Polyamide composition

Abstract

To provide a polyamide composition which is excellent in machine physical properties, heat resistant aging properties at 180°C for a long term of about 2,000 hours, and electric characteristic, is suppressed in bleedout of an additive agent at 80°C and a relative humidity of 95%, makes an additive agent hardly elute in water, and enables obtaining a molded article having excellent external appearance.SOLUTION: A polyamide composition contains: (A) polyamide; 0.1 pt.mass or more and 3 pts.mass or less of (B) branch type polyamine based on 100 pts.mass of the (A) polyamide; 0.05 pt.mass or more and 3 pts.mass or less of (C) steric hindrance phenol; and 0.01 pt.mass or more and 0.5 pt.mass or less of (D) azine dye or phthalocyanine dye. A concentration of (F) halide ion measured by combustion ion chromatography is 500 mass ppm or less based on the total mass of the polyamide composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyamide composition.

Background Art

[0002] Polyamides are excellent in strength, heat resistance, chemical resistance, and specific gravity. That is, since the specific gravity is smaller than that of metals, they have conventionally been used as metal substitute materials for automotive structural parts and the like.

[0003] Among automotive parts, there are those that are exposed to a high-temperature environment for a long time. In this case, the component material is required to have heat stability (hereinafter referred to as "long-term heat aging resistance") that maintains its strength even when exposed to a high-temperature environment for a long time. Furthermore, with the electrification and EVization of automobiles, there are also components having electronic contacts and exposed to a high-temperature environment (for example, 180°C or lower). The materials used for such components are required to have long-term heat aging resistance at 180°C and high electrical properties (for example, volume resistivity and tracking resistance).

[0004] As heat stabilizers used for polyamides, copper halides and alkali metal halides used in combination therewith are known (see, for example, Patent Document 1, etc.). However, the addition of these heat stabilizers has a great effect as a heat stabilizer, but there is a problem that the halide ions contained in this heat stabilizer cause a decrease in electrical resistivity and tracking resistance. Due to the above restrictions, it is difficult to achieve both long-term heat aging resistance at 180°C and high electrical resistivity and high tracking resistance, and research is still actively being conducted.

[0005] From the above background, it is desired to realize a polyamide material that simultaneously satisfies all of the long-term heat aging resistance at 180°C, high electrical properties, and appearance.

[0006] As a technique for improving the long-term heat aging resistance without degrading the electrical properties of polyamide, for example, a method of using an organic heat stabilizer such as a sterically hindered phenol, an aromatic amine, or a sterically hindered amine is known. However, when using only an organic heat stabilizer, the heat aging resistance at 180 °C is insufficient. In addition, when increasing the addition amount of the organic heat stabilizer to improve the long-term heat aging resistance, there is a problem that the additive bleeds out from the molded product and the appearance is impaired.

[0007] On the other hand, as a technique for improving the long-term heat aging resistance of polyamide resin, a method of adding polyethyleneimine as an effective heat stabilizer to polyamide is known (see, for example, Patent Documents 2, 3, etc.).

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in Patent Documents 2 and 3, only examples of using a copper halide in combination are shown. Halide ions cause a decrease in electrical properties. In addition, in Patent Documents 2 and 3, examples using an additive that absorbs a laser have not been specifically studied. That is, a polyamide resin composition having excellent long-term heat aging resistance, electrical properties, appearance, and suppression of additive bleed-out has not yet been obtained.

[0010] The present invention has been made in view of the above circumstances, and provides a polyamide composition that is excellent in mechanical properties, heat resistance aging property for a long period of about 2000 hours at 180 ° C, and electrical properties, suppresses bleed-out of additives at 80 ° C and a relative humidity of 95%, is difficult for the additives to elute into water, and can obtain a molded product with excellent appearance.

Means for Solving the Problems

[0011] That is, the present invention includes the following aspects. (1) (A) A polyamide, Based on 100 parts by mass of the (A) polyamide, 0.1 part by mass or more and 3 parts by mass or less of (B) a branched polyamine, 0.05 part by mass or more and 3 parts by mass or less of (C) a sterically hindered phenol, 0.01 part by mass or more and 0.5 part by mass or less of (D) an azine-based dye or a phthalocyanine-based dye A polyamide composition containing The concentration of (F) halide ions measured by combustion ion chromatography with respect to the total mass of the polyamide composition is 500 ppm by mass or less. (2) The (A) polyamide contains polyamide 66, and the content of polyamide 66 is 50% by mass or more with respect to the total mass of the (A) polyamide. The polyamide composition according to (1). (3) The (B) branched polyamine is a (Ba) polyethyleneimine homopolymer or copolymer. The polyamide composition according to (1) or (2). (4) The weight average molecular weight of the (B) branched polyamine is 400 or more and 2000 or less. The polyamide composition according to any one of (1) to (3). (5) The (C) sterically hindered phenol contains one or more amide groups. The polyamide composition according to any one of (1) to (4). (6) Based on 100 parts by mass of the (A) polyamide, further contains 0.01 part by mass or more and 0.5 part by mass or less of (E) carbon black. The polyamide composition according to any one of (1) to (5). (7) The polyamide composition according to any one of (1) to (6), wherein the concentration of (F) halide ions measured by combustion ion chromatography is less than 1% by mass with respect to the mass of the (D) azine-based dye or phthalocyanine-based dye. (8) The polyamide composition according to any one of (1) to (7), wherein the weight ratio of the (B) branched polyamine to the (C) sterically hindered phenol is 0.06 to 30, and the weight ratio of the (C) sterically hindered phenol to the (D) azine-based dye or phthalocyanine-based dye is 0.5 to 60. (9) The polyamide composition according to any one of (1) to (8), further comprising (G) a filler. (10) (A) Polyamide, A polyamide composition comprising, with respect to 100 parts by mass of the (A) polyamide, 0.1 part by mass or more and 3 parts by mass or less of (B) a branched polyamine, wherein the viscosity of the (B) branched polyamine at 20 °C measured by a Brookfield viscometer in accordance with ISO 2555 is 1000 mPa·s or more and 2500 mPa·s or less. (11) The polyamide composition according to (10), wherein the (A) polyamide contains polyamide 66, and the content of the polyamide 66 is 50% by mass or more with respect to the total mass of the (A) polyamide. (12) The polyamide composition according to (10) or (11), wherein the (B) branched polyamine is a (Ba) polyethyleneimine homopolymer or copolymer. (13) The polyamide composition according to any one of (10) to (12), wherein the weight average molecular weight of the (B) branched polyamine is 400 or more and 2000 or less. (14) The polyamide composition according to any one of (10) to (13), further comprising 0.05 part by mass or more and 3 parts by mass or less of (C) an organic heat stabilizer with respect to 100 parts by mass of the (A) polyamide. (15) The polyamide composition according to (14), wherein the (C) organic heat stabilizer is a (C1) sterically hindered phenol. (16) The polyamide composition according to (15), wherein the (C1) sterically hindered phenol contains one or more amide groups. (17) The polyamide composition according to any one of (10) to (16), further comprising (D) an azine-based dye or a phthalocyanine-based dye. (18) The polyamide composition according to (17), wherein the concentration of (F) halide ions measured by combustion ion chromatography is less than 1% by mass with respect to the mass of the (D) azine-based dye or phthalocyanine-based dye. (19) The polyamide composition according to any one of (10) to (18), further comprising (E) carbon black in an amount of 0.001 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass of the (A) polyamide. (20) The polyamide composition according to any one of (10) to (19), wherein the concentration of (F) halide ions measured by combustion ion chromatography is 500 ppm by mass or less with respect to the total mass of the polyamide composition. (21) The polyamide composition according to any one of claims 10 to 20, further comprising (G) a filler. [Advantages of the Invention]

[0012] According to the polyamide composition of the above aspect, it is excellent in mechanical properties, heat aging resistance at 180°C for a long period of about 2000 hours, and electrical properties, suppresses the bleed-out of additives at 80°C and a relative humidity of 95%, the additives are hardly eluted in water, and a molded product with excellent appearance can be obtained. [Embodiments for Carrying Out the Invention]

[0013] Hereinafter, embodiments for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an exemplification for explaining the present invention and is not intended to limit the present invention to the following content. The present invention can be appropriately modified and implemented within the scope of its gist.

