Polyamide composition and molded article

Abstract

To provide a polyamide composition having excellent low-temperature impact resistance, high moldability and high heat deflection temperature, and excellent flame retardancy, wherein the inventive polyamide resin composition offers excellent low-temperature impact resistance, mechanical properties, and electrical properties, as well as high heat resistance, such that it can play a role in maintaining and enhancing the performance of photovoltaic and fuel cell module devices.SOLUTION: Provided is a polyamide resin composition, comprising: (A) 25 to 60 wt.% of a polyamide; (B) 10 to 30 wt.% of a phosphorus-based flame retardant; (C) 2 to 20 wt.% of a polyamide elastomer; and (D) 10 to 60 wt.% of glass fibers.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyamide composition and a molded article. [Background technology]

[0002] Polyamides, such as polyamide 66 (hereinafter also referred to as "PA66"), have excellent moldability, mechanical properties, and chemical resistance, and are therefore widely used as various parts and materials for automobiles, electrical and electronic products, industrial materials, industrial materials, daily necessities, household goods, etc.

[0003] Polyamides are often flame retarded by the addition of halogen compounds. However, recently, various regulations have been established to prevent the use of products containing halogen compounds in electrical and electronic components due to hazardous substance restrictions such as RoHS (Restriction of Hazardous Substances) and PoHS (Prohibition on Certain Hazardous Substances in Consumer Products). For this reason, several non-halogen flame retardants for polyamides have been developed.

[0004] Non-halogen flame retardants include, for example, phosphorus compounds. The use of calcium and aluminum salts of phosphinic or diphosphinic acids as flame retardants for polyamides has been disclosed.

[0005] Recently, photovoltaic power generation has been attracting attention again from the viewpoint of sustainability. Photovoltaic power generation modules are often installed outdoors, and thermoplastic resins forming connection structures such as junction boxes and connectors are now required to have impact strength at low temperatures in addition to the conventional properties required for electrical and electronic component applications, such as electrical insulation properties represented by tracking resistance, excellent flame retardancy, mechanical properties, impact properties, water resistance, chemical resistance, and dimensional stability. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-43762 A [Patent Document 2] Patent Publication No. 2021-50323 [Patent Document 3] International Publication No. 2021 / 257531 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the technology disclosed in Patent Document 1, a non-reinforced polyamide composition using polyamide 12, polyamide 12 elastomer and metal phosphinate is disclosed to improve impact resistance, but there is room for improvement in low-temperature impact properties and load deflection. In the technology disclosed in Patent Document 2, a reinforced polyamide composition using polyamide 66 and polyamide 6I is disclosed, but there is room for improvement in impact resistance. In Patent Document 3, a non-reinforced polyamide using a polyamide elastomer and metal phosphinate is disclosed, but there is room for improvement in heat resistance.

[0008] As described above, in the prior art, the fact is that no polyamide composition is yet known that is capable of achieving low-temperature impact properties, deflection temperature under load, and a rating of V-0 in the UL94V test.

[0009] The present invention has been made in consideration of the above circumstances, and provides a polyamide composition having excellent low-temperature impact properties, high heat resistance, excellent electrical properties, and excellent flame retardancy, as well as a molded article using the polyamide composition. [Means for solving the problem]

[0010] That is, the present invention includes the following aspects. [1] A polyamide resin composition comprising: (A) 20-60 wt% of polyamide; (B) 10-30 wt% of a phosphorus-based flame retardant; (C) 2-20 wt% of a polyamide elastomer; and (D) 10-60 wt% of an inorganic filler. [2] The polyamide composition according to [1], wherein the (B) phosphorus-based flame retardant contains at least one kind of phosphinate selected from the group consisting of a phosphinate represented by the following general formula (1), a diphosphinate represented by the following general formula (2), and a condensate thereof: [ka] (In general formula (1), R 11 and R 12 Each of M is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. n11+ is a metal ion having a valence of n11. M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n11 is 2 or 3. When n11 is 2 or 3, multiple R 11 and R 12 may be the same or different. In general formula (2), R 21 and R 22 Each of Y is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. 21 M' is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms. x m21+ is a metal ion having 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 to 3. When n21 is 2 or 3, multiple R 21 , R 22 and Y 21may be the same or different. m21 is 2 or 3. x is 1 or 2. When x is 2, multiple M' may be the same or different. n21, x, and m21 are integers that satisfy the relational formula 2×n21=m21×x. (B) (in general formula (3), R 1 , R 2 and R 3 Each of M is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. m+ is a metal ion having a valence of m. M is an element belonging to Group 2 or 15 of the periodic table, a transition element, zinc, or aluminum. m is 2 or 3. When m is 2 or 3, multiple R 1 and R 2 may be the same or different. [3] The polyamide composition according to [1] or [2], wherein the phosphorus-based flame retardant (B) comprises a metal phosphinate or a complex metal phosphinate-phosphonate salt. [4] (C) The polyamide elastomer is a polyamide 6-based polyamide elastomer. [5] The polyamide composition according to [1] or [2], wherein the polyamide (A) is a crystalline polyamide (A-1). [6] The (A) polyamide further comprises (A-2) an amorphous polyamide. [7] The polyamide composition according to any one of [1] to [2], wherein the (A-2) amorphous polyamide contains isophthalic acid units in an amount of 50 mol % or more of all dicarboxylic acid units constituting the amorphous polyamide. [8] The polyamide composition according to any one of [1] to [4], wherein the (A-2) amorphous polyamide contains 75 mol % or more of isophthalic acid units in all dicarboxylic acid units constituting the amorphous polyamide. [9] The polyamide composition according to any one of [1] to [5], wherein the (A-2) amorphous polyamide contains 100 mol % of isophthalic acid units in all dicarboxylic acid units constituting the polyamide. Effect of the Invention

[0011] According to the polyamide composition of the above embodiment, it is possible to provide a polyamide composition which, when formed into a molded article, has high low-temperature impact resistance, excellent deflection under load, and excellent flame retardancy. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0013] In this specification, the term "polyamide" refers to a polymer having an amide (-NHCO-) ​​group in the main chain.

[0014] <Polyamide composition> The polyamide composition of the present embodiment contains [1] a polyamide resin composition including (A) 20 to 60 wt % of a polyamide, (B) 10 to 30 wt % of a phosphorus-based flame retardant, (C) 2 to 20 wt % of a polyamide elastomer, and (D) 10 to 60% of an inorganic filler.

[0015] <(A) Polyamide> Examples of the polyamide (A) include polycaprolactam (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polyhexamethylene cyclohexylamide (polyamide 6C), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecalactam (polyamide 11), and polydodecalactam. (polyamide 12), polyhexamethylene isophthalamide (polyamide 6I), polyhexamethylene terephthalamide (polyamide 6T), polynonamethylene terephthalamide (polyamide 9T), polydodecamethylene terephthalamide (polyamide 12T), polymetaxylylene adipamide (polyamide MXD6), and polyamide copolymers obtained by copolymerizing two or more of these polyamides. These polyamides may be used alone or in combination of two or more.

[0016] The (A-1) crystalline polyamide has a melting point (Tm) of 290.0°C or lower, preferably 280.0°C or lower, more preferably 220.0°C or higher and 280.0°C or lower, even more preferably 220.0°C or higher and 270.0°C or lower, and particularly preferably 240.0°C or higher and 270.0°C or lower. When the melting point Tm of the polyamide composition is within the above range, the polyamide composition is excellent in melt processing such as extrusion and molding, the thermal decomposition of the phosphorus-based flame retardant can be further suppressed, and the deflection temperature under load is excellent.

[0017] The melting point Tm of the (A-1) crystalline polyamide can be measured in accordance with JIS-K7121, and examples of the measuring device include a differential scanning calorimeter (DSC), more specifically, a Diamond-DSC manufactured by PERKIN-ELMER.

[0018] The content of the (A-2) amorphous polyamide is 10.0% by mass or more and 50.0% by mass or less, preferably 10.0% by mass or more and 45.0% by mass or less, more preferably 12.5% ​​by mass or more and 45.0% by mass or less, even more preferably 15.0% by mass or more and 42.5% by mass or less, even more preferably 17.5% by mass or more and 40.0% by mass or less, and particularly preferably 20.0% by mass or more and 35.0% by mass or less. By making the content of the (B) amorphous polyamide within the above range, a polyamide composition having excellent mechanical properties, particularly rigidity under atmospheric equilibrium moisture absorption, flame retardancy, plasticization stability, and other moldability properties can be obtained. In addition, a polyamide composition containing a component typified by an inorganic filler has excellent load deflection.

[0019] The polyamide composition of the present embodiment has the above-mentioned configuration, and is therefore excellent in melt processing such as extrusion and molding. It is possible to provide a polyamide composition that can further suppress the thermal decomposition of the phosphorus-based flame retardant, has an excellent deflection temperature under load, has good moldability, and is excellent in flame retardancy. In the following description, the (A) polyamide, the (B) phosphorus-based flame retardant, the (C) polyamide elastomer, and the (D) inorganic filler may be referred to as the (A) component, the (B) component, the (C) component, and the (D) component, respectively.

[0020] <Characteristics of polyamide composition> In the polyamide composition of the present embodiment, the melting point Tm can be set as follows.

[0021] [Melting point Tm of polyamide composition] The melting point Tm of the polyamide composition is preferably 330.0°C or lower, more preferably 300.0°C or lower, even more preferably 290.0°C or lower, even more preferably 280.0°C or lower, even more preferably 220.0°C or higher and 280.0°C or lower, particularly preferably 220.0°C or higher and 270.0°C or lower, and most preferably 240.0°C or higher and 270.0°C or lower.

[0022] By having the melting point Tm of the polyamide composition within the above range, the polyamide composition has excellent mechanical properties, particularly rigidity under atmospheric equilibrium moisture absorption, flame retardancy, and moldability. In addition, the polyamide composition containing a component such as an inorganic filler has excellent heat resistance, such as deflection temperature under load. On the other hand, when the melting point Tm of the polyamide composition is within the above range, it is possible to obtain a polyamide composition having superior properties such as hot rigidity. The melting point Tm of the polyamide composition can be measured in accordance with JIS-K7121, and an example of a measuring device is Diamond-DSC manufactured by PERKIN-ELMER.

[0023] <(A-1) Crystalline polyamide> A crystalline polyamide is a polyamide having a heat of fusion of crystals of 15 J / g or more when measured at 20° C. / min by a differential scanning calorimeter.

[0024] Examples of the crystalline polyamide (A-1) include, but are not limited to, (Aa) polyamides obtained by ring-opening polymerization of lactams, (Ab) polyamides obtained by self-condensation of ω-aminocarboxylic acids, (Ac) polyamides obtained by condensing diamines and dicarboxylic acids, and copolymers thereof. The crystalline polyamides may be used alone or in combination of two or more kinds. Among them, the crystalline polyamide is preferably an aliphatic amide in which the carbon skeleton forming the monomer unit is composed of an aliphatic hydrocarbon group.

[0025] (A-1a) Lactam used in the polyamide obtained by ring-opening polymerization of lactam is not limited to the following, but examples thereof include pyrrolidone, caprolactam, undecalactam, and dodecalactam.

[0026] (A-1b) The ω-amino carboxylic acid used in the polyamide obtained by self-condensation of ω-amino carboxylic acid is not limited to the following, but examples thereof include ω-amino fatty acid which is a ring-opening compound of the above-mentioned lactam with water, etc. As the lactam or ω-amino carboxylic acid, two or more monomers may be used in combination and condensed.

[0027] (A-1c) Diamines (monomers) used in the polyamide obtained by condensing diamines and dicarboxylic acids include, but are not limited to, linear saturated aliphatic diamines having 2 to 20 carbon atoms, such as ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine.

[0028] Examples of diamines constituting the diamine unit having a substituent branched from the main chain include, but are not limited to, branched saturated aliphatic diamines having 3 to 20 carbon atoms, such as 2-methylpentamethylenediamine (also referred to as 2-methyl-1,5-diaminopentane), 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyl-1,8-octanediamine (also referred to as 2-methyloctamethylenediamine), and 2,4-dimethyloctamethylenediamine.

