Polyamide composition

Abstract

Provided is a polyamide composition which comprises a polyamide, a polyolefin, and a copper-based stabilizer, wherein: the polyolefin contains at least one kind of polyolefin (A) that contains a copolymer of ethylene, alkyl (meth)acrylate, and an unsaturated epoxide and at least one kind of polyolefin (B) that contains an unsaturated dicarboxylic anhydride; the mass ratio [B] / [A] of the content [B] of the polyolefin (B) to the content [A] of the polyolefin (A) is 0.1-2.9; and the value Z calculated by formula (1) is 33-200. Also provided are a production method therefor, use thereof, and a molded body obtained therefrom.　Formula (1): Z=1000×(|[ANH]-[EPO]|+[EPO]) / X2 [EPO] is the concentration (mmol / kg) of the unsaturated epoxide, which is derived from the polyolefin, per unit mass of the composition.　[ANH] is the concentration (mmol / kg) of the unsaturated dicarboxylic anhydride, which is derived from the polyolefin, per unit mass of the composition.　The X is the content (mass%) of the polyolefin in the composition.

Description

Technical Field

[0001] The present invention relates to a polyamide composition having excellent heat resistance, and further excellent flexibility, impact resistance, processing stability, and whitening resistance.

Background Art

[0002] Polyamide resins are excellent in strength, heat resistance, chemical resistance, etc., and have conventionally been used for automotive mechanical parts such as fuel pipes and fuel pipe joints (connectors) for automobiles. For example, polyamide resin compositions are also used for tubes for circulating long-life coolants used for automotive engine cooling and refrigerants for air-conditioning cooling. From the viewpoints of ease of extrusion molding and flexibility, aliphatic polyamides such as polyamide 12, polyamide 11, and polyamide 6 are widely used for the above tubes. On the other hand, problems such as insufficient chemical resistance and insufficient heat resistance have been pointed out for these aliphatic polyamides. In particular, in recent years, resinization of tubes through which cooling water, high-temperature gas, and oil flow has been actively studied for the purpose of improving the fuel efficiency of automobiles, and the emergence of materials with better heat resistance and impact resistance than conventional tubes is desired.

[0003] Patent Document 1 discloses that a tube composed of a semi-aromatic polyamide and a modified elastomer and having a specific phase separation structure exhibits excellent surface smoothness and flexibility. Also, it is preferred that the functional group concentration of the elastomer used for the above tube is within a specific range.

[0004] Patent Document 2 discloses a composition containing a semi-aromatic polyamide, a specific polyolefin, and a plasticizer, and shows excellent flexibility, heat aging resistance, and impact resistance.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] It has been known for a long time that flexibility and impact resistance can be imparted by blending a polyamide with a polyolefin containing a functional group that reacts with the polyamide. At this time, by increasing the concentration of the functional group, the affinity of the polyolefin for the polyamide increases, and the dispersibility can be improved. However, there is a problem that the viscosity of the composition increases and the moldability decreases. On the other hand, when the concentration of the functional group is decreased, it has been pointed out that the affinity of the polyolefin for the polyamide decreases, and a part of the polyolefin bleeds out during melt kneading, resulting in a decrease in processability. In addition, it has been pointed out that when a molded article made of a composition of a polyamide and a polyolefin is secondary processed, the surface becomes whitened and the quality as a product decreases. Therefore, an object of the present invention is to provide a polyamide composition having excellent heat resistance, and further excellent flexibility, impact resistance, processing stability, and whitening resistance, a method for producing the same, use of the polyamide composition, and a molded article using the polyamide composition. MEANS FOR SOLVING THE PROBLEMS

[0007] As a result of intensive studies, the present inventors have found that a polyamide composition excellent in flexibility, impact resistance, processing stability, and whitening resistance can be obtained by melt-kneading a polyamide, a specific polyolefin, and a copper-based stabilizer while maintaining excellent heat resistance. Based on this finding, further studies were repeated to complete the present invention.

[0008] That is, the present invention is as follows. [1] A composition containing a polyamide, a polyolefin, and a copper-based stabilizer, The polyolefin contains at least one polyolefin (A) including a copolymer of ethylene, an alkyl (meth)acrylate, and an unsaturated epoxide, and at least one polyolefin (B) including an unsaturated dicarboxylic anhydride, and the mass ratio [B] / [A] of the content [B] of the polyolefin (B) to the content [A] of the polyolefin (A) is 0.1 to 2.9. A polyamide composition in which the value Z calculated from the following formula (1) is 33 to 200. Z = 1000×(|[ANH] - [EPO]| + [EPO]) / X 2 Formula (1) [EPO] is the concentration (mmol / kg) of the unsaturated epoxide derived from the polyolefin per unit mass of the composition. [ANH] is the concentration (mmol / kg) of the unsaturated dicarboxylic anhydride derived from the polyolefin per unit mass of the composition. X is the content rate (mass%) of the polyolefin in the composition. [2] The polyamide composition according to [1], wherein the polyamide contains at least 1 type selected from terephthalic acid units and naphthalenedicarboxylic acid units in an amount of 50 mol% or more based on all dicarboxylic acid units. [3] The polyamide composition according to [1] or [2], wherein the polyamide contains an aliphatic diamine unit having 4 to 13 carbon atoms or a metaxylylenediamine unit in an amount of 60 mol% or more based on all diamine units. [4] The polyamide composition according to [3], wherein the aliphatic diamine unit is a unit derived from at least one aliphatic diamine selected from the group consisting of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine. [5] The polyamide composition according to [3] or [4], wherein the aliphatic diamine unit is a unit derived from at least one aliphatic diamine selected from 1,9-nonanediamine and 2-methyl-1,8-octanediamine. [6] The polydispersity index of the polyamide measured by gel permeation chromatography is 3.7 or more, the content of terminal amino groups in the polyamide is 10 to 70 μeq / g, and the content of terminal carboxyl groups is 10 to 70 μeq / g. The polyamide composition according to any one of [1] to [5] above. [7] The polyamide composition according to any one of [1] to [6] above, wherein the content of the polyolefin is 14 to 40% by mass. [8] The polyamide composition according to any one of [1] to [7] above, wherein the content of the polyolefin is 15 to 30% by mass. [9] The polyamide composition according to any one of [1] to [8] above, wherein the polyolefin (B) is a copolymer of ethylene, alkyl (meth)acrylate and unsaturated dicarboxylic anhydride.

[10] The polyamide composition according to any one of [1] to [9] above, wherein the content of the copper-based stabilizer is 0.01 to 2% by mass.

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

[10] above, wherein the copper-based stabilizer contains at least one copper compound selected from the group consisting of copper iodide, copper bromide, and copper acetate, and at least one metal halide selected from the group consisting of potassium iodide and potassium bromide.

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

[11] above, which contains at least one additive selected from the group consisting of other polymers, antioxidants, fillers, crystal nucleating agents, colorants, antistatic agents, plasticizers, lubricants, flame retardants, and flame retardant aids, other than the polyamide and the polyolefin.

[13] A method for producing the polyamide composition according to any one of [1] to

[12] above, A method for producing a polyamide composition, wherein the polyamide, the polyolefin, and the copper-based stabilizer are top-fed into a twin-screw extruder and melt-kneaded.

[14] Use of the polyamide composition according to any one of [1] to

[12] above for producing a single-layer structure or for producing at least one layer of a multilayer structure.

[15] A molded article made of the polyamide composition according to any one of [1] to

[12] above.

[16] The molded article according to

[15] above, which is an extrusion molded article, a co-extrusion molded article, or a blow molded article.

[17] The molded article according to

[16] above, which is a fuel tube, an engine coolant tube, a battery coolant tube, a motor coolant tube, a fuel cell cooling tube, a urea solution transfer tube, an air conditioner refrigerant tube, a blow-by tube, a brake booster tube, a brake tube, an oil cooling tube, a turbo duct pipe, an air suspension tube, or an oil transportation tube.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a polyamide composition having excellent heat resistance, and further excellent flexibility, impact resistance, processing stability, and whitening resistance, a method for producing the same, use of the above polyamide composition, and a molded article using the above polyamide composition.

Embodiments for Carrying Out the Invention

[0010] Further features, aspects, and advantages of the present invention will become more apparent by reading the following detailed description and examples.

[0011] Also, in this specification, although preferred forms of the embodiments are shown, combinations of two or more of the individual preferred forms are also preferred forms. For matters indicated by numerical ranges, when there are several numerical ranges, their lower limit values and upper limit values can be selectively combined to form preferred forms. For example, the description "XX to YY" means "XX or more and YY or less". Also, "~ unit" (where "~" represents a monomer) means "a structural unit derived from ~". For example, "dicarboxylic acid unit" means "a structural unit derived from dicarboxylic acid". "Diamine unit" means "a structural unit derived from diamine". Also, "(meth)acrylate" means "acrylate" and the corresponding "methacrylate". In addition, the "tube" means a tubular structure such as a pipe or a hose.

[0012] <Polyamide composition> [Polyamide] The polyamide composition of this embodiment contains at least one kind of polyamide.

[0013] The above polyamide contains at least one repeating unit composed of polycondensation of dicarboxylic acid units and diamine units.