[0014] In this specification, "polyamide" means a polymer having an amide (-NHCO-) group in the main chain.

[0015] ≪Polyamide Composition (1)≫ The polyamide composition of one embodiment of the present invention is (A) polyamide, and Based on 100 parts by mass of the (A) polyamide, 0.1 part by mass or more and 3 parts by mass or less of (B) branched polyamine, 0.05 part by mass or more and 3 parts by mass or less of (C) sterically hindered phenol, 0.01 part by mass or more and 0.5 part by mass or less of (D) azine dye or phthalocyanine dye, and

[0016] Also, the concentration of (F) halide ions measured by combustion ion chromatography with respect to the total mass of the polyamide composition is 500 ppm by mass or less.

[0017] By having the above configuration, the polyamide composition of this embodiment is excellent in heat aging resistance and electrical properties over a long period of about 2000 hours at 180°C, the bleed-out of additives is suppressed at 80°C and 95% relative humidity, and a molded product excellent in appearance and laser marking properties can be obtained.

[0018] Hereinafter, the above (A) polyamide to (D) azine dye or phthalocyanine dye and (F) halide ions may be referred to as (A) component to (D) component and (F) component, respectively.

[0019] The components of the polyamide composition of this embodiment will be described in detail below.

[0020] <(A) Polyamide> (A) Examples of the polyamide include (a-1) a polyamide obtained by ring-opening polymerization of a lactam, (a-2) a polyamide obtained by self-condensation of an ω-aminocarboxylic acid, (a-3) a polyamide obtained by condensing a diamine and a dicarboxylic acid, and copolymers thereof. The polyamide may be used alone or in combination of two or more.

[0021] Examples of the lactam used for producing the (a-1) polyamide include, but are not limited to, pyrrolidone, caprolactam, undecalactam, dodecalactam, etc. Examples of the ω-aminocarboxylic acid used for producing the (a-2) polyamide include, but are not limited to, ω-amino fatty acids which are ring-opening compounds of the above lactam with water. Also, as the above lactam or the above ω-aminocarboxylic acid, two or more kinds of monomers may be used in combination for condensation.

[0022] Examples of the diamine (monomer) used for producing the (a-3) polyamide include, but are not limited to, linear aliphatic diamines, branched aliphatic diamines, alicyclic diamines, aromatic diamines, etc. Examples of the linear aliphatic diamine include, but are not limited to, hexamethylenediamine, pentamethylenediamine, etc. Examples of the branched aliphatic diamine include, but are not limited to, 2-methylpentanediamine, 2-ethylhexamethylenediamine, etc. Examples of the alicyclic diamine include, but are not limited to, cyclohexanediamine, cyclopentanediamine, cyclooctanediamine, etc. Examples of the aromatic diamine include, but are not limited to, p-phenylenediamine, m-phenylenediamine, etc. Examples of the dicarboxylic acid (monomer) used for producing the (a-3) polyamide include, but are not limited to, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, etc. Examples of the aliphatic dicarboxylic acid include, but are not limited to, adipic acid, pimelic acid, sebacic acid, etc. Examples of the alicyclic dicarboxylic acid include, but are not limited to, cyclohexanedicarboxylic acid, etc. Examples of the aromatic dicarboxylic acid include, but are not limited to, phthalic acid, isophthalic acid, etc. The diamine and dicarboxylic acid as the above-mentioned monomers may be condensed alone or in combination of two or more.

[0023] Specific examples of the polyamide contained in the polyamide composition include, for example, polyamide 4 (poly-α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecanamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 56 (polypentamethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonamethylene terephthalamide), and copolymer polyamides containing these as constituent components. Among them, as the polyamide, polyamide 66 (PA66), polyamide 6 (PA6), polyamide 610 (PA610), or polyamide 612 (PA612) is preferable. Since PA66 is excellent in heat resistance, moldability, and toughness, it is a suitable material for automotive parts. Also, long-chain aliphatic polyamides such as PA610 and PA612 are excellent in chemical resistance.

[0024] Further, from the viewpoints of heat resistance, moldability, and toughness, the content of PA66 with respect to the total mass of the polyamide (A) is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 100% by mass or more.

[0025] [Terminal blocking agent] (A) The terminals of the polyamide may be terminated with a known terminal blocking agent. Such a terminal blocking agent can also be added as a molecular weight regulator when producing a polyamide from the above dicarboxylic acid, the above diamine, and, if necessary, at least one of the above lactam and the above aminocarboxylic acid.

[0026] Examples of the terminal blocking agent include, but are not limited to, monocarboxylic acids, monoamines, acid anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols, etc. Examples of the acid anhydride include, but are not limited to, phthalic anhydride, etc. These terminal blocking agents may be used alone or in combination of two or more. Among them, monocarboxylic acids or monoamines are preferred as the terminal blocking agent. When the terminals of the polyamide are blocked with a terminal blocking agent, the polyamide composition tends to have better thermal stability.

[0027] The monocarboxylic acid that can be used as the terminal blocking agent only needs to have reactivity with the amino group that may be present at the terminal of the polyamide. Specific examples of the monocarboxylic acid include, but are not limited to, aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids, etc. Examples of the aliphatic monocarboxylic acid 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, isobutyric acid, etc. Examples of the alicyclic monocarboxylic acid include, but are not limited to, cyclohexanecarboxylic acid, etc. Examples of the aromatic monocarboxylic acid include, but are not limited to, benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid, and the like. These monocarboxylic acids may be used alone or in combination of two or more.

[0028] The monoamine that can be used as the end-capping agent may be any one having reactivity with the carboxy 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, aromatic monoamines, and the like. Examples of the aliphatic amine include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, and the like. Examples of the alicyclic amine include, but are not limited to, cyclohexylamine, dicyclohexylamine, and the like. Examples of the aromatic amine 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.

[0029] The polyamide composition containing the (A) polyamide end-capped with the end-capping agent tends to be excellent in heat resistance, fluidity, toughness, low water absorption, and rigidity.

[0030] [Content of (A) polyamide] The (A) polyamide in the polyamide composition can be, for example, 40.0% by mass or more and 99.8% by mass or less, for example, 50.0% by mass or more and 90.0% by mass or less, for example, 55.0% by mass or more and 80.0% by mass or less, based on the total mass of the polyamide.

[0031] [Method for producing polyamide (A)] When producing polyamide (A), the addition amount of dicarboxylic acid and the addition amount of diamine are preferably in the vicinity of equimolar amounts. Considering also the amount of diamine escaping from the reaction system during the polymerization reaction in terms of molar ratio, the molar amount of the total diamine is preferably 0.9 or more and 1.2 or less, more preferably 0.95 or more and 1.1 or less, and even more preferably 0.98 or more and 1.05 or less, relative to 1 of the molar amount of the total dicarboxylic acid.

[0032] The method for producing polyamide (A) is not limited to the following, but for example, includes a step of polymerizing a dicarboxylic acid constituting a dicarboxylic acid unit, a diamine constituting a diamine unit, and, if necessary, at least one of a lactam constituting a lactam unit and an aminocarboxylic acid constituting an aminocarboxylic acid unit to obtain a polymer. Further, in the method for producing polyamide, it is preferable to further include a step of increasing the degree of polymerization of the polyamide. Moreover, if necessary, it may include a sealing step of sealing the terminals of the obtained polymer with a terminal sealing agent.