[0029] Among them, as the diamine constituting the diamine unit having a substituent branched from the main chain, 2-methylpentamethylenediamine or 2-methyl-1,8-octanediamine is preferable, and 2-methylpentamethylenediamine is more preferable. By including such an aliphatic diamine, the polyamide composition tends to have better heat resistance, rigidity, etc.

[0030] The diamines as the monomers described above may be used alone or in combination of two or more kinds.

[0031] The carbon number of the diamine unit is preferably from 4 to 12, and more preferably from 4 to 10. When the carbon number is equal to or more than the lower limit, the heat resistance is superior, whereas when the carbon number is equal to or less than the upper limit, the crystallinity and releasability are superior.

[0032] The aliphatic diamine may further contain a polyvalent aliphatic amine having a valence of three or more, such as bishexamethylenetriamine, if necessary. These diamines may be used alone or in combination of two or more kinds.

[0033] (Ac) Dicarboxylic acid (monomer) used in polyamide obtained by condensing diamine and dicarboxylic acid includes, but is not limited to, aliphatic dicarboxylic acids such as succinic acid, adipic acid, pimelic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, etc.; aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, etc.; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, etc. The above-mentioned dicarboxylic acids as monomers may be used alone or in combination of two or more kinds.

[0034] The crystalline polyamide (A-1) may further contain units derived from a trivalent or higher polyvalent carboxylic acid such as trimellitic acid, trimesic acid, pyromellitic acid, etc., as necessary. The trivalent or higher polyvalent carboxylic acid may be used alone or in combination of two or more kinds.

[0035] Specific examples of the crystalline polyamide (A-1) include polyamide 4 (poly-α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecane amide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 56 (polypentamethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 4T (polytetramethylene terephthalamide), polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonamethylene terephthalamide), and copolymer polyamides containing these as constituent components.

[0036] Among these, polyamide 6, polyamide 46, polyamide 66, or polyamide 610 is preferable, polyamide 6, polyamide 66, or polyamide 610 is more preferable, polyamide 6 or polyamide 66 is further preferable, and polyamide 66 is particularly preferable. Polyamide 66 is excellent in heat resistance, moldability, and toughness, and is therefore considered to be a material suitable for connector parts.

[0037] [(A-1) Characteristics of crystalline polyamide] ((A-1) Weight average molecular weight Mw of crystalline polyamide) As an index of the molecular weight of the (A-1) crystalline polyamide, the weight average molecular weight can be used.

[0038] The weight average molecular weight (Mw) of the (A-1) crystalline polyamide is preferably 10,000 or more and 50,000 or less, more preferably 15,000 or more and 45,000 or less, even more preferably 20,000 or more and 40,000 or less, and particularly preferably 25,000 or more and 40,000 or less.

[0039] By having Mw in the above range, it is possible to obtain a polyamide composition which is simultaneously satisfactory in mechanical properties, particularly water absorption rigidity, hot rigidity, fluidity, corrosion resistance, etc. Furthermore, a molded article obtained from the polyamide composition containing a component typified by an inorganic filler has a more excellent surface appearance.

[0040] The weight average molecular weight (Mw) of the crystalline polyamide (A-1) can be measured by gel permeation chromatography (GPC).

[0041] ((A-1) Molecular weight distribution of crystalline polyamide) The molecular weight distribution of the crystalline polyamide (A-1) is indicated by Mw / Mn, which is the weight average molecular weight (Mw) of the crystalline polyamide (A-1) divided by the number average molecular weight (Mn) of the crystalline polyamide (A-1). Mw / Mn is preferably 1.0 or more, more preferably 1.8 or more and 2.2 or less, and even more preferably 2.0 or more and 2.2 or less. When the Mw / Mn is within the above range, a polyamide composition having superior flowability can be obtained. In addition, a molded article obtained from the polyamide composition containing a component typified by an inorganic filler has superior surface appearance.

[0042] Examples of methods for controlling Mw / Mn within the above range include the following methods 1) and 2). 1) A method in which a known polycondensation catalyst such as phosphoric acid or sodium hypophosphite is added as an additive during the thermal melt polymerization of polyamide. 2) In addition to the above method 1), a method of controlling polymerization conditions such as heating conditions and reduced pressure conditions.

[0043] The Mw / Mn can be calculated using the Mw and Mn values ​​obtained by GPC.

[0044] [(A-1) Crystalline polyamide content] In the polyamide composition of this embodiment, the content of the crystalline polyamide (A-1) can be 50.0 mass% or more and 90.0 mass% or less, preferably 55.0 mass% or more and 90.0 mass% or less, more preferably 55.0 mass% or more and 87.5 mass% or less, even more preferably 57.5 mass% or more and 87.5 mass% or less, even more preferably 60.0 mass% or more and 82.5 mass% or less, and particularly preferably 62.5 mass% or more and 80.0 mass% or less, based on the total amount of polyamide in the polyamide composition.

[0045] By setting the blending amount of the crystalline polyamide (A-1) within the above range, a polyamide composition having excellent mechanical properties, particularly excellent hot rigidity, flowability, corrosion resistance, etc., can be obtained.

[0046] In the polyamide composition of the present embodiment, the content of the crystalline polyamide (A-1) relative to the total mass of the polyamide composition can be, for example, 10.0 mass% or more and 60.0 mass% or less, 15.0 mass% or more and 55.0 mass% or less, 20.0 mass% or more and 53.0 mass% or less, or 25.0 mass% or more and 50.0 mass% or less.

[0047] <(A-2) Amorphous polyamide> Amorphous polyamide refers to a polyamide having a crystallization enthalpy ΔH of less than 15 J / g when measured by a differential scanning calorimeter at 20° C. / min. The crystallization enthalpy of (A-2) amorphous polyamide is preferably 10 J / g or less, more preferably 5 J / g or less, and even more preferably 0 J / g. The crystallization enthalpy ΔH can be measured, for example, using a measuring device such as Diamond-DSC manufactured by PERKIN-ELMER in accordance with JIS-K7121.

[0048] The (B) amorphous polyamide is not particularly limited as long as it has a crystallization enthalpy ΔH of not more than the above upper limit, but may be a semi-aromatic polyamide.

[0049] When the (A-2) amorphous polyamide is a semi-aromatic polyamide, it is preferable that the polyamide contains diamine units and dicarboxylic acid units. The (A-2) amorphous polyamide is preferably a polyamide containing (A-2a) dicarboxylic acid units containing at least 50 mol % isophthalic acid units and (A-2b) diamine units containing at least 50 mol % diamine units having 4 to 10 carbon atoms.

[0050] The total amount of the isophthalic acid units and the diamine units having 4 to 10 carbon atoms is preferably 75 mol % to 100 mol %, more preferably 90 mol % to 100 mol %, and even more preferably 100 mol %, based on the total amount of all structural units of the amorphous polyamide (A-2). In the present invention, the proportion of the predetermined monomer unit constituting the amorphous polyamide (A-2) can be measured by nuclear magnetic resonance spectroscopy (NMR) or the like.

[0051] [(A-2a) Dicarboxylic acid unit] In the (A-2a) dicarboxylic acid unit, the content of isophthalic acid units relative to the total molar amount of the dicarboxylic acid units is preferably 50 mol% or more, particularly preferably 75 mol% or more and 100 mol% or less, further preferably 90 mol% or more and 100 mol% or less, and particularly preferably 100 mol%.

[0052] When the content of isophthalic acid units relative to the total moles of dicarboxylic acids is equal to or more than the above lower limit, it is possible to obtain a polyamide composition having excellent mechanical properties, rigidity upon atmospheric equilibrium moisture absorption, moldability, surface appearance, and flame retardancy.

[0053] The dicarboxylic acid unit (A-2a) may contain an aromatic dicarboxylic acid unit other than an isophthalic acid unit, an aliphatic dicarboxylic acid unit, or an alicyclic dicarboxylic acid unit.

[0054] (aromatic dicarboxylic acid unit) Examples of aromatic dicarboxylic acids constituting aromatic dicarboxylic acid units other than isophthalic acid units include, but are not limited to, dicarboxylic acids having a phenyl group or a naphthyl group. The aromatic group of the aromatic dicarboxylic acid may be unsubstituted or substituted.

[0055] The substituent is not particularly limited, but examples thereof include alkyl groups having 1 to 4 carbon atoms, aryl groups having 6 to 10 carbon atoms, arylalkyl groups having 7 to 10 carbon atoms, halogen groups such as chloro and bromo groups, silyl groups having 1 to 6 carbon atoms, sulfonic acid groups and salts thereof (sodium salts, etc.).

[0056] Specific examples include, but are not limited to, aromatic dicarboxylic acids having 8 to 20 carbon atoms, which are unsubstituted or substituted with a specific substituent, such as terephthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodiumsulfoisophthalic acid. Among these, terephthalic acid is preferred. The aromatic dicarboxylic acids constituting the aromatic dicarboxylic acid unit may be used alone or in combination of two or more kinds.

[0057] (Aliphatic dicarboxylic acid unit) Examples of the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid unit include, but are not limited to, linear or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms, such as malonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, 2,3-diethylglutaric acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosane dioic acid, and diglycolic acid.

[0058] (alicyclic dicarboxylic acid unit) Examples of alicyclic dicarboxylic acids constituting an alicyclic dicarboxylic acid unit (hereinafter also referred to as an "alicyclic dicarboxylic acid unit") include, but are not limited to, alicyclic dicarboxylic acids having an alicyclic structure with 3 to 10 carbon atoms, and alicyclic dicarboxylic acids having an alicyclic structure with 5 to 10 carbon atoms are preferred. Examples of such alicyclic dicarboxylic acids include, but are not limited to, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. Among these, 1,4-cyclohexanedicarboxylic acid is preferred. The alicyclic dicarboxylic acids constituting the alicyclic dicarboxylic acid unit may be used alone or in combination of two or more kinds.

[0059] The alicyclic group of the alicyclic dicarboxylic acid may be unsubstituted or may have a substituent, which may include, but is not limited to, an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a tert-butyl group. The dicarboxylic acid units other than the isophthalic acid units preferably contain aromatic dicarboxylic acid units, and more preferably contain aromatic dicarboxylic acids having 6 or more and 12 or less carbon atoms. By using such a dicarboxylic acid, the mechanical properties of the polyamide composition, in particular, rigidity upon absorption of water, rigidity when hot, flowability, surface appearance, corrosion resistance, etc. tend to be more excellent.

[0060] In the polyamide composition of this embodiment, the dicarboxylic acid constituting the (A-2a) dicarboxylic acid unit is not limited to the compounds described above as the dicarboxylic acid, and may be a compound equivalent to the above dicarboxylic acid. Here, the term "compound equivalent to a dicarboxylic acid" refers to a compound that can have a dicarboxylic acid structure similar to the dicarboxylic acid structure derived from the above dicarboxylic acid. Examples of such compounds include, but are not limited to, anhydrides and halides of dicarboxylic acids.

[0061] Furthermore, the (A-2) amorphous polyamide may further contain units derived from a trivalent or higher polyvalent carboxylic acid such as trimellitic acid, trimesic acid, and pyromellitic acid, as necessary. The trivalent or higher polyvalent carboxylic acids may be used alone or in combination of two or more kinds.

[0062] [(A-2b) Diamine unit] The (A-2b) diamine units constituting the (A-2) amorphous polyamide preferably contain at least 50 mol % of diamine units having from 4 to 10 carbon atoms. Examples include, but are not limited to, aliphatic diamine units, alicyclic diamine units, and aromatic diamine units.

[0063] (Aliphatic diamine unit) Examples of the aliphatic diamine constituting the aliphatic diamine unit include, but are not limited to, linear saturated aliphatic diamines having 2 to 20 carbon atoms, such as ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine.

[0064] (alicyclic diamine unit) Examples of alicyclic diamines (hereinafter also referred to as "alicyclic diamines") constituting the alicyclic diamine unit include, but are not limited to, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine, and the like.

[0065] (aromatic diamine unit) The aromatic diamine constituting the aromatic diamine unit is not limited to the following as long as it is a diamine containing an aromatic group, and examples thereof include metaxylylenediamine.