[0014] Examples of the dicarboxylic acid units include aromatic dicarboxylic acid units such as terephthalic acid units, naphthalenedicarboxylic acid units, isophthalic acid units, 1,4-phenylenedioxydiacetic acid units, 1,3-phenylenedioxydiacetic acid units, diphenic acid units, diphenylmethane-4,4'-dicarboxylic acid units, diphenylsulfone-4,4'-dicarboxylic acid units, 4,4'-biphenyldicarboxylic acid units, etc. Examples of the above naphthalenedicarboxylic acid units include units derived from 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 1,4-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid units are preferred. In addition, as the dicarboxylic acid units, aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, dimethylmalonic acid, 2,2-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid, dimer acid, etc.; units derived from alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cycloheptanedicarboxylic acid, cyclooctanedicarboxylic acid, cyclodecanedicarboxylic acid, etc. are included. The units derived from these dicarboxylic acids may contain only one kind or may contain two or more kinds.

[0015] The polyamide used in the present invention preferably contains at least 1 type selected from terephthalic acid units and naphthalenedicarboxylic acid units in an amount of 50 mol% or more based on all dicarboxylic acid units. Further, from the viewpoint of obtaining a polyamide having good chemical resistance and heat resistance, the polyamide used in the present invention more preferably contains at least 1 type selected from terephthalic acid units and naphthalenedicarboxylic acid units in an amount of 75 mol% or more based on all dicarboxylic acid units, and even more preferably 90 mol% or more.

[0016] Examples of the diamine units include units derived from linear aliphatic diamines such as ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine; branched aliphatic diamines such as 2-methyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine; alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, isophoronediamine; and aromatic diamines such as p-phenylenediamine, m-phenylenediamine, xylylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether. The units derived from these diamines may contain only 1 type or may contain 2 types or more.

[0017] The polyamide used in the present invention preferably contains 60 mol% or more of an aliphatic diamine unit having 4 to 13 carbon atoms or a metaxylylenediamine unit with respect to all diamine units. When a polyamide containing an aliphatic diamine unit having 4 to 13 carbon atoms in the above ratio is used, a polyamide composition excellent in toughness, heat resistance, chemical resistance, and light weight can be obtained. The polyamide used in the present invention more preferably contains at least one selected from aliphatic diamine units having 4 to 13 carbon atoms in an amount of 75 mol% or more, and even more preferably 90 mol% or more with respect to all diamine units.

[0018] The above aliphatic diamine unit having 4 to 13 carbon atoms is more preferably a unit derived from at least one aliphatic diamine selected from the group consisting of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine. Since a polyamide composition having further excellent heat resistance, low water absorption, and chemical resistance can be obtained, the above aliphatic diamine unit having 4 to 13 carbon atoms is more preferably a unit derived from at least one aliphatic diamine selected from 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and even more preferably 1,9-nonanediamine unit and 2-methyl-1,8-octanediamine unit. When the aliphatic diamine unit contains both units derived from 1,9-nonanediamine and 2-methyl-1,8-octanediamine, the molar ratio of the 1,9-nonanediamine unit to the 2-methyl-1,8-octanediamine unit is preferably in the range of 1,9-nonanediamine unit / 2-methyl-1,8-octanediamine unit = 95 / 5 to 40 / 60, more preferably in the range of 90 / 10 to 40 / 60, and even more preferably in the range of 80 / 20 to 40 / 60.

[0019] The polyamide used in the present invention may contain an aminocarboxylic acid unit and / or a lactam unit. Examples of the above amino carboxylic acid units include units derived from 11-aminoundecanoic acid, 12-aminododecanoic acid, etc. Two or more kinds of amino carboxylic acid units may be included. The content rate of the amino carboxylic acid units in the polyamide is preferably 50 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less with respect to 100 mol% of all the monomer units constituting the polyamide.

[0020] Examples of the above lactam units include units derived from ε-caprolactam, enanthlactam, undecalactam, lauryllactam, α-pyrrolidone, α-piperidone, etc., and two or more kinds of lactam units may be included. The content rate of the lactam units in the polyamide is preferably 50 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less with respect to 100 mol% of all the monomer units constituting the polyamide.

[0021] In the present embodiment, the polyamide is preferably a semi-aromatic polyamide containing a dicarboxylic acid unit mainly composed of an aromatic dicarboxylic acid unit and a diamine unit mainly composed of an aliphatic diamine unit having 4 to 13 carbon atoms. Here, in this specification, "mainly composed of" means constituting 50 to 100 mol%, preferably 60 to 100 mol%, more preferably 80 to 100 mol% of all the units. Typical semi-aromatic polyamides include polytetramethylene terephthalamide (polyamide 4T), polypentamethylene terephthalamide (polyamide 5T), polyhexamethylene terephthalamide (polyamide 6T), polynonamethylene terephthalamide (polyamide 9T), poly(2-methyloctamethylene) terephthalamide (nylon M8T), polynonamethylene terephthalamide / poly(2-methyloctamethylene) terephthalamide copolymer (polyamide 9T / M8T), polynonamethylene naphthalenedicarboxamide (polyamide 9N), polynonamethylene naphthalenedicarboxamide / poly(2-methyloctamethylene) naphthalenedicarboxamide copolymer (polyamide 9N / M8N), polydecamethylene terephthalamide (polyamide 10T), polyhexamethylene isophthalamide (polyamide 6I), copolymer of polyamide 6I and polyamide 6T (polyamide 6I / 6T), copolymer of polyamide 6T and polyundecanamide (polyamide 11) (polyamide 6T / 11), and copolymer of polyamide 10T and polyundecanamide (polyamide 11) (polyamide 10T / 11), and the like. Among these, at least one selected from polyamide 10T / 11, polynonamethylene naphthalenedicarboxamide (polyamide 9N), polynonamethylene naphthalenedicarboxamide / poly(2-methyloctamethylene) naphthalenedicarboxamide copolymer (polyamide 9N / M8N), polynonamethylene terephthalamide (polyamide 9T), polynonamethylene terephthalamide / poly(2-methyloctamethylene) terephthalamide copolymer (polyamide 9T / M8T), and polydecamethylene terephthalamide (polyamide 10T) is preferable. At least one selected from polynonamethylene naphthalenedicarboxamide / poly(2-methyloctamethylene) naphthalenedicarboxamide copolymer (polyamide 9N / M8N), polynonamethylene terephthalamide / poly(2-methyloctamethylene) terephthalamide copolymer (polyamide 9T / M8T), and polyamide 10T / 11 is more preferable. From the viewpoints of ensuring moldability and rigidity at high temperatures, polynonamethylene terephthalamide / poly(2-methyloctamethylene) terephthalamide copolymer (polyamide 9T / M8T) is even more preferable.

[0022] In addition, as the polyamide, a semi-aromatic polyamide containing a dicarboxylic acid unit mainly composed of an aliphatic dicarboxylic acid unit and a diamine unit mainly composed of an aromatic diamine unit can also be used. Examples of the aliphatic dicarboxylic acid unit include units derived from the above-described aliphatic dicarboxylic acids, and one or more of these can be included. Examples of the aromatic diamine unit include units derived from the above-described aromatic diamines, and one or more of these can be included. Also, within a range that does not inhibit the effects of the present invention, other units may be included. Typical semi-aromatic polyamides containing a dicarboxylic acid unit mainly composed of an aliphatic dicarboxylic acid unit and a diamine unit mainly composed of an aromatic diamine unit include polymetaxylylene adipamide (MXD6), polyparaxylylene sebacamide (PXD10), and the like.

[0023] Also, an aliphatic polyamide can be used as the polyamide. Examples of the aliphatic polyamide include polycaproamide (polyamide 6), polyundecanamide (polyamide 11), polydodecanamide (polyamide 12), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polynonamethylene oxide (polyamide 92), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polynonamethylene sebacamide (polyamide 910), polynonamethylene dodecamide (polyamide 912), polydecamethylene sebacamide (polyamide 1010), polydecamethylene dodecamide (polyamide 1012), polydodecamethylene sebacamide (polyamide 1210), polydodecamethylene dodecamide (polyamide 1212), and the like.

[0024] It is preferable that in the polyamide used in the present invention, 10 mol% or more of all the terminal groups of the molecular chain are blocked by a terminal blocking agent. When a polyamide with a terminal blocking rate of 10 mol% or more is used, a polyamide composition having more excellent physical properties such as melt stability and hot water resistance can be obtained.

[0025] As the terminal blocking agent, a monofunctional compound having reactivity with a terminal amino group or a terminal carboxyl group can be used. Specifically, monocarboxylic acids, acid anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols, monoamines, and the like can be mentioned. From the viewpoints of reactivity and stability of the blocked terminal, a monocarboxylic acid is preferable as the terminal blocking agent for the terminal amino group, and a monoamine is preferable as the terminal blocking agent for the terminal carboxyl group. From the viewpoint of ease of handling, a monocarboxylic acid is more preferable as the terminal blocking agent.

[0026] The monocarboxylic acid used as the terminal blocking agent is not particularly limited as long as it has reactivity with an amino group. Examples of the monocarboxylic acid include aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid; alicyclic monocarboxylic acids such as cyclopentanecarboxylic acid and cyclohexanecarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid; and any mixtures thereof. Among these, at least one selected from acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, and benzoic acid is preferable from the viewpoints of reactivity, stability of the blocked terminal, price, etc.