[0033] Specific methods for producing polyamide include, for example, various methods as exemplified in the following 1) to 4). 1) A method of heating an aqueous solution of a dicarboxylic acid-diamine salt or a mixture of a dicarboxylic acid and a diamine, or a suspension of these in water, and polymerizing while maintaining a molten state (hereinafter sometimes referred to as the "thermal melt polymerization method"). 2) A method of increasing the degree of polymerization while maintaining a solid state at a temperature below the melting point of the polyamide obtained by the thermal melt polymerization method (hereinafter sometimes referred to as the "thermal melt polymerization / solid phase polymerization method"). 3) A method of polymerizing a dicarboxylic acid-diamine salt or a mixture of a dicarboxylic acid and a diamine while maintaining a solid state (hereinafter sometimes referred to as the "solid phase polymerization method"). 4) A method of polymerizing using a dicarboxylic acid halide component and a diamine component equivalent to a dicarboxylic acid (hereinafter sometimes referred to as the "solution method"). Among them, as a specific production method of polyamide, a production method including a thermal melting polymerization method is preferable. Further, when producing polyamide by the thermal melting polymerization method, it is preferable to maintain the molten state until the polymerization is completed. Examples of the method for maintaining the molten state include a method of producing under polymerization conditions suitable for the composition of polyamide. Examples of the polymerization conditions include the following conditions. First, control the polymerization pressure in the thermal melting polymerization method to 14 kg / cm 2 or more and 25 kg / cm 2 or less (gauge pressure), and continue heating. Next, lower the pressure over 30 minutes or more until the pressure in the tank reaches atmospheric pressure (gauge pressure is 0 kg / cm 2 ), and polyamide with a desired composition can be obtained.

[0034] In the production method of polyamide, the polymerization form is not particularly limited, and it may be a batch type or a continuous type. The polymerization apparatus used for the production of polyamide is not particularly limited, and a known apparatus can be used. Examples include an autoclave type reactor, a tumbler type reactor, an extruder type reactor such as a kneader, etc.

[0035] Hereinafter, as a production method of polyamide, a method of producing polyamide by a batch type thermal melting polymerization method will be specifically shown, but the production method of polyamide is not limited thereto. First, an aqueous solution containing the raw material components of polyamide (dicarboxylic acid, diamine, and, if necessary, at least one of lactam and aminocarboxylic acid) in an amount of about 40% by mass or more and 60% by mass or less is concentrated in a concentration tank operated at a temperature of 110°C or more and 180°C or less and a pressure of about 0.035 MPa or more and 0.6 MPa or less (gauge pressure) to about 65% by mass or more and 90% by mass or less to obtain a concentrated solution. Next, transfer the obtained concentrated solution to an autoclave and continue heating until the pressure in the autoclave reaches about 1.2 MPa or more and 2.2 MPa or less (gauge pressure). Thereafter, in an autoclave, while discharging at least one of water and gas components, the pressure is maintained at about 1.2 MPa or more and 2.2 MPa or less (gauge pressure), and when the temperature reaches about 220 °C or more and 260 °C or less, the pressure is reduced to atmospheric pressure (gauge pressure is 0 MPa). After the pressure inside the autoclave is reduced to atmospheric pressure, by reducing the pressure as necessary, by-products of water can be effectively removed. Thereafter, the autoclave is pressurized with an inert gas such as nitrogen, and the polyamide melt is extruded from the autoclave as strands. The extruded strands are cooled and cut to obtain polyamide pellets.

[0036] [(A) Polymer terminals of polyamide] (A) The polymer terminals of polyamide are not particularly limited, but can be classified and defined as follows. That is, 1) amino terminal, 2) carboxy terminal, 3) terminal formed by a terminator, and 4) other terminals. 1) The amino terminal is a polymer terminal having an amino group (-NH2 group) and is derived from the diamine unit of the raw material. 2) The carboxy terminal is a polymer terminal having a carboxy group (-COOH group) and is derived from the dicarboxylic acid of the raw material. 3) The terminal formed by a terminator is a terminal formed when a terminator is added during polymerization. Examples of the terminator include the above-mentioned end-capping agents. 4) Other terminals are polymer terminals not classified into the above 1) to 3). Specific examples of other terminals include, for example, terminals formed by deammoniation reaction of amino terminals, terminals formed by decarboxylation reaction from carboxy terminals, and the like.

[0037] [(A) Characteristics of polyamide] ((A) Molecular weight of polyamide) As an index of the molecular weight of the polyamide, the weight average molecular weight Mw can be used. The weight average molecular weight Mw of the polyamide can be, for example, 10,000 or more and 100,000 or less, can be, for example, 15,000 or more and 95,000 or less, can be, for example, 20,000 or more and 90,000 or less, and can be, for example, 25,000 or more and 85,000 or less. Incidentally, the measurement of the weight average molecular weight Mw can be carried out using gel permeation chromatography (GPC) as described in the following examples.

[0038] ((A) Molecular weight distribution of polyamide) The molecular weight distribution of the polyamide is indicated by the weight average molecular weight Mw / number average molecular weight Mn. The Mw / Mn of the polyamide can be 1.8 or more, and can be, for example, 1.8 or more and 3.0 or less, and can be, for example, 1.9 or more and 2.5 or less.

[0039] As a method for controlling the Mw / Mn of the polyamide within the above range, for example, a method of adding a known polycondensation catalyst such as phosphoric acid or sodium hypophosphite as an additive during the thermal melt polymerization of the polyamide, and a method of controlling polymerization conditions such as heating conditions and reduced pressure conditions can be mentioned. The Mw / Mn of the polyamide can be calculated using the weight average molecular weight Mw and the number average molecular weight Mn obtained using GPC as described in the following examples.

[0040] <(B) Branched polyamine> (B) Examples of the branched polyamine include polyalkyleneimine and polyalkylene polyamine. Examples of the polyalkyleneimine include polyethyleneimine and polytrimethyleneimine.

[0041] (B) Among the branched polyamines, (Ba) polyethyleneimine homopolymer or copolymer is particularly preferable in terms of heat aging resistance and the strength and appearance of the molded product.

[0042] As used herein, "polyethyleneimine" refers to homopolymers and copolymers obtained by the method described with the keyword "aziridine" in the electronic version of Ullmann or the method described in WO 94 / 012560 (Reference 1). Hereinafter, "(Ba) polyethyleneimine homopolymer or copolymer" may sometimes be referred to as "(Ba) polyethyleneimine".

[0043] Generally, the homopolymer of ethyleneimine is obtained by polymerization of ethyleneimine (aziridine) in an aqueous solution or an organic solution in the presence of a reaction initiator, an acid or a Lewis acid. The homopolymer of ethyleneimine obtained by such a method is generally a branched polymer containing primary, secondary, and tertiary amino groups in a molar ratio of primary amino group:secondary amino group:tertiary amino group = about 30%:40%:30%. The distribution of amino groups can be 13 measured using C-NMR spectroscopy.

[0044] Examples of the comonomer for forming the copolymer of ethyleneimine include amines having at least two amino groups as described above. The comonomer is not limited to the following, and examples thereof include alkylenediamines having 2 to 10 C atoms in the alkylene group. In particular, ethylenediamine or propylenediamine is preferred. Examples of the comonomer include, in addition to the above, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, tripropylenetetramine, dihexamethylenetriamine, aminopropylethylenediamine, bisaminopropylethylenediamine, and the like.

[0045] As the (Ba) polyethyleneimine, in addition to the above, crosslinkable polyethyleneimine obtained by reacting polyethyleneimine with a bifunctional or polyfunctional crosslinking agent having at least one selected from the group consisting of halohydrin-, glycidyl-, aziridine-, isocyanate unit, and halogen atom as a functional group is preferably used. For example, polyalkylene glycol and epichlorohydrin with any one or more and 100 or less units selected from the group consisting of ethylene oxide units and propylene oxide units; bis-chlorohydrin ether, compounds described in German Patent Application Publication No. 19931720 (Reference 2) and U.S. Patent No. 4144123 (Reference 3), etc. can be mentioned. As a method for producing crosslinkable polyethyleneimine, the methods described in the above references, European Patent Application Publication No. 0895521 (Reference 4) and European Patent Application Publication No. 0025515 (Reference 5) can be applied.