[0066] Among these, an aliphatic diamine unit is preferred, a diamine unit having a linear saturated aliphatic group having 4 to 10 carbon atoms is more preferred, a diamine unit having a linear saturated aliphatic group having 6 to 10 carbon atoms is even more preferred, and a hexamethylenediamine unit is particularly preferred. Use of such a diamine tends to result in a polyamide composition that is more excellent in mechanical properties, particularly rigidity when absorbing water, rigidity when hot, flowability, surface appearance, corrosion resistance, and the like. The diamines may be used alone or in combination of two or more kinds.

[0067] As the (A-2) amorphous polyamide, polyamide 6I, 6I / 6T, 9I, or 10I is preferred, 6I or 6I / 6T is more preferred, and 6I is most preferred.

[0068] The (A-2) amorphous polyamide may further contain a trivalent or higher polyvalent aliphatic amine, such as bishexamethylenetriamine, if necessary. The trivalent or higher polyvalent aliphatic amines may be used alone or in combination of two or more kinds.

[0069] [At least one unit selected from the group consisting of lactam units and aminocarboxylic acid units] (A-2) Amorphous polyamide may further contain at least one unit selected from the group consisting of lactam units and aminocarboxylic acid units. By containing such units, polyamides with better toughness tend to be obtained. Here, the lactam and aminocarboxylic acid constituting the lactam unit and aminocarboxylic acid unit refer to lactam and aminocarboxylic acid capable of polymerization (condensation).

[0070] The lactam and aminocarboxylic acid constituting the lactam unit and aminocarboxylic acid unit are not limited to the following, but for example, lactams and aminocarboxylic acids having 4 to 14 carbon atoms are preferred, and lactams and aminocarboxylic acids having 6 to 12 carbon atoms are more preferred.

[0071] Examples of lactams constituting the lactam unit include, but are not limited to, butyrolactam, pivalolactam, ε-caprolactam, caprylolactam, enantholactam, undecanolactam, laurolactam (dodecanolactam), and the like. Among them, the lactam is preferably ε-caprolactam or laurolactam, and more preferably ε-caprolactam. By including such a lactam, the polyamide composition tends to have better toughness.

[0072] Examples of aminocarboxylic acids constituting the aminocarboxylic acid unit include, but are not limited to, ω-aminocarboxylic acids, which are compounds formed by ring-opening of lactams, and α,ω-amino acids. The aminocarboxylic acid is preferably a linear or branched saturated aliphatic carboxylic acid having 4 to 14 carbon atoms and substituted with an amino group at the ω-position. Examples of such aminocarboxylic acids include, but are not limited to, 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Other examples of aminocarboxylic acids include paraaminomethylbenzoic acid.

[0073] The lactam and aminocarboxylic acid constituting the lactam unit and the aminocarboxylic acid unit may each be used alone or in combination of two or more kinds.

[0074] The total proportion (mol %) of lactam units and aminocarboxylic acid units is preferably 0 mol % or more and 20 mol % or less, more preferably 0 mol % or more and 10 mol % or less, and even more preferably 0 mol % or more and 5 mol % or less, based on the entire polyamide. When the total ratio of lactam units and aminocarboxylic acid units is within the above range, effects such as improved fluidity tend to be obtained.

[0075] [(A-2) Characteristics of amorphous polyamide] ((A-2) Weight average molecular weight Mw of amorphous polyamide) As an index of the molecular weight of the amorphous polyamide (A-2), the weight average molecular weight (Mw) of the amorphous polyamide (A-2) can be used.

[0076] The weight average molecular weight (Mw) of the amorphous polyamide (A-2) is preferably 10,000 or more and 35,000 or less, more preferably 10,000 or more and 33,000 or less, even more preferably 13,000 or more and 30,000 or less, even more preferably 15,000 or more and 29,000 or less, particularly preferably 18,000 or more and 27,000 or less, and most preferably 19,000 or more and 21,000 or less.

[0077] By making the weight-average molecular weight (Mw) of the (A-2) amorphous polyamide fall within the above range, a polyamide composition having excellent mechanical properties, particularly excellent water absorption rigidity, hot rigidity, and flame retardancy, can be obtained. In addition, a molded article obtained from the polyamide composition containing a component such as an inorganic filler has an excellent surface appearance.

[0078] Furthermore, in order to reduce the number average particle size of the domains in the (A-1) crystalline polyamide, it is desirable to improve the physical kneading efficiency, and the number average particle size can be reduced by bringing the melt viscosities in the molten state closer to each other.

[0079] Amorphous polyamide (A-2), which contains aromatic compound units in its molecular structure, has a higher melt viscosity than crystalline polyamide (A) if they have the same molecular weight. Therefore, it is preferable that the molecular weight of the amorphous polyamide (A-2) is smaller than that of crystalline polyamide (A-1).

[0080] The weight average molecular weight (Mw) of the amorphous polyamide (A-2) can be measured by GPC.

[0081] ((A-2) Molecular weight distribution of amorphous polyamide) The molecular weight distribution of the amorphous polyamide (A-2) is indicated by Mw / Mn, which is the weight average molecular weight (Mw) of the amorphous polyamide (A-2) divided by the number average molecular weight (Mn) of the amorphous polyamide (A-2).

[0082] Mw / Mn is preferably 1.0 or more and 2.6 or less, more preferably 1.3 or more and 2.5 or less, even more preferably 1.5 or more and 2.5 or less, particularly preferably 1.8 or more and 2.4 or less, and most preferably 2.0 or more and 2.4 or less. When the Mw / Mn is within the above range, a polyamide composition having superior moldability and appearance can be obtained. Furthermore, molded articles obtained from polyamide compositions containing components such as inorganic fillers have superior surface appearance.

[0083] Examples of methods for controlling Mw / Mn within the above range include the following methods 1) and 2). 1) A method in which a known polycondensation catalyst such as phosphoric acid or sodium hypophosphite is added as an additive during the thermal melt polymerization of polyamide. 2) In addition to the above method 1), a method in which polymerization conditions such as heating conditions and reduced pressure conditions are controlled to complete the polycondensation reaction at as low a temperature as possible and in as short a time as possible.

[0084] When the molecular structure of a polyamide contains an aromatic compound unit, the molecular weight distribution (Mw / Mn) tends to increase with increasing molecular weight. A high molecular weight distribution indicates a high proportion of polyamide molecules having a three-dimensional molecular structure. By reducing the proportion of polyamide molecules having a three-dimensional molecular structure, the compatibility with (A-1) crystalline polyamide can be increased and the number average particle size of the domains can be reduced. Therefore, by controlling Mw / Mn within the above range, the progress of three-dimensional structuring of molecules during high-temperature processing can be suppressed, and a polyamide composition with excellent flowability, welding strength, and product appearance can be obtained. In addition, the surface appearance of molded products obtained from polyamide compositions containing components typified by inorganic fillers can be improved.

[0085] The Mw / Mn can be calculated using Mw and Mn values ​​obtained by GPC.

[0086] ((A-2) Crystallization enthalpy ΔH of amorphous polyamide) From the viewpoint of appearance, the crystallization enthalpy ΔH of the amorphous polyamide (A-2) is preferably 15 J / g or less, more preferably 10 J / g or less, further preferably 5 J / g or less, and particularly preferably 0 J / g. The method of controlling the crystallization enthalpy ΔH of the (A-2) amorphous polyamide within the above range can be a method of reducing the crystallinity of a known polyamide, and is not particularly limited. Specific examples of the method of reducing the crystallinity of a known polyamide include a method of increasing the ratio of meta-substituted aromatic dicarboxylic acid units to dicarboxylic acid units, and a method of increasing the ratio of meta-substituted aromatic diamine units to diamine units. From this viewpoint, the (A-2) amorphous polyamide preferably contains 50 mol% or more of isophthalic acid units, more preferably 75 mol% or more, and even more preferably 100 mol% of isophthalic acid units as (A-2a) dicarboxylic acid units, out of all dicarboxylic acid units constituting the (A-2) amorphous polyamide.

[0087] The crystallization enthalpy ΔH of the (A-2) amorphous polyamide can be measured, for example, in accordance with JIS-K7121 using a measuring device such as Diamond-DSC manufactured by PERKIN-ELMER.

[0088] [(A-2) Amorphous polyamide content] In the polyamide composition of the present embodiment, the content of the amorphous polyamide (A-2) relative to the total mass of the polyamide composition can be, for example, 1.0 mass% or more and 60.0 mass% or less, 3.0 mass% or more and 40.0 mass% or less, 5.0 mass% or more and 30.0 mass% or less, or 7.0 mass% or more and 25.0 mass% or less.

[0089] <End-capping agent> At least one polyamide selected from the group consisting of (A-1) crystalline polyamides and (A-2) amorphous polyamides has ends capped with an end-capping agent. Such an end-capping agent can also be added as a molecular weight regulator when producing a polyamide from the above-mentioned dicarboxylic acid and diamine, and at least one compound selected from the group consisting of lactams and aminocarboxylic acids, which is used as necessary.

[0090] Examples of the end-capping agent include, but are not limited to, acid anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols, etc. Examples of the acid anhydrides include monocarboxylic acids, monoamines, phthalic anhydride, etc. Among these, monocarboxylic acids or monoamines are preferred. By capping the ends of the polyamide with an end-capping agent, the polyamide composition tends to have better thermal stability. The end-capping agents may be used alone or in combination of two or more kinds.

[0091] The monocarboxylic acid usable as the end-capping agent may be any one that is reactive with amino groups that may be present at the terminals of the polyamide. Specific examples of the monocarboxylic acid include, but are not limited to, aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids. Examples of aliphatic monocarboxylic acids include, but are not limited to, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid. Examples of alicyclic monocarboxylic acids include, but are not limited to, cyclohexane carboxylic acid. Examples of aromatic monocarboxylic acids include, but are not limited to, benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid. These monocarboxylic acids may be used alone or in combination of two or more kinds.

[0092] The monoamine usable as the end-capping agent may be any monoamine that is reactive with a carboxyl group that may be present at the end of the polyamide. Specific examples of the monoamine include, but are not limited to, aliphatic monoamines, alicyclic monoamines, and aromatic monoamines. Examples of the aliphatic amine include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine. Examples of alicyclic amines include, but are not limited to, cyclohexylamine, dicyclohexylamine, and the like. Examples of aromatic amines include, but are not limited to, aniline, toluidine, diphenylamine, naphthylamine, and the like. These monoamines may be used alone or in combination of two or more kinds.

[0093] Polyamide compositions containing polyamide end-capped with an end-capping agent tend to be excellent in heat resistance, flowability, toughness, low water absorption, rigidity, corrosion resistance, moldability, and appearance.

[0094] <Polyamide manufacturing method> When each polyamide ((A-1) crystalline polyamide and (A-2) amorphous polyamide) is obtained, the amount of dicarboxylic acid and the amount of diamine added are preferably approximately the same molar amount. Taking into consideration the amount of diamine that escapes to the outside of the reaction system during the polymerization reaction in the molar ratio, the molar amount of the total diamine per molar amount of the total dicarboxylic acids is preferably 0.9 to 1.2, more preferably 0.95 to 1.1, and even more preferably 0.98 to 1.05.

[0095] A method for producing a polyamide includes, but is not limited to, the following polymerization step (1) or (2). (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. (2) A step of polymerizing one or more members selected from the group consisting of lactam constituting the lactam unit and aminocarboxylic acid constituting the aminocarboxylic acid unit to obtain a polymer.

[0096] The method for producing a polyamide preferably further comprises, after the polymerization step, an increasing step of increasing the degree of polymerization of the polyamide. If necessary, the method may comprise, after the polymerization step and the increasing step, a capping step of capping the ends of the resulting polymer with a terminal capping agent.