[0027] The monoamine used as the terminal blocking agent is not particularly limited as long as it has reactivity with a carboxyl group. Examples of the monoamine include aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine; and any mixtures thereof. Among these, at least one selected from butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline is preferable from the viewpoints of reactivity, high boiling point, stability of the blocked terminal, and price.

[0028] The polyamide used in the present invention uses concentrated sulfuric acid as a solvent, and the intrinsic viscosity [η] measured at a concentration of 0.2 g / dl and a temperature of 30 °C inhis preferably 0.6 dl / g or more, more preferably 0.8 dl / g or more, and even more preferably 1.0 dl / g or more. Further, the intrinsic viscosity is preferably 2.0 dl / g or less, more preferably 1.8 dl / g or less, and even more preferably 1.6 dl / g or less. The intrinsic viscosity [η inh is within the above range, various physical properties such as moldability are further improved. The intrinsic viscosity [η inh can be determined from the flow-down time t0 (seconds) of the solvent (concentrated sulfuric acid), the flow-down time t1 (seconds) of the sample solution, and the sample concentration c (g / dl) in the sample solution (that is, 0.2 g / dl) by the relational expression of η inh = [ln(t1 / t0)] / c.

[0029] The polyamide used in the present invention preferably has a terminal amino group content (hereinafter, also referred to as "terminal amino group content") ([NH2]) of 10 to 70 μeq / g, more preferably 10 to 65 μeq / g, and even more preferably 10 to 60 μeq / g. When the terminal amino group content ([NH2]) is 10 μeq / g or more, the compatibility between the polyamide and the polyolefin described later is good. Further, when the above terminal amino group content is 70 μeq / g or less, when using the modified polyolefin described later as the polyolefin, it is possible to avoid the progress of gelation due to an excessive reaction between the terminal amino group and the modified portion of the polyolefin. The terminal amino group content ([NH2]) referred to in this specification refers to the amount of terminal amino groups contained in 1 g of the polyamide (unit: μeq) and can be determined by a neutralization titration method using an indicator.

[0030] The polyamide used in the present invention preferably has a content of terminal carboxyl groups (hereinafter also referred to as "terminal carboxyl group content") ([COOH]) of 10 to 70 μeq / g, more preferably 12 to 65 μeq / g, and even more preferably 14 to 60 μeq / g. If the terminal carboxyl group content ([COOH]) is 10 μeq / g or more, the compatibility between the polyamide and the polyolefin described below is good. Further, if the terminal carboxyl group content is 70 μeq / g or less, when using a modified polyolefin described below as the polyolefin, it is possible to avoid the progress of gelation due to an excessive reaction between the terminal carboxyl group and the modified portion of the polyolefin. The terminal carboxyl group content ([COOH]) referred to in this specification refers to the amount (unit: μeq) of terminal carboxyl groups contained in 1 g of the polyamide, and can be determined by a neutralization titration method using an indicator.

[0031] A polyamide containing a dicarboxylic acid unit and a diamine unit, and having a terminal amino group content ([NH2]) and a terminal carboxyl group content ([COOH]) within the above ranges can be produced, for example, as follows. First, a dicarboxylic acid, a diamine, and, if necessary, an aminocarboxylic acid, a lactam, a catalyst, and a terminal capping agent are mixed to produce a nylon salt. At this time, the number of moles (X) of all carboxyl groups and the number of moles (Y) of all amino groups contained in the above reaction raw materials satisfy the following formula (Q) for calculating the excess amount -0.5 ≦ [(Y - X) / Y] × 100 ≦ 2.0 Formula (Q) When this is satisfied, it becomes easy to produce a polyamide having a terminal amino group content ([NH2]) and a terminal carboxyl group content ([COOH]) of 10 to 70 μeq / g, which is preferable. Next, the produced nylon salt is heated to a temperature of 200 to 250°C to obtain a prepolymer having an intrinsic viscosity [η inh of 0.10 to 0.60 dl / g at 30°C in concentrated sulfuric acid, and further increasing the degree of polymerization to obtain a polyamide. The intrinsic viscosity [η inhWhen [the value] is within the range of 0.10 to 0.60 dl / g, there is little deviation in the molar balance between the carboxyl group and the amino group and little decrease in the polymerization rate at the stage of increasing the degree of polymerization, and a polyamide with a smaller molecular weight distribution and more excellent various properties and moldability can be obtained. When the stage of increasing the degree of polymerization is carried out by the solid-phase polymerization method, it is preferably carried out under reduced pressure or under the flow of an inert gas. If the polymerization temperature is within the range of 200 to 280°C, the polymerization rate is high, the productivity is excellent, and coloring and gelation can be effectively suppressed. Further, when the stage of increasing the degree of polymerization is carried out by a melt extruder, the polymerization temperature is preferably 370°C or lower. When polymerization is carried out under such conditions, a polyamide with almost no decomposition of the polyamide and little deterioration can be obtained.

[0032] 〈Polyamide content〉 The content of the polyamide contained in the polyamide composition of this embodiment is preferably 60 to 86% by mass, more preferably 65 to 86% by mass, still more preferably 70 to 86% by mass, and even more preferably 70 to 80% by mass with respect to 100% by mass of the polyamide composition. When the content of the polyamide is within the above range, a polyamide composition with further excellent heat resistance, further excellent processing stability, flexibility, and impact resistance during melt kneading can be obtained.

[0033] 〈Polydispersity index〉 The polydispersity index Mw / Mn (Mw is the weight average molecular weight, Mn is the number average molecular weight) of the polyamide contained in the polyamide composition of this embodiment is preferably 3.7 or more, and may be 4.0 or more. If the polydispersity index is 3.7 or more, a composition excellent in melt tension during extrusion molding can be obtained. Further, the polydispersity index Mw / Mn of the polyamide is preferably 8.0 or less. If the polydispersity index is 8.0 or less, a composition excellent in fluidity during extrusion molding can be obtained. The polydispersity index of the polyamide can be measured by gel permeation chromatography, and more specifically, it is a value measured by the method described in the examples.

[0034] Examples of catalysts that can be used in the production of polyamides include phosphoric acid, phosphorous acid, hypophosphorous acid, or salts or esters thereof. Examples of the above salts or esters include salts of phosphoric acid, phosphorous acid, or hypophosphorous acid with metals such as potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, antimony, etc.; ammonium salts of phosphoric acid, phosphorous acid, or hypophosphorous acid; ethyl esters, isopropyl esters, butyl esters, hexyl esters, isodecyl esters, octadecyl esters, decyl esters, stearyl esters, phenyl esters, etc. of phosphoric acid, phosphorous acid, or hypophosphorous acid. The amount of the above catalyst used is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, preferably 1.0% by mass or less, and more preferably 0.5% by mass or less, based on 100% by mass of the total mass of the raw materials. If the amount of the catalyst used is at least the above lower limit, the polymerization proceeds well. If it is at most the above upper limit, impurities derived from the catalyst are less likely to occur, and for example, when the polyamide composition is extrusion-molded, problems caused by the above impurities can be prevented.

[0035] [Polyolefin] The polyamide composition of this embodiment contains polyamide and polyolefin, and the polyolefin exists as a phase dispersed in the polyamide which is the matrix. The above polyolefin contains at least one polyolefin (A) including a copolymer of ethylene, alkyl (meth)acrylate, and unsaturated epoxide, and at least one polyolefin (B) including an unsaturated dicarboxylic anhydride. The total content of polyolefin (A) and polyolefin (B) contained in the polyolefin is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and may be substantially 100% by mass.

[0036] 〈Polyolefin (A)〉 The polyolefin (A) includes a copolymer of ethylene, an alkyl (meth)acrylate, and an unsaturated epoxide. Also, from the viewpoint of avoiding gelation due to intramolecular reaction, it is desirable that the polyolefin (A) does not contain an unsaturated dicarboxylic anhydride.

[0037] Examples of the above unsaturated epoxide include aliphatic glycidyl ethers and esters such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and itaconate, glycidyl acrylate and methacrylate; alicyclic glycidyl ethers and esters such as 2-cyclohexen-1-yl glycidyl ether, diglycidyl cyclohexene-4,5-dicarboxylate, glycidyl cyclohexene-4-carboxylate, glycidyl 5-norbornene-2-methyl-2-carboxylate, and diglycidyl endo-cis-bicyclo[2.2.1]hepta-5-ene-2,3-dicarboxylate; and the like epoxides.

[0038] The above alkyl (meth)acrylate preferably contains 2 to 10 carbon atoms. Examples of the alkyl (meth)acrylate include methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate.

[0039] Particularly preferred examples of the polyolefin (A) include a copolymer of ethylene, methyl acrylate, and glycidyl methacrylate, and a copolymer of ethylene, butyl acrylate, and glycidyl methacrylate. As the polyolefin (A), commercially available products can also be used. For example, products with the trade names Lotader AX8900, Lotader AX8750, and Lotader AX8390 sold by SK global chemical can be used.

[0040] 〈Polyolefin (B)〉 Polyolefin (B) is a polymer containing an unsaturated dicarboxylic anhydride. This unsaturated dicarboxylic anhydride is introduced into the polymer by either grafting or copolymerization. Also, from the viewpoint of avoiding gelation due to intramolecular reaction, it is desirable that polyolefin (B) does not contain an unsaturated epoxide.