[0046] Furthermore, as the (Ba) polyethyleneimine, grafted polyethyleneimine is also preferably used. As the grafting agent, all compounds that can react with the amino group or imino group of polyethyleneimine can be used. As a method for producing the grafting agent and grafted polyethyleneimine, for example, the method described in European Patent Application Publication No. 0675914 (Reference 6) can be applied.

[0047] In addition, (Ba) polyethyleneimine may be amidated by reaction with a carboxylic acid, an ester or anhydride of a carboxylic acid, a carboxamide or a carboxylic acid halide. Depending on the proportion of amidated nitrogen atoms in the polyethyleneimine chain, the amidated polymer can be crosslinked later with a predetermined crosslinking agent. At this time, in order to be able to supply at least any one atom selected from the group consisting of primary nitrogen atoms and secondary nitrogen atoms sufficiently for the subsequent crosslinking reaction, up to 30 mol% of the amino functional groups are amidated. That is, in the amidated polymer, in order to ensure that at least any one atom selected from the group consisting of a sufficient amount of primary nitrogen atoms and secondary nitrogen atoms is present, the amino functional groups in the amidated polymer are preferably amidated at a ratio of 30 mol% or less. Note that all carboxylic acids are consumed by amidation, and the amidated polymer has no carboxylic acid end groups and can be clearly distinguished from organic acids.

[0048] In addition, (Ba) polyethyleneimine may be an alkoxylated polyethyleneimine obtained, for example, by reaction of polyethyleneimine with at least any one selected from the group consisting of ethylene oxide and propylene oxide. Such an alkoxylated polymer can be crosslinked thereafter.

[0049] In addition, (Ba) polyethyleneimine may be, for example, a hydroxy group-containing polyethyleneimine, an amphoteric polyethyleneimine (incorporation of an anionic group), and generally, a lipophilic polyethyleneimine obtained by incorporation of a long-chain hydrocarbon group into the polymer chain, from the viewpoint of affinity with a polyamide resin. Methods for producing such polyethyleneimine polymers are known to those skilled in the art.

[0050] [Properties of (Ba) Polyethyleneimine] [Weight-Average Molecular Weight of (Ba) Polyethyleneimine] (Ba) The weight average molecular weight of polyethyleneimine is preferably 100 or more and 3,000,000 or less, more preferably 200 or more and 2,000,000 or less, still more preferably 300 or more and 20,000 or less, particularly preferably 400 or more and 2,000 or less, and most preferably 700 or more and 1,000 or less. (Ba) By the weight average molecular weight of polyethyleneimine being at least the above lower limit value, the heat aging resistance can be made better. On the other hand, by the weight average molecular weight of polyethyleneimine being at most the above upper limit value, the appearance when made into a molded product can be made better. (Ba) The weight average molecular weight of polyethyleneimine can be measured by a light scattering method.

[0051] ((Viscosity of (Ba) polyethyleneimine)) (Ba) The viscosity of polyethyleneimine is preferably 1000 mPa·s or more and 2500 mPa·s or less, more preferably 1200 mPa·s or more and 2300 mPa·s or less, still more preferably 1200 mPa·s or more and 2100 mPa·s or less, and particularly preferably 1400 mPa·s or more and 1900 Pa·smPa·s or less. (Ba) When the viscosity of polyethyleneimine is at least the above lower limit value, the heat aging resistance and mechanical properties become better. (Ba) When the viscosity of polyethyleneimine is at most the above upper limit value, the heat aging resistance and appearance when made into a molded product become better, and the (B) polyethyleneimine contained in the molded product is less likely to elute into water. (Ba) The viscosity of polyethyleneimine can be measured by a Brookfield viscometer in accordance with ISO 2555 at 20°C.

[0052] [(Content of (Ba) polyethyleneimine)] In the polyamide composition of the present embodiment, from the viewpoints of heat aging resistance, appearance, strength, and rigidity when formed into a molded article, the content of (Ba) polyethyleneimine is 0.1 part by mass or more and 3 parts by mass or less, preferably 0.2 part by mass or more and 2 parts by mass or less, and more preferably 0.3 part by mass or more and 1.4 parts by mass or less with respect to 100 parts by mass of (A) polyamide. When the content of (Ba) polyethyleneimine is at least the above lower limit value, the heat aging resistance and appearance are improved. On the other hand, when the content of (Ba) polyethyleneimine is at most the above upper limit value, the strength, rigidity, etc. when formed into a molded article are improved.

[0053] <(C) Sterically hindered phenol> The polyamide composition of the present embodiment contains (C) sterically hindered phenol, and thus is excellent in heat aging resistance when formed into a molded article and can suppress the bleed-out of additives at 80°C and a relative humidity of 95%.

[0054] (C) Examples of the sterically hindered phenols include, but are not limited to, N,N'-hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanamide], triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2'-thiobis(4-methyl-6-1-butylphenol), N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydroxynnamamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-butyl-4-hydroxybenzyl)benzene, bis(3,5-di-tert-butyl-4-hydroxybenzylsulfonic acid ethyl calcium, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(4-ethyl-6-tert-butylphenol), 4,4'-thiobis-(3-methyl-6-tert-butylphenol), octylated diphenylamine, 2,4-bis[(octylthio)methyl]-o-cresol, isooctyl-3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionate, 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 3,9-bis[1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-sec-triazine-2,4,6-(1H,3H,5H)trione, d-α-tocopherol and the like can be mentioned.,

[0055] Among the sterically hindered phenols (C) listed above, sterically hindered phenols having one or more amide groups are preferred, and N,N'-hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanamide] is more preferred. The sterically hindered phenol (C) having one or more amide groups interacts more strongly with the azine-based dye or phthalocyanine-based dye (D) than the sterically hindered phenol (C) having no amide group, thereby more effectively suppressing the bleed-out of the sterically hindered phenol (C).

[0056] [Content of (C) sterically hindered phenol] In the polyamide composition of this embodiment, from the viewpoints of heat aging resistance and suppression of bleed-out when formed into a molded article, the content of the sterically hindered phenol (C) is 0.05 part by mass or more and 3 parts by mass or less, preferably 0.1 part by mass or more and 2 parts by mass or less, and more preferably 0.2 part by mass or more and 1.5 parts by mass or less with respect to 100 parts by mass of the polyamide (A). (C) The heat aging resistance is improved by the content of the sterically hindered phenol being equal to or higher than the above lower limit value. On the other hand, bleeding out can be suppressed by the content of the sterically hindered phenol (C) being equal to or lower than the above upper limit value. In the polyamide composition of the present embodiment, from the viewpoints of heat aging resistance, mechanical properties, and suppression of bleeding out when formed into a molded article, the weight ratio of the content of (B) branched polyamine to (C) sterically hindered phenol is preferably 0.06 to 30, more preferably 0.3 to 8.0, and even more preferably 0.67 to 5.0. When the weight ratio of the content of (B) branched polyamine to (C) sterically hindered phenol is equal to or higher than the above lower limit value, the heat aging resistance is improved and bleeding out of the (C) sterically hindered phenol can be prevented. On the other hand, when the weight ratio of the content of (B) branched polyamine to (C) sterically hindered phenol is equal to or lower than the above upper limit value, the heat aging resistance and mechanical properties are improved.

[0057] <(D) Azine dye or phthalocyanine dye> The polyamide composition of the present embodiment contains (D) azine dye or phthalocyanine dye, and these act as crystallization retarders to further improve the appearance of the molded article.

[0058] As the azine dye, nigrosine is preferred. As the phthalocyanine dye, copper phthalocyanine-based dyes are preferred.

[0059] (D) Azine dyes or phthalocyanine dyes have the effect of suppressing bleeding out of (C) sterically hindered phenol due to the interaction with (C) sterically hindered phenol. From the viewpoint of the magnitude of this bleeding out suppressing effect, among the (D) components, it is preferable to use azine dyes, and nigrosine is more preferable. At this time, the bleeding out of (C) sterically hindered phenol is further suppressed by the strong interaction between (C) sterically hindered phenol having an amide group and nigrosine.