[0097] Specific examples of the method for producing polyamide include the following various methods 1) to 4). 1) A method in which an aqueous solution or suspension of one or more selected from the group consisting of a dicarboxylic acid-diamine salt, a mixture of a dicarboxylic acid and a diamine, a lactam, and an aminocarboxylic acid is heated and polymerized while maintaining the molten state (hereinafter, sometimes referred to as a "thermal melt polymerization method"). 2) A method in which the degree of polymerization of polyamide obtained by hot melt polymerization is increased while maintaining the polyamide in a solid state at a temperature below the melting point (hereinafter sometimes referred to as "hot melt polymerization / solid-state polymerization method"). 3) A method of polymerizing one or more members selected from the group consisting of dicarboxylic acid-diamine salts, mixtures of dicarboxylic acids and diamines, lactams, and aminocarboxylic acids while maintaining the solid state (hereinafter, sometimes referred to as the "solid-state polymerization method"). 4) A method of polymerization using a dicarboxylic acid halide component equivalent to a dicarboxylic acid and a diamine component (hereinafter, sometimes referred to as a "solution method").

[0098] Among them, as a specific method for producing polyamide, a production method including a hot melt polymerization method is preferable. When producing polyamide by the hot 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 produce polyamide under polymerization conditions suitable for the polyamide. Examples of the polymerization conditions include the following conditions. First, the polymerization pressure in the hot melt polymerization method is set to 14 kg / cm. 2 More than 25kg / cm 2 Heating is continued while controlling the pressure in the vessel to below atmospheric pressure (gauge pressure is 0 kg / cm 2 ) over 30 minutes or more until the blood pressure drops to 0.

[0099] In the method for producing a polyamide, the polymerization form is not particularly limited, and may be a batch type or a continuous type. The polymerization apparatus used for producing polyamide is not particularly limited, and known apparatuses can be used. Specific examples of the polymerization apparatus include an autoclave type reactor, a tumbler type reactor, and an extruder type reactor (such as a kneader).

[0100] Hereinafter, as a method for producing polyamide, a method for producing polyamide by a batch-type hot melt polymerization method will be specifically described, but the method for producing polyamide is not limited thereto.

[0101] First, an aqueous solution containing about 40% to 60% by mass of raw material components for polyamide (a combination of dicarboxylic acid and diamine, and, if necessary, at least one selected from the group consisting of lactam and aminocarboxylic acid) is prepared.The aqueous solution is then concentrated to about 65% to 90% by mass in a concentration tank operated at a temperature of 110°C to 180°C and a pressure of about 0.035 MPa to 0.6 MPa (gauge pressure) to obtain a concentrated solution.

[0102] The concentrated solution obtained is then transferred to an autoclave, and heating is continued until the pressure in the autoclave reaches about 1.2 MPa or more and 2.2 MPa or less (gauge pressure). Next, in the autoclave, the pressure is maintained at about 1.2 MPa to 2.2 MPa (gauge pressure) while removing at least one of water and gas components. Next, when the temperature reaches about 220° C. to 260° C., the pressure is reduced to atmospheric pressure (gauge pressure: 0 MPa). After the pressure in the autoclave is reduced to atmospheric pressure, the pressure can be reduced as necessary to effectively remove the by-produced water.

[0103] The autoclave is then pressurized with an inert gas such as nitrogen, and the polyamide melt is extruded from the autoclave as a strand. The extruded strand is cooled and cut to obtain polyamide pellets.

[0104] <Polyamide polymer end> The polymer ends of the polyamides ((A) crystalline polyamide and (B) amorphous polyamide) contained in the polyamide composition of the present embodiment are not particularly limited, but can be classified and defined as follows: 1) to 4). That is, 1) the amino terminus, 2) the carboxy terminus, 3) the terminus provided by a capping agent, and 4) other terminus. 1) The amino terminus is a polymer end having an amino group (-NH2 group) and is derived from a diamine unit. 2) The carboxyl end is a polymer end having a carboxyl group (-COOH group) and is derived from a dicarboxylic acid. 3) The term "terminal end by a capping agent" refers to an end formed when a capping agent is added during polymerization. Examples of the capping agent include the terminal capping agents described below. 4) The other terminals are polymer terminals not classified into the above 1) to 3). Specific examples of the other terminals include terminals generated by deammonia reaction of amino terminals, terminals generated by decarboxylation of carboxy terminals, etc.

[0105] <(B) Phosphorus-based flame retardants> (B) The phosphorus-based flame retardant is not particularly limited as long as it is a flame retardant containing a phosphorus element without containing a halogen element. Examples of the phosphorus-based flame retardant include a phosphate ester-based flame retardant, a melamine polyphosphate-based flame retardant, a phosphazene-based flame retardant, a phosphinic acid-based flame retardant, and a red phosphorus-based flame retardant. Among them, the phosphorus-based flame retardant is preferably a phosphate-based flame retardant, a melamine polyphosphate-based flame retardant, a phosphazene-based flame retardant or a phosphinic acid-based flame retardant, and more preferably a phosphinic acid-based flame retardant.

[0106] Specifically, the phosphinic acid-based flame retardant may contain at least one phosphinic acid salt selected from the group consisting of a phosphinic acid salt represented by the following general formula (1) (hereinafter, may be abbreviated as "phosphinic acid salt (1)"), a diphosphinic acid salt represented by the following general formula (2) (hereinafter, may be abbreviated as "diphosphinic acid salt (2)"), and condensates thereof.

[0107] [ka]

[0108] (In general formula (1), R 11 and R 12 Each of M is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. n11+ is a metal ion having a valence of n11. M is an element belonging to Group 2 or Group 15 of the periodic table, a transition element, zinc, or aluminum. n11 is 2 or 3. When n11 is 2 or 3, multiple R 11 and R 12 may be the same or different. In general formula (2), R 21 and R 22 Each of Y is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. 21 M' is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms. m21+is a metal ion having 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 to 3. When n21 is 2 or 3, multiple R 21 , R 22 and Y 21 may be the same or different. m21 is 2 or 3. x is 1 or 2. When x is 2, multiple M' may be the same or different. n21, x, and m21 are integers that satisfy the relational formula 2×n21=m21×x.

[0109] [R 11 , R 12 , R 21 , R 22 , R1, R2 and R3] R 11 , R 12 , R 21 , R 22 R1, R2, and R3 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, a plurality of R 11 and R 12 may be the same or different, but are preferably the same in terms of ease of production. 21 and R 22 may be the same or different, but is preferably the same in terms of ease of production.

[0110] The alkyl group may be chain-like or cyclic, but is preferably chain-like. The chain-like alkyl group may be linear or branched. Examples of the linear alkyl group include methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl groups. Examples of branched alkyl groups include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1,1-dimethylethyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, a 2,2-dimethylpropyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 4-methylpentyl group, a 1,1-dimethylbutyl group, a 1,2-dimethylbutyl group, a 1,3-dimethylbutyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, a 3,3-dimethylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, and a 1,1,2-trimethylpropyl group.

[0111] Examples of the aryl group include a phenyl group and a naphthyl group. The alkyl group and the aryl group may have a substituent. Examples of the substituent in the alkyl group include an aryl group having 6 to 10 carbon atoms. Examples of the substituent in the aryl group include an alkyl group having 1 to 6 carbon atoms.

[0112] Specific examples of the alkyl group having a substituent include a benzyl group. Specific examples of the aryl group having a substituent include a tolyl group and a xylyl group. Among them, R 11 , R 12 , R 21 and R 22 As the alkyl group, an alkyl group having 1 to 6 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.

[0113] [Y 21 ] Y 21is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 10 carbon atoms. 21 may be the same or different, but is preferably the same in terms of ease of production.

[0114] The alkylene group may be either chain-like or cyclic, but is preferably chain-like. The chain-like alkylene group may be either linear or branched. Examples of linear alkylene groups include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups. Examples of branched alkylene groups include 1-methylethylene and 1-methylpropylene groups.

[0115] Examples of the arylene group include a phenylene group and a naphthylene group. The alkylene group and the arylene group may have a substituent. Examples of the substituent in the alkylene group include an aryl group having 6 to 10 carbon atoms. Examples of the substituent in the arylene group include an alkyl group having 1 to 6 carbon atoms.

[0116] Specific examples of the alkylene group having a substituent include a phenylmethylene group, a phenylethylene group, a phenyltrimethylene group, and a phenyltetramethylene group. Specific examples of the substituted arylene group include a methylphenylene group, an ethylphenylene group, a tert-butylphenylene group, a methylnaphthylene group, an ethylnaphthylene group, and a tert-butylnaphthylene group. Among them, Y 21 As the alkyl group, an alkylene group having 1 to 10 carbon atoms is preferable, and a methylene group or an ethylene group is more preferable.

[0117] [M and M'] 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. Examples of the ion of an element belonging to Group 2 of the periodic table include a calcium ion and a magnesium ion. Examples of the ion of an element belonging to Group 15 of the periodic table include a bismuth ion. Furthermore, when x is 2, a plurality of M' may be the same or different, but it is preferable that they are the same in terms of ease of production. Among these, M and M' are preferably calcium, zinc or aluminum, and more preferably calcium or aluminum.

[0118] [x] x represents the number of M' and is 1 or 2. x can be appropriately selected depending on the type of M' and the number of diphosphinic acids.

[0119] [n11 and n21] n11 represents the number of phosphinic acids and the valence of M, and is 2 or 3. n11 can be appropriately selected depending on the type and valence of M. n21 represents the number of diphosphinic acids and is an integer of 1 to 3. n21 can be appropriately selected depending on the type and number of M'.

[0120] [m21] m21 represents the valence of M' and is 2 or 3. n21, x, and m21 are integers that satisfy the relational expression 2×n21=m21×x.

[0121] Specific examples of preferred phosphinates (1) include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, methane di(methylphosphinate), ) calcium, magnesium methane di(methylphosphinate), aluminum methane di(methylphosphinate), zinc methane di(methylphosphinate), calcium benzene-1,4-(dimethylphosphinate), magnesium benzene-1,4-(dimethylphosphinate), aluminum benzene-1,4-(dimethylphosphinate), zinc benzene-1,4-(dimethylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, zinc diphenylphosphinate, etc. Among them, as the phosphinate (1), calcium diethylphosphinate or aluminum diethylphosphinate is particularly preferred because of its excellent flame retardancy.

[0122] Specific examples of preferred diphosphinates (2) include calcium methane di(methylphosphinate), magnesium methane di(methylphosphinate), aluminum methane di(methylphosphinate), zinc methane di(methylphosphinate), calcium benzene-1,4-di(methylphosphinate), magnesium benzene-1,4-di(methylphosphinate), aluminum benzene-1,4-di(methylphosphinate), and zinc benzene-1,4-di(methylphosphinate).

[0123] The method for producing phosphinates is not particularly limited, but examples thereof include the methods described in JP 2005-179362 A, EP 699708 A, and JP 08-073729 A. Specifically, they are produced in an aqueous solution using phosphinic acid and a metal carbonate, metal hydroxide, or metal oxide. These are essentially monomeric compounds, but also include polymeric phosphinates, which are condensates with a condensation degree of 1 to 3 depending on the reaction conditions and environment.

[0124] Specific examples of phosphinate products include "Exolit OP1230", "Exolit OP1240", "Exolit OP1312", "Exolit OP1314", and "Exolit OP1400" manufactured by Clariant, and "HR8900", "MADP8900SP", "MADP8900BS", and "HR8966" manufactured by Weihai Hairun Co., Ltd. Furthermore, among the phosphinates, a flame retardant represented by chemical formula (3), which is a complex salt of a phosphinate and a phosphonate, is more preferable from the viewpoints of heat resistance and flame retardancy. [ka] Most preferably, the flame retardant is represented by the formula (3) in which R1=ethyl group, R2=ethyl group, R3=ethyl group, a=4, b=1, a hexavalent anion, M=aluminum, and m=3, two hexavalent cations. Specific product examples include Weihai Hairun's "HR8900", "MADP8900SP", "MADP8900BS", and "HR8966".

[0125] <(C) Polyamide elastomer> The (C) polyamide elastomer is preferably a polyamide elastomer having a polyamide unit as a hard segment and a polyether unit as a soft segment. Examples of such an elastomer include a polyetheresteramide elastomer in which a hard segment and a soft segment are bonded via an ester bond, and a polyetheramide elastomer in which a hard segment and a soft segment are bonded via an amide bond.

[0126] The hard segment can be derived from a polyamide having carboxyl groups at both terminal groups, and is a segment containing a polyamide-forming unit and at least one dicarboxylic acid selected from the group consisting of an aliphatic dicarboxylic acid, an alicyclic dicarboxylic acid, and an aromatic dicarboxylic acid.