[0041] Examples of the unsaturated dicarboxylic anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, and tetrahydrophthalic anhydride in particular.

[0042] Also, as polyolefin (B), for example, an α-olefin copolymer, an (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) copolymer, an ionomer, or an aromatic vinyl compound / conjugated diene compound block copolymer (hereinafter sometimes referred to as "copolymer etc.") can be used as a modified polyolefin modified with an unsaturated dicarboxylic anhydride. The above copolymer etc. can be used alone or in combination of two or more.

[0043] Examples of the above α-olefin copolymer include copolymers of ethylene and an α-olefin having 3 or more carbon atoms, copolymers of propylene and an α-olefin having 4 or more carbon atoms, and the like. Examples of α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. One or more of these can be used.

[0044] In addition, polyenes of non-conjugated dienes such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene (DMDT), dicyclopentadiene, cyclohexadiene, cyclooctadiene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, and 2-propenyl-2,5-norbornadiene may be copolymerized. One or more of these can be used.

[0045] The above-mentioned (ethylene and / or propylene) / (α,β-unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) copolymer is a polymer obtained by copolymerizing ethylene and / or propylene with an α,β-unsaturated carboxylic acid and / or an unsaturated carboxylic acid ester. Examples of the above-mentioned α,β-unsaturated carboxylic acid include acrylic acid and methacrylic acid. Examples of the above-mentioned α,β-unsaturated carboxylic acid ester include methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester, hexyl ester, heptyl ester, octyl ester, nonyl ester, decyl ester, etc. of the above-mentioned unsaturated carboxylic acid. These can be used alone or in combination of two or more.

[0046] The above-mentioned ionomer is a copolymer of an olefin and an α,β-unsaturated carboxylic acid, in which at least a part of the carboxyl groups are ionized by neutralization with metal ions. Ethylene is preferably used as the olefin, and acrylic acid and methacrylic acid are preferably used as the α,β-unsaturated carboxylic acid, but the examples are not limited thereto. An unsaturated carboxylic acid ester may be further copolymerized as a monomer with the copolymer of the above-mentioned olefin and α,β-unsaturated carboxylic acid. Examples of the metal ions include alkali metals such as Li, Na, K, alkaline earth metals such as Mg, Ca, Sr, Ba, and also Al, Sn, Sb, Ti, Mn, Fe, Ni, Cu, Zn, Cd, etc. These can be used alone or in combination of two or more.

[0047] The above-mentioned aromatic vinyl compound / conjugated diene compound block copolymer is a block copolymer composed of an aromatic vinyl compound polymer block and a conjugated diene polymer block, and a block copolymer having at least one aromatic vinyl compound polymer block and at least one conjugated diene polymer block is used. In the above-mentioned block copolymer, the unsaturated bonds in the conjugated diene polymer block may be hydrogenated.

[0048] The aromatic vinyl compound-based polymer block is a polymer block mainly composed of structural units derived from aromatic vinyl compounds. Examples of the aromatic vinyl compound in that case include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, etc., and one or more of these can be used. Further, the aromatic vinyl compound-based polymer block may optionally have structural units composed of a small amount of other unsaturated monomers. The conjugated diene-based polymer block is a polymer block formed from one or more of conjugated diene compounds such as butadiene, chloroprene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene. In the hydrogenated aromatic vinyl compound / conjugated diene compound-based block copolymer, part or all of the unsaturated bond portions in the conjugated diene polymer block are hydrogenated.

[0049] The molecular structures of the aromatic vinyl compound / conjugated diene compound-based block copolymer and its hydrogenated product may be linear, branched, radial, or any combination thereof. Among these, as the aromatic vinyl compound / conjugated diene compound-based block copolymer and / or its hydrogenated product, a diblock copolymer in which one aromatic vinyl compound-based polymer block and one conjugated diene-based polymer block are linearly bonded, a triblock copolymer in which three polymer blocks are linearly bonded in the order of aromatic vinyl compound-based polymer block - conjugated diene-based polymer block - aromatic vinyl compound-based polymer block, and one or more of their hydrogenated products are preferably used. Examples of the aromatic vinyl compound / conjugated diene compound-based block copolymer and its hydrogenated product include, for example, unhydrogenated or hydrogenated styrene / butadiene block copolymer, unhydrogenated or hydrogenated styrene / isoprene block copolymer, unhydrogenated or hydrogenated styrene / isoprene / styrene block copolymer, unhydrogenated or hydrogenated styrene / butadiene / styrene block copolymer, unhydrogenated or hydrogenated styrene / isoprene / butadiene / styrene block copolymer, and the like.

[0050] The polyolefin (B) is preferably a copolymer of ethylene, an alkyl (meth)acrylate, and an unsaturated dicarboxylic anhydride. The alkyl (meth)acrylate preferably contains 2 to 10 carbon atoms. Examples of the alkyl (meth)acrylate include methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate.

[0051] More preferred examples among the above polyolefins (B) include a copolymer of ethylene, ethyl acrylate, and maleic anhydride, and a copolymer of ethylene, butyl acrylate, and maleic anhydride. Commercially available products can also be used as the polyolefin (B). For example, Lotader 4700 and Lotader 3410 sold by SK global chemical can be used.

[0052] In addition, in the polyolefin (B), even if a part of maleic anhydride exemplified as the unsaturated dicarboxylic anhydride is partially hydrolyzed, it does not deviate from the scope of the present invention.

[0053] 〈Mass ratio [B] / [A]〉 The mass ratio [B] / [A] of the content [B] of the polyolefin (B) to the content [A] of the polyolefin (A) is 0.1 to 2.9, preferably 0.2 to 2.9, more preferably 0.4 to 2.9, and still more preferably 0.5 to 2.9. When the mass ratio [B] / [A] is less than 0.1, the melt viscosity increases and the moldability tends to decrease. When the mass ratio [B] / [A] exceeds 2.9, it tends to be difficult to achieve both the stability during melt kneading and the excellent elongation characteristics.

[0054] 〈Polyolefin content〉 The content of the polyolefin contained in the polyamide composition of the present embodiment is preferably 14 to 40% by mass, more preferably 15 to 40% by mass, still more preferably 15 to 35% by mass, and even more preferably 15 to 30% by mass with respect to 100% by mass of the polyamide composition. When the content of the polyolefin is within the above range, a polyamide composition excellent in processing stability, flexibility, and impact resistance during melt kneading can be obtained.

[0055] From the viewpoint of improving the flexibility of the molded body made of the polyamide composition of the present embodiment, the content of the polyolefin is preferably adjusted to an amount such that the flexural modulus of the molded body of the polyamide composition measured under the conditions of 23°C and 50% RH in accordance with ISO 178 (4th edition, 2001) is 2.0 GPa or less, more preferably 1.7 GPa or less, and still more preferably 1.5 GPa or less.

[0056] 〈Functional group concentration〉 In the polyamide composition of this embodiment, the value Z calculated from the following formula (1) is 33 to 200, preferably 33 to 150. The value of Z may be 35 to 130. When the value of Z is less than 33, the affinity between the polyamide and the polyolefin becomes insufficient, and the stability during melt-kneading may decrease. When the value of Z exceeds 200, the melt viscosity increases, making molding difficult or possibly resulting in insufficient flexibility and impact resistance. In this specification, the "functional group" in the "functional group concentration" means the epoxy group of the unsaturated epoxide derived from the polyolefin, as well as the carboxyl group and acid anhydride group of the unsaturated dicarboxylic acid anhydride derived from the polyolefin. And the "functional group concentration" means the following [EPO] and [ANH].

[0057] Formula (1) Z = 1000×(|[ANH] - [EPO]| + [EPO]) / X 2 In the above formula (1), [EPO], [ANH], and X are as follows, respectively. [EPO]: The concentration of the unsaturated epoxide derived from the polyolefin per unit mass of the polyamide composition (mmol / kg). [ANH]: The concentration of the unsaturated dicarboxylic acid anhydride derived from the polyolefin per unit mass of the polyamide composition (mmol / kg). X: The content rate of the polyolefin in the polyamide composition (mass%).

[0058] Also, the concentration [EPO] of the unsaturated epoxide and the concentration [ANH] of the unsaturated dicarboxylic acid in the above formula (1) are calculated according to the following formula (2). Formula (2) [EPO] or [ANH] = 100×N×W / M In the above formula (2), M, W, and N are as follows, respectively. M: The molecular weight of the unsaturated epoxide or the unsaturated dicarboxylic acid anhydride. W: The mass percentage of the unsaturated epoxide or unsaturated dicarboxylic anhydride contained in the polyolefin (A) or polyolefin (B). W can be measured by a general method for those skilled in the art, such as NMR. N: The mass percentage of the polyolefin (A) or polyolefin (B) per unit mass of the polyamide composition.