[0060] [Content of azine-based dye or phthalocyanine-based dye] In the polyamide composition of this embodiment, the content of the (D) azine-based dye or phthalocyanine-based dye is 0.01 part by mass or more and 0.5 part by mass or less, preferably 0.05 part by mass or more and 0.32 part by mass or less, and more preferably 0.08 part by mass or more and 0.2 part by mass with respect to 100 parts by mass of the (A) polyamide. When the content of the (D) azine-based dye or phthalocyanine-based dye is at least the above lower limit value, the appearance of the molded product becomes good, and further, the bleed-out of the (C) sterically hindered phenol can be prevented. On the other hand, when the content of the (D) azine-based dye or phthalocyanine-based dye is at most the above upper limit value, there is a tendency to prevent a decrease in the strength and rigidity of the molded product. In the polyamide composition of this embodiment, the weight ratio of the content of the (C) sterically hindered phenol to the (D) azine-based dye or phthalocyanine-based dye is preferably 0.5 to 60, more preferably 1.0 to 20, and still more preferably 1.67 to 12. When the weight ratio of the content of the (C) sterically hindered phenol to the (D) azine-based dye or phthalocyanine-based dye is at least the above lower limit value, the tensile strength can be improved. When the weight ratio of the content of the (C) sterically hindered phenol to the (D) azine-based dye or phthalocyanine-based dye is at most the above upper limit value, the bleed-out of the (C) sterically hindered phenol can be prevented.

[0061] [Content of halide ion] The (D) azine-based dye or phthalocyanine-based dye may contain halide ions. Since halide ions cause a decrease in electrical properties, the concentration of halide ions contained in the (D) azine-based dye or phthalocyanine-based dye is preferably less than 1% by mass, more preferably less than 0.6% by mass, and still more preferably less than 0.2% by mass with respect to the mass of the (D) azine-based dye or phthalocyanine-based dye. Here, the concentration of halide ions is measured by combustion ion chromatography.

[0062] <(E) Carbon black> The polyamide composition of this embodiment can contain (E) carbon black. By including (E) carbon black, the laser marking property can be made good. Further, when used together with (D) azine-based dye or phthalocyanine-based dye, even if (E) carbon black functions as a crystal nucleating agent, due to the crystallization delay effect of (D) azine-based dye or phthalocyanine-based dye, the appearance of the molded product can be made good without being impaired.

[0063] Note that the laser marking mentioned here means printing product name, manufacturing number, precautions, etc. using a laser. In order to enable laser marking, black additives such as (E) carbon black are used as additives that absorb the laser.

[0064] However, such additives that absorb the laser may function as crystal nucleating agents and promote the crystallization of the matrix resin. Therefore, the appearance of the molded product is likely to be impaired.

[0065] When the polyamide composition of this embodiment is used together with the (D) component, even if (E) carbon black functions as a crystal nucleating agent, due to the crystallization delay effect of the (D) component, the appearance of the molded product can be made better without being impaired.

[0066] Examples of (E) carbon black include acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, gas black, and oil black. These (E) carbon blacks can be used alone or in combination of two or more.

[0067] [Content of (E) carbon black] In the polyamide composition of this embodiment, the content of (E) carbon black is preferably 0.01 part by mass or more and 0.5 part by mass or less, more preferably 0.05 part by mass or more and 0.25 part by mass or less, and even more preferably 0.1 part by mass or more and 0.2 part by mass or less, based on 100 parts by mass of (A) polyamide. When the content of (E) carbon black is at least the above lower limit value, the heating efficiency by laser is improved and the laser marking property becomes good. On the other hand, when the content of (E) carbon black is at most the above upper limit value, carbonization of the resin due to heating can be prevented.

[0068] <(F) Halide ion> In the polyamide composition of this embodiment, the concentration of (F) halide ion is 500 mass ppm or less, preferably 400 mass ppm or less, more preferably 300 mass ppm or less, even more preferably 200 mass ppm or less, and particularly preferably 100 mass ppm or less, based on the total mass of the polyamide composition. On the other hand, the lower the lower limit value of the concentration of (F) halide ion, the more preferable. For example, it can be 0.0 mass ppm, it can be 0.1 mass ppm, and it can be 1 mass ppm.

[0069] In the polyamide composition of this embodiment, the components (A) to (E) may contain halide ions as impurities depending on their production methods. When the content of (F) halide ion in the polyamide composition of this embodiment exceeds the above upper limit value, there is a risk that electrical properties such as volume resistivity and tracking resistance are impaired. Therefore, by suppressing the amount of (F) halide ion contained in each of the components (A) to (E) and making the concentration of (F) halide ion contained in the polyamide composition not exceed the above upper limit value, a polyamide composition excellent in electrical properties when formed into a molded product can be obtained.

[0070] <(G) Filler> In addition to components (A) to (E), the polyamide composition of the present embodiment preferably further contains a (G) filler. By containing the (G) filler, the mechanical properties such as strength and rigidity when formed into a molded article can be further improved.

[0071] (G) The filler is not particularly limited. For example, glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, glass flake, calcium carbonate, talc, kaolin, mica, hydrotalcite, zinc carbonate, calcium hydrogen phosphate, wollastonite, zeolite, boehmite, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, ketjen black, acetylene black, furnace black, carbon nanotube, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swelling fluorine mica, apatite, mild fiber, etc. may be mentioned. These (G) fillers may be used alone or in combination of two or more.

[0072] Among them, as the (G) filler, from the viewpoints of rigidity and strength, etc., glass fiber, carbon fiber, glass flake, talc, kaolin, mica, calcium hydrogen phosphate, wollastonite, carbon nanotube, graphite, calcium fluoride, montmorillonite, swelling fluorine mica, or apatite is preferable. Also, the (G) filler is more preferably one or more selected from the group consisting of glass fiber, calcium carbonate, talc, mica, wollastonite, and mild fiber, still more preferably glass fiber or carbon fiber, and particularly preferably glass fiber.

[0073] (G) When the filler is glass fiber or carbon fiber, the number average fiber diameter (d1) is preferably 3 μm or more and 30 μm or less. Also, the weight average fiber length (L) is preferably 100 μm or more and 5 mm or less. Further, the aspect ratio ((L) / (d1)) of the weight average fiber length (L) to the number average fiber diameter (d1) is preferably 10 or more and 100 or less. By using the glass fiber or carbon fiber having the above configuration, higher properties can be exhibited.

[0074] Also, when the (G) filler is glass fiber, the number average fiber diameter (d1) is more preferably 3 μm or more and 30 μm or less. The weight average fiber length (L) is more preferably 103 μm or more and 5 mm or less. Further, the aspect ratio ((L) / (d1)) of 3 or more and 100 or less is more preferable.

[0075] The number average fiber diameter and the weight average fiber length of the (G) filler can be measured using the following method. First, the molded product is dissolved in a solvent such as formic acid in which (A) polyamide is soluble. Next, for example, 100 or more (G) fillers are arbitrarily selected from the obtained insoluble components. Next, the (G) filler is observed with an optical microscope, a scanning electron microscope, etc., and the number average fiber diameter can be obtained by dividing the total of the measured fiber diameters by the number of the measured (G) fillers. Alternatively, the weight average fiber length can be obtained by dividing the total of the measured fiber lengths by the total weight of the measured (G) fillers.

[0076] [Content of (G) filler] In the polyamide composition of this embodiment, the content of the (G) filler is preferably 0 parts by mass or more and 150 parts by mass or less, more preferably 10 parts by mass or more and 140 parts by mass or less, further preferably 20 parts by mass or more and 135 parts by mass or less, particularly preferably 25 parts by mass or more and 130 parts by mass or less, and most preferably 30 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of (A) polyamide. (G) The content of the filler being equal to or higher than the above lower limit value tends to further improve the mechanical properties such as the strength and rigidity of the molded product. On the other hand, when the content of the (G) filler is equal to or lower than the above upper limit value, it tends to be possible to obtain a molded product that is more excellent in surface appearance and more excellent in laser marking properties. In particular, when the (G) filler is glass fiber and the content of the (G) filler is within the above range with respect to 100 parts by mass of (a) polyamide, the mechanical properties such as the strength and rigidity of the molded product tend to be further improved.