[0127] The polyamide forming units in the hard segment are composed of lactam, aminocarboxylic acid, and / or diamine and dicarboxylic acid (nylon salt), and examples thereof include units obtained by reacting one or more selected from the group consisting of lactam, aminocarboxylic acid, and diamine and dicarboxylic acid (nylon salt).

[0128] Examples of lactams include aliphatic lactams having 5 to 20 carbon atoms, such as ε-caprolactam, ω-enantholactam, ω-undecalactam, ω-lauryllactam, and 2-pyrrolidone. Examples of aminocarboxylic acids include aliphatic ω-aminocarboxylic acids having 5 to 20 carbon atoms, such as 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 10-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of the diamine include diamine compounds such as aliphatic diamines having 2 to 20 carbon atoms, such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexane-1,6-diamine, 2,4,4-trimethylhexane-1,6-diamine, and 3-methylpentane-1,5-diamine.

[0129] Among these, ε-caprolactam is preferred from the viewpoints of heat resistance, chemical resistance, and mechanical properties.

[0130] The number average molecular weight of the hard segment is preferably from 200 to 15,000, and more preferably from 300 to 10,000 from the viewpoints of flexibility and moldability.

[0131] The soft segment is preferably a polyether, for example based only on at least one C2-C5 polyoxyalkylene unit, particularly preferably on units selected from the following group: ethylene oxide, propylene oxide, tetrahydrofuran and mixtures thereof. The number average molecular weight of the soft segment is preferably 200-6000, more preferably 400-3000.

[0132] The melting point (Tm) of the polyamide elastomer is preferably 160.0°C or higher and 230.0°C or lower, more preferably 180.0°C or higher and 220.0°C or lower, and particularly preferably 190.0°C or higher and 210.0°C or lower. When the melting point Tm of the polyamide composition is within the above range, the polyamide composition is excellent in melt processing such as extrusion and molding, the thermal decomposition of the phosphorus-based flame retardant can be further suppressed, and the deflection temperature under load is excellent.

[0133] The content of the phosphorus-based flame retardant is preferably from 10% by mass to 30% by mass, more preferably from 12% by mass to 25% by mass, and particularly preferably from 14% by mass to 20% by mass, based on the total mass of (A) the crystalline polyamide and (B) the amorphous polyamide. By setting the content of the phosphorus-based flame retardant to the above lower limit or more, a polyamide composition having superior flame retardancy can be obtained. On the other hand, by setting the content of the phosphorus-based flame retardant to the above upper limit or less, a polyamide composition having superior flame retardancy can be obtained without impairing the properties of the polyamide.

[0134] ≪(D) ​​Inorganic filler≫ The polyamide composition of the present embodiment may further contain (D) an inorganic filler in addition to the above components (A) to (C).

[0135] Examples of inorganic fillers include, but are not limited to, glass fibers, carbon fibers, calcium silicate fibers, potassium titanate fibers, aluminum borate fibers, clay, flaky glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, calcium hydrogen phosphate, wollastonite, silica, zeolite, alumina, boehmite, aluminum hydroxide, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, ketjen black, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swellable fluoromica, apatite, etc. These inorganic fillers may be used alone or in combination of two or more.

[0136] Among them, from the viewpoint of further improving the mechanical strength, one or more selected from the group consisting of glass fiber, carbon fiber, wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate fiber, aluminum borate fiber, and clay are preferable. Among them, one or more selected from the group consisting of glass fiber, carbon fiber, wollastonite, kaolin, mica, talc, calcium carbonate, and clay are more preferable. Glass fiber is the most preferable.

[0137] When the inorganic filler is glass fiber or carbon fiber, the number average fiber diameter (d) is preferably 3 μm or more and 30 μm or less, more preferably 3 μm or more and 20 μm or less, even more preferably 3 μm or more and 12 μm or less, particularly preferably 3 μm or more and 9 μm or less, and most preferably 4 μm or more and 6 μm or less.

[0138] By setting the number average fiber diameter to the above upper limit or less, a polyamide composition having better toughness and surface appearance of a molded product can be obtained. On the other hand, by setting the number average fiber diameter to the above lower limit or more, a polyamide composition having a better balance between cost, powder handling, and physical properties (fluidity, etc.) can be obtained. Furthermore, by setting the number average fiber diameter to 3 μm or more and 9 μm or less, a polyamide composition having better vibration fatigue properties and sliding properties can be obtained.

[0139] When the inorganic filler is a glass fiber or a carbon fiber, the cross section may be a perfect circle or a flattened shape. Examples of such a flattened cross section include, but are not limited to, a rectangle, an oval shape close to a rectangle, an ellipse, and a cocoon shape with a narrowed central portion in the longitudinal direction. Here, the "flatness" in this specification refers to a value expressed by d2 / d1, where d2 is the major axis of the fiber cross section and d1 is the minor axis of the fiber cross section (a perfect circle has a flatness of about 1).

[0140] When the inorganic filler is glass fiber or carbon fiber, from the viewpoint of imparting excellent mechanical strength to the polyamide composition, it is preferable that the number average fiber diameter (d) is 3 μm or more and 30 μm or less, the weight average fiber length (l) is 100 μm or more and 750 μm or less, and the ratio of the weight average fiber length (l) to the number average fiber diameter (d), i.e., the aspect ratio (l / d) is 10 to 100. The "number average fiber diameter (d)" referred to here is the average value of the major axis (above d2) of the fiber cross section, and is calculated using the calculation method described later.

[0141] From the viewpoint of reducing warpage of the plate-shaped molded product and improving heat resistance, toughness, low water absorption, and heat aging resistance, the aspect ratio is preferably 1.5 or more, more preferably 1.5 to 10.0, even more preferably 2.5 to 10.0, particularly preferably more than 3.0 to 6.0, and most preferably 3.1 to 6.0. By having the aspect ratio within the above range, crushing can be more effectively prevented during processing such as mixing with other components, kneading, and molding, and the desired effects for the molded product can be more fully obtained.

[0142] The thickness of the glass fiber or carbon fiber having an aspect ratio of 1.5 or more is not limited to the following, but it is preferable that the short diameter d1 of the fiber cross section is 0.5 μm to 25 μm and the long diameter d2 of the fiber cross section is 1.25 μm to 250 μm. It is more preferable that the short diameter d1 of the fiber cross section is 3.0 μm to 25 μm and the long diameter d2 of the fiber cross section is 1.25 μm to 250 μm. By having the short diameter (d1) and the long diameter (d2) within the above ranges, the difficulty in spinning the fiber can be more effectively avoided, and the strength of the molded product can be further improved without reducing the contact area with the resin (polyamide).

[0143] The glass fibers or carbon fibers having an aspect ratio of 1.5 or more are preferably glass fibers produced using either an orifice plate having a number of orifices on the bottom surface, the orifice plate having a convex edge surrounding the multiple orifice outlets and extending downward from the bottom surface, or a nozzle tip for spinning modified cross section glass fibers having a nozzle tip having a single or multiple orifice holes and having multiple convex edges extending downward from the tip of the outer periphery. These fibrous reinforcing materials may be used as they are as fiber strands in the form of rovings, or may be further cut and used as chopped glass strands.

[0144] In addition, the "number average fiber diameter (d)" and the "weight average fiber length (l)" in this specification can be determined by the following method. First, the polyamide composition is placed in an electric furnace, and the organic matter contained therein is incinerated. From the residue after the treatment, 100 or more glass fibers (or carbon fibers) are arbitrarily selected, observed with a scanning electron microscope (SEM), and the fiber diameter (long diameter) of these glass fibers (or carbon fibers) is measured, whereby the number average fiber diameter can be determined. In addition, the fiber length can be measured using an SEM photograph of the 100 or more glass fibers (or carbon fibers) taken at a magnification of 1000 times, whereby the weight average fiber length can be determined.

[0145] The glass fibers or carbon fibers may be surface-treated with a silane coupling agent or the like. Examples of the silane coupling agent include, but are not limited to, aminosilanes, mercaptosilanes, epoxysilanes, vinylsilanes, and the like. Examples of aminosilanes include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane.

[0146] Examples of mercaptosilanes include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane. These silane coupling agents may be used alone or in combination of two or more kinds. Among these, aminosilanes are preferred as the silane coupling agent.

[0147] Furthermore, the glass fibers or carbon fibers may further contain a sizing agent. Examples of sizing agents include copolymers containing, as structural units, carboxylic acid anhydride-containing unsaturated vinyl monomers and unsaturated vinyl monomers other than carboxylic acid anhydride-containing unsaturated vinyl monomers, epoxy compounds, polyurethane resins, homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, and salts of these with primary, secondary, and tertiary amines, etc. These sizing agents may be used alone or in combination of two or more.

[0148] Among them, from the viewpoint of mechanical strength of the obtained polyamide composition, the sizing agent is preferably one or more selected from the group consisting of a copolymer containing a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer as a constituent unit, an epoxy compound, and a polyurethane resin.More preferably, the sizing agent is one or more selected from the group consisting of a copolymer containing a carboxylic anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer other than the carboxylic anhydride-containing unsaturated vinyl monomer as a constituent unit, and a polyurethane resin.

[0149] The glass fiber or carbon fiber can be obtained by continuously reacting the above-mentioned sizing agent on the fiber using a known method such as a roller-type applicator in a known production process for the fiber, and drying the produced fiber strand. The fiber strands may be used as rovings as they are, or may be further cut and used as chopped glass strands.

[0150] The bundling agent is preferably provided (added) in an amount of about 0.2% by mass or more and 3% by mass or less, and more preferably about 0.3% by mass or more and 2% by mass or less, in terms of solid content, relative to the total mass of the glass fibers or carbon fibers. When the amount of the sizing agent added is equal to or more than the lower limit in terms of solid content relative to the total mass of the glass fibers or carbon fibers, the bundling of the fibers can be more effectively maintained. On the other hand, when the amount of the sizing agent added is equal to or less than the upper limit in terms of solid content relative to the total mass of the glass fibers or carbon fibers, the thermal stability of the obtained polyamide composition is further improved. Drying of the strands may occur after the cutting step, or the strands may be dried and then cut.

[0151] As inorganic fillers other than glass fibers and carbon fibers, from the viewpoint of improving the strength, rigidity and surface appearance of the molded product, wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate fiber, aluminum borate fiber or clay is preferable. Wollastonite, kaolin, mica, talc, calcium carbonate or clay is more preferable. Wollastonite, kaolin, mica or talc is further preferable. Wollastonite, mica or talc is particularly preferable. These inorganic fillers may be used alone or in combination of two or more kinds.

[0152] From the viewpoint of improving toughness and the surface appearance of a molded article, the average particle size of the inorganic filler other than the glass fiber and the carbon fiber is preferably 0.01 μm or more and 38 μm or less, more preferably 0.03 μm or more and 30 μm or less, even more preferably 0.05 μm or more and 25 μm or less, even more preferably 0.10 μm or more and 20 μm or less, and particularly preferably 0.15 μm or more and 15 μm or less.

[0153] By setting the average particle size of the inorganic filler other than the glass fiber and the carbon fiber to the upper limit or less, a polyamide composition having better toughness and surface appearance of a molded product can be obtained. On the other hand, by setting the average particle size to the lower limit or more, a polyamide composition having a better balance between cost, powder handling, and physical properties (fluidity, etc.) can be obtained.

[0154] For needle-shaped inorganic fillers such as wollastonite other than glass fiber and carbon fiber, the number average particle diameter (hereinafter sometimes simply referred to as "average particle diameter") is taken as the average particle diameter. In addition, if the cross section is not circular, the maximum length is taken as the (number average) fiber diameter.

[0155] The number average particle length of the acicular inorganic filler (hereinafter sometimes simply referred to as "average particle length") is preferably within the numerical range calculated from the preferred range of the number average particle diameter described above and the preferred range of the aspect ratio (l / d) of the number average particle length (l) to the number average particle diameter (d) described below.

[0156] Although the particles have an acicular shape, the aspect ratio (l / d) of the number average particle length (l) to the number average particle diameter (d) is preferably 1.5 to 10, more preferably 2.0 to 5, and even more preferably 2.5 to 4, from the viewpoints of improving the surface appearance of molded articles and preventing wear of metallic parts of injection molding machines and the like.