[0059] The value of Z above is useful for predicting the melt stability of the obtained polyamide composition when melt-kneading the polyamide, the polyolefin having an unsaturated epoxide, and the polyolefin having an unsaturated dicarboxylic anhydride, and obtaining a polyamide composition having excellent melt stability, flexibility, and impact resistance. Although the unsaturated epoxide and the unsaturated dicarboxylic anhydride each react with the polyamide to exhibit a compatibilizing effect, since the above functional groups can react with each other, the remaining amount of the functional groups available for reaction with the polyamide is considered to be related to the difference between the two (|[ANH]-[EPO]|). However, the two do not react completely, and since the unsaturated epoxide has high reactivity in that it can react with both the terminal amino group and the terminal carboxyl group of the polyamide, the term of the molecule meaning the affinity and reactivity with the polyamide is weighted by the unsaturated epoxide concentration. Also, generally, as the blending amount of the polyolefin increases, the melt stability of the polyamide composition tends to decrease, so the content X of the polyolefin is placed in the denominator.

[0060] Note that the concentration of the unsaturated epoxide and the concentration of the unsaturated dicarboxylic anhydride in the polyamide composition are particularly difficult to determine because the terminal amino group, carboxyl group, unsaturated epoxide, and unsaturated dicarboxylic anhydride of the polyamide react with each other during the melt-kneading process. Therefore, the value of Z shall be calculated based on the usage amount of each component used in the polyamide composition.

[0061] [Copper-based stabilizer] The polyamide composition of this embodiment contains at least one copper-based stabilizer to improve heat aging resistance.

[0062] The content rate of the copper-based stabilizer is preferably 0.01 to 2% by mass, more preferably 0.1 to 1.5% by mass, and even more preferably 0.5 to 1.2% by mass with respect to 100% by mass of the polyamide composition. If the content rate of the copper-based stabilizer is within the above range, a polyamide composition excellent in heat aging resistance and having a small amount of gas generation during extrusion molding can be obtained.

[0063] The copper-based stabilizer can be used as a mixture of a copper compound and a metal halide. Regarding the ratio of the copper compound and the metal halide in the polyamide composition, it is preferable to contain the copper compound and the metal halide in the polyamide composition so that the ratio of the total molar amount of halogen atoms to the total molar amount of copper atoms (halogen / copper) is 2 / 1 to 50 / 1. The above ratio (halogen / copper) is preferably 3 / 1 or more, more preferably 4 / 1 or more, and even more preferably 5 / 1 or more. Also, the above ratio (halogen / copper) is preferably 45 / 1 or less, more preferably 40 / 1 or less, and even more preferably 30 / 1 or less. When the ratio (halogen / copper) is at least the above lower limit, copper precipitation and metal corrosion during molding can be more effectively suppressed. When the ratio (halogen / copper) is at most the above upper limit, corrosion of the screw of the molding machine etc. can be more effectively suppressed without impairing the mechanical properties such as the tensile physical properties of the obtained polyamide composition.

[0064] Examples of the copper compound include copper halides, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, copper complex salts coordinated with chelating agents such as ethylenediamine and ethylenediaminetetraacetic acid, and the like. Examples of the copper halide include copper iodide; copper bromides such as cuprous bromide and cupric bromide; copper chlorides such as cuprous chloride, and the like. Among these copper compounds, from the viewpoint of excellent heat aging resistance and the ability to suppress metal corrosion in the screw and cylinder parts during extrusion, at least one selected from the group consisting of copper halides and copper acetate is preferable, at least one selected from the group consisting of copper iodide, copper bromide, copper chloride, and copper acetate is more preferable, and at least one selected from the group consisting of copper iodide, copper bromide, and copper acetate is even more preferable. The copper compound may be used alone or in combination of two or more.

[0065] As the metal halide, a metal halide that does not fall under the copper compound can be used, and a salt of a Group 1 or Group 2 metal element of the periodic table of elements and a halogen is preferable. Examples of the metal halide include potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, and the like. Among these, from the viewpoint that the obtained polyamide composition has excellent high-temperature heat resistance such as heat aging resistance and can suppress metal corrosion, at least one selected from the group consisting of potassium iodide and potassium bromide is preferable, and potassium iodide is more preferable. The metal halide may be used alone or in combination of two or more. Among the copper compound and the metal halide, the copper-based stabilizer preferably contains at least one copper compound selected from the group consisting of copper iodide, copper bromide, and copper acetate, and at least one metal halide selected from the group consisting of potassium iodide and potassium bromide.

[0066] In order to enhance the dispersibility of copper compounds and metal halides in polyamide, a dispersant may be used. Examples of the above-mentioned dispersant include higher fatty acids such as lauric acid, palmitic acid, stearic acid, behenic acid, and montanic acid; metal salts of higher fatty acids composed of higher fatty acids and metals such as aluminum; higher fatty acid amides such as ethylene bisstearylamide; waxes such as polyethylene wax; organic compounds having at least one amide group, and the like.

[0067] [Other Additives] The polyamide composition of this embodiment may optionally contain other additives in addition to the polyamide, polyolefin, and copper-based stabilizer described above.

[0068] Examples of other additives include other types of polymers other than the above polyamide and polyolefin, antioxidants, fillers, crystal nucleating agents, colorants, antistatic agents, plasticizers, lubricants, flame retardants, flame retardant aids, and the like. These other additives may be used alone or in combination of two or more.

[0069] Examples of other polymers include polyacetal, polyether resins such as polyphenylene oxide; polysulfone resins such as polysulfone and polyethersulfone; polythioether resins such as polyphenylene sulfide and polythioether sulfone; polyketone resins such as polyetheretherketone and polyallyletherketone; polynitrile resins such as polyacrylonitrile, polymethacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, and methacrylonitrile-butadiene-styrene copolymer; polymethacrylate resins such as polymethyl methacrylate and polyethyl methacrylate; polyvinyl ester resins such as polyvinyl acetate; polyvinyl chloride resins such as polyvinylidene chloride, polyvinyl chloride, vinyl chloride-vinylidene chloride copolymer, and vinylidene chloride-methyl acrylate copolymer; cellulose resins such as cellulose acetate and cellulose butyrate; fluorine resins such as polyvinylidene fluoride, polyvinyl fluoride, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer; polycarbonate resins; polyimide resins such as thermoplastic polyimide, polyamideimide, and polyetherimide; thermoplastic polyurethane resins; and the like.

[0070] The antioxidant is not particularly limited, and one or a combination of two or more thereof may be used from among amine-based antioxidants, hindered phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, etc. Among these, amine-based antioxidants are preferred as a combination with the above copper-based stabilizer.

[0071] Examples of the filler include fibrous fillers such as glass fibers, and powdery fillers such as calcium carbonate, wollastonite, silica, silica alumina, alumina, titanium dioxide, potassium titanate, magnesium hydroxide, molybdenum disulfide; and flaky fillers such as hydrotalcite, glass flakes, mica, clay, montmorillonite, kaolin, etc.

[0072] The crystal nucleating agent is not particularly limited as long as it is generally used as a crystal nucleating agent for polyamide. Examples of the crystal nucleating agent include talc, calcium stearate, aluminum stearate, barium stearate, zinc stearate, antimony oxide, magnesium oxide, and any mixture thereof. Among these, talc is preferred because it has a large effect of increasing the crystallization rate of polyamide. The crystal nucleating agent may be treated with a silane coupling agent, a titanium coupling agent, etc. for the purpose of improving the compatibility with polyamide.

[0073] The colorant is not particularly limited and can be appropriately selected from inorganic or organic pigments and dyes according to the use of the polyamide composition. Examples of the colorant to be incorporated into the polyamide composition used for the chemical solution transport tube include black inorganic pigments such as carbon black, lamp black, acetylene black, bone black, thermal black, channel black, furnace black, and titanium black.

[0074] The antistatic agent is not particularly limited and may be organic or inorganic. For example, organic antistatic agents include ionic compounds such as lithium ion salts, quaternary ammonium salts, and ionic liquids; and electronically conductive polymer compounds such as polythiophene, polyaniline, polypyrrole, and polyacetylene. Inorganic antistatic agents include metal oxide-based conductive agents such as ATO, ITO, PTO, GZO, antimony pentoxide, and zinc oxide; and carbon-based conductive agents such as carbon nanotubes and fullerenes. From the perspective of heat resistance, inorganic antistatic agents are preferred. Note that carbon black, which is a colorant, may also function as an antistatic agent.

[0075] The plasticizer is not particularly limited as long as it is generally used as a plasticizer for polyamide. Examples of plasticizers include alkylamide benzenesulfonate compounds, alkylamide toluenesulfonate compounds, alkyl ester hydroxybenzoate compounds, and alkylamide hydroxybenzoate compounds.

[0076] The lubricant is not particularly limited as long as it is generally used as a lubricant for polyamide. Examples of lubricants include higher fatty acid-based compounds, oxyfatty acid-based compounds, fatty acid amide-based compounds, alkylene bisfatty acid amide-based compounds, fatty acid lower alcohol ester-based compounds, metal soap-based compounds, and polyolefin waxes. Fatty acid amide-based compounds, such as various stearates such as calcium stearate, stearic acid amide, palmitic acid amide, methylene bisstearylamide, and ethylene bisstearylamide, are preferred because of their excellent external lubricating effect. These lubricants may be added internally or externally to the composition. In particular, when stearate is added externally, it has the effect of reducing the motor load of the extruder.