[0077] <Other additives> The polyamide composition may also contain other additives commonly used in polyamides as long as the object of the present embodiment is not impaired. Examples of other additives include fibrillating agents, lubricants, fluorescent bleaching agents, plasticizers, ultraviolet absorbers, antistatic agents, fluidity improvers, reinforcing agents, spreading agents, nucleating agents, rubbers, strengthening agents, and other polymers. The content of other additives in the polyamide composition of the present embodiment can be appropriately set by those skilled in the art according to the purpose.

[0078] <Method for producing polyamide composition> In the method for producing a polyamide composition, the method of adding each constituent component is not particularly limited as long as it is a method of mixing the components (A) to (E) and, if necessary, the component (G) and the other additives described above.

[0079] Examples of the mixing method of the constituent materials include a method of mixing using a Henschel mixer or the like and supplying it to a melt kneader for kneading, a method of melting the component (A) from a top feeder with a single-screw or twin-screw extruder, and the components (B) to (E), and blending the filler (C) and other additives (D) from a side feeder as necessary.

[0080] The method of supplying the components constituting the polyamide composition may be to supply all the components at once to the same supply port, or the components (A) to (E) and, if necessary, the component (G) may be supplied from different supply ports.

[0081] The melt-kneading temperature is preferably about 250°C or higher and 375°C or lower as the resin temperature.

[0082] The melt-kneading time is preferably about 0.5 minutes or longer and 5 minutes or shorter.

[0083] The apparatus for performing melt-kneading is not particularly limited, and known apparatuses such as single-screw or twin-screw extruders, Banbury mixers, and mixing rolls can be used as the melt-kneading machine. ≪Polyamide composition (2)≫ The polyamide composition according to another embodiment of the present invention is (A) polyamide and 0.1 part by mass or more and 3 parts by mass or less of (B) branched polyamine with respect to 100 parts by mass of the (A) polyamide. Further, the viscosity of the (B) branched polyamine at 20°C measured by a Brookfield viscometer in accordance with ISO2555 is 1000 mPa·s or more and 2500 mPa·s or less.

[0084] By having the above configuration, the polyamide composition of the present embodiment is excellent in heat aging resistance, electrical properties, appearance, and mechanical properties, and a molded product in which the additive is hardly eluted in water can be obtained.

[0085] Each component of the polyamide composition of the present embodiment will be described in detail below. [(A) Polyamide] In the polyamide composition of the present embodiment, the (A) polyamide is as described in <(A) polyamide> of the above-described ≪Polyamide composition (1)≫.

[0086] [(B) Branched polyamine] In the polyamide composition of the present embodiment, the (B) branched polyamine is as described in <(B) branched polyamine> of the above-described << polyamide composition (1) >>.

[0087] [(C) Organic heat stabilizer] The polyamide composition of the present embodiment can contain a (C) organic heat stabilizer. By including the (C) organic heat stabilizer, the heat aging resistance when formed into a molded product can be made better. In the polyamide composition of the present embodiment, from the viewpoints of heat aging resistance and suppression of bleed-out when formed into a molded product, the content of the (C) organic heat stabilizer is preferably 0.05 parts by mass or more and 3 parts by mass or less, more preferably 0.1 parts by mass or more and 2 parts by mass or less, and particularly preferably 0.2 parts by mass or more and 1.5 parts by mass or less with respect to 100 parts by mass of the (A) polyamide.

[0088] When the content of the (C) organic heat stabilizer is at least the above lower limit value, the heat aging resistance is improved. On the other hand, when the content of the (C) organic heat stabilizer is at most the above upper limit value, bleed-out can be suppressed.

[0089] The (C) organic heat stabilizer is not particularly limited, and for example, a sterically hindered phenol-based organic heat stabilizer, a phosphorus-based organic heat stabilizer, an aromatic amine-based organic heat stabilizer, a sterically hindered amine-based organic heat stabilizer, etc. can be used. Among them, as the (C) organic heat stabilizer, a sterically hindered phenol-based organic heat stabilizer is preferred. The sterically hindered phenol-based organic heat stabilizer may be described as "(C1) sterically hindered phenol". (C1) sterically hindered phenol is as described in <(C) sterically hindered phenol> of the above-described << polyamide composition (1) >>.

[0090] [(D) Azine dye or phthalocyanine dye] In the polyamide composition of the present embodiment, the (D) azine dye or phthalocyanine dye is as described in <(D) azine dye or phthalocyanine dye> of the above-described << polyamide composition (1) >>.

[0091] [(E) Carbon black] In the polyamide composition of this embodiment, (E) carbon black is as described in <(E) Carbon black> of the above-mentioned <<Polyamide composition (1)>>. However, in the polyamide composition of this embodiment, the content of (E) carbon black is 0.001 part by mass or more and 0.5 part by mass or less, preferably 0.005 part by mass or more and 0.25 part by mass or less, and more preferably 0.01 part by mass or more and 0.2 part by mass or less with respect to 100 parts by mass of (A) polyamide. When the content of (E) carbon black is at least the above lower limit value, the heating efficiency by laser is improved and the laser marking property becomes good. On the other hand, when the content of (E) carbon black is at most the above upper limit value, carbonization of the resin by heating can be prevented.

[0092] [(F) Halide ion] In the polyamide composition of this embodiment, (F) halide ion is as described in <(F) Halide ion> of the above-mentioned <<Polyamide composition (1)>>.

[0093] [(G) Filler] In the polyamide composition of this embodiment, (G) filler is as described in <(G) Filler> of the above-mentioned <<Polyamide composition (1)>>.

[0094] [Usage] The molded article obtained from the polyamide composition of the embodiment of the present invention is suitably used, for example, as material parts for various uses such as automotive, mechanical industry, electric and electronic, industrial materials, industrial materials, building materials, daily and household products. Among them, it is particularly preferably used as an automotive part because of its excellent heat aging resistance and electrical properties. [Examples]

[0095] Hereinafter, the present invention will be described in detail with specific examples and comparative examples, but the present invention is not limited to the following examples. Hereinafter, each constituent component of the resin compositions used in the present examples and comparative examples will be described.

[0096] <Constituent components> [(A) Polyamide] A-1: Polyamide 66 (PA66) A-2: Polyamide 66 (PA66) A-3: Polyamide 6 (PA6) (manufactured by Ube Industries, SF1013)

[0097] The synthesis methods of polyamides A-1 and A-2 will be described later. The obtained polyamides A-1 and A-2 were dried in a nitrogen stream and adjusted to a moisture content of about 0.1% by mass, and then used as raw materials for the polyamide composition.

[0098] [(B) Branched polyamine] B-1: Lupasol (trademark registered) FG (manufactured by BASF, weight average molecular weight 800, viscosity 1680 mPa·s) B-2: Epomin (trademark registered) SP-006 (manufactured by Nippon Shokubai, number average molecular weight 600, viscosity 2900 mPa·s) B-3: Lupasol (trademark registered) G20 WF (manufactured by BASF, weight average molecular weight 1300, viscosity 8000 mPa·s) B-4: Epomin (trademark registered) SP-003 (manufactured by Nippon Shokubai, number average molecular weight 300, viscosity 300 mPa·s)

[0099] [(C) Sterically hindered phenol] C-1: N,N’-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)) (manufactured by BASF, trade name "Irganox (registered trademark) 1098", with amide group) C-2: 3,9-Bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane (manufactured by ADEKA Corporation, trade name "ADEKA STAB (registered trademark) AO-80", without amide group)

[0100] [(C’) Heat stabilizer] C’-1: Hindered amine-based heat stabilizer (manufactured by Clariant, trade name "Nylostab (trademark registration) S-EED") C’-2: Aromatic amine-based heat stabilizer (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name "No Crack CD") C’-3: Aromatic amine-based heat stabilizer (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name "No Crack 224") C’-4: Mixture of copper iodide and potassium iodide