[0157] Inorganic fillers other than glass fibers and carbon fibers may be surface-treated with a silane coupling agent, a titanate coupling agent, or the like. Examples of the silane coupling agent include the same ones as those exemplified for the glass fibers and carbon fibers above. Among these, aminosilanes are preferred as the silane coupling agent. Such a surface treatment agent may be applied to the surface of the inorganic filler in advance, or may be added when mixing the polyamide and the inorganic filler. The amount of the surface treatment agent added is preferably 0.05% by mass or more and 1.5% by mass or less based on the total mass of the inorganic filler.

[0158] [(D) Inorganic filler content] The content of the inorganic filler is preferably 5% by mass or more and 70% by mass or less, more preferably 20% by mass or more and 70% by mass or less, even more preferably 20% by mass or more and 65% by mass or less, even more preferably 20% by mass or more and 60% by mass or less, even more preferably 25% by mass or more and 60% by mass or less, particularly preferably 30% by mass or more and 60% by mass or less, even more particularly preferably 35% by mass or more and 60% by mass or less, and most preferably 35% by mass or more and 50% by mass or less. By setting the content of the inorganic filler to the above lower limit or more, the effect of further improving the strength and rigidity of the obtained polyamide composition is exhibited, whereas by setting the content of the inorganic filler to the above upper limit or less, a polyamide composition having better extrudability and moldability can be obtained.

[0159] <(E) Other ingredients> The polyamide composition of the present embodiment may contain, in addition to the above-mentioned components (A) to (D), one or more other components (E) selected from the group consisting of lubricants, heat stabilizers, phosphorus-based flame retardants, nucleating agents, other polymers, and other additives.

[0160] [Lubricant] The lubricant is not particularly limited, but examples thereof include higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, higher fatty acid amides, etc. The lubricant can also be used as a molding improver.

[0161] (higher fatty acids) Examples of higher fatty acids include linear or branched, saturated or unsaturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms. Examples of the linear or branched, saturated or unsaturated aliphatic monocarboxylic acid having from 8 to 40 carbon atoms include lauric acid, palmitic acid, stearic acid, behenic acid, and montanic acid. Examples of branched saturated aliphatic monocarboxylic acids having 8 to 40 carbon atoms include isopalmitic acid and isostearic acid. Examples of the linear unsaturated aliphatic monocarboxylic acid having 8 to 40 carbon atoms include oleic acid and erucic acid. Examples of the branched unsaturated aliphatic monocarboxylic acid having 8 to 40 carbon atoms include isooleic acid. Among these, stearic acid or montanic acid is preferred as the higher fatty acid.

[0162] (Higher fatty acid metal salts) The higher fatty acid metal salt is a metal salt of a higher fatty acid. Examples of the metal element of the metal salt include Group 1, Group 2 and Group 3 elements of the Periodic Table, zinc, aluminum, and the like. Examples of Group 1 elements in the Periodic Table include sodium and potassium. Examples of Group 2 elements in the Periodic Table include calcium and magnesium. Examples of Group 3 elements in the periodic table include scandium and yttrium. Among these, elements of Groups 1 and 2 of the Periodic Table of the Elements or aluminum are preferred, and sodium, potassium, calcium, magnesium or aluminum is more preferred.

[0163] Specific examples of higher fatty acid metal salts include calcium stearate, aluminum stearate, zinc stearate, magnesium stearate, calcium montanate, sodium montanate, calcium palmitate, and the like. Among these, as the higher fatty acid metal salt, a metal salt of montanic acid or a metal salt of stearic acid is preferred.

[0164] (Higher fatty acid ester) The higher fatty acid ester is an esterification product of a higher fatty acid and an alcohol. As the higher fatty acid ester, an ester of an aliphatic carboxylic acid having 8 to 40 carbon atoms and an aliphatic alcohol having 8 to 40 carbon atoms is preferred. Examples of the aliphatic alcohol having 8 to 40 carbon atoms include stearyl alcohol, behenyl alcohol, and lauryl alcohol. Specific examples of higher fatty acid esters include stearyl stearate and behenyl behenate.

[0165] (Higher fatty acid amide) Higher fatty acid amides are amide compounds of higher fatty acids. Examples of higher fatty acid amides include stearic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearylamide, ethylene bisoleylamide, N-stearyl stearic acid amide, and N-stearyl erucic acid amide.

[0166] These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters and higher fatty acid amides may be used alone or in combination of two or more kinds.

[0167] The content of the lubricant in the polyamide composition is preferably from 0.01% by mass to 1% by mass, and more preferably from 0.1% by mass to 1% by mass, based on the total mass of the polyamide composition. When the content of the lubricant is equal to or more than the above lower limit, the moldability of the polyamide composition can be improved, whereas when the content is equal to or less than the above upper limit, the rigidity of the molded product can be improved.

[0168] [Heat stabilizer] Examples of the heat stabilizer include, but are not limited to, phenol-based heat stabilizers, phosphorus-based heat stabilizers, amine-based heat stabilizers, metal salts of elements in groups 3, 4, and 11 to 14 of the periodic table, and halides of alkali metals and alkaline earth metals.

[0169] (Phenol-based heat stabilizer) Examples of the phenol-based heat stabilizer include, but are not limited to, hindered phenol compounds, etc. Hindered phenol compounds have the property of imparting excellent heat resistance and light resistance to resins such as polyamides and fibers.

[0170] Examples of the hindered phenol compound include, but are not limited to, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid. These hindered phenol compounds may be used alone or in combination of two or more kinds. In particular, from the viewpoint of improving heat aging resistance, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)] is preferred as the hindered phenol compound.

[0171] When a phenol-based heat stabilizer is used, the content of the phenol-based heat stabilizer in the polyamide composition is preferably 0.01 mass % or more and 1 mass % or less, and more preferably 0.1 mass % or more and 1 mass % or less, relative to the total mass of the polyamide composition. When the content of the phenol-based heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the amount of gas generation can be further reduced.

[0172] (Phosphorus-based heat stabilizer) Examples of phosphorus-based heat stabilizers include, but are not limited to, pentaerythritol-type phosphite compounds, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, trisisodecyl phosphite, phenyl diisodecyl phosphite, phenyl di(tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris(nonyl) phosphite, phenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tris(2,4-di-tert-butyl-5-methylphenyl)phosphite, tris(butoxyethyl)phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl-tetra-tridecyl)diphosphite, tetra(C12-C15 mixed alkyl)-4,4'-isopropylidene diphenyl diphosphite, 4,4'-isopropylidenebis(2-tert-butylphenyl)-di(no nylphenyl)phosphite, tris(biphenyl)phosphite, tetra(tridecyl)-1,1,3-tris(2-methyl-5-tert-butyl-4-hydroxyphenyl)butane diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-tert-butylphenyl)diphosphite, tetra(C1-C15 mixed alkyl)-4,4'-isopropylidene diphenyl diphosphite, tris(mono, dimixed nonylphenyl)phosphite, 4,4'-isopropylidenebis(2 -tert-butylphenyl)-di(nonylphenyl)phosphite, 9,10-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, tris(3,5-di-tert-butyl-4-hydroxyphenyl)phosphite, hydrogenated-4,4'-isopropylidene diphenyl polyphosphite, bis(octylphenyl)-bis(4,4'-butylidenebis(3-methyl-6-tert-butylphenyl))-1,6-hexanol diphosphite, hexatridecyl-1,1,Examples of such phosphite include 3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)diphosphite, tris(4,4'-isopropylidenebis(2-tert-butylphenyl))phosphite, tris(1,3-stearoyloxyisopropyl)phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, 2,2-methylenebis(3-methyl-4,6-di-tert-butylphenyl)2-ethylhexylphosphite, tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylene diphosphite, and tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite. These phosphorus-based heat stabilizers may be used alone or in combination of two or more. Among them, from the viewpoint of further improving the heat aging resistance of the polyamide composition and reducing the amount of gas generation, the phosphorus-based heat stabilizer is preferably at least one selected from the group consisting of pentaerythritol-type phosphite compounds and tris(2,4-di-tert-butylphenyl)phosphite.

[0173] Examples of the pentaerythritol type phosphite compound include, but are not limited to, 2,6-di-tert-butyl-4-methylphenyl-phenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-methyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2-ethylhexyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-isodecyl-pentaerythritol diphosphite, 2, 6-di-tert-butyl-4-methylphenyl-lauryl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-isotridecyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-stearyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-cyclohexyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-benzyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl ethyl cellosolve-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-butylcarbitol-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-octylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-nonylphenyl-pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl)pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,6-di-tert-butylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,4-di-tert-butylphenyl-pentaerythritol diphosphite, 2,6-di-tert-butyl-4-methylphenyl-2,4-di-tert-octylphenyl-pentaerythritol diphosphite, 2,Examples of such diphosphite include 6-di-tert-butyl-4-methylphenyl-2-cyclohexylphenyl-pentaerythritol diphosphite, 2,6-di-tert-amyl-4-methylphenyl-phenyl pentaerythritol diphosphite, bis(2,6-di-tert-amyl-4-methylphenyl) pentaerythritol diphosphite, and bis(2,6-di-tert-octyl-4-methylphenyl) pentaerythritol diphosphite. These pentaerythritol type phosphite compounds may be used alone or in combination of two or more kinds. Among them, from the viewpoint of reducing the amount of gas generated from the polyamide composition, the pentaerythritol-type phosphite compound is preferably one or more selected from the group consisting of bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-amyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,6-di-tert-octyl-4-methylphenyl)pentaerythritol diphosphite, and more preferably bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite.

[0174] When a phosphorus-based heat stabilizer is used, the content of the phosphorus-based heat stabilizer in the polyamide composition is preferably 0.01 mass % or more and 1 mass % or less, and more preferably 0.1 mass % or more and 1 mass % or less, based on the total mass of the polyamide composition. When the content of the phosphorus-based heat stabilizer is within the above range, the heat aging resistance of the polyamide composition can be further improved, and the amount of gas generation can be further reduced.

[0175] (Amine-based heat stabilizer) Examples of the amine-based heat stabilizer include, but are not limited to, 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, and 4-stearyloxy-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, biphenyl Bis(2,2,6,6-tetramethyl-4-piperidyl)tolylene-2,4-dicarbamate, bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylene-1,6-dicarbamate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,5-tricarboxylate, tris(2,2,6,6-tetramethyl-4-piperidyl)-benzene-1,3,4-tricarboxylate, 1-[2-{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy}butyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]2,2,6,6-tetramethylpiperidine, a condensate of 1,2,3,4-butanetetracarboxylic acid, 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, and the like. These amine-based heat stabilizers may be used alone or in combination of two or more kinds.

[0176] When an amine-based heat stabilizer is used, the content of the amine-based heat stabilizer in the polyamide composition is preferably 0.01 mass % or more and 1 mass % or less, and more preferably 0.1 mass % or more and 1 mass % or less, based on the total mass of the polyamide composition. 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 amount of gas generation can be further reduced.

[0177] Among them, the copper salt is preferably at least one selected from the group consisting of copper iodide, copper (I) bromide, copper (II) bromide, copper (I) chloride, and copper acetate, and more preferably at least one selected from the group consisting of copper iodide and copper acetate. When the above-mentioned preferred copper salts are used, a polyamide composition is obtained which is more excellent in heat aging resistance and can more effectively suppress metal corrosion of the screw and cylinder during extrusion (hereinafter, may be simply referred to as "metal corrosion").

[0178] When a copper salt is used as a heat stabilizer, the content of the copper salt in the polyamide composition is preferably 0.01 mass % or more and 0.60 mass % or less, and more preferably 0.02 mass % or more and 0.40 mass % or less, based on the total mass of the polyamide ((A) crystalline polyamide and (B) amorphous polyamide). 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 copper precipitation and metal corrosion can be more effectively suppressed.

[0179] In addition, the content of the copper element derived from the above copper salt is set to 100% by mass of polyamide ((A) crystalline polyamide and (B) amorphous polyamide) from the viewpoint of improving the heat aging resistance of the polyamide composition. 6 The amount is preferably from 10 to 2000 parts by mass, more preferably from 30 to 1500 parts by mass, and even more preferably from 50 to 500 parts by mass, based on parts by mass (1 million parts by mass).