[0077] The content of other additives in the polyamide composition is preferably 50% by mass or less, more preferably 20% by mass or less, and even more preferably 5% by mass or less based on 100% by mass of the polyamide composition.

[0078] [Method for Producing Polyamide Composition] The polyamide composition of this embodiment can be produced, for example, by top-feeding the above polyamide, the above polyolefin, and the above copper-based stabilizer into a twin-screw extruder and melt-kneading them. Since the method for producing the polyamide composition of this embodiment has a step of melt-kneading the above mixture containing a polyamide, a polyolefin, and a copper-based stabilizer, at the time of melt-kneading, the end groups of the polyamide and the modified portions of the polyolefin react with each other, and the resulting composition is excellent in flexibility and impact resistance. Further, by reacting a part of the modified site of polyolefin (A) with a part of the modified site of polyolefin (B), a composition excellent in heat resistance can be obtained. Further, by appropriately adjusting the concentration and blending ratio of the modified site of the polyolefin, a composition excellent in melt-kneadability can be obtained.

[0079] The temperature and time during melt-kneading can be appropriately adjusted according to the melting point of the polyamide used, etc., but from the viewpoint of suppressing the deterioration of the polyolefin, the melt-kneading temperature is preferably 380°C or lower, more preferably 370°C or lower, and even more preferably 360°C or lower. The melt-kneading time is preferably about 1 to 5 minutes. There is no particular limitation on the method of melt-kneading, and a method capable of uniformly mixing a polyamide, a polyolefin, a copper-based stabilizer, and other additives used as required can be preferably employed. As the melt-kneading machine, a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, etc. are preferable, and a twin-screw extruder is more preferable from the viewpoints of good dispersibility of the polyolefin and copper-based stabilizer and industrial productivity.

[0080] As described above, the polyamide composition of the present embodiment can be obtained by the mutual reaction of polyamide, polyolefin (A), and polyolefin (B) during melt-kneading. Therefore, it is preferable to ensure a certain kneading time during melt-kneading. Specifically, when a twin-screw extruder is used as the melt-kneading apparatus, it is preferable to introduce (top-feed) polyamide, polyolefin, a copper-based stabilizer, and other additives added as necessary from the first feed port at the root of the twin-screw extruder.

[0081] <Molded article> The molded article made of the polyamide composition of the present embodiment can be obtained by molding the polyamide composition using various molding methods such as injection molding, blow molding, extrusion molding, co-extrusion molding, coating molding, compression molding, stretch molding, vacuum molding, foam molding, rotational molding, impregnation method, laser sintering method, and hot melt lamination method. Furthermore, a molded article can also be obtained by composite molding the polyamide composition of the present embodiment with other polymers, etc.

[0082] The polyamide composition of the present embodiment has excellent extrusion moldability, co-extrusion moldability, blow moldability, and coating moldability due to its properties, and a molding method that takes advantage of these moldabilities can be preferably used to obtain a molded article.

[0083] <Use> Since the molded article of the present embodiment is mainly composed of a polyamide composition, it exhibits excellent mechanical properties. Furthermore, since the polyamide composition contains a specific polyolefin and a copper-based stabilizer, it is also excellent in heat resistance, flexibility, and impact resistance. Therefore, it can be used in automotive parts, internal combustion engine applications, crude oil extraction and transportation applications, electrical and electronic parts, medical, food, household and office supplies, building materials related parts, etc. In particular, due to its excellent heat resistance, flexibility and impact resistance, for hollow body applications, fuel tubes such as feed tubes, return tubes, evaporation tubes, fuel filler tubes, ORVR tubes, reserve tubes, vent tubes, etc.; cooling water tubes such as engine coolant tubes, battery coolant tubes, motor coolant tubes, fuel cell cooling tubes, etc.; urea solution transfer tubes, air conditioner refrigerant tubes, blow-by tubes, brake booster tubes, brake tubes, oil cooling tubes, turbo duct pipes, air suspension tubes, and oil transportation tubes, road heating tubes, floor heating tubes, infrastructure supply tubes, fire extinguisher and fire protection equipment tubes, medical cooling equipment tubes, ink, paint spraying tubes, and other chemical solution tubes can be mentioned. Preferably, it can be used as fuel tubes, engine coolant tubes, battery coolant tubes, motor coolant tubes, fuel cell cooling tubes, urea solution transfer tubes, air conditioner refrigerant tubes, blow-by tubes, brake booster tubes, brake tubes, oil cooling tubes, turbo duct pipes, air suspension tubes, and oil transportation tubes, and in particular, it can be preferably used as cooling water tubes, urea water tubes, fuel tubes, blow-by tubes, oil cooling tubes, and brake booster tubes. In addition, as a coated molded body, it can be preferably used as wire coating, bus bar coating, and wire coating. The polyamide composition of this embodiment can be used to produce a single-layer structure, and can also be used to produce at least one layer of a multi-layer structure. For example, in a tube having a single-layer structure or a multi-layer structure, the polyamide composition of this embodiment can be preferably used for at least one of the constituent layers.

[0084] When the molded body of this embodiment is used as a tube, they can be used after performing bending processing, terminal processing, and fastening of various connectors. Generally, the bending processing process is carried out in the following process. · Preheating process: Preheat the tube to soften it so that it does not collapse at the required bending dimensions. · Bending process: Attach the tube to the jig or deform it with a guide roller to process the tube into the desired shape. · Heat treatment process: Relax the stress generated in the tube and fix the shape. The heat treatment temperature needs to be carried out between the glass transition temperature and the melting point of the material constituting the tube. The higher the temperature, the shorter the heat treatment time can fix the shape. When the melting point of the material with the lowest melting point among the materials constituting the tube is Tm, the heat treatment temperature Tf is preferably in the range of Tm - 80°C ≤ Tf ≤ Tm - 10°C, and more preferably Tm - 60°C ≤ Tf ≤ Tm - 15°C. By setting the temperature within the above range, bending processing can be carried out in an economical time, and melting of the tube material due to heat treatment can be prevented. · For the fastening of the connector, various methods such as press - fitting method, spin welding method, laser welding method, etc. can be used. When the use environment is high temperature and high pressure, from the perspective of reliability, it is desirable to use welding methods such as spin welding method or laser welding method. When using the welding method, it is desirable that the tube material and the connector material have high chemical affinity. When using the laser welding method, it is desirable to design the connector side as a laser - transmitting material and the tube side as an absorbing material, and irradiate the laser in the circumferential direction of the tube from the upper part of the connector with the tube arranged inside the connector.

[0085]

Examples

Examples

[0086] Hereinafter, the present invention will be specifically described by examples and comparative examples, but the present invention is not limited thereto.

[0087] The measurement of each physical property in the examples, comparative examples, and production examples was carried out according to the methods shown below. [Measurement of Physical Properties of Polyamide] · Intrinsic viscosity Regarding the semi-aromatic polyamide (sample) obtained in the production example, using concentrated sulfuric acid as the solvent, the intrinsic viscosity (dl / g) at a concentration of 0.2 g / dl and a temperature of 30 °C was determined from the following relational expression. η inh =[ln(t1 / t0)] / c In the above relational expression, η inh represents the intrinsic viscosity (dl / g), t0 represents the flow-down time (seconds) of the solvent (concentrated sulfuric acid), t1 represents the flow-down time (seconds) of the sample solution, and c represents the concentration (g / dl) of the sample in the sample solution (that is, 0.2 g / dl).

[0088] · Melting point The melting point of the semi-aromatic polyamide (sample) obtained in the production example was measured using a differential scanning calorimeter "DSC7020" manufactured by Hitachi High-Technologies Corporation. The melting point was measured in accordance with ISO11357-3 (2nd edition, 2011). Specifically, in a nitrogen atmosphere, the sample was heated from 30 °C to 340 °C at a rate of 10 °C / min, held at 340 °C for 5 minutes to completely melt the sample, then cooled to 50 °C at a rate of 10 °C / min and held at 50 °C for 5 minutes. When the temperature was raised again to 340 °C at a rate of 10 °C / min, the peak temperature of the melting peak that appeared was taken as the melting point (°C). When there were multiple melting peaks, the peak temperature of the melting peak on the highest temperature side was taken as the melting point (°C).

[0089] · Terminal amino group content 1 g of the semi-aromatic polyamide obtained in the production example was dissolved in 35 mL of phenol, and 2 mL of methanol was mixed therein to obtain a sample solution. Using thymol blue as an indicator, titration was carried out using a 0.01 N hydrochloric acid aqueous solution, and the terminal amino group content ([NH2], unit: μeq / g) of the semi-aromatic polyamide was measured.

[0090] · Terminal carboxyl group content 0.5 g of the semi-aromatic polyamide obtained in the production example was dissolved in 40 mL of ortho-cresol to prepare a sample solution. The obtained sample solution was titrated using a potentiometric titrator manufactured by Kyoto Electronics Industry Co., Ltd. with a 0.01 N ethanolic potassium hydroxide solution, and the end carboxyl group content ([COOH], unit: μeq / g) of the semi-aromatic polyamide was measured by detecting the inflection point of the potential.

