 30% by mass or less, relative to the total mass of the polyamides in the polyamide composition, the content of the (B) semi-aromatic polyamide in the polyamide composition is 5% by mass or more and 50% by mass or less, the (B) semi-aromatic polyamide contains 50 mol% or more of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide, the (D) polymer is polyphenylene sulfide or maleic anhydride-modified polyphenylene ether, In general formula (1), R 11 and R 12 are each independently an alkyl group having 1 or more and 6 or less carbon atoms or an aryl group having 6 or more and 10 or less carbon atoms; M n11+ is an n11-valent metal ion; M is an element belonging to Group 2 of the periodic table, zinc, or aluminum; n11 is 2 or 3; when n11 is 2 or 3, the plurality of R 11 and R 12 may be the same or different from each other; In general formula (2), R 21 and R 22 are each independently an alkyl group having 1 or more and 6 or less carbon atoms or an aryl group having 6 or more and 10 or less carbon atoms; Y 21 is an alkylene group having 1 or more and 10 or less carbon atoms or an arylene group having 6 or more and 10 or less carbon atoms; M’ m21+ is an m21-valent metal ion; M’ is an element belonging to Group 2 of the periodic table, zinc, or aluminum; n21 is an integer of 1 or more and 3 or less; when n21 is 2 or 3, the plurality of R 21 , R 22 and Y 21 may be the same or different from each other; m21 is 2 or 3; x is 1 or 2; when x is 2, the plurality of M’ present may be the same or different; n21, x, and m21 are integers that satisfy the relationship 2×n21 = m21×x.

2. The polyamide composition according to claim 1, wherein, the (A) aliphatic polyamide contains diamine units and dicarboxylic acid units.

3. The polyamide composition according to claim 1, wherein, the (A) aliphatic polyamide is polyamide 66.

4. The polyamide composition according to claim 2, wherein, the (A) aliphatic polyamide is polyamide 66.

5. The polyamide composition according to any one of claims 1 to 4, wherein, the tanδ peak temperature of the polyamide composition is 90 °C or more.

6. The polyamide composition according to any one of claims 1 to 4, wherein, the (B) semi-aromatic polyamide contains 75 mol% or more of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

7. The polyamide composition according to claim 5, wherein, the (B) semi-aromatic polyamide contains 75 mol% or more of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

8. The polyamide composition according to any one of claims 1 to 4, 7, wherein, the (B) semi-aromatic polyamide contains 100 mol% of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

9. The polyamide composition according to claim 5, wherein, the (B) semi-aromatic polyamide contains 100 mol% of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

10. The polyamide composition according to claim 6, wherein, The (B) semi-aromatic polyamide contains 100 mol% of isophthalic acid units among all the dicarboxylic acid units constituting the (B) semi-aromatic polyamide.

11. The polyamide composition according to any one of claims 1 to 4, 7, 9 to 10, wherein, the weight-average molecular weight of the polyamide composition is 10,000 or more and 50,000 or less.

12. The polyamide composition according to claim 5, wherein, the weight-average molecular weight of the polyamide composition is 10,000 or more and 50,000 or less.

13. The polyamide composition according to claim 6, wherein, the weight-average molecular weight of the polyamide composition is 10,000 or more and 50,000 or less.

14. The polyamide composition according to claim 8, wherein, the weight-average molecular weight of the polyamide composition is 10,000 or more and 50,000 or less.

15. The polyamide composition according to any one of claims 1 to 4, 7, 9 to 10, 12 to 14, wherein, the polyamide composition further contains at least one (E) filler.

16. The polyamide composition according to claim 5, wherein, the polyamide composition further contains at least one (E) filler.

17. The polyamide composition according to claim 6, wherein, the polyamide composition further contains at least one (E) filler.

18. The polyamide composition according to claim 8, wherein, the polyamide composition further contains at least one (E) filler.

19. The polyamide composition according to claim 11, wherein, the polyamide composition further contains at least one (E) filler.

20. A molded article obtained by molding the polyamide composition according to any one of claims 1 to 19.

21. A method for manufacturing a polyamide composition, which is a method for manufacturing the polyamide composition according to any one of claims 1 to 19, wherein, the raw material components containing the (A) aliphatic polyamide, the (B) semi-aromatic polyamide, the (C) hypophosphite salts, and the (D) polymer are melt-kneaded.

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