[0180] (Alkali metal and alkaline earth metal halides) Examples of the alkali metal and alkaline earth metal halides include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, and the like.

[0181] These alkali metal and alkaline earth metal halides may be used alone or in combination of two or more kinds. Among these, from the viewpoints of improving heat aging resistance and suppressing metal corrosion, the alkali metal and alkaline earth metal halides are preferably one or more selected from the group consisting of potassium iodide and potassium bromide, and more preferably potassium iodide.

[0182] When alkali metal and alkaline earth metal halides are used, the content of the alkali metal and alkaline earth metal halides in the polyamide composition is preferably 0.05 parts by mass or more and 20 parts by mass or less, and more preferably 0.2 parts by mass or more and 10 parts by mass or less, per 100 parts by mass of polyamide ((A) crystalline polyamide and (B) amorphous polyamide). When the content of alkali metal and alkaline earth metal halides is within the above range, the heat aging resistance of the polyamide composition is further improved, and copper precipitation and metal corrosion can be more effectively suppressed.

[0183] The heat stabilizer components explained above may be used alone or in combination of two or more kinds. Among these, as the heat stabilizer, a hindered phenol compound is preferred from the viewpoint of further improving the heat aging resistance of the polyamide composition.

[0184] [Nucleating agent] The nucleating agent refers to a substance that, when added, provides at least one of the following effects (1) to (3). (1) The effect of increasing the crystallization peak temperature of the polyamide composition. (2) The effect of reducing the difference between the extrapolated onset temperature and the extrapolated end temperature of the crystallization peak. (3) The effect of making the spherulites in the resulting molded product finer or more uniform in size.

[0185] Examples of the nucleating agent include, but are not limited to, talc, boron nitride, mica, kaolin, silicon nitride, potassium titanate, and molybdenum disulfide. The nucleating agents may be used alone or in combination of two or more kinds. Among these, talc or boron nitride is preferred as the nucleating agent from the viewpoint of nucleating agent effect.

[0186] In addition, since the effect of the nucleating agent is high, the number average particle size of the nucleating agent is preferably 0.01 μm or more and 10 μm or less. The number average particle size of the nucleating agent can be measured by the following method. First, the molded product is dissolved in a solvent in which polyamide is soluble, such as formic acid. Next, from the insoluble components obtained, nucleating agents having, for example, 100 or more particles are arbitrarily selected. Then, the particle size can be determined by observing the particles with an optical microscope, a scanning electron microscope, or the like.

[0187] The content of the nucleating agent in the polyamide composition of this embodiment is preferably 0.001 mass % or more and 1 mass % or less, more preferably 0.001 mass % or more and 0.5 mass % or less, and even more preferably 0.001 mass % or more and 0.09 mass % or less, relative to the total mass of the polyamide composition. By setting the content of the nucleating agent to not less than the above lower limit, the heat resistance of the polyamide composition tends to be further improved, and by setting the content of the nucleating agent to not more than the above upper limit, a polyamide composition having superior toughness can be obtained.

[0188] [Other polymers] The other polymers are not particularly limited as long as they are not polyamides, and examples thereof include polyesters, liquid crystal polyesters, polyphenylene sulfides, polyphenylene ethers, polycarbonates, polyarylates, phenolic resins, epoxy resins, etc. The polyesters are not limited to the following, and examples thereof include polybutylene terephthalate, polytrimethylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, etc.

[0189] The content of the other polymer is preferably 1% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 20% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less, based on the total amount of polyamide in the polyamide composition. When the content of the other polymer is within the above range, the polyamide composition can have better heat resistance and releasability.

[0190] [Other additives] In addition to the above-mentioned components, the polyamide composition obtained by the production method of this embodiment may contain other additives commonly used in polyamide compositions, within the range that does not impair the effects of the polyamide composition obtained by the production method of this embodiment. Examples of other additives include colorants such as pigments and dyes (including colored masterbatches), flame retardants, fibrillating agents, fluorescent bleaching agents, plasticizers, antioxidants, ultraviolet absorbers, antistatic agents, flow improvers, spreading agents, etc.

[0191] When the polyamide composition obtained by the production method of the present embodiment contains other additives, the content of the other additives varies depending on the type and use of the polyamide composition, and is not particularly limited as long as it is within a range that does not impair the effects of the polyamide composition obtained by the production method of the present embodiment. [Flame retardant synergist] Anhydrous zinc borate can be used as a flame retardant auxiliary. When anhydrous zinc borate is selected, the ratio of anhydrous zinc borate to (B) phosphorus-based flame retardant is preferably 1:98 to 20:80, more preferably 3:97 to 10:90, from the viewpoint of flame retardancy efficiency.

[0192] <Method of producing polyamide composition> The method for producing the polyamide composition of the present embodiment is not particularly limited as long as it is a method including a step of melt-kneading the raw material components including the above-mentioned (A) polyamide, (B) phosphorus-based flame retardant, (C) polyamide elastomer and (D) inorganic filler. For example, a method including a step of melt-kneading the raw material components including the above-mentioned (A) polyamide, (B) phosphorus-based flame retardant, (C) polyamide elastomer and (D) inorganic filler in an extruder, and setting the extruder temperature to the melting peak temperature Tm of the above-mentioned polyamide composition + 30°C or less is preferred.

[0193] Examples of methods for melt-kneading raw material components containing polyamide include a method in which (A) polyamide, (C) polyamide elastomer, and other raw materials are mixed using a tumbler, Henschel mixer, or the like, and then fed to a melt kneader and kneaded; and a method in which (B) a phosphorus-based flame retardant and (D) other raw materials including an inorganic filler are blended from a side feeder to the above-mentioned (A) polyamide and (C) polyamide elastomer that have been molten in a single-screw or twin-screw extruder.

[0194] The components constituting the polyamide composition may be supplied to the melt kneader by supplying all of the components to the same supply port at once, or by supplying each of the components from a different supply port.

[0195] The melt-kneading temperature is preferably about 250° C. or more and 350° C. or less in terms of the resin temperature. The melt-kneading time is preferably about 0.25 minutes or more and 5 minutes or less. The melt-kneading device is not particularly limited, and for example, a known melt-kneading device such as a single-screw or twin-screw extruder, a Banbury mixer, or a mixing roll can be used. The melt kneader is preferably a co-rotating twin-screw extruder with a screw diameter of 30 mm or more, and the ratio (L / D) of the barrel length (L) to the screw diameter length (D) of the twin-screw extruder is preferably at least 35. When the L / D of the extruder is within the above range, appropriate kneading can be performed without significant heat generation during kneading, and the domain diameter of the amorphous polyamide can be adjusted to the preferred range in the present application. In the twin-screw extruder, the screw rotation speed (N) is preferably 350 rpm or more, and the ratio Q / N of the screw rotation speed (N) to the discharge rate (Q) is preferably 1.14 or less. When Q / N is in the above range, appropriate kneading can be performed without significant heat generation during kneading, and the domain diameter of the amorphous polyamide can be adjusted to the preferred range in the present application. In addition, when adding the phosphorus-based flame retardant (B) and the inorganic filler (D), since the phosphorus-based flame retardant (B) and the inorganic filler (D) improve the kneading efficiency, it is preferable to dry-blend the polyamide (A) and the polyamide elastomer (C) and then supply them from an upstream supply port of the twin-screw extruder, and then supply the phosphorus-based flame retardant (B) and the inorganic filler (D) from a first downstream supply port of the twin-screw extruder.

[0196] <Molded products> The molded article of the present embodiment is produced by molding the above-mentioned polyamide composition.

[0197] The molded article of the present embodiment uses the above-mentioned polyamide composition, and thus has excellent low-temperature impact properties, deflection temperature under load, electrical properties, and flame retardancy.

[0198] The molded article of the present embodiment can be obtained by molding the above-mentioned polyamide composition using a well-known molding method, such as press molding, injection molding, gas-assisted injection molding, welding molding, extrusion molding, blow molding, film molding, blow molding, multi-layer molding, melt spinning, etc.

[0199] ≪Applications≫ The polyamide resin composition of the present embodiment can be used in applications where heat resistance, flame retardancy, and electrical properties are particularly important, and can be suitably used for electric and electronic parts and electric and electronic parts for automobiles. The electrical components can be used as industrial equipment such as office machines, measuring instruments, chassis, internal parts of electrical equipment, power adapters for home appliances and the like, recording media and their drives, sensor equipment, terminal blocks, electrical and electronic components used in secondary batteries, fuel cells, solar cells, solar thermal power generation, geothermal power generation, wind power generation, smart meters, etc. in the energy and environment fields, electrical components that make up power transmission equipment, cable terminals, automotive components, in particular connection structures for solar power generation modules such as solar cell junction boxes and solar cell module connectors, and parts for hybrid automobiles and electric automobiles. EXAMPLES

[0200] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0201] The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples. First, the measurement methods, evaluation methods, and raw materials used in the examples and comparative examples are shown below. In the present examples, 2 means 0.098 MPa.

[0202] <Components> [(A) Polyamide] A-1a: Polyamide 66 (synthesized by the method described below) A-1b: Polyamide 12 A-2: Polyamide 6I (synthesized by the synthesis method described below) [(B) Phosphorus-based flame retardants] B1: Phosphinic acid flame retardant Aluminum diethylphosphinate (manufactured by Clariant, product name "Exolit OP1230") B2: Phosphinic acid flame retardant: A composite salt of aluminum diethylphosphinate and aluminum ethylphosphonate (manufactured by Weikaijun Co., Ltd., product name "MADP8900BS") [Other flame retardants] B3: Melamine cyanurate (Nissan Chemical Co., Ltd. product name "MC4500") B4: Anhydrous zinc borate (Kinseimatic Firebrake 500) [(C) Polyamide elastomer] C1: PA6 elastomer, Sanyo Chemical Industries, Ltd., product name "Pelestat NC6321" C2: PA12 elastomer, manufactured by Arkema, product name "PEBAX MV2080" C3: Other elastomers Maleic anhydride modified hydrogenated styrene-butadiene copolymer (Made by Asahi Kasei, product name "Tuftec M1943") C4: Other elastomers Maleic anhydride modified ethylene-octene copolymer (Product name: "Fusabond N493" manufactured by DuPont) [(D) Inorganic filler] D-1: Glass fiber (GF) (manufactured by Nippon Electric Glass, product name "ECS03T275H", average fiber diameter 10 μmφ, cut length 3 mm)

[0203] <Production of polyamide> The manufacturing methods of crystalline polyamide A-1 and amorphous polyamide A-2 are described in detail below. The crystalline polyamide A-1 and amorphous polyamide A-2 obtained by the manufacturing methods described below were dried in a nitrogen stream to adjust the moisture content to about 0.2% by mass, and then used as raw materials for polyamide compositions in the examples and comparative examples described below.

[0204] [Synthesis Example 1] (Synthesis of crystalline polyamide A-1 (polyamide 66)) The polymerization reaction of polyamide was carried out by the "thermal melt polymerization method" as follows. First, 1500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500 g of distilled water to prepare a homogeneous aqueous solution of 50% by mass of the raw material monomers. This aqueous solution was charged into an autoclave with an internal volume of 5.4 L and substituted with nitrogen. Next, the solution was concentrated by gradually removing steam to a solution concentration of 70% by mass while stirring at a temperature of about 110°C to 150°C. Next, the internal temperature was raised to 220°C. At this time, the autoclave was pressurized to 1.8 MPa. The reaction was continued for 1 hour while gradually removing steam and maintaining the pressure at 1.8 MPa until the internal temperature reached 245°C. Next, the pressure was lowered over 1 hour. Next, the inside of the autoclave was maintained under 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. The mixture was then pressurized with nitrogen to form a strand from the lower spinneret (nozzle), cooled with water, cut, and discharged in pellet form. The pellets were then dried at 100°C under a nitrogen atmosphere for 12 hours to obtain crystalline polyamide A-1 (polyamide 66). The obtained crystalline polyamide A-1 (polyamide 66) had Mw(A)=40,000, Mw / Mn=2.0 and a melting point Tm of 260°C.