[0091] · Polydispersity index The number average molecular weight Mn and weight average molecular weight Mw of the semi-aromatic polyamide obtained in the production example were measured by gel permeation chromatography, and the polydispersity index was determined by the following formula. Polydispersity index = Mw / Mn The above number average molecular weight and weight average molecular weight were measured using HLC-8320GPC manufactured by Tosoh Corporation and column TSK-gel SuperHM-N manufactured by Tosoh Corporation, with 10 mM trifluoroacetic acid in hexafluoro-2-propanol as the eluent, at a measurement temperature of 40 °C, and calculated in terms of polymethyl methacrylate.

[0092] [Evaluation items of polyamide composition] · Functional group concentration As the functional group concentration in the polyamide compositions obtained in the examples and comparative examples, Z was calculated from the following formula (1) based on the charged amounts of the respective components used. Formula (1) Z = 1000×(|[ANH] - [EPO]| + [EPO]) / X 2 In the above formula (1), [EPO], [ANH], and X are as follows. [EPO]: Concentration of unsaturated epoxide derived from polyolefin per unit mass of the polyamide composition (mmol / kg). [ANH]: Concentration of unsaturated dicarboxylic anhydride derived from polyolefin per unit mass of the polyamide composition (mmol / kg). X: Content rate of polyolefin in the polyamide composition (mass%). In addition, the concentration [EPO] of the unsaturated epoxide and the concentration [ANH] of the unsaturated dicarboxylic acid in the above formula (1) were calculated according to the following formula (2). Formula (2) [EPO] or [ANH] = 100 × N × W / M In the above formula (2), M, W, and N are as follows, respectively. M: Molecular weight of the unsaturated epoxide or unsaturated dicarboxylic anhydride. W: Mass percentage of the unsaturated epoxide or unsaturated dicarboxylic anhydride contained in the polyolefin (A) or polyolefin (B). In this example, W is a catalog value. N: Mass percentage of the polyolefin (A) or polyolefin (B) per unit mass of the polyamide composition. In the examples and comparative examples, the molecular weight of glycidyl methacrylate was calculated as 142.2 (g / mol), and the molecular weight of maleic anhydride was calculated as 98.06 (g / mol).

[0093] · Stability during melt-kneading In the examples and comparative examples, the processing stability when producing the polyamide composition with a twin-screw extruder was evaluated in the following four levels. It is judged that the stability is excellent in the order of A, B, B', and C. A: There is no vent-up or strand breakage at the vacuum vent, and it can be stably produced. B: The strand is stable, but there is a tendency for the polyolefin bled out at the vacuum vent to deposit, and there are concerns on the foreign matter surface. It is considered that the bleed-out of the polyolefin is caused by the low affinity between the polyamide and the polyolefin. B': The strand is stable, but the viscosity of the composition is high, and the pressure of the twin-screw extruder is very high. In addition, a large amount of deposits existed near the die after compounding. It is considered to be a phenomenon caused by the high reactivity of the epoxide with the polyamide. C: Strand breakage occurs frequently, and it is difficult to obtain pellets. In the composition where strand breakage of C frequently occurs, it is considered that the domain size of the polyolefin in the polyamide matrix has become enlarged, and the reason is that the affinity of the polyolefin for the polyamide is low. Regarding the polyamide composition that was "C", since pellets could not be obtained, the melt viscosity, tensile test, and impact resistance test were not performed.

[0094] ·Melt Viscosity The melt viscosity of the polyamide compositions obtained in the examples and comparative examples was measured using a capillary rheometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the conditions of a barrel temperature of 300 °C and a shear rate of 121.6 sec -1 (Capillary: inner diameter 1.0 mm × length 10 mm, extrusion speed 10 mm / min), and the melt viscosity (Pa·s) was used as an index of fluidity.

[0095] 《Preparation of Test Specimens》 Using an injection molding machine (clamping force: 100 tons, screw diameter: φ32 mm) manufactured by Sumitomo Heavy Industries, Ltd., and using the polyamide compositions obtained in the examples and comparative examples, a cylinder temperature 20 - 30 °C higher than the melting point of the polyamide was set, and under the condition of a mold temperature of 140 °C, the polyamide composition was molded using a T-runner mold to produce a multi-purpose test piece type A1 (a dumbbell-shaped test piece described in JIS K7139; 4 mm thick, total length 170 mm, parallel part length 80 mm, parallel part width 10 mm). Then, a rectangular parallelepiped test piece (dimensions: length × width × thickness = 80 mm × 10 mm × 4 mm) was cut out from the above multi-purpose test piece and used as a test piece for evaluating the tensile test and impact resistance test.

[0096] ·Tensile Test Using the multi-purpose test piece type A1 (4 mm thick) prepared by the above method, in accordance with ISO527-1 (2nd edition 2012), using an autograph (manufactured by Instron), the tensile strength (maximum point) (MPa), tensile fracture elongation (%) and tensile modulus (GPa) at 23 °C were measured. When measuring the tensile modulus, the measurement was carried out at a tensile speed of 1 mm / min in the range of strain 0.05 - 0.25% and 50 mm / min after 0.3%.

[0097] · Impact resistance test A test piece (4 mm thick, 80 mm in total length, 10 mm in width, with notch) was prepared by cutting from the multi-purpose test piece type A1 (4 mm thick) prepared by the above method, and using an impact testing machine (manufactured by Toyo Seiki Seisakusho Co., Ltd.) in accordance with ISO179-1 (2nd edition, 2010), the notched Charpy impact values at 23 °C and -40 °C were measured to evaluate the impact resistance (kJ / m 2 ).

[0098] · Impact strength retention rate The test piece for impact resistance test prepared by the above method was left standing in a constant temperature bath (manufactured by Mita Sangyo Co., Ltd., "DE-303") set at 160 °C for 1000 hours. After 1000 hours, an impact resistance test at 23 °C was performed on the test piece taken out from the constant temperature bath in the same manner as above, and the impact strength of the test piece after heating was measured. The impact strength retention rate was determined from the following formula (X) to evaluate the long-term heat resistance. Impact strength retention rate (%) = {Impact strength after 1000 hours / Initial impact strength} × 100 Formula (X)

[0099] 《Fabrication of tube》 Using a tube forming device in which a straight die (die inner diameter: φ21.0 mm, mandrel outer diameter: φ14.9 mm) was connected to a single-screw extruder (screw diameter: φ50 mm, L / D = 28) manufactured by AGC Inc., the polyamide compositions obtained in the examples and comparative examples were discharged under the conditions of a cylinder temperature of 280 °C, a die temperature of 280 °C, and a screw rotation speed of 30 rpm. Subsequently, size control and cooling were performed in a vacuum sizing bath, and a tube with an outer diameter of 8.0 mm and an inner diameter of 6.0 mm was formed at a take-up speed of 10 m / min.

[0100] · Whitening resistance test The end of the tube obtained by the above method was flared with a conical heater heated to 80 °C. After confirming that the temperature had dropped to room temperature, a quick connector with an outer diameter of 8.9 mm at the farthest tree part was press-fitted, and the presence or absence of whitening on the surface of the tube end was visually confirmed. The whitening resistance was evaluated as A when no whitening was observed and C when whitening was observed. The flaring treatment was carried out to facilitate centering when press-fitting the connector.

[0101] [Production Example] Production Example 1 [Production of Polyamide PA-1] 9870.6 g (59.42 mol) of terephthalic acid, 9497.4 g (60.30 mol) of a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine [50 / 50 (molar ratio)], 142.9 g (1.17 mol) of benzoic acid, 9.8 g (0.05% by mass based on the total mass of the raw materials) of sodium hypophosphite monohydrate, and 5 liters of distilled water were placed in an autoclave with an internal volume of 40 liters and purged with nitrogen. While stirring, the temperature inside the autoclave was raised to 220 °C over 2 hours. At this time, the pressure inside the autoclave rose to 2 MPa. After continuing the reaction for 2 hours as it was, the temperature was raised to 230 °C, and then the temperature was maintained at 230 °C for 2 hours, and the reaction was carried out while gradually removing water vapor and maintaining the pressure at 2 MPa. Next, the pressure was lowered to 1 MPa over 30 minutes, and the reaction was further carried out for 1 hour to obtain a prepolymer with an intrinsic viscosity [η] of 0.2 dl / g. This was pulverized to a particle size of 2 mm or less using a Hosokawa Micron flake crusher, dried at 100 °C under reduced pressure for 12 hours, and then solid-phase polymerized at 230 °C and 13 Pa (0.1 mmHg) for 10 hours to obtain a white polyamide resin (polyamide PA-1). Polyamide PA-1 consists of terephthalic acid units, 1,9-nonanediamine units, and 2-methyl-1,8-octanediamine units (1,9-nonanediamine units / 2-methyl-1,8-octanediamine units = 50 / 50 (molar ratio)), and its melting point is 265 °C, and the intrinsic viscosity [η inhThe [η] was 1.26 dl / g, the terminal amino group content ([NH2]) was 15.6 μeq / g, and the terminal carboxyl group content ([COOH]) was 55.1 μeq / g. Also, the polydispersity index determined by gel permeation chromatography was 5.0.