[0101] [(D) Azine dye or phthalocyanine dye] D-1: Nigrosine dye (manufactured by Orient Chemical Co., TH807) (concentration of halide ion: 0.06 mass%) D-2: Nigrosine dye (manufactured by Orient Chemical Co., TH870) (concentration of halide ion: 1.6 mass%)

[0102] [(E) Carbon black] E-1: Carbon black (primary particle size 27 nm)

[0103] [(G) Filler] G-1: Glass fiber (GF) (manufactured by Nippon Electric Glass Co., Ltd., trade name "ECS03T275H", average fiber diameter 10 μm, cut length 3 mm)

[0104] <(A) Synthesis of polyamide> [Synthesis Example 1] (Synthesis of polyamide A-1 (PA66)) The polymerization reaction of polyamide was carried out as follows by the "thermal melting polymerization method". First, 1500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500 g of distilled water to prepare a 50 mass% homogeneous aqueous solution of equimolar raw material monomers. This aqueous solution was charged into an autoclave with an internal volume of 5.4 L and purged with nitrogen. Then, while stirring at a temperature of 110°C or higher and 150°C or lower, water vapor was gradually removed to concentrate the solution to a concentration of 70 mass%. Next, the internal temperature was raised to 220°C. At this time, the pressure in the autoclave increased to 1.8 MPa. While maintaining the pressure at 1.8 MPa, water vapor was gradually removed over 1 hour until the internal temperature reached 245°C, and the reaction was carried out for 1 hour. Then, the pressure was reduced 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. Then, it was pressurized with nitrogen and extruded in a strand shape from the lower spinning nozzle (nozzle), cooled with water, cut, and discharged in pellet form, and dried at 100°C in a nitrogen atmosphere for 12 hours to obtain polyamide A-1 (PA66). The obtained polyamide A-1 (PA66) had a weight average molecular weight of 35,000 and a molecular weight distribution (Mw / Mn) of 2.0.

[0105] [Synthesis Example 2] (Synthesis of polyamide A-2 (PA66)) The polymerization reaction of polyamide was carried out as follows by the "thermal melt polymerization method". First, 1500 g of an equimolar salt of adipic acid and hexamethylenediamine was dissolved in 1500 g of distilled water to prepare a 50 mass% homogeneous aqueous solution of equimolar raw material monomers. This aqueous solution was charged into an autoclave with an internal volume of 5.4 L. Copper iodide and potassium iodide were added thereto, and nitrogen substitution was performed. Then, while stirring at a temperature of 110°C or higher and 150°C or lower, water vapor was gradually removed to concentrate the solution to a concentration of 70 mass%. Next, the internal temperature was raised to 220°C. At this time, the pressure in the autoclave increased to 1.8 MPa. While maintaining the pressure at 1.8 MPa, water vapor was gradually removed for 1 hour until the internal temperature reached 245°C and the reaction was carried out for 1 hour. Then, the pressure was reduced over 1 hour. Next, the inside of the autoclave was maintained under a reduced pressure of 650 torr (86.66 kPa) for 10 minutes with a vacuum device. At this time, the final internal temperature of the polymerization was 265°C. Then, it was pressurized with nitrogen, formed into strands from the lower spinning nozzle, cooled with water, cut, discharged in the form of pellets, and dried at 100°C in a nitrogen atmosphere for 12 hours to obtain polyamide A-2 (PA66). The obtained polyamide A-2 (PA66) had a weight average molecular weight of 35,000 and a molecular weight distribution (Mw / Mn) of 2.0.

[0106] <Production of Polyamide Composition> [Examples 1 to 22 and Comparative Example 1] Using a TEM35 mm twin-screw extruder manufactured by Toshiba Machine Co., Ltd. (set temperature: 290°C, screw rotation speed 300 rpm), the components (A), (B), (C) or (C'), (D), and (E) were supplied from the top feed port provided at the most upstream part of the extruder so as to have the compounding amounts shown in Tables 1 to 4. Further, the component (G) was supplied from the side feed port on the downstream side of the extruder (in a state where the resin supplied from the top feed port was sufficiently melted). Then, the melt-kneaded product extruded from the die head was cooled in the form of strands and pelletized to obtain pellets of the polyamide composition.

[0107] <Measurement Method of Physical Properties> [Physical Property 1] (Concentration of Halide Ions) The concentration of halide ions (Cl - , Br - , I - ) contained in the pellets of the polyamide composition was quantified by combustion ion chromatography. Specifically, using AQF-2100H manufactured by Mitsubishi Chemical Analytech, samples were prepared by the combustion tube combustion method using ultrapure water (containing hydrogen peroxide solution and hydrazine hydrate) as the absorption liquid. For the ion chromatography (IC) apparatus, Integrion RFIC manufactured by Thermo Fisher Scientific was used, for the column, IonPac AS18-4μm (4 mmφ×150 mm) manufactured by Thermo Fisher Scientific was used, for the eluent, an aqueous KOH solution was used, and for the detector, a UV detector was used.

[0108] From the measurement results, the concentration of halide ions (Cl - , Br - , I - ) was calculated using the following formula. Specifically, the concentration in the sample was calculated for each of Cl - , Br - , and I - respectively, and the sum of these values was taken as the concentration of halide ions.

[0109] "Concentration (mass ppm) of Cl - , Br - , or I - " =[(IC measurement value (mg / L)) × (dilution ratio) - (IC measurement value of blank (mg / L))] × [(amount of absorption liquid (mL)) / 1000] × [1000000 / (mass of sample (mg))]

[0110] <Evaluation Method> [Manufacture of Multi-Purpose Test Specimens] The pellets of the polyamide composition were dried in a nitrogen stream to reduce the moisture content in the polyamide composition to 500 ppm by mass or less. Subsequently, the pellets of each polyamide composition with adjusted moisture content were molded into multi-purpose test pieces (Type A, dumbbell-shaped tensile test pieces) in accordance with ISO 3167 using an injection molding machine (PS-40E, manufactured by Nissei Plastic Industrial Co., Ltd.). The dimensions of the multi-purpose test pieces are as follows: total length ≥ 170 mm, distance between tab portions 109.3 ± 3.2 mm, length of parallel portion 80 ± 2 mm, radius of shoulder 24 ± 1 mm, width of end portion 20 ± 0.2 mm, width of central parallel portion 10 ± 0.2 mm, and thickness 4 ± 0.2 mm. As specific conditions during injection molding, the injection and holding pressure time was set to 25 seconds, the cooling time was set to 15 seconds, the mold temperature was set to 80°C, and the cylinder temperature was set to 290°C.

[0111] [Evaluation 1] (Tensile strength and heat aging resistance) Using the multi-purpose test pieces (Type A), a tensile test was conducted in accordance with ISO 527 at a tensile speed of 5 mm / min to measure the initial tensile strength (MPa) (S0). Subsequently, each multi-purpose test piece (Type A) was placed in an oven compliant with ISO 188 and heated at 180°C for 2000 hours each to conduct a heat aging test. After 2000 hours, each multi-purpose test piece (Type A) was taken out of the oven and cooled at 23°C for 24 hours. Subsequently, each multi-purpose test piece (Type A) after the heat aging test was subjected to a tensile test in accordance with ISO 527 at a tensile speed of 5 mm / min to measure the tensile strength (MPa) after the heat aging test (S1). Then, the tensile strength retention rate (%) was calculated using the formula shown below.

[0112] "Tensile strength retention rate (%)" = S1 / S0 × 100

[0113] [Manufacture of flat molded product] The flat molded product was manufactured as follows. Using an injection molding machine (NEX50III-5EG: manufactured by Nissei Plastic Industrial Co., Ltd.), the cooling time was set to 25 seconds, the screw rotation speed was set to 200 rpm, the mold temperature was set to 80 °C, and the cylinder temperature was set to 290 °C. The injection pressure and injection speed were adjusted as appropriate so that the filling time was in the range of 1.6 ± 0.1 seconds, and flat molded products (6 cm × 9 cm, thickness 2 mm) were manufactured.