[0205] [Synthesis Example 2] (Synthesis of amorphous polyamide A-2 (polyamide 6I)) The polymerization reaction of polyamide was carried out by the "thermal melt polymerization method" as follows. First, 1500 g of an equimolar salt of isophthalic acid and hexamethylenediamine, 1.5 mol % excess adipic acid relative to the total equimolar salt components, and 0.5 mol % acetic acid were dissolved in 1500 g of distilled water to prepare a 50 mass % equimolar homogeneous aqueous solution of the raw material monomers. Next, the solution was concentrated by gradually removing steam to a solution concentration of 70 mass % while stirring at a temperature of about 110 ° C. to 150 ° C. Next, the internal temperature was raised to 220 ° C. At this time, the autoclave was pressurized to 1.8 MPa. The reaction was continued for 1 hour while gradually removing steam and maintaining the pressure at 1.8 MPa until the internal temperature reached 245 ° C. Next, 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. The mixture was then pressurized with nitrogen to form a strand from the lower spinneret (nozzle), cooled with water, cut, and discharged in pellet form. The pellets were then dried at 100°C in a nitrogen atmosphere for 12 hours to obtain amorphous polyamide A-2 (polyamide 6I). The resulting amorphous polyamide A-2 (polyamide 6I) had a content of isophthalic acid units in dicarboxylic acid units of 100 mol %, Mw(B)=20,000, and Mw / Mn=2.0.

[0206] <Method of measuring physical properties> The following various physical properties were measured using the raw material polyamide and the polyamide composition after adjusting the water content.

[0207] [Physical Properties 1] (Molecular Weight and Molecular Weight Distribution of Polyamide Composition) The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured using a gel permeation chromatograph (GPC) (HLC-8020, manufactured by Tosoh Corporation) and a hexafluoroisopropanol solvent, converted into a PMMA (polymethyl methacrylate) standard sample (manufactured by Polymer Laboratory Co., Ltd.). The molecular weight distribution (Mw / Mn) was calculated from the values.

[0208] [Physical Properties 2] (Melting peak temperature Tm (melting point)) The measurement was carried out in accordance with JIS-K7121 using a Diamond-DSC manufactured by PERKIN-ELMER Co., Ltd. Specifically, the measurement was carried out as follows. First, in a nitrogen atmosphere, about 10 mg of a sample was heated from room temperature to 300°C to 350°C depending on the melting point of the sample at a heating rate of 20°C / min. The highest peak temperature of the endothermic peak (melting peak) that appeared at this time was taken as Tm (°C).

[0209] Details of the raw materials are as follows:

[0210] (polyamide) Crystalline polyamide A-1a (polyamide 66) The one obtained by the synthesis described above was used. Crystalline polyamide A-1b (polyamide 12) (Rilsamid AMN P20TL manufactured by Arkema) Amorphous polyamide A-2 (polyamide 6I) The one obtained by the above synthesis was used.

[0211] (Phosphorus-based flame retardants) B-1 Phosphinic acid flame retardant Aluminum diethylphosphinate (Clariant, product name "Exolit OP1230" powder) B-2 Phosphinic acid flame retardant: Aluminum diethylphosphinate and aluminum ethylphosphonate complex salt (manufactured by Weikaijun Co., Ltd., product name "MADP8900BS") (Polyamide elastomer) PA6 elastomer, manufactured by Sanyo Chemical Industries, Ltd. Product name: "Pellestat NC6321" PA12 elastomer manufactured by Arkema Product name "PEBAX MV2080"

[0212] (Inorganic filler) Inorganic filler: Inorganic filler E-1 (glass fiber (GF) (manufactured by Nippon Electric Glass, product name "ECS03T275H", average fiber diameter 10 μmφ, cut length 3 mm))

[0213] [Rating 1] (23℃ Charpy impact strength) The pellets of each polyamide resin composition were molded into a multipurpose test piece A type molded piece of ISO 3167 using an injection molding machine [PS-40E: manufactured by Nissei Plastics Co., Ltd.] with the injection + pressure holding time set to 25 seconds, cooling time set to 15 seconds, mold temperature set to 80 ° C, and molten resin temperature set to 270 ° C. Next, the multipurpose test piece A type molded piece was processed into a notched test piece according to ISO 2818. The Charpy impact strength of the obtained notched test piece was measured in a 23 ° C environment according to JIS K 7111 (JISO 179). The larger the value, the better the mechanical strength was evaluated to be.

[0214] [Rating 2] (-40℃ low temperature Charpy impact strength) The pellets of each polyamide resin composition were molded into a multipurpose test piece A type molded piece of ISO 3167 using an injection molding machine [PS-40E: manufactured by Nissei Plastics Co., Ltd.] with the injection + pressure holding time set to 25 seconds, cooling time set to 15 seconds, mold temperature set to 80 ° C, and molten resin temperature set to 270 ° C. Next, the multipurpose test piece A type molded piece was processed into a notched test piece according to ISO 2818. The Charpy impact strength of the obtained notched test piece was measured in a -40 ° C environment according to JIS K7111 (JISO179). The larger the value, the better the impact strength was evaluated to be.

[0215] [Rating 4] (23℃ Dart impact test) Each polyamide resin composition pellet was prepared by injection molding using an injection molding machine [PS-40E: manufactured by Nissei Plastics Co., Ltd.], with the injection + pressure holding time set to 25 seconds, cooling time set to 15 seconds, mold temperature set to 80 ° C, and molten resin temperature set to 270 ° C., and the injection molded test piece (length 70 mm × width 70 mm, thickness 3 mm) was measured using a dart impact tester "CEAST9340" manufactured by Instron Co., Ltd. in a 23 ° C. environment. The test piece was sandwiched and fixed between a cylinder with a diameter of 50 mm, and a striker weighing 6.55 kg was dropped vertically from a height of 500 mm onto the center of a flat plate, and the impact energy J was measured. The larger the value, the better the impact strength was evaluated to be.

[0216] [Rating 4] (-40℃ Dart impact test) The injection molded test pieces (70mm long x 70mm wide, 3mm thick) were left in a -40℃ thermostatic chamber for 5 hours and then measured using the Instron Dart Impact Tester "CEAST9340". The test pieces were clamped between a cylinder with a diameter of 50mm, and a striker weighing 6.55kg was dropped vertically onto the center of the plate from a height of 500mm, and the impact energy J was measured. The higher the value, the better the impact strength was evaluated to be.

[0217] [Rating 5] (Deflection temperature under load (DTUL)) The pellets of each polyamide resin composition were molded into a molded piece of 80×10×4 mm using an injection molding machine [PS-40E: manufactured by Nissei Plastics Co., Ltd.] with the following settings: injection + pressure holding time 25 seconds, cooling time 15 seconds, mold temperature 80°C, and molten resin temperature 270°C. The heat distortion temperature was measured at a load of 1.82 MPa in accordance with JIS K 7191-2:2015. The higher the deflection temperature under load, the better the heat resistance was evaluated.

[0218] [Rating 6] (Flame retardant) Measurements were performed using the method of UL94 (a standard established by Underwriters Laboratories Inc., USA). The test pieces (length 127 mm, width 12.7 mm, thickness 0.75 mm and length 127 mm, width 12.7 mm, thickness 1.50 mm) were prepared by attaching a mold for UL test pieces (mold temperature = 100 ° C.) to an injection molding machine (PS40E manufactured by Nissei Kogyo Co., Ltd.) and molding each polyamide composition at a cylinder temperature of 290 ° C. The injection pressure was set at a pressure of + 2% of the full filling pressure when molding the UL test pieces. The flame retardant grade was evaluated according to the UL94 standard (vertical flame test) to see whether it was V-0, V-1, or V-2. The smaller the grade number, the higher the flame retardant.

[0219] <Production of polyamide composition> [Examples 1 to 10 and Comparative Examples 1 to 7] Polyamide compositions were produced as follows using (A) polyamide, (B) phosphorus-based flame retardant, (C) polyamide elastomer, and (D) inorganic filler in the types and proportions shown in the tables below.

[0220] The raw material polyamide (A) was dried in a nitrogen stream to adjust the moisture content to about 0.2% by mass, and then used as a raw material for the polyamide composition.

[0221] As the apparatus for producing the polyamide composition, a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., product name "TEM-58SX" (L / D=53.8) was used.

[0222] In the twin-screw extruder, the temperature from the upstream supply port to the die was set to the melting point Tm2 + 20°C of each crystalline polyamide (A) produced in the above production examples, the screw rotation speed was set to 350 rpm, and the discharge rate was set to 400 kg / h (Q / N = 1.14).

[0223] (A) polyamide and (C) polyamide elastomer were dry-blended to the types and ratios shown in the following tables, and then fed from the upstream feed port of a twin-screw extruder, (B) phosphorus-based flame retardant was fed from the downstream first feed port of the twin-screw extruder, and (D) glass fiber was fed from the downstream second feed port, and the molten mixture extruded from the die head was cooled in a strand shape and pelletized to obtain pellets of a polyamide composition. The pellets of the polyamide composition thus obtained were dried in a nitrogen stream to reduce the moisture content in the polyamide composition to 500 ppm or less.

[0224] [Table 1]

[0225] From Table 1, it can be seen that the materials containing the specified amounts of (A) polyamide, (B) phosphorus-based flame retardant, (C) polyamide elastomer, and (D) inorganic filler maintained the flame retardancy of UL94 V-0, had excellent low-temperature impact properties, excellent deflection temperature under load, and also had excellent electrical properties. [Industrial Applicability]

[0226] Having the above-mentioned properties, the material can be suitably used in electrical and electronic components, and electrical and electronic components for automobiles.

[0227] According to the polyamide composition of the present embodiment, it is possible to provide a polyamide composition that is excellent in low-temperature impact properties, electrical properties, deflection temperature under load, and flame retardancy.

Claims

1. A polyamide composition comprising (A) 20-60 wt% polyamide, (B) 10-30 wt% phosphorus-based flame retardant, (C) 2-20 wt% polyamide elastomer, and (D) 10-60 wt% inorganic filler.

2. The polyamide composition according to claim 1, wherein the (B) phosphorus-based flame retardant comprises at least one phosphinate selected from the group consisting of a phosphinate represented by the following general formula (1), a diphosphinate represented by the following general formula (2), and a complex salt of a phosphinate and a phosphonate represented by the following general formula (3). 【Chemistry 1】 【change】 (In general formula (1), R １１ and R １２ Each of these is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. ｎ１１＋ R 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. If n11 is 2 or 3, there are multiple R １１ and R １２ These may be the same or different. In the 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’ ｘ ｍ２１＋ is a metal ion having 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 to 3. 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 from each other. n21, x, and m21 are integers satisfying the relational expression of 2 × n21 = m21 × x. In general formula (3), R １ , R ２ and R ３ Each of these is independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. ｍ＋ R is a metal ion. M is an element belonging to group 2 or group 15 of the periodic table, a transition element, zinc, or aluminum. m is 2 or 3. If m is 2 or 3, there are multiple R １ and R ２ These may be the same or different.

3. The polyamide composition according to claim 1 or 2, wherein the (B) phosphorus-based flame retardant comprises a phosphinate metal salt or a phosphinate-phosphonic acid composite metal salt.

4. The polyamide composition according to claim 1 or 2, wherein the (C) polyamide elastomer is a polyamide 6-based polyamide elastomer.

5. The polyamide composition according to claim 1 or 2, wherein the (A) polyamide is (A-1) crystalline polyamide.

6. The polyamide composition according to claim 5, wherein the (A) polyamide further comprises (A-2) amorphous polyamide.

7. The polyamide composition according to claim 6, wherein the amorphous polyamide (A-2) contains 50 mol% or more of isophthalic acid units in the total dicarboxylic acid units comprising 50 mol% or more.

8. The polyamide composition according to claim 7, wherein the amorphous polyamide (A-2) contains 75 mol% or more of isophthalic acid units in total dicarboxylic acid units.

9. The polyamide composition according to claim 8, wherein the (A-2) amorphous polyamide contains 100 mol% isophthalic acid units in total dicarboxylic acid units.

Images