[0102] Production Example 2 [Production of Polyamide PA-2] 9870.6 g (59.42 mol) of terephthalic acid, 9497.4 g (60.90 mol) of a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine [50 / 50 (molar ratio)], 142.9 g (1.17 mol) of benzoic acid, 9.8 g (0.05% by mass based on the total mass of the raw materials) of sodium hypophosphite monohydrate, and 5 liters of distilled water were placed in an autoclave with an internal volume of 40 liters and purged with nitrogen. Thereafter, polymerization was carried out in the same manner as in Production Example 1 to obtain a white polyamide resin (polyamide PA-2). In polyamide PA-2, the melting point was 265 °C, and the intrinsic viscosity [η inh was 1.28 dl / g, the terminal amino group content ([NH2]) was 51.5 μeq / g, and the terminal carboxyl group content ([COOH]) was 23.4 μeq / g. Also, the polydispersity index determined by gel permeation chromatography was 4.1.

[0103] [Examples and Comparative Examples] Examples 1 to 7 and Comparative Examples 1 to 13 were prepared according to the formulations shown in Table 1 or Table 2 to obtain polyamide compositions. Specifically, the polyamide, copper-based stabilizer, antioxidant, lubricant, and colorant shown in Table 1 or Table 2 were premixed at a predetermined mass ratio and fed into the upstream feed port of a twin-screw extruder ("TEM-26SS" manufactured by Toshiba Machine Co., Ltd.) together with polyolefin (A) and polyolefin (B) (however, together with polyolefin (A) in Comparative Example 10 and together with polyolefin (C) in Comparative Examples 11 to 13). The mixture was melt-kneaded and extruded under the conditions of a cylinder temperature of 300 to 320 °C (the melt-kneading temperature was 310 to 340 °C, and the melt-kneading temperature indicates the resin temperature), a rotation speed of 150 rpm, and a discharge of 10 kg / hr, and then cooled and cut to produce pellet-shaped polyamide compositions. Test pieces for various physical property evaluations were prepared using the above pellets, and various evaluations were performed by the method described above. The results are shown in Tables 1 and 2. At this time, the presence or absence of vent-up at the vacuum vent port in the downstream part was confirmed. In Table 1, *1 indicates that measurement was impossible.

[0104] Each component shown in Tables 1 and 2 is as follows. <Polyamide> Polyamide PA-1 obtained in Production Example 1 Polyamide PA-2 obtained in Production Example 2

[0105] <Polyolefin (A)> Lotader (registered trademark) AX8930: Copolymer of ethylene, methyl acrylate and glycidyl methacrylate [Et / MA / GMA = 72 / 25 / 3 (mass ratio)] Lotader (registered trademark) AX8900: Copolymer of ethylene, methyl acrylate and glycidyl methacrylate [Et / MA / GMA = 68 / 24 / 8 (mass ratio)] <Polyolefin (B)> Lotader (registered trademark) 4700: Copolymer of ethylene, ethyl acrylate and maleic anhydride [Et / EA / MAH = 68.7 / 30 / 1.3 (mass ratio)] Lotader (registered trademark) 3410: Copolymer of ethylene, butyl acrylate and maleic anhydride [Et / BA / MAH = 80 / 17 / 3.1 (mass ratio)] <Polyolefin (C)> Tafmer (registered trademark) MH7010: Elastomer obtained by modifying an ethylene-butene copolymer with maleic anhydride [Acid anhydride group concentration: 50 μeq / g], manufactured by Mitsui Chemicals, Inc. (for comparative example)

[0106] <Copper-based stabilizer> KG HS01-P: Molar ratio: CuI / KI = 10 / 1, manufactured by PolyAd Services <Antioxidant> Naugard® 445: 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, manufactured by Addivant

[0107] <Lubricant> WH-255: Amide Wax Light Amide, manufactured by Kyoeisha Chemical Co., Ltd. <Colorant> #980B: Carbon Black, manufactured by Mitsubishi Chemical Corporation

[0108]

Table 1

[0109]

Table 2

[0110] From Table 1, it can be seen that the polyamide compositions of Examples 1 to 7 achieve high heat resistance, manufacturing stability during melt-kneading, high tensile elongation at break, low-temperature impact resistance, and whiteness resistance simultaneously. The composition of Comparative Example 1 did not contain polyolefin (A), resulting in insufficient affinity with polyamide, and a composition compatibilized by a compound could not be obtained. The compositions of Comparative Examples 2, 3, and 5 did not contain a copper-based stabilizer, resulting in low impact strength retention rate and insufficient heat aging resistance. The compositions of Comparative Examples 4, 6, and 8 had insufficient stability during melt-kneading because the value of Z was smaller than the range defined in this embodiment. Furthermore, in Comparative Example 6, a compatibilized composition could not be obtained. The composition of Comparative Example 7 had insufficient tensile elongation at break because [B] / [A] was not within the range defined in this embodiment. The composition of Comparative Example 9 had inferior tensile elongation at break and tensile modulus, insufficient flexibility, low impact strength retention rate, and insufficient heat aging resistance because the value of Z was larger than the range defined in this embodiment. Since the composition of Comparative Example 10 does not contain polyolefin (B), its melt viscosity becomes extremely high, and the balance between flexibility and viscosity deteriorates. Since the compositions of Comparative Examples 11 to 13 do not contain polyolefin (A) and polyolefin (B), even if they contain polyolefin (C) instead, their whitening resistance is insufficient.

Claims

1. A composition comprising a polyamide, a polyolefin, and a copper-based stabilizer, wherein the polyolefin contains at least one polyolefin (A) comprising a copolymer of ethylene, an alkyl (meth)acrylate, and an unsaturated epoxide, and at least one polyolefin (B) comprising an unsaturated dicarboxylic anhydride, and the mass ratio [B] / [A] of the content [B] of the polyolefin (B) to the content [A] of the polyolefin (A) is 0.1 to 2.9, the value Z calculated from the following formula (1) is 33 to 200, the polydispersity index of the polyamide measured by gel permeation chromatography is 4.0 or more and 8.0 or less, the content rate of the polyamide in the composition is 60 to 86% by mass, A polyamide composition. Z = 1000×(|[ANH] - [EPO]| + [EPO]) / X ２ Equation (1) The [EPO] is the concentration (mmol / kg) of the unsaturated epoxide derived from the polyolefin per unit mass of the composition. The [ANH] is the concentration (mmol / kg) of the unsaturated dicarboxylic anhydride derived from the polyolefin per unit mass of the composition. The X is the content rate (% by mass) of the polyolefin in the composition.

2. The polyamide composition according to claim 1, wherein the polyamide contains at least one selected from terephthalic acid units and naphthalenedicarboxylic acid units in an amount of 50 mol% or more based on all dicarboxylic acid units.

3. The polyamide composition according to claim 1, wherein the polyamide contains an aliphatic diamine unit having 4 to 13 carbon atoms or a metaxylylenediamine unit in an amount of 60 mol% or more based on all diamine units.

4. The polyamide composition according to claim 3, wherein the aliphatic diamine unit is a unit derived from at least one aliphatic diamine selected from the group consisting of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine.

5. The polyamide composition according to claim 3, wherein the aliphatic diamine unit is a unit derived from at least one aliphatic diamine selected from 1,9-nonanediamine and 2-methyl-1,8-octanediamine.

6. The polyamide composition according to claim 1, wherein the content of terminal amino groups in the polyamide is 10 to 70 μeq / g and the content of terminal carboxyl groups is 10 to 70 μeq / g.

7. The content of the polyamide is 60 to 80% by mass, and the content of the polyolefin is 14 to 35% by mass, the polyamide composition according to claim 1.

8. The content of the polyamide is 60 to 80% by mass, and the content of the polyolefin is 15 to 30% by mass, the polyamide composition according to claim 1.

9.

9. The polyolefin (B) is a copolymer of ethylene, alkyl (meth)acrylate and unsaturated dicarboxylic anhydride, the polyamide composition according to claim 1.

10.

10. The content of the copper-based stabilizer is 0.01 to 2% by mass, the polyamide composition according to claim 1.

11.

11. The copper-based stabilizer contains at least one copper compound selected from the group consisting of copper iodide, copper bromide, and copper acetate, and at least one metal halide selected from the group consisting of potassium iodide and potassium bromide, the polyamide composition according to claim 1.

12.

12. The polyamide composition according to claim 1, comprising at least one additive selected from the group consisting of other polymers, antioxidants, fillers, crystal nucleating agents, colorants, antistatic agents, plasticizers, lubricants, flame retardants, and flame retardant aids, other than the polyamide and the polyolefin.

13.

13. A method for producing the polyamide composition according to any one of claims 1 to 12, wherein the polyamide, the polyolefin, and the copper-based stabilizer are top-fed into a twin-screw extruder and melt-kneaded, a method for producing a polyamide composition.

14.

14. Use of the polyamide composition according to any one of claims 1 to 12 for producing a single-layer structure or for producing at least one layer of a multi-layer structure.

15.

15. A molded article comprising the polyamide composition according to any one of claims 1 to 12.

16.

16. The molded article according to claim 15, which is an extrusion molded article, a co-extrusion molded article, or a blow molded article.

17. A fuel tube, an engine coolant tube, a battery coolant tube, a motor coolant tube, a fuel cell cooling tube, a urea solution transfer tube, an air conditioner refrigerant tube, a blow-by tube, a brake booster tube, a brake tube, an oil cooling tube, a turbo duct pipe, an air suspension tube or an oil transportation tube. The molded body according to claim 16.

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