[0114] [Evaluation 2] (Tracking resistance) Using the flat molded product, a test was conducted in accordance with IEC60112 using a tracking resistance tester (manufactured by Yamayo Test Instruments Co., Ltd.), and the comparative tracking index (CTI) was calculated. It was judged that the higher the comparative tracking index (CTI), the better the electrical characteristics.

[0115] [Evaluation 3] (Volume resistivity) Using the flat molded product, the volume resistivity was measured in accordance with ASTM D257. It was judged that the higher the volume resistivity, the better the electrical characteristics.

[0116] [Evaluation 4] (Surface appearance) The central part of the flat molded product was measured for 60-degree gloss in accordance with JIS-K7150 using a gloss meter (IG320 manufactured by HORIBA). It was judged that the higher the gloss value, the better the surface appearance.

[0117] [Evaluation 5] (Bleed-out test) (C) When a sterically hindered phenol or (C') a heat stabilizer is included and the color of the molded product is black, bleed-out of the (C) sterically hindered phenol or (C') heat stabilizer becomes visually observable. When a (C) sterically hindered phenol or (C') heat stabilizer is included and (D) an azine-based dye or a phthalocyanine-based dye or (E) carbon black is included, a bleed-out test was conducted. A flat molded product was used and left standing in a thermo-hygrostat chamber (temperature: 80 °C, relative humidity: 95%) for 500 hours. The flat molded product was taken out, and the bleed-outs generated on the surface were observed, and the ease of bleed-out was evaluated according to the following criteria. It was indicated as "bleed-out suppression" in the table.

[0118] (Evaluation criteria) ◎: No bleed-outs are visible on the flat molded product. 〇: Bleed-outs are visible on a part of the flat molded product. △: Bleed-outs are visible on the entire flat molded product. ×: A large amount of bleed-outs are visible on the entire flat molded product.

[0119] [Evaluation 6] (Laser marking property) On the flat molded product, printing consisting of a 3 mm × 3 mm square was applied by laser marking using MD-V9920 or MD-S9910 manufactured by Keyence Corporation. As the conditions for laser marking, the wavelength was 1064 nm and the output was 7.8 W. The laser-marked part was observed, and the laser marking property was evaluated as follows.

[0120] (Evaluation criteria) ○: The laser-marked part looks white. ×: The laser-marked part does not look white.

[0121] [Evaluation 7] (Charpy impact strength) Using the polyamide composition molded products (multi-purpose test pieces) obtained in the examples and comparative examples, the notched Charpy impact strength was measured in accordance with ISO 179.

[0122] [Evaluation 8] (Evaluation of the difficulty of elution of the additive into water) 30 g of pellets of the polyamide composition and 30 g of distilled water were placed in a plastic bottle with a volume of 100 mL, sealed, and left in an electric oven at 80 °C for 24 hours. After cooling, the water in the plastic bottle was taken out into a beaker, and the pH at 23 °C was measured with a pH meter. (B) Since the aqueous polyethyleneimine solution is basic, it was judged that the closer the pH value is to 7, the less likely (B) polyethyleneimine is to elute into water. It was designated as the eluted water pH in the table.

[0123] For each polyamide composition, the above-described measurement methods and evaluation methods for physical properties were carried out. The results are shown in Tables 1 to 4. The tensile strength shown in the tables is the initial tensile strength (S0) (MPa).

[0124] [Table 1]

[0125] [Table 2]

[0126] [Table 3]

[0127] [Table 4] [Industrial Applicability]

[0128] According to the polyamide composition of the present embodiment, it is excellent in mechanical properties, heat aging resistance over a long period of about 2000 hours at 180°C, and electrical properties. The bleed-out of additives at 80°C and 95% relative humidity is suppressed, the additives are hardly eluted in water, and a molded product with excellent appearance can be obtained. The molded product obtained from the polyamide composition of the present embodiment is suitably used, for example, as material parts for various applications such as automotive, mechanical industry, electrical and electronic, industrial materials, industrial materials, building materials, daily and household products, etc.

Claims

1. (A) a polyamide, based on 100 parts by mass of the (A) polyamide, 0.1 part by mass or more and 3 parts by mass or less of (B) a branched polyamine, 0.05 part by mass or more and 3 parts by mass or less of (C) a sterically hindered phenol, 0.01 part by mass or more and 0.5 part by mass or less of (D) an azine dye or a phthalocyanine dye, A polyamide composition comprising: A polyamide composition in which the concentration of (F) halide ions measured by combustion ion chromatography is 500 ppm by mass or less based on the total mass of the polyamide composition.

2. The (A) polyamide contains polyamide 66, The polyamide composition according to Claim 1, wherein the content of polyamide 66 is 50% by mass or more based on the total mass of the (A) polyamide.

3. The polyamide composition according to Claim 1 or 2, wherein the (B) branched polyamine is a polyethyleneimine homopolymer or copolymer.

4. The polyamide composition according to Claim 1 or 2, wherein the weight average molecular weight of the (B) branched polyamine is 400 or more and 2000 or less.

5. The polyamide composition according to Claim 1 or 2, wherein the (C) sterically hindered phenol contains one or more amide groups.

6. The polyamide composition according to Claim 1 or 2, further comprising 0.01 part by mass or more and 0.5 part by mass or less of (E) carbon black based on 100 parts by mass of the (A) polyamide.

7. The polyamide composition according to Claim 1 or 2, wherein the concentration of (F) halide ions measured by combustion ion chromatography is less than 1% by mass based on the mass of the (D) azine dye or phthalocyanine dye.

8. The polyamide composition according to Claim 1 or 2, wherein the weight ratio of the (B) branched polyamine to the (C) sterically hindered phenol is 0.06 to 30, and the weight ratio of the (C) sterically hindered phenol to the (D) azine dye or phthalocyanine dye is 0.5 to 60.

9. The polyamide composition according to Claim 1 or 2, further comprising (G) a filler.

10. (A) a polyamide, A polyamide composition comprising 0.1 part by mass or more and 3 parts by mass or less of (B) a branched polyamine based on 100 parts by mass of the (A) polyamide. The viscosity of the (B) branched polyamine at 20 °C measured by a Brookfield viscometer in accordance with ISO 2555 is 1000 mPa·s or more and 2500 mPa·s or less, a polyamide composition.

11. The (A) polyamide contains polyamide 66, and the content of the polyamide 66 is 50% by mass or more based on the total mass of the (A) polyamide, the polyamide composition according to Claim 10.

12. The (B) branched polyamine is a polyethyleneimine homopolymer or copolymer, the polyamide composition according to Claim 10 or 11.

13. The weight average molecular weight of the (B) branched polyamine is 400 or more and 2000 or less, the polyamide composition according to Claim 10 or 11.

14. The (A) polyamide 100 parts by mass further contains 0.05 parts by mass or more and 3 parts by mass or less of (C) an organic heat stabilizer, the polyamide composition according to Claim 10 or 11.

15. The (C) organic heat stabilizer is (C1) a sterically hindered phenol, the polyamide composition according to Claim 14.

16. The (C1) sterically hindered phenol contains one or more amide groups, the polyamide composition according to Claim 15.

17. The polyamide composition according to Claim 10 or 11 further contains (D) an azine dye or a phthalocyanine dye.

18. The concentration of (F) halide ions measured by combustion ion chromatography with respect to the mass of the (D) azine dye or phthalocyanine dye is less than 1% by mass, the polyamide composition according to Claim 17.

19. The (A) polyamide 100 parts by mass further contains 0.001 parts by mass or more and 0.5 parts by mass or less of (E) carbon black, the polyamide composition according to Claim 10 or 11.

20. The concentration of (F) halide ions measured by combustion ion chromatography with respect to the total mass of the polyamide composition is 500 ppm by mass or less, the polyamide composition according to Claim 10 or 11.

21. The polyamide composition according to Claim 10 or 11 further contains (G) a filler